KR102427523B1 - Mask assembly for large area OLED deposition with minimal step difference - Google Patents

Abstract

The present invention relates to a mask assembly for OLED deposition. The mask assembly for OLED deposition according to the present invention is applied to large-area displays of 5.5 generations (1,300 × 1,500 mm) or more, which can only be manufactured as a divided mask assembly, not a mother-of-pearl. In the mask assembly for OLED deposition, by minimizing a height error due to a step at an intersection where a plurality of mask sticks cross each other to effectively prevent the separation between a substrate and a mask sheet portion formed by the intersection of the plurality of mask sticks, it is possible to improve the deposition accuracy of a deposition target. The mask assembly for OLED deposition according to the present invention is a segmented mask assembly used for manufacturing a large-area OLED panel exceeding the maximum size width of the currently supplied invar alloy metal sheet principal. As the present invention effectively prevents the gap problem and lifting phenomenon, the present invention is specifically suitable for manufacturing large-area displays of 5.5 generations (1,300 × 1,500 mm) or more, for example, 8 generations or more.

Description

Mask assembly for large area OLED deposition with minimal step difference

The present invention relates to a mask assembly for deposition of a large area OLED with a minimized step difference.

Commonly known flat panel displays include a liquid crystal display device (LCD) and an organic light emitting display device (OLED). Among them, OLED is a thin film light emitting diode in which a light-emitting layer is made of an organic compound. In a general OLED manufacturing process, when thin film layers such as an electrode layer, an organic light emitting layer, and an insulating film are laminated and patterned, an evaporation process is performed using a mask assembly having a corresponding pattern, respectively.

During the deposition process, an open metal mask (hereinafter referred to as OMM) is used for the process of forming the organic common layer that performs a functional role on the OLED substrate, and red (R), green (G), blue (B) ), a fine metal mask (hereinafter referred to as FMM) is used in the RGB deposition process for depositing each of the three light-emitting pixels.

The mask assembly used in the deposition process has a structure in which a mask sheet or a mask stick, which is a relatively thin metal thin film, is bonded to a mask frame having a relatively strong structure. The mask frame is a frame structure in the form of a window frame or a door frame having a thickness of about 5 to 80 mm, and functions to stably maintain the shape of the mask assembly. On the other hand, the mask sheet or mask stick is formed by forming a predetermined pattern to be used during deposition on a thin metal sheet or strip having a thickness of about 0.01 to 5.00 mm.

A general mask assembly is manufactured using a metal having a very small coefficient of thermal expansion according to temperature change, such as, for example, Invar-36 Alloy. Furthermore, when the precision of the pattern is not greatly required, the mask frame may be manufactured using, for example, heat-resistant stainless steel such as SUS420 in order to reduce costs. As an example, the open metal mask (OMM) assembly used in the OLED display organic common layer deposition process is to coat a dry photosensitive film (DFR) on both sides of a mask sheet, perform UV exposure, and then develop and wet etching (Wet Etching). After forming a pattern on the mask sheet through a process such as ), it can be manufactured by bonding to the mask frame in a tensioned state by laser welding.

In a situation where the demand for large-area OLED panels ranging from 6th to 8th generation today is greatly increasing, the maximum size of the Invar alloy mask sheet ledger currently supplied is only about 1,100 mm wide, Since it is almost impossible to manufacture a mask assembly for a large area OLED, it is inevitable to manufacture a mask assembly in the form of a split mask assembly bonded to a mask frame by pulling individual mask sticks.

On the other hand, in the case of a split mask assembly in which a plurality of mask sticks are joined to a mask frame in a form that crosses and crosses the inner space of the mask frame, respectively, and is joined to the mask frame, the height error due to the step at the intersection where the mask sticks intersect is reduced. When the mask assembly comes into contact with the substrate, the mask sheet portion and the substrate are spaced apart, thereby causing a lifting phenomenon, whereby the organic material incident for the common layer formation is introduced into the unwanted portion, resulting in product defect. , or there is a problem that reduces product precision.

The present invention is a mask assembly for OLED deposition applied to a large-area display of 5.5 generations (1,300 × 1,500 mm) or more, which can only be manufactured with a split mask assembly rather than a ledger, at the intersection where a plurality of mask sticks cross each other An object of the present invention is to improve deposition accuracy on a deposition target by effectively preventing a gap between a mask sheet portion formed by the intersection of a plurality of mask sticks and a substrate by minimizing a height error due to a step difference.

In addition, the present invention performs edge etching on the edge of the mask stick corresponding to the edge of the cell opening, and includes a protrusion having a relatively thin thickness compared to the thickness of the mask stick on the outer peripheral surface of the cell opening, thereby reducing the processing time after laser trimming. This is to significantly improve the Cell Position Accuracy (CPA) by enabling more precise trimming and post-processing while shortening it.

The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

In the present specification, the inside of the open frame-shaped mask frame; and a plurality of mask sticks having both ends mounted on the mask frame and intersecting each other, wherein the mask frame and each of the plurality of mask sticks are positioned on the same plane as their top surfaces, providing a mask assembly for OLED deposition do.

The mask frame may be half-etched to form mounting grooves with a thickness equal to or less than a first reference thickness at predetermined positions where both ends of the mask stick are mounted, and both ends of the mask stick are mounted in the mounting grooves.

The mask stick may include: a first stick crossing the inner space of the mask frame; and a second stick that terminates the inner space and intersects the first stick.

The first stick and the second stick may be half-etched at intersections that cross each other so as to be superimposed on each other, and the sum of the half-etching depths of each of the sticks crossing at the intersection may have the same value as the first reference thickness.

The first stick and the second stick may be coupled to each other by laser welding at intersections that cross each other so as to be superimposed on each other.

The mask stick may be stretched to a predetermined width or length so that both ends are mounted on the mask frame and positioned properly.

The inner space of the mask frame is divided into a plurality of cells due to the plurality of mask sticks intersecting each other, and the edge of the mask stick corresponding to the edge of the partitioned cell opening has a second reference thickness smaller than the first reference thickness. it may be

The protrusion formed by the edge etching may have a thickness less than or equal to a second reference thickness, and the second reference thickness may be in a range of 15 to 35 μm.

The end of the protruding piece may be processed after laser trimming.

The mask stick or mask frame may be made of Invar-36 Alloy or stainless steel (SUS420).

The mask assembly may be a split mask assembly applied to a large-area display of 1,300 × 1,500 mm (5.5 generations) or more.

The mask assembly for OLED deposition according to the present invention is a mask assembly for OLED deposition applied to a large-area display of 5.5 generations (1,300 × 1,500 mm) or more, which can only be manufactured by a split mask assembly, not a director, a plurality of mask sticks By minimizing a height error due to a step difference at the intersecting portion, effectively preventing the mask sheet portion formed by the intersection of a plurality of mask sticks from being spaced apart from the substrate, deposition accuracy on the deposition target can be improved.

In addition, in the present invention, edge etching is performed on the edge portion of the mask stick corresponding to the edge of the cell opening, and a protrusion having a relatively thin thickness compared to the thickness of the mask stick is included on the outer peripheral surface of the cell opening, so that the laser trimming post-processing time It enables more precise trimming and post-processing while shortening the length of the process, significantly improving the cell position accuracy (CPA).

Accordingly, the mask assembly for OLED deposition according to the present invention effectively prevents the step problem and the lifting phenomenon in the split mask assembly used for manufacturing a large-area OLED panel exceeding the maximum size width of the currently supplied Invar alloy metal sheet ledger. Therefore, it is particularly suitable for the manufacture of large-area displays of 5.5 generations (1,300 × 1,500 mm) or more, for example, 8 generations or more.

1 is a plan view showing a mask assembly for OLED deposition according to the prior art.
2 is a plan view illustrating a mask assembly for OLED deposition according to an embodiment of the present invention.
3 is a perspective view three-dimensionally illustrating a mask assembly for OLED deposition according to an embodiment of the present invention.
4 is a view showing the assembly of the mask stick of the mask assembly for OLED deposition according to an embodiment of the present invention.
5 is a view showing the configuration of the cross section of the mask stick of the mask assembly for OLED deposition according to an embodiment of the present invention.
6 is a view showing that the mask stick of the mask assembly for OLED deposition according to an embodiment of the present invention is interposed in the mounting groove of the mask frame.
7 is a cross-sectional view illustrating edge etching of the mask assembly for OLED deposition according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments disclosed below.

Hereinafter, with reference to the drawings, the mask assembly 10 for depositing a large area OLED with a minimized step difference according to the present invention will be described in more detail.

mask assembly (10)

The mask assembly 10 for OLED deposition according to an embodiment of the present invention includes a mask frame 200 having a frame shape having an open inside; and a plurality of mask sticks 100 having both ends mounted on the mask frame 200 and intersecting each other, wherein each of the mask frame 200 and the plurality of mask sticks 100 has an upper surface on the same plane. It may be positioned directly in

For example, the mask assembly 10 for OLED deposition of the present invention is an auxiliary metal mask for supporting a fine metal mask (FMM) when manufacturing an OLED display for mobile use, and an open metal mask for forming an organic common layer. It can be applied to all CVD masks used in Metal Mask, OMM) and encapsulation processes. In particular, it can be applied to an open metal mask for forming a common organic layer when manufacturing a large-area OLED display for TV.

2 to 4 , the mask frame 200 of the present invention is configured to allow the mask stick 100 to be properly seated and maintain its shape.

Specifically, the mask frame 200 may have a frame structure in the form of a window frame or a door frame having a thickness of about 5 to 80 mm to which the tensioned mask stick 100 is bonded, and may have a shape of the mask assembly 10 . It functions to keep it stable. The mask frame 200 may be provided in various frame shapes, but may be generally provided in a rectangular or rectangular shape, and a rectangular shape will be described herein.

In addition, the mask frame 200 is provided in a frame shape with an opening inside so that an organic material can pass between the mask sticks 100 from an evaporation source and be deposited on a substrate after a plurality of mask sticks 100 are cross-bonded. can be In detail, the mask frame 200 has an opening inside, and is partitioned into a plurality of cells due to a plurality of mask sticks 100 to be described later, and each partitioned cell C is displayed on one display for each partitioned cell. can respond. The divided plurality of cells C may have a circular or polygonal shape, but is not particularly limited and may have a shape corresponding to a finally completed display shape. Meanwhile, the mask frame 200 may be made of Invar-36 Alloy or stainless steel (SUS420).

The mask frame according to an embodiment of the present invention is half-etched to form mounting grooves with a thickness equal to or less than a first reference thickness at predetermined positions where both ends of a mask stick, which will be described later, are mounted, and both ends of the mask stick are mounted on the mounting grooves. It may be mounted in a groove. Meanwhile, an end of the mask stick 100 mounted on (or interposed between) on the mask frame 200 may be fixed to the mask frame through laser welding.

On the other hand, the mask assembly 10 of the present invention is a division mask assembly for application to a large-area display panel of 5.5 generations (1,300 × 1,500 mm) or more, which exceeds the maximum size (width: 1,100 mm) of the currently supplied Invar alloy metal sheet ledger. may be, and for this purpose, it may be manufactured by tensioning a plurality of mask sticks 100 and bonding them on a frame.

2 to 6 , a plurality of mask sticks 100 are mounted on the mask frame 200 and are bonded to the mask frame 200 in an intersecting form to form the cell C and the cell opening 101 . It may be configured to form a mask sheet including.

In detail, the mask stick 100 may be provided in a bar shape, and the mask stick 100 is positioned according to the size, shape, number or arrangement of the deposition target (display) corresponding to the predetermined cell C. can be different For example, the plurality of mask sticks 100 may be provided to cross each other, thereby partitioning the desired cell C. The mask stick 100 may also be made of Invar-36 Alloy or stainless steel (SUS420).

Specifically, the mask stick 100 is a first stick 110 that crosses (W1) the inner space of the mask frame 200, and ends (W2) the inner space and intersects with the first stick 110 . A second stick 120 may be included.

Meanwhile, the first stick 110 and the second stick 120 may be provided to cross each other. In addition, a plurality of first sticks 110 and a plurality of second sticks 120 may be provided, respectively, and in this case, intersections 111 and 121 that are a plurality of intersection points may be formed. That is, the number of intersections of the first stick 110 may be the same as the number of intersections of the second stick 120 . For example, the first stick 110 and the second stick 120 may be formed to be perpendicular to each other. On the other hand, the mask stick 100 including the first stick 110 and the second stick 120 is a mask frame 200 , in detail, both ends are mounted in the above-described mounting groove and welded to the mask frame 200 . may be integrated with In addition, the mask stick 100 may be tensioned through a tensioning process and then bonded to the mask frame 200 . In the tensioning process, only the long side length of the bar-shaped mask stick 100 may be tensioned, or both the long side and the short side width may be tensioned. Therefore, after the assembly is completed, the mounting groove may be formed through half etching to have the first reference thickness RT1 in order to match the level. Meanwhile, the first reference thickness is a value corresponding to the thickness of the mask stick, and in detail, may be the thickness of the mask stick after being stretched. Due to the mounting groove, the mask assembly including the mask frame 200 and the mask stick 100 can maintain a level with the substrate positioned on the upper surface during the deposition process, the mask frame 200 and the plurality of mask sticks 100, respectively. The upper surface of the may be directly positioned on the same plane.

Meanwhile, as described above, the mask stick 100 is provided to have a predetermined first reference thickness RT1. Each of the plurality of mask sticks may be half-etched so that the top surface of the mask stick 100 having the first reference thickness RT1 may be positioned on the same level as the top surface of the mask frame 200 . have.

As previously defined, the mask stick 100 should be positioned so that the upper surfaces of the mask stick 100 and the mask frame 200 are positioned on the same plane (Level). However, when the mask stick 100 is crossed according to the prior art, since the thickness of the mask stick 100 is overlapped at the intersection portion, a step is generated, thereby preventing a lifting phenomenon that is spaced apart from the substrate in the deposition process without being in close contact with the substrate. There is a problem in that the product precision is deteriorated by this.

Specifically, the plurality of mask sticks 100, in detail, the first stick 110 traversing (W1) the inner space of the mask frame 200 and the second stick 120 terminating (W2) the inner space of the mask frame 200 are Steps may occur due to intersections that cross each other. Therefore, in the present invention, even after the first stick 110 and the second stick 120 are crossed to overlap each other, the top surfaces of the first stick 110 , the second stick 120 and the mask frame 200 are on the same plane. The first stick 110 and the second stick 120 may be half-etched at each intersection so as to be positioned in the .

When the first stick 110 and the second stick 120 are orthogonal to each other, the first stick 110 and the second stick 120 are rectangular (when the first stick 110 and the second stick 120 have different widths) or a square (the first stick 110 and the second stick 120 ). If the two sticks 120 have the same width) shape intersections, each intersection is half etched.

In detail, each intersection of the first stick 110 and the second stick 120 is half-etched on the surface where the first stick 110 and the second stick 120 are in contact with each other. In this case, the sum of the depths of the half etching formed at the intersections of the first stick 110 and the second stick 120 is the same as the first reference thickness RT1 of the mask stick 100 or the mounting groove. It is preferable to do this.

To explain with a specific example, when the value of the first reference thickness RT1, which is the thickness of the mask stick 100, is 100, the intersection of the first stick 110 and the second stick 120 is half-etched by 50, respectively. When the first stick 110 and the second stick 120 are superimposed on each other by having a depth (1/2RT1), a cross shape is formed, but the thickness of the intersection is the first reference thickness (RT1) so that it is positioned properly. do. On the other hand, when the intersection of the first stick 110 is half-etched by 40, the intersection of the second stick 120 must be half-etched by 60 in order to be properly positioned.

Thereafter, the intersection portions where the first stick 110 and the second stick 120 intersect each other may be integrally coupled to each other, and may be joined to one another by a method such as laser welding or the like. In addition, since the first stick 110 and the second stick 120 are half-etched at the intersection of each, the step error becomes less than 1 μm, specifically 0.5 μm, when combined with each other, and thus the mask assembly 10 is removed from the substrate. When in contact with the substrate, the lifting phenomenon of the substrate can be effectively prevented.

Mask assembly manufacturing

An additional example according to an embodiment of the present invention will be described.

Meanwhile, the inner space of the mask frame 200 may be divided into a plurality of cells due to the plurality of mask sticks 100 intersecting each other. As described above, one display corresponds to each cell C.

On the other hand, in the deposition process, the substrate to be deposited is positioned on the upper portion of the assembled mask assembly 10 , the deposition source is positioned below the mask assembly 10 , and the organic material OM is the cell ( ) of the mask assembly 10 . C) and passing through the cell opening 101 and depositing on the substrate may be performed. In order to perform the deposition process more precisely, the cell C and the cell opening 101 partitioned by the stretched mask sticks 100 should be formed at predetermined positions.

However, since the mask stick 100 may be deformed or a position error may occur due to the process of tensioning or bonding the mask stick 100 , processing to more precisely control the cell position accuracy may be additionally performed. .

This may be performed by cutting off the edge of the mask stick 100 forming the outer peripheral surface of the cell opening 101 after the mask assembly is manufactured. This process is defined as laser trimming post-processing. After laser trimming, the deposition source can be irradiated to a predetermined cell (C) by removing a part of the edge of the mask stick 100 by irradiating a microwave laser. The post-processing after laser trimming is a microwave laser, and may be performed using processing equipment such as a pico-second laser or a femto-second laser.

On the other hand, when a femtosecond laser is used for the trimming operation, the surface of the workpiece is vaporized in the form of particles without melting, and the processing is completed before heat is transferred to the surroundings. It is possible. Therefore, in the case of using a femtosecond laser, it is possible to perform a fine and sophisticated trimming process without causing any significant damage to the mask stick 100 in the trimming step.

However, as the thickness of the target portion to be laser trimmed increases, a considerable amount of time is required for laser processing. In particular, in the case of the mask assembly 10 having a plurality of cells C, when all the edges of the mask stick 100 have to be laser-trimmed, the time is considerably increased, so that the efficiency of the manufacturing process is lowered.

Therefore, in order to shorten the laser trimming post-processing time, the mask stick 100 having the first reference thickness RT1 has a thickness value smaller than the first reference thickness at the edge of the mask to be subjected to the laser trimming post-processing. To this end, a separate etching process may be additionally performed before laser trimming and post-processing after manufacturing the mask assembly.

In detail, the mask stick 100 is provided with a first reference thickness RT1, and the edge of the mask stick 100 has a second reference thickness having a smaller thickness than the first reference thickness RT1. An etching or half-etching process for forming the edge of the stick 100 to a second reference thickness may be performed, and this is defined as edge etching.

The edge of the mask stick 100 may be the edges of all four sides, but considering the shape mounted on the mask frame 200 , only the edge of the mask stick 100 except for the position mounted on the mask frame 200 . The second reference thickness may be provided, or only the long side edge or part of the long side edge of the mask stick 100 may have the second reference thickness. In addition, at the intersection between the mask sticks 100, edge etching is omitted for the intersection so that the mask stick 100 can be positioned by minimizing the step difference of the intersection, or edge etching is performed in consideration of the crossed shape. can

The edge etching of the mask stick 100 may be performed on the upper surface or the lower surface of the edge of the mask stick 100 , in particular, both the upper surface and the lower surface. When the edge etching is performed on the upper surface, an additional effect of solving the problem of damage or damage to the pattern formed on the substrate due to the mask sheet in contact with the substrate is exhibited. On the other hand, the edge-etched intaglio on the upper surface direction edge of the mask stick 100 is defined as the first groove portion 1010 , and the edge-etched intaglio edge-etched intaglio edge of the mask stick 100 in the lower surface direction is defined as the second groove portion 1020 . do.

On the other hand, a protrusion piece having a shape protruding toward the penetrating portion may be formed through the edge etching process, and the protrusion piece may have a thickness less than or equal to a second reference thickness, and in detail, the second reference thickness is It may range from 15 to 35 μm.

The laser trimming post-processing of the mask stick 100 may be performed after the mask stick 100 is tensioned, bonded to the mask frame 200, and edge etching is performed as described above to provide the protruding piece. On the other hand, since it is difficult to accurately grasp the position value at which laser trimming and post-processing should be performed in advance, in consideration of this, the edge etching of the mask stick 100 may be made to have a relatively wide shape in the width (width) direction. Specifically, the edge etching may make the shape of the cell opening to have a branched shape or a reverse-branched shape.

More specifically, the edge etching may be etched into a branched shape having a larger etch width value than an etching depth value, or a reverse-branching shape having a branched shape when turned over. Accordingly, the first groove portion 1010 is edge-etched on the upper surface of the mask stick 100 to have a branched shape when viewing the cell opening cross-section, and the second groove portion 1020 is edge-etched on the lower surface of the mask to reverse the cell opening cross-section. - It may have a branched shape.

Meanwhile, the first and second grooves may be formed through the following process.

In detail, the first groove portion 1010 is formed by etching the first edge from the top surface of the mask stick 100 to the bottom direction, that is, toward the inside of the mask stick 100 . The first groove portion 1010 may have a first width D1 and a first depth T1, and the first width D1 may be provided in a branched shape having a length greater than the first depth T1. Both end edges of the first width D1 of the first groove portion 1010 may be sufficiently spaced apart in the horizontal direction so as not to interfere with the edge of the thin film layer. The first depth T1 of the first groove portion 1010 may be formed as shallow as possible so that the size of the shadow region to be generated at the edge of the thin film layer can be reduced as much as possible. In detail, the first depth T1 of the first groove portion 1010 may be formed in a range of 10 to 25 μm, or more specifically, in a range of 10 to 20 μm. The first width D1 and the first depth T1 of the first groove portion 1010 may be controlled by adjusting the concentration of the etching solution or the etching time.

The second groove portion 1020 is formed by etching the second edge from the lower surface of the mask stick 100 to the upper surface direction, that is, toward the inside of the mask stick 100 . Since the second groove portion 1020 is formed on the lower surface of the mask stick 100 , which is opposite to the first groove portion 1010 , it is sequentially etched after the first groove portion 1010 is formed or is etched simultaneously with the first groove portion 1010 . can be formed by Meanwhile, the second groove portion 1020 has a second width D2 and a second depth T2, and the second width D2 may be provided with a length greater than the second depth T2, and the second groove portion When the 1020 is turned over, it may have the same branching shape as the first groove portion 1010 (reverse-branching shape). The second width D2 of the second groove portion 1020 has a size sufficient to allow sufficient processing of the protrusion piece 1040 in consideration of the cell position precision during a laser trimming post-processing process to be described later. It can be determined by the width range in which this is formed. In detail, the second depth T2 of the second groove portion 1020 has a predetermined thickness D0 in which the protruding piece 1040 is preset in a predetermined thickness D0 range, so that the time required for the laser trimming post-processing process to be described later can be significantly reduced. For example, it may be determined in consideration of making the thickness range from 15 to 35 μm, specifically, from 20 to 30 μm. For example, when the thickness of the mask sheet is 50 to 200 μm, the second depth T2 of the second groove 1020 may be in the range of 20 to 145 μm. The second width D2 and the second depth T2 of the second groove portion 1020 may be controlled by adjusting the concentration of the etching solution or the etching time, similarly to the first groove portion 1010 .

Meanwhile, the protruding piece 1040 formed through the edge etching may form an outer peripheral surface of the through hole 1030 of the cell opening, and laser trimming may be performed on the end of the protruding piece 1040 .

The thickness D0 of the protruding piece 1040 formed after the edge etching is performed as described above may be in the range of 15 to 35 μm, specifically 20 to 30 μm, and the thickness of the protruding piece 1040 is 20 to 30 In the case of having a thickness range of ㎛, the process time required for post-processing after laser trimming per one cell opening is about 3 to 5 minutes. Compared to the process that takes about 3 to 4 hours, the required time is significantly reduced.

As another example, the width of the protruding piece 1040 may have a width of 700 μm or less, specifically, 150 μm or less. When the protruding piece 1040 has the above width range, a trimming range may be widened, and cell positioning accuracy (CPA) may be improved. On the other hand, when the protruding piece exceeds the above width and thickness ranges, there is a risk that the protruding piece is torn between the cleaning process of the mask sheet and the assembly.

According to an embodiment of the present invention, when the thickness D0 of the protruding piece 1040 is 20 μm and the width is 150 μm, the cell positioning accuracy (CPA) value after the laser trimming post-processing process is the reference value. Since it can be controlled within the range of ± 20 μm, the error range is significantly lowered, so that the precision and edge precision of the display product can be significantly improved.

On the other hand, the through-hole 1030 refers to a portion penetrated through the cell opening, and the width (width) of the through-hole 1030 according to the present invention may correspond to the width (width) range between the mask sticks arranged in parallel. And, as described above, the width (width) of the end portion of the protruding piece formed through edge etching may be expanded according to the degree to which it is processed after laser trimming. Accordingly, since the deformation or position error of the mask stick 100 generated by the process of tensioning or bonding the mask stick 100 can be effectively corrected, the cell position accuracy can be more precisely controlled.

The mask assembly 10 according to the present invention described as described above is a mask assembly for OLED deposition applied to a large-area display of 5.5 generations (1,300 × 1,500 mm) or more, which can only be manufactured by a division mask assembly, not a director, By minimizing the height error due to the step at the intersection where the plurality of mask sticks cross each other, it effectively prevents the mask sheet portion formed by the intersection of the plurality of mask sticks from being spaced apart from the substrate, thereby improving the deposition precision on the deposition target. can

In addition, the present invention performs edge etching on the edge portion of the mask stick corresponding to the edge of the cell opening, and includes a protrusion having a relatively thin thickness compared to the thickness of the mask stick on the outer circumferential surface of the cell opening, so that the laser trimming post-processing time It enables more precise trimming and post-processing while shortening the length of the process, significantly improving the cell position accuracy (CPA).

Accordingly, the mask assembly for OLED deposition according to the present invention effectively prevents the step problem and the lifting phenomenon in the split mask assembly used for manufacturing a large-area OLED panel exceeding the maximum size width of the currently supplied Invar alloy metal sheet ledger. Therefore, it is particularly suitable for the manufacture of large-area displays of 5.5 generations (1,300 × 1,500 mm) or more, for example, 8 generations or more.

In the foregoing, specific embodiments of the present invention have been described and illustrated, but it is common knowledge in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have Accordingly, such modifications or variations should not be individually understood from the technical spirit or point of view of the present invention, and modified embodiments should be said to belong to the claims of the present invention.

10: mask assembly
100: mask stick 101: cell opening
110: first stick 120: second stick
111, 121: intersection
200: mask frame 201: mounting groove
1010: first groove 1020: second groove
1030: through hole
1040: protrusion
RT1: first reference thickness
C: cell space
W1: transverse direction W2: longitudinal direction
Level: flat

Claims (11)

a frame-shaped mask frame with an opening inside; and a plurality of mask sticks having both ends mounted on the mask frame and intersecting each other;
Each of the mask frame and the plurality of mask sticks is positioned on the same plane as the top surface,
The mask stick may include a first stick crossing the inner space of the mask frame; and a second stick that terminates the inner space and intersects the first stick.
The first stick and the second stick are respectively half-etched at intersections that cross each other so as to be superimposed on each other, and the sum of the half-etched depths of each stick has the same value as the first reference thickness,
The inner space of the mask frame is divided into a plurality of cells due to the plurality of mask sticks intersecting each other, and the edge of the mask stick corresponding to the edge of the opening of the partitioned cell has a second reference thickness smaller than the first reference thickness. become,
The protrusion formed by the edge etching has a width of 150 μm or less and a thickness in a range of 15 to 35 μm, an open metal mask assembly for OLED deposition. The method of claim 1,
The mask frame is half-etched to form a mounting groove with a first reference thickness at a predetermined position where both ends of the mask stick are mounted, and both ends of the mask stick are mounted in the mounting groove. metal mask assembly. delete delete The method of claim 1,
The first stick and the second stick are laser-welded at intersections that cross each other so that they are superimposed on each other and are coupled to each other, an open metal mask assembly for OLED deposition. The method of claim 1,
The mask stick is stretched to a predetermined width or length, and both ends are mounted on the mask frame and positioned properly. delete delete The method of claim 1,
An end of the protruding piece is processed after laser trimming, an open metal mask assembly for OLED deposition. The method of claim 1,
The mask stick or mask frame is made of Invar-36 Alloy or stainless steel (SUS420), an open metal mask assembly for OLED deposition. The method of claim 1,
The mask assembly is an open metal mask assembly for OLED deposition, which is a split mask assembly applied to a large-area display of 1,300 × 1,500 mm (5.5 generations) or more.

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