KR20200016622A - Transfer system of mask and producing method of mask integrated frame - Google Patents

Abstract

The present invention relates to a transfer system of a mask capable of improving the adhesion between a mask (100) and a frame (200), and a manufacturing method of a frame integrated mask. According to the present invention, the transfer system of a mask for forming an OLED element to integrally form a mask (100) and a frame (200) supporting the mask (100) comprises: a mask loading unit (90) adsorbing one surface of the mask (100) to load the mask (100); and a tray (50) supporting the other surface of the mask (100) and making the mask (100) correspond to the frame (200).

Description

Transfer system of mask and manufacturing method of frame integrated mask {TRANSFER SYSTEM OF MASK AND PRODUCING METHOD OF MASK INTEGRATED FRAME}

The present invention relates to a transfer system of a mask and a method of manufacturing a frame-integrated mask. More specifically, it is possible to make the mask integral with the frame, to improve the adhesion between the mask and the frame, and to clarify the alignment between the masks. It relates to a manufacturing method and a tray used for mask support.

Recently, studies on electroforming methods have been underway in thin plate manufacturing. The electroplating method is to immerse the positive electrode and the negative electrode in the electrolyte, and to apply the power to electrodeposit the metal thin plate on the surface of the negative electrode, it is possible to manufacture the ultra-thin plate, the mass production is expected.

Meanwhile, as a technology of forming pixels in an OLED manufacturing process, a fine metal mask (FMM) method of depositing an organic material at a desired position by closely attaching a thin metal mask to a substrate is mainly used.

In the conventional OLED manufacturing process, the mask is manufactured in the form of a stick, a plate, and the like, and then the mask is welded and fixed to the OLED pixel deposition frame. Each mask may include a plurality of cells corresponding to one display. In addition, in order to manufacture a large area OLED, several masks may be fixed to the OLED pixel deposition frame. In the process of fixing to the frame, each mask is tensioned to be flat. Adjusting the tension to make the entire part of the mask flat is a very difficult task. In particular, in order to align the mask pattern having a size of only a few to several tens of micrometers while flattening each cell, a high-level operation of checking the alignment in real time while finely adjusting the tension applied to each side of the mask is required. do.

Nevertheless, in the process of fixing several masks in one frame, there is a problem in that the alignment between the mask cells and the mask cells is not good. In addition, the mask film is too thin and large in the process of welding and fixing the mask to the frame, which causes the mask to be squeezed or distorted due to the load, wrinkles, burrs, etc. generated in the welded part in the welding process. There was a problem of misalignment.

In the case of ultra-high definition OLED, QHD image quality is 500 ~ 600 pixel per inch (PPI), and the pixel size is about 30 ~ 50㎛, and 4K UHD, 8K UHD high definition is higher than 860 PPI, ~ 1600 PPI, etc. It has a resolution of. As such, in consideration of the pixel size of the ultra-high-definition OLED, the alignment error between the cells must be reduced to several micrometers, and the error beyond this can lead to product failure, resulting in very low yield. Therefore, there is a need for development of a technique for preventing deformation, such as knocking or twisting of a mask and making alignment clear, a technique for fixing a mask to a frame, and the like.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, the mask transfer system that can prevent deformation of the mask when the mask is bonded to the frame and improve the adhesion between the mask and the frame To provide that purpose.

In addition, an object of the present invention is to provide a mask transfer system capable of unfolding the mask flat and stable transfer.

It is also an object of the present invention to provide a method for manufacturing a frame-integrated mask in which the mask and the frame can form a unitary structure.

It is also an object of the present invention to provide a method for manufacturing a frame-integrated mask that can prevent deformation such as knocking or twisting of the mask and to clarify the alignment.

Moreover, an object of this invention is to provide the manufacturing method of the frame-integrated mask which markedly reduced manufacturing time and raised the yield significantly.

The above object of the present invention is a transfer system of a mask for forming an OLED pixel for integrally forming a mask and a frame for supporting the mask, comprising: a mask loading unit capable of absorbing and loading one surface of a mask; And a tray supporting the other side of the mask and corresponding the mask to the frame.

The mask loading portion may have a flat plate shape, and a plurality of vacuum holes may be formed on one surface corresponding to the mask.

A depression may be formed at the edge of the mask loading portion.

When the mask is loaded in the mask loading portion, at least an edge of the mask may protrude outside the depression.

The mask loading unit may include a heating unit.

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

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

The tray may be a wafer.

The tray may comprise any of the materials of the glass (glass), silica (silica), heat-resistant glass, quartz (quartz), alumina (Al ₂ O _3).

Align holes may be formed in a portion of the tray corresponding to a portion of at least one of the mask cell and the mask dummy.

The tray is formed with a larger area than the mask, and when the tray is in contact with the mask, at least an edge of the tray may protrude outside the depression.

In addition, the above object of the present invention, a method of manufacturing a frame-integrated mask formed integrally with at least one mask and a frame for supporting the mask, comprising: (a) providing a frame having at least one mask cell area; (b) absorbing and loading one surface of the mask into the mask loading unit; (c) contacting the tray on the other side of the mask and supporting the mask; (d) loading the tray onto the frame to correspond to the mask cell area of the frame; And (e) irradiating a laser to the welded portion of the mask to adhere the mask to the frame.

Step (a) comprises the steps of: (a1) providing an edge frame portion comprising a hollow region; (a2) connecting the planar mask cell sheet portion to the edge frame portion; And (a3) forming a plurality of mask cell regions in the mask cell sheet part to manufacture a frame.

Step (a) comprises the steps of: (a1) providing an edge frame portion comprising a hollow region; And (a2) manufacturing a frame by connecting a mask cell sheet part having a plurality of mask cell areas to an edge frame part.

The mask loading portion has a flat plate shape, and a plurality of vacuum holes are formed on one surface corresponding to the mask. In step (b), the mask loading portion is applied by applying pressure to one surface of the mask in the plurality of vacuum holes. It can adsorb to the phase.

Step (b) may include: (b1) adsorbing at least two sides of the mask to the vacuum transfer unit; And (b2) moving the vacuum transfer unit to absorb and load one surface of the mask onto the mask loading unit.

In step (b1) or (b2), the vacuum transfer unit may pull out the adsorbed mask to the outside to flatten the mask.

A depression is formed at the edge of the mask loading portion, and in step (b), when the mask is loaded in the mask loading portion, at least the edge of the mask protrudes out of the depression, and in step (c), the tray is brought into contact with the mask on the mask. At least the edges of may protrude out of the depression.

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

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

The tray may be a wafer.

The tray may comprise any of the materials of the glass (glass), silica (silica), heat-resistant glass, quartz (quartz), alumina (Al ₂ O _3).

Align holes may be formed in a portion of the tray corresponding to a portion of at least one of the mask cell and the mask dummy.

A plurality of pressure absorbing holes are formed in the tray, and the pressure can be applied to the pressure absorbing hole to adsorb and support the mask.

In step (c), the mask may be adsorbed and supported by applying a suction pressure to a part of the laser passage hole on the tray.

The laser irradiated from the upper part of the tray may pass through the laser through hole and may be irradiated to the welding part of the mask.

A welding bead is formed on a portion of the welded portion to which the laser is irradiated, and the welding bead may mediate the mask and the frame to be integrally connected.

Before or after the mask corresponds to the mask cell region, the temperature of the process region containing the frame is raised to the first temperature, and after the mask is adhered to the frame, the temperature of the process region containing the frame is changed to the second temperature. Can be lowered.

The first temperature may be equal to or higher than the OLED pixel deposition process temperature, and the second temperature may be at least lower than the first temperature.

The first temperature is any one of 25 ° C to 60 ° C, the second temperature is any one of 20 ° C to 30 ° C that is lower than the first temperature, and the OLED pixel deposition process temperature is any of 25 ° C to 45 ° C. It may be one temperature.

When the mask corresponds to the mask cell area, no tension may be applied to the mask.

When the temperature of the process region is lowered to the second temperature, the mask adhered to the frame may be contracted to apply a tension.

The mask loading unit includes a heating unit, and may maintain the mask at a temperature of 3 ° C. to 10 ° C. higher than the first temperature between steps (b) and (c).

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

The mask cell sheet portion includes an edge sheet portion; And at least one first grid sheet part extending in the first direction and both ends connected to the edge sheet part.

The mask cell sheet part may further include at least one second grid sheet part extending in a second direction perpendicular to the first direction to intersect the first grid sheet part, and both ends of which are connected to the edge sheet part.

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

According to the present invention configured as described above, when the mask is bonded to the frame, there is an effect that can prevent deformation of the mask and improve the adhesion between the mask and the frame.

In addition, according to the present invention, there is an effect that the mask can be unfolded and transported stably.

In addition, according to the present invention, there is an effect that the mask and the frame can form an integrated structure.

In addition, according to the present invention, there is an effect that can prevent the deformation, such as knocking or twisting the mask and to clarify the alignment.

In addition, according to the present invention, there is an effect that can significantly reduce the production time, significantly increasing the yield.

1 is a schematic view showing a conventional mask for OLED pixel deposition.
2 is a schematic diagram illustrating a process of adhering a conventional mask to a frame.
3 is a schematic view showing that alignment errors between cells occur in the process of tensioning a conventional mask.
4 is a front and side cross-sectional view showing a frame-integrated mask according to an embodiment of the present invention.
5 is a front and side cross-sectional view showing a frame according to an embodiment of the present invention.
6 is a schematic diagram illustrating a manufacturing process of a frame according to an embodiment of the present invention.
7 is a schematic diagram illustrating a manufacturing process of a frame according to another embodiment of the present invention.
8 is a schematic diagram illustrating components of a transfer system of a mask according to an embodiment of the present invention.
9 is a schematic diagram illustrating a state in which a vacuum transfer unit adsorbs a mask according to an embodiment of the present invention.
10 is a schematic view showing an operation process of the mask transfer system according to an embodiment of the present invention.
11 is a schematic diagram illustrating a state in which a tray is loaded onto a frame according to an embodiment of the present invention so that a mask corresponds to a cell area of the frame.
12 is a schematic diagram illustrating a process of bonding a mask to a cell region of a frame by loading a tray on a frame according to a comparative example, and an interface state between the mask and the tray.
13 is a schematic diagram illustrating a process of bonding a mask to a cell region of a 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.
14 is a schematic diagram illustrating a process of sequentially bonding a mask to a cell region according to an embodiment of the present invention.
15 is a schematic diagram illustrating a process of lowering a temperature of a process region after attaching a mask to a cell region of a frame according to an embodiment of the present invention.
16 is a schematic diagram illustrating an OLED pixel deposition apparatus using a frame-integrated mask according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be embodied in other embodiments without departing from the spirit and scope of the invention with respect 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 invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. In the drawings, like reference numerals refer to the same or similar functions throughout the several aspects, and length, area, thickness, and the like may be exaggerated for convenience.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

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

Referring to FIG. 1, the mask 10 may be manufactured in a stick type or a plate type. The mask 10 shown in FIG. 1A is a stick type mask, and both sides of the stick may be welded and fixed to the 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 forming process.

A plurality of display cells C are provided in the body (or mask film 11) of the mask 10. One cell C corresponds to one display such as a smartphone. In the cell C, a pixel pattern P is formed 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 × 140. That is, a large number of pixel patterns P may be clustered to form one cell C, and a plurality of cells C may be formed in the mask 10.

2 is a schematic diagram illustrating a process of adhering the mask 10 to the frame 20. 3 is a schematic view showing that alignment errors between cells occur in the process of tensioning the mask 10 (F1 to F2). A stick mask 10 having 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 should be flattened. The stick mask 10 is unfolded as the tensile force F1 to F2 is applied in the major axis direction of the stick mask 10 and pulled. In this state, the stick mask 10 is loaded onto the frame 20 having a rectangular frame shape. The cells C1 to C6 of the stick mask 10 are positioned in the empty area of the frame 20 of the frame 20. The frame 20 may be large enough so that the cells C1 to C6 of one stick mask 10 are located in an empty area inside the frame, and the cells C1 to C6 of the plurality of stick masks 10 are framed. It may also be large enough to fit inside the 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 surface of the stick mask 10 is welded (W). Accordingly, the stick mask 10 and the frame 20 are interconnected. 2 (c) shows the side surface of the stick mask 10 and the frame connected to each other.

Referring to FIG. 3, in spite of finely adjusting the tensile forces F1 to F2 applied to each side of the stick mask 10, problems of misalignment of the mask cells C1 to C3 appear. For example, the distances D1 to D1 ″ and D2 to D2 ″ may be different from each other or the patterns P may be skewed between the patterns P of the cells C1 to C3. The stick mask 10 is a large area including a plurality of (eg, six) cells C1 to C6 and has a very thin thickness on the order of tens of micrometers, and thus is easily struck or warped by a load. In addition, it is very difficult to check the alignment between the cells C1 to C6 in real time through a microscope while adjusting the tensile forces F1 to F2 to flatten each of the cells C1 to C6.

Therefore, the minute error of the tensile force (F1 ~ F2) may cause an error in the extent that the cells (C1 ~ C3) of the stick mask 10 is extended or unfolded, and thus the distance (D1) between the mask pattern (P) ~ D1 ", D2-D2") cause a problem that becomes different. Of course, it is difficult to perfectly align the error to 0, but in order that the mask pattern P having a size of several to several tens of micrometers does not adversely affect the pixel process of the ultra-high definition OLED, the alignment error does not exceed 3 micrometers. It is preferable not to. This alignment error between adjacent cells is referred to as pixel position accuracy (PPA).

In addition, between the plurality of stick masks 10 and the plurality of cells C of the stick masks 10 while connecting the plurality of stick masks 10 of about 6 to 20 to each of the frames 20, respectively. It is also very difficult to clarify the alignment between ~ C6), and the process time due to alignment is inevitably increased, which is a significant reason for reducing productivity.

On the other hand, after fixing the stick mask 10 to the frame 20, the tensile force (F1 ~ F2) applied to the stick mask 10 may act inversely to the frame 20. That is, the stick mask 10, which is stretched by the tension forces F1 to F2, may be tensioned to the frame 20 after being connected to the frame 20. In general, the tension may not be large and may not have a large influence on the frame 20. However, when the size of the frame 20 is miniaturized and the rigidity is low, the tension may slightly change the frame 20. Thus, a problem may arise in that the alignment state is changed between the plurality of cells C to C6.

Accordingly, the present invention proposes a frame 200 and a frame integrated mask that allow the mask 100 to form an integrated structure with the frame 200. The mask 100 integrally formed in the frame 200 may be prevented from being deformed 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 tension may not be applied to the frame 200 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 may be significantly reduced, and the yield may be significantly increased.

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)) which show a frame.

4 and 5, the frame integrated mask may include a plurality of masks 100 and one frame 200. In other words, each of the plurality of masks 100 is bonded to the frame 200. Hereinafter, for convenience of description, the rectangular mask 100 will be described as an example, but the masks 100 may be in the form of a stick mask having protrusions clamped at both sides before being bonded to the frame 200, and the frame 200. The protrusions can be removed after they have been glued to them.

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. In order to form a thin thickness, the mask 100 may be formed by electroforming. The mask 100 may be an invar having a thermal expansion coefficient of about 1.0 × 10 ⁻⁶ / ° C. and a super invar material having about 1.0 × 10 ⁻⁷ / ° C. Since the mask 100 of this material has a very low coefficient of thermal expansion, there is little possibility that the pattern shape of the mask is deformed by thermal energy, and thus, the mask 100 may be used as a fine metal mask (FMM) or a shadow mask in high-resolution OLED manufacturing. In addition, in consideration of the recent development of techniques for performing the pixel deposition process in a range where the temperature change is not large, the mask 100 has a slightly larger thermal expansion coefficient than that of nickel (Ni) and nickel-cobalt (Ni-Co). It may be a material such as). The thickness of the mask may be formed to about 2 to 50㎛.

The frame 200 is formed to bond the plurality of masks 100. The frame 200 may include various edges formed in a first direction (eg, a horizontal direction) and a second direction (eg, a vertical direction) including an outermost edge. These various corners may define the area to which the mask 100 is to be bonded on the frame 200.

The frame 200 may include an edge frame portion 210 having a substantially rectangular shape and a rectangular frame shape. The inside of the frame frame 210 may be hollow. That is, the frame frame 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 may be made of Inbar, Super Invar, Nickel, or Nickel-Cobalt having the same thermal expansion coefficient as a mask in consideration of thermal deformation. Preferably, the materials may be applied to both the edge frame portion 210 and the mask cell sheet portion 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 portion 220 connected to the edge frame portion 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 be connected to the edge frame part 210 after forming a plurality of mask cell areas CR through laser scribing, etching, etc. on a flat sheet. Alternatively, the mask cell sheet unit 220 may form a plurality of mask cell regions CR through laser scribing, etching, etc. after connecting the planar sheet to the edge frame unit 210. In the present specification, a plurality of mask cell regions CR are first formed in the mask cell sheet part 220, and then the main parts of the mask cell sheet part 220 are connected to the edge frame part 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 edge sheet portion 221 and the first and second grid sheet portions 223 and 225 refer to respective portions partitioned from the same sheet, which are integrally formed with each other.

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

In addition, the first grid sheet part 223 may extend in a first direction (horizontal direction). The first grid sheet part 223 may be formed in a straight line shape and both ends thereof may be connected to the edge sheet part 221. When the mask cell sheet portion 220 includes a plurality of first grid sheet portions 223, each of the first grid sheet portions 223 may be equally spaced apart.

In addition, in addition, the second grid sheet part 225 may be formed to extend in a second direction (vertical direction). The second grid sheet part 225 may be formed in a straight line shape and both ends thereof may be connected to the edge sheet part 221. The first grid sheet part 223 and the second grid sheet part 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 may be equally spaced apart.

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

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 may be a rectangle, a square shape such as a parallelogram, a triangular shape, or the like. The edges, edges and corners may be partially rounded. The cross-sectional shape is adjustable in the process of laser scribing, etching and the like.

The thickness of the edge frame portion 210 may be thicker than the thickness of the mask cell sheet portion 220. The edge frame part 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, a process of manufacturing a substantially thick sheet is difficult, and if it is too thick, a path through which the organic source 600 (see FIG. 16) passes through the mask 100 in an OLED pixel deposition process is used. This can cause problems. On the contrary, if the thickness is too thin, it may be difficult to secure rigidity enough to support the mask 100. Accordingly, the mask cell sheet portion 220 is thinner than the thickness of the edge frame portion 210, but preferably thicker than the mask 100. The mask cell sheet part 220 may have a thickness of about 0.1 mm to about 1 mm. In addition, the widths of the first and second grid sheet parts 223 and 225 may be formed to about 1 to 5 mm.

A plurality of mask cell areas CR: CR11 to CR56 may be provided except for an area occupied by the edge sheet part 221 and the first and second grid sheet parts 223 and 225 in the planar sheet. In another aspect, the mask cell region CR is a region occupied by the edge sheet portion 221 and the first and second grid sheet portions 223 and 225 in the hollow region R of the edge 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, the mask C may be used as a passage through which the pixels of the OLED are deposited through the mask pattern P. FIG. As described above, one mask cell C corresponds to one display such as a smartphone. Mask patterns P that form 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 region CR of the frame 200. It is necessary to avoid the large area mask 100, and the small area mask 100 provided with 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 the sake of clear alignment, it may be considered to correspond to the mask 100 having a few cells C of about 2-3.

The frame 200 may include a plurality of mask cell regions CR, and each mask 100 may be bonded 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 (corresponding to a portion of the mask film 110 except for the cell C) around the mask cell C. have. The dummy may include only the mask film 110 or the mask film 110 having a predetermined dummy pattern having a similar shape to the mask pattern P. FIG. The mask cell C may correspond to the mask cell region CR of the frame 200, and part or all of the dummy may be adhered to the frame 200 (mask cell sheet portion 220). Accordingly, the mask 100 and the frame 200 may form an integrated structure.

On the other hand, according to another embodiment, the frame is not manufactured by adhering the mask cell sheet portion 220 to the edge frame portion 210, the frame frame portion 210 in the hollow region (R) portion of the edge frame portion 210 ), A frame in which a grid frame (corresponding to the grid sheet portions 223 and 225) which is integral with the frame) is formed immediately. The frame of this type also includes at least one mask cell region CR, and the mask integrated region may be manufactured by corresponding the mask 100 to the mask cell region CR.

Hereinafter, the process of manufacturing a frame integrated mask is demonstrated.

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

Referring to FIG. 6A, an edge frame unit 210 is provided. The edge frame portion 210 may have a rectangular frame shape including the hollow area R.

Next, referring to FIG. 6B, a mask cell sheet part 220 is manufactured. The mask cell sheet unit 220 may be manufactured by fabricating a flat sheet using pre-plating or other film forming process, and then removing the mask cell region CR through laser scribing or etching. have. In the present specification, a description is given taking an example of forming a 6 × 5 mask cell region (CR: CR11 to CR56). There may be five first grid sheet portions 223 and four second grid sheet portions 225.

Next, the mask cell sheet part 220 may correspond to the edge frame part 210. In the corresponding process, all the sides of the mask cell sheet part 220 are stretched (F1 to F4), and the edge sheet part 221 is connected to the edge frame part 210 while the mask cell sheet part 220 is flattened. It can respond. On one side, the mask cell sheet part 220 may be grasped and tensioned at various points (for example, 1 to 3 points in FIG. 6B). On the other hand, the mask cell sheet portion 220 may be stretched (F1, F2) not in all sides but in some lateral direction.

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

7 is a schematic diagram illustrating 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 adhered to the edge frame part 210. However, the embodiment of FIG. After adhesion to 210, the mask cell region CR is formed.

First, as shown in FIG. 6A, the edge frame part 210 including the hollow area R is provided.

Next, referring to FIG. 7A, the edge frame portion 210 may correspond to a planar sheet (the plane mask cell sheet portion 220 ′). The mask cell sheet portion 220 ′ is in a planar state in which the mask cell region CR is not yet formed. In the corresponding process, all sides of the mask cell sheet part 220 'may be stretched (F1 to F4) to correspond to the edge frame part 210 in a state where the mask cell sheet part 220' is flattened. On one side, the mask cell sheet portion 220 'may be grasped and tensioned at several points (for example, 1 to 3 points in FIG. 7A). On the other hand, the mask cell sheet portion 220 'may be stretched (F1, F2) not in all sides but in some lateral direction.

Next, when the mask cell sheet portion 220 'corresponds to the edge frame portion 210, the edge portion of the mask cell sheet portion 220' may be welded (W) and bonded. It is preferable to weld (W) all sides so that the mask cell sheet portion 220 ′ can be firmly adhered to the edge frame portion 220. Welding (W) should be performed as close as possible to the edge of the edge frame portion 210 as much as possible to reduce the excited space between the edge frame portion 210 and the mask cell sheet portion 220 'as much as possible to increase the adhesion. The welded W portion may be formed in a line or spot shape, and may have the same material as that of the mask cell sheet portion 220 ′ and have an edge frame portion 210 and a mask cell sheet portion 220 ′. It can be a medium to connect the integrally.

Next, referring to FIG. 7B, a mask cell region CR is formed in 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 through laser scribing or etching. In the present specification, a description is given taking an example of forming a 6 × 5 mask cell region (CR: CR11 to CR56). When the mask cell region CR is formed, a portion welded to the edge frame portion 210 becomes the edge sheet portion 221, and five first grid sheet portions 223 and four second grids are formed. The mask cell sheet part 220 having the sheet part 225 may be configured.

8 is a schematic diagram illustrating components of a transfer system of a mask 100 according to an embodiment of the present invention. 8A is a plan view and a side cross-sectional view showing a mask 100, FIG. 8B is a plan view and a side cross-sectional view showing a tray 50, and FIG. 8C is a mask loading portion 90 It is a plan cross section and a side cross section which show. The tray 50 and the mask loading unit 90, which are transfer systems of the mask 100, support a system for transferring the mask 100 to the frame 200 before the mask 100 is attached to the frame 200. Can mean.

Referring to FIG. 8A, a mask 100 having a plurality of mask patterns P 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 around the mask cell C. FIG. The dummy DM corresponds to a portion of the mask layer 110 except for the cell C, includes only the mask layer 110, or the mask layer 110 in which a predetermined dummy pattern having a shape similar to the mask pattern P is formed. It may include. In the dummy DM, a part or all of the dummy DM may be attached to the frame 200 (the mask cell sheet 220) in correspondence with the edge of the mask 100. It is possible to manufacture a mask 100 of the Invar, super Invar material by electroplating method.

The mother plate used as a cathode in electroplating is made of a conductive material. As the conductive material, in the case of metal, metal oxides may be generated on the surface, impurities may be introduced during the metal manufacturing process, and in the case of the polycrystalline silicon substrate, inclusions or grain boundaries may exist, and the conductive polymer may be present. In the case of a base material, it is highly likely to contain an impurity, and strength. Acid resistance may be weak. Elements that interfere with the uniform formation of an electric field on the surface of the substrate (or negative electrode body), such as metal oxides, impurities, inclusions, grain boundaries, etc., are referred to as "defects." Due to the defect, a uniform electric field may not be applied to the negative electrode body of the above-described material, so that a part of the plating film (mask 100) may be unevenly formed.

Non-uniformity of the plating film and the plating film pattern (mask pattern P) may adversely affect the formation of the pixel in implementing a UHD-class or higher definition pixel. For example, QHD image quality is 500 ~ 600 pixel per inch (PPI), and the size of pixel is about 30 ~ 50㎛. For 4K UHD and 8K UHD high definition, it is higher than 860 PPI and ~ 1600 PPI. Have the same resolution. The micro display applied directly to the VR device, or the micro display used in the VR device, aims at an ultra high resolution of about 2,000 PPI or more, and the size of the pixel reaches about 5 to 10 μm. The pattern width of the FMM and shadow mask applied to this may be formed in a size of several to several tens of micrometers, preferably smaller than 30 micrometers, so that even a defect having a size of several micrometers occupies a large proportion in the pattern size of the mask. to be. In addition, an additional process for removing metal oxides, impurities, and the like may be performed to remove the defects in the cathode material of the material described above, and another defect such as etching of the anode material may be caused in this process. have.

Therefore, in the present invention, a mother plate (or a negative electrode body) of a single crystal material can be used. In particular, it is preferable that it is a single crystal silicon material. In order to have conductivity, a high concentration doping of 10 ¹⁹ / cm ³ or more may be performed on the single crystal silicon base plate. Doping may be performed on the entirety of the mother plate or only on the surface portion of the mother plate.

On the other hand, the single crystal material is a metal such as Ti, Cu, Ag, carbon-based materials such as semiconductors such as GaN, SiC, GaAs, GaP, AlN, InN, InP, Ge, graphite, graphene _{, CH 3 NH 3 PbCl 3,} CH 3 NH 3 PbBr 3, CH 3 NH 3 PbI 3, SrTiO 3 , etc. page containing the perovskite (perovskite) superconductor single crystalline ceramic, aircraft single crystal second heat-resistant alloy for components for such structures And the like can be used. Metal and carbon-based materials are basically conductive materials. In the case of a semiconductor material, high concentration doping of 1019 or more may be performed to have conductivity. In the case of other materials, conductivity may be formed by performing doping or forming oxygen vacancies. Doping may be performed on the entirety of the mother plate or only on the surface portion of the mother plate.

Since there is no defect in the case of a single crystal material, there is an advantage 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 the uniform plating layer may further improve the image quality level of the OLED pixel. In addition, since an additional process of removing and eliminating defects does not have to be performed, there is an advantage in that process costs are reduced and productivity is improved.

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

On the other hand, the material of the mother plate of the present invention is not limited to the above-described single crystal material as long as it is within the range for reducing the defect of the negative electrode body.

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. Since the frame 200 includes a plurality of mask cell regions CR11 to CR56, the mask 100 having mask cells C11 to C56 corresponding to the respective mask cell regions CR11 to CR56. ) Can also be provided in plurality.

Referring to FIG. 8B, a tray 50 may be provided. The tray 50 may be used to move the mask 100 in a state where the mask 100 is attached to a tray 50 so as to correspond to the frame 200. The tray 50 is preferably flat in shape so that the mask 100 can be attached flat. The tray 50 may have a flat plate shape larger than that of the mask 100 so that the mask 100 may be flatly attached to the entire surface.

The tray 50 may use a wafer having a surface roughness Ra of one surface of 100 nm or less. Alternatively, a material such as glass, silica, heat-resistant glass, quartz, alumina (Al ₂ O ₃ ) having a surface roughness Ra of 100 nm or less may be used. On the other hand, the tray 50 of the wafer material may be opaque to the laser (L) light. Accordingly, in the tray 50 of the present invention, the laser passing hole 51 is provided in the tray 50 so that the laser L irradiated from the upper portion of the tray 50 can reach the welded portion of the mask 100. Can be formed.

Referring to FIG. 8B again, the laser through hole 51 may be formed in the tray 50 so as to correspond to the position and the number of welds. Since a plurality of welding parts are disposed along a predetermined interval at the edge or dummy DM portion of the mask 100, a plurality of laser passing holes 51 may also be formed along the predetermined interval to correspond thereto. For example, since a plurality of welding parts are disposed at both sides (left / right side) of the mask 100 at a portion of the dummy DM along a predetermined interval, the laser passing holes 51 are also disposed on both sides (left / right side) of the tray 50. A plurality may be formed along a predetermined interval.

The laser through hole 51 does not necessarily correspond to the position and the number of welds. For example, welding may be performed by irradiating the laser L only to a part of the laser passing holes 51. In addition, some of the laser through holes 51 that do not correspond to the welding part may be used in place of vacuum holes, which are passages for applying vacuum suction pressure to the mask 100 in contact with one surface of the tray 50. In addition, some of the laser through holes 51 which do not correspond to the welding part may be used in place of the alignment mark when the mask 100 and the tray 50 are aligned. If the material of the tray 50 is transparent to the laser light, the laser through hole 51 may not be formed.

On the other hand, the tray 50 has an alignment hole 53 used to align the mask 100 before the mask 100 is applied to the cell region CR of the frame 200 and then bonded. Can be further formed. The alignment camera unit (not shown) may check the alignment of the mask 100 through the alignment hole 53. The alignment hole 53 may be formed in a portion of the tray 50 corresponding to a portion of at least one of the mask cell C and the mask dummy DM. The alignment holes 53 must correspond to at least some mask patterns P of the mask cells C to align the masks 100, and the mask dummy DM must correspond to at least a portion of the mask cells C to be aligned with the mask cells C. FIG. The boundary of the dummy DM may be divided to facilitate alignment.

Referring to FIG. 8C, the mask loading unit 90 may be provided. The mask loading unit 90 may flatten the manufactured mask 100 to provide a space for loading the mask 100 before moving to the frame 200. The mask loading unit 90 may have a flat plate shape so that the mask 100 may be loaded flat. The size of the mask loading unit 90 may have a flat plate shape larger than that of the mask 100 so that the mask 100 may be loaded flat throughout.

When the mask 100 is loaded or after being loaded, the mask loading unit 90 may absorb one surface of the mask 100 so that the mask 100 may remain flat without wrinkles. A plurality of vacuum holes VH may be formed on one surface of the mask loading unit 90 corresponding to the mask 100 so that the mask loading unit 90 may absorb one surface of the mask 100. have. The mask loading unit 90 may be connected to an external pumping means (not shown) to pump air in the mask loading unit 90 to transmit a suction pressure to the vacuum hole VH. The mask 100 may be sucked to the mask loading unit 90 by the suction pressure of the plurality of vacuum holes VH.

The mask loading part 90 may have a depression 91 formed at an edge thereof. Considering the mask loading unit 90 having a square shape, recesses 91 may be formed at four corners, respectively. When the mask 100 and the tray 50 are loaded on the mask loading unit 90, a portion of the mask 100 and the tray 50 may protrude and be exposed to the outside of the recess 91. Accordingly, the mask 100 may be flattened using the protruding and exposed portions, or the tray 50 may be gripped by the grip means (not shown).

Hereinafter, a series of processes in which the mask 100 is processed in the mask transfer system will be described.

9 is a schematic view showing a state in which the vacuum transfer unit 60 adsorbs the mask 100 according to an embodiment of the present invention.

Referring to FIG. 9, the vacuum transfer unit 60 may adsorb the side of the mask 100. The vacuum transfer unit 60 may flatten the mask 100 by pulling the mask 100 outward after pulling the mask 100.

The manufactured mask 100 may be loaded and bonded onto the frame 200 in a flat and flat state. At this time, in the process of moving the mask 100, the mask 100 is a thin film having a thickness of about 2㎛ ~ 50㎛, wrinkles may occur even if a little force is applied, so care must be taken for its handling. In addition, since the plurality of fine mask patterns P are formed in the mask 100, the mask 100 must be flattened without wrinkles so that the alignment of the mask patterns P is not misaligned. If both sides of the mask 100 are gripped by the gripper to move the mask 100 in the unfolded state, damage may occur to the mask 100, and since both sides of the mask 100 are gripped, it is not easy to load on the frame 200. In addition, it is also very difficult to grab the mask 100 with the gripper and to move it flat without any misalignment of the mask pattern P and load it onto the frame 200.

Accordingly, the vacuum transfer unit 60 may perform suction by the vacuum V on the side of the mask 100. Here, the adsorption by the vacuum (V) does not mean that the environment around the mask 100 is vacuumed and adsorbed, but air is pumped out along the internal gas flow path 63 of the vacuum transfer unit 60, so that the adsorption force is increased. It can be understood that the mask 100 is generated and adsorbed to the vacuum transfer unit 60.

The vacuum transfer unit 60 may include a housing 61, and a gas flow path 63 may be provided inside the housing 61. One end of the housing 61 may contact the side of the mask 100, and the other end may be connected to an external pumping means (not shown). Pumping means (not shown), such as a pump, can pump air from the gas flow path 63 inside the housing 61 to make the inside of the housing 61 into a vacuum atmosphere. Accordingly, the mask 100 in contact with one end of the housing 61 may be absorbed by the vacuum transfer unit 60.

The porous part 65 may be disposed at one end of the housing 61. The porous portion 65 may be made of a porous material containing very small pores. When the mask 100 is adsorbed to the vacuum transfer unit 60 through a hole or a slit, the holes and the slit have a large size and the adsorption force is not uniform in the hole and slit formation area. Some can be stressful. Therefore, when vacuum is applied between the pores of the porous part 65, the adsorption force can be generated uniformly on the surface of the porous part 65, thereby stably adsorbing and moving the mask 100.

The vacuum transfer unit 60 may adsorb at least two sides of the mask 100. For example, two sides of the left and right sides of the mask 100 may be adsorbed, or four upper, lower, left, and right sides of the mask 100 may be adsorbed. For example, FIG. 9A illustrates an example in which two vacuum transfer units 60 may attract left and right sides of the mask 100 and pull the left and right directions. As another example, FIG. 9B illustrates an example in which four vacuum transfer units 60 ′ may pull the mask 100 in left, right, top, and bottom directions by absorbing four corner portions of the mask 100. have. However, the present invention is not limited thereto, and the number of the vacuum transfer units 60 may be determined in consideration of the pulling direction, movement, and the like of the mask 100. A moving means (not shown) such as a rail, a belt, or the like for moving the vacuum conveyer 60 to the X, Y, Z, and θ axes may be connected to the vacuum conveyer 60 to pull, adsorb, and move the mask 100. Can be. In the following, it is assumed in the form of FIG. 9B and described.

10 is a schematic view showing an operation process of the mask transfer system according to an embodiment of the present invention.

Referring to FIG. 10A, the vacuum transfer unit 60 may absorb the mask 100 and move to the mask loading unit 90. The mask 100 may be loaded on the mask loading unit 90 in a state where four corners are sucked and flattened by the vacuum transfer unit 60. Alternatively, the vacuum transfer unit 60 may flatten the mask 100 while the mask 100 is loaded on the mask loading unit 90.

Subsequently, the mask 100 may be adsorbed onto the mask loading unit 90 by applying a suction pressure to the mask 100 in the vacuum hole VH on the mask loading unit 90. Alternatively, the vacuum transfer unit 60 may apply a pressure to the mask 100 in the vacuum hole VH in the process of moving the mask 100 on the mask loading unit 90.

On the other hand, even when the vacuum transfer unit 60 is not used, for example, after the edge of the mask 100 is gripped by a gripper (not shown) and moved to the mask loading unit 90, the mask 100 is opened while the mask 100 is unfolded. The mask 100 may be adsorbed by applying a suction pressure in the vacuum hole VH of the loading unit 90. Since the recess 91 is formed at the corner of the mask loading unit 90, the gripper may not interfere with the mask loading unit 90 even when the gripper grips both edges of the mask 100.

When the mask 100 is loaded on the mask loading unit 90, at least a corner portion of the mask 100 may protrude and be exposed to the outside of the recess 91.

Next, referring to FIG. 10B, the tray 50 may be brought into contact with the other surface of the mask 100 that is in contact with the mask loading unit 90. The tray 50 has an area larger than that of the mask 100, and when the tray 50 contacts the mask 100, at least an edge portion of the tray 50 protrudes and is exposed to the outside of the recess 91. Can be.

Next, referring to FIG. 10C, the mask 100 may be supported by the tray 50 so that the mask 100 may be separated from the mask loading unit 90. For example, as the mask 100 is adsorbed and supported by the tray 50, the other surface of the mask 100 and the tray 50 may be mutually adsorbed to separate the mask 100 from the mask loading unit 90. In this case, the suction pressure may not be applied to the vacuum hole VH of the mask loading unit 90, or at least less than the suction force between the tray 50 and the mask 100 may be applied.

For example, the tray 50 may be formed with a plurality of suction holes (not shown). The plurality of suction holes (not shown) may be a passage for applying pressure to the mask 100, similar to the vacuum hole VH of the mask loading unit 90. Accordingly, a pumping means (not shown) capable of applying pressure to a plurality of suction holes (not shown) may be connected to the tray 50. As another example, a pumping means (not shown) may apply a suction pressure to at least a portion of the laser passage hole 51 of the tray 50 to adsorb and support the mask 100. The laser passing hole 51 is used as a passage for applying the pressure in this process, and when the mask 100 is subsequently adhered to the frame 200, the connection with the pumping means (not shown) is released, and the laser L ) Can be used as a passage through.

Next, the mask 100 may be supported by the tray 50 to be transported to the area of the frame 200.

Hereinafter, a series of processes in which the mask 100 corresponds to the frame 200, are aligned, and then bonded are described.

FIG. 11 is a schematic diagram illustrating a state in which the tray 100 is loaded onto a frame and the mask 100 corresponds to the cell region CR of the frame 200 according to an embodiment of the present invention. 12 shows a process of bonding the mask 100 to the cell region CR of the frame 200 by loading the tray 50 'on the frame 200 according to the comparative example, and the mask 100 and the tray 50'. Side cross-sectional view and partial enlarged side cross-sectional view showing an interface state of 13 is a process of bonding the mask 100 to the cell region CR of the frame 200 by loading the tray 50 on the frame 200 according to an embodiment of the present invention, and the mask 100 and the tray. It is a side cross-sectional view and partial enlarged side cross-sectional view which shows the interface state of (50).

Next, referring to FIGS. 11A and 11B, the mask 100 may correspond to one mask cell region CR of the frame 200. By loading the tray 50 on which the mask 100 is adsorbed and supported on the frame 200 (or the mask cell sheet portion 220), the mask 100 can be corresponded to the mask cell region CR. When the tray 50 is loaded on the frame 200 (or the mask cell sheet part 220), the mask 100 is the tray 50 and the frame 200 (or the mask cell sheet part 220). While being disposed therebetween, it may be compressed by the tray 50.

Meanwhile, the lower supporter 70 may be further disposed below the frame 200. The lower supporter 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. In addition, a predetermined support groove (not shown) corresponding to the shape of the mask cell sheet part 220 may be formed on the upper surface of the lower supporter 70. In this case, the edge sheet part 221 and the first and second grid sheet parts 223 and 225 are fitted into the support groove, so that the mask cell sheet part 220 may be more securely fixed.

The lower supporter 70 may compress the opposite surface of the mask cell region CR that the mask 100 contacts. That is, the lower supporter 70 may support the mask cell sheet part 220 in the upper direction to prevent the mask cell sheet part 220 from sagging in the lower direction during the bonding process of the mask 100. At the same time, the edge of the mask 100 and the frame 200 (or the mask cell sheet part 220) are pressed in a direction in which the lower support 70 and the tray 50 are opposite to each other, so that the mask 100 is pressed. The alignment state of the can be maintained without being disturbed.

As such, the mask 100 is attached to the mask cell region CR of the frame 200 by simply attaching the mask 100 to the tray 50 and loading the tray 50 onto the frame 200. Since the process is completed, no tensile force may be applied to the mask 100 in this process.

Subsequently, the mask 100 may be irradiated with the laser L to bond the mask 100 to the frame 200 by laser welding. A weld bead WB is generated in the welded portion of the laser welded mask, and the weld bead WB may be integrally connected with the same material as that of the mask 100 / frame 200.

11 and 12, on the other hand, in addition to pressing the mask 100 by the tray 50, the mask 100 and the frame 200 (or the edge sheet part 221, the first and the second). In order for the grid sheet portions 223 and 225 to be in close contact with each other, pressing may be further applied to the pressing body M (see FIG. 13) at the upper portion of the tray 50. In addition to the load by the weight of the press body (M) may further comprise a means for pressing the press body (M). 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 transparent tray (50 ') after passing through the through hole (MH) and the mask (100). Can be irradiated to the weld portion (area to be welded).

However, as shown in FIG. 11, in spite of the loads of the tray 50 'and the compressed body M, a minute air gap AG may exist on the interface between the tray 50' and the mask 100. . Since the glass 50 'of the glass tray 50 has a surface roughness Ra of about 20 to 30 μm, when the surface of the tray 50' is examined at a micrometer scale, there is a slight curvature. Accordingly, even when the mask 100 is compressed, there may be a portion where the tray 50 'and the mask 100 are not in close contact with each other, and the compressive load is not transmitted well in this portion, so that the mask 100 and the frame 200 are not in contact with each other. The edge sheet portion 221 and the first and second grid sheet portions 223 and 225 may not be in close contact with each other.

In the part where the tray 50 'and the mask 100 closely contact each other without the air gap AG, the welding bead WB is well generated between the mask 100 and the frame 200 by laser L1 irradiation. In this case, the mask 100 and the frame 200 are integrally connected, and as a result, welding may be well performed. However, in the part where the air gap AG exists between the tray 50 'and the mask 100 and does not come in close contact with each other, the welding bead between the mask 100 and the frame 200 is irradiated by the laser L2. WB) is not generated well, and as a result, welding is not performed well.

Accordingly, as shown in FIG. 12, one surface of the tray 50 which contacts the mask 100 may be mirrored so that the air gap AG does not occur between interfaces with the mask 100. Specifically, the surface roughness Ra of one surface of the tray 50 may be 100 nm or less. Since the surface roughness Ra is about 20 to 30 μm in the glass tray 50 ′ described above with reference to FIG. 11, the air gap AG is present between the interface with the mask 100 and the mask pattern is μm scale. This may affect the alignment error of (P). However, the tray 50 of the present invention does not affect the alignment error of the mask pattern P to a level where the surface roughness Ra is nm scale and there is no or little air gap AG.

In order to implement the tray 50 having the surface roughness Ra of 100 nm or less, the tray 50 may use a wafer. Since the wafer has a surface roughness Ra of about 10 nm, many products on the market, and many surface treatment processes are known, the wafer is suitable for use as the tray 50. In addition, if the surface roughness (Ra) can satisfy the surface roughness (Ra) of 100nm or less, the tray 50 is made of glass, silica, heat-resistant glass, quartz, alumina (Al ₂ O ₃ ) may be used. The following description assumes the use of the wafer as the tray 50.

Since the surface roughness Ra is 100 nm or less and the interface between the mask 100 and the interface of the mask 100 can be intimately contacted without the air gap AG, the laser L is irradiated to the welded portion of the mask 100. The welding beads WB can be well produced when performing the welding. The welding part of the mask 100 may refer to a target area in which the welding bead WB is formed by irradiating the laser L. FIG. The welding part may correspond to at least a portion of the edge or dummy portion DM of the mask 100. A weld bead WB is generated in the welded portion of the laser welded mask, and the weld bead WB may be integrally connected with the same material as that of the mask 100 / frame 200.

On the other hand, the tray 50 of the wafer material may be opaque to the laser (L) light. Accordingly, in the tray 50 of the present invention, the laser passing hole 51 is provided in the tray 50 so that the laser L irradiated from the upper portion of the tray 50 can reach the welded portion of the mask 100. Can be formed.

Referring back to FIG. 11, since the mask cell sheet part 220 of the frame 200 has a thin thickness, when the mask cell sheet part 220 is adhered to the mask cell sheet part 220 while a tensile force is applied to the mask 100, the mask ( The tensile force remaining in the 100 may act on the mask cell sheet portion 220 and the mask cell region CR to deform them. Therefore, the mask 100 should be adhered to the mask cell sheet part 220 without applying a tensile force to the mask 100. Thus, it is possible to prevent the tensile force applied to the mask 100 from acting as a tension on the frame 200 to deform the frame 200 (or the mask cell sheet part 220).

However, there is one problem when the frame integrated mask is manufactured by adhering to the frame 200 (or the mask cell sheet part 220) without applying a tensile force to the mask 100, and using the frame integrated mask in a pixel deposition process. May occur. In the pixel deposition process performed at about 25-45 ° C., the mask 100 thermally expands by a predetermined length. Even in the mask 100 made of Invar, a length of about 1 to 3 ppm may be changed according to a temperature rise of about 10 ° C. for forming a pixel deposition process atmosphere. For example, when the total length of the mask 100 is 500 mm, a length of about 5 to 15 μm may be increased. Then, a problem arises in that the alignment error of the patterns P becomes large while causing deformation such as the mask 100 is struck by its own weight or stretched and twisted while being fixed in the frame 200.

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

The “process area” may refer to a space in which components such as the mask 100 and the frame 200 are located and an adhesion process of the mask 100 is performed. The process region may be a space in a closed chamber, or may be an open space, and may mean only a space around a stage part (not shown) in which a process of bonding the mask 100 to the frame 200 is performed. In addition, “first temperature” may mean a temperature that is 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 ° C to 45 ° C, the first temperature may be about 25 ° C to 60 ° C. The temperature rise in the process region may be performed by providing a heating means in the chamber, or installing a heating means around the process region.

Referring back to FIG. 11, after the temperature ET of the process region including the frame 200 is raised to the first temperature, the mask 100 may correspond to the mask cell region CR. Alternatively, after the mask 100 corresponds to the mask cell region CR, the temperature of the process region including the frame 200 may be raised to the first temperature (ET). Alternatively, although only one mask 100 corresponds to one mask cell region CR in the drawing, the temperature of the process region may be changed after the masks 100 correspond to each mask cell region CR. It is also possible to raise (ET1).

Since the mask 10 of FIG. 1 includes six cells C1 to C6, the mask 10 has a long length, 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 the 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 May reduce the above error range by 1 / n according to the reduction of the relative length (corresponding to the reduction of the number of cells C). For example, if the length of the mask 100 of the present invention is 100mm, it has a length reduced to 1/10 at 1m of the conventional mask 10, the PPA error of 1㎛ occurs in the entire 100mm length As a result, the alignment error is significantly reduced.

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

In the case of the present invention, since only one cell C of the mask 100 needs to be corresponded and the alignment state is confirmed, the plurality of cells C: C1 to C6 must be simultaneously associated and the alignment state must be confirmed. In comparison with the conventional method (see Fig. 2), the production time can be significantly reduced.

That is, according to the method of manufacturing a frame-integrated mask of the present invention, each cell C11 to C16 included in the six masks 100 corresponds to one cell region CR11 to CR16 and checks the alignment state. Through the process, the time can be much shorter than the conventional method of simultaneously matching six cells C1 to C6 and confirming the alignment of all six cells C1 to C6 at the same time.

In addition, in the method of manufacturing a frame-integrated mask of the present invention, the product yield in 30 processes of matching and aligning 30 masks 100 with 30 cell areas CR: CR11 to CR56 respectively is 6 cells (C1). 5 masks 10 (see FIG. 2A), each comprising ˜C6), may appear much higher than the conventional product yield in 5 steps of matching and aligning the frame 20. Since the conventional method of aligning six cells C1 to C6 in a region corresponding to six cells C at a time is a much more cumbersome and difficult task, product yield is low.

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

Also, according to one embodiment, the mask 100 may be preheated to a temperature higher than the first temperature before corresponding to the frame 200. Referring back to FIG. 8C, the mask loading unit 90 may further include a heating unit 95. In step (a) of FIG. 10, when the mask 100 is loaded onto the mask loading unit 90, the heating unit 95 of the mask loading unit 90 may move the mask 100 to a temperature higher than the first temperature. For example, the mask 100 may be preheated to a temperature of about 3 ° C to 10 ° C higher than the first temperature.

While the mask 100 is stretched to correspond to the frame 200 while raising the mask 100 directly to the first temperature, fine wrinkles, bends, or the like of nm or μm may be generated on the surface thereof. The alignment may be difficult to perform immediately before the mask 100 is adhered to the frame 200, and the alignment between the mask pattern P and the cell C may be performed even if the alignment is performed and the mask 100 is adhered to the frame 200. This error may occur.

Accordingly, after the mask 100 is preheated in the mask loading unit 90, when the mask 100 is supported by the tray 50 and corresponds to the frame 200, the mask 100 is about 3 ° C. to 10 ° C. at the first temperature. As the degree temperature decreases, a tension may be applied in which the mask 100 contracts while being contracted. For this reason, it is possible to maintain a flat unfolded state without causing wrinkles, bends, or the like of the mask 100. Since the temperature is lowered only by a small temperature of about 3 ° C. to 10 ° C., the mask 100 does not deform enough to affect the alignment of the mask pattern P and the cell C, and only shrinkage that is flattened occurs. Can be.

Next, the flattened mask 100 may be perfectly aligned with the frame 200. Through the alignment holes 53, alignment may be performed by checking the alignment state under a microscope in real time. Subsequently, at least a part of the edge of the mask 100 may be attached to the frame 200. The adhesion may preferably be carried out by laser welding. Laser welding should be performed as close to the edge of the frame 200 as possible to reduce the excitement space between the mask 100 and the frame 200 as much as possible to increase the adhesion. A weld bead WB is generated in the welded portion of the laser welded mask, and the weld bead WB may be integrally connected with the same material as that of the mask 100 / frame 200.

Since the present invention performs welding on the mask cell sheet portion 220 without applying a tensile force to the mask 100, the mask cell sheet portion 220 (or the edge sheet portion 221, the first and the second grid sheet) is welded. (223, 225) is not applied to the tension.

14 is a schematic diagram illustrating a process of sequentially bonding the mask 100 according to an embodiment of the present invention to the cell region CR.

After the one mask 100 is adhered to the frame 200, the remaining masks 100 may be sequentially corresponded to the remaining mask cells C, and the process of adhering to the frame 200 may be repeated. The remaining masks 100 may be sequentially corresponded to the remaining mask cells C, and the temperature of the process region may be controlled as the first temperature and the second temperature in the process of adhering. Since the mask 100 already bonded to the frame 200 may present a reference position, the time required to sequentially match the remaining masks 100 to the cell region CR and to confirm the alignment state is significantly reduced. There is an advantage that can be. In addition, the pixel position accuracy (PPA) between the mask 100 adhered to one mask cell region and the mask 100 adhered to the mask cell region adjacent thereto does not exceed 3 μm, and the alignment is very high. There is an advantage that a mask for forming an OLED pixel can be provided.

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

Next, referring to FIG. 15, the temperature of the process region may be lowered to the second temperature LT. The “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. provided that it is lower than the first temperature, and preferably, the second temperature may be room temperature. The temperature drop in the process region can be performed by providing a cooling means in the chamber, installing a cooling means around the process region, naturally cooling to room temperature, or the like.

When the temperature of the process region is lowered to the second temperature LT, the mask 100 may heat shrink by a predetermined length. The mask 100 may be thermally contracted isotropically along all lateral directions. However, since the mask 100 is fixedly connected to the frame 200 (or the mask cell sheet part 220) by welding, the thermal contraction of the mask 100 is itself tensioned with the surrounding mask cell sheet part 220. (TS) is applied. By applying a tension (TS) of the mask 100, the mask 100 may be more tightly adhered to the frame 200.

In addition, since each of the masks 100 is bonded onto 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 thermal contraction. The problem that the 200 is deformed or the patterns P are misaligned can be prevented. In more detail, even when the tension TS is applied to the mask cell sheet part 220, since the plurality of masks 100 apply the tension TS in opposite directions, the force is canceled to the mask cell sheet part. Deformation does not occur at 220. For example, the first grid sheet portion 223 between the mask 100 attached to the CR11 cell region and the mask 100 attached to the CR12 cell region may move in the right direction of the mask 100 attached to the CR11 cell region. The acting tension TS and the acting tension TS in the left direction of the mask 100 attached to the CR12 cell region may be offset. Therefore, the deformation is minimized in the frame 200 (or the mask cell sheet part 220) due to the tension TS, thereby minimizing the alignment error of the mask 100 (or the mask pattern P). There is this.

16 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. 16, the OLED pixel deposition apparatus 1000 includes a magnet plate 300 in which a magnet 310 is accommodated and a coolant 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) for supplying ().

A target substrate 900, such as glass, on which the organic 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 FMMs) for allowing the organic material source 600 to be deposited pixel by pixel may be disposed on or close to the target substrate 900. The magnet 310 may generate 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 supply the organic source 600 while reciprocating the left and right paths, and the organic source 600 supplied from the deposition source supply unit 500 may have patterns P formed in the frame integrated masks 100 and 200. Pass through) may be deposited on one side of the target substrate (900). The deposited organic source 600 passing through the pattern P of the frame-integrated masks 100 and 200 may serve as the pixel 700 of the OLED.

In order to prevent uneven deposition of the pixel 700 by the shadow effect, the pattern of the frame-integrated masks 100 and 200 may be formed to be inclined S (or formed into a tapered shape S). . Since the organic 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 overall thickness.

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

Although the present invention has been shown and described with reference to preferred embodiments as described above, it is not limited to the above embodiments and various modifications made by those skilled in the art without departing from the spirit of the present invention. Modifications and variations are possible. Such modifications and variations are intended to fall within the scope of the invention and the appended claims.

50: tray
51: laser through hole
53: alignment hole
60: vacuum transfer unit
70: lower support
90: mask loading unit
91: depression
95: heating section
100: mask
110: mask film
200: frame
210: border frame portion
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
DM: Dummy, Mask Dummy
ET: raise the temperature of the process region to the first temperature
L: laser
LT: Lower the temperature of the process area to the second temperature
R: Hollow area of the border frame portion
P: mask pattern
TS: tension
VH: vacuum hole
W: welding
WB: welding bead

Claims (37)

A transfer system of a mask for forming an OLED pixel for integrally forming a mask and a frame supporting the mask,
A mask loading unit capable of sucking and loading one surface of the mask; And
A tray supporting the other side of the mask and corresponding the mask to a frame;
Including, the transfer system of the mask. The method of claim 1,
The mask loading portion has a flat plate shape, and a plurality of vacuum holes are formed on one surface corresponding to the mask. The method of claim 1,
A transport system for a mask, wherein depressions are formed at the edges of the mask loading portion. The method of claim 3,
And at least an edge of the mask protrudes out of the depression when the mask is loaded in the mask loading portion. The method of claim 1,
The mask loading portion comprises a heating portion. The method of claim 1,
A laser transfer hole is formed in the portion of the tray corresponding to the welded portion of the mask. The method of claim 1,
The tray has a flat plate shape, and includes a material having a surface roughness Ra of one surface in contact with the mask of 100 nm or less (greater than 0). The method of claim 7, wherein
The tray is a wafer, the transfer system of the mask. The method of claim 7, wherein
The tray includes a material of any one of glass, silica, heat-resistant glass, quartz, and alumina (Al ₂ O ₃ ). The method of claim 6,
An alignment hole is formed in a portion of the tray corresponding to a portion of at least one of the mask cell and the mask dummy. The method of claim 4, wherein
The tray is formed with a larger area than the mask,
And at least an edge of the tray protrudes out of the depression when the tray is in contact with the mask. A method of manufacturing a frame-integrated mask in which at least one mask and a frame supporting the mask are integrally formed,
(a) providing a frame having at least one mask cell area;
(b) absorbing and loading one surface of the mask into the mask loading unit;
(c) contacting the tray on the other side of the mask and supporting the mask;
(d) loading the tray onto the frame to correspond to the mask cell area of the frame; And
(e) irradiating a laser to the weld of the mask to bond the mask to the frame
Including, a frame-integrated mask manufacturing method. The method of claim 12,
(a) step,
(a1) providing a border frame portion comprising a hollow region;
(a2) connecting the planar mask cell sheet portion to the edge frame portion; And
(a3) forming a frame by forming a plurality of mask cell regions in the mask cell sheet portion;
Including, a frame-integrated mask manufacturing method. The method of claim 12,
(a) step,
(a1) providing a border frame portion comprising a hollow region; And
(a2) manufacturing a frame by connecting a mask cell sheet portion having a plurality of mask cell regions to an edge frame portion;
Including, a frame-integrated mask manufacturing method. The method of claim 12,
The mask loading portion has a flat plate shape, and a plurality of vacuum holes are formed on one surface corresponding to the mask.
In step (b), the mask is applied to one surface of the mask in a plurality of vacuum holes to adsorb the mask on the mask loading portion, the manufacturing method of the frame-integrated mask. The method of claim 15,
(b) step,
(b1) adsorbing at least two sides of the mask to the vacuum conveying unit; And
(b2) moving the vacuum transfer unit to absorb and load one surface of the mask into the mask loading unit;
Including, a frame-integrated mask manufacturing method. The method of claim 16,
in step (b1), or, in step (b2),
The vacuum conveying part pulls out the mask which adsorbed to the outside, and makes a mask flat, The manufacturing method of the frame integrated mask. The method of claim 12,
A depression is formed at the corner of the mask loading portion,
In step (b), when the mask is loaded in the mask loading portion, at least an edge of the mask protrudes out of the depression,
In step (c), when the tray is in contact with the mask at least the edge of the tray protrudes out of the depression, the manufacturing method of the frame-integrated mask. The method of claim 12,
A method of manufacturing a frame-integrated mask, wherein a laser passing hole is formed in a portion of the tray corresponding to the welded portion of the mask. The method of claim 12,
The tray has a flat plate shape, and includes a material having a surface roughness Ra of one surface in contact with the mask of 100 nm or less (greater than 0). The method of claim 20,
The tray is a wafer, the method of manufacturing a frame-integrated mask. The method of claim 20,
The tray comprises a material of any one of glass, silica, heat-resistant glass, quartz, and alumina (Al ₂ O ₃ ). The method of claim 12,
An alignment hole is formed in a portion of a tray corresponding to a portion of at least one of a mask cell and a mask dummy. The method of claim 12,
A plurality of suction holes are formed in the tray, and the suction mask is applied to the suction holes to suck and support the mask. The method of claim 19,
In step (c), at least a portion of the laser pass-through hole on the tray is applied to absorb and support the mask, thereby manufacturing a frame-integrated mask. The method of claim 19,
The laser irradiated from the upper part of a tray passes a laser through hole, and is irradiated to the welding part of a mask, The manufacturing method of the frame integrated mask. The method of claim 12,
A welding bead is formed in a portion of the welded portion to which the laser is irradiated, and the welding bead mediates the mask and the frame to be integrally connected. The method of claim 12,
Before or after the mask corresponds to the mask cell region, the temperature of the process region containing the frame is raised to a first temperature,
A method of manufacturing a frame-integrated mask, wherein the temperature of the process region in which the frame is contained is lowered to a second temperature after the mask is adhered to the frame. The method of claim 28,
Wherein the first temperature is equal to or higher than the OLED pixel deposition process temperature and the second temperature is at least lower than the first temperature. The method of claim 29,
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 ℃ manufacturing method of the frame-integrated mask. The method of claim 12,
A method of manufacturing a frame-integrated mask, wherein no tension is applied to the mask when the mask corresponds to the mask cell region. The method of claim 28,
When the temperature of the process region is lowered to the second temperature, the mask bonded to the frame is contracted so that a tension is applied. The method of claim 28,
The mask loading portion includes a heating portion,
A method of manufacturing a frame-integrated mask, between (b) and (c), wherein the mask is maintained at a temperature of 3 ° C to 10 ° C higher than the first temperature. The method according to claim 13 or 14,
The mask cell sheet portion includes a plurality of mask cell regions in at least one of a first direction and a second direction perpendicular to the first direction. The method according to claim 13 or 14,
The mask cell sheet part,
Border sheet portion; And
A method of manufacturing a frame-integrated mask, comprising at least one first grid sheet portion extending in a first direction and both ends connected to an edge sheet portion. 36. The method of claim 35 wherein
The mask cell sheet part further includes at least one second grid sheet part extending in a second direction perpendicular to the first direction to intersect with the first grid sheet part and both ends connected to the edge sheet part. Method of preparation. The method of claim 12,
The mask and frame are made of any one of invar, super invar, nickel, nickel-cobalt, the manufacturing method of the frame-integrated mask.

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