Mask device
By using boundary positioners to accurately locate the edge pixels of the mask plate in the evaporation mask device, the color shift and color mixing problems at the splicing of the automobile display panel are solved, and the precise control of the edges and chromatic uniformity are achieved.
Patent Information
- Application Number
- CN202411539257.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-01-07
AI Technical Summary
Color shift or color mixing often occurs at the splicing of automobile display panels, mainly due to the color mixing of the mask device at the edge of the pixel during evaporation.
An evaporation mask device is designed, including a support mask plate and a mask mask plate, and the edge pixel opening of the mask plate is accurately positioned through the boundary positioning member, controlling the edge pixel position, and avoiding color mixing.
Accurate control of splicing and evaporated edges is achieved, eliminating the edge color mixing and mura problems, and improving the color uniformity of the display panel.
Smart Images
Figure CN119265520A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of display technology, and in particular to an evaporation mask device. Background Art
[0002] With the upgrading of intelligent automobiles (such as electric vehicles), large-size display panels are widely used in automobiles to improve the user's operating experience. Currently, display panels used in automobiles are mostly set up in the form of splicing multiple screens (such as two display panels) due to the limitations of the manufacturing process. There is a color shift or color mixing phenomenon at the splicing of the display panels. This phenomenon is mostly caused by the evaporation color mixing at the edge of the pixel when the mask device mold is evaporated. Summary of the invention
[0003] In view of this, an object of the present disclosure is to provide a vapor deposition mask device, which can avoid the problem of uneven color at the edge of a display panel being evaporated.
[0004] Based on the above purpose, the present disclosure provides a mask device, which includes a frame, a supporting mask plate and a mask plate, wherein the supporting mask plate is arranged on the frame, and includes a supporting mask portion, a shielding mask plate and at least two boundary positioning members;
[0005] The shielding mask has a raised portion on one side close to the mask, and in the length direction of the shielding mask, a first flat portion and a second flat portion are respectively provided on both sides of the raised portion;
[0006] The boundary positioning member is arranged on the first flat portion and the second flat portion, and the boundary positioning member overlaps the mask plate, and the boundary positioning member is used to locate the opening (position of the opening) of the edge pixel of the mask plate. Through such a design, the boundary positioning member is used to avoid the boundary pixel / boundary pixel opening of the mask plate to control the position of its boundary pixel, thereby realizing precise control of the splicing evaporation edge PPA, thereby eliminating the problem of edge color mixing and mura. The support mask part is designed to be vertical to the shielding mask plate.
[0007] In one embodiment, in the length direction of the shadow mask, the first flat portion and the second flat portion are symmetrically arranged on both sides of the protruding portion.
[0008] In one embodiment, a length L1 of the first flat portion along a length direction of the mask is less than 10 mm, and / or a length L2 of the second flat portion along a length direction of the mask is less than 10 mm.
[0009] In one embodiment, the height H1 of the protruding portion protruding from the first flat portion or the second flat portion is less than 10 μm. Preferably, in the thickness direction of the shielding mask, the size of the supporting mask is less than or equal to 100 μm.
[0010] In one embodiment, the boundary positioning member has a plurality of perforations along the thickness direction thereof, through which accurate positioning can be achieved. Reference points can be set during implementation to assist in positioning.
[0011] In one embodiment, the shape of the perforation includes one or a combination of circle, oval, triangle, rectangle, square or diamond.
[0012] In one embodiment, the shape of the through hole is the same as the shape of the pixel opening at the edge position in the pixel matrix array on the mask.
[0013] In one of the embodiments, the mask plate includes a clamping portion, a welding portion and a hollow area, the mask plate is fixed to the frame through the welding portion, and the hollow area is used to pass through the evaporation material and adhere to a predetermined position of the substrate.
[0014] In one of the embodiments, the mask plate has connecting parts on both sides, and the connecting parts are used to overlap the first flat part and the second flat part. The first flat part and the second flat part are respectively provided with a plurality of through holes extending along the thickness direction thereof, and the orthographic projections of the through holes on the mask plate are located on the connecting parts.
[0015] In one embodiment, the through holes in the first flat portion and the second flat portion are connected to the corresponding through holes in the boundary positioning member. The boundary positioning member is used to accurately position the edge pixel position of the mask matched therewith, thereby eliminating the problem of edge color mixing and mura. In implementation, each mask is matched with a boundary positioning member.
[0016] The present application sets a boundary positioning piece, which is installed on the first flat portion and the second flat portion. The boundary positioning piece is used to locate and match the position of the edge pixels of the corresponding mask plate to control the position of the boundary pixels, thereby achieving precise control of the splicing vapor deposition edge PPA and eliminating the problems of edge color mixing and mura. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0018] Figure 1 A schematic diagram of evaporating multiple panels on a substrate according to an embodiment of the present disclosure;
[0019] Figure 2A schematic diagram of a frame provided in an embodiment of the present disclosure;
[0020] Figure 3 A schematic diagram of a hidden mask of an evaporation mask device provided in an embodiment of the present disclosure;
[0021] Figure 4 A schematic diagram of a pixel mask provided by an embodiment of the present disclosure;
[0022] Figure 5 A schematic cross-sectional view of a masking mask provided in one embodiment of the present disclosure;
[0023] Figure 6 A cross-sectional schematic diagram of a pixel mask provided in an embodiment of the present disclosure being placed on a supporting mask;
[0024] Figure 7 A schematic top view of a boundary positioning member provided in one embodiment of the present disclosure;
[0025] Figure 8 for Figure 6 A local enlarged schematic diagram of point a in the middle. DETAILED DESCRIPTION
[0026] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.
[0027] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" 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 indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0028] FMM (Fine Metal Mask) is usually used in the manufacture of OLED (Organic Light-Emitting Diode) display panels, through which organic light-emitting materials are evaporated in the pixel units of the backplane. The FMM mask is welded to the frame through a supporting mask. The supporting mask includes a Howling mask and a Cover mask, which are separately spread on the Frame. There is evaporation color mixing at the edge of the mask during evaporation. The applicant conducted further research on the color mixing at the edge and mura and found that when preparing a long screen, the FMM mask was spliced for evaporation. The inaccurate positioning of the FMM mask boundary caused the PPA (Pixel position accuracy) at the edge to shift, and it is difficult to control the accuracy of the edge under the current design architecture.
[0029] To this end, a mask device is proposed. The mask device includes a frame, a supporting mask plate and a mask plate. The supporting mask plate includes a supporting mask portion (also called a Howling mask plate), a shielding mask plate (also called a Cover mask plate) and at least two boundary positioning members. Through such a design, the boundary positioning members are used to avoid the boundary pixels / boundary pixel openings at the edge of the mask plate to accurately control the position of its boundary pixels, thereby achieving accurate control of the splicing evaporation edge PPA, and through which the organic light-emitting material is evaporated in the pixel unit of the backplane, so as to eliminate the edge color mixing and mura problems. The supporting mask plate and the mask plate can be made of the same material. The supporting mask plate is arranged on the frame. Preferably, the supporting mask portion and the shielding mask plate are perpendicular to each other.
[0030] When display panels are evaporated on the production line, they are usually cut into size on the entire substrate or according to the generation of the production line. The size of the substrate varies depending on the generation of the production line. Figure 1 The figure shows an uncut display panel on a substrate, which may be a glass substrate (such as an LTPS glass substrate). The panel 20 (which can also be understood as the area for making the display panel) is regularly arranged on the substrate 10. According to the size of the substrate 10 (such as 950mm*1500mm), the panel 20 is configured into 5 columns and 19 rows. In other embodiments, the specific number of 5 columns and 19 rows is not limited. After evaporation (preparation of OLED materials), the substrate 10 enters subsequent processes, such as preparation of cathodes and anodes, etc. After completion, cutting is performed (such as cutting by laser or cutting tool), and the panel 20 is prepared into a display panel / also called a display module. The display module can be used for vehicle-mounted, VR display / AR display.
[0031] During evaporation, multiple masks are spliced together for evaporation. R / G / B pixels can be evaporated separately using three RGB masks, such as using R / G / B masks to evaporate R / G / B pixels in sequence on the substrate. When evaporating the R pixel, a grinding device that matches the number of rows can be used for evaporation at the same time (thereby completing the evaporation of the R pixels on the entire surface of the substrate). During evaporation, the substrate and the mask device are placed in a closed vacuum environment space, and an evaporation source is placed on the lower side of the mask device, which contains evaporation materials such as organic light-emitting materials. The evaporation source is heated by a heater to evaporate the evaporation material through the opening of the grinding device and adhere to the preset position (panel 20) on the surface of the substrate.
[0032] Next, the mask device proposed in the present application is described in conjunction with the accompanying drawings.
[0033] The mask device includes a frame, a supporting mask and a mask plate (FMM). The frame supports the mask plate in a state of stretching the mask plate along its surface direction to suppress the mask plate from being bent.
[0034] The frame 100 (see Figure 2 ), is square, and can be made of the same material as the mask described later, such as an iron alloy containing nickel. The frame 100 can be an integrated design or a split design, such as a combination of four components.
[0035] The support mask (see Figure 3 ) includes a supporting mask portion 200 (i.e., Howling mask) and a shielding mask 300 (i.e., Cover mask), two adjacent supporting mask portions 200 are arranged in parallel, two adjacent shielding mask plates 300 are arranged in parallel, and the supporting mask portion 200 and the shielding mask plate 300 are perpendicular to each other. The supporting mask portion 200 and the shielding mask plate 300 can be made of the same material as the mask plate described later. The number of supporting mask portions 200 and shielding mask plates 300 is not limited, as long as it meets the production line operation requirements. The supporting mask plate also includes a boundary positioning piece.
[0036] In one embodiment, the thickness of the support mask portion 200 and the shielding mask 300 may be greater than 50 μm and less than 1 mm. Preferably, the thickness of the support mask portion 200 and the shielding mask 300 may be greater than 50 μm and less than 60 μm. The shielding mask 300 is also called Cover, and its cross-section in the y direction (i.e., the length direction of the shielding mask 300) is shown as follows: Figure 5 As shown, a central portion of one side of the mask 300 has a raised portion 330, one side of the raised portion 330 has a first flat portion 310, and one side of the raised portion 330 away from the first flat portion 310 has a second flat portion 320. Preferably, the first flat portion 310 and the second flat portion 320 are symmetrically arranged along the raised portion 330.
[0037] In other embodiments, whether the first flat portion 310 and the second flat portion 320 are symmetrical along the protrusion 330 is not limited. The length L1 of the first flat portion 310 in the y direction is less than 10 mm, and the length L2 of the second flat portion 320 in the y direction is less than 10 mm. The length L1 of the first flat portion 310 and the length L2 of the second flat portion 320 may be the same or different.
[0038] The height H1 of the protrusion 330 protruding from the first flat portion 310 or the second flat portion 320 is less than 10 μm. The thickness of the mask 300 in the z direction (i.e., the thickness direction perpendicular to the length direction of the mask 300) is less than 100 μm. The first flat portion 310 and the second flat portion 320 are used to place the boundary positioning member 500.
[0039] The mask 400 (see Figure 4 ), including a hollow area 430, a clamping portion 420 and a welding portion 410. The hollow area 430 is used to pass through the evaporation material and attach to a predetermined position of the substrate 10. One hollow area 430 may correspond to the display area of one organic electro-optical display device or the display areas of multiple organic electro-optical display devices. The two ends of the mask 400 are respectively provided with a clamping portion 420, and the clamping portion 420 is used to facilitate the taking, moving and stretching of the mask 400. The two ends of the mask 400 are also respectively provided with a welding portion 410, which is located on the side of the clamping portion 420 away from the hollow area 430, and is used to fix the mask 400 on the frame 100. During implementation, the clamping part 420 is first clamped by a clamping device, and then the mask 400 is stretched by the clamping device until the hollow area 430 reaches a predetermined position (or coordinate), and then the welding part 410 is welded by a welding device to fix the mask 400 on the frame 100. The mask 400 can be used for the splicing evaporation of an organic electroluminescent display device.
[0040] The boundary positioning member 500 is in the form of a sheet (see the top view schematic diagram Figure 7 ), which can be made of the same material as the mask 400 described later, such as a nickel-containing iron alloy for the boundary positioning piece. The thickness of the boundary positioning piece 500 is less than 5 μm. The boundary positioning piece 500 has a plurality of through holes 510 extending along the z direction. The shape of the through hole 510 can be circular, elliptical, triangular, rectangular, square or diamond, etc. By moving the boundary positioning piece 500, the through hole 510 is aligned with the edge position of the mask 400, thereby realizing the precise positioning of the mask 400 by using the boundary positioning piece 500. In other embodiments of the present invention, the shape of the through hole 510 is not limited to the above-mentioned shape, as long as the positioning can be achieved.
[0041] In one embodiment, a mask 400 is placed on Figure 3 The cross section along the y direction of the support mask shown is shown as follows Figure 6 As shown, a boundary positioning member 500 is placed on the first flat portion 310 and the second flat portion 320 respectively. By adjusting the position of the boundary positioning member 500 relative to the first flat portion 310 or the second flat portion 320 (i.e., by adjusting the distance between the boundary positioning member 500 and the raised portion 330), the precise positioning of the boundary pixels of the mask 400 (FMM) can be achieved.
[0042] The positioning of this embodiment is shown as follows Figure 8 As described, the mask plate 400 is provided with a connecting portion 401, which is overlapped on the first flat portion 310 and / or the second flat portion 320 (the masking mask plate 300 is connected to the mask plate 400 through the boundary positioning piece 500, and the precise positioning of the edge is achieved by adjusting the position of the boundary positioning piece 500, such as whether to block the boundary pixel opening 402). The boundary positioning piece 500 is provided with a perforation 510 (opening, sometimes used as a pixel opening) extending along its z direction. The boundary positioning piece 500 is used to avoid the boundary pixels (boundary pixel opening 402) of the mask plate (FMM) to control its boundary pixels, thereby achieving precise control of the splicing evaporation edge PPA, thereby eliminating problems such as color mixing and mura (poor display) at the edge of the panel. When performing alignment, the alignment between the mask 400 and the boundary positioning member 500 can be determined by shining light on the side of the mask 400 away from the boundary positioning member 500, setting a reflector on the side of the boundary positioning member 500 away from the mask 400 to check the reflection, or shining light on the side of the mask 400 away from the boundary positioning member 500, and directly checking whether there is light passing through the side of the boundary positioning member 500 away from the mask 400. In other embodiments, the alignment between the mask 400 and the boundary positioning member 500 can also be determined by shining light on the side of the boundary positioning member 500 away from the mask 400, and observing the light passing through the side of the mask 400 away from the boundary positioning member 500. The mask 400 has connecting parts 401 on both sides. Preferably, the connecting part 401 can be located in the full thickness area of the mask 400.
[0043] Preferably, the shape of the perforation 510 is the same as the shape of the pixel opening at the edge position (such as 1 row or 1-2 rows at the edge) in the array of the pixel matrix on the mask 400. The mask 400 can be made of a nickel-containing iron alloy (also known as an Invar alloy material), and can also contain cobalt (also known as a super Invar alloy material) in addition to nickel. This type of iron alloy can reduce the thermal expansion coefficient of the mask 400. The closer the thermal expansion coefficient is to the thermal expansion coefficient of the substrate 10 (such as an LTPS glass substrate), the better. During evaporation, multiple mask plates 400 are spliced for evaporation. For example, when evaporating green (G) pixels, a grinding device matching the number of rows can be used for evaporation at the same time, so as to complete the evaporation of green (G) pixels on the entire surface of the substrate 10. The edge pixel position of each mask 400 is accurately positioned by the boundary positioning member 500, eliminating the problems of color mixing and mura at the edge of the panel. The edge position control method of pixels of other colors can refer to the edge position control method of the green (G) pixel mentioned above.
[0044] In other embodiments, a magnet is further included to attract the grinding device to prevent the mask 400 from bending during evaporation.
[0045] In one embodiment, the first flat portion 310 and the second flat portion 320 are respectively provided with a plurality of through holes extending along the z direction thereof, and the through holes can also be used for positioning. Specifically, by adjusting the position between the through holes and the mask 400, the orthographic projection of the through holes on the mask 400 is caused to be located on the connection portion 401 of the mask 400, so that the first flat portion 310 and the second flat portion 320 are respectively overlapped with the corresponding connection portion 401 to achieve the positioning operation, thereby achieving the purpose of controlling the boundary pixels of the mask 400 and achieving precise control of the PPA of the spliced evaporation edge. In this way, the problem of edge color mixing and mura is eliminated. In this way, the display panel evaporated by the grinding device avoids the problem of color mixing and mura at the splicing when splicing.
[0046] Furthermore, by aligning the through hole 510 in the boundary positioning member 500 with the through hole on the first flat portion 310 or the second flat portion 320, the through holes in the first flat portion 310 and the second flat portion 320 are connected to the corresponding through holes 510 in the boundary positioning member 500, respectively, and the boundary pixels of the mask plate can be controlled, and the PPA of the spliced evaporation edge can be precisely controlled to eliminate the problems of edge color mixing and mura.
[0047] While the disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art in light of the foregoing description.
[0048] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.
[0049] It should be noted that the above describes some embodiments of the present disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
[0050] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.
Claims
1. A mask device, characterized in that: include: Frame, support mask and mask, The supporting mask is arranged on the frame, and the supporting mask comprises a supporting mask portion, a shielding mask and at least two boundary positioning members; The shielding mask has a raised portion on one side close to the mask, and in the length direction of the shielding mask, a first flat portion and a second flat portion are respectively provided on both sides of the raised portion; The boundary positioning member is disposed on the first flat portion and the second flat portion, and the boundary positioning member overlaps the mask plate. The boundary positioning member is used to position the opening of the edge pixel of the mask plate.
2. The mask device according to claim 1, characterized in that A length L1 of the first flat portion along a length direction of the shadow mask is less than 10 mm, and / or a length L2 of the second flat portion along a length direction of the shadow mask is less than 10 mm.
3. The mask device according to claim 1 or 2, characterized in that: In the length direction of the shadow mask, the first flat portion and the second flat portion are symmetrically arranged on both sides of the raised portion.
4. The mask device according to claim 3, characterized in that: The height H1 of the protruding portion protruding from the first flat portion or the second flat portion is less than 10 μm; Preferably, in the thickness direction of the shielding mask, the size of the supporting mask is less than or equal to 100 μm.
5. The mask device according to claim 1, characterized in that: The boundary positioning piece is provided with a plurality of through holes extending along the thickness direction thereof.
6. The mask device according to claim 5, characterized in that: The shape of the perforation includes one or a combination of circle, oval, triangle, rectangle, square or diamond.
7. The mask device according to claim 5 or 6, characterized in that: The shape of the through hole is the same as the shape of the pixel opening at the edge position in the pixel array on the mask.
8. The mask device according to claim 1, characterized in that: The mask plate includes a clamping portion, a welding portion and a hollow area. The mask is fixed on the frame through the welding part, and the hollow area is used to pass through the evaporation material and adhere to the predetermined position of the substrate.
9. The mask device according to claim 8, characterized in that: The mask has connecting parts on both sides. The connecting portion overlaps the first flat portion and the second flat portion, The first flat portion and the second flat portion are respectively provided with a plurality of through holes extending along the thickness direction thereof, and the orthographic projections of the through holes on the mask are located on the connecting portion.
10. The mask device according to claim 9, characterized in that: The through holes in the first flat portion and the second flat portion are communicated with the corresponding through holes in the boundary positioning member.