Deposition mask and method of manufacturing the same, and deposition mask assembly comprising the deposition mask

Abstract

The present invention provides a deposition mask manufactured in combination of an etching method and a plating method, a manufacturing method thereof, and a deposition mask assembly including the same. The deposition mask manufacturing method includes the steps of 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 a remaining portion except for the portion where the first resist patterns are left, leaving a plurality of second resist patterns on the first surface, etching a remaining portion except for the portion where the second resist patterns are left, and peeling off the first resist patterns and the second resist patterns.

Description

Technical Field

[0001] This invention relates to a deposition mask for depositing organic materials for organic light-emitting diodes (OLEDs), a method for manufacturing the same, and a deposition mask assembly including the deposition mask. Background Technology

[0002] When fabricating a deposition mask, a photoresist is applied to both sides of a metal sheet manufactured by a rolling process, and holes penetrating the metal sheet are formed by etching. A deposition mask manufactured in this way can include multiple through-holes and multiple inclusions unevenly distributed on or inside the surface of the metal sheet.

[0003] When manufacturing metal sheets by rolling, defects such as scratches or dents may occur. Additionally, these defects may also occur due to inclusions within the metal sheet. When forming through-holes in the metal sheet, if these defects exist in the boundary region of the etching process, the size of the through-hole may become uneven, such as causing over-etching defects during hole etching. Summary of the Invention

[0004] The technical problem that the invention aims to solve

[0005] The technical problem to be solved by the present invention is to provide a deposition mask manufactured by combining etching and plating methods, a method for manufacturing the same, and a deposition mask assembly including the deposition mask.

[0006] The technical problems to be solved by the present invention are not limited to those described above. Those skilled in the art will clearly understand other technical problems not mentioned in the following description.

[0007] Technical solutions for solving the problem

[0008] According to one aspect, the deposition mask manufacturing method of the present invention for solving the aforementioned technical problem includes the following steps: forming a resist on a first surface and a second surface of a metal plate; retaining 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 are retained; retaining a plurality of second resist patterns on the first surface; etching the remaining portion except for the portion where the second resist patterns are retained; and stripping the first resist patterns and the second resist patterns.

[0009] According to one aspect, the deposition mask of the present invention for solving the aforementioned technical problem is manufactured by the deposition mask manufacturing method.

[0010] According to another aspect, a deposition mask according to the invention for solving the aforementioned technical problem comprises: 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 coating comprising a second groove on the second surface corresponding to the first groove, the second surface comprising a plurality of groove-shaped defects, a portion of which is filled by the coating.

[0011] According to one aspect, the deposition mask assembly of the present invention for solving the aforementioned technical problem includes: a frame; the deposition mask disposed on the frame; and a support for fixing the deposition mask to the frame.

[0012] Specific details of other embodiments are included in the detailed description and accompanying drawings.

[0013] The effects of the invention

[0014] According to the present invention, by combining the advantages of rolled substrates and plated substrates and combining etching and plating processes to manufacture deposition masks, the following effects can be achieved.

[0015] First, by using rolled substrate as the core, the coefficient of thermal expansion (CTE) and rigidity can be maintained, and the pinhole surface can be plated with the same composition, thereby eliminating the inherent problems of rolled substrate, such as defects caused by inclusions and surface defects.

[0016] Secondly, it can achieve low and uniform step height (SH), high hole size uniformity, and small corner-R values ​​that are limited in etching methods.

[0017] Third, it is suitable for manufacturing high-resolution organic light-emitting displays with 500 pixels per inch (PPI) or higher.

[0018] The effects of the present invention are not limited to those described above, and those skilled in the art will clearly understand other effects not mentioned from the following description. Attached Figure Description

[0019] Figure 1 This is a schematic diagram used to illustrate the structure of a deposition mask.

[0020] Figure 2 This is a schematic diagram illustrating a component formed in an effective area within a metal plate.

[0021] Figure 3This is a schematic diagram used to illustrate defects formed on the surface of a metal plate.

[0022] Figure 4 This is a first schematic diagram used to illustrate the problems caused by defects formed on the surface of a metal plate.

[0023] Figure 5 This is a second schematic diagram used to illustrate the problems caused by defects formed on the surface of a metal plate.

[0024] Figure 6 This is a schematic diagram illustrating a method for solving defects formed on the surface of a metal plate.

[0025] Figure 7 This is a flowchart illustrating the manufacturing method of the deposition mask.

[0026] Figure 8 This is a schematic diagram illustrating the resist coating process in a deposition mask manufacturing method.

[0027] Figure 9 This is a schematic diagram illustrating the exposure process and the first development process in a deposition mask manufacturing method.

[0028] Figure 10 This is a schematic diagram illustrating the coating process in a deposition mask manufacturing method.

[0029] Figure 11 This is a schematic diagram used to illustrate the protective layer formation process in the deposition mask manufacturing method.

[0030] Figure 12 This is a first schematic diagram illustrating the second development process in a deposition mask manufacturing method.

[0031] Figure 13a This is a second schematic diagram illustrating the second development process in a deposition mask manufacturing method.

[0032] Figure 13b This is a third schematic diagram illustrating the second development process in a deposition mask manufacturing method.

[0033] Figure 13c This is a fourth schematic diagram illustrating the second development process in a deposition mask manufacturing method.

[0034] Figure 14 This is a first schematic diagram illustrating the etching process in a deposition mask manufacturing method.

[0035] Figure 15 This is a second schematic diagram illustrating the etching process in a deposition mask manufacturing method.

[0036] Figure 16This is a third schematic diagram used to illustrate the etching process in a deposition mask manufacturing method.

[0037] Figure 17 This is a fourth schematic diagram illustrating the etching process in a deposition mask manufacturing method.

[0038] Figure 18 This is a schematic diagram illustrating the stripping process in a deposition mask manufacturing method.

[0039] Figure 19 This is a first schematic diagram illustrating a deposition mask assembly including a deposition mask.

[0040] Figure 20 This is a second schematic diagram illustrating a deposition mask assembly including a deposition mask. Detailed Implementation

[0041] 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 parts, and repeated descriptions thereof are omitted.

[0042] Figure 1 This is a schematic diagram illustrating the structure of a deposition mask. Figure 1 In this diagram, the first direction D1 and the second direction D2 form a plane in the horizontal direction. For example, the first direction D1 can be a front-back direction, and the second direction D2 can be a left-right direction. Alternatively, the first direction D1 can be a left-right direction, and the second direction D2 can be a front-back direction. The third direction D3 is the height direction, perpendicular to the plane formed by the first direction D1 and the second direction D2. The third direction D3 can be a vertical direction.

[0043] The deposition mask 100, also referred to as a metal mask, has a structure with through-holes forming through a metal plate 110, in which effective regions 120 and ineffective regions 130 are formed respectively. The deposition mask 100 can use the through-holes to deposit organic materials on display panels (e.g., OLED panels) used in organic light-emitting displays, such as organic light-emitting diodes (OLEDs). The deposition mask 100 can deposit various types of organic materials, such as red (R), green (G), and blue (B), on the panel using the through-holes in a vacuum atmosphere; therefore, the RGB pattern formed on the panel can be used as pixels in an organic light-emitting display.

[0044] Metal sheet 110 can be made of an iron alloy containing iron and nickel, such as Invar. Additives such as aluminum and silicon can be added during the melting process of the base material used to manufacture metal sheet 110 to remove impurities. Metal sheet 110 can also contain other components besides iron, nickel, and cobalt. Metal sheet 110 can be manufactured using rolling and annealing processes.

[0045] Multiple valid regions 120 and multiple invalid regions 130 can be respectively disposed on the metal plate 110. Valid regions 120 can be disposed in the central region of the metal plate 110, and invalid regions 130 can be disposed around the valid regions 120 in the metal plate 110. For example, four valid regions 210a, 210b, 210c, 210d and four invalid regions 220a, 220b, 230a, 230b can be disposed on the metal plate 110. The four valid regions 210a, 210b, 210c, 210d can be disposed in the central region of the metal plate 110, and two invalid regions 220a, 230a and two other invalid regions 220b, 230b can be disposed on either side thereof. However, this is not a limitation; any one of the valid regions 120 and invalid regions 130 can be disposed on the metal plate 110 in an odd number. Alternatively, both valid regions 120 and invalid regions 130 can be disposed on a metal plate 110 in an odd number simultaneously.

[0046] If multiple effective regions 120 are provided in the metal plate 110, adjacent effective regions can be separated. For example, a separation region is formed between the first effective region 210a and the second effective region 210b. A separation region is formed between the second effective region 210b and the third effective region 210c. A separation region is formed between the third effective region 210c and the fourth effective region 210d. The separation region between two adjacent effective regions can be included in the non-effective region 130.

[0047] like Figure 2 As shown, the effective region 120 can also be called the core region (Cell Region), and a first groove 310, a second groove 320, etc. can be formed in the effective region 120. Figure 2 This is a schematic diagram illustrating a component forming an effective area in a metal plate. See below for reference. Figure 2 Please provide an explanation.

[0048] A first groove 310 and a second groove 320 of different sizes can be formed on both sides of the metal plate 110. The first groove 310 can penetrate through the first surface 110a and the second surface 110b of the metal plate 110. The first groove 310 can be a recessed portion formed by recessing along 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.

[0049] The second groove 320 can be formed on the second surface 110b of the metal plate 110. The second groove 320 can be connected to the first groove 310. The first groove 310 and the second groove 320 can be formed as through holes 330 in the metal plate 110 to allow organic material to flow along the direction of the display panel so that the organic material is deposited on the display panel.

[0050] The second groove 320 can be formed using an anti-corrosion pattern and a plating layer PL formed on the second surface 110b. The second groove 320 can have a constant width in the depth direction D3. The width W2 of the second groove 320 can be less than the width W1 of the first groove 310 on the first surface 110a, and the same as the width W2 of the first groove 310 on the second surface 110b. The depth H2 of the second groove 320 can be less than the depth H1 of the first groove 310. The first groove 310 can be a large hole, and the second groove 320 can be a small hole.

[0051] The second surface 110b, where the second groove 320 is formed, may include multiple defects. As described above, the metal sheet 110 can be manufactured by rolling, and its surface or interior may contain multiple inclusions. Inclusions refer to particles or components other than iron, nickel, and cobalt that may be contained in the metal sheet 110. Therefore, during the manufacturing process of the metal sheet 110, multiple defects such as scratches and dents may be generated on the second surface 110b.

[0052] refer to Figure 3 Three types of defects 410a, 410b, and 410c may appear on the second surface 110b: first defect 410a, second defect 410b, and third defect 410c. First defect 410a refers to a defect occurring below the region 420a where the second groove 320 is formed. Second defect 410b refers to a defect within the region 420b where the second groove 320 is not formed. Third defect 410c refers to a defect occurring in both the region 420a where the second groove 320 is formed and the region 420b where the second groove 320 is not formed. Figure 3 This is a schematic diagram used to illustrate defects formed on the surface of a metal plate.

[0053] In the case of the first defect 410a, it may occur within the region 420a where the second groove 320 is formed, and can be removed when the first groove 310 is formed. (See reference) Figure 4 The first defect 410a may 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 both the region 420a where the second groove 320 is formed and the region 420b where the second groove 320 is not formed, and a portion of the third defect 410c may not be removed when the first groove 310 is formed. (See reference...) Figure 5The third defect 410c can change the size of the through hole 330 (W3→W4 (>W3)). Figure 4 This is a first schematic diagram used to illustrate the problems caused by defects formed on the surface of a metal plate. Figure 5 This is a second schematic diagram used to illustrate the problems caused by defects formed on the surface of a metal plate.

[0054] refer to Figure 6 To address the defects 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 excluding the area where the resist patterns 440a and 440b are formed. That is, the plating layer 430 may not be formed in the area 420a where the second groove 320 is formed, but rather in the area 420b where the second groove 320 is not formed. The plating layer 430 can fill the defects 410b and 410c formed on the second surface 110b with plating portions 450a and 450b. The plating portion 450b can partially fill the defect 410c, or it can completely fill the defect 410c. By filling the defects 410b and 410c with plating portions 450a and 450b, uneven size of the through-holes 330 formed on the metal plate 110 can be prevented. Figure 6 This is a schematic diagram illustrating a method for solving defects formed on the surface of a metal plate.

[0055] Defects 410a, 410b, and 410c, which occur during the manufacturing process of the metal plate 110, are randomly distributed across the entire area of ​​the metal plate 110. Therefore, it is impossible to avoid the problematic defects 410b and 410c forming multiple through-holes 330 of uniform size in the metal plate 110. If the multiple through-holes 330 formed in the metal plate 110 are not uniform in size, the deposition mask 100 may become defective, and the yield may decrease when mass-producing the deposition mask 100. Therefore, in this invention, the plated portions 450a and 450b are formed by filling the problematic defects 410b and 410c with a plating layer 430, thereby making the multiple through-holes 330 uniform in size.

[0056] On the other hand, the plating layer 430 may not be formed on the entire surface of the metal plate 110. In the deposition mask 100, the vias for organic material deposition are formed in the effective region 120 and not in the ineffective region 130. Therefore, the plating layer 430 may be formed only in the effective region 120 of the metal plate 110 and not in the ineffective region 130. In this case, the defects 410b and 410c in the effective region 120 may be filled by the plating portions 450a and 450b, and the defects 410b and 410c in the ineffective region 120 may not be filled by the plating portions 450a and 450b.

[0057] The following is for reference. Figure 1 Let me explain again.

[0058] The non-effective region 130 is located in the area surrounding the effective region 120 and, unlike the effective region 120, does not have a through hole 330 formed therein. The non-effective region 130 may include clamping regions 220a, 220b and tension correction regions 230a, 230b.

[0059] Clamping regions 220a and 220b are the portions secured to the clamp when the deposition mask 100 is stretched and attached to the mask frame. Clamping regions 220a and 220b may be formed at both ends of the metal plate 110 in the long axis direction D1. The mask frame will be described later.

[0060] Although Figure 1 Not shown, the non-effective area 130 may also include a welding area. The welding area refers to the portion welded to the mask frame. The fixture can apply tensile force to both ends of the metal plate 110 while it is secured to the metal plate 110 via clamping areas 220a and 220b. With this tensile force applied, the metal plate 110 is welded to the mask frame via the welding area. The welding area may be located between the clamping areas 220a and 220b and the tension correction areas 230a and 230b, but is not limited thereto. The clamping areas 220a and 220b and the welding area can be removed by a cutting process between organic material deposition processes using the deposition mask 100.

[0061] The stretch correction regions 230a and 230b are areas where stretch correction patterns are formed. If welded to the mask frame under a tensile force applied to the deposition mask 100, the tensile force can also affect the vias 330 in the effective region 120. Therefore, to minimize the effect of the tensile force and prevent damage to the vias 330, a stretch correction pattern can be formed in the non-effective region 130 to mitigate the effect of the tensile force on the vias 330. The stretch correction pattern may include multiple grooves.

[0062] Tensile correction regions 230a and 230b can be formed between the effective region 120 and the clamping regions 220a and 220b. That is, the first tensile correction region 230a can be formed between the first effective region 210a and the first clamping region 220a. Furthermore, the second tensile correction region 230b can be formed between the fourth effective region 210d and the second clamping region 220b.

[0063] However, this is not the only possibility; the tension correction regions 230a and 230b may also be formed in a spaced region between two adjacent effective regions. For example, the tension correction regions 230a and 230b may be formed in at least one of the following spaced regions: the spaced region between the first effective region 210a and the second effective region 210b, the spaced region between the second effective region 210b and the third effective region 210c, and the spaced region between the third effective region 210c and the fourth effective region 210d.

[0064] The following describes a method for manufacturing a deposition mask 100 in which problematic defects 410b and 410c are filled by plating portions 450a and 450b. Figure 7 This is a flowchart used to sequentially explain the manufacturing method of the deposition mask.

[0065] First, prepare a metal plate 110. The metal plate 110 can be made of an iron alloy containing iron and nickel. For example, the metal plate 110 can be made of Invar. The thickness of the metal plate 110 can be from 10 μm to 50 μm. Preferably, the thickness of the metal plate 110 can be from 15 μm to 30 μm.

[0066] After preparing the metal plate 110, surface treatment is performed on the metal plate 110 (S510). When surface treating the metal plate 110, both sides of the metal plate 110 can be surface treated. However, it is not limited to this, and surface treatment can also be performed on one side of the metal plate 110. For example, the second surface 110b on which the plated portions 450a and 450b are formed can be surface treated.

[0067] When performing surface treatment on the metal plate 110, a soft etching method can be used. Soft etching can remove contaminants, impurities, and foreign matter distributed on the surface of the metal plate 110, thereby improving plating adhesion. The thickness of the plating layer 430 can be adjusted by considering the thickness of the metal plate 110 when using soft etching.

[0068] When performing surface treatment on the metal plate 110, a chemical treatment method can be used. The entire surface or part of the surface of the metal plate 110 can be etched using a chemical treatment method. If the metal plate 110 is a rolled substrate, the thickness of the etched portion can be from 10 nm to 20 μm.

[0069] After surface treatment of the metal plate 110, a resist (S520) is applied to both sides 110a and 110b of the metal plate 110. (Reference) Figure 8The photoresists 610a and 610b can be photosensitive resin materials and can be dry film resists (DFR). Alternatively, the photoresists 610a and 610b can be coating photoresists. The photoresists 610a and 610b formed on both sides 110a and 110b of the metal plate 110 can be negative photoresists. Figure 8 This is a schematic diagram illustrating the resist coating process in the deposition mask manufacturing method.

[0070] In this invention, a dry film resist can be applied to both sides 110a and 110b of the metal plate 110. However, it is not limited to this; a liquid resist can also be applied to both sides 110a and 110b of the metal plate 110. When a liquid resist is applied to both sides 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 cavitation tension, the liquid resist can only cover the edge portions of the defects 410b and 410c. On the other hand, when a dry film resist is applied to both sides 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 a dry film resist helps to fill the defects generated on the surface of the metal plate 110 and ensures the linearity associated with the filling of said defects.

[0071] When dry film resist is applied to both sides 110a and 110b of the metal plate 110, protective films 615a and 615b can be attached to each resist 610a and 610b. The first protective film 615a and the second protective film 615b protect each resist 610a and 610b. The first protective film 615a can protect the first surface 110a on which the large hole is formed during the step of forming the small hole. In this invention, the process of forming a separate protective layer for the large hole can be omitted during the step of forming the small hole using the first protective film 615a, thereby reducing the number of processes. For ease of explanation, illustrations of the protective films 615a and 615b are omitted below.

[0072] Reference Figure 7 To reiterate.

[0073] After forming resists 610a and 610b on both sides 110a and 110b of the metal plate 110, an exposure process (S530) is performed on both sides 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.

[0074] After sequentially performing the exposure process (S530) and the first development process (S540), multiple resist patterns are retained in the portion of the second surface 110b where the second groove 320 is to be formed. (Reference) Figure 9 The first DFR pattern 620a and the second DFR pattern 620b can be retained on the second surface 110b. The first defect 410a can be located in the region adjacent to the first DFR pattern 620a. The third defect 410c can be located in the region adjacent to the second DFR pattern 620b. The second defect 410b can be located in the region not adjacent to the first DFR pattern 620a and the second DFR pattern 620b. Figure 9 This is a schematic diagram used to illustrate the exposure process and the first development process in the deposition mask manufacturing method.

[0075] Reference Figure 7 To reiterate.

[0076] After performing the first developing process (S540) on the second surface 110b, a coating 430 is formed on the second surface 110b (S550). Reference Figure 10 The plating layer 430 can be formed on the remaining portion of the second surface 110b, excluding the portions retained by the first DFR pattern 620a and the second DFR pattern 620b. The first plating portion 450a can fill all the second defects 410b based on the plating layer 430. The second plating portion 450b can fill at least a portion of the third defects 410b based on the plating layer 430. Figure 10 This is a schematic diagram used to illustrate the coating process in the deposition mask manufacturing method.

[0077] The plating layer 430 can be formed on the second surface 110b by an additive method. However, it is not limited to this; 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, and therefore the step height (SH) can be 4 μm or less. 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 second surface 110b by the plating layer 430 can be 50% or more and 100% or less. Furthermore, when 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 filling portion within the defect corresponding to the boundary of the second groove 320 can be ±1.5 μm or less from the boundary of the second groove 320.

[0078] The plating 430 can be formed using a metal with the same composition as that constituting the metal plate 110. For example, the plating 430 can be formed using at least one metal selected from iron or nickel. However, it is not limited to this; the plating 430 can also be formed using a metal with a different composition than that constituting the metal plate 110, as long as it is a metal that can guarantee adhesion to the composition of the metal plate 110, that is, a metal that has adhesion to the composition of the metal plate 110.

[0079] When the metal plate 110 is a rolled substrate, the coefficient of thermal expansion (CTE) of the metal plate 110 in the longitudinal direction can be less than 1.5 ppm in the range of 25°C to 100°C. The coefficient of thermal expansion of the metal plate 110 including the coating 430 can be less than 2 ppm. The Rz and Ra of the metal plate 110 including the coating 430 can be less than 0.8 μm and less than 0.08 μm, respectively.

[0080] Reference Figure 7 To reiterate.

[0081] After performing the plating process (S550) to fill the second defect 410b and the third defect 410c with the first plating portion 450a and the second plating portion 450b, a protective layer is formed on the plating layer 430 (S560). Reference Figure 11The protective layer 630 can be in the form of a masking film to protect the plating layer 430 while retaining the first DFR pattern 620a and the second DFR pattern 620b 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 other than 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. Figure 11 This is a schematic diagram used to illustrate the protective layer formation process in the deposition mask manufacturing method.

[0082] Reference Figure 7 To reiterate.

[0083] After forming a 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) is completed, multiple resist patterns are retained on the first surface 110a, and the first groove 310 can be formed in the portion where multiple resist patterns are not formed (e.g., the area between two different resist patterns). Reference Figure 12 In order to form a 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 be retained on the first surface 110a. Figure 12 This is a first schematic diagram used to illustrate the second development process in a deposition mask manufacturing method.

[0084] refer to Figure 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 less than the lower surface length L2. However, it is not limited to this, as... Figure 13b As shown, 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. Alternatively, as... Figure 13c As shown, 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 this invention, in order to expand the range of organic material deposited on the display panel through the via 330, the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c can be formed as follows: Figure 13a The shape shown. Figure 13a This is a second schematic diagram used to illustrate the second development process in the deposition mask manufacturing method. Figure 13b This is a third schematic diagram used to illustrate the second development process in the deposition mask manufacturing method. Figure 13c This is a fourth schematic diagram used to illustrate the second development process in the deposition mask manufacturing method.

[0085] On the other hand, similarly 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 as follows: Figure 13a The shape shown, such as Figure 13b The shape shown and as Figure 13c One of the shapes shown. Therefore, the angle of inclination of the inner wall of the second groove 320 relative to the second surface 110b can be 90 degrees or less. Preferably, the angle of inclination of the inner wall of the second groove 320 relative to the second surface 110b can be 60 degrees to 90 degrees.

[0086] Reference Figure 7 To reiterate.

[0087] After performing the second developing process (S570), consider performing an etching process (S580) according to the positions of the resist patterns 640a, 640b, and 640c left on the first surface 110a. The etching process can be performed using photo etching. (See reference) Figure 14 The area between the third DFR pattern 640a and the fourth DFR pattern 640b can be etched, and a first groove 310a that contacts the first DFR pattern 620a is formed in the corresponding area. The first groove 310a that contacts the first DFR pattern 620a can remove the first defect 410a from the second surface 110b of the metal plate 110.

[0088] Similarly, the area between the fourth DFR pattern 640b and the fifth DFR pattern 640c can be etched, and a first groove 310b that contacts the second DFR pattern 620b is formed in the corresponding area. The first groove 310b that contacts 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. Figure 14 This is a first schematic diagram used to illustrate the etching process in a deposition mask manufacturing method.

[0089] As described above, a plurality of first grooves 310a, 310b can be recessed along the direction from the first surface 110a to the second surface 110b. The plurality of first grooves 310a, 310b can have the maximum width on the first surface 110a and the minimum width on the second surface 110b. Figure 14 The example shown is one 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; 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, such as... Figure 15 As shown. The minimum width of the plurality of first grooves 310a, 310b can also be large enough to completely remove the first defect 410a and the third defect 410c. Figure 15 This is a second schematic diagram used to illustrate the etching process in the deposition mask manufacturing method.

[0090] refer to Figure 16 In the case of the first groove 310a contacting the first DFR pattern 620a, the side portion 650a and the other side portion 650b contacting the second surface 110b can be formed on the same line. On the other hand, refer to Figure 17 In the case of the first groove 310b contacting the second DFR pattern 620b, due to the second plating portion 450b, the side portion 650c and the other side portion 650d that contact 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 may be formed higher than the side portion 650c.

[0091] In this invention, the heights of one side portion 650c and the other side portion 650d can be different without limiting the range of organic material deposition required for each through-hole 330. The difference in volume (DV) between 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 limiting the range of organic material deposition. The reference value can be determined taking into account the thickness of the coating 430, and can be 4 μm or less. Figure 16 This is the third schematic diagram used to illustrate the etching process in the deposition mask manufacturing method. Figure 17 This is the fourth schematic diagram used to illustrate the etching process in the deposition mask manufacturing method.

[0092] Reference Figure 7 To reiterate.

[0093] After forming multiple first grooves 310a, 310b, a peeling process (S590) is performed on the first surface 110a and the second surface 110b. (See reference) Figure 18The plurality of resist patterns 640a, 640b, and 640c retained on the first surface 110a after the second developing process (S570), namely the third DFR pattern 640a, the fourth DFR pattern 640b, and the fifth DFR pattern 640c, can be removed by a stripping process (S590). Furthermore, the plurality of resist patterns 620a and 620b retained on the second surface 110b after the first developing process (S540), namely the first DFR pattern 620a, the second DFR pattern 620b, and the protective layer 630, can be removed in one step by a stripping process (S590). In this 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 away in one step by a stripping process (S590). Figure 18 This is a schematic diagram used to illustrate the stripping process in the deposition mask manufacturing method.

[0094] Based on the above reference Figures 7 to 18 The deposition mask 100 manufactured by the described method can simultaneously perform coating and exposure processes on both sides of the metal plate 110. Then, a development process is sequentially performed on the small-hole surface (i.e., the second surface 110b) and the large-hole surface (i.e., the first surface 110a). An additional plating process is performed on the small-hole surface, and an additional etching process is performed on the large-hole surface, thereby forming a plurality of through-holes 330 in the effective area 120 of the metal plate 110. The intersection of the large-hole surface and the small-hole surface may contain inclusions or defects filled during the plating of the small-hole surface.

[0095] A groove-shaped semi-pattern can be formed on the second surface 110b of the metal plate 110. The semi-pattern can be formed in the space between a particular through hole and another through hole. The semi-pattern can be formed in the space adjacent to each through hole. The depth of the semi-pattern can be 30% to 60% of the thickness of the metal plate 110.

[0096] When forming through holes 330 in the metal plate 110, its length direction can be machined to be the same as the rolling direction. Furthermore, its width direction can be machined to be perpendicular to the rolling direction. The metal plate 110 can be surface-treated before plating to ensure its surface contact angle is 65 degrees or less. Preferably, its surface contact angle can be 45 degrees or more and 65 degrees or less.

[0097] In this invention, etching and plating processes can be combined to manufacture the deposition mask 100. When a second groove 320 is formed on the second surface 110b of the metal plate 110 by plating, the second defect 410b and the third defect 410c can be filled with plating layer 430 to form the first plating portion 450a and the second plating portion 450b. The deposition mask 100 is then manufactured by etching to form the first groove 310 on the first surface 110a of the metal plate 110. When the deposition mask 100 is manufactured in this way, the second defect 410b and the third defect 410c appearing on the second surface 110b can be filled, and a plurality of uniformly sized through holes 330 can be formed in the deposition mask 100. Furthermore, the deposition efficiency or deposition yield of the deposition mask 100 can be improved.

[0098] 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 formed on the first surface 110a has no effect on the variation in the size of the narrower width of the first groove 310. Therefore, in this invention, the second defect 410b and the third defect 410c can be filled with the first plating portion 450a and the second plating portion 450b, limited to the second surface 110b.

[0099] To fabricate organic light-emitting displays (OLEDs) with high resolution, a precise deposition process for forming RGB pixels on the substrate is crucial. However, in the deposition process, a high step height can increase the shadow distance and potentially reduce process accuracy. Therefore, it is necessary to reduce the step height, which can negatively impact deposition yield.

[0100] By reducing the step height, the amount of etching on one or both sides of the metal plate 110 may increase, and the height of the through-hole 330 may decrease. Furthermore, as the amount of metal per unit area decreases, the through-hole 330 may become defective due to small inclusions. That is, as the rigidity of the metal plate 110 decreases, defects in the through-hole 330 due to inclusion shedding will increase.

[0101] In this invention, a plating layer 430 can be used to fill defects appearing in the second surface 110b. Therefore, to reduce the step height, even if etching in the metal plate 110 increases, the thickness of the plating layer 430 can prevent a decrease in the height of the through-hole 330. Furthermore, since inclusions appearing in the second surface 110b can also be filled by the plating layer 430, the problem of defects in the through-hole 330 due to inclusions can be improved. In this 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 experimental results, a step of less than 2 μm can be achieved, which is 50% less than that of existing products.

[0102] When manufacturing high-resolution organic light-emitting displays with a pixel density of 500 ppi or higher, improving the hole size uniformity (Hole Size Uniformity) and reducing the corner-R (CR) value of the via 330 is necessary to enhance deposition efficiency. However, in etching methods using chemicals, increasing the hole size distribution and reducing the CR value are limited by factors such as substrate grain size and orientation, substrate surface condition, substrate thickness distribution, differences in exposure resolution, and etching rate. This problem can be solved by using a plating process to process the second surface 110b of the metal plate 110 into a uniform thickness and shape.

[0103] In 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 plating 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.

[0104] Furthermore, in etching processes, differences in etching rates can occur between etching straight sections and etching corners, and even with design improvements, there are limitations in reducing these differences. On the other hand, in plating processes, the difference in etching rates can be reduced by controlling the shape of the resist pattern.

[0105] In this invention, the second groove 320 is formed by removing the resist pattern retained after the coating 430 is formed on the second surface 110b, thereby improving the uniformity of the hole size of the through hole 330 and reducing the corner-R value. According to experimental results, the hole size distribution range can be less than 1 μm, preferably less than 0.5 μm, which is 200% higher than existing products. According to experimental results, the CR value can be less than 5 μm, preferably less than 3.5 μm, which is 40% lower than existing products.

[0106] Next, the deposition mask assembly, which includes multiple deposition masks 100, will be described. Figure 19 This is a first schematic diagram illustrating a deposition mask assembly including a deposition mask. Figure 20 This is a second schematic diagram illustrating a deposition mask assembly including a deposition mask.

[0107] Figure 19 This shows a top view of the deposition mask 100 before assembly. Furthermore, Figure 20 Showing a top view of the deposition mask 100 after assembly. Reference Figure 19 and Figure 20 The deposition mask assembly 700 may include a deposition mask 100, a mask frame 710, and a support member 720. In this invention, the mask frame 710 and the support member 720 may be defined together as a mask support mechanism.

[0108] The deposition mask 100 can be fixed to the mask frame 710 by a support member 720. The deposition mask 100 can also be fixed to the mask frame 710 by welding. Multiple deposition masks 100 can be fixed to the mask frame 710. For example, each deposition mask 100 can be arranged along the length direction of a first direction D1, and multiple deposition masks can be arranged along a second direction D2.

[0109] The mask frame 710 may include a frame component consisting of multiple parts and an opening 715 formed inside the frame component. For example, the frame component may include four parts 711, 712, 713, and 714: a first part 711, a second part 712, a third part 713, and a fourth part 714. The material constituting the mask frame 710 may be the same as the material of the metal plate 110 of the deposition mask 100. For example, the material constituting the mask frame 710 may be an iron alloy containing nickel.

[0110] The first part 711 and the second part 712 may face each other along the second direction D2, separated by an opening 715. The third part 713 and the fourth part 714 may face each other along the first direction D1, separated by an opening 715. The first part 711 and the second part 712 may extend along the first direction D1. The third part 713 and the fourth part 714 may extend along the second direction D2. The length of the first part 711 and the second part 712 may be shorter than the length of the third part 713 and the fourth part 714.

[0111] The end of the support member 720 can be fixed to the first part 711 and the second part 712. The end 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.

[0112] The support member 720 may include a plurality of support components arranged along the first direction D1. For example, the support member 720 may include seven support components: 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, and 727 is fixed to the first portion 711 of the mask frame 710, and the other end is fixed to the second portion 712 of the mask frame 710.

[0113] The first support member 721 can be closest to the midpoint between the third part 713 and the fourth part 714 of the mask frame 710. The midpoint between the third part 713 and the fourth part 714 is a position where the distance from the third part 713 to the fourth part 714 is the same as the distance from the fourth part 714 in the first direction D1.

[0114] The second support member 722 may be closer to the third part 713 than the first support member 721. The third support member 723 may be closer to the fourth part 714 than the first support member 721. The fourth support member 724 may be closer to the third part 713 than the second support member 722. The fifth support member 725 may be closer to the fourth part 714 than the third support member 723. The sixth support member 726 may be closer to the third part 713 than the fourth support member 724. The seventh support member 727 may be closer to the fourth part 714 than the fifth support member 725.

[0115] When viewed in planar view, the plurality of support members of support member 720 may overlap with the surrounding area of ​​deposition mask 100. In this case, it is possible to prevent deposited material passing through the vias 330 in the effective area 120 of deposition mask 100 from adhering to support member 720. The material of each support member constituting support member 720 may be the same as the material of metal plate 110 of deposition mask 100. For example, the material of each support member constituting support member 720 may be an iron alloy containing nickel.

[0116] Although embodiments of the invention have been described above with reference to the accompanying drawings, the invention is not limited to the above embodiments and can be made in various different forms. Those skilled in the art will understand that the invention can be implemented in other specific forms without altering its technical spirit or essential characteristics. Therefore, the above embodiments should be understood in all respects as illustrative rather than restrictive.

[0117] Industrial applicability

[0118] This invention relates to a metal mask. This invention can be used to manufacture organic light-emitting diode (OLED) displays.

Claims

1. A method for manufacturing a deposition mask, characterized in that, Includes the following steps: A corrosion resist is formed on the first and second surfaces of the metal plate; Multiple first anti-corrosion patterns are retained on the second surface; A coating is formed on the remaining portion except for the portion where the first anti-corrosion pattern is retained; Multiple second anti-corrosion patterns are retained on the first surface; Etch the remaining portion except for the portion retained by the second resist pattern; as well as The first and second resist patterns are stripped off.

2. The deposition mask manufacturing method according to claim 1, characterized in that, The second surface includes a plurality of groove-shaped defects, a portion of which are filled by the coating.

3. The deposition mask manufacturing method according to claim 1, characterized in that, A first groove is formed on the first surface by etching, and a second groove is formed on the second surface by plating. The first groove and the second groove overlap each other to form a through hole through the metal plate.

4. The deposition mask manufacturing method according to claim 3, characterized in that, The boundary surface of the plated filling portion of the defect corresponding to the boundary of the second groove is located at ±1.5 μm below the boundary of the second groove.

5. The deposition mask manufacturing method according to claim 3, characterized in that, The size of the first groove is larger than the size of the second groove.

6. The deposition mask manufacturing method according to claim 3, characterized in that, 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 deposition mask manufacturing method according to claim 1, characterized in that, The coating is 1 μm or larger and 4 μm or smaller.

8. The deposition mask manufacturing method according to claim 6, characterized in that, One side of the portion of the first groove that contacts the second groove has a different height than the other side.

9. The deposition mask manufacturing method according to claim 8, characterized in that, The height difference between the two sides is less than 4 μm.

10. The deposition mask manufacturing method according to claim 1, characterized in that, The resist comprises a protective film and is formed on the first surface and the second surface, respectively.

11. The deposition mask manufacturing method according to claim 1, characterized in that, Before retaining the first resist pattern, the following steps are also included: Simultaneously expose the first surface and the second surface.

12. The deposition mask manufacturing method according to claim 1, characterized in that, The steps for retaining the first resist pattern include the following: Remove the protective film formed on the resist on the second surface; and The resist formed on the second surface is developed.

13. The deposition mask manufacturing method according to claim 1, characterized in that, The step of retaining the second anti-corrosion pattern after forming a coating on the second surface includes the following steps: Remove the protective film formed on the resist on the first surface; and The resist formed on the first surface is developed.

14. The deposition mask manufacturing method according to claim 1, characterized in that, The following steps are included before applying the resist: The metal plate is then subjected to surface treatment.

15. The deposition mask manufacturing method according to claim 14, characterized in that, The thickness of the coating varies depending on the thickness of the metal plate being surface-treated.

16. The deposition mask manufacturing method according to claim 1, characterized in that, It also includes the following steps: A protective layer is formed on the coating.

17. The deposition mask manufacturing method according to claim 16, characterized in that, In the stripping step, the protective layer is simultaneously stripped from both the first resist pattern and the second resist pattern.

18. The deposition mask manufacturing method according to claim 1, characterized in that, In the step of forming the resist, a dry film resist is applied to the first surface and the second surface.

19. The deposition mask manufacturing method according to claim 1, characterized in that, The coating is made of the same metal composition as the metal plate.

20. The deposition mask manufacturing method according to claim 1, characterized in that, One side of the second anti-corrosion pattern has a different size than the other side.

21. The deposition mask manufacturing method according to claim 20, characterized in that, 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 deposition mask manufacturing method according to claim 1, characterized in that, 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 the manufacturing method according to any one of claims 1 to 22.

24. A deposition mask, characterized in that, 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; as well as The plating includes a second groove on the second surface that corresponds to the first groove. The second surface includes multiple groove-shaped defects. A portion of the aforementioned defects is filled by the coating.

25. The deposition mask according to claim 24, characterized in that, 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 according to claim 24, characterized in that, The thickness of the metal plate is 10 μm to 50 μm.

27. The deposition mask according to claim 24, characterized in that, 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 according to claim 24, characterized in that, The coating is 1 μm or larger and 4 μm or smaller.

29. A deposition mask assembly, characterized in that, include: frame; The deposition mask according to any one of claims 24 to 28 is disposed on the frame; as well as Support members are used to secure the deposition mask to the frame.

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

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