KR20200033585A - A deposition mask and method for manufacturing of the same - Google Patents

Abstract

According to one embodiment of the present invention, in a metallic deposition mask for depositing OLED pixels, a deposition mask comprises deposition regions for forming deposition patterns and non-deposition regions for the other regions except deposition region, wherein the deposition regions are spaced apart in the longitudinal direction, and includes a plurality of effective portions having a plurality of through holes and non-effective portions except the effective portion. The through holes comprise: a small area hole formed on one surface of the deposition mask; a large area hole formed on the other surface of the deposition mask opposite to the one surface; and a communication portion in which the boundary between the small area hole and the large area hole is connected, wherein the root mean square of surface roughness (RMS) of the inner surface of at least one of the small area hole and the large area hole is less than 150 nm.

Description

A deposition mask and a manufacturing method therefor {A DEPOSITION MASK AND METHOD FOR MANUFACTURING OF THE SAME}

The present invention relates to a deposition mask capable of improving deposition efficiency when depositing an OLED pixel and a method for manufacturing the same.

2. Description of the Related Art Display devices are applied to various devices. For example, the display device is applied to a large device such as a TV, a monitor, a public display (PD), as well as a small device such as a smart phone or a tablet PC. In particular, in recent years, the demand for ultra-high definition UHD (UHD) of 500 PPI (Pixel Per Inch) or higher has increased, and high-resolution display devices have been applied to small devices and large devices. Accordingly, interest in technologies for realizing low power and high resolution is increasing.

2. Description of the Related Art Display devices that are generally used may be largely classified into a liquid crystal display (LCD) and an organic light emitting diode (OLED).

The LCD is a display device driven using a liquid crystal, and has a structure in which a light source including a Cold Cathode Fluorescent Lamp (CCFL) or Light Emitting Diode (LED) is disposed under the liquid crystal, and on the light source. It is a display device that is driven by controlling the amount of light emitted from the light source by using the disposed liquid crystal.

In addition, the OLED is a display device driven by using an organic material, and a separate light source is not required, and the organic material itself may serve as a light source and be driven with low power. In addition, OLEDs are drawing attention as display devices that can replace LCDs because they can express an infinite contrast ratio, have a response speed that is about 1000 times faster than LCDs, and have excellent viewing angles.

In particular, in the OLED, the organic material included in the light emitting layer may be deposited on a substrate by a deposition mask called a fine metal mask (FMM), and the deposited organic material corresponds to a pattern formed in the deposition mask. Formed in a pattern, it can serve as a pixel.

In detail, the deposition mask is generally formed of a metal plate. The deposition mask may be manufactured by forming a through hole in a position corresponding to the pattern of the pixel on the metal plate. In this case, the through hole may include first and second face holes communicating with each other on the metal plate through a wet etching process of iron chloride.

At this time, the inner wall of the through-hole including the first and second face holes has a square average surface roughness (RMS) of a predetermined level or more. That is, the inner wall of the through hole has a square mean surface roughness (RMS) in the range of 150 to 200 nm. Here, the square mean surface roughness (RMS) of the inner wall of the through hole may be determined by the etching solution used when forming the through hole rather than the properties of the metal plate. Generally, iron chloride is used as an etchant in the wet etching process of the through hole. In addition, the inner wall of the through hole formed by the iron chloride has a mean square surface roughness (RMS) in the range of 150 to 200 nm due to the properties of the iron chloride. At this time, the durability of the deposition mask is closely related to the square mean surface roughness (RMS) of the inner wall of the through hole. That is, when the square mean surface roughness (RMS) of the inner wall of the through hole increases, difficulty occurs in the cleaning process of the deposition source. In other words, as the squared average surface roughness (RMS) increases, the bonding force with the deposition element also increases. Accordingly, there is a problem in that the deposition element attached to the inner wall of the through hole is not completely removed and remains partially during the cleaning process.

Accordingly, recently, the surface roughness of the surface of the deposition mask or the inner wall of the through-hole is adjusted by changing the etching process conditions or etching solution conditions. However, there is a limitation in improving the surface roughness of the inner wall of the through hole only by changing the etching process conditions or etching solution conditions as described above. In addition, as the etching process conditions or etching solution conditions change, the size of the through-holes also changes, and accordingly, there is a problem in that the uniformity or precision of the through-holes decreases.

Accordingly, there is a need for a deposition mask and a method for manufacturing the same, which can improve the square average surface roughness (RMS) of the inner wall of the through hole while maintaining the uniformity or precision of the through hole.

In an embodiment according to the present invention, a mask for deposition and a method of manufacturing the same can be provided to improve deposition efficiency by controlling the squared average surface roughness (RMS) of the inner wall of the through hole.

In addition, in an embodiment according to the present invention, to provide a deposition mask and a method for manufacturing the same, which can improve the cleaning property of a deposition source during a cleaning process performed after deposition of a deposition element.

In addition, in an embodiment according to the present invention, an electrolytic polishing process is further performed after the wet etching process to provide a deposition mask and a method for manufacturing the same, which can improve the square average surface roughness (RMS) of the through-hole inner wall.

In addition, an embodiment according to the present invention provides a deposition mask and a method of manufacturing the same to enhance the quality and durability by enhancing the corrosion resistance inside the through-hole.

The technical problems to be achieved in the proposed embodiment are not limited to the technical problems mentioned above, and other technical problems that are not mentioned are clear to a person having ordinary knowledge in the technical field to which the proposed embodiment belongs from the following description. It can be understood.

The deposition mask of a metal material for OLED pixel deposition according to an embodiment, wherein the deposition mask includes a deposition region for forming a deposition pattern and a non-deposition region other than the deposition region, and the deposition regions are spaced apart in the longitudinal direction It includes a plurality of effective portions formed with a plurality of through-holes and non-effective portions other than the effective portion, the through-holes comprising: a small surface hole formed on one surface of the deposition mask; A large surface hole formed on the other surface of the deposition mask opposite to the one surface; And a communication portion connecting a boundary between the small face hole and the large face hole, and the square mean surface roughness (RMS) of at least one inner surface of the small face hole and the large face hole is less than 150 nm.

In addition, the square mean surface roughness (RMS) of at least one inner surface of the small face hole and the large face hole satisfies a range between 50 nm and 100 nm.

In addition, the square mean surface roughness (RMS) of the inner surface of the small surface hole is smaller than the square mean surface roughness (RMS) of the one surface on which the small surface hole is formed.

Further, the square mean surface roughness (RMS) of the inner surface of the face hole is smaller than the square mean surface roughness (RMS) of the other surface on which the face hole is formed.

Further, the first diameter of the small surface hole is larger than the second diameter of the communication portion, and the first diameter is 1.2 times or less of the second diameter.

Further, the first diameter has a range between 1.05 times and 1.1 times the second diameter.

In addition, a first inflection point is formed on the inner surface of the small surface hole, and the inner surface of the small surface hole includes a first sub first inner surface formed between one surface of the deposition mask and the first inflection point, and the first surface. And a second sub-first inner surface formed between the inflection point and the communication portion.

In addition, a second inflection point is formed on the inner surface of the face hole, and the inner face of the face hole includes a first sub-second inner surface formed between the other surface of the deposition mask and the second inflection point, and the second. And a second sub-second inner surface formed between the inflection point and the communication portion.

In addition, the through-holes have a resolution of 500 PPI or more, the diameter of which is 33 μm or less, and the spacing between the plurality of through holes is 48 μm or less.

On the other hand, the manufacturing method according to the embodiment prepares a metal plate having a predetermined thickness, and etching the one surface and the other surface of the metal plate, respectively, has a first surface having a communicating portion connecting the boundary between the small surface hole, the large surface hole, and the small surface hole Forming a through hole and electropolishing the inner surface of the formed first through hole to form a second through hole, wherein the square mean surface roughness (RMS) of the inner surface of the second through hole is the first The square mean surface roughness (RMS) of the inner surface of the through hole is smaller than that, and the square mean surface roughness (RMS) of the inner surface of the second through hole is less than 150 nm.

In addition, the square mean surface roughness (RMS) of at least one inner surface of the small face hole and the large face hole of the second through hole satisfies a range between 50 nm and 100 nm.

In addition, the square average surface roughness (RMS) of the inner surface of the small face hole of the second through hole is smaller than the square average surface roughness (RMS) of one surface of the metal material, and the square average of the inner surface of the large face hole of the second through hole The surface roughness (RMS) is smaller than the square mean surface roughness (RMS) of the other surface of the metal material.

In addition, the first cross-sectional inclination angle of the small surface hole of the second through hole is greater than the second cross-sectional inclination angle of the small surface hole of the first through hole, and the first cross-sectional inclination angle has a range between 75 degrees and 89 degrees.

According to an embodiment of the present invention, the deposition mask includes a plurality of through holes formed by communicating the first surface hole and the second surface hole. In this case, the through hole may be formed by additionally performing an electrolytic polishing process after a wet etching process. Accordingly, in the present invention, the deposition mask has a mean square surface roughness (RMS) of the through-hole inner wall smaller than that of the first and / or second surface of the deposition mask. Preferably, the deposition mask in the present invention has a through-hole inner wall having a mean square surface roughness (RMS) of less than 150 nm. More preferably, the deposition mask in the present invention satisfies the range of the square mean surface roughness (RMS) of the inner wall of the through hole in the range of 50 nm to 100 nm.

According to the present invention as described above, it is possible to improve the square mean surface roughness (RMS) of the inner wall of the through hole of the deposition mask, and accordingly, to improve the cleaning properties of the deposition mask. In addition, according to the present invention, the number of times that the deposition mask can be used can be dramatically increased according to the improvement of the above-described cleaning properties. Further, according to the present invention, it is possible to enhance the corrosion resistance inside the through-holes of the deposition mask, thereby enhancing the quality and durability of the deposition mask.

In addition, in the related art, as only the wet etching process is performed, the inclination angle that can be formed to the maximum is 75 ° with respect to the small surface hole corresponding to the first surface hole. However, in the present invention, as the electrolytic polishing process is further performed as described above, an inclination angle with respect to the small surface hole may be formed to be 75 ° or more. Preferably, the inclination angle of the small hole in the present invention may have a range between 75 ° ~ 85 °.

According to the present invention as described above, it is possible to improve the shadow effect as the inclination angle of the through-hole of the deposition mask is increased. In addition, according to the present invention, it is possible to prevent deposition defects due to an increase in the inclination angle, to improve deposition efficiency, and thus to provide a deposition mask capable of uniformly depositing an OLED pixel pattern having a resolution of 400 PPI or higher. It is possible.

In addition, according to the present invention, the boundary surface between the first surface hole and the second surface hole of the deposition mask has a gentle round shape, and accordingly, the durability of the deposition mask for high tensile load during tension can be improved.

1 is a perspective view showing an organic material deposition apparatus including a deposition mask according to an embodiment.
2 is a cross-sectional view showing an organic material deposition apparatus including a deposition mask according to an embodiment.
3 is a view illustrating that a deposition mask according to an embodiment is stretched to be mounted on a mask frame.
4 is a view showing that a plurality of deposition patterns are formed on the substrate through a plurality of through holes of the deposition mask.
5 is a plan view of a deposition mask according to an embodiment.
6A is a view showing a plan view of an effective portion of a deposition mask.
6B is a photograph showing a plan view of an effective portion of a deposition mask.
FIG. 6C is a diagram illustrating a cross-sectional view of A-A 'and B-B' of FIG. 6A or 6B.
7 is a view showing another plan view of the deposition mask according to the embodiment.
8 is a view showing a through hole after a wet etching process according to an embodiment of the present invention.
9 is a view showing a through hole after the electropolishing process according to an embodiment of the present invention.
10 is a view comparing the square mean surface roughness of the inner surface of the through-hole of the embodiment of the present invention and the comparative example.
11 is a view showing a method of manufacturing a deposition mask 100 according to an embodiment.
12 and 13 are views showing a deposition pattern formed through a deposition mask according to an embodiment.

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of its components between the embodiments It can be used by selectively bonding, replacing. In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless clearly defined and specifically described, can be generally understood by those skilled in the art to which the present invention pertains. It can be interpreted as a meaning, and terms that are commonly used, such as predefined terms, may be interpreted by considering the contextual meaning of the related technology. In addition, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In the present specification, the singular form may also include a plural form unless specifically stated in the phrase, and when described as “at least one (or more than one) of A and B, C”, A, B, and C may be combined. It can contain one or more of all possible combinations. In addition, in describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the term is not limited to the nature, order, or order of the component. And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also to the component It may also include a case of 'connected', 'coupled' or 'connected' due to another component between the other components. Further, when described as being formed or disposed in the "top (top) or bottom (bottom)" of each component, the top (top) or bottom (bottom) is not only when the two components are in direct contact with each other, but also one It also includes a case in which another component described above is formed or disposed between two components. In addition, when expressed as "up (up) or down (down)", it may include the meaning of the downward direction as well as the upward direction based on one component.

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

1 to 4 are conceptual views for explaining a process of depositing an organic material on the substrate 300 using the deposition mask 100 according to the embodiment.

1 is a perspective view showing an organic material deposition apparatus including a deposition mask according to an embodiment, FIG. 2 is a cross-sectional view showing an organic material deposition apparatus including a deposition mask 100 according to an embodiment, and FIG. 3 is an embodiment It is a figure showing that the deposition mask 100 according to an example is stretched to be mounted on the mask frame 200. In addition, FIG. 4 is a diagram illustrating that a plurality of deposition patterns are formed on the substrate 300 through a plurality of through holes of the deposition mask 100.

Referring to FIGS. 1 to 4, 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 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 in an effective portion for deposition. The deposition mask 100 may be a substrate for a deposition mask including a plurality of through holes TH. At this time, the through hole may be formed to correspond to a pattern to be formed on the substrate. The deposition mask 100 may include a non-effective portion other than the effective portion including the deposition region.

The mask frame 200 may include an opening 205. The plurality of through holes of the deposition mask 100 may be disposed on an area corresponding to the opening 205 of the mask frame 200. Accordingly, an 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 is tensioned with a constant tensile force, and may be fixed by welding on the mask frame 200.

That is, the mask frame 200 includes a plurality of frames 201, 202, 203, and 204 surrounding the opening 205. The plurality of frames 20, 202, 203, and 204 may be connected to each other. The mask frame 200 faces each other in the X direction, and includes a first frame 201 and a second frame 202 extending along the Y direction, facing each other in the Y direction, and extending along the X direction. It includes a third frame 203 and a fourth frame (204). The first frame 201, the second frame 202, the third frame 203, and the fourth frame 204 may be square frames connected to each other. The mask frame 200 may be made of a material having a small deformation when the mask 130 is welded, such as a metal having high rigidity.

The deposition mask 100 may be stretched in opposite directions from an edge disposed at the outermost edge of the deposition mask 100. In the longitudinal direction of the deposition mask 100, the deposition mask 100 may be pulled in a direction opposite to one end of the deposition mask 100 and the other end opposite to the one end. Therefore, the tensile direction of the deposition mask 100, the X-axis direction, and the longitudinal direction of the deposition mask may all be the same direction.

 One end and the other end of the deposition mask 100 may be disposed parallel to each other. One end of the deposition mask 100 may be any one of four end surfaces forming the outermost sides of the deposition mask 100. For example, the deposition mask 100 may be tensioned with a tensile force of about 0.1 kgf to about 2 kgf. In detail, the deposition mask may be tensioned with a tensile force of 0.4 kgf to about 1.5 kgf to be fixed on the mask frame 200. Accordingly, the stress of the deposition mask 100 may be reduced. However, the embodiment is not limited thereto, and may be tensioned with various tensile forces capable of reducing the stress of the deposition mask 100 and fixed on the mask frame 200.

Subsequently, the deposition mask 100 may fix the deposition mask 100 to the mask frame 200 by welding an ineffective portion of the deposition mask 100. Next, a portion of the deposition mask 100 disposed outside the mask frame 200 may be removed by a method such as cutting.

The substrate 300 may be a substrate used 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. Red, green, and blue organic patterns may be formed on the substrate 300 to form a pixel having three primary colors of light. That is, an RGB pattern may be formed on the substrate 300.

The organic material deposition container 400 may be a crucible. An organic material may be disposed inside the crucible. The organic material deposition container 400 may move within the vacuum chamber 500. That is, the organic material deposition container 400 may move in the Y-axis direction in the vacuum chamber 500. That is, the organic material deposition container 400 may move in the width direction of the deposition mask 100 in the vacuum chamber 500. That is, the organic material deposition container 400 may move in a direction perpendicular to the tensile direction of the deposition mask 100 in the vacuum chamber 500.

As the heat source and / or current is supplied to the crucible of the organic material deposition container 400 in the vacuum chamber 500, the organic material may be deposited on the substrate 100.

Referring to FIG. 4, the deposition mask 100 may include one surface 101 and the other surface 102 opposite to the one surface.

The one surface 101 of the deposition mask 100 may include a small surface hole V1, and the other surface may include a large surface hole V2. For example, each of the one surface 101 and the other surface 102 of the deposition mask 100 may include a plurality of small face holes V1 and a plurality of face holes V2.

In addition, the deposition mask 100 may include a through hole TH. The through hole TH may be communicated by a communication portion CA to which the boundary between the small face hole V1 and the large face hole V2 is connected. The communication portion CA refers to a point that becomes a boundary between the small face hole V1 and the large face hole V2, which may also be expressed as a boundary portion, a boundary point, and a boundary surface.

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

Meanwhile, the first inner surface ES1 in the small face hole V1 may include a plurality of sub first inner surfaces ES2. A first inflection point IP1 may be formed on the first inner surface ES1 of the small surface hole V1 between the one surface 101 and the communication portion CA. Accordingly, the first inner surface ES1 includes a first sub-first inner surface formed between the one surface 101 and the first inflection point IP1, and the first inflection point IP1 and the communication portion ( CA) may include a second sub-first inner surface formed between.

In addition, the second inner surface ES2 of the face hole V2 may include a plurality of sub second inner surfaces ES2. A second inflection point IP2 may be formed between the other surface 102 and the communication portion CA on the second inner surface ES2 of the large hole V2. Accordingly, the second inner surface ES2 includes a first sub-second inner surface formed between the other surface 102 and the second inflection point IP2, and the second inflection point IP2 and the communication portion CA ) May include a second sub-second inner surface formed therebetween.

Here, the first inner surface ES1, the second inner surface ES2, the first sub first inner surface, the second sub first inner surface, the first sub second inner surface, and the second sub second The inner surface may also be referred to as an etched surface formed by etching. More preferably, the first inner surface ES1, the second inner surface ES2, the first sub first inner surface, the second sub first inner surface, the first sub second inner surface, and the second sub The second inner surface may be referred to as a polishing surface formed through an additional electrolytic polishing process after the etching process.

The width of the large face hole V2 may be greater than the width of the small face hole V1. At this time, the width of the small hole V1 is measured on one surface 101 of the deposition mask 100, and the width of the large surface hole V2 is measured on the other surface 102 of the deposition mask 100. Can be.

The small hole V1 may be disposed toward the substrate 300. The small hole V1 may be disposed close to the substrate 300. Accordingly, the small hole V1 may have a shape corresponding to a deposition material, that is, a deposition pattern DP.

The large hole V2 may be disposed toward the organic material deposition container 400. Accordingly, the large-surface hole V2 can accommodate the organic material supplied from the organic material deposition container 400 in a wide width, and the small-surface hole V1 is smaller in width than the large-surface hole V2. A fine pattern can be quickly formed on the substrate 300.

5 is a plan view of a deposition mask according to an embodiment. Referring to FIG. 5, the deposition mask according to the 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. One deposition mask may include a plurality of deposition regions DA. For example, the deposition area DA of the embodiment may include a plurality of effective parts AA1, AA2, and AA3 capable of forming a plurality of deposition patterns.

The plurality of effective parts may include a first effective part AA1, a second effective part AA2, and a third effective part AA3. One deposition region 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 part of any one of a plurality of deposition regions included in a deposition mask may be for forming a single display device. Accordingly, one deposition mask may include a plurality of effective portions, and thus multiple display devices may be simultaneously formed. Therefore, the deposition mask according to the embodiment may improve process efficiency.

Alternatively, in the case of a large-sized display device such as a television, several effective parts included in one deposition mask may be part for forming a single display device. At this time, the plurality of effective parts may be to prevent deformation due to the load of the mask.

The deposition area DA may include a plurality of separation areas IA1 and IA2 included in one deposition mask. Separation regions IA1 and IA2 may be disposed between adjacent effective portions. The separation region may be a separation region between a plurality of effective portions. For example, a first separation region IA1 may be disposed between the first effective portion AA1 and the second effective portion AA2. For example, a second separation region IA2 may be disposed between the second effective portion AA2 and the third effective portion AA3. The separation region can distinguish adjacent effective regions, and allows a single deposition mask to support multiple effective regions.

The separation regions IA1 and IA2 may have the same height as the island portion or the non-deposition region or the non-effective region. The separation regions IA1 and IA2 may be regions that are not etched when forming through holes.

The deposition mask may include non-deposition regions NDA on both sides in the longitudinal direction of the deposition region DA. The deposition mask according to the embodiment may include the non-deposition area NDA on both sides of the deposition area DA in the horizontal direction.

The non-deposition region NDA of the deposition mask may be a region not involved in deposition. The non-deposition region NDA may include frame fixing regions FA1 and FA2 for fixing to the mask frame. For example, the non-deposition area NDA of the deposition mask may include a first frame fixing area FA1 on one side of the deposition area DA, and the one side of the deposition area DA. A second frame fixing area FA2 may be included on the other side opposite. The first frame fixing area FA1 and the second frame fixing area FA2 may be areas fixed to the mask frame by welding.

The non-deposition region NDA may include half-etched portions HF1 and HF2. For example, the non-deposition area NDA of the deposition mask may include a first half-etching part HF1 on one side of the deposition area DA, and the one side of the deposition area DA. A second half-etching portion HF2 may be included on the other side opposite. The first half-etching part HF1 and the second half-etching part HF2 may be regions in which grooves are formed in a depth direction of a deposition mask. The first half-etching portion HF1 and the second half-etching portion HF2 may have a groove portion having a thickness of about 1/2 of the deposition mask, so that stress during dispersion of the deposition mask can be dispersed.

The half-etched portion may be formed at the same time when forming the small-sided hole or the large-sided hole. Through this, process efficiency can be improved.

A surface treatment layer different from a metal plate material may be formed in the deposition region DA of the deposition mask, and the surface treatment layer may not be formed in the non-deposition region NDA. Alternatively, a surface treatment layer different from the material of the metal plate may be formed on only one surface of the deposition mask or the other surface opposite to the one surface. Alternatively, a surface treatment layer different from the material of the metal plate may be formed only on a part of one surface of the deposition mask. For example, one side and / or the other side of the deposition mask, and all and / or a portion of the deposition mask may include a surface treatment layer having a slower etching rate than the metal plate material, thereby improving the etching factor. Accordingly, the deposition mask of the embodiment can form a fine size through hole with high efficiency. In one example, the deposition mask of the embodiment can form a deposition pattern having a high resolution of 500 PPI or higher with high efficiency. Here, the surface treatment layer may include a metal plate material and other elements, or may mean that the composition of the same element includes a different metal material.

The half-etched portion may be formed on the non-effective portion UA of the deposition region DA. In order to disperse the stress during the stretching of the deposition mask, the half-etched portion may be dispersed in all or part of the non-effective portion UA to be disposed in plural.

Further, the half-etched portion may be formed in the frame fixing region and / or the peripheral region of the frame fixing region. Accordingly, the stress of the deposition mask generated when the deposition mask is fixed to the frame and / or when the deposition mask is deposited after the deposition mask is fixed to the frame can be uniformly dispersed. Accordingly, the deposition mask can be maintained to have a uniform through hole.

The frame fixing areas FA1 and FA2 for fixing to the mask frame of the non-deposition area NDA are provided with the half-etching parts HF1 and HF2 and the half-etching parts HF1 and HF2 of the non-deposition area NDA. It may be disposed between adjacent effective portions of the deposition area DA. For example, the first frame fixing area FA1 includes a first half-etching part HF1 of the non-deposition area NDA and a deposition area DA adjacent to the first half-etching part HF1. It may be disposed between one effective portion (AA1). For example, the second frame fixing area FA2 includes a second half-etching part HF2 of the non-deposition area NDA and a deposition area DA adjacent to the second half-etching part HF2. It may be disposed between the three effective portions (AA3). Accordingly, a plurality of deposition pattern portions can be fixed at the same time.

The deposition mask may include semi-circular open portions at both ends of the horizontal direction (X). The non-deposition region NDA of the deposition mask may include one semicircular open portion at both ends in the horizontal direction. For example, the non-deposition region NDA of the deposition mask may include an open portion in which the center of the vertical direction Y is open on one side of the horizontal direction. For example, the non-deposition region NDA of the deposition mask may include an open portion in which the center of the vertical direction is opened on the other side opposite to the one side in the horizontal direction. That is, at both ends of the deposition mask, a half point of a vertical length may include an open portion. For example, both ends of the deposition mask may be shaped like a horseshoe.

The half-etched portion included in the deposition mask of the embodiment may be formed in various shapes. The half-etched portion may include a semi-circular groove. Alternatively, the half-etched portion may include various groove portions such as a square shape, a rhombus shape, a triangular shape, an ellipse shape, a star shape, or a polygonal shape. The groove may be formed on at least one of one surface of the deposition mask and the other surface opposite to the one surface. Preferably, the half-etched portion may be formed on a surface corresponding to a small surface hole (side surface to be deposited). Accordingly, the half-etched portion can be formed at the same time as the small surface hole, thereby improving process efficiency. In addition, the half-etched portion may disperse the stress that may occur due to the size difference between the large holes.

Alternatively, the half-etched portion may be formed on both sides of the deposition mask in order to disperse the stress of the deposition mask. At this time, the half-etched region of the half-etching portion may be wider in a surface corresponding to the first surface hole (the side of the deposited surface). That is, the deposition mask according to the embodiment may include the half-etching portion as grooves are formed on the first and second surfaces of the deposition mask, respectively. In detail, the depth of the groove of the half-etched portion formed on the first surface may be greater than the depth of the groove of the half-etched portion formed on the second surface. Accordingly, the half-etched portion may disperse the stress that may occur due to the difference in size between the small facet and the large facet. The formation of the small-faced hole, the large-faced hole, and the half-etched portion can make the surface area on the first and second surfaces of the deposition mask similar, thereby preventing distortion of the through hole.

In addition, the grooves formed in the first and second surfaces may be formed to be offset from each other. Through this, the half-etched portion may not penetrate.

The half-etching portion may include a curved surface and a flat surface. The plane of the first half-etching portion HF1 may be disposed adjacent to the first effective portion AA1, and the plane may be disposed horizontally with the longitudinal end of the deposition mask. The curved surface of the first half-etching portion HF1 may be convex toward one end in the longitudinal direction of the deposition mask. For example, the curved surface of the first half-etching portion HF1 may be formed such that a half point of the vertical length of the deposition mask corresponds to a semicircular radius.

The plane of the second half-etching portion HF2 may be disposed adjacent to the third effective portion AA3, and the plane may be disposed horizontally with the longitudinal end of the deposition mask. The curved surface of the second half-etching portion HF2 may be convex toward the other end in the longitudinal direction of the deposition mask. For example, the curved surface of the second half-etching portion HF2 may be formed such that half of the vertical length of the deposition mask corresponds to a semicircular radius.

Meanwhile, the curved surface of the open portion located at both ends of the deposition mask may face the half-etching portion. Accordingly, an open portion located at both ends of the deposition mask may have the shortest separation distance at 1/2 of the vertical length of the first or second half-etching portion and the deposition mask.

Although not illustrated in the drawings, the half-etching portion may have a rectangular shape. The first half-etching part HF1 and the second half-etching part HF2 may have a rectangular or square shape.

The deposition mask according to the embodiment may include a plurality of half-etching portions. The deposition mask according to the embodiment may include a plurality of half-etching regions in at least one of the deposition region DA and the non-deposition region NDA. The deposition mask according to the embodiment may include a half-etching portion only in the non-effective portion UA. The non-effective portion UA may be an area other than the effective portion AA.

The deposition mask according to the embodiment may include two half-etching portions. Although not shown in the drawings, the deposition mask according to the embodiment may include four half-etching parts. For example, the half-etched portion may include an even number of half-etched portions, thereby effectively dispersing stress. The deposition mask according to the embodiment may be disposed only in the non-deposition area NDA.

The half-etched portion is preferably formed to be symmetrical in the X-axis direction or symmetrical in the Y-axis direction based on the center of the mask. Through this, the tensile force in both directions can be uniformly controlled.

The length d1 in the vertical direction of the first half-etching portion HF1 or the second half-etching portion HF2 may correspond to the length d2 in the vertical direction of the open portion. Accordingly, when the deposition mask is stretched, stress can be evenly distributed, thereby reducing the wave deformation of the deposition mask. Therefore, the deposition mask according to the embodiment may have a uniform through hole, and thus the deposition efficiency of the pattern may be improved. Preferably, the length d1 in the vertical direction of the first half-etching part HF1 or the second half-etching part HF2 may be 80 to 200% of the length d2 in the vertical direction of the open part ( d1: d2 = 0.8-2: 1). The length d1 in the vertical direction of the first half-etching part HF1 or the second half-etching part HF2 may be 90 to 150% of the length d2 in the vertical direction of the open part (d1: d2) = 0.9-1.5: 1). The length d1 in the vertical direction of the first half-etching portion HF1 or the second half-etching portion HF2 may be 95 to 110% of the length d2 in the vertical direction of the open portion (d1: d2) = 0.95 ~ 1.1: 1).

The deposition mask may include a plurality of effective portions spaced apart in the longitudinal direction (AA1, AA2, AA3) and non-effective portions (UA) other than the effective portion.

The effective portions AA1, AA2, and AA3 of the deposition mask 100 may include a plurality of through holes TH and an island portion IS supporting between the plurality of through holes. The island portion IS may mean a portion that is not etched when forming a through hole on one side or the other side of the effective portion of the deposition mask. In detail, the island portion IS may be an etched region between the through-hole and the through-hole on the other surface on which the opposite side of the effective portion of the deposition mask is formed. Therefore, the island portion IS may be disposed parallel to one surface of the deposition mask.

The island portion IS may be disposed on the same plane as the other surface of the deposition mask. Accordingly, the island portion IS may have the same thickness as at least a portion of the non-effective portion on the other surface of the deposition mask. In detail, the island portion IS may have the same thickness as the non-etched portion of the non-effective portion on the other surface of the deposition mask. Accordingly, the deposition uniformity of the sub-pixels may be improved through the deposition mask.

Alternatively, the island portion IS may be disposed on a plane parallel to the other surface of the deposition mask. Here, the parallel plane means that the height difference between the other surface of the deposition mask in which the island portion IS is disposed by the etching process around the island portion IS and the other surface of the non-etched deposition mask among the ineffective portions is ± It may contain 1 μm or less.

An island portion IS may be positioned between adjacent through-holes among the plurality of through-holes. That is, regions other than the through-holes in the effective portions AA1, AA2, and AA3 of the deposition mask 100 may be island portions IS.

The effective portion (AA1, AA2, AA3) is a plurality of small surface holes (V1) 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, the small surface It may include a through hole (TH) formed by the communication portion (CA) is connected to the boundary of the ball and the face hole.

The deposition mask 100 may include a non-effective portion (UA) disposed outside the effective portion.

The effective portion AA may be an inner region when connecting the outermost of the through-holes located at the outermost for depositing the organic material among the plurality of through-holes. The ineffective portion UA may be an outer region when connecting the outer portions of the through-holes located on the outermost side for depositing an organic material among the plurality of through-holes.

The non-effective portion UA is an area excluding the effective portion of the deposition area DA and the non-deposition area NDA. The non-effective portion UA may include outer regions OA1, OA2, and OA3 surrounding the outer portions of the effective portions AA1, AA2, and AA3.

The deposition mask according to the embodiment may include a plurality of outer regions (OA1, OA2, OA3). The number of outer regions may correspond to the number of effective portions. That is, one effective portion may include one outer region separated from each other by a predetermined distance in the horizontal and vertical directions from the ends of the effective portion.

The first effective portion AA1 may be included in the first outer region OA1. The first effective portion AA1 may include a plurality of through holes for forming a deposition material. The first outer region OA1 surrounding the outer periphery of the first effective portion AA1 may include a plurality of through holes.

The shape of the through hole TH of the first effective portion AA1 may correspond to the shape of the through hole of the first outer region OA1. Accordingly, uniformity of the through-holes included in the first effective portion AA1 may be improved. For example, the shape of the through hole TH of the first effective portion AA1 and the shape of the through hole of the first outer region OA1 may be circular. However, the embodiment is not limited to this, and the through-holes may have various shapes such as a diamond pattern and an oval pattern.

The plurality of through holes included in the first outer region OA1 is for reducing etching defects of the through holes located at the outermost portion of the effective portion. Accordingly, the deposition mask according to the embodiment can improve the uniformity of a plurality of through-holes located in the effective portion, thereby improving the quality of the deposition pattern produced.

The through hole included in the effective portion may have a shape partially corresponding to the through hole included in the non-effective portion. In some cases, the through-holes included in the effective portion may have different shapes from the through-holes located at the edge portion of the non-effective portion. Accordingly, the difference in stress according to the position of the deposition mask can be adjusted.

The second effective portion AA2 may be included in the second outer region OA2. The second effective portion AA2 may have a shape corresponding to the first effective portion AA1. The second outer region OA2 may have a shape corresponding to the first outer region OA1.

The second outer region OA2 may further include two through holes in a horizontal direction and a vertical direction, respectively, from the through holes located at the outermost portion of the second effective portion AA2. For example, in the second outer area OA2, two through holes may be arranged in a row in the horizontal direction at positions of upper and lower portions of the through holes located at the outermost portions of the second effective portion AA2. For example, in the second outer area OA2, two through holes may be arranged in a vertical direction in the left and right sides of the through hole located at the outermost portion of the second effective portion AA2. The plurality of through holes included in the second outer region OA2 is for reducing etching defects of the through holes located at the outermost portion of the effective portion. Accordingly, the deposition mask according to the embodiment can improve the uniformity of a plurality of through-holes located in the effective portion, thereby improving the quality of the deposition pattern produced.

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

The third effective portion AA3 may have a shape corresponding to the first effective portion AA1. The third outer region OA3 may have a shape corresponding to the first outer region OA1.

Surface roughness measured in the non-deposition area NDA, except for the half-etched portions HF1 and HF2 of the deposition mask according to the embodiment, is approximately in the longitudinal direction (x direction) and the width direction (y direction), and in the longitudinal direction and the width direction. The value in the diagonal direction located at 45 degrees may have a certain range. The diagonal direction may be an inclined direction of about + 45 degrees, or about-45 degrees, and may mean an angle between the x direction and the y direction. The diagonal direction may include an angle between +40 degrees and +50 degrees, or -40 degrees and -50 degrees.

Average centerline average surface roughness in the longitudinal direction of the non-deposition area DA, average centerline average surface roughness in the diagonal about +45 degree direction, average centerline average surface roughness in the diagonal about -45 degree direction and width direction The average centerline average surface roughness is 0.1 µm to 0.3 µm, the average 10-point average surface roughness in the longitudinal direction of the non-deposited area DA, the average 10-point average surface roughness in the diagonal direction about + 45 degrees, and the diagonal about − The average 10-point average surface roughness in the 45 degree direction and the average 10-point average surface roughness in the width direction may be 0.5 μm to 2.0 μm. For example, the average centerline average surface roughness in the longitudinal direction of the non-deposition area DA, the average centerline average surface roughness in the diagonal about +45 degree direction, the average centerline average surface roughness in the diagonal about -45 degree direction, and The average centerline average surface roughness in the width direction is 0.1 µm to 0.2 µm, the average 10-point average surface roughness in the longitudinal direction of the non-deposited area DA, and the average 10-point average surface roughness in the diagonal about +45 degree direction , Diagonal about-The average surface roughness of 10 points in the direction of 45 degrees and the average surface roughness of 10 points in the width direction may be 0.5 µm to 1.5 µm. For example, the average centerline average surface roughness in the longitudinal direction of the non-deposition area DA, the average centerline average surface roughness in the diagonal about +45 degree direction, the average centerline average surface roughness in the diagonal about -45 degree direction, and The average centerline average surface roughness in the width direction is 0.1 μm to 0.15 μm, the average 10-point average surface roughness in the longitudinal direction of the non-deposited area DA, and the average 10-point average surface roughness in the diagonal about +45 degree direction , Diagonal about-The average surface roughness of 10 points in the direction of 45 degrees and the average surface roughness of 10 points in the width direction may be 0.5 µm to 1.0 µm.

In the OLED deposition mask having a QHD-class resolution of 500 PPI or higher in the embodiment, the diameter of the through-holes is 33 μm or less, and the distance between each center of two adjacent through-holes among the plurality of through-holes is 48 μm or less, and the face-to-face hole for the other surface The inclination angle of is 40 to 55 degrees, and the deviation of the average center line average surface roughness (Ra (RD)) value in the longitudinal direction with respect to the average center line average surface roughness (Ra (TD)) in the width direction ((| (Ra (RD) -Ra (TD)) | / Ra (TD) x 100 (%))) is less than 50%, the length for 10-point average surface roughness (Rz (TD)) in the width direction The deviation of the 10-point average surface roughness (Rz (RD)) value in the direction (| (Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) may be less than 50%.

The OLED deposition mask having a UHD-class resolution of 800 PPI or higher in the embodiment has a through hole diameter of 20 µm or less, an inclination angle of a large hole with respect to the other surface of 45 to 55 degrees, and two adjacent through-holes among the plurality of through-holes The distance between each center of the hole is 32 µm or less, and the deviation of the average centerline average surface roughness (Ra (RD)) value in the longitudinal direction from the average centerline average surface roughness (Ra (TD)) in the width direction ( (| (Ra (RD) -Ra (TD)) | / Ra (TD) x 100 (%))) is 30% or less, and the average 10-point average surface roughness (Rz (TD)) in the width direction is Deviation of the average 10-point average surface roughness (Rz (RD)) value in the longitudinal direction for (| (Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) is 30% or less You can. For example, the deviation of the average centerline average surface roughness (Ra (RD)) value in the longitudinal direction from the average centerline average surface roughness (Ra (TD)) in the width direction ((| (Ra (RD)- Ra (TD)) | / Ra (TD) x 100 (%))) is 15% or less, average 10 points in the width direction average 10 in the length direction to the average surface roughness (Rz (TD)) The deviation of the point average surface roughness (Rz (RD)) value (| (Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) may be 15% or less.

For example, the deviation of the average centerline average surface roughness (Ra (RD)) value in the longitudinal direction from the average centerline average surface roughness (Ra (TD)) in the width direction ((| (Ra (RD)- Ra (TD)) | / Ra (TD) x 100 (%))) is 13% or less, average 10 points in the width direction average 10 in the length direction to the average surface roughness (Rz (TD)) The deviation of the point average surface roughness (Rz (RD)) value (| (Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) may be 10% or less.

The vapor deposition region includes an ineffective portion in an area other than the effective portion, and the surface roughness of the island portion among the ineffective portions includes an average centerline average surface roughness in the longitudinal direction, an average centerline average surface roughness in the diagonal direction, and a width direction. The average centerline average surface roughness is 0.1 μm to 0.3 μm, the average 10-point average surface roughness in the longitudinal direction, the average centerline average surface roughness in the diagonal direction, and the average 10-point average surface roughness in the width direction is 0.5 μm to 2.0 Deviation ((| (Ra (RD) -Ra) of the average centerline average surface roughness (Ra (RD)) value in the longitudinal direction with respect to the average centerline average surface roughness (Ra (TD)) in the width direction (TD)) | / Ra (TD) x 100 (%))) is less than 50%, average 10 points in the width direction average 10 points in the length direction to the average surface roughness (Rz (TD)) Deviation of the average surface roughness (Rz (RD)) value (| (Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) may be less than 50%.

Alternatively, the surface roughness of the island portion of the non-effective portion is 0.1 μm to 0.2 μm, and the average center line average surface roughness in the longitudinal direction, the average center line average surface roughness in the diagonal direction, and the average center line average surface roughness in the width direction are 0.1 μm to 0.2 μm. The average 10-point average surface roughness to, the average centerline average surface roughness in the diagonal direction, and the average 10-point average surface roughness in the width direction are 0.5 μm to 1.5 μm, and the average centerline average surface roughness in the width direction (Ra Deviation of the average centerline average surface roughness (Ra (RD)) value in the longitudinal direction for (TD)) ((| (Ra (RD) -Ra (TD)) | / Ra (TD) x 100 (%) )) Is less than 30%, and the deviation of the average 10-point average surface roughness (Rz (RD)) value in the longitudinal direction from the average 10-point average surface roughness (Rz (TD)) in the width direction (| ( Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) may be less than 30%.

Alternatively, the surface roughness of the island portion among the non-effective portions is 0.1 μm to 0.15 μm, and the average centerline average surface roughness in the longitudinal direction, the average centerline average surface roughness in the diagonal direction, and the average centerline average surface roughness in the width direction are 0.1 μm to 0.15 μm. The average 10-point average surface roughness to, the average centerline average surface roughness in the diagonal direction, and the average 10-point average surface roughness in the width direction are 0.5 μm to 1.0 μm, and the average centerline average surface roughness in the width direction (Ra Deviation of the average centerline average surface roughness (Ra (RD)) value in the longitudinal direction for (TD)) ((| (Ra (RD) -Ra (TD)) | / Ra (TD) x 100 (%) )) Is less than 15%, and the deviation of the average 10-point average surface roughness (Rz (RD)) value in the longitudinal direction from the average 10-point average surface roughness (Rz (TD)) in the width direction (| ( Rz (RD) -Rz (TD)) | / Rz (TD) x 100 (%)) may be less than 15%.

The separation regions IA1 and IA2 located between adjacent effective regions AA1, AA2, and AA3 have average centerline average surface roughness in the longitudinal direction, average centerline average surface roughness in the diagonal direction, and average centerline average surface roughness in the width direction. Is 0.1 µm to 0.3 µm, the average 10-point average surface roughness in the longitudinal direction of the ineffective portion, the average 10-point average surface roughness in the diagonal direction, and the average 10-point average surface roughness in the width direction from 0.5 µm to 2.0 Μm.

6A, 6B, and 7 are diagrams and photographs showing plan views of an effective portion of a deposition mask. 6A, 6B, and 7 are plan views or photographs of any one of the first effective portion AA1, the second effective portion AA2, and the third effective portion AA3. 6A, 6B, and 7 are for explaining the shape of the silver through hole and the arrangement between the through holes, and the deposition mask according to the embodiment is not limited to the number of through holes in the drawing.

6A and 6B, the deposition mask 100 may include a plurality of through holes. The plurality of through holes may have a circular shape. Accordingly, the horizontal diameter Cx and the vertical diameter Cy of the through-holes may correspond to each other.

Alternatively, referring to FIG. 7, it may have an elliptical shape. Accordingly, the horizontal diameter Cx of the through-hole and the vertical diameter Cy of the through-hole may be different. For example, the diameter Cx in the horizontal direction of the through-hole may be larger than the diameter Cy in the vertical direction. However, the embodiment is not limited to this, and the through-hole may have a rectangular shape, an octagonal shape, or a rounded octagonal shape. As an example, when measuring a horizontal diameter (Cx) and a vertical diameter (Cy) of a reference hole as any one through hole, each horizontal diameter (Cx) between holes adjacent to the reference hole The deviation between them and the deviation between the diameters Cy in the vertical direction may be implemented in 2% to 10%. That is, when the size variation between adjacent holes of one reference hole is 2% to 10%, uniformity of deposition can be secured. The size difference between the reference hole and the adjacent holes may be 4% to 9%. For example, the size deviation between the reference hole and the adjacent holes may be 5% to 7%. For example, the size deviation between the reference hole and the adjacent holes may be 2% to 5%. If the size difference between the reference hole and the adjacent holes is less than 2%, the moire generation rate in the OLED panel after deposition may be increased. When the size difference between the reference hole and the adjacent holes exceeds 10%, the incidence of color unevenness in the OLED panel after deposition may be increased. The average deviation of the through hole diameter may be ± 5㎛. For example, the average deviation of the through hole diameter may be ± 3 μm. For example, the average deviation of the through-hole diameter may be ± 1 μm. According to an embodiment, as the size variation between the reference hole and the adjacent holes is implemented within ± 3 μm, deposition efficiency may be improved.

The through holes may be arranged in a line or staggered with each other depending on the direction. 6A and 6B, the through-holes may be arranged in a line in the vertical axis and may be arranged in a line in the horizontal axis.

The first through hole TH1 and the second through hole TH2 may be arranged in a line on the horizontal axis. In addition, the third through hole TH1 and the fourth through hole TH4 may be arranged in a line on the horizontal axis.

The first through hole TH1 and the third through hole TH3 may be arranged in a line at the vertical axis. Also, the second through hole TH2 and the fourth through hole TH4 may be arranged in a line on the horizontal axis.

When the through-holes are arranged in a line in the vertical axis and the horizontal axis, the island portion may be located between two adjacent through-holes in diagonal directions, which are directions that intersect both the vertical axis and the horizontal axis. That is, an island portion may be located between two adjacent through holes located diagonally to each other.

An island portion IS may be disposed between the first through hole TH1 and the fourth through hole TH4. Also, an island portion IS may be disposed between the second through hole TH2 and the third through hole TH3. Island portions (IS) may be located in a diagonal direction of about +45 degrees around and a diagonal direction of about -45 degrees around the horizontal axis traversing two adjacent through holes. Here, the diagonal direction of about ± 45 may mean a diagonal direction between the horizontal axis and the vertical axis, and the diagonal angle in the diagonal direction may be measured in the same plane of the horizontal axis and the vertical axis.

Referring to FIG. 7, the through-holes may be arranged in a line on either the vertical axis or the horizontal axis, and may be alternately arranged on the other axis.

The first through hole TH1 and the second through hole TH2 may be arranged in a line on the horizontal axis. The third through hole TH1 and the fourth through hole TH4 may be arranged to be staggered from the vertical axis of the first through hole TH1 and the second through hole TH2, respectively.

If the through-holes are arranged in a line in either the longitudinal or transverse axis, and are alternately arranged in the other direction, the island portion may be positioned between two adjacent through-holes in the other direction of the longitudinal or transverse axis. have. Alternatively, an island portion may be located between three through holes positioned adjacent to each other. Of the three adjacent through-holes, two through-holes are arranged in a line, and the other through-hole may be disposed in an area between the two through-holes at adjacent positions in a direction corresponding to the line-direction. It may mean a through hole. An island portion IS may be disposed between the first through hole TH1, the second through hole TH2, and the third through hole TH3. Alternatively, the island portion IS may be disposed between the second through hole TH2, the third through hole TH3, and the fourth through hole TH4.

The island portion IS of FIGS. 6A, 6B, and 7 may mean an unetched surface between through holes on the other surface of the deposition mask in which a large hole of the effective portion AA is formed. In detail, the island portion IS may be the other side of the etched deposition mask excluding the second inner surface ES2 and the through hole TH located in the large hole in the effective portion AA of the deposition mask. The deposition mask of the embodiment may be for high-resolution to ultra-high resolution OLED pixel deposition with a resolution of 500 PPI to 800 PPI or more.

For example, the deposition mask of the embodiment may be for forming a deposition pattern having a high resolution of QHD (Quad High Definition) having a resolution of 500 PPI or more. For example, the deposition mask of the embodiment may be for depositing an OLED pixel in which the number of pixels in the horizontal direction and the vertical direction is 2560 * 1440 or more and 530 PPI or more. Through the deposition mask of the embodiment, the number of pixels per inch may be 530 PPI or more based on a 5.5 inch OLED panel. That is, one effective part included in the deposition mask of the embodiment may be for forming a number of pixels having a resolution of 2560 * 1440 or more.

For example, the deposition mask of the embodiment may be for forming a deposition pattern having ultra-high resolution of UHD (Ultra High Definition) having a resolution of 700 PPI or more. For example, the deposition mask of the embodiment has a deposition pattern having an Ultra High Definition (UHD) level resolution for depositing OLED pixels having a pixel count in the horizontal direction and a vertical direction of 3840 * 2160 or more, and 794 PPI (800PPI level) or more. It may be to form.

The diameter of one through hole may be a width between the communication parts CA. In detail, the diameter of one through hole can be measured at the point where the end of the inner surface in the small face hole meets the end of the inner surface in the large face hole. The measuring direction of the diameter of the through hole may be any one of a horizontal direction, a vertical direction, and a diagonal direction. The diameter of the through hole measured in the horizontal direction may be 42 μm or less. Alternatively, the diameter of the through hole measured in the horizontal direction may be 42 μm or less. Alternatively, the diameter of the through hole may be an average value of values measured in horizontal, vertical, and diagonal directions, respectively.

Accordingly, the deposition mask according to the embodiment may implement QHD-level resolution.

For example, the diameter of the through hole in the horizontal direction may be 20 μm or less. Accordingly, the deposition mask according to the embodiment may implement UHD-level resolution.

For example, the diameter of the through hole may be 15 μm to 33 μm. For example, the diameter of the through hole may be 19 μm to 33 μm. For example, the diameter of the through hole may be 20 μm to 17 μm. When the diameter of the through hole is greater than 33 μm, it may be difficult to realize a resolution of 500 PPI or higher. On the other hand, when the diameter of the through hole is less than 15 μm, deposition failure may occur. That is, the diameter of the through hole may vary depending on the resolution of the deposition mask.

The diameter of the through hole can be measured based on the green (G) pattern. This is because, among the R, G, and B patterns, the G pattern has a lower recognition rate through time, and thus a larger number is required than the R and B patterns, and the distance between the through holes may be narrower than the R and B patterns.

The measuring direction of the diameter of the through hole and the measuring direction of the gap between the two through holes may be the same. The gap between the through holes may be a measure of a gap between two adjacent through holes in a horizontal direction or a vertical direction.

6A and 56, a pitch between two adjacent through-holes among a plurality of through-holes in the horizontal direction may be 48 μm or less. For example, a pitch between two adjacent through-holes among a plurality of through-holes in the horizontal direction may be 20 μm to 48 μm. For example, a pitch between two adjacent through-holes among a plurality of through-holes in the horizontal direction may be 30 μm to 35 μm.

Here, the gap may mean a gap P1 between the center of two adjacent first through holes TH1 and the center of the second through holes TH2 in the horizontal direction.

Alternatively, here, the gap may mean a gap P2 between the center of two adjacent first island portions and the center of the second island portions in the horizontal direction. Here, the center of the island portion may be a center on an etched other surface between four adjacent through holes in the horizontal and vertical directions. For example, the center of the island portion is based on two first through holes TH1 and second through holes TH2 adjacent in the horizontal direction, and a third through hole adjacent to the first through hole TH1 in the vertical direction. A point at which the horizontal axis connecting the edges of one island portion IS and the vertical axis connecting the edges intersect in the region between the TH3 and the second through hole TH2 and the adjacent fourth through hole TH4 in the vertical direction. Can mean

Alternatively, here, the gap may mean a distance P2 between the center of the first island portion between the three adjacent through-holes in the horizontal direction and the center of the second island portion adjacent to the first island portion.

Referring to FIG. 7, the distance P2 between the centers of two adjacent first island portions and the center of the second island portions may be referred to in the horizontal direction. Here, the center of the island portion may be a center on an etched other surface between one through hole and two adjacent through holes in a vertical direction. Or, here, the center of the island portion may be the center on the other side that is not etched between two through holes and one adjacent through hole in the vertical direction. That is, the center of the island portion is the center on the other side that is not etched between the three adjacent through-holes, and the three adjacent through-holes may mean that a triangular shape can be formed when the center is the center.

For example, the center of the island portion may include two first through holes TH1 and second through holes TH2 adjacent to each other in the horizontal direction, and the first through holes TH1 and the second through holes TH2, respectively. It may be a center on the other side that is not etched between the third through holes TH3 in which at least some or all of the regions are located in a region between vertical directions.

As the deposition mask according to the embodiment has a through-hole diameter of 33 µm or less and a gap between the through-holes of 48 µm or less, an OLED pixel having a resolution of 500 PPI or more can be deposited. That is, QHD-level resolution may be implemented using a deposition mask according to an embodiment.

The diameter of the through hole and the distance between the through holes may be sized to form a green sub-pixel. The deposition mask may be an OLED deposition mask for realizing quad high display pixels.

For example, the deposition mask may be for depositing at least one sub-pixel of red (R), first green (G1), blue (B), and second green (G2). In detail, the deposition mask may be for depositing red (R) sub-pixels. Alternatively, the deposition mask may be for depositing a blue (B) sub-pixel. Alternatively, the deposition mask may be for simultaneously forming a first green (G1) subpixel and a second green (G2) subpixel.

The pixel arrangement of the organic light emitting diode display may be arranged in the order of 'Red (R)-first green (G1)-blue (B)-second green (G2)' (RGBG). 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 that of the red light-emitting organic material and the blue light-emitting organic material, a deposition mask of the same type as the present invention may be required.

The deposition mask according to the embodiment may deposit an OLED pixel having a resolution of 800 PPI as the diameter of the through hole is 20 μm or less and the distance between the through holes is 32 μm or less. That is, a UHD-level resolution may be implemented using a deposition mask according to an embodiment.

The diameter of the through hole and the distance between the through holes may be sized to form a green sub-pixel. The deposition mask may be an OLED deposition mask for implementing ultra high display pixels.

6C and 6B, cross-sections in the A-A 'direction and cross-sections in the B-B' direction will be described, respectively.

6C is a cross-section of each of the cross-sections in order to explain the height difference and size between the cross-section in the A-A 'direction and the cross-section in the B-B' direction of FIGS. 6A and 6B.

First, the cross section in the A-A 'direction of FIGS. 6A and 6B will be described. The A-A 'direction is a cross section transverse to a central region between two first through holes TH1 and third through holes TH3 adjacent in the vertical direction. That is, the cross section in the A-A 'direction may not include a through hole.

In the cross-section in the A-A 'direction, an island portion IS, which is the other surface of the deposition mask that is not etched, may be located between the inner surface ES2 in the large hole and the inner surface ES2 in the large hole. Accordingly, the island portion IS may include a surface parallel to an unetched surface of the deposition mask. Alternatively, the island portion IS may include a surface that is the same as or parallel to the other surface of the deposition mask.

Next, the cross section in the B-B 'direction of FIGS. 6A and 6B will be described. The B-B 'direction is a cross section crossing the center of each of the two first through holes TH1 and the second through holes TH2 adjacent in the horizontal direction. That is, the cross section in the B-B 'direction may include a plurality of through holes.

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

In the cross-section in the B-B 'direction, an inner surface ES2 in the face hole and a rib RB, which is an area where the inner face ES2 in the adjacent face hole connect to each other, may be located. Here, the rib (RB) may be an area in which the boundary between two adjacent large holes is connected. Since the rib RB is a surface formed by etching, thickness may be smaller than that of the island portion IS.

For example, the width of the island portion may be 2um or more. That is, a width in a direction parallel to the other surface of the portion remaining without being etched on the other surface may be 2 μm or less. When the width of one island portion is 2 μm or more, the total volume of the deposition mask can be increased. The mask for deposition of such a structure is to ensure sufficient stiffness against the tensile force applied in the organic material deposition process, etc., it may be advantageous to maintain the uniformity of the through hole.

Hereinafter, with reference to FIGS. 8 and 9, a cross section of an enlarged through hole between ribs RB and ribs of an effective area according to an embodiment of the present invention will be described.

8 is a view showing a through hole after a wet etching process according to an embodiment of the present invention, Figure 9 is a view showing a through hole after an electropolishing process according to an embodiment of the present invention.

In general, the surface roughness refers to the degree of fine irregularities occurring on the metal surface when processing the metal surface. Surface roughness is caused by tools used for processing, suitability of processing methods, scratches and rust on the surface. A statistical value indicating the degree of surface roughness is called a roughness parameter. The roughness parameters include Ra (center line average value), Rmax (Rt-maximum roughness), Rz (10 point average roughness), and Rq (square mean roughness, RMS).

The Ra (center line average value) uses Ra, AA, or CLA as a symbol of the center line average value for surface roughness, and means the average roughness, the arithmentic average, and the center line average, respectively. It includes. The value of Ra is obtained as the average within the reference length of absolute values of the length from the center line to the cross-section curve of the surface.

Rmax (Rt, maximum roughness) means maximum peak to maximum roughness height, and Rmax or Rt is used as its symbol. This refers to the distance between two parallel lines that are taken by the reference length from the roughness cross-section curve, parallel to the center line of the cross-section curve, and which contact the highest mountain and the deepest valley.

Rz is the ten point height. This is obtained by taking a reference length from the roughness cross-section curve, drawing an arbitrary straight line (base line) parallel to the average line of the cross-section curve, and plotting the average value of the distances from the highest five mountain baselines and the distance from the lowest five goal baselines. It is expressed as the difference from the average value. (See picture below)

Rq is a parameter having a similar meaning to the square mean roughness Ra, but the calculation method is slightly different. Ra is the arithmetic mean, which is obtained by using the general mean method, but Rq is obtained by using the root-mean-square (RMS) method. That is, Rq is an RMS value of roughness.

Hereinafter, provided average surface roughness (Rq, RMS) was used as a roughness parameter for the first inner surface of the small face hole including the through hole and the second inner face of the large face hole.

On the other hand, after the wet etching process in the present invention and before the electrolytic polishing process, the deposition mask has a thickness as shown in FIG. 8 and is orthogonal to the thickness direction and faces each other 101 and the other surface 102. It is provided with a metal plate having a), penetrating the one surface 101 and the other surface 102, and comprises a plurality of unit holes having small face holes (V1) and face holes (V2) communicating with each other. In this case, the small surface hole V1 and the large surface hole V2 communicate with each other by sharing the communication portion CA, which is a boundary portion communicating with each other. Such through-holes may be implemented in a structure in which a plurality of through holes are provided.

At this time, the third squared average surface roughness (RMS3) of the one surface 101 or the other surface 102 after the wet etching process implemented in the deposition mask in the present invention is the first squared average surface roughness of the small face hole V1 ( RMS1) or the second square mean surface roughness (RMS2) of the large hole V2 may be formed to have a smaller value (RMS3 ≤ RMS1 or RMS2). This is because the wet etching process is performed by an etchant such as iron chloride, and the squared average surface roughness (RMS1, RMS2) of the inner surface of the through hole increases due to the properties of the etchant.

In addition, the second squared average surface roughness RMS2 of the second inner surface ES2, which is the inner surface of the large hole V2, is the first of the first inner surface ES1, which is the inner surface of the small surface hole V1. It may be formed to have a value less than or equal to the squared average surface roughness (RMS1). [RMS2 ≤ RMS1] Preferably, the etching process for the large-surface hole V2 and the small-surface hole V1 will be performed under the same conditions except for the etching time. Accordingly, the first squared average surface roughness (RMS1) and the second squared average surface roughness (RMS2) may have similar levels to each other. Preferably, the second squared average surface roughness RMS2 of the second inner surface ES2 may be implemented as 95% to 99% of the first squared average surface roughness RMS1 of the first inner surface ES1. have. For example, each of the first square average surface roughness (RMS1) and the second square average surface roughness (RMS2) may have a square average surface roughness (RMS) of 200 nm or more. For example, the first square mean surface roughness (RMS1) and the second square mean surface roughness (RMS2) may each have a mean square surface roughness (RMS) in the range of 150 nm to 200 nm.

In addition, the cross-sectional inclination angle θ1 of the first inner surface ES1, which is the inner surface of the small surface hole V1, may be formed to be 75 ° or less. Preferably, the cross-sectional inclination angle θ1 of the first inner surface ES1, which is the inner surface of the small surface hole V1, may satisfy a range between 60 and 70 °. At this time, the cross-section inclination angle θ1 is an imaginary straight line L1 connecting one end C1 of the small face hole V1 and one end A1 of the communication part CA, and one surface of the deposition mask ( 101). That is, the cross-sectional inclination angle θ1 of the first inner surface ES1, which is the inner surface of the small surface hole V1, may be formed up to 75 °.

In addition, the relationship ratio between the diameter (A) of the communication portion (CA) and the diameter (C) of the small face hole (V1) may be implemented to have a range that satisfies 1: (1.2 to 1.3). That is, the diameter A of the communication portion CA may be smaller than the diameter C of the small face hole V1. Preferably, the difference between the diameter (A) of the base communication portion (CA) and the diameter (C) of the small hole V1 may be 3 μm or more. The diameter A of the communication portion CA may mean a width between both ends A1 and A2 of the communication portion CA corresponding to an imaginary straight line passing through the center of the communication portion CA. In addition, the diameter (C) of the small surface hole (V1), on one surface 101 of the deposition mask, both ends of the small surface hole (V1) corresponding to a virtual straight line passing through the center of the small surface hole (V1) ( C1, C2).

As described above, each inner surface of the small face hole V1 and the large face hole V2 after the wet etching process has a square average surface roughness (RMS) of 150 nm or more. In this case, when the squared average surface roughness (RMS) of the inner surface has 150 nm or more as described above, there is a problem in that the cleaning property is deteriorated due to the influence of the surface roughness during the subsequent cleaning process of the deposition source. In addition, the cross-sectional inclination angle of the small surface hole V1 after the wet etching process may be formed up to 75 degrees as described above. However, when the cross-sectional inclination angle of the small surface hole V1 is formed at a level of 75 degrees as described above, the shadow effect cannot be completely removed, and thus the deposition efficiency is reduced.

Therefore, in the present invention, after the wet etching process, an additional electrolytic polishing process is performed to perform a square mean of the first inner surface ES1 of the small face hole V1 and the second inner face ES2 of the large face hole V2. It is possible to adjust the surface roughness (RMS). In addition, in the present invention, by performing the electropolishing process, it is possible to form a cross-sectional inclination angle of the small surface hole (V1) to a level of 75 degrees or more.

9 shows a through hole finally formed after the electropolishing process according to an embodiment of the present invention.

Hereinafter, a cross section of B-B 'of FIGS. 6A and 6B and a cross section of the rib RB of the effective area according to FIG. 6C and a through hole between the ribs are enlarged with reference to FIG. 9. In the deposition mask of the embodiment, the thickness in the effective portion AA in which the through-holes are formed by the etching and electropolishing process and the thickness in the non-etched non-effective portion UA may be different. In detail, the thickness of the ribs RB may be smaller than the thickness in the non-etched non-effective portion UA.

In the deposition mask of the embodiment, the thickness of the non-effective portion may be greater than that of the effective portion. For example, in the deposition mask of the embodiment, the maximum thickness of the non-effective portion to the non-deposited region may be 30 μm or less. For example, the deposition mask of the embodiment may have a maximum thickness of 25 μm or less in the non-effective area to the non-deposition area. For example, in the deposition mask of the embodiment, the maximum thickness of the non-effective portion to the non-deposited region may be 15 μm to 25 μm. When the maximum thickness of the ineffective region to the non-deposited region of the deposition mask according to the embodiment is greater than 30 μm, it may be difficult to form a through hole having a fine size because the thickness of the metal plate material is thick. When the maximum thickness of the ineffective region to the non-deposited region of the deposition mask according to the embodiment is less than 15 μm, it may be difficult to form a through hole having a uniform size because the thickness of the metal plate material is thin.

On the other hand, the through hole of the deposition mask may be implemented to have a depth in the thickness direction of the metal plate of the small hole V1 and a depth in the thickness direction of the metal plate of the large hole V2.

That is, the depth (b) from the small surface hole (V1) to the communication portion (CA) may be implemented to be smaller than the depth (a) from the large surface hole (V2) to the communication portion (CA). In addition, the depth (a) of the small surface hole (V1) as a whole may be implemented to have a range in which the relationship ratio with the total thickness (c) of the metal plate satisfies 1: (3 to 30). That is, the depth (a) of the small hole V1 may act as an important factor that can control the thickness of the deposition. At this time, when the depth (a) of the small surface hole (V1) becomes too deep to exceed the ratio range of the above-described thickness in relation to the thickness (c) of the entire substrate, the thickness change of the organic material becomes large. Areas where deposition is not possible may occur. In addition, the area where the deposition is not performed decreases the area of the organic material in the entire OLED, thereby acting as a cause of reducing the life.

Therefore, the ratio of the depth (a) of the small surface hole (V1) and the thickness (c) of the metal plate may satisfy 1: (3.5 to 12.5) within the aforementioned range. More preferably, it can be implemented to satisfy a ratio of 1: (4.5 to 10.5). In an embodiment of the present invention, the thickness (c) of the metal plate satisfying this ratio range may be implemented as 10 μm to 50 μm. When the thickness of the metal plate is less than 10 µm, the degree of twisting of the substrate increases, so process control is difficult, and when the thickness of the substrate exceeds 50 µm, the generation of a dead space during subsequent deposition increases, resulting in OLED. It is not possible to implement a fine pattern of. In particular, within the above range, the thickness (c) of the above-described substrate may be implemented to satisfy a thickness of 15 μm to 40 μm. Furthermore, more preferably, it can be implemented in 20㎛ ~ 30㎛.

In addition, the depth (a) of the small surface hole (V1) corresponding to the thickness (c) of the metal plate is preferably implemented to meet the range of 0.1㎛ ~ 7㎛. This is difficult to implement a groove when the depth (a) of the small hole V1 is less than 0.1 μm, and when the depth (a) of the small hole V1 exceeds 7 μm, it is not deposited later. Due to the deposition space (Dead Space), it is difficult to form an OLED fine pattern, and the area of the organic material is reduced, which causes a decrease in OLED life. In particular, the depth (a) of the small face hole V1 may be implemented in a depth range within the above range from 1 μm to 6 μm, and more preferably from 2 μm to 4.5 μm.

Meanwhile, the maximum thickness measured at the center of the rib (RB) among the thicknesses of each region of the deposition mask may be 15 μm or less. For example, the maximum thickness measured at the center of the rib (RB) may be 7㎛ to 10㎛. For example, the maximum thickness measured at the center of the rib may be 6 μm to 9 μm. When the maximum thickness measured at the center of the rib (RB) is more than 15㎛, it may be difficult to form an OLED deposition pattern having a high resolution of 500 PPI or higher. If the maximum thickness measured at the center of the rib (RB) is less than 6㎛, uniform formation of the deposition pattern may be difficult.

In addition, the depth (a) of the small face hole V1 of the deposition mask may be 0.2 to 0.4 times the maximum thickness measured at the center of the rib RB. In one example, the maximum thickness measured at the center of the rib (RB) is 7㎛ to 9㎛, the depth (a) between the one surface of the small hole V1 of the deposition mask and the communication portion is 1.4㎛ to 3 Μm. The depth (a) of the small surface hole of the deposition mask may be 3.5 μm or less. For example, the depth of the small hole may be 0.1 μm to 3.2 μm. For example, the depth of the small hole of the deposition mask may be 0.5 μm to 3.5 μm. For example, the depth of the small surface hole of the deposition mask may be 2 μm to 3.2 μm. Here, the depth may be measured in the thickness measurement direction of the deposition mask, that is, in the depth direction, and may be a measurement of the height from one surface of the deposition mask to the communicating portion. In detail, the horizontal direction (x direction) and the vertical direction (y direction) described above in the plan view of FIG. 5 or 6 may be measured in the z-axis direction forming 90 degrees.

When the height between the one surface of the deposition mask and the communication portion is more than 3.5 µm, deposition defects may occur due to a shadow effect in which the deposition material spreads to a region larger than the area of the through-hole during OLED deposition.

The diameter (C ′) at one side where the small face hole (V1) of the deposition mask is formed and the diameter (A`) at the communication portion which is the boundary between the small face hole (V1) and the large face hole (V2) are similar to each other or can be different. The diameter C1 on one surface where the small face hole V1 of the deposition mask is formed may be larger than the diameter A` in the communication portion.

For example, the difference between the diameter (C`) of the small surface hole (V1) on one surface of the deposition mask and the diameter (A1) in the communication portion may be 0.01 μm to 1.1 μm. For example, the difference between the diameter (C`) of the small surface hole (V1) on one surface of the deposition mask and the diameter (A`) in the communication portion may be 0.03㎛ to 1.1㎛. For example, the difference between the diameter (C`) of the small surface hole (V1) on one surface of the deposition mask and the diameter (A`) in the communication portion may be 0.05 μm to 1.1 μm.

When the difference between the diameter (C`) of the small face hole (V1) on one surface of the deposition mask and the diameter (A`) in the communication portion is greater than 1.1 μm, deposition defects due to a shadow effect may occur.

At this time, the difference between the diameter of the small surface hole V1 and the diameter of the communicating portion CA was 3 μm or more before the electropolishing process proceeded. However, in the present invention, the electropolishing process is further performed on the first inner surface ES1 of the small face hole V1 and the second inner face ES2 of the large face hole V2 as described above. Accordingly, the inner surface around the communication portion CA is additionally removed. And, as the inner surface around the communication portion CA is further removed, the difference between the diameter C` of the small face hole V1 and the diameter A` at the communication portion may be smaller than 1.1 μm. . Preferably, the relationship ratio between the diameter (A`) of the communicating portion (CA) and the diameter (C`) of the small face hole (V1) may be implemented to have a range that satisfies 1: (1.01 to 1.2). . Preferably, the relationship ratio between the diameter (A`) of the communication portion (CA) and the diameter (C`) of the small face hole (V1) may be implemented to have a range that satisfies 1: (1.05 ~ 1.1). .

The inclination angle θ2 of the small surface hole measured on one surface of the deposition mask may be 89 degrees or less. The inclination angle of the small surface hole may mean that measured by a rib (RB). Between one end (C1`) of the small surface hole located on one surface 101 of the deposition mask and one end (A1`) of the communication portion between the small surface hole and the large surface hole between the virtual straight line L2 and the one surface 101 The inclination angle (θ2) of the cross section of the small surface hole V1, which is the internal angle of the may be 89 degrees or less. For example, a cross-sectional inclination angle (θ2) of the small surface hole V1 connecting one end (C1`) of the small surface hole and one end (A1`) of the communicating portion between the small surface hole and the large surface hole located on one surface of the deposition mask May be 75 degrees to 89 degrees. For example, a cross-sectional inclination angle (θ2) of the small surface hole V1 connecting one end (C1`) of the small surface hole and one end (A1`) of the communicating portion between the small surface hole and the large surface hole located on one surface of the deposition mask May be 78 degrees to 89 degrees. For example, a cross-sectional inclination angle (θ2) of the small surface hole V1 connecting one end (C1`) of the small surface hole and one end (A1`) of the communicating portion between the small surface hole and the large surface hole located on one surface of the deposition mask May be 85 degrees to 89 degrees.

When the cross-sectional inclination angle of the small surface hole (V1) connecting one end (C1`) of the small surface hole located on one surface of the deposition mask and one end (A1`) of the communication portion between the small surface hole and the large surface hole is greater than 89 degrees, Although the shadow effect can be prevented, a problem in which organic matter remains in the through hole during deposition may occur. Accordingly, it may be difficult to form a deposition pattern having a uniform size.

When the inclination angle of the cross section of the small face hole (V1) connecting one end (C1`) of the small face hole located on one surface of the deposition mask and the one end (A1`) of the communicating portion between the small face hole and the large face hole is less than 70 degrees, the shadow Deposition defects may occur due to effects.

That is, the sectional angle of inclination between the virtual straight line connecting the one end of the small surface hole V1 and the one end of the communication portion CA before the electrolytic polishing process and the one surface 101 was at a maximum of 75 degrees.

However, in the present invention, the electrolytic polishing process is further performed as described above to further remove the first inner surface ES1 of the small face hole V1 and the second inner face ES2 of the large face hole V2. The process proceeds. Accordingly, the communication portion CA, which is a boundary surface between the first inner surface ES1 and the second inner surface ES2, is processed in a gentle round shape, and accordingly, the inclined cross-section angle of the small surface hole V1 is Can increase.

This is because an additional inflection point IP is formed on the first inner surface ES1 of the small face hole V1 and the second inner face ES2 of the large face hole V2 by the electrolytic polishing process.

That is, each of the small hole V1 and the large hole V2 of the through-hole, which has undergone only the wet etching process, has a constant curvature around the communication portion CA. The small surface hole V1 in which only the wet etching process is performed has a first curvature corresponding to the first etching factor. At this time, between the one end (A1) of the small surface hole (V1) constituting the small surface hole (V1) and one end of the communication portion (CA) has a constant curvature without an inflection point. The face hole V2 in which only the wet etching process is performed has a second curvature corresponding to the second etching factor. At this time, between the one end (B1) of the face hole (V2) constituting the face hole (V2) and one end of the communication portion (CA) has a constant curvature without an inflection point.

 At this time, when an additional electrolytic polishing process is performed for the through hole, the first inner surface ES1 of the small face hole V1 and the second inner side surface ES2 of the large face hole V2 are additionally removed. Accordingly, the communication portion CA communicating the small face hole V1 and the large face hole V2 has a gentle round shape curvature different from the conventional one.

In other words, the small surface hole V1 has a first inflection point IP1 between one end C2` of the small surface hole V1 corresponding to the one surface 101 and one end A2` of the communication portion CA. ) Is formed. Accordingly, the first inner surface ES1 of the small face hole V1 is a first sub-first inner surface between one end C2` corresponding to the one surface 101 and the first inflection point IP1. And a second sub-first inner surface between the first inflection point IP1 and the communication portion CA.

Likewise, the face hole V2 has a second inflection point IP2 between one end B2 of the face hole V2 corresponding to the other surface 102 and one end A2` of the communication portion CA. Is formed. Accordingly, the second inner surface ES2 of the face hole V2 includes a first sub-second inner surface between one end B2 corresponding to the other surface 102 and the second inflection point IP2, And a second sub-second inner surface between the second inflection point IP2 and the communication portion CA.

At this time, the first sub-first inner surface has a first curvature, and the second sub-first inner surface and the second sub-second inner surface have one different second curvature, and the first sub-second The inner surface may have another third curvature.

Accordingly, in the present invention, as the inner surface of the through-hole is additionally removed as described above, an additional curvature in the form of a smooth round may be formed around the communication portion CA, and accordingly, the small-sided hole V1 may be formed. The angle of inclination of the section can be increased.

On the other hand, the cross-sectional inclination angle of the large hole V2 may be 55 degrees or less. The imaginary straight line connecting one end (B1) of the face hole (V2) and one end (A1`) of the connecting portion between the small face hole and the face hole, and the face corresponding to the cabinet between the other face (102) of the deposition mask The cross-sectional inclination angle of the ball V2 may be 40 to 55 degrees. Accordingly, it is possible to form a high-resolution deposition pattern of 500 PPI or higher, and at the same time, an island portion may exist on the other surface of the deposition mask.

The imaginary straight line connecting one end (B1) of the face hole (V2) and one end (A1`) of the connecting portion between the small face hole and the face hole, and the face corresponding to the cabinet between the other face (102) of the deposition mask The cross-sectional inclination angle of the ball V2 may be 45 degrees to 55 degrees. Accordingly, it is possible to form a high-resolution deposition pattern of 800 PPI or higher, and at the same time, island portions may be present on the other surface of the deposition mask.

10 is a view comparing the square mean surface roughness of the inner surface of the through-hole of the embodiment of the present invention and the comparative example.

Referring to FIG. 10, the third squared average surface roughness (RMS3) of one surface 101 or the other surface 102 after the electrolytic polishing process in the present invention is the first inner surface ES1 of the small surface hole V1. It can be formed to have a larger value than the 1st mean surface roughness (RMS1`) or the 2nd mean surface roughness (RMS2`) of the second inner surface ES2 of the large hole V2 [RMS1 or RMS2 ≤ RMS3 ]. This is because the etchant such as iron chloride in the wet etching process is removed by the electrolytic polishing process, thereby reducing the squared average surface roughness (RMS1, RMS2) of the inner surface of the through hole.

In addition, the second inner surface of the large surface hole (V2) after the electrolytic polishing process (ES2) of the second square mean surface roughness (RMS2`) of the first inner surface of the small surface hole (V1) (ES1) may be formed to have a value equal to or greater than the first squared average surface roughness (RMS1`). [RMS1` ≤ RMS2`] Preferably, electropolishing for the large-sized hole V2 and small-sized hole V1 The process may be performed under the same conditions, so that the first squared average surface roughness (RMS1`) and the second squared average surface roughness (RMS2`) may have similar levels to each other. Preferably, the first squared average surface roughness (RMS1`) of the first inner surface ES1 is realized as 95% to 99% of the second squared average surface roughness (RMS2`) of the second inner surface ES2. Can be. For example, each of the first average surface roughness (RMS1`) and the second square average surface roughness (RMS2`) may have a square average surface roughness (RMS) of less than 150 nm. For example, the first square average surface roughness (RMS1`) and the second square average surface roughness (RMS2`) may each have a square average surface roughness (RMS) in a range of 50 nm to 150 nm. For example, the first squared average surface roughness (RMS1`) and the second squared average surface roughness (RMS2`) may each have a squared average surface roughness (RMS) ranging from 50 nm to 100 nm.

According to an embodiment of the present invention, the deposition mask includes a plurality of through holes formed by communicating the first surface hole and the second surface hole. In this case, the through hole may be formed by additionally performing an electrolytic polishing process after a wet etching process. Accordingly, in the present invention, the deposition mask has a mean square surface roughness (RMS) of the through-hole inner wall smaller than that of the first and / or second surface of the deposition mask. Preferably, the deposition mask in the present invention has a through-hole inner wall having a mean square surface roughness (RMS) of less than 150 nm. More preferably, the deposition mask in the present invention satisfies the range of the square mean surface roughness (RMS) of the inner wall of the through hole in the range of 50 nm to 100 nm.

According to the present invention as described above, it is possible to improve the square mean surface roughness (RMS) of the inner wall of the through hole of the deposition mask, and accordingly, to improve the cleaning properties of the deposition mask. In addition, according to the present invention, the number of times that the deposition mask can be used can be dramatically increased according to the improvement of the above-described cleaning properties. Further, according to the present invention, it is possible to enhance the corrosion resistance inside the through-holes of the deposition mask, thereby enhancing the quality and durability of the deposition mask.

In addition, in the related art, as only the wet etching process is performed, the inclination angle that can be formed to the maximum is 75 ° with respect to the small surface hole corresponding to the first surface hole. However, in the present invention, as the electrolytic polishing process is further performed as described above, an inclination angle with respect to the small surface hole may be formed to be 75 ° or more. Preferably, the inclination angle of the small hole in the present invention may have a range between 75 ° ~ 85 °.

According to the present invention as described above, it is possible to improve the shadow effect as the inclination angle of the through-hole of the deposition mask is increased. In addition, according to the present invention, it is possible to prevent deposition defects due to an increase in the inclination angle, to improve deposition efficiency, and thus to provide a deposition mask capable of uniformly depositing an OLED pixel pattern having a resolution of 400 PPI or higher. It is possible.

In addition, according to the present invention, the boundary surface between the first surface hole and the second surface hole of the deposition mask has a gentle round shape, and accordingly, the durability of the deposition mask for high tensile load during tension can be improved.

11 is a view showing a method of manufacturing a deposition mask 100 according to an embodiment.

Referring to FIG. 11, a method of manufacturing a deposition mask 100 according to an embodiment includes preparing a metal plate 10, and placing a photoresist layer on the metal plate 10 to form a through hole according to wet etching A step of forming a through hole by further performing an electropolishing process on the wet etched through hole, and forming a deposition mask 100 including the through hole by removing the photoresist layer. can do.

First, the metal plate 10, which is a basic material for manufacturing the deposition mask 100, is prepared (S410).

The metal plate 10 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). More specifically, the metal plate 10 may include iron (Fe), nickel (Ni), oxygen (O), and chromium (Cr). In addition, the metal plate 10 is a small amount of carbon (C), silicon (Si), sulfur (S), phosphorus (P), manganese (Mn), titanium (Ti), cobalt (Co), copper (Cu), It may further include at least one element of silver (Ag), vanadium (V), niobium (Nb), indium (In), and antimony (Sb). The Invar is an alloy containing iron and nickel, and is a low thermal expansion alloy having a coefficient of thermal expansion close to zero. That is, since the thermal expansion coefficient of the invar is very small, it is used for precision components such as masks and precision equipment. Therefore, the deposition mask manufactured using the metal plate 10 may have improved reliability, thereby preventing deformation, and also increasing life.

The iron may be included in the metal plate 10 by about 60% to about 65% by weight, and the nickel may be included by about 35% to about 40% by weight. In detail, the metal plate 10 may contain about 63.5 wt% to about 64.5 wt% of the iron, and the nickel may contain about 35.5 wt% to about 36.5 wt%. In addition, the metal plate 10 is 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) at least one or more elements of about 1% by weight or less may be further included. The component, content, and weight% of the metal plate 10 are selected specimens (a *) corresponding to the thickness (t) of the metal plate 10 by selecting a specific area (a * b) on the plane of the metal plate 10 b * t) can be identified by using a method of sampling and dissolving it in strong acids to investigate the weight percent of each component. However, the embodiment is not limited thereto, and the composition may be investigated by weight percent in various ways to confirm the composition of the metal plate.

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 about 30 μm through the processes. It may have the following thickness. Alternatively, the metal plate 10 may have a thickness of about 30 μm or less through an additional thickness reduction process after the process.

In addition, the step of preparing the metal plate 10 (S410) may further include a step of reducing the thickness according to the thickness of the target metal plate 10. The step of reducing the thickness may be a step of reducing the thickness by rolling and / or etching the metal plate 10.

For example, a metal plate 10 having a thickness of about 30 μm may be required to manufacture a deposition mask for realizing a resolution of 400 PPI or more, and about 20 μm for manufacturing a deposition mask for realizing a resolution of 500 PPI or more. A metal plate 10 having a thickness of about 30 μm may be required, 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 realizing a resolution of 800 PPI or more.

In addition, the step of preparing the metal plate 10 may optionally further include a surface treatment step. In detail, a nickel alloy such as Invar may have a high etch rate at the beginning of etching, so that the etch factor of each small hole V1 of each through hole may be reduced. In addition, when etching for forming the through hole V2, the photoresist layer for forming the large hole V2 may be peeled off by side etching of the etching solution. Accordingly, it may be difficult to form a through hole having a fine size, and it is difficult to uniformly form the through hole, and manufacturing yield may decrease.

Accordingly, a surface treatment layer for surface modification having different components, content, crystal structure and corrosion rate may be disposed on the surface of the metal plate 10. Here, surface modification may mean a layer made of various materials disposed on a surface in order to improve an etching factor.

That is, the surface treatment layer is a layer for preventing fast etching on the surface of the metal plate 10 and may be a barrier layer having a slower etching rate than the metal plate 10. The surface treatment layer may have a different crystal surface and crystal structure from the metal plate 10. For example, as the surface treatment layer includes different elements from the metal plate 10, a crystal surface and a crystal structure may be different from each other.

For example, in the same corrosion environment, the surface treatment layer may have a different corrosion potential from the metal plate 10. For example, when the same etching solution at the same temperature is treated for the same time, the surface treatment layer may have a different corrosion current or corrosion potential from the metal plate 10.

The metal plate 10 may include a surface treatment layer or a surface treatment portion on one side and / or both sides, the entire area, and / or the effective area. The surface treatment layer to the surface treatment part may include elements different from the metal plate 10 or metal elements having a slow corrosion rate in a larger content than the metal plate 10.

Subsequently, a step of forming a through hole TH by arranging a photoresist layer on the metal plate 10 may be performed.

To this end, a first photoresist layer PR1 may be disposed on one surface of the metal plate 10 to form a small hole V1 of a through hole on one surface of the metal plate 10 (step 420). The first photoresist layer PR1 may be exposed and developed to form a patterned first photoresist layer PR1 on one surface of the metal plate 10. That is, a first photoresist layer PR1 including an open portion may be formed on one surface of the metal plate. In addition, an etch-stop layer such as a coating layer or a film layer for blocking etch may be disposed on the other surface opposite to one surface of the metal plate 10.

Subsequently, a first groove may be formed on one surface of the metal plate 10 by half etching the open portion of the patterned first photoresist layer PR1 (step 430). The open portion of the first photoresist layer PR1 may be exposed to an etchant or the like, and etching may occur in an open portion of the metal plate 10 where the first photoresist layer PR1 is not disposed.

The forming of the first groove may be a step of etching the metal plate 10 having a thickness of about 20 μm to about 30 μm until the thickness is about 1/2. The depth of the first groove formed through this step may be about 10 μm to 15 μm. That is, the thickness of the metal plate measured at the center of the first groove formed after this step may be about 10 μm to about 15 μm.

The step of forming the first groove (S430) may be a step of forming the groove by anisotropic etching or a semi-additive process (SAP). In detail, an anisotropic etching or semi-addition method may be used to half etch the open portion of the first photoresist layer PR1. Accordingly, the first groove formed through the half etching may have an etching rate in the depth direction (b direction) faster than that of the side etching (a direction) than isotropic etching.

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

Subsequently, a second photoresist layer PR2 may be disposed on the other surface of the metal plate 10. Subsequently, the second photoresist layer PR2 may be exposed and developed to pattern the second photoresist layer PR2 on the other surface of the metal plate 10 (S440). In addition, an etch-stop layer such as a coating layer or a film layer for blocking etch may be disposed on one surface of the metal plate 10.

Since the open portion of the second photoresist layer PR2 may be exposed to an etchant or the like, etching may occur in an open portion of the other surface of the metal plate 10 where the second photoresist layer PR2 is not disposed. The other surface of the metal plate 10 may be etched by anisotropic etching or isotropic etching.

As the open portion of the second photoresist layer PR2 is etched, the first groove on one surface of the metal plate 10 may be connected to the large surface hole V2 to form a through hole (S460).

In the forming of the through hole, after forming the first groove for forming the small face hole V1, the step of forming the second groove for forming the large face hole V2 proceeds and the through hole ( TH).

Alternatively, forming the through hole TH may include forming a first groove for forming the small face hole V1 after forming a second groove for forming the large face hole V2. Proceeding may be a step of forming the through hole TH.

Alternatively, the forming of the through hole TH may include forming a first groove for forming the small face hole V1 and forming a second groove for forming the large face hole V2. At the same time, it may be a step of simultaneously forming the through hole TH.

Next, an inner surface of the formed through hole TH may be additionally removed by performing an electropolishing process (S470). Preferably, the electropolishing process may be performed simultaneously with respect to the small hole and the large hole of the through hole TH. When the electropolishing process is performed, the square average surface roughness of the inner surfaces of the small facets and the large face holes is reduced compared to the through hole before the electropolishing step, and the cross-sectional inclination angle of the small face holes is increased.

Meanwhile, in the present invention, the electropolishing process may be performed only in one direction around the through hole. In other words, in order to proceed with the electrolytic polishing process, a protective layer may be formed on one surface or the other surface of the metal plate. The surface on which the protective layer is formed may be a portion in which a groove not to be subjected to the electrolytic polishing process is formed. For example, when the electropolishing process is performed only on the small surface hole, the protective layer may be disposed on the other surface of the metal plate. In addition, when the electropolishing process is performed only for the large-sized hole, the protective layer may be disposed on one surface of the metal plate.

In other words, when the square average surface roughness with respect to the inner surface of the small face hole and the square average surface roughness with respect to the inner surface of the large face hole are respectively decreased by the electropolishing process, the following effects are obtained. When the small face hole is electropolished, there is an effect that can improve the shadow effect. In addition, in the case of electropolishing the face hole, the etching factor may be improved, and the cleaning property according to the improvement of the square average surface roughness of the face hole may be enhanced. Accordingly, the electrolytic polishing process may be performed only in some directions based on the effect to be improved among the above effects.

Next, through the electropolishing process, the face hole V2 finally formed on the one surface, the small face hole V1 formed on the other surface opposite to the one face, the face face hole V2 and the face face hole V1 The deposition mask 100 may be formed through the step of forming the deposition mask 100 including the through hole TH formed by the communication portion to which the boundary of the is connected.

The deposition mask 100 formed through the above steps may include the same material as the metal plate 10. For example, the deposition mask 100 may include a material having the same composition as the metal plate 10. In addition, the island portion (IS) of the deposition mask 100 may indicate the above-described surface treatment layer.

12 and 13 are views showing a deposition pattern formed through a deposition mask according to an embodiment.

Referring to FIG. 12, the deposition mask 100 according to an embodiment may have a height (a) between one side and a communication portion of the deposition mask 100 in which the small hole V1 is formed, to be about 3.5 μm or less. For example, the height (a) may be from 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, the distance between one surface of the deposition mask 100 and the substrate on which the deposition pattern is disposed may be close, thereby reducing deposition defects due to the shadow effect. For example, when the R, G, and B patterns are formed using the deposition mask 100 according to the embodiment, defects in which different deposition materials are deposited in an area between two adjacent patterns may be prevented. In detail, as illustrated in FIG. 18, when the patterns are formed in the order of R, G, and B from the left, R patterns and G patterns are prevented from being deposited with a shadow effect in the region between the R patterns and the G patterns. You can.

In addition, the deposition mask 100 according to the embodiment may reduce the size of the island portion IS in the effective portion. In detail, the area of the upper surface of the island portion IS, which is a non-etched surface, can be reduced, so that the organic material can easily pass through the through hole TH when depositing the organic material, thereby improving deposition efficiency.

In addition, the area of the island portion IS may decrease from the center of the effective portions AA1, AA2, AA3 toward the non-effective portion UA. Accordingly, organic materials can be smoothly supplied to the through-holes located at the edges of the effective portions AA1, AA2, and AA3, thereby improving deposition efficiency and improving the quality of the deposition pattern.

Features, structures, effects, and the like described in the above-described embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, and the like exemplified in each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

In addition, although the embodiments have been mainly described above, this is merely an example and does not limit the present invention, and those skilled in the art to which the present invention pertains are exemplified in the above without departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be implemented by modification. And differences related to these modifications and applications should be construed as being included in the scope of the invention defined in the appended claims.

Claims (14)

In the mask for deposition of a metal material for the OLED pixel deposition,
The deposition mask includes a deposition area for forming a deposition pattern and a non-deposition area other than the deposition area,
The deposition region is spaced apart in the longitudinal direction and includes a plurality of effective portions having a plurality of through holes and non-effective portions other than the effective portion,
The through hole,
A small surface hole formed on one surface of the deposition mask;
A large surface hole formed on the other surface of the deposition mask opposite to the one surface; And
Includes; a communication portion that is connected to the boundary between the small face hole and the large face hole,
The mean surface roughness (RMS) of the inner surface of at least one of the small and large face holes is less than 150 nm.
Deposition mask. According to claim 1,
The square mean surface roughness (RMS) of at least one inner surface of the small face hole and the large face hole is:
Satisfying the range between 50nm and 100nm
Deposition mask. According to claim 1,
The square mean surface roughness (RMS) of the inner surface of the small surface hole is:
Smaller than the squared mean surface roughness (RMS) of the one surface where the small facet is formed
Deposition mask. According to claim 1,
The square mean surface roughness (RMS) of the inner surface of the face hole is:
Smaller than the squared average surface roughness (RMS) of the other surface on which the large hole is formed
Deposition mask. According to claim 1,
The first diameter of the small surface hole,
Greater than the second diameter of the communication part,
The first diameter,
1.2 times or less of the second diameter
Deposition mask. The method of claim 5,
The first diameter,
Having a range between 1.05 and 1.1 times the second diameter
Deposition mask. According to claim 1,
A first inflection point is formed on the inner surface of the small surface hole,
The inner surface of the small surface hole,
A first sub-first inner surface formed between one surface of the deposition mask and the first inflection point,
And a second sub first inner surface formed between the first inflection point and the communication portion.
Deposition mask. The method of claim 7,
A second inflection point is formed on the inner surface of the face hole,
The inner surface of the face hole,
A first sub-second inner surface formed between the other surface of the deposition mask and the second inflection point,
And a second sub-second inner surface formed between the second inflection point and the communication portion.
Deposition mask. According to claim 1,
The through hole,
The diameter is less than 33㎛,
The gap between the plurality of through holes has a resolution of 500 PPI or more, which is 48 μm or less.
Deposition mask. Prepare a metal plate having a predetermined thickness,
Etching one surface and the other surface of the metal plate, respectively, to form a first through hole having a small surface hole, a large surface hole, and a communication portion connecting a boundary between the small surface hole and the large surface hole,
And electrolytically polishing the inner surface of the formed first through hole to form a second through hole,
The mean surface roughness (RMS) of the inner surface of the second through hole is:
Less than the squared average surface roughness (RMS) of the inner surface of the first through hole,
The mean surface roughness (RMS) of the inner surface of the second through hole is less than 150 nm.
Method of manufacturing a deposition mask. The method of claim 10,
The square mean surface roughness (RMS) of at least one inner surface of the small face hole and the large face hole of the second through hole is:
Satisfying the range between 50nm and 100nm
Method of manufacturing a deposition mask. The method of claim 10,
The squared average surface roughness (RMS) of the inner surface of the small face hole of the second through hole is:
Less than the squared average surface roughness (RMS) of one side of the metal material,
The squared average surface roughness (RMS) of the inner surface of the face hole of the second through hole is:
Less than the squared mean surface roughness (RMS) of the other side of the metal material
Method of manufacturing a deposition mask. The method of claim 10,
The first cross-section inclination angle of the small surface hole of the second through hole,
Greater than the second cross-section inclination angle of the small face hole of the first through hole,
The first cross-section inclination angle,
Having a range between 75 degrees and 89 degrees
Method of manufacturing a deposition mask. A method for manufacturing an OLED panel by depositing an organic material by tensile welding the deposition mask according to any one of claims 1 to 9 to a mask frame.

Images