Metal plate and deposition mask comprising same

Abstract

A metal plate according to an embodiment includes a first region and a second region, the metal plate including an invar alloy containing iron and nickel, the thickness of the metal plate being 20 [mu] m to 50 [mu] m, the thickness of the second region being smaller than the thickness of the first region, the first region and the second region include 40% or less by weight of nickel in a region from a surface of the metal plate to a depth of at most 2.5 [mu] m, and a nickel content in a region from a first surface of the first region to a depth of 2.5 [mu] m is less than a nickel content in a region from a second surface of the second region to a depth of 2.5 [mu] m.

Description

Technical Field

[0001] Embodiments relate to a metal plate and a deposition mask including the metal plate. Background Art

[0002] Display devices are used in various devices. For example, display devices can be applied to small devices such as smartphones or tablet PCs and large devices such as TVs, monitors, or public displays (PDs). Recently, the demand for ultra-high definition (UHD) with an ultra-high resolution of 500 PPI (pixels per inch) or higher has been increasing. Therefore, interest in technologies for achieving low power consumption and high resolution is increasing.

[0003] According to a driving method, commonly used display devices can be roughly divided into liquid crystal displays (LCD) and organic light emitting diodes (OLED).

[0004] An LCD is a display device that uses liquid crystals. A light source, such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED), is placed beneath the liquid crystals. The LCD uses the liquid crystals to control the amount of light emitted from the light source.

[0005] OLEDs are displays powered by organic materials. They do not require a separate light source. Instead, the organic material itself serves as the light source, allowing for low-power operation. OLEDs also offer unlimited contrast and a response speed approximately 1,000 times faster than LCDs. OLEDs are also gaining attention as a potential alternative to LCDs due to their superior viewing angles.

[0006] The organic material included in the light-emitting layer of an OLED is deposited through a deposition mask called an open mask (OM) or a fine metal mask (FMM). The deposited organic material is formed in a pattern corresponding to the pattern formed in the deposition mask. Therefore, the deposited organic material performs the role of a pixel.

[0007] An aperture mask is a thin plate that only allows deposition at specific locations during OLED display manufacturing. After the backplane is completed during the display manufacturing process, the aperture mask is used in the deposition process to form the light-emitting layer on the backplane. Specifically, an aperture mask is an aperture mask that does not cover the operating range of the display in order to deposit the entire display. This aperture mask is also used when depositing a light-emitting layer containing a single color of light-emitting material, or when depositing layers such as the EIL and HTL.

[0008] On the other hand, a fine metal mask is used to change the color of the sub-pixels of the light-emitting layer to be realized, and ultra-fine holes are formed for this purpose. The process using a fine metal mask requires multiple deposition stages and therefore requires precise alignment, making it more difficult than the technology using only an opening mask.

[0009] When an open mask is used to deposit the light-emitting layer of an OLED display, only one color can be emitted, so the color implementation requires a separate layer, such as a color filter (C / F). On the other hand, when a fine metal mask is used to form the RGB light-emitting layer, no separate color filter is required. In other words, the technology of using a fine metal mask for sub-pixels is difficult, but because no filter is required to block light compared to the method using an open mask, it has excellent light efficiency.

[0010] The fine metal mask is made of an Invar metal plate containing iron (Fe) and nickel (Ni). Through holes are formed through one surface and the other surface of the metal plate, and these through holes can be formed at positions corresponding to the pixel pattern. Therefore, organic materials such as red, green, and blue can pass through the through holes of the metal plate and be deposited on the substrate, forming a pixel pattern on the substrate.

[0011] At the same time, before manufacturing the fine metal mask, a process of reducing the thickness of the metal plate may be performed. In addition, a process of polishing the surface of the metal plate may be performed.

[0012] Due to the above process, the internal composition of the metal plate may vary depending on the region of the metal plate. For example, one region of the metal plate may be changed to a region having a higher nickel content than an iron content.

[0013] Therefore, the etching characteristics of the metal plate may change. Therefore, the size or shape of the through-hole formed in the metal plate may become uneven. As a result, the deposition quality of the deposition mask may be reduced.

[0014] Therefore, a metal plate and a deposition mask that can solve the above problems are needed.

[0015] As a technology related to a deposition mask, Korean Publication No. KR10-2020-0058072 (May 27, 2020) has been disclosed. Summary of the Invention

[0016] Technical issues

[0017] Embodiments provide a metal sheet having a uniform composition.

[0018] This embodiment provides a metal plate with improved deposition efficiency.

[0019] Technical Solutions

[0020] A metal plate according to an embodiment includes a first region and a second region, wherein the metal plate includes an Invar alloy containing iron and nickel, the metal plate has a thickness of 20 μm to 50 μm, the thickness of the second region is smaller than the thickness of the first region, the first region and the second region include 40 weight % or less of nickel in a region from a surface of the metal plate to a depth of 2.5 μm, and the nickel content in a region from the first surface of the first region to a depth of 2.5 μm is smaller than the nickel content in a region from the second surface of the second region to a depth of 2.5 μm.

[0021] A metal plate according to an embodiment includes an Invar alloy containing iron and nickel, wherein the thickness of the metal plate is 20 μm to 30 μm, the metal plate includes 40 weight % or less of nickel in a region from the surface of the metal plate to a depth of 2.5 μm, and the metal plate has a nickel weight deviation of 1 weight % to 6 weight % in a region from the surface of the metal plate to a depth of 2.5 μm.

[0022] Beneficial effects

[0023] The metal plate according to the embodiment may have improved surface properties.

[0024] Specifically, the metal plate according to the embodiment can have a small surface roughness. In addition, the metal plate according to the embodiment can have a small thickness deviation.

[0025] The metal plate according to the embodiment can be polished on the surface of the metal plate before forming the through hole in the metal plate after the cold rolling process. Therefore, the nickel content in the region from the surface of the metal plate to a set depth range can be formed to be 40 wt % or less.

[0026] Therefore, it is possible to prevent the etching characteristics of the metal plate from varying due to the different nickel contents in each region on the surface of the metal plate. Therefore, when the thickness of the metal plate is further reduced, the thickness uniformity of the metal plate finally manufactured can be improved.

[0027] Furthermore, when forming through holes in the metal plate, the shape and size of the through holes can be made uniform.

[0028] Therefore, a deposition mask manufactured by the metal plate may have improved deposition reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 1 is a diagram for explaining a surface of a metal plate after a first surface treatment process according to an embodiment.

[0030] Figure 2 is a diagram for explaining a surface of a metal plate after a cold rolling process according to an embodiment.

[0031] Figure 3 is a diagram for explaining a surface of a metal plate after a cold rolling process according to an embodiment.

[0032] Figure 4 It is a diagram for explaining a region of a metal plate after a cold rolling process.

[0033] Figures 5 to 7 It is a diagram for explaining a process of checking the surface of a metal plate after a cold rolling process.

[0034] Figure 8 It is a diagram for explaining the second surface treatment process.

[0035] Figure 9 and Figure 10 It is a diagram for explaining a metal plate manufactured by the second surface treatment process.

[0036] Figures 11 to 15 It is a diagram for explaining the characteristics of metal plates according to the embodiment and comparative examples.

[0037] Figure 16 is a diagram for explaining that a deposition mask is coupled to a frame according to an embodiment.

[0038] Figure 17 is a cross-sectional view illustrating an organic deposition apparatus including a deposition mask according to an embodiment.

[0039] Figure 18 FIG. 1 is a diagram for explaining forming a deposition pattern on a deposition substrate using a deposition mask according to an embodiment.

[0040] Figure 19 is a diagram illustrating a plan view of a deposition mask according to an embodiment.

[0041] Figure 20 FIG. 1 is a diagram for explaining a defect of a through hole of a deposition mask according to an embodiment. DETAILED DESCRIPTION

[0042] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. However, the spirit and scope of the present invention are not limited to the parts of the described embodiments, and can be implemented in various other forms, and within the spirit and scope of the present invention, one or more of the elements of the embodiments can be selectively combined and reset. In addition, unless otherwise clearly defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention can be interpreted as having the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs, and terms such as those defined in commonly used dictionaries can be interpreted as having a meaning consistent with their meaning in the context of the relevant field.

[0043] In addition, the terms used in the embodiments of the present invention are used to describe the embodiments and are not intended to limit the present invention. In this specification, unless otherwise specified in a phrase, a singular form may also include a plural form and may include at least one of all combinations that can be combined in A, B, and C when described in "at least one (or more) of A (and), B, and C".

[0044] In addition, when describing elements of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish an element from other elements and are not limited to the nature, order, or sequence of the elements.

[0045] In addition, when an element is described as being “connected,” “coupled” or “connected to” another element, it may include not only the case where the element is directly “connected,” “coupled” or “connected to” other elements, but also the case where the element is “connected,” “coupled” or “connected to” other elements between the element and the other element.

[0046] In addition, when described as being formed or arranged "on (above)" or "under (below)" each element, "on (above)" or "under (below)" may include not only the case when the two elements are directly connected to each other, but also the case when one or more other elements are formed or arranged between the two elements.

[0047] In addition, when the expression "upper" or "lower" is used, it can include not only an upper direction but also a lower direction based on one element.

[0048] 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 an open mask (OM).

[0049] In the following description, a first direction 1D is defined as a length direction of the metal plate or the deposition mask, and a second direction 2D is defined as a width direction of the metal plate or the deposition mask.

[0050] Hereinafter, a metal plate and a deposition mask including the same according to embodiments are described with reference to the accompanying drawings.

[0051] Preferably, reference will be made to Figures 1 to 10 A metal plate according to an embodiment is described.

[0052] Metal plate and method for manufacturing the same

[0053] The metal plate 10 according to the embodiment described below may be a raw material for manufacturing a deposition mask. For example, a deposition mask described later may also be formed by forming a plurality of through holes in the metal plate 10.

[0054] The metal plate 10 may include an alloy. Specifically, the metal plate 10 may include iron (Fe) and nickel (Ni). More specifically, the metal plate may include iron (Fe), nickel (Ni), oxygen (O), and chromium (Cr). In addition, the metal plate may further include a small amount 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, the metal plate 10 may include Invar alloy.

[0055] Invar is an alloy composed of iron and nickel. It is a low-thermal expansion alloy with a coefficient of thermal expansion close to zero. Invar has a very low coefficient of thermal expansion. Therefore, it is used in precision parts such as masks and precision devices. Therefore, when a deposition mask is manufactured using the metal plate 10, deformation of the deposition mask can be prevented, and the life of the deposition mask can be increased.

[0056] The metal plate 10 may include an Invar alloy containing 60 to 65 weight percent of iron and 35 to 40 weight percent of nickel. Furthermore, the metal plate 10 may further include 1 weight percent or less of at least one of 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).

[0057] The composition, content, and weight percentage of the metal plate can be confirmed by selecting an arbitrary 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 confirm the weight percentage of each component. However, the embodiment is not limited thereto, and the composition and weight percentage of the metal plate can be confirmed by various methods capable of confirming the composition of the metal plate.

[0058] The metal plate 10 may be subjected to a pretreatment process before forming the through-holes. Specifically, a pretreatment process for reducing the thickness of the metal plate 10 may also be performed. In addition, a pretreatment process for improving the surface characteristics of the metal plate 10 may also be performed.

[0059] The thickness of the metal plate 10 can be reduced through the pretreatment process. In addition, the surface roughness of the metal plate 10 can be reduced through the pretreatment process. In addition, the surface composition of the metal plate 10 can be changed through the pretreatment process. Therefore, the metal plate can have a thin thickness and improved surface properties.

[0060] For example, the pretreatment process may include a thickness control process and a surface treatment process. The thickness control process may include a hot rolling process and a cold rolling process. Alternatively, the thickness control process may include a hot rolling process, a cold rolling process and an etching process.

[0061] 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.

[0062] For example, the hot rolling process, the first surface treatment process, the cold rolling process, and the second surface treatment process may also be performed in sequence.

[0063] Alternatively, the hot rolling process, the first surface treatment process, the cold rolling process, the second surface treatment process, and the etching process may also be performed in sequence.

[0064] Hereinafter, a method of manufacturing a metal plate is described.

[0065] First, a hot rolling process is performed. The thickness of the metal plate 10 is reduced by the hot rolling process. For example, the thickness of the metal plate 10 is reduced from a thickness of more than 3 mm to 3 mm or less.

[0066] Next, a first surface treatment process is performed.

[0067] The first surface treatment process is performed to remove impurities from the surface of 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 grinder. In this case, the surface S of the metal plate 10 may be scratched or burred due to the first surface treatment process. Alternatively, byproducts such as particles may be generated by the first surface treatment process, and the byproducts may adhere to the surface of the metal plate 10.

[0068] For example, refer to Figure 1 , a recessed area SA1 may be formed on the surface S of the metal plate, where the surface S of the metal plate is partially removed by the scratch. Alternatively, a region SA2 may be formed on the surface S of the metal plate, where it is raised from the surface S of the metal plate by a burr. Alternatively, a region SA3 may be formed on the surface S of the metal plate, where byproducts are attached.

[0069] Therefore, a plurality of protruding regions PA1 may be formed on the metal plate 10 by the recessed region SA1 , the raised region SA2 , and the region SA3 to which the by-products are attached.

[0070] Subsequently, a cold rolling process is performed. The thickness of the metal plate 10 is reduced by the cold rolling process. For example, the thickness of the metal plate 10 after cold rolling is reduced to 50 μm or less. Specifically, the thickness of the metal plate 10 after cold rolling is reduced to a thickness of 40 μm to 50 μm.

[0071] When the metal plate 10 including the protruding area PA1 is cold rolled, the protruding area PA1 can be pressed into the surface S of the metal plate 10 by pressure. Figure 2 , a plurality of pressing areas PA2 that press the protruding area PA1 can be formed on the surface S of the metal plate 10 .

[0072] Figure 3 It is a diagram for explaining the surface of the metal plate 10 . Figure 3 (a) is a photograph of the metal plate 10 after cold rolling, taken using an optical microscope. Figure 3 (b) is a photograph of the metal plate 10 after cold rolling analyzed using a scanning electron microscope (SEM).

[0073] Reference Figure 3 , the surface properties of the metal plate may be degraded by the pressing area PA2. For example, the surface thickness of the metal plate may become uneven due to the pressing area PA, and the surface roughness of the metal plate may increase.

[0074] The pressed area PA2 may have a higher nickel (Ni) content than other areas. Specifically, the pressed area PA2 may have a higher nickel content than areas other than the pressed area PA2. Specifically, the pressed area PA2 forms a nickel (Ni)-rich layer through the following reaction formula, thereby increasing the nickel content.

[0075] Reactive

[0076] 4FeO->Fe3O4+Fe

[0077] NiO+Fe->FeO+Ni

[0078] Therefore, refer to Figure 4 , after cold rolling, the metal plate 10 may include a first surface area 1SA and a second surface area 2SA.

[0079] The first surface area 1SA may be defined as an area with a relatively low nickel content. Specifically, the first surface area 1SA may be defined as an area with a nickel content of 40 wt % or less. Additionally, the first surface area 1SA may be defined as an area with an iron (Fe) content of 60 wt % or more.

[0080] The second surface area 2SA may be defined as an area with a relatively high nickel content. Specifically, the second surface area 2SA may be defined as an area with a nickel content greater than 40% by weight. Alternatively, the second surface area 2SA may be defined as an area with an iron (Fe) content less than 60% by weight. Due to the pressing area PA2, the second surface area 2SA may have a higher nickel content than the first surface area 2SA.

[0081] Therefore, when the process of forming a through hole in the metal plate is performed after the cold rolling process, a difference in etching speed may occur between the first surface area 1SA and the second surface area 2SA. Specifically, since the first surface area 1SA has a high iron content and a low nickel content, it may have a faster etching speed. However, since the second surface area 2SA has a low iron content and a high nickel content, it may have a slower etching speed.

[0082] Therefore, when a through hole is formed in the metal plate 10 , an etching amount varies depending on the region of the metal plate, and thus a defect may be generated in the through hole.

[0083] Alternatively, when etching the metal plate to further reduce the thickness of the metal plate 10, the amount of etching may vary depending on the area of ​​the metal plate. Consequently, the thickness of the second surface area 2SA may be thicker than that of the first surface area 1SA. Consequently, when forming a through hole in the metal plate 10, etching uniformity may be reduced due to the difference in thickness of the metal plate. Consequently, the shape or size of the through hole of the deposition mask may become uneven. Consequently, the deposition efficiency of the deposition mask may be reduced.

[0084] Figures 5 to 7 It is a diagram for explaining the surface changes of a metal plate after the cold rolling process.

[0085] Reference Figure 5 , prepare a cold-rolled metal plate 10. Then, the metal plate 10 is etched to a thickness (t) within a set range.

[0086] Figure 6 This is a photograph of the cold-rolled metal plate 10 after etching. Figure 7 yes Figure 6 Scanning electron microscope (SEM) image of area A.

[0087] Reference Figure 6 , a line pattern or a dot pattern is confirmed on the metal plate 10. The pattern PA is formed by a nickel-enriched layer. That is, after the cold rolling process, a nickel-rich area is formed on the surface of the metal plate. That is, after the cold rolling process, a nickel-rich area is formed in the metal plate 10.

[0088] Reference Figure 7 The pattern PA includes a plurality of protrusions P. The protrusions P are formed in a linear or dotted shape. The composition ratio of the region where the protrusions P are formed is different from the composition ratio of other regions. Specifically, the nickel content of the region where the protrusions P are formed is higher than that of other regions.

[0089] That is, the metal plate 10 forms a nickel-rich region after the cold rolling process.

[0090] In order to solve the above-mentioned problem, the metal sheet according to the embodiment may also be additionally subjected to a second surface treatment process after the cold rolling process.

[0091] In the second surface treatment process, the metal plate 10 may be polished. Specifically, the entire surface of the metal plate 10 may be polished. For example, the metal plate may be polished by mechanical polishing or chemical polishing.

[0092] Specifically, in the second surface treatment process, the surface of the metal plate 10 may be polished to a thickness of 0.4 μm or less. For example, the surface of the metal plate 10 may be polished to a thickness of 0.2 μm to 0.4 μm.

[0093] The nickel-rich layer can be removed by a second surface treatment process.

[0094] Reference Figure 8 , the protrusion P can be removed. Specifically, the nickel-rich layer of the metal plate 10 can be removed.

[0095] Therefore, the surface of the metal plate 10 has a uniform composition ratio over the entire surface, thereby improving the surface properties of the metal plate 10 .

[0096] The metal plate 10 may have improved surface properties through the second surface treatment process performed after the cold rolling process.

[0097] Next, an etching process is performed. During the etching process, the entire surface of the metal plate 10 is etched. The thickness of the metal plate 10 is reduced by the etching process. Specifically, the thickness of the metal plate is reduced to 30 μm or less by the etching process. More specifically, the thickness of the metal plate is reduced to 20 μm to 30 μm by the etching process.

[0098] The etching process may also be omitted. Specifically, the thickness of the metal plate 10 may be reduced by the second surface treatment process. For example, the thickness of the metal plate 10 may be reduced to 20 μm to 30 μm by the second surface treatment process.

[0099] The metal plate according to the embodiment has improved surface properties. Specifically, the protrusions are removed by the second surface treatment process. Therefore, the surface composition of the metal plate can be made uniform. In addition, the surface roughness of the metal plate can be made uniform.

[0100] Therefore, when forming through holes in the metal plate, the size or shape of the through holes can be made uniform.

[0101] In addition, when the metal plate is additionally etched, the thickness of the metal plate can be uniformly etched. In addition, after the etching process, the surface composition and surface roughness of the metal plate can be made uniform.

[0102] Figure 9 is a diagram showing a cross-sectional view of a metal plate manufactured by a process in which an etching process is omitted.

[0103] Reference Figure 9 When a metal plate is manufactured by this process, the metal plate may include a first region 1A and a second region 2A. The second region 2A is defined as a region where the nickel-rich layer is removed by the second surface treatment process.

[0104] After the second surface treatment process, the thickness of the metal plate 10 may be 20 μm to 50 μm. The surface of the metal plate 10 may be divided into two surfaces. For example, the first region 1A may have a first surface S1, and the second region 2A may have a second surface S2.

[0105] The first region 1A and the second region 2A may have different thicknesses. Specifically, the thickness T1 of the first region 1A may be greater than the thickness of the second region 2A. For example, the difference (D) between the thickness T1 of the first region 1A and the thickness of the second region 2A may be greater than 0 μm and less than or equal to 0.5 μm.

[0106] The nickel content in a region from first surface S1 to a depth of 2.5 μm may be 40 wt % or less. In addition, the nickel content in a region from second surface S2 to a depth of 2.5 μm may be 40 wt % or less.

[0107] The first region 1A and the second region 2A may have different composition ratios. Specifically, the first region 1A and the second region 2A may have different nickel contents. In addition, the first region 1A and the second region 2A may also have different iron contents.

[0108] Specifically, the nickel content in the region from the first surface S1 to a depth of 2.5 μm can be less than the nickel content in the region from the second surface S2 to a depth of 2.5 μm. For example, the difference between the nickel content in the region from the first surface S1 to a depth of 2.5 μm and the nickel content in the region from the second surface S2 to a depth of 2.5 μm can be 6 weight % or less, 4 weight % or less, or 2 weight % or less. Specifically, the difference between the nickel content in the region from the first surface S1 to a depth of 2.5 μm and the nickel content in the region from the second surface S2 to a depth of 2.5 μm can be 1 weight % to 6 weight %.

[0109] In addition, the iron content in the region from the first surface S1 to a depth of 2.5 μm can be greater than the iron content in the region from the second surface S2 to a depth of 2.5 μm. For example, the difference between the iron content in the region from the first surface S1 to a depth of 2.5 μm and the iron content in the region from the second surface S2 to a depth of 2.5 μm can be 6 weight % or less, 4 weight % or less, or 2 weight % or less. Specifically, the difference between the iron content in the region from the first surface S1 to a depth of 2.5 μm and the iron content in the region from the second surface S2 to a depth of 2.5 μm can be 1 weight % to 6 weight %.

[0110] The second region 2A is a region where the nickel-rich layer is removed, and since the nickel-rich layer remains, the nickel content may be high and the iron content may be low.

[0111] The nickel content and nickel content deviation in the region from the surface S of the metal plate to a depth of 2.5 μm can be controlled.

[0112] As a result, the surface composition can be uniform across all regions of the metal plate. That is, the difference in nickel weight percentage and iron weight percentage in the region from the metal plate's surface to a depth of 2.5 μm is reduced. Therefore, when forming a through-hole in the metal plate, the difference in etching rate due to the difference in nickel weight percentage and iron weight percentage can be reduced. Consequently, the variation in the shape and size of the through-hole formed in the metal plate can be reduced.

[0113] The first region 1A and the second region 2A may have different surface roughnesses. Specifically, the first surface S1 and the second surface 2S may have different roughnesses. Specifically, the surface roughness of the second region may be less than the surface roughness of the first region. The second region 2A is a region where the nickel-rich layer has been removed by polishing. Therefore, the surface roughness of the second region 2A may be less than the surface roughness of the first region 1A.

[0114] Figure 10 is a diagram illustrating a cross-sectional view of a metal plate manufactured by performing an etching process after a second surface treatment process.

[0115] After the etching process, the thickness of the metal plate 10 may be 20 μm to 30 μm.

[0116] The metal plate 10 may include nickel and iron within a set weight % range in a region from the surface S of the metal plate 10 to a depth of 2.5 μm.

[0117] Specifically, the nickel content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 40 wt % or less. Furthermore, the difference in nickel content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 6 wt % or less, 4 wt % or less, or 2 wt % or less. For example, the difference in nickel content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 1 wt % to 6 wt %.

[0118] In addition, the iron content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 60% by weight or more. Specifically, the iron content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 60% by weight to 64% by weight. In addition, the difference in the iron content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 6% by weight or less, 4% by weight or less, or 2% by weight or less. For example, the difference in the iron content in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 1% by weight to 6% by weight.

[0119] Any two sample areas may be selected from the surface S of the metal plate 10. The difference in nickel weight % and iron weight % measured in the area from the surface of each sample area to a depth of 2.5 μm may have a set range.

[0120] Specifically, the difference in nickel weight percent measured in the region from the surface of each sample region to a depth of 2.5 μm may be 6 weight percent or less, 4 weight percent or less, or 2 weight percent or less. For example, the difference in nickel weight percent measured in the region from the surface of each sample region to a depth of 2.5 μm may be 1 weight percent to 6 weight percent.

[0121] In addition, the difference in the weight percent of iron measured in the region from the surface of each sample region to a depth of 2.5 μm may be 6 weight percent or less, 4 weight percent or less, or 2 weight percent or less. For example, the difference in the weight percent of iron measured in the region from the surface of each sample region to a depth of 2.5 μm may be 1 weight percent to 6 weight percent.

[0122] Alternatively, the metal plate 10 may have an average nickel weight % and an average iron weight % within a set range in a region from the surface S of the metal plate 10 to a depth of 2.5 μm. The average nickel weight % may be defined as a value obtained by selecting n sample regions from the surface S of the metal plate 10 and dividing the sum of the nickel weight % measured in each sample region by n. In addition, the average iron weight % may be defined as a value obtained by selecting n sample regions from the surface S of the metal plate 10 and dividing the sum of the iron weight % measured in each sample region by n.

[0123] The average nickel wt% in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 36 to 40 wt% and the average iron wt% in the region from the surface S of the metal plate 10 to a depth of 2.5 μm may be 64 to 36 wt%.

[0124] The metal plate 10 may have a surface roughness within a set range. Specifically, the metal plate 10 may include a first surface 1S and a second surface 2S opposite to the first surface 1S. The first surface 1S may be defined as a surface on which the metal plate 10 is surface-treated.

[0125] The first surface 1S and the second surface 2S may have different surface roughnesses. Specifically, the surface roughness of the first surface 1S may be less than the surface roughness of the second surface 2S. For example, the minimum arithmetic mean roughness (Ra) of the first surface 1S may be 30 nm to 59 nm. In addition, the minimum 10-point average roughness (Rz) of the first surface 1S may be 0.5 nm to 0.79 nm.

[0126] In addition, the metal plate may also have a thickness deviation within a set range. The thickness deviation of the metal plate may be defined as the ratio of the maximum value to the minimum value of the metal plate. The metal plate may have a thickness deviation of 3% or less in the first direction and the second direction.

[0127] Since the metal plate 10 may be etched to a uniform thickness through the second surface treatment process, the metal plate may have less surface roughness and improved thickness uniformity.

[0128] The metal plate 10 may include nickel and iron within a set range in a region from the surface of the metal plate to a depth of 2.5 μm. Furthermore, the metal plate 10 may have a nickel weight percent deviation and an iron weight percent deviation within a set range in a region from the surface of the metal plate to a depth of 2.5 μm.

[0129] As a result, the surface composition of the metal plate can be made uniform across the entire area of ​​the metal plate. Specifically, the difference in nickel and iron weight percentages can be reduced in the region from the metal plate's surface to a depth of 2.5 μm. Consequently, when forming a through-hole in the metal plate, the difference in etching rate due to the difference in nickel and iron weight percentages can be reduced. Consequently, the variation in the shape and size of the through-holes formed in the metal plate can be reduced.

[0130] Hereinafter, the present invention is described in more detail by way of examples and comparative examples.

[0131] Example 1

[0132] An Invar metal sheet having a thickness of 3 mm was manufactured.

[0133] Subsequently, a hot rolling process, a first surface treatment process, a cold rolling process, and a second surface treatment process were sequentially performed, thereby manufacturing a metal plate having a thickness of 40 μm.

[0134] At this time, the first surface treatment process is performed by grinding the surface of the metal plate using a grinder.

[0135] In addition, a second surface treatment process is performed by chemical polishing or mechanical polishing.

[0136] Subsequently, an arbitrary area of ​​the metal plate is sampled as a test piece, and the nickel and iron contents of the metal plate are measured by dissolving the test piece in a strong acid.

[0137] Example 2

[0138] After the second surface treatment process, the metal plate was additionally etched.Thus, a metal plate was manufactured in the same manner as in Example 1 except that the metal plate had a thickness of 20 μm.

[0139] Subsequently, an arbitrary area of ​​the metal plate is sampled as a test piece, and the nickel and iron contents of the metal plate are measured by dissolving the test piece in a strong acid.

[0140] Comparative Example 1

[0141] A metal plate was manufactured in the same manner as in Example 1, except that the second surface treatment process was not performed.

[0142] Subsequently, the pattern area was sampled as a test piece, and the nickel and iron contents of the metal plate were measured by dissolving the test piece in a strong acid.

[0143] Comparative Example 2

[0144] A metal plate was manufactured in the same manner as in Example 2, except that the second surface treatment process was not performed.

[0145] Subsequently, an arbitrary area of ​​the metal plate is sampled as a test piece, and the nickel and iron contents of the metal plate are measured by dissolving the test piece in a strong acid.

[0146] Figure 11 is a graph showing the contents of iron and nickel of the metal plates according to Examples 1 and 2. In addition, Figure 12 is a graph showing the contents of iron and nickel of the metal plates according to Comparative Examples 1 and 2.

[0147] Reference Figure 11 The metal plate according to the example has a nickel content of 40 wt % or less and an iron content of 60 wt % in a region from the surface to a depth of 2.5 μm.

[0148] On the other hand, refer to Figure 12 , the metal plate according to the comparative example includes a region in which the nickel content exceeds 40 wt % and the iron content is less than 60 wt % in a region from the surface to a depth of 2.5 μm.

[0149] The metal plate according to the example undergoes a second surface treatment process to remove a region containing a large amount of nickel. Therefore, the metal plate according to the example may have a nickel content of 40 wt % or less and an iron content of 60 wt % in a region from the surface to 2.5 μm.

[0150] On the other hand, the metal plate according to the embodiment does not undergo the second surface treatment process for removing the region containing a large amount of nickel. Therefore, the metal plate according to the comparative example includes a region with a nickel content exceeding 40% by weight and an iron content less than 60% by weight in a region with a depth of 2.5 μm from the surface due to the nickel-rich layer.

[0151] Therefore, the embodiment and the comparative example may have different surface characteristics. Figures 13 to 15 It is a figure which shows the surface photograph of the metal plate according to embodiment and comparative example. Figure 13 、 Figure 14 、 Figure 15 (a) is a surface photograph of a metal plate according to a comparative example, Figure 13 、 Figure 14 、 Figure 15 (b) is a surface photograph of a metal plate according to an embodiment.

[0152] Reference Figures 15 to 17 The metal plate according to the comparative example may also have a large surface roughness due to the protrusions formed by the nickel-enriched layer. In addition, the metal plate according to the comparative example may also have a small thickness uniformity due to the protrusions formed by the nickel-enriched layer.

[0153] On the other hand, the metal plate according to the embodiment may have small surface roughness and improved thickness uniformity due to the removal of the nickel-rich layer.

[0154] Deposition mask

[0155] In the following, reference is made to Figures 16 to 18 A deposition mask according to an embodiment is described.

[0156] Reference Figure 16 and Figure 17 , 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 .

[0157] The deposition mask 100 can be formed using the metal plate 10 described above. The deposition mask 100 includes a plurality of through holes TH formed in an effective portion for deposition. At this time, the through holes are formed to correspond to the pattern to be formed on the deposition substrate. That is, the deposition mask 100 includes the metal plate 10, and a plurality of through holes TH can be formed in the metal plate 10.

[0158] The mask frame 200 includes an opening 205. A plurality of through-holes of the deposition mask 100 are provided in regions corresponding to the openings 205 of the mask frame 200. Thus, the organic material supplied to the organic material deposition vessel 400 is deposited on the deposition substrate 300. The deposition mask 100 is provided and fixed on the mask frame 200. For example, the deposition mask 100 may be stretched with a set tension and welded and fixed to the mask frame 200.

[0159] For example, the deposition mask 100 may be fixed to the mask frame 200 by welding a non-deposition region of the deposition mask 100. Subsequently, a portion of the deposition mask 100 disposed at the outside of the mask frame 200 is removed by a method such as cutting.

[0160] The mask frame 200 is made of a material that is less deformed when the deposition mask 100 is welded, for example, a metal having high rigidity.

[0161] Deposition substrate 300 is a substrate used in the manufacture of display devices. For example, deposition substrate 300 may be a substrate for depositing organic materials for OLED pixel patterns. Red, green, and blue organic material patterns are formed on deposition substrate 300 to form pixels. Red, green, and blue are the three primary colors of light. In other words, an RGB pattern can be formed on deposition substrate 300.

[0162] The organic material deposition container 400 is a crucible. An organic material is placed in the crucible. The organic material deposition container 400 moves within the vacuum chamber 500. That is, the organic material deposition container 400 moves in a single direction within the vacuum chamber 500. For example, the organic material deposition container 400 moves within the vacuum chamber 500 in the width direction of the deposition mask 100. That is, the organic material deposition container 400 moves within the vacuum chamber 500 in a direction perpendicular to the length direction of the deposition mask 100.

[0163] Inside the vacuum chamber 500 , while a heat source and / or electric current is supplied to the crucible serving as the organic deposition container 400 , an organic material is deposited on the deposition substrate 300 .

[0164] Reference Figure 18 , the deposition mask 100 includes a first surface 1S and a second surface 2S opposite to the first surface.

[0165] The first surface 1S includes small-area holes V1 and the second surface 2S includes large-area holes 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.

[0166] In addition, the deposition mask 100 includes through holes TH. The through holes TH are connected by communication portions CA that connect boundaries of the small-area holes V1 and the large-area holes V2.

[0167] The width of the large-area hole V2 is greater than that 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.

[0168] Furthermore, the width of the interconnecting portions CA has a set size. Specifically, the width of the interconnecting portions CA may be from 15 μm to about 33 μm. More specifically, the width of the interconnecting portions CA may be from 19 μm to about 33 μm. More specifically, the width of the interconnecting portions CA may be from 20 μm to about 27 μm. If the width of the interconnecting portions CA exceeds 33 μm, achieving a resolution of 500 PPI or higher may be difficult. Furthermore, if the width of the interconnecting portions CA is less than 15 μm, deposition defects may sometimes occur.

[0169] The small-area hole V1 is disposed toward the deposition substrate 300. The small-area hole V1 is disposed close to the substrate 300. Therefore, the small-area hole V1 has a shape corresponding to the deposition material, ie, the deposition pattern DP.

[0170] The large-area hole V2 is disposed toward the organic material deposition container 400. Therefore, the large-area hole V2 can accommodate the organic material supplied from the organic material deposition container 400 with a wide width, and a fine pattern can be quickly formed on the deposition substrate 300 through the small-area hole V1 having a smaller width than the large-area hole V2.

[0171] Therefore, the organic material received through the large-area holes V1 is deposited through the small-area holes V1 on the deposition substrate 300. As a result, one of the red, green, or blue pixel patterns is formed on the deposition substrate 300. Subsequently, by repeating the above process, all of the red, green, or blue pixel patterns can be formed on the deposition substrate 300.

[0172] Figure 19 is a diagram illustrating a plan view of a deposition mask 100 according to an embodiment.

[0173] Reference Figure 19 , the deposition mask 100 according to an embodiment may include a deposition area DA and a non-deposition area NDA.

[0174] The deposition area DA is an area for forming a deposition pattern. The deposition area DA may include an active area AA and an unactive area UA. The active area AA is defined as an area where through-holes TH are formed, through which organic material passes. Furthermore, the unactive area UA is defined as an area where through-holes TH are not formed, through which organic material passes. Furthermore, the unactive area UA is defined as an area where through-holes TH are formed, but the through-holes TH in the unactive area UA are defined as areas through which organic material does not pass.

[0175] In the drawings, the active area AA is illustrated as a square, but the embodiment is not limited thereto, and the active area AA may have a rectangular, circular, or elliptical shape.

[0176] The active area AA may include a plurality of active areas, and the plurality of active areas may be disposed to be spaced apart from each other in a length direction of the deposition mask.

[0177] The deposition area DA may be defined as an area from a point where a first active area starts to a point where a last active area ends in a length direction of the deposition mask 100 .

[0178] In addition, the deposition area DA may be defined as an area from a point where a first inactive area starts to a point where a last inactive area ends in a length direction of the deposition mask 100 .

[0179] The unavailable area UA may be defined as an area other than the active area AA in the deposition area DA. The unavailable area UA may be divided into a first unavailable area UA1 and a second unavailable area UA2 according to a position of the unavailable area UA.

[0180] The first unactive area UA1 may be defined as an area between the active areas AA. Therefore, a plurality of first unactive areas UA1 may be provided to be spaced apart in the length direction of the deposition mask 100. In addition, the second unactive area UA2 may be defined as an area between the active area AA and both ends of the width direction of the deposition mask 100.

[0181] The non-deposition area NDA is an area that does not participate in deposition. The non-deposition area NDA may include a frame fixing area for fixing the deposition mask 100 to the mask frame 200. Furthermore, the non-deposition area NDA may include at least one of a half-etched portion and an opening portion OA. The half-etched portion may also be formed by partially etching the metal plate 10. Alternatively, the opening portion OA may be formed by completely etching the metal plate 10.

[0182] The half-etched portion may disperse residual stress generated when the deposition mask 100 is stretched. Therefore, the waviness of the deposition mask may be reduced.

[0183] In addition, the opening portion OA is a region for fixing a jig such as a clamp when the deposition mask 100 is stretched.

[0184] The through hole TH may be provided in the active area AA. Specifically, the active 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 connecting the small-area hole V1 and the large-area hole V2.

[0185] Since the deposition mask is manufactured from the above-described metal plate 10 , it can have nickel and iron contents, surface roughness, and thickness uniformity within set ranges.

[0186] For example, the sample SM can be measured in any area of ​​the deposition mask. For example, the sample S can also be sampled in at least one of the non-deposition area NDA, the first unused area UA1, and the second unused area UA2. When the composition, surface roughness, and thickness of the sample are measured, the deposition mask can have nickel and iron content, surface roughness, and thickness uniformity within the set ranges corresponding to the above-mentioned metal plate.

[0187] If the nickel content and iron content of the deposition mask exceed the above ranges, the difference in etching uniformity when forming the through hole may increase. As a result, the defects of the through hole of the deposition mask may increase. That is, if Figure 20As shown, sometimes defective through holes are formed in which the size of the through holes is larger or smaller than that of other through holes due to impurities, and defective through holes may also be formed in which through holes are connected to each other.

[0188] Therefore, when a deposition pattern is formed on a deposition substrate through the deposition mask, deposition quality may be degraded.

[0189] The characteristics, structures, and effects described in the above embodiments are included in at least one embodiment, but are not limited to one embodiment. In addition, the characteristics, structures, and effects shown in each embodiment can even be combined or modified with respect to other embodiments by a person skilled in the art to which the embodiments belong. Therefore, the content related to such combinations and such modifications should be interpreted as being included within the scope of the embodiments.

[0190] The above description focuses on the embodiments, but is illustrative only and does not limit the embodiments. Those skilled in the art will appreciate that various modifications and applications not shown above are possible without departing from the basic features of the embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. In addition, differences associated with such variations and applications should be interpreted as being included within the scope of the embodiments defined in the appended claims.

Claims

1. A metal plate comprising a first region and a second region, the metal plate comprising: in, The metal plate comprises an Invar alloy containing iron and nickel, wherein the metal plate has a thickness of 20 μm to 50 μm, wherein the thickness of the second region is smaller than the thickness of the first region, wherein the first region and the second region include 40 wt % or less of nickel in a region from the surface of the metal plate to a depth of 2.5 μm, and The nickel content in the region from the first surface of the first region to a depth of 2.5 μm is smaller than the nickel content in the region from the second surface of the second region to a depth of 2.5 μm.

2. The metal plate according to claim 1, wherein The difference between the nickel content in the region from the first surface of the first region to a depth of 2.5 μm and the nickel content in the region from the second surface of the second region to a depth of 2.5 μm is 1 wt % to 6 wt %.

3. The metal plate according to claim 1, wherein A thickness difference between the first region and the second region is greater than 0 μm and less than 0.5 μm. The metal plate according to claim 1 , wherein: The roughness of the second surface is smaller than the roughness of the first surface.

5. A metal plate comprising an Invar alloy containing iron and nickel, the metal plate comprising: in, The thickness of the metal plate is 20 μm to 30 μm, wherein the metal plate includes 40 wt % or less of nickel in a region from a surface of the metal plate to a depth of 2.5 μm, and The metal plate has a nickel weight deviation of 1 wt % to 6 wt % in a region from a surface of the metal plate to a depth of 2.5 μm. The metal plate according to claim 5 , wherein: Two random sample areas were selected from the surface of the metal plate, and the deviation of nickel weight % measured from the surface to a depth of 2.5 μm in each sample area was 1 weight % to 6 weight %.

7. The metal plate according to claim 5, wherein When n sample areas are selected from the surface of the metal plate and the sum of the nickel weight % measured in each sample area is divided by n to define the average nickel weight %, the average nickel weight % in the area from the surface of the metal plate to a depth of 2.5 μm is 36 weight % to 40 weight %.

8. The metal plate according to claim 5, wherein The metal plate includes a first surface and a second surface opposite to the first surface, wherein the minimum arithmetic mean roughness (Ra) of the first surface is 30 nm to 59 nm, and The minimum 10-point average roughness (Rz) of the first surface is 0.5 nm to 0.79 nm.

9. The metal plate according to claim 5, wherein The metal sheet has a thickness deviation defined by the ratio of a maximum thickness value to a minimum thickness value, and Wherein, the thickness deviation of the metal plate is 3% or less.

10. A deposition mask comprising: The metal plate according to any one of claims 1 to 9, and Wherein, the metal plate includes a deposition area and a non-deposition area, wherein the deposition area includes an effective area in which a through hole is formed and an ineffective area other than the effective area, and The through hole is formed by: a small-area hole; a large-area hole; and a connecting portion connecting the small-area hole and the large-area hole.

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