Mask plate and preparation method thereof

Abstract

The invention provides a mask plate and a preparation method thereof, and belongs to the technical field of display. The mask plate disclosed by the invention comprises a mask main body structure, wherein the mask main body structure is provided with a plurality of openings; the plurality of support structures are arranged in a crossed manner and are positioned on one side of the mask main body structure; the opening is positioned between the crossed supporting structures; at least part of the supporting structure comprises a body part and a plurality of protruding parts connected with the body part, the protruding parts are at least located on the side, close to the opening, of the body part, and the extending direction of the protruding parts is the direction where the body part points to the opening.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of display, and particularly relates to a mask plate and a preparation method thereof. BACKGROUND

[0002] In the manufacturing process of an organic electroluminescence display (OLED) display panel, a vacuum evaporation technology is needed to form an electroluminescent (EL) film layer (hereinafter referred to as an EL film layer) in the display panel. The evaporation process uses a fine metal mask (FMM) to control the evaporation position of red R, green G and blue B pixel light-emitting materials. In the manufacturing process of a conventional metal mask assembly, the support mask (F-Mask) and the fine metal mask (FMM) are subjected to a screen stretching process respectively, and are then laser welded to a metal frame (Frame) after stretching to be assembled into a complete mask plate.

[0003] With the wide application of large-size OLED display products, the larger the display product, the higher the generation line is needed to produce it more efficiently, at a lower cost, and more conducive to popularization and popularization. At present, the highest generation line for R, G and B evaporation OLED is 6-generation line half-cut (i.e. G6H), so the industry is actively laying out production plants with higher generation lines, of which the highest evaporation OLED generation line is 8.6H.

[0004] The inventors have found that at least the following problems exist in the prior art: At present, there is no corresponding wide raw material for high 8.6H (referred to as G8.6H). The currently mass-produced roll material with a thickness of 100um has a width of 1040mm and a maximum width of 1400mm, which can only meet the needs of the Mask for evaporation / encapsulation in the G6H generation line, and the development of larger width roll materials has not been carried out due to large equipment investment, unclear market demand and great development difficulty. SUMMARY

[0005] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a mask plate and a preparation method thereof.

[0006] In a first aspect, a technical solution adopted to solve the technical problems of the present disclosure is a mask plate, comprising a mask main structure, wherein the mask main structure has a plurality of openings;

[0007] A plurality of cross-disposed support structures are located on one side of the mask main structure, and the openings are located between the cross-disposed support structures.

[0008] At least part of the support structure comprises a main body and a plurality of protruding parts connected to the main body, the protruding parts are located at least on one side of the main body close to the opening, and the extending direction of the protruding parts is the direction of the main body pointing to the opening.

[0009] In some embodiments, the openings are arranged in an array, the ratio of the minimum distance between two adjacent openings in the column direction to the minimum width of the main body in the column direction extending along the row direction is between 0.3 and 0.35.

[0010] The ratio of the minimum distance between two adjacent openings in the row direction to the minimum width of the main body in the row direction extending along the column direction is between 0.3 and 0.35.

[0011] In some embodiments, the shortest distance between the orthographic projection of the protruding part on the mask main body structure to the nearest opening is less than or equal to 0.5mm, and a is not equal to 0.

[0012] In some embodiments, for at least part of the support structure, the protruding parts are arranged symmetrically on both sides of the extending direction of the main body with the main body as the axis of symmetry.

[0013] In some embodiments, for at least part of the main body, the protruding parts on the same side of the extending direction of the main body define an intermediate region, and an intermediate structure is arranged in the intermediate region.

[0014] In some embodiments, the intermediate structure and the support structure are connected as an integral structure.

[0015] In some embodiments, the thickness of the intermediate structure gradually decreases in the direction away from the support structure connected thereto.

[0016] In some embodiments, the thickness of the intermediate structure is less than or equal to the thickness of the support structure connected thereto.

[0017] In some embodiments, the side of the mask main body structure away from the support structure has a groove corresponding to each opening; the orthographic projection of the groove on a reference plane parallel to the mask main body structure has a contour surrounding the orthographic projection of the opening corresponding to the groove on the reference plane, and the groove and the opening corresponding thereto are in communication.

[0018] In some embodiments, the orthographic projection of the main body on the mask main body structure has a gap from the outermost boundary of the mask main body structure away from the opening.

[0019] In some embodiments, the convex portion has a contour shape of at least one of a quadrangle, an arc, a semicircle, and a triangle in a normal projection on the mask body structure.

[0020] In some embodiments, the support structure and the mask body structure are connected as an integrated structure.

[0021] In some embodiments, a surface of the support structure and the mask body structure connected as an integrated structure is wrapped with an insulating layer.

[0022] In some embodiments, a width f of the convex portion in an extension direction of the body portion to which the convex portion is connected is between 0.05 mm and a, where a represents a width of the body portion perpendicular to the extension direction.

[0023] In some embodiments, for each body portion, a shortest distance between two convex portions located on the same side of the body portion in the extension direction of the body portion is less than or equal to 3xf.

[0024] In a second aspect, the disclosure also provides a preparation method of a mask plate, including providing a roll of material;

[0025] forming a pattern including a support structure on one side surface of the roll of material through a patterning process;

[0026] forming a pattern including a plurality of openings arranged in an array and a mask body structure on one side surface of the pattern of the support structure through a patterning process to obtain a mask plate; the support structure includes a body portion and a plurality of convex portions connected to the body portion, the convex portions are located at least on a side of the body portion close to the openings, and an extension direction of the convex portions is a direction in which the body portion points to the openings. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 a schematic diagram of stress conduction when a related mask plate is screen printed;

[0028] Figure 2 a schematic diagram of the relationship between the formation of a shadow and the tightness of the fit between a mask plate and a substrate;

[0029] Figure 3a a schematic diagram of a film layer protruding outward during an etching process of a related mask plate;

[0030] Figure 3b a schematic diagram of an opening curling phenomenon of a related mask plate;

[0031] Figure 4 a schematic diagram of a mask plate provided by an embodiment of the disclosure;

[0032] Figure 5 a schematic diagram of another mask plate provided by an embodiment of the disclosure;

[0033] Figure 6 A schematic diagram of the size design of a support structure in an example;

[0034] Figure 7a A schematic diagram of a convex portion with a semicircular profile shape;

[0035] Figure 7b A schematic diagram of a convex portion with a trapezoidal profile shape;

[0036] Figure 8 A schematic diagram of a support structure in an example; Figure 5 A cross-sectional view in the A-A' direction of an example;

[0037] Figure 9 A schematic diagram of another mask plate provided by the embodiments of the present disclosure;

[0038] Figure 10 A schematic diagram of another mask plate provided by the embodiments of the present disclosure;

[0039] Figure 11a A schematic diagram of a support structure in an example; Figure 5 A cross-sectional view in the B-B' direction of an example;

[0040] Figure 11b A schematic diagram of a support structure in an example; Figure 5 A cross-sectional view in the B-B' direction of another example;

[0041] Figure 12a A top view of a mask plate provided by the embodiments of the present disclosure, facing away from the side of the support structure;

[0042] Figure 12b Figure 12a A cross-sectional view in the C-C' direction;

[0043] Figure 12c A schematic diagram of a mask plate and a substrate being attached;

[0044] Figure 13 A schematic diagram of a mask plate being welded with a metal frame (Frame);

[0045] Figure 14 A schematic diagram of another mask plate provided by the embodiments of the present disclosure;

[0046] Figure 15 A schematic diagram of another mask plate being welded with a metal frame (Frame);

[0047] Figure 16 A schematic diagram of a support structure in an example; Figure 5 A cross-sectional view in the A-A' direction of another example;

[0048] Figures 17a-17drespectively are schematic diagrams of a mask plate preparation process under an example;

[0049] Figures 18a-18d respectively are schematic diagrams of a mask plate preparation process under another example. DETAILED DESCRIPTION

[0050] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the following will be combined with the accompanying drawings for the embodiments of the present disclosure to make a clear and complete description of the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The components of the embodiments of the present disclosure generally described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed present disclosure, but only represents selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present disclosure.

[0051] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning understood by a person skilled in the art to which the present disclosure pertains. The terms “one”, “second” and similar words used in the present disclosure do not represent any order, number or importance, but are only used to distinguish different components. Similarly, “one”, “a” or “the” and similar words do not represent a quantity limitation, but represent the existence of at least one. “Including” or “containing” and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. “Connected” or “connected” and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. “Up”, “down”, “left”, “right” and the like are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0052] “Multiple or several” mentioned in the present disclosure refers to two or more. “And / or” describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. The character “ / ” generally represents that the associated objects before and after it are in an “or” relationship.

[0053] In the related art, the following types of masks are used for G8.6H evaporation / encapsulation: The first type, a stick mask, can be stretched on a factory stretching machine. It requires high material precision, resulting in larger shadows on display panels produced using it. It has no width restrictions and is easily repairable. However, differential tension in the X and Y directions can cause significant frame deformation. The second type, a split mask structure, involves the manufacturer stretching the mask and splicing it multiple times to overcome width restrictions. This ensures precision at the splices and minimizes film loss. However, solder joints at the splices are susceptible to damage during the chemical vapor deposition (CVD) process. The third type, a full-fill mask structure, requires raw materials to be developed, while the manufacturer is responsible for etching and stretching the mask. This is consistent with the G6H approach. However, based on G6H experience, the full-fill mask structure offers the highest stability and is most conducive to evaporation yield. However, due to the limited roll width of the G8.6H, only cover / whistle and split mask structures can be considered.

[0054] Coils are typically manufactured using a calendering process. While the calendering process thins the coil thickness, stress release and other boundary issues can create irregularities or cracks along the edges. Trimming is necessary to remove these irregularities and cracks during the continuous calendering process. Therefore, given a consistent incoming coil width, the thinner the coil, the smaller the final width after trimming. For example, with a 300um coil thickness, a width of 1500mm or greater is more easily achieved. However, with a 100um coil thickness, the current maximum width is approximately 1040mm, which only meets the requirements for evaporation / encapsulation masks in the G6H generation line and cannot meet the requirements for evaporation / encapsulation masks (1500mm or greater) in the G8.6H generation line.

[0055] Figure 1 Schematic diagram of stress conduction when the relevant mask plate is stretched, as shown in Figure 1 As shown in the figure, under the tension of the net, the tension at position A (the edge) of the mask is greater than that at position B (near the center of the mask). However, while the positional accuracy of point A can be easily adjusted by tension, achieving the same accuracy at point B is more difficult. Positional accuracy determines the aperture accuracy, and therefore the accuracy of the mask. To ensure that deformation around the aperture does not occur and maintain a certain level of positional accuracy, the tension of the net should be limited. However, if the tension is too low, the overall sag of the mask will increase. The matching of the sag of the mask and the sag of the glass determines the tightness of the mask-to-glass fit. The tightness of the fit affects the shadow of the vapor deposition, which is related to the frame design. Reducing the shadow is beneficial for narrow frame designs.

[0056] G8.6H scheme due to the large size of the glass, the glass substrate is placed on the mask plate for evaporation, a mask plate needs to correspond to a large amount of glass for a long time, continuous pressing, fitting and evaporation process, the traditional design is not enough, the mask plate after multiple processes, the precision decreases or even can be damaged. The precision decrease after multiple processes mainly manifests in the increase of the sag of the mask plate, and the matching between the sag of the mask plate and the sag of the glass determines the fitting tightness of the mask plate and the glass. Figure 2 The schematic diagram of the relationship between the formation of the shadow and the fitting tightness between the mask plate and the substrate is shown in Figure 2 As shown by taking the evaporation mask plate 01 as an example (the same for the packaging mask plate), during the evaporation source evaporation process, the spray head is inclined, so there is an evaporation angle a. At this time, the edge position of the evaporation pattern 03 is thinner than the middle position, as shown in Figure 2 The dotted line away from the center of the evaporation pattern 03 is the evaporation pattern shadow (Shadow). As can be seen, the larger the gap (h) between the mask plate 01 and the substrate 02, that is, the lower the fitting tightness, the larger the pattern shadow (Shadow) to be formed, which is not conducive to the formation of narrow frame. On the contrary, the higher the fitting tightness, the smaller the pattern shadow (Shadow) to be formed, which is conducive to the formation of narrow frame.

[0057] In the G6H evaporation line, the thickness of the mask plate is generally reduced to reduce the shadow (Shadow), for example, the thickness of the mask plate is reduced from 150um to 100um, which can reduce the shadow (Shadow) by about 50um. However, in the evaporation process of high generation line (G8.6H), due to the increase in size, the sag of the glass will increase, and the 100um thick mask plate has the problem of insufficient strength. Specifically, the sag of the mask plate increases after the glass is pressed, the deformation of the opening edge increases, and even after multiple uses, there will be an irreversible deformation problem, fatigue problem, etc., which ultimately affects the service life of the mask plate.

[0058] In addition, due to the existence of internal and surface stress of the mask plate material, during the etching (such as etching opening or etching groove) of the first side surface la of the mask body structure to a certain depth, there is a difference in stress distribution between the first side surface la and the second side surface lb opposite to it, which is actually manifested as the convexity of the side opposite to the etching area (that is, the second side surface lb here), as shown in Figure 3a After that, taking the etching opening as an example, as the etching depth increases, finally penetrating the thickness of the mask plate, affected by the self-gravity of the etching area and the supporting force of the outermost edge of the mask plate, etc., there will be different degrees of curling phenomenon around the opening, as shown in Figure 3b The curling degree of different openings is different, causing display difference of the display panel.

[0059] In view of this, the present disclosure provides a mask that substantially eliminates one or more of the problems caused by the limitations and defects of the related art. The mask disclosed in the present disclosure can be applied to the evaporation / packaging process scenarios of high-generation lines.

[0060] Figure 4 A schematic diagram of a mask provided in an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the mask plate comprises a main mask structure 1 and multiple cross-arranged support structures 2. The cross-arranged support structures 2 are located on one side of the main mask structure 1. The main mask structure 1 has multiple openings V, and the openings V are located between the cross-arranged support structures 2. The addition of the support structures 2 serves as the overall support framework of the main mask structure 1, increasing the strength of the mask plate and reducing its sag. The reduced sag is almost negligible, or can be overcome with only a small tensile force. This force is insufficient to cause deformation of the openings V during the stretching phase, thus ensuring the positional accuracy of the openings V and facilitating the realization of a high-precision mask plate.

[0061] Further, Figure 5 A schematic diagram of another mask provided in an embodiment of the present disclosure, Figure 5 The structure shown is Figure 4 The difference between the structures shown is that the support structure 2 is patterned to improve the curling problem around the opening V.

[0062] like Figure 5 As shown, at least part of the support structure 2 includes a main body 201 and a plurality of protrusions 202 connected to the main body 201 . The protrusions 202 are located at least on one side of the main body 201 close to the opening V, and their extension direction is the direction in which the main body 201 points to the opening V.

[0063] Here, the main body 201 serves as the skeleton supporting the main mask structure 1, strengthening the strength of the main force transmission path during the stretching process of the main mask structure 1, improving the uniformity of mechanical distribution, and reducing the amount of mask plate sagging during the application phase. For any supporting structure 2, multiple protrusions 202 are distributed on the side of the main body 201 close to the opening V, specifically adjacent to the edge of the opening V. This can improve the strength of the main mask structure 1 near the opening V, reduce the uneven stress distribution on the etched surface and its opposite side when etching the opening V, and thus improve the edge curling of the opening V.

[0064] Optionally, for any support structure 2, when there are openings V on both sides of the main body 201 in the extension direction, the multiple protrusions 202 are distributed on both sides of the extension direction of the main body 201. For example, the support structure 2 here refers to the remaining support structures 2 among the multiple support structures 2 except the support structure 2 closest to the edge of the mask plate.

[0065] Optionally, for any support structure 2, when the main body part 201 has an opening V on one side and no opening V on the other side, the plurality of protruding parts 202 are distributed on the side of the main body part 201 extending direction and close to the opening V. For example, the support structure 2 here is the support structure 2 closest to the edge of the mask plate among the plurality of support structures 2.

[0066] For example, the thickness of the mask main body structure 1 is 100um, which is conducive to reducing the influence of the pattern shadow to be formed.

[0067] For example, the thickness of the main body part 201 is 50um. For example, the thickness of the mask main body structure 1 is 150um, which ensures the overall strength of the mask plate.

[0068] For example, the thickness of the main body part 201 is 50um. For example, the thickness of the mask main body structure 1 is 150um, which ensures the overall strength of the mask plate.

[0069] For example, the thickness of the main body part 201 is 50um. For example, the thickness of the mask main body structure 1 is 150um, which ensures the overall strength of the mask plate.

[0070] For example, the thickness of the main body part 201 is 50um. For example, the thickness of the mask main body structure 1 is 150um, which ensures the overall strength of the mask plate.

[0071] In some embodiments, as shown in Figure 5 The array arrangement referred to in the present disclosure refers to a rectangular array arrangement, that is, including a plurality of rows of openings V and a plurality of columns of openings V, and the adjacent rows of openings V are arranged opposite to each other. The row direction X and the column direction Y are perpendicular to each other in the same horizontal plane.

[0072] The stress distribution of the array arrangement of the opening V is simple, and the stress distribution difference at different positions is small. Each embodiment of the present disclosure takes the array arrangement of the opening V as an example for description.

[0073] For the convenience of understanding, the support structure 2 extending along the row direction X is referred to as a first support structure 21, and the support structure 2 extending along the column direction Y is referred to as a second support structure 22. The width of the first support structure 21 represents the maximum width of the first support structure 21 in the column direction Y, and the width of the second support structure 22 represents the maximum width of the second support structure 22 in the row direction X. Similarly, the first support structure 21 includes a first main body portion 2011 and a first protruding portion 2021, and the second support structure 22 includes a second main body portion 2012 and a second protruding portion 2022; the width of the first main body portion 2011 represents the minimum width of the first main body portion 2011 in the column direction Y, and the width of the second main body portion 2012 represents the minimum width of the second main body portion 2012 in the column direction Y. It should be noted that, for the support structure 2 not explicitly indicated, it essentially includes the first support structure 21 and the second support structure 22. Similarly, for the main body portion 201 not explicitly indicated, it essentially includes the first main body portion 2011 and the second main body portion 2012; for the protruding portion 202 not explicitly indicated, it essentially includes the first protruding portion 2021 and the second protruding portion 2022.

[0074] In some embodiments, as shown in FIG. 2, for the first support structure 21 located between adjacent row openings V, the center line S1 of the first support structure 21 passes through the midpoint of the center line of any two adjacent openings V in the column direction Y; for the second support structure 22 located between adjacent column openings V, the center line S2 of the second support structure 22 passes through the midpoint of the center line of any two adjacent openings V in the row direction X. Figure 5 In some embodiments, as shown in FIG. 2, the width of the first support structure 21 is actually smaller than the minimum spacing between two adjacent openings V in the column direction Y, so as to reduce the pattern shadow to be formed. The width of the second support structure 22 is smaller than the minimum spacing between two adjacent openings V in the row direction X, so as to reduce the pattern shadow to be formed.

[0075] Figure 5 In some embodiments, as shown in FIG. 2, the width of the first support structure 21 is actually smaller than the minimum spacing between two adjacent openings V in the column direction Y, so as to reduce the pattern shadow to be formed. The width of the second support structure 22 is smaller than the minimum spacing between two adjacent openings V in the row direction X, so as to reduce the pattern shadow to be formed.

[0076] Optionally, Figure 6 For the size design of the support structure in an example, as shown in FIG. 2, the ratio of the minimum spacing H1 between two adjacent openings V in the column direction Y to the minimum width W1 of the first main body portion 2011 is between 0.3 and 0.35; the ratio of the minimum spacing H2 between two adjacent openings V in the row direction X to the minimum width W2 of the second main body portion 2012 is between 0.3 and 0.35. Figure 6

[0077] ​​Optionally, the minimum distance H1 between two adjacent openings V in the column direction Y is equal to the minimum distance H2 between two adjacent openings V in the row direction X; the minimum width W1 of the first body part 2011 is equal to the minimum width W2 of the second body part 2012.

[0078] For example, the minimum distance H1 between two adjacent openings V in the column direction Y, i.e. the minimum width of the mask body structure 1 in the column direction Y between two adjacent rows of openings V. The minimum distance H2 between two adjacent openings V in the row direction X, i.e. the minimum width of the mask body structure 1 in the row direction X between two adjacent columns of openings V.

[0079] In some embodiments, as shown in Figure 6 The shortest distance a between the orthogonal projection of the protrusion 202 on the mask body structure 1 to the nearest opening V is less than or equal to 0.5mm, and a is not equal to 0.

[0080] Optionally, the shortest distance a between the orthogonal projection of the first protrusion 2021 on the mask body structure 1 to the nearest opening V is equal to the shortest distance a between the orthogonal projection of the second protrusion 2022 on the mask body structure 1 to the nearest opening V.

[0081] In this embodiment, there is a gap between the protrusion 202 and the nearest opening V, which is beneficial to reduce the generation of the pattern Shadow to be formed.

[0082] In some embodiments, as shown in Figure 6 The width b of the protrusion 202 in the extension direction of the body part 201 to which the protrusion 202 is connected is between 0.05mm and c, and c represents the width (H1 or H2) of the body part 201 perpendicular to the extension direction thereof.

[0083] Optionally, the width b of the first protrusion 2021 in the row direction X is between 0.05mm and H1; the width b of the second protrusion 2022 in the column direction Y is between 0.05mm and H2. Optionally, the width b of the first protrusion 2021 in the row direction X is equal to the width b of the second protrusion 2022 in the column direction Y.

[0084] This embodiment reduces b as much as possible on the basis of ensuring the improvement of the edge curling of the opening V, which is beneficial to reduce the generation of the pattern Shadow to be formed.

[0085] In some embodiments, as shown in Figure 6 For each body part 201, the shortest distance d between two protrusions 202 located on the same side of the extension direction of the body part 201 is less than or equal to 3×b.

[0086] Optionally, as shown in Figure 6As shown, the shortest distance between the two first protrusions 2021 is equal to the shortest distance between the two second protrusions 2022 .

[0087] In this embodiment, d is increased as much as possible on the basis of ensuring that the shadow of the pattern to be formed is reduced, which is beneficial to improving the curling of the edge of the opening V.

[0088] In some embodiments, as Figure 5 As shown, at least a portion of the support structure 2 is provided with protrusions 202 on both sides of the main portion 201 in the direction of extension, and the two protrusions 202 are symmetrically arranged with the main portion 201 as the axis of symmetry. Here, while ensuring that the curling of the edge of the opening V is reduced, the symmetrical arrangement of the protrusions 202 helps to improve the support strength of the support structure 2, improve the uniformity of the mechanical distribution, and reduce the amount of sagging of the mask during the application stage.

[0089] Alternatively, as Figure 5 As shown, for any supporting structure 2, protrusions 202 are provided on both sides of the main body 201 in the extending direction, and the protrusions 202 distributed on both sides of the main body 201 in the extending direction are symmetrically arranged with the main body 201 as the symmetry axis.

[0090] In some embodiments, the contour shape of the orthographic projection of the protrusion 202 on the mask main structure 1 is at least one of a quadrilateral, an arc, a semicircle, and a triangle. Figure 7a and Figure 7b Of course, the contour shape of the orthographic projection of the protrusion 202 on the mask main structure 1 can also be other shapes and combinations thereof with the above shapes, which are not listed here one by one.

[0091] In some embodiments, the thickness of the protrusion 202 is less than or equal to the thickness of the main body 201. This embodiment reduces the thickness of the protrusion 202 as much as possible while ensuring that the curling of the edge of the opening V is improved, which is beneficial to reducing the generation of shadows of the pattern to be formed.

[0092] In some embodiments, Figure 8 for Figure 5 An example of a cross-sectional view in the A-A' direction is shown in FIG. Figure 8 As shown, the surface of the protrusion 202 facing away from the main mask structure 1 is a curved surface that is concave in the direction toward the main mask structure 1. While ensuring that the curl of the edge of the opening V is reduced, this embodiment minimizes the thickness of the protrusion 202, which helps reduce the shadow of the pattern being formed. This embodiment also achieves a better shadow reduction effect than a case where the thickness of the protrusion 202 is equal to that of the main mask 201.

[0093] In some embodiments, Figure 9 Another schematic diagram of the mask plate provided by the embodiments of the present disclosure is shown in FIG. 3, which is different from the structure shown in FIG. 2 in that an intermediate structure 3 is additionally provided. Figure 5

[0094] As shown in FIG. 2, for at least part of the main body 201, an intermediate region is defined between the protruding portions 202 located on the same side of the extension direction of the main body 201, and the intermediate structure 3 is arranged in the intermediate region. Figure 9

[0095] Optionally, as shown in FIG. 3, the intermediate structure 3 includes a first portion 31 and a second portion 32, and the first portion 31 and the second portion 32 are arranged in a cross manner, and the orthographic projection of the two on the mask main body structure 1 shows an “X” pattern. Figure 9

[0096] Optionally, as shown in FIG. 4, for any support structure 2 and the intermediate structure 3 in the intermediate region thereof: the intermediate structure 3 includes a plurality of inclined portions, the extension direction of the main body 201 and the protruding portion 202 connected thereto are perpendicular, and the extension direction of each inclined portion intersects with the extension direction of the main body 201 and the extension direction of the protruding portion 202 connected thereto, respectively. For example, as shown in FIG. 4, the plurality of inclined portions include a first inclined portion 3a, a second inclined portion 3b, a third inclined portion 3c, and a fourth inclined portion 3d; wherein the first end of the first inclined portion 3a is connected to the main body 201, the second end of the first inclined portion 3a is connected to the nearest protruding portion 202, and there is a certain spacing between the first end of the first inclined portion 3a and the protruding portion 202 connected thereto; the extension direction of the first inclined portion 3a is parallel to the extension direction of the second inclined portion 3b, and the first end of the second inclined portion 3b is connected to the main body 201. Similarly, the first end of the third inclined portion 3c is connected to the main body 201, the second end of the third inclined portion 3c is connected to the nearest protruding portion 202, and there is a certain spacing between the first end of the third inclined portion 3c and the protruding portion 202 connected thereto; the extension direction of the third inclined portion 3c is parallel to the extension direction of the fourth inclined portion 3d, and the first end of the fourth inclined portion 3d is connected to the main body 201. The first end of the second inclined portion 3b and the first end of the third inclined portion 3c intersect, and the included angle between the second inclined portion 3b and the third inclined portion 3c is greater than or equal to 60° and less than 180°. Figure 10 Figure 10 Optionally, the intermediate structure 3 is a mesh structure.

[0097] The above Only some examples of the intermediate structure 3 in the present disclosure are shown, and the pattern of the intermediate structure 3 provided by the embodiments of the present disclosure can also select other patterns similar to the hollow or mesh structure, which will not be listed one by one here.

[0098] The above Figures 9-10 Only some examples of the intermediate structure 3 in the present disclosure are shown, and the pattern of the intermediate structure 3 provided by the embodiments of the present disclosure can also select other patterns similar to the hollow or mesh structure, which will not be listed one by one here. ​​​

[0099] Optionally, for the first main body part 2011, a first intermediate region is defined between the first protruding parts 2021 located at the same side of the extension direction of the first main body part 2011, and a first intermediate structure is arranged in the first intermediate region; and / or for the second main body part 2012, a second intermediate region is defined between the second protruding parts 2022 located at the same side of the extension direction of the second main body part 2012, and a second intermediate structure is arranged in the second intermediate region. Wherein, the first intermediate structure can adopt a pattern as shown in any one or more combinations of Figures 9-10 ; and the second intermediate structure can adopt a pattern as shown in any one or more combinations of Figures 9-10 .

[0100] The present embodiment, by arranging the intermediate structure 3 between the protruding parts 202, further improves the edge curling of the opening V and improves the strength of the mask plate compared with the structure shown in Figure 5 .

[0101] In some embodiments, as shown in Figures 9-10 , the intermediate structure 3 and the support structure 2 are connected as an integrated structure, thereby improving the integrity of the mask plate and further improving the support strength of the mask plate.

[0102] For example, the intermediate structure 3 and the support structure 2 can be integrally formed by a one-time patterning process.

[0103] In some embodiments, the thickness of the intermediate structure 3 gradually decreases in the direction away from the support structure 2 connected thereto.

[0104] For example, the intermediate structure 3 and the support structure 2 are respectively formed by different patterning processes, for example, first, a pattern containing the support structure 2 and the intermediate structure 3 is formed by a one-time patterning process; then, the intermediate structure 3 is etched and thinned separately to form a shape with gradually decreasing thickness.

[0105] The present embodiment, by designing the thickness decreasing trend of the intermediate structure 3, not only improves the edge curling of the opening V and improves the strength of the mask main body structure 1, but also reduces the weight of the mask plate itself, which is conducive to reducing the overall sag of the mask plate.

[0106] In some embodiments, the thickness of the intermediate structure 3 is less than or equal to the thickness of the support structure 2 connected thereto.

[0107] Compared with the case where the thickness of the intermediate structure 3 and the support structure 2 connected thereto is the same, the present embodiment, by reducing the thickness of the intermediate structure 3 as a whole, not only improves the edge curling of the opening V and improves the strength of the mask main body structure 1, but also reduces the weight of the mask plate itself, which is conducive to reducing the overall sag of the mask plate.

[0108] In some embodiments,Figure 11a As shown in FIG. 1A, the mask body structure 1 includes a first region and a second region. The mask body structure 1 in the first region is in contact with the support structure 2, and the mask body structure 1 in the second region is used to define an opening V. In other words, the second region is a closed region defined by the first support structure 21 and the second support structure 22. Figure 5 As shown in FIG. 1B, a cross-sectional view of the mask body structure 1 in the B-B’ direction of FIG. 1A, Figure 11b As shown in FIG. 1C, a cross-sectional view of the mask body structure 1 in another example of the B-B’ direction of FIG. 1A, Figure 5 As shown in FIG. 1D, a cross-sectional view of the mask body structure 1 in another example of the B-B’ direction of FIG. 1A, Figure 11a As shown in FIG. 1E, the mask body structure 1 includes a first surface 11 and a second surface 12 arranged oppositely along the thickness direction of the mask body structure 1, and a third surface 13 connecting the first surface 11 and the second surface 12 and away from the first region. The third surface 13 includes a first sub-surface 131 connected with the first surface 11 and a second sub-surface 132 connected with the second surface 12, and the first sub-surface 131 and the second sub-surface 132 are connected. The dihedral angle formed by the first sub-surface 131 and the first surface 11 is greater than or equal to 90°. The dihedral angle formed by the extension of the first sub-surface 131 and the second sub-surface 132 is less than 90°. The dihedral angle formed by the extension of the second sub-surface 132 and the second surface 12 is less than 90°. Figure 11b As shown in FIG. 1F, the dihedral angle formed by the third surface 13 and the first surface 11 is less than 90°. The dihedral angle formed by the extension of the third surface 13 and the second surface 12 is less than 90°. Figure 11a As shown in FIG. 1E, the first sub-surface 131 includes a first boundary and a second boundary connected with the first surface 11 and the second sub-surface 132 respectively, and the distance between the first boundary and the second boundary is less than or equal to 10 um. Figure 11b As shown in FIG. 1F, the dihedral angle formed by the third surface 13 and the first surface 11 is less than 90°. The dihedral angle formed by the extension of the third surface 13 and the second surface 12 is less than 90°. Figure 11a As shown in FIG. 1E, the first sub-surface 131 includes a first boundary and a second boundary connected with the first surface 11 and the second sub-surface 132 respectively, and the distance between the first boundary and the second boundary is less than or equal to 10 um.

[0109] As shown in FIG. 1G, compared with the structure shown in FIG. 1A, the edge region of the mask body structure 1 used to define the opening V is further thinned, which not only ensures the shape of the opening V, but also reduces the generation of the pattern shadow. Figure 5 As shown in FIG. 1H, a top view of the mask plate provided by the embodiment of the present disclosure is shown,

[0110] Figure 12a As shown in FIG. 1I, a cross-sectional view of the mask body structure 1 in the C-C’ direction of FIG. 1H, Figure 12b Figure 12a As shown in FIG. 1I, a cross-sectional view of the mask body structure 1 in the C-C’ direction of FIG. 1H, Figure 12a Figure 12b ​​As shown, the side of the mask body structure 1 away from the support structure 2 has a groove 4 arranged corresponding to each opening V respectively; the contour of the orthographic projection of the groove 4 on the reference plane parallel to the mask body structure 1, surrounds the orthographic projection of the opening V corresponding to the groove 4 on the reference plane, and the groove 4 and the opening V corresponding thereto are communicated.

[0111] The shape of the orthographic projection of the groove 4 on the reference plane can be the same as the shape of the outer contour of the opening V corresponding thereto.

[0112] The mask plate of the embodiment is applied to an evaporation process, Figure 12c A schematic view of the evaporation mask plate and the substrate is shown in FIG. 2, and the evaporation mask plate is shown in FIG. 3. Figure 12c As shown, the depth of the groove 4 can be set according to the height of the isolation column dam in the actual display panel, and the embodiment of the present disclosure is not specifically limited. The depth of the groove 4 can be slightly greater than the height of the isolation column dam, so as to avoid interference with the isolation column dam when the mask plate supports the display substrate 02, thereby reducing the risk of packaging failure.

[0113] Optionally, the thickness of the main part 201 can be greater than or equal to half of the maximum thickness of the mask plate, so as to reserve space for etching of the groove 4.

[0114] In the scenario of being applied to a high-generation line (G8.6H), the large-size mask plate web 6 is designed to be thinned, so the stress distribution is relatively complex, and the resulting curling problem is more serious than that of a conventional mask plate. The embodiment of the present disclosure effectively improves the edge curling problem in the etching process of the opening V and the groove 4 by using the patterned support structure 2.

[0115] In some embodiments, Figure 13 A schematic view of the welding of the mask plate and the metal frame (Frame) is shown in FIG. 6. Figure 5 and Figure 13 As shown, the end of the support structure 2 is flush with the outermost boundary of the mask body structure 1 away from the opening V, which is beneficial to improve the support strength of the mask plate.

[0116] In some embodiments, Figure 14 A schematic view of another mask plate provided by the embodiment of the present disclosure is shown in FIG. 7. Figure 15 A schematic view of the welding of another mask plate and the metal frame (Frame) is shown in FIG. 8. Figure 14 and Figure 15 As shown, the orthographic projection of the main part 201 on the mask body structure 1 has a gap between the mask body structure 1 away from the outermost boundary of the opening V, compared to Figure 13The difference between the embodiment and the structure shown in the figure is that the end of the support structure 2 is recessed and abuts against the metal frame when welded with the metal frame (welding can also be selected), and at this time the edge of the mask body structure 1 away from the support structure 2 is welded with the metal frame, which reduces the difficulty of welding the mask plate with the metal frame while ensuring the support strength of the mask plate.

[0117] In some embodiments, the support structure 2 is connected with the mask body structure 1 as an integrated structure. Compared with the traditional mask plate including a multi-layer structure design, the embodiment does not form residues of the evaporation material / cleaning liquid when the film layer pattern is evaporated and cleaned, which is conducive to cleaning and also reduces the vacuum time in the evaporation chamber due to the presence of residues of the liquid / material at the position during evaporation, thereby reducing the overall process production time. In addition, the support structure 2 is connected with the mask body structure 1 as an integrated structure, which is conducive to improving the integrity of the mask plate and thereby improving the support strength of the mask plate.

[0118] In some embodiments, Figure 16 For Figure 5 In another example of the cross-sectional view in the A-A' direction, as shown in the figure, the support structure 2 and the mask body structure 1 connected as an integrated structure are wrapped with an insulating layer 5. Figures 17a-17d

[0119] It should be noted that in the packaging process, that is, the Chemical Vapor Deposition (CVD) process, which belongs to high-energy plasma deposition, can damage the mask plate made of metal material. The mask plate of the embodiment is applied to the packaging process, and by coating an insulating layer 5 on the entire surface of the support structure 2 and the mask body structure 1 connected as an integrated structure, the damage to the mask plate can be reduced.

[0120] Optionally, the material of the insulating layer 5 can include but is not limited to aluminum oxide (AlO), aluminum trioxide (Al2O3), etc. Optionally, the thickness of the insulating layer 5 is about 1 um.

[0121] Optionally, when the mask plate is applied to the packaging process, the sum of the thickness of the mask body structure 1, the thickness of the main part 201, and the thickness of the two insulating layers 5 is between 80 um and 300 um, for example, when the mask plate is applied to the packaging process, the sum of the thickness of the mask body structure 1, the thickness of the main part 201, and the thickness of the two insulating layers 5 is 150 um.

[0122] It should be noted that the use state of the evaporation mask plate and the packaging mask plate is different. The evaporation mask plate is deposited from bottom to top; the packaging mask plate is deposited from top to bottom.

[0123] ​It should be noted that the thickness of the mask plate is different in different applications. When the mask plate is applied to the evaporation process, the sum of the thickness of the mask body structure 1 and the thickness of the main body part 201 is between 20um and 500um, for example, the sum of the thickness of the mask body structure 1 and the thickness of the main body part 201 is 100um. When the mask plate is applied to the packaging process, the sum of the thickness of the mask body structure 1 and the thickness of the main body part 201 is between 30um and 800um, for example, the sum of the thickness of the mask body structure 1 and the thickness of the main body part 201 is 150um.

[0124] In addition, the disclosure also provides a preparation method of the mask plate, comprising steps S11-S13.

[0125] S11, providing a roll material 6.

[0126] The roll material 6 can be a roll film after the original material roll film is thinned. The thickness of the original material roll film is greater than the thickness of the roll material 6. The original material roll film with a thickness of 200um-500um can be selected and thinned on both sides (to improve the preparation efficiency) to form a roll material 6 with a thickness of 100um-150um to meet the requirement of the sum of the thickness of the mask body and the thickness of the main body part 201 in the mask plate. Then, wait for the next step (for example, steps S12 and S13).

[0127] S12, forming a pattern including the support structure 2 on one side surface of the roll material 6 by a patterning process.

[0128] S13, forming a pattern including a plurality of openings V arranged in an array and the mask body structure 1 on one side surface of the pattern of the support structure 2 by a patterning process to obtain the mask plate.

[0129] The support structure 2 includes a main body part 201 and a plurality of protruding parts 202 connected to the main body part 201. The protruding part 202 is located at least on one side of the main body part 201 close to the opening V, and the extension direction of the protruding part 202 is the direction of the main body part 201 pointing to the opening V.

[0130] In one possible implementation, single-sided etching technology is used to perform S12 and S13 respectively. Figure 17a The schematic diagram of the mask plate preparation process in one example is shown in Figure 17b The fourth surface C1 and the fifth surface C2 of the roll material 6 are coated with photoresist PR1 and PR2 respectively along the thickness direction; then, as shown in Figure 17c The fourth surface C1 is exposed, developed and etched to form the pattern of the support structure 2; then, as shown in Figure 17d and Figures 18a-18dAs shown, the fifth surface C2 is developed and etched to form a pattern including the arrayed plurality of openings V and the mask body structure 1, to obtain the mask plate.

[0131] In one possible implementation, S12 and S13 are performed simultaneously by using double-sided etching technology. The fourth surface and the fifth surface of the web 6 are oppositely arranged along the thickness direction of the web 6, and then the fourth surface and the fifth surface are coated with photoresist, and then exposed, developed and etched simultaneously. The fourth surface is etched on one side to form the pattern of the support structure 2, and the fifth surface is etched to a partial depth of the opening V, to form a pattern including the arrayed plurality of openings V and the mask body structure 1, to obtain the mask plate.

[0132] In some embodiments, Figure 18a are respectively schematic diagrams of the mask plate preparation process according to another example. As shown, Figure 18b The fourth surface C1 and the fifth surface C2 of the web 6 are oppositely arranged along the thickness direction of the web 6, and then the fourth surface C1 and the fifth surface C2 are coated with photoresist PR1 and PR2 respectively by using double-sided etching technology. Then, as shown, Figure 18c The fourth surface C1 and the fifth surface C2 are sequentially subjected to the first exposure, the first development and the first etching. The fourth surface C1 is etched to form the pattern of the support structure 2, and the fifth surface is etched to form the groove 4. Then, as shown, Figure 18d and ​ The fourth surface C1 and the fifth surface C2 are sequentially subjected to the second exposure, the second development and the second etching to form the opening V, which is in communication with the groove 4.

[0133] It can be understood that the above embodiments are only exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also considered to be within the protection scope of the present disclosure.

Claims

1. A mask plate, comprising a mask main structure having a plurality of openings; A plurality of cross-arranged support structures are located on one side of the mask main structure; The opening is located between the cross-arranged support structures; At least part of the support structure includes a main body and a plurality of protrusions connected to the main body. The protrusions are located at least on one side of the main body close to the opening, and extend in the direction of the main body pointing to the opening.

2. The mask according to claim 1, wherein: The openings are arranged in an array, and the ratio of the minimum spacing between two adjacent openings in the column direction to the minimum width of the main body extending along the row direction in the column direction is between 0.3 and 0.35; The ratio of the minimum spacing between two adjacent openings in the row direction to the minimum width of the main body extending along the column direction in the row direction is between 0.3 and 0.

35.

3. The mask according to claim 1, wherein: The shortest distance between the orthographic projection of the protrusion on the main mask structure and the nearest opening is less than or equal to 0.5 mm, and a is not equal to 0.

4. The mask according to any one of claims 1 to 3, wherein: For at least part of the supporting structure, the protruding portions are provided on both sides of the extending direction of the main body, and the two protruding portions are symmetrically arranged with the main body as a symmetry axis.

5. The mask according to claim 4, wherein: For at least a portion of the main body, an intermediate area is defined between the protrusions located on the same side of the extending direction of the main body, and an intermediate structure is provided in the intermediate area. The mask according to claim 5 , wherein: The intermediate structure and the supporting structure are connected to form an integral structure.

7. The mask according to claim 6, wherein: The thickness of the intermediate structure gradually decreases in a direction away from the supporting structure connected thereto.

8. The mask according to claim 6, wherein: The thickness of the intermediate structure is less than or equal to the thickness of the supporting structure connected thereto.

9. The mask according to claim 1, wherein: The side of the mask main structure facing away from the support structure has grooves arranged corresponding to each of the openings; the outline of the positive projection of the groove on a reference plane parallel to the mask main structure surrounds the positive projection of the opening corresponding to the groove on the reference plane, and the groove is connected to the corresponding opening.

10. The mask according to claim 1, wherein: A gap is formed between an orthographic projection of the main body portion on the mask main structure and an outermost boundary of the mask main structure away from the opening.

11. The mask according to claim 1, wherein: The contour shape of the orthographic projection of the protrusion on the main mask structure is at least one of a quadrilateral, an arc, a semicircle, and a triangle.

12. The mask according to claim 1, wherein: The support structure and the mask main structure are connected into an integrated structure.

13. The mask according to claim 12, wherein: The surfaces of the support structure and the mask main structure connected into an integral structure are wrapped with an insulating layer.

14. The mask according to claim 1, wherein: The width f of the protrusion in the extending direction of the main body connected thereto is between 0.05 mm and a, where a represents the width of the main body perpendicular to its extending direction.

15. The mask according to claim 14, wherein: For each of the main body portions, the shortest distance between the two protruding portions located on the same side of the extending direction of the main body portion is less than or equal to 3×f.

16. A method for preparing a mask plate, wherein: Including providing a roll of material; By a patterning process, a pattern including a support structure is formed on one side surface of the coil; Through a patterning process, a pattern including a plurality of openings arranged in an array and a mask main structure is formed on one side surface of the pattern of the support structure to obtain a mask plate; the support structure includes a main body and a plurality of protrusions connected to the main body, and the protrusions are located at least on one side of the main body close to the opening, and their extension direction is the direction in which the main body points to the opening.

Images