KR102278606B1 - Mask frame assembly, and apparatus for deposition comprising the same and manufacturing method of organic light emitting display device using the same - Google Patents

Abstract

An embodiment of the present invention includes a frame and a plurality of masks having both ends supported by the frame, each mask having a body portion supported by the frame in an outer region, and spaced apart from each other in the longitudinal direction of each mask and a pattern portion including a plurality of pattern holes through which the deposition material passes and a rib formed between each pattern hole, and the body portion is formed to extend along at least one of both sides of the pattern portion and is disposed to be spaced apart from each other and a step portion concavely formed on at least one surface of a first surface of the body portion formed in a direction in contact with the frame and a second surface opposite to the first surface, wherein the step portion includes a center of gravity of the rib It is formed by etching at least one surface of the first surface and the second surface of the body part as a reference, and the thickness from the center of gravity to the third surface of the stepped part formed on the first surface side of the body part, and the opposite side of the third surface from the center of gravity Disclosed is a mask frame assembly, characterized in that the thickness up to the fourth surface of the step portion is formed to substantially correspond.

Description

A mask frame assembly, a deposition apparatus including the same, and a method of manufacturing an organic light emitting display device using the same

Embodiments of the present invention relate to a mask frame assembly, a deposition apparatus including the same, and a method of manufacturing an organic light emitting display using the same.

In general, among display devices, an organic light emitting diode display has a wide viewing angle, excellent contrast, and a fast response speed.

The organic light emitting display device can realize color by recombination of holes and electrons injected into an anode and a cathode to emit light in a light emitting layer, and has a stacked structure in which a light emitting layer is inserted between an anode and a cathode. However, since it is difficult to obtain high-efficiency light emission with the single structure, an intermediate layer such as an electron injection layer, an electron transport layer, a hole transport layer and a hole injection layer is selectively inserted and used between each electrode and the light emitting layer.

Meanwhile, the electrodes of the organic light emitting diode display and the intermediate layer including the emission layer may be formed by various methods, one of which is a deposition method. In order to manufacture an organic light emitting display device using the deposition method, a fine metal mask (FMM) having the same pattern as a pattern of a thin film to be formed on a substrate is aligned, and the raw material of the thin film is deposited to obtain a desired A thin film of the pattern is formed.

Typically, high resolution VGA masks have very small pattern sizes. Therefore, there should be almost no shading affecting the thickness of the thin film to be deposited. To minimize shading, the mask should be very thin.

When the mask is stretched to one side by reducing the thickness of the mask, wrinkles are generated in the mask. When deposition is performed by aligning the mask with respect to the substrate in a state in which wrinkles are generated, a region that cannot contact the substrate is generated in the mask in which wrinkles are generated. Accordingly, it is impossible to form a precise pattern in the non-contact area.

Typically, the height of the wrinkles is measured to be about 500 to 700 micrometers, and may vary depending on the type of mask, the tensile rate, and the like. The reason wrinkles occur is due to the structural instability of the mask, and in order to form a precise pattern, wrinkles must be removed or minimized. In particular, when a thinly processed mask is stretched, wrinkles are generated at some point and the wrinkles are further increased. It is not easy to accurately predict the onset of wrinkling.

The above-mentioned background art is technical information that the inventor possessed for the derivation of the embodiments of the present invention or acquired in the process of derivation, and it cannot be said that it is necessarily known technology disclosed to the general public prior to filing the embodiments of the present invention none.

SUMMARY Embodiments of the present invention provide a mask frame assembly, a deposition apparatus including the same, and a method of manufacturing an organic light emitting display using the same.

An embodiment of the present invention includes a frame and a plurality of masks having both ends supported by the frame, each mask having a body portion supported by the frame in an outer region, and spaced apart from each other in the longitudinal direction of each mask and a pattern portion including a plurality of pattern holes through which the deposition material passes and a rib formed between each pattern hole, and the body portion is formed to extend along at least one of both sides of the pattern portion and is disposed to be spaced apart from each other and a step portion concavely formed on at least one surface of a first surface of the body portion formed in a direction in contact with the frame and a second surface opposite to the first surface, wherein the step portion includes a center of gravity of the rib It is formed by etching at least one surface of the first surface and the second surface of the body part as a reference, and the thickness from the center of gravity to the third surface of the stepped part formed on the first surface side of the body part, and the opposite side of the third surface from the center of gravity Disclosed is a mask frame assembly, characterized in that the thickness up to the fourth surface of the step portion is formed to substantially correspond.

In this embodiment, the rib has a fifth surface formed on the first surface side of the body portion, and a sixth surface opposite to the fifth surface is formed, and the fifth surface is formed longer than the length of the sixth surface. can be done with

In this embodiment, the step portion may be characterized in that the second surface of the body portion is etched.

로 하고, 단차부의 제3 면으로부터 제4 면 까지의 두께는 제1 두께의 두배로 형성되는 것을 특징으로 할 수 있다.In this embodiment, when a is the length of the fifth surface of the rib, b is the length of the sixth surface of the rib, and t is the thickness of the rib, from the center of gravity expressed as a function of these to the fifth surface The first thickness t ₁ of [Equation 1]

and the thickness from the third surface to the fourth surface of the step portion may be characterized in that it is formed to be twice the first thickness.

In this embodiment, the step portion may be characterized in that the body portion is formed by etching the first surface and the second surface.

로 하고, 단차부의 제3 면으로부터 제4 면까지의 두께는 제2 두께로 형성되는 것을 특징으로 할 수 있다.In this embodiment, when a is the length of the fifth surface side of the rib, b is the length of the sixth surface side of the rib, and t is the thickness of the rib, the second thickness t ₂ expressed as a function of these is [ Equation 2]

And, the thickness from the third surface to the fourth surface of the step portion may be characterized in that it is formed as a second thickness.

Another embodiment of the present invention includes an evaporation source, a mask frame assembly disposed on one surface of a substrate facing the evaporation source, and a magnet plate disposed on the other surface of the substrate opposite to the first surface to magnetically attach the mask frame assembly to the machine. and a mask frame assembly including a frame and a plurality of masks having both ends supported by the frame, each mask being spaced apart from each other in a longitudinal direction of each mask with a body portion having an outer region supported by the frame and a pattern portion including a plurality of pattern holes through which the deposition material passes and a rib formed between each pattern hole, and the body portion is formed to extend along at least one of both sides of the pattern portion and is disposed to be spaced apart from each other and a step portion concavely formed on at least one surface of a first surface of the body portion formed in a direction in contact with the frame and a second surface opposite to the first surface, wherein the step portion includes a center of gravity of the rib It is formed by etching at least one surface of the first surface and the second surface of the body part as a reference, and the thickness from the center of gravity to the third surface of the stepped part formed on the first surface side of the body part, and the opposite side of the third surface from the center of gravity Disclosed is a deposition apparatus characterized in that the thickness up to the fourth surface of the step portion is formed to substantially correspond to each other.

In this embodiment, it may further include a pressure plate positioned between the substrate and the magnet plate to press the substrate.

In this embodiment, the rib has a fifth surface formed on the first surface side of the body portion, and a sixth surface opposite to the fifth surface is formed, and the fifth surface is formed longer than the length of the sixth surface. can be done with

In this embodiment, the step portion may be characterized in that the second surface of the body portion is etched.

로 하고, 단차부의 제3 면으로부터 제4 면 까지의 두께는 제1 두께의 두배로 형성되는 것을 특징으로 할 수 있다.In this embodiment, when a is the length of the fifth surface of the rib, b is the length of the sixth surface of the rib, and t is the thickness of the rib, from the center of gravity expressed as a function of these to the fifth surface The first thickness t ₁ of [Equation 1]

and the thickness from the third surface to the fourth surface of the step portion may be characterized in that it is formed to be twice the first thickness.

In this embodiment, the step portion may be characterized in that the body portion is formed by etching the first surface and the second surface.

로 하고, 단차부의 제3 면으로부터 제4 면까지의 두께는 제2 두께로 형성되는 것을 특징으로 할 수 있다.In this embodiment, when a is the length of the fifth surface side of the rib, b is the length of the sixth surface side of the rib, and t is the thickness of the rib, the second thickness t ₂ expressed as a function of these is [ Equation 2]

And, the thickness from the third surface to the fourth surface of the step portion may be characterized in that it is formed as a second thickness.

Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to the exemplary embodiment of the present invention made as described above, it is possible to implement a mask frame assembly capable of minimizing deformation of a mask that occurs when the mask is stretched, a deposition apparatus including the same, and a method of manufacturing an organic light emitting display device using the same. Of course, the scope of the present invention is not limited by these effects.

1 is a perspective view illustrating a mask frame assembly according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II of FIG. 1 .
3A is an enlarged cross-sectional view showing an enlarged portion A of FIG. 2 .
3B is an enlarged cross-sectional view showing an enlarged portion B of FIG. 2 .
4 is a perspective view illustrating a modified example of the mask shown in FIG. 1 .
FIG. 5 is a cross-sectional view taken along line II-II of FIG. 4 .
6 is an enlarged cross-sectional view showing an enlarged portion C of FIG. 5 .
7A is a cross-sectional view illustrating a state before the step portion is formed in the body portion of FIG. 1 .
7B is a cross-sectional view illustrating a state in which the first surface side of the step portion of FIG. 1 is half-etched.
7C is a cross-sectional view illustrating a state in which the second surface side of the step portion of FIG. 1 is half-etched.
FIG. 7D is a cross-sectional view illustrating the step portion of FIG. 1 .
7E is a cross-sectional view illustrating the step portion of FIG. 4 .
8 is a conceptual diagram schematically illustrating a deposition apparatus including a mask frame assembly according to embodiments of the present invention.
FIG. 9 is a diagram illustrating an organic light emitting diode display manufactured by using the deposition apparatus shown in FIG. 8 .

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and a method of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

In the following embodiments, terms such as first, second, etc. are used for the purpose of distinguishing one component from another, not in a limiting sense. Also, the singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, terms such as include or have means that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components will be added.

In addition, in the drawings, the size of the components may be exaggerated or reduced for convenience of description. For example, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In addition, when certain embodiments are otherwise practicable, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order opposite to the order described.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. .

1 is a perspective view showing a mask frame assembly 10 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1 .

1 and 2 , the mask frame assembly 10 includes a frame 100 and a mask 200 .

The frame 100 is disposed to be spaced apart from each other in the x-axis direction, and the first support part 101 and the second support part 102 are disposed parallel to each other, and are disposed to be spaced apart from each other in the y-axis direction and disposed parallel to each other. It includes a third support 103 and a fourth support 104 . The first support part 101 and the second support part 102 are connected to each other with the third support part 103 and the fourth support part 104 to form an outer frame of the mask frame assembly 10, FIG. 1 shows It is formed to have one opening 105 in a square shape in the center, but embodiments of the present invention are not limited thereto, and for example, it may be formed in various shapes of a circle, an ellipse, and a polygon. In addition, the frame 100 may be made of metal or synthetic resin.

Meanwhile, the third support part 103 and the fourth support part 104 are installed in a direction parallel to each mask 200 , and are preferably formed of a material having an elastic force, but are not necessarily limited thereto.

Since the frame 100 is supported in a state in which the plurality of masks 200 are tensioned, it must have sufficient rigidity. In addition, the frame 100 is not limited to any one structure as long as it does not interfere when the mask 200 is in close contact with the substrate (see 500 of FIG. 9 ) on which the deposition material is deposited in a subsequent deposition process.

The mask 200 is a stick-type mask divided into a plurality of parts, the body portion 210 having an outer region supported by the frame 100 and the body portion 210 being spaced apart from each other in the longitudinal direction of each mask 200 , and depositing material It includes a plurality of pattern holes 221 passing through, and a pattern portion 220 including a rib 222 formed between each pattern hole 221 , and both ends thereof may be welded to the frame 100 . .

The mask 200 is a magnetic thin film, and may be formed of nickel or a nickel alloy. Preferably, it may be formed of a nickel-cobalt alloy that is easy to form a fine pattern and has excellent surface roughness.

In addition, the mask 200 may be manufactured by an etching method. A photoresist layer having the same pattern as each pattern hole 221 is formed on a thin plate using a photoresist, or a photoresist layer having the same pattern as each pattern hole 221 is formed on a thin plate. It can be produced by attaching a film with a pattern to the thin plate and then etching the thin plate. Also, the mask 200 may be formed by electroforming.

Although not shown in the drawing, the mask 200 may be formed of one large member, but in that case, the sagging phenomenon due to its own weight may be severe, so as shown in the drawing, the mask 200 is manufactured by dividing the mask into a plurality of stick-type masks. In addition, although one mask 200 is disassembled and illustrated in FIG. 1 for convenience of description, the plurality of masks 200 may be disposed to cover all of the openings 105 after the actual manufacturing is completed.

Each mask 200 has a body portion 210 and a pattern portion 220 formed as described above, and clamping portions (not shown) are also provided at both ends of the mask 200 before welding. Meanwhile, as a welding method, there are generally various methods such as laser welding and resistance heating welding, and in addition, methods such as electroforming and electroless plating may be used.

When the mask 200 is welded to the frame 100, the mask 200 is pulled taut in the longitudinal direction (x-axis direction in FIG. 1) of the mask 200, tensioned, and then welded. The clamping portion may be a portion provided at both ends of the mask 200 to grip when pulling. These clamps are cut off after welding is complete.

The body portion 210 is a region in which deposition does not occur because there is no pattern hole 221 . The body portion 210 is not a region directly contributing to deposition, but basically serves to maintain the rigidity of the mask 200 . That is, since a plurality of pattern holes 221 are formed in the pattern part 220 , the rigidity is relatively weak. Accordingly, the body portion 210 is formed to be thicker than the pattern portion 220 in order to secure rigidity enough to prevent the mask 200 from sagging or bending easily.

The pattern part 220 is a region in which a plurality of pattern holes 221 are formed. During the deposition process, the deposition material passes through the pattern holes 221 and is applied to the substrate (refer to 500 in FIG. 9 ) in close contact with the mask 200 . A thin film layer is formed. The pattern portions 220 may be disposed to be spaced apart from each other along the length direction of the mask 200 , and ribs 222 are formed between the plurality of pattern holes 221 formed in the pattern portion 220 .

As described above, when the body portion 210 and the pattern portion 220 are formed to have different thicknesses, a step of a predetermined height may be formed at the interface between the body portion 210 and the pattern portion 220 . In such a step, when the mask 200 for welding the frame 100 and the mask 200 is stretched, stress is concentrated in a portion having the step, which may become a weak area in which wrinkles occur.

In order to compensate and prevent the deformation of the mask 200 that occurs when the mask 200 is stretched, the body portion 210 is provided with a concave stepped portion 211 having a predetermined depth. These step portions 211 are formed to extend along at least one of both sides of the pattern portion 220 and are disposed to be spaced apart from each other. 2 is a step difference between the first surface 210a of the body portion 210 formed in the direction in contact with the frame 100 and the second surface 210b of the second surface 210b opposite to the first surface 210a. Although the portion 211 is shown to be formed, the present invention is not limited thereto and may be formed on at least one of the first surface 210a and the second surface 210b.

Hereinafter, the step portion 211 will be described in detail with reference to FIGS. 3A and 3B .

3A is an enlarged cross-sectional view showing an enlarged portion A of FIG. 2 , and FIG. 3B is an enlarged cross-sectional view illustrating an enlarged portion B of FIG. 2 .

First, referring to FIG. 3A , the step portion 211 may include a first concave groove 211B formed by etching the second surface 210b of the body portion 210 by a predetermined depth. Here, the depth of the first concave groove 211B may be determined as follows.

Referring to FIG. 3B , the ribs 222 may be formed in a parallelogram shape. The rib 222 may have a fifth surface 222a formed on the first surface 210a side of the body 210 and a sixth surface 222b opposite to the fifth surface 222a may be formed. In this case, the fifth surface 222a of the rib 222 may be formed to be longer than the sixth surface 222b (a>b).

Here, reference symbol a denotes the length of the fifth surface 222a, reference symbol b denotes the length of the sixth surface 222b, and reference symbol t denotes the thickness of the rib 222. In addition, the center of gravity of the reference symbol t _a and t _b is the thickness (t _a) to a fifth surface (222a) of the ribs 222 at the center of gravity (G) of the ribs 222, respectively, and rib 222 ( It means _{the thickness t b} from G) to the sixth surface 222b of the rib 222 . Accordingly, the thickness t of the rib is the sum of t _a and t _b .

_{Here, if the thickness t a} from the center of gravity G of the rib 222 to the fifth surface 222a is a first thickness t ₁ , the first thickness t ₁ is obtained by the following equation 1 can be obtained.

[Equation 1]

_{Referring back to FIG. 3A , the point having the first thickness t 1} from the first surface 210a of the body 210 becomes the central axis OA of the step 211 . Then, the etching process is performed _{from the central axis OA to a point separated by the first thickness t 1} in the direction of the second surface 210b of the body 210 . Then, the space between the second surface 210b of the body portion 210 and the fourth surface 211b of the stepped portion 211 becomes the depth of the first concave groove 211B. In addition, the first surface 210a of the body portion 210 that is not etched becomes the third surface 211a of the stepped portion 211 .

When the first concave groove 211B is formed by etching the second surface 210b of the body portion 210 as described above, the first surface of the body portion 210 from the center of gravity G of the rib 222 . The thickness up to the third surface 211a of the step portion 211 formed on the side (210a) and the fourth surface 211b opposite to the third surface 211a from the center of gravity G of the rib 222 It is formed so that the thickness up to and substantially corresponds to _{the first thickness t 1 .}

_{When the step portion 211 is formed to have a first thickness t 1} symmetrical with respect to the central axis OA of the step portion 211 in this way, the center of gravity G of the rib 222 and the step portion ( The central axis OA of the 211 may be formed at substantially the same height.

The reason for determining the thickness and depth of the step portion 211 and the first concave portion 211B formed in the step portion 211 as described above is that the center of gravity of the body portion 210 and the pattern portion 220 is as close as possible. This is to minimize deformation of the mask 200 that occurs when the mask 200 is stretched.

In detail, since the pattern part 220 is composed of the pattern hole 221 , which is an empty space, and the rib 222 , which is the main body of the mask 200 formed between the pattern hole 221 , the center of gravity of the pattern part 220 . is not located on the central plane of the rib 222 . Instead, as described above, since only the rib 222 generally formed in a parallelogram shape is used to calculate the center of gravity of the pattern part 220, the center of gravity of the pattern part 220 is the rib as shown in FIG. 3B. It is positioned substantially the same as the center of gravity (G) of (222).

On the other hand, in the case of the body portion 210 without the pattern hole 221 , the center of gravity is located on the central axis of the body portion 210 . As described above, in general, when the concave portion 211B is not formed, the center of gravity of the body portion 210 is the middle point of the body portion 210, and the center of gravity G of the rib 222 is relatively long. Considering that it is formed closer to the side of the fifth surface 222a, which is a surface, the center of gravity of the body portion 210 is located higher than the center of gravity (G) of the rib 222 . Therefore, in order to arrange the center of gravity of the body portion 210 and the rib 222 to be as close as possible to each other, a method of lowering the center of gravity of the body portion 210 by etching the second surface 210b of the body portion 210 is used. can

Accordingly, the method of etching the second surface 210b of the body portion 210 so that the central axis OA of the step portion 211 is adjacent to the axis on which the center of gravity G of the rib 222 is located. By using , it is possible to prevent deformation of the mask 200 that occurs when the mask 200 is stretched. This effect has been experimentally proven, and specific values will be described later.

4 is a perspective view illustrating a modified example of the mask shown in FIG. 1 , and FIG. 5 is a cross-sectional view taken along line II-II of FIG. 4 .

4 and 5 , a body part 310 and a pattern part 320 may be formed in the mask 300 . The body portion 310 may include a step portion 311 formed by etching the first surface 310a and the second surface 310b of the body portion. And a first concave groove 311A and a second concave groove 311B may be formed in the stepped portion 311, and in detail, the groove 311A is on the third surface 311a side of the stepped portion 311, The second concave groove 311B may be formed on the side of the fourth surface 311b of the step portion 311 .

Hereinafter, since the mask 300 shown in FIGS. 4 and 5 shows the configuration and function corresponding to the mask 200 of the mask frame assembly 10 according to an embodiment of the present invention, a detailed description thereof is omitted here. or to be abbreviated.

Next, with reference to FIG. 6 , the step portion 311 will be described in detail.

6 is an enlarged cross-sectional view showing an enlarged portion C of FIG. 5 .

Referring to FIG. 6 , the stepped portion 311 includes a second concave groove 311A formed by etching the first surface 310a of the body portion 210 by a predetermined depth, and the second surface of the body portion 210 . The third concave groove 311B may be formed by etching the 310b by a predetermined depth. Here, the second depth (T _a and T _b) of the groove (311A) and the third groove (311B) may be defined as follows:

The thickness of the stepped portion 311 from the third surface 311a to the fourth surface 311b of the stepped portion with respect to the central axis OB may be formed as _{a second thickness t 2 .} Here, the central axis OB of the step portion 311 is located at the same height as the center of gravity G of the rib 222 shown in FIG. 3B . Meanwhile, the second thickness t ₂ is a value obtained by dividing the total volume of the pattern part 320 by the total area of the pattern part 320 , and may be obtained by the following Equation 2 with reference to FIG. 3B .

[Equation 2]

As described above, reference numeral a denotes the length of the fifth surface 322a of the pattern part 320, and reference numeral b denotes the length of the sixth surface 322b of the pattern part 320, see The symbol t denotes the thickness of the rib 322 .

Thus, the second depth of the groove (311A), (T _a) has a thickness (t _a) to the first surface (310a) of the body portion 310 in the center axis (OB) of the step portion 311, a second The thickness t ₂ becomes a difference value from the half length, and the depth T _b of the third concave groove 311B is the second surface of the body 310 at the central axis OB of the step 311 . It becomes a difference value between the half length _{of the thickness t b} up to (310b) and the second thickness t _{2 .}

When the first surface 310a and the second surface 310b of the body portion 310 are etched to form the second concave groove 311A and the third concave groove 311B, the thickness of the step portion 311 is may be formed with a second thickness t _{2 .}

Next, the results of the deformation of the masks 200 and 300 according to the experiment are as follows.

7A is a cross-sectional view illustrating a state before the stepped portion 211 is formed in the body portion 210 of FIG. 1 , and FIG. 7B is a half-etched side of the first surface 211a of the stepped portion 211 of FIG. 1 . (half-etched) is a cross-sectional view, FIG. 7c is a cross-sectional view showing a half-etched state of the second surface 211b side of the stepped portion 211 of FIG. 1, and FIG. 7D is a cross-sectional view of FIG. It is a cross-sectional view showing the step portion 211 , and FIG. 7E is a cross-sectional view illustrating the step portion 311 of FIG. 4 .

Here, it is assumed that the upper surface and the lower surface shown in FIGS. 7A to 7E are an upper surface and a surface located in a direction away from the substrate as a lower surface in a direction facing the substrate (see 500 in FIG. 9 ).

And Table 1 below shows that when a tensile force is applied in the longitudinal direction of the mask frame assembly (not shown) including the step portions 11a, 11b, 11c, 11d, and 11e of FIGS. 7A to 7E, the substrate (500 in FIG. 9) _{Reference) and a table showing the change amount (t max} ) of the mask (not shown) in a direction away from it, the change _{amount (t min} ) of the mask in the direction facing the substrate, and the difference therebetween. Here, the larger the difference between the respective variations, the larger the deformation of the mask is, and the unit of each numerical value in Table 1 is mm.

<Table 1>

Referring to Table 1 and FIG. 7A , in the case of the mask frame assembly in which the step portions 11a , 11b , 11c , 11d and 11e are not formed, the amount of change t _max in the direction away from the substrate and the direction facing the substrate The difference in the amount of change (t _min ) is 0.2309 mm. And, in the case of the upper surface half etching shown in FIG. 7B, the difference in the amount of change is about 0.018 mm. In addition, in the case of the lower surface half etching shown in FIG. 7C, the difference in the amount of change is about 0.01 mm. Comparing FIGS. 7B and 7C, the step portion is processed by half etching on the lower surface located in the direction away from the substrate than the upper surface facing the substrate It can be seen that this further reduces the deformation of the mask.

Next, the step portion 11d shown in FIG. 7D is an example of applying the method of forming the step portion 211 according to an embodiment of the present invention using Equation 1 above. In addition, the step portion 11e shown in FIG. 7E is another example in which the method of forming the step portion 311 according to another embodiment of the present invention is applied using Equation 2 above.

It can be seen that when the step portions 11d and 11e shown in FIGS. 7D and 7E are formed on the mask, the deformation of the mask can be further reduced compared to the methods shown in FIGS. 7A to 7C (each about 0.0094 mm, about 0.0094 mm, about 0.0077mm). Furthermore, it can be seen that the most effective method can reduce the deformation of the mask when both the upper and lower surfaces of the stepped portion 11e are etched by applying Equation 2 as shown in 7e.

Thus, according to the mask frame assemblies 10 and 20 according to the embodiments of the present invention, deformation of the mask 200 due to the tension of the masks 200 and 300 during welding of the frame 100 and the masks 200 and 300 is reduced. This can be minimized, and further, by improving the precision of the deposition material deposited on the display panel (not shown), effects such as improvement in yield of the display device (not shown) and reduction of defective products can be obtained.

8 is a conceptual diagram schematically illustrating a deposition apparatus including a mask frame assembly according to embodiments of the present invention.

Referring to FIG. 8 , the deposition apparatus 20 is disposed on one surface of the deposition source 400 , which radiates a deposition material toward the substrate 500 in the chamber 50 , and the substrate 500 facing the deposition source 400 . It may include a mask frame assembly 10 to be used, and a magnet plate 600 disposed on the other side of the substrate 500 opposite to the one surface to magnetically adhere the mask frame assembly 10 to the substrate 500 . .

In addition, the deposition apparatus 20 may further include a pressure plate 700 interposed between the substrate 500 and the magnet plate 600 to press the substrate 500 with its own weight. The pressure plate 700 serves to improve the adhesion between the substrate 500 and the mask frame assembly 10 before the magnet plate 600 moves toward the substrate 500 and applies a magnetic force to the mask frame assembly 10 . do.

Meanwhile, although FIG. 8 illustrates that the mask frame assembly 10 according to an embodiment of the present invention is interposed between the deposition source 400 and the substrate 500, the present invention is not limited thereto. Of course, the mask frame assembly 10 according to the example may also be included in the deposition apparatus 20 .

FIG. 9 is a diagram illustrating an organic light emitting diode display manufactured using the deposition apparatus 20 shown in FIG. 8 .

An organic light emitting diode display manufactured by the deposition apparatus 20 including the mask frame assembly 10 will be reviewed with reference to FIGS. 8 and 9 .

Referring to FIG. 8 , the organic light emitting diode display 800 may include a substrate 810 and a display unit (not shown). Also, the organic light emitting diode display 800 may include a thin film encapsulation layer E or an encapsulation substrate (not shown) formed on the display unit. In this case, since the encapsulation substrate is the same as or similar to that used in a general display device, a detailed description thereof will be omitted. In addition, for convenience of description, the organic light emitting diode display 800 will be described in detail below focusing on the case in which the thin film encapsulation layer E is included.

The display unit may be formed on the substrate 810 . In this case, the display unit may include a thin film transistor (TFT), a passivation layer 870 may be formed to cover them, and an organic light emitting diode 880 may be formed on the passivation layer 870 .

In this case, the substrate 810 may use a glass material, but is not necessarily limited thereto, and a plastic material may be used, or a metal material such as SUS or Ti may be used. In addition, the substrate 810 may use polyimide (PI). Hereinafter, for convenience of description, a case in which the substrate 810 is formed of a glass material will be described in detail.

A buffer layer 820 made of an organic compound and/or an inorganic compound is further formed on the upper surface of the substrate 810 , and may be formed of SiOx (x≥1) or SiNx (x≥1).

After the active layer 830 arranged in a predetermined pattern is formed on the buffer layer 820 , the active layer 830 is buried by the gate insulating layer 840 . The active layer 830 has a source region 831 and a drain region 833 , and further includes a channel region 832 therebetween.

The active layer 830 may be formed to contain various materials. For example, the active layer 830 may contain an inorganic semiconductor material such as amorphous silicon or crystalline silicon. As another example, the active layer 830 may contain an oxide semiconductor. As another example, the active layer 830 may contain an organic semiconductor material. However, hereinafter, for convenience of description, a case in which the active layer 830 is formed of amorphous silicon will be described in detail.

The active layer 830 may be formed by forming an amorphous silicon film on the buffer layer 820 , crystallizing it to form a polycrystalline silicon film, and patterning the polycrystalline silicon film. In the active layer 830 , a source region 831 and a drain region 833 of the active layer 830 are doped with impurities, depending on the type of TFT such as a driving TFT (not shown) and a switching TFT (not shown).

A gate electrode 350 corresponding to the active layer 830 and an interlayer insulating layer 860 filling the same are formed on the upper surface of the gate insulating layer 840 .

Then, after forming the contact hole H1 in the interlayer insulating layer 860 and the gate insulating layer 840, the source electrode 871 and the drain electrode 872 are respectively formed on the interlayer insulating layer 860 in the source region ( 831 ) and the drain region 833 .

A passivation layer 870 is formed on the thin film transistor thus formed, and a pixel electrode 881 of an organic light emitting diode (OLED) is formed on the passivation layer 870 . The pixel electrode 881 is contacted to the drain electrode 872 of the TFT by a via hole H2 formed in the passivation film 870 . The passivation film 870 may be formed of an inorganic material and/or an organic material, a single layer, or two or more layers, and may be formed as a planarization film so that the upper surface is flat regardless of the curvature of the lower film, whereas the curvature of the film located below It may be formed so as to be curved along the . In addition, the passivation film 870 is preferably formed of a transparent insulator to achieve a resonance effect.

After the pixel electrode 881 is formed on the passivation film 870 , a pixel defining film 890 is formed of an organic material and/or an inorganic material to cover the pixel electrode 881 and the passivation film 870 , and the pixel The electrode 881 is opened to be exposed.

In addition, an intermediate layer 882 and a counter electrode 883 are formed on at least the pixel electrode 881 .

The pixel electrode 881 functions as an anode electrode and the counter electrode 883 functions as a cathode electrode. Of course, the polarities of the pixel electrode 881 and the counter electrode 883 may be reversed.

The pixel electrode 881 and the counter electrode 883 are insulated from each other by the intermediate layer 882 , and voltages of different polarities are applied to the intermediate layer 882 so that the organic light emitting layer emits light.

The intermediate layer 882 may include an organic light emitting layer. As another optional example, the intermediate layer 882 includes an organic emission layer, in addition to a hole injection layer (HIL), a hole transport layer, and an electron transport layer. and at least one of an electron injection layer.

Meanwhile, one unit pixel P includes a plurality of sub-pixels R, G, and B, and the plurality of sub-pixels R, G, and B may emit light of various colors. For example, the plurality of sub-pixels R, G, and B may include sub-pixels R, G, and B emitting red, green, and blue light, respectively, and red, green, blue, and white light. It may be provided with a sub-pixel (not marked) that emits

Meanwhile, the thin film encapsulation layer (E) as described above may include a plurality of inorganic layers or may include an inorganic layer and an organic layer.

The organic layer of the thin film encapsulation layer (E) is formed of a polymer, preferably a single film or a laminate film formed of any one of polyethylene terephthalate, polyimide, polycarbonate, epoxy, polyethylene, and polyacrylate. More preferably, the organic layer may be formed of polyacrylate, and specifically may include a polymerized monomer composition including a diacrylate-based monomer and a triacrylate-based monomer. The monomer composition may further include a monoacrylate-based monomer. In addition, a known photoinitiator such as TPO may be further included in the monomer composition, but is not limited thereto.

The inorganic layer of the thin film encapsulation layer (E) may be a single film or a laminated film including a metal oxide or a metal nitride. Specifically, the inorganic layer may include any one of SiNx, Al2O3, SiO2, and TiO2.

The uppermost layer exposed to the outside of the thin film encapsulation layer (E) may be formed of an inorganic layer to prevent moisture permeation to the organic light emitting diode.

The thin film encapsulation layer (E) may include at least one sandwich structure in which at least one organic layer is inserted between at least two inorganic layers. As another example, the thin film encapsulation layer (E) may include at least one sandwich structure in which at least one inorganic layer is inserted between at least two organic layers. As another example, the thin film encapsulation layer (E) may include a sandwich structure in which at least one organic layer is inserted between at least two inorganic layers, and a sandwich structure in which at least one inorganic layer is inserted between at least two organic layers. .

The thin film encapsulation layer E may include a first inorganic layer, a first organic layer, and a second inorganic layer sequentially from an upper portion of the organic light emitting diode OLED.

As another example, the thin film encapsulation layer E may include a first inorganic layer, a first organic layer, a second inorganic layer, a second organic layer, and a third inorganic layer sequentially from an upper portion of the organic light emitting diode OLED.

As another example, the thin film encapsulation layer (E) is sequentially formed from an upper portion of the organic light emitting diode (OLED) with a first inorganic layer, a first organic layer, a second inorganic layer, the second organic layer, a third inorganic layer, and a third It may include an organic layer and a fourth inorganic layer.

A metal halide layer including LiF may be further included between the organic light emitting diode (OLED) and the first inorganic layer. The metal halide layer may prevent the organic light emitting diode OLED from being damaged when the first inorganic layer is formed by sputtering.

The first organic layer may have a smaller area than the second inorganic layer, and the second organic layer may also have a smaller area than the third inorganic layer.

As described above, the present invention has been described with reference to one embodiment shown in the drawings, but it will be understood by those skilled in the art that various modifications and variations of the embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10, 20: mask frame assembly 210, 310: body part
30: deposition apparatus 211, 311: step part
50: chamber 220, 320: pattern part
100: frame 221, 321: pattern hole
101: first support 222, 322: rib
102: second support 400: evaporation source
103: third support 500: substrate
104: fourth support 600: magnet plate
105: opening 700: platen
200, 300: mask

Claims (14)

frame; and
Including; a plurality of masks supported by the frame at both ends;
Each mask is
a body portion in which an outer region is supported by the frame;
and a pattern portion disposed to be spaced apart from each other along the longitudinal direction of each mask, and including a plurality of pattern holes through which the deposition material passes, and a rib formed between the respective pattern holes,
The body part,
It extends along at least one side of both sides of the pattern part and is disposed to be spaced apart from each other, and at least one of the first surface of the body part formed in a direction in contact with the frame and the second surface opposite to the first surface is concave on one surface Including a step portion formed to
The step portion,
A thickness from a center of gravity of the rib to a third surface of the step portion formed on the first surface side of the body portion, and a fourth surface of the step portion opposite to the third surface from the center of gravity A mask frame assembly, characterized in that it is formed to correspond to a thickness of up to . According to claim 1,
In the rib,
A fifth surface formed on the first surface side of the body portion and a sixth surface opposite to the fifth surface are formed,
The fifth surface is formed to be longer than the length of the sixth surface, the mask frame assembly. 3. The method of claim 2,
The step portion,
The mask frame assembly, characterized in that formed by etching the second surface of the body portion. 4. The method of claim 3,
When a is the length of the fifth surface side of the rib, b is the length of the sixth surface side of the rib, and t is the thickness of the rib, the fifth surface from the center of gravity expressed as a function thereof The first thickness t ₁ to
[Equation 1]

with
The mask frame assembly, characterized in that the thickness from the third surface to the fourth surface of the step portion is formed to be twice the first thickness. 3. The method of claim 2,
The step portion,
The mask frame assembly, characterized in that formed by etching the first surface and the second surface of the body part. 6. The method of claim 5,
When the length of the fifth surface side of the rib is a, the length of the sixth surface side of the rib is b, and the thickness of the rib is t, the second thickness t _{2 expressed as a function of these}
[Equation 2]

with
A thickness from the third surface to the fourth surface of the step portion is formed to have the second thickness. An evaporation source, a mask frame assembly disposed on one surface of the substrate facing the evaporation source, and a magnet plate disposed on the other surface of the substrate opposite to the first surface to magnetically attach the mask frame assembly to the substrate, ,
The mask frame assembly,
frame; and
Including; a plurality of masks supported by the frame at both ends;
Each mask is
a body portion in which an outer region is supported by the frame;
and a pattern part disposed to be spaced apart from each other along the length direction of each mask, and including a plurality of pattern holes through which the deposition material passes, and a rib formed between each of the pattern holes,
The body part,
It extends along at least one side of both sides of the pattern part and is disposed to be spaced apart from each other, and at least one of the first surface of the body part formed in a direction in contact with the frame and the second surface opposite to the first surface is concave on one surface Including a step portion formed to
The step portion,
A thickness from a center of gravity of the rib to a third surface of the step portion formed on the first surface side of the body portion, and a fourth surface of the step portion opposite to the third surface from the center of gravity Deposition apparatus, characterized in that it is formed to correspond to the thickness up to. 8. The method of claim 7,
The deposition apparatus further comprising a pressure plate positioned between the substrate and the magnet plate to press the substrate. 8. The method of claim 7,
In the rib,
A fifth surface formed on the first surface side of the body portion and a sixth surface opposite to the fifth surface are formed,
The fifth surface is formed to be longer than the length of the sixth surface, the deposition apparatus. 10. The method of claim 9,
The step portion,
The deposition apparatus, characterized in that formed by etching the second surface of the body portion. 11. The method of claim 10,
When a is the length of the fifth surface side of the rib, b is the length of the sixth surface side of the rib, and t is the thickness of the rib, the fifth surface from the center of gravity expressed as a function thereof The first thickness t ₁ to
[Equation 1]

with
The step portion is characterized in that formed by etching the second surface side of the body portion by tt _{1 .} 10. The method of claim 9,
The step portion,
The deposition apparatus, characterized in that formed by etching the first surface and the second surface of the body portion. 13. The method of claim 12,
When the length of the fifth surface side of the rib is a, the length of the sixth surface side of the rib is b, and the thickness of the rib is t, the second thickness t _{2 expressed as a function of these}
[Equation 2]

with
A thickness from the third surface to the fourth surface of the step portion is formed as the second thickness. A method of manufacturing an organic light emitting diode display including first and second electrodes facing each other on a substrate and an organic layer provided between the first and second electrodes, the method comprising:
The method of manufacturing an organic light emitting display device, wherein the organic layer or the second electrode is formed by deposition using the deposition apparatus of any one of claims 7 to 12.

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