KR20210144630A - Metal substrate and Mask using the same - Google Patents

Abstract

According to an embodiment of the present invention, a metal substrate and a mask for vapor deposition using the same maximize vapor deposition efficiency and has twist index (Hr) that can minimize twist that occurs when etching a metal substrate to manufacture a vapor deposition mask. The vapor deposition mask comprises a metal plate comprising a first surface and a second surface opposite to the first surface.

Description

Metal substrate and mask for deposition using the same

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

In the manufacturing process of an organic EL color display made of an organic EL light emitting device, an organic layer made of an 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 provided. is being used In general, in the case of the penetration hole constituting the deposition mask, a photoetching method in which etching is applied after pattern exposure using a photoresist film on a metal thin film, or an electroforming method in which a glass original is electroplated in a desired pattern and then peeled off can be formed

A conventional deposition mask is typically implemented as a metal mask, which is focused on accurately implementing only an open area for deposition. However, this method does not show a great effect in reducing the deposition efficiency and the area where deposition is not performed (dead space).

In particular, the deposition mask itself is implemented as a very thin metal plate. This metal plate is manufactured with a large number of through holes. After production, the distortion of the substrate increases, which acts as a fatal defect that lowers the uniformity of deposition. are doing

Embodiments of the present invention have been devised to solve the above-described problems, and in particular, to provide a metal substrate capable of minimizing distortion that occurs when the metal substrate is etched to prepare a deposition mask. Furthermore, it is possible to implement a deposition mask having a plurality of deposition unit holes based on such a metal substrate.

In addition, it is possible to increase the deposition efficiency by controlling the roughness of the unit hole of the deposition mask.

As a means for solving the above problems, in an embodiment of the present invention, a base metal plate having a thickness; The base metal plate is orthogonal to the thickness direction and has first and second surfaces opposite to each other, and both sides of the sample substrate taken at an arbitrary point of the base metal plate by 30mm * 180mm (horizontal * vertical) An etched area is etched to a thickness of 2/3 to 1/2 of the thickness with respect to the inside, leaving 10 mm inward from the end, and when the sample substrate is mounted on a horizontal target surface, the torsion index of the sample substrate ( Hr) to provide a metal substrate that satisfies the following relationship.

{Formula 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 separation distance of the distances (H1, H2, H3, H4) at which the four corners of the sample substrate are spaced apart from the horizontal target plane.

In addition, it is possible to provide a deposition mask having a plurality of deposition unit holes using the above-described metal substrate.

According to an embodiment of the present invention, there is an effect that it is possible to provide a metal substrate capable of minimizing the distortion that occurs when the metal substrate is etched in order to be manufactured as 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 embodiment of the present invention described above, the distortion of the deposition mask itself can be significantly reduced, so that the deposition uniformity And there is an effect of maximizing the 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 embodiment of the present invention, the surface roughness of the inner peripheral surface of the unit hole is controlled. Thus, there is an effect of increasing the deposition efficiency and uniformity.

1 and 2 are conceptual views for explaining the characteristics of a metal substrate according to an embodiment of the present invention.
3 is a conceptual diagram for explaining a deposition process and an application process of a deposition mask.
4 is a cross-sectional view showing a main part of the deposition mask when the deposition mask is implemented using the metal substrate described above in the first embodiment.
5 and 6 are graphs for explaining the concept of illuminance.
7 and 8 show an actual image of the appearance of the first surface hole of FIG.
9 is a graph for explaining straightness.
FIG. 10 is a plan view of the second surface of the 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 surface of the deposition mask in the structure of FIG. 4 .
12 shows a modified example of the structure of FIG. 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 accompanying drawings. In the description with reference to the accompanying drawings, the same components are given the same reference, regardless of the reference numerals, and redundant description thereof will be omitted. Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

1. Example 1

1 and 2 show a metal substrate according to an embodiment of the present invention by etching a base metal plate having a thickness to implement a metal substrate having a thickness for manufacturing a deposition mask. makes it possible to implement a metal substrate that can minimize the phenomenon.

To this end, in the metal substrate according to the first embodiment of the present invention, as shown in FIG. 1 , a sample substrate is extracted from a base metal plate having a predetermined thickness as a whole, and etching is performed on the sample substrate 200 . The applied etching region 210 and the unetched region 220 may be implemented. Substrates that are not applied are defined as 'unit substrates'.)

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, leave 10 mm inward from both ends of the sample substrate 200 taken at any point of the base metal plate by 30 mm * 180 mm (width * length) (220 parts), and the thickness of the inside The etching region 210 etched to a thickness of 2/3 to 1/2 of meet the

{Formula 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 separation distance of the distances (H1, H2, H3, H4) at which the four edges of the etched sample substrate are separated from the horizontal target plane.)

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

Referring to FIG. 3 , a 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 a deposition source (S; Source) glass providing a deposition material To implement the deposition target (T) on the substrate (G) such as. In this case, the deposition mask (M; 100) is implemented in a structure including a plurality of unit holes. In general, in order to improve deposition uniformity during OLED deposition, a deposition mask should be maintained in a uniform state during the deposition process.

However, basically, when etching a metal plate to produce a deposition mask, the thickness becomes very thin, and when a plurality of deposition holes are implemented here, the deposition mask is easily twisted, It is impossible to ensure uniformity of deposition in the same arrangement structure.

Accordingly, in the embodiment of the present invention, it is possible to provide a metal plate or a metal substrate capable of minimizing distortion occurring during etching of the metal plate. In the manufacturing process of the metal substrate of the present invention, a sample substrate is taken as a base metal plate with a size of 30 mm X 180 mm.

Thereafter, ½ to 2/3 of the sample substrate is etched, leaving 10 mm on both sides of the 180 mm long axis. Thereafter, when the sample substrate on which the etching has been made is placed on a plane in which the horizontality is secured, for example, on an object such as a surface plate, the height at which the four corners of the sample substrate are spaced apart from the reference plane of the horizontal object surface of the surface plate H1, Measure H2, H3 and H4.

In this case, when H1, H2, H3, and H4, which are the heights at which the four corners of the sample substrate are spaced apart, are equal to or greater than '0', this state is defined as 'twist' of the sample substrate, and the degree of this twist is described in detail. The indexed thing as in Equation 1 is defined as the torsion index (Hr).

Therefore, as the torsion index (Hr) of the sample substrate increases, the degree of distortion of the substrate becomes severe, and in this embodiment of the present invention, an unetched sample substrate extracted with the same size (30 mm × 180 mm) at any point of the base metal plate ( Hereinafter, referred to as a 'unit substrate') and the torsion index of the etched sample substrate is compared, the torsion index of the etched sample substrate is formed to be larger than the torsion index of the unetched sample substrate.

That is, the unetched sample substrate (unit substrate) collected at 30 mm × 180 mm (horizontal × vertical) for any point of the above-described base metal plate is mounted on a horizontal target surface, and the four corner points of the substrate T1. The torsion index (Hr(T1)) according to the {Equation 1} and {Equation 2} obtained for , which can be expressed in the following way.

{expression 3}

Hr(T1) ≤ Hr(T2)

In particular, in the embodiment of the present invention, the torsion index of the sample substrate may be implemented to be 10 or less. For example, when the thickness of the base substrate is 20 μm, the sample substrate is extracted and etched, and four corners of the sample substrate on which the etching is performed are 10 μm or less with respect to the horizontal plane. That is, the torsion index of the sample substrate to which the etching is applied may be implemented to be 10 or less, and preferably may be implemented in the range of 0.2-7, or 0.5-5. If the twist index of the sample substrate is 10 or less, it is possible to prevent distortion during the manufacture of the final deposition mask, and the left and right deviations during OLED deposition are reduced, thereby increasing the deposition uniformity.

In order to realize the torsion index of the sample substrate according to the embodiment of the present invention to be 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. Once the cooling process is carried out at a temperature of 10-20 ℃ in the state of the base material, and then rolling is implemented, the rolling process is implemented to realize a metal plate of the desired thickness. In this case, the degree of rolling is important, In this case, the rolling rate can be implemented in a ratio of 2/3 to ^{1/5 of the unit volume (1mm 3 ) of any point of the base material.}

2 is a view for explaining a torsion index when a sample substrate is taken and etched from the base metal plate 200 according to the embodiment of the present invention. As shown, the sample substrate is 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 in the minor 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, a plurality of unit holes penetrating the first and second surfaces of the etching region of the metal substrate and having first and second surface holes communicating with each other are included. It can be implemented as a deposition mask. In particular, in the deposition mask implemented in this way, the distortion of the mask is remarkably reduced, so that the reliability of deposition can be realized.

2. Second embodiment

4 is a cross-sectional view showing a 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 has a thickness as shown in the structure shown in FIG. 4, is orthogonal to the thickness direction, and includes a metal plate having first and second surfaces opposite to each other. and a plurality of unit holes having a first surface hole 110 and a second surface hole 130 that pass through the first surface and the second surface and communicate with each other. In this case, the first surface hole 110 and the second surface hole 130 communicate by sharing the boundary portion 120 that is a mutually communicating portion. Such unit holes may be implemented in a structure in which a plurality of holes are provided.

In particular, in this case, the unit hole implemented in the deposition mask may have a roughness value equal to or less than the roughness value of the third roughness Ra3 that is the surface roughness of the first surface 112 . That is, based on the third roughness Ra3, the value of the first roughness Ra1 of the first inner surface or the second roughness Ra2 of the second inner surface 131 that is the inner surface of the second surface hole is more Make it small. [Ra3≥(Ra2 or Ra1)]

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

This affects the straightness (line roughness of FIG. 7) of the unit hole, which is a hole for deposition, when the deposition mask is manufactured when the roughness is greater than a certain amount on the surface of the deposition mask implemented as a metal mask, so that organic material deposition is difficult. This is not good, and when cleaning after deposition of organic materials such as OLED, the cleaning power is lowered and the lifespan of the deposition mask is shortened.

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

In this case, the arithmetic mean 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 FIG. 5, and the surface within one reference length It is defined as the value obtained by averaging the heights and depths of the mountains and valleys of 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 reference line (center line) of the surface for measuring the roughness, and this is implemented as an arithmetic average.

Furthermore, in another aspect of the embodiment of the present invention, the 10-point average roughness (Rz) value of at least one of the first inner surface, the second inner surface, and the first surface in the deposition mask is 3.0 μm or less. to be implemented as 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 2.5 or less and 1.5 to 2.5 or less, so that the deposition is more reliable efficiency can be realized. In this case, the '10-point average roughness (Rz)' is, as shown in FIG. 6, the surface roughness of ten points (Ten Point Height of Irregularities, Rz).

Furthermore, the deposition mask according to the embodiment of the present invention allows the line roughness of the outer diameter of the unit hole described above in FIG. 4 , so-called 'straightness of the unit hole' to be implemented as 1.5 μm. Line roughness of the outer diameter of the unit hole, that is, straightness, is a measure that draws a straight line from the center point of the outer diameter of the hole to be measured as a reference line (center line) and deviates from this center line in either direction. Express the distance away as a straight line.

The measurement of this straightness in the embodiment of the present invention will be described with reference to FIGS. 7 to 9 . 7 and 8 show an actual image of the state of the first face hole of FIG. 4, and with reference to this, the minor and major axes of the opening of the first face hole are respectively referred to as x and y, and only the long axis of the y-axis If the total length of the measured y-axis is divided by 1/2, and the center is y2, the roughness of the outer diameter line of the opening is measured in the range of 1.5㎛ left and right from y2, 3㎛ in total. In this case, the measurement range should not exceed 3 μm, and the straightness within the range of 3 μm may be realized for the deposition mask according to the embodiment of the present invention to be 1.5 μm or less. That is, in a measurement range of 3㎛, straightness can be implemented to 1.5㎛ or less.

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 with a structure in which the features of the second embodiment are added. However, in the following description, an example of independently implementing only the characteristic parts of the third embodiment of the present invention will be described.

The characteristics of the third embodiment will be described with reference to the cross-sectional view of the deposition mask of FIG. 4 . That is, the deposition mask 100 according to the embodiment of the present invention has a thickness, as in the structure shown in FIG. 4 , is orthogonal to the thickness direction, and has a first surface and a second surface facing each other. It is configured to include a plurality of unit holes having a metal plate, passing through the first and second surfaces, and having first and second surface holes 110 and 130 communicating with each other. In this case, the first surface hole 110 and the second surface hole 130 communicate by sharing the boundary portion 120 that is a mutually communicating portion. Such unit holes may be implemented in a structure in which a plurality of them are provided. In particular, in an embodiment of the present invention, the size deviation of the first surface hole or the second surface hole between adjacent unit holes is based on the size deviation between arbitrary unit holes. It should be implemented within 2%~10%.

In this case, the size deviation between adjacent unit holes may be compared based on a difference in diameter between the first surface holes and the second surface holes with respect to each other.

This structure will be described with reference to FIGS. 10 and 11 . FIG. 10 is a plan view of the second surface of the deposition mask according to an embodiment of the present invention in the structure of FIG. 4 , and FIG. 11 is the deposition mask in the structure of FIG. 4 . A plan view of the first surface of

Referring to FIG. 10 , the vertical diameter (Cy) and the horizontal diameter (Cx) of an arbitrary entity (hereinafter, referred to as a 'reference hole') of the second surface hole of the unit hole implemented in a plurality on the second surface is obtained. In the case of measurement, the deviation between the diameters Cy in the vertical direction between the holes adjacent to the reference hole (a total of six in the drawing shown) can be realized within 2% to 10%. In addition, the deviation of the diameter (Cx) in the horizontal direction of the reference hole and other adjacent holes can also be realized within 2% to 10%. That is, when the size deviation 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 diameter (Cx) in the vertical direction or the diameter (Cx) in the horizontal direction of the reference hole and the other adjacent hole is within 4% to 9%, in particular, the vertical diameter (Cx) of the reference hole and the other adjacent hole However, when the deviation of the diameter (Cx) in the horizontal direction is realized within 5% to 7%, the uniformity of deposition is further increased. Conversely, when all the holes have the same size, the generation rate of moire increases in the OLED panel after deposition, and when the size deviation between adjacent holes exceeds 10% based on the reference hole The occurrence rate of color blemishes in the OLED panel after deposition increases.

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

For example, in FIG. 10 , when 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 realized within 2% to 10%, and deposition efficiency is increased.

As another example, when the horizontal diameter (Cx) of the reference hole in FIG. 10 is 125 μm, when the diameter of the neighboring hole is 122 μm or 128 μm, the deviation rate of the diameter compared to the reference hole is 2.4%, 2% to 10% above In this case, the deposition efficiency is increased.

12 is a plan view of the first surface hole 110 and the second surface hole 130 viewed from the second surface in the structure of FIG. 11, and when calculating the size deviation between the holes, any projections on the outer peripheral surface of the hole In this case, it is preferable that the maximum value of the width (Y1) or the height (X1) of the protrusion protruding from the outer circumferential surface of the second surface hole in the central direction can be realized to be 20 μm or less. These protruding protrusions correspond to a defective structure that inevitably occurs 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-described protrusion can be realized to be 11 μm or less, and further 6 μm or less.

4. Example 4

Hereinafter, the structure of the deposition mask according to another embodiment of the present invention described above with reference to FIGS. 4, 10, and 11 will be described. It goes without saying that the structure of the fourth embodiment may have the features of the third embodiment described above at the same time. Furthermore, in the following embodiments, the metal substrate of the first embodiment described above can be applied, and of course, it can be implemented with a structure in which the characteristics of the second embodiment are added. However, in the following description, an example in which the characteristic structure of the fourth embodiment is independently implemented will be described as an example.

As shown in FIGS. 4 and 13, the deposition mask according to the fourth embodiment includes a metal plate having a thickness, passing through the first surface and the second surface to the metal plate, and communicating with each other. The structure is the same as that of the first embodiment in that it has a structure including a plurality of unit holes having a single surface hole and a second surface hole. However, it is characterized 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 to be shifted so that they do not coincide with each other.

As in the fourth embodiment of the present invention, when the centers of the first surface hole and the second surface hole are displaced so as not to coincide with each other, a superior advantage is realized in that a high deposition uniformity can be secured. As shown in FIG. 13, when the radiation angle emitted from the deposition source S spaced apart from the deposition mask having a plurality of unit holes is taken into consideration, the positions corresponding to the deposition source source and the unit holes are all different. As a result, it becomes difficult to evenly transfer the deposition material. 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 implemented to be shifted from each other for each hole, so that even in the deposition process over the entire surface of the large area of the substrate, the deposition material is delivered evenly. It can be realized 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 do not coincide with each other is to set an imaginary vertical line orthogonal to the surface of the first surface or the second surface of the metal plate on the center of the first surface hole, or , in the case of standing on the center of the second surface hole, it means a structure in which this vertical line passes through only one of the two centers. In other words, the central axes of the first surface hole or the second surface hole are disposed to be shifted from 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 of the first and second surface holes when the outer peripheral surfaces of the first and second surface holes are circles or ellipses. In this case, it means the center of gravity.

Alternatively, as in the structure shown in FIG. 13 , if the center of gravity can be determined even in the case of having a curvature structure in which a round treatment is performed on the corner portion, the center of gravity is taken as the center. Furthermore, the curvature of the outer part of the face ball (in the embodiment of the present invention, if there is an attachment, the attachment is taken as a corner, and in the case of an edge part having a curvature, the curvature is greater than the curvature of the periphery connected to the 'curvature') The case where it becomes smaller is defined as an edge.) is implemented, if there are n corners with curvature, if n is an even number, draw a straight line with the opposite corner, and if the number of these drawn straight lines is "K" , If the number of straight lines (K) is 3, draw a circle around the point where three straight lines meet, and if K is 2, draw a circle around the point where the two straight lines meet. Alternatively, if the number of edges n is odd, draw a straight line on the side opposite to the edge, and if the number of straight lines is "k", until the number of straight lines (k) becomes 3 or 2, and through this, each The point where the straight lines meet is the center of the face hole.

For example, FIG. 14 is an exemplary view for explaining a method of determining the center (F) of the first surface hole 110 in FIG. 13, and there are a total of four (even) rounded corners, one center point of the curvature If straight lines (b1, b2) are drawn with the center point of the other corners facing each other, the number of straight lines (K) is two, and the point where these two straight lines meet is the center (F) of the first face hole.

In addition, the center (E) of the second surface hole 130 is also determined in the same way, and a unit groove is implemented so that the respective centers (E, F) are disposed to be shifted from each other. In particular, as shown in the figure 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 length (A) of the diameter of the second surface hole % or less, that is, it can be implemented with 0.9A or less. Further, the distance (d) between the center (F) of the first face hole and the center (E) of the second face hole is preferably within this range 50% of the length (A) of the diameter of the second face hole or less, more preferably 0.1% to 10% or less, 0.2 to 8% or less, or 0.2 to 5% or less. When the deviation of the distance between the central axes can be realized in the range of 90% or less of the length (A) of the diameter of the second surface hole, the uniformity of the deposition efficiency can be further increased.

As described above, in the deposition operation applying the deposition mask, since all the unit holes of the deposition source and the mask cannot be arranged vertically lower, respectively, in order to improve the deposition uniformity of the OLED, the unit Each hole requires a certain angle or higher back height.

In this case, when the deposition mask according to the embodiment of the present invention is applied, the deposition efficiency may be increased by mismatching the arrangement positions of the first surface hole and the second surface hole (Miss Match). Furthermore, due to this arrangement structure, it is possible to reduce a dead space during deposition, and it is possible to increase the deposition thickness or apply a thick material to high utilization during deposition. This is because, in the equipment for OLED deposition, there is a problem in that the tensile force is increased during large-area deposition. When the unit hole pattern is used, it is possible to evenly distribute the tensile force, thereby ensuring OLED deposition uniformity.

5. Example 5

Hereinafter, a 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 have the features of the second to fourth embodiments described above at the same time. Furthermore, it goes without saying that the metal substrate of the first embodiment can be applied to the following embodiments. However, in the following description, an example in which the characteristic structure of the fifth embodiment is independently implemented will be described as an example.

15 is a conceptual diagram illustrating a cross-sectional structure of a deposition mask according to a fifth embodiment of the present invention configured to include a plurality of unit holes described above in FIG. 4 .

4 and 15 , a deposition mask according to a fifth embodiment of the present invention includes a metal plate having a thickness, wherein the metal plate is orthogonal to the thickness direction, and has a first surface and a first surface opposite to each other. A unit hole having two surfaces, passing through the first surface and the second surface in this case, and having a first surface hole 110 and a second surface hole 130 communicating through a boundary portion 120 connected to each other It consists of many

In particular, in the unit hole, a depth in a thickness direction of the metal plate of the first surface hole and a depth in a thickness direction of the metal plate of the second surface hole may be different from each other. In this case, the first surface hole 110 and the second surface hole 130 are the second surface hole 130 in which deposition is implemented based on the outermost protruding points A1 to A21 of the boundary portion 120, which is a part communicating with each other. The area in which this arrangement is placed is called the effective area (AC), and the first surface hole 110 and the second surface hole 130 are the outermost protrusion point ( An area in which the second surface hole included in the outer area of A1 and A21 is not disposed is defined as an ineffective area NC.

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

When realizing unit holes having different widths and depths as in the embodiment of the present invention, the depth (a) of the second surface hole 130 acts as an important factor for controlling the thickness of the deposition. When the depth (a) of the second surface hole 130 becomes too deep, and exceeds 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, and this causes the deposition A fatal problem occurs in that a dead space (hereinafter, referred to as an 'undeposited area') occurs, and this non-deposited area reduces the area of organic materials in the entire OLED, thereby reducing the lifespan. will act as

Accordingly, 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 to the thickness (c) of the metal plate is 1: (3.5 to 12.5) within the above-described range. ) can be satisfied. , more preferably 1: (4.5 to 10.5) can be implemented to satisfy the ratio. In an embodiment of the present invention, the thickness (c) of the metal plate satisfying this ratio range may be implemented in a range of 10 μm to 50 μm. When the thickness of the metal plate is less than 10 μm, the degree of distortion of the substrate increases, making process control difficult, and when the thickness of the substrate exceeds 50 μm, the occurrence of a dead space increases during subsequent deposition to OLED It becomes impossible to implement a fine pattern of In particular, the thickness (c) of the above-described substrate in this range can be implemented to satisfy a thickness of 15㎛ ~ 40㎛. Furthermore, more preferably, it can be implemented in 20 μm to 30 μm.

In addition, the depth (a) of the second surface hole corresponding to the thickness (c) of the metal plate is preferably implemented to satisfy the range of 0.1㎛ ~ 7㎛. When the depth (a) of the second surface hole is less than 0.1 μm, it is difficult to implement the groove, and when the depth (a) of the second surface hole exceeds 7 μm, when deposited later, the non-deposited area (dead) Space), it is difficult to form an OLED fine pattern, and the organic material area is reduced, which reduces the OLED lifespan. In particular, the depth (a) of the second surface hole may be implemented as 1㎛ ~ 6㎛ in the depth range within the above range, more preferably, it may be implemented as 2㎛ ~ 4.5㎛.

Here, as a factor that can be considered to further increase the deposition efficiency, the inclination angle of the inner surface of the first surface hole 110 through which the deposition material is introduced may be considered. _{As shown in FIG. 4, it connects an arbitrary point (A 1} ) of the outermost portion of the boundary portion 120 _{and an arbitrary point (B 1} ) of the outermost portion of the first surface hole 110 of the first surface. The inclination angle θ may be implemented to satisfy the range of 20 degrees to 70 degrees. This is because the deposition source uses a point source during deposition of organic materials due to the characteristics of deposition equipment, so that the slope angle satisfies the above range to ensure uniformity of deposition. When the range of the inclination angle is exceeded or out of the range, the occurrence rate of the non-deposited area increases, making it difficult to secure uniform deposition reliability. As a preferred embodiment that can be implemented within the range of the inclination angle θ in the embodiment of the present invention, 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.

The structure of the first surface hole of a structure communicating by sharing the interface with the second surface hole according to an embodiment of the present invention is advantageous in terms of deposition efficiency to have a configuration in which the width of each groove is narrowed in the central direction of the metal plate, , particularly preferably, the inner surface of the second surface hole or the first surface hole may be implemented in a structure having a curvature. Such a curvature structure has the advantage of controlling the input density of the deposition material and improving the uniformity of deposition compared to the simple slope structure.

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

In addition, according to an embodiment of the present invention, the corner portion of the opening on the one surface of the second surface hole (or the first surface hole) 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 on one surface of the substrate, it is implemented in a rectangular or square structure, and in this case, each corner portion has It is preferable to be implemented in a rounded structure to have a constant curvature. In particular, when the diameter (R) of the virtual circle formed by extending the curvature of the rounded portion of the corner portion is implemented in the range of 5um to 20um, the deposition area can be further increased. The shape of the groove portion having the edge where the attachment is formed makes it difficult to smoothly implement the deposition, inevitably causes an undeposited area, and increases the deposition efficiency in a rounded structure. can be implemented. If the diameter is less than 5㎛, there is no big difference from that without the curvature treatment, and if it exceeds 20㎛, the deposition rate is rather decreased. In particular, as a preferred embodiment within the range of the above-mentioned diameter (R), the diameter (R) may be implemented in the range of 7㎛ ~ 15㎛, more preferably 8㎛ ~ 12㎛.

In particular, in an embodiment of the present invention, the surface roughness (Ra) of the one surface or the other surface of the substrate is preferably implemented to be 2 μm or less, which can act as a factor for improving the deposition quality of organic materials. When the surface roughness is large, resistance occurs in moving the mounting material through the groove, and when the surface roughness is greater than the above roughness, it is difficult to achieve smooth deposition, and the rate of occurrence of undeposited areas increases.

6. Example 6

Hereinafter, a 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 sixth embodiment may have the features of the second to fifth embodiments described above at the same time. Furthermore, it goes without saying that the metal substrate of the first embodiment can be applied to the following embodiments. However, in the following description, an example in which the characteristic structure of the sixth embodiment is independently implemented will be described as an example.

Also in the sixth embodiment, the deposition mask has a metal plate having first and second surfaces opposite to each other and perpendicular to the thickness direction, passing through the first and second surfaces, , the same in that it is configured to include a plurality of unit holes having a first surface hole 110 and a second surface hole 130 that communicate with each other.

The difference between the structure of FIG. 16 and the structure of FIG. 15 is that in the structure of the deposition mask including the effective area AC in which the unit holes are disposed and the ineffective area NC outside the effective area, the thickness of the metal plate in the effective area is different from the thickness of the metal plate of the ineffective region NC to be implemented.

Referring to FIG. 16 , in the sixth embodiment, considering the maximum thickness h1 of the metal plate of the effective area in which the unit hole is disposed and the maximum thickness h ₂ of the metal plate of the non-effective area outside the effective area, The maximum thickness h1 of the metal plate of the effective region may be realized to be smaller than _{the maximum thickness h 2 of the metal plate of the non-effective region.} In this case, the 'maximum thickness (h1) of the metal plate in the effective area' is the maximum protruding portion of the metal plate protruding in the thickness direction of the metal plate from the surface of the second surface realized of the second surface hole (hereinafter referred to as 'protrusion') .;g ₁ ) is defined as the maximum value among the thicknesses.

_{In this case, the maximum thickness h 2} of the metal plate in the non-effective region may satisfy _{0.2h 1} <h ₂ <1.0h ₁ in relation to the maximum thickness h1 of the metal plate in the effective region. Furthermore, it can be implemented to satisfy _{0.2h 1} <h ₂ <0.9h _{1 within this range.}

And the maximum thickness (h1) of the effective area, the metal plate than the maximum thickness (h ₂₎ of the metal plate of the non-effective region is implemented to have a thickness of 20 to 100%, of the maximum thickness (h ₂₎ in the range It can be formed to have a thickness of 25 to 85%, further 30 to 60%. _{For example, when the maximum thickness (h 2} ) of the metal plate in the non-effective area is 30 µm, the maximum thickness (h1) of the metal plate in the effective area is 6 µm to 27 µm, or 7.5 µm to 25.5 µm, or 9 µm to It should be implemented in the range of 18㎛.

In the above numerical range, the inspection 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 is realized as a high-resolution deposition mask. This is possible.

17 is a conceptual view illustrating a unit hole through which the first surface hole and the second surface hole communicate in FIG. 16 . As described above, in particular in terms of securing such a deposition angle, referring to FIGS. 16 and 17, based on one point of the opening on the surface of the metal plate of the first surface hole or the second surface hole, an arbitrary point up to the boundary Considering the connecting inclination angle, a slope implemented from one point in the major axis direction to the boundary portion of the opening and a slope from one point in the minor axis direction to the boundary portion may be implemented differently from each other.

Specifically, at one point in the long axis direction of the opening of the first surface hole 110 or the second surface hole 130 exposed on 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 of and at a point in the minor axis direction of the opening of the first or 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 a point of the boundary portion 120 is implemented to be different from each other. That is, the slopes of the same inner surface of the first surface hole or the second surface hole may be implemented differently. In this embodiment, in particular, the first inclination angle θ1 is implemented to be smaller than the second inclination angle θ2, and in this case, the first inclination angle θ1 is implemented in the range of 20° to 80°. If the angle of the slope is implemented differently even within the same second surface hole (or the 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 the curvature is realized at the point of the protrusion g1 opposite to the attachment of the effective area described above in the drawing of FIG. 16 . In this way, when the curvature is realized at the point of the protrusion g1 opposite to the attachment of the effective area, the deposition material introduced through the first surface hole during deposition is efficiently dispersed and introduced into other adjacent areas. As a result, deposition efficiency and deposition uniformity can be increased. To this end, the curvature formed at the point of the protrusion g1 is such that the radius of curvature R is realized to be 0.5 μm or more. When the radius of curvature R is implemented to be less than 0.5 μm, the above-described dispersion efficiency is lowered.

In addition, in the structure of the sixth embodiment, the tensile force 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 tensile force control pattern HF may be implemented as a groove pattern structure (hereinafter, defined as a 'half-etched region') implemented in a structure that does not penetrate the metal plate. The half-etched region may be implemented to have a thickness smaller than the thickness h1 of the metal plate. In this case, the equipment applies a tensile force to the deposition mask itself during OLED deposition. In this case, it is possible to efficiently deposit by dispersing the phenomenon in which the tensile force is concentrated in the effective region (active region) and to ensure uniformity of the deposition material. perform the function

In particular, in the case of the half-etched region, it may be implemented to have a thickness of 10% to 100% compared to the thickness h1 of the metal plate. That is, the thickness h3 of the half-etched region may be implemented to satisfy the relationship of 0.1h1<h3<1.0h1 with respect to the thickness h1 of the metal plate of the ineffective region. In the thickness range of 10% to 100% compared to the thickness h1 of the metal plate, the thickness of the half-etched region may be implemented as 20% to 80%, or 30% to 70%.

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

18 is an image of a portion of the first surface in which the first surface hole of FIG. 17 is implemented. 17 and 18, in the structure of the sixth embodiment, a plurality of portions of the first surface opposite to the protrusion g1 against the attachment of the above-described effective area are implemented. By implementing different heights of the first surface portion, it is possible to reduce the pitch of deposition 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 spirit of the present invention should not be limited to the above-described embodiments of the present invention, and should be defined by the claims as well as the claims and equivalents.

100: mask for deposition
110: first face hole
120: border
130: second surface hole
200: sample substrate
210: etching area
220: unetched area

Claims (8)

A metal plate comprising a first surface and a second surface opposite to the first surface,
The metal plate includes 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 do,
The width of the first face hole is greater than the width of the second face hole,
A first inclination angle formed by an imaginary line connecting a point in the long axis direction of the opening of the first face hole exposed on the surface of the metal plate and one point of the boundary portion and the long axis direction of the first face hole is exposed on the surface of the metal plate An imaginary line connecting a point in the minor axis direction of the opening of the first face hole and a point of the boundary part and a second inclination angle formed by the minor axis direction are different from each other in a deposition mask. Deposition mask. A metal plate comprising a first surface and a second surface opposite to the first surface,
The metal plate includes 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 do,
The width of the first face hole is greater than the width of the second face hole,
A first inclination angle formed by an imaginary line connecting a point in the long axis direction of the opening of the second surface hole exposed on the surface of the metal plate and a point in the boundary portion and the long axis direction of the second surface hole is exposed on the surface of the metal plate An imaginary line connecting one point in the minor axis direction of the opening of the second face hole and one point of the boundary part and the second inclination angle formed by the minor axis direction are different from each other in the size of the deposition mask. Deposition mask. 3. The method of claim 1 or 2,
The first inclination angle is smaller than the second inclination angle. 3. The method of claim 1 or 2,
The first inclination angle is 20 to 80 degrees for the deposition mask. 3. The method of claim 1 or 2,
The ratio of the depth of the second surface hole to the thickness of the metal plate is 1: (3 to 30) for a deposition mask. 3. The method of claim 1 or 2,
The depth of the second surface hole is 0.1㎛ to 7㎛ deposition mask. 3. The method of claim 1 or 2,
A difference (CA) between the width of the second surface hole and the width of the boundary portion is 0.2 μm to 14 μm. 3. The method of claim 1 or 2,
A deposition mask having a curvature in which an edge of the first face hole or an edge of the second face hole has a radius of curvature of 2.5 μm to 10 μm.

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