OLED deposition mask manufactured by electroplating method and its manufacturing method

Abstract

The present invention relates to an electroplating manufacturing process for a Fine Metal Mask (FMM) for OLED deposition, and more specifically, to a technology for solving deformation problems such as warping, curling, and wrinkling that occur during welding or after substrate separation. To this end, a second plating layer formed on the welded portion is formed from a single Ni metal or a Ni-Fe alloy in which the Ni ratio is higher than Fe, and the contact area is minimized by ensuring that the first and second plating layers do not come into full contact in the longitudinal direction, thereby effectively mitigating stress concentration and residual stress caused by differences in shrinkage rates. As a result, the dimensional stability and flatness of the FMM are improved, and precision and productivity in the high-resolution OLED deposition process can be increased.

Description

Technology Field

[0001] The present invention relates to a manufacturing technology for a Fine Metal Mask (FMM) used in an OLED display manufacturing process, and in particular, to an over-plating process for minimizing warping of the welded part and wrinkles at the boundary between the patterned part and the welded part during the process of manufacturing the FMM by electroplating. Background Technology

[0002] OLED displays are widely used in various application fields, such as smartphones, TVs, and automotive displays, due to their advantages including lightweight design, high resolution, wide viewing angles, and excellent color reproduction. In the manufacturing process of these OLED displays, a Fine Metal Mask (hereinafter FMM) is used as an essential component to form precise pixel-level patterns during the organic material deposition process.

[0004] FMMs generally use Invar metal (Fe-Ni alloy), which has a coefficient of thermal expansion close to zero, to minimize distortion caused by thermal expansion during the deposition process. This material maintains its shape even in high-temperature environments and provides characteristics suitable for forming precise patterns. Generally, FMMs are fabricated by rolling an Invar metal sheet to a predetermined thickness and then forming deposition holes using methods such as wet etching with chemical reactions, dry etching with plasma, or laser processing with high-power lasers. Although FMMs manufactured in this manner are widely used, they have limitations in terms of thickness and precision.

[0006] To overcome these limitations, FMM manufacturing methods utilizing electroplating have recently been developed. Electroplating is a method of fabricating FMMs by plating a metal layer onto a patterned mold (substrate), and it is considered more suitable for manufacturing high-resolution OLED displays because it enables thinner thicknesses and the formation of precise deposition holes compared to conventional methods.

[0008] The FMM manufactured by electroplating is formed as a plating layer and, as shown in FIG. 4, consists of a pattern part (A) in which a deposition hole is formed in the plating layer and a weld part (B) in which the plating layer is welded to the frame to fix it. The pattern part (A) and the weld part (B) are referred to to distinguish the areas of the FMM, and will be explained below as concepts of areas.

[0009] The welded portion (B) is formed as an extension at both ends of the pattern portion (A), and since the plating layer of the welded portion (B) must be thicker than the plating layer of the pattern portion (A) in order to weld it to the frame, there are process difficulties in manufacturing it by electroplating. For this reason, recently, as described below, it is common to perform an over-plating process to thicken the plating layer by sequentially plating the plating layer of the welded portion (B) in two stages.

[0011] FIG. 4 illustrates a process flow diagram of a conventional over-plating process for manufacturing FMM. Hereinafter, the conventional over-plating process for manufacturing FMM will be explained with reference to FIG. 4. FIG. 4 is explained on the premise that the substrate serving as the base is a conductive substrate (for example, a Ti substrate). FIG. 4 is a diagram explained based on a side view. In addition, with respect to FIG. 4, the length direction is the x-axis, the vertical direction is the z-axis, and the width direction is the y-axis.

[0013] Refer to Fig. 4(a).

[0014] First, a photoresist is applied to the upper surface of a substrate (100) to form a first photoresist layer (200). At this time, the photoresist is, for example, a negative photoresist, which has the characteristic that the irradiated portion (exposed portion) hardens when light (such as UV) is irradiated. As another example, a positive photoresist may be used, but for convenience of explanation, this specification will describe everything based on a negative photoresist.

[0015] A mask (1000) is placed on the upper vertical side of the applied first photoresist layer (200). At this time, the mask (1000) is divided into a first-1 mask (1001) located in the pattern section (A) and a first-2 mask (1002) located in the weld section (B). However, for the convenience of explanation, the names are different.

[0016] A plurality of first mask holes (1100) are formed in the first mask (1001), and the corresponding portion is opened so that light irradiated from the upper vertical direction can pass through the first mask holes (1100) and reach the first photoresist layer (200). After the mask (1000) is placed, an exposure (1a) process is performed. The exposure (1a) process at this time is a 'front exposure' method in which light is irradiated from the upper vertical direction to the lower direction.

[0018] Next, refer to Fig. 4(b).

[0019] When a developing process is performed after the exposure (1a) process, only the portion of the first photoresist layer (200a) that is in contact with the light penetrating the first mask hole (1100) is cured and remains. The state is as shown in FIG. 4(b).

[0021] Next, refer to Fig. 4(c).

[0022] A first plating step is performed based on the remaining first photoresist layer (200a), and a first plating layer (300) is formed. The first plating layer (300) that is plated between the multiple remaining first photoresist layers (200a) is a plating layer formed on the pattern portion (A) and is referred to as the first-1 plating layer (310) for convenience, and the first plating layer (300) that is plated on both sides of the entire multiple remaining first photoresist layers (200a) is a plating layer formed on the weld portion (B) and is referred to as the first-2 plating layer (320) for convenience.

[0024] Next, refer to Fig. 4(d).

[0025] After the first plating layer (300) is formed, if the plurality of remaining first photoresist layers (200a) are removed, a shape as shown in FIG. 4(d) is obtained, and deposition holes are formed between the plurality of first-1 plating layers (310) plated on the pattern portion (A).

[0027] Next, refer to Fig. 4(e).

[0028] A second photoresist layer (400) is applied to cover the entire first plating layer (300). At this time, for convenience of explanation, the second photoresist layer applied to the pattern portion (A) is referred to as the second-1 photoresist layer (410), and the second photoresist layer applied to the weld portion (B) is referred to as the second-2 photoresist layer (420).

[0029] At this time, a second mask (2000) covering the entire weld (B) (in the longitudinal direction) is placed on the upper vertical side of the weld (B). When placed in this way, only the second-1 photoresist layer (410) applied to the pattern (A) can be exposed to light. Subsequently, an exposure (3a) process is performed. The exposure (3a) process at this time is a 'full exposure' method in which light is irradiated from the upper vertical side to the lower side.

[0031] Next, refer to Fig. 4(f).

[0032] When exposure and development are performed, as shown in FIG. 4(f), the second photoresist layer does not exist in the weld (B), so the first-2 plating layer (320) is exposed, and the first-1 plating layer (310) is in a form where the hardened second-1 photoresist layer (410a) covers the first-1 plating layer (310).

[0034] Next, refer to Fig. 4(g).

[0035] Afterward, when a second plating is performed, a second plating layer (500) is formed on the upper surface in the vertical direction of the exposed first-second plating layer (320).

[0037] Next, refer to Fig. 4(h).

[0038] When the hardened second-1 photoresist layer (410a) is removed, the first-1 plating layer (310) and deposition holes remain in the pattern portion (A), and the first-2 plating layer (320) and the second plating layer (500) are formed in the weld portion (B), thereby completing the over-plating. At this time, the first-2 plating layer (320) and the second plating layer (500) are all in contact in the longitudinal direction. Afterwards, the FMM manufactured from the substrate (100) is detached.

[0040] Referring to Fig. 7, the problems of FMM manufactured through a conventional over-plating process will be explained.

[0041] FIG. 7 illustrates a plan view of an FMM manufactured by a conventional over-plating process. It is an FMM after being separated from a substrate (100). The width of the pattern portion (A) is referred to as 'y1', and the width of the weld portion (B) is referred to as 'y2'. At this time, in the case of an FMM manufactured by a conventional over-plating process, a difference in shrinkage rate between the pattern portion (A) and the weld portion (B) occurs due to differences in opening ratio, thickness, and composition between the pattern portion (A) and the weld portion (B) during the process of separating the FMM from the substrate, and there is a problem in that the FMM is manufactured in a state where the weld portion (B) shrinks more in the width direction than the pattern portion (A) (y1 > y2). More specifically, both the first and second plating layers (320) and the second plating layer (500) of the weldment (B) are conventionally formed from an Fe-Ni alloy. As the Fe content increases, the amount of shrinkage increases, and as the area between the Fe-Ni plating layers in contact along the length of the weldment (B) increases, the amount of curl increases, which causes the above-mentioned problem. In particular, as shown in FIG. 4(h), the first and second plating layers (320) and the second plating layer (500) are manufactured by plating in a state where they are all in contact along the length of the weldment (B), so the amount of shrinkage of the weldment (B) becomes greater than that of the pattern portion (A).

[0042] As a result, the weld (B), which contracts further, pulls the pattern (A), so there is a problem where wrinkles occur at the boundary between the pattern (A) and the weld (B) as shown in Fig. 8, or curls occur in the weld (B) as shown in Fig. 9.

[0044] Next, we will explain the over-plating process for conventional FMM manufacturing using the ‘back exposure’ method rather than the ‘front exposure’ method.

[0045] FIG. 1 illustrates a process flow diagram of a plating process for manufacturing a conventional FMM using a back exposure method. Hereinafter, the plating process for manufacturing a conventional FMM using a back exposure method will be explained with reference to FIG. 1. The 'back exposure' method uses a non-conductive and transparent substrate (for example, a glass substrate) as the base substrate, and is a method in which the photoresist coated through the substrate can be exposed when light is irradiated onto the substrate from the bottom to the top in a vertical direction. Both the 'front exposure' and 'back exposure' methods can be used when manufacturing an FMM by electroplating.

[0046] In addition, FIG. 1 is a drawing explained based on a side view. Also, with respect to FIG. 1, the length direction is the x-axis, the vertical direction is the z-axis, and the width direction is the y-axis.

[0048] Refer to Fig. 1(a).

[0049] First, a conductive layer (20) is sputtered onto the upper surface of the substrate (10), and then a hole (21a) is formed. The conductive layer (20) may include, for example, Cu (copper) or ITO (indium tin oxide), and unlike the 'front exposure' method, since direct plating on the substrate is not possible, it serves to provide electrical conductivity to enable plating and at the same time facilitate the attachment and detachment of the manufactured FMM.

[0050] The conductive layer (20) includes a first conductive layer (21) and a second conductive layer (22). For convenience of explanation, the conductive layer formed in the area corresponding to the pattern portion (A) is referred to as the first conductive layer (21), and the conductive layer formed in the area corresponding to the weld portion (B) is referred to as the second conductive layer (22).

[0052] Next, refer to Fig. 1(b).

[0053] A first photoresist layer (30) is formed by applying a photoresist to the upper surface of a substrate (10). At this time, the photoresist is, for example, a negative photoresist, which has the characteristic that the irradiated portion (exposed portion) hardens when light (such as UV) is irradiated. As another example, a positive photoresist may be used, but for convenience of explanation, this specification will describe everything based on a negative photoresist.

[0054] When light is irradiated from the bottom to the top in the vertical direction of the substrate (10) while the first photoresist layer (30) is applied, the light penetrates the substrate (10). At this time, the first photoresist layer (30) applied to the hole (21a) can come into contact with the light. That is, an exposure (1) process is performed using a 'back exposure' method.

[0056] Next, refer to Fig. 1(c).

[0057] After performing the exposure (1) process and then performing the development process, the first photoresist layer (30a) remains hardened along the length of the hole (21a). The state is as shown in FIG. 1(c).

[0059] Next, refer to Fig. 1(d).

[0060] A first plating step is performed based on the remaining first photoresist layer (30a), and a first plating layer (40) is formed. The first plating layer (40) that is plated between the multiple remaining first photoresist layers (30a) is a plating layer formed on the pattern portion (A) and is referred to as the first-1 plating layer (41) for convenience, and the first plating layer (40) that is plated on both sides of the entire multiple remaining first photoresist layers (30a) is a plating layer formed on the weld portion (B) and is referred to as the first-2 plating layer (42) for convenience.

[0062] Next, refer to Fig. 1(e).

[0063] After the first plating layer (40) is formed, when the multiple remaining first photoresist layers (30a) are removed, a shape like that of FIG. 1(e) is produced, and deposition holes are formed between the multiple first-1 plating layers (41) plated on the pattern portion (A).

[0065] Next, refer to Fig. 1(f).

[0066] A second photoresist layer (50) is applied to cover the entire first plating layer (40). At this time, for convenience of explanation, the second photoresist layer applied to the pattern portion (A) is referred to as the second-1 photoresist layer (51), and the second photoresist layer applied to the weld portion (B) is referred to as the second-2 photoresist layer (52).

[0067] At this time, light is irradiated from the upper to the lower direction in a vertical direction using a 'full exposure' method, so that only the 2-1 photoresist layer (51) is exposed. For this structure, for example, a mask may be placed in the upper vertical direction of the 2-2 photoresist layer (52) applied to the weld portion (B) to perform 'full exposure,' or a method of direct exposure (for example, LDI) may be performed so that only the 2-1 photoresist layer (51) applied to the pattern portion (A) is partially exposed. After undergoing the exposure (3) and development processes, the 2-2 photoresist layer (52) applied to the weld portion (B) is removed (2, 4).

[0069] Next, refer to Fig. 1(g).

[0070] Since the second photoresist layer does not exist in the welded portion (B), the first-2 plating layer (42) is exposed, and the first-1 plating layer (41) is in a form where the hardened second-1 photoresist layer (51a) covers the first-1 plating layer (41). Afterward, when a second plating is performed, the second plating layer (60) is formed on the upper surface in the vertical direction of the exposed first-2 plating layer (42).

[0072] Next, refer to Fig. 1(h).

[0073] When the cured 2-1 photoresist layer (51a) is removed, the 1-1 plating layer (41) and deposition holes remain in the pattern portion (A), and the 1-2 plating layer (42) and the 2 plating layer (60) are formed in the weld portion (B), thereby completing the over-plating. At this time, the 1-2 plating layer (42) and the 2 plating layer (60) are in contact with each other in the longitudinal direction. Afterwards, the FMM manufactured from the substrate (10) is detached. During this process, the conductive layer (20) is also removed.

[0075] The 'front exposure' method described above has the same structure as the FMM manufactured by the 'back exposure' method and has the same problems as previously mentioned. Accordingly, the present invention proposes the following invention to solve the problems of the prior art. Prior art literature

[0076] Korean Registered Patent Publication No. 10-2125676 The problem to be solved

[0077] The problem that the present invention aims to solve is to prevent issues such as warping, curling, and wrinkling caused by the difference in shrinkage rates between the welded part and the patterned part in an FMM manufactured by an electroplating method, thereby providing an FMM with a more precise and stable structure. means of solving the problem

[0078] To achieve the objective of the present invention, an OLED deposition mask manufactured by an electroplating method according to the present invention comprises: a first plating layer having a plurality of deposition holes formed therein, located in a pattern area; a second plating layer located on both sides in the longitudinal direction of the first plating layer and located in a weld area; and a second plating layer located in the weld area and covering a portion of the first plating layer.

[0079] Additionally, the second plating layer of the OLED deposition mask manufactured by the electroplating method according to the present invention comprises: a 2-1 plating layer covering a portion of the 1-2 plating layer; and a 2-2 plating layer extending from the 2-1 plating layer and formed in the welded portion area excluding the 1-2 plating layer.

[0080] In addition, the second-1 plating layer of the OLED deposition mask manufactured by the electroplating method according to the present invention is formed in the area extending from the boundary point of the first-2 plating layer to the boundary point of the second-2 plating layer at a point spaced apart from the outer side of the pattern part by a predetermined distance in the longitudinal direction from the boundary point of the pattern part and the weld part.

[0081] In addition, the second plating layer of the OLED deposition mask manufactured by the electroplating method according to the present invention is formed of a single material of Ni.

[0082] In addition, the second plating layer of the OLED deposition mask manufactured by the electroplating method according to the present invention is formed of a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio.

[0083] A method for manufacturing an OLED deposition mask by an electroplating method comprising a pattern portion and a weld portion where a frame is joined, comprising: a step of forming a first photoresist layer on the upper surface of a conductive substrate; a step of curing the first photoresist layer at a position complementary to a deposition hole to be formed in the pattern portion area; a step of curing the first photoresist layer in an area extending from a point spaced at a predetermined distance in the longitudinal direction outward from the boundary point of the pattern portion and the weld portion to the end of the weld portion area; a step of forming a first plating layer on the conductive substrate in a portion where the cured first photoresist layer is absent; a step of removing the first photoresist layer; a step of forming a second photoresist layer on the conductive substrate to cover the first plating layer; a step of curing the second photoresist layer formed in the pattern portion area and a portion of the second photoresist layer formed in the weld portion area; a step of developing to remove the uncured second photoresist layer; and a step of forming a second plating layer on the conductive substrate. and the step of removing the hardened second photoresist layer; is included.

[0084] In addition, the step of curing a portion of the second photoresist layer formed in the weld area involves curing the second photoresist layer formed on the first plating layer formed in the weld area, in the area extending from the boundary point between the pattern area and the weld area to a point spaced apart at a predetermined distance in the longitudinal direction from the outer side of the pattern area.

[0085] In addition, the step of forming a second plating layer on the conductive substrate is formed such that the second plating layer covers only a portion of the longitudinal direction of the first plating layer formed in the weld area.

[0086] In addition, the first photoresist layer and the second photoresist layer are cured by a front exposure method.

[0087] In addition, the second plating layer is formed from a single material of Ni.

[0088] In addition, the second plating layer is formed of a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio.

[0089] A method for manufacturing an OLED deposition mask by an electroplating method comprising a pattern portion and a weld portion where a frame is joined, comprising the steps of: forming a conductive layer having a hole formed at a position complementary to a deposition hole to be formed in the pattern portion area on the upper surface of a non-conductive transparent substrate; forming a first photoresist layer to cover the conductive layer; performing back exposure on the pattern portion area to cure a portion of the first photoresist layer formed in the pattern portion area; curing the first photoresist layer formed in the area from a point spaced at a predetermined distance in the longitudinal direction from the boundary point of the pattern portion and the weld portion to the end of the weld portion; forming a first plating layer in a portion where the cured first photoresist layer is absent; removing the cured first photoresist layer; forming a second photoresist layer to cover the first plating layer and the conductive layer; and curing a portion of the second photoresist layer formed in the pattern portion area and the second photoresist layer formed in the weld portion area. A step of removing the second photoresist layer that has not been developed and cured; a step of forming a second plating layer on the non-conductive transparent substrate; and

[0090] The step of removing the hardened second photoresist layer; is included.

[0091] In addition, the step of curing a portion of the second photoresist layer formed in the weld area involves curing the second photoresist layer formed on the first plating layer formed in the weld area, in the area extending from the boundary point between the pattern area and the weld area to a point spaced apart at a predetermined distance in the longitudinal direction from the outer side of the pattern area.

[0092] In addition, the step of forming a second plating layer on the non-conductive transparent substrate is formed such that the second plating layer covers only a portion of the longitudinal direction of the first plating layer formed in the weld area.

[0093] In addition, the step of curing the second photoresist layer formed in the pattern area and a portion of the second photoresist layer formed in the weld area is a full-front exposure method.

[0094] In addition, the second plating layer is formed from a single material of Ni.

[0095] In addition, the second plating layer is formed of a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio. Effects of the invention

[0096] According to the present invention, by composing the second plating layer formed on the weld portion of a Fine Metal Mask (FMM) for OLED deposition manufactured by an electroplating method with a single Ni metal or a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio, deformation problems such as distortion, curl, and wrinkle that may occur during welding or after substrate separation can be effectively reduced.

[0097] In addition, unlike conventional structures where the first and second plating layers are in full contact along the length, the present invention forms the contact area of ​​both plating layers to be minimized, thereby significantly reducing the possibility of deformation occurring at the boundary between the pattern portion and the weld portion due to differences in physical properties between the plating layers.

[0098] This configuration improves the dimensional stability and flatness of the FMM, enables precise pattern alignment and consistent deposition quality in the OLED deposition process, and can also contribute to improving the production yield of high-resolution OLED displays and maintaining equipment precision.

[0099] In addition, since both back exposure and front exposure methods can be applied, it can be flexibly utilized in various manufacturing environments, and since the over-plating area can be controlled according to the design, it also offers the advantage of enabling process optimization and customized FMM manufacturing. Brief explanation of the drawing

[0100] Figure 1 illustrates a process diagram of an over-plating process for manufacturing a conventional back-exposure type FMM. FIG. 2 illustrates a process diagram of an over-plating process for manufacturing an FMM according to the back exposure method according to the present invention. Figure 3 is an enlarged view of the welded portion of an FMM according to the back exposure method according to the present invention. Figure 4 illustrates a process diagram of an over-plating process for manufacturing a conventional front exposure FMM. FIG. 5 illustrates a process diagram of an over-plating process for manufacturing an FMM according to the front exposure method according to the present invention. Figure 6 is an enlarged view of the welded portion of an FMM according to the front exposure method according to the present invention. Figure 7 shows a plan view of an FMM manufactured by a conventional over-plating process. Figures 8 and 9 show enlarged views of an actual FMM manufactured according to the prior art. FIGS. 10 and FIGS. 11 are enlarged views of an actual FMM manufactured according to the present invention. Specific details for implementing the invention

[0101] The present invention will be described in detail below with reference to the drawings. The embodiments described below are provided as examples to ensure that the concept of the present invention is sufficiently conveyed to a person skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. Furthermore, in the drawings, the size and thickness of the device, etc., may be exaggerated for convenience. Throughout the specification, the same reference numerals indicate the same components.

[0103] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity of description.

[0105] FIG. 5 illustrates a process flow diagram of an over-plating process for manufacturing an FMM according to a front exposure method according to the present invention. Hereinafter, the over-plating process for manufacturing an FMM according to a front exposure method according to the present invention will be explained with reference to FIG. 5. FIG. 5 is explained on the premise that the substrate serving as the base is a conductive substrate (for example, a Ti substrate). FIG. 5 is a drawing explained based on a side view. In addition, with respect to FIG. 5, the length direction is the x-axis, the vertical direction is the z-axis, and the width direction is the y-axis.

[0107] Refer to Fig. 5(a).

[0108] First, a photoresist is applied to the upper surface of a substrate (100) to form a first photoresist layer (200). At this time, the photoresist is, for example, a negative photoresist, which has the characteristic that the irradiated portion (exposed portion) hardens when light (such as UV) is irradiated. As another example, a positive photoresist may be used, but for convenience of explanation, this specification will describe everything based on a negative photoresist.

[0109] A mask (1000) is placed on the upper vertical side of the applied first photoresist layer (200). At this time, the mask (1000) is divided into a first mask (1001) located on the pattern portion (A) and a second mask (1003) located on only a part of the weld portion (B). However, for the convenience of explanation, the names are different.

[0110] Referring to FIG. 4, in the conventional case, the second mask (2000) covers the entire length direction of the weld portion (B), but according to the present invention, it covers only a part of the weld portion (B) and the rest is exposed. More specifically, it is preferable that a portion of the second mask (1003) is formed in the outer direction of the length direction of the pattern portion (A) based on the boundary surface between the pattern portion (A) and the weld portion (B).

[0112] In the first mask (1001), a plurality of first mask holes are formed as in the prior art, and the corresponding portion is opened so that light irradiated from the upper vertical direction can penetrate the first mask holes and reach the first photoresist layer (200). After the mask (1000) is placed, an exposure (1a) process is performed. The exposure (1a) process at this time is a 'full exposure' method in which light is irradiated from the upper vertical direction to the lower direction.

[0114] Next, refer to Fig. 5(b).

[0115] When the development process is performed after the exposure (1a) process, the first photoresist layer portion (200a) that the light penetrating the first mask hole contacts remains and is formed on the pattern portion (A). Additionally, the first photoresist layer portion (200b) located in the remaining portion excluding the lengthwise area of ​​the second mask (1003) remains and is formed on the weld portion (B). Unlike conventional methods, the first photoresist layer remains on the weld portion (B). At this time, the first photoresist layer does not remain on the portion where the second mask (1003) is formed, and a hole (H) is formed in that portion.

[0117] Next, refer to Fig. 5(c).

[0118] A first plating step is performed based on the remaining first photoresist layers (200a, 200b), and a first plating layer (300) is formed. The first plating layer (300) located in the pattern portion (A) and plated between a plurality of remaining first photoresist layers (200a) is referred to as the first-1 plating layer (310) for convenience, and the first plating layer (300) plated on the aforementioned hole (H) is referred to as the first-2 plating layer (330) for convenience.

[0120] Next, refer to Fig. 5(d).

[0121] After the first plating layer (300) is formed, when the multiple remaining first photoresist layers (200a, 200b) are removed, a shape as shown in FIG. 5(d) is obtained, and deposition holes are formed between the multiple first-1 plating layers (310) plated on the pattern portion (A).

[0123] Next, refer to Fig. 5(e).

[0124] A second photoresist layer (400) is applied to cover the entire first plating layer (300).

[0126] Next, refer to Fig. 5(f).

[0127] A second mask (3000) is placed on the upper vertical side of the weld (B) to cover a portion of the weld (B) (in the longitudinal direction). More specifically, regarding the first-second plating layer (330) formed on the weld (B), the second mask (3000) is placed so that only a portion of the first-second plating layer (330) is exposed in the outer direction of the pattern portion (A) based on the boundary surface between the pattern portion (A) and the weld (B) (if the length in the longitudinal direction of the first-second plating layer (330) is 'd', the length in the longitudinal direction is exposed by a length 'k', and the second mask (3000) is placed over the 'd-k' portion). When arranged in this way, the second photoresist layer (400) applied to the pattern portion (A) and the second photoresist layer (400) applied to the weld portion (B) which is partially applied in the vertical direction upper part of the first-second plating layer (330) (where the length in the longitudinal direction does not overlap with the second mask (3000)) can be exposed to light. Subsequently, an exposure (3a) process is performed. The exposure (3a) process at this time is a 'full exposure' method in which light is irradiated from the vertical upper direction to the lower direction.

[0129] Next, refer to Fig. 5(g).

[0130] When exposure and development are performed, as shown in FIG. 5(g), only a portion (400c) of the second photoresist layer remains in the welded portion (B), and more specifically, it remains in a state where it partially covers the first-2 plating layer (330). This portion is referred to as the second-2 photoresist layer (400cb). Additionally, the entire second photoresist layer remains in the pattern portion (A) and covers the entire first-1 plating layer (310). This portion is referred to as the second-1 photoresist layer (400ca).

[0132] Next, refer to Fig. 5(h).

[0133] Subsequently, when a second plating is performed, a second plating layer (500) is formed. At this time, the second plating layer (500) is formed in the portion where the second-2 plating layer (400cb) does not cover the first-2 plating layer (330) and in the outer portion of the first-2 plating layer (330). For convenience, these are referred to as the second-2 plating layer (520) and the second-1 plating layer (510), respectively.

[0135] Next, refer to Fig. 5(i).

[0136] When the entire hardened second photoresist layer (400c) is removed, the first-1 plating layer (310) and deposition holes remain in the pattern portion (A), and the first-2 plating layer (330) and the second plating layer (500) are formed in the weld portion (B), thereby completing the over-plating. At this time, conventionally, the first-2 plating layer (320) and the second plating layer (500) are in contact in the longitudinal direction, but when manufactured by the process according to the present invention, the first-2 plating layer (330) and the second plating layer (500) are not in contact in the longitudinal direction. FIG. 6 is an enlarged view of the weld portion (B), in which it can be seen that only a part of the first-2 plating layer (330) is in contact with the second plating layer (500). Afterwards, the FMM manufactured from the substrate (100) is detached.

[0138] In this case, in the present invention, as an example, it is preferable to form the second plating layer (500) with a single Ni metal, and as another example, it is preferable to form the second plating layer (500) with a Ni-Fe alloy in which the ratio of Ni is higher than the ratio of Fe. That is, conventionally, it is an Fe-Ni alloy in which the ratio of Fe is higher than Ni, but in the present invention, the ratio of Fe is configured to be smaller than the ratio of Ni. By configuring the second plating layer (500) as described above, there is an advantage of being able to reduce the aforementioned conventional warping and curl.

[0139] In alloys containing Fe and Ni, distortion increases as the proportion of Fe increases. Since Fe has a higher coefficient of thermal expansion than Ni, a higher Fe content leads to increased stress due to shrinkage differences and causes distortion. Additionally, because Fe has high mechanical strength and a high elastic modulus, stress concentration occurs easily. This is because residual stress develops within the metal after plating, and as the proportion of Fe increases, this residual stress is more likely to manifest as distortion or deformation.

[0140] Accordingly, as in the present invention, it is preferable to form the second plating layer (500) with a single Ni metal or with a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio.

[0142] In addition, as previously mentioned regarding the problems of the conventional technology, the larger the contact area between the first plating layer and the second plating layer in the longitudinal direction, the greater the difference in shrinkage amount, so there is a high possibility that wrinkles will occur at the boundary between the pattern part and the weld part or that warping will occur in the weld part.

[0143] In this case, if the second plating layer (500) is formed from a single Ni metal or from a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio, there is a possibility that wrinkles may occur at the boundary between the pattern portion and the weld portion or warping may occur in the weld portion due to the difference in physical properties with the first plating layer (300) composed of an Fe-Ni alloy. To compensate for this, the invention is characterized by being able to compensate by minimizing the longitudinal contact area between the second plating layer (500) and the first plating layer (300). In the present invention, a first-second plating layer (330) is formed on the weld portion (B). Unlike conventional methods, only a portion of the area adjacent to the pattern portion (A) in the weld portion (B) is formed as the first-second plating layer (330) ('d'), and only a portion of the upper surface of the first-second plating layer (330) is in contact with the second plating layer (500) rather than the entire surface ('d-k'), thereby minimizing the contact area between the second plating layer (500) and the first plating layer (300). As a result, problems such as wrinkles occurring at the boundary between the pattern portion and the weld portion or warping occurring in the weld portion can be prevented. As shown in FIG. 10, it can be confirmed that no wrinkles occur at the boundary between the pattern portion (A) and the weld portion (B), and as shown in FIG. 11, it can be confirmed that no curl occurs in the weld portion (B). FIGS. 8 and 9 are enlarged views of an actual FMM manufactured according to the prior art, and FIGS. 10 and 11 are enlarged views of an actual FMM manufactured according to the present invention.

[0145] FIG. 2 illustrates a process flow diagram of an over-plating process for manufacturing an FMM according to a back exposure method according to the present invention. Hereinafter, the over-plating process for manufacturing an FMM according to a back exposure method according to the present invention will be explained with reference to FIG. 2. FIG. 5 is explained on the premise that the substrate serving as the base is a conductive substrate (for example, a Ti substrate).

[0147] Refer to Fig. 2(a).

[0148] Figure 2(a) is a process performed in the state of the conventional Figure 1(b).

[0149] A conductive layer (20) with a hole formed on the upper surface of a substrate (10) is sputtered. The conductive layer (20) may include MoTi (molybdenum-titanium), Cu (copper), and ITO (indium tin oxide) layers, and unlike the 'front exposure' method, it is not possible to plate directly on the substrate, so it serves to provide electrical conductivity to enable plating and at the same time facilitate the detachment of the manufactured FMM.

[0150] The conductive layer (20) includes a first conductive layer (21) and a second conductive layer (22). For convenience of explanation, the conductive layer formed in the area corresponding to the pattern portion (A) is referred to as the first conductive layer (21), and the conductive layer formed in the area corresponding to the weld portion (B) is referred to as the second conductive layer (22).

[0151] A first photoresist layer (30) is formed by applying a photoresist to the upper surface of a substrate (10). At this time, the photoresist is, for example, a negative photoresist, which has the characteristic that the irradiated portion (exposed portion) hardens when light (such as UV) is irradiated. As another example, a positive photoresist may be used, but for convenience of explanation, this specification will describe everything based on a negative photoresist.

[0152] When the first photoresist layer (30) is applied, light is irradiated from the bottom to the top in the vertical direction of the substrate (10), and the light penetrates the substrate (10). At this time, the first photoresist layer (30) applied to the pattern portion (A) is referred to as the first-1 photoresist layer (31), and the first photoresist layer (30) applied to the weld portion (B) is referred to as the first-2 photoresist layer (32).

[0154] The first-1 photoresist layer (31) applied to the hole among the first-1 photoresist layers (31) formed in the pattern portion (A) can come into contact with light. That is, an exposure (1) process is performed by a 'rear exposure' method.

[0155] At this time, unlike in the past, partial curing is also performed on the first-second photoresist layer (32) located in the welded portion (B). In the first-second photoresist layer (32) located in the welded portion (B), exposure (5) is performed so that only the area extending from a point spaced apart at a predetermined distance in the longitudinal direction (by 'd' in the longitudinal direction) from the boundary point between the pattern portion (A) and the welded portion (B) to the outer end point of the first-second photoresist layer (32) is cured. For such partial curing, a method of direct exposure (e.g., LDI) to the corresponding area can be performed. Additionally, a mask can be placed excluding the area to be cured, and a full exposure method can be performed.

[0157] Next, refer to Fig. 2(b).

[0158] After performing the exposure (1, 5) process and then performing the development process, the first-1 photoresist layer (31a) is cured and remains for a length of the length of the hole in the pattern part (A). Additionally, the first-2 photoresist layer (32a) is cured and remains for an area extending from the point (lengthwise by 'd') that is spaced outward from the boundary point between the pattern part (A) and the weld part (B) in the lengthwise direction (lengthwise by 'd') to the outer end point of the first-2 photoresist layer (32). Accordingly, the first-2 photoresist hole (H) is formed in the area extending from the boundary point between the pattern part (A) and the weld part (B) in the lengthwise direction (lengthwise by 'd') in the lengthwise direction (lengthwise by 'd').

[0160] Next, refer to Fig. 2(c).

[0161] A first plating step is performed based on the remaining first photoresist layer (31a, 32a), and a first plating layer (40) is formed. The first plating layer (40) that is plated between the multiple remaining first-1 photoresist layers (31a) is a plating layer formed on the pattern portion (A) and is referred to as the first-1 plating layer (41) for convenience, and the first plating layer (40) that is plated on the first-2 photoresist hole (H) of the first-2 photoresist layer (32a) is a plating layer formed on a part of the weld portion (B) and is referred to as the first-2 plating layer (43) for convenience.

[0163] Next, refer to Fig. 2(d).

[0164] After the first plating layer (40) is formed, when the multiple remaining first photoresist layers (31a, 32a) are removed, a shape as shown in FIG. 2(d) is obtained, and deposition holes are formed between the multiple first-1 plating layers (41) plated on the pattern portion (A).

[0166] Next, refer to Fig. 2(e).

[0167] A second photoresist layer (50) is applied to cover the entire first plating layer (40). At this time, for convenience of explanation, the second photoresist layer applied to the pattern portion (A) is referred to as the second-1 photoresist layer (51), and the second photoresist layer applied to the weld portion (B) is referred to as the second-2 photoresist layer (52).

[0168] At this time, light is irradiated from the upper to the lower direction in a vertical direction using a 'front exposure' method, thereby exposing a portion of the 2-1 photoresist layer (51) and the 2-2 photoresist layer (52). The configuration is different from the conventional one in that a portion of the 2-2 photoresist layer (52) is exposed.

[0169] More specifically, in the second-second photoresist layer (52) located on the upper surface of the first-second plating layer (43), the area (53) extending from the boundary point between the pattern portion (A) and the weld portion (B) to a point spaced apart at a predetermined distance in the longitudinal direction outward from the pattern portion (A) (a distance of 'k' in the longitudinal direction) is exposed and cured.

[0170] For this structure, for example, a mask may be placed on the upper vertical side of the second-2 photoresist layer (52), excluding the area (53) to be exposed in the welded part (B), and 'front exposure' may be performed, or a method of direct exposure (for example, LDI, reference numeral '6') may be performed to expose the area to be exposed in the welded part (B). The area located in the pattern part (A) may be exposed and front exposure (3) may be performed separately from the area (53) to be exposed. After undergoing the exposure (3, 6) and development processes, a portion of the second-2 photoresist layer (52) applied to the welded part (B) is removed, and only the area corresponding to reference numeral '53' exposed in the second-2 photoresist layer (52) remains.

[0172] Next, refer to Fig. 2(f).

[0173] FIG. 2(f) is a state after exposure and development, in which the first-1 plating layer (41) of the pattern portion (A) is covered by a hardened second-1 photoresist layer (51a), and a portion of the first-2 plating layer (43) of the weld portion (B) is covered by a hardened second-2 photoresist layer (53a). The second-1 photoresist layer (51a) and the second-2 photoresist layer (53a) are extended.

[0175] Next, refer to Fig. 2(g).

[0176] When a second plating is performed, a second plating layer (60) is formed on the welded portion (B). At this time, the second plating layer (60) includes a second-1 plating layer (61) formed in the area from a point spaced apart at a predetermined distance in the longitudinal direction outward from the boundary point between the pattern portion (A) and the welded portion (B) (a distance of 'd' in the longitudinal direction) to the outer end point of the second conductive layer (22), and a second-2 plating layer (62) formed in the area where the second-2 photoresist layer (53a) is not formed on the upper surface of the first-2 plating layer (43).

[0178] Next, refer to Fig. 2(h).

[0179] When the hardened 2-1 photoresist layer (51a) and 2-2 photoresist layer (53a) are removed, the 1-1 plating layer (41) and deposition holes remain in the pattern portion (A), and the 1-2 plating layer (43) and 2 plating layer (60) are formed in the weld portion (B), thereby completing the over-plating. At this time, unlike in the past, the 1-2 plating layer (42) and the 2 plating layer (60) are in contact only partially in the longitudinal direction. During this process, the conductive layer (20) is also removed.

[0180] FIG. 3 is an enlarged view of the welded portion (B), showing that only a part ('dk' region) of the first-2 plating layer (43) is in contact with the second plating layer (60) (second-2 plating layer (62)). Afterwards, the FMM manufactured from the substrate (10) is detached. During this process, the conductive layer (20) is also removed.

[0181] As described above, the same structure as the FMM manufactured by the aforementioned 'front exposure' method can be formed by the 'back exposure' method, and it shares the same effects. This prevents redundant explanation.

[0183] Although preferred embodiments of the present invention have been described above, the present invention may use various variations, modifications, and equivalents. It is clear that the present invention can be applied in the same way by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims. Explanation of the symbols

[0184] 10, 100 : Substrate 20: Conductive layer 30, 200 : 1st photoresist layer 40, 300: 1st plating layer 50, 400: Second photoresist layer 60, 500: Second plating layer 1000 : 1st Mask 2000: 2nd mask

Claims

Claim 1 An OLED deposition mask manufactured by an electroplating method comprising a pattern portion and a weld portion where a frame is joined, wherein the mask comprises: a first-1 plating layer located in the pattern portion area and having a plurality of deposition holes formed therein; a first-2 plating layer located on both sides in the longitudinal direction of the first-1 plating layer and located in the weld portion area from the boundary point between the pattern portion and the weld portion; and a second plating layer located in the weld portion area and covering a portion of the first-2 plating layer in the longitudinal direction; wherein the second plating layer comprises a second-1 plating layer covering a portion of the first-2 plating layer; and a second-2 plating layer formed extending from the second-1 plating layer and formed in the weld portion area excluding the first-2 plating layer. Claim 2 delete Claim 3 An OLED deposition mask manufactured by an electroplating method, wherein, in claim 1, the 2-1 plating layer is formed in the region from the boundary point of the 1-2 plating layer to the boundary point of the 2-2 plating layer, at a point spaced apart from the outer side of the pattern part by a predetermined lengthwise distance from the boundary point of the pattern part and the weld part. Claim 4 In paragraph 3, the second plating layer is formed from a single material of Ni and is an OLED deposition mask manufactured by an electroplating method. Claim 5 In paragraph 3, the second plating layer is formed of a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio, and the OLED deposition mask is manufactured by an electroplating method. Claim 6 A method for manufacturing an OLED deposition mask by an electroplating method comprising a pattern portion and a weld portion where a frame is joined, comprising: a step of forming a first photoresist layer on the upper surface of a conductive substrate; a step of curing the first photoresist layer at a position complementary to a deposition hole to be formed in the pattern portion area; a step of curing the first photoresist layer in an area extending from a point spaced at a predetermined distance in the longitudinal direction outward from the boundary point of the pattern portion and the weld portion to the end of the weld portion area; a step of forming a first plating layer on the conductive substrate in a portion where the cured first photoresist layer is absent; a step of removing the first photoresist layer; a step of forming a second photoresist layer on the conductive substrate to cover the first plating layer; a step of curing the second photoresist layer formed in the pattern portion area and a portion of the second photoresist layer formed in the weld portion area; a step of developing and removing the uncured second photoresist layer; and a step of forming a second plating layer on the conductive substrate. A method for manufacturing an OLED deposition mask manufactured by an electroplating method, comprising the step of removing the hardened second photoresist layer; and the step of hardening a portion of the second photoresist layer formed in the weld area, wherein the second photoresist layer formed in the area extending from the boundary point of the pattern area to the point spaced apart at a predetermined distance in the longitudinal direction from the boundary point to the spaced-away point on the first plating layer formed in the weld area is hardened so that the second photoresist layer remains in the section from the boundary point to the spaced-away point, thereby preventing the second plating layer from being formed. Claim 7 delete Claim 8 A method for manufacturing an OLED deposition mask manufactured by an electroplating method, wherein, in claim 6, the step of forming a second plating layer on the conductive substrate is formed such that the second plating layer covers only a portion of the longitudinal direction of the first plating layer formed in the weld area. Claim 9 A method for manufacturing an OLED deposition mask manufactured by an electroplating method, wherein, in claim 8, the first photoresist layer and the second photoresist layer are cured by a full-front exposure method. Claim 10 A method for manufacturing an OLED deposition mask manufactured by an electroplating method, wherein, in claim 9, the second plating layer is formed of a single Ni material. Claim 11 A method for manufacturing an OLED deposition mask manufactured by an electroplating method, wherein, in claim 9, the second plating layer is formed of a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio. Claim 12 A method for manufacturing an OLED deposition mask by an electroplating method comprising a pattern portion and a weld portion where a frame is joined, comprising the steps of: forming a conductive layer having a hole formed at a position complementary to a deposition hole to be formed in the pattern portion area on the upper surface of a non-conductive transparent substrate; forming a first photoresist layer to cover the conductive layer; performing back exposure on the pattern portion area to cure a portion of the first photoresist layer formed in the pattern portion area; curing the first photoresist layer formed in the area from a point spaced at a predetermined distance in the longitudinal direction from the boundary point of the pattern portion and the weld portion to the end of the weld portion; forming a first plating layer in a portion where the cured first photoresist layer is absent; removing the cured first photoresist layer; forming a second photoresist layer to cover the first plating layer and the conductive layer; curing the second photoresist layer formed in the pattern portion area and a portion of the second photoresist layer formed in the weld portion area; and developing the uncured second photoresist layer A method for manufacturing an OLED deposition mask manufactured by an electroplating method, comprising: a step of removing; a step of forming a second plating layer on the non-conductive transparent substrate; and a step of removing the cured second photoresist layer; wherein the step of curing a portion of the second photoresist layer formed in the weld area is such that, on the first plating layer formed in the weld area, the second photoresist layer formed in the area extending from the boundary point of the pattern area to a point spaced apart at a predetermined distance in the longitudinal direction from the boundary point to the spaced-away point is cured so that the second photoresist layer remains in the section from the boundary point to the spaced-away point, thereby preventing the second plating layer from being formed. Claim 13 delete Claim 14 A method for manufacturing an OLED deposition mask manufactured by an electroplating method, wherein, in claim 12, the step of forming a second plating layer on the non-conductive transparent substrate is formed such that the second plating layer covers only a portion of the longitudinal direction of the first plating layer formed in the weld area. Claim 15 In claim 14, the step of curing a portion of the second photoresist layer formed in the pattern portion area and the second photoresist layer formed in the weld portion area is a full-front exposure method, in a method for manufacturing an OLED deposition mask manufactured by an electroplating method. Claim 16 In claim 15, a method for manufacturing an OLED deposition mask manufactured by an electroplating method in which the second plating layer is formed of a single Ni material. Claim 17 A method for manufacturing an OLED deposition mask manufactured by an electroplating method, wherein, in claim 15, the second plating layer is formed of a Ni-Fe alloy in which the Ni ratio is higher than the Fe ratio.

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