KR102556805B1 - Metal substrate, metal mask for deposition, and oled pannel using the same - Google Patents

Abstract

In the embodiment, in the metal plate used for fabrication of the deposition mask, the metal layer; and a surface layer on the metal layer, wherein the metal plate includes two or more crystal planes having different orientations, and the ratio of {220} crystal planes of the metal plate includes that the metal layer and the surface layer are different from each other.
In the embodiment, in the metal plate used for fabrication of the deposition mask, the metal layer; a first surface layer disposed on one surface of the metal layer; and a second surface layer disposed on the other surface of the metal layer opposite to the one surface, wherein the etching rate of the first surface layer is slower than the etching rate of the metal layer, and the etching rate of the second surface layer is the etching rate of the metal layer. including slower ones.
A deposition mask according to an embodiment includes a metal layer including a metal plate; a first surface layer disposed on one surface of the metal layer; and a second surface layer disposed on the other surface opposite to the one surface, the metal plate including crystal grain boundaries having an average size of 30 μm or less, the metal plate including a plurality of through holes, the first surface layer, the first surface layer, and the first surface layer. 2 surface layer and the metal layer are open in the region where the through hole is disposed, and the etching factor of the through hole calculated by Equation 1 below is 2.0 or more.
<Equation 1>

In the above formula, B is the width of the etched through hole,
A is the width of the photoresist layer,
The C means the depth of the through hole.
In addition, the embodiment includes an OLED panel manufactured with the deposition mask.

Description

Metal plate, mask for deposition and OLED panel using the same {METAL SUBSTRATE, METAL MASK FOR DEPOSITION, AND OLED PANNEL USING THE SAME}

The embodiment relates to a metal plate. In detail, the embodiment relates to a metal plate that can be used for a mask for deposition. In more detail, an OLED panel may be manufactured using the deposition mask according to the embodiment.

As a display device having high resolution and low power is required, various display devices such as a liquid crystal display device or an electroluminescence display device are being developed.

An electroluminescent display device is in the limelight as a next-generation display device due to its superior characteristics, such as low light emission, low power consumption, and high resolution, compared to a liquid crystal display device.

The electric field display device includes an organic light emitting display device and an inorganic light emitting display device. That is, depending on the material of the light emitting layer, organic light emitting display devices and inorganic light emitting display devices can be distinguished.

Among them, the organic light emitting display device is attracting attention in that it has a wide viewing angle, has a fast response speed, and requires low power.

The organic material constituting the light emitting layer may form a pattern for forming a pixel on a substrate using a fine metal mask method.

In this case, the fine metal mask, that is, the deposition mask may have a through hole corresponding to a pattern to be formed on the substrate, and after aligning the fine metal mask on the substrate, depositing an organic material, forming a red pixel. (Red), green (Green), and blue (Blue) patterns can be formed.

A plurality of through holes may be formed in a metal plate that may be used as a deposition mask by an etching process.

At this time, when the plurality of through holes are not uniform, the uniformity of deposition may deteriorate, and as a result, the deposition efficiency of the formed pattern decreases, resulting in a decrease in process efficiency.

An embodiment is to provide a metal plate capable of forming uniform through holes.

In the embodiment, in the metal plate used for fabrication of the deposition mask, the metal layer; and a surface layer on the metal layer, wherein the metal plate includes two or more crystal planes having different orientations, and the ratio of {220} crystal planes of the metal plate includes that the metal layer and the surface layer are different from each other.

In the embodiment, in the metal plate used for fabrication of the deposition mask, the metal layer; a first surface layer disposed on one surface of the metal layer; and a second surface layer disposed on the other surface of the metal layer opposite to the one surface, wherein the etching rate of the first surface layer is slower than the etching rate of the metal layer, and the etching rate of the second surface layer is the etching rate of the metal layer. including slower ones.

A deposition mask according to an embodiment includes a metal layer including a metal plate; a first surface layer disposed on one surface of the metal layer; and a second surface layer disposed on the other surface opposite to the one surface, the metal plate including crystal grain boundaries having an average size of 30 μm or less, the metal plate including a plurality of through holes, the first surface layer, the first surface layer, and the first surface layer. 2 surface layer and the metal layer are open in the region where the through hole is disposed, and the etching factor of the through hole calculated by Equation 1 below is 2.0 or more.

<Equation 1>

In the above formula, B is the width of the etched through hole,

A is the width of the photoresist layer,

The C means the depth of the through hole.

In addition, the embodiment includes an OLED panel manufactured with the deposition mask.

A metal plate according to an embodiment may include a metal layer and a surface layer disposed on the metal layer. In this case, the metal plate may include two or more crystal planes having different orientations.

The surface layer may have different ratios of {220} crystal planes on the surface of the metal layer and the metal plate. That is, by adjusting the ratio of the surface layer and the {220} crystal plane of the metal layer, the etching rate of the surface layer may be slower than that of the metal layer. Accordingly, the metal plate may form uniform through holes.

That is, since the metal plate used to manufacture the deposition mask includes through holes having improved uniformity, the uniformity of the pattern formed therethrough can be improved, and the process efficiency is improved as the deposition efficiency of the pattern is increased. It can be.

In addition, the metal plate according to the embodiment may include crystal grain boundaries having an average size of 30 μm or less. By controlling the size of the grain boundary, it is possible to improve the etching characteristics of the metal plate.

Therefore, the OLED panel fabricated with the deposition mask according to the embodiment has excellent pattern deposition efficiency and improved deposition uniformity.

1 and 2 are conceptual diagrams for explaining a process of depositing an organic material on a substrate.
3 and 4 are views showing a front view of a metal plate.
Fig. 5 is a diagram showing the relationship between the crystal plane orientation and the rolling direction of a metal sheet.
FIG. 6 is a cross-sectional view taken along line A-A' of FIG. 3;
7 to 10 are diagrams illustrating a manufacturing process of a metal plate.
11 and 12 are views showing cross-sectional views in an etching process of an embodiment.
13 is a cross-sectional view in an etching process of a comparative example.
14 is a diagram showing X-ray diffraction intensities of Examples and Comparative Examples.
15 is a graph showing etching rates according to etching depth in Examples and Comparative Examples.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

In the description with reference to the accompanying drawings, the same elements are given the same reference numerals, and redundant description thereof will be omitted.

Terms such as first and second may be used to describe components, but the components are not limited to the above terms and are used only for the purpose of distinguishing one component from another.

In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

In the drawings, the thickness or size of each layer (film), region, pattern, or structure may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

A process of depositing an organic material on a substrate will be described with reference to FIGS. 1 and 2 .

1 is a view illustrating an organic material deposition apparatus including a metal plate 100 as a deposition mask according to an embodiment.

The organic material deposition apparatus may include a metal plate 100 used as a deposition mask, a mask frame 200, a substrate 300, an organic material deposition container 400, and a vacuum chamber 500.

The deposition mask may be the metal plate 100 according to the embodiment. The metal plate 100 may include a plurality of through holes. In this case, the through hole may be formed to correspond to a pattern to be formed on the substrate.

The mask frame 200 may include an opening. A plurality of through holes of the metal plate 100 may be disposed on an area corresponding to the opening. Accordingly, the organic material supplied to the organic material deposition vessel 400 may be deposited on the substrate 300 .

The deposition mask may be disposed on and fixed to the mask frame 200 . For example, the deposition mask may be tensioned and fixed on the mask frame 200 by welding.

The substrate 300 may be a substrate used for manufacturing a display device. Red, green, and blue patterns may be formed on the substrate 300 to form pixels of three primary colors of light.

The organic material deposition vessel 400 may be a crucible. An organic material may be disposed inside the crucible.

As a heat source and/or current are supplied to the crucible in the vacuum chamber 500 , the organic material may be deposited on the substrate 100 .

2 is an enlarged view of one through hole of the metal plate 100 .

The metal plate 100 may include a first surface 101 and a second surface 102 opposite to the first surface.

The first surface 101 of the metal plate 100 may include a first surface hole V1 , and the second surface 102 of the metal plate 100 may include a second surface hole V2 .

The through hole may be formed by a connection portion CA through which the first face hole V1 and the second face hole V2 communicate.

A width of the second face hole V2 may be greater than a width of the first face hole V1. In this case, the width of the first surface hole V1 may be measured on the first surface 101 , and the width of the second surface hole V2 may be measured on the second surface 102 .

The first surface hole V1 may be disposed toward the substrate 300 . Accordingly, the first surface hole V1 may have a shape corresponding to the deposited material D, that is, the pattern.

The second surface hole V2 may be disposed toward the organic material deposition container 400 . Accordingly, the second surface hole V2 can accommodate the organic material supplied from the organic material deposition container 400 in a wide width, and the first surface hole V1 has a smaller width than the second surface hole V2. Through this, it is possible to quickly form a fine pattern on the substrate 300 .

3 and 4 are views showing a front view of the metal plate 100.

The metal plate 100 may include a plurality of through holes. The plurality of through holes shown in FIG. 3 may represent the second surface holes V2. When measuring the diameter (Cx) in the horizontal direction and the diameter (Cy) in the vertical direction of a reference hole, which is any one through hole, each of the horizontal The deviation between the diameters Cx in the direction and the deviation between the diameters Cy in the vertical direction may be 2% to 10%. That is, when the size deviation between adjacent holes of one reference hole is 2% to 10%, the uniformity of deposition can be secured.

For example, a size deviation between the reference hole and the adjacent holes may be 4% to 9%. For example, a size deviation between the reference hole and the adjacent holes may be 5% to 7%.

When the size deviation between the reference hole and the adjacent holes is less than 2%, the rate of occurrence of moiré in the OLED panel after deposition may increase. When the size difference between the reference hole and the adjacent holes exceeds 10%, the rate of occurrence of color unevenness in the OLED panel after deposition may increase.

In an embodiment, a size deviation between the reference hole and the adjacent holes may be implemented within ±3 μm. Accordingly, deposition efficiency may be improved.

For example, referring to FIG. 3 , the through holes may be arranged in a line along a longitudinal axis and arranged in a line along a transverse axis.

For example, referring to FIG. 4 , the through holes may be arranged in a line along a longitudinal axis, and may be alternately arranged along a horizontal axis.

In the through hole, a first diameter measured in a longitudinal direction and a second diameter measured in a transverse direction may correspond to or be different from each other. In the through hole, a third diameter measured in a first diagonal direction corresponding to the cross-sectional direction of A-A' and a fourth diameter measured in a second diagonal direction intersecting the first diagonal direction may correspond to or differ from each other. can The through hole may be round.

Fig. 5 is a diagram showing the relationship between the crystal plane orientation and the rolling direction of a metal sheet.

The metal plate 100 may include a metal material. Most metals are composed of polycrystals. The polycrystals may exhibit a crystal texture having a preferential orientation through a manufacturing process such as rolling, annealing, and heat treatment.

For example, the metal plate 100 may include a nickel alloy. For example, the metal plate 100 may be Invar containing 36% by weight of nickel and 64% by weight of iron. Since the invar nickel alloy has a low coefficient of thermal expansion, the lifetime of the deposition mask can be increased. However, nickel alloys such as Invar have a problem in that uniform etching is difficult.

That is, as the etching rate of a nickel alloy such as invar is high at the initial stage of etching, the through hole may become larger laterally, and thus, the photoresist layer may be delaminated. In addition, when invar is etched, it may be difficult to form finely-sized through-holes as the size of through-holes increases. Also, since the through holes are non-uniformly formed, the manufacturing yield of the deposition mask may decrease.

The first purpose of the embodiment is to slow down the etching rate on the surface of the metal plate 100 .

Face centered cubic invar may have a recrystallized cubic structure by rolling, heat treatment, or the like.

For example, in the case of rolled invar, the recrystallized texture may have a {100} orientation in the rolling direction, that is, in the longitudinal direction of the metal plate. The metal plate 100 may include two or more crystal planes having different orientations. For example, the rolling plane may include {111}, {200} and {220} crystal planes. That is, the surface of the metal plate 100 may include {111}, {200}, and {220} crystal planes.

The recrystallized texture may have different etching characteristics depending on the ratio of crystal planes collected on the rolling plane.

The embodiment increases the etching rate in the first surface 101 and the second surface 202 of the metal plate 100 by assembling {220} planes on the rolled surface, that is, the surface of the metal plate. can be delayed That is, the embodiment can slow down the etching rate in the initial stage of etching, thereby preventing film detachment or separation of the photoresist layer, thereby improving the uniformity of through holes. In addition, fine through-holes can be formed, and the manufacturing yield and process efficiency of the through-holes can be improved.

The second purpose of the embodiment is to increase etching uniformity on the surface of the metal plate 100 .

The metal plate 100 according to the embodiment may include crystal grain boundaries having an average size of 30 μm or less.

Since the metal plate 100 includes two or more crystal planes having different orientations, it may include a grain boundary. The grain boundary may have a faster etching rate than the crystal grain. That is, since the metal plate 100 according to the embodiment includes crystal grain boundaries having an average size of 30 μm or less, etching uniformity may be increased. Accordingly, the shape of the through hole may be uniform, and the surface roughness of the through hole may be low.

That is, since the metal plate 100 according to the embodiment includes crystal grain boundaries having an average size of 30 μm or less, the inner circumferential surface of the through hole may have a smooth curve, thereby improving the uniformity of the pattern shape to be deposited.

For example, when the average size of the grain boundary is 30 μm or more, since etching may occur along the grain boundary, the etching shape may be irregular and the surface roughness of the through hole may be large. In addition, if the etched shape is non-uniform at the initial stage of etching, corrosion may proceed in the non-uniform shape gap, and thus the uniformity of the through hole may be deteriorated. Accordingly, the uniformity of the pattern shape deposited through this may be deteriorated.

The metal plate 100 may be ASTM E112 standard, and the number of crystal grains may be 7 to 13. For example, the metal plate 100 may have an ASTM E112 standard, and the number of crystal grains may be 7 to 12. For example, the metal plate 100 may have an ASTM E112 standard, and the number of crystal grains may be 8 to 11.

When the metal plate according to the embodiment meets the ASTM E112 standard, since it may include 7 to 13 crystal grains, it may have excellent etching characteristics and may form a through hole having a smooth inner circumferential surface.

6 is an enlarged view of cross sections of a plurality of through holes.

Referring to FIG. 6 , the metal plate 100 used to manufacture a deposition mask may include a metal layer 100a and surface layers 100b and 100c. For example, the metal plate 100 includes the metal layer 100a, a first surface layer 100b disposed on one surface of the metal layer 100a, and a second surface layer 100c disposed on the other surface opposite to the one surface. can include

The first surface layer 100b may be disposed on the first surface 101 of the metal plate 100, and the second surface layer 100c may be disposed on the second surface 102 of the metal plate 100. there is.

The thickness of the metal layer 100a may be greater than that of the surface layer. For example, the thickness of the metal layer 100a may be greater than the thickness of the first surface layer 100b and the thickness of the second surface layer 100c.

The thickness T of the metal plate 100 may be 10 μm to 50 μm. For example, the thickness T of the metal plate 100 may be 10 μm to 30 μm. When the thickness T of the metal plate 100 is less than 10 μm, manufacturing efficiency may be low.

When the thickness T of the metal plate 100 exceeds 50 μm, process efficiency for forming through holes may decrease. Here, the thickness T of the metal plate 100 may mean a measurement after a rolling process.

The thickness of the metal layer 100a may be 50 μm or less. For example, the thickness of the metal layer 100a may be 30 μm or less.

The first surface layer 100b and the second surface layer 100c may have thicknesses corresponding to each other. Here, matching may include an error due to tolerance.

For example, the thickness of the first surface layer 100b may be 1 μm or less from the first surface 101 , which is the surface of the metal plate 100 . For example, the thickness of the first surface layer 100b may be 0.5 μm or less from the first surface 101 , which is the surface of the metal plate 100 . For example, the thickness of the first surface layer 100b may be 0.1 μm or less from the first surface 101 , which is the surface of the metal plate 100 .

For example, the thickness of the second surface layer 100c may be 1 μm or less from the second surface 102 that is the surface of the metal plate 100 . For example, the thickness of the second surface layer 100c may be 0.5 μm or less from the second surface 102 , which is the surface of the metal plate 100 . For example, the thickness of the second surface layer 100c may be 0.1 μm or less from the second surface 102 that is the surface of the metal plate 100 . However, the embodiment is not limited thereto and may have various thicknesses. That is, of course, the surface layer may have various thicknesses within a range in which the ratio of crystal planes is different.

The metal layer 100a, the first surface layer 100b, and the second surface layer 100c may include a nickel alloy. For example, the metal layer 100a, the first surface layer 100b, and the second surface layer 100c may include invar. However, the embodiment is not limited thereto, and may include various metal materials, of course.

The metal layer 100a may have a different crystal plane ratio from the surface layers 100b and 100c. For example, the metal layer 100a may have a different ratio of {220} crystal planes from the surface layers 100b and 100c and the surface of the metal plate.

The ratio of {220} crystal planes on the surface of the metal plate may be greater in the surface layers 100b and 100c than in the metal layer 100a.

As the metal plate 100 adjusts the ratio of {220} crystal planes in the surface layers 100b and 100c to be higher than that in the metal layer 100a, the etching rate in the surface layers 100b and 100c increases with respect to the metal layer 100a. can be slower Accordingly, the metal plate 100 according to the embodiment may have excellent etching characteristics in the thickness direction of the metal plate, that is, in the depth direction of the through hole, so that the etching factor may increase. In addition, as the metal plate 100 is adjusted to have a higher ratio of {220} crystal planes in the surface layers 100b and 100c than in the metal layer 100a, the etching rate in the metal layer 100a is increased in the surface layer 100b and 100c. 100c) may be faster. Accordingly, the metal plate 100 according to the embodiment may have excellent etching characteristics in the thickness direction of the metal plate, that is, in the depth direction of the through hole, so that the etching factor may increase.

Therefore, according to the embodiment, a deposition mask having excellent etching characteristics and improved etching uniformity of through holes can be manufactured even when a nickel alloy such as Invar is used.

X-ray diffraction intensity ratios of the metal layer 100a and the surface layers 100b and 100c may be different from each other. For example, the X-ray diffraction intensity ratio of {220} crystal planes on the surface of the metal plate may be greater in the surface layers 100b and 100c than in the metal layer 100a. Accordingly, it can be confirmed that the surface layers 100b and 100c have a higher ratio of {220} crystal planes than the metal layer 100a.

That is, in the metal plate 100 according to the embodiment, the proportion of {220} crystal planes may decrease as it goes from the surface toward the thickness of the metal plate. In detail, the metal plate 100 according to the embodiment is the area between the first surface 101 and the second surface 102 from the first surface 101 and the second surface 102, that is, the metal plate The ratio of {220} crystal planes may decrease toward the middle region having a thickness of 1/2 of (100).

The metal plate 100 may have different through-hole widths according to the thickness direction of the through-hole. For example, the width W1 of the first surface hole V1 may be greater than the width W3 of the connection portion CA. In detail, the width of the first surface hole V1 may decrease from the first surface 101 toward the connection portion CA. In more detail, the width of the through hole of the first surface hole V1 may gradually decrease from the first surface 101 toward the connection portion CA.

For example, the width W2 of the second surface hole V2 may be greater than the width W3 of the connection portion CA. In detail, the width of the through hole of the second face hole V2 may decrease from the second face 102 toward the connection portion CA. In more detail, the width of the through hole of the second face hole V2 may gradually decrease from the second face 102 toward the connection portion CA.

A width of the through hole may be 20 μm or more. For example, the width of the through hole may be 20 μm to 40 μm. For example, at least one of the width W1 of the first surface hole and the width W2 of the second surface hole may have a width of 20 μm or more. For example, at least one of the width W1 of the first surface hole and the width W2 of the second surface hole may have a width of 20 μm to 40 μm.

The height H2 of the second surface hole V2 may be greater than the height H1 of the first surface hole V1.

Meanwhile, the relationship ratio between the height H1 of the first surface hole V1 and the thickness T of the metal plate 100 may be 1:(3 to 30). For example, the relationship ratio between the height H1 of the first surface hole V1 and the thickness T of the metal plate 100 may be 1:(3.5 to 12.5). For example, the height H1 of the first surface hole V1 may have a relationship ratio of 1:(4.5 to 10.5) with the thickness T of the metal plate 100 .

When the height H1 of the first surface hole V1 exceeds the above ratio in relation to the thickness T of the metal plate 100, the height H1 of the first surface hole V1 increases, The change in the thickness of the material becomes large, and as a result, a region where the organic material is not deposited may occur. Accordingly, the manufacturing yield of the OLED panel manufactured through the deposition mask may decrease.

The height H1 of the first surface hole V1 may be 0.1 μm to 7 μm. For example, the height H1 of the first surface hole V1 may be 1 μm to 6 μm. For example, the height H1 of the first surface hole V1 may be 2 μm to 4.5 μm. When the height H1 of the first surface hole V1 is less than 0.1 μm, the deposition efficiency of the organic material through the metal plate may decrease. When the height H1 of the first surface hole V1 is greater than 7 μm, it is difficult to form a fine-sized pattern, and an area where organic materials are not deposited may occur, thereby yielding an OLED panel manufactured through this. this may deteriorate.

Meanwhile, a third surface hole V3 formed on the first surface 101 adjacent to the first surface hole V1 is adjacent to the second surface hole V1 and formed on the second surface 102. A plurality of through-holes may be formed as they communicate with the fourth face hole V4 formed therein through the connection portion CA.

An inclination angle connecting an arbitrary point A1 at the end of the connection portion CA and an arbitrary point B1 at the end of the second face hole V2 may be in the range of 20 degrees to 70 degrees. For example, an inclination angle connecting an arbitrary point A1 at the end of the connection portion CA and an arbitrary point B1 at the end of the second surface hole V2 may be in the range of 30 degrees to 60 degrees. For example, an inclination angle connecting an arbitrary point A1 at the end of the connection portion CA and an arbitrary point B1 at the end of the second face hole V2 is 32 degrees to 38 degrees or 52 degrees to 58 degrees. It may be within the range of degrees. When the inclination angle connecting the arbitrary point A1 at the end of the connection portion CA and the arbitrary point B1 at the end of the second surface hole V2 is in the range of 20 degrees to 70 degrees, the uniformity of deposition is can be improved If the inclination angle is out of the range, an area in which organic materials are not deposited may occur, and thus deposition efficiency and process efficiency may be reduced.

The width of the through hole of the first face hole V1 may become narrower toward the center of the metal plate 100 . For example, the inner surface of the first face hole V1 may have a structure having a curvature. In addition, the width of the through hole of the second surface hole V2 may become narrower toward the center of the metal plate 100 . For example, the inner surface of the first face hole V1 may have a structure having a curvature. Accordingly, the input density of the deposition material can be controlled, and the uniformity of deposition can be improved compared to a simple slope structure.

A difference (W1-W3) between the width W1 of the first surface hole V1 and the width W3 of the connection portion CA may be in the range of 0.2 μm to 14 μm.

A vertical distance from an arbitrary point C1 at the end of the first face hole V1 to an arbitrary point A1 at the end of the connection portion CA may be in the range of 0.1 μm to 7 μm. A vertical distance from an arbitrary point C1 at the end of the first face hole V1 to an arbitrary point A1 at the end of the connection portion CA may be in the range of 1 μm to 6 μm. A vertical distance from an arbitrary point C1 at the end of the first face hole V1 to an arbitrary point A1 at the end of the connection portion CA may be in the range of 2 μm to 4.5 μm.

When the vertical distance is less than 0.1 μm, the deposition efficiency of the organic material through the metal plate 100 may decrease. When the vertical distance is greater than 7 μm, it is difficult to form a fine-sized pattern, and an area in which organic materials are not deposited may occur, which may reduce the yield of the OLED panel manufactured through this.

The first face hole V1 may have a curvature at a corner portion of an open area on the first surface 101, that is, at an outer portion of the open area. Alternatively, the second surface hole V2 may have a curvature at a corner of the open area on the second surface 102, that is, at an outer portion of the open area. For example, the corner portion of the open area may have a rounded structure having a curvature within a certain range. A diameter of an imaginary circle formed by extending the curvature of the rounded portion of the corner portion may range from 5 μm to 20 μm. For example, the diameter of an imaginary circle formed by extending the curvature of the rounded portion of the corner portion may be in the range of 7 μm to 15 μm. A diameter of an imaginary circle formed by extending the curvature of the rounded portion of the corner portion may range from 8 μm to 12 μm. In the above range, the deposition rate is high and uniform deposition of the organic material may be possible.

When the diameter of the virtual circle formed by extending the curvature of the rounded portion of the corner portion is less than 5 μm, there may not be a large difference in deposition rate from that without curvature treatment. When the diameter of an imaginary circle formed by extending the curvature of the rounded portion of the corner portion exceeds 20 μm, the deposition rate may decrease.

A width W5 of the fourth through hole V4 may be greater than a width W4 of the third through hole V3. For example, the width W4 of the third through hole V3 may be greater than the width W6 of the connection portion CA. In detail, the width of the through hole of the third surface hole V3 may decrease from the first surface 101 toward the connection portion CA. In detail, the width of the through hole of the third surface hole V3 may gradually decrease from the first surface 101 toward the connection portion CA.

For example, the width W5 of the fourth face hole V4 may be greater than the width W6 of the connection portion CA. In detail, the width of the through hole of the fourth surface hole V4 may decrease from the second surface 102 toward the connection portion CA. In more detail, the width of the through hole of the fourth surface hole V4 may gradually decrease from the second surface 102 toward the connection portion CA.

A height H4 of the fourth surface hole V4 may be greater than a height H3 of the third surface hole V3.

An etching rate of the first surface layer 100b may be slower than an etching rate of the metal layer 100a. The etching rate of the second surface layer 100c may be slower than that of the metal layer 100a.

The deposition mask made of the metal plate 100, in which the ratio of {220} crystal planes on the surface of the metal plate is smaller than the ratio of the {220} crystal planes inside the metal plate, has a high etching rate on the surface of the metal plate 100 in contact with the etchant. Accordingly, the width of the through hole formed on the surface of the metal plate 100 may be increased. Accordingly, it is difficult to form a through hole having a fine pattern, and the manufacturing yield may decrease. Also, the uniformity of the plurality of through holes may deteriorate. Therefore, the OLED panel manufactured through this may have low pattern deposition efficiency and reduced pattern deposition uniformity.

When the ratio of {220} crystal planes in the surface layers 100b and 100c is greater than that in the metal layer 100a, the width W1 of the first surface hole V1 and the width W4 of the third through hole V3 ) may correspond, and the width W2 of the second face hole V2 may correspond to the width W5 of the fourth through hole V4.

When the ratio of {220} crystal planes in the surface layers 100b and 100c is greater than that in the metal layer 100a, the height H1 of the first surface hole V1 and the height H3 of the third surface hole V3 corresponds, and the height H2 of the second face hole V2 and the height H4 of the fourth face hole V4 may correspond.

That is, as the ratio of {220} crystal planes in the surface layers 100b and 100c is greater than that in the metal layer 100a, uniformity of width and height of the plurality of through-holes may be improved.

The metal plate according to the embodiment may have a slow etching rate in the region where the first surface layer 100b and the second surface layer 100c are disposed, so that the through hole may have a small width and a deep thickness. Accordingly, it is possible to prevent a delamination phenomenon of the photoresist layer, which may occur due to rapid etching on the metal surface.

In addition, since the etching speed on the surface of the metal plate used in fabricating the deposition mask according to the embodiment can be controlled, a through hole having a fine pattern can be manufactured. In addition, the manufacturing yield of the metal plate used for manufacturing the deposition mask may be improved, and the uniformity of the plurality of through holes may be improved. Accordingly, an OLED panel fabricated with such a deposition mask may have excellent pattern deposition efficiency and improved deposition uniformity.

In the metal plate 100 used to manufacture the deposition mask according to the embodiment, the metal layer 100a and the surface layers 100b and 100c may have different etching rates.

For example, the etching rate of the surface layers 100b and 100c may be 0.03 um/sec or less. For example, the etching rate of the surface layers 100b and 100c may be 0.01 to 0.03 um/sec or less. For example, the etching rate of the surface layers 100b and 100c may be 0.02 to 0.03 um/sec or less.

For example, the etching rate of the metal layer 100a may be 0.03 to 0.06 um/sec. For example, the etching rate of the metal layer 100a may be 0.03 to 0.05 um/sec.

That is, since the etching rate of the surface layers 100b and 100c of the metal plate used to manufacture the deposition mask according to the embodiment may be slower than that of the metal layer 100a, the etching characteristics of the through hole may be excellent. In addition, the OLED panel fabricated with the deposition mask according to the embodiment has excellent pattern deposition efficiency and improved deposition uniformity.

The metal plate used to manufacture the deposition mask according to the embodiment may have an etching factor of 2.0 or more.

Accordingly, the metal plate according to the embodiment may have excellent through-hole etching characteristics, and thus, a decrease in manufacturing yield due to lifting or separation of the photoresist layer may be prevented.

For example, the etch factor may be calculated by Equation 1 below.

<Equation 1>

In the above formula, B is the width of the through hole after etching, A is the width of the photoresist layer, and C is the depth of the through hole.

The greater the etching factor, the better the etching characteristics in the thickness direction of the metal layer, that is, in the depth direction of the through hole.

It may mean that the width of the through hole increases as the etching factor decreases. That is, as the width of the through hole increases as the etching factor decreases, a phenomenon in which the photoresist layer is lifted or separated may occur.

Referring to Figs. 7 to 10, a manufacturing process of the metal plate according to the embodiment will be described.

Referring to FIG. 7 , the rolled metal plate 100 may have a thickness T1 of 50 μm or less.

Referring to FIG. 8 , a first photoresist layer P1 may be disposed on the first surface layer 110 and a second photoresist layer P2 may be disposed on the second surface layer 120 .

In detail, a photoresist material is applied on the first surface layer 110 and the second surface layer 120, respectively, and the first photoresist layer P1 and the second photoresist layer are formed by exposure and development processes. (P2) can be arranged respectively.

As the first photoresist layer P1 and the second photoresist layer P2 are arranged to have different open area widths, the first surface hole V1 formed on the first surface 101 and The second surface hole V2 formed on the second surface 102 may have different widths.

Referring to FIG. 9 , the first surface hole V1 and the second surface hole V2 are formed by an etching process, and the first surface hole V1 and the second surface hole V2 are formed by the connection portion CA. ) may form through holes as they communicate.

For example, the etching process may be performed by a wet etching process. Accordingly, the first surface 101 and the second surface 102 may be etched simultaneously. For example, the wet etching process may be performed at about 45° C. using an etchant containing iron chloride. In this case, the etchant may include 35 to 45% by weight of FeCl ₃ . In detail, the etchant may include 36% by weight of FeCl ₃ . For example, the specific gravity of the etchant containing 43% by weight of FeCl ₃ may be 1.47 at 20°C. The specific gravity of the etchant containing 41% by weight of FeCl ₃ may be 1.44 at 20°C. The specific gravity of the etchant containing 38% by weight of FeCl ₃ may be 1.39 at 20°C.

Referring to FIG. 10 , as the first photoresist layer P1 and the second photoresist layer P2 are removed, a metal plate having a plurality of through holes may be formed.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. These embodiments are only presented as examples in order to explain the present invention in more detail. Therefore, the present invention is not limited to these examples.

<Experimental Example 1: Measurement of X-ray diffraction intensity>

Example One

Rolled and annealed invar metal was prepared. At this time, invar metal having excellent etching characteristics was used. That is, invar metal having an etching factor of 2.0 was used. Through-holes were formed in the invar metal through an etching process.

At this time, the etching process was performed at 45° C. as a wet etching process, and the etchant contained 36% by weight of FeCl 3 .

comparative example

Rolled and annealed invar metal was prepared. At this time, invar metal having low etching characteristics was used. That is, invar metal having an etching factor of less than 2.0 was used. Through-holes were formed in the invar metal through an etching process.

At this time, the etching process was carried out under the same conditions as in Example 1.

X-ray diffraction analysis reveals the distribution of crystal planes. Since the embodiment is a polycrystal in which several crystal planes are non-uniformly mixed, it can be seen that several peaks appear with different intensities.

Through measurement of X-ray diffraction intensity, the ratio of crystal planes arranged on the surface of the metal plate can be known.

Since the surface layers 100b and 100c show a strong peak at the {220} crystal plane, it can be seen that the {220} crystal plane ratio of the surface layers 100b and 100c is greater than that of the metal layer 100a.

Referring to FIG. 14 , the ratio of {220} crystal planes of the surface layer according to Example 1 may be greater than the ratio of {111} crystal planes or {200} crystal planes. Meanwhile, the ratio of {220} crystal planes of the surface layer according to the comparative example may be smaller than the ratio of {111} crystal planes or {220} crystal planes.

The ratio of the rotation intensity of the {220} crystal plane to the X-ray diffraction intensity of the {200} crystal plane on the surface of the metal plate measured in the surface layer according to Example 1 may be 1 or more ({220} X-ray intensity ratio / {200} } X-ray intensity ratio > 1}

On the other hand, the ratio of the rotational intensity of the {220} crystal plane to the X-ray diffraction intensity of the {200} crystal plane on the surface of the metal plate measured in the surface layer according to the comparative example may be less than 1. ({220} X-ray intensity ratio /{ 200} X-ray intensity ratio < 1} In detail, the ratio of the rotational intensity of {220} crystal planes to the X-ray diffraction intensity of {200} crystal planes on the surface of the metal plate measured in the surface layer according to the comparative example may be less than 0.5. For example, the ratio of the rotational intensity of {220} crystal planes to the X-ray diffraction intensity of {200} crystal planes on the surface of the metal plate measured in the surface layer according to the comparative example may be 0.1 to 0.4.

The ratio of {220} crystal planes of the metal layer measured inside 10 μm from the surface according to Example 1 may be greater than the ratio of {111} crystal planes or {200} crystal planes. Meanwhile, the ratio of {220} crystal planes of the surface layer according to the comparative example may be smaller than the ratio of {220} crystal planes.

The ratio of the rotational intensity of the {220} crystal plane to the X-ray diffraction intensity of the {200} crystal plane on the surface of the metal plate, measured inside 10 μm from the surface according to Example 1, may be 1 or more. ({220} X-ray intensity ratio /{200} X-ray intensity ratio > 1}

On the other hand, the ratio of the rotational intensity of the {220} crystal plane to the X-ray diffraction intensity of the {200} crystal plane on the surface of the metal plate, measured inside 10 μm from the surface according to the comparative example, may be less than 1. ({220} X- ray intensity ratio /{200} X-ray intensity ratio < 1}

The ratio of {220} crystal planes in the embodiment may decrease from the surface layer toward the center of the metal layer. In detail, in the embodiment, the ratio of {220} crystal planes in the surface layer is greater than the ratio of {220} crystal planes in the metal layer measured inside 10 μm from the surface. Further, in the examples, the ratio of {220} crystal planes in the surface layer is greater than the ratio of {220} crystal planes in the metal layer measured inside 15 μm from the surface. Further, the ratio of {220} crystal planes of the metal layer measured inside 10 μm from the surface is greater than the ratio of {220} crystal planes of the metal layer measured inside 15 μm from the surface. Accordingly, the embodiment can reduce the etching rate in the surface layer compared to the etching rate in the metal layer, thereby improving the etching factor. In addition, since the ratio of {220} crystal planes decreases from the surface layer to the center of the metal layer, etching characteristics can be excellent in the thickness direction of the metal layer, that is, in the depth direction of the through hole, so that fine-sized through holes can be formed with excellent uniformity. can be formed to have

On the other hand, in the comparative example, the {220} crystal plane ratio of the metal layer measured inside 10 μm from the surface is greater than the {220} crystal plane ratio of the surface layer. Accordingly, in the comparative example, since the etching rate in the surface layer is faster than the etching rate in the metal layer, the etching factor is low, and OLED deposition efficiency may be reduced.

<Experimental Example 2: Etching factor and etching rate evaluation>

Example 1 comparative example etch factor 2.2 1.3 Etch rate of metal layer
(μm/sec) 0.05 0.05 Etch rate of surface layer
(μm/sec) 0.02 0.5

Table 1 shows etching factors and etching rates according to Example 1 and Comparative Example.

Referring to Table 1 and FIG. 15, it can be seen that the etching rate of the surface layer in Comparative Example is faster than the etching rate of the inner metal layer. That is, in the comparative example, it can be seen that the etching rate on the surface having a large contact area of the etchant is faster than the etching rate on the inside.

On the other hand, in the embodiment, it can be seen that the etching rate of the inner metal layer is faster than that of the surface layer. That is, in the embodiment, since a surface layer having a high ratio of {220} crystal planes is disposed on the metal layer, the etching rate on the surface of the metal sheet may be slower than the etching rate on the inside of the metal sheet. Accordingly, the metal plate according to the embodiment may form fine through holes.

11 is a cross-sectional view of a through hole according to Example 1 having an etching factor of 2.2.

12 is a cross-sectional view of a through hole according to Example 2 having an etching factor of 2.0.

Referring to FIGS. 11 and 12 , it can be seen that Examples 1 and 2 have a high etching factor of 2.0 or more, so that the width of the through hole is small and the etching characteristics are excellent in the depth direction. Accordingly, deformation of the photoresist layer can be prevented. In addition, the pattern that can be formed through the metal plate according to Examples 1 and 2 can implement a fine pattern.

Referring to FIG. 13 , it can be seen that as the through-holes according to the comparative example overlap, the photoresist layer is de-filmed. Accordingly, it can be seen that when the etching factor is less than 2.0, the manufacturing yield and process efficiency of through-holes are reduced.

A deposition mask according to an embodiment includes a metal plate, a first surface layer disposed on one surface of the metal layer, and a second surface layer disposed on the other surface opposite to the one surface, and the metal plate has an average size of 30 ㎛ or less, the metal plate includes a plurality of through holes, the first surface layer and the second surface layer are open in a region where the through holes are disposed, and the etching factor of the through holes is 2.0 or more. can

That is, in the etching process for forming through-holes in the deposition mask according to the embodiment, the metal layer may be etched faster than the surface layer, so that etching efficiency and uniformity of through-holes may be improved.

In addition, the OLED panel fabricated with the deposition mask according to the embodiment has excellent pattern deposition efficiency and improved deposition uniformity.

The features, structures, effects, etc. described in the foregoing embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified with respect to other embodiments by those skilled in the art in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

In addition, although the embodiments have been described above, these are merely examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention belongs can exemplify the above to the extent that does not deviate from the essential characteristics of the present embodiment. It will be seen that various variations and applications that have not been made are possible. For example, each component specifically shown in the embodiments can be modified and implemented. And differences related to these variations and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (11)

In the metal plate used for fabrication of the deposition mask,
metal layer; and
Including a surface layer on the metal layer,
The metal plate includes Invar,
The thickness of the metal plate is 10 μm to 50 μm,
The surface layer may include a first surface layer disposed on one surface of the metal layer; And a second surface layer disposed on the other surface opposite to the one surface,
The first surface layer has a thickness range of 1 μm or less from the first surface of the metal plate,
The second surface layer has a thickness range of 1 μm or less from a second surface facing the first surface of the metal plate,
The thickness of the metal layer includes a thickness greater than the thickness of the first surface layer and the second surface layer,
The metal plate includes {111}, {200}, and {220} crystal planes having different orientations,
A metal sheet in which the ratio of {220} crystal planes of the surface layer is greater than the ratio of {220} crystal planes of the metal layer. delete According to claim 1,
The metal plate including the one in which the X-ray diffraction intensity ratio of the {220} crystal plane of the metal plate is greater in the surface layer than in the metal layer. According to claim 1 or 3,
The metal plate includes crystal grain boundaries having an average size of 30 μm or less. According to claim 1 or 3,
Etch rates of the first and second surface layers are 0.03 um/sec or less,
The etching rate of the metal layer is 0.03 to 0.05 um / sec metal plate. delete According to claim 1 or 3,
The number of crystal grains of the metal plate is 7 to 13. delete delete delete delete

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