CN111373564B

CN111373564B - Mask for deposition and method for manufacturing the same

Info

Publication number: CN111373564B
Application number: CN201880074235.1A
Authority: CN
Inventors: 李相侑; 曹荣得; 金南昊
Original assignee: LG Innotek Co Ltd
Current assignee: LG Innotek Co Ltd
Priority date: 2017-11-16
Filing date: 2018-10-22
Publication date: 2023-12-26
Anticipated expiration: 2038-10-22
Also published as: WO2019098547A2; WO2019098547A3; KR20190055910A; CN111373564A; CN117769337A

Abstract

Embodiments relate to a method for manufacturing a deposition mask for depositing OLED pixels, the method comprising the steps of: preparing a metal plate; providing a first photoresist layer on one surface of the metal plate, and patterning the first photoresist layer by exposing and developing the first photoresist layer; forming a first groove on the one surface of the metal plate by half-etching an opening portion of the patterned first photoresist layer; providing a second photoresist layer on the other surface of the metal plate opposite to the one surface, and patterning the second photoresist layer by exposing and developing the second photoresist layer; forming a via hole connected to the first groove by half etching the opening portion of the patterned second photoresist layer; and forming a mask pattern on the metal plate by removing the first photoresist layer and the second photoresist layer, wherein the metal plate has a flatness value represented by the following equation 1, and the flatness of the metal plate is 0.006% or less.

Description

Mask for deposition and method for manufacturing the same

Technical Field

The present invention relates to a deposition mask capable of minimizing a length deviation and a method of manufacturing the same.

Background

The display device is used by being applied to various devices. For example, the display device is used by being applied not only to a small device such as a smart phone and a tablet computer but also to a large device such as a television, a monitor, and a Public Display (PD). In particular, recently, demand for Ultra High Definition (UHD) of 500 Pixels Per Inch (PPI) or more has increased, and high resolution display devices have been applied to small devices and large devices. Accordingly, there is increasing interest in techniques for achieving low power and high resolution.

The display devices generally used may be broadly classified into a Liquid Crystal Display (LCD), an Organic Light Emitting Diode (OLED), and the like according to a driving method.

The LCD is a display device driven by using liquid crystal, and has the following structure: in this structure, a light source including a Cold Cathode Fluorescent Lamp (CCFL), a Light Emitting Diode (LED), and the like is provided at a lower portion of the liquid crystal. The LCD is a display device driven by controlling the amount of light emitted from a light source using liquid crystals provided on the light source.

In addition, the OLED is a display device that is driven by using an organic material and does not require a separate light source, and the organic material itself may serve as a light source and may be driven with low power consumption. In addition, the OLED attracts attention as a display device that can exhibit infinite contrast, has a response speed about 1000 times faster than the LCD, and can replace the LCD with an excellent viewing angle.

Specifically, an organic material included in a light emitting layer of the OLED may be deposited on the substrate through a deposition mask called a Fine Metal Mask (FMM), and the deposited organic material may be formed in a pattern corresponding to the pattern formed on the deposition mask to serve as pixels. Typically, the deposition mask is made of a metal plate of invar alloy containing iron (Fe) and nickel (Ni). In this case, through holes penetrating one surface and the other surface may be formed on the one surface and the other surface of the metal plate, and the through holes may be formed at positions corresponding to the pixel pattern. Accordingly, organic materials such as red, green, and blue may be deposited on the substrate through the through holes of the metal plate, and pixel patterns may be formed on the substrate.

The metal plate may be manufactured by a rolling process, and the metal plate may have a rectangular shape including a long axis and a short axis. In addition, the metal plate may contain stress due to a rolling process or the like, and a warp phenomenon (wave deformation) may occur in the metal plate. As a result, the lengths of the two edges (coils) in the long axis direction of the metal plate may be different from each other.

The deposition mask may be manufactured by feeding a metal plate in a roll-to-roll method, and the metal plate may be fed in a state where a predetermined amount of tensile force is applied by the roll-to-roll method. In addition, during the patterning process for forming the through holes on the metal plate, a separate tensile force may be further applied to the metal plate.

That is, when a mask pattern is formed on a metal plate in a state where an individual pulling force is further applied and the individual pulling force is removed, the formed mask pattern may be uneven due to the above-described warping phenomenon. Therefore, uniformity of the shape of the mask pattern formed on the metal plate and uniformity of the position of the through hole may be deteriorated, and there is a problem that the diameter of the through hole is not uniform, and thus there is a problem that the pattern deposition efficiency may be lowered, and deposition failure may occur.

Accordingly, there is a need for a novel deposition mask and a method of manufacturing the deposition mask that can solve the above problems.

Disclosure of Invention

Technical problem

Embodiments are directed to providing a deposition mask capable of minimizing a deviation in length of a mask pattern formed on a metal plate and a method of manufacturing the deposition mask.

In addition, embodiments are directed to providing a deposition mask and a method of manufacturing the same that can achieve high resolution by uniformly forming a mask pattern and the shape and position of a via hole.

Technical proposal

Embodiments relate to a method of manufacturing a deposition mask for OLED pixel deposition, the method including: preparing a metal plate; providing a first photoresist layer on one surface of the metal plate, and patterning the first photoresist layer by exposing and developing the first photoresist layer; forming a first groove on the one surface of the metal plate by half-etching an opening portion of the patterned first photoresist layer; providing a second photoresist layer on the other surface of the metal plate opposite to the one surface, and patterning the second photoresist layer by exposing and developing the second photoresist layer; forming a via hole connected to the first groove by half etching the opening portion of the patterned second photoresist layer; and forming a mask pattern on the metal plate by removing the first photoresist layer and the second photoresist layer, wherein the metal plate has a flatness value represented by the following equation 1, and the flatness of the metal plate is 0.006% or less.

In addition, in a deposition mask made of a metal material for OLED pixel deposition according to an embodiment, the deposition mask includes a deposition region for forming a deposition pattern and a non-deposition region other than the deposition region, wherein the deposition region includes a non-pattern region and a pattern region including an effective portion, wherein the effective portion includes: a plurality of small-surface holes formed on one surface of the metal material; a plurality of large surface holes formed on the other surface of the metal material opposite to the one surface; the through holes are used for respectively communicating the small surface holes with the large surface holes; and an island portion formed between the adjacent via holes, wherein the via holes have a resolution of 400PPI or more, and the metal material has a flatness value represented by the following equation 1, and the flatness of the metal material is 0.006% or less.

[ equation 1 ]]Flatness (%) = (d) _x /d ₀ )*100

(flatness is based on the long axis along the metallic materialA reference line extending in the direction is defined, and flatness means a distance (d) representing the farthest distance from the reference line in the short axis direction of the metal material _x ) Length from reference line (d ₀ ) Is a ratio of (2). )

Advantageous effects

The deposition mask according to the embodiment may form a uniform mask pattern. Specifically, when forming a mask pattern on a metal plate, different tensile forces may be applied according to the length deviation of the metal plate to manufacture the mask pattern. Accordingly, a uniform mask pattern can be formed on the metal plate from which the tensile force has been removed. Accordingly, the deposition mask according to the embodiment may have more precise and uniform through holes, and may uniformly deposit OLED pixel patterns having a resolution of 400PPI or more, a high resolution of 500PPI or more, and an ultra-high resolution of 800PPI or more.

Drawings

Fig. 1 to 3 are conceptual views describing a process of depositing an organic material on a substrate using a deposition mask according to an embodiment.

Fig. 4 is a view showing a plan view of a deposition mask according to an embodiment.

Fig. 5 is a view showing a plan view of an effective portion of a deposition mask according to an embodiment.

Fig. 6 is a microscope image, viewed from a plane, of an active portion of a deposition mask according to an embodiment.

Fig. 7 is a view illustrating another plan view of a deposition mask according to an embodiment.

Fig. 8 is a view in which a cross-sectional view taken along a line A-A 'and a cross-sectional view taken along a line B-B' in fig. 5 or 6 overlap.

Fig. 9 is a view showing a cross-sectional view taken along line B-B' in fig. 5 or 6.

Fig. 10 is a view showing a perspective view and a plan view in which a metal plate, which is a raw material of a deposition mask according to an embodiment, is wound.

Fig. 11 and 12 are views illustrating a manufacturing process of a deposition mask according to an embodiment.

Fig. 13 is a view showing a manufacturing process of a deposition mask according to a comparative example.

Fig. 14 and 15 are views showing a deposition pattern formed by the deposition mask according to an embodiment.

Detailed Description

Hereinafter, the configuration and operation according to the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the drawings, like elements are denoted by like reference numerals regardless of the reference numerals, and redundant description of the like elements will be omitted. The terms "first," "second," and the like may be used to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one element from another element.

In addition, in the description of embodiments, it will be understood that a layer (or film), region, pattern, or structure is referred to as being "on/over" or "under" another layer (or film), region, pad, or pattern, including the meaning of "directly" or "through the interposition of another layer (indirectly)". Further, references to "on/above" or "below" each layer will be described with reference to the drawings.

In addition, when an element is referred to as being "connected" to another element, it includes the case of "direct connection" but also the case of "indirect connection" through another member between the element and the other element. Furthermore, when an element is referred to as being "comprising" another element, it is intended that the element may comprise the other element without excluding the other element unless the specifically indicated.

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

Fig. 1 to 3 are conceptual views describing a process of depositing an organic material on a substrate 300 using a deposition mask 100 according to an embodiment.

Fig. 1 is a schematic view illustrating an organic material deposition apparatus including a deposition mask 100 according to an embodiment, and fig. 2 is a view illustrating that the deposition mask 100 according to an embodiment is drawn to be seated on a mask frame 200. In addition, fig. 3 is a view showing that a plurality of deposition patterns are formed on a substrate 300 through a plurality of through holes of the deposition mask 100.

Referring to fig. 1 to 3, the organic material deposition apparatus may include a deposition mask 100, a mask frame 200, a substrate 300, an organic material deposition container 400, and a vacuum chamber 500.

The deposition mask 100 may include a metal. For example, the deposition mask may include iron (Fe) and nickel (Ni).

The deposition mask 100 may include a plurality of through holes TH at an effective portion for deposition. The deposition mask 100 may be a substrate for a deposition mask including a plurality of through holes TH. In this case, the through holes may be formed to correspond to a pattern to be formed on the substrate. In addition to including an active portion of the deposition area, the deposition mask 100 may also include an inactive portion.

The mask frame 200 may include an opening. A plurality of through holes of the deposition mask 100 may be disposed on regions corresponding to the openings. Accordingly, the organic material supplied to the organic material deposition container 400 may be deposited on the substrate 300. The deposition mask 100 may be disposed and fixed on the mask frame 200. For example, the deposition mask 100 may be drawn and fixed to the mask frame 200 by welding.

The deposition mask 100 may be drawn in opposite directions at an end portion disposed on an outermost portion of the deposition mask 100. In the deposition mask 100, one end portion of the deposition mask 100 and the other end portion opposite to the one end portion may be drawn in opposite directions in the longitudinal direction of the deposition mask 100. One end portion and the other end portion of the deposition mask 100 may be disposed to face each other and in parallel. One end of the deposition mask 100 may be one of end portions forming four side surfaces disposed on an outermost portion of the deposition mask 100. For example, the deposition mask 100 may be drawn with a tensile force of 0.1kgf to 2 kgf. Specifically, the deposition mask 100 may be drawn at a tensile force of 0.4kgf to 1.5kgf to be fixed on the mask frame 200. Accordingly, stress of the deposition mask 100 may be reduced. However, the embodiment is not limited thereto, and the deposition mask 100 may be drawn by various pulling forces capable of reducing stress of the deposition mask 100 to be fixed on the mask frame 200.

Then, the deposition mask 100 may be fixed to the mask frame 200 by welding the non-effective portion of the deposition mask 100. Subsequently, the portion of the deposition mask 100 disposed outside the mask frame 200 may be removed by a method such as dicing.

The substrate 300 may be a substrate for manufacturing a display device. For example, the substrate 300 may be a substrate 300 for depositing an organic material for an OLED pixel pattern. Patterns of red (R), green (G), and blue (B) may be formed on the substrate 300 to form pixels of three primary colors as light. That is, an RGB pattern may be formed on the substrate 300.

The organic material deposition container 400 may be a crucible. The organic material may be disposed inside the crucible.

When a heat source and/or a current is supplied to the crucible in the vacuum chamber 500, an organic material may be deposited on the substrate 100.

Referring to fig. 3, the deposition mask 100 may include one surface 101 and another surface 102 opposite to the one surface.

One surface 101 of the deposition mask 100 may include small surface holes Vl and the other surface may include large surface holes V2. One surface 101 and the other surface 102 of the deposition mask 100 may include a plurality of small surface holes V1 and a plurality of large surface holes V2, respectively.

In addition, the deposition mask 100 may include through holes TH. The through holes may communicate through a communication portion to which the boundaries of the small-surface hole V1 and the large-surface hole V2 are connected.

The deposition mask 100 may include a first etched surface ES1 in the small surface hole V1. The deposition mask 100 may include a second etched surface ES2 in the large surface hole V2. The through holes TH may be formed by making the first etched surface ES1 in the small surface hole V1 and the second etched surface ES2 in the large surface hole V2 communicate with each other. For example, a first etched surface ES1 in a small surface hole V1 may communicate with a second etched surface ES2 in a large surface hole V2 to form a through hole. Accordingly, the number of through holes TH may correspond to the number of small surface holes V1 and large surface holes V2.

The width of the large surface holes V2 may be larger than the width of the small surface holes V1. At this time, the width of the small surface hole V1 may be measured at one surface 101 of the deposition mask 100, and the width of the large surface hole V2 may be measured at the other surface 102 of the deposition mask 100.

The small surface hole V1 may be disposed toward the substrate 300. The small surface hole V1 may be disposed near the substrate 300. Therefore, the small surface holes V1 may have a shape corresponding to the deposition material, i.e., the deposition pattern DP.

The large surface hole V2 may be disposed toward the organic material deposition container 400. Accordingly, the large surface hole V2 may accommodate the organic material supplied from the organic material deposition container 400 in a wide width, and a fine pattern may be rapidly formed on the substrate 300 through the small surface hole V1 having a smaller width than that of the large surface hole V2.

Fig. 4 is a view showing a plan view of the deposition mask 100 according to an embodiment. Referring to fig. 4, the deposition mask 100 will be described in more detail.

Referring to fig. 4, the deposition mask 100 according to an embodiment may include a deposition area DA and a non-deposition area NDA.

The deposition area DA may be an area for forming a deposition pattern. The deposition area DA may include a pattern area and a non-pattern area. The pattern region may be a region including the small surface holes V1, the large surface holes V2, the through holes TH, and the island-shaped portions IS, and the non-pattern region may be a region excluding the small surface holes V1, the large surface holes V2, the through holes TH, and the island-shaped portions IS.

In addition, one deposition mask 100 may include a plurality of deposition areas DA. For example, the deposition area DA of the embodiment may include a plurality of active portions AA1, AA2, and AA3 capable of forming a plurality of deposition patterns. The pattern area may include a plurality of effective portions AA1, AA2, and AA3.

The plurality of effective portions may include a first effective portion AA1, a second effective portion AA2, and a third effective portion AA3. Here, one deposition area DA may be any one of the first effective portion AA1, the second effective portion AA2, and the third effective portion AA3.

In the case of a small display device such as a smart phone, an effective portion of any one of a plurality of deposition regions included in the deposition mask 100 may be an effective portion for forming one display device. Accordingly, one deposition mask 100 may include a plurality of active portions to simultaneously form a plurality of display devices. Therefore, the deposition mask according to the embodiment may improve the process efficiency.

Alternatively, in the case of a large display device such as a television, a plurality of effective portions included in one deposition mask may be a portion for forming one display device. In this case, the plurality of effective portions may be used to prevent deformation due to the load of the mask.

The deposition area DA may include a plurality of isolation areas IA1 and IA2 included in one deposition mask. Isolation regions IA1 and IA2 may be disposed between adjacent active portions. The isolation regions IA1 and IA2 may be spaced apart regions between the plurality of active portions. For example, the first isolation region IA1 may be disposed between the first effective portion AA1 and the second effective portion AA 2. Further, the second isolation region IA2 may be disposed between the second effective portion AA2 and the third effective portion AA3. That is, the isolation regions IA1 and IA2 may distinguish adjacent active regions, and one deposition mask 100 may support a plurality of active portions.

The deposition mask 100 may include non-deposition regions NDA at both side portions in the longitudinal direction of the deposition region DA. The deposition mask 100 according to the embodiment may include the non-deposition region NDA at both sides of the deposition region DA in the horizontal direction.

The non-deposition area NDA of the deposition mask 100 may be an area that does not participate in deposition. The non-deposition region NDA may include frame fixing regions FA1 and FA2 for fixing the deposition mask to the mask frame. In addition, the non-deposition area NDA may include half-etched portions HF1 and HF2.

As described above, the deposition area DA may be an area for forming a deposition pattern, and the non-deposition area NDA may be an area not participating in deposition. In this case, a surface treatment layer different from the material of the metal plate 10 may be formed in the deposition area DA of the deposition mask 100, and the surface treatment layer may not be formed in the non-deposition area NDA. Alternatively, a surface treatment layer different from the material of the metal plate 10 may be formed only on any one of the one surface 101 and the other surface 102 of the deposition mask 100. Alternatively, a surface treatment layer different from the material of the metal plate 10 may be formed on only a portion of one surface 101 of the deposition mask 100. For example, one surface and/or the other surface of the deposition mask, as well as the entirety and/or a portion of the deposition mask 100, may include a surface treatment layer having an etch rate lower than that of the material of the metal plate 10, thereby improving the etch factor. Accordingly, the deposition mask 100 of the embodiment can efficiently form the through-holes having a fine size. As an example, the deposition mask 100 of the embodiment may have a resolution of 400PPI or more. In particular, the deposition mask 100 may efficiently form a deposition pattern having a high resolution of 500PPI or more. Here, the surface treatment layer may include a material different from that of the metal plate 10, or may include a metal material having a different composition of the same element. In this regard, the deposition mask will be described in more detail in the manufacturing process of the deposition mask described later.

The non-deposition area NDA may include half-etched portions HF1 and HF2. For example, the non-deposition region NDA of the deposition mask 100 may include a first half-etched portion HF1 at one side of the deposition region DA and may include a second half-etched portion HF2 at the other side opposite to the one side of the deposition region DA. The first half etching portion HF1 and the second half etching portion HF2 may be regions in which grooves are formed in the depth direction of the deposition mask 100. The first half etching portion HF1 and the second half etching portion HF2 may have grooves having a thickness of about 1/2 of the deposition mask so as to disperse stress when the deposition mask 100 is pulled. In addition, it is preferable that the half-etched portions HF1 and HF2 are formed to be symmetrical in the X-axis direction or the Y-axis direction with respect to the center of the deposition mask 100. Thus, the pulling force in both directions can be uniformly controlled.

The half-etched portions HF1 and HF2 may be formed in various shapes. The half-etched portions HF1 and HF2 may include groove portions of semicircular shape. A groove may be formed on at least one of one surface 101 of the deposition mask 100 and the other surface 102 opposite to the one surface 101. Preferably, half-etched portions HF1 and HF2 may be formed on the surface corresponding to the small-surface hole V1. Therefore, the half-etched portions HF1 and HF2 can be formed simultaneously with the small surface holes V1, thereby improving the processing efficiency. In addition, the half-etched portions HF1 and HF2 may disperse stress that may be generated due to the dimensional difference between the large surface holes V2. However, the embodiment is not limited thereto, and the half-etched portions HF1 and HF2 may have a quadrangular shape. For example, the half etching portion HF1 and the second half etching portion HF2 may have rectangular or square shapes. Accordingly, the deposition mask 100 may effectively disperse stress.

In addition, the half-etched portions HF1 and HF2 may include curved surfaces and flat surfaces. The flat surface of the first half etching portion HF1 may be disposed adjacent to the first effective area AA1, and the flat surface may be horizontally disposed to have an end in the longitudinal direction of the deposition mask 100. The curved surface of the first half etching portion HF1 may have a convex shape toward one end in the longitudinal direction of the deposition mask 100. For example, the curved surface of the first half etching portion HF1 may be formed such that 1/2 point of the length in the vertical direction of the deposition mask 100 corresponds to the radius of the semicircular shape.

Further, a flat surface of the second half etching portion HF2 may be disposed adjacent to the third effective area AA3, and the flat surface may be horizontally disposed to have an end in the longitudinal direction of the deposition mask 100. The curved surface of the second half etching portion HF2 may have a convex shape toward the other end portion in the longitudinal direction of the deposition mask 100. For example, the curved surface of the second half etching portion HF2 may be formed such that 1/2 point of the length in the vertical direction of the deposition mask 100 corresponds to the radius of the semicircular shape.

The half-etched portions HF1 and HF2 may be formed simultaneously when forming the small surface holes V1 or the large surface holes V2. Therefore, the processing efficiency can be improved. In addition, grooves formed on one surface 101 and the other surface 102 of the deposition mask 100 may be formed to be shifted from each other. Thus, the half-etched portions HF1 and HF2 may not be penetrated.

In addition, the deposition mask 100 according to an embodiment may include four half-etched portions. For example, the half-etched portions HF1 and HF2 may include an even number of half-etched portions HF1 and HF2, thereby dispersing stress more effectively.

In addition, half-etched portions HF1 and HF2 may also be formed in the inactive portion UA of the deposition area DA. For example, the half-etched portions HF1 and HF2 may be dispersed in whole or in part of the non-effective portion UA to be disposed in plural to disperse stress when the deposition mask 100 is pulled.

In addition, half etching portions HF1 and HF2 may be formed in the frame fixing areas FA1 and FA2 and/or the outer peripheral edge areas of the frame fixing areas FA1 and FA 2. Accordingly, the stress of the deposition mask 100 generated when the deposition mask 100 is fixed to the mask frame 200 and/or when the deposition material is deposited after the deposition mask 100 is fixed to the mask frame 200 may be uniformly dispersed. Accordingly, the deposition mask 100 may be maintained to have uniform through holes.

That is, the deposition mask 100 according to an embodiment may include a plurality of half-etched portions. In detail, the deposition mask 100 according to the embodiment is shown to include half-etched portions HF1 and HF2 only in the non-deposition region NDA, but the embodiment is not limited thereto, and at least one of the deposition region DA and the non-deposition region NDA may further include a plurality of half-etched portions. Accordingly, the stress of the deposition mask 100 can be uniformly dispersed.

The non-deposition region NDA may include frame fixing regions FA1 and FA2 for fixing the deposition mask 100 to the mask frame 200. For example, the non-deposition area NDA may include a first frame fixing area FA1 at one side of the deposition area DA and may include a second frame fixing area FA2 at the other side opposite to the one side of the deposition area DA. The first frame fixing area FA1 and the second frame fixing area FA2 may be areas fixed to the mask frame 200 by welding.

The frame fixing regions FA1 and FA2 may be disposed between the half-etched portions HF1 and HF2 of the non-deposition region NDA and an effective portion of the deposition region DA adjacent to the half-etched portions HF1 and HF 2. For example, the first frame fixing area FA1 may be disposed between the first half etching portion HF1 of the non-deposition area NDA and the first effective portion AA1 of the deposition area DA adjacent to the first half etching portion HF 1. For example, the second frame fixing area FA2 may be disposed between the second half etching portion HF2 of the non-deposition area NDA and the third active portion AA3 of the deposition area DA adjacent to the second half etching portion HF 2. Thus, a plurality of deposition pattern portions can be fixed at the same time.

In addition, the deposition mask 100 may include semicircular shaped opening portions at both ends in the horizontal direction X. For example, the non-deposition area NDA may include an opening portion. In detail, the non-deposition area NDA may include one semicircular shaped opening portion at each of both ends in the horizontal direction. For example, the non-deposition region NDA of the deposition mask 100 may include an opening portion whose center in the vertical direction Y is open at one side in the horizontal direction. For example, the non-deposition region NDA of the deposition mask 100 may include an opening portion whose center in the vertical direction is open at the other side opposite to the one side in the horizontal direction. That is, both end portions of the deposition mask 100 may include an opening portion at 1/2 of the length in the vertical direction. For example, both ends of the deposition mask 100 may be shaped like a horseshoe.

In this case, the curved surface of the opening portion may be oriented toward the half-etched portions HF1 and HF 2. Accordingly, the opening portions at both ends of the deposition mask 100 may have the shortest separation distance at 1/2 points of the lengths of the first half-etched portions HF1 and HF2 or the second half-etched portions HF1 and HF2 and the vertical direction of the deposition mask 100.

In addition, the length h1 in the vertical direction of the first half etching portion HF1 or the second half etching portion HF2 may correspond to the length h2 in the vertical direction of the opening portion. Therefore, when the deposition mask 100 is pulled, the stress may be uniformly dispersed, so that deformation (wave deformation) of the deposition mask may be reduced. Accordingly, the deposition mask 100 according to the embodiment may have uniform through holes, so that deposition efficiency of the pattern may be improved. Preferably, the length h1 in the vertical direction of the first half etching portion HF1 or the second half etching portion HF2 may be about 80% to 200% of the length h2 in the vertical direction of the opening portion (h1:h2=0.8 to 2:1). The length h1 in the vertical direction of the first half etching portion HF1 or the second half etching portion HF2 may be about 90% to about 150% of the length h2 in the vertical direction of the opening portion (h1:h2=0.9 to 1.5:1). The length h1 in the vertical direction of the first half etching portion HF1 or the second half etching portion HF2 may be about 95% to about 110% of the length h2 in the vertical direction of the opening portion (h1:h2=0.95 to 1.1:1).

In addition, although not shown in the drawings, a half-etched portion may also be formed in the inactive portion UA of the deposition area DA. The half-etched portions may be dispersed in whole or in part of the non-effective portion UA to be disposed in plural to disperse stress when the deposition mask 100 is pulled.

In addition, half-etched portions HF1 and HF2 may be formed in the frame fixing areas FA1 and FA2 and/or the outer peripheral edge area of the frame fixing area. Accordingly, the stress of the deposition mask 100 generated when the deposition mask 100 is fixed to the mask frame 200 and/or when the deposition material is deposited after the deposition mask 100 is fixed to the mask frame 200 may be uniformly dispersed. Accordingly, the deposition mask 100 may be maintained to have uniform through holes.

The deposition mask 100 may include a plurality of active portions AA1, AA2, and AA3 spaced apart in the longitudinal direction, and an inactive portion UA other than the active portions. In detail, the deposition area DA may include a plurality of active portions AA1, AA2, and AA3 and inactive portions UA other than the active portions AA.

The deposition mask may include a plurality of active portions AA1, AA2, and AA3 spaced apart in the longitudinal direction, and an inactive portion UA other than the active portions.

The effective portions AA1, AA2, and AA3 may include a plurality of small surface holes Vl formed on one surface of the deposition mask 100, a plurality of large surface holes V2 formed on the other surface opposite to the one surface, through holes TH formed by the communication portion CA in which boundaries between the small surface holes V1 and the large surface holes V2 are connected.

In addition, the effective portions AA1, AA2, and AA3 may include island portions IS supported between the plurality of through holes TH.

The island portion IS may be positioned between adjacent ones of the plurality of through holes TH. That IS, in the effective portions AA1, AA2, and AA3 of the deposition mask 100, the region other than the through holes TH may be the island-shaped portion IS.

The island portion IS may refer to a portion that IS not etched in one surface 101 or the other surface 102 of the effective portion of the deposition mask when the via hole IS formed. In detail, the island portion IS may be an unetched region between the through holes TH and TH on the other surface 102 where the large surface hole V2 of the effective portion of the deposition mask 100 IS formed. Accordingly, the island portion IS may be disposed in parallel with one surface 101 of the deposition mask 100. In detail, the upper surface of the island portion IS may be disposed in parallel with one surface 101.

The island IS may be disposed coplanar with the other surface 102 of the deposition mask 100. Accordingly, the island portion IS may have the same thickness as at least a portion of the inactive portion on the other surface 102 of the deposition mask 100. In detail, the island portion IS may have the same thickness as an unetched portion of an unexecuted portion on the other surface 102 of the deposition mask 100. Accordingly, deposition uniformity of the sub-pixels may be improved through the deposition mask 100.

Alternatively, the island portion IS may be disposed in a flat surface parallel to the other surface 102 of the deposition mask 100. Here, the parallel flat surfaces may include: by the etching process around the island portion IS, the difference in height between the other surface of the deposition mask 100 provided with the island portion IS and the other surface of the unetched deposition mask 100 of the non-effective portion IS ±1 μm or less.

The deposition mask 100 may include an inactive portion UA disposed at an outer circumference of the active region. The effective portion AA may be an inner region connected to an outer periphery of a through hole for depositing an organic material at an outermost portion among the plurality of through holes. The inactive portion UA may be an outer region to which outer circumferences of through holes for depositing an organic material located at an outermost portion among the plurality of through holes are connected.

The non-effective portion UA is an area other than the effective portions AA1, AA2, and AA3 of the deposition area DA and the non-deposition area NDA. The non-effective portion UA may include outer areas OA1, OA2, and OA3 surrounding the outer circumferences of the effective portions AA1, AA2, and AA 3.

The number of the outer areas OA1, OA2, and OA3 may correspond to the number of the effective portions AAl, AA2, and AA 3. That is, one effective portion may include one outer region spaced apart from an end of one effective portion by a predetermined distance in the horizontal and vertical directions.

The first effective portion AA1 may be included in the first outer area OA 1. The first effective portion AA1 may include a plurality of through holes TH for forming a deposition material. The first outer area OA1 surrounding the outer circumference of the first effective portion AA1 may include a plurality of through holes.

For example, the plurality of through holes included in the first outer area OA1 serve to reduce etching failure of the through holes TH located at the outermost portion of the effective portion. Accordingly, the deposition mask 100 according to the embodiment may improve uniformity of the plurality of through holes located in the effective portions AA1, AA2, and AA3, and may improve quality of a deposition pattern formed through the deposition mask 100.

In addition, the shape of the through holes TH of the first effective portion AA1 may correspond to the shape of the through holes TH of the first outer area OA 1. Accordingly, uniformity of the through holes included in the first effective portion AA1 can be improved. For example, the shape of the through holes TH of the first effective portion AA1 and the shape of the through holes of the first outer area OA1 may be circular shapes. However, the embodiment is not limited thereto, and the through holes TH may have various shapes, such as diamond patterns, oval patterns, and the like.

The second effective portion AA2 may be included in the second outer area OA 2. The second effective portion AA2 may have a shape corresponding to the first effective portion AA 1. The second outer area OA2 may have a shape corresponding to the first outer area OA 1.

The second outer area OA2 may further include two through holes in the horizontal and vertical directions, respectively, starting from the through hole located at the outermost portion of the second effective portion AA 2. For example, in the second outer area OA2, two through holes may be disposed in a row in the horizontal direction at an upper portion and a lower portion of the through holes located at an outermost portion of the second effective portion AA2, respectively. For example, in the second outer area OA2, two through holes may be disposed in a row in the vertical direction at the left and right sides of the through hole at the outermost portion of the second effective portion AA2, respectively. The plurality of through holes included in the second outer area OA2 serve to reduce etching failure of the through holes located at the outermost portion of the effective portion. Accordingly, the deposition mask according to the embodiment may improve uniformity of the plurality of through holes located in the effective portion, and may improve quality of a deposition pattern manufactured through the deposition mask.

The third effective portion AA3 may be included in the third outer area OA 3. The third effective portion AA3 may include a plurality of through holes for forming a deposition material. The third outer area OA3 surrounding the outer circumference of the third effective portion AA3 may include a plurality of through holes.

The third effective portion AA3 may have a shape corresponding to that of the first effective portion AA 1. The third outer area OA3 may have a shape corresponding to the shape of the first outer area OA 1.

The shape of the through holes TH included in the effective portions AA1, AA2, and AA3 may partially correspond to the shape of the through holes included in the non-effective portions UA. As an example, the through holes included in the effective portions AA1, AA2, and AA3 may have a shape different from that of the through holes located at the edge portions of the non-effective portions UA. Accordingly, the stress difference may be adjusted according to the position of the deposition mask 100.

Fig. 5 and 6 are views showing a plan view of an effective portion of the deposition mask 100 according to an embodiment, and fig. 7 is a view showing another plan view of the deposition mask according to an embodiment.

Fig. 5 to 7 may be plan views of any one of the first, second, and third effective portions AA1, AA2, AA3 of the deposition mask 100 according to an embodiment. In addition, fig. 5 to 7 show the shape of the through holes TH and the arrangement between the through holes TH, and the deposition mask 100 according to the embodiment is not limited to the number of through holes TH shown in the drawings.

Referring to fig. 5 to 7, the deposition mask 100 may include a plurality of through holes TH. In this case, the through holes TH may be arranged in a row or may be disposed to cross each other according to directions. For example, the through holes TH may be arranged in rows along a vertical axis, and may be arranged in rows along a horizontal axis.

First, referring to fig. 5 and 6, the deposition mask 100 may include a plurality of through holes TH. At this time, the plurality of through holes TH may have a circular shape. In detail, the through holes TH may have a diameter Cx in the horizontal direction and a diameter Cy in the vertical direction, and the diameter Cx in the horizontal direction and the diameter Cy in the vertical direction of the through holes TH may correspond to each other.

The through holes TH may be arranged in rows according to the direction. For example, the through holes TH may be arranged in rows along a vertical axis and a horizontal axis.

Specifically, the first through holes TH1 and the second through holes TH2 may be arranged in a row along a horizontal axis. In addition, the third through holes TH1 and the fourth through holes TH4 may be arranged in a row along the horizontal axis.

In addition, the first through holes TH1 and the third through holes TH3 may be arranged in a row along the vertical axis. In addition, the second through holes TH2 and the fourth through holes TH4 may be arranged in a row along the horizontal axis.

That IS, when the through holes TH are arranged in a row along the vertical axis and the horizontal axis, the island-like portion IS disposed between two through holes TH adjacent to each other in the diagonal direction in which both the vertical axis and the horizontal axis intersect. That IS, the island portion IS may be located between two adjacent through holes TH positioned with respect to each other in the diagonal direction.

For example, the island portion IS may be disposed between the first through hole TH1 and the fourth through hole TH 4. Further, the island portion IS may be disposed between the second through holes TH2 and the third through holes TH 3. The island portions IS are disposed in tilt angle directions of about +45 degrees and about-45 degrees, respectively, with respect to a horizontal axis crossing two adjacent through holes. Here, the inclination angle direction of about ±45 may represent a diagonal direction between the horizontal axis and the vertical axis, and the diagonal inclination angle is measured on the same plane of the horizontal axis and the vertical axis.

In addition, referring to fig. 7, another deposition mask 100 according to an embodiment may include a plurality of through holes. At this time, the plurality of through holes may have an elliptical shape. In detail, the diameter Cx of the through hole in the horizontal direction and the diameter Cy in the vertical direction may be different from each other. For example, the diameter Cx of the through-hole in the horizontal direction may be larger than the diameter Cy in the vertical direction. However, the embodiment is not limited thereto, and of course, the through hole may have a rectangular shape, an octagonal shape, or a circular octagonal shape.

The through holes TH may be arranged in a row on any one of the vertical axis and the horizontal axis, and may be arranged to intersect each other on the other axis.

Specifically, the first through holes TH1 and the second through holes TH2 may be disposed in a row on a horizontal axis, and the third through holes TH1 and the fourth through holes TH4 may be disposed to intersect the first through holes TH1 and the second through holes TH2, respectively, on a vertical axis.

When the through holes TH are arranged in a row in any one of the vertical axis and the horizontal axis and intersect in the other direction, the island portion IS may be positioned between two adjacent through holes TH1 and TH2 in the other of the vertical axis and the horizontal axis. Alternatively, the island portion IS may be positioned between three through holes TH1, TH2, and TH3 adjacent to each other. Two through holes TH1 and TH2 of the three adjacent through holes TH1, TH2, and TH3 are through holes arranged in a row, and the remaining one through hole TH3 may refer to a through hole in a region between the two through holes TH1 and TH2 that may be arranged at adjacent positions in a direction corresponding to the direction of the row. The island portion IS may be disposed between the first through holes TH1, the second through holes TH2, and the third through holes TH 3. Alternatively, the island portion IS may be disposed between the second through holes TH2, the third through holes TH3, and the fourth through holes TH 4.

In addition, in the deposition mask 100 according to the embodiment, in the case of measuring the diameter Cx in the horizontal direction and the diameter Cy in the vertical direction of the reference hole as any one of the through holes, the deviation between the diameter Cx in the horizontal direction and the deviation between the diameter Cy in the vertical direction of each of the holes adjacent to the reference hole may be implemented to be 2% to 10%. That is, when the dimensional deviation between adjacent holes of one reference hole is implemented to be 2% to 10%, deposition uniformity can be ensured. The dimensional deviation between the reference hole and the adjacent hole may be 4% to 9%. For example, the dimensional deviation between the reference hole and the adjacent hole may be 5% to 7%. For example, the dimensional deviation between the reference hole and the adjacent hole may be 2% to 5%. When the dimensional deviation between the reference hole and the adjacent hole is less than 2%, the incidence of moire (moire) in the OLED panel after deposition increases. When the dimensional deviation between the reference hole and the adjacent hole is more than 10%, the occurrence of color unevenness in the OLED panel after deposition increases. The average deviation of the diameter of the through holes may be + -5 μm. For example, the average deviation of the diameter of the through holes may be ±3 μm. For example, the average deviation of the diameter of the through holes may be ±1 μm. In an embodiment, deposition efficiency may be improved by achieving a dimensional deviation between the reference hole and the adjacent hole within ±3 μm.

The island portion IS of fig. 5 to 7 may refer to an unetched surface between the through holes TH in the other surface of the deposition mask 100 where the large surface holes V2 of the effective portion AA are formed. In detail, the island portion IS may be the other surface of the unetched deposition mask 100 except the second etched surface ES2 and the through holes TH in the large surface holes in the effective portion AA of the deposition mask. The deposition mask 100 of the embodiment may be used to deposit high-resolution to ultra-high-resolution OLED pixels having a resolution of 400PPI or more, in detail, 400PPI to 800PPI or more.

For example, the deposition mask 100 of the embodiment may be used to form a high-resolution deposition pattern having a full High Definition (HD) with a resolution of 400PPI or more. For example, the deposition mask 100 of the embodiment may be used to deposit OLED pixels having a pixel number of 1920×1080 or more in the horizontal direction and the vertical direction and a resolution of 400PPI or more. That is, one effective portion included in the deposition mask 100 of the embodiment may be used to form the number of pixels having a resolution of 1920×1080 or more.

For example, the deposition mask 100 of the embodiment may be used to form a high-resolution deposition pattern having a Quadruple High Definition (QHD) with a resolution of 500PPI or more. For example, the deposition mask 100 of the embodiment may be used to deposit OLED pixels having a number of pixels of 2560×1440 or greater in the horizontal and vertical directions and a resolution of 530PPI or greater. According to the deposition mask 100 of the embodiment, the number of pixels per inch may be 530PPI or more based on the OLED panel of 5.5 inches. That is, one effective portion included in the deposition mask 100 of the embodiment may be used to form the number of pixels having a resolution of 2560×1440 or more.

For example, the deposition mask 100 of the embodiment may be used to form an ultra-high resolution deposition pattern having an ultra-high definition (UHD) of 700PPI or more. For example, the deposition mask of the embodiment may be used to form a deposition pattern having a UHD-level resolution for depositing OLED pixels having a pixel count of 3840×2160 or more in the horizontal and vertical directions and a resolution of 794PPI or more.

The diameter of the through holes TH may be the width between the communication portions CA. In detail, the diameter of the through hole TH may be measured at a point where an end of the inner side surface in the small surface hole V1 intersects an end of the inner side surface in the large surface hole V2. The measurement direction of the diameter of the through hole TH may be any one of a horizontal direction, a vertical direction, and a diagonal direction. The diameter of the through holes TH measured in the horizontal direction may be 33 μm or less. Alternatively, the diameter of the through holes TH measured in the horizontal direction may be 33 μm or less. Alternatively, the diameter of the through hole TH may be an average value of values measured in the horizontal direction, the vertical direction, and the diagonal direction, respectively.

Thus, the deposition mask 100 according to the embodiment may achieve QHD level resolution. For example, the diameter of the through holes TH may be about 15 μm to about 33 μm. For example, the diameter of the through holes TH may be about 19 μm to about 33 μm. For example, the diameter of the through holes TH may be about 20 μm to about 27 μm. When the diameter of the through hole TH exceeds about 33 μm, it may be difficult to achieve a resolution of 500PPI or more. On the other hand, when the diameter of the through hole TH is less than about 15 μm, deposition failure may occur.

Referring to fig. 5 and 6, a pitch between two adjacent through holes of the plurality of through holes TH in the horizontal direction may be about 48 μm or less. For example, the pitch between two adjacent through holes TH among the plurality of through holes TH in the horizontal direction may be about 20 μm to about 48 μm. For example, the pitch between two adjacent through holes TH among the plurality of through holes TH in the horizontal direction may be about 30 μm to about 35 μm. Here, the pitch may refer to a pitch P1 between the center of the first through hole TH1 and the center of the second through hole TH2 adjacent in the horizontal direction. In addition, the pitch may refer to a pitch P2 between the center of the first island portion and the center of the second island portion adjacent in the horizontal direction. Here, the center of the island portion IS may be a center at the other surface which IS not etched between four adjacent through holes TH in the horizontal direction and the vertical direction. For example, based on the first through holes TH1 and the second through holes TH2 being adjacent in the horizontal direction, the center of the island-shaped portion IS may refer to a point where a horizontal axis and a vertical axis connecting edges of one island-shaped portion IS positioned in a region between the third through holes TH3 being vertically adjacent to the first through holes TH1 and the fourth through holes TH4 being vertically adjacent to the second through holes TH2 intersect.

In addition, referring to fig. 7, a pitch between two adjacent through holes of the plurality of through holes TH in the horizontal direction may be about 48 μm or less. For example, the pitch between two adjacent through holes TH among the plurality of through holes TH in the horizontal direction may be about 20 μm to about 48 μm. For example, a pitch between two adjacent through holes TH among the plurality of through holes TH in the horizontal direction may be about 30 μm to about 35 μm. Here, the pitch may refer to a pitch P1 between the center of the first through hole TH1 and the center of the second through hole TH2 adjacent in the horizontal direction. Further, the pitch may refer to a pitch P2 between the center of the first island portion and the center of the second island portion adjacent in the horizontal direction. Here, the center of the island portion IS may be the center at the other surface where no etching IS performed between one through hole and two through holes adjacent in the vertical direction. Alternatively, here, the center of the island portion IS may be the center at the other surface which IS not etched between two through holes and one through hole adjacent in the vertical direction. That IS, the center of the island portion IS the center of the unetched surface between three adjacent through holes, and the three adjacent through holes may mean that triangles may be formed when the centers are connected.

The measuring direction of the diameter of the through hole TH and the measuring direction of the interval between two adjacent through holes TH may be the same. The pitch of the through holes TH may be a value measured as a pitch between two adjacent through holes TH in the horizontal direction or the vertical direction.

That is, the deposition mask 100 according to the embodiment may deposit OLED pixels having a resolution of 400PPI or more. In detail, in the deposition mask 100 according to the embodiment, the diameter of the through holes is 33 μm or less, and the interval between the through holes TH is 48 μm or less, and thus, OLED pixels having a resolution of 500PPI or more may be deposited. That is, the QHD level resolution may be achieved using the deposition mask 100 according to an embodiment.

The diameter of the through holes TH and the pitch between the through holes TH may be the size for forming the green sub-pixels. For example, the diameter of the through holes TH may be measured based on a green (G) pattern. Since the green (G) pattern has a low recognition rate visually, a larger number than the R and B patterns is required, and the pitch between the through holes TH may be narrower than the R and B patterns. The deposition mask 100 may be an OLED deposition mask for implementing QHD display pixels.

For example, the deposition mask 100 may be used to deposit at least one subpixel of red R, first green G1, blue B, and second green G2. In detail, the deposition mask 100 may be used to deposit the red R sub-pixel. Alternatively, the deposition mask 100 may be used to deposit the blue B sub-pixel. Alternatively, the deposition mask 100 may be used to simultaneously form the first green G1 sub-pixel and the second green G2 sub-pixel.

The pixel arrangement of the organic light emitting display device may be disposed in the order of "red R-first green G1-blue B-second green G2". In this case, the red R-first green G1 may form one pixel RG, and the blue B-second green G2 may form another pixel BG. In the organic light emitting display device having such an arrangement, since the deposition interval of the green light emitting organic material is narrower than the deposition intervals of the red light emitting organic material and the blue light emitting organic material, a form of the deposition mask 100 like the present invention may be required.

In addition, the deposition mask 100 according to the embodiment may have a through hole TH having a diameter of about 20 μm or less in the horizontal direction. Thus, the deposition mask 100 according to the embodiment may achieve UHD-fraction. For example, in the deposition mask according to the embodiment, the diameter of the through holes TH is about 20 μm or less, and the pitch between the through holes is about 32 μm or less, and thus, OLED pixels having a resolution of 800PPI level may be deposited. That is, the UHD fraction can be achieved using the deposition mask according to an embodiment.

The diameter of the through holes and the spacing between the through holes may be the size used to form the green sub-pixels. The deposition mask may be an OLED deposition mask for implementing UHD display pixels.

Fig. 8 is a view showing that the respective cross sections overlap for describing the height difference and the size between the cross section in the A-A 'direction and the cross section in the B-B' direction of fig. 5 and 6.

First, a cross section along the A-A' direction will be described. The A-A' direction is a cross section intersecting a central region between the first through hole TH1 and the third through hole TH3 adjacent in the vertical direction. That is, the cross section along the A-A' direction may not include the through hole.

Island-like portions IS of the other surface, which IS not etched, between the etched surface ES2 in the large-surface hole and the etched surface ES2 in the large-surface hole as a deposition mask may be positioned in a cross section in the A-A' direction. Thus, the island IS may include a surface parallel to one unetched surface of the deposition mask. Alternatively, the island IS may include the same or parallel surface as another unetched surface of the deposition mask.

Next, a cross section along the B-B' direction will be described. The B-B' direction is a cross section intersecting the center of each of the first through holes TH1 and the second through holes TH2 adjacent in the horizontal direction. That is, the cross section along the direction B-B' may include a plurality of through holes.

A rib may be positioned between the adjacent third through holes TH3 and fourth through holes TH4 in the direction B-B'. Another rib may be positioned between the fourth through hole TH4 and the fifth through hole adjacent to the fourth through hole in the horizontal direction but positioned in the opposite direction to the third through hole TH 3. A through hole may be positioned between the one rib and the other rib. That is, a through hole may be positioned between two ribs adjacent in the horizontal direction.

In addition, in the cross section along the B-B' direction, a rib RB as the following region may be located: in this region, the etched surface ES2 in the large surface hole and the etched surface ES2 in the adjacent large surface hole are connected to each other. Here, the rib RB may be a region where boundaries of two adjacent large surface holes are connected. Since the rib RB IS an etched surface, the rib RB may have a smaller thickness than the island portion IS. For example, the island portion IS may have a width of 2 μm or more. That is, the width in the direction parallel to the other surface of the portion that remains unetched on the other surface may be about 2 μm or more. When the width of one end portion and the other end portion of one island portion IS about 2 μm or more, the total volume of the deposition mask 100 may be increased. The deposition mask 100 having such a structure ensures sufficient rigidity against a tensile force applied to an organic material deposition process or the like, and is thus advantageous for maintaining uniformity of the through-holes.

Fig. 9 is a view showing a cross-sectional view along the B-B' direction of fig. 5 and 6. Referring to fig. 9, a cross section in the B-B' direction and through holes TH between ribs RB of the effective region according to fig. 8 and the ribs RB will be described.

Referring to fig. 9, in the deposition mask 100 according to the embodiment, the thickness of the active portion AA where the through-hole is formed by etching may be different from the thickness of the non-active portion UA which is not etched. In detail, the rib RB may have a thickness smaller than that in the non-effective portion UA that is not etched.

In the deposition mask 100 of the present embodiment, the thickness of the non-effective portion UA may be greater than the thicknesses of the effective portions AA1, AA2, and AA 3. For example, in deposition mask 100, the maximum thickness of non-active portion UA or non-deposition region NDA may be about 30 μm or less. For example, in deposition mask 100, the maximum thickness of non-active portion UA or non-deposition region NDA may be about 25 μm or less. For example, in the deposition mask of the present embodiment, the maximum thickness of the non-effective portion or non-deposition region may be about 15 μm to about 25 μm. When the maximum thickness of the non-effective portion or the non-deposition region of the deposition mask according to the present embodiment exceeds about 30 μm, it may be difficult to form the through holes TH having a fine size due to the thicker thickness of the metal plate 10. In addition, when the maximum thickness of the non-effective portion UA or the non-deposition region NDA of the deposition mask 100 is less than about 15 μm, it may be difficult to form a via hole having a uniform size due to the thin thickness of the metal plate.

The maximum thickness T3 measured at the center of the rib RB may be about 15 μm or less. For example, the maximum thickness T3 measured at the center of the rib RB may be about 7 μm to about 10 μm. For example, the maximum thickness T3 measured at the center of the rib RB may be about 6 μm to about 9 μm. When the maximum thickness T3 measured at the center of the rib RB exceeds about 15 μm, it may be difficult to form an OLED deposition pattern having a high resolution of 500PPI level or higher. In addition, when the maximum thickness T3 measured at the center of the rib RB is less than about 6 μm, it may be difficult to uniformly form a deposition pattern.

The height H1 of the small surface hole of the deposition mask 100 may be about 0.2 to about 0.4 times the maximum thickness T3 measured at the center of the rib RB. For example, the maximum thickness T3 measured at the center of the rib RB may be about 7 μm to about 9 μm, and the height H1 between one surface of the deposition mask 100 and the communication part may be about 1.4 μm to about 3.5 μm. The height H1 of the small surface holes of the deposition mask 100 may be about 3.5 μm or less. For example, the height of the small surface pores V1 may be about 0.1 μm to about 3.4 μm. For example, the height of the small surface apertures V1 of the deposition mask 100 may be about 0.5 μm to about 3.2 μm. For example, the height of the small surface holes V1 of the deposition mask 100 may be about 1 μm to about 3 μm. Here, the height may be measured in a thickness measuring direction of the deposition mask 100, i.e., in a depth direction, and the height may be measured from one surface of the deposition mask 100 to the communication portion. In detail, the height may be measured in a z-axis direction forming 90 degrees with the horizontal direction (x-direction) and the vertical direction (y-direction) described above in the plan views of fig. 4 to 7.

When the height between one surface of the deposition mask 100 and the communication portion exceeds about 3.5 μm, deposition failure may occur due to the following shadow effect: in this shadow effect, the deposited material diffuses to a region that is larger than the area of the via during OLED deposition.

In addition, the aperture W1 at one surface where the small surface hole V1 of the deposition mask 100 is formed and the aperture W2 at a communicating portion that is a boundary between the small surface hole V1 and the large surface hole V2 may be similar to or different from each other. The aperture W1 at one surface where the small surface hole V1 of the deposition mask 100 is formed may be larger than the aperture W2 at the communication portion. For example, the difference between the aperture W1 at one surface of the deposition mask 100 and the aperture W2 at the communication portion may be about 0.01 μm to about 1.1 μm. For example, the difference between the aperture W1 at one surface of the deposition mask and the aperture W2 at the communication portion may be about 0.03 μm to about 1.1 μm. For example, the difference between the aperture W1 at one surface of the deposition mask and the aperture W2 at the communication portion may be about 0.05 μm to about 1.1 μm.

When the difference between the aperture W1 at one surface of the deposition mask 100 and the aperture W2 at the communication portion is greater than about 1.1 μm, deposition failure may occur due to a shadow effect.

In addition, an inclination angle θ connecting one end E1 of the large surface hole V2 positioned at the other surface opposite to the one surface of the deposition mask 100 and one end E2 of a communication portion between the small surface hole V1 and the large surface hole V2 may be 40 to 55 degrees. Accordingly, a deposition pattern having a high resolution of 400PPI level or more, in detail, 500PPI level or more may be formed, and at the same time, an island portion IS may exist on the other surface of the deposition mask 100.

Fig. 10 to 12 are views illustrating a manufacturing process of the deposition mask 100 according to an embodiment.

Referring to fig. 10, the metal plate 10 according to the embodiment may include a metal material. For example, the metal plate 10 may include nickel (Ni). In detail, the metal plate 10 may include iron (Fe) and nickel (Ni). In more detail, the metal plate 10 may include iron (Fe), nickel (Ni), oxygen (O), and chromium (Cr). In addition, the metal plate 10 may further contain a small amount of at least one element of carbon (C), silicon (Si), sulfur (S), phosphorus (P), manganese (Mn), titanium (Ti), cobalt (Co), copper (Cu), silver (Ag), vanadium (V), niobium (Nb), indium (In), and antimony (Sb). Invar is an alloy comprising iron and nickel, and is a low thermal expansion alloy with a coefficient of thermal expansion close to zero. That is, invar is used for precision parts such as masks and precision equipment because the coefficient of thermal expansion of invar is very small. Accordingly, the deposition mask manufactured using the metal plate 10 may have improved reliability, thereby preventing deformation and increasing lifetime.

The metal plate 10 may include about 60 wt% to about 65 wt% iron, and may include about 35 wt% to about 40 wt% nickel. In detail, the metal plate 10 may include about 63.5 to about 64.5 wt% of iron, and may include about 35.5 to about 36.5 wt% of nickel. In addition, the metal plate 10 may further include about 1 wt% or less of at least one element of carbon (C), silicon (Si), sulfur (S), phosphorus (P), manganese (Mn), titanium (Ti), cobalt (Co), copper (Cu), silver (Ag), vanadium (V), niobium (Nb), indium (In), antimony (Sb). The composition, content and weight% of the metal plate 10 can be determined using the following method: in this method, the weight% of each component is detected by selecting a specific region a×b on the plane of the metal plate 10, taking a test piece (a×b×t) corresponding to the thickness t of the metal plate 10, and dissolving the test piece in a strong acid or the like. However, the embodiment is not limited thereto, and the content may be determined by various methods.

The metal plate 10 may be manufactured by a cold rolling method. For example, the metal plate 10 may be formed through melting, forging, hot rolling, normalizing, primary cold rolling, primary annealing, secondary cold rolling, and secondary annealing processes, and may have a thickness of about 30 μm or less through the above processes. Alternatively, the metal plate 10 may have a thickness of about 30 μm or less through an additional thickness reduction process after the above-described process.

The metal plate 10 may be wound as shown in fig. 10. For example, the metal sheet 10 manufactured by the cold rolling method may be wound around a winding roller or the like. In detail, since the manufacturing process of the deposition mask may be performed in a roll-to-roll process, the metal plate 10 may be wound.

The metal plate 10 may have a rectangular shape (dotted line in fig. 10) as shown in fig. 10. For example, the metal plate 10 may have a rectangular shape including a long axis and a short axis. However, when the metal plate 10 is manufactured by the above-described rolling method, a buckling phenomenon (wave deformation) may occur. Specifically, when the metal plate 10 is formed by rolling in the long axis direction of the metal plate 10, a warping phenomenon may occur in the long axis direction of the metal plate 10. Alternatively, when the metal plate 10 is rolled in the long axis direction, a warping phenomenon may occur in the short axis direction of the metal plate 10. Alternatively, when the metal plate 10 is rolled in the long axis direction, a warp phenomenon may occur in both the long axis direction and the short axis direction of the metal plate 10. Thus, the edge of the metal plate 10 may have a curve (solid line in fig. 10) like a wave shape.

The metal plate 10 may have a flatness value due to the warpage phenomenon. For example, the flatness of the metal plate 10 according to the present embodiment may be about 0.006% or less. When the flatness of the metal plate 10 exceeds about 0.006%, uniformity of a mask pattern formed on the metal plate 10 may be degraded. Therefore, when the organic material is deposited by using the deposition mask manufactured by the metal plate 10, deposition failure may occur. Here, the flatness may be represented by [ equation 1 ] ]The flatness is a numerical value indicating the degree of the warpage phenomenon. In detail, the flatness is determined with reference to a reference line extending in the long axis direction of the metal plate 10, andflatness refers to the distance d furthest from the reference line in the short axis direction of the metal plate 10 _x The whole length d relative to the reference line ₀ Is a ratio of (2). Here, the length of the reference line may refer to a cut length of the metal plate 10. Preferably, the length of the reference line may refer to a length in a state where the metal plate 10 is drawn.

For example, a maximum value d of deviation in the short axis direction of a metal plate (indicated by a solid line in fig. 10) in which a warp phenomenon has occurred may be used _x Length d of long axis relative to metal plate (indicated by broken line in fig. 10) in which warpage phenomenon does not occur ₀ To calculate flatness.

[ equation 1 ]]Flatness (%) = (d) _x /d ₀ )*100

That IS, when the flatness of the metal plate 10 exceeds about 0.006%, uniformity of the small surface holes V1, the large surface holes V2, and the through holes TH formed on the metal plate 10 IS lowered, and thus deposition failure may occur, and since the island portion IS may be unevenly formed, effective stress distribution may be difficult.

Fig. 11 is a view schematically showing a manufacturing process of the deposition mask 100 according to the embodiment, and fig. 12 is a view showing that a mask pattern PA is formed on the metal plate 10 to manufacture the deposition mask 100.

Referring to fig. 11 and 12, the deposition mask 100 according to the embodiment may be manufactured using the above-described metal plate 10.

Here, the manufacturing process of the small-surface holes Vl such as S410, S420, and S430 in fig. 12 may be performed in step S100 of preparing the metal plate 10 below, and the manufacturing process of the large-surface holes V2 may be performed in step 400 of forming the mask pattern.

The manufacturing process of the deposition mask 100 may include a step S100 of preparing the metal plate 10, a step S200 of drawing, and a step S400 of forming a mask pattern.

The metal plate 10 may include a first edge L1 and a second edge L2 extending in the long axis direction. In detail, the metal plate 10 may include a first edge L1 extending in a long axis direction of the metal plate 10 and a second edge L2 spaced apart from the first edge L1 in a short axis direction of the metal plate 10.

The first edge L1 may include a first vertex P1 and a second vertex P2, and the second edge L2 may include a third vertex P3 and a fourth vertex P4. Specifically, the first edge L1 may be an edge connecting the first and second apexes P1 and P2 of the metal plate 10, and the second edge L2 may be an edge connecting the third and fourth apexes P3 and P4. In addition, the metal plate 10 may further include an edge connecting the first vertex P1 and the third vertex P3 and an edge connecting the second vertex P2 and the fourth vertex P4. That is, the metal plate 10 may further include an edge extending in the short axis direction of the metal plate 10.

The first and second apexes P1 and P2 may be spaced apart by a first length d 1. The first length d1 may be the shortest length between the first vertex P1 and the second vertex P2. Further, the third and fourth vertices P3, P4 may be spaced apart by a second length d2. The second length d2 may be the shortest length between the third vertex P3 and the fourth vertex P4.

The first length dl and the second length d2 may be different from each other. Specifically, the first length d1 and the second length d2 may be different from each other due to the stress of the metal plate 10. For example, the metal plate 10 is manufactured through a rolling process, and wave deformation may occur according to the position, direction, magnitude, etc. of the force applied in the rolling process. Furthermore, the region where the wave deformation occurs may be different according to the process conditions in the metal plate 10. Thus, the first length d1 may be longer or shorter than the second length d2.

The step S100 of preparing the metal plate 10 may be a step for determining the flatness of the metal plate 10. The flatness of the metal plate 10 according to the present embodiment may be about 0.006% or less. As an example, the long axis length d of the metal plate 10 where no warpage occurs ₀ May be about 6,000mm, and at least one of the first edge L1 and the second edge L2 is deviated from a reference line in the long axis direction of the metal plate 10 in which the warp phenomenon does not occur by a maximum distance d in the short axis direction _x May be about 0.36mm or less.

In addition, the step S100 of preparing the metal plate 10 may further include a step of reducing the thickness.

For example, a metal plate 10 having a thickness of about 30 μm or less may be required to manufacture a deposition mask for achieving a resolution of 400PPI or more, and a metal plate 10 having a thickness of about 20 μm to about 30 μm may be required to manufacture a deposition mask for achieving a resolution of 500PPI or more, and a metal plate 10 having a thickness of about 15 μm to about 20 μm may be required to manufacture a deposition mask capable of achieving a resolution of 800PPI or more. That is, the step of reducing the thickness may be a step of forming a desired thickness by rolling and/or etching the metal plate 10.

In addition, the step of preparing the metal plate 10 may further optionally include a surface treatment step for increasing an etching factor. In detail, in a nickel alloy such as invar, the etching rate may increase at the start of etching, and thus the etching factor of the small-surface holes V1 may be lowered. Therefore, it may be difficult to form the through holes TH having a fine size and the through holes TH at uniform positions.

Accordingly, a surface treatment layer for preventing rapid etching can be formed on the surface of the metal plate 10. The surface treatment layer may be an etch-blocking layer having an etch rate lower than that of the metal plate 10. The surface treatment layer may have a crystal plane and a crystal structure different from those of the metal plate 10. For example, since the surface treatment layer contains an element different from that of the metal plate 10, crystal planes and crystal structures may be different from each other.

For example, in the same etching environment, the surface treatment layer may have an etching potential different from that of the metal plate 10. For example, when the same etchant is applied at the same temperature for the same time, the surface treatment layer may have an erosion current or erosion potential different from that of the metal plate 10.

The metal plate 10 may include a surface treatment layer or a surface treatment portion on one surface and/or both surfaces, the entire surface, and/or the effective area of the metal plate 10. The surface treatment layer or surface treatment portion may contain an element different from the metal plate 10, or may contain a larger content of a metal element having a slow erosion rate than the metal plate 10.

When the manufacturing process of the deposition mask 100 is performed in a roll-to-roll process, the metal plate 10 may be supplied in a state where a predetermined amount of tensile force is applied.

In addition, the step S100 of preparing the metal plate 10 may further include forming a mask pattern. Preferably, the step S100 of preparing the metal plate 10 may further include forming the small surface hole V1.

In this case, the region where the mask pattern PA is formed in step S100 may refer to a region where the small surface hole V1 is formed.

That is, in a state where a tensile force is applied in a roll-to-roll process, forming the small surface hole V1 on one surface of the metal plate 10 may be performed.

A first photoresist layer PR1 may be disposed on one surface of the metal plate 10 to form a small surface hole V1 in the metal plate 10. Subsequently, the patterned first photoresist layer PR1 may be disposed on one surface of the metal plate 10 by exposing and developing the first photoresist layer PR1 (S420). An etching barrier layer such as a coating layer or a film layer for preventing etching may be provided on the other surface of the metal plate 10 opposite to the one surface.

Subsequently, a groove may be formed on one surface of the metal plate 10 by half etching the opening portion of the patterned first photoresist layer PRl (S430). In detail, the opening portion of the first photoresist layer PR1 may be exposed to an etchant or the like, and thus etching may occur in the opening portion of one surface of the metal plate 10 where the first photoresist layer PR1 is not disposed.

The step S430 of forming a groove on one surface of the metal plate 10 is a step of etching the metal plate 10 having a thickness T1 of about 20 μm to about 30 μm to a thickness of about 1/2. The depth of the grooves formed by this step may be about 10 μm to 15 μm. That is, the thickness T2 of the metal plate measured at the center of the formed groove after this step may be about 10 μm to about 15 μm.

Step S430 of forming the groove may be an anisotropic etching or a semi-additive process (SAP). In detail, an anisotropic etching or a semi-additive process may be used to semi-etch the opening portion of the photoresist layer. Therefore, in the groove formed by half etching, the etching rate in the depth direction (b direction) can be faster than the etching rate of the side etching (a direction) compared to the isotropic etching.

The etching factor of the small surface holes V1 may be 2.0 to 3.0. For example, the etching factor of the small surface holes V1 may be 2.1 to 3.0. For example, the etching factor of the small surface holes V1 may be 2.2 to 3.0. Here, the etching factor may refer to the depth B of the etched small-surface hole divided by the width a of the photoresist layer extending from the island portion IS on the small-surface hole and protruding toward the center of the through hole TH (etching factor=b/a). A may refer to an average value of the width of one side of the photoresist layer protruding over one surface hole and the width of the other side opposite to the one side.

The drawing step S200 may be a step of drawing the metal plate 10. The drawing step S200 may be a step of applying a tension different from the tension applied to supply the metal plate 10 in the roll-to-roll method. In detail, the drawing step S200 may be a step of drawing the metal plate 10 to form mask patterns PA such as small surface holes V1 and large surface holes V2 on the metal plate 10.

The drawing step S200 may be a step of drawing the metal plate 10 in the long axis direction. For example, in the drawing step S200, the metal plate 10 may be drawn with a pulling force of 3kgf to 15 kgf. In detail, the metal plate 10 may be drawn with a tensile force of 5kgf to 10 kgf.

In the drawing step S200, the tensile force applied to the metal plate 10 may be different. For example, when the first length d1 and the second length d2 are different from each other due to the stress of the metal plate 10, the tensile force applied to each of the first edge L1 and the second edge L2 may be different from each other.

As an example, when the first length dl is longer than the second length d2, the wave deformation amount in the second edge L2 may be larger than the wave deformation amount in the first edge L1. That is, when the first length d1 is longer than the second length d2, it may mean that a greater curvature due to wave deformation is formed from the first edge L1 toward the second edge L2. Accordingly, the pulling force applied to the second edge L2 may be greater than the pulling force applied to the first edge L1.

As another example, when the first length d1 is shorter than the second length d2, the wave deformation amount in the first edge L1 may be greater than the wave deformation amount in the second edge L2. Thus, the pulling force applied to the first edge L1 may be greater than the pulling force applied to the second edge L2.

That is, in the drawing step S200 of the present embodiment, the tensile force applied to the metal plate 10, that is, the first edge L1 and the second edge L2 may be different according to the difference in length between the first length d1 and the second length d2 of the metal plate 10. In addition, in the drawing step S200 of the present embodiment, the tensile force applied to the first edge L1 and the second edge L2 may be different according to the flatness of the metal plate 10. In addition, in the drawing step, the tensile force applied to the first edge L1 and the second edge L2 may be different according to the tendency of the arc formed at the metal plate 10.

In addition, since the difference in length between the first length d1 and the second length d2 of the metal plate 10 is small in the drawing step S200, the difference in tensile force applied to the first edge L1 and the second edge L2 may be small. That is, the difference in tension applied to the first and second edges L1 and L2 may be proportional to the difference between the first and second lengths d1 and d 2. Further, since the flatness of the metal plate 10 is small, the difference in tension applied to the first edge L1 and the second edge L2 can be small. That is, the difference in tension applied to the first edge L1 and the second edge L2 may be proportional to the flatness value of the metal plate 10.

In the drawing step S200, the shape of the metal plate 10 may be changed.

For example, the metal plate 10 may have a fan shape before the tensile force for forming the mask pattern PA is applied. That is, the metal plate 10 may have a fan shape due to a length difference between the first length d1 and the second length d 2.

That is, in the metal plate 10, the tensile forces in the width direction are different from each other at the surface portions, and when the metal plate 10 is cut into unit products, the tensile forces at the surface portions are cut into different portions, and thus the metal plate 10 has the fan-like shape as described above.

In addition, in the manufacturing process of the deposition mask 100, when the metal plate 10 at step S100 is manufactured by punching after the small-surface holes V1 are formed in a state in which the metal plate 10 is drawn by the roll-to-roll method, the metal plate 100 after punching becomes in a fan shape. At this time, when the surface of the small-surface hole side of the fan-shaped metal plate 10 is blocked with resin and then the metal plate 10 is drawn over the glass substrate by the frame, the metal plate 10 again has a square shape, and when the metal plate 10 is separated from the glass substrate, the metal plate 10 again has a fan-shape.

In this case, when deposition of the deposition source is performed by using the deposition mask in the deposition enterprise, deposition is performed by pulling the deposition mask again, and thus, the deposition mask may have a square shape again. However, the deposition mask has a fan shape before drawing, and thus, a problem in reliability of the deposition mask may occur, and thus, a problem in entry of the deposition mask may occur.

In other words, since the deposition process using the deposition source of the deposition mask is performed in a state in which the deposition mask is drawn, there is no problem in terms of the shape of the deposition mask. However, before drawing is performed in the deposition process, the deposition mask has a fan shape, and thus, there are the following problems: a process of setting different pulling forces at the upper and lower portions of the fan-shaped deposition mask is additionally required.

The drawing step S200 may be a step of applying a tensile force to the metal plate 10 in consideration of the difference in length. For example, when the first length d1 of the metal plate 10 is longer than the second length d2 of the metal plate 10, the tensile force applied to the second edge L2 may be greater than the tensile force applied to the first edge L1. Accordingly, the metal plate 10 may be changed to a rectangular shape as shown at step S300 of fig. 11. In addition, the first length d1 and the second length d2 may be changed to correspond to each other due to the step S200 of drawing the metal plate 10. Accordingly, the metal plate 10 may have a flatness value close to 0% compared to before the tensile force is applied, and may also have a flatness value of 0%.

The step S400 of forming the mask pattern may be a step of forming the mask pattern PA on the metal plate 10. For example, the step S400 of forming the mask pattern may be a step of forming the deposition area DA on the metal plate 10. In detail, the step S400 of forming the mask pattern may be a step of forming the large surface hole V2 and the through hole TH communicating with the small surface hole V1 and the large surface hole V2 using the photoresist layer. That is, the small surface holes V1 may be formed at the step S100 of preparing, and thus, in the step S400 of forming the mask pattern, the large surface holes V2 are formed to form the through holes TH communicating with the small surface holes V1 and the large surface holes V2.

Here, the region where the mask pattern PA is formed may be a region including the effective portions AA1, AA2, and AA3 affecting the deposition of the organic material and the outer regions OA1, OA2, and OA3 surrounding the effective portions AA1, AA2, and AA 3. In addition, the region where the mask pattern PA is formed may refer to a region including isolation regions IA1 and IA2 disposed between adjacent effective portions AA1, AA2, and AA 3.

The step S400 of forming a mask pattern may include a step of forming a large surface hole V2 at the other surface of the metal plate 10.

For this, a second photoresist layer PR2 may be disposed on the other surface of the metal plate 10. Subsequently, a patterned second photoresist layer PR2 may be disposed on the other surface of the metal plate 10 by exposing and developing the second photoresist layer PR2 (S440). A patterned second photoresist layer PR2 having an opening portion may be disposed on the other surface of the metal plate 10 to form a large surface hole V2. An etching barrier layer such as a coating layer or a film layer for preventing etching may be provided on one surface of the metal plate 10. For example, an etching stopper layer such as a coating layer or a film layer for preventing etching may be provided in one surface of the metal plate 10 and the small-surface hole V1.

The opening portion of the patterned second photoresist layer PR2 may be exposed to an etchant or the like, and thus etching may occur in the opening portion of the other surface of the metal plate 10 where the second photoresist layer PR2 is not disposed (S440). The other surface of the metal plate 10 may be etched by anisotropic etching or isotropic etching.

Since the opening portion of the second photoresist layer PR2 is etched, a groove on one surface of the metal plate 10 may be connected to the large-surface hole V2 to form a through hole.

The step S450 of forming the through-hole may be a step of forming the through-hole by performing the step S440 of forming the groove for forming the large-surface hole V2 on the small-surface hole Vl formed previously.

In addition, the step S400 of forming the mask pattern may be performed in a state of maintaining the tensile force of the step S200 of drawing. In detail, when the photoresist layer is exposed or developed at steps S440 and S450 for forming the grooves for forming the large surface holes V2, the step S400 of forming the mask pattern may be performed in a state in which a tensile force is applied. That is, the tensile force may reduce the stress of the metal plate 10 and improve the accuracy of the mask pattern PA formed on the metal plate 10.

The step S400 of forming the mask pattern is a step of forming the effective portions AA1, AA2, AA3 and the outer areas OA1, OA2, OA3 surrounding the effective portions AA1, AA2, AA 3. For example, the step S400 of forming the mask pattern may be a step of forming the small surface holes V1, the large surface holes V2, the through holes TH, and the island portions IS.

The mask pattern PA may have a plurality of edges. The mask pattern PA may include a third edge L3 and a fourth edge L4 extending in the long axis direction of the metal plate 10. In detail, the mask pattern PA may include a third edge L3 extending in the long axis direction and a fourth edge L4 spaced apart from the third edge in the short axis direction of the metal plate 10. Assuming that the pattern area including the effective portions AA1, AA2 and AA3 and the outer areas OA1, OA2 and OA3 and the isolation areas IA1 and IA2 are one pattern, the third edge L3 and the fourth edge L4 may refer to edges as shown in step S400 of fig. 11.

The third edge L3 may be an edge connecting the fifth and sixth vertices P5 and P6 of the mask pattern PA. That is, the fifth vertex P5 may be one of the vertices of the first outer area OA1, and the sixth vertex P6 may be one of the vertices of the third outer area OA. In addition, the fourth edge L4 may be an edge connecting the seventh and eighth apexes P7 and P8 of the mask pattern PA. That is, the seventh vertex P7 may be one of the vertices of the first outer area OA1, and the eighth vertex P8 may be one of the vertices of the third outer area OA. In addition, the mask pattern PA may further include an edge connecting the fifth and seventh vertices P5 and P7, and may further include an edge connecting the sixth and eighth vertices P6 and P8. That is, the mask pattern PA may further include an edge extending in the short axis direction of the metal plate 10.

The fifth and sixth vertices P5, P6 may be spaced apart by a third length d 3. The third length d3 may be the shortest length between the fifth vertex P5 and the sixth vertex P6. Further, the seventh vertex P7 and the eighth vertex P8 may be spaced apart by a fourth length d4. The fourth length d4 may be the shortest length between the seventh vertex P7 and the eighth vertex P8.

In particular, in the step S400 of forming the mask pattern, the mask pattern PA may be formed in consideration of the flatness of the metal plate 10. In detail, step S400 may be performed in consideration of the tensile force applied to the first and second edges L1 and L2.

As an example, a case where the first length d1 is longer than the second length d2 will be described. In this case, the pulling force applied to the second edge L2 may be greater than the pulling force applied to the first edge L1. Accordingly, the metal plate 10 may be changed into a shape in which the first length d1 and the second length d2 correspond to each other by the applied tensile force, as shown in S300 of fig. 11.

Subsequently, a mask pattern PA may be formed on the metal plate 10 using the above-described photoresist layer. At this time, the mask pattern PA may be formed such that the third length d3 is shorter than the fourth length d4.

In addition, after the step S400 of forming the mask pattern, the tensile force applied in the step S200 of drawing may be removed. Accordingly, the metal plate 10 can be restored to the shape before the tensile force is applied. That is, the metal plate 10 may be restored to a shape in which the first length d1 is longer than the second length d2, and the mask pattern PA in which the third length d3 and the fourth length d4 correspond to each other may be formed on the metal plate 10.

In more detail, in the step S400 of forming the mask pattern, the distance between the adjacent small surface holes V1 and the distance between the adjacent large surface holes V2 may be changed according to the flatness of the metal plate 10.

As an example, a case where the first length d1 is longer than the second length d2 will be described. In order to form the mask pattern PA in which the third length d3 and the fourth length d4 correspond to each other on the metal plate 10 from which the pulling force has been removed, the center-to-center distance of the opening portions of the photoresist layer for forming the small surface holes V1 and the large surface holes V2 may be changed in the step S400 of forming the mask pattern. In detail, the center-to-center spacing of the opening portions formed in the long axis direction of the metal plate 10 may vary from the third edge L3 toward the fourth edge L4. For example, the center-to-center spacing of the opening portions formed in the long axis direction of the metal plate 10 may become further from the third edge L3 toward the fourth edge L4. That is, in a state where the tensile force is applied, the center-to-center spacing of the through holes TH adjacent in the long axis direction of the metal plate 10 may become further from the third edge L3 toward the fourth edge L4.

As another example, although not shown in the drawings, a case where the second length d2 is longer than the first length dl will be described. In order to form the mask pattern PA in which the third length d3 and the fourth length d4 correspond to each other on the deposition mask 100 from which the tensile force is removed, the center-to-center spacing of the opening portion formed in the long axis direction of the metal plate 10 may become closer from the third edge L3 toward the fourth edge L4. That is, the center-to-center spacing of the through holes TH adjacent in the long axis direction of the metal plate 10 may become closer from the third edge L3 toward the fourth edge L4 in a state where the tensile force is applied.

Next, after removing the photoresist layer, the deposition mask 100 may be formed by: in this step, the deposition mask 100 including the large surface hole V2 formed on one surface, the small surface hole V1 formed on the other surface opposite to the one surface, and the through hole TH formed by the communicating portion connecting the boundary between the large surface hole V2 and the small surface hole V1 is formed.

The deposition mask 100 may include the same material as the metal plate 10. For example, a region in which surface etching in the deposition mask 100 is not performed may have the same conductivity as the surface of the metal plate 10. Thus, the island portion IS may include the surface treatment layer described above.

In addition, in the deposition mask 100 formed through the above steps, the maximum thickness at the center of the rib RB may be smaller than the maximum thickness of the non-effective portion UA that is not etched. For example, the maximum thickness at the center of the rib RB may be about 15 μm. For example, the maximum thickness at the center of the rib RB may be less than about 10 μm. However, the maximum thickness in the non-active portion UA of the deposition mask 100 may be about 20 μm to about 30 μm, and may be about 15 μm to about 25 μm. That is, the maximum thickness in the non-effective portion UA of the deposition mask 100 may correspond to the thickness of the metal plate 10 prepared in the step of preparing the metal plate 10. Accordingly, the deposition mask 100 may have a thickness of about 30 μm or less.

Referring to fig. 13, a process of manufacturing a deposition mask according to a comparative example will be described. In the description of the manufacturing process of the deposition mask according to the comparative example, the same or similar components as those of the manufacturing process according to the above-described embodiment will be omitted, and the same or similar components are denoted by the same reference numerals.

Referring to fig. 13, the manufacturing process of the deposition mask according to the comparative example may include a step S100 of preparing the metal plate 10, a step S200 of drawing, and a step S400 of forming a mask pattern.

The metal plate 10 according to the comparative example may have a flatness of 0.006% or less, and the first length d1 and the second length d2 of the metal plate 10 may be different from each other due to stress.

The drawing step S200 may be a step of drawing the metal plate 10 in the long axis direction of the metal plate 10. For example, in the drawing step S200, the metal plate 10 may be drawn with a force of 3kgf to 15 kgf. In detail, the metal plate 10 may be drawn with a force of 5kgf to 10 kgf.

In step S200 of drawing according to the comparative example, the same tensile force may be applied to the metal plate 10. For example, when the first length dl is longer than the second length d2, the metal plate 10 may be drawn by applying the same pulling force to the first edge L1 and the second edge L2.

That is, the drawing step S200 of the comparative example may be a step of applying the same pulling force to each edge regardless of the difference in length between the first length d1 and the second length d2 of the metal plate 10. In addition, the drawing step S200 of the comparative example may be a step of applying the same tensile force to each edge of the metal plate regardless of the flatness of the metal plate 10. In addition, the drawing step S200 of the comparative example may be a step of applying the same tensile force to each edge regardless of the tendency of the arc formed at the metal plate 10.

The step S400 of forming the mask pattern may be a step of forming the mask pattern PA on the metal plate 10. The mask pattern PA may refer to effective portions AAl, AA2, and AA3 affecting the deposition of the organic material and outer areas OA1, OA2, and OA3 surrounding the effective portions AA1, AA2, and AA 3. In detail, the mask pattern PA may refer to the effective portions AA1, AA2, and AA3, the outer areas OA1, OA2, and OA3, and the isolation areas IA1 and IA2.

The mask pattern PA may include third and fourth edges L3 and L4 extending in the long axis direction of the metal plate, and the mask pattern PA may be formed such that the third and fourth lengths d3 and d4 correspond to each other in the step S400 of forming the mask pattern.

After the step S400 of forming the mask pattern, the pulling force applied in the step S200 of drawing may be removed. Accordingly, the metal plate 10 can be restored to the shape before the tensile force is applied. That is, the metal plate 10 may be restored to a shape in which the first length d1 is longer than the second length d2, and the mask pattern PA in which the third length d3 and the fourth length d4 are different from each other may be formed on the metal plate 10. That is, the third length d3 may be longer than the fourth length d4 due to the stress of the metal plate 10.

Therefore, uniformity of the mask pattern PA may be reduced. In detail, in the deposition mask 100 manufactured in the comparative example, the center-to-center spacing of the through holes TH may be changed. In more detail, in the deposition mask 100 manufactured by the comparative example, the center-to-center spacing of the through holes TH adjacent in the long axis direction may become closer from the third edge L3 toward the fourth edge L4. Therefore, when the organic material is deposited using the deposition mask 100 of the comparative example, deposition failure may occur.

Fig. 14 and 15 are views showing a deposition pattern formed via a deposition mask according to an embodiment.

Referring to fig. 14, in the deposition mask 100 according to the embodiment, a height H1 between one surface of the deposition mask 100 where the small surface holes V1 are formed and the communication portion may be about 3.5 μm or less. For example, the height H1 may be about 0.1 μm to about 3.4 μm. For example, the height H1 may be about 0.5 μm to about 3.2 μm. For example, the height H1 may be about 1 μm to about 3 μm.

Accordingly, a distance between one surface of the deposition mask 100 and the substrate provided with the deposition pattern may be short, and thus deposition defects due to shadow effects may be reduced. For example, it is possible to prevent the bad deposition of different deposition materials in the region between two adjacent patterns when forming R, G and B patterns by using the deposition mask 100 according to the embodiment. Specifically, as shown in fig. 15, when the above patterns are formed in the order of R, G and B from the left, the R pattern and the G pattern can be prevented from being deposited in the region between the R pattern and the G pattern by a shadow effect.

In addition, the deposition mask 100 according to the embodiment may be manufactured in consideration of the stress and flatness of the metal plate 10. In detail, the deposition mask 100 may be manufactured in consideration of the pulling force applied to the metal plate 10 to be removed and restore the original shape.

For example, the deposition mask 100 may form a mask pattern PA such as a small surface hole V1, a large surface hole V2, and a through hole TH in a state where the metal plate 10 is drawn. Thereafter, the mask pattern PA may be formed in consideration of the recovery of the metal plate 10 after the removal of the tensile force. Accordingly, uniformity of the mask pattern PA formed on the deposition mask 100, that is, uniformity of the through holes TH, may be improved, thereby preventing deposition defects, and thus, deposition efficiency may be improved.

The characteristics, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, but are not limited to only one embodiment. Furthermore, the characteristics, structures, and effects shown in each embodiment may be combined or modified for other embodiments by those skilled in the art. Accordingly, it is to be understood that such combinations and modifications are included within the scope of the present invention.

In addition, the foregoing description has focused on the embodiments, but is merely illustrative and not limiting of the invention. It will be apparent to those skilled in the art that various modifications and applications not shown above are possible without departing from the essential features of the present embodiment. For example, elements of the embodiments described herein may be modified and implemented. Moreover, it is to be understood that differences relating to such modifications and applications are included in the scope of the present invention as defined in the appended claims.

Claims

1. A method of fabricating a deposition mask for organic light emitting diode deposition, the method comprising:

preparing a metal plate having a long axis and a short axis; and

drawing the metal plate in the long axis direction by a tensile force;

Forming a mask pattern on the drawn metal plate, the mask pattern including a photoresist layer;

forming a plurality of through holes penetrating one surface and the other surface of the drawn metal plate;

wherein the metal plate includes a first edge extending in the long axis direction of the metal plate and a second edge extending in the long axis direction of the metal plate and spaced apart from the first edge in the short axis direction of the metal plate,

wherein the first edge comprises a first vertex and a second vertex spaced apart from the first vertex by a first length, and the second edge comprises a third vertex and a fourth vertex spaced apart from the third vertex by a second length,

wherein a pulling force is applied according to a difference such that a first edge length and a second edge length correspond to each other along the long axis when the metal plate is drawn,

wherein the drawn mask pattern on the drawn metal sheet includes a third edge extending in the long axis direction and a fourth edge extending in the long axis direction and spaced apart from the third edge in the short axis direction of the metal sheet,

Wherein, in the drawn mask pattern on the drawn metal plate, the length of the third edge is different from the length of the fourth edge, and the center-to-center spacing of each of the through holes adjacent in the long axis direction becomes further from the third edge toward the fourth edge,

wherein, in the metal plate, when the pulling force is removed after the plurality of through holes are formed, the length of the third edge corresponds to the length of the fourth edge, and

wherein each of the length of the third edge, the length of the fourth edge is shorter than the length of the first edge, the length of the second edge, respectively, and

wherein the metal plate is invar containing iron (Fe) and nickel (Ni) having a thickness of 30 μm or less.

2. The method of claim 1, wherein the forming of the mask pattern comprises:

providing a first photoresist layer on one surface of the metal plate, and patterning the first photoresist layer;

forming a first groove by etching the one surface of the metal plate that is opened by the patterned first photoresist layer;

Providing a second photoresist layer on the other surface of the metal plate opposite to the one surface, and patterning the second photoresist layer;

forming a second groove connected to the first groove by etching the other surface of the metal plate that is opened by the patterned second photoresist layer; and

removing the first photoresist layer and the second photoresist layer,

the patterning of the first photoresist layer and the patterning of the second photoresist layer includes drawing the metal plate along the long axis direction of the metal plate,

wherein the pulling applies a different pulling force to each of the first edge and the second edge according to a difference between the first length and the second length, and

wherein, in the drawn mask pattern on the drawn metal plate, the length of the third edge is shorter than the length of the fourth edge.

3. The method of claim 1, wherein when the first length is longer than the second length,

the magnitude of the pulling force applied to the first edge is less than the magnitude of the pulling force applied to the second edge,

Wherein the metal plate has a flatness value expressed by the following equation 1, and the flatness of the metal plate is 0.006% or less,

[ equation 1]

Flatness (%) = (d) _x /d ₀ )*100

Wherein the flatness is defined based on a reference line extending in the long axis direction of the metal plate, and refers to a vertically farthest distance (d _x ) Length (d) to the reference line ₀ ) Is a ratio of (c).

4. The method of claim 1, wherein the drawing comprises drawing at the pulling force of 3kgf to 15 kgf.