KR102617825B1 - Metal substrate and Mask using the same - Google Patents

Abstract

An embodiment of the present invention relates to a metal substrate and a vapor deposition mask that maximizes deposition efficiency using the same, and provides a torsion index that can minimize the distortion phenomenon that occurs when etching a metal substrate to produce a deposition mask. It is possible to provide a metal substrate with (Hr) and a deposition mask.

Description

Metal substrate and mask for deposition using the same {Metal substrate and Mask using the same}

An embodiment of the present invention relates to a metal substrate and a mask for vapor deposition that maximizes deposition efficiency using the same.

In the manufacturing process of organic EL color displays made of organic EL light-emitting devices, an organic layer made of organic material is formed by vacuum deposition, and at this time, a deposition mask provided with a plurality of penetration holes for transmitting the material according to the pattern of the organic layer is used. It is being used. Generally, in the case of penetration holes that make up a deposition mask, the photoetching method involves exposing a metal thin film to a pattern using a photoresist film and then etching it, or the electroforming method of electroplating a glass disk with a desired pattern and then peeling it off. can be formed.

Conventional deposition masks are usually implemented as metal masks, and are focused on accurately creating only the open area for deposition. However, this method does not show much effectiveness in reducing deposition efficiency and dead space.

In particular, the deposition mask itself is implemented with a very thin metal plate. This metal plate is manufactured with a large number of through holes, which causes a fatal defect in the distortion of the substrate after production, reducing the uniformity of deposition. I'm doing it.

Embodiments of the present invention have been devised to solve the above-described problems, and in particular, provide a metal substrate that can minimize the distortion phenomenon that occurs when etching a metal substrate to manufacture a deposition mask. Furthermore, it is possible to implement a deposition mask having a plurality of deposition unit holes based on this metal substrate.

In addition, the roughness of the unit hole of the deposition mask can be controlled to increase deposition efficiency.

As a means to solve the above-described problem, in an embodiment of the present invention, a base metal plate having a thickness; The base metal plate is perpendicular to the thickness direction and has first and second surfaces facing each other, and both sides of a sample substrate of 30 mm * 180 mm (width * height) taken at an arbitrary point of the base metal plate. An etched area is created by leaving 10 mm from the end to the inside and etching the inside with a thickness of 2/3 to 1/2 of the above thickness. When the sample substrate is placed on a horizontal target surface, the torsion index of the sample substrate ( Hr) allows to provide a metal substrate that satisfies the following relationship.

{Equation 1}

Hr = {(H1 - Ha) ² + (H2 - Ha) ² + (H3 - Ha) ² + (H4 - Ha) ² } ^1/2

{Equation 2}

Ha = (H1 + H2 + H3 + H4)/4

(Ha is defined as the average distance (H1, H2, H3, H4) of the four corners of the sample substrate from the horizontal target plane.

In addition, it is possible to provide a deposition mask having a plurality of unit holes for deposition by using the above-described metal substrate.
The deposition mask of the example is,
A metal plate comprising a first side and a second side opposite the first side,
The metal plate has a plurality of unit holes including a first surface hole formed on the first surface, a second surface hole formed on the second surface, and a boundary portion communicating the first surface hole and the second surface hole. may include.
The width of the first surface hole may be larger than the width of the second surface hole.
The first inclination angle formed between the long axis direction of the first surface hole and an imaginary line connecting a point in the long axis direction of the opening of the first surface hole exposed to the surface of the metal plate and the first point of the boundary portion is the surface of the metal plate An imaginary line connecting a point in the minor axis direction of the opening of the first surface hole exposed to and a second point of the boundary may be different from the size of the second inclination angle formed by the minor axis direction.
A point along the major axis of the opening of the first surface hole and a point along the minor axis of the opening of the first surface hole may be located at the same height.
The deposition mask of the embodiment includes a metal plate including a first side and a second side opposite the first side,
The metal plate has a plurality of unit holes including a first surface hole formed on the first surface, a second surface hole formed on the second surface, and a boundary portion communicating the first surface hole and the second surface hole. may include.
The first inclination angle formed between the long axis direction of the second surface hole and an imaginary line connecting a point in the long axis direction of the opening of the second surface hole exposed to the surface of the metal plate and the first point of the boundary portion is the surface of the metal plate The size of the second inclination angle formed by the imaginary line connecting a point in the minor axis direction of the opening of the second surface hole exposed to and the second point of the boundary portion may be different from the size of the second inclination angle formed by the minor axis direction.
A point along the major axis of the opening of the second surface hole and a point along the minor axis of the opening of the second surface hole may be located at the same height.

According to an embodiment of the present invention, it is possible to provide a metal substrate that can minimize the distortion phenomenon that occurs when etching a metal substrate to manufacture a deposition mask.

In particular, when a deposition mask having a plurality of deposition unit holes is implemented using the metal substrate according to the above-described embodiment of the present invention, the distortion phenomenon of the deposition mask itself can be significantly reduced, thereby improving the uniformity of deposition. It also has the effect of maximizing deposition efficiency.

Furthermore, according to another embodiment of the present invention, when a deposition mask having a plurality of deposition unit holes is implemented using the metal substrate according to the above-described embodiment of the present invention, the surface roughness of the inner peripheral surface of the unit holes is controlled. This has the effect of increasing the efficiency and uniformity of deposition.

1 and 2 are conceptual diagrams for explaining the characteristics of a metal substrate according to an embodiment of the present invention.
Figure 3 is a conceptual diagram for explaining the deposition process and the application process of the deposition mask.
Figure 4 shows a cross-sectional view of the main part of the deposition mask when the deposition mask is implemented using the metal substrate described above in the first embodiment.
Figures 5 and 6 are graphs to explain the concept of illuminance.
Figures 7 and 8 show actual images of the first surface hole of Figure 4.
Figure 9 is a graph for explaining straightness.
FIG. 10 is a plan view of the second side of a deposition mask according to an embodiment of the present invention in the structure of FIG. 4, and FIG. 11 is a plan view of the first side of the deposition mask in the structure of FIG. 4.
Figure 12 shows a modified example of the structure of Figure 11.
13 to 18 are conceptual diagrams for explaining an embodiment of the present invention.

Hereinafter, the configuration and operation according to the present invention will be described in detail with reference to the attached drawings. In the description with reference to the accompanying drawings, identical components will be given the same reference regardless of their reference numerals, and redundant description thereof will be omitted. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

1. First embodiment

1 and 2 show that the metal substrate according to an embodiment of the present invention is capable of implementing a thick metal substrate for producing a deposition mask by etching a base metal plate having a thickness, and in particular, the metal substrate is not distorted in local areas or as a whole. It is possible to implement a metal substrate that can minimize the phenomenon.

To this end, the metal substrate according to the first embodiment of the present invention is, as shown in FIG. 1, a sample substrate is extracted from a base metal plate having a certain overall thickness, and the sample substrate 200 is etched. It can be implemented as an applied etching area 210 and a non-etching area 220. (Hereinafter, the substrate collected for etching from the base metal plate is referred to as the 'sample substrate', and the substrate sampled from the base substrate for etching is referred to as the 'sample substrate'. A board that has not been applied is defined as a ‘unit board’.)

In this case, the base metal plate has a first surface and a second surface that are perpendicular to the thickness direction and face each other. For this base metal plate, a sample substrate 200 of 30 mm * 180 mm (width * height) was taken at an arbitrary point of the base metal plate, leaving 10 mm inward from both ends (220 portions), and the thickness described above for the inside. The etching area 210 is etched to a thickness of 2/3 to 1/2, and then, when the sample substrate is placed on a horizontal target surface, the torsion index (Hr) of the etched sample substrate has the following relationship. meets.

{Equation 1}

Hr = {(H1 - Ha) ² + (H2 - Ha) ² + (H3 - Ha) ² + (H4 - Ha) ² } ^1/2

{Equation 2}

Ha = (H1 + H2 + H3 + H4)/4

(Ha is defined as the average distance (H1, H2, H3, H4) between the four corners of the etched sample substrate from the horizontal target plane.)

Specifically, the characteristics of the metal substrate according to an embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3 as follows.

Referring to FIG. 3, the deposition mask manufactured using a metal substrate according to an embodiment of the present invention is a mask structure that implements the formation of an organic layer of OLDE, and includes a deposition source (S;Suorce) glass that provides a deposition material. It is possible to implement a deposition target (T) on a substrate (G) such as. In this case, the deposition mask (M; 100) is implemented in a structure including a plurality of unit holes. Generally, in order to improve deposition uniformity during OLED deposition, the deposition mask must be maintained in a uniform state during the deposition process.

However, when etching a metal plate to produce a deposition mask, the thickness becomes very thin, and if multiple deposition holes are implemented here, the produced deposition mask is easily distorted, as shown in Figures 3 and 3. Uniformity of deposition cannot be secured in the same arrangement structure.

Accordingly, in an embodiment of the present invention, it is possible to provide a metal substrate that minimizes distortion that occurs when etching a metal plate or metal plate. In the manufacturing process of the metal substrate of the present invention, a sample substrate of 30 mm x 180 mm is taken from the base metal plate.

Afterwards, ½ to 2/3 of the sample substrate is etched, leaving 10 mm on both sides of the 180 mm long axis. Afterwards, when the etched sample substrate is placed on a flat surface with guaranteed horizontality, such as an object such as a surface, H1 is the height at which the four corners of the sample substrate are spaced apart from the reference plane of the horizontal target surface of the surface. Measure H2, H3, and H4.

In this case, if H1, H2, H3, and H4, which are the heights at which the four corners of the sample board are spaced apart, are greater than '0', this state is defined as 'twisted' of the sample board, and the degree of this twist is described in detail. The exponent as in Equation 1 is defined as the torsion index (Hr).

Therefore, as the twist index (Hr) of the sample substrate increases, the degree of distortion of the substrate becomes more severe. In the embodiment of the present invention, an unetched sample substrate (30 mm × 180 mm) extracted from an arbitrary point of the base metal plate of the same size (30 mm × 180 mm) When comparing the torsion index of the etched sample substrate (hereinafter referred to as 'unit substrate') and the etched sample substrate, the torsion index of the etched sample substrate becomes larger than that of the unetched sample substrate.

That is, an unetched sample substrate (unit substrate) sampled at 30 mm The torsion index (Hr(T1)) according to {Equation 1} and {Equation 2} obtained for This can be expressed in the equation below.

{Equation 3}

Hr(T1) ≤ Hr(T2)

In particular, in an embodiment of the present invention, the torsion index of the sample substrate may be 10 or less. For example, when the thickness of the base substrate is 20㎛, a sample substrate is extracted and etched, and the four corners of the etched sample substrate are 10㎛ or less with respect to the horizontal plane. That is, the torsion index of the sample substrate to which the etching has been applied may be implemented as 10 or less, and preferably in the range of 0.2 to 7, or 0.5 to 5. If the torsion index of the sample substrate is set to 10 or less, the distortion phenomenon can be prevented when manufacturing the final deposition mask, and the left and right deviations are reduced during OLED deposition, thereby increasing deposition uniformity.

In order to implement the torsion index of the sample substrate according to an embodiment of the present invention to 10 or less, it can be formed by performing a cooling process and a rolling process in the process of implementing the metal substrate in the state of the base material. First, the cooling process is carried out at a temperature of 10~20℃ in the base material state, and then rolling is implemented to realize a metal plate of the desired thickness. In this case, the degree of rolling is important, and this In this case, the rolling rate can be implemented at a rate of 2/3 to 1/5 of the unit volume (1mm ³ ) of any point of the base material.

Figure 2 is a diagram for explaining the torsion index when a sample substrate is collected and etched from the base metal plate 200 according to the above-described embodiment of the present invention. As shown, the sample substrate has a horizontal target surface (ST). ), the four corners are separated, and at least one of these separation distances (H1 to H4) has a different length. That is, H1 and H2, or H3 and H4, adjacent to each other in the short axis direction of the sample substrate may be different from each other.

In the case of the metal substrate according to the above-described embodiment of the present invention, it penetrates the first and second surfaces of the etching area of the metal substrate and includes a plurality of unit holes having first and second surface holes communicating with each other. It can be implemented as a deposition mask. In particular, in the deposition mask implemented in this way, the distortion of the mask is significantly reduced, enabling deposition reliability.

2. Second embodiment

Figure 4 shows a cross-sectional view of the main part of the deposition mask when the deposition mask is implemented using the metal substrate described above in the first embodiment.

Referring to FIG. 4, the deposition mask according to the present embodiment includes a metal plate having a thickness, orthogonal to the thickness direction, and having first and second surfaces facing each other, as in the structure shown in FIG. 4. It is configured to include a plurality of unit holes penetrating through the first and second surfaces and having first surface holes 110 and second surface holes 130 communicating with each other. In this case, the first surface hole 110 and the second surface hole 130 communicate by sharing a boundary portion 120, which is a part that communicates with each other. These unit holes may be implemented in a structure in which a plurality is provided.

In particular, in this case, the unit hole implemented in the deposition mask can have a roughness value lower than the roughness value of the third roughness Ra3, which is the surface roughness of the first surface 112. That is, based on the third roughness (Ra3), the first roughness (Ra1) of the first inner surface or the second roughness (Ra2) of the second inner surface 131, which is the inner surface of the second surface hole, is higher. It can be formed small. [Ra3≥(Ra2 or Ra1)]

Furthermore, the second roughness Ra2 of the second inner surface 131, which is the inner surface of the second surface hole, is the first roughness Ra1 of the first inner surface 111, which is the inner surface of the first surface hole 110. It can be formed to have a value above [Ra2≥Ra1].

This means that if the surface roughness of the deposition mask, which is made of a metal mask, is above a certain amount, it affects the straightness (line roughness in FIG. 7) of the unit hole, which is a hole for deposition when manufacturing the deposition mask, and causes organic material deposition. It is not good, and when cleaning after depositing organic materials such as OLED, the cleaning power is reduced and the lifespan of the deposition mask is shortened.

In this embodiment, the arithmetic mean illuminance (Ra1) of the first inner surface and the arithmetic mean illuminance (Ra2) of the second inner surface are implemented to be 1.0 μm or less. Alternatively, within this range, the arithmetic average roughness (Ra) of the first inner surface, the second inner surface, and the first surface is 0.08 ~ 0.5㎛ or less, 0.15 ~ 0.3㎛ or less, more reliable deposition efficiency. can be implemented.

In this case, the arithmetic average roughness (Ra) is also expressed as center line surface roughness (Roughness Average, Ra), CLA (Center Line Average), and AA (Arith Metic Average), as shown in Figure 5, and is the surface within one standard length. It is defined as the value obtained by averaging the height and depth of the mountains and valleys around the baseline. That is, as shown in the graph of FIG. 5, the degree of roughness is displayed based on the reference line (center line), which is the standard of the surface for measuring roughness, and this is implemented as an arithmetic mean.

Furthermore, in another aspect of the embodiment of the present invention, the 10-point average illuminance (Rz) value of at least one of the first inner surface, the second inner surface, and the first surface of the deposition mask is 3.0 μm or less. So that it can be implemented. Furthermore, the 10-point average roughness (Rz) value of at least one of the first inner surface, the second inner surface, and the first surface within this range is implemented to be 2.5 or less, 1.5 to 2.5 or less, thereby enabling more reliable deposition. Efficiency can be realized. In this case, the '10-point average roughness (Rz)' is the surface roughness of 10 points (Ten Point Height of Irregularities, based on the baseline of the reference surface of the surface that is the target of roughness measurement, as shown in Figure 6). Rz).

Furthermore, the deposition mask according to the embodiment of the present invention enables the line roughness of the outer diameter of the unit hole described above in FIG. 4, or the so-called 'straightness of the unit hole', to be implemented at 1.5㎛. Line roughness of the outer diameter of the unit hole, that is, straightness, is a straight line drawn from the center point of the outer diameter of the hole to be measured as a baseline (center line), and is a measure of deviation in one direction from this center line, which is the furthest from the center line. The distance deviated is expressed as straightness.

Measurement of this straightness in an embodiment of the present invention will be explained with reference to FIGS. 7 to 9. Figures 7 and 8 show actual images of the first surface hole in Figure 4. Referring to this, the minor axis and long axis of the opening of the first surface hole are referred to as x and y, respectively, and only the long axis, y-axis, If the total length of the measured y-axis is divided into 1/2 and the center is called y2, the roughness of the outer diameter line of the opening is measured in a range of 1.5㎛ left and right from y2, and a total of 3㎛. In this case, the measuring range should not exceed 3㎛, and within the range of 3㎛, the straightness of the deposition mask according to an embodiment of the present invention should be implemented to be 1.5㎛ or less. In other words, it is possible to achieve a straightness of 1.5 ㎛ or less in a measurement range of 3 ㎛.

3. Third embodiment

Hereinafter, another embodiment that implements the characteristics of the deposition mask according to the embodiment of the present invention that can be implemented by applying the metal substrate of the first embodiment described above will be described. Of course, in the following embodiments, the metal substrate of the first embodiment described above can be applied, and of course, it can be implemented in a structure in which the features of the second embodiment described above are added. However, in the following description, only the characteristic parts of the third embodiment of the present invention are independently implemented as an example.

The features of this third embodiment are described with reference to the cross-sectional view of the deposition mask in FIG. 4 as follows. That is, the deposition mask 100 according to an embodiment of the present invention has a thickness, is perpendicular to the thickness direction, and has a first surface and a second surface facing each other, as shown in FIG. 4. It is provided with a metal plate, and is configured to include a plurality of unit holes having first surface holes 110 and second surface holes 130 that penetrate the first and second surfaces and communicate with each other. In this case, the first surface hole 110 and the second surface hole 130 communicate by sharing a boundary portion 120, which is a part that communicates with each other. Such unit holes may be implemented in a structure in which a plurality of units are provided. In particular, in the embodiment of the present invention, the size deviation of the first or second surface holes between neighboring unit holes is based on the size deviation between arbitrary unit holes. Ensure that it can be implemented within 2% to 10%.

In this case, the size difference between neighboring unit holes can be compared based on the difference in diameter between the first surface holes and the second surface holes with their neighbors.

When explaining this structure with reference to FIGS. 10 and 11, FIG. 10 is a plan view of the second side of a deposition mask according to an embodiment of the present invention in the structure of FIG. 4, and FIG. 11 is a plan view of the deposition mask in the structure of FIG. 4. It shows a plan view of the first side of .

Referring to FIG. 10, the vertical diameter (Cy) and the horizontal diameter (Cx) of any unit hole (hereinafter referred to as 'reference hole') of the second surface hole of the plurality of unit holes implemented on the second surface are When measuring, the deviation between the vertical diameters (Cy) of the holes (total 6 in the drawing) adjacent to the reference hole is ensured to be within 2% to 10%. In addition, the deviation of the horizontal diameter (Cx) of the reference hole and other adjacent holes can also be implemented within 2% to 10%. In other words, if the size difference between adjacent holes of one reference hole is implemented in the range of 2% to 10%, the advantage of ensuring uniformity of deposition is realized.

Preferably, the deviation of the vertical diameter (Cx) or the horizontal diameter (Cx) of the reference hole and the other adjacent hole is within 4% to 9%, especially, the vertical diameter (Cx) of the reference hole and the other adjacent hole is within 4% to 9%. If the deviation of the horizontal diameter (Cx) is implemented within 5% to 7%, the uniformity of deposition is further increased. Conversely, if all holes are implemented with the same size, the Moire occurrence rate in the OLED panel after deposition increases, and if the size difference between adjacent holes exceeds 10% based on the reference hole, the The occurrence rate of color stains increases in OLED panels after deposition.

This is the same standard applied to the first surface hole implemented on the first surface of the metal plate in Figure 11, and the vertical diameter (By) and the horizontal diameter (Bx) of the first surface hole, which are arbitrary standards, Ensure that the deviation rate compared to the diameter between adjacent adjacent holes is implemented within 2% to 10%. Furthermore, as described above, it can be particularly preferably implemented within 4% to 9% or within 5% to 7%. In particular, in the embodiment of the present invention, the size difference between the reference hole and the neighboring hole can be implemented within ±3㎛.

For example, in Figure 10, if the vertical diameter (Cy) of the reference hole is 36㎛, and the diameter of the neighboring hole is 33㎛ or 39㎛, and the deviation is ±3㎛, the deviation rate of the diameter compared to the reference hole is 8.3%. It is implemented within 2% to 10%, increasing deposition efficiency.

As another example, in Figure 10, when the horizontal diameter (Cx) of the reference hole is 125㎛, and the diameter of the neighboring hole is 122㎛ or 128㎛, the deviation rate of the diameter compared to the reference hole is 2.4%, ranging from 2% to 10% above. This is implemented within a short period of time, thereby increasing deposition efficiency.

Figure 12 is a plan view of the first surface hole 110 and the second surface hole 130 as seen from the second surface in the structure of Figure 11. When calculating the size difference between the holes described above, an arbitrary protrusion on the outer peripheral surface of the hole is used. In this case, it is desirable to ensure that the maximum width (Y1) or height (X1) of the protrusion protruding from the outer peripheral surface of the second surface hole toward the center is 20 um or less. These protruding protrusions correspond to defective structures that inevitably occur during deposition, and in the embodiment of the present invention, these protruding protrusions are implemented in a range of 20 μm or less to ensure uniformity of deposition. In particular, in the embodiment of the present invention, the above-mentioned protruding protrusions can be implemented to be 11㎛ or less, and further 6㎛ or less.

4. Fourth Embodiment

Hereinafter, the structure of a deposition mask according to another embodiment of the present invention described above with reference to FIGS. 4, 10, and 11 will be described. Of course, the structure of this fourth embodiment can also have the features of the third embodiment described above. Furthermore, in the following embodiments, the metal substrate of the first embodiment described above can be applied, and of course, it can be implemented in a structure in which the features of the second embodiment described above are added. However, in the following description, an example will be given where the characteristic structure of the fourth embodiment is implemented independently.

The deposition mask according to the fourth embodiment includes a metal plate having a thickness, as shown in FIGS. 4 and 13, and a first and second surfaces of the metal plate penetrate through and communicate with each other. It is the same as the structure of the first embodiment in that it has a structure including a plurality of unit holes having one-sided holes and second-sided holes. However, it is unique in that the center (F) of the first surface hole 110 and the center (E) of the second surface hole 130 are disposed at positions that do not match each other with respect to the surface of the first surface. That is, the centers of the first surface hole and the second surface hole are arranged misaligned so that they do not coincide with each other.

When the centers of the first surface hole and the second surface hole are arranged misaligned as in the fourth embodiment of the present invention, a superior advantage is realized in that high uniformity of deposition can be secured. As shown in FIG. 13, considering the radiation angle emitted from the deposition source source (S) spaced apart from the deposition mask having a plurality of unit holes, the positions where the deposition source source and the unit holes correspond are all different. As a result, even delivery of the deposition material becomes difficult. Accordingly, in the present invention, in order to improve the uniformity of deposition, the central axes of the second surface hole and the first surface hole are offset from each other in each hole to ensure even delivery of the deposition material even during the deposition process over the entire surface of the large-area substrate. This allows implementation to increase the uniformity of deposition. Furthermore, even when it is necessary to increase the thickness of the deposition, this structure allows the deposition thickness to be efficiently controlled in a local area or the entire area of the deposition target.

The arrangement structure in which the center of the first surface hole and the center of the second surface hole are inconsistent with each other can be achieved by setting an imaginary vertical line perpendicular to the surface of the first or second surface of the metal plate on the center of the first surface hole. , When erected on the center of the second surface hole, this means a structure in which the vertical line passes through either one of the two centers. In another sense, the central axes of the first or second surface holes are arranged misaligned with each other.

In addition, the center of the first surface hole and the center of the second surface hole defined in the fourth embodiment of the present invention are the centers if the outer peripheral surfaces of the first surface hole and the second surface hole are a circle or an ellipse, and the center is a polygon. In the case of , it means the center of gravity.

Alternatively, as in the structure shown in FIG. 13, if the center of gravity can be determined for a surface ball that has a curvature structure with rounded corners, the center of gravity is used as the center. Furthermore, the edge curvatured on the outer portion of the surface hole (in the embodiment of the present invention, if there is an attachment, the attachment is considered a corner, and in the case of an edge portion with a curvature, the curvature is greater than the curvature of the surrounding surrounding area to which 'curvature' is connected). The case where it becomes smaller is defined as an edge.) The center of the case where is implemented is, if there are n edges with curvature, if n is an even number, draw a straight line with the facing edge, and let the number of straight lines drawn be "K". , if the number of straight lines (K) is 3, a circle is drawn centered on the point where 3 straight lines meet, and if K is 2, a circle is drawn centered on the point where 2 straight lines meet, and the center of this circle is set as the center of the plane ball. Or, if the number n of the edges is an odd number, draw a straight line on the side facing the edge, and call the number of these straight lines "k", until the number of straight lines (k) becomes 3 or 2, and through this, each The point where straight lines meet is considered the center of the ball.

For example, Figure 14 is an example diagram for explaining a method of determining the center (F) of the first surface hole 110 in Figure 13. There are a total of 4 (even number) rounded corners, and one central point of curvature If straight lines (b1, b2) are drawn from the center points of the other edges facing each other, the number of straight lines (K) is two, and the point where these two straight lines meet is taken as the center (F) of the first faceted hole.

In addition, the center (E) of the second surface hole 130 is determined in the same manner, and unit grooves are implemented so that the centers (E, F) are arranged to be offset from each other. In particular, as shown in the drawing of FIG. 13, the distance (d) between the center (F) of the first surface hole and the center (E) of the second surface hole is 90% of the diameter length (A) of the second surface hole. % or less, that is, 0.9A or less. Furthermore, the distance (d) between the center (F) of the first surface hole and the center (E) of the second surface hole is within this range, preferably 50% of the diameter length (A) of the second surface hole. Or less, more preferably 0.1% to 10% or less, 0.2 to 8% or less, or 0.2 to 5% or less. If the degree of deviation of the distance between the central axes can be realized in a range of 90% or less of the diameter length (A) of the second surface hole, the uniformity of deposition efficiency can be further increased.

As described above, in a deposition operation using a deposition mask, all unit holes of the deposition source and mask cannot be placed at the bottom in the vertical direction, so to improve the uniformity of deposition for OLED, unit holes are used. Each hole requires a certain angle, back height, etc.

In this case, when applying the deposition mask according to an embodiment of the present invention, deposition efficiency can be increased by implementing a miss match in the arrangement positions of the first surface hole and the second surface hole. Furthermore, due to this arrangement structure, dead space during deposition can be reduced, and it can be applied with high utilization even during deposition by thickening the deposition thickness or applying thicker materials. This is because, in OLED deposition equipment, a problem occurs in which the tensile force increases during large-area deposition. In this case, the arrangement positions of the first and second surface holes according to the second embodiment of the present invention are mismatched. When using a unit hole pattern, this tensile force can be distributed evenly, thereby ensuring OLED deposition uniformity.

5. Fifth Embodiment

Below, the structure of a deposition mask according to another embodiment of the present invention will be described. It goes without saying that the structure of the fifth embodiment may simultaneously have the features of the second to fourth embodiments described above. Furthermore, it goes without saying that the metal substrate of the first embodiment described above can be applied in the following embodiments. However, in the following description, an example will be given where the characteristic structure of the fifth embodiment is implemented independently.

Figure 15 is a conceptual diagram showing the cross-sectional structure of a deposition mask according to the fifth embodiment of the present invention, which includes a plurality of unit holes described above in Figure 4.

Referring to Figures 4 and 15, the deposition mask according to the fifth embodiment of the present invention includes a metal plate having a thickness, the metal plate being perpendicular to the thickness direction and having a first surface and a second surface facing each other. A unit hole has two sides, and in this case, has a first side hole 110 and a second side hole 130 that penetrate the first side and the second side and communicate through a boundary portion 120 connected to each other. It consists of many.

In particular, the unit hole may be implemented so that the depth of the first surface hole in the thickness direction of the metal plate is different from the depth of the second surface hole in the thickness direction of the metal plate. In this case, the first surface hole 110 and the second surface hole 130 are the second surface holes 130 where deposition is implemented based on the outermost protruding points (A1 to A21) of the boundary portion 120, which is a part that communicates with each other. This arranged area is called the effective area (AC), and is an area not involved in deposition, and the first surface hole 110 and the second surface hole 130 are the outermost protruding points of the boundary portion 120, which is a part that communicates with each other ( The area in which the second surface hole included in the outer area of A1, A21) is not placed is defined as a non-effective area (NC).

That is, in the case of the unit holes in the effective area AC in the structure of FIG. 4, the depth (b) to the boundary 120 of the first surface hole 110 is the depth to the border of the second surface hole 130 ( a) It can be implemented larger. In addition, overall, the depth (a) of the second surface hole may be implemented so that the ratio of the relationship with the overall thickness (c) of the metal plate has a range that satisfies 1:(3 to 30).

When implementing unit holes with different widths and depths, as in the embodiment of the present invention, the depth (a) of the second surface hole 130 serves as an important factor in controlling the thickness of deposition. If the depth (a) of the second surface hole 130 becomes too deep and exceeds the thickness ratio range described above in relation to the thickness (c) of the entire substrate, the change in the thickness of the organic material increases, resulting in deposition. A fatal problem arises in which dead space (hereinafter referred to as 'non-deposited area') occurs, and this non-deposited area reduces the area of organic matter in the entire OLED, causing a decrease in lifespan. It acts as

Therefore, in the deposition mask according to the fifth embodiment of the present invention, the ratio of the depth (a) of the second surface hole 130 and the thickness (c) of the metal plate is 1:(3.5 to 12.5) within the above-mentioned range. ) can be satisfied. , More preferably, it can be implemented to meet the ratio of 1:(4.5~10.5). In an embodiment of the present invention, the thickness (c) of the metal plate that satisfies this ratio range can be implemented as 10㎛ to 50㎛. If the thickness of the metal plate is less than 10㎛, the degree of distortion of the substrate increases, making process control difficult, and if the thickness of the substrate exceeds 50㎛, the occurrence of dead space increases during subsequent deposition, resulting in OLED It becomes impossible to implement fine patterns. In particular, in this range, the thickness (c) of the above-described substrate can be implemented to satisfy a thickness of 15㎛ to 40㎛. Furthermore, it can be more preferably implemented at 20㎛~30㎛.

In addition, it is preferable that the depth (a) of the second surface hole corresponding to the thickness (c) of the metal plate is implemented to meet the range of 0.1㎛ to 7㎛. This means that if the depth (a) of the second surface hole is less than 0.1㎛, it is difficult to implement a groove, and if the depth (a) of the second surface hole exceeds 7㎛, a non-deposited area (dead) is formed when deposited later. Due to the space, it is difficult to form OLED fine patterns, and the organic matter area is reduced, which reduces OLED lifespan. In particular, the depth (a) of the second surface hole can be implemented as 1㎛ to 6㎛, more preferably 2㎛ to 4.5㎛ in the depth range within the above range.

Here, as a factor that can be considered to further increase the efficiency of deposition, the inclination angle of the inner surface of the first surface hole 110 through which the deposition material flows can be considered. As shown in FIG. 4, this connects an arbitrary point (A ₁ ) on the outermost side of the boundary portion 120 and an arbitrary point (B ₁ ) on the outermost side of the first surface hole 110 on the first side. It can be implemented so that the inclination angle (θ) satisfies the range of 20 degrees to 70 degrees. This is because the deposition source uses a point source due to the characteristics of the deposition equipment when depositing organic materials, so that the slope angle satisfies the above range, thereby ensuring uniformity of deposition. If the inclination angle exceeds or exceeds the range above, the occurrence rate of non-deposited areas increases, making it difficult to secure uniform deposition reliability. In a preferred embodiment of the present invention that can be implemented within the range of the inclination angle (θ), the inclination angle (θ) is in the range of 30 degrees to 60 degrees, more preferably 32 degrees to 38 degrees or 52 degrees to 58 degrees. It can be implemented to meet the scope.

In the structure of the first surface hole that communicates by sharing an interface with the second surface hole according to an embodiment of the present invention, it is advantageous in terms of deposition efficiency to have a configuration in which the width of each groove narrows toward the center of the metal plate. , Especially preferably, the inner surface of the second surface hole or the first surface hole may be implemented in a structure having a curvature. This curvature structure has the advantage of controlling the input density of the deposition material and improving the uniformity of deposition compared to a simple slope structure.

In addition, the width (C) of the opening on the one side of the second side hole and the width (A) of the boundary portion according to the embodiment of the present invention, and the width (B) of the opening on the other side of the first side hole are B>C. It can be provided with a ratio of >A, which, like the effectiveness of the curvature structure described above, can control the input density of the deposition material and improve the uniformity of deposition. In addition, the difference (d=C-A) between the width (C) of the opening on the one side of the second surface hole and the width (A) of the boundary portion can be implemented to meet the range of 0.2㎛ to 14㎛. That is, the vertical distance (d1) from the outermost arbitrary point (C1) on the one side of the second surface hole to the outermost arbitrary point (A1) of the boundary portion is set to satisfy 0.1 μm to 7 μm. If the vertical distance (d1) is less than 0.1㎛, it is difficult to implement a groove, and if it exceeds 7㎛, it is difficult to form an OLED fine pattern due to a dead space during the subsequent deposition process, and the organic material area is reduced. This causes a decrease in OLED lifespan. In addition, as a preferred embodiment that can be implemented within the numerical range of the vertical distance (d1), the vertical distance (d1) can be implemented in the range of 1㎛ to 6㎛, or more preferably in the range of 2㎛ to 4.5㎛.

In addition, the corner of the opening on the one surface of the second surface hole (or first surface hole) according to an embodiment of the present invention can be implemented in a structure having a curvature. Referring to FIG. 11, considering the horizontal cross-sectional shape of the upper plane of the second surface hole 110, that is, the opening area exposed to one surface of the substrate, it is implemented as a rectangular or square structure. In this case, each corner has a rectangular or square structure. It is desirable to implement a rounded structure to have a constant curvature. In particular, when the diameter (R) of a virtual circle formed by extending the curvature of the rounded portion of the corner is implemented in the range of 5um to 20um, the deposition area can be further expanded. The shape of the groove with the edge where the attachment is formed makes it difficult to implement deposition smoothly, and non-deposited areas inevitably occur. Deposition efficiency increases in a rounded structure, and in particular, the deposition rate is highest and uniform at curvatures within the above numerical range. can be implemented. If the diameter is less than 5㎛, there is no significant difference compared to no curvature treatment, and if it exceeds 20㎛, the deposition rate actually decreases. In particular, in a preferred embodiment within the range of the diameter (R) described above, the diameter (R) can be implemented in the range of 7㎛ to 15㎛, more preferably in the range of 8㎛ to 12㎛.

In particular, in embodiments of the present invention, the surface roughness (Ra) of the one side or the other side of the substrate is preferably implemented at 2 μm or less, because this can serve as a factor that can improve the deposition quality of organic materials. If the surface roughness increases, resistance occurs when the mounting material moves along the groove, and if the surface roughness exceeds the above roughness, smooth deposition is difficult and the rate of occurrence of non-deposited areas increases.

6. Embodiment 6

Below, the structure of a deposition mask according to another embodiment of the present invention will be described. Of course, the structure of this sixth embodiment may also have the features of the second to fifth embodiments described above. Furthermore, it goes without saying that the metal substrate of the first embodiment described above can be applied in the following embodiments. However, in the following description, an example will be given where the characteristic structure of the sixth embodiment is implemented independently.

Also in this sixth embodiment, the configuration of the deposition mask includes a metal plate having first and second surfaces that are orthogonal to the thickness direction and opposing each other, and penetrates the first and second surfaces. , are the same in that they are configured to include a plurality of unit holes having first surface holes 110 and second surface holes 130 that communicate with each other.

The difference between FIG. 16 and the structure of FIG. 15 described above is that in the structure of the deposition mask including an effective area (AC) where unit holes are arranged and a non-effective area (NC) outside the effective area, the thickness of the metal plate within the effective area The difference is that it can be implemented differently from the thickness of the metal plate of the non-effective area (NC).

Referring to FIG. 16, in the sixth embodiment, considering the maximum thickness (h1) of the metal plate in the effective area where the unit hole is disposed and the maximum thickness (h ₂ ) of the metal plate in the non-effective area outside the effective area, The maximum thickness (h1) of the metal plate in the effective area can be implemented to be smaller than the maximum thickness (h ₂ ) of the metal plate in the non-effective area. In this case, the 'maximum thickness (h1) of the metal plate in the effective area' refers to the maximum protruding portion of the metal plate (hereinafter referred to as 'protrusion') that protrudes in the thickness direction of the metal plate from the surface of the second surface formed by the second surface hole. It is defined as the maximum value among the thicknesses of .;g ₁ ).

In this case, the maximum thickness (h ₂ ) of the metal plate in the non-effective area can be set to satisfy 0.2h ₁ <h ₂ <1.0h ₁ in relation to the maximum thickness (h1) of the metal plate in the effective area. Furthermore, it can be implemented to satisfy 0.2h ₁ <h ₂ <0.9h ₁ within this range.

The maximum thickness (h1) of the metal plate in the effective area can be implemented to have a thickness of 20 to 100% compared to the maximum thickness (h ₂ ) of the metal plate in the non-effective area, and within this range, the maximum thickness (h ₂ ) It can be formed to have a thickness of 25 to 85%, and even 30 to 60%. For example, when the maximum thickness (h ₂ ) of the metal plate in the non-effective area is 30㎛, the maximum thickness (h1) of the metal plate in the effective area is 6㎛~27㎛, or 7.5㎛~25.5㎛, or 9㎛~ It can be implemented in the range of 18㎛.

In this numerical range, the deposition efficiency can be increased by adjusting the slope (inclination angle) of the first surface hole, and when the height of the effective area is lowered, the deposition angle can be easily secured and controlled, which can be implemented as a high-resolution deposition mask. This is possible.

FIG. 17 conceptually illustrates the unit hole in which the first surface hole and the second surface hole in FIG. 16 communicate. As described above, especially in terms of securing this deposition angle, referring to FIGS. 16 and 17, an arbitrary point up to the boundary is selected based on a point of the opening on the surface of the metal plate of the first or second surface hole. Considering the connecting inclination angle, the slope implemented from a point in the major axis direction of the opening to the boundary and the slope implemented from a point in the minor axis direction to the boundary may be implemented differently.

Specifically, at a point in the long axis direction of the opening of the first surface hole 110 or the second surface hole 130 exposed to the surface of the metal plate, the boundary portion 120 between the first surface hole and the second surface hole A first inclination angle (θ1) up to an arbitrary point, and at a point in the short axis direction of the opening of the first surface hole or the second surface hole exposed to the surface of the metal plate, the first surface hole and the second surface hole. The second inclination angle θ2 up to the first point of the boundary portion 120 is implemented differently. That is, the slopes of the inner surfaces of the same first or second surface holes can be implemented differently. In this embodiment, the first tilt angle θ1 is implemented to be smaller than the second tilt angle θ2, and in this case, the first tilt angle θ1 can be implemented in the range of 20° to 80°. When the angle of the slope is implemented differently even within the same second surface hole (or first surface hole), the advantage of improving the uniformity of the deposit is realized.

In addition, in the structure of the sixth embodiment, it is possible to form a structure in which curvature is implemented at the point of the protrusion g1 that opposes the attachment of the effective area described above in the drawing of FIG. 16. In this way, if the curvature is implemented at the point of the protrusion (g1) opposing the attachment of the effective area, the deposition material flowing in through the first surface hole during deposition can be efficiently dispersed and introduced into other adjacent areas. As a result, deposition efficiency and deposition uniformity can be increased. To achieve this, the curvature formed at the point of the protrusion g1 is implemented so that the radius of curvature (R) is 0.5 μm or more. If the radius of curvature (R) is implemented as less than 0.5㎛, the above-mentioned dispersion efficiency is reduced.

In addition, in the structure of this sixth embodiment, a tension control pattern (HF) etched in the thickness direction of the metal plate can be implemented in the non-effective area (NC) shown in the drawing of FIG. 16. The tension control pattern (HF) may be implemented as a groove pattern structure (hereinafter defined as a 'half-etching area') that does not penetrate the metal plate. The half-etched area may be implemented to have a thickness thinner than the thickness (h1) of the metal plate. This means that during OLED deposition, the equipment applies tension to the deposition mask itself. In this case, the phenomenon of tensile force being concentrated in the active area can be dispersed to enable efficient deposition and ensure uniformity of the deposition material. performs its function.

In particular, in the case of the half-etched area, it can be implemented to have a thickness of 10% to 100% of the thickness (h1) of the metal plate. That is, the thickness (h3) of the half-etched area can be implemented to satisfy the relationship of 0.1h1<h3<1.0h1 in relation to the thickness (h1) of the metal plate in the non-effective area. In a thickness range of 10% to 100% of the thickness (h1) of the metal plate, the thickness of the half-etched area can be implemented as 20% to 80%, or 30% to 70%.

For example, in the case of a 30㎛ thick metal plate, the half-etched area may have a thickness of 3㎛ to 27㎛ (a thickness range of 10% to 90% of the thickness (h1) of the metal plate). Furthermore, in order to realize the tensile force distribution effect by implementing a slimmer structure, it can be implemented in the range of 6㎛~24㎛, which is 20%~80% of the metal plate thickness, or 9㎛~21㎛, which is 30%~70% of the metal plate thickness. You can.

Figure 18 is an image of the first surface portion where the first surface hole of Figure 17 is implemented. Referring to FIGS. 17 and 18, in the structure of the sixth embodiment, a plurality of portions of the first surface, which are opposite surfaces to the protrusion g1 opposing the attachment of the effective area described above, are implemented. The height of the first side can be implemented to be different from each other so that the pitch of deposition can be reduced during the deposition process. That is, in the structure of FIG. 18, the heights of points Z1, Z2, and Z3 can be implemented differently.

In the detailed description of the present invention as described above, specific embodiments have been described. However, various modifications are possible without departing from the scope of the present invention. The technical idea of the present invention should not be limited to the above-described embodiments of the present invention, but should be determined not only by the claims but also by equivalents to the claims.

100: Mask for deposition
110: 1st side ball
120: border
130: 2nd side ball
200: Sample board
210: Etching area
220: Non-etching area

Claims (8)

A metal plate comprising a first side and a second side opposite the first side,
The metal plate has a plurality of unit holes including a first surface hole formed on the first surface, a second surface hole formed on the second surface, and a boundary portion communicating the first surface hole and the second surface hole. Including,
The width of the first surface hole is greater than the width of the second surface hole,
The first inclination angle formed between the long axis direction of the first surface hole and an imaginary line connecting a point in the long axis direction of the opening of the first surface hole exposed to the surface of the metal plate and the first point of the boundary portion is the surface of the metal plate An imaginary line connecting a point in the minor axis direction of the opening of the first surface hole exposed to and a second point of the boundary portion is different from the size of the second inclination angle formed by the minor axis direction,
A mask for deposition, wherein a point along the major axis of the opening of the first surface hole and a point along the minor axis of the opening of the first surface hole are located at the same height. A metal plate comprising a first side and a second side opposite the first side,
The metal plate has a plurality of unit holes including a first surface hole formed on the first surface, a second surface hole formed on the second surface, and a boundary portion communicating the first surface hole and the second surface hole. Including,
The width of the first surface hole is greater than the width of the second surface hole,
The first inclination angle formed between the long axis direction of the second surface hole and an imaginary line connecting a point in the long axis direction of the opening of the second surface hole exposed to the surface of the metal plate and the first point of the boundary portion is the surface of the metal plate An imaginary line connecting a point in the minor axis direction of the opening of the second surface hole exposed to and a second point of the boundary portion is different from the size of the second inclination angle formed by the minor axis direction,
A mask for deposition, wherein a point along the major axis of the opening of the second surface hole and a point along the minor axis of the opening of the second surface hole are located at the same height. According to claim 1 or 2,
A deposition mask wherein the first inclination angle is smaller than the second inclination angle. According to claim 1 or 2,
The first inclination angle is a deposition mask of 20 to 80 degrees. According to claim 1 or 2,
A deposition mask wherein the ratio of the depth of the second surface hole and the thickness of the metal plate satisfies 1:(3-30). According to claim 1 or 2,
A deposition mask wherein the depth of the second surface hole is 0.1㎛ to 7㎛. According to claim 1 or 2,
A deposition mask where the difference (CA) between the width of the second surface hole and the width of the boundary portion is 0.2 ㎛ to 14 ㎛. According to claim 1 or 2,
An edge of the first surface hole or an edge of the second surface hole has a curvature with a radius of curvature of 2.5㎛ to 10㎛.