JP2023085372A - mask - Google Patents

Abstract

To provide a mask of which edge part of a through hole hardly catches a foreign object when washing the mask.SOLUTION: A mask includes a first surface 201, a second surface 202 positioned in an opposite side of the first surface, a through hole 40, and a metal plate 30 having a thickness of 5 μm or less. The through hole 40 has a wall surface 41 that includes a first edge that is an edge of the first surface 201 and a second edge that is an edge of the second surface. The wall surface 41 is positioned between the first edge and the second edge in a thickness direction of the metal plate 30, and a minimum opening diameter part having a minimum opening diameter. In the thickness direction of the metal plate 30, a distance between the minimum opening diameter part and the first edge is 2.0 μm or less. The second edge has a curved cross-sectional shape.SELECTED DRAWING: Figure 4

Description

An embodiment of the present disclosure relates to a mask with a metal plate containing through holes.

Display devices used in portable devices such as smartphones and tablet PCs preferably have high definition, and preferably have a pixel density of 400 ppi or more, for example. Also, there is an increasing demand for portable devices to support Ultra High Definition (UHD), and in this case, it is preferable that the pixel density of the display device is, for example, 800 ppi or more.

Among display devices, an organic EL display device has attracted attention because of its good responsiveness, low power consumption, and high contrast. As a method of forming pixels of an organic EL display device, a method of forming pixels in a desired pattern using a mask having through holes arranged in a desired pattern is known. Specifically, first, a mask is combined with a substrate for an organic EL display device. Subsequently, a vapor deposition material containing an organic material is deposited on the substrate through the through-holes of the mask. By carrying out such a vapor deposition process, it is possible to form pixels having a vapor deposition layer containing a vapor deposition material in a pattern corresponding to the pattern of the through holes of the mask on the substrate.

As a method of manufacturing a mask, a method of forming through holes in a metal plate by etching using a photolithographic technique is known. For example, first, a first resist layer is formed on the first surface of the metal plate, and a second resist layer is formed on the second surface of the metal plate. Next, a region of the first surface of the metal plate that is not covered with the first resist layer is etched to form a first recess in the first surface of the metal plate. After that, a region of the second surface of the metal plate that is not covered with the second resist layer is etched to form a second concave portion on the second surface of the metal plate. At this time, etching is performed so that the first concave portion and the second concave portion communicate with each other, thereby forming a through hole penetrating the metal plate.

Japanese Patent No. 5382259

When the mask is manufactured by etching the region of the second surface of the metal plate that is not covered with the second resist layer, the cross-sectional shape of the end of the through hole located on the side opposite to the substrate is It tends to be sharp and pointy. In this case, when cleaning the mask, the ends of the through-holes are likely to be entangled with foreign matters.

An object of the embodiments of the present disclosure is to provide a mask that can effectively solve such problems.

A mask according to one embodiment of the present disclosure comprises:
A metal plate having a thickness of 10 μm or less, including a first surface, a second surface located on the opposite side of the first surface, and a through hole,
The through hole has a wall surface including a first end that is an end on the first surface and a second end that is an end on the second surface,
The wall surface includes a minimum opening diameter portion located between the first end and the second end in the thickness direction of the metal plate and having the smallest opening diameter,
In the thickness direction of the metal plate, the distance between the minimum opening diameter portion and the first end is 2.0 μm or less,
The second end has a curved cross-sectional shape.

In a mask according to one embodiment of the present disclosure,
The metal plate may have a thickness of 2 μm or less.

In a mask according to one embodiment of the present disclosure,
A distance between the minimum opening diameter portion and the first end may be 0.1 μm or more in the thickness direction of the metal plate.

In a mask according to one embodiment of the present disclosure,
A ratio of the distance between the minimum opening diameter portion and the first end in the thickness direction of the metal plate to the thickness of the metal plate may be 0.1 or more and 0.4 or less.

In a mask according to one embodiment of the present disclosure,
The second surface of the metal plate located between the two through holes may be flat.

In a mask according to one embodiment of the present disclosure,
An angle between a direction in which a straight line passing through the minimum opening diameter portion and the second end extends and a plane direction of the first surface may be 80° or less.

In a mask according to one embodiment of the present disclosure,
The metal plate may have an iron alloy containing 34% by mass or more and 38% by mass or less of nickel.

In a mask according to one embodiment of the present disclosure,
A minimum opening dimension of the through-hole may be 50 μm or less.

According to the mask according to the embodiment of the present disclosure, it is possible to suppress the entanglement of foreign substances and the like at the end of the through-hole when cleaning the mask.

1 illustrates a deposition apparatus with a deposition mask device according to an embodiment of the present disclosure; FIG. 1 is a plan view showing a vapor deposition mask device according to an embodiment of the present disclosure; FIG. 3B is a plan view showing the effective area of the vapor deposition mask of the vapor deposition mask device of FIG. 3A as viewed from the second surface side; FIG. FIG. 3C is a plan view showing a modified example of the arrangement of the effective areas of the vapor deposition mask of the vapor deposition mask device of FIG. 3B; FIG. 3B is a cross-sectional view along line AA of FIG. 3A; It is sectional drawing which expands and shows a through-hole and a shielding part. It is a top view which expands and shows a through-hole. FIG. 4 is an enlarged cross-sectional view showing a shielding portion that defines a through hole; FIG. 4 is a cross-sectional view showing a further enlarged shielding portion that defines a through hole; It is a figure which shows the process of forming a resist layer on a metal plate. It is a figure which shows the process of patterning a resist layer. FIG. 10 illustrates a first etching step; It is a figure which shows a filling process. FIG. 10 illustrates a second etching step; FIG. 10 illustrates a second etching step; It is a figure which shows a filler removal process. FIG. 10 is a diagram showing a step of patterning a resist layer in a comparative embodiment; FIG. 10 is a diagram showing a step of etching a metal plate in a comparative form; FIG. 4 is a cross-sectional view showing a vapor deposition substrate produced using a mask; It is sectional drawing which expands and shows the vapor deposition layer formed by a vapor deposition process. 1 is a cross-sectional view showing a vapor deposition mask produced in Example 1. FIG. FIG. 4 is a cross-sectional view showing a vapor deposition mask produced in Example 2; FIG. 10 is a cross-sectional view showing a vapor deposition mask produced in Example 3;

Hereinafter, a configuration of a mask and a method for manufacturing the mask according to one embodiment will be described in detail with reference to the drawings. The embodiments shown below are examples of the embodiments of the present disclosure, and the present disclosure should not be construed as being limited to these embodiments. Also, in this specification, terms such as "plate", "substrate", "sheet", and "film" are not to be distinguished from each other based only on the difference of names. For example, "plate" is a concept that includes members that can be called sheets and films. In addition, "surface (sheet surface, film surface)" means a target plate-shaped member (sheet-shaped member) when the target plate-shaped (sheet-shaped, film-shaped) member is viewed as a whole , film-like member). Further, the normal direction used for a plate-like (sheet-like, film-like) member refers to the normal direction to the surface (sheet surface, film surface) of the member. Furthermore, terms used herein to specify shapes and geometric conditions and their degrees, such as terms such as "parallel" and "perpendicular", length and angle values, etc., are bound by strict meanings. However, it is interpreted to include the extent to which similar functions can be expected.

In addition, in the drawings referred to in this embodiment, the same reference numerals or similar reference numerals may be assigned to the same portions or portions having similar functions, and repeated description thereof may be omitted. Also, the dimensional ratios in the drawings may differ from the actual ratios for convenience of explanation, and some of the configurations may be omitted from the drawings.

It should be noted that the embodiments of the present disclosure can be combined with other embodiments and modifications as long as there is no contradiction. Further, other embodiments may be combined with each other, and other embodiments and modifications may be combined within a range that does not cause contradiction. Modifications can also be combined within a range that does not cause contradiction.

Also, in embodiments of the present disclosure, when multiple steps are disclosed for a method, such as a manufacturing method, other undisclosed steps may be performed between the disclosed steps. Also, the order of the disclosed steps is arbitrary as long as there is no contradiction.

In this embodiment, an example will be described in which the mask is a vapor deposition mask used for patterning an organic material on a substrate in a desired pattern when manufacturing an organic EL display device. However, the use of the mask is not particularly limited, and the present embodiment can be applied to masks used for various purposes. For example, the mask of the present embodiment may be used to manufacture a device for displaying or projecting images or videos for expressing virtual reality (VR) or augmented reality (AR).

First, a vapor deposition apparatus 80 that performs a vapor deposition process for vapor-depositing a vapor deposition material on an object will be described with reference to FIG. As shown in FIG. 1, the vapor deposition device 80 may include a vapor deposition source (for example, a crucible 81), a heater 83, and a vapor deposition mask device 10 therein. In addition, the vapor deposition device 80 may further include exhaust means for creating a vacuum atmosphere inside the vapor deposition device 80 . Crucible 81 contains deposition material 82, such as an organic light emitting material. A heater 83 heats the crucible 81 to evaporate the deposition material 82 under a vacuum atmosphere. The vapor deposition mask device 10 is arranged so as to face the crucible 81 .

The vapor deposition mask device 10 will be described below. As shown in FIG. 1 , the deposition mask device 10 includes at least one deposition mask 20 . The vapor deposition mask device 10 may further include a frame 15 that supports the vapor deposition mask 20 . The frame 15 supports the vapor deposition mask 20 while pulling it in its surface direction so that the vapor deposition mask 20 does not bend.

As shown in FIG. 1, the vapor deposition mask device 10 is arranged in the vapor deposition device 80 so that the vapor deposition mask 20 faces the substrate 91, which is the object to which the vapor deposition material 82 is to be deposited. The vapor deposition mask 20 has a plurality of through holes 40 through which the vapor deposition material 82 flying from the vapor deposition source 81 passes. In the following description, of the surfaces of the vapor deposition mask 20, the surface positioned on the side of the substrate 91 to which the flying vapor deposition material 82 adheres is referred to as a first surface 201, and the surface positioned on the opposite side of the first surface 201 is referred to as a first surface. This is referred to as 2nd side 202 .

The vapor deposition mask device 10 may include a magnet 85 arranged on the surface of the substrate 91 opposite to the vapor deposition mask 20, as shown in FIG. By providing the magnet 85 , the vapor deposition mask 20 can be attracted to the magnet 85 side by magnetic force, and the vapor deposition mask 20 can be brought into close contact with the substrate 91 . As a result, the generation of shadows in the vapor deposition process can be suppressed, and the dimensional accuracy and positional accuracy of the vapor deposition layer formed on the substrate 91 by the vapor deposition material 82 adhering to the substrate 91 can be improved. Alternatively, the vapor deposition mask 20 may be brought into close contact with the substrate 91 using an electrostatic chuck that utilizes electrostatic force.

FIG. 2 is a plan view showing the vapor deposition mask device 10 viewed from the first surface 201 side of the vapor deposition mask 20 . As shown in FIG. 2 , the vapor deposition mask device 10 may have a plurality of vapor deposition masks 20 . In the present embodiment, each vapor deposition mask 20 has a rectangular shape extending in one direction. In the vapor deposition mask device 10 , the plurality of vapor deposition masks 20 are arranged in the width direction crossing the length direction of the vapor deposition mask 20 . Each vapor deposition mask 20 is fixed to the frame 15 by, for example, welding at both ends in the length direction of the vapor deposition mask 20 .

The vapor deposition mask 20 shown in FIG. 2 has a pair of ear portions 21 fixed to the frame 15 by welding or the like, and an intermediate portion 22 positioned between the ear portions 21 . The intermediate portion 22 may have at least one active area 23 and a peripheral area 24 located around the active area 23 . In the example shown in FIG. 2 , the intermediate portion 22 includes a plurality of effective regions 23 arranged at predetermined intervals along the length direction of the vapor deposition mask 20 . Surrounding area 24 surrounds a plurality of active areas 23 .

When a display device such as an organic EL display device is manufactured using the vapor deposition mask 20, one effective area 23 corresponds to the display area of one organic EL display device. Therefore, according to the vapor deposition mask apparatus 10 shown in FIG. 2, multi-surface vapor deposition of an organic EL display device is possible. Note that one effective area 23 may correspond to a plurality of display areas. Although not shown, a plurality of effective regions 23 may be arranged at predetermined intervals in the width direction of the vapor deposition mask 20 as well.

The effective area 23 has, for example, a substantially rectangular shape in plan view, more precisely, a substantially rectangular contour in plan view. Although not shown, each effective area 23 can have contours of various shapes according to the shape of the display area of the organic EL display device. For example, each active area 23 may have a circular contour.

FIG. 3A is a plan view showing the effective area 23 of the vapor deposition mask 20 viewed from the second surface 202 side. 4 is a cross-sectional view of the effective area 23 of FIG. 3A along line AA. Effective area 23 includes metal plate 30 and a plurality of through holes 40 provided in metal plate 30 . The metal plate 30 includes a first surface 31 and a second surface 32 opposite to the first surface 31, as shown in FIG. The first surface 31 of the metal plate 30 constitutes the first surface 201 of the vapor deposition mask 20 , and the second surface 32 of the metal plate 30 constitutes the second surface 202 of the vapor deposition mask 20 . The through hole 40 penetrates from the first surface 31 to the second surface 32 of the metal plate 30 . The through hole 40 has a wall surface 41 extending from the first surface 31 to the second surface 32 .

As a material forming the metal plate 30, for example, an iron alloy containing nickel can be used. The iron alloy may further contain cobalt in addition to nickel. For example, as the material of the metal plate 30, an iron alloy having a total nickel and cobalt content of 30% by mass or more and 54% by mass or less and a cobalt content of 0% by mass or more and 6% by mass or less is used. can be used. Specific examples of nickel or an iron alloy containing nickel and cobalt include an Invar material containing 34% by mass or more and 38% by mass or less of nickel, a super alloy containing 30% by mass or more and 34% by mass or less of nickel and further cobalt. Invar materials, low thermal expansion Fe--Ni plating alloys containing 38 mass % or more and 54 mass % or less of nickel, and the like can be mentioned. By using such an iron alloy, the thermal expansion coefficient of the metal plate 30 can be lowered. For example, when a glass substrate is used as the substrate 91, the thermal expansion coefficient of the metal plate 30 can be made as low as that of the glass substrate. Accordingly, during the vapor deposition process, the dimensional accuracy and positional accuracy of the vapor deposition layer formed on the substrate 91 are reduced due to the difference in thermal expansion coefficient between the vapor deposition mask 20 including the metal plate 30 and the substrate 91. can be suppressed.

The shape of through hole 40 is defined by metal plate 30 around through hole 40 . For example, the side surface of the shielding portion 35 constitutes the wall surface 41 of the through hole 40 . The metal plate 30 around the through hole 40 functions to shield the deposition material 82 from adhering to the display area of the substrate 91 . In the following description, the metal plate 30 around the through hole 40 is also referred to as the shielding portion 35 .

When the metal plate 30 constituting the vapor deposition mask 20 is viewed along the normal direction of the surface direction D1 of the first surface 31 of the metal plate 30, that is, along the thickness direction D2 of the metal plate 30, the plurality of through holes 40 At least some of them are arranged at predetermined first pitches C1 and second pitches C2 along a first direction D11 and a second direction D12 that intersect each other. Both the first direction D11 and the second direction D12 are directions in the surface direction D1. The smaller one of the first pitch C1 and the second pitch C2 is determined according to the pixel density of the display device or projection device, for example, as follows.
・When the pixel density is 600ppi or more: Pitch is 42.3μm or less ・When the pixel density is 1200ppi or more: Pitch is 21.2μm or less ・When the pixel density is 3000ppi or more: Pitch is 8.5μm or less When the pixel density is 600ppi The display device or projection device is used, for example, as an organic EL display device for smartphones.
A display device or projection device with a pixel density of 1200 ppi is used, for example, to display or project images and videos for representing virtual reality.
A display device or projection device with a pixel density of 3000 ppi is used, for example, to display or project images and videos for expressing augmented reality.

The arrangement of the effective area 23 is arbitrary. For example, as the arrangement of the effective areas 23, a parallel arrangement may be employed as shown in FIG. 3A, or a staggered arrangement may be employed as shown in FIG. 3B.

In the example shown in FIGS. 3A and 3B , the through-hole 40 when the metal plate 30 is viewed along the thickness direction D2 of the metal plate 30 has a substantially rectangular outline with four curved corners. Note that the shape of the contour can be arbitrarily determined according to the shape of the pixels. For example, it may have other polygonal shapes such as hexagons and octagons, or it may have a circular shape. Also, the contour shape may be a combination of a plurality of shapes. Also, the plurality of through holes 40 may have contour shapes different from each other. When through-hole 40 has a polygonal profile, the opening dimension of through-hole 40 is the distance between a pair of opposing sides of the polygon, as shown in FIG. 3A.

As shown in FIG. 4 , the peripheral area 24 is also made of the same metal plate 30 as the effective area 23 . Thickness H0 of metal plate 30 in peripheral region 24 may be greater than thickness H1 of metal plate 30 in effective region 23 . Similarly, the above-described ear portion 21 may also be made of the same metal plate 30 as the effective area 23 , and the thickness of the ear portion 21 may be greater than the thickness H<b>1 of the effective area 23 . Although not shown, the thickness H0 of the surrounding area 24 and the thickness of the ear portion 21 may be the same as the thickness H1 of the effective area 23 or may be smaller than the thickness H1 of the effective area 23 .

As will be described later, the effective area 23 is formed by subjecting the metal plate 30 to a first etching process from the first surface 31 side and then subjecting the metal plate 30 to a second etching process from the second surface 32 side. . Therefore, the thickness H1 of the metal plate 30 in the effective area 23 is the thickness of the metal plate 30 after the second etching process.

The thickness H1 of the metal plate 30 forming the shielding portion 35 is preferably 10 μm or less. The thickness H1 of the metal plate 30 forming the shielding portion 35 may be 7 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less. may By setting the thickness H1 of the metal plate 30 forming the shielding portion 35 to 10 μm or less, it is possible to prevent the vapor deposition material 82 from adhering to the wall surface 41 of the through hole 40 in the vapor deposition process. As a result, the ratio of the vapor deposition material 82 that cannot pass through the through holes 40 can be reduced, and the utilization efficiency of the vapor deposition material 82 can be increased. On the other hand, if the thickness H1 of the metal plate 30 forming the shielding portion 35 is too small, the vapor deposition mask 20 is likely to be deformed or damaged when the vapor deposition mask 20 is used or transported. Considering this point, it is preferable that the thickness H1 of the metal plate 30 forming the shielding portion 35 is 0.5 μm or more. The thickness H1 of the metal plate 30 may be 1.0 μm or more, or may be 1.5 μm or more.

The range of the thickness H1 of the metal plate 30 forming the shielding portion 35 is determined by a combination of any one of the plurality of upper limit candidate values and any one of the plurality of lower limit candidate values. may be For example, the range of the thickness H1 of the metal plate 30 forming the shielding portion 35 may be 0.5 μm or more and 10 μm or less, 1.0 μm or more and 5 μm or less, or 1.5 μm or more and 2 μm or less. may Also, the range of the thickness H1 of the metal plate 30 forming the shielding portion 35 may be determined by a combination of any two of the plurality of upper limit candidate values described above. For example, the thickness H1 of the metal plate 30 forming the shielding portion 35 may range from 2 μm to 10 μm. Also, the range of the thickness H1 of the metal plate 30 forming the shielding portion 35 may be determined by a combination of any two of the plurality of lower limit candidate values described above. For example, the thickness H1 of the metal plate 30 forming the shielding portion 35 may range from 0.5 μm to 1.5 μm.

The through hole 40 and the shielding portion 35 defining the through hole 40 will be described in detail with reference to FIGS. 5 and 6. FIG. FIG. 5 is an enlarged cross-sectional view showing the through hole 40 and the shielding portion 35. As shown in FIG. FIG. 6 is a plan view showing an enlarged through-hole 40. FIG.

As shown in FIG. 5, the wall surface 41 of the through hole 40 includes a first end 411, a second end 412, and a minimum opening diameter portion 46. As shown in FIG. The first end 411 is the end of the wall surface 41 on the first surface 31 of the metal plate 30 , and the second end 412 is the end of the wall surface 41 on the second surface 32 of the metal plate 30 . The minimum opening diameter portion 46 is located between the first end 411 and the second end 412 of the wall surface 41 and has the smallest opening dimension.

In the example shown in FIG. 5, the wall surface 41 includes a first wall surface 43 extending from the first end 411 to the second end 412 side, a second wall surface 44 extending from the second end 412 to the first end 411 side, and a first wall surface 44 extending from the second end 412 to the first end 411 side. a tip 45 where 43 and the second wall surface 44 meet. The tip 45 is the innermost portion of the wall surface 41 in the cross-sectional view of the through hole 40 and the shielding portion 35 . The inner side is the side closer to the central axis C of the through-hole 40 in the cross-sectional view of the through-hole 40 and the shielding portion 35 . The central axis C is a straight line that passes through the midpoint between the opposing first ends 411 and the midpoint between the opposing second ends 412 in the cross-sectional view of the through hole 40 . Further, the outside, which will be described later, is the side away from the central axis C of the through-hole 40 in the cross-sectional view of the through-hole 40 and the shielding portion 35 . The minimum opening diameter portion 46 described above includes a tip 45 .

As shown in FIG. 5, the first wall surface 43 may widen inward from the first end 411 toward the second end 412 side. Further, the second wall surface 44 may widen inward from the second end 412 toward the first end 411 side. It should be noted that there is a state of "spreading inward from the first end 411 toward the second end 412 side", and a state of "the second wall surface 44 extends inward from the second end 412 toward the first end 411 side". It suffices that the state of "spreads out as much as possible" is established when minute irregularities having a depth or height of 200 nm or less existing on the wall surface 41 are ignored.

5 and 6, symbol S1 represents the opening dimension of the through-hole 40 in the minimum opening diameter portion 46 (hereinafter also referred to as the minimum opening dimension), and symbol S2 represents the opening dimension of the through-hole 40 in the first surface 31. (hereinafter also referred to as the first surface opening dimension), and the symbol S3 represents the opening dimension of the through hole 40 in the second surface 32 (hereinafter also referred to as the second surface opening dimension). Reference S4 represents the width of the shielding portion 35 in the direction in which the plurality of through holes 40 are arranged. The first surface opening dimension S2 is greater than or equal to the minimum opening dimension S1, and the second surface opening dimension S3 is greater than or equal to the first surface opening dimension S2. It is preferable that the difference between the first surface opening size S2 and the minimum opening size S1 is small. A value obtained by subtracting the minimum opening size S1 from the first surface opening size S2 is, for example, 0 μm or more and 2.0 μm or less. Moreover, the second surface opening dimension S3 is preferably larger than the first surface opening dimension S2. For example, the second surface opening dimension S3 is preferably at least 0.5 μm larger than the first surface opening dimension S2. The second surface opening dimension S3 may be larger than the first surface opening dimension S2 by 1 μm or more, 1.5 μm or more, or 2 μm or more. Moreover, the value obtained by subtracting the first surface opening dimension S2 from the second surface opening dimension S3 is preferably 10 μm or less. The value obtained by subtracting the first-surface opening dimension S2 from the second-surface opening dimension S3 may be 8 μm or less, 6 μm or less, or 4 μm or less. As shown in FIG. 6, when the through hole 40 is viewed along the thickness direction of the metal plate 30, the contour of the first end 411 may surround the contour of the minimum opening diameter portion 46, and the second The contour of end 412 may surround the contour of first end 411 .

The range of values obtained by subtracting the first surface opening dimension S2 from the second surface opening dimension S3 is any one of the plurality of upper limit candidate values and any of the plurality of lower limit candidate values. It may be defined by one combination. For example, the value obtained by subtracting the first surface opening dimension S2 from the second surface opening dimension S3 may be 0.5 μm or more and 10 μm or less, 1 μm or more and 8 μm or less, or 1.5 μm or more and 6 μm or less. It may be 2 μm or more and 4 μm or less. Also, the range of values obtained by subtracting the first-surface opening dimension S2 from the second-surface opening dimension S3 may be determined by a combination of any two of the plurality of upper limit candidate values described above. For example, the value obtained by subtracting the first surface opening dimension S2 from the second surface opening dimension S3 may be 4 μm or more and 10 μm or less. Also, the range of values obtained by subtracting the first-surface opening dimension S2 from the second-surface opening dimension S3 may be determined by a combination of any two of the plurality of lower limit candidate values described above. For example, the value obtained by subtracting the first surface opening dimension S2 from the second surface opening dimension S3 may be 0.5 μm or more and 2 μm or less.

The minimum aperture dimension S1, the first-surface aperture dimension S2, the second-surface aperture dimension S3, and the width S4 are determined according to the pixel density of the display device or projection device, for example, as shown in Table 1 below.

The minimum opening dimension S1, the first surface opening dimension S2, the second surface opening dimension S3, and the width S4 may be defined as ratios to the thickness H1 of the metal plate 30 in the effective area 23. FIG. For example, the ratio of the minimum opening dimension S1 to the thickness H1 (=S1/H1) is, for example, 0.3 or more, may be 0.5 or more, may be 0.7 or more, or may be 1.0. or more. Also, S1/H1 is, for example, 30 or less, may be 25 or less, may be 20 or less, or may be 15 or less.

The range of S1/H1 may be defined by a combination of any one of the multiple candidate upper limits and any one of the multiple candidate lower limits. For example, S1/H1 may be 0.3 or more and 30 or less, 0.5 or more and 25 or less, 0.7 or more and 20 or less, or 1.0 or more and 15 or less. There may be. Also, the range of S1/H1 may be determined by a combination of any two of the multiple upper limit candidate values. For example, S1/H1 may be 15 or more and 30 or less. Also, the range of S1/H1 may be determined by a combination of any two of the plurality of lower limit candidate values described above. For example, S1/H1 may be 0.3 or more and 1.0 or less.

In FIG. 5, reference character L1 represents an imaginary straight line passing through the minimum opening diameter portion 46 and the second end 412 in the cross-sectional view of the through hole 40. As shown in FIG. A symbol θ1 represents an angle between the direction in which the straight line L1 extends and the surface direction of the first surface 31 of the metal plate 30 . The angle θ1 is preferably 80° or less. The angle θ1 may be 70° or less, 60° or less, 50° or less, 45° or less, or 40° or less. Also, the angle θ1 is preferably 10° or more. The angle θ1 may be 15° or more, 20° or more, 25° or more, or 30° or more.

The range of the angle θ1 may be defined by a combination of any one of multiple upper limit candidate values and any one of multiple lower limit candidate values. For example, the angle θ1 may be 10° or more and 80° or less, 15° or more and 70° or less, 20° or more and 60° or less, or 25° or more and 50° or less. 30° or more and 45° or less. Also, the range of the angle θ1 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the angle θ1 may be 40° or more and 80° or less. Also, the range of the angle θ1 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the angle θ1 may be 10° or more and 30° or less.

The technical meaning of the angle θ1 will be described below. In the vapor deposition process using the vapor deposition mask 20 , the vapor deposition material 82 is inclined with respect to the thickness direction of the metal plate 30 in addition to the component flying from the vapor deposition source 81 toward the substrate 91 along the thickness direction of the metal plate 30 . It may contain a component that comes along the direction. Some of the vapor deposition material 82 flying along the inclined direction reaches and adheres to the second surface 32 of the metal plate 30 and the wall surface 41 of the through hole 40 before reaching the substrate 91 . For this reason, the thickness of the deposited layer formed on the substrate 91 tends to become thinner closer to the wall surface 41 of the through hole 40 . Such a phenomenon that the deposition material 82 is prevented from adhering to the substrate 91 by the wall surface 41 of the through-hole 40 is also called a shadow. According to the present embodiment, by configuring wall surface 41 of through-hole 40 such that angle θ1 is 80° or less, it is possible to suppress the occurrence of shadows.

By the way, reducing the angle θ1 leads to an increase in the distance S5 (see FIG. 5) between the minimum opening diameter portion 46 and the second end 412 in the planar direction of the first surface 31 of the metal plate 30 . Increasing the distance S5 leads to increasing the width S4 of the shielding portion 35 . The pitch of the through holes 40 described above is equal to the sum of the minimum opening size S1 and the width S4 of the shielding portion 35 . Therefore, if the distance S5 is increased, it is restricted to reduce the pitch of the through-holes 40 .

Here, in the present embodiment, as described above, the thickness H1 of the metal plate 30 in the effective area 23 is small, for example, 10 μm or less. Therefore, the distance S5 required to reduce the angle θ1 is shorter than that of a conventional vapor deposition mask having a thickness exceeding 10 μm, for example. Therefore, according to the present embodiment, the angle θ1 can be set to 80° or less while maintaining the pitch of the through holes 40 small.

Next, with reference to FIG. 7, the shape of the through-hole 40 and the shielding portion 35 will be described in more detail. FIG. 7 is a cross-sectional view showing an enlarged shielding portion 35 that defines the through hole 40. As shown in FIG.

In FIG. 7, symbol H2 represents the distance between the minimum opening diameter portion 46 and the first end 411 in the thickness direction D2 of the metal plate 30 . In the description below, the distance H2 is also referred to as the height of the first wall surface 43 . The height H2 of the first wall surface 43 is preferably 2.0 μm or less. The height H2 of the first wall surface 43 may be 1.5 μm or less, 1.0 μm or less, 0.8 μm or less, or 0.6 μm or less. By setting the height H2 of the first wall surface 43 to 1.0 μm or less, it is possible to suppress variations in the positions of the ends of the deposited layer 92 formed on the substrate 91 in the planar direction of the substrate 91 by the deposition process. can. This can reduce the margin provided for the spacing between two adjacent pixels.

On the other hand, in the manufacturing process of the vapor deposition mask 20, if the design value of the height H2 of the first wall surface 43 is too small, the etching performed from the second surface 32 side may reach the first surface 31 side. Conceivable. When the etching performed from the second surface 32 side reaches the first surface 31 side, variations in the minimum opening size S1 and the first surface opening size S2 increase. Considering this point, the height H2 of the first wall surface 43 is preferably 0.1 μm or more. The height H2 of the first wall surface 43 may be 0.2 μm or more, or may be 0.3 μm or more.

The range of the height H2 of the first wall surface 43 may be determined by a combination of any one of multiple upper limit candidate values and any one of multiple lower limit candidate values. For example, the height H2 of the first wall surface 43 may be 0.1 μm or more and 2.0 μm or less, 0.2 μm or more and 1.5 μm or less, or 0.3 μm or more and 1.0 μm or less. may Also, the range of the height H2 of the first wall surface 43 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the height H2 of the first wall surface 43 may be 0.6 μm or more and 2.0 μm or less. Also, the range of the height H2 of the first wall surface 43 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the height H2 of the first wall surface 43 may be 0.1 μm or more and 0.3 μm or less.

A preferable range of the height H2 of the first wall surface 43 may be determined as a relative value with respect to the thickness H1 of the metal plate 30 forming the shielding portion 35 . For example, the ratio (H2/H1) of the height H2 to the thickness H1 of the metal plate 30 forming the shielding portion 35 is preferably 0.4 or less. H2/H1 may be 0.35 or less, or may be 0.3 or less. Also, H2/H1 is preferably 0.1 or more. H2/H1 may be 0.15 or more, or may be 0.2 or more.

Also, the range of H2/H1 may be defined by a combination of any one of multiple upper limit candidate values and any one of multiple lower limit candidate values. For example, H2/H1 may be 0.1 or more and 0.4 or less, 0.15 or more and 0.35 or less, or 0.2 or more and 0.3 or less. Also, the range of H2/H1 may be defined by a combination of any two of multiple upper limit candidate values. For example, H2/H1 may be 0.3 or more and 0.4 or less. Also, the range of H2/H1 may be defined by a combination of any two of a plurality of lower limit candidate values. For example, H2/H1 may be 0.1 or more and 0.2 or less.

In FIG. 7 , symbol H3 represents the distance between the minimum opening diameter portion 46 and the second end 412 in the thickness direction D2 of the metal plate 30 . In the description below, the distance H3 is also referred to as the height of the second wall surface 44 . The height H3 of the second wall surface 44 is preferably 4 μm or less. The height H3 of the second wall surface 44 may be 3.5 μm or less, or may be 3 μm or less. Also, the height H3 of the second wall surface 44 is preferably 1 μm or more. The height H3 of the second wall surface 44 may be 1.5 μm or more, or may be 2 μm or more.

The range of the height H3 of the second wall surface 44 may be determined by a combination of any one of multiple upper limit candidate values and any one of multiple lower limit candidate values. For example, the height H3 of the second wall surface 44 may be 1 μm or more and 4 μm or less, 1.5 μm or more and 3.5 μm or less, or 2 μm or more and 3 μm or less. Also, the range of the height H3 of the second wall surface 44 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the height H3 of the second wall surface 44 may be 3 μm or more and 4 μm or less. Also, the range of the height H3 of the second wall surface 44 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the height H3 of the second wall surface 44 may be 1 μm or more and 2 μm or less.

As will be described later, the second surface 32 of the shielding portion 35 positioned between the two through-holes 40 extends from the second surface 32 side of the metal plate 30 over the entire area of the metal plate 30 corresponding to the effective area 23 . It is formed by etching. Therefore, the second surface 32 of the shielding portion 35 located between the two through holes 40 is flat. "The second surface is flat" means that, as shown in FIG. , means that the maximum value H4 of the distance between the valley portion and the peak portion appearing on the second surface 32 is 1 μm or less. The distance S6 is 1/2 the width S4 of the shielding portion 35 . H4 may be 0.8 μm or less, or may be 0.6 μm or less.

Since the first surface 31 of the shielding portion 35 is not etched in the manufacturing process of the vapor deposition mask 20, the maximum value H4 of the distance between the valleys and peaks appearing on the second surface 32 is It is larger than the maximum value of the distance between the ridges and ridges. H4 is, for example, 0.05 μm or more, may be 0.07 μm or more, or may be 0.1 μm or more.

The range of the maximum value H4 of the distance between the troughs and the peaks appearing on the second surface 32 is any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values. It may be defined by a combination. For example, H4 may be 0.05 μm or more and 1 μm or less, 0.07 μm or more and 0.8 μm or less, or 0.1 μm or more and 0.6 μm or less. Also, H4 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, H4 may be 0.6 μm or more and 1 μm or less. Also, H4 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, H4 may be 0.05 μm or more and 0.1 μm or less.

Further, as will be described later, the second wall surface 44 of the wall surface 41 of the through hole 40 is metallized by the etchant that has entered between the metal plate 30 and the filler 52 filled on the first surface 31 side of the metal plate 30 . This surface is formed by side-etching the plate 30 . In this case, as shown in FIG. 7, the cross-sectional shape of the second end 412 of the wall surface 41 is curved. Since the cross-sectional shape of the second end 412 is curved, the vapor deposition material 82 that flies in a direction inclined with respect to the thickness direction of the metal plate 30 adheres to the second end 412 and the periphery of the second end 412 . become difficult. Also, in the process of cleaning the vapor deposition mask 20, foreign matter is less likely to get entangled in the second end 412 compared to the case where the second end 412 is sharp. A foreign substance is, for example, cellulose.

A protective film or the like may be attached to the second surface 32 of the metal plate 30 of the vapor deposition mask 20 when the vapor deposition mask 20 is transported, and then the protective film may be peeled off. In this case, the curved cross-sectional shape of the second end 412 makes it easier to peel off the protective film than when the second end 412 is sharply pointed. For example, it is possible to prevent the protective film from being caught on the second end 412 and the adhesive of the protective film from adhering to the second end 412 and remaining as a foreign substance.

The cross-sectional curvature radius R1 of the second end 412 is preferably 0.3 μm or more. The curvature radius R1 may be 0.5 μm or more, or may be 1.0 μm or more. Thereby, the second end 412 can exhibit the above-described effects more remarkably. Also, the radius of curvature R1 of the cross-sectional shape of the second end 412 is preferably 2.0 μm or less. The curvature radius R1 may be 1.5 μm or less, or may be 1.0 μm or less.

Further, the range of the radius of curvature R1 is determined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values, as in the case of the thickness H1 described above. may For example, the cross-sectional curvature radius R1 of the second end 412 may be 0.3 μm or more and 2.0 μm or less, or may be 0.5 μm or more and 1.5 μm or less. Also, the range of the curvature radius R1 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the cross-sectional curvature radius R1 of the second end 412 may be 1.0 μm or more and 2.0 μm or less. Also, the range of the radius of curvature R1 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the cross-sectional curvature radius R1 of the second end 412 may be 0.3 μm or more and 1.0 μm or less.

A method for identifying the second end 412 will now be described with reference to FIG. FIG. 8 is a further enlarged view of the shielding portion 35 that defines the through hole 40. As shown in FIG. The second end 412 may be defined as a portion including an angle change point where the amount of change in the spreading direction of the second wall surface 44 is 30° or more. The angle change point will be described below.

In FIG. 8, reference P1 represents one point located on the second wall surface 44 in the cross-sectional view of the effective area 23. As shown in FIG. Reference P2 represents a point displaced from point P1 by 500 nm along the second wall surface 44 toward the second surface 32 . Symbol Q1 represents a straight line that contacts the second wall surface 44 at point P1, and symbol Q2 represents a straight line that contacts the second wall surface 44 at point P2. Symbol δ represents an angle formed by the direction in which the straight line Q1 extends and the direction in which the straight line Q2 extends. The angle δ calculated in this manner is the amount of change in the angle of the second wall surface 44 at the point P1. The second end 412 includes an angle change point at which the calculated angle change amount is 30° or more.

In the example shown in FIG. 8, not only the point P1, but also the point located between the point Px and the point Py in FIG. 8 has an angle change amount of 30° or more. In this case, the second end 412 is defined as the center point of the extent of the second wall surface 44 over which the angular variation is greater than or equal to 30°.

Method for Manufacturing Deposition Mask Next, a method for manufacturing the deposition mask 20 by processing the metal plate 30 will be described mainly with reference to FIGS. 9 to 15. FIG.

First, the metal plate 30 is prepared. As the metal plate 30, a continuously extending metal plate 30 unwound from a roll may be used. In this case, the manufacturing process of the vapor deposition mask 20 may be performed on the metal plate 30 conveyed along the guide rollers. Moreover, as the metal plate 30, a single metal plate 30 having dimensions corresponding to an apparatus such as an exposure machine used according to the manufacturing process of the vapor deposition mask 20 may be used.

A thickness H0 of the metal plate 30 is preferably 15 μm or more. Thickness H0 of metal plate 30 may be 20 μm or more, or may be 30 μm or more. By setting the thickness H0 of the metal plate 30 to 10 μm or more, it is possible to prevent the metal plate 30 from being damaged due to the load applied to the metal plate 30 in the manufacturing process of the vapor deposition mask 20 . Moreover, the thickness H0 of the metal plate 30 is preferably 200 μm or less. The thickness H0 may be 100 μm or less, or may be 50 μm or less.

Also, the range of thickness H0 of metal plate 30 may be determined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values. For example, the thickness H0 of the metal plate 30 may be 10 μm or more and 200 μm or less, 15 μm or more and 100 μm or less, or 20 μm or more and 50 μm or less. Also, the range of the thickness H0 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the thickness H0 of the metal plate 30 may be 50 μm or more and 200 μm or less. Also, the range of the thickness H0 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the thickness H0 of the metal plate 30 may be 10 μm or more and 20 μm or less.

Subsequently, as shown in FIG. 9 , a first resist layer 51 is formed on the first surface 31 of the metal plate 30 . The first resist layer 51 may be a layer formed by applying a solution containing a resist material to the first surface 31 and solidifying the solution. Alternatively, the first resist layer 51 may be a layer formed by attaching a film such as a dry film to the first surface 31 . In order to reduce the thickness of the first resist layer 51, it is preferable to employ a so-called coating-type resist layer in which a solution containing a resist material is applied and solidified.

When the coating type is employed, for example, the first resist layer 51 can be formed by coating the first surface 31 with a solution containing a photodissolving type, so-called positive photosensitive material, and solidifying the solution. At this time, a resist layer baking step of baking the first resist layer 51 may be performed. Incidentally, the photosensitive material may be of a photocurable type, a so-called negative type.

Examples of positive type photosensitive materials include novolac type positive resists such as SC500. Examples of negative photosensitive materials include casein resist.

The resist layer baking temperature for baking the first resist layer 51 is set according to the photosensitive material. For example, when a novolac-based positive resist is used as the photosensitive material, the resist layer baking temperature is preferably 40° C. or higher, may be 50° C. or higher, or may be 60° C. or higher. When a novolac positive resist is used as the photosensitive material, the resist layer baking temperature is preferably 180° C. or lower, may be 170° C. or higher, or may be 160° C. or lower.

When a novolak-based positive resist is used as the photosensitive material, the resist layer baking temperature may be determined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values. good. For example, the resist layer baking temperature may be 40° C. or higher and 180° C. or lower, 50° C. or higher and 170° C. or lower, or 60° C. or higher and 160° C. or lower. Also, the range of the resist layer baking temperature may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the resist layer baking temperature may be 160° C. or higher and 180° C. or lower. Also, the range of the resist layer baking temperature may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the resist layer baking temperature may be 40° C. or higher and 60° C. or lower.

When a casein resist is used as the photosensitive material, the resist layer baking temperature is preferably 80° C. or higher, may be 100° C. or higher, or may be 120° C. or higher. Further, when a novolak-based positive resist is used as the photosensitive material, the resist layer baking temperature is preferably 250° C. or lower, may be 230° C. or higher, or may be 200° C. or lower.

When casein resist is used as the photosensitive material, the resist layer baking temperature may be determined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values. For example, the resist layer baking temperature may be 80° C. or higher and 250° C. or lower, 100° C. or higher and 230° C. or lower, or 120° C. or higher and 200° C. or lower. Also, the range of the resist layer baking temperature may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the resist layer baking temperature may be 200° C. or higher and 250° C. or lower. Also, the range of the resist layer baking temperature may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the resist layer baking temperature may be 80° C. or higher and 120° C. or lower.

The thickness of the first resist layer 51 is preferably 5.0 μm or less. The thickness of the first resist layer 51 may be 3.0 μm or less, or may be 2.0 μm or less. By setting the thickness of the first resist layer 51 to 5.0 μm or less, it is possible to suppress variations in the first surface opening dimension S2 among the plurality of through holes 40 . Moreover, the thickness of the first resist layer 51 is preferably 1.0 μm or more. The thickness of the first resist layer 51 may be 1.5 μm or more, or may be 2.0 μm or more.

The range of the thickness of the first resist layer 51 is determined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values, as in the case of the thickness H1 described above. may be defined. For example, the thickness of the first resist layer 51 may be 1.0 μm or more and 5.0 μm or less, or may be 1.5 μm or more and 3.0 μm or less. Also, the range of the thickness of the first resist layer 51 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the thickness of the first resist layer 51 may be 2.0 μm or more and 5.0 μm or less. Also, the range of the thickness of the first resist layer 51 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the thickness of the first resist layer 51 may be 1.0 μm or more and 2.0 μm or less.

A second resist layer 56 may be formed on the second surface 32 of the metal plate 30 as shown in FIG. The photosensitive material contained in the second resist layer 56 may be the same as or different from the photosensitive material contained in the first resist layer 51 . Although not shown, the second resist layer 56 may not be provided on the second surface 32 of the metal plate 30 .

Subsequently, an exposure step of exposing the first resist layer 51 is performed, and then a developing step of developing the first resist layer 51 is performed. As a result, as shown in FIG. 10, the first resist layer 51 is partially removed, and the portion of the first surface 31 of the metal plate 30 corresponding to the effective region 23 is covered with the first resist layer 51. A plurality of exposed areas 53 may be provided that are not exposed.

When the second resist layer 56 is formed on the second surface 32 of the metal plate 30, the second resist layer 56 may be exposed and developed as shown in FIG. In the present embodiment, the second resist layer 56 is removed from the portion of the second surface 32 corresponding to the effective region 23 , and the second resist layer 56 is left on portions corresponding to the peripheral region 24 and the ear portion 21 . Then, the second resist layer 56 is exposed and developed. Although not shown, the second resist layer 56 is removed from the portions of the second surface 32 corresponding to the effective region 23 and the peripheral region 24 so that the second resist layer 56 remains on the portions corresponding to the ear portions 21. The second resist layer 56 may be exposed and developed.

Although not shown, the second resist layer 56 may remain slightly on the portion of the second surface 32 corresponding to the effective region 23 to the extent that the etching uniformity of the second surface 32 is not impaired. For example, the portion of the second surface 32 that corresponds to the effective area 23 and is not provided with the second resist layer 56 has a continuous exposed area of 0.5 μm in at least one surface direction of the second surface 32 . It may have dimensions equal to or greater than.

Subsequently, a first etching step is performed in which the metal plate 30 is etched from the third first surface 31 side using the first resist layer 51 as a mask. Thereby, as shown in FIG. 11, the first concave portion 50 can be formed in the first surface 31 . The first recess 50 has, for example, a hemispherical shape.

Subsequently, as shown in FIG. 12, a filling step of filling the first concave portion 50 with the filler 52 is performed. For example, a solution containing the filler 52 is applied to the first surface 31 side of the metal plate 30 . A thermoplastic resin, a photoresist, or the like can be used as the filler 52 . The photoresist is, for example, a positive resist containing a positive photosensitive material. As shown in FIG. 12, a filler 52 may cover the first resist layer 51 . Specific examples of the resin forming the filler 52 include acrylic resins and novolac resins.

Subsequently, a filler baking process for baking the filler 52 is performed. Note that when a thermoplastic resin is used as the filler 52, the filler baking process may not be performed.

In FIG. 12 , symbol H5 represents the distance from the first surface 31 to the top of the filler 52 in the thickness direction of the metal plate 30 . The top portion is the portion of the filler 52 that is farthest from the first surface 31 in the thickness direction of the metal plate 30 . Distance H5 is equal to the depth of first recess 50 . The distance H5 is preferably 7.0 μm or less. The distance H5 may be 6.0 μm or less, or may be 5.0 μm or less. Also, the distance H5 is preferably 1.0 μm or more. The distance H5 may be 2.0 μm or more, 3.0 μm or more, or 4.0 μm or more.

The range of the distance H5 may be defined by a combination of any one of the plurality of upper limit candidate values and any one of the plurality of lower limit candidate values. For example, the distance H5 may be 1.0 μm or more and 7.0 μm or less, 2.0 μm or more and 6.0 μm or less, or 3.0 μm or more and 5.0 μm or less. Also, the range of the distance H5 may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the distance H5 may be 6.0 μm or more and 7.0 μm or less. Also, the range of the distance H5 may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the distance H5 may be 1.0 μm or more and 4.0 μm or less.

Also, the ratio of distance H5 to thickness H0 of metal plate 30 before etching (=H5/H0) is preferably 0.1 or more. H5/H0 may be 0.3 or more, or may be 0.5 or more. By setting H5/H0 to 0.1 or more, it is possible to suppress variations in the time required for etching on the second surface 32 side, which will be described later, to reach the filling material 52 depending on the position. Also, H5/H0 is preferably 0.9 or less, may be 0.7 or less, or may be 0.5 or less.

The range of H5/H0 may be defined by a combination of any one of a plurality of candidate upper limits and any one of a plurality of candidate lower limits. For example, H5/H0 may be 0.1 or more and 0.9 or less, or may be 0.3 or more and 0.7 or less. Also, the range of H5/H0 may be defined by a combination of any two of a plurality of upper limit candidate values. For example, H5/H0 may be 0.5 or more and 0.9 or less. Also, the range of H5/H0 may be defined by a combination of any two of a plurality of lower limit candidate values. For example, H5/H0 may be 0.1 or more and 0.5 or less.

Subsequently, a second etching step is performed to etch the metal plate 30 from the second surface 32 side. As an etchant, one containing a ferric chloride solution and hydrochloric acid can be used. The temperature of the etchant is, for example, 25° C. or higher, may be 30° C. or higher, or may be 35° C. or higher. Also, the temperature of the etchant is, for example, 80° C. or lower, may be 70° C. or lower, or may be 60° C. or lower.

The etchant temperature range may be defined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values. For example, the temperature of the etchant may be 25° C. or higher and 80° C. or lower, 30° C. or higher and 70° C. or lower, or 35° C. or higher and 60° C. or lower. Also, the range of the temperature of the etchant may be determined by a combination of any two of a plurality of upper limit candidate values. For example, the temperature of the etchant may be 60° C. or higher and 80° C. or lower. Also, the range of the temperature of the etchant may be determined by a combination of any two of a plurality of lower limit candidate values. For example, the temperature of the etchant may be 25° C. or higher and 35° C. or lower.

The second etching step is continued until the second surface 32 of the metal plate 30 located in the effective area 23 is positioned closer to the first surface 31 than the top portion 521 of the filler 52, as shown in FIG. be done. By allowing the etching from the second surface 32 side to reach the top portion 521 of the filler 52 , the through holes 40 can be formed in the vapor deposition mask 20 .

Further, the second etching process is continued until the opening dimension S3 on the second surface of the through hole 40 becomes equal to or larger than the minimum opening dimension S1 at the tip 45. Next, as shown in FIG. The second etching step is preferably performed until the opening dimension S3 on the second surface of the through-hole 40 becomes larger than the minimum opening dimension S1 by 1 μm or more, more preferably until the opening dimension S3 on the second surface of the through-hole 40 becomes the minimum opening dimension. It is continued until it becomes 2 μm or more larger than S1. Also, the second etching process may be continued until the opening dimension S3 on the second surface of the through-hole 40 becomes larger than the opening dimension S2 on the first surface. The second etching step is preferably performed until the opening dimension S3 on the second surface of the through hole 40 becomes larger than the opening dimension S2 on the first surface by 1 μm or more, more preferably until the opening dimension S3 on the second surface of the through hole 40 becomes larger than the opening dimension S3 on the first surface. This is continued until the size becomes 2 μm or more larger than the one-side opening size S2.

Also, preferably, the second etching step, as shown in FIG. 14, has a ratio ( =H1/H5) is 0.9 or less. This makes it easier for the etchant to enter between the filler 52 and the metal plate 30 . As a result, as shown in FIG. 14 , the metal plate 30 around the filler 52 is side-etched, and a gap 57 is likely to occur between the filler 52 and the metal plate 30 . The surface formed on the metal plate 30 by side etching constitutes the above-described second wall surface 44 of the wall surface 41 of the through hole 40 . By controlling the amount of side etching, the second wall surface 44 can have a shape that widens inward from the second end 412 toward the first end 411 side. H1/H5 may be 0.8 or less, 0.7 or less, or 0.6 or less. Also, H1/H5 may be 0.1 or more, 0.2 or more, or 0.3 or more.

The range of H1/H5 may be defined by a combination of any one of a plurality of upper limit candidate values and a plurality of lower limit candidate values, as in the case of thickness H1 described above. good. For example, H1/H5 may be 0.1 or more and 0.9 or less, 0.2 or more and 0.8 or less, or 0.3 or more and 0.7 or less. Also, the range of H1/H5 may be defined by a combination of any two of a plurality of upper limit candidate values. For example, H1/H5 may be 0.6 or more and 0.9 or less. Also, the range of H1/H5 may be defined by a combination of any two of a plurality of lower limit candidate values. For example, H1/H5 may be 0.1 or more and 0.3 or less.

The time to continue etching in the second etching step can be determined, for example, based on previously obtained etching condition data. The etching condition data includes, for example, the relationship between the etching continuation time and the thickness H1 of the effective region 23 . The etching condition data may include the relationship between the duration of etching and the height H2 of the first wall surface 43, and the relationship between the duration of etching and the height H3 of the second wall surface 44. You can stay. Based on these etching condition data, it is possible to determine the time to continue etching in the second etching step so that the thickness H1, height H2, height H3, etc., have appropriate values.

Subsequently, as shown in FIG. 15, a filler removing step for removing the filler 52 is performed. Through holes 40 are thereby formed in the metal plate 30 . As a solution for removing the filler 52, a solution containing sodium hydroxide or the like can be used. Further, a resist layer removing step for removing the first resist layer 51 and the second resist layer 56 is performed. As a solution for removing the resist layer, a solution containing sodium hydroxide or the like can be used. Thus, the vapor deposition mask 20 including the metal plate 30 provided with the plurality of through holes 40 can be obtained. The filler removing step and the resist layer removing step may be performed simultaneously by using a solution capable of removing both the filler and the resist layer.

In the present embodiment, as described above, etching of the second surface 32 of the portion of the metal plate 30 corresponding to the effective region 23 is performed without providing a resist layer on the second surface 32 . In other words, a recess extending across the plurality of first recesses 50 formed on the first surface 31 side is formed on the second surface 32 side. As a result, variations in the position of the minimum opening diameter portion 46 and the minimum opening size S1 of the through holes 40 among the plurality of through holes 40 can be suppressed.

Next, the effects of this embodiment will be further described by comparing this embodiment with a comparative embodiment. FIG.16 and FIG.17 is a figure which shows the manufacturing method of the vapor deposition mask 20 in a comparative form. In the comparative form shown in FIGS. 16 and 17, the same reference numerals are assigned to the same parts or parts having the same functions as those of the above-described embodiment, and detailed description thereof will be omitted.

FIG. 16 is a cross-sectional view showing the first resist layer 51 provided on the first surface 31 and the second resist layer 56 provided on the second surface 32 of the metal plate 30 in a comparative embodiment. As shown in FIG. 16, in the comparative embodiment, a plurality of exposed regions 58 that are not covered with the second resist layer 56 are provided on the portion of the second surface 32 of the metal plate 30 corresponding to the effective region 23 . After that, similarly to the case of the present embodiment, the metal plate 30 is etched from the first surface 31 side to form the first recesses 50 , and then the first recesses 50 are filled with the filler 52 . Thereafter, using the second resist layer 56 as a mask, the metal plate 30 is etched from the second surface 32 side to form a plurality of second concave portions 55 on the second surface 32 . By connecting the plurality of first recesses 50 and the plurality of second recesses 55 to each other, a plurality of through holes 40 can be formed in the metal plate 30 as shown in FIG. 17 .

By the way, in the comparative form, due to the alignment error of the exposure mask, etc., as shown in the right part of FIG. There may be deviation. In this case, as shown in the right part of FIG. 55 may vary in the thickness direction of the metal plate 30 . 17, the position of the minimum opening diameter portion 46 of the through hole 40 may vary in the thickness direction of the metal plate 30, as indicated by H6 in FIG. As a result, the height H2 of the first wall surface 43 varies.

Further, in the comparative form, etching from the second surface 32 side of the metal plate 30 progresses individually in the plurality of second recesses 55 . In this case, variations in the etching speed in each of the second recesses 55 may occur due to variations in the position of the top of the filling material 52, variations in the concentration of the etchant, variations in the flow of the etchant, and the like. As a result, the position at which the first concave portion 50 and the second concave portion 55 meet varies, and the minimum opening dimension of the through-hole 40 tends to vary. In addition, the height H2 of the first wall surface 43 also varies.

In contrast, in the present embodiment, the second resist layer 56 is not provided on at least most of the portion of the second surface 32 corresponding to the effective region 23 . Therefore, in the second etching step, the speed and concentration of the etchant in the portion corresponding to the effective region 23 are more likely to be uniform than in the comparative embodiment. Therefore, it is possible to suppress variations in the size and position of the minimum opening diameter portion 46 and the height H2 of the first wall surface 43 among the plurality of through holes 40 in the effective area 23 .

In addition, in the present embodiment, the second resist layer 56 is not provided on at least most of the portion of the second surface 32 corresponding to the effective region 23 , and therefore the positional error of the second resist layer 56 causes Errors in the size and position of the minimum opening diameter portion 46 are less likely to occur. In this respect as well, it is possible to suppress variations in the size and position of the minimum opening diameter portion 46 and the height H2 of the first wall surface 43 among the plurality of through holes 40 in the effective area 23 .

Further, in the present embodiment, it is possible to suppress variations in the etching speed and the like in the second etching step. It becomes easier to carry out the etching process. Therefore, the design value and actual measurement value of the height H2 of the first wall surface 43 can be reduced, for example, 2.0 μm or less. Thereby, it is possible to suppress the occurrence of shadows during the vapor deposition process.

Manufacturing Method of Evaporation Mask Device Next, a welding step of welding the deposition mask 20 obtained as described above to the frame 15 is carried out. Thereby, the vapor deposition mask device 10 including the vapor deposition mask 20 and the frame 15 can be obtained.

Evaporation Method Next, a method for depositing the deposition material 82 on the substrate 91 using the deposition mask 20 according to the present embodiment and forming the deposition layer 92 on the substrate 91 as shown in FIG. 18 will be described. In the following description, an article including at least a substrate 91 and a vapor deposition layer 92 formed on the substrate 91 by a vapor deposition process is also referred to as a vapor deposition substrate 90 . The deposition substrate 90 is used in an organic EL display device or the like.

In the vapor deposition step of attaching the vapor deposition material 82 to the substrate 91 using the vapor deposition mask 20 , first, the vapor deposition mask device 10 is arranged so that the vapor deposition mask 20 faces the substrate 91 . Also, the vapor deposition mask 20 is brought into close contact with the substrate 91 using the magnet 85 . Moreover, the inside of the vapor deposition apparatus 80 is made into a vacuum atmosphere. By evaporating the vapor deposition material 82 and causing it to fly to the substrate 91 in this state, the vapor deposition material 82 can be adhered to the substrate 91 in a pattern corresponding to the through holes 40 of the vapor deposition mask 20 .

FIG. 22 is a cross-sectional view showing an enlarged deposition layer 92 formed on the substrate 91 by the deposition process. According to the method for manufacturing the vapor deposition mask 20 described above, it is possible to suppress variations in the etching speed and the like in the second etching step, so that the height H2 of the first wall surface 43 of the through-hole 40 can be set small. . Therefore, the width K1 of the first wall surface 43 in the surface direction of the first surface 31 of the metal plate 30 can be reduced. As a result, as shown in FIG. 22, the width K1 of the portion of the vapor deposition layer 92 formed outside the minimum opening diameter portion 46 of the through hole 40 of the vapor deposition mask 20 varies among a plurality of pixels. can be suppressed. Therefore, it is possible to reduce the margin provided in the design of the vapor deposition substrate 90 in consideration of the interference between adjacent pixels.

Moreover, according to the method for manufacturing the vapor deposition mask 20 described above, it is possible to suppress variation in the size and position of the minimum opening diameter portion 46 among the plurality of through holes 40 . Therefore, when the vapor deposition layer 92 is formed so as to overlap the electrode 93 on the substrate 91 as shown in FIG. can be done. This can also contribute to reducing the margin considered in designing the deposition substrate 90 .

By reducing the margins considered in the design of the deposition substrate 90, the pixel density of the deposition substrate 90 can be increased. Further, when the pixel density of the deposition substrate 90 is constant, the area of the electrode 93 can be increased while preventing interference between adjacent pixels by reducing the margin. Thereby, the ratio of the area overlapping with the electrode 93 to the area of the deposition layer 92 can be increased. This leads to an improvement in the luminous efficiency of the vapor deposition layer 92 when the vapor deposition layer 92 is a light emitting layer. As a result, the brightness of the vapor deposition layer 92 can be increased and the life of the vapor deposition layer 92 can be extended.

Next, the embodiments of the present disclosure will be described in more detail with reference to examples, but the embodiments of the present disclosure are not limited to the description of the following examples as long as they do not exceed the gist thereof.

(Example 1)
First, a metal plate 30 made of an iron alloy having a thickness of 30 μm and containing 34 mass % or more and 38 mass % or less of nickel was prepared. Next, as shown in FIG. 10 described above, a first resist layer 51 was formed on the first surface 31 of the metal plate 30 . Specifically, first, the first surface 31 of the metal plate 30 was coated with SC500, which is a novolac-based positive resist. Subsequently, the positive resist was heated at 140° C. for 600 seconds to obtain a first resist layer 51 . After that, the exposed region 53 shown in FIG. 10 was formed by exposing and developing the first resist layer 51 . Subsequently, using the first resist layer 51 as a mask, the metal plate 30 was etched from the first surface 31 side to form the first recesses 50 . The opening dimension S2 of the first recesses 50 was 5.0 μm, the depth H5 of the first recesses 50 was 2.3 μm, and the pitch of the first recesses 50 was 8.0 μm.

Subsequently, the first concave portion 50 was filled with the filler 52, and the filler 52 was baked. SC500 was used as the filler 52 . The firing temperature and firing time of the filler 52 were 140° C. and 600 seconds.

Subsequently, in a state where the second surface 32 of the metal plate 30 is not provided with the resist layer, a second etching step is performed to etch the metal plate 30 from the second surface 32 side, thereby forming the through holes 40 in the metal plate 30 . formed. As an etching solution, one containing a ferric chloride solution and hydrochloric acid was used. The temperature of the etchant was 45°C. The etching time was determined based on previously acquired etching condition data so that the opening dimension S3 on the second surface of the through-hole 40 was larger than the opening dimension S2 on the first surface by 1 μm or more.

Subsequently, the filler 52 and the first resist layer 51 were removed. FIG. 23 shows the result of observing the cross section of the through hole 40 of the vapor deposition mask 20 thus obtained. As an apparatus for observing the cross section of the through-hole 40, a scanning electron microscope ULTRA55 manufactured by ZEISS was used. In the example shown in FIG. 23, the first wall surface 43 and the second wall surface 44 of the wall surface 41 of the through-hole 40 were found to have fine unevenness with a depth or height of 100 nm or less.

(Example 2)
A through-hole 40 was formed in the same manner as in Example 1, except that the etching time in the second etching step was made longer than in Example 1. Further, in the same manner as in Example 1, the cross section of the through hole 40 of the vapor deposition mask 20 was observed. Results are shown in FIG.

(Example 3)
A through-hole 40 was formed in the same manner as in Example 1, except that the etching time in the second etching step was longer than in Example 2. Further, in the same manner as in Example 1, the cross section of the through hole 40 of the vapor deposition mask 20 was observed. Results are shown in FIG.

10 vapor deposition mask device 15 frame 20 vapor deposition mask 201 first surface 202 second surface 21 ear portion 22 intermediate portion 23 effective area 24 surrounding area 30 metal plate 31 first surface 32 second surface 35 shielding portion 40 through hole 41 wall surface 411 second surface First end 412 Second end 43 First wall surface 44 Second wall surface 45 Tip 46 Minimum opening diameter portion 50 First recess 51 First resist layer 52 Filling material 53 Exposed region 55 Second recess 56 Second resist layer 57 Gap 58 Exposed region 80 vapor deposition device 81 vapor deposition source 82 vapor deposition material 83 heater 85 magnet 90 vapor deposition substrate 91 substrate 92 vapor deposition layer 93 electrode

Claims (1)

A metal plate having a thickness of 10 μm or less, including a first surface, a second surface located on the opposite side of the first surface, and a through hole,
The through hole has a wall surface including a first end that is an end on the first surface and a second end that is an end on the second surface,
The wall surface includes a minimum opening diameter portion located between the first end and the second end in the thickness direction of the metal plate and having the smallest opening diameter,
In the thickness direction of the metal plate, the distance between the minimum opening diameter portion and the first end is 2.0 μm or less,
A mask, wherein the second end has a curved cross-sectional shape.

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