Deposition masks for OLED pixel deposition

Abstract

According to the embodiment, the deposition mask includes a metal plate, the metal plate includes a deposition area and a non-deposition area, the deposition area includes at least one effective portion, the effective portion includes a plurality of unit through holes and a plurality of protrusions, the unit through holes include: a small surface hole formed on the first surface of the metal plate; a large surface hole formed on the second surface of the metal plate; and a connecting portion connecting the small surface hole and the large surface hole, the protrusion being arranged between adjacent small surface holes on the first surface.

Description

Technical Field

[0001] Embodiments relate to deposition masks for OLED pixel deposition. Background Art

[0002] The display device is applicable to various devices. For example, the above-mentioned display device is applicable to small devices such as smart phones or tablet PCs. Alternatively, the above-mentioned display device is applicable to large devices such as TVs, display screens or public displays (PD, Public Display). In recent years, the demand for ultra-high resolution UHD (UHD, Ultra High Definition) above 500PPI (Pixel Per Inch) is increasing. Therefore, display devices with high resolution are used in small devices and large devices.

[0003] Display devices are classified into LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diode) according to a driving method.

[0004] The above-mentioned LCD is a display device driven by liquid crystal, and the OLED is a display device driven by organic matter.

[0005] The OLED can display an infinite light-dark ratio, has a response speed that is more than 1,000 times faster than an LCD, and has an excellent viewing angle. Therefore, the OLED has attracted attention as a display device that can replace the LCD.

[0006] The OLED includes a light-emitting layer. The light-emitting layer includes an organic substance. The organic substance is deposited on a substrate through a deposition mask. The deposition mask may include 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. Thus, the deposition pattern may function as a pixel.

[0007] The open mask is a thin plate that forms a deposition pattern only at a specific position when manufacturing OLED. The open mask is used in the deposition process of forming a light-emitting layer on the backplane after the backplane is completed in the display manufacturing process. That is, the open mask is a mask for depositing the entire display without blocking any part within the operating range of the display. Therefore, the open mask is used when depositing a light-emitting layer using a light-emitting substance of one color.

[0008] In contrast, a fine metal mask is used to change the color on the sub-pixel of the light-emitting layer. Therefore, the fine metal mask includes ultra-fine holes. The process using the fine metal mask must be deposited in multiple steps. Therefore, the process requires accurate alignment. Therefore, the process using the fine metal mask is more difficult than the process using an open mask.

[0009] When the light-emitting layer of the above-mentioned OLED is deposited through an open mask, only a light-emitting layer of one color is formed. Therefore, in order to achieve multiple colors, an additional color filter (Color Filter, C / F) is required. On the contrary, when the above-mentioned fine metal mask is used, an RGB light-emitting layer can be formed. Therefore, no additional color filter is required. That is, the technical difficulty of using the above-mentioned fine metal mask is high. However, compared with the method of using an open mask, a light-shielding filter is not required, so the light efficiency is high.

[0010] The above-mentioned fine metal mask is usually made of an Invar alloy metal plate containing iron (Fe) and nickel (Ni). Through holes that penetrate the above-mentioned one surface and the other surface are formed on one surface and the other surface of the above-mentioned metal plate. The above-mentioned through holes are formed at positions corresponding to the pixel pattern. Therefore, red (Red), green (Green) and blue (Blue) organic matter can be deposited on the substrate through the through holes of the above-mentioned metal plate. Thus, a pixel pattern can be formed on the above-mentioned substrate.

[0011] On the other hand, the fine metal mask includes small surface holes formed on one surface of the metal plate and large surface holes formed on the other surface of the metal plate. The through hole is formed by connecting the small surface hole and the large surface hole by a connecting portion.

[0012] The organic matter is sprayed toward the fine metal mask, and is deposited on the deposition substrate with the large surface holes as inlets and the small surface holes as outlets.

[0013] Therefore, the deposition substrate and the fine metal mask are arranged adjacent to each other. At this time, the fine metal mask and the deposition substrate may be in contact. Therefore, static electricity may be generated during the separation process. As a result, the fine metal mask may be damaged. For this reason, in the past, another spacer was arranged between the fine metal mask and the deposition substrate.

[0014] However, the distance between the small surface holes and the deposition surface of the deposition substrate increases due to the thickness of the spacer. In addition, the deposition quality of the fine metal mask decreases due to the thickness deviation of the spacer.

[0015] Therefore, a deposition mask having a new structure and a method for manufacturing the same that can solve the above-mentioned problems are required. Summary of the invention

[0016] Embodiments provide a deposition mask having improved deposition efficiency and deposition quality.

[0017] According to the embodiment, the deposition mask includes a metal plate, the metal plate includes a deposition area and a non-deposition area, the deposition area includes at least one effective portion, the effective portion includes a plurality of unit through holes and a plurality of protrusions, the unit through holes include: a small surface hole formed on the first surface of the metal plate; a large surface hole formed on the second surface of the metal plate; and a connecting portion connecting the small surface hole and the large surface hole, the protrusion being arranged between adjacent small surface holes on the first surface.

[0018] The deposition mask according to the embodiment includes a protrusion, which is disposed in a deposition region of the deposition mask, and is disposed in an effective portion where organic matter moves in the deposition region of the deposition mask.

[0019] The protrusion is arranged on the first surface of the metal plate having the small surface hole formed therein. The protrusion is formed integrally with the metal plate. That is, the protrusion contains the same material as the metal plate.

[0020] Therefore, the protrusions can be formed simultaneously in the process of forming the small surface holes and the large surface holes, thereby improving process efficiency.

[0021] When the organic material is deposited on the deposition substrate, the protrusion is disposed between the deposition substrate and the deposition mask, so that the protrusion functions as a spacer.

[0022] Therefore, when the organic material is deposited on the above-mentioned deposition substrate, the step of disposing an additional isolation sheet can be omitted.

[0023] The protrusion may have a set size. Specifically, the protrusion has a thickness and a width within a set range. Therefore, the degradation of the deposition quality caused by the protrusion can be prevented. In addition, a high-resolution pixel pattern can be formed.

[0024] In addition, the plurality of protrusions have a deviation within a set range. Therefore, the distance deviation between the plurality of small surface holes and the deposition substrate is reduced. Therefore, the degradation of deposition quality caused by the above-mentioned protrusions can be prevented.

[0025] In addition, a plurality of protrusions may be configured to have different sizes at different positions. In detail, the width of the protrusion may increase as it extends from the edge of the effective portion toward the central portion. That is, the width of the protrusion configured at the edge of the effective portion is smaller than the width of the protrusion configured in the central portion. The central portion is a portion where many holes are distributed. Therefore, the strength of the central portion may be small. Therefore, when the deposition mask is attached to the deposition substrate, a gap may be formed. Therefore, if many protrusions are formed in the central portion, the gap can be prevented. In addition, the strength of the central portion is improved. Therefore, the deposition reliability of the deposition mask can be improved.

[0026] Therefore, when the deposition mask and the deposition substrate are separated, they can be easily separated. In addition, it is possible to prevent the deposition mask from being damaged during the separation process.

[0027] In addition, the surface roughness of the protrusion may be greater than that of the metal plate. Therefore, the contact area of ​​the protrusion increases, and thus the width of the protrusion may be reduced. Therefore, the size of the deposition mask may be prevented from increasing due to the protrusion.

[0028] In addition, the protrusion may be formed of at least two layers. Specifically, the protrusion may include a first layer and a second layer on the first layer.

[0029] The second layer may include a substance having low conductivity. Alternatively, the second layer may include a non-conductive substance. Therefore, static electricity generated when the protrusion contacts the deposition substrate can be reduced. Therefore, the deposition mask can be prevented from being damaged by the static electricity.

[0030] In addition, the area of ​​the upper surface of the protrusion is formed to be smaller than the area of ​​the first surface. Therefore, the contact area between the deposition substrate and the deposition mask can be reduced. Therefore, the static electricity generated when the deposition substrate contacts the protrusion can be reduced. In addition, the static electricity generated when the deposition substrate is separated can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a diagram illustrating a combination of a deposition mask and a frame according to an embodiment.

[0032] Figure 2 is a cross-sectional view of an organic deposition apparatus including a deposition mask according to an embodiment.

[0033] Figure 3 is a diagram illustrating forming a deposition pattern on a deposition substrate through a through hole of a deposition mask according to an embodiment.

[0034] Figure 4 is a top view of a deposition mask according to an embodiment.

[0035] Figures 5 to 8 It is cutting Figure 4 A cross-sectional diagram obtained from the A-A' region. DETAILED DESCRIPTION

[0036] Below, the preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. However, the technical idea of ​​the present invention is not limited to the partial embodiments described, but can be implemented in different various forms. As long as it is within the scope of the technical idea of ​​the present invention, it can be optionally combined and replaced between the embodiments. One or more of its constituent elements can be used. In addition, the terms (including technical terms and scientific terms) used in the embodiments of the present invention can be interpreted as meanings that are generally understood by those skilled in the art unless they are particularly clearly described and defined. Commonly used terms such as terms defined in dictionaries can be interpreted in light of the definition of the context of the relevant technology.

[0037] In addition, the terms used in the embodiments of the present invention are used to illustrate the embodiments and are not intended to limit the present invention. In this specification, unless otherwise specified in a sentence, a singular form may also include a plural form, and when recorded as "A and (and) at least one (or more than one) of B and C", it may include more than one of all combinations that can be combined by A, B, and C.

[0038] In addition, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are only used to distinguish the components from other components, and the nature, order or sequence of the corresponding components are not limited by the terms.

[0039] In addition, when it is recorded that a certain constituent element is "connected", "combined" or "accessed" to other constituent elements, it may include not only the situation where the constituent element is directly connected, combined or accessed to the other constituent elements, but also the situation where the constituent element is "connected", "combined" or "accessed" due to the existence of other constituent elements between the constituent element and the other constituent elements.

[0040] In addition, when recorded as being formed or arranged "on (above)" or "under (below)" each component, on (above) or under (below) includes not only a case where two components are in direct contact with each other, but also includes a case where one or more additional components are formed or arranged between the two components.

[0041] In addition, when the expression "on (upper side) or lower (lower side)" is used, it can include not only the upper side but also the lower side based on one component.

[0042] Hereinafter, a deposition mask according to an embodiment will be described with reference to the accompanying drawings.

[0043] The deposition mask described below is a fine metal mask (FMM) that can form an RGB pixel pattern on the above deposition substrate by depositing red (Red), green (Green) and blue (Blue) organic matter on the deposition substrate. In addition, for the open mask (OM), the following description does not apply.

[0044] Figures 1 to 3 is a diagram for explaining a process of depositing an organic substance on a deposition substrate 300 using the deposition mask 100 according to an embodiment.

[0045] Reference Figure 1 and Figure 2 The organic deposition apparatus includes a deposition mask 100 , a mask frame 200 , a deposition substrate 300 , an organic deposition container 400 , and a vacuum chamber 500 .

[0046] The deposition mask 100 includes a metal. For example, the deposition mask includes iron (Fe) and nickel (Ni). Specifically, the deposition mask includes an Invar alloy including iron (Fe) and nickel (Ni).

[0047] The deposition mask 100 includes a plurality of through holes TH. The through holes are arranged in an effective portion. The through holes are arranged to correspond to a pixel pattern to be formed on a deposition substrate. The deposition mask 100 includes a non-effective portion except for an effective portion including a deposition area.

[0048] The mask frame 200 includes an opening 205. The plurality of through holes are disposed on a region corresponding to the opening 205. Therefore, the organic substance supplied to the organic deposition container 400 is deposited on the deposition substrate 300. The deposition mask 100 is disposed on the mask frame 200 and fixed. For example, the deposition mask 100 is stretched with a certain tensile force. In addition, the deposition mask 100 is welded to the mask frame 200 and fixed.

[0049] For example, welding is performed on the inactive region of the deposition mask 100. Thus, the deposition mask 100 is fixed to the mask frame 200. Next, a portion protruding to the outside of the mask frame 200 is cut and removed.

[0050] The mask frame 200 includes a metal having high rigidity, thereby reducing deformation of the mask frame during a welding process.

[0051] The deposition substrate 300 is a substrate used in 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 three primary colors of light. That is, an RGB pattern is formed on the deposition substrate 300.

[0052] The organic deposition container 400 is a crucible. The organic substance is disposed inside the crucible. The organic deposition container 400 moves in the vacuum chamber 500. That is, the organic deposition container 400 moves in one direction in the vacuum chamber 500. For example, the organic deposition container 400 moves in the vacuum chamber 500 along the width direction of the deposition mask 100.

[0053] A heat source and / or an electric current is supplied to the organic deposition container 400 , so that the organic substance is deposited on the deposition substrate 300 .

[0054] Reference Figure 3 The deposition mask 100 includes a metal plate 10. The metal plate includes a first surface 1S and a second surface 2S. The first surface 1S and the second surface 2S are opposite surfaces to each other.

[0055] The first surface 1S includes small surface holes V1, and the second surface 2S includes large surface holes V2. For example, a plurality of small surface holes V1 and a plurality of large surface holes V2 are formed on the first surface 1S and the second surface 2S, respectively.

[0056] In addition, the deposition mask 100 includes a through hole TH. The through hole TH is formed by a connection portion CA connecting the boundary of the small surface hole V1 and the large surface hole V2.

[0057] The width of the large surface hole V2 is greater than the width of the small surface hole V1. The width of the small surface hole V1 is measured at the first surface 1S of the deposition mask 100. The width of the large surface hole V2 is measured at the second surface 2S of the deposition mask 100.

[0058] In addition, the width of the above-mentioned connection portion CA has a set size. In detail, the width of the above-mentioned connection portion CA may be 15μm to 33μm. In more detail, the width of the above-mentioned connection portion CA may be 19μm to 33μm. In more detail, the width of the above-mentioned connection portion CA may be 20μm to 27μm. If the width of the above-mentioned connection portion CA is greater than 33μm, it is difficult to achieve a resolution of 500PPI level or above. In addition, when the width of the above-mentioned connection portion CA is less than 15μm, defects may occur in the deposition process.

[0059] The small surface hole V1 faces the deposition substrate 300. The small surface hole V1 is disposed close to the deposition substrate 300. Therefore, the small surface hole V1 has a shape corresponding to the deposition pattern DP.

[0060] The large surface hole V2 faces the organic deposition container 400. Therefore, the organic material supplied from the organic deposition container 400 can be accommodated in a wide width by the large surface hole V2. In addition, a fine pattern can be quickly formed on the deposition substrate 300 through the small surface hole V1.

[0061] Therefore, the organic substance contained in the large surface hole V1 is deposited on the deposition substrate 300 through the small surface hole V1. Therefore, any one of the red, green and blue pixel patterns is formed on the deposition substrate 300. Then, the above process is repeated. Thus, all the red, green or blue pixel patterns are formed on the deposition substrate 300.

[0062] On the other hand, the deposition mask 100 is disposed adjacent to the deposition substrate 300 to form a pixel pattern on the deposition substrate 300. At this time, the deposition mask 100 and the deposition substrate 300 may be in contact. Therefore, static electricity may be generated when the deposition mask 100 is separated. Therefore, the deposition mask 100 may be damaged by the static electricity.

[0063] In the past, a spacer was disposed between the deposition mask and the deposition substrate. However, the thickness of the spacer increased the shadow effect. The shadow effect is a phenomenon in which organic matter diffuses during deposition. Therefore, the deposition efficiency of the deposition mask is reduced. In addition, the thickness deviation of the pixel pattern is generated due to the thickness deviation of the spacer.

[0064] Next, a deposition mask that can solve the above-mentioned problems will be described.

[0065] Figure 4 is a top view of a deposition mask 100 according to an embodiment.

[0066] Reference Figure 4 , the above-mentioned deposition mask 100 includes a deposition area DA and a non-deposition area NDA.

[0067] The deposition area DA is an area for forming a deposition pattern. The deposition area DA includes a pattern area and a non-pattern area. The pattern area is an area including small surface holes V1, large surface holes V2, through holes TH and islands IS. In addition, the non-pattern area is an area not including small surface holes V1, large surface holes V2, through holes TH and islands IS.

[0068] In addition, the deposition area DA includes a plurality of effective areas AA where a plurality of deposition patterns can be formed. That is, the pattern area includes the plurality of effective areas AA. The effective area is an area in the deposition area DA where the small surface holes V1, the large surface holes V2, the through holes TH, and the island IS are formed. That is, in the deposition mask 100, organic substances can move through the effective area AA.

[0069] The active area AA may include a first active area AA1 and a second active area AA2. The second active area AA surrounds the first active area AA1. In addition, the area of ​​the first active area AA1 is larger than that of the second active area AA.

[0070] The deposition area DA includes a plurality of separation areas IA1 and IA2 included in one deposition mask 100. Separation areas IA1 and IA2 are arranged between adjacent effective areas. The separation areas IA1 and IA2 are spacing areas between the plurality of effective areas. The adjacent effective areas can be distinguished by the separation areas IA1 and IA2. In addition, one deposition mask 100 can support a plurality of effective areas.

[0071] The non-deposition area NDA is an area that does not participate in deposition. The non-deposition area NDA includes frame fixing areas FA1 and FA2. The frame fixing area is an area for fixing the deposition mask 100 to the mask frame 200. In addition, the non-deposition area NDA may include half-etching parts HF1 and HF2 and an opening.

[0072] The half-etched portions HF1 and HF2 disperse stress generated when the deposition mask 100 is stretched.

[0073] In addition, the opening OA disperses stress generated when the deposition mask 100 is stretched, thereby reducing deformation of the deposition mask.

[0074] Figures 5 to 8 It is cutting Figure 4 That is, Figures 5 to 8 This is a cross-sectional view obtained by cutting a partial area of ​​the effective portion of the above-mentioned deposition area DA.

[0075] Reference Figure 5 The deposition mask 100 includes a metal plate 10. The metal plate 10 includes a first surface 1S and a second surface 2S opposite to the first surface 1S. The small surface holes V1 are formed on the first surface 1S. The large surface holes V2 are formed on the second surface 2S. The small surface holes V1 and the large surface holes V2 are connected by a connecting portion CA. Therefore, a plurality of through holes TH are formed on the metal plate 10.

[0076] The protrusion 600 is disposed on the first surface 1S. The protrusion 600 may be in contact with the first surface 1S. The protrusion 600 may be formed integrally with the metal plate 10. Therefore, the protrusion 600 may include the same material as the metal plate 10. That is, the protrusion 600 may include a nickel-iron alloy.

[0077] Therefore, the protrusion 600 can be formed in the process of forming the small surface hole V1 and the large surface hole V2. For example, the protrusion 600 can be formed on the metal plate 10 by an etching process, and then the small surface hole and the large surface hole can be continuously formed in the same process step. Therefore, the process efficiency can be improved.

[0078] The protrusion 600 may be disposed between the small surface holes V1. Specifically, the protrusion 600 may be disposed between adjacent small surface holes. The figure shows a case where one protrusion is disposed between adjacent small surface holes. However, the embodiment is not limited thereto. At least one protrusion 600 may be disposed between adjacent small surface holes.

[0079] The protrusion 600 may function as a spacer of the deposition mask 100. In detail, when a pixel pattern is formed on the deposition substrate 300 through the deposition mask 100, the protrusion 600 may contact the deposition substrate 300.

[0080] Therefore, the deposition mask 100 and the deposition substrate 300 are not in direct contact. Therefore, when the deposition mask 100 and the deposition substrate 300 are separated after depositing a pixel pattern, the deposition mask 100 may be prevented from being damaged due to static electricity.

[0081] In addition, only the protrusion 600 contacts the deposition substrate 300. Therefore, the contact area between the deposition mask 100 and the deposition substrate 300 is reduced. Therefore, static electricity generated when the deposition mask 100 and the deposition substrate 300 are separated can be reduced.

[0082] The protrusion 600 may have a thickness T and a width W1 within a set range.

[0083] The thickness T of the protrusion 600 may be smaller than the height h of the small surface hole V1. Specifically, the thickness T of the protrusion 600 may be less than 50%, less than 40%, or less than 30% of the height h of the small surface hole V1. For example, the thickness T of the protrusion 600 may be 25% to 50% of the height h of the small surface hole V1.

[0084] The process of forming the thickness T of the protrusion 600 to be less than 25% of the height h of the small surface hole V1 is difficult. Therefore, the thickness deviation of the plurality of protrusions may increase. Therefore, the deposition efficiency of the deposition mask may decrease.

[0085] When the thickness T of the protrusion 600 is formed to be greater than 50% of the height h of the small surface hole V1, the distance between the small surface hole V1 and the deposition substrate 300 increases. Therefore, the shadow formed on the deposition substrate 300 increases, thereby reducing the deposition quality. The shadow is an area where the organic substance from the small surface hole diffuses. The thickness of the shadow is smaller than the thickness of the pixel pattern to be deposited.

[0086] For example, the thickness T of the protrusion 600 may be less than 3 μm. Specifically, the thickness T of the protrusion 600 may be greater than or equal to 0.5 μm and less than 3 μm, 1 μm to 2.5 μm, or 1.5 μm to 2 μm.

[0087] In addition, the maximum thickness of the protrusion 600 may be smaller than the maximum thickness of the small surface hole. In addition, the minimum thickness of the protrusion 600 may be smaller than the minimum thickness of the small surface hole.

[0088] The size of the minimum thickness, the maximum thickness, and the thickness of the small surface holes of the protrusion 600 can be determined by comparison between the small surface holes that are most adjacent to the protrusion.

[0089] The width W1 of the protrusion 600 may be smaller than the hole pitch P of the small surface holes V1.

[0090] If the width W1 of the protrusion 600 is larger than the hole pitch P of the small surface holes V1, the size of the deposition mask increases in order to form the protrusion 600. In addition, the number of small surface holes may decrease. Therefore, the number of pixels formed on the deposition substrate decreases.

[0091] For example, the width W1 of the protrusion 600 may be greater than or equal to 10 μm. That is, the width W1 of the protrusion 600 may be greater than or equal to 10 μm and smaller than the hole pitch P of the small surface holes V1.

[0092] The thickness T of the protrusion 600 may have a predetermined range. Specifically, the thickness T of the protrusion 600 may have a predetermined range. Specifically, the thickness T of the protrusion 600 may have a predetermined range. Specifically, the thickness T of the protrusion 600 may have a predetermined range. Specifically, the thickness T of the protrusion 600 may have a predetermined range. Specifically, the thickness T of the protrusion 600 may have a predetermined range.

[0093] If the deviation of the thickness T of the protrusion 600 is greater than 20%, the deviation of the distance between the small surface hole V1 and the deposition substrate 300 may increase. Therefore, the width or thickness deviation of the pixel pattern deposited through each small surface hole V1 may increase. Therefore, the deposition quality of the deposition mask may be reduced.

[0094] In addition, the thickness deviation of the small surface hole V1 may be 40% or less. Specifically, the thickness deviation of the small surface hole V1 may be 1% to 40%, 1.2% to 20%, 1.5% to 10%, or 2% to 6%.

[0095] When the deviation of the thickness of the small surface holes V1 is greater than 40%, the thickness of the deposition pattern deposited through each of the small surface holes V1 is not uniform, and thus the deposition quality of the deposition mask may be reduced.

[0096] Reference Figure 6 The size of the protrusion 600 may vary depending on the position. Specifically, the width of the protrusion 600 may vary depending on the position.

[0097] For example, the width of the protrusion 600 may vary as it extends from the edge of the effective portion AA toward the central portion. Specifically, the width of the protrusion 600 may increase as it extends from the edge of the effective portion AA toward the central portion. That is, the width of the protrusion 600 may increase as it extends from the outer side of the effective portion AA toward the inner side.

[0098] Therefore, the width W1-1 of the protrusion adjacent to the effective portion AA is formed to be smaller than the widths W1-2 and W1-3 of the protrusions farther from the effective portion AA. Therefore, the width of the protrusion adjacent to the edge of the effective portion AA is small. In addition, the width of the protrusion adjacent to the central portion of the effective portion AA is large.

[0099] At this time, the widths W1 - 1 , W1 - 2 , and W1 - 3 of the protrusions may be 10 μm or more, which are larger than the width W2 of the small surface holes V1 and smaller than the hole pitch P of the small surface holes V1 .

[0100] The width of the protrusion 600 increases as it extends from the edge of the effective portion AA toward the central portion. Therefore, the contact area between the protrusion 600 and the deposition substrate 300 decreases at the edge of the effective portion AA and the region adjacent thereto. In addition, the contact area between the protrusion 600 and the deposition substrate 300 increases at the central portion of the effective portion AA and the region adjacent thereto.

[0101] Therefore, after forming a pixel pattern on the deposition substrate 300 through the deposition mask 100, the deposition mask 100 can be easily separated. In detail, the deposition mask 100 is separated from the edge to the center. At this time, the edge of the effective portion AA has a small contact area, so the deposition mask 100 can be separated with a small force. Therefore, the deposition mask 100 can be easily separated. In addition, the deposition mask 100 can be prevented from being damaged during the separation process.

[0102] Reference Figure 7 , the protrusion 600 may have a surface roughness different from that of the metal plate 10 .

[0103] The protrusion 600 includes a bottom surface BS and a top surface TS. The bottom surface BS is a surface in contact with the metal plate 10. The top surface TS is a surface opposite to the bottom surface BS. The top surface TS is a surface in contact with the deposition substrate when the pixel pattern is deposited on the deposition substrate through the deposition mask.

[0104] The surface roughness of the top surface TS may be different from the surface roughness of the first surface 1S. Specifically, the surface roughness of the top surface TS may be greater than the surface roughness of the first surface 1S. For example, the top surface TS may include a plurality of patterns PA. As an example, the top surface TS may include a concave-convex pattern.

[0105] Since the surface roughness of the top surface TS is large, the contact area between the protrusion 600 and the deposition substrate 300 may be increased. Therefore, even if the width of the protrusion 600 is reduced, the contact area between the deposition substrate 300 and the protrusion 600 may be maintained.

[0106] Reference Figure 8 , the protrusion 600 may include a plurality of layers.

[0107] The protrusion 600 may include a first layer L1 and a second layer L2 on the first layer L1. The first layer L1 is in contact with the first surface 1S of the metal plate 10, and the second layer L2 is in contact with the first layer L1.

[0108] The first layer L1 and the second layer L2 may have different properties. For example, the first layer L1 and the second layer L2 may have different conductivities. Specifically, the conductivity of the first layer L1 may be greater than the conductivity of the second layer L2. For example, the second layer L2 may be non-conductive.

[0109] For example, the first layer L1 may include a nickel-iron alloy, and the second layer L2 may include a metal with low conductivity. For example, the second layer L2 may include an oxide layer. For example, the second layer L2 may be formed by oxidizing the surface of the first layer L1.

[0110] Alternatively, the first layer L1 may include a nickel-iron alloy, and the second layer L2 may include a non-conductive material. For example, the second layer L2 may include a resin layer. That is, the first layer L1 and the second layer L2 may include different materials.

[0111] Therefore, static electricity generated when the protrusion 600 and the deposition substrate 300 are separated can be prevented. The static electricity is generated by the friction between conductors. Therefore, the contact surface of the protrusion 600 is formed of a non-conductor or a material with low conductivity. Therefore, static electricity generated between the protrusion 600 and the deposition substrate 300 can be prevented.

[0112] The deposition mask according to the embodiment includes a protrusion, which is disposed in a deposition region of the deposition mask, and is disposed in an effective portion where organic matter moves in the deposition region of the deposition mask.

[0113] The protrusion is arranged on the first surface of the metal plate having the small surface hole formed therein. The protrusion is formed integrally with the metal plate. That is, the protrusion contains the same material as the metal plate.

[0114] Therefore, the protrusions can be formed simultaneously in the process of forming the small surface holes and the large surface holes, thereby improving process efficiency.

[0115] When the organic material is deposited on the deposition substrate, the protrusion is disposed between the deposition substrate and the deposition mask, so that the protrusion functions as a spacer.

[0116] Therefore, when the organic material is deposited on the above-mentioned deposition substrate, the step of disposing an additional isolation sheet can be omitted.

[0117] The protrusion may have a set size. Specifically, the protrusion has a thickness and a width within a set range. Therefore, the degradation of the deposition quality caused by the protrusion can be prevented. In addition, a high-resolution pixel pattern can be formed.

[0118] In addition, the plurality of protrusions have a deviation within a set range. Therefore, the distance deviation between the plurality of small surface holes and the deposition substrate is reduced. Therefore, the degradation of the deposition quality caused by the above-mentioned protrusions can be prevented.

[0119] In addition, a plurality of protrusions may be configured to have different sizes depending on the position. In detail, the width of the protrusion may increase as it extends from the edge of the effective portion toward the central portion. That is, the width of the protrusion arranged at the edge of the effective portion is smaller than the width of the protrusion arranged in the central portion. The central portion is a portion where many holes are distributed. Therefore, the strength of the central portion may be small. Therefore, a gap may be formed when the deposition mask is attached to the deposition substrate. Therefore, if many protrusions are formed in the central portion, the gap can be prevented. In addition, the strength of the central portion is improved. Therefore, the deposition reliability of the deposition mask can be improved.

[0120] Therefore, when the deposition mask and the deposition substrate are separated, they can be easily separated, and further, the deposition mask can be prevented from being damaged during the separation process.

[0121] In addition, the surface roughness of the protrusion may be greater than that of the metal plate. Therefore, since the contact area of ​​the protrusion increases, the width of the protrusion may be reduced. Therefore, the size of the deposition mask may be prevented from increasing due to the protrusion.

[0122] In addition, the protrusion may be formed of at least two layers. Specifically, the protrusion may include a first layer and a second layer on the first layer.

[0123] The second layer may include a substance having low conductivity. Alternatively, the second layer may include a non-conductive substance. Therefore, static electricity generated when the protrusion contacts the deposition substrate can be reduced. Therefore, the deposition mask can be prevented from being damaged by the static electricity.

[0124] In addition, the area of ​​the upper surface of the protrusion is formed to be smaller than the area of ​​the first surface. Therefore, the contact area between the deposition substrate and the deposition mask can be reduced. Therefore, the static electricity generated when the deposition substrate and the protrusion contact can be reduced. In addition, the static electricity generated when the deposition substrate is separated can be reduced.

[0125] 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. Moreover, the exemplified features, structures, effects, etc. in each embodiment may also be implemented by a person skilled in the art of the embodiment for other embodiments by combining or modifying them. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

[0126] In addition, the above description is based on the embodiments, but it is only an example and does not limit the present invention. As long as the technical personnel in the field to which the present invention belongs, it can be known that various deformations and applications not illustrated in the above description can be performed within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiment can be deformed and implemented. In addition, the differences related to such deformations and applications should be interpreted as being included in the scope of the present invention specified in the attached claims.

Claims

1. A deposition mask, wherein: comprising a metal plate, the metal plate comprising a deposition area and a non-deposition area, The deposition area includes at least one effective portion, The effective portion includes a plurality of unit through holes and a plurality of protrusions, The unit through hole includes: a small surface hole formed on the first surface of the metal plate; a large surface hole formed on the second surface of the metal plate; and a connecting portion connecting the small surface hole and the large surface hole. The protrusions are disposed between adjacent small surface holes on the first surface.

2. The deposition mask according to claim 1, wherein: The protrusion is formed integrally with the metal plate.

3. The deposition mask according to claim 1, wherein: The thickness of the protrusion is smaller than the height of the small surface hole.

4. The deposition mask according to claim 3, wherein: The thickness of the protrusion is greater than or equal to 0.5 μm and less than 3 μm.

5. The deposition mask according to claim 1, wherein: The width of the protrusion is larger than the width of the small surface hole and smaller than the hole pitch of the small surface hole.

6. The deposition mask according to claim 5, wherein: The width of the protrusion is 10 μm or more.

7. The deposition mask according to claim 1, wherein: The deviation of the plurality of protrusions is greater than or equal to 1% and less than 5%.

8. The deposition mask according to claim 1, wherein: The width of the protrusion increases as it extends from the edge of the effective portion toward the central portion.

9. The deposition mask according to claim 1, wherein: The surface roughness of the protrusion is greater than the surface roughness of the first surface.

10. The deposition mask according to claim 1, wherein: The protrusion includes a first layer and a second layer on the first layer, The second layer has a lower conductivity than the first layer.

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