Deposition mask and manufacturing method thereof, and deposition mask assembly including the same

Abstract

This invention provides a deposition mask manufactured by combining etching and coating methods, a method for manufacturing the same, and a deposition mask assembly including the deposition mask. The deposition mask manufacturing method includes the following steps: forming a resist on a first surface and a second surface of a metal plate; leaving a plurality of first resist patterns on the second surface; forming a coating on the remaining portion except for the portion where the first resist patterns remain; leaving a plurality of second resist patterns on the first surface; etching the remaining portion except for the portion where the second resist patterns remain; and stripping the first and second resist patterns.

Description

Technical Field

[0001] The present invention relates to a deposition mask for depositing organic materials for an organic light emitting diode (OLED), a method for manufacturing the same, and a deposition mask assembly including the deposition mask. Prior Art

[0002] When manufacturing a deposition mask, a photoresist can be applied to both sides of a metal plate manufactured by a rolling process, and holes penetrating the metal plate can be formed by an etching method. The deposition mask manufactured in this way can include a plurality of through-holes and a plurality of inclusions unevenly distributed on the surface or inside of the metal plate.

[0003] When manufacturing a metal plate by rolling, defects such as scratches or dents may occur in the metal plate. In addition, due to the presence of inclusions in the metal plate, such defects may also occur in the metal plate. When forming through-holes in the metal plate, if the defects exist in the boundary area of the etching process, the size of the through-holes may become uneven, for example, causing over-etching defects during hole etching. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a deposition mask manufactured by combining an etching method and a plating method, a method for manufacturing the same, and a deposition mask assembly including the deposition mask.

[0005] The technical problem to be solved by the present invention is not limited to the above technical problems, and those skilled in the art can clearly understand other technical problems not mentioned from the following description.

[0006] According to one aspect, a method for manufacturing a deposition mask of the present invention for solving the above technical problem includes the following steps: forming a resist on a first surface and a second surface of a metal plate; leaving a plurality of first resist patterns on the second surface; forming a plating layer on the remaining portion except for the portion where the first resist pattern remains; leaving a plurality of second resist patterns on the first surface; etching the remaining portion except for the portion where the second resist pattern remains; and peeling off the first resist pattern and the second resist pattern.

[0007] According to one aspect, a deposition mask of the present invention for solving the above technical problem is manufactured by the method for manufacturing a deposition mask.

[0008] According to another aspect, a deposition mask according to the present invention for solving the above technical problem includes: a metal plate having a first surface and a second surface; at least one first groove penetrating the first surface and the second surface; and a plating layer including a second groove corresponding to the first groove on the second surface, wherein the second surface includes a plurality of groove-shaped defects, and a part of the plurality of defects is filled with the plating layer.

[0009] According to one aspect, a deposition mask assembly of the present invention for solving the above technical problem includes: a frame; the deposition mask disposed on the frame; and a support member for fixing the deposition mask to the frame.

[0010] Specific details of other embodiments are included in the detailed description and the drawings.

[0011] According to the present invention, by combining the advantages of a rolled substrate and a coated substrate and applying an etching process and a coating process in combination to manufacture a deposition mask, the following effects can be obtained.

[0012] First, by using a rolled substrate as a core, the coefficient of thermal expansion (CTE) and rigidity can be maintained, and the small hole surface can be coated with the same composition, thereby eliminating problems inherent in the rolled substrate, such as defects caused by inclusions and surface defects.

[0013] Second, it is possible to achieve a low and uniform step height (SH), high hole size uniformity, and a small corner-R value, which are restricted in the etching method.

[0014] Third, it is suitable for manufacturing high-resolution organic light-emitting displays with 500 pixels per inch (PPI) or higher.

[0015] The effects of the present invention are not limited to the above effects, and those skilled in the art can clearly understand other effects not mentioned from the following description. Brief Description of the Drawings

[0016] FIG. 1 is a schematic diagram for explaining the structure of a deposition mask.

[0017] Figure 2 is a schematic diagram for explaining the components formed in the effective area of the metal plate.

[0018] Figure 3 is a schematic diagram for explaining the defects formed on the surface of the metal plate.

[0019] Figure 4 is the first schematic diagram for explaining the problems caused by the defects formed on the surface of the metal plate.

[0020] Figure 5 is the second schematic diagram for explaining the problems caused by the defects formed on the surface of the metal plate.

[0021] Figure 6 is a schematic diagram for explaining the method of solving the problem of defects formed on the surface of the metal plate.

[0022] Figure 7 is a flowchart for sequentially explaining the manufacturing method of the deposition mask.

[0023] Figure 8 is a schematic diagram for explaining the resist coating process in the deposition mask manufacturing method.

[0024] Figure 9 is a schematic diagram for explaining the exposure process and the first development process in the deposition mask manufacturing method.

[0025] Figure 10 is a schematic diagram for explaining the plating process in the deposition mask manufacturing method.

[0026] Figure 11 is a schematic diagram for explaining the protective layer formation process in the deposition mask manufacturing method.

[0027] Figure 12 is the first schematic diagram for explaining the second development process in the deposition mask manufacturing method.

[0028] Figure 13A is the second schematic diagram for explaining the second development process in the deposition mask manufacturing method.

[0029] Figure 13B is the third schematic diagram for explaining the second development process in the deposition mask manufacturing method.

[0030] Figure 13C is the fourth schematic diagram for explaining the second development process in the deposition mask manufacturing method.

[0031] Figure 14 is the first schematic diagram for explaining the etching process in the deposition mask manufacturing method.

[0032] FIG. 15 is a second schematic diagram for explaining an etching process in a deposition mask manufacturing method.

[0033] FIG. 16 is a third schematic diagram for explaining an etching process in a deposition mask manufacturing method.

[0034] FIG. 17 is a fourth schematic diagram for explaining an etching process in a deposition mask manufacturing method.

[0035] FIG. 18 is a schematic diagram for explaining a stripping process in a deposition mask manufacturing method.

[0036] FIG. 19 is a first schematic diagram for explaining a deposition mask assembly including a deposition mask.

[0037] FIG. 20 is a second schematic diagram for explaining a deposition mask assembly including a deposition mask. Embodiment

[0038] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same components, and their repeated description is omitted.

[0039] FIG. 1 is a schematic diagram for explaining the structure of a deposition mask. In FIG. 1, a first direction D1 and a second direction D2 form a plane in the horizontal direction. For example, the first direction D1 can be the front-back direction, and the second direction D2 can be the left-right direction. Alternatively, the first direction D1 can be the left-right direction, and the second direction D2 can be the front-back direction. A third direction D3 is the height direction, a direction perpendicular to the plane formed by the first direction D1 and the second direction D2. The third direction D3 can be the up-down direction.

[0040] The deposition mask 100 can also be referred to as a metal mask and has a structure in which through holes are formed in a metal plate 110, and an effective area 120 and a non-effective area 130 are respectively formed in the metal plate 110. The deposition mask 100 can deposit an organic material on a display panel (for example, an OLED panel) applied to an organic light-emitting display, such as an organic light-emitting diode (OLED), using the through holes. The deposition mask 100 can deposit various types of organic materials such as red (R), green (G), and blue (B) on the panel in a vacuum atmosphere, and thus the RGB pattern formed on the panel can be used as a pixel in an organic light-emitting display.

[0041] The metal plate 110 can be made of a ferroalloy containing iron and nickel, such as Invar. Additives such as aluminum and silicon can be added during the melting process of the base material for manufacturing the metal plate 110 to remove impurities. The metal plate 110 can also contain other components in addition to iron, nickel, and cobalt. The metal plate 110 can be manufactured by a rolling process and an annealing process.

[0042] A plurality of active regions 120 and a plurality of non-active regions 130 can be respectively disposed on the metal plate 110. The active regions 120 can be disposed in the central region of the metal plate 110, and the non-active regions 130 can be disposed on the periphery of the active regions 120 in the metal plate 110. For example, four active regions 210a, 210b, 210c, 210d and four non-active regions 220a, 220b, 230a, 230b can be disposed on the metal plate 110. The four active regions 210a, 210b, 210c, 210d can be disposed in the central region of the metal plate 110, and two non-active regions 220a, 230a and the other two non-active regions 220b, 230b can be disposed on both sides thereof. However, it is not limited thereto, and either one of the active regions 120 and the non-active regions 130 can be disposed on the metal plate 110 in an odd number. Or, the active regions 120 and the non-active regions 130 can also be disposed on a metal plate 110 in an odd number at the same time.

[0043] If a plurality of active regions 120 are disposed on the metal plate 110, two adjacent active regions can be separated. For example, a separation region is formed between the first active region 210a and the second active region 210b. A separation region is formed between the second active region 210b and the third active region 210c. A separation region is formed between the third active region 210c and the fourth active region 210d. The separation region between two adjacent active regions can be included in the non-active region 130.

[0044] As shown in FIG. 2, the active region 120 can also be referred to as a cell region, and a first groove 310, a second groove 320, etc. can be formed in the active region 120. FIG. 2 is a schematic diagram for explaining the components of the active region formed in the metal plate. The following will be described with reference to FIG. 2.

[0045] On both sides of the metal plate 110, first grooves 310 and second grooves 320 of different sizes can be formed respectively. The first grooves 310 can penetrate the first surface 110a and the second surface 110b of the metal plate 110. The first grooves 310 can be recessed portions recessed in the direction from the first surface 110a to the second surface 110b. The first surface 110a can be one of the upper surface and the lower surface of the metal plate 110. The second surface 110b can be a surface different from the first surface 110a. The second surface 110b can be the other of the upper surface and the lower surface of the metal plate 110.

[0046] The second grooves 320 can be formed on the second surface 110b of the metal plate 110. The second grooves 320 can be connected to the first grooves 310. The first grooves 310 and the second grooves 320 can be formed into through holes 330 in the metal plate 110, allowing an organic material to pass through along the front direction where the display panel is located, so as to deposit the organic material on the display panel.

[0047] The second grooves 320 can be formed using a resist pattern and a plating layer PL formed on the second surface 110b. The second grooves 320 can have a constant width in the depth direction D3. The width W2 of the second grooves 320 can be smaller than the width W1 of the first grooves 310 on the first surface 110a and be the same as the width W2 of the first grooves 310 on the second surface 110b. The depth H2 of the second grooves 320 can be smaller than the depth H1 of the first grooves 310. The first grooves 310 can be large hole portions, and the second grooves 320 can be small hole portions.

[0048] The second surface 110b formed with the second grooves 320 can include multiple defects. As described above, the metal plate 110 can be manufactured by a rolling method, and its surface or interior may contain multiple inclusions. Among them, inclusions refer to other particles or components that may be contained in the metal plate 110 except iron, nickel, and cobalt. Therefore, during the manufacturing process of the metal plate 110, multiple defects such as scratches and dents may be generated on the second surface 110b.

[0049] Referring to FIG. 3, three types of defects 410a, 410b, 410c such as the first defect 410a, the second defect 410b, and the third defect 410c may appear on the second surface 110b. The first defect 410a is a defect that appears below the area 420a where the second groove 320 is formed. The second defect 410b is a defect within the area 420b where the second groove 320 is not formed. The third defect 410c is a defect that appears on both the area 420a where the second groove 320 is formed and the area 420b where the second groove 320 is not formed. FIG. 3 is a schematic diagram for explaining the defects formed on the surface of the metal plate.

[0050] In the case of the first defect 410a, it can appear within the area 420a where the second groove 320 is formed and can be removed when the first groove 310 is formed. Referring to FIG. 4, the first defect 410a can not change the size (W3) of the through hole 330. On the other hand, in the case of the third defect 410c, it can appear in the area 420a where the second groove 320 is formed and the area 420b where the second groove 320 is not formed, and a part of the third defect 410c may not be removed when the first groove 310 is formed. Referring to FIG. 5, the third defect 410c can change the size of the through hole 330 (W3 → W4 (>W3)). FIG. 4 is a first schematic diagram for explaining the problems caused by the defects formed on the surface of the metal plate. FIG. 5 is a second schematic diagram for explaining the problems caused by the defects formed on the surface of the metal plate.

[0051] Referring to FIG. 6, in order to solve the defect problem formed on the second surface 110b of the metal plate 110, a plating layer 430 can be formed on the second surface 110b. The plating layer 430 can be formed in the remaining area of the second surface 110b except for the areas where the anti-corrosion patterns 440a, 440b are formed. That is, the plating layer 430 can not be formed in the area 420a where the second groove 320 is formed, but can be formed in the area 420b where the second groove 320 is not formed. The plating layer 430 can be filled with the plating film parts 450a, 450b to form the whole on the second. The plating film part 450b can partially fill the defect 410c, but can also completely fill the defect 410c. By filling the defects 410b, 410c with the plating film parts 450a, 450b, it is possible to prevent the non-uniformity of the size of the through hole 330 formed in the metal plate 110. FIG. 6 is a schematic diagram for explaining the method of solving the defect problem formed on the surface of the metal plate.

[0052] Defects 410a, 410b, and 410c that occur during the manufacturing of the metal plate 110 are randomly distributed over the entire area of the metal plate 110. Therefore, it is impossible to avoid the problematic defects 410b and 410c from forming a plurality of through-holes 330 of uniform size in the metal plate 110. If the sizes of the plurality of through-holes 330 formed in the metal plate 110 are not uniform, the deposition mask 100 may become defective, and when the deposition mask 100 is mass-produced, the yield may decrease. Therefore, in the present invention, the problematic defects 410b and 410c are filled with the plating layer 430 to form the plating film portions 450a and 450b, thereby enabling the sizes of the plurality of through-holes 330 to be uniform.

[0053] On the other hand, the plating layer 430 can be formed not on the entire surface of the metal plate 110. In the deposition mask 100, through-holes for organic material deposition are formed in the effective area 120 and are not formed in the non-effective area 130. Therefore, the plating layer 430 can be formed only in the effective area 120 of the metal plate 110 and is not formed in the non-effective area 130 of the metal plate 110. In this case, the defects 410b and 410c in the effective area 120 can be filled by the plating film portions 450a and 450b, and the defects 410b and 410c in the non-effective area 130 can be not filled by the plating film portions 450a and 450b.

[0054] The following is a description again with reference to FIG. 1.

[0055] The non-effective area 130 is provided in the area surrounding the effective area 120 and is different from the effective area 120, and no through-holes 330 are formed. The non-effective area 130 can include the clamping areas 220a and 220b and the stretching correction areas 230a and 230b.

[0056] The clamping areas 220a and 220b are the parts that are fastened to the clamp when the deposition mask 100 is stretched and bonded to the mask frame. The clamping areas 220a and 220b can be formed at both ends in the long axis direction D1 of the metal plate 110. The mask frame will be described later.

[0057] Although not shown in FIG. 1, the non-effective area 130 may further include a welding area. The welding area refers to the portion welded to the mask frame. The jig can apply a tensile force in the direction of both ends of the metal plate 110 in a state of being fastened to the metal plate 110 by the clamping areas 220a and 220b. In a state where the tensile force is applied in this way, the metal plate 110 is welded to the mask frame through the welding area. The welding area can be provided between the clamping areas 220a and 220b and the stretching correction areas 230a and 230b, but is not limited thereto. The clamping areas 220a, 220b and the welding area can be removed by a cutting process between the deposition of the mask 100 for the organic material deposition process.

[0058] The stretching correction areas 230a and 230b are areas where stretching correction patterns are formed. If welded to the mask frame in a state where a tensile force is applied to the deposition mask 100, the tensile force may also affect the through holes 330 in the effective area 120. Therefore, in order to prevent damage to the through holes 330 by suppressing the influence of the tensile force as much as possible, stretching correction patterns can be formed in the non-effective area 130 to reduce the influence of the tensile force on the through holes 330. The stretching correction pattern can include a plurality of grooves.

[0059] The stretching correction areas 230a and 230b can be formed between the effective area 120 and the clamping areas 220a and 220b. That is, the first stretching correction area 230a can be formed between the first effective area 210a and the first clamping area 220a. And the second stretching correction area 230b can be formed between the fourth effective area 210d and the second clamping area 220b.

[0060] However, not limited thereto, the stretching correction areas 230a and 230b can also be formed in the separated area between two adjacent effective areas. For example, the stretching correction areas 230a and 230b can be formed in at least one of the separated areas between the first effective area 210a and the second effective area 210b, the separated area between the second effective area 210b and the third effective area 210c, and the separated area between the third effective area 210c and the fourth effective area 210d.

[0061] Hereinafter, a method for manufacturing the deposition mask 100 in which the problematic defects 410b and 410c are filled with the plating parts 450a and 450b will be described. FIG. 7 is a flowchart for sequentially explaining the method for manufacturing the deposition mask.

[0062] First, prepare a metal plate 110. The metal plate 110 can be made of a ferroalloy containing iron and nickel. For example, the metal plate 110 can be made of Invar. The thickness of the metal plate 110 can be 10 μm to 50 μm. Preferably, the thickness of the metal plate 110 can be 15 μm to 30 μm.

[0063] After preparing the metal plate 110, perform a surface treatment on the metal plate 110 (S510). When performing the surface treatment on the metal plate 110, the surface treatment can be performed on both sides of the metal plate 110. However, it is not limited thereto, and the surface treatment can also be performed on one side of the metal plate 110. For example, the surface treatment can be performed on the second surface 110b on which the plating portions 450a and 450b are formed.

[0064] When performing the surface treatment on the metal plate 110, the surface treatment of the metal plate 110 can be performed using a Soft Etching method. Using the Soft Etching method can remove contaminants, impurities, and foreign substances distributed on the surface of the metal plate 110, thereby improving the plating adhesion. The thickness of the plating layer 430 can be adjusted by considering the thickness of the metal plate 110 using the Soft Etching method.

[0065] When performing the surface treatment on the metal plate 110, the surface treatment of the metal plate 110 can be performed using a Chemical treatment method. The entire surface or a partial surface of the metal plate 110 can be etched using the Chemical treatment method. If the metal plate 110 is a rolled substrate, the thickness of the etched portion can be 10 nm to 20 μm.

[0066] After performing the surface treatment on the metal plate 110, apply a resist on both sides 110a and 110b of the metal plate 110 (S520). Referring to FIG. 8, the resists 610a and 610b can be a photosensitive resin material and can be a Dry Film Resist (DFR). Alternatively, the resists 610a and 610b can be a coating type Photo Resist. The resists 610a and 610b formed on both sides 110a and 110b of the metal plate 110 can be a negative resist. FIG. 8 is a schematic diagram for explaining the resist coating process in the deposition mask manufacturing method.

[0067] In the present invention, a dry film resist can be applied to both surfaces 110a and 110b of the metal plate 110. However, it is not limited thereto, and a liquid resist can also be applied to both surfaces 110a and 110b of the metal plate 110. When the liquid resist is applied to both surfaces 110a and 110b of the metal plate 110, the liquid resist can cover the defects 410b and 410c generated on the second surface 110b. Due to air trap, the liquid resist can only cover the edge portions of the defects 410b and 410c. On the other hand, when the dry film resist is applied to both surfaces 110a and 110b of the metal plate 110, the dry film resist can cover all the defects 410b and 410c generated on the second surface 110b. Therefore, using the dry film resist helps to fill the defects generated on the surface of the metal plate 110 and ensures linearity related to the filling of the defects.

[0068] When the dry film resist is applied to both surfaces 110a and 110b of the metal plate 110, the protective films 615a and 615b can be attached to the respective resists 610a and 610b. The first protective film 615a and the second protective film 615b protect the respective resists 610a and 610b. The first protective film 615a can function to protect the first surface 110a side where the large hole portion is formed during the step of forming the small hole portion. In the present invention, during the step of forming the small hole portion by the first protective film 615a, the process of forming a separate protective layer for protecting the large hole portion can be omitted, thereby achieving the effect of reducing the number of processes. Hereinafter, for convenience of explanation, the illustration of the protective films 615a and 615b is omitted.

[0069] This will be described again with reference to FIG. 7.

[0070] After the resists 610a and 610b are formed on both surfaces 110a and 110b of the metal plate 110, an exposure process (S530) is performed on both surfaces 110a and 110b of the metal plate 110. Next, a first development process (S540) is performed on the second surface 110b of the metal plate 110. As described above, the second surface 110b refers to the surface of the metal plate 110 where the second groove 320 is formed. Specifically, after removing the second protective film 615b on the second surface 110b, the first development process is performed on the corresponding resist 610b.

[0071] After sequentially performing the exposure process (S530) and the first development process (S540), a plurality of resist patterns remain in a portion of the second surface 110b where the second groove 320 is to be formed. Referring to FIG. 9, the first DFR pattern 620a and the second DFR pattern 620b can remain on the second surface 110b. The first defect 410a can be located in a region adjacent to the first DFR pattern 620a. The third defect 410c can be located in a region adjacent to the second DFR pattern 620b. The second defect 410b can be located in a region not adjacent to the first DFR pattern 620a and the second DFR pattern 620b. FIG. 9 is a schematic diagram for explaining the exposure process and the first development process in the deposition mask manufacturing method.

[0072] This will be described again with reference to FIG. 7.

[0073] After performing the first development process (S540) on the second surface 110b, a plating layer 430 is formed on the second surface 110b (S550). Referring to FIG. 10, the plating layer 430 can be formed on the remaining portion of the second surface 110b except for the portions where the first DFR pattern 620a and the second DFR pattern 620b remain. The first plating film portion 450a can fill all the second defects 410b based on the plating layer 430. The second plating film portion 450b can fill at least a part of the third defect (410b) based on the plating layer 430. FIG. 10 is a schematic diagram for explaining the plating process in the deposition mask manufacturing method.

[0074] The plating layer 430 can be formed on the second surface 110b by an additive method. However, it is not limited thereto, and the plating layer 430 can also be formed on the second surface 110b by a subtractive method. The thickness of the plating layer 430 can be 4 μm or less, so the step height (SH) can be 4 μm or less. Herein, the step height refers to the depth H2 of the second groove 320. Preferably, the thickness of the plating layer 430 can be 3 μm or less. The defect filling rate of the plating layer 430 for the second surface 110b can be 50% or more and 100% or less. And, when an organic material is deposited on the display panel, in order to ensure the uniformity and shape quality of the deposited organic material, the boundary surface of the plating film filling portion in the defect corresponding to the boundary of the second groove 320 can be ±1.5 μm or less of the boundary of the second groove 320.

[0075] The coating layer 430 can be formed using the same metal as the component constituting the metal plate 110. For example, the coating layer 430 can be formed using at least one metal selected from iron or nickel. However, it is not limited to this. As long as it is a metal that can ensure the bonding force with the component constituting the metal plate 110, that is, a metal having adhesion to the component constituting the metal plate 110, the coating layer 430 can also be formed using a metal different from the component constituting the metal plate 110.

[0076] When the metal plate 110 is a rolled substrate, the coefficient of thermal expansion (CTE) in the length direction of the metal plate 110 can be 1.5 ppm or less in the range of 25°C to 100°C. The coefficient of thermal expansion of the metal plate 110 including the coating layer 430 can be 2 ppm or less. The Rz and Ra of the metal plate 110 including the coating layer 430 can be 0.8 µm or less and 0.08 µm or less, respectively.

[0077] This will be described again with reference to FIG. 7.

[0078] After performing the coating process (S550) to fill the second defect 410b and the third defect 410c with the first coating portion 450a and the second coating portion 450b, a protective layer is formed on the coating layer 430 (S560). Referring to FIG. 11, the protective layer 630 can be in the form of a masking film to protect the coating layer 430 in a state where the first DFR pattern 620a and the second DFR pattern 620b are retained on the second surface 110b. The protective layer 630 can cover the entire second surface 110b including the first DFR pattern 620a and the second DFR pattern 620b. However, it is not limited to this. The protective layer 630 can also cover the remaining area of the second surface 110b except for the first DFR pattern 620a and the second DFR pattern 620b. The protective layer 630 can be formed by applying a protective film to the second surface 110b. FIG. 11 is a schematic diagram for explaining the protective layer formation process in the deposition mask manufacturing method.

[0079] This will be described again with reference to FIG. 7.

[0080] After forming the protective layer 630 on the plating layer 430, a second developing process (S570) is performed on the first surface 110a of the metal plate 110. Specifically, after removing the first protective film 615a on the first surface 110a, a second developing process is performed on the corresponding resist 610a. After the second developing process (S570) ends, a plurality of resist patterns remain on the first surface 110a, and the first groove 310 can be formed by the portions where the plurality of resist patterns are not formed (for example, the area between two different resist patterns). Referring to FIG. 12, in order to form the first groove 310 that can contact the first DFR pattern 620a and the second DFR pattern 620b, the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c can remain on the first surface 110a. FIG. 12 is a first schematic diagram for explaining the second developing process in the deposition mask manufacturing method.

[0081] Referring to FIG. 13A, the upper surface length L1 of the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c can be smaller than the lower surface length L2. However, it is not limited thereto. As shown in FIG. 13B, the upper surface length L1 of the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c can be the same as the lower surface length L2. Or, as shown in FIG. 13C, the upper surface length L1 of the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c can be greater than the lower surface length L2. In the present invention, in order to expand the range of the organic material deposited on the display panel through the through hole 330, the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c can be formed in the shape shown in FIG. 13A. FIG. 13A is a second schematic diagram for explaining the second developing process in the deposition mask manufacturing method. FIG. 13B is a third schematic diagram for explaining the second developing process in the deposition mask manufacturing method. FIG. 13C is a fourth schematic diagram for explaining the second developing process in the deposition mask manufacturing method.

[0082] On the other hand, similar to the three DFR patterns 640a, 640b, and 640c formed on the first surface 110a, the two DFR patterns 620a and 620b formed on the second surface 110b can also be formed in one of the shapes shown in FIG. 13A, FIG. 13B, and FIG. 13C. Therefore, the inclination angle of the inner wall of the second groove 320 with respect to the second surface 110b can be 90 degrees or less. Preferably, the inclination angle of the inner wall of the second groove 320 with respect to the second surface 110b can be 60 degrees to 90 degrees.

[0083] This will be described again with reference to FIG. 7.

[0084] After performing the second developing process (S570), an etching process (S580) is considered to be performed according to the positions of the resist patterns 640a, 640b, and 640c remaining on the first surface 110a. The etching process can be performed by a photo etching method. Referring to FIG. 14, the area between the third DFR pattern 640a and the fourth DFR pattern 640b can be etched, and a first groove 310a in contact with the first DFR pattern 620a is formed in the corresponding area. The first groove 310a in contact with the first DFR pattern 620a can remove the first defect 410a from the second surface 110b of the metal plate 110.

[0085] Similarly, the area between the fourth DFR pattern 640b and the fifth DFR pattern 640c can be etched, and a first groove 310b in contact with the second DFR pattern 620b is formed in the corresponding area. The first groove 310b in contact with the second DFR pattern 620b can remove the third defect 410c that is not filled by the second plating portion 450b from the second surface 110b of the metal plate 110. FIG. 14 is a first schematic diagram for explaining the etching process in the deposition mask manufacturing method.

[0086] As described above, the plurality of first grooves 310a, 310b can be recessed in the direction from the first surface 110a to the second surface 110b. The plurality of first grooves 310a, 310b can have a maximum width on the first surface 110a and a minimum width on the second surface 110b. The example in FIG. 14 is an example of the case where the minimum width of the plurality of first grooves 310a, 310b is the same as the width of the first DFR pattern 620a and the width of the second DFR pattern 620b. However, it is not limited to this, and the minimum width of the plurality of first grooves 310a, 310b can also be greater than the width of the first DFR pattern 620a and the width of the second DFR pattern 620b, as shown in FIG. 15. The minimum width of the plurality of first grooves 310a, 310b can also have a size sufficient to completely remove the first defect 410a and the third defect 410c. FIG. 15 is a second schematic diagram for explaining the etching process in the deposition mask manufacturing method.

[0087] Referring to FIG. 16, in the case of the first groove 310a in contact with the first DFR pattern 620a, the one-side portion 650a and the other-side portion 650b in contact with the second surface 110b can be formed on the same line. On the other hand, referring to FIG. 17, in the case of the first groove 310b in contact with the second DFR pattern 620b, due to the second plating portion 450b, the one-side portion 650c and the other-side portion 650d in contact with the second surface 110b may not be formed on the same line. That is, due to the influence of the second plating portion 450b, the other-side portion 650d can be formed to be higher than the one-side portion 650c.

[0088] In the present invention, without restricting the deposition range of the organic material required for each through hole 330, the heights of the one-side portion 650c and the other-side portion 650d can be different. Among them, the difference value (DV) between the one-side portion 650c and the other-side portion 650d can not exceed a reference value. The reference value can be determined as an appropriate value without restricting the deposition range of the organic material. The reference value can be determined in consideration of the thickness of the plating layer 430 and can be 4 μm or less. FIG. 16 is a third schematic diagram for explaining the etching process in the deposition mask manufacturing method. FIG. 17 is a fourth schematic diagram for explaining the etching process in the deposition mask manufacturing method.

[0089] This will be described again with reference to FIG. 7.

[0090] After forming the plurality of first grooves 310a, 310b, a stripping process (S590) is performed on the first surface 110a and the second surface 110b. Referring to FIG. 18, the plurality of resist patterns 640a, 640b, 640c remaining on the first surface 110a after the second developing process (S570), that is, the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c, can be removed by the stripping process (S590). And, the plurality of resist patterns 620a, 620b remaining on the second surface 110b after the first developing process (S540), that is, the first DFR pattern 620a and the second DFR pattern 620b and the protective layer 630, can be removed. In the present invention, the plurality of resist patterns 620a, 620b, 640a, 640b, 640c and the protective layer 630 formed on the first surface 110a and the second surface 110b can be stripped at one time by the stripping process (S590). FIG. 18 is a schematic diagram for explaining the stripping process in the deposition mask manufacturing method.

[0091] The deposition mask 100 manufactured according to the method described above with reference to FIGS. 7 to 18 can perform a coating process and an exposure process on both sides of the metal plate 110 simultaneously, and then perform a development process on the small-hole surface (i.e., the second surface 110b) and the large-hole surface (i.e., the first surface 110a) in sequence, perform a plating process on the small-hole surface additionally, and perform an etching process on the large-hole surface additionally, so as to form a plurality of through holes 330 in the effective area 120 of the metal plate 110. The intersection point of the large-hole surface and the small-hole surface may include a part filled with inclusions or defects during the plating of the small-hole surface.

[0092] A groove-shaped half-pattern can be formed on the second surface 110b of the metal plate 110. The half-pattern can be formed in the space between a specific through hole and another through hole. The half-pattern can be formed in the space adjacent to each through hole. The depth of the half-pattern can be 30% - 60% of the thickness of the metal plate 110.

[0093] When forming the through hole 330 in the metal plate 110, its length direction can be processed to be the same as the rolling direction. And its width direction can be processed to be perpendicular to the rolling direction. The surface contact angle of the metal plate 110 can be made 65 degrees or less by surface treatment before plating. Preferably, its surface contact angle can be 45 degrees or more and 65 degrees or less.

[0094] In the present invention, an etching process and a plating process can be combined and applied to manufacture the deposition mask 100. When forming the second groove 320 on the second surface 110b of the metal plate 110 by the plating process, the second defect 410b and the third defect 410c can be filled with the plating layer 430 to form the first plating part 450a and the second plating part 450b, and the first groove 310 is formed on the first surface 110a of the metal plate 110 by the etching process to manufacture the deposition mask 100. When manufacturing the deposition mask 100 in this way, the second defect 410b and the third defect 410c appearing in the second surface 110b can be filled, and a plurality of through holes 330 with uniform sizes can be formed in the deposition mask 100. And the deposition efficiency or deposition yield of the deposition mask 100 can also be improved.

[0095] On the other hand, the first defect 410a, the second defect 410b and the third defect 410c may also appear on the first surface 110a. However, the wider width of the first groove 310 is formed on the first surface 110a, which does not have any influence on the size change of the narrower width of the first groove 310. Therefore, in the present invention, only on the second surface 110b, the second defect 410b and the third defect 410c can be filled with the first plating part 450a and the second plating part 450b.

[0096] In order to manufacture an organic light-emitting display with high resolution, the deposition process of precisely forming RGB pixels on a substrate is very important. However, in the deposition process, if the step height is high, the shadow distance may increase and the process accuracy may decrease. Therefore, it is necessary to reduce the step height that may affect the deposition yield.

[0097] In the case of reducing the step height, the etching amount on one or both surfaces of the metal plate 110 may increase, and the height of the through hole 330 may decrease. Also, as the amount of metal per unit area decreases, there may be a problem that the through hole 330 becomes defective due to small inclusions. That is, as the rigidity of the metal plate 110 decreases, the defects in the through hole 330 due to the detachment of inclusions increase.

[0098] In the present invention, the defects occurring in the second surface 110b can be filled with the plating layer 430. Therefore, in order to reduce the step height, even if the etching in the metal plate 110 increases, the height reduction of the through hole 330 can be prevented by the thickness of the plating layer 430. Also, since the inclusions occurring in the second surface 110b can be filled with the plating layer 430, the problem of the through hole 330 being defective due to inclusions can be improved. In the present invention, the influence of inclusions can be minimized by the thickness of the plating layer 430, and a low and uniform step can be achieved. According to the experimental results, a step of 2 μm or less can be achieved, which is 50% less than that of the existing product.

[0099] When manufacturing a high-resolution organic light-emitting display of 500 ppi or more, in order to improve the deposition efficiency, it is necessary to improve the hole size uniformity of the through hole 330 and reduce the corner CR (Corner-R) value. However, in the etching method using chemicals for etching, due to the influence of the grain size and orientation of the substrate, the surface condition of the substrate, the thickness distribution of the substrate, the difference in exposure resolution, and the difference in etching speed, etc., increasing the distribution of the hole size and reducing the CR value are limited. This problem can be solved by processing the second surface 110b of the metal plate 110 into a uniform thickness and shape using a thin film process.

[0100] During the etching process, the hole size may change under the influence of various factors, such as the crystal structure of the metal plate 110, the surface condition of the metal plate 110, the etching rate, the exposure resolution, and the thickness distribution of the metal plate 110. On the other hand, since the coating process is only affected by the exposure resolution, the hole size deviation can be minimized and the hole size uniformity in the deposition mask 100 can be improved.

[0101] In addition, during the etching process, a difference in etching rate may occur between the straight etching part and the corner etching part, and even if the process is improved in design, there are limitations in reducing the difference in etching rate. On the other hand, during the coating process, the difference in etching rate can be reduced by controlling the shape of the resist pattern.

[0102] In the present invention, the second groove 320 is formed by removing the resist pattern remaining after forming the coating layer 430 on the second surface 110b, improving the hole size uniformity of the through hole 330 and reducing the corner CR (Corner - R) value. According to the test results, the distribution range of the hole size can be 1 μm or less, preferably 0.5 μm or less, and can be increased by 200% compared with the existing product. According to the test results, the CR value can be 5 μm or less, preferably 3.5 μm or less, and can be reduced by 40% compared with the existing product.

[0103] Next, a deposition mask assembly including a plurality of deposition masks 100 will be described. FIG. 19 is a first schematic diagram for explaining a deposition mask assembly including a deposition mask. FIG. 20 is a second schematic diagram for explaining a deposition mask assembly including a deposition mask.

[0104] FIG. 19 shows a top view of the deposition mask 100 before assembly. And, FIG. 20 shows a top view of the deposition mask 100 after assembly. Referring to FIGS. 19 and 20, the deposition mask assembly 700 can include a deposition mask 100, a mask frame 710, and a support member 720. In the present invention, the mask frame 710 and the support member 720 can be defined together as a mask support mechanism.

[0105] The deposition mask 100 can be fixed to the mask frame 710 by the support member 720. The deposition mask 100 can be fixed to the mask frame 710 by welding. A plurality of deposition masks 100 can be fixed on the mask frame 710. For example, each deposition mask 100 can be arranged along the length direction of the first direction D1, and a plurality of deposition masks can also be arranged in the second direction D2.

[0106] The mask frame 710 can include a frame member composed of multiple parts and an opening 715 formed inside the frame member. For example, the frame member can include four parts such as a first part 711, a second part 712, a third part 713, and a fourth part 714. The material forming the mask frame 710 can be the same as the material of the metal plate 110 of the deposition mask 100. For example, the material forming the mask frame 710 can include an iron alloy containing nickel.

[0107] The first part 711 and the second part 712 can face each other along the second direction D2 with the opening 715 therebetween. The third part 713 and the fourth part 714 can face each other along the first direction D1 with the opening 715 therebetween. The first part 711 and the second part 712 can extend along the first direction D1. The third part 713 and the fourth part 714 can extend along the second direction D2. The lengths of the first part 711 and the second part 712 can be shorter than the lengths of the third part 713 and the fourth part 714.

[0108] The ends of the support member 720 can be fixed to the first part 711 and the second part 712. The ends of the deposition mask 100 can be fixed to the third part 713 and the fourth part 714. The length of the support member 720 can be longer than the length of the deposition mask 100.

[0109] The support member 720 can include multiple support components arranged along the first direction D1. For example, the support member 720 can include seven support components such as a first support component 721, a second support component 722, a third support component 723, a fourth support component 724, a fifth support component 725, a sixth support component 726, and a seventh support component 727. One end of each support component 721, 722, 723, 724, 725, 726, 727 is fixed to the first part 711 of the mask frame 710 and the other end is fixed to the second part 712 of the mask frame 710.

[0110] The first support component 721 can be closest to the middle position between the third part 713 and the fourth part 714 of the mask frame 710. The middle position between the third part 713 and the fourth part 714 is the position where the distances to the third part 713 and the fourth part 714 in the first direction D1 are the same.

[0111] The second support member 722 can be closer to the third portion 713 side than the first support member 721. The third support member 723 can be closer to the fourth portion 714 side than the first support member 721. The fourth support member 724 can be closer to the third portion 713 side than the second support member 722. The fifth support member 725 can be closer to the fourth portion 714 side than the third support member 723. The sixth support member 726 can be closer to the third portion 713 side than the fourth support member 724. The seventh support member 727 can be closer to the fourth portion 714 side than the fifth support member 725.

[0112] When observed in a plane, the plurality of support members of the support member 720 can overlap with the peripheral region of the deposition mask 100. In this case, it is possible to prevent the deposition material of the through hole 330 in the effective region 120 of the deposition mask 100 from adhering to the support member 720. The material of each support member constituting the support member 720 can be the same as the material of the metal plate 110 of the deposition mask 100. For example, the material of each support member constituting the support member 720 can be a ferroalloy containing nickel.

[0113] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art should understand that those skilled in the art who understand the present invention in various different forms will understand that the present invention can be implemented in other specific forms without changing its technical spirit or basic characteristics. Therefore, the above embodiments should be understood as illustrative in all aspects rather than restrictive.

[0114] 100: Deposition mask 110: Metal plate 110a: First surface of the metal plate 110b: Second surface of the metal plate 120: Effective region 130: Non-effective region 220a, 220b: Clamping region 230a, 230b: Tensile correction region 310, 310a, 310b: First groove 320: Second groove 330: Through hole 410a: First defect 410b: Second defect 410c: Third defect 430: Coating 440a, 440b: Anti-etching pattern 450a, 450b: Coated film part 610a, 610b: Resist 615a: First protective film 615b: Second protective film 620a: First DFR pattern 620b: Second DFR pattern 630: Protective layer 640a: Third DFR pattern 640b: Fourth DFR pattern 640c: Fifth DFR pattern 700: Deposition mask assembly 710: Mask frame 720: Support 711: First part 712: Second part 713: Third part 714: Fourth part 715: Opening 721: First support component 722: Second support component 723: Third support component 724: Fourth support component 725: Fifth support component 726: Sixth support component 727: Seventh support component 210a: First effective area 210b: Second effective area 210c: Third effective area 210d: Fourth effective area 420a, 420b: Area 650a, 650c: One side part 650b, 650d: The other side part D1: First direction D2: Second direction D3: Third direction DV: Difference H1, H2: Depth L1: Upper surface length L2: Lower surface length PL: Coating W1, W2: Width W3, W4: Sizes of the through holes S510~S590: Steps of the deposition mask manufacturing method

Claims

1. A method for manufacturing a deposition mask, wherein, The method includes the following steps: forming a resist on a first surface and a second surface of a metal plate; leaving a plurality of first resist patterns on the second surface; forming a plating layer on the remaining portion except for the portion where the first resist patterns remain; leaving a plurality of second resist patterns on the first surface; etching the remaining portion except for the portion where the second resist patterns remain; peeling off the first resist patterns and the second resist patterns; and forming a first groove on the first surface by the etching, wherein the first groove contacts the second surface, and the width of the portion of the first groove that contacts the second surface is greater than the width of the first resist pattern.

2. The method for manufacturing a deposition mask as described in claim 1, wherein, The second surface includes a plurality of groove-shaped defects, a portion of which are filled by the coating.

3. The method for manufacturing a deposition mask as described in claim 1, wherein, A second groove is formed on the second surface by means of the plating layer, and the first groove and the second groove overlap each other to form a through hole through the metal plate.

4. The method for manufacturing a deposition mask as described in claim 3, wherein, The boundary surface of the coating filling portion of the defect corresponding to the boundary of the second groove is located at ±1.5 mm below the boundary of the second groove.

5. The method for manufacturing a deposition mask as described in claim 3, wherein, The size of the first groove is larger than the size of the second groove.

6. The method for manufacturing a deposition mask as described in claim 3, wherein, The width of the portion of the first groove that contacts the second groove is equal to or greater than the width of the portion of the second groove that contacts the first groove.

7. The method for manufacturing a deposition mask as claimed in claim 1, wherein, The coating thickness is 1 mm or more and 4 mm or less.

8. The method for manufacturing a deposition mask as described in claim 6, wherein, One side of the portion of the first groove that contacts the second groove has a different height than the other side.

9. The method for manufacturing a deposition mask as described in claim 8, wherein, The height difference between the one side and the other side is less than 4 mm.

10. The method for manufacturing a deposition mask as claimed in claim 1, wherein, The inhibitor includes a protective film and is formed on the first surface and the second surface, respectively.

11. The method for manufacturing a deposition mask as claimed in claim 1, wherein, Before leaving the first resist pattern, the process further includes the following step: simultaneously exposing the first surface and the second surface.

12. The method for manufacturing a deposition mask as claimed in claim 1, wherein, The steps for leaving the first resist pattern include the following steps: removing the protective film formed on the resist on the second surface; and developing the resist formed on the second surface.

13. The method for manufacturing a deposition mask as claimed in claim 1, wherein, The step of leaving the second resist pattern after forming a coating on the second surface includes the following steps: removing the protective film formed on the resist on the first surface; and developing the resist formed on the first surface.

14. The method for manufacturing a deposition mask as claimed in claim 1, wherein, Before applying the resist, the following steps are also included: surface treatment of the metal plate.

15. The method for manufacturing a deposition mask as claimed in claim 14, wherein, The thickness of the coating varies depending on the thickness of the metal plate being surface-treated.

16. The method for manufacturing a deposition mask as claimed in claim 1, wherein, It also includes the following step: forming a protective layer on the coating.

17. The method for manufacturing a deposition mask as claimed in claim 16, wherein, In the stripping step, the protective layer is simultaneously stripped from both the first resist pattern and the second resist pattern.

18. The method for manufacturing a deposition mask as claimed in claim 1, wherein, In the step of forming the resist, a dry film resist is applied to the first surface and the second surface.

19. The method for manufacturing a deposition mask as claimed in claim 1, wherein, The coating is made of the same metal composition as the metal plate.

20. The method for manufacturing a deposition mask as claimed in claim 1, wherein, One side of the second anti-corrosion pattern has a different size than the other side.

21. The method for manufacturing a deposition mask as claimed in claim 20, wherein, The one side is the surface that contacts the first surface, and the other side is the surface that faces the one side. The size of the one side is larger than the size of the other side.

22. The method for manufacturing a deposition mask as claimed in claim 1, wherein, The metal plate is Invar, a nickel-iron alloy, and the coating comprises the same metal as the metal plate, or another metal that has adhesion to the metal plate.

23. A deposition mask manufactured by any one of the manufacturing methods described in claims 1 to 22.

24. A deposition mask, wherein, include: A metal plate having a first surface and a second surface; At least one first groove extends through the first surface and the second surface; The coating includes a second groove on the second surface corresponding to the first groove, the second surface including a plurality of groove-shaped defects, a portion of the plurality of defects being filled by the coating, and the width of the portion of the first groove in contact with the second surface being greater than the width of the resist pattern relative to the second groove.

25. The deposition mask as claimed in claim 24, wherein, The metal plate is Invar, a nickel-iron alloy, and the coating comprises the same metal as the metal plate, or another metal that has adhesion to the metal plate.

26. The deposition mask as claimed in claim 24, wherein, The thickness of the metal plate is 10 mm to 50 mm.

27. The deposition mask as claimed in claim 24, wherein, The inner wall of the second groove is inclined at an angle of 60° to 90° relative to the second surface.

28. The deposition mask as claimed in claim 24, wherein, The coating thickness is 1 mm or more and 4 mm or less.

29. A deposition mask assembly, wherein, include: frame; The deposition mask of any of claims 24 to 28 is disposed on the frame; and support members for securing the deposition mask to the frame.

30. The deposition mask assembly as claimed in claim 29, wherein, The deposition mask is used to manufacture organic light-emitting displays.

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