JP6895129B2 - Method of manufacturing vapor deposition mask and vapor deposition mask - Google Patents

Description

The present invention relates to a method for producing a thin-film deposition mask used for performing thin-film deposition in a desired pattern, and more particularly to a method for producing a thin-film deposition mask capable of using a thin-film deposition material for film formation with excellent utilization efficiency. The present invention also relates to a thin-film deposition mask used for performing thin-film deposition in a desired pattern, and more particularly to a thin-film deposition mask capable of using a thin-film deposition material for film formation with excellent utilization efficiency.

Conventionally, a method of forming a thin film with a desired pattern by using a vapor deposition mask containing through holes arranged in a desired pattern has been known. In recent years, thin-film deposition may be used when depositing an extremely expensive material, for example, when an organic material is vapor-deposited on a substrate during the manufacture of an organic EL display device. The vapor deposition mask can generally be manufactured by forming through holes in a metal plate by etching using a photolithography technique (for example, Patent Document 1).

When a vapor deposition material is deposited on a substrate using a thin film deposition mask, the vapor deposition material also adheres to the vapor deposition mask. That is, not all of the vapor deposition materials used adhere to the substrate. When an expensive thin-film deposition material is used, low utilization efficiency becomes a big problem. The utilization efficiency referred to here refers to the ratio of the material adhering to the substrate among the evaporated vaporized materials.

Japanese Unexamined Patent Publication No. 2004-39319

By the way, some of the vapor-deposited materials move toward the substrate in a direction greatly inclined with respect to the normal direction to the vapor-deposited mask. In order to effectively utilize the deposited material that moves diagonally and improve the utilization efficiency of the vapor deposition material, it is preferable to form a through hole in the metal plate in which the wall surface is greatly inclined and tapered. However, when a through hole is formed in a metal plate by a conventional etching method, the wall surface of the through hole cannot be inclined sufficiently large. Therefore, the current vapor deposition mask cannot sufficiently improve the utilization efficiency of the vapor deposition material.

The present invention has been made in consideration of such a point, and an object of the present invention is to provide a method for manufacturing a thin-film deposition mask capable of forming a film-deposited material with high utilization efficiency.

The method for manufacturing a vapor deposition mask according to the present invention
A method for manufacturing a vapor deposition mask including an effective region in which a plurality of through holes are formed and a peripheral region located around the effective region.
The metal plate is etched from the side of the first surface using the resist pattern arranged on the first surface of the metal plate having the first surface and the second surface facing each other as a mask to form the effective region. In the region of the metal plate, a step of forming a recess for defining the through hole from the side of the first surface is provided, and in the step of forming the recess, erosion due to etching occurs on the plate surface of the metal plate. Proceeding along the direction, two adjacent recesses merge under the resist pattern, and the wall surface of at least one recess is located around the one recess over the entire circumference of the other recess. It merges with the wall surface of one of the recesses.

In the method for manufacturing a vapor deposition mask according to the present invention, the wall surface of the recess merges with the wall surface of any other recess located around the recess over the entire circumference, or a part of the entire circumference thereof. In the first portion of the metal plate, the first portion of the metal plate extends into a region that merges with the wall surface of any other recess located around the recess and forms the peripheral region in another portion of the entire circumference thereof. It may be connected to the surface.

In the step of forming the recess in the method for manufacturing a vapor deposition mask according to the present invention, the resist pattern may be separated from the metal plate within the entire region of the metal plate forming the effective region. ..

In the step of forming the recess in the method for producing a vapor-deposited mask according to the present invention, the erosion of the first surface by etching may proceed within the entire region of the metal plate forming the effective region.

In the step of forming the recesses in the method for manufacturing a vapor deposition mask according to the present invention, in the joining portion formed by merging the two adjacent recesses, the merging portion is separated from the resist pattern and is under the resist pattern. The erosion due to etching may proceed in the normal direction of the metal plate, and the confluence portion may be chamfered.

In the step of forming the recess in the method for manufacturing a vapor deposition mask according to the present invention, the maximum thickness of the metal plate along the normal direction in the region forming the effective region is the maximum thickness of the metal plate before etching. It may be 35% or more and 65% or less of the thickness. In such a method for manufacturing a vapor deposition mask according to the present invention, the recesses may be formed in a lattice arrangement on the first surface of the metal plate.

In the step of forming the recess in the method for manufacturing a vapor deposition mask according to the present invention, the maximum thickness of the metal plate along the normal direction in the region forming the effective region is the maximum thickness of the metal plate before etching. It may be 45% or more and 65% or less of the thickness. In such a method for producing a vapor deposition mask according to the present invention, the recesses may be formed in a lattice arrangement or a staggered arrangement on the first surface of the metal plate.

In the method for manufacturing a vapor deposition mask according to the present invention, the metal plate is etched from the side of the second surface using the resist pattern arranged on the second surface of the metal plate as a mask, and the second recess is formed on the second surface. Further prepared for the process of forming from the side of
The recess and the second recess may be formed so that the recess and the second recess are connected to form the through hole.

In the method for producing a thin-film deposition mask according to the present invention, laser light is irradiated into each recess formed from the side of the first surface so as not to penetrate the metal plate, and the first portion of the metal plate is irradiated from the inside of the recess. Further provided with a step of forming a second recess reaching up to two surfaces,
The recess and the second recess may be formed so that the recess and the second recess are connected to form the through hole.

The vapor deposition mask according to the present invention
An effective area with multiple through holes and
With a peripheral area located around the effective area,
In the effective region, a plurality of recesses that become wider toward the other side are provided on one side of the vapor deposition mask along the normal direction, and the recesses define through holes. And
The wall surface of at least one recess merges with the wall surface of any other recess located around the recess over its entire circumference.

In the vapor deposition mask according to the present invention, the wall surface of the recess is merged with the wall surface of any other recess located around the recess over the entire circumference, or a part of the entire circumference thereof. In, it may be merged with the wall surface of any other recess located around the recess and extend into the peripheral region in another part of the entire circumference thereof.

In the entire region of the vapor deposition mask according to the present invention, one side surface of the vapor deposition mask may be an uneven surface.

In the thin-film deposition mask according to the present invention, a ridge line is formed by the confluence of the wall surface of the recess and the wall surface of the other recess, and the height of the ridge line along the normal direction of the vapor deposition mask fluctuates. It may be.

In the vapor deposition mask according to the present invention, the height of the wall surface of the recess that joins the wall surface of the other recess along the normal direction of the vapor deposition mask is the penetration portion of the through hole defined by the recess. The longer the distance along the plate surface of the vapor deposition mask from the above, the higher the distance may be.

In the vapor deposition mask according to the present invention, the outer contour of the confluence portion where the wall surfaces of the two recesses meet in a cross section along the normal direction of the vapor deposition mask may have a chamfered shape.

In the vapor deposition mask according to the present invention, the outer contour of the confluence portion where the wall surfaces of the two recesses meet in the cross section along the normal direction of the vapor deposition mask is directed to one side along the normal direction of the vapor deposition mask. It may have a curved shape that is convex toward it.

In the vapor deposition mask according to the present invention, the maximum thickness in the effective region along the normal direction of the vapor deposition mask is 35% or more and 65% of the maximum thickness in the peripheral region along the normal direction of the vapor deposition mask. It may be as follows. In such a vapor deposition mask according to the present invention, the recesses may be arranged in a lattice arrangement.

In the vapor deposition mask according to the present invention, the maximum thickness in the effective region along the normal direction of the vapor deposition mask is 45% or more and 65% of the maximum thickness in the peripheral region along the normal direction of the vapor deposition mask. It may be as follows. In such a vapor deposition mask according to the present invention, the recesses may be arranged in a lattice arrangement or a houndstooth arrangement.

In the effective region of the vapor deposition mask according to the present invention, a second recess that widens toward the other side is provided on the other side along the normal direction of the vapor deposition mask, and the recess and the recess are described. The second recess may be connected to form the through hole.

In the effective region of the vapor deposition mask according to the present invention, a second recess whose width becomes narrower toward the other side is provided on the other side along the normal direction of the vapor deposition mask, and the recess and the recess are described. The second recess may be connected to form the through hole.

According to the present invention, there is provided a thin-film mask capable of forming a thin-film deposition material with high utilization efficiency.

FIG. 1 is a diagram for explaining an embodiment of the present invention, and is a schematic perspective view showing an example of a thin-film deposition mask device including a thin-film deposition mask. FIG. 2 is a diagram for explaining a method of vapor deposition using the vapor deposition mask device shown in FIG. FIG. 3 is a partial plan view showing the vapor deposition mask shown in FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. FIG. 5 is a cross-sectional view taken along the line VV of FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 7 is a schematic view for explaining an example of the method for manufacturing the vapor deposition mask shown in FIG. 1 as a whole. FIG. 8 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 9 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 10 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 11 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 12 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 13 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 14 is a diagram for explaining an example of a method for manufacturing a vapor deposition mask, and is a diagram showing a long metal plate in a cross section along a normal direction. FIG. 15 is a diagram corresponding to FIG. 9 and is a diagram for explaining a modified example of a method of forming a through hole. 16 and 17 are views for explaining another modification of the method for forming the through hole, and FIG. 16 is a diagram showing a method for forming the first recess. 16 and 17 are views for explaining another modification of the method for forming the through hole, and FIG. 17 is a diagram showing a method for forming the second recess. 18 and 19 are views for explaining a modification of a method for manufacturing a vapor deposition mask, and FIG. 18 is a diagram showing a method for forming a first recess. 18 and 19 are diagrams for explaining a variation of the method for manufacturing a vapor deposition mask, and FIG. 19 is a diagram showing a method for forming a second recess. FIG. 20 is a top view for explaining the pattern of through holes of the first vapor deposition mask actually produced. FIG. 21 is a top view for explaining the pattern of through holes of the second vapor deposition mask actually produced.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

1 to 14 are diagrams for explaining one embodiment according to the present invention. In the following embodiments and modifications thereof, a method for manufacturing a vapor deposition mask used for patterning an organic light emitting material on a glass substrate in a desired pattern when manufacturing an organic EL display device will be described as an example. .. However, the present invention is not limited to such application, and the present invention can be applied to a vapor deposition mask and a method for manufacturing a vapor deposition mask used for various purposes.

In addition, in this specification, the terms "board", "sheet", and "film" are not distinguished from each other based only on the difference in designation. For example, "plate" is a concept that includes members that can be called sheets or films. Therefore, for example, "metal plate" is distinguished only by the difference in name from members called "metal sheet" or "metal film". Can't be done.

Further, the "plate surface (sheet surface, film surface)" is a plate-like member (sheet-like) that is a target when the target plate-like (sheet-like, film-like) member is viewed as a whole and from a broad perspective. A surface that coincides with the plane direction of a member or film-like member). Further, the normal direction used for the plate-shaped (sheet-shaped, film-shaped) member refers to the normal direction with respect to the plate surface (sheet surface, film surface) of the member.

Furthermore, as used in the present specification, the terms such as "parallel", "orthogonal", and "identical" and the values of length and angle that specify the shape and geometric conditions and their degrees are strictly used. Without being bound by meaning, we will interpret it including the range in which similar functions can be expected.

First, an example of a vapor deposition mask apparatus including a vapor deposition mask to be manufactured will be described mainly with reference to FIGS. 1 to 6. Here, FIG. 1 is a perspective view showing an example of a thin-film deposition mask device including a thin-film deposition mask, and FIG. 2 is a diagram for explaining how to use the thin-film deposition mask device shown in FIG. FIG. 3 is a plan view showing the vapor deposition mask from the side of the first surface, and FIGS. 4 to 6 are cross-sectional views at each position of FIG.

The thin-film deposition mask device 10 includes a thin-film deposition mask 20 made of a rectangular metal plate 21 and a frame 15 attached to the peripheral edge of the thin-film deposition mask 20. The thin-film mask 20 is provided with a large number of through holes 25 formed by etching a metal plate 21 having a first surface 21a and a second surface 21b facing each other from at least the first surface 21a. As shown in FIG. 2, the vapor deposition mask device 10 is supported in the vapor deposition device 90 so that the vapor deposition mask 20 faces a substrate to be vapor-deposited, for example, a glass substrate 92, and the vapor deposition material is deposited on the substrate. Used for.

In the vapor deposition apparatus 90, the vapor deposition mask 20 and the glass substrate 92 come into close contact with each other due to the magnetic force from a magnet (not shown). In the vapor deposition apparatus 90, a crucible 94 for accommodating a vapor deposition material (for example, an organic light emitting material) 98 and a heater 96 for heating the crucible 94 are arranged below the glass substrate 92 sandwiching the vapor deposition mask apparatus 10. Has been done. The vaporized material 98 in the crucible 94 is vaporized or sublimated by heating from the heater 96 and adheres to the surface of the glass substrate 92. As described above, a large number of through holes 25 are formed in the vapor deposition mask 20, and the vapor deposition material 98 adheres to the glass substrate 92 through the through holes 25. As a result, the vapor deposition material 98 is formed on the surface of the glass substrate 92 in a desired pattern corresponding to the position of the through hole 25 of the vapor deposition mask 20.

As shown in FIG. 1, in the present embodiment, the vapor deposition mask 20 is made of a metal plate 21 and has a substantially quadrangular contour in a plan view, or more accurately, a substantially rectangular contour in a plan view. The metal plate 21 of the vapor deposition mask 20 includes an effective region 22 in which through holes 25 are formed in a regular arrangement, and a peripheral region 23 surrounding the effective region 22. The peripheral region 23 is a region for supporting the effective region 22, and is not a region through which the vapor-deposited material intended to be vapor-deposited on the substrate passes. For example, in the vapor deposition mask 20 used for vapor deposition of an organic light emitting material for an organic EL display device, the effective region 22 is an area on a substrate (glass substrate 92) on which the organic light emitting material is vapor-deposited to form pixels. That is, the region in the vapor deposition mask 20 facing the area on the substrate that forms the display surface of the produced substrate for the organic EL display device. However, through holes and recesses may be formed in the peripheral region 23 for various purposes. In the example shown in FIG. 1, each effective region 22 has a substantially quadrangular contour in a plan view, or more accurately, a substantially rectangular contour in a plan view.

In the illustrated example, the plurality of effective regions 22 are arranged at predetermined intervals along one direction parallel to one side of the vapor deposition mask 20 and are predetermined along the other direction orthogonal to the one direction. They are arranged at intervals. In the illustrated example, one effective region 22 corresponds to one organic EL display device. That is, according to the thin-film deposition mask device 10 (thin-film deposition mask 20) shown in FIG. 1, multi-sided vapor deposition is possible. However, not limited to the illustrated example, the thin-film deposition mask 20 includes a plurality of effective regions 22 arranged in a row along one direction, and the thin-film deposition mask device 10 is orthogonal to the longitudinal direction (one direction) thereof. It is also possible to have a plurality of thin-film deposition masks 20 arranged in the same direction and attached to the frame 15.

As shown in FIG. 3, in the illustrated example, the plurality of through holes 25 formed in each effective region 22 are arranged in a lattice arrangement. That is, the plurality of through holes 25 are arranged at predetermined pitches in the effective region 22 along two directions orthogonal to each other. An example of the through hole 25 formed in the metal plate 21 will be described in more detail with reference mainly to FIGS. 3 to 6.

FIG. 3 is a partial plan view showing the vapor deposition mask 20 from the first surface 20a side. Further, FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3, FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3, and FIG. It is sectional drawing along the line. As shown in FIGS. 4 to 6, the plurality of through holes 25 are a first surface 20a on one side along the normal direction of the vapor deposition mask 20 and the other side along the normal direction of the vapor deposition mask 20. It extends between the second surface 20b on the side and penetrates the vapor deposition mask 20. In the illustrated example, as will be described in detail later, a first recess 30 is formed in the metal plate 21 by etching from the side of the first surface 21a of the metal plate 21 which is one side in the normal direction of the vapor deposition mask. A second recess 35 is formed in the metal plate 21 from the side of the second surface 21b which is the other side in the normal direction of the metal plate 21, and a through hole 25 is formed by the first recess 30 and the second recess 35. ing.

As shown in FIGS. 3 to 6, from one side to the other side in the normal direction of the vapor deposition mask 20, that is, from the side of the first surface 20a of the vapor deposition mask 20 to the side of the second surface 20b. Therefore, the cross-sectional area of each first recess 30 in the cross section along the plate surface of the vapor deposition mask 20 at each position along the normal direction of the vapor deposition mask 20 gradually becomes smaller. In other words, in the cross section along the normal direction of the vapor deposition mask 20, the width of each first recess 30 along the plate surface of the vapor deposition mask 20 at each position along the normal direction of the vapor deposition mask 20 is the vapor deposition mask 20. The size gradually decreases from the side of the first surface 20a to the side of the second surface 20b. In particular, in the illustrated example, the cross-sectional area of each of the first recesses 30 continues to change from the side of the first surface 20a to the side of the second surface 20b of the vapor deposition mask 20. As shown in FIG. 3, the wall surface 31 of the first recess 30 extends in a direction intersecting the normal direction of the vapor deposition mask 20 in the entire region thereof, and one of the wall surfaces 31 along the normal direction of the vapor deposition mask 20. It is exposed toward the side.

Similarly, the cross-sectional area of each second recess 35 in the cross section along the plate surface of the vapor deposition mask 20 at each position along the normal direction of the vapor deposition mask 20 is from the other side in the normal direction of the vapor deposition mask 20. It gradually becomes smaller toward one side, that is, from the side of the second surface 20b of the vapor deposition mask 20 toward the side of the first surface 20a. In other words, in the cross section along the normal direction of the vapor deposition mask 20, the width of each second recess 35 along the plate surface of the vapor deposition mask 20 at each position along the normal direction of the vapor deposition mask 20 is the vapor deposition mask 20. The size gradually decreases from the side of the second surface 20b to the side of the first surface 20a. In particular, in the illustrated example, the cross-sectional area of each of the second recesses 35 continues to change from the side of the second surface 20b of the vapor deposition mask 20 toward the side of the first surface 20a. The wall surface 36 of the second recess 35 extends in a direction intersecting the normal direction of the vapor deposition mask 20 in the entire region, and is exposed toward the other side along the normal direction of the vapor deposition mask 20. There is.

As shown in FIGS. 4 to 6, the through hole 25 is formed from the tapered first recess 30 formed from the side of the first surface 20a of the vapor deposition mask 20 and the side of the second surface 20b of the vapor deposition mask 20. It is defined by connecting with a second concave portion 35 that is tapered. As shown in FIG. 3, in the illustrated example, one first recess 30 and one second recess 35 are formed for one through hole 25. Therefore, each through hole 25 is formed by connecting one first recess 30 and the second recess 35 provided corresponding to the first recess 30.

As shown in FIGS. 4 to 6, the wall surface 31 of the first recess 30 and the wall surface 36 of the second recess 35 are connected via a circumferential connecting portion 41. The connecting portion 41 is an overhanging portion where the wall surface 31 of the first recess 30 inclined with respect to the normal direction of the vapor deposition mask and the wall surface 36 of the second recess 35 inclined with respect to the normal direction of the vapor deposition mask meet. It is defined by the ridgeline. Then, the connecting portion 41 defines the penetrating portion 42 in which the area of the through hole 25 is the smallest in the plan view of the vapor deposition mask 20.

As shown in FIGS. 4 to 6, on the other side surface of the vapor deposition mask along the normal direction, that is, on the second surface 20b of the vapor deposition mask 20, two adjacent through holes 25 are formed of the vapor deposition mask. They are separated from each other along the plate surface. That is, as in the manufacturing method described later, when the metal plate 21 is etched from the second surface 21b side of the metal plate 21 corresponding to the second surface 20b of the vapor deposition mask 20 to produce the second recess 35. , The second surface 21b of the metal plate 21 remains between the two adjacent second recesses 35.

On the other hand, as shown in FIGS. 4 to 6, two adjacent first recesses 30 are connected on the other side along the normal direction of the vapor deposition mask, that is, on the side of the first surface 20a of the vapor deposition mask 20. ing. That is, as in the manufacturing method described later, when the metal plate 21 is etched from the first surface 21a side of the metal plate 21 corresponding to the first surface 20a of the vapor deposition mask 20 to form the first recess 30. The first surface 21a of the metal plate 21 does not remain between the two adjacent first recesses 30. According to the first surface 20a of the vapor deposition mask 20 formed by the first recess 30, the vapor deposition mask is such that the first surface 20a of the vapor deposition mask 20 faces the vapor deposition material 98 as shown in FIG. When 20 is used, the utilization efficiency of the thin-film deposition material 98 can be effectively improved.

When the vapor deposition mask device 10 is housed in the vapor deposition device 90 as shown in FIG. 2, the first surface 20a of the vapor deposition mask 20 holds the vapor deposition material 98 on the side of the pot 94 as shown by the alternate long and short dash line in FIG. The second surface 20b of the vapor deposition mask 20 faces the glass substrate 92. Therefore, the thin-film deposition material 98 passes through the first recess 30 whose cross-sectional area is gradually reduced and adheres to the glass substrate 92. As shown in FIG. 4, the thin-film deposition material 98 not only moves from the crucible 94 toward the glass substrate 92 along the normal direction of the glass substrate 92, but also is greatly inclined with respect to the normal direction of the glass substrate 92. It may move in the direction. At this time, assuming that the cross-sectional shape of the first recess 30 has the contour shown by the dotted line in FIG. 4, the thin-film deposition material 98 that moves diagonally adheres to the thin-film deposition mask 20 and does not reach the glass substrate 92. Further, in the region of the glass substrate 92 facing the through hole 25, there are a region where the vapor deposition material 98 can easily reach and a portion where the vapor deposition material 98 cannot reach easily. Specifically, the vapor deposition material 98 can reach the region on the glass substrate 92 facing the center of the through hole 25, but the region on the glass substrate 92 facing the peripheral edge of the through hole 25 can be reached. The vapor deposition material 98 is less likely to reach. This phenomenon, also called shadow, causes the film thickness of the vapor deposition film to fluctuate greatly within the planned vapor deposition region, and further, the vapor deposition material cannot be attached to the peripheral edge of the planned vapor deposition region, in other words, a desired pattern. It appears as a problem that the vapor deposition cannot be performed in.

That is, in order to increase the utilization efficiency of the thin-film deposition material (deposition efficiency: the ratio of adhesion to the glass substrate 92) to save the expensive vapor-deposited material, and to stabilize the film formation using the expensive-deposited material in a desired region. In order to carry out the process evenly, in the cross sections of FIGS. 4 to 6 orthogonal to the sheet surface of the vapor deposition mask 20, the connecting portion 41 which is a portion having the minimum cross-sectional area of the through hole 25 and the wall surface 31 of the first recess 30. _{It is advantageous that the minimum angle θ 1} (see FIG. 4) formed by the straight line L1 passing through the other arbitrary position with respect to the normal direction of the vapor deposition mask 20 is sufficiently large. Then, according to the illustrated example, as compared with the concave portion having the wall surface (contour) indicated by the dotted line which does not merge with the other concave portions by merging the wall surfaces 31 of the two adjacent first concave portions 30. Therefore, this angle θ ₁ can be made significantly smaller.

The first recess 30 is formed by etching the first surface 21a of the metal plate 21, as will be described in detail later. The wall surface of the recess formed by etching generally has a curved surface shape that is convex in the erosion direction. Therefore, the wall surface 31 of the recess formed by etching is cut off in the region on the etching start side, and the metal plate 21 method is used in the region opposite to the etching start side, that is, on the deepest side of the recess. It will be inclined relatively large with respect to the line direction. Then, in the illustrated vapor deposition mask 20, since the wall surfaces 31 of the two adjacent first recesses 30 are merged on the etching start side, the wall surface 31 of the first recess 30 forming most of the through holes 25 is formed. Can be effectively tilted with respect to the normal direction of the vapor deposition mask. Further, even when compared with the recess formed by etching a metal plate whose thickness is thin from the beginning, the wall surface 31 of the first recess 30 shown in the figure includes a steep portion on the etching start side. Therefore, the inclination angle θ ₁ of the wall surface 31 can be made sufficiently large. As a result, when the thin-film deposition mask 20 described here is used, the thin-film deposition in a desired pattern can be stably performed with high accuracy while effectively improving the utilization efficiency of the thin-film deposition material 98.

In particular, in the illustrated example, the tip edge (upper edge, edge edge located on one side along the normal direction of the vapor deposition mask) 32 of all the first recesses 30 of the effective region 22 is its. It merges with the tip edge 32 of the wall surface 31 of any other first recess 30 located around the first recess 30 over the entire circumference, or the first portion of the entire circumference thereof. It merges with the tip edge 32 of the wall surface 31 of any other first recess 30 located around the recess 30 and extends into the peripheral region 23 in other parts of the entire circumference thereof. As shown in FIGS. 4 to 6, a part of the tip edge 32 of the wall surface 31 with respect to the first recess 30 defining the outermost through hole 25 among the through holes 25 arranged in a predetermined pattern. Is connected to the tip edge 32 of the wall surface 31 of the other first recess 30, and the other part of the tip edge 32 of the wall surface 31 extends to the peripheral region 23 to form a flat surface of the vapor deposition mask 20, which will be described later. According to the method, it is connected to the first surface 21a of the metal plate 21. On the other hand, with respect to the first recess 30 that defines the through hole 25 located at a position other than the outermost of the through holes 25 arranged in a predetermined pattern, the tip edge 32 of the wall surface 31 covers the entire circumference thereof. It merges with the tip edge 32 of the wall surface 31 of any other first recess 30 located around the first recess 30.

That is, in the examples shown in FIGS. 3 to 6, in the entire region within the effective region 22 of the vapor deposition mask 20, the first surface 20a of the vapor deposition mask 20 faces one side in the normal direction of the vapor deposition mask. It is formed by the wall surface 31 of the first recess 30 that has been formed. As a result, the first surface 20a of the vapor deposition mask 20 forms an uneven surface in the entire region within the effective region 22 of the vapor deposition mask 20.

_{According to such a vapor deposition mask 20, the inclination angle θ 1} formed by the wall surface 31 of the first recess 30 with respect to the normal direction of the vapor deposition mask can be effectively increased in the entire effective region 22. As a result, it is possible to stably carry out thin-film deposition in a desired pattern with high accuracy while effectively improving the utilization efficiency of the thin-film deposition material 98.

Further, when the metal plate 21 is etched from the first surface 21a side of the metal plate 21 corresponding to the first surface 20a of the vapor deposition mask 20 as in the manufacturing method described later to produce the first recess 30. In the entire region of the metal plate 21 forming the effective region 22 of the vapor deposition mask 20, the first surface 21a of the metal plate 21 is eroded by etching. That is, the first surface 21a of the metal plate 21 does not exist in the effective region 22. In other words, the maximum thickness Ta in the effective region 22 along the normal direction of the vapor deposition mask is less than 100% of the maximum thickness Tb in the peripheral region 23 along the normal direction of the vapor deposition mask. It is preferable that the thickness in the effective region 22 is reduced as a whole from the viewpoint of improving the utilization efficiency of the vapor-deposited material. On the other hand, from the viewpoint of the strength of the vapor deposition mask, the maximum thickness Ta in the effective region 22 along the normal direction of the vapor deposition mask is constant of the maximum thickness Tb in the peripheral region 23 along the normal direction of the vapor deposition mask. The above ratio is preferable. Deformation of the vapor deposition mask 20 in the effective region 22 when the vapor deposition mask 20 is stretched on the frame 15 can be effectively suppressed, whereby vapor deposition in a desired pattern can be effectively performed. Because it can be done.

Further, since the width of the first recess 30 increases from the other side along the normal direction of the vapor deposition mask toward one side, the tip edge 32 of the wall surface 31 of the first recess 30 and others The ridge line 33 is formed by merging with the tip edge 32 of the wall surface 31 of the first recess 30 of the above. In the illustrated example, the through holes 25 are formed in a substantially rectangular shape in a plan view, and are arranged at predetermined pitches in each of two directions orthogonal to each other. Therefore, as shown in FIG. 3, the tip edge 32 of the wall surface 31 of the first recess 30 defining the through hole 25 located outside the outermost portion in the effective region 22 extends along a substantially rectangular shape, and also. The ridge line 33 extending between the two adjacent first recesses 30 extends in two directions parallel to the arrangement direction of the through holes 25, respectively.

Further, when the first recess 30 is formed by etching as in the manufacturing method described later, the height of the ridge line 33, that is, the position of the ridge line 33 in the normal direction of the vapor deposition mask is not constant but fluctuates. In other words, the position of the tip edge 32 of the wall surface 31 of the first recess 30 that joins the tip edge 32 of the wall surface 31 of the other first recess 30 in the normal direction of the vapor deposition mask is not constant but fluctuates. Due to the method of forming the first recess 30 described later, the heights of the ridge line 33 and the tip edge 32 are the plate surface of the vapor deposition mask from the penetration portion 42 of the through hole 25 where the depth of the first recess 30 is the deepest. It changes according to the distance along the. Specifically, the height of the tip edge 32 of the wall surface 31 of the first recess 30 that joins the tip edge 32 of the wall surface 31 of the other first recess 30 along the normal direction of the vapor deposition mask is usually the said. The longer the distance along the plate surface of the vapor deposition mask from the through portion 42 of the through hole 25 defined by the first recess 30 to the tip edge 32, the higher the distance. Therefore, when the through holes 25 (first recesses 30) are arranged squarely as shown in the drawing, the positions are intermediate between the adjacent through holes 25 in each of the two arrangement directions (FIGS. 3 to 6). At the highest portion 32a) in the above, the height of the tip edge 32 and the ridge line 33 is the highest.

As a general tendency, in such a vapor deposition mask 20, as can be well understood from FIG. 5, the height of the tip edge 32 of the wall surface 31 of the first recess 30 is from the position of the target tip 32. The distance k in the plan view to the center of the region (through portion 42 in this example) penetrating the metal plate 21 in the plan view of the through hole 25 defined by the first recess 30 (see FIG. 3). The shorter the, the lower. _{Therefore, the above-mentioned angle θ 1} formed by the wall surface 31 with respect to the normal direction of the vapor deposition mask 20 can be effectively increased. Thereby, the utilization efficiency of the thin-film deposition material 98 can be improved more effectively, and the thin-film deposition in a desired pattern can be carried out with high accuracy and stability.

Further, in the illustrated example, due to the manufacturing method described later, the portion 43 where the tip edges 32 of the wall surfaces 31 of the two first recesses 30 meet in the cross section along the normal direction of the vapor deposition mask. The outer contour (the line forming the outer shape of the portion 43 in the cross section) has a chamfered shape. As described above, in general, the wall surface of the recess formed by etching has a curved surface shape that is convex in the main traveling direction by etching. Therefore, when the two first recesses 30 formed by etching are simply partially overlapped, as shown by the dotted lines in FIGS. 4 to 6, the confluence portion 43 is the method of the vapor deposition mask which is the starting side of etching. It has a sharp shape toward one side along the line direction. On the other hand, in the illustrated vapor deposition mask 20, the sharp portion in the confluence portion 43 is chamfered. As can be seen from FIGS. 4 to 6, this chamfering can effectively increase the _{above-mentioned angle θ 1} formed by the wall surface 31 with respect to the normal direction of the vapor deposition mask 20. Thereby, the utilization efficiency of the thin-film deposition material 98 can be improved more effectively, and the thin-film deposition in a desired pattern can be carried out with high accuracy and stability.

As described above, in the present embodiment, the through holes 25 are arranged in a predetermined pattern in each effective region 22. As an example, when the vapor deposition mask 20 (vapor deposition mask device 10) is used to manufacture a display (about 2 to 5 inches) of a mobile phone, a digital camera, or the like, the arrangement pitch P of the through holes 25 is 58 μm (440 ppi). It can be about 254 μm (100 ppi) or less. When color display is desired, the thin-film deposition mask 20 (deposited-film deposition mask device 10) and the glass substrate 92 are gradually moved relative to each other along the arrangement direction of the through holes 25 (one direction described above), and the red color is displayed. The organic light emitting material, the organic light emitting material for green, and the organic light emitting material for blue may be vapor-deposited in this order. Further, when the vapor deposition mask 20 (vapor deposition mask device 10) is used for manufacturing a display of a mobile phone, the width (slit width) W along the arrangement direction (one direction described above) of each through hole 25 is 28 μm. It can be more than 84 μm or less.

The frame 15 of the vapor deposition mask device 10 is attached to the peripheral edge of the rectangular vapor deposition mask 20. The frame 15 is held in a state in which the vapor deposition mask is stretched so that the vapor deposition mask 20 does not bend. The vapor deposition mask 20 and the frame 15 are fixed to each other by spot welding, for example.

The vapor deposition mask device 10 is held inside the vapor deposition device 90 which has a high temperature atmosphere. Therefore, the vapor deposition mask 20 and the frame 15 are preferably made of the same material having a low coefficient of thermal expansion in order to prevent the vapor deposition frame from bending and generating thermal stress. As such a material, for example, a 36% Ni Invar material can be used.

According to the vapor deposition mask 20 as described above, the tip edge 32 of the wall surface 31 of at least one first recess 30 is located on the entire circumference of the first recess 30 and is located around the first recess 30. 1 It merges with the wall surface 31 of the recess 30. Therefore, while effectively improving the utilization efficiency of the thin-film deposition material 98, the thin-film deposition in a high-definition pattern can be performed with a desired thickness and accuracy. In particular, in an organic EL display device, it is desired to pattern an expensive thin-film deposition material 98 on a substrate 42 in a high-definition pattern. Therefore, the vapor deposition mask 20 of the present embodiment is particularly suitable for the vapor deposition mask used for manufacturing an organic EL display device.

Next, a method for manufacturing such a vapor deposition mask 20 will be described mainly with reference to FIGS. 7 to 14. In the method for manufacturing the vapor deposition mask 20 described below, as shown in FIG. 7, a long metal plate 64 extending in a strip shape is supplied, a through hole 25 is formed in the long metal plate 64, and a long metal plate 64 is further formed. By cutting the plate 64, a vapor deposition mask 20 made of a single-wafer-shaped metal plate 21 can be obtained.

More specifically, the method for manufacturing the vapor deposition mask 20, the process of supplying the long metal plate 64 extending in a strip shape, and the etching using the photolithography technique are applied to the long metal plate 64 to apply the long metal plate 64. The process of forming the first recess 30 from the side of the first surface 64a on the 64 and the etching using the photolithography technique are applied to the long metal plate 64, and the long metal plate 64 is formed from the side of the second surface 64b. 2 Includes a step of forming the recess 35. Then, the first recess 30 and the second recess 35 formed in the long metal plate 64 communicate with each other to form a through hole 25 in the long metal plate 64. In the example shown in FIG. 7, the step of forming the second recess 35 is performed before the step of forming the first recess 30, and between the steps of forming the second recess 35 and the step of forming the first recess 30. Further, a step of sealing the produced second recess 35 is provided. The details of each step will be described below.

FIG. 7 shows a manufacturing apparatus 60 for manufacturing the vapor deposition mask 20. As shown in FIG. 7, first, a winding body 62 in which a long metal plate 64 is wound around a supply core 61 is prepared. Then, the supply core 61 rotates and the winding body 62 is rewound, so that the long metal plate 64 extending in a strip shape is supplied as shown in FIG. The long metal plate 64 is formed with a through hole 25 to form a single-wafer-shaped metal plate 21 and further a vapor deposition mask 20. Therefore, as described above, the long metal plate 64 is made of, for example, a 36% Ni Invar material. However, the present invention is not limited to this, and a sheet made of stainless steel, copper, iron, or aluminum can be used as the long metal plate 64. Further, the thickness of the metal plate 64 can be, for example, 20 μm or more and 80 μm or less.

The supplied long metal plate 64 is conveyed to the etching apparatus (etching means) 70 by the conveying roller 72. The etching means 70 performs each of the treatments shown in FIGS. 8 to 14. First, as shown in FIG. 8, a resist pattern (also simply referred to as a resist) 65a is formed on the first surface 64a of the long metal plate 64, and a resist is formed on the second surface 64b of the long metal plate 64. A pattern (also simply referred to as a resist) 65b is formed. As a specific example, a negative resist pattern is formed as follows. First, a photosensitive resist material is applied on the first surface 64a (on the lower surface in the paper surface of FIG. 8) and the second surface 64b of the long metal plate 64, and a resist film is formed on the long metal plate 64. Form. Next, a glass dry plate that does not allow light to pass through the region of the resist film to be removed is prepared, and the glass dry plate is placed on the resist film. Then, the resist film is exposed through the glass dry plate, and the resist film is further developed. As described above, a resist pattern (simply also referred to as resist) 65a is formed on the first surface 64a of the long metal plate 64, and a resist pattern (simply resist) is formed on the second surface 64b of the long metal plate 64. (Also also referred to as) 65b can be formed.

Next, as shown in FIG. 9, the second surface of the long metal plate 64 is used with an etching solution (for example, ferric chloride solution) using the resist pattern 65b formed on the long metal plate 64 as a mask. Etching is performed from the 64b side. For example, the etching solution is ejected from a nozzle arranged on the side facing the second surface 64b of the long metal plate 64 to be conveyed toward the second surface 64b of the long metal plate 64 through the resist pattern 65b. To. As a result, as shown in FIG. 9, erosion by the etching solution proceeds in the region of the long metal plate 64 that is not covered by the resist pattern 65b. As described above, a large number of second recesses 35 are formed in the long metal plate 64 from the side of the second surface 64b.

After that, as shown in FIG. 10, the formed second recess 35 is covered with the resin 69 having resistance to the etching solution. That is, the second recess 35 is sealed with the resin 69 having resistance to the etching solution. In the example shown in FIG. 10, the film of the resin 69 is formed so as to cover not only the formed second recess 35 but also the second surface 64b (resist pattern 65b).

Next, as shown in FIG. 11, the long metal plate 64 is subjected to the second etching. In the second etching, the long metal plate 64 is etched only from the side of the first surface 64a, and the formation of the first recess 30 proceeds from the side of the first surface 64a. This is because the side of the second surface 64b of the long metal plate 64 is coated with the resin 69 having resistance to the etching solution. Therefore, the shape of the second recess 35 formed into a desired shape by the first etching is not impaired.

Erosion by etching is performed on the portion of the long metal plate 64 that is in contact with the etching solution. Therefore, the erosion proceeds not only in the normal direction (thickness direction) of the long metal plate 64 but also in the direction along the plate surface of the long metal plate 64. As a result, as shown in FIG. 12, etching proceeds in the normal direction of the long metal plate 64, and not only the first recess 30 is connected to the second recess 35, but also two adjacent holes 66a of the resist pattern 65a are adjacent to each other. The two first recesses 30 formed at positions facing each other meet at the back side of the bridge portion 67a located between the two holes 66a.

As shown in FIG. 13, etching from the side of the first surface 64a of the long metal plate 64 further proceeds. As shown in FIG. 13, the merging portion 43 formed by merging two adjacent first recesses 30 is separated from the resist pattern 65a, and the erosion due to etching is caused by etching in the merging portion 43 below the resist pattern 65a. It also proceeds in the normal direction (thickness direction) of 64. As a result, as shown in FIG. 12, the confluence portion 43 sharpened toward one side along the normal direction of the vapor deposition mask is etched from one side along the normal direction of the vapor deposition mask, and FIG. 13 It is chamfered as shown in.

Further, as described above, the wall surface of the recess formed by etching is generally directed in the erosion direction, and in this example, from one side to the other along the normal direction of the vapor deposition mask. It has a convex curved surface. Therefore, the wall surface of the first recess 30 becomes steep on the side of the first surface 64a of the long metal plate 64. However, when the two adjacent first recesses 30 merge, the steep wall surface 31 can be conveniently removed. _{As a result, the inclination angle θ 1} formed by the wall surface 31 of the first recess 30 with respect to the normal direction of the vapor deposition mask can be increased.

In this way, the tip edge 32 of the wall surface 31 of at least one first recess 30 is located on the entire circumference of the other first recess 30 located around the one first recess 30. It will merge with the wall surface 31. In particular, in the illustrated example, as shown in FIG. 3, the tip edge 32 of the wall surface 31 of the first recess 30 is located around the first recess 30 over the entire circumference of the first recess 30. It merges with the wall surface 31 of one recess 30, or merges with the wall 31 of any other first recess 30 located around the first recess 30 in a part of the entire circumference thereof, and the entire circumference thereof. In other parts of the metal plate 64, it extends into the region forming the peripheral region 22 and connects to the first surface 64a of the metal plate 64.

In this way, the erosion of the first surface 64a of the long metal plate 64 by etching proceeds in the entire region that forms the effective region 22 of the long metal plate 64. As a result, the maximum thickness Ta along the normal direction of the long metal plate 64 in the region forming the effective region 22 becomes thinner than the maximum thickness Tb of the long metal plate 64 before etching. However, from the viewpoint of the mask strength of the vapor deposition mask 20, the maximum thickness Ta along the normal direction of the long metal plate 64 in the region forming the effective region 22 is the length Ta of the long metal plate 64 before etching. It is preferable that the erosion by etching is controlled so that the maximum thickness Tb becomes a certain ratio or more. In this case, the deformation of the effective region 22 in which a large number of through holes 25 are formed is effective during the subsequent processing described later, for example, during the processing such as transporting or cutting the metal plate 64, removing the resin 69, and attaching to the frame 15. Can be prevented.

As described above, the etching from the side of the first surface 64a of the long metal plate 64 proceeds by a preset amount, and the second etching of the long metal plate 64 is completed. At this time, the first recess 30 extends along the thickness direction of the long metal plate 64 to a position where it reaches the second recess 35, whereby the first recess 30 and the second recess 35 are in communication with each other. A through hole 25 is formed in the long metal plate 64.

After that, as shown in FIG. 14, the resin 69 is removed from the long metal plate 64. The resin film 69 can be removed with, for example, an alkaline release agent.

Next, the resist patterns 65a and 65b are removed from the long metal plate 64. In the step of forming the first recess 30, erosion of the first surface 64a by etching proceeds in the entire region of the metal plate 64 forming the effective region 22. Therefore, the resist pattern 65a provided on the first surface 64a is already separated from the metal plate 64 in the entire region of the metal plate 64 forming the effective region 22. Therefore, when removing the resist pattern 65a, it is not necessary to apply a treatment such as brushing to the metal plate 21, damage such as deformation of the effective region 22 of the vapor deposition mask 20 can be effectively avoided, and the yield of the vapor deposition mask 20 can be avoided. Can be effectively improved.

The long metal plate 64 having a large number of through holes 25 formed in this way is transported to the cutting device (cutting means) 73 by the transport rollers 72 and 72 that rotate while holding the long metal plate 64 in a narrow position. Will be done. The above-mentioned supply core 61 is rotated through the tension (pulling force) acting on the long metal plate 64 by the rotation of the transport rollers 72 and 72, and the long metal plate 64 is supplied from the winding body 62. It has become like.

After that, the long metal plate 64 in which a large number of recesses 61 are formed is cut to a predetermined length by a cutting device (cutting means) 73, whereby the single-wafer-shaped metal plate 21 in which a large number of through holes 25 are formed is formed. can get.

The through hole 25 can also be formed by etching the long metal plate 64 from only one surface. However, when the long metal plate 64 is etched only from the upper surface, the etching solution that has already been used for erosion and has a low erosion ability remains in the tapered holes formed by erosion. After that, when the hole of the metal plate reaches the lower surface, the etching solution remaining in the hole flows out from the lower surface, and the etching solution having a high erosion ability is formed in the hole. It flows in. At this time, in the lower region of the hole where the cross-sectional area (opening area) becomes smaller, the lower region of the hole is violently eroded by the fresh etching solution. That is, the shape of the hole cannot be sufficiently controlled. On the other hand, when the metal plate is etched only from the lower surface via the resist pattern, when the tapered holes formed by erosion penetrate the metal plate, the etching solution may remain around the holes on the upper side surface. As a result, the residual etching solution also causes erosion from the upper surface of the metal plate, and the shape of the holes cannot be sufficiently controlled. On the other hand, according to the etching method described above, the shape of the through hole 25 can be stabilized.

As described above, the vapor deposition mask 20 made of the metal plate 21 having a large number of through holes 25 formed therein can be obtained. Then, by attaching the frame 15 to each vapor deposition mask 20, the vapor deposition mask device 10 is obtained. The frame 15 may be attached to one surface 20a of the vapor deposition mask 20 or may be attached to the other surface 20b of the vapor deposition mask 20.

According to the method for manufacturing a vapor deposition mask device according to the present embodiment as described above, in the step of forming the first recess 30 in the metal plates 21 and 64, erosion due to etching also occurs in the direction along the plate surface of the metal plate. Proceeding, two adjacent first recesses 30 merge under the resist pattern 65a, and the tip edge 32 of the wall surface 31 of at least one first recess 30 extends over the entire circumference of the first one. It merges with the wall surface 31 of any other first recess 30 located around the recess 30. The wall surface 31 of the first recess 30 formed in this way to form the through hole 25 is greatly inclined with respect to the normal direction of the vapor deposition mask 20. As a result, by using the manufactured thin-film deposition mask 20, it is possible to stably perform thin-film deposition in a high-definition pattern while using the thin-film deposition material 98 with high utilization efficiency.

By the way, in the above-mentioned manufacturing method, when the metal plate 21 is etched from the first surface 21a side of the metal plate 21 corresponding to the first surface 20a of the vapor deposition mask 20 to produce the first recess 30, vapor deposition is performed. In the entire region of the metal plate 21 forming the effective region 22 of the mask 20, the first surface 21a of the metal plate 21 is eroded by etching. That is, the maximum thickness Ta in the effective region 22 along the normal direction of the vapor deposition mask is less than 100% of the maximum thickness Tb in the peripheral region 23 along the normal direction of the vapor deposition mask. As described above, it is preferable that the thickness of the vapor deposition mask 20 in the effective region 22 is reduced as a whole from the viewpoint of improving the utilization efficiency of the vapor deposition material and from the viewpoint of suppressing the generation of shadows.

In addition, as a result of intensive research by the present inventor, the maximum thickness Ta in the effective region 22 along the normal direction of the vapor deposition mask with respect to the maximum thickness Tb in the peripheral region 23 along the normal direction of the vapor deposition mask. It has been found that it is effective to set the ratio (hereinafter, this ratio is also simply referred to as the "maximum thickness ratio") to 65% or less. As described above, when the metal plate 21 is etched over the entire area of the effective region 22 when the first recess 30 is formed in the metal plate 21, the first recess 30 to be formed depends on the regular arrangement of the first recess 30. The highest portion 32a having the maximum thickness is formed. The height at the highest portion 32a is a factor that determines the thickness ratio of the highest portion. The highest portion 32a will be present in large numbers in a regular arrangement in accordance with the regular arrangement of the first recesses 30. According to the current etching technology, it is possible to control the thickness of the highest portion 32a as an average. In the present specification, the maximum thickness Ta in the effective region 22 along the normal direction of the vapor deposition mask is the average value of the thicknesses in the highest portion 32a.

As confirmed by the inventor of the present invention, when the thickness ratio of the highest portion is 65% or less, the variation in height of the highest portion 32a can be sharply reduced. Moreover, such a phenomenon is caused by an arrangement of the first recesses 30 (arrangement of through holes 25) in a vapor deposition mask having a general aperture ratio used at least when an organic material is vapor-deposited on a substrate during the manufacture of an organic EL display device. The same occurred regardless of, that is, not only in the lattice arrangement shown in FIGS. 3 and 20, but also in the staggered arrangement shown in FIG. 21, for example. That is, in the vapor deposition mask 20 used for vapor deposition of an organic material on a substrate during the manufacture of an organic EL display device, the average value of the thickness at the maximum portion 32a is highly accurate by setting the maximum thickness ratio to 65% or less. It is possible to effectively reduce the variation in the thickness of the highest portion 32a in the effective region 22 and accurately control each of the thicknesses of the highest portions 32a located in the effective region 22. It becomes. As a result, by setting the maximum thickness ratio to 65% or less, the generation of shadows is effectively prevented regardless of the arrangement of the first recesses 30 and the thickness of the metal plate 21 forming the vapor deposition mask 20. We were able to. Such an action effect is remarkable beyond the range predicted from the conventional technical level in which only the inclination angle of the wall surface of the through hole is considered.

On the other hand, as described above, the ratio of the maximum thickness Ta in the effective region 22 along the normal direction of the vapor deposition mask to the maximum thickness Tb in the peripheral region 23 along the normal direction of the vapor deposition mask (maximum thickness ratio). Is preferably above a certain level from the viewpoint of the strength of the vapor deposition mask. The vapor deposition mask 20 is stretched on the frame 15. A thin-film mask with a low maximum thickness ratio will be deformed during tensioning. As a result, a thin-film deposition mask having a low maximum thickness ratio cannot perform thin-film deposition in a desired pattern. Specifically, as the thickness ratio of the highest portion is lowered, the amount of deviation from the position (design position) where the vapor-deposited material should be placed on the substrate on which the vapor-deposited material should be deposited to the position where the vapor-deposited material is actually vapor-deposited. Although the average value of can be suppressed to a small value, the variation in the amount of deviation becomes large. As a result of investigation by the present inventor on this point, if the maximum thickness ratio (Ta / Tb) is 45% or more, it is used at least when depositing an organic material on a substrate at the time of manufacturing an organic EL display device. It was possible to sufficiently prevent deformation of the vapor deposition mask having a general aperture ratio, and this vapor deposition mask made it possible to carry out vapor deposition with the accuracy required for a commercially available display device.

Furthermore, as a result of intensive research by the present inventor, arranging the through holes 25 (accordingly to this, the first recess 30) in a lattice arrangement suppresses deformation of the vapor deposition mask 20 at the time of stretching. , It was found to be effective. In the thin-film deposition mask 20 in which the through holes 25 (the first recess 30) are arranged in a lattice arrangement, even if the maximum thickness ratio (Ta / Tb) is 35%, at least an organic EL display device is manufactured. It is possible to sufficiently prevent deformation of a vapor deposition mask having a general aperture ratio, which is sometimes used when vapor deposition an organic material on a substrate, and this vapor deposition mask enables vapor deposition with the accuracy required for a commercially available display device. Was able to be carried out.

Here, a part of the experimental results conducted by the present inventor will be described. Here, the experimental results of the first vapor deposition mask in which the through holes are arranged in a lattice arrangement and the experimental results of the second vapor deposition mask in which the through holes are arranged in a staggered arrangement will be described. The arrangement of the through holes of the vapor deposition mask to be manufactured is as shown in FIGS. 20 and 21. In the lattice arrangement shown in FIG. 20, the through holes are arranged at a predetermined pitch in the x-axis direction and also at a predetermined pitch in the y-axis direction orthogonal to the x-axis. In the staggered arrangement shown in FIG. 21, the through-hole groups arranged in the y-axis direction have the arrangement pitch of the through-holes in the y-axis direction with other through-hole groups adjacent to the through-hole group in the x-axis direction. It differs from the lattice arrangement shown in FIG. 20 in that it is arranged so as to be offset by half.

First, by the above-mentioned method for manufacturing a thin-film deposition mask, a first recess and a second recess were formed on a metal plate to manufacture a vapor deposition mask having a through hole composed of the first recess and the second recess. In this vapor deposition mask, the wall surface of each first recess merges with the wall surface of any other recess located around the recess over the entire circumference, or the recess is part of the entire circumference thereof. It extends into a region that merges with the wall surface of any other recess located around the metal plate and forms the peripheral region in other parts of the entire circumference thereof, and is connected to the first surface of the metal plate. I tried to do it. The metal plate used as the raw material for the vapor deposition mask was an invar material. The thickness of the Invar material was various as shown in Tables 1 to 8. Further, in the metal plate of each thickness, the target value of the maximum thickness ratio was also variously changed as shown in Tables 1 to 8.

For each of the actually manufactured vapor deposition masks, the thickness at the highest portion having the maximum thickness according to the arrangement of the first recesses was measured at the highest portions at 300 locations, and the thickness ratio of the highest portion was calculated for each. The average value and standard deviation σ were calculated from the calculated maximum thickness ratio. A laser length measuring device (OLS-3000) manufactured by Olympus Corporation was used to measure the thickness at the highest portion. In the lattice arrangement shown in FIG. 20, the highest portion 32a was formed at a position between the four through holes. On the other hand, in the staggered arrangement shown in FIG. 21, as shown in FIG. 21, in the linear region ls located between two through holes adjacent in the y-axis direction, for example, in the x-axis direction of the linear region ls. The highest portion 32a was formed at a central position and a position at the end of the linear region ls in the x-axis direction.

Table 1 shows the value of the standard deviation σ × 3 of the maximum thickness ratio for each first vapor deposition mask in which the through holes are arranged in a lattice arrangement. Here, when the graph random variable X of the standard normal distribution ^{follows N (μ, σ 2} ), the probability that X is included in the range where the deviation from the mean μ is ± 1σ or less is 68.27%, and if it is ± 2σ or less, it is 95. If it is .45% and ± 3σ, it will be 99.73%. That is, σ × 3 is an index for predicting the range of variation in the maximum thickness ratio. Further, Table 2a and Table 2b show the values of the measured average values of the maximum thickness ratios for each first vapor deposition mask. The measured average value of the maximum thickness ratio was within ± 1.5% of the target value. Further, from the results in Table 1, it can be understood that when the thickness ratio of the highest portion is 65% or less, the thickness at the highest portion is stable in each first vapor deposition mask. The same results as in Table 1 were obtained for the vapor deposition masks other than the lattice arrangement.

Next, each of the manufactured vapor deposition masks was stretched on the frame to produce a vapor deposition mask device. Using the produced thin-film deposition mask device, an organic material as a vapor deposition material was vapor-deposited on a glass substrate to prepare a sample assuming a substrate for an organic EL display device. After that, the presence or absence of shadows was confirmed for each sample. Tables 2a and 2b show the results of confirming the presence or absence of shadows for each first vapor deposition mask in which the through holes are arranged in a lattice arrangement. As shown in Tables 2a and 2b, shadows were generated when the vapor deposition mask in which the thickness at the highest portion was not stable and the thickness ratio at the highest portion was 70% was used.

Further, for each sample, the vapor-deposited material is actually deposited from the deviation amount from the design placement position of the vapor-deposited material, that is, the position (design position) where the vapor-deposited material should be placed on the glass substrate on which the vapor-deposited material should be deposited. The amount of deviation to the position was measured at 300 points, and the standard deviation σ was calculated from the measured value of the amount of deviation. The values of the standard deviation σ × 3 are shown in Tables 4 to 8. The values of the standard deviation σ × 3 for each first vapor deposition mask in which the through holes are arranged in a grid arrangement are also shown in Tables 2a and 2b. In Tables 2a and 2b, the overall evaluation column is marked with a circle for samples in which the “standard deviation σ × 3” is 10.0 [μm] or less and no shadow is generated. The standard of "standard deviation σ x 3" ≤ 10.0 [μm] or less is a standard with higher accuracy than the adhesion accuracy of organic materials required when manufacturing a commercially available organic EL display device. There is.

As shown in Tables 4 to 8, the first vapor deposition mask in which the through holes are arranged in a lattice arrangement has a vapor deposition position of the vapor deposition material as compared with the second vapor deposition mask in which the through holes are arranged in a staggered arrangement. It was possible to suppress the variation in the amount of deviation. As shown in Tables 2a and 2b, in the first vapor deposition mask in which the through holes are arranged in a lattice arrangement, the variation in the deposition position of the vapor deposition material is suppressed by setting the maximum thickness ratio to 35% or more. That is, the vapor deposition material could be deposited in a desired pattern. As shown in Tables 3 to 8, in the second vapor deposition mask in which the through holes are arranged in a staggered arrangement, the variation in the deposition position of the vapor deposition material is suppressed by setting the maximum thickness ratio to 45% or more. That is, the vapor deposition material could be deposited in the desired pattern. Regarding the vapor deposition mask in which the shape of the through holes is changed from a square shape to a circular shape or a rectangular shape, and the vapor deposition mask in which the direction of the square forming the through holes is changed, if the arrangement of the through holes is a lattice arrangement, Table 2a , Table 2b, Tables 3 to 8 obtained the same results as the lattice arrangement, and if the through-hole arrangement was a staggered arrangement, the same results as the staggered arrangement of Tables 3 to 8 were obtained.

It is possible to make various changes to the above-described embodiment. Hereinafter, an example of modification will be described with reference to the drawings. In the drawings used in the following description, the same reference numerals as those used for the corresponding portions in the above-described embodiment are used, and duplicate description will be omitted.

First, as a first modification, the method of forming the through hole 25 in the long metal plate 64 can be changed. In the above-described embodiment, the step of forming the second recess 35 is performed before the step of forming the first recess 30, but the step of forming the first recess 30 is not limited to this. , May be carried out before the step of forming the second recess 35, and further, the metal plates 21 and 64 are simultaneously etched from the sides of the first surfaces 21a and 64a and the second surfaces 21b and 64b. , The step of forming the first recess 30 and the step of forming the second recess 35 may be performed in parallel. Further, since the amount of erosion of the long metal plate 64 by etching when forming the first recess 30 is larger than the amount of erosion of the long metal plate 64 by etching when forming the second recess 35, FIG. As shown in the above, the metal plates 21 and 64 are simultaneously etched from both sides of the first surfaces 21a and 64a and the second surfaces 21b and 64b to form the first recess 30 and the second recess 35 in parallel. After that, only the step of forming the first recess 30 may be continued.

Further, in the above-described embodiment, both the production of the resist pattern 65a on the first surface 64a of the long metal plate 64 and the production of the resist pattern 65b on the second surface 64b of the long metal plate 64 are performed. It was carried out before the formation of the first recess 30 and the second recess 35, but the present invention is not limited to this. For example, one of the resist patterns 65a and 65b is produced and the resist pattern produced is used to form one recess, and then the other resist pattern is produced and the other is used. The recess may be formed.

Next, a second modification will be described. In the above-described embodiment, an example in which the second recess 35 is formed by etching is shown, but the present invention is not limited to this. As shown in FIG. 16, first, the first recess 30 is formed by etching from the side of the first surfaces 21a, 64a of the metal plates 21, 64, and then, as shown in FIG. 17, a laser irradiator 80 is used. By irradiating the inside of the first recess 30 with a laser beam, the second recess 35 may be formed so as to reach the second surfaces 21b and 64b of the metal plates 21 and 64 from the inside of the first recess 30.

As shown in FIG. 16, the first recess 30 is made by half-etching the metal plates 21 and 64 from the side of the first surfaces 21a and 64a using the resist pattern 65a. At this time, similarly to the above-described embodiment, the metal plates 21 and 64 are etched from the side of the first surfaces 21a and 64a, the two adjacent first recesses 30 merge, and at least one first one is further formed. If the wall surface 31 of the recess 30 merges with the wall surface 31 of any other first recess 30 located around the one first recess 30 over the entire circumference thereof, the above-described embodiment can be performed. It can exert the same action and effect as the morphology.

In addition, as shown in FIG. 17, when the laser beam is irradiated from the half-etched first surface (64a) side, the energy density of the luminous flux of the laser beam is generally high in the central portion and low in the outer peripheral portion. Due to the nature of the second recess 35 formed by irradiation with laser light, the width of the second recess 35 becomes narrower from one side along the normal direction of the vapor deposition mask 20 to the other side, similarly to the first recess 30. In other words, the cross-sectional area can be made smaller. According to the thin-film deposition mask 20 formed in this way, the through holes 25 taper from the side of the first surface 20a to the side of the second surface 20b of the vapor deposition mask 20 as a whole. While improving the utilization efficiency, the peripheral edge of the thin-film deposition film can be made clear.

Next, a third modification will be described. In the above-described embodiment, an example of producing the vapor deposition mask 20 by forming through holes 25 in the metal plates 21 and 64 has been shown, but the present invention is not limited to this. As shown in FIG. 18, the metal plate 21 is etched from the metal plate 21 (64) side of the laminate 51 having the metal plate 21 (64) and the resin layer 50 laminated on the metal plate 21 (64). A first recess 30 that penetrates (64) and reaches the resin layer 50 is formed, and then a laser beam is irradiated into the first recess 30 using a laser irradiator 80 to penetrate the resin layer 50. The second recess 35 may be formed.

As shown in FIG. 18, the first recess 30 is made by etching the metal plates 21 and 64 using the resist pattern 65a. At this time, similarly to the above-described embodiment, the metal plates 21 and 64 are etched to join the two adjacent first recesses 30, and the wall surface 31 of at least one first recess 30 is the whole. By merging with the wall surface 31 of any of the other first recesses 30 located around the one first recess 30 over the circumference, the same effect as that of the above-described embodiment can be obtained. Can be done.

In addition, as shown in FIG. 19, the second recess 35 formed by irradiation with the laser beam is, similarly to the first recess 30, from one side to the other side along the normal direction of the vapor deposition mask 20. In other words, the width becomes narrower, in other words, the cross-sectional area becomes smaller. According to the thin-film deposition mask 20 formed in this way, the through holes 25 taper from the side of the first surface 20a to the side of the second surface 20b of the vapor deposition mask 20 as a whole. While improving the utilization efficiency, the peripheral edge of the thin-film deposition film can be made clear.

As yet another modification, in the above-described embodiment, in producing a plurality of through holes 25 arranged along each of two different arrangement directions, one first through hole 25 is used. An example of forming one recess 30 and one second recess 35 has been shown, but the present invention is not limited to this. For example, even if an elongated first recess 30 extending in one of the arrangement directions of the through holes 25 is formed and a plurality of second recesses 35 are formed at positions facing the elongated first recess 30. Good. Also in such an example, two adjacent first recesses 30 are merged, and at least one wall surface 31 of the first recess 30 is formed around the one first recess 30 over the entire circumference thereof. By merging with the wall surface 31 of any of the other first recesses 30 located, the same effect as that of the above-described embodiment can be obtained.

As yet another modification, the pattern of the through holes 25 formed in the vapor deposition mask 20 may be changed. The arrangement pattern of the through holes 25 described in the above-described embodiment is merely an example, and the vapor deposition mask 20 in which the through holes 25 are arranged in various patterns may be manufactured.

As yet another modification, in the above-described embodiment, after forming the through hole 25 in the long metal plate 64, the long metal plate 64 is cut into the sheet metal plate 21 by the cutting device 73. Although shown, it is not limited to this. For example, in the case of producing the second recess 35 by irradiating the laser beam as in the above-described modification, first, the first recess 30 is formed on the long metal plate 64 (long laminate 51). Next, the long metal plate 64 (long laminated body 51) is cut into a single-wafer-shaped metal plate 21 (single-leaf-shaped laminated body 51) by the cutting device 73, and then the single-leaf-shaped metal plate 21 (single-leaf-shaped laminated body 51) is cut. The second recess 35 may be formed in the laminated body 51).

Although some modifications to the above-described embodiments have been described above, it is naturally possible to apply a plurality of modifications in combination as appropriate.

20 Vapor deposition mask 20a First surface of vapor deposition mask 20b Second surface of vapor deposition mask 21 Metal plate 21a First surface of metal plate 21b Second surface of metal plate 22 Effective area 23 Peripheral area 25 Through hole 30 First recess 31 Wall surface 35 Second recess 36 Wall surface 64 Long metal plate 64a First surface of long metal plate 64b Second surface of long metal plate

Claims (1)

A method for manufacturing a vapor deposition mask including an effective region in which a plurality of through holes are formed and a peripheral region located around the effective region.
The metal plate is etched from the side of the first surface using the resist pattern arranged on the first surface of the metal plate having the first surface and the second surface facing each other as a mask to form the effective region. A step of forming a recess for defining the through hole in the region of the metal plate from the side of the first surface is provided.
In the step of forming the recess, erosion due to etching proceeds in the direction along the plate surface of the metal plate, two adjacent recesses merge under the resist pattern, and the wall surface of the recess is the entire surface. It merges with the wall surface of any other recess located around the recess over its circumference, or merges with the wall surface of any other recess located around the recess on a portion of its entire circumference. And it extends into the region that forms the peripheral region in other parts of its entire circumference and connects to the first surface of the metal plate.
The plurality of through holes are arranged in a lattice arrangement in the first direction and the second direction.
A position intermediate between a through hole defined by one recess in the first direction and another through hole adjacent to the through hole in the first direction, and in the second direction. On one side of the metal plate in the normal direction, at a position intermediate between the through hole defined by the one recess and the other through hole adjacent to the through hole in the second direction. The highest part protruding into is formed,
After performing the step of forming the recess, the standard deviation of the ratio (%) of the thickness of the highest portion to the thickness along the normal direction of the metal plate in the peripheral region is 3.3. % Or less, a method for manufacturing a vapor deposition mask.

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