Metal plate and deposition mask comprising same

Abstract

An embodiment includes a metal plate including iron and nickel, and the metal plate includes a first region and a second region divided based on an average thickness of the metal plate, where the metal plate has a thickness of 15 [mu] m to 50 [mu] m, where each of the first region and the second region is provided with a plurality of grooves, where each of the first region and the second region is provided with a plurality of grooves. The number of grooves per unit area provided in the first region is greater than the number of grooves per unit area provided in the second region.

Description

TECHNICAL FIELD

[0001] Embodiments relate to a metal plate and a deposition mask including the same. BACKGROUND

[0002] Display devices are applied to various apparatuses. For example, display devices can be applied to small-sized apparatuses such as smart phones or tablet PCs and large-sized apparatuses such as TVs, monitors, or PDs. Recently, there has been a growing demand for UHD having a super-high resolution of 500 PPI (pixels per inch) or more. Accordingly, attention is being paid to technologies for realizing low power and high resolution.

[0003] According to a driving method, commonly used display devices can be largely classified into LCDs and OLEDs.

[0004] An LCD is a display device driven using liquid crystals. A light source including a CCFL or an LED is disposed under the liquid crystals. The LCD controls the amount of light emitted from the light source using the liquid crystals.

[0005] In addition, an OLED is a display device driven using organic matter. The OLED does not need a separate light source. In the OLED, the organic material itself can be used as a light source and can be driven with low power consumption. In addition, the OLED can exhibit infinite contrast and has a response speed about 1000 times faster than that of the LCD. In addition, the OLED is attracting attention as a display device that can replace the LCD due to its excellent viewing angle.

[0006] An organic material included in a light emitting layer in the OLED is deposited through a deposition mask called an OM or an FMM. The deposited organic material is formed in a pattern corresponding to a pattern formed in the deposition mask. Accordingly, the deposited organic material functions as a pixel.

[0007] An OM is a thin plate that allows deposition only at a specific location during the manufacture of an OLED display. The OM is used in a deposition process to form a light emitting layer on a backplane after the backplane is completed in the display manufacturing process. That is, the OM is an OM that does not have a cover area within a range in which the display operates and covers the entire front surface of the display, and is also used when depositing a light emitting layer with a light emitting material of one color or when depositing layers such as an EIL and an HTL.

[0008] On the other hand, a fine metal mask is used to change the color of a sub-pixel of a light emitting layer to be implemented, and for this purpose, a super fine hole is formed. The process using the fine metal mask requires a plurality of deposition stages, and thus requires precise alignment, and thus is more difficult than a technique using only an opening mask.

[0009] When a light emitting layer of an OLED display is deposited using an opening mask, only one color can be emitted, and thus a separate layer such as a color filter (C / F) is required for color implementation. On the other hand, when an RGB light emitting layer is formed using a fine metal mask, a separate color filter is not required. In other words, the technique using a fine metal mask for a sub-pixel is difficult, but has excellent light efficiency because it does not require a light blocking filter compared to a method using an opening mask.

[0010] The fine metal mask is manufactured from an Invar alloy metal plate including iron (Fe) and nickel (Ni). At this time, a through hole is formed through one surface and the other surface of the metal plate, and the through hole can be formed at a position corresponding to a pixel pattern. Thus, organic materials such as red, green, and blue can pass through the through hole of the metal plate and be deposited on a substrate, and a pixel pattern can be formed on the substrate.

[0011] On the other hand, before manufacturing the fine metal mask, a process of reducing the thickness of the metal plate can be performed. For example, the metal plate can be cold-pressed in one direction.

[0012] Through the rolling process, the thickness of the metal plate can become non-uniform. In detail, the thickness deviation of the metal plate can increase.

[0013] Thus, the etching characteristics of the metal plate can be changed. Thus, the size or shape of the through hole formed in the metal plate can become non-uniform. Thereby, the deposition quality of the deposition mask can be reduced.

[0014] Thus, there is a need for a metal plate and a deposition mask that can solve the above problems.

[0015] As a technique related to a deposition mask, Korean Publication No. KR10-2020-0058072 (2020.05.27) is disclosed. SUMMARY

[0016] TECHNICAL PROBLEM The embodiment provides a metal plate having a uniform thickness.

[0017] The embodiment provides a deposition mask having improved deposition efficiency.

[0018] TECHNICAL SOLUTION An embodiment includes a metal plate including iron and nickel, the metal plate including a first region and a second region divided based on an average thickness of the metal plate, wherein the thickness of the metal plate is 15 μm to 50 μm, wherein each of the first region and the second region is provided with a plurality of grooves, wherein the number of grooves per unit area provided in the first region is greater than the number of grooves per unit area provided in the second region.

[0019] In addition, a maximum size of the grooves provided in the first region is greater than a maximum size of the grooves provided in the second region.

[0020] In addition, a difference between a maximum size and a minimum size of the grooves provided in the first region is greater than a difference between a maximum size and a minimum size of the grooves provided in the second region.

[0021] In addition, a surface roughness of the first region and a surface roughness of the second region are different.

[0022] In addition, an arithmetic mean roughness in a rolling direction of the second region is less than an arithmetic mean roughness in the rolling direction of the first region.

[0023] In addition, a 10-point average roughness (Rz) in the rolling direction of the second region is less than a 10-point average roughness (Rz) in the rolling direction of the first region (1A).

[0024] In addition, a thickness deviation of the metal plate is defined as (maximum thickness - minimum thickness / average thickness 2) 100, wherein the first region and the second region are regions magnified at a magnification of 5000 times by a scanning electron microscope, wherein the thickness deviation of the metal plate in the first region and the second region is ±0.5% to ±1.7%.

[0025] In addition, a difference between a maximum thickness and a minimum thickness of the metal plate is 0.8 μm to 1.4 μm.

[0026] In addition, the deposition mask according to an embodiment includes a metal plate, wherein the metal plate includes a deposition region and a non-deposition region, wherein the metal plate includes a first surface and a second surface opposite to the first surface, wherein the deposition region includes an effective region in which a plurality of through-holes are formed and a non-effective region other than the effective region, wherein the through-holes include: a plurality of small-area holes formed on the first surface; a plurality of large-area holes formed on the second surface; and a communication portion communicating the small-area holes and the large-area holes.

[0027] In addition, the height of the small-area hole is defined as the height from the first surface to the communication portion, and the height deviation of the plurality of small-area holes is defined as (maximum height - minimum height / average height 2) 100, wherein the height deviation of the plurality of small-area holes is ±0.5% to ±1.7%.

[0028] Advantageous Effects The metal plate according to the embodiment has a small thickness deviation.

[0029] In detail, the metal plate undergoes a surface treatment process after cold rolling. Accordingly, the region of the metal plate having a large thickness can be controlled.

[0030] Accordingly, the average thickness and the thickness deviation of the metal plate can be reduced.

[0031] Accordingly, when a through-hole is formed in the metal plate, the size and shape of the through-hole can be uniform.

[0032] Accordingly, the deposition mask including the metal plate can have improved deposition efficiency.

[0033] The deposition mask frame can be fixed. At this time, the deposition mask is stretched in the length direction of the deposition mask.

[0034] Since the thickness of the metal plate varies little, the difference in stretching is reduced. Accordingly, misalignment of the through-hole of the deposition mask can be prevented. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a graph illustrating a thickness deviation after rolling of a metal plate according to an embodiment.

[0036] Figure 2 is a graph illustrating a surface treatment method of a metal plate according to an embodiment.

[0037] Figure 3 is a plan view of a metal plate according to an embodiment.

[0038] Figure 4 is a sectional view taken along Figure 3 Area A-A'.

[0039] Figure 5 is a scanning electron microscope photograph of a region of a metal plate according to an embodiment.

[0040] Figure 6 is a view for explaining a thickness variation before and after surface treatment of a metal plate according to an embodiment.

[0041] Figure 7 is a graph illustrating a deposition mask attached to a frame according to an embodiment.

[0042] Figure 8 This is a cross-sectional view showing an organic material deposition apparatus including a deposition mask according to an embodiment.

[0043] Figure 9 This is a diagram illustrating the formation of a deposition pattern on a deposition substrate using a deposition mask according to an embodiment.

[0044] Figure 10 This is a plan view of the deposition mask according to an embodiment. Detailed Implementation

[0045] In the following, embodiments will be described in detail with reference to the accompanying drawings. However, the spirit and scope of this disclosure are not limited to the portion of the described embodiments and may be implemented in various other forms. Furthermore, within the spirit and scope of this disclosure, one or more elements of the embodiments may be selectively combined and rearranged. Additionally, unless otherwise expressly defined and described, the terms used in the embodiments of this disclosure (including technical and scientific terms) may be interpreted as having the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains, and terms such as those defined in common dictionaries may be interpreted as having a meaning consistent with their meaning in the context of the relevant art.

[0046] Furthermore, the terminology used in the embodiments of this disclosure is for describing embodiments and is not intended to limit this disclosure. In this specification, the singular form may also include the plural form unless specifically stated in the wording, and when described as “at least one (or more) of A (and) B and C”, it may include at least one of all combinations that can be combined with A, B and C.

[0047] Furthermore, in describing the elements of embodiments of this disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are used only to distinguish elements from other elements, and these terms are not limited to the nature, order, or sequence of the elements.

[0048] In addition, when an element is described as being “connected,” “joined,” or “engaged” with another element, it can include not only cases where the element is directly “connected,” “joined,” or “engaged” with other elements, but also cases where the element is “connected,” “joined,” or “engaged” with another element through which the element is connected, joined, or “engaged” with other elements.

[0049] Furthermore, when described as forming or setting “above” or “below” the various elements, “above” or “below” can include not only cases where two elements are directly connected to each other, but also cases where one or more other elements are formed or set between the two elements.

[0050] Furthermore, when expressed as "above" or "below", it can include not only an upward direction based on a single element, but also a downward direction based on a single element.

[0051] The deposition mask described below is a fine metal mask (FMM) capable of depositing red, green, and blue organic materials on a deposition substrate to form an RGB pixel pattern on the deposition substrate, and the following description does not apply to aperture masks (OM).

[0052] In the following description, the first direction 1D is defined as the length direction of the metal plate or deposition mask, and the second direction 2D is defined as the width direction of the metal plate or deposition mask.

[0053] In the following description, a metal plate and a deposition mask including the metal plate according to an embodiment will be described with reference to the accompanying drawings.

[0054] Preferably, the reference Figures 1 to 6 Describes a metal plate according to an embodiment.

[0055] Metal Plate and its Manufacturing Method The metal plate 10 can be a raw material used to manufacture a deposition mask. For example, a deposition mask can be formed by forming a plurality of through holes in the metal plate 10.

[0056] Metal plate 10 may comprise an alloy. Specifically, metal plate 10 may comprise iron (Fe) and nickel (Ni). More specifically, metal plate may comprise iron (Fe), nickel (Ni), oxygen (O), and chromium (Cr). Additionally, metal plate may contain small amounts of at least one element selected from carbon (C), silicon (Si), sulfur (S), phosphorus (P), manganese (Mn), titanium (Ti), cobalt (Co), copper (Cu), silver (Ag), vanadium (V), niobium (Nb), indium (In), and antimony (Sb). For example, metal plate 10 may comprise an Invar alloy.

[0057] Invar alloy is an alloy containing iron and nickel. It is a low-thermal-expansion alloy with a coefficient of thermal expansion close to zero. Invar alloy has a very small coefficient of thermal expansion. Therefore, it is used for precision parts, such as masks and precision devices. Thus, when using metal plate 10 to manufacture deposition masks, deformation of the deposition mask can be prevented, and the service life of the deposition mask can be extended.

[0058] The metal plate 10 may contain an Invar alloy containing 60 wt% to 65 wt% iron and 35 wt% to 40 wt% nickel. Additionally, the metal plate 10 may contain less than 1 wt% of at least one element selected from carbon (C), silicon (Si), sulfur (S), phosphorus (P), manganese (Mn), titanium (Ti), cobalt (Co), copper (Cu), silver (Ag), vanadium (V), niobium (Nb), indium (In), and antimony (Sb).

[0059] The composition, content, and weight percentage of the metal plate can be determined by selecting any sample area on the plane of the metal plate 10 and sampling a sample corresponding to the thickness of the metal plate 10. Then, the sample can be dissolved in a strong acid or the like to determine the weight percentage of each component. However, the embodiments are not limited to this, and the composition and weight of the metal plate can be determined by various methods capable of determining the composition of the metal plate.

[0060] The metal plate 10 may undergo a pretreatment process before forming the through-hole. Specifically, a pretreatment process to reduce the thickness of the metal plate 10 may be performed. In addition, a pretreatment process to improve the surface properties of the metal plate 10 may be performed.

[0061] The thickness of the metal plate 10 can be reduced through a pretreatment process. Furthermore, the surface roughness of the metal plate 10 can be reduced through a pretreatment process. Additionally, the surface composition of the metal plate 10 can be altered through a pretreatment process. Therefore, the metal plate can have a thinner thickness and improved surface properties.

[0062] For example, pretreatment processes may include thickness control processes and surface treatment processes. Thickness control processes may include hot rolling processes and cold rolling processes.

[0063] The surface treatment process includes a first surface treatment process and a second surface treatment process. The surface treatment process can be performed together with a thickness control process.

[0064] For example, the hot rolling process, the first surface treatment process, the cold rolling process, and the second surface treatment process can be performed sequentially.

[0065] The manufacturing method of the metal sheet will be described below.

[0066] First, a hot rolling process is performed. The thickness of the metal sheet 10 is reduced by the hot rolling process. For example, the thickness of the metal sheet 10 is reduced from more than 3 mm to less than 3 mm.

[0067] Next, the first surface treatment process is performed.

[0068] A first surface treatment process is performed to remove surface inclusions from the metal plate 10. This improves the surface properties of the metal plate 10. The first surface treatment process can be performed by mechanical polishing using equipment such as a grinding machine.

[0069] Next, a cold rolling process is performed. The cold rolling process reduces the thickness of the metal sheet 10. For example, after the cold rolling process, the thickness of the metal sheet 10 is reduced to less than 50 μm. Specifically, after the cold rolling process, the thickness of the metal sheet 10 is reduced to 30 μm to 50 μm.

[0070] After the cold rolling process, the thickness of the metal sheet decreases. However, the thickness deviation of the metal sheet may increase.

[0071] Reference Figure 1 The metal sheet 10 can be cold-rolled in one direction. Therefore, the rolling direction of the metal sheet 10 is defined. The thickness deviation of the metal sheet 10 may increase in the rolling direction.

[0072] In detail, the pressure applied to the metal sheet 10 may vary in different regions. Therefore, the metal sheet 10 may have thickness deviations in the rolling direction.

[0073] Therefore, the metal plate 10 can be divided into multiple regions according to its thickness. For example, the metal plate 10 may include region A, region B, and region C.

[0074] Region A can include areas with a thickness greater than the average thickness of the metal sheet and areas with a thickness less than the average thickness of the metal sheet. Similarly, region B can include only areas with a thickness less than the average thickness of the metal sheet. Likewise, region C can include only areas with a thickness greater than the average thickness of the metal sheet.

[0075] Therefore, when forming vias in the metal plate 10, the etching uniformity may be reduced due to the thickness difference of the metal plate. The vias are formed by etching the metal plate. Due to the different thicknesses, the vias formed in regions A, B, and C may have different sizes. For example, the heights of small or large area vias formed in regions A, B, and C may vary. Therefore, the deposition efficiency of the deposition mask may be reduced.

[0076] To address the aforementioned issues, the metal sheet 10 can undergo a second surface treatment process after the cold rolling process.

[0077] Reference Figure 2The second surface treatment process can be performed only on specific areas of the metal plate 10. Alternatively, the second surface treatment process can be performed only on areas of the metal plate 10 with greater thickness. For example, the second surface treatment process can be performed only on areas A and C. In other words, the second surface treatment process can be performed selectively.

[0078] The metal plate 10 can be etched using a second surface treatment process. This removes areas in region A 1A and region B 3A that have a thickness greater than the average thickness. Therefore, the thickness deviation of the metal plate 10 can be reduced.

[0079] The second surface treatment process can be performed using various methods. For example, the second surface treatment process may include at least one of dry etching, wet etching, chemical polishing, electrolytic polishing, strip polishing, chemical mechanical polishing, and magnetorheological fluid polishing.

[0080] The metal plate 10 can be further divided into multiple regions through a second surface treatment process. Specifically, refer to... Figure 3 and Figure 4 After the second surface treatment process, the metal plate 10 can be divided into a first region 1A, a second region 2A and a third region 3A.

[0081] The first region 1A corresponds to region A, the second region 2A corresponds to region B, and the third region 3A corresponds to region C.

[0082] At least one of the first region 1A, the second region 2A, and the third region 3A may include a groove. A groove can be defined as a circular recess in the surface of the metal plate. For example, the first region 1A and the third region 3A may include multiple grooves.

[0083] Alternatively, the first region 1A, the second region 2A, and the third region 3A may include multiple grooves. Furthermore, the number of grooves per unit area formed in the first region 1A may be greater than the number of grooves per unit area formed in the second region 2A. Additionally, the number of grooves per unit area formed in the third region 3A may be greater than the number of grooves per unit area formed in the second region 2A.

[0084] Alternatively, the first region 1A, the second region 2A, and the third region 3A may include multiple grooves. Furthermore, the maximum size of the groove formed in the first region 1A may be greater than the maximum size of the groove formed in the second region 2A. Additionally, the maximum size of the groove formed in the third region 3A may be greater than the maximum size of the groove formed in the second region 2A.

[0085] Alternatively, the first region 1A, the second region 2A, and the third region 3A may include multiple grooves. Furthermore, the difference between the maximum and minimum dimensions of the groove formed in the first region 1A may be greater than the difference between the maximum and minimum dimensions of the groove formed in the second region 2A. Similarly, the difference between the maximum and minimum dimensions of the groove formed in the third region 3A may be greater than the difference between the maximum and minimum dimensions of the groove formed in the second region 2A.

[0086] The first region 1A and the third region 3A are regions that undergo the second surface treatment. Metal particles can be precipitated from the first region 1A and the third region 3A through the second surface treatment. Therefore, grooves can be formed in the regions from which metal particles are precipitated. On the other hand, the second region 2A is a region that does not undergo the second surface treatment. Therefore, almost no grooves are formed in the second region 2A.

[0087] Figure 5 This is a scanning electron microscope (SEM) image of the surface of metal plate 10. Figure 5 (a) is a scanning electron microscope image of the second region 2A. Figure 5 (b) is a scanning electron microscope image of the first region 1A and the third region 3A. Figure 5 (c) is Figure 5 (b) Enlarged view of the dashed circle portion.

[0088] Each of the first region 1A, the second region 2A, and the third region 3A is a region magnified at 5000x using a scanning electron microscope.

[0089] Reference Figure 5 The first region 1A and the third region 3A include multiple grooves. For example, the first region 1A and the third region 3A may include a first groove G1 and a second groove G2. The first groove G1 and the second groove G2 may be formed as a circle or approximately a circle. The first groove G1 and the second groove G2 may be formed as recesses on the surface of the metal plate 10. The first groove G1 and the second groove G2 may have different sizes. For example, the first groove G1 may be larger than the second groove G2. For example, the first groove G1 may be a region where large metal particles are deposited. In addition, the second groove G2 may be a region where small metal particles are deposited.

[0090] The first region 1A, the second region 2A, and the third region 3A may have different surface roughnesses. Specifically, the arithmetic mean roughness (Ra) of the second region 2A may be different from the arithmetic mean roughness (Ra) of at least one of the first region 1A and the third region 3A. More specifically, the arithmetic mean roughness (Ra) of the second region 2A in the rolling direction may be less than the arithmetic mean roughness (Ra) of the first region 1A and the third region 3A in the rolling direction.

[0091] Furthermore, the 10-point average roughness (Rz) of the second region 2A may be different from the 10-point average roughness (Rz) of at least one of the first region 1A and the third region 3A. Specifically, the 10-point average roughness (Rz) of the second region 2A in the rolling direction may be less than the 10-point average roughness (Rz) of the first region 1A and the third region 3A in the rolling direction.

[0092] The first region 1A and the third region 3A undergo a second surface treatment process. Therefore, due to the second surface treatment process, the arithmetic mean roughness (Ra) and the 10-point mean roughness (Rz) of the first region 1A and the third region 3A can become greater than the arithmetic mean roughness (Ra) and the 10-point mean roughness (Rz) of the second region 2A.

[0093] This can reduce the thickness deviation of the metal sheet. Specifically, it can reduce the thickness deviation of the metal sheet in the rolling direction. The thickness deviation (%) can be defined as the metal sheet's (maximum thickness - minimum thickness / average thickness)... 2) 100. Specifically, the thickness deviation of the metal plate 10 can be less than ±1.8%. Specifically, the thickness deviation of the metal plate 10 can be ±0.5% to ±1.7%, ±1.0% to ±1.5%, or ±1.1% to ±1.4%.

[0094] Furthermore, the difference between the maximum and minimum thickness of the metal plate can be less than 1.4 μm. Specifically, the difference between the maximum and minimum thickness of a metal plate with a thickness of 30 μm to 50 μm can be 0.8 μm to 1.4 μm, 0.9 μm to 1.3 μm, or 1.0 μm to 1.2 μm.

[0095] The present disclosure will be described in more detail below with reference to embodiments and comparative examples.

[0096] Example A metal sheet containing Invar alloy was prepared, having a thickness greater than 3 mm and a length of 1.2 m. Next, the metal sheet was hot-rolled. This reduced the thickness of the metal sheet to below 3 mm.

[0097] Next, a grinding machine is used to perform an initial surface treatment on the metal plate.

[0098] Next, the metal sheet is cold-rolled. This cold rolling reduces the thickness of the metal sheet to approximately 40 μm.

[0099] Next, the surface thickness of the metal sheet is measured. Specifically, 32 points are designated along the rolling direction of the metal sheet, and the thickness at these points is measured. Specifically, the average thickness at these points is measured, and areas with a thickness greater than the average thickness are identified.

[0100] Next, a secondary surface treatment is performed on the surface of the metal plate. This secondary surface treatment is performed on areas of the metal plate where the thickness is greater than the average thickness. The secondary surface treatment may include at least one of dry etching, wet etching, chemical polishing, electrolytic polishing, strip polishing, chemical mechanical polishing, and magnetorheological fluid polishing.

[0101] Then, the surface thickness of the metal plate was measured again.

[0102] Then determine the average thickness and thickness deviation of the metal sheet. The thickness deviation (%) of the metal sheet is calculated as (maximum thickness - minimum thickness / average thickness). 2) 100.

[0103] Comparative example The surface of the metal sheet does not undergo secondary surface treatment. Subsequently, the average thickness and thickness deviation of the metal sheet are determined.

[0104] [Table 1] Refer to Table 1 and Figure 6 The average thickness of the metal plate according to the comparative example is 40.64 μm. Furthermore, the minimum thickness of the metal plate according to the comparative example is 39.85 μm, and the maximum thickness is 41.4 μm. Therefore, the difference between the maximum and minimum thickness is 1.45 μm. Thus, the thickness deviation of the metal plate is ±1.8%.

[0105] The average thickness of the metal plate according to the embodiment is 40.36 μm. Furthermore, the minimum thickness of the metal plate according to the embodiment is 39.8 μm, and the maximum thickness is 40.85 μm. Therefore, the difference between the maximum and minimum thickness is 1.05 μm. Thus, the thickness deviation of the metal plate is ±1.3%.

[0106] According to an embodiment, the metal plate has regions with a thickness greater than the average thickness, such as points 1 to 3, points 14 to 15, and points 29 to 32. Furthermore, these regions undergo a second surface treatment process. Therefore, the thickness of these regions is reduced. Consequently, the average thickness, maximum thickness, and minimum thickness of the metal plate are reduced. Therefore, the thickness deviation of the metal plate can be reduced.

[0107] Therefore, the metal plate according to the embodiment can form through holes of uniform shape and size. Thus, the deposition mask including the metal plate according to the embodiment can have improved deposition efficiency.

[0108] The examples and comparative examples illustrate the case where the metal plate is formed to a thickness of 40 μm. However, similar results can be obtained even when the metal plate is 30 μm or less, or 20 μm or less.

[0109] In detail, metal plates with a thickness of less than 30 μm or less than 20 μm are manufactured according to the following example, and the thickness deviation is measured.

[0110] A metal sheet containing Invar alloy was prepared, having a thickness greater than 3 mm and a length of 1.2 m. The metal sheet was then hot-rolled. Therefore, the thickness of the metal sheet was reduced to less than 3 mm.

[0111] Next, a grinding machine is used to perform the initial surface treatment on the metal plate.

[0112] The metal sheet is then cold-rolled. Through cold rolling, the thickness of the metal sheet is reduced to approximately 30 μm, approximately 25 μm, and approximately 20 μm.

[0113] Next, the surface thickness of the metal sheet is measured. Specifically, 32 points are designated along the rolling direction of the metal sheet, and the thickness at each point is measured. Specifically, the average thickness at each point is measured, and regions with thicknesses greater than the average thickness are identified. (Comparative Example) Next, a secondary surface treatment is performed on the surface of the metal sheet. (Example) A secondary surface treatment is performed on areas with a thickness greater than the average thickness of the metal sheet. The secondary surface treatment may include at least one of dry etching, wet etching, chemical polishing, electrolytic polishing, strip polishing, chemical mechanical polishing, and magnetorheological fluid polishing.

[0114] Next, measure the surface thickness of the metal plate again. (Example) Next, determine the average thickness and thickness deviation of the metal sheet. The thickness deviation (%) of the metal sheet is calculated as (maximum thickness - minimum thickness / average thickness). 2) 100.

[0115] Deposition mask In the following text, reference will be made to Figures 7 to 10 Describes a deposition mask according to an embodiment.

[0116] Reference Figure 7 and Figure 10 The organic deposition apparatus includes a deposition mask 100, a mask frame 200, a deposition substrate 300, an organic material deposition container 400, and a vacuum chamber 500.

[0117] The aforementioned metal plate 10 can be used to form a deposition mask 100. The deposition mask 100 includes a plurality of vias TH formed in the effective portion for deposition. In this case, the vias are formed to correspond to a pattern to be formed on the deposition substrate. That is, the deposition mask 100 includes the metal plate 10, and a plurality of vias TH can be formed in the metal plate 10.

[0118] The mask frame 200 includes an opening 205. A plurality of through-holes in the deposition mask 100 are disposed in regions corresponding to the openings 205 of the mask frame 200. Therefore, organic material supplied to the organic material deposition container 400 is deposited on the deposition substrate 300. The deposition mask 100 is disposed and fixed to the mask frame 200. For example, the deposition mask 100 can be stretched with a set tensile force and then welded and fixed to the mask frame 200.

[0119] For example, the deposition mask 100 can be fixed to the mask frame 200 by welding the non-deposition area of ​​the deposition mask 100. Subsequently, the portion of the deposition mask 100 disposed outside the mask frame 200 is removed by a method such as cutting.

[0120] The mask frame 200 is made of a material (e.g., a metal with high rigidity) that deforms little when the deposition mask 100 is welded.

[0121] Because the thickness deviation of the metal plate is reduced, misalignment of the vias can be prevented when the deposition mask is stretched. When the thickness deviation of the metal plate is large, stretching differences may occur in the deposition mask. Specifically, the difference in stretching dimensions between thick and thin regions may increase.

[0122] Therefore, misalignment of the vias in the deposition mask may occur, potentially reducing the deposition efficiency of the deposition mask.

[0123] However, the deposition mask according to the embodiment is made of a metal plate with small thickness variations. Therefore, the above-mentioned problems can be solved.

[0124] The deposition substrate 300 is a substrate used to manufacture display devices. For example, the deposition substrate 300 can be a substrate for depositing organic materials for OLED pixel patterns. Red, green, and blue organic material patterns are formed on the deposition substrate 300 to form pixels that are the three primary colors of light. That is, RGB patterns can be formed on the deposition substrate 300.

[0125] The organic material deposition container 400 is a crucible. Organic material is placed inside the crucible. The organic material deposition container 400 moves within the vacuum chamber 500. That is, the organic material deposition container 400 moves in one direction within the vacuum chamber 500. For example, the organic material deposition container 400 moves along the width direction of the deposition mask 100 within the vacuum chamber 500. In other words, the organic material deposition container 400 moves in a direction perpendicular to the length direction of the deposition mask 100 within the vacuum chamber 500.

[0126] When a heat source and / or current is supplied to the crucible within the vacuum chamber 500, which serves as an organic material deposition container 400, organic material is deposited on the deposition substrate 300.

[0127] Reference Figure 9 The deposition mask 100 includes a first surface 1S and a second surface 2S opposite to the first surface.

[0128] The first surface 1S includes a small-area hole V1, and the second surface 2S includes a large-area hole V2. For example, each of the first surface 1S and the second surface 2S includes a plurality of small-area holes V1 and a plurality of large-area holes V2.

[0129] Additionally, the deposition mask 100 includes a via TH. The via TH is connected by a connecting portion CA that connects the boundaries of the small-area via V1 and the large-area via V2.

[0130] The width of the large-area hole V2 is greater than the width of the small-area hole V1. At this time, the width of the small-area hole V1 is measured on the first surface 1S of the deposition mask 100, and the width of the large-area hole V2 is measured on the second surface 2S of the deposition mask 100.

[0131] Furthermore, the width of the connecting portion CA has a predetermined size. Specifically, the width of the connecting portion CA can be from 15 μm to approximately 33 μm. More specifically, the width of the connecting portion CA can be from 19 μm to approximately 33 μm. More specifically, the width of the connecting portion CA can be from 20 μm to approximately 27 μm. If the width of the connecting portion CA exceeds 33 μm, it may be difficult to achieve a resolution of 500 PPI or higher. Additionally, if the width of the connecting portion CA is less than 15 μm, deposition defects may occur.

[0132] The small-area aperture V1 is positioned facing the deposition substrate 300. The small-area aperture V1 is positioned close to the substrate 300. Therefore, the small-area aperture V1 has a shape corresponding to the deposition material (i.e., the deposition pattern DP).

[0133] The large-area aperture V2 is positioned facing the organic material deposition container 400. Therefore, the large-area aperture V2 can accommodate organic material supplied from the organic material deposition container 400 with a wider width, and fine patterns can be quickly formed on the deposition substrate 300 through the small-area aperture V1 with a width smaller than that of the large-area aperture V2.

[0134] Therefore, the organic material contained through the large-area aperture V2 is deposited on the deposition substrate 300 through the small-area aperture V1. Thus, one of the red, green, or blue pixel patterns is formed on the deposition substrate 300. Subsequently, all red, green, or blue pixel patterns can be formed on the deposition substrate 300 by repeating the above process.

[0135] Organic material is deposited on the deposition substrate 300 through small-area holes V1. Therefore, if the size difference of the small-area holes V1 increases, the deposition efficiency of the deposition mask may decrease. For example, the height H of the small-area holes V1 can be defined as the distance from the first surface 1S to the connecting portion.

[0136] The height H of the small-area aperture V1 can be 0.1 μm to 3 μm, 0.1 μm to 2.5 μm, or 0.1 μm to 2 μm. The height deviation of the small-area aperture V1 can be proportional to the thickness deviation of the metal plate. Specifically, as the thickness deviation of the metal plate decreases, the height deviation of the small-area aperture V1 can also decrease.

[0137] The height deviation of the small-area hole V1 is defined as (maximum height - minimum height / average height) of the small-area hole. 2) 100.

[0138] When the thickness deviation of the metal plate is ±0.5% to ±1.7%, the height deviation of the small area hole V1 can be ±0.5% to ±1.7%.

[0139] The deposition mask according to the embodiment includes the aforementioned metal plate, i.e., a metal plate with a small thickness deviation. Therefore, when forming a small-area aperture V1, the height deviation of the small-area aperture can be reduced.

[0140] Therefore, the amount of organic material deposited on the deposition substrate 300 through the small-area aperture V1 can be uniform. Consequently, the thickness of the deposited material on the deposition substrate 300 can be uniform.

[0141] Figure 10 This is a diagram showing a plan view of the deposition mask 100 according to an embodiment.

[0142] Referring to FIG19, the deposition mask 100 according to the embodiment may include a deposition region DA and a non-deposition region NDA.

[0143] The deposition region DA is the area used to form the deposition pattern. The deposition region DA can include an effective region AA and an ineffective region UA. The effective region AA is defined as a region with through-holes TH through which organic material can pass. Conversely, the ineffective region UA ​​is defined as a region without through-holes TH through which organic material can pass. Alternatively, the ineffective region UA ​​can be defined as a region with through-holes TH, but the through-holes TH in the ineffective region UA ​​are defined as regions where organic material cannot pass.

[0144] In the accompanying drawings, the effective area AA is shown as a square, but the embodiments are not limited to this, and the effective area AA may be rectangular, circular or elliptical.

[0145] The effective region AA can include multiple effective regions. These multiple effective regions can be set to be spaced apart from each other along the length of the deposition mask.

[0146] The deposition region DA can be defined as the region from the point where the first effective region begins along the length of the deposition mask 100 to the point where the last effective region ends.

[0147] In addition, the deposition region DA can be defined as the region from the point where the first ineffective region begins along the length of the deposition mask 100 to the point where the last ineffective region ends.

[0148] The ineffective region UA ​​can be defined as the region in the sedimentation region DA other than the effective region AA. The ineffective region UA ​​can be divided into the first ineffective region UA1 and the second ineffective region UA2 according to its location.

[0149] The first ineffective region UA1 can be defined as the region between the effective regions AA. Therefore, multiple first ineffective regions UA1 can be set to be spaced apart along the length direction of the deposition mask 100. In addition, the second ineffective region UA2 can be defined as the region between the effective regions AA and the two ends in the width direction of the deposition mask 100.

[0150] The non-deposition region NDA is a region that does not participate in deposition. The non-deposition region NDA may include a frame fixing region for fixing the deposition mask 100 to the mask frame 200. Additionally, the non-deposition region NDA may include at least one of a semi-etched portion and an opening OA. The semi-etched portion can be formed by partially etching the metal plate 10. Conversely, the opening OA can be formed by fully etching the metal plate 10.

[0151] The semi-etched portion can disperse the residual stress generated when stretching the deposition mask 100. Therefore, the waviness of the deposition mask can be reduced.

[0152] Additionally, the opening OA is the area where the fixture (e.g., jig) is fixed when the deposition mask 100 is stretched.

[0153] The aforementioned through-hole TH can be disposed in the effective area AA. Specifically, the effective area AA may include the through-hole TH, which includes a small-area hole V1, a large-area hole V2, and a connecting portion CA that connects the small-area hole V1 and the large-area hole V2.

[0154] The features, structures, and effects described in the above embodiments are included in at least one embodiment, but are not limited to one embodiment. Furthermore, the features, structures, and effects shown in the various embodiments can be combined or modified by those skilled in the art to which the embodiments pertain. Therefore, it should be understood that content related to such combinations and modifications is included within the scope of the embodiments.

[0155] The above description focuses on embodiments, but is merely illustrative and not limiting. Those skilled in the art will understand that various modifications and applications, not shown above, can be made without departing from the essential characteristics of the embodiments. For example, the various components specifically represented in the embodiments can be modified and implemented. Furthermore, it should be understood that differences associated with such changes and applications are included within the scope of the embodiments defined in the appended claims.

Claims

1. A metal plate comprising iron and nickel, The metal plate includes a first region and a second region, defined based on the average thickness of the metal plate. in, The thickness of the metal plate is 15 μm to 50 μm. Each of the first and second regions is provided with multiple grooves, and The number of grooves per unit area in the first region is greater than the number of grooves per unit area in the second region.

2. The metal plate according to claim 1, wherein, The maximum size of the groove in the first region is greater than the maximum size of the groove in the second region.

3. The metal plate according to claim 1, wherein, The difference between the maximum and minimum dimensions of the groove in the first region is greater than the difference between the maximum and minimum dimensions of the groove in the second region.

4. The metal plate according to claim 1, wherein, The surface roughness of the first region is different from that of the second region.

5. The metal plate according to claim 1, wherein, The arithmetic mean roughness of the second region in the rolling direction is less than the arithmetic mean roughness of the first region in the rolling direction.

6. The metal plate according to claim 1, wherein, The average roughness (Rz) of the second region in the rolling direction is less than that of the first region (1A) in the rolling direction.

7. The metal plate according to claim 1, wherein, The thickness deviation of the metal plate is defined as (maximum thickness - minimum thickness / average thickness) of the metal plate. 2) 100, The first region and the second region are regions magnified by scanning electron microscopy at a magnification of 5000x, and The thickness deviation of the metal plate in the first region and the second region is ±0.5% to ±1.7%.

8. The metal plate according to claim 1, wherein, The difference between the maximum and minimum thickness of the metal plate is 0.8 μm to 1.4 μm.

9. A deposition mask, comprising: The metal plate according to any one of claims 1 to 8, The metal plate includes a deposition region and a non-deposition region. The metal plate includes a first surface and a second surface opposite to the first surface. The deposition region includes an effective region in which multiple through-holes are formed and a non-effective region other than the effective region. The through hole includes: Multiple small-area holes are formed on the first surface; Multiple large-area holes are formed on the second surface; and A connecting portion, wherein the connecting portion connects the small area hole and the large area hole.

10. The deposition mask according to claim 9, wherein, The height of the small-area hole is defined as the height from the first surface to the connecting portion. The height deviation of the plurality of small-area holes is defined as the (maximum height - minimum height / average height) of the small-area holes. 2) 100, and The height deviation of the plurality of small-area holes is ±0.5% to ±1.7%.

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