WO2020076020A1 - Frame-integrated mask and method for manufacturing frame-integrated mask - Google Patents

Abstract

The present invention relates to a frame-integrated mask and a method for manufacturing a frame-integrated mask. The frame-integrated mask according to the present invention comprises: multiple masks (100); and a frame (200) integrated with the masks (100) so as to support the masks (100), wherein the frame (200) comprises: an edge frame part (210) including a hollow region (R); and a mask cell seat part (220) comprising multiple mask cell regions (CR) and connected to the edge frame part (210), and each of the masks (100) is formed of a metal sheet manufactured by a rolling process and is connected to the top of the mask cell seat part (200).

Description

Frame-integrated mask and method for manufacturing frame-integrated mask

The present invention relates to a frame-integrated mask and a method for manufacturing the frame-integrated mask. More specifically, the present invention relates to a frame-integrated mask and a method for manufacturing the frame-integrated mask, which can make the mask integrally with the frame, and can clearly align the masks between the masks.

As a technique for forming a pixel in an OLED manufacturing process, a FMM (Fine Metal Mask) method is used, in which a thin metal mask is closely adhered to a substrate to deposit an organic material at a desired location.

In the conventional OLED manufacturing process, the mask is manufactured in a stick form, a plate form, etc., and then the mask is welded and fixed to the OLED pixel deposition frame. In one mask, a plurality of cells corresponding to one display may be provided. In addition, several masks can be fixed to the OLED pixel deposition frame for large-area OLED manufacturing. In the process of fixing to the frame, each mask is tensioned to be flat. Adjusting the tensile force so that the entire part of the mask is flat is a very difficult task. In particular, in order to align the mask patterns having a size of only a few to several tens of µm while all cells are flattened, a high-level operation to check the alignment state in real time while finely adjusting the tensile force applied to each side of the mask is required. do.

Nevertheless, in the process of fixing several masks to one frame, there was a problem in that alignment between the masks and between the mask cells did not work well. In addition, in the process of welding and fixing the mask to the frame, the thickness of the mask film was too thin and the large area had a problem that the mask was struck or distorted by the load.

In the case of ultra-high-definition OLED, the current QHD image quality is 500 ~ 600 pixel per inch (PPI), and the pixel size reaches about 30 ~ 50㎛, and 4K UHD, 8K UHD high image quality is higher than ~ 860 PPI, ~ 1600 PPI, etc. It has the resolution of. As described above, the alignment error between each cell should be reduced to a few μm in consideration of the pixel size of the ultra-high quality OLED, and an error out of this may lead to product failure, so the yield may be very low. Therefore, there is a need to develop a technique that prevents deformation such as a mask being crushed or distorted, a technique for making alignment clear, and a technique for fixing a mask to a frame.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, and an object thereof is to provide a frame-integrated mask and a method for manufacturing a frame-integrated mask capable of forming an integrated structure.

In addition, an object of the present invention is to provide a frame-integrated mask and a method for manufacturing the frame-integrated mask, which can prevent deformation such as a mask being crushed or distorted and make alignment clear.

In addition, an object of the present invention is to provide a frame-integrated mask and a method for manufacturing the frame-integrated mask, which significantly reduce the manufacturing time and significantly increase the yield.

The above object of the present invention is a frame-integrated mask in which a plurality of masks and a frame supporting the mask are integrally formed, the frame comprising: a border frame portion including a hollow region; It has a plurality of mask cell regions, includes a mask cell sheet portion connected to the edge frame portion, each mask is composed of a metal sheet (sheet) produced by a rolling (rolling) process, each mask is a mask cell sheet It is achieved by a frame-integrated mask, connected to the top of the part.

The mask cell sheet portion may include a plurality of mask cell regions along at least one of a first direction and a second direction perpendicular to the first direction.

The mask cell sheet portion includes a border sheet portion; At least one first grid sheet portion extending in the first direction and having both ends connected to the edge sheet portion; And at least one second grid sheet portion formed to extend in a second direction perpendicular to the first direction, intersecting the first grid sheet portion, and having both ends connected to the edge sheet portion.

Each mask may correspond to each mask cell region.

The mask includes a mask cell on which a plurality of mask patterns are formed, and a dummy around the mask cell, and at least a portion of the dummy may be attached to the mask cell sheet portion.

The thickness of the border frame portion may be thicker than that of the mask cell sheet portion, and the thickness of the mask cell sheet portion may be thicker than that of the mask.

The mask may be formed to have a thinner thickness on the metal sheet produced by the rolling process.

The mask and the frame may be made of any one of invar, super invar, nickel, and nickel-cobalt.

And, the above object of the present invention is a method of manufacturing a frame-integrated mask in which a plurality of masks and a frame supporting a mask are integrally formed, comprising: (a) preparing a border frame portion including a hollow region; (b) connecting a mask cell sheet portion having a plurality of mask cell regions to an edge frame portion; (c) a mask made of a metal sheet manufactured by a rolling process corresponding to one mask cell region of the mask cell sheet portion; And (d) attaching at least a portion of the rim of the mask to the mask cell sheet portion.

And, the above object of the present invention is a method of manufacturing a frame-integrated mask in which a plurality of masks and a frame supporting a mask are integrally formed, comprising: (a) preparing a border frame part including a hollow region; (b) connecting the planar mask cell sheet portion to the border frame portion; (c) forming a plurality of mask cell regions on the mask cell sheet portion; (d) corresponding to a mask cell region of a mask cell sheet portion comprising a mask made of a metal sheet manufactured by a rolling process; And (e) attaching at least a portion of the rim of the mask to the mask cell sheet portion.

The mask cell sheet portion includes a border sheet portion; At least one first grid sheet portion extending in one direction and having both ends connected to the edge sheet portion; And at least one second grid sheet portion formed to extend in a second direction perpendicular to the first direction, intersecting the first grid sheet portion, and having both ends connected to the edge sheet portion.

In step (b), the edges of the mask cell sheet portion may be welded to the edge frame portion.

Before or after the step of the mask corresponding to one mask cell region of the mask cell sheet portion, the step of raising the temperature of the process region including the frame to the first temperature is further performed, and at least a part of the border of the mask is mask cell. After the step of attaching to the sheet portion, the step of lowering the temperature of the process region including the frame to the second temperature may be further performed.

The first temperature is a temperature equal to or higher than the OLED pixel deposition process temperature, the second temperature is at least a temperature lower than the first temperature, the first temperature is any one of 25 ° C to 60 ° C, and the second temperature is the first temperature. The temperature is any one of 20 ° C to 30 ° C lower than 1 temperature, and the OLED pixel deposition process temperature may be any one of 25 ° C to 45 ° C.

When the mask corresponds to the mask cell region, tension may not be applied to the mask.

When the temperature of the process region is lowered to the second temperature, the mask attached to the frame is contracted so that tension can be applied.

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

In addition, according to the present invention, it is possible to prevent deformation such as a mask being struck or distorted and to make alignment clear.

In addition, according to the present invention, there is an effect that can significantly reduce the manufacturing time, and significantly increase the yield.

1 is a schematic view 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 occurs between cells in the process of stretching 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 state in which a tension type of a mask according to an embodiment of the present invention and a mask correspond to a cell region of a frame.

9 is a schematic diagram illustrating a process of attaching a mask according to an embodiment of the present invention in correspondence with a cell region of a frame.

10 is a partially enlarged cross-sectional view illustrating a form in which a mask according to various embodiments of the present invention is attached to a frame.

11 to 13 are schematic views showing a process of attaching a frame to a mask according to another embodiment of the present invention.

14 is a schematic diagram showing an OLED pixel deposition apparatus using an integrated frame mask according to an embodiment of the present invention.

<Description of code>

100: mask

110: mask film

150: adhesive plating

200: frame

210: border frame

220: mask cell sheet portion

221: border sheet portion

223: first grid sheet portion

225: second grid sheet portion

1000: OLED pixel deposition device

C: cell, mask cell

CR: mask cell area

EM: adhesive material

ET: the temperature of the process zone is raised to the first temperature

F1 ~ F4: tensile force

LT: the temperature in the process region is lowered to the second temperature

R: Hollow area of the border frame

P: mask pattern

W: Welding

For a detailed description of the present invention, which will be described later, reference is made to the accompanying drawings that illustrate, by way of example, specific embodiments in which the present invention may be practiced. These examples are described in detail enough to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain shapes, structures, and properties described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in relation to one embodiment. In addition, it should be understood that the location or placement of individual components within each disclosed embodiment can be changed without departing from the spirit and scope of the invention. Therefore, the following detailed description is not intended to be taken in a limiting sense, and the scope of the present invention, if appropriately described, is limited only by the appended claims, along with all ranges equivalent to those claimed. In the drawings, similar reference numerals refer to the same or similar functions across various aspects, and length, area, thickness, and the like may be exaggerated 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 skilled 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, the 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-shaped mask and can be used by welding and fixing both sides of the stick to an OLED pixel deposition frame. The mask 100 illustrated in FIG. 1B is a plate-type mask and may be used in a large area pixel formation process.

The body 10 of the mask 10 (or the mask film 11) is provided with a plurality of display cells C. One cell C corresponds to one display such as a smartphone. The 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, the 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 form a cluster to form one cell C, and a plurality of cells C may be formed on the mask 10.

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

Referring to (a) of FIG. 2, first, the stick mask 10 must be flattened. The stick mask 10 is stretched as it is pulled by applying tensile force F1 to F2 in the long axis direction of the stick mask 10. In this state, the stick mask 10 is loaded on the frame 20 in the form of a square frame. The cells C1 to C6 of the stick mask 10 are positioned in an empty area inside the frame of the frame 20. The frame 20 may be sized such that cells C1 to C6 of one stick mask 10 are positioned in an empty area inside the frame, and cells C1 to C6 of the plurality of stick masks 10 are framed. It may be large enough to be located in the interior empty area.

Referring to (b) of FIG. 2, 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) to Accordingly, the stick mask 10 and the frame 20 are interconnected. Fig. 2 (c) shows a cross-section of a stick mask 10 and a frame connected to each other.

Referring to Figure 3, despite the fine adjustment of the tensile force (F1 ~ F2) applied to each side of the stick mask 10, there is a problem that the alignment between the mask cells (C1 ~ C3) does not work well. 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. The stick mask 10 is a large area including a plurality of (for example, six) cells C1 to C6 and has a very thin thickness of several tens of μm, so it is easily struck or distorted by a load. In addition, it is very difficult to check in real time the alignment between the cells (C1 to C6) while adjusting the tensile force (F1 to F2) so that all the cells (C1 to C6) are flat.

Therefore, the fine error of the tensile force (F1 ~ F2) may cause an error in the degree of stretching or unfolding each cell (C1 ~ C3) of the stick mask 10, accordingly, the distance (D1) between the mask pattern (P) ~ D1 ", D2 ~ D2") causes a problem that is different. Of course, it is difficult to perfectly align the error to 0, but in order to prevent the mask pattern P having a size of several to several tens of µm from adversely affecting the pixel process of the ultra-high-definition OLED, the alignment error does not exceed 3 µm. It is desirable not to. The alignment error between adjacent cells is referred to as pixel position accuracy (PPA).

In addition, while connecting the plurality of stick masks 10 of approximately 6 to 20 to one of the frame 20, between the plurality of stick masks 10 and the plurality of cells C of the stick mask 10 It is also very difficult to clarify the alignment between ~ C6), and it is a significant reason to reduce productivity because the process time due to the alignment is forced to increase.

Accordingly, the present invention proposes a frame 200 and a frame-integrated mask that enable 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 deformed, such as being struck or twisted, and can be clearly aligned with the frame 200. In addition, the manufacturing time for integrally connecting the mask 100 to the frame 200 is significantly reduced, and the yield can be significantly increased.

Figure 4 is a front view showing a frame-integrated mask according to an embodiment of the present invention [Fig. 4 (a)] and side cross-sectional view [Fig. 4 (b)], Figure 5 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, the mask 100 having a square shape will be described as an example, but the masks 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.

A plurality of mask patterns P may be formed in each mask 100, and one cell C may be formed in one mask 100. One mask cell C may correspond to one display such as a smartphone.

The mask 100 may use a metal sheet produced by a rolling process. The mask 100 may be made of an invar having a coefficient of thermal expansion of about 1.0 X 10 ^-6 / ° C, and a super invar of about 1.0 X 10 ^-7 / ° C. Since the mask 100 of this material has a very low coefficient of thermal expansion, it is less likely that the pattern shape of the mask is deformed by thermal energy, and thus can be used as a fine metal mask (FMM) or shadow mask in manufacturing a high-resolution OLED. In addition, considering that technologies for performing a pixel deposition process in a range in which the temperature change value is not large recently, the mask 100 has nickel (Ni), nickel-cobalt (Ni-Co) having a slightly higher thermal expansion coefficient than this. ).

The metal sheet produced by the rolling process may have a thickness of tens to hundreds of μm in the manufacturing process. In order to form the mask pattern P, which will be described later, in a relatively thick metal sheet, it needs to be made thinner. A process of thinning the metal sheet to a thickness of about 50 μm or less by using a method such as CMP may be further performed on the metal sheet. The thickness of the mask is preferably formed to about 2㎛ to 50㎛, more preferably, the thickness can be formed to about 5㎛ to 20㎛. However, it is not necessarily limited thereto.

In the case of using the metal sheet produced by the rolling process, there is a problem in that it is thicker in thickness than the plated film formed by electroforming, but since the coefficient of thermal expansion (CTE) is low, there is no need to perform a separate heat treatment process and corrosion resistance. This has a strong advantage.

The frame 200 is formed to attach a plurality of masks 100. The frame 200 may include various edges formed in a first direction (for example, a horizontal direction) and a second direction (for example, a vertical direction) including the outermost border. These various corners may partition the area to which the mask 100 is to be attached on the frame 200.

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

In addition to this, the frame 200 may include a plurality of mask cell regions CR, and may include a mask cell sheet portion 220 connected to the edge frame portion 210. The mask cell sheet portion 220 may be formed by rolling like the mask 100 or may be formed using other film forming processes such as electroforming. In addition, the mask cell sheet unit 220 may be connected to the edge frame unit 210 after forming a plurality of mask cell regions CR through laser scribing, etching, or the like on a flat sheet. Alternatively, the mask cell sheet unit 220 may form a plurality of mask cell regions CR through laser scribing, etching, or the like after connecting a planar sheet to the edge frame unit 210. In this specification, it is assumed that a plurality of mask cell regions CR are first formed in the mask cell sheet unit 220 and then connected to the frame unit 210.

The mask cell sheet unit 220 may include at least one of the edge sheet unit 221 and the first and second grid sheet units 223 and 225. The border sheet portions 221 and the first and second grid sheet portions 223 and 225 refer to portions divided in the same sheet, and they are integrally formed with each other.

The edge sheet portion 221 may be substantially connected to the edge frame portion 210. Therefore, the edge sheet portion 221 may have an approximately square shape and a square frame shape corresponding to the edge frame portion 210.

In addition, the first grid sheet portion 223 may be formed to extend in the first direction (horizontal direction). The first grid sheet portion 223 is formed in a straight 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 has equal intervals.

In addition, in addition to this, the second grid sheet portion 225 may be formed to extend in the second direction (vertical direction). The second grid sheet portion 225 may be formed in a straight line shape, and 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 cross each other vertically. When the mask cell sheet portion 220 includes a plurality of second grid sheet portions 225, it is preferable that each second grid sheet portion 225 has an equal interval.

Meanwhile, an interval between the first grid sheet parts 223 and an interval between the second grid sheet parts 225 may be the same or different depending on 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 the cross section perpendicular to the longitudinal direction is a rectangular shape, a rectangular shape such as a trapezoid (Fig. 5 (b). And FIG. 10], a triangular shape, etc., and the sides and corners may be partially rounded. The cross-sectional shape can be adjusted in processes such as laser scribing and etching.

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

In the case of the mask cell sheet portion 220, the process of manufacturing a substantially thick sheet is difficult, and if it is too thick, the organic material source 600 (see FIG. 14) passes through the mask 100 in the OLED pixel deposition process. This can cause clogging problems. Conversely, if the thickness is too thin, it may be difficult to secure rigidity sufficient to support the mask 100. Accordingly, the mask cell sheet portion 220 is thinner than the thickness of the frame portion 210, but is preferably thicker than the mask 100. The thickness of the mask cell sheet portion 220 may be formed about 0.1 mm to 1 mm. In addition, the widths of the first and second grid sheet portions 223 and 225 may be formed about 1 to 5 mm.

A plurality of mask cell regions CR: CR11 to CR56 may be provided except for regions occupied by the border sheet portions 221 and the first and second grid sheet portions 223 and 225 in the planar sheet. In another aspect, the mask cell region CR is an area occupied by the border sheet portions 221 and the first and second grid sheet portions 223 and 225 in the hollow region R of the border frame portion 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 pixels of the OLED are substantially deposited 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 in 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 the clear alignment of the mask 100 may be performed. For this, it is necessary to avoid the large area mask 100, and the 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 region 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 2-3.

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

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

First, the frame 200 described above with reference to 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 (a) of FIG. 6, a border frame unit 210 is provided. The border frame part 210 may have a rectangular frame shape including the hollow region R.

Next, referring to FIG. 6B, a mask cell sheet portion 220 is manufactured. The mask cell sheet portion 220 may be manufactured by manufacturing a planar sheet using a rolling or other film forming process, and then removing the mask cell region CR through laser scribing, etching, or the like. . In this specification, description will be given taking an example in which 6 X 5 mask cell regions CR: CR11 to CR56 are formed. Five first grid sheet portions 223 and four second grid sheet portions 225 may be present.

Next, the mask cell sheet portion 220 may correspond to the border frame portion 210. In the process of matching, by stretching (F1 to F4) all sides of the mask cell sheet portion 220, the mask cell sheet portion 220 is flattened and the border sheet portion 221 is attached to the border frame portion 210. You can respond. One side can hold and hold the mask cell sheet portion 220 with several points (eg, 1 to 3 points in FIG. 6 (b), for example). On the other hand, the mask cell sheet portion 220 may be tensioned (F1, F2) along some side directions rather than all sides.

Next, when the mask cell sheet portion 220 corresponds to the edge frame portion 210, the edge sheet portion 221 of the mask cell sheet portion 220 may be welded (W) and attached. It is preferable to weld (W) all sides so that the mask cell sheet portion 220 can be firmly attached to the frame portion 220. Welding (W) should be performed as close as possible to the edge of the edge frame portion 210 to reduce the excitation space between the edge frame portion 210 and the mask cell sheet portion 220 as much as possible to increase adhesion. The welding (W) portion may be generated in the form of a line or a spot, and has the same material as the mask cell sheet portion 220 and integrally forms the border frame portion 210 and the mask cell sheet portion 220. It can be a medium to connect to.

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 portion 220 having the mask cell region CR is first manufactured and attached to the border frame portion 210. However, in the embodiment of FIG. 7, the flat sheet of the border frame portion ( After attaching to 210), a portion of the mask cell region CR is formed.

First, as illustrated in (a) of FIG. 6, a border frame portion 210 including a hollow region R is provided.

Next, referring to (a) of FIG. 7, a flat sheet (the flat mask cell sheet part 220 ′) may correspond to the border frame part 210. The mask cell sheet portion 220 ′ is in a planar state in which the mask cell region CR is not yet formed. In the process of matching, all sides of the mask cell sheet portion 220 'are tensioned (F1 to F4), so that the mask cell sheet portion 220' can be flattened to correspond to the border frame portion 210. One side can hold and hold the mask cell sheet portion 220 'with several points (for example, 1 to 3 points in FIG. 7 (a)). On the other hand, the mask cell sheet portion 220 'may be tensioned (F1, F2) along some side directions rather than all sides.

Next, when the mask cell sheet portion 220 'corresponds to the frame portion 210, the edge portion of the mask cell sheet portion 220' may be welded (W) and attached. It is preferable to weld (W) all sides so that the mask cell sheet portion 220 ′ can be firmly attached to the frame portion 220. The welding (W) should be performed as close as possible to the edge of the edge frame portion 210 to minimize the excitation space between the edge frame portion 210 and the mask cell sheet portion 220 'and increase adhesion. The welding (W) portion may be generated in the form of a line or a spot, and has the same material as the mask cell sheet portion 220 ', and the frame portion 210 and the mask cell sheet portion 220'. It can be a medium to integrally connect.

Next, referring to FIG. 7B, a mask cell region CR is formed on a planar sheet (planar mask cell sheet portion 220 '). The mask cell region CR may be formed by removing the sheet of the mask cell region CR portion through laser scribing, etching, or the like. In this specification, description will be given taking an example in which 6 X 5 mask cell regions CR: CR11 to CR56 are formed. When the mask cell region 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 The mask cell sheet portion 220 having the sheet portion 225 may be configured.

Meanwhile, in FIGS. 6 and 7, an embodiment in which the frame frame portion 210 and the mask cell sheet portion 220 are attached by welding (W) is described, but the present invention is not limited thereto. The adhesion may be performed by a method using a tick adhesion part (EM), an electroplating part 150, and other organic / inorganic adhesives.

8 is a state in which the tensile form of the mask 100 (FIG. 8 (a)) and the mask 100 correspond to the cell region CR of the frame 200 according to an embodiment of the present invention [FIG. 8] (b)].

Next, the mask 100 on which a plurality of mask patterns P are formed may be provided. It has been described above that a mask 100 made of an in-bar and super-in-bar material may be manufactured by a rolling method, and one cell C may be formed in the mask 100.

A mask pattern (P) may be formed by applying an etch process using photolithography on a metal sheet made thin. The width of the mask pattern P may be smaller than 40 μm, and the thickness of the mask 100 may be about 2 to 50 μm, preferably about 5 to 20 μm. Since the frame 200 includes a plurality of mask cell regions (CR: CR11 to CR56), a mask 100 having mask cells (C: C11 to C56) corresponding to each of the mask cell regions (CR: CR11 to CR56) ) Can also be provided in plural.

Referring to (a) of FIG. 8, the mask 100 may correspond to one mask cell area CR of the frame 200. As shown in (a) of FIG. 8, in the process of matching, the mask cell C is flattened in a state where the mask 100 is flattened by stretching (F1 to F2) the two sides along the uniaxial direction of the mask 100 ) May correspond to the mask cell area CR. One side can hold and hold the mask 100 with several points (eg, 1 to 3 points in FIG. 8). Meanwhile, all sides of the mask 100 may be tensioned (F1 to F4) along the axial direction, not the uniaxial direction.

For example, the tensile force applied to each side of the mask 100 may not exceed 4N. The tensile force applied according to the size of the mask 100 may be the same or different. In other words, since the mask 100 of the present invention is a size including one mask cell C, the tensile force required is the same as that of the conventional stick mask 10 including a plurality of cells C1 to C6, or , At least it is likely to shrink. Considering that 9.8N means a gravitational force of 1 kg, since 1N is a force smaller than the gravitational force of 400 g, even if the mask 100 is attached to the frame 200 after being stretched, the mask 100 remains in the frame 200 The tension applied to the, or, conversely, the frame 200 exerts very little tension on the mask 100. Thus, deformation of the mask 100 and / or the frame 200 due to tension is minimized, so that alignment errors of the mask 100 (or mask pattern P) can be minimized.

In addition, the conventional mask 10 of FIG. 1 includes six cells (C1 to C6), and thus has a long length, while the mask 100 of the present invention includes a cell (C) to shorten the length. As a result, the degree of distortion of the pixel position accuracy (PPA) may 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 is generated in 1 m as a whole, the mask 100 of the present invention Can be 1 / n of the above error range according to the relative length reduction (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 is generated over the entire length of 100 mm. , 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 region CR of the frame 200, within the range in which the alignment error is minimized, The mask 100 may correspond to a plurality of mask cell areas CR of the frame 200. Alternatively, the mask 100 having a plurality of cells C may correspond to one mask cell area CR. Also in this case, considering the process time and productivity according to the alignment, it is preferable that the mask 100 has as few cells C as possible.

While adjusting the tensile forces F1 to F4 so that the mask 100 corresponds to the mask cell region CR in a flat state, it is possible to check the alignment state in real time through a microscope. In the case of the present invention, since only one cell C of the mask 100 needs to be matched and the alignment state is checked, it is necessary to simultaneously correspond to a plurality of cells C: C1 to C6 and check all of the alignment state. Compared to the conventional method (see Fig. 2), the manufacturing time can be significantly reduced.

That is, in the frame-integrated mask manufacturing method of the present invention, each cell C11 to C16 included in the six masks 100 corresponds to one cell region CR11 to CR16, respectively, and the alignment state is checked. Through the process, time can be significantly shortened compared to a conventional method in which six cells C1 to C6 are simultaneously mapped and all six cells C1 to C6 are aligned at the same time.

In addition, in the method for manufacturing a frame-integrated mask of the present invention, the product yield in 30 processes of 30 masks 100 corresponding to and aligned with 30 cell regions (CR: CR11 to CR56) is 6 cells (C1). ~ C6), each of the five masks 10 (see FIG. 2 (a)), which correspond to and align the frame 20, may appear to be much higher than the conventional product yield in the five steps. Since the conventional method of arranging six cells C1 to C6 in a region corresponding to six cells C at a time is a much cumbersome and difficult operation, the product yield is low.

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

9 is a schematic diagram showing a process of attaching the mask 100 according to an embodiment of the present invention in correspondence with the cell area CR of the frame 200. FIG. 10 is a cross-sectional view taken along line B-B 'of FIG. 9, and is a partially enlarged cross-sectional view showing a form in which a mask 100 according to various embodiments of the present invention is attached to a frame 200 (first grid sheet portion 223).

Next, referring to FIGS. 9 and 10 (a) and (b), a part or all of the border of the mask 100 may be attached to the frame 200. The attachment can be performed by welding (W), preferably by laser welding (W). The welded (W) portion may be integrally connected with the same material as the mask 100 / frame 200.

When the laser is irradiated on the upper portion of the rim portion (or dummy) of the mask 100, a part of the mask 100 may be melted and welded to the frame 200. Welding (W) should be performed as close to the edge of the frame 200 as possible to reduce the excitation space between the mask 100 and the frame 200 as much as possible and increase adhesion. The welding (W) portion may be generated in the form of a line or a spot, and may be a medium having the same material as the mask 100 and integrally connecting the mask 100 and the frame 200. .

On the upper surface of the first grid sheet portion 223 (or the second grid sheet portion 225), a shape in which one border of two neighboring masks 100 is attached (W) is shown. The width and thickness of the first grid sheet portion 223 (or the second grid sheet portion 225) may be formed to about 1 to 5 mm, and to improve product productivity, the first grid sheet portion 223 [ Or, it is necessary to reduce the width of the overlap of the border of the second grid sheet portion 225] and the mask 100 to about 0.1 to 2.5 mm.

The shape of the cross section perpendicular to the longitudinal direction of the first and second grid sheet portions 223 and 225 may be a low-height square or a trapezoidal shape.

The welding (W) method is only one method of attaching the mask 100 to the frame 200, and is not limited to this embodiment.

In another example, as illustrated in FIG. 10C, the mask 100 may be adhered to the frame 200 using an adhesive material EM. The adhesive material EM is an adhesive containing at least two metals, and may have various shapes such as a film, a line, or a bundle, and may have a thin thickness of about 10 to 30 μm. For example, the adhesive portion EM of the eutectic material may include at least one metal in groups such as In, Sn, Bi, Au, and Sn, Bi, Ag, Zn, Cu, Sb, Ge. . The adhesive material (EM) of the eutectic material includes at least two metallic solid phases, and at the specific temperature / pressure eutectic point, both metallic solid phases may be in a liquid phase. . And if you leave the eutectic point, you can become two metal solids again. Accordingly, it is possible to perform a role as an adhesive through a phase change of solid-> liquid-> solid.

Unlike the organic adhesives, the eutectic adhesive part (EM) does not contain any volatile organic substances. Therefore, the volatile organic material of the adhesive reacts with the process gas to adversely affect the pixels of the OLED, or the outgas of the organic material contained in the adhesive itself contaminates the pixel process chamber or prevents the adverse effect of being deposited on the OLED pixel as an impurity I can do it. In addition, since the eutectic adhesive portion (EM) is a solid, it is not cleaned by an OLED organic cleaning solution, and thus has corrosion resistance. In addition, since it includes two or more metals, it can be connected with a high adhesiveness to the mask 100 and the frame 200, which are the same metal material as compared to the organic adhesive, and since it is a metal material, there is an advantage that the possibility of deformation is low.

Referring to another example, as shown in FIG. 10D, the mask 100 may be adhered to the frame 200 by further forming an adhesive plating portion 150 of the same material as the mask 100. After the mask 100 corresponds to the frame 200, an insulating portion such as PR may be formed in the direction of the lower surface of the mask 100. In addition, the adhesive plating unit 150 may be electrodeposited on the rear surface of the mask 100 and the frame 200 exposed without the insulating unit covering.

As the adhesive plating portion 150 is electrodeposited on the exposed surface of the mask 100 and the frame 200, it may be a medium for integrally connecting the mask 100 and the frame 200. At this time, since the adhesive plating unit 150 is integrally connected to the rim portion of the mask 100 and electrodeposited, it has a state in which a tensile force is applied in an inner or outer direction of the frame 200 and can support the mask 100. Thus, without the need to perform the process of tensioning and aligning the mask separately, it is possible to integrally form the mask 100 stretched toward the frame 200 and the frame 200.

In FIG. 10, for convenience of explanation, it is revealed that the thickness and width of the welded (W) part and the adhesive part (EM) part of the eutectic material are somewhat exaggerated, and in fact, this part is hardly projected and is attached to the mask 100. It may be a part that connects the frame 200 in an included state.

Next, when the process of attaching one mask 100 to the frame 200 is completed, the remaining masks 100 are sequentially mapped to the remaining mask cells C, and the process of attaching them to the frame 200 is repeated. can do. Since the mask 100 already attached to the frame 200 can present a reference position, the time in the process of sequentially matching the remaining masks 100 to the cell area CR and checking the alignment state is significantly reduced. It has the advantage of being. In addition, the pixel position accuracy (PPA) between the mask 100 attached to one mask cell region and the mask 100 attached to a neighboring mask cell region does not exceed 3 μm, so that the alignment is clear and ultra-high definition. There is an advantage that can provide a mask for forming an OLED pixel.

11 to 13 are schematic views showing a process of attaching a frame to a mask according to another embodiment of the present invention.

Referring to (a) of FIG. 11, a mask 100 on which a plurality of mask patterns P are formed may be provided. This process is the same as in Fig. 8 (a).

Next, referring to FIG. 11B, the mask 100 may correspond to one mask cell area CR of the frame 200. Another embodiment of the present invention is characterized in that no tension is applied to the mask 100 in a process in which the mask 100 corresponds to the mask cell area CR of the frame 200.

Since the mask cell sheet portion 220 of the frame 200 has a thin thickness, when attached to the mask cell sheet portion 220 with tensile force applied to the mask 100, the tensile force remaining in the mask 100 is masked. The cell sheet portion 220 and the mask cell region CR may be actuated to deform them. Therefore, the mask 100 should be attached to the mask cell sheet portion 220 without applying a tensile force to the mask 100. Thus, it is possible to prevent the frame 200 (or the mask cell sheet portion 220) from being deformed by the tension applied to the mask 100 acting as a tension on the frame 200.

However, a frame-integrated mask is manufactured by attaching it to the frame 200 (or the mask cell sheet portion 220) without applying a tensile force to the mask 100, and there is one problem when using the frame-integrated mask 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 mask 100 made of an invar material, a length of about 1 to 3 ppm may change according to a temperature rise of about 10 ° C. to form a pixel deposition process atmosphere. For example, when the total length of the mask 100 is 500 mm, the length may be increased by about 5 to 15 μm. Then, the mask 100 is struck by its own weight, or it is stretched in a fixed state in the frame 200, causing deformation such as warping, which causes a problem that the alignment errors of the patterns P become large.

Accordingly, the present invention is characterized in that it corresponds to and attaches to the mask cell region CR of the frame 200 without applying a tensile force to the mask 100 at a higher temperature than normal temperature. In this specification, it is expressed that the mask 100 corresponds to and adheres to the frame 200 after raising (ET) the temperature of the process region to the first temperature.

The term “process area” may mean a space in which components such as the mask 100 and the frame 200 are located, and an attachment process of the mask 100 is performed. The process region may be a space in a closed chamber or an open space. Also, the term “first temperature” may mean a temperature that is higher than or equal to the temperature of the pixel deposition process 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 ° C to 60 ° C. The temperature rise of the process region can be performed by installing a heating means in the chamber or by providing a heating means around the process region.

Referring again to FIG. 11B, after the mask 100 corresponds to the mask cell region CR, the temperature of the process region including the frame 200 may be increased (ET) to the first temperature. have. Alternatively, after raising the temperature of the process region including the frame 200 to the first temperature (ET), the mask 100 may correspond to the mask cell region CR. Although only one mask 100 is associated with one mask cell region CR in the drawing, the temperature of the process region is increased to the first temperature after the masks 100 are mapped to each mask cell region CR. (ET).

Next, referring to FIG. 12, a part or all of a frame of the mask 100 may be attached to the frame 200. This process is the same as in FIGS. 9 and 10.

Next, referring to FIG. 13, the temperature of the process region is 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 premise that it is lower than the first temperature, and preferably, the second temperature may be room temperature. The temperature drop of the process region may be performed by a method of installing a cooling means in the chamber, a method of installing a cooling means around the process region, a method of naturally cooling to room temperature, or the like.

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-shrinked along all lateral directions. However, since the mask 100 is fixedly connected by welding (W) to the frame 200 (or the mask cell sheet portion 220), the heat shrinkage of the mask 100 is applied to the surrounding mask cell sheet portion 220. The tension (TS) is applied by itself. The mask 100 may be more tightly attached to the frame 200 by applying the own tension (TS) of the mask 100.

In addition, since each of the masks 100 is attached to the corresponding mask cell region CR, the temperature of the process region is lowered to the second temperature (LT), so that all the masks 100 simultaneously cause heat shrink, thereby framing the frame. A problem in which the alignment errors of the 200 or the patterns P are increased may be prevented. In more detail, even if the tension TS is applied to the mask cell sheet portion 220, since the plurality of masks 100 apply the tension TS in opposite directions, the force is canceled and the mask cell sheet portion is canceled. No deformation occurs at 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 directed to the right side of the mask 100 attached to the CR11 cell area. The acting tension TS and the tension 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) by 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.

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

Referring to FIG. 14, the OLED pixel deposition apparatus 1000 includes an organic material source 600 from a magnet plate 300 in which a magnet 310 is accommodated, a coolant line 350 is disposed, and a lower portion of the magnet plate 300. It includes a deposition source supply unit 500 for supplying.

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

The deposition source supply unit 500 may supply the organic material source 600 while reciprocating the left and right paths, and the organic material sources 600 supplied from the deposition source supply unit 500 may include patterns P formed in the frame-integrated masks 100 and 200. ) To be deposited on one side of the target substrate 900. The deposited organic source 600 that has passed through the pattern P of the frame-integrated masks 100 and 200 may act as the pixel 700 of the OLED.

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

The present invention has been illustrated and described with reference to preferred embodiments, as described above, but is not limited to the above embodiments and is varied by those skilled in the art to which the present invention pertains without departing from the spirit of the present invention. Modifications and modifications are possible. Such modifications and variations are to be regarded as falling within the scope of the invention and appended claims.

Claims (16)

1. A frame-integrated mask in which a plurality of masks and a frame supporting the mask are integrally formed,

   The frame,

   A border frame portion including a hollow region;

   A mask cell sheet portion having a plurality of mask cell regions and connected to the edge frame portion

   Including,

   Each mask is composed of a metal sheet produced by a rolling process,

   Each mask is connected to the upper portion of the mask cell sheet portion, frame-integrated mask.
2. According to claim 1,

   The mask cell sheet portion includes a plurality of mask cell regions along at least one of a first direction and a second direction perpendicular to the first direction, the frame-integrated mask.
3. According to claim 1,

   The mask cell sheet portion,

   Border sheet portion;

   At least one first grid sheet portion extending in the first direction and having both ends connected to the edge sheet portion; And

   A frame-integrated mask comprising at least one second grid sheet portion formed to extend in a second direction perpendicular to the first direction to intersect the first grid sheet portion, and both ends of which are connected to the edge sheet portion.
4. According to claim 1,

   A frame-integrated mask, each mask corresponding to each mask cell region.
5. According to claim 4,

   The mask,

   A mask cell in which a plurality of mask patterns are formed, and a dummy around the mask cell,

   A frame-integrated mask, wherein at least a portion of the dummy is attached to the mask cell sheet portion.
6. According to claim 1,

   The thickness of the border frame portion is thicker than the thickness of the mask cell sheet portion,

   The thickness of the mask cell sheet portion is thicker than that of the mask, and the frame-integrated mask.
7. According to claim 1,

   The mask is formed of a thinner thickness from the metal sheet produced by the rolling process, the frame-integrated mask.
8. According to claim 1,

   The mask and the frame are any one of invar, super invar, nickel, and nickel-cobalt, frame-integrated masks.
9. A method of manufacturing a frame-integrated mask in which a plurality of masks and a frame supporting the mask are integrally formed,

   (A) preparing a border frame portion including a hollow region;

   (b) connecting a mask cell sheet portion having a plurality of mask cell regions to an edge frame portion;

   (c) a mask made of a metal sheet manufactured by a rolling process corresponding to one mask cell region of the mask cell sheet portion; And

   (d) attaching at least a portion of the rim of the mask to the mask cell sheet portion

   A method of manufacturing a frame-integrated mask comprising a.
10. A method of manufacturing a frame-integrated mask in which a plurality of masks and a frame supporting the mask are integrally formed,

    (A) preparing a border frame portion including a hollow region;

    (b) connecting the planar mask cell sheet portion to the border frame portion;

    (c) forming a plurality of mask cell regions on the mask cell sheet portion;

    (d) corresponding to a mask cell region of a mask cell sheet portion comprising a mask made of a metal sheet manufactured by a rolling process; And

    (e) attaching at least a portion of the rim of the mask to the mask cell sheet portion

    A method of manufacturing a frame-integrated mask comprising a.
11. The method of claim 9 or 10,

    The mask cell sheet portion,

    Border sheet portion;

    At least one first grid sheet portion extending in the first direction and having both ends connected to the edge sheet portion; And

    A method for manufacturing a frame-integrated mask comprising at least one second grid sheet portion formed to extend in a second direction perpendicular to the first direction to cross the first grid sheet portion and having both ends connected to the edge sheet portion.
12. The method of claim 9 or 10,

    In step (b),

    A method of manufacturing a frame-integrated mask, in which a corner of a mask cell sheet portion is welded and connected to an edge frame portion.
13. The method of claim 9 or 10,

    Before or after the step of the mask corresponding to one mask cell region of the mask cell sheet portion, further performing the step of raising the temperature of the process region including the frame to the first temperature,

    After attaching at least a portion of the rim of the mask to the mask cell sheet portion, the method of manufacturing a frame-integrated mask further comprising the step of lowering the temperature of the process region including the frame to a second temperature.
14. The method of claim 13,

    The first temperature is a temperature equal to or higher than the OLED pixel deposition process temperature,

    The second temperature is at least a temperature lower than the first temperature,

    The first temperature is any one of 25 ℃ to 60 ℃,

    The second temperature is any one of 20 ° C to 30 ° C lower than the first temperature,

    OLED pixel deposition process temperature is any one of 25 ℃ to 45 ℃, the method of manufacturing a frame-integrated mask.
15. The method of claim 13,

    A method of manufacturing a frame-integrated mask in which tension is not applied to the mask when the mask corresponds to the mask cell region.
16. The method of claim 13,

    When the temperature of the process region is lowered to the second temperature, the mask attached to the frame contracts and receives a tension, thereby producing a frame-integrated mask.

Images