Mask assembly and method of manufacturing the same

Abstract

A mask assembly comprises, from bottom to top, a mask frame, a support sheet, a precision support sheet mask plate and a precision metal mask plate, wherein the support sheet is arranged on the mask frame and intersects with the precision metal mask plate at an invalid mask area of the precision metal mask plate, and the precision support sheet mask plate is arranged on the mask frame and penetrates through an effective mask area of the precision metal mask plate, wherein the opening of the precision support sheet mask plate in the effective mask area is larger than the opening of the precision metal mask plate, so that the problems of gravity sagging and edge wrinkles of a large-size precision metal mask plate can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic printing, in particular to a mask assembly and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the display industry towards large size and high resolution, the size requirement of the precision metal mask plate (FMM) used in the production of display screens has significantly increased, and the mainstream FMM size has gradually expanded to 27 inches and above to meet the production requirements of large-size display panels. Then with the increase of FMM size, the center area of FMM is caused to sag due to gravity and wrinkles exist at the edge. At present, the use of precision support sheet mask plate in the non-effective area of FMM cannot improve the sagging and edge wrinkling problems of FMM. In view of the above problems, the industry currently optimizes the material system of the precision support sheet mask plate, and then the effect of the improvement of the material strength is effective; or a whole metal support net is added on the back of the FMM, and distributed mechanical support is provided through double net bonding, but the high-precision bonding process of the support net and the FMM is difficult to implement, and the introduction of the support net also increases the overall thickness and weight, affecting the stability of the display screen production process. SUMMARY

[0003] The purpose of the present application is a mask assembly, comprising: a mask frame, a support sheet, a precision support sheet mask plate, and a precision metal mask plate arranged in turn from bottom to top, wherein the support sheet is arranged on the mask frame and intersects with the precision metal mask plate in the non-effective mask area of the precision metal mask plate, and the precision support sheet mask plate is arranged on the mask frame and penetrates the effective mask area of the precision metal mask plate, wherein the opening of the precision support sheet mask plate in the effective mask area is larger than the opening of the precision metal mask plate.

[0004] Further, the opening shape of the precision support sheet mask plate is the same as the opening shape of the precision metal mask plate.

[0005] Further, the opening shape of the precision support sheet mask plate is a composite shape containing the opening shapes of pixels R, B and G.

[0006] Further, the thickness of the precision support sheet mask plate in the first area is greater than the thickness of the second area.

[0007] Further, the precision support sheet mask plate intersects with the center of gravity of the precision metal mask plate.

[0008] Further, the precision support sheet mask plate is welded on the mask frame, the first welding point size is 200-500um, and the first welding point spacing is 1.5-2.5mm.

[0009] Further, the precise metal mask plate is welded on the mask frame, the second welding point size is 200-400 um, and the second welding point spacing is 1-2 mm.

[0010] Further, the first welding point size is greater than the second welding point size, and the first welding point and the second welding point are arranged at intervals.

[0011] In another aspect, the application provides a preparation method of a mask assembly, comprising: providing a mask frame, a support sheet, a precise support sheet mask plate, and a precise metal mask plate, and welding the support sheet, the precise support sheet mask plate, and the precise metal mask plate on the mask frame in sequence.

[0012] Further, before welding the support sheet, a pre-pressure is applied to the mask frame at the outer periphery of the mask frame.

[0013] The application has at least the following advantages or beneficial effects: the problem of sagging and wrinkles at the edge of a large-size precise metal mask plate due to gravity can be solved, the application adopts a partition support design, the support sheet is placed in the invalid mask area (non-pattern area) of the precise metal mask plate, the support sheet provides a rigid support at the edge; the precise support sheet mask plate is placed in the effective mask area (pattern area) of the precise metal mask plate, the precise support sheet mask plate supports the FMM in the central effective area, reduces the sagging and wrinkles caused by gravity, realizes partition support, ensures the support strength, significantly reduces the weight of the assembly, and reduces the requirement for the lamination precision process. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0015] Figure 1 It is a schematic diagram of part of the mask assembly;

[0016] Figure 2 It is a sectional view of the mask assembly;

[0017] Figure 3 It is an enlarged view of the welding point of the mask assembly.

[0018] 1-mask frame; 2-support sheet; 3-precise support sheet mask plate; 4-precise metal mask plate; 11-recess; 31-first area; 32-second area; 33-first welding point; 41-second welding point. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the drawings and specific implementations to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0020] It should be noted that similar reference numerals and letters refer to like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0021] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0022] In addition, the terms "horizontal", "vertical" and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0023] In the description of the present application, it should also be noted that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] The embodiments of the present application provide a mask assembly, which can solve the problems of gravity sagging and edge wrinkles of large-size precision metal mask plates. Figure 1As shown, a mask assembly comprises, from bottom to top, a mask frame 1, a support sheet 2, a precision support sheet mask plate 3, and a precision metal mask plate 4, wherein the support sheet 2 is arranged on the mask frame 1 and intersects the precision metal mask plate 4 at the invalid mask area of the precision metal mask plate 4, and the precision support sheet mask plate 3 is arranged on the mask frame 1 and penetrates the effective mask area of the precision metal mask plate 4, wherein the opening of the precision support sheet mask plate in the effective mask area is larger than the opening of the precision metal mask plate.

[0025] The present application adopts a partition support design, the support sheet 2 is placed in the invalid mask area (non-pattern area) of the precision metal mask plate 4, the support sheet 2 provides rigid support at the edge; the precision support sheet mask plate 3 is placed in the effective mask area (pattern area) of the precision metal mask plate 4, the precision support sheet mask plate 3 supports the FMM in the central effective area, reduces the sagging and wrinkles caused by gravity, realizes partition support, ensures the support strength while significantly reduces the weight of the assembly, and reduces the requirements for the lamination precision process.

[0026] In addition, the opening size of the precision support sheet mask plate 3 in the effective mask area is larger than the opening of the FMM, avoiding blocking the evaporation material path, and ensuring the accuracy of the evaporation pattern.

[0027] The precision support sheet mask plate 3 is placed below the effective mask area of the precision metal mask plate 4, the effective mask area of the precision metal mask plate 4 is distributed with pixel openings, the pixel openings have small openings and large openings, the precision support sheet mask plate 3 is tightly attached to one side of the large opening of the precision metal mask plate 4, the precision support sheet mask plate 3 cannot block the pixel openings of the precision metal mask plate 4, and cannot affect the evaporation effect of the precision metal mask plate 4, therefore the size of the opening of the precision metal mask plate 4 is larger than the size of the large opening of the pixel opening. The opening of the precision support sheet mask plate 3 can be an inverted trapezoidal opening or other shaped opening, and the thickness of the precision support sheet mask plate 3 is 20-40um.

[0028] The opening of the precision support sheet mask plate 3 is an inverted trapezoidal opening (wide at the top and narrow at the bottom), which can guide the evaporation material flow field to pass through the opening more uniformly, reduce the accumulation of material at the edge of the precision support sheet mask plate 3, and at the same time enhance the structural rigidity of the precision support sheet mask plate 3 by using the trapezoidal side wall.

[0029] The precision metal mask plate 4 is mainly used for the manufacture of display screens, specifically for the manufacture of pixel points (R, G, B) in the display screen, so at least three types of precision metal mask plates 4 are needed for the manufacture of pixel points in the display screen, and each precision metal mask plate 4 has pixel R openings, pixel B openings, and pixel G openings.

[0030] The shape of the opening of the precision support sheet mask plate 3 can be the shape of the pixel opening of its corresponding precision metal mask plate 4, such as the opening shape of pixel R, or the opening shape of pixel B, or the opening shape of pixel G. If the opening shape of the precision support sheet mask plate 3 is the detailed opening shape of its corresponding precision metal mask plate 4, the precision support sheet mask plate 3 can maintain its rigidity to improve the support strength of the precision metal mask plate 4.

[0031] The opening shape of the precision support sheet mask plate 3 can also be a composite shape containing the opening shapes of pixel R, pixel B, and pixel G. If the opening of the precision support sheet mask plate 3 contains the opening shapes of pixel R, pixel B, and pixel G, it can be adapted to multiple version mask multiplexing, improving the etching production efficiency of the precision support sheet mask plate 3.

[0032] The thickness of the precision support sheet mask plate 3 in the first area 31 is greater than the thickness of the second area 32, where the first area 31 refers to the area where the precision support sheet mask plate 3 overlaps with the mask frame 1, and the second area 32 refers to the area of the precision support sheet mask plate 3 within the mask frame 1. The thickness of the first area 31 is greater, which can increase the support strength and lifting force of the precision support sheet mask plate 3, and enhance the tensile strength of the precision support sheet mask plate 3; the thickness of the second area 32 is small, so that the thickness of the area where the precision support sheet mask plate 3 overlaps with the precision metal mask plate 4 is small, which can eliminate the influence of the pixel shadow caused by the precision support sheet mask plate 3, and the small weight of the precision support sheet mask plate 3 itself avoids the problem of excessive sagging of itself, which is not good for the support effect of the FMM.

[0033] As shown in Figure 2 The precision metal mask plate 4 needs to be welded on the mask frame 1, and the precision support sheet mask plate 3 and the precision metal mask plate 4 overlap on the mask frame 1. A sunken recess 11 needs to be made on the mask frame 1, and the depth of the recess 11 is equal to the thickness of the first area of the precision support sheet mask plate 3, so that after the precision support sheet mask plate 3 is welded on the mask frame 1, it is on the same surface as the surface of the mask frame, without affecting the welding of the precision metal mask plate.

[0034] The centers of gravity of the precision support sheet mask plate 3 and the precision metal mask plate 4 intersect. Since the effective mask area of the precision metal mask plate 4 has pixel openings, the center of gravity of the precision metal mask plate 4 is usually not in the center of the FMM. Before welding the precision support sheet mask plate 3, the center of gravity of the precision metal mask plate 4 is found by using simulation software to simulate the precision metal mask plate 4, so that the centers of gravity of the precision support sheet mask plate 3 and the precision metal mask plate 4 intersect.

[0035] As shown in Figure 3As shown, the precision support sheet mask plate 3 is welded on the mask frame 1, and the welding points of the precision support sheet mask plate 3 on the mask frame are first welding points 33, wherein the size of the first welding points 33 is 200-500um, and the interval of the first welding points 33 is 1.5-2.5mm; the precision metal mask plate 4 is welded on the mask frame 1, and the welding points of the precision metal mask plate 4 are second welding points 41, wherein the size of the second welding points 41 is 200-400um, and the interval of the second welding points 41 is 1-2mm.

[0036] The size of the first welding points 33 is larger than the size of the second welding points 41, and the first welding points 33 are arranged in at least two rows along the frame of the mask frame 1, and the second welding points 41 are arranged in at least two rows along the frame of the mask frame 1, and the first welding points 33 and the second welding points 41 are arranged alternately.

[0037] The thickness of the precision support sheet mask plate 3 in the first area is large, the size of the first welding points 33 is large, which reduces the requirement for welding precision, and the size of the first welding points 33 is large, which can increase the welding contact area of the precision support sheet mask plate 3 and the mask frame 1, significantly improve the tensile strength of a single welding point, and avoid tearing or welding of the welding point.

[0038] The interval of the first welding points 33 is 1.5-2.5mm, which is cooperatively designed with the size of the welding points, to ensure that the welding area of the precision support sheet mask plate 3 and the mask frame 1 forms a periodic high-strength fixed point, and the wide interval can disperse the local stress concentration of the welding points. At least two rows of first welding points 33 are arranged along the edge of the mask frame 1 to form multiple rows of tensile load paths to enhance the welding firmness.

[0039] The size of the second welding points 41 is small, and the precision micro-point welding can be used for welding the precision metal mask plate 4, which can reduce the size of the welding points and the interval of the welding points under the condition of ensuring the fixing strength of the precision metal mask plate 4 and the mask frame 1, reduce the heat generated by welding, and interfere with the micro-deformation of the precision metal mask plate 4. At least two rows of second welding points 41 are arranged along the edge of the mask frame 1 to form multiple rows of tensile load paths to enhance the welding firmness.

[0040] The first welding points 33 and the second welding points 41 are arranged alternately on the mask frame 1, and the staggered arrangement of the two types of welding points makes the load distribution of the mask frame 1 more uniform, reduces the internal stress caused by the shrinkage rate difference between the precision support sheet mask plate 3 and the precision metal mask plate 4, and improves the overall tensile stability.

[0041] In another embodiment of the present application, a preparation method of a mask assembly is provided, which comprises a mask frame 1, a support sheet 2, a precision support sheet mask plate 3, and a precision metal mask plate 4. The support sheet 2, the precision support sheet mask plate 3, and the precision metal mask plate 4 are sequentially welded on the mask frame 1.

[0042] Before welding the support sheet, a pre-pressure is applied to the mask frame 1 at the periphery of the mask frame 1, and the pressure is applied at the center points of each side of the mask frame 1 or at 3-5 equidistantly distributed points. Before welding the support sheet 2, a directional pre-pressure is applied to the mask frame 1, so that when the frame naturally rebounds after the welding is completed, a reverse pre-stress is formed. The pre-stress can completely offset the inward tensile stress caused by the tensile force and the self-gravity of the subsequent support sheet 2, the precision support sheet mask plate 3, and the precision metal mask plate 4 after installation, significantly improving the initial flatness of the mask assembly and reducing the time-consuming leveling process before evaporation.

[0043] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A mask assembly, characterized by The mask frame, the support sheet, the precision support sheet mask plate, and the precision metal mask plate are arranged in sequence from bottom to top, wherein the support sheet is arranged on the mask frame in the invalid mask area of the precision metal mask plate, and the precision support sheet mask plate is arranged on the mask frame through the effective mask area of the precision metal mask plate, and the opening of the precision support sheet mask plate in the effective mask area is larger than the opening of the precision metal mask plate. The opening shape of the precision support sheet mask plate is the same as the opening shape of the precision metal mask plate.

2. The masking assembly of claim 1, wherein: The opening shape of the precision support sheet mask plate is a composite shape, and simultaneously contains the opening shapes of pixels R, B, and G.

3. The masking assembly of claim 1, wherein: The thickness of the precision support sheet mask plate in the first area is greater than the thickness in the second area, the first area refers to the area where the precision support sheet mask plate overlaps with the mask frame, and the second area refers to the area of the precision support sheet mask plate in the mask frame.

4. The masking assembly of claim 1, wherein The precision support sheet mask plate intersects with the center of gravity of the precision metal mask plate.

5. The masking assembly of claim 1, wherein: The precision support sheet mask plate is welded on the mask frame, the first welding point size is 200-500um, and the first welding point spacing is 1.5-2.5mm.

6. The masking assembly of claim 1, wherein: The precision metal mask plate is welded on the mask frame, the second welding point size is 200-400um, and the second welding point spacing is 1-2mm.

7. The masking assembly of claim 6, wherein: The first welding point size is greater than the second welding point size, and the first welding point and the second welding point are arranged at intervals.

8. The masking assembly of claim 7, wherein: The mask frame, the support sheet, the precision support sheet mask plate, and the precision metal mask plate are provided, and the support sheet, the precision support sheet mask plate, and the precision metal mask plate are welded on the mask frame in sequence.

9. A method for preparing a mask assembly, which can be used to prepare the mask assembly according to any one of claims 1 to 8, characterized in that: Before welding the support sheet, a pre-pressure is applied to the mask frame on the outer periphery of the mask frame. ​ 10. The method of claim 9, wherein the mask assembly is prepared by, ​

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