Metal plate and deposition mask including same

Abstract

The metal plate according to the embodiment has a length L of 900 mm to 1100 mm, a width W of 290 mm to 300 mm, and a thickness T of 15 μm to 100 μm. The metal plate includes Invar, and the thickness of the metal plate is adjusted to an inspection thickness X of 3 μm to 10 μm to form a unit metal plate having a unit size of L×W×X. The number of inclusions per unit size of the unit metal plate is 10 or less, and the inclusions have a size exceeding the inspection thickness.

Description

[Technical Field]

[0001] The examples relate to a metal plate and a deposition mask including the same. [Background technology]

[0002] Display devices are applied to a variety of devices. For example, the display devices are applied to small devices such as smartphones or tablet PCs. Alternatively, the display devices are applied to large devices such as TVs, monitors, and public displays (PDs). Recently, there has been an increasing demand for ultra-high resolution (UHD) of 500 pixels per inch (PPI) or more. As a result, display devices with high resolution are being applied to both small and large devices.

[0003] Display devices are classified into liquid crystal displays (LCDs) and organic light emitting diodes (OLEDs) depending on their driving methods.

[0004] The LCD is a display device driven by using liquid crystal, and the OLED is a display device driven by using organic materials.

[0005] OLEDs can display an infinite contrast ratio, have a response speed 1,000 times faster than LCDs, and have a wide viewing angle, making them a promising display device that can replace LCDs.

[0006] The OLED includes an emitting layer. The emitting layer includes an organic material. The organic material is deposited on a substrate using a deposition mask. The deposition mask may be an open mask (OM) or a fine metal mask (FMM). A deposition pattern corresponding to the pattern formed on the deposition mask is formed on the substrate. As a result, the deposition pattern can function as a pixel.

[0007] The open mask is a thin plate that forms a deposition pattern only in specific locations when manufacturing an OLED. The open mask is used in the deposition process to form an emitting layer on a backplane after the backplane is completed during the display manufacturing process. That is, the open mask is a mask that does not block any areas within the display's operating range in order to deposit the entire surface of the display. Therefore, the open mask is used when depositing an emitting layer with a single color emitting material.

[0008] On the other hand, a fine metal mask is used to create different colors for each sub-pixel of the light-emitting layer. Therefore, the fine metal mask contains ultra-fine holes. The process using the fine metal mask requires multiple deposition steps. Therefore, the process requires precise alignment. Therefore, the process using the fine metal mask is more difficult than the process using an open mask.

[0009] When the OLED light-emitting layer is deposited using an open mask, only one color light-emitting layer is formed. Therefore, a separate color filter (C / F) is required to realize various colors. On the other hand, when the fine metal mask is used, RGB light-emitting layers can be formed. Therefore, a separate color filter is not required. In other words, the technology using the fine metal mask is difficult. However, compared to the method using an open mask, light efficiency is better because a filter that blocks light is not required.

[0010] The fine metal mask is generally manufactured using an Invar alloy metal plate containing iron (Fe) and nickel (Ni). Through holes are formed on one side and the other side of the metal plate, penetrating the one side and the other side. The through holes are formed at positions corresponding to pixel patterns. As a result, red, green, and blue organic materials pass through the through holes in the metal plate and are deposited on the substrate. As a result, pixel patterns are formed on the substrate.

[0011] The fine metal mask may be made of a metal plate made of an iron (Fe)-nickel (Ni) alloy. For example, the deposition mask may be made of invar.

[0012] The metal plate may contain various impurities such as oxygen, iron element, and sulfur element in addition to iron and nickel. The impurities form crystals inside the metal plate, and thus the impurities may remain as inclusions in the metal plate.

[0013] If the size of the inclusions is large, the size of the through holes may be deformed by the inclusions, or adjacent through holes may be connected by the inclusions, which may result in a deterioration in deposition quality of the deposition mask.

[0014] Therefore, there is a need for an inclusion inspection method, a metal plate, and a deposition mask that can solve the above problems. Summary of the Invention [Problem to be solved by the invention]

[0015] The embodiment provides a deposition mask that reduces through-hole defects.

[0016] The embodiments provide a deposition mask with improved through-hole uniformity. [Means for solving the problem]

[0017] The metal plate according to the embodiment has a length of 900 mm to 1100 mm, a width of 290 mm to 300 mm, and a thickness of 15 μm to 100 μm. The metal plate includes Invar. The thickness of the metal plate is adjusted to an inspection thickness of 3 μm to 10 μm to form a unit metal plate having a unit size of L×W×X. The number of inclusions per unit size of the unit metal plate is 10 or less. The size of the inclusions exceeds the inspection thickness. [Effects of the Invention]

[0018] The metal plate according to the embodiment can control the number of inclusions, specifically, the number of inclusions having a size equal to or larger than a set size in a unit metal plate of a unit size.

[0019] The metal plate controls the DPU (Defects Per Unit) of the unit metal plate within a set range, thereby reducing defects in through holes of deposition masks manufactured using the unit metal plate, thereby improving deposition quality and deposition reliability.

[0020] In addition, before manufacturing the deposition mask, it is possible to check whether the unit metal plate is normal or defective in advance, thereby preventing a process of manufacturing a deposition mask using a defective unit metal plate, thereby improving process efficiency.

[0021] In addition, the number of inclusions having a size equal to or larger than a set size can be controlled in a test piece of unit size.

[0022] Therefore, the DPU (Defects Per Unit) of the deposition mask is controlled within a set range, thereby reducing defects in the through holes, and the deposition mask has improved deposition quality and deposition reliability.

[0023] In addition, after manufacturing the deposition mask, the deposition quality and deposition reliability of the deposition mask can be confirmed in advance based on the size of the DPU (Defects Per Unit). Therefore, only deposition masks with a low through-hole defect rate can be selectively selected. Therefore, the efficiency of the deposition process is improved. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 2] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 3] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 4] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 5] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 6] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 7] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 8] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 9] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 10] 1 is a diagram for explaining a metal plate inspection method according to an embodiment. [Figure 11] This is a photograph of an example experiment. [Figure 12] This is a photograph of an example experiment. [Figure 13] 1 is a view illustrating a combination of a deposition mask and a frame according to an embodiment; [Figure 14] 1 is a cross-sectional view of an organic vapor deposition apparatus including a vapor deposition mask according to an embodiment. [Figure 15]1 is a view illustrating that a deposition pattern is formed on a deposition substrate by through holes of a deposition mask according to an embodiment. [Figure 16] FIG. 2 is a plan view of an evaporation mask according to an embodiment. [Figure 17] 10 is a diagram for explaining defects in through holes in a deposition mask according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the technical concept of the present invention is not limited to the described embodiments, but may be embodied in various forms, and the components of the embodiments may be selectively combined or substituted within the scope of the technical concept of the present invention. Furthermore, terms (including technical and scientific terms) used in the embodiments of the present invention should be interpreted as meanings that are commonly understood by those skilled in the art to which the present invention pertains, unless otherwise expressly specified. Generally used terms, such as dictionary-defined terms, should be interpreted in light of the context of the relevant technology.

[0026] Furthermore, the terms used in the examples of the present invention are intended to explain the examples and are not intended to limit the present invention. In this specification, the singular form can include the plural form unless otherwise specified, and when it is described as "A and at least one (or one or more) of B and C," it can include one or more of all possible combinations of A, B, and C.

[0027] Furthermore, in describing components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. are used to distinguish the components from other components, and the terms do not limit the essence or order of the components.

[0028] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, this includes both cases where the component is directly coupled or connected to the other component, and cases where other components are further "coupled," "coupled," or "connected" between the components.

[0029] Furthermore, when it is described as being formed or positioned "above or below" each component, "above or below" does not only include cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or positioned between the two components.

[0030] Furthermore, when the expression "above or below" is used, it can mean not only an upward direction but also a downward direction with respect to one component.

[0031] The deposition mask described below is a fine metal mask (FMM) that can form an RGB pixel pattern on a deposition substrate by depositing organic materials such as red, green, and blue on the deposition substrate, and the following description does not apply to an open mask (OM).

[0032] In the following description, the first direction is the length direction of the metal plate or the deposition mask, and the second direction is the width direction of the metal plate or the deposition mask.

[0033] A metal plate and an inspection method therefor according to an embodiment will be described with reference to FIGS.

[0034] <Metal plates and their inspection methods> The metal plate 10 according to the embodiment is a raw material for manufacturing the deposition mask according to the embodiment. That is, the deposition mask is formed by forming a plurality of through holes in the metal plate 10.

[0035] Referring to FIG. 1, the inspection method includes a first step of preparing a unit metal plate, a second step of placing a support layer on one side of the unit metal plate, a third step of controlling the thickness of the unit metal plate, a fourth step of checking the DPU (Defect Per Unit) of the unit metal plate, and a fifth step of evaluating the unit metal plate.

[0036] Referring to FIGS. 1 to 3, in the first step, a metal plate having a predetermined size is prepared.

[0037] The metal plate 10 includes a first surface 1S and a second surface 2S opposite to the first surface 1S, and has a predetermined size.

[0038] The metal plate 10 is wound around a roller for the roll-to-roll process, and in the first step, unit metal plates having a set size are cut from the roller.

[0039] The unit metal plate 10 has a set thickness. For example, the thickness T of the unit metal plate 10 may be 100 μm or less. More specifically, the thickness T of the unit metal plate 10 may be 15 μm to 100 μm or 60 μm to 80 μm. The thickness T of the unit metal plate 10 is defined as the maximum distance from the first surface 1S to the second surface 2S.

[0040] In addition, the unit metal plate 10 has a predetermined width W and length L. For example, the length L of the unit metal plate 10 may be 900 mm to 1100 mm. The width W of the unit metal plate 10 may be 290 mm to 300 mm.

[0041] The metal plate includes an alloy. Specifically, the metal plate includes iron (Fe) and nickel (Ni). More specifically, the metal plate includes iron (Fe), nickel (Ni), oxygen (O), and chromium (Cr). The metal plate may further include a small amount of at least one element selected from the group consisting 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). For example, the metal plate may include an Invar alloy.

[0042] Invar is an alloy containing iron and nickel. Invar has a thermal expansion coefficient close to zero. Because Invar has a very low thermal expansion coefficient, it is used for precision parts such as masks. Therefore, deposition masks manufactured using the unit metal plates 10 have improved reliability. That is, deformation of the deposition mask is prevented. In addition, the life of the deposition mask is extended.

[0043] The metal plate may contain about 60% to about 65% by weight of iron. The metal plate may also contain about 35% to about 40% by weight of nickel. Specifically, the metal plate may contain about 63.5% to about 64.5% by weight of iron and about 35.5% to about 36.5% by weight of nickel. The metal plate may also contain about 1% by weight or less of at least one element selected from the group consisting 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).

[0044] The components, content, and weight percentage of the metal plate can be confirmed by sampling a test piece. Specifically, a specific area is selected on the plane of the metal plate 10. Then, a test piece corresponding to the thickness of the metal plate 10 is sampled. Then, the test piece is dissolved in a strong acid to confirm the weight percentage of each component. However, the examples are not limited thereto. The weight percentage of the composition can be confirmed by various methods that can confirm the composition of the metal plate.

[0045] The metal plate contains various elements in addition to iron and nickel. Accordingly, the metal plate contains inclusions with various compositions, composition ratios, and sizes. Through holes are formed in the metal plate. If the number of inclusions is large or the size of the inclusions is large, defects in the through holes may occur.

[0046] Therefore, the metal plate inspection method checks the size and number of the inclusions in advance, thereby allowing for the selection of metal plates suitable for manufacturing the deposition mask in advance, or for the prediction of the defective rate of through holes according to the size and number of the inclusions after manufacturing the deposition mask.

[0047] 1 and 4, in the second step, the support layer 20 is disposed on the first surface 1S or the second surface 2S. For example, the support layer 20 is formed by rolling a roller on the first surface 1S. In this way, the support layer 20 is disposed on the first surface 1S.

[0048] The support layer 20 may include a resin material. The support layer 20 may also be transparent. Specifically, the support layer 20 may include a light-transmitting material.

[0049] When the unit metal plate 10 is etched, the unit metal plate 10 is supported by the support layer 20. Furthermore, when light is irradiated onto the unit metal plate, the support layer 20 can transmit the light, as will be described below.

[0050] 1 and 5, in the third step, the thickness of the unit metal plate 10 is reduced to a set thickness. Specifically, the unit metal plate 10 is etched. This controls the thickness of the unit metal plate 10. As a result, the thickness of the unit metal plate 10 changes to an inspection thickness X.

[0051] For example, in the third step, the thickness of the unit metal plate 10 changes from the initial thickness T to the inspection thickness X. The inspection thickness X is the thickness of the unit metal plate 10 after etching.

[0052] For example, when the support layer 20 is disposed on the first surface 1S, the second surface 2S is etched.

[0053] The thickness of the unit metal plate 10 can be controlled by various processes. For example, the unit metal plate 10 can be etched by a wet etching process. More specifically, the unit metal plate 10 can be etched with an acidic etching solution.

[0054] The etching solution can etch Invar metal, and can include a ferric chloride solution, or can include a solution obtained by mixing ferric chloride solution with at least one of perchloric acid, hydrochloric acid, sulfuric acid, formic acid, and acetic acid.

[0055] The unit metal plate 10 may be immersed in the etching solution, or the etching solution may be sprayed onto the second surface 2S. That is, the unit metal plate 10 may be etched by a dipping process or a spraying process.

[0056] Thus, the thickness of the unit metal plate 10 is adjusted to a set thickness range. Specifically, the unit metal plate 10 is adjusted to an inspection thickness X of X μm, where X may be between 3 μm and 10 μm.

[0057] The unit metal plates 10 may be rolled before etching. The rolling process is optional.

[0058] For example, the unit metal plate 10 can be formed by a cold rolling process, whereby the thickness of the unit metal plate 10 is formed to about 30 μm or less, followed by the etching process.

[0059] After controlling the thickness of the unit metal plate 10, the unit size of the unit metal plate is defined by the thickness, length, and width of the unit metal plate 10. Specifically, the unit size is defined as length x width x inspection thickness (L x W x X). The unit size may correspond to the size of at least one deposition mask manufactured using the unit metal plate 10. That is, one or more deposition masks may be manufactured using the unit metal plate 10. The unit size is used when checking the DPU (Defects Per Unit) of the metal plate, which will be described below.

[0060] 6 to 9, the fourth step involves checking the size and number of inclusions in the unit metal plate 10. The inclusions contain at least one element selected from the group consisting of carbon, oxygen, magnesium, aluminum, silicon, sulfur, calcium, and iron. That is, the fourth step involves checking the DPU, which is the number of inclusions per unit size of the unit metal plate.

[0061] Referring to Figure 6, when X is adjusted to the range of 3µm to 10µm, most of the inclusions whose maximum size is Xµm or less remain. For example, the inclusions whose maximum size is Xµm or less may include a first inclusion D1-1 and a first inclusion D1-2. The first inclusion D1-1 may remain. Furthermore, the first inclusion D1-2 may protrude outside the second surface 2S.

[0062] In addition, the unit metal plate 10 may include second inclusions D2 having a maximum size exceeding X μm. The second inclusions D2 protrude outward from the unit metal plate 10. As a result, the second inclusions D2 protrude outward from the second surface 2S.

[0063] That is, the inspection thickness varies depending on the size of the inclusions to be measured. For example, if the number of inclusions exceeding 10 μm is to be checked, the thickness X is controlled to 10 μm. Alternatively, if the number of inclusions exceeding 3 μm is to be checked, the thickness X is controlled to 3 μm.

[0064] That is, the DPU (Defect Per Unit) is defined as an inclusion having a size exceeding the thickness of the unit metal plate, i.e., the size of the inclusion is larger than the thickness of the unit metal plate.

[0065] The inclusions are related to the step height of the small hole V1 of the deposition mask. Specifically, the small hole V1 is formed on one side of the unit metal plate, and the large hole V2 is formed on the other side. The small hole V1 and the large hole V2 are connected by a connecting portion CA to form a through hole. The step height of the small hole V1 is the vertical distance from one side of the metal plate to the connecting portion. The size of the inclusions is equal to or greater than the step height of the small hole V1.

[0066] 7, the inclusions protruding out of the second surface 2S may exit the unit metal plate 10. The inclusions and the unit metal plate 10 form crevice corrosion. The first-1 inclusion D1-1 and the second inclusion D2 exit the unit metal plate 10 due to the crevice corrosion.

[0067] 8, surface holes are formed in the areas where the first-1 inclusion D1-1 and the second inclusion D2 are removed. For example, the unit metal plate 10 includes a first surface hole H1 and a second surface hole H2. The first surface hole H1 is the area where the first-1 inclusion D1-1 is removed. The second surface hole H2 is the area where the second inclusion D2 is removed.

[0068] 9, a light source 30 is disposed below the second surface 2S. Then, light is irradiated onto the second surface 2S. The light from the light source 30 can travel from the second surface 2S to the first surface 1S.

[0069] The DPU (Defect Per Unit) can be confirmed by light that is transmitted through the support layer 20 and reflected.

[0070] Specifically, light incident on the first surface hole H1 and the second surface hole H2 passes through the support layer 20. Light incident on areas of the unit metal plate 10 other than the surface holes does not pass through the unit metal plate 10.

[0071] 10, light transmitted through the first surface hole H1 and the second surface hole H2 can be seen in the support layer 20. More specifically, a first transmission region TA1 and a second transmission region TA2 can be seen in the support layer 20. The first transmission region TA1 is a region transmitted through the first surface hole H1. The second transmission region TA2 is a region transmitted through the second surface hole H2. The first transmission region TA1 and the second transmission region TA2 have different sizes.

[0072] The DPU (Defects Per Unit) is determined based on the number of the second transmission regions TA2. That is, the first transmission regions TA1 are regions that are transmitted through the first surface H1 and are formed by the first inclusions. When determining the number of DPU (Defects Per Unit), the number of the first transmission regions TA1 is excluded.

[0073] 1, in the fifth step, the unit metal plate 10 is determined to be normal or defective based on the DPU (Defect Per Unit). That is, if the number of the second transmission regions with respect to the unit size (L×W×X) is within a set range, the unit metal plate 10 is determined to be normal.

[0074] Furthermore, if the number of the second transmission regions exceeds a set range for the unit size (L×W×X) of the metal plate, the unit metal plate 10 is determined to be defective.

[0075] For example, the unit metal plate 10 may have a length L of 900 mm to 1100 mm, a width W of 290 mm to 300 mm, and a thickness X of 3 μm to 10 μm. If the number of defects per unit (DPU) per unit size (L×W×X) of the metal plate is 10 or less, it is determined to be normal. Specifically, if the number of defects per unit (DPU) per unit size (L×W×X) of the metal plate is 0 to 10 or 1 to 10, it is determined to be normal. If the number of defects per unit (DPU) per unit size (L×W×X) of the metal plate is more than 10, it is determined to be defective.

[0076] Specifically, the metal plate 10 may have a length L of 900 mm to 1100 mm, a width W of 290 mm to 300 mm, and a thickness X of 3 μm to 10 μm. If the number of inclusions exceeding the thickness X of the unit metal plate 10 is 10 or less, the unit metal plate 10 is judged to be normal. If the number exceeds 10, the unit metal plate 10 is judged to be defective.

[0077] In particular, when a deposition mask is manufactured using a metal plate having a DPU (Defects Per Unit) of 10 or less, defects in through holes formed in the metal plate 10 can be minimized. However, when a deposition mask is manufactured using a metal plate having a DPU (Defects Per Unit) of more than 10, the size or shape of the through holes formed in the metal plate 10 may change. This may result in a deterioration in the quality of the deposition pattern formed by the deposition mask.

[0078] Example 1 A unit metal plate having a length L of 900 mm, a width W of 290 mm, and a thickness X of 3 μm to 10 μm is manufactured. Then, the number of DPUs is measured using the metal plate inspection method.

[0079] Next, three deposition masks are manufactured using the unit metal plate, and 70 million through-holes are formed in each deposition mask.

[0080] Next, defects in through holes are checked according to the number of DPU (Defects Per Unit) for one deposition mask. The DPU (Defects Per Unit) inclusions are inclusions whose size exceeds the thickness X of a unit metal plate.

[0081] Furthermore, the defects of the through holes are as shown in Figure 17. For example, a through hole having a larger diameter than other through holes as shown in Figure 17(a) is determined to be defective. Through holes connected to each other as shown in Figure 17(b) are determined to be defective. Through holes having a smaller diameter than other through holes as shown in Figure 17(c) are determined to be defective.

[0082] <Example 2> A unit metal plate having a length L of 1000 mm, a width W of 300 mm, and a thickness X of 3 μm to 10 μm is manufactured. Then, the number of DPUs is measured using the metal plate inspection method. Then, defects in the through holes of the deposition mask are checked in the same manner as in Example 1.

[0083] Example 3 A unit metal plate having a length L of 1100 mm, a width W of 310 mm, and a thickness X of 3 μm to 10 μm is manufactured. Then, the number of DPUs is measured using the metal plate inspection method. Then, defects in the through holes of the deposition mask are checked in the same manner as in Example 1. [Table 1] [Table 2] [Table 3]

[0084] Table 1 shows the results for Example 1. Table 2 shows the results for Example 2. Table 3 shows the results for Example 3. Also, FIG. 11 is a photograph of Experimental Example 9 of Example 1. FIG. 12 is a photograph of Experimental Example 10 of Example 1.

[0085] Referring to Tables 1 to 3, it can be seen that when the number of inclusions exceeding the thickness of the unit metal plate exceeds 10, the through-hole defect rate increases significantly.

[0086] In the embodiment, the DPU (Defects Per Unit) of the unit metal plate is controlled within a set range, thereby reducing defects in through holes of deposition masks manufactured using the unit metal plate, thereby improving deposition quality and deposition reliability.

[0087] In addition, the unit metal plates can be checked for normality or defect before manufacturing the deposition mask, thereby eliminating the process of manufacturing a deposition mask from a unit metal plate that has been determined to be defective, thereby improving process efficiency.

[0088] <Deposition mask> Hereinafter, an evaporation mask according to an embodiment will be described with reference to FIGS.

[0089] 13 and 14, the organic material deposition apparatus includes a deposition mask 100, a mask frame 200, a deposition substrate 300, an organic material deposition vessel 400, and a vacuum chamber 500.

[0090] The deposition mask 100 is formed of the metal plate 10 described above. The deposition mask 100 includes a plurality of through holes TH. The through holes are arranged in an effective area. The through holes are arranged to correspond to pixel patterns formed on a deposition substrate.

[0091] The mask frame 200 includes openings 205. The through-holes are disposed in areas corresponding to the openings 205. Thus, the organic material supplied from the organic material deposition chamber 400 is deposited on the deposition substrate 300. The deposition mask 100 is disposed on and fixed to the mask frame 200. For example, the deposition mask 100 is stretched with a certain tension. The deposition mask 100 is also welded and fixed to the mask frame 200.

[0092] For example, the non-effective area of ​​the deposition mask 100 is welded, so that the deposition mask 100 is fixed on the mask frame 200. Then, the portion of the mask frame 200 that protrudes outward is cut off and removed.

[0093] The mask frame 200 includes a metal having high rigidity, which reduces deformation of the mask frame during the welding process.

[0094] The deposition substrate 300 is a substrate used when manufacturing a display device. For example, an OLED pixel pattern is formed on the deposition substrate 300. Organic patterns of red, green, and blue are formed on the deposition substrate 300 to form pixels of the three primary colors of light. That is, an RGB pattern is formed on the deposition substrate 300.

[0095] The organic material deposition container 400 is a crucible. An 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 in the width direction of the deposition mask 100 within the vacuum chamber 500.

[0096] A heat source and / or an electric current is supplied to the organic material deposition chamber 400, so that the organic material is deposited on the deposition substrate 300.

[0097] Referring to FIG. 15, the deposition mask 100 includes a first surface 1S and a second surface 2S opposite to the first surface 1S.

[0098] The first surface 1S includes a small surface hole V1, and the second surface 2S includes a large surface hole V2. For example, the first surface 1S and the second surface 2S are each formed with a plurality of small surface holes V1 and a plurality of large surface holes V2.

[0099] The deposition mask 100 also includes through holes TH, which are formed by connecting portions CA at the boundaries of the small surface holes V1 and the large surface holes V2.

[0100] The width of the large-surface hole V2 is larger than the width of the small-surface hole V1. The width of the small-surface hole V1 is measured on a first surface 1S of the deposition mask 100. The width of the large-surface hole V2 is measured on a second surface 2S of the deposition mask 100.

[0101] Furthermore, the width of the connecting portion CA has a predetermined size. Specifically, the width of the connecting portion CA may be 15 μm to 33 μm. More specifically, the width of the connecting portion CA may be 19 μm to 33 μm. Even more specifically, the width of the connecting portion CA may be 20 μm to 27 μm. If the width of the connecting portion CA exceeds 33 μm, it becomes difficult to realize a resolution of 500 PPI or higher. Furthermore, if the width of the connecting portion CA is less than 15 μm, defects may occur during the deposition process.

[0102] The small facet hole V1 faces the deposition substrate 300. The small facet hole V1 is disposed close to the deposition substrate 300. Therefore, the small facet hole V1 has a shape corresponding to the deposition pattern DP.

[0103] The large hole V2 faces the organic material deposition container 400. Therefore, the organic material supplied from the organic material deposition container 400 is accommodated in a wide area by the large hole V2. In addition, a fine pattern can be quickly formed on the deposition substrate 300 through the small hole V1.

[0104] As a result, the organic material accommodated in the large-surface hole V1 is deposited on the deposition substrate 300 through the small-surface hole V1. As a result, one of red, green, and blue pixel patterns is formed on the deposition substrate 300. Then, the above process is repeated. As a result, all of red, green, and blue pixel patterns are formed on the deposition substrate 300.

[0105] Referring to FIG. 16, the deposition mask 100 according to the embodiment includes a deposition area DA and a non-deposition area NDA.

[0106] The deposition area DA is an area for forming a deposition pattern. The deposition area DA includes an effective area AA and a non-effective area UA. The effective area AA is an area where through-holes TH, through which the organic material passes, are formed. The non-effective area UA is an area where the through-holes TH are not formed. The through-holes TH may be formed in the non-effective area UA. However, the organic material does not pass through the through-holes TH in the non-effective area UA.

[0107] Although the effective area AA is shown in a square shape in the drawings, the embodiment is not limited thereto, and the effective area AA may be rectangular or circular.

[0108] The effective area AA includes a plurality of effective areas spaced apart from each other in the first direction.

[0109] The deposition area DA may be an area extending from a start point of a first effective area to an end point of a last effective area in the first direction.

[0110] The deposition area DA may be an area extending from a point where the first non-effective area starts to a point where the last non-effective area ends in the first direction.

[0111] The non-effective area UA is a deposition area other than the effective area AA, and may be divided into a first non-effective area UA1 and a second non-effective area UA2 according to their positions.

[0112] The first non-effective areas UA1 are areas between the effective areas AA, whereby the first non-effective areas UA1 are spaced apart in the first direction, and the second non-effective areas UA2 are areas between the effective areas AA and both ends in the second direction.

[0113] The non-deposition area NDA is an area that is not involved in deposition. The non-deposition area NDA includes a frame fixing area. The frame fixing area is an area for fixing the deposition mask 100 to the mask frame 200. The non-deposition area NDA may include at least one of a half-etched portion and an open portion OA. The half-etched portion HF is formed by partially etching the metal plate 10. The open portion OA is formed by completely etching the metal plate 10.

[0114] Residual stress generated when the deposition mask 100 is stretched is dispersed by the half-etched portions HF, thereby reducing waviness of the deposition mask.

[0115] In addition, a jig such as a clamp used to pull the deposition mask 100 is fixed to the opening OP.

[0116] The effective area AA is provided with through holes TH, specifically, the small surface hole V1, the large surface hole V2, and the through hole TH including the small surface hole V1 and the connecting portion CA.

[0117] The deposition mask 100 may have a DPU (Defect Per Unit) within a set range.

[0118] The DPU (Defects Per Unit) of the deposition mask 100 can be confirmed by sampling a test piece. Specifically, a specific area (length a × width b) is selected on the plane of the deposition mask 100. Then, a test piece (a × b × t1) corresponding to the thickness t1 of the deposition mask 100 is sampled. Then, the DPU (Defects Per Unit) is confirmed using the inspection method. Specifically, a support layer is placed on one side of the test piece. Then, the other side of the test piece is etched to adjust the thickness of the test piece to an inspection thickness t2. Then, the test piece is irradiated with light to confirm the DPU (Defects Per Unit).

[0119] The DPU (Defect Per Unit) of the deposition mask is the number of inclusions having a set size per size of the test piece. Specifically, the DPU (Defect Per Unit) is the number of inclusions having a size exceeding the inspection thickness t2 per size of the test piece. The inspection thickness t2 may be 3 μm to 10 μm.

[0120] For example, the test piece S can be sampled to have dimensions of 30 mm x 60 mm x t1 (first test piece), 60 mm x 30 mm x t1 (second test piece), or 60 mm x 60 mm x t1 (third test piece).

[0121] The test piece S may be sampled in various regions of the deposition mask 100. Specifically, the test piece S may be sampled in at least one of the non-deposition area NDA, the first non-effective area UA1, and the second non-effective area UA2.

[0122] The DPU (Defects Per Unit) of the deposition mask varies depending on the size of the test piece S. Specifically, when the size of the test piece is 30 mm x 60 mm x t1 or 60 mm x 30 mm x t1, the DPU (Defects Per Unit) may be 1 or less. When the size of the test piece is 60 mm x 60 mm x t1, the DPU (Defects Per Unit) may be 3 or less.

[0123] If the number of DPU (Defects Per Unit) exceeds the above range, the number of defects in the through holes increases, which reduces the quality of the deposition pattern formed on the deposition substrate.

[0124] Example 4 A deposition area and a non-deposition area are defined on a metal plate having a length of 330 mm, a width of 100 mm, and a thickness of 25 μm. Then, a plurality of through holes are formed in the deposition area to manufacture a deposition mask. Approximately 70 million through holes are formed.

[0125] Next, the DPU is measured using the above-mentioned test method.

[0126] Specifically, a test piece measuring 30 mm x 60 mm x t1 (length x width x thickness) is sampled from the non-evaporation area of ​​the deposition mask. Then, a support layer is placed on one side of the test piece. The thickness of the test piece is controlled on the other side of the test piece. Specifically, the thickness of the test piece is controlled to an inspection thickness t2. Then, light is irradiated from the lower part of the other side of the test piece. Then, the number of DPUs is measured based on the size and number of light-transmitting areas in the support layer. At this time, the inspection thickness t2 is 3 μm to 10 μm.

[0127] Next, the presence or absence of defects in the through holes is confirmed by DPU (Defect Per Unit). The size of the inclusions in the DPU (Defect Per Unit) exceeds the test thickness t2 of the test piece.

[0128] The defect in the through-hole is as shown in FIG.

[0129] <Example 5> A deposition mask is manufactured using a metal plate having a length of 340 mm, a width of 100 mm, and a thickness of 20 μm. A test piece measuring 60 mm x 30 mm x t1 (length x width x thickness) is sampled from the non-effective region of the deposition area of ​​the deposition mask. No through-holes are formed in the non-effective region. The number of DPUs of the deposition mask is measured using the test piece. Next, the presence or absence of defects in the through-holes of the deposition mask is confirmed in the same manner as in Example 4.

[0130] Example 6 A deposition mask is manufactured using a metal plate having a length of 320 mm, a width of 100 mm, and a thickness of 30 μm. A test piece measuring 60 mm x 60 mm x t1 (length x width x thickness) is sampled from the non-effective region of the deposition area of ​​the deposition mask. No through-holes are formed in the non-effective region. The number of DPUs of the deposition mask is measured using the test piece. Next, the presence or absence of defects in the through-holes of the deposition mask is confirmed in the same manner as in Example 4. [Table 4] [Table 5] [Table 6]

[0131] Table 4 shows the results of Example 4. Table 5 shows the results of Example 5. Table 6 shows the results of Example 6. Referring to Tables 4 and 5, when the DPU (Defects Per Unit) of the deposition mask exceeds 1, the through-hole defect rate increases significantly. Also, referring to Table 6, when the DPU (Defects Per Unit) of the deposition mask exceeds 3, the through-hole defect rate increases significantly.

[0132] Therefore, the embodiment controls the DPU (Defects Per Unit) within a set range, thereby reducing defects in the through-holes, and thus the deposition mask has improved deposition quality and deposition reliability.

[0133] In addition, after manufacturing the deposition mask, the deposition quality and deposition reliability of the deposition mask can be confirmed in advance based on the size of the DPU (Defects Per Unit). Therefore, only deposition masks with a small defect rate of through holes can be selectively selected for the deposition process, thereby improving the efficiency of the deposition process.

[0134] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person skilled in the art to which the embodiment belongs. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

[0135] Furthermore, although the above description has focused on the embodiments, these are merely examples and are not intended to limit the present invention. A person skilled in the art to which the present invention pertains may make various modifications and applications not exemplified above within the scope of the essential characteristics of the present invention. For example, each component specifically presented in the embodiments may be modified and implemented. Differences related to such modifications and applications should be construed as being included within the scope of the present invention as defined by the appended claims.

Claims

1. A metal plate having a length L of 900 mm to 1100 mm, a width W of 290 mm to 300 mm, and a thickness T of 15 μm to 100 μm, the metal plate includes Invar; The thickness of the metal plate is adjusted to a test thickness X of 3 μm to 10 μm to form a unit metal plate having a unit size of L×W×X; The number of inclusions per unit size of the unit metal plate is 10 or less, The metal plate, wherein the inclusion has a size exceeding the inspection thickness.

2. The metal plate according to claim 1 , wherein the inclusions contain at least one element selected from the group consisting of carbon, oxygen, magnesium, aluminum, silicon, sulfur, calcium, and iron.

3. including a deposition region and a non-deposition region; the deposition area includes an effective area where a through-hole is to be formed and an ineffective area other than the effective area, the through-hole is formed by a small-surface hole, a large-surface hole, and a communication portion that communicates the small-surface hole and the large-surface hole; A first test piece having a size of 30 mm (length) × 60 mm (width) × t1 (thickness) is sampled from at least one of the non-effective area and the non-vapor-deposited area; A deposition mask, wherein when the thickness of the first test piece is adjusted to an inspection thickness t2, the first test piece has one or less inclusions having a size exceeding the inspection thickness.

4. 4. The deposition mask according to claim 3, wherein the inclusions contain at least one element selected from the group consisting of carbon, oxygen, magnesium, aluminum, silicon, sulfur, calcium, and iron.

5. A second test piece having a size of 60 mm (length) × 30 mm (width) × t1 (thickness) is sampled from at least one of the non-effective area and the non-vapor-deposited area; 5. The deposition mask of claim 4, wherein when the thickness of the second test piece is adjusted to an inspection thickness t2, the second test piece has one or less inclusions having a size exceeding the inspection thickness.

6. A third test piece having a size of 60 mm (length) × 60 mm (width) × t1 (thickness) is sampled from at least one of the non-effective area and the non-vapor-deposited area; 5. The deposition mask of claim 4, wherein when the thickness of the third test piece is adjusted to an inspection thickness t2, the third test piece has three or less inclusions having a size exceeding the inspection thickness.

7. preparing a unit metal plate; disposing a support layer on one surface of the unit metal plate; controlling the thickness of the unit metal plate; checking the DPU (Defect Per Unit) of the unit metal plate; and determining the unit metal plate; checking the DPU (Defect Per Unit) of the unit metal plate; An inspection method for checking the number of inclusions in the unit metal plate by irradiating the unit metal plate with light.

8. In the step of controlling the thickness of the unit metal plate, the thickness of the unit metal plate is changed to a test thickness of 3 μm to 10 μm, The inspection method according to claim 7 , wherein the inclusion has a size exceeding the inspection thickness.

9. When the unit metal plate is irradiated with light, a first transmission area having a size equal to or smaller than the inspection thickness and a second transmission area having a size exceeding the inspection thickness are formed in the support layer, The inspection method according to claim 8 , wherein the inclusions are identified based on the number of the second transmission regions.

10. 8. The inspection method according to claim 7, wherein the inclusions contain at least one element selected from the group consisting of carbon, oxygen, magnesium, aluminum, silicon, sulfur, calcium, and iron.

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