KR20200131788A - Mask for forming oled picture element and mask supporting tray - Google Patents

Abstract

The present invention relates to a mask for forming an OLED pixel and a mask support tray which prevent deformation of the mask when attaching the mask to a frame and improve positional accuracy by reducing the deformation of the mask during welding. According to the present invention, a mask for forming an OLED pixel comprises: a mask cell on which a plurality of mask patterns are formed; and a dummy around the mask cell. A plurality of welding portions are formed at least in part of the dummy at intervals, and an anti-wrinkle pattern is formed around each of the welding portions spaced apart by a predetermined interval.

Description

Mask for forming OLED pixels and mask supporting tray {MASK FOR FORMING OLED PICTURE ELEMENT AND MASK SUPPORTING TRAY}

The present invention relates to an OLED pixel forming mask and a mask supporting tray. More specifically, masks and masks for forming OLED pixels that can make the mask integral with the frame, and improve the positional accuracy by reducing the deformation of the mask during welding, thereby clarifying the alignment between each mask. It relates to a support tray.

In recent years, research on an electroforming method in manufacturing a thin plate is in progress. The electroplating method is a method of immersing an anode body and a cathode body in an electrolyte solution, and applying power to deposit a metal thin plate on the surface of the cathode body, so that an ultra-thin plate can be manufactured and mass production can be expected.

Meanwhile, as a technology for forming pixels in the OLED manufacturing process, a Fine Metal Mask (FMM) method is mainly used in which an organic material is deposited at a desired location by attaching a thin metal mask to a substrate.

In the existing OLED manufacturing process, the mask is manufactured in the form of a stick or plate, and then the mask is welded and fixed to the OLED pixel deposition frame. One mask may include several cells corresponding to one display. In addition, in order to manufacture a large area OLED, several masks can be fixed to the OLED pixel deposition frame. In the process of fixing to the frame, each mask is stretched so that it is flat. It is a very difficult task to adjust the tension so that the entire part of the mask is flat. In particular, in order to align a mask pattern with a size of only a few to tens of μm while making all the cells flat, a high level of work is required to check the alignment in real time while finely adjusting the tension applied to each side of the mask. do.

Nevertheless, in the process of fixing several masks to one frame, there is a problem in that the alignment between the masks and the mask cells is not good. In addition, in the process of welding and fixing the mask to the frame, the thickness of the mask film is too thin and large area, so the mask is struck or distorted by the load, and wrinkles and burrs occur in the welding part during the welding process. There were problems such as misalignment.

In the case of ultra-high-definition OLED, the current QHD quality is 500-600 PPI (pixel per inch), and the pixel size reaches about 30-50㎛, and 4K UHD, 8K UHD high-definition is higher than this, ~860 PPI, ~1600 PPI, etc. Will have a resolution of. In this way, in consideration of the pixel size of the ultra-high-definition OLED, the alignment error between cells should be reduced to about several µm, and the error beyond this leads to product failure, so the yield may be very low. Therefore, there is a need to develop a technique for preventing deformation such as a mask being struck or distorted, a technique for clarifying alignment, a technique for fixing a mask to a frame, and the like.

Accordingly, the present invention has been devised to solve the problems of the prior art as described above, and an object thereof is to provide a method of manufacturing a frame-integrated mask in which a mask and a frame can be integrated.

In addition, it is an object of the present invention to provide a method of manufacturing a frame-integrated mask capable of preventing deformation such as being struck or distorted and clarifying alignment.

In addition, an object of the present invention is to provide a method for manufacturing a frame-integrated mask in which the manufacturing time is remarkably reduced and the yield is remarkably increased.

In addition, it is an object of the present invention to provide a mask for forming OLED pixels that prevents deformation of the mask when attaching the mask to a frame and improves positional accuracy by reducing the deformation of the mask during welding.

The above object of the present invention is a mask for forming an OLED pixel, including a mask cell in which a plurality of mask patterns are formed, and a dummy around the mask cell, and a plurality of welding portions are formed at intervals in at least a part of the dummy It is achieved by a mask for forming an OLED pixel, in which an anti-wrinkle pattern is formed around the weld portion spaced apart by a predetermined distance.

The anti-wrinkle pattern may include a plurality of unit anti-wrinkle patterns, and at least one width of the unit anti-wrinkle pattern may be smaller than a diameter of the welding portion.

The anti-wrinkle pattern and the mask pattern may further include a plurality of buffer patterns that are formed to form a gap between the anti-wrinkle pattern and the mask pattern and have a width greater than that of the mask pattern.

In addition, the above object of the present invention is to support a mask for forming an OLED pixel to correspond to a frame, comprising: a tray; A mask bonded on the tray; wherein the mask includes a mask cell on which a plurality of mask patterns are formed, and a dummy around the mask cell, and a plurality of welding portions are formed at intervals on at least a portion of the dummy, and each It is achieved by a mask support tray, in which an anti-wrinkle pattern is formed around the welded portion spaced a predetermined distance.

A laser through hole may be formed in a portion of the tray corresponding to the welding portion of the mask.

The tray has a flat plate shape and may include a material having a surface roughness Ra of 100 nm or less (greater than 0) on one surface in contact with the mask.

The tray may include any one of a wafer, glass, silica, heat-resistant glass, quartz, and alumina (Al ₂ O ₃ ).

The formation of an air gap at the interface between the tray and the mask may be prevented.

The anti-wrinkle pattern can occupy at least a circumferential region concentric with the welded portion and having a larger diameter than the welded portion.

The anti-wrinkle pattern may include a plurality of unit anti-wrinkle patterns, and at least one width of the unit anti-wrinkle pattern may be smaller than a diameter of the welding portion.

The anti-wrinkle pattern and the mask pattern may further include a plurality of buffer patterns that are formed to form a gap between the anti-wrinkle pattern and the mask pattern and have a width greater than that of the mask pattern.

According to the present invention configured as described above, there is an effect that the mask and the frame can form an integral structure.

In addition, according to the present invention, there is an effect of preventing deformation, such as being struck or distorted, of the mask, and enabling clear alignment.

Further, according to the present invention, there is an effect of remarkably reducing the manufacturing time and increasing the yield remarkably.

In addition, according to the present invention, when the mask is attached to the frame, it is possible to prevent deformation of the mask and reduce the deformation of the mask during welding, thereby improving positioning accuracy.

1 is a schematic diagram showing a conventional OLED pixel deposition mask.
2 is a schematic diagram showing a process of attaching a conventional mask to a frame.
3 is a schematic diagram showing that an alignment error between cells occurs in a process of tensioning a conventional mask.
4 is a front view and a side cross-sectional view showing a frame-integrated mask according to an embodiment of the present invention.
5 is a front view and a side cross-sectional view showing a frame according to an embodiment of the present invention.
6 is a schematic diagram showing a manufacturing process of a frame according to an embodiment of the present invention.
7 is a schematic diagram showing a manufacturing process of a frame according to another embodiment of the present invention.
8 is a schematic diagram showing a shape of a mask and a state in which the mask is adhered onto a tray according to an exemplary embodiment of the present invention.
9 to 12 are schematic diagrams showing anti-wrinkle patterns of a mask according to various embodiments of the present invention.
13 is a schematic diagram showing a state in which a mask according to a comparative example is adhered onto a tray.
14 is a schematic diagram showing a state in which a mask according to a comparative example is attached to a cell region of a frame.
15 is a schematic diagram illustrating a state in which a mask is attached to a cell area of a frame according to an exemplary embodiment of the present invention.
16 is a schematic diagram showing a state in which a tray according to a comparative example is loaded onto a frame and a mask is associated with a cell area of the frame.
17 is a schematic diagram illustrating a process of loading a tray according to a comparative example onto a frame and attaching a mask to a cell region of the frame and an interface state between the mask and the tray.
18 is a schematic diagram illustrating a process of attaching a mask to a cell area of the frame by loading a tray onto a frame according to an embodiment of the present invention, and an interface state between the mask and the tray.
19 is a schematic diagram showing a tray according to an embodiment of the present invention.
20 is a schematic diagram illustrating a state in which a tray according to an embodiment of the present invention is loaded onto a frame and a mask is associated with a cell area of the frame.
21 is a schematic diagram illustrating a process of sequentially attaching a mask to a cell area according to an embodiment of the present invention.
22 is a schematic diagram illustrating a process of lowering a temperature of a process area after attaching a mask to a cell area of a frame according to an embodiment of the present invention.
23 is a schematic diagram showing an OLED pixel deposition apparatus using a frame-integrated mask according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description refers to the accompanying drawings, which illustrate specific embodiments in which the present invention may be practiced. These embodiments are described in detail sufficient to enable a person skilled in the art to practice the present invention. It is to be understood that the various embodiments of the present invention are different from each other, but need not be mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the present invention in relation to one embodiment. In addition, it is to be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the detailed description to be described below is not intended to be taken in a limiting sense, and the scope of the present invention, if properly described, is limited only by the appended claims, along with all scopes equivalent to those claimed by the claims. In the drawings, similar reference numerals refer to the same or similar functions over several aspects, and the length, area, thickness, and the like may be exaggerated and expressed for convenience.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to enable those of ordinary skill in the art to easily implement the present invention.

1 is a schematic diagram showing a conventional OLED pixel deposition mask 10.

Referring to FIG. 1, a conventional mask 10 may be manufactured in a stick-type or plate-type. The mask 10 shown in (a) of FIG. 1 is a stick-type mask, and both sides of the stick can be welded and fixed to an OLED pixel deposition frame. The mask 100 shown in (b) of FIG. 1 is a plate-type mask and may be used in a process of forming a pixel having a large area.

A plurality of display cells C are provided on the body of the mask 10 (or the mask layer 11). One cell C corresponds to one display such as a smartphone. A pixel pattern P is formed in the cell C to correspond to each pixel of the display. When the cell C is enlarged, a plurality of pixel patterns P corresponding to R, G, and B appear. For example, a pixel pattern P is formed in the cell C to have a resolution of 70 X 140. That is, a number of pixel patterns P are clustered to form one cell C, and a plurality of cells C may be formed on the mask 10.

2 is a schematic diagram showing a process of attaching the conventional mask 10 to the frame 20. 3 is a schematic diagram showing that an alignment error occurs between cells in a process of stretching the conventional mask 10 (F1 to F2). A stick mask 10 including six cells C: C1 to C6 shown in FIG. 1A will be described as an example.

Referring to FIG. 2A, first, the stick mask 10 must be flattened. The stick mask 10 is unfolded as it is pulled by applying a tensile force F1 to F2 in the long axis direction of the stick mask 10. In that state, the stick mask 10 is loaded on the frame 20 in the form of a square frame. Cells C1 to C6 of the stick mask 10 are located in a blank area inside the frame of the frame 20. The frame 20 may have a size such that cells C1 to C6 of one stick mask 10 are located in an empty area inside the frame, and cells C1 to C6 of a plurality of stick masks 10 are It may be large enough to be located in an internal empty area.

Referring to FIG. 2(b), after aligning while finely adjusting the tensile forces (F1 to F2) applied to each side of the stick mask 10, a part of the side of the stick mask 10 is welded (W). Accordingly, the stick mask 10 and the frame 20 are interconnected. 2C shows a cross-sectional side view of the frame and the stick mask 10 connected to each other.

Referring to FIG. 3, although the tensile forces F1 to F2 applied to each side of the stick mask 10 are finely adjusted, there is a problem in that the mask cells C1 to C3 are not well aligned with each other. For example, the distances D1 to D1" and D2 to D2" between the patterns P of the cells C1 to C3 are different from each other, or the patterns P are skewed. Since the stick mask 10 has a large area including a plurality (for example, 6) of cells C1 to C6 and has a very thin thickness of several tens of µm, it is easily struck or distorted by a load. In addition, it is a very difficult task to check the alignment between each cell (C1 to C6) in real time through a microscope while adjusting the tensile force (F1 to F2) to flatten all of the cells (C1 to C6).

Therefore, a minute error in the tensile force (F1 to F2) may cause an error in the extent to which each of the cells (C1 to C3) of the stick mask 10 is stretched or unfolded, and accordingly, the distance D1 between the mask patterns (P) ~D1", D2 ~ D2") causes a problem that becomes different. Of course, it is difficult to completely align the error to be 0, but in order to prevent the mask pattern (P) having a size of several to tens of µm from adversely affecting the pixel process of an ultra-high-definition OLED, the alignment error should not exceed 3 µm. It is desirable not to. This alignment error between adjacent cells is referred to as PPA (pixel position accuracy).

In addition, a plurality of stick masks 10 of about 6 to 20 are connected to one frame 20, respectively, between a plurality of stick masks 10, and a plurality of cells C of the stick mask 10 It is also a very difficult task to clarify the alignment state between ~C6), and the process time according to the alignment is inevitably increased, which is a significant reason for reducing productivity.

On the other hand, after the stick mask 10 is connected and fixed to the frame 20, the tensile forces F1 to F2 applied to the stick mask 10 may act in reverse to the frame 20. That is, after the stick mask 10, which was stretched by the tensile force F1 to F2, is connected to the frame 20, a tension may be applied to the frame 20. Usually, this tension is not large and may not have a large effect on the frame 20, but when the size of the frame 20 is reduced in size and the rigidity is lowered, this tension may finely deform the frame 20. As a result, there may be a problem of misalignment between the plurality of cells C to C6.

Accordingly, the present invention proposes a frame 200 and a frame-integrated mask that enables the mask 100 to form an integral structure with the frame 200. The mask 100 integrally formed in the frame 200 is prevented from being struck or warped, and may be clearly aligned with the frame 200. Since no tensile force is applied to the mask 100 when the mask 100 is connected to the frame 200, the frame 200 may not be deformed after the mask 100 is connected to the frame 200. . In addition, the manufacturing time for integrally connecting the mask 100 to the frame 200 can be significantly reduced, and the yield can be remarkably increased.

Figure 4 is a front view [Fig. 4 (a)] and a side cross-sectional view [Fig. 4 (b)] showing a frame-integrated mask according to an embodiment of the present invention, Figure 5 is according to an embodiment of the present invention It is a front view [FIG. 5(a)] and a side cross-sectional view [FIG. 5(b)] showing the frame.

4 and 5, the frame-integrated mask may include a plurality of masks 100 and one frame 200. In other words, a plurality of masks 100 are attached to the frame 200, one by one. Hereinafter, for convenience of explanation, a square-shaped mask 100 will be described as an example, but the mask 100 may be in the form of a stick mask having protrusions clamped on both sides before being attached to the frame 200, and the frame 200 ), the protrusion can be removed after being attached.

A plurality of mask patterns P may be formed on each mask 100, and one cell C may be formed on one mask 100. One mask cell C may correspond to one display such as a smartphone. In order to form a thin thickness, the mask 100 may be formed by electroforming. Mask 100 may be a coefficient of thermal expansion of about 1.0 X 10 ^-6 / ℃ of invar (invar), about 1.0 X 10 ^-7 / ℃ Super Invar (super invar) material. Since the mask 100 made of this material has a very low coefficient of thermal expansion, it is less likely that the pattern shape of the mask may be deformed by thermal energy, so it can be used as a Fine Metal Mask (FMM) or a shadow mask in high-resolution OLED manufacturing. In addition, considering the recent development of technologies for performing a pixel deposition process in a range where the temperature change value is not large, the mask 100 is made of nickel (Ni) and nickel-cobalt (Ni-Co) having a slightly larger coefficient of thermal expansion than this. ), etc. The mask may have a thickness of about 2 μm to 50 μm.

The frame 200 is formed to attach a plurality of masks 100. The frame 200 may include several corners formed in a first direction (eg, horizontal direction) and a second direction (eg, vertical direction) including an outermost edge. These various corners may partition a region on the frame 200 to which the mask 100 is to be attached.

The frame 200 may include a frame portion 210 having a substantially square shape or a square frame shape. The inside of the frame frame 210 may have a hollow shape. That is, the frame frame unit 210 may include a hollow region R. The frame 200 may be made of metal materials such as Invar, Super Invar, aluminum, titanium, etc., and in consideration of thermal deformation, it is composed of materials such as Invar, Super Invar, nickel, nickel-cobalt, etc., which have the same coefficient of thermal expansion as the mask. Preferably, these materials may be applied to both the frame part 210 and the mask cell sheet part 220 which are components of the frame 200.

In addition, the frame 200 may include a plurality of mask cell regions CR, and may include a mask cell sheet part 220 connected to the frame frame part 210. Like the mask 100, the mask cell sheet part 220 may be formed by electroplating, or may be formed using another film forming process. In addition, the mask cell sheet part 220 may form a plurality of mask cell regions CR on a planar sheet through laser scribing, etching, or the like, and then connect to the frame frame part 210. Alternatively, the mask cell sheet part 220 may form a plurality of mask cell regions CR through laser scribing, etching, or the like after connecting the planar sheet to the frame frame part 210. In the present specification, it is assumed that a plurality of mask cell regions CR are first formed in the mask cell sheet part 220 and then connected to the frame frame part 210.

The mask cell sheet part 220 may be configured to include at least one of an edge sheet part 221 and first and second grid sheet parts 223 and 225. The frame sheet portion 221 and the first and second grid sheet portions 223 and 225 refer to respective portions partitioned in the same sheet, and they are integrally formed with each other.

The frame sheet part 221 may be substantially connected to the frame frame part 210. Accordingly, the frame sheet part 221 may have a substantially square shape and a square frame shape corresponding to the frame frame part 210.

In addition, the first grid sheet portion 223 may be formed to extend in a first direction (horizontal direction). The first grid sheet portion 223 may be formed in a linear shape so that both ends may be connected to the edge sheet portion 221. When the mask cell sheet portion 220 includes a plurality of first grid sheet portions 223, it is preferable that each of the first grid sheet portions 223 form equal intervals.

Further, in addition to this, the second grid sheet portion 225 may be formed to extend in a second direction (vertical direction). The second grid sheet portion 225 may be formed in a linear shape so that both ends may be connected to the edge sheet portion 221. The first grid sheet portion 223 and the second grid sheet portion 225 may vertically cross each other. When the mask cell sheet portion 220 includes a plurality of second grid sheet portions 225, each of the second grid sheet portions 225 is preferably formed at an equal interval.

Meanwhile, the spacing between the first grid sheet parts 223 and the spacing between the second grid sheet parts 225 may be the same or different according to the size of the mask cell C.

The first grid sheet portion 223 and the second grid sheet portion 225 have a thin thickness in the form of a thin film, but the shape of a cross-section perpendicular to the length direction may be a rectangle, a square shape such as a trapezoid, a triangle shape, etc., Some of the sides and corners may be rounded. The cross-sectional shape can be adjusted in the process of laser scribing and etching.

The thickness of the frame frame part 210 may be thicker than the thickness of the mask cell sheet part 220. Since the frame frame portion 210 is responsible for the overall rigidity of the frame 200, it may be formed to a thickness of several mm to several cm.

In the case of the mask cell sheet part 220, the process of manufacturing a substantially thick sheet is difficult, and if it is too thick, the organic material source 600 (see FIG. 23) passes through the mask 100 in the OLED pixel deposition process. It can cause clogging problems. Conversely, if the thickness is too thin, it may be difficult to secure enough rigidity to support the mask 100. Accordingly, the mask cell sheet portion 220 is thinner than the thickness of the frame frame portion 210, but is preferably thicker than the mask 100. The thickness of the mask cell sheet part 220 may be about 0.1 mm to 1 mm. In addition, the first and second grid sheet portions 223 and 225 may have a width of about 1 to 5 mm.

A plurality of mask cell areas CR (CR11 to CR56) may be provided except for the area occupied by the edge sheet portion 221 and the first and second grid sheet portions 223 and 225 in a flat sheet. In another aspect, the mask cell area CR is an area occupied by the frame sheet part 221 and the first and second grid sheet parts 223 and 225 in the hollow area R of the frame frame part 210. Except for, it may mean an empty area.

As the cell C of the mask 100 corresponds to the mask cell region CR, it can be used as a passage through which the pixel of the OLED is deposited substantially through the mask pattern P. As described above, one mask cell C corresponds to one display such as a smartphone. Mask patterns P constituting one cell C may be formed on one mask 100. Alternatively, one mask 100 may include a plurality of cells C, and each cell C may correspond to each cell area CR of the frame 200, but clear alignment of the mask 100 is achieved. In order to do so, it is necessary to avoid the large-area mask 100, and a small-area mask 100 having one cell C is preferable. Alternatively, one mask 100 having a plurality of cells C may correspond to one cell area CR of the frame 200. In this case, for clear alignment, it may be considered to correspond to the mask 100 having a small number of cells C of about 2-3.

The frame 200 includes a plurality of mask cell areas CR, and each mask 100 may be attached such that one mask cell C corresponds to the mask cell area CR. Each mask 100 may include a mask cell C having a plurality of mask patterns P formed thereon, and a dummy around the mask cell C (corresponding to a portion of the mask layer 110 excluding the cell C). have. The dummy may include only the mask layer 110 or may include the mask layer 110 in which a predetermined dummy pattern similar to the mask pattern P is formed. The mask cell C corresponds to the mask cell area CR of the frame 200, and a part or all of the dummy may be attached to the frame 200 (mask cell sheet part 220). Accordingly, the mask 100 and the frame 200 can form an integral structure.

Meanwhile, according to another embodiment, the frame is not manufactured by attaching the mask cell sheet part 220 to the frame frame part 210, but the frame frame part 210 is formed in the hollow region R part of the frame frame part 210. ) And an integral grid frame (corresponding to the grid seat portions 223 and 225) may be directly formed. This type of frame also includes at least one mask cell area CR, and a frame-integrated mask can be manufactured by matching the mask 100 to the mask cell area CR.

Hereinafter, a process of manufacturing a frame-integrated mask will be described.

First, the frame 200 described above in FIGS. 4 and 5 may be provided. 6 is a schematic diagram showing a manufacturing process of the frame 200 according to an embodiment of the present invention.

Referring to FIG. 6A, a frame frame part 210 is provided. The frame frame part 210 may have a rectangular frame shape including a hollow region R.

Next, referring to FIG. 6B, a mask cell sheet part 220 is manufactured. The mask cell sheet part 220 can be manufactured by manufacturing a flat sheet using electroplating or other film forming processes, and then removing a portion of the mask cell area (CR) through laser scribing or etching. have. In this specification, an example in which a 6 X 5 mask cell region (CR: CR11 to CR56) is formed will be described. Five first grid sheet portions 223 and four second grid sheet portions 225 may be present.

Next, the mask cell sheet part 220 may correspond to the frame frame part 210. In the process of correspondence, all sides of the mask cell sheet part 220 are stretched (F1 to F4) to flatten the mask cell sheet part 220 and the frame sheet part 221 is attached to the frame frame part 210. Can respond. In one side, it is possible to hold the mask cell sheet portion 220 at several points (for example, 1 to 3 points in FIG. 6 (b)) and stretch it. On the other hand, the mask cell sheet portion 220 may be stretched (F1, F2) along some side directions instead of all sides.

Next, when the mask cell sheet part 220 corresponds to the frame frame part 210, the frame sheet part 221 of the mask cell sheet part 220 may be attached by welding (W). It is preferable to weld (W) all sides so that the mask cell sheet part 220 can be firmly attached to the frame part 220. Welding (W) should be performed as close as possible to the edge of the frame frame part 210 to reduce the excitement space between the frame part 210 and the mask cell sheet part 220 and increase adhesion. The welding (W) part may be created in a line or spot shape, and the frame frame part 210 and the mask cell sheet part 220 are integrally made of the same material as the mask cell sheet part 220. It can be a medium to connect with.

7 is a schematic diagram showing a manufacturing process of a frame according to another embodiment of the present invention. In the embodiment of FIG. 6, the mask cell sheet part 220 having the mask cell area CR is first manufactured and attached to the frame frame part 210. However, in the embodiment of FIG. 210), a mask cell region CR is formed.

First, as shown in (a) of FIG. 6, a frame part 210 including a hollow region R is provided.

Next, referring to FIG. 7A, a flat sheet (a flat mask cell sheet 220 ′) may correspond to the frame frame 210. The mask cell sheet part 220 ′ is in a planar state in which the mask cell area CR has not yet been formed. In the matching process, all sides of the mask cell sheet part 220 ′ are stretched (F1 to F4) to correspond to the frame frame part 210 with the mask cell sheet part 220 ′ flattened. One side can also hold the mask cell sheet portion 220 ′ at several points (eg, 1 to 3 points in FIG. 7 (a)) and tension. On the other hand, the mask cell sheet portion 220 ′ may be stretched (F1, F2) along some side directions instead of all sides.

Next, when the mask cell sheet part 220 ′ corresponds to the frame frame part 210, the rim part of the mask cell sheet part 220 ′ may be attached by welding (W). It is preferable to weld (W) all sides so that the mask cell sheet part 220 ′ can be firmly attached to the frame frame part 220. Welding (W) should be performed as close as possible to the edge of the frame frame part 210 to reduce the excitement space between the frame part 210 and the mask cell sheet part 220 ′ and increase adhesion. The welding (W) portion may be generated in a line or spot shape, and has the same material as the mask cell sheet portion 220 ′, and the frame frame portion 210 and the mask cell sheet portion 220 ′ It can be a medium that connects all together.

Next, referring to FIG. 7B, a mask cell region CR is formed on a planar sheet (a planar mask cell sheet portion 220'). The mask cell area CR may be formed by removing the sheet in the mask cell area CR through laser scribing or etching. In this specification, an example in which a 6 X 5 mask cell region (CR: CR11 to CR56) is formed will be described. When the mask cell area CR is formed, the edge frame portion 210 and the welded (W) portion become the edge sheet portion 221, and the five first grid sheet portions 223 and the four second grids A mask cell sheet portion 220 having a sheet portion 225 may be configured.

8 is a schematic diagram showing a shape of a mask 100 and a state in which the mask 100 is adhered onto the tray 50 according to an exemplary embodiment of the present invention.

Referring to FIG. 8A, a mask 100 in which a plurality of mask patterns P is formed may be provided. The mask 100 may include a mask cell C on which a plurality of mask patterns P are formed and a dummy DM surrounding the mask cell C. The dummy DM corresponds to a portion of the mask layer 110 excluding the cell C, and includes only the mask layer 110, or the mask layer 110 in which a predetermined dummy pattern similar to the mask pattern P is formed. It may include. In the dummy DM, part or all of the dummy DM may be attached to the frame 200 (mask cell sheet part 220) corresponding to the edge of the mask 100. The mask 100 made of Invar and Super Invar may be manufactured by electroplating.

The mother plate used as a cathode in electroplating is made of a conductive material. As a conductive material, in the case of metal, metal oxides may be generated on the surface, impurities may be introduced during the metal manufacturing process, in the case of a polycrystalline silicon substrate, inclusions or grain boundaries may exist, and conductive polymers In the case of the base material, the possibility of containing impurities is high and strength. Acid resistance may be weak. An element that prevents uniform formation of an electric field on the surface of the mother plate (or cathode) such as metal oxide, impurities, inclusions, grain boundaries, etc. is referred to as “defect”. Due to defects, a uniform electric field may not be applied to the cathode body made of the above-described material, so that a part of the plating film (mask 100) may be formed unevenly.

In implementing ultra-high definition pixels of the UHD level or higher, non-uniformity of the plating film and the plating film pattern [mask pattern P] may adversely affect the formation of pixels. For example, in the case of current QHD quality, the size of the pixel reaches about 30-50㎛ at 500~600 PPI (pixel per inch), and in the case of 4K UHD and 8K UHD high quality, ~860 PPI and ~1600 PPI are higher. It has the same resolution. Micro-displays directly applied to VR devices, or micro-displays inserted into VR devices, aim for ultra-high quality of about 2,000 PPI or higher, and the size of the pixels reaches about 5 to 10 μm. The pattern width of the FMM and shadow mask applied to this can be formed in a size of several to several tens of µm, preferably smaller than 30 µm, so that even defects of several µm can occupy a large proportion of the pattern size of the mask to be. In addition, in order to remove defects in the cathode material of the above-described material, an additional process for removing metal oxides and impurities may be performed, and in this process, another defect such as etching of the cathode material may be caused. have.

Accordingly, in the present invention, a single crystal base plate (or a cathode body) may be used. In particular, it is preferably made of single crystal silicon. In order to have conductivity, a high concentration doping of 10 ¹⁹ /cm ³ or more may be performed on the mother plate made of single crystal silicon. Doping may be performed on the entire parent plate, or may be performed only on the surface portion of the parent plate.

Meanwhile, as a single crystal material, metals such as Ti, Cu, and Ag, semiconductors such as GaN, SiC, GaAs, GaP, AlN, InN, InP, Ge, and carbon-based materials such as graphite and graphene , such as _{CH 3 NH 3 PbCl 3, CH} 3 NH 3 PbBr 3, CH3NH 3 PbI 3, SrTiO 3 , etc. page containing the perovskite single crystal ceramic, aircraft single crystal second heat-resistant alloy for components for a superconductor, such as (perovskite) structure Can be used. Metal and carbon-based materials are basically conductive materials. In the case of a semiconductor material, doping with a high concentration of 1019 or higher may be performed to have conductivity. In the case of other materials, doping may be performed or oxygen vacancy may be formed to form conductivity. Doping may be performed on the entire parent plate, or may be performed only on the surface portion of the parent plate.

Since there are no defects in the case of a single crystal material, there is an advantage in that a uniform plating film (mask 100) can be generated due to the formation of a uniform electric field on the entire surface during electroplating. The frame-integrated masks 100 and 200 manufactured through a uniform plating film can further improve the quality level of OLED pixels. In addition, since there is no need to perform an additional process for removing and eliminating defects, there is an advantage in that process cost is reduced and productivity is improved.

In addition, if a silicon material or a single crystal material capable of forming an insulating film on the surface by oxidation or nitridation, there is an advantage that the insulating part can be formed only by oxidizing and nitriding the surface of the parent plate as needed. have. The insulating portion may also be formed using a photoresist. Electrodeposition of the plated film (mask 100) is prevented in the portion where the insulating portion is formed, and a pattern (mask pattern P) is formed on the plated film.

On the other hand, it should be noted that the material of the base plate of the present invention is not necessarily limited to the single crystal material described above as long as it is within the range of reducing defects in the cathode body.

The width of the mask pattern P may be less than 40 μm, and the thickness of the mask 100 may be about 2 to 50 μm. Since the frame 200 includes a plurality of mask cell regions CR: CR11 to CR56, the mask 100 having mask cells C: C11 to C56 corresponding to respective mask cell regions CR: CR11 to CR56 ) May also be provided.

The mask 100 may be attached to the frame 200 by laser welding. The laser L may be irradiated to the welding portion WP of the mask 100. The welding part WP may mean a target area capable of forming the welding bead WB by irradiation of the laser L0. The welding part WP is at least a part of the edge or dummy DM of the mask 100. Hereinafter, it is assumed that a plurality of welding portions WP are arranged at regular intervals in the dummy DM area of the mask 100, and the shape of the welding portion WP is substantially circular. It should be noted that, it is not necessarily limited thereto.

On the other hand, the mask 100 of the present invention is characterized in that the anti-wrinkle pattern (150 ~ 170) is formed around the weld (WP). The anti-wrinkle pattern (150 ~ 170) prevents deformation due to distortion or contraction of the periphery of the weld (WP) in the process of forming the weld bead (WB) by irradiating the laser (L) to the weld (WP). It characterized in that [see Figs. 14 and 15].

Similar to the mask pattern P, the anti-wrinkle patterns 150 to 170 are the same as holes formed in the dummy DM (or the edge portion) of the mask 100, and in the process of forming the mask pattern P It can be formed identically. For example, during the electroplating process of the mask 100, the plating layer 110 may not be formed, such as the mask pattern P, or may be formed through a pattern forming process after electroplating of the mask 100.

The anti-wrinkle patterns 150 to 170 are formed around the welded portion WP at a predetermined interval, and may be disposed to surround the welded portion WP as a whole, or may be disposed on both sides of the welded portion WP. For convenience of explanation, the anti-wrinkle patterns 150 to 170 are illustrated as simple figures in FIG. 8A, but specific shapes according to various embodiments will be described later with reference to FIGS. 9 to 12.

Next, referring to FIGS. 8B and 8C, the prepared mask 100 may be adhered onto a tray 50'. The mask 100 electrodeposited on the base plate may be removed and adhered onto the tray 50'. Electrostatic force, magnetic force, vacuum, or the like may be used so that the mask 100 is spread and adhered flatly without wrinkles or wrinkles on one surface of the tray 50 ′. The tray 50 ′ may be made of a glass material through which the laser light L can be transmitted.

9 to 12 are schematic diagrams showing anti-wrinkle patterns 150 to 170 of a mask according to various embodiments of the present invention. 9 to 12 are enlarged portions D of FIG. 8. For convenience of understanding, the mask cell C including the mask pattern P is shown on the right side, but the anti-wrinkle pattern 150-170, the pattern size of the buffer pattern 190, and the pattern are compared with the mask pattern P It should be noted that the arrangement position and the like are not limited to the items illustrated in FIGS. 9 to 12.

9 to 12, the anti-wrinkle patterns 150 to 170 may be formed around the weld WP at a predetermined interval. According to an embodiment, the anti-wrinkle pattern 150 to 170 is a virtual circle having a diameter (R2, R3) that is concentric with the weld (WP) and has a larger diameter (R2, R3) than the diameter (R1) of the weld (WP). The area on the circumference of (AC) can be occupied. In the form of occupying an area on the circumferences R2 and R3 having a diameter larger than the diameter R1 of the weld WP, when a unit anti-wrinkle pattern is disposed on the circumference, a part of the circumference is It can be implemented by including itself.

Referring to FIG. 9, the anti-wrinkle pattern 150 according to the first embodiment may include a plurality of unit anti-wrinkle patterns 151. In order to facilitate dispersion of stress and tension applied to the mask 100 film, it is preferable that the plurality of unit anti-wrinkle patterns 151 have a curvature such as a circular shape or an ellipse rather than a shape including an angled corner.

The plurality of unit anti-wrinkle patterns 151 are arranged at mutual intervals, and are concentric with the weld WP (WPC) and have a diameter R2 greater than the diameter R1 of the weld WP (AC) It can be arranged on the circumference of. The unit anti-wrinkle pattern 151 may be disposed around the welding portion WP in a single layer, but may be disposed in a double or triple manner.

In addition to the anti-wrinkle pattern 150, a plurality of buffer patterns 190 may be further formed. The buffer pattern 190 may be formed with a mutual spacing between the anti-wrinkle pattern 150 and the mask pattern P. The buffer pattern 190 may be disposed substantially along the inner edge of the dummy DM area.

Since the buffer pattern 190 does not surround the periphery of the welding portion WP, it serves to distribute stress and tension applied to the mask 100 film in a larger range. Accordingly, it may have a width greater than the width of the mask pattern P, and may have a greater width than the anti-wrinkle patterns 150 to 170. The buffer pattern 190 includes a plurality of unit buffer patterns 191 and 192, and the unit buffer patterns 191 and 192 are preferably in a shape having a curvature such as a circle or an ellipse, rather than a shape including an angled corner. Do.

According to an embodiment, the first unit buffer patterns 191 may be disposed on a horizontal axis passing through the middle of the pair of anti-wrinkle patterns 150. In addition, the second unit buffer patterns 192 may be disposed on the same horizontal axis as the first unit buffer pattern 191, and may be further disposed on a horizontal axis passing through the middle of the pair of first unit buffer patterns 191. have. However, the arrangement form is not necessarily limited thereto.

Referring to FIG. 10, the anti-wrinkle pattern 160 according to the second embodiment may include a plurality of unit anti-wrinkle patterns 161.

The plurality of unit anti-wrinkle patterns 161 are arranged at mutual intervals, and are concentric with the weld (WP) (WPC) and have a larger diameter (R2) than the diameter (R1) of the weld (WP). It may have a shape including at least some of the circumferences of (162, 163). In other words, one unit anti-wrinkle pattern 161 is concentric with the specific weld WP1 (WPC) and at least a portion 162 of the circumference having a larger diameter R2 than the specific weld WP1, and the specific weld WP1 ) May have a shape including at least a portion 163 of a circumference having a larger diameter R2 than the neighboring weld WP2 and concentric WPC. The unit anti-wrinkle pattern 161 may have a closed figure shape as it further includes edges 164 and 165 connecting them in addition to at least a portion 162 and 163 of the circumference. Since the unit anti-wrinkle pattern 161 includes portions of the curvature 162 and 163 having a predetermined distance from the weld WP, there is an advantage in that it is easy to disperse stress and tension applied to the weld WP.

Referring to FIG. 11, the anti-wrinkle pattern 160 ′ according to the third exemplary embodiment may include a plurality of unit anti-wrinkle patterns 161 ′.

The anti-wrinkle pattern 160 ′ according to the third exemplary embodiment may include portions of curvatures 162 and 163, similar to the anti-wrinkle pattern 160 according to the second exemplary embodiment. However, in addition to the portions of the curvatures 162 and 163 and the edges 164 and 165 connecting them, the closed figure shape may further include sides 166 that are parallel to each other. Since the unit anti-wrinkle pattern 161 includes portions of the curvature 162 and 163 having a predetermined distance from the weld WP, there is an advantage in that it is easy to disperse stress and tension applied to the weld WP.

Referring to FIG. 12, the anti-wrinkle pattern 170 according to the fourth embodiment may include a plurality of unit anti-wrinkle patterns 171.

The unit anti-wrinkle pattern 171 is concentric with the weld WP (WPC) and at least a portion 172 of a virtual circumference having a first diameter R2 greater than the diameter R1 of the weld WP, and a first It may have a shape including at least a portion 173 of a virtual circumference having a second diameter R3 greater than the diameter R1. The unit anti-wrinkle pattern 171 may have a closed figure shape as it further includes edges 174 and 175 connecting them in addition to at least a portion 172 and 173 of the circumference.

The plurality of unit anti-wrinkle patterns 171 may have mutual spacing and may be disposed to surround one welding portion WP. The unit anti-wrinkle pattern 171 may be disposed around the welding portion WP in a single layer, but may be disposed in a double or triple manner. The unit anti-wrinkle pattern 171 includes a portion of the curvature 172 and 173 having a predetermined distance from the weld WP, and is disposed to surround the weld WP, thereby distributing stress and tension applied to the weld WP. It has the advantage of being easy to do.

13 is a plan view of a shape of a mask 100' according to a comparative example (FIG. 13(a)) and a state in which the mask 100' according to the comparative example is attached on the tray 50' [Fig. b)] and a sectional side view [Fig. 13(c)] are shown. 14 is a side cross-sectional view showing a state in which the mask 100 according to the comparative example is attached to the cell region CR of the frame 200 [Fig. 14A] and an enlarged plan view of E [Fig. 14B] ]to be.

Referring to FIG. 13A, in contrast to the mask 100 of the exemplary embodiment of the present invention described above in FIG. 8, the mask 100 ′ according to the comparative example includes a plurality of mask patterns ( P) is included, and there is no separate pattern in the dummy DM. Subsequently, referring to FIGS. 13B and 13C, the mask 100 ′ may be attached on a tray 50 ′. The mask 100 electrodeposited on the base plate may be removed and attached to the tray 50'.

Referring to FIG. 14A, some or all of the edges of the mask 100 may be attached to the frame 200 (the first grid sheet part 223 or the second grid sheet part 225). Attachment can be carried out by welding, preferably laser welding. Laser welding should be performed as close as possible to the edge of the frame 200 so as to reduce the excitement space between the mask 100 and the frame 200 as much as possible and increase adhesion.

When the laser L is irradiated onto the welding portion WP from the upper portion of the mask 100 ′, the laser L may melt a portion of the mask 100 ′ in the welding portion WP region. A portion of the mask 100 ′ may be melted to form a welding bead (WB). Further, the welding bead WB may be a medium that integrally connects the mask 100 ′ and the frame 200.

In this case, a tension T that shrinks around the weld bead WB may be applied in the process of solidifying after the mask 100 ′ of the portion where the welding bead WB is formed is melted and then solidified. Deformation 105 ′, such as wrinkles, warps, bleeding, etc., may occur around the weld bead WB due to the shrinking tension T. In addition, deformation 106 ′, such as wrinkles and distortions, may occur in the space between the welding bead WB and the mask cell C. Eventually, deformations 105 ′ and 106 ′ occur due to tension T, and due to these deformations 105 ′ and 106 ′, the alignment state between the mask pattern P and the cells C is changed. Problems may occur.

The mask 100 of the present invention may prevent the above problem as the anti-wrinkle patterns 150 to 170 and the buffer pattern 190 are formed.

15 is a schematic diagram showing a state in which the mask 100 is attached to the cell area CR of the frame 200 according to an exemplary embodiment of the present invention.

Referring to FIG. 15A, the laser L may be irradiated on the welding portion WP of the dummy DM (or edge region) of the mask 100 from the top of the mask 100. A portion of the mask 100 may be melted to form a welding bead (WB). In addition, the welding bead (WB) may be a medium that integrally connects the mask 100 and the frame 200 (or, the frame sheet portion 221, and the first and second grid sheet portions 223, 225). have.

At this time, in the process of solidifying after the mask 100 at the portion where the welding bead WB is formed is melted, a tension T that shrinks around the welding bead WB may be applied. The tension T applied to the periphery of the welding bead WB may be dispersed in the anti-wrinkle patterns 150 to 170, respectively. Since the tension T is dispersed in the plurality of anti-wrinkle patterns 150 to 170, deformation 105 ′, such as wrinkles, distortion, and bleeding around the welding bead WB, may be eliminated.

In addition, the contracted tension T applied in the space between the welding bead WB and the mask cell C may be distributed to the buffer patterns 190, respectively. Since the tension T is dispersed in the plurality of buffer patterns 190, the deformation 106 ′ such as wrinkles and distortions in the space between the welding bead WB and the mask cell C may be eliminated.

As above, since the deformation 105 ′ and 106 ′ disappears due to the plurality of anti-wrinkle patterns 150 to 170 and the buffer pattern 190, or is deformed only at a level that has little effect on the alignment of the mask pattern P, In the process of attaching the mask 100 to the frame 200, it is possible to maintain an alignment state between the mask pattern P and the cells C.

16 is a plan view of a state in which the tray 50 ′ according to the comparative example is loaded onto the frame 200 and the mask 100 ′ corresponds to the cell area CR of the frame 200 (FIG. 16A) ] And a cross-sectional side view [Fig. 16(b)]. 17 illustrates a process of loading the tray 50 ′ according to the comparative example on the frame 200 and attaching the mask 100 ′ to the cell area CR of the frame 200, and the mask 100 and the tray 50. ') shows a side cross-sectional view showing the interface state and a partially enlarged side cross-sectional view.

Referring to FIGS. 16A and 16B, the mask 100 ′ may correspond to one mask cell area CR of the frame 200. The mask 100' is formed by turning over the tray 50' to which the mask 100' is adhered, and loading the tray 50' onto the frame 200 (or the mask cell sheet part 220). It may correspond to the mask cell area CR. When the tray 50' is loaded on the frame 200 (or the mask cell sheet part 220), the mask 100' is formed with the tray 50' and the frame 200 (or the mask cell sheet part ( 220)], while being disposed between, can be compressed by the tray 50'

Referring to FIG. 17, the mask 100 ′ may be attached to the frame 200 by laser welding by irradiating a laser L on the mask 100 ′. A welding bead WB is generated in the welding portion WP of the laser-welded mask, and the welding bead WB may be integrally connected with the mask 100 / frame 200 and having the same material.

On the other hand, in addition to pressing the mask 100 ′ by the tray 50 ′, the mask 100 and the frame 200 (or, the frame sheet portion 221, the first and second grid sheet portions 223, 225 )] to more closely abut, it is possible to further press the compression body (M) at the top of the tray (50'). In addition to the load by the weight of the compact (M), a means for pressing the compact (M) may be further provided. A through hole (MH) through which the laser (L) passes may be formed in the compressed body (M), and the laser (L) passes through the through hole (MH) and then passes through the transparent tray 50 ′ to the mask 100 It can be irradiated to the weld (area to perform welding) of.

However, despite the load of the tray 50 ′ and the presser M as described above, a fine air gap (AG) may exist on the interface between the tray 50 ′ and the mask 100. Since the glass tray 50' has a surface roughness (Ra) of about 20 to 30 μm, there are fine curves when looking at the surface of the tray 50' at the micrometer scale. Accordingly, even if the mask 100 ′ is compressed, there may be a part where the tray 50 ′ and the mask 100 ′ do not come into close contact, and in this part, the crimping load is not well transmitted, so that the mask 100 ′ and the frame 200 (or the frame sheet portion 221, the first and second grid sheet portions 223, 225) may also not be in close contact.

In the portion where the tray 50' and the mask 100' are in close contact without the air gap AG, the welding bead WB is well formed between the mask 100' and the frame 200 by irradiation of the laser L1. Is generated, and integrally connects the mask 100 ′ and the frame 200, and as a result, welding can be performed well. However, in a portion where the air gap AG exists between the tray 50 ′ and the mask 100 and does not come into close contact, a welding bead between the mask 100 and the frame 200 by irradiation of the laser L2 WB) is not generated well, and as a result, there is a problem that welding is not performed well.

Accordingly, the present invention is characterized in that it provides a tray 50 that can be in close contact with the mask 100 and without the air gap AG.

18 is a process of loading the tray 50 on the frame 200 and attaching the mask 100 to the cell area CR of the frame 200 according to an embodiment of the present invention, and the mask 100 and the tray (50) shows a side cross-sectional view and a partially enlarged side cross-sectional view of the interface state. 19 is a plan view [FIG. 19A] and a rear view [FIG. 19B] showing a tray 50 according to an embodiment of the present invention. 20 is a schematic diagram showing a state in which the tray 50 according to an embodiment of the present invention is loaded onto the frame 200 and the mask 100 corresponds to the cell area CR of the frame 200.

18 and 19, the mask 100 may be adhered on a tray 50. The mask 100 electrodeposited on the mother plate may be removed and adhered to the tray 50. The tray 50 is preferably in a flat plate shape so that the mask 100 can be adhered flatly. The size of the tray 50 may be a flat plate shape larger than that of the mask 100 so that the mask 100 may be adhered flatly.

Electrostatic force, magnetic force, vacuum, etc. may be used so that the mask 100 is flatly spread and adhered to one surface of the tray 50 without wrinkles or wrinkles. The method of using the electrostatic force is a method of inducing static electricity by rubbing an electric charge onto one surface of the tray 50. In addition, the method of using electrostatic force is to apply a voltage to the transparent electrode disposed on the upper or lower surface of the tray 50, and applying a voltage to the mask 100 also induces static electricity and spreads the mask 100 flat. It is a method of being adhered to one side of the tray 50 while having a predetermined adhesive force. A method of using magnetic force is a method of holding the mask 100 with magnetic force and spreading it while moving by using a plurality of magnets on the opposite surface of the tray 50 on which the mask 100 is disposed. A method of using a vacuum is a method of unfolding while moving the mask 100 by using a vacuum device from one end to the other end of the mask 100 disposed on the tray 50.

In particular, the tray 50 of the present invention is characterized in that one surface in contact with the mask 100 is a mirror surface so that an air gap AG does not occur between the interface with the mask 100. Specifically, the surface roughness Ra of one surface of the tray 50 may be 100 nm or less. Since the general glass tray 50 ′ described above in FIG. 17 has a surface roughness Ra of about 20 to 30 μm, the presence of the air gap AG affects the alignment error of the mask pattern P of the μm scale. Is enough to give. However, since the tray 50 of the present invention has a surface roughness Ra of nm scale, there is no or almost no air gap AG, so that the alignment error of the mask pattern P is not affected.

In order to implement the tray 50 having a surface roughness Ra of 100 nm or less, the tray 50 may use a wafer. The wafer (wafer) has a surface roughness (Ra) of about 10 nm, there are many commercially available products, and many surface treatment processes are known, so it is suitable for use as the tray 50. In addition, if the surface is micro-mirrored to satisfy the surface roughness (Ra) of 100 nm or less, the tray 50 is made of glass, silica, heat-resistant glass, quartz, alumina (Al ₂ O ₃ ) You can also use materials such as. Hereinafter, it is assumed that the wafer is used as the tray 50 and described.

Referring to the enlarged portion of FIG. 18, it can be seen that the interface between the tray 50 having a surface roughness Ra of 50 nm or less and the mask 100 is in close contact without an air gap AG. Laser welding may be performed by irradiating the laser L to the welding portion WP of the mask 100.

Meanwhile, the wafer tray 50 may be opaque to the laser (L) light. Accordingly, the tray 50 of the present invention is provided in the tray 50 so that the laser L irradiated from the top of the tray 50 can reach the welding portion WP of the mask 100. 51) is characterized in that it is formed.

Referring to FIGS. 19A and 19B, the laser through-hole 51 may be formed in the tray 50 to correspond to the position and number of the welding portions WP. Since a plurality of welding portions WP are disposed along a predetermined interval in the edge or dummy DM portion of the mask 100, a plurality of laser through holes 51 may be formed along a predetermined interval to correspond thereto. As an example, since a plurality of welding portions WP are disposed at predetermined intervals on both sides (left/right) dummy DM portions of the mask 100, the laser through hole 51 also has a tray 50 on both sides (left/right). The right side) may be formed in a plurality along a predetermined interval.

The laser through-hole 51 need not necessarily correspond to the position and number of welding parts. For example, it is also possible to perform welding by irradiating the laser (L) to only a part of the laser through hole (51). In addition, some of the laser through-holes 51 that do not correspond to the welding part may be used instead of the alignment mark when aligning the mask 100 and the tray 50. If the material of the tray 50 is transparent to the laser (L) light, the laser through hole 51 may not be formed.

To make the mask 100 and the frame 200 (or the frame sheet portion 221, the first and second grid sheet portions 223, 225) in tighter contact, the presser (M) is placed on the tray 50 You can do more compression. In addition to the load by the weight of the compact (M), a means for pressing the compact (M) may be further provided. A through hole (MH) through which the laser (L) passes may be formed in the compressed body (M), and the area where the through hole (MH) is formed may overlap with the area where the laser through hole 51 of the tray 50 is formed. I can. After passing through the through hole MH, the laser L may pass through the laser through hole 51 of the tray 50 to be irradiated onto the weld WP of the mask 100. Laser welding should be performed as close as possible to the edge of the frame 200 so as to reduce the excitement space between the mask 100 and the frame 200 as much as possible and increase adhesion.

The tray 50 and the mask 100 can be in close contact with each other without an air gap AG, and compression by the load of the upper compression body M and the tray 50 itself is added, so that the tray 50 and the mask ( 100), the mask 100 and the frame 200 (or, the edge sheet portion 221, the first and second grid sheet portions 223, 225) may be in close contact with each other. Accordingly, the welding bead WB may be well generated between the mask 100 and the frame 200 by the laser (L) irradiation. The welding bead (WB) can be viewed as a part where a part of the mask 100 is melted, has a shape of a spot or a line, and is mediated to integrally connect the mask 100 and the frame 200 Thus, welding can be performed well as a result.

Next, referring to FIGS. 20A and 20B, the mask 100 may correspond to one mask cell area CR of the frame 200. By turning over the tray 50 to which the mask 100 is attached to the top, and loading the tray 50 onto the frame 200 (or the mask cell sheet part 220), the mask 100 is transferred to the mask cell area ( CR). While controlling the position of the tray 50, it is possible to check whether the mask 100 corresponds to the mask cell area CR through a microscope. When the tray 50 is loaded onto the frame 200 (or the mask cell sheet part 220), the mask 100 includes the tray 50 and the frame 200 (or the mask cell sheet part 220). While disposed between, it can be pressed by the tray 50.

Meanwhile, the lower support 70 may be further disposed under the frame 200. The lower support 70 may have a size enough to fit into the hollow region R of the frame rim 210 and may have a flat plate shape. Further, a predetermined support groove (not shown) corresponding to the shape of the mask cell sheet portion 220 may be formed on the upper surface of the lower support body 70. In this case, the edge sheet portion 221 and the first and second grid sheet portions 223 and 225 are fitted into the support grooves, so that the mask cell sheet portion 220 may be better fixed.

The lower support 70 may press the opposite surface of the mask cell area CR to which the mask 100 contacts. That is, the lower support 70 may support the mask cell sheet part 220 in an upward direction to prevent the mask cell sheet part 220 from sagging downward during the attaching process of the mask 100. At the same time, since the lower support 70 and the tray 50 press the frame 200 (or the mask cell sheet part 220) of the mask 100 in opposite directions to each other, the mask 100 Can be maintained without being disturbed.

In the present invention, the mask 100 corresponds to the mask cell area CR of the frame 200 simply by attaching the mask 100 to the tray 50 and loading the tray 50 onto the frame 200 Since the process is completed, it is characterized in that no tensile force is applied to the mask 100 during this process.

Since the mask cell sheet portion 220 of the frame 200 has a thin thickness, when a tensile force is applied to the mask 100 and attached to the mask cell sheet portion 220, the tensile force remaining in the mask 100 is masked. It acts on the cell sheet part 220 and the mask cell area CR, and thus, they may be deformed. Therefore, it is necessary to attach the mask 100 to the mask cell sheet part 220 without applying a tensile force to the mask 100. Thus, it is possible to prevent deformation of the frame 200 (or the mask cell sheet part 220) by acting as a tension on the frame 200 as opposed to the tensile force applied to the mask 100.

However, one problem arises when a frame-integrated mask is manufactured by attaching it to the frame 200 (or mask cell sheet part 220) without applying a tensile force to the mask 100, and the frame-integrated mask is used in the pixel deposition process. Can occur. In the pixel deposition process performed at about 25 to 45° C., the mask 100 thermally expands by a predetermined length. Even in the case of the mask 100 made of an Invar material, the length of about 1 to 3 ppm may change according to a temperature increase of about 10° C. to form an atmosphere of the pixel deposition process. For example, when the total length of the mask 100 is 500 mm, the length may increase by about 5 to 15 μm. Then, there is a problem that the alignment error of the patterns P increases while causing deformation such as the mask 100 being struck by its own weight or being stretched and distorted while being fixed in the frame 200.

Accordingly, the present invention may correspond to and attach to the mask cell area CR of the frame 200 without applying a tensile force to the mask 100 at a temperature higher than that of room temperature. In this specification, after raising (ET) the temperature of the process region to the first temperature, it is expressed that the mask 100 is attached to the frame 200.

The term "process area" may mean a space in which constituent elements such as the mask 100 and the frame 200 are located, and a process of attaching the mask 100 is performed. The process area may be a space within a closed chamber or an open space. Further, the term “first temperature” may mean a temperature higher than or equal to the pixel deposition process temperature when the frame-integrated mask is used in the OLED pixel deposition process. Considering that the pixel deposition process temperature is about 25 to 45°C, the first temperature may be about 25 to 60°C. The temperature increase in the process area may be performed by installing a heating means in the chamber or by installing a heating means around the process area.

Referring again to FIG. 13, after the mask 100 corresponds to the mask cell region CR, the temperature of the process region including the frame 200 may be raised (ET) to the first temperature. Alternatively, after raising (ET) the temperature of the process region including the frame 200 to the first temperature, the mask 100 may correspond to the mask cell region CR. In the drawing, only one mask 100 is mapped to one mask cell area CR, but after matching the masks 100 for each mask cell area CR, the temperature of the process area is increased to the first temperature. You can also (ET).

The conventional mask 10 of FIG. 1 has a long length because it includes 6 cells (C1 to C6), whereas the mask 100 of the present invention has a short length including one cell (C). The degree of distortion of the pixel position accuracy (PPA) can be reduced. For example, assuming that the length of the mask 10 including a plurality of cells (C1 to C6, ...) is 1 m and a PPA error of 10 μm occurs in the entire 1 m, the mask 100 of the present invention The above error range can be 1/n according to the reduction in the relative length (corresponding to the reduction in the number of cells C). For example, if the length of the mask 100 of the present invention is 100 mm, since it has a length reduced from 1 m to 1/10 of the conventional mask 10, a PPA error of 1 μm occurs in the entire 100 mm length. , There is an effect that the alignment error is significantly reduced.

On the other hand, if the mask 100 includes a plurality of cells C, and each cell C corresponds to each cell area CR of the frame 200 within a range in which the alignment error is minimized, The mask 100 may correspond to a plurality of mask cell regions CR of the frame 200. Alternatively, the mask 100 having a plurality of cells C may correspond to one mask cell area CR. Even in this case, in consideration of the process time and productivity according to the alignment, the mask 100 is preferably provided with as few cells (C) as possible.

In the case of the present invention, it is only necessary to match one cell (C) of the mask 100 and check the alignment state, so that a plurality of cells (C: C1 to C6) must be matched at the same time and check all alignment states. Compared to the conventional method [see Fig. 2], the manufacturing time can be significantly reduced.

That is, in the method of manufacturing a frame-integrated mask of the present invention, each of the cells C11 to C16 included in the six masks 100 correspond to each of the cell regions CR11 to CR16 and check the alignment state. Through a single process, the time can be much shorter than that of a conventional method in which the six cells C1 to C6 are simultaneously matched and the alignment state of the six cells C1 to C6 is checked at the same time.

In addition, in the method of manufacturing a frame-integrated mask of the present invention, the product yield in the process of 30 times of matching and aligning 30 masks 100 to 30 cell regions (CR: CR11 to CR56), respectively, is 6 cells (C1 The five masks 10 each including ~C6) (see Fig. 2 (a)) may appear much higher than the conventional product yield in the five processes of matching and aligning the frame 20. Since the conventional method of arranging six cells (C1 to C6) in a region corresponding to six cells (C) at a time is much cumbersome and difficult operation, the product yield is low.

Meanwhile, after attaching the mask 100 to the frame 200, the mask 100 may be temporarily fixed to the frame 200 by interposing a predetermined adhesive. Thereafter, the attaching step of the mask 100 may be performed.

FIG. 21 is a plan view (FIG. 21(a)) and a side cross-sectional view (FIG. 21(a)) showing a process of sequentially attaching the mask 100 according to an embodiment of the present invention to the cell regions CR11 to CR56. b)].

Referring to FIG. 21, after attaching the mask 100 to the mask cell area CR11 correspondingly, the mask 100 may be correspondingly attached to the mask cell area CR12 adjacent thereto. Although only two masks 100 are attached in FIG. 21, the mask 100 may be attached to all mask cell regions CR in correspondence with each other.

The first grid sheet portion 223 (or the second grid sheet portion 225) has a shape in which an edge of two adjacent masks 100 is attached (welded bead (WB) formed), respectively. The width and thickness of the first grid sheet portion 223 (or the second grid sheet portion 225) may be formed to be about 1 to 5 mm, and to improve product productivity, the first grid sheet portion 223 [ Alternatively, it is necessary to reduce the width of the second grid sheet portion 225] and the overlapping edge of the mask 100 to about 0.1 to 2.5 mm as much as possible.

Since welding (LW) is performed on the mask cell sheet part 220 without applying a tensile force to the mask 100, the mask cell sheet part 220 (or the frame sheet part 221, the first and second grid sheets) No tension is applied to the parts (223, 225)].

After attaching one mask 100 to the frame 200, the remaining masks 100 are sequentially corresponded to the remaining mask cells C, and a process of attaching to the frame 200 may be repeated. Since the mask 100 already attached to the frame 200 can present the reference position, the time in the process of sequentially matching the remaining masks 100 to the cell area CR and checking the alignment status is significantly reduced. There is an advantage that can be. In addition, since the PPA (pixel position accuracy) between the mask 100 attached to one mask cell area and the mask 100 attached to the neighboring mask cell area does not exceed 3 μm, the alignment is clear, ultra-high quality. There is an advantage of being able to provide a mask for forming an OLED pixel.

22 is a schematic diagram illustrating a process of lowering (LT) the temperature of the process area after attaching the mask 100 according to an embodiment of the present invention to the cell area CR of the frame 200.

Next, referring to FIG. 22, the temperature of the process region may be lowered (LT) to the second temperature. The term "second temperature" may mean a temperature lower than the first temperature. Considering that the first temperature is about 25° C. to 60° C., the second temperature may be about 20° C. to 30° C. on the assumption that the first temperature is lower than the first temperature, and preferably, the second temperature may be room temperature. Lowering the temperature of the process region may be performed by installing a cooling means in the chamber, a method of installing a cooling means around the process region, and a method of naturally cooling to room temperature.

When the temperature of the process region is lowered (LT) to the second temperature, the mask 100 may heat-shrink by a predetermined length. The mask 100 may be isotropically heat-shrinkable along all side directions. However, since the mask 100 is fixedly connected to the frame 200 (or the mask cell sheet part 220) by welding, the heat contraction of the mask 100 is self-tensioned by the surrounding mask cell sheet part 220 (TS) is applied. The mask 100 may be attached on the frame 200 more tightly by the application of the self-tension TS of the mask 100.

In addition, since the temperature of the process area is lowered (LT) to the second temperature after each of the masks 100 are attached to the corresponding mask cell area CR, all of the masks 100 simultaneously cause heat contraction and A problem that the 200 is deformed or the alignment error of the patterns P increases may be prevented. More specifically, even if the tension TS is applied to the mask cell sheet part 220, since the plurality of masks 100 apply tension TS in opposite directions to each other, the force is canceled and the mask cell sheet part No deformation occurs in 220. For example, the first grid sheet portion 223 between the mask 100 attached to the CR11 cell area and the mask 100 attached to the CR12 cell area is in the right direction of the mask 100 attached to the CR11 cell area. The applied tension TS and the tension TS acting in the left direction of the mask 100 attached to the CR12 cell region may be canceled. Thus, the deformation of the frame 200 (or the mask cell sheet part 220) due to the tension TS is minimized so that the alignment error of the mask 100 (or the mask pattern P) can be minimized. There is this.

23 is a schematic diagram showing an OLED pixel deposition apparatus 1000 using the frame-integrated masks 100 and 200 according to an embodiment of the present invention.

Referring to FIG. 23, the OLED pixel deposition apparatus 1000 includes a magnet plate 300 in which a magnet 310 is accommodated and a cooling water line 350 is disposed, and an organic material source 600 from a lower portion of the magnet plate 300. ) And a deposition source supply unit 500 to supply.

A target substrate 900 such as glass on which the organic material source 600 is deposited may be interposed between the magnet plate 300 and the source deposition unit 500. The frame-integrated masks 100 and 200 (or FMM) that allow the organic material source 600 to be deposited for each pixel may be disposed on the target substrate 900 in close contact or very close to each other. The magnet 310 generates a magnetic field and may be in close contact with the target substrate 900 by the magnetic field.

The deposition source supply unit 500 may reciprocate the left and right path to supply the organic material source 600, and the organic material sources 600 supplied from the deposition source supply unit 500 are pattern P formed on the frame-integrated masks 100 and 200. ) May be deposited on one side of the target substrate 900. The deposited organic material source 600 passing through the pattern P of the frame-integrated masks 100 and 200 may function as the pixel 700 of the OLED.

In order to prevent non-uniform deposition of the pixel 700 due to a shadow effect, the pattern of the frame-integrated masks 100 and 200 may be formed to be inclined (S) (or formed in a tapered shape (S)) . Since the organic material sources 600 passing through the pattern in a diagonal direction along the inclined surface may also contribute to the formation of the pixel 700, the overall thickness of the pixel 700 may be uniformly deposited.

Since the mask 100 is attached and fixed to the frame 200 at a first temperature higher than the pixel deposition process temperature, even if it is raised to the process temperature for pixel deposition, the position of the mask pattern P is hardly affected. The PPA between 100 and the mask 100 adjacent thereto may be maintained not to exceed 3 μm.

Although the present invention has been shown and described with reference to a preferred embodiment as described above, it is not limited to the above embodiment, and within the scope not departing from the spirit of the present invention, various It can be transformed and changed. Such modifications and variations should be viewed as falling within the scope of the present invention and the appended claims.

50: tray
51: laser through hole
70: lower support
100: mask
110: mask film
150, 160, 160', 170: anti-wrinkle pattern
151, 161, 161', 171: unit anti-wrinkle pattern
190: buffer pattern
191, 192: unit buffer pattern
200: frame
210: frame frame portion
220: mask cell sheet portion
221: border sheet portion
223: first grid seat portion
225: second grid seat portion
1000: OLED pixel deposition device
C: cell, mask cell
CR: Mask cell area
DM: dummy, mask dummy
ET: Raise the temperature of the process area to the first temperature
L: laser
LT: Lower the temperature of the process area to the second temperature
M: upper press
R: hollow area of the frame part
P: mask pattern
TS: tension
W: welding
WB: welding bead
WP: weld
WPC: Welding center point

Claims (11)

As a mask for forming OLED pixels,
Including a mask cell in which a plurality of mask patterns are formed, and a dummy around the mask cells,
A plurality of welds are formed at intervals on at least part of the pile,
A mask for forming an OLED pixel, wherein an anti-wrinkle pattern is formed around each of the welds spaced apart by a predetermined distance. The method of claim 1,
The anti-wrinkle pattern includes a plurality of unit anti-wrinkle patterns,
At least one width of the unit anti-wrinkle pattern is smaller than the diameter of the welding portion, the OLED pixel forming mask. The method of claim 1,
A mask for forming an OLED pixel, further comprising a plurality of buffer patterns formed to form a mutual gap between the anti-wrinkle pattern and the mask pattern, and having a width greater than that of the mask pattern. As a tray that supports an OLED pixel forming mask and corresponds to the frame,
tray;
A mask adhered on the tray;
Including,
The mask includes a mask cell on which a plurality of mask patterns are formed, and a dummy around the mask cell, and a plurality of welding portions are formed at intervals in at least a portion of the dummy, and a wrinkle-preventing pattern around each welding portion spaced apart a predetermined interval Is formed, the mask support tray. The method of claim 4,
A mask supporting tray, wherein a laser through hole is formed in a portion of the tray corresponding to the welding portion of the mask. The method of claim 4,
The tray has a flat plate shape, and includes a material having a surface roughness Ra of 100 nm or less (greater than 0) on one surface in contact with the mask. The method of claim 4,
The tray is a wafer (wafer), glass (glass), silica (silica), heat-resistant glass, quartz (quartz), alumina (Al ₂ O ₃ ) comprising any one of the material, mask support tray. The method of claim 6,
A mask support tray that prevents the formation of an air gap at the interface between the tray and the mask. The method of claim 4,
The anti-wrinkle pattern occupies at least a circumferential region concentric with the welded portion and having a larger diameter than the welded portion. The method of claim 4,
The anti-wrinkle pattern includes a plurality of unit anti-wrinkle patterns,
At least one width of the unit anti-wrinkle pattern is smaller than the diameter of the welding portion, the mask support tray. The method of claim 4,
The mask support tray, further comprising a plurality of buffer patterns formed to form a mutual gap between the anti-wrinkle pattern and the mask pattern, and having a width greater than the width of the mask pattern.

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