KR20210112419A - Metal plate, metal plate production method, and method for producing vapor deposition mask using metal plate - Google Patents

Abstract

An object of the present invention is to provide a metal plate having a small elongation difference. The elongation difference ratio in the central portion in the width direction of the metal plate is 10×10 ⁻⁵ or less. Moreover, the elongation difference ratio at the edge part of the width direction of a metal plate is 20x10 ^-5 or less. Moreover, the elongation difference ratio in the edge part of the width direction of a metal plate is larger than the maximum value of the elongation difference ratio in the center part of the width direction of a metal plate.

Description

A metal plate, the manufacturing method of a metal plate, and the method of manufacturing a deposition mask using a metal plate {METAL PLATE, METAL PLATE PRODUCTION METHOD, AND METHOD FOR PRODUCING VAPOR DEPOSITION MASK USING METAL PLATE}

The present invention relates to a metal plate used for manufacturing a deposition mask by forming a plurality of through holes. The present invention also relates to a method for manufacturing a metal plate. Moreover, this invention relates to the method of manufacturing using a metal plate, the vapor deposition mask used in order to vapor-deposit in a desired pattern.

In recent years, display devices used in portable devices such as smartphones and tablet PCs are required to have high resolution, for example, a pixel density of 300 ppi or more. Moreover, also in a portable device, the demand for the thing corresponding to full hi-vision is increasing, and in this case, it is calculated|required that the pixel density of a display apparatus is 450 ppi or more, for example.

Because of good responsiveness and low power consumption, organic EL display devices are attracting attention. As a method of forming a pixel of an organic EL display device, a method of forming a pixel in a desired pattern using a deposition mask including through holes arranged in a desired pattern is known. Specifically, first, a vapor deposition mask is brought into close contact with a substrate for an organic EL display device, and then, both the vapor deposition mask and the substrate that are in close contact are put into the vapor deposition apparatus, and vapor deposition of an organic material or the like is performed. A deposition mask can be generally manufactured by forming a through hole in a metal plate by etching using a photolithography technique (for example, patent document 1). For example, first, a resist film is formed on a metal plate, and then the resist film is exposed in a state in which an exposure mask is in close contact with the resist film to form a resist pattern, and then, a through hole is formed by etching the metal plate using the resist pattern as a mask. is formed

(Patent Document 1) Japanese Patent Laid-Open No. 2004-39319

When a vapor deposition material is formed into a film on a board|substrate using a vapor deposition mask, a vapor deposition material adheres not only to a board|substrate but also to a vapor deposition mask. For example, some of the vapor deposition materials face the substrate along a direction that is largely inclined with respect to the normal direction of the deposition mask. Such deposition materials reach and adhere to the wall surface of the through hole of the deposition mask even before reaching the substrate. . In this case, it becomes difficult for the deposition material to adhere to the region of the substrate located near the wall surface of the through hole of the deposition mask. It is possible to think of a case in which a part that does not occur occurs. That is, the case where vapor deposition in the vicinity of the wall surface of the through-hole of a vapor deposition mask becomes unstable is conceivable. Therefore, when a vapor deposition mask is used to form the pixel of an organic electroluminescent display, the dimensional accuracy and positional precision of a pixel fall, As a result, the luminous efficiency of an organic electroluminescent display falls.

In order to solve such a subject, it is possible to make the thickness of the metal plate used in order to manufacture a vapor deposition mask small. This is because, by reducing the thickness of the metal plate, the height of the wall surface of the through hole of the vapor deposition mask can be reduced, and thereby, the proportion of the vapor deposition material adhering to the wall surface of the through hole can be reduced. However, in order to obtain a metal plate with small thickness, it is necessary to increase the rolling ratio at the time of rolling a base material and manufacturing a metal plate. Here, a rolling rate is a value computed by (thickness of a base material - metal plate)/(thickness of a base material). Even when heat treatment, such as annealing, is performed after rolling, the degree of nonuniformity of the deformation|transformation based on rolling becomes large, so that a rolling rate is normally large. For example, it is known that the elongation rate of a metal plate differs according to the position in the width direction (direction orthogonal to the conveyance direction of a base material), As a result, a wave shape appears in a metal plate. Specifically, a wave shape at the end in the width direction called ear generation and a wave shape at the center part in the width direction called central elongation are mentioned. When such a wave shape appears, the exposure mask cannot be sufficiently brought into close contact with the resist film on the metal plate, and as a result, the positional accuracy and dimensional accuracy of the through hole formed in the metal plate may be deteriorated. When the positional accuracy and dimensional accuracy of a through hole fall, the dimensional accuracy and positional accuracy of the pixel of the organic electroluminescent display obtained by using a vapor deposition mask will fall.

In addition, in order to reduce the manufacturing cost of the deposition mask, first, a plurality of effective regions including a plurality of through holes corresponding to one organic EL display device are formed over the entire metal plate, and then in the longitudinal direction of the metal plate. It is known to cut a plurality of metal plates along the slab and thereby produce a plurality of deposition masks having an elongated shape at once. However, when the elongation rate of a metal plate differs according to the position of the width direction, the length of the some elongate vapor deposition mask obtained after cutting|disconnection will differ. In this case, the pitch of each through-hole in the effective area of the deposition mask is different for each deposition mask, and as a result, the dimensions and positions of pixels of the organic EL display device obtained by using the deposition mask fluctuate depending on the individual. can also think

An object of the present invention is to provide a metal plate, a method for manufacturing a metal plate, and a method for manufacturing a deposition mask, which can effectively solve such problems.

A first aspect of the present invention is a method for manufacturing a metal plate used for manufacturing a deposition mask by forming a plurality of through holes, wherein the through holes of the deposition mask are formed by etching the metal plate, the method for manufacturing the metal plate comprising: a rolling step of rolling a base material to obtain the metal plate, and a cutting step of cutting both ends of the metal plate in a width direction over a predetermined range, wherein the metal plate after the cutting step has a length in the longitudinal direction thereof It has at least partly a wavy shape resulting from being different depending on the position in the width direction, and the minimum value of the length of the metal plate after the cutting step is referred to as a reference length, and the width of the metal plate after the cutting step with respect to the reference length When the ratio of the difference in the length of the metal plate at each position in the direction is referred to as the elongation difference ratio, the following conditions (1) to (3) are satisfied,

(1) the elongation difference ratio at the central portion in the width direction of the metal plate after the cutting step is 10×10 ^-5 or less;

(2) the elongation difference ratio at the end of the metal plate in the width direction after the cutting step is 20×10 ^-5 or less; and

(3) the elongation difference ratio at the end portion is greater than the maximum value of the elongation difference ratio at the central portion;

The said central part is a manufacturing method of the metal plate which is a part which occupies 40% of the width of the said metal plate including the central part of the width direction of the said metal plate after the said cutting process.

The manufacturing method of the metal plate by this invention may further be equipped with the annealing process of annealing the said metal plate obtained by the said rolling process, and removing the internal stress of the said metal plate.

In the manufacturing method of the metal plate by this invention, the said annealing process may be implemented, pulling the said metal plate in a longitudinal direction.

In the manufacturing method of the metal plate by this invention, the said annealing process may be performed in the state in which the said metal plate was wound around the core.

In the manufacturing method of the metal plate by this invention, Preferably, the thermal expansion coefficient of the said base material becomes equal to the thermal expansion coefficient of the board|substrate on which the vapor deposition material is formed into a film via the vapor deposition mask manufactured from the said metal plate.

In the manufacturing method of the metal plate by this invention, the said base material may be comprised with the invar material.

A second aspect of the present invention is a metal plate used for manufacturing a vapor deposition mask by forming a plurality of through holes, wherein the metal plate has at least a wavy shape resulting from the fact that the length in the longitudinal direction differs depending on the position in the width direction. The minimum value of the length of the metal plate is called a reference length, and the ratio of the difference between the length of the metal plate at each position in the width direction of the metal plate to the reference length is called the elongation difference ratio, The following conditions (1) to (3) are satisfied,

(1) the elongation difference ratio at the central portion in the width direction of the metal plate is 10×10 ^-5 or less;

(2) the elongation difference ratio at the end of the metal plate in the width direction is 20×10 ^-5 or less; and

(3) the elongation difference ratio at the end portion is greater than the maximum value of the elongation difference ratio at the central portion;

The said central part is a metal plate which is a part which occupies 40% of the width of the said metal plate, including the central part of the width direction of the said metal plate.

The coefficient of thermal expansion of the metal plate according to the present invention is preferably a value equal to the coefficient of thermal expansion of the substrate on which the deposition material is formed through a deposition mask manufactured from the metal plate.

The metal plate by this invention may be comprised from the invar material.

A third aspect of the present invention is a method for manufacturing a deposition mask comprising an effective region in which a plurality of through holes are formed and a peripheral region positioned around the effective region, the metal plate having a length in its longitudinal direction equal to its width in its width direction. A step of preparing a metal plate at least partially having a wavy shape due to a different position depending on a position; a resist pattern forming step of forming a resist pattern on the metal plate; an etching step of forming a concave portion for partitioning the through hole in the region of the metal plate constituting the region, the minimum value of the length of the metal plate is referred to as a reference length, When the ratio of the difference in the length of the metal plate at each position in the width direction is referred to as the elongation difference ratio, the following conditions (1) to (3) are satisfied,

(1) the elongation difference ratio at the central portion in the width direction of the metal plate is 10×10 ^-5 or less;

(2) the elongation difference ratio at the end of the metal plate in the width direction is 20×10 ^-5 or less; and

(3) the elongation difference ratio at the end portion is greater than the maximum value of the elongation difference ratio at the central portion;

The said central part is a manufacturing method of the vapor deposition mask which is a part which occupies 40% of the width of the said metal plate, including the central part of the width direction of the said metal plate.

In the method for manufacturing a deposition mask according to the present invention, the resist pattern forming step includes: forming a resist film on the metal plate; You may have a process of exposing a film|membrane in a predetermined pattern.

In the method for manufacturing a deposition mask according to the present invention, preferably, the coefficient of thermal expansion of the metal plate is a value equal to the coefficient of thermal expansion of the substrate on which the deposition material is formed through the deposition mask manufactured from the metal plate.

In the manufacturing method of the vapor deposition mask by this invention, the said metal plate may be comprised with the invar material.

According to the present invention, it is possible to obtain a vapor deposition mask having a small degree of wavy shape and a small variation in pitch of each through hole in the effective area. For this reason, the dimensional accuracy and positional precision of the vapor deposition material adhering on a board|substrate can be raised.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating one Embodiment of this invention, and is a schematic plan view which shows an example of the vapor deposition mask apparatus containing a vapor deposition mask.
FIG. 2 is a diagram for explaining a method of vapor deposition using the deposition mask apparatus shown in FIG. 1 .
FIG. 3 is a partial plan view illustrating the deposition mask shown in FIG. 1 .
FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3 .
FIG. 5 is a cross-sectional view taken along line VV of FIG. 3 .
FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 3 .
Fig. 7(a) is a view showing a process of obtaining a metal plate having a desired thickness by rolling a base material, and Fig. 7(b) is a diagram showing a process of annealing the metal plate obtained by rolling.
Fig. 8 is a perspective view showing a metal plate obtained by the steps shown in Figs. 7A and 7B.
9(a), (b), (c), and (d) are cross-sectional views taken along lines aa, bb, cc, and dd of FIG. 8, respectively.
It is a figure which shows the elongation difference rate at each position in the width direction of a metal plate.
It is a schematic diagram for demonstrating an example of the manufacturing method of the vapor deposition mask shown in FIG. 1 as a whole.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is sectional drawing which shows the process of forming a resist film on a metal plate.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is sectional drawing which shows the process of making an exposure mask closely_contact|adherent to a resist film.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows an elongate metal plate in the cross section along the normal line direction.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows an elongate metal plate in the cross section along the normal line direction.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows the elongate metal plate in the cross section along the normal line direction.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows the elongate metal plate in the cross section along the normal line direction.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows the elongate metal plate in the cross section along the normal line direction.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows the elongate metal plate in the cross section along the normal line direction.
It is a figure for demonstrating an example of the manufacturing method of a vapor deposition mask, and is a figure which shows an elongate metal plate in the cross section along the normal line direction.
Fig. 21 is a plan view showing the first sample loaded on the surface plate.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described with reference to drawings. In addition, in the drawings attached to this specification, for convenience of illustration and comprehension, the scale and the aspect ratio of the aspect ratio and the like are appropriately exaggerated by changing them from those of the real thing.

1 to 20 are diagrams for explaining an embodiment according to the present invention. In the following embodiment and its modifications, a manufacturing method of a vapor deposition mask used for patterning an organic material onto a 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 this application, and the present invention can be applied to a method for manufacturing a deposition mask used for various purposes.

In addition, in this specification, the terms "plate", "sheet", and "film" are not distinguished from each other based only on the difference in names. For example, "plate" is a concept that also includes members that can be called sheets and films, and therefore, for example, "metal plate" is only a difference in name from a member called "metal sheet" or "metal film" cannot be distinguished

In addition, "plate surface (sheet surface, film surface)" refers to a target plate-shaped member (sheet-shaped member, film-shaped member) when the target plate-shaped member (sheet-shaped, film-shaped) is viewed as a whole and on a large scale. ) that coincides with the plane direction. In addition, the normal line direction used with respect to a plate-shaped (sheet shape, film shape) member points out the normal line direction with respect to the plate surface (sheet surface, film surface) of the said member.

In addition, as used herein, terms such as "parallel", "orthogonal", "same", "equivalent", length, angle and physical Regarding the values of characteristics, etc., it is decided not to be bound by a strict meaning, but to include the range of the extent to which the same function can be expected.

(Deposition mask device)

First, an example of a deposition mask apparatus including a deposition mask used as a manufacturing method object will be mainly described with reference to FIGS. 1 to 6 . Here, FIG. 1 is a plan view showing an example of a deposition mask device including a deposition mask, and FIG. 2 is a diagram for explaining a method of using the deposition mask device shown in FIG. 1 . 3 is a plan view showing the deposition mask from the first surface side, and FIGS. 4 to 6 are cross-sectional views at each position in FIG. 3 .

The deposition mask apparatus 10 shown in FIGS. 1 and 2 includes a plurality of deposition masks 20 including a substantially rectangular metal plate 21 , and a frame 15 provided at the periphery of the plurality of deposition masks 20 . ) is provided. Each deposition mask 20 has a plurality of through holes 25 formed by etching a metal plate 21 having a first surface 21a and a second surface 21b opposite to each other from at least the first surface 21a. is formed As shown in Fig. 2, the deposition mask apparatus 10 is supported in the deposition apparatus 90 such that the deposition mask 20 faces the lower surface of the substrate to be deposited, for example, a glass substrate 92. , used for deposition of deposition materials on substrates.

In the vapor deposition apparatus 90, the vapor deposition mask 20 and the glass substrate 92 come into close_contact with the magnetic force from a magnet (not shown). In the vapor deposition apparatus 90 , below the vapor deposition mask apparatus 10 , a crucible 94 accommodating a vapor deposition material (eg, an organic light emitting material) 98 , and a heater 96 heating the crucible 94 . ) is placed. The vapor deposition material 98 in the crucible 94 is vaporized or sublimed by heating from the heater 96 and adheres to the surface of the glass substrate 92 . As described above, a plurality of through holes 25 are formed in the deposition mask 20 , and the deposition material 98 is attached to the glass substrate 92 through the through holes 25 . As a result, the 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 deposition mask 20 .

As described above, in the present embodiment, the through holes 25 are arranged in a predetermined pattern in each effective area 22 . In addition, when color display is desired, the deposition mask 20 (evaporation mask apparatus 10) and the glass substrate 92 are relatively moved little by little along the arrangement direction of the through-holes 25 (one direction described above). , an organic light emitting material for red, an organic light emitting material for green, and an organic light emitting material for blue may be deposited in order.

In addition, the frame 15 of the vapor deposition mask apparatus 10 is provided in the periphery of the rectangular vapor deposition mask 20. As shown in FIG. The frame 15 holds the deposition mask in a state in which the deposition mask 20 is not warped. The deposition mask 20 and the frame 15 are fixed to each other by, for example, spot welding.

The vapor deposition process is performed inside the vapor deposition apparatus 90 used as a high-temperature atmosphere. Therefore, during the deposition process, the deposition mask 20, the frame 15 and the substrate 92 held inside the deposition apparatus 90 are also heated. At this time, the deposition mask, the frame 15 and the substrate 92 exhibit a dimensional change behavior based on their respective coefficients of thermal expansion. In this case, when the thermal expansion coefficients of the deposition mask 20 or the frame 15 and the substrate 92 are significantly different, a positional shift due to the difference in their dimensional changes occurs, and as a result, adhesion on the substrate 92 occurs. The dimensional precision and positional precision of the vapor deposition material used will fall. In order to solve such a subject, it is preferable that the thermal expansion coefficient of the vapor deposition mask 20 and the flame|frame 15 is a value equivalent to the thermal expansion coefficient of the board|substrate 92. As shown in FIG. For example, when a glass substrate 92 is used as the substrate 92 , an invar material which is an alloy obtained by adding 36% nickel to iron can be used as the material for the deposition mask 20 and the frame 15 . .

(Deposition Mask)

* Next, the deposition mask 20 will be described in detail. As shown in FIG. 1 , in this embodiment, the deposition mask 20 includes a metal plate 21 and has a substantially rectangular shape in plan view, and more precisely, a substantially rectangular shape in plan view. . The metal plate 21 of the 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 a deposition material intended to be 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 a substrate (a glass substrate 92 ) on which an organic light emitting material is deposited to form a pixel. )) above, that is, a region within the deposition mask 20 facing the region above the substrate which will constitute the display surface of the fabricated substrate for an organic EL display device. However, for various purposes, a through hole or a recess may be formed in the peripheral region 23 . In the example shown in Fig. 1, each effective area 22 has a substantially rectangular shape in plan view, and more precisely, a substantially rectangular shape in plan view.

In the illustrated example, the plurality of effective regions 22 of the deposition mask 20 are arranged in a line at a predetermined interval along one direction parallel to the longitudinal direction of the deposition mask 20 . In the illustrated example, one effective area 22 is adapted to correspond to one organic EL display device. That is, according to the vapor deposition mask apparatus 10 (evaporation mask 20) shown in FIG. 1, multi-sided vapor deposition is possible.

As shown in FIG. 3 , in the illustrated example, the plurality of through holes 25 formed in each effective area 22 have a predetermined pitch along two directions orthogonal to each other in the effective area 22 , respectively. are arranged as 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 .

As shown in FIGS. 4 to 6 , the plurality of through holes 25 have a first surface 20a on one side along the normal direction of the deposition mask 20 , and the normal direction of the deposition mask 20 . It extends between the second surfaces 20b on the other side along , and penetrates through the deposition mask 20 . In the illustrated example, the first concave portion 30 is formed in the metal plate 21 from the side of the first surface 21a of the metal plate 21 serving as one side in the normal direction of the deposition mask, as will be described in detail later. A second concave portion 35 is formed in the metal plate 21 from the side of the second surface 21b formed by etching, which is the other side in the normal direction of the metal plate 21, and this first concave portion ( 30) and the second recessed portion 35, a through hole 25 is formed.

3 to 6 , from the first surface 20a side of the deposition mask 20 toward the second surface 20b side, deposition at each position along the normal direction of the deposition mask 20 . The cross-sectional area of each of the first concave portions 30 in the cross-section along the plate surface of the mask 20 becomes gradually smaller. As shown in FIG. 3 , the wall surface 31 of the first concave portion 30 extends in a direction intersecting with the normal direction of the deposition mask 20 in its entire area, and It is exposed toward one side along the normal direction. Similarly, the cross-sectional area of each second concave portion 35 in the cross section along the plate surface of the deposition mask 20 at each position along the normal direction of the deposition mask 20 is the second surface ( You may become gradually small toward the 1st surface 20a side from the 20b) side. The wall surface 36 of the second concave portion 35 extends in a direction intersecting the normal direction of the deposition mask 20 in its entire area, and extends on the other side along the normal direction of the deposition mask 20 . exposed towards

Further, as shown in FIGS. 4 to 6 , the wall surface 31 of the first concave portion 30 and the wall surface 36 of the second concave portion 35 are connected via a circumferential connecting portion 41 . connected. The connecting portion 41 includes a wall surface 31 of the first concave portion 30 inclined with respect to the normal direction of the deposition mask, and a wall surface 36 of the second concave portion 35 inclined with respect to the normal line direction of the deposition mask. A division is formed by the ridge line of the protrusion that joins. Then, the connecting portion 41 partitions the through portion 42 in which the area of the through hole 25 is the smallest in the planar view of the deposition mask 20 .

4 to 6 , on the other side of the deposition mask in the normal direction, that is, on the second surface 20b of the deposition mask 20 , the two adjacent through holes 25 are , are spaced apart from each other along the plate surface of the deposition mask. That is, like the manufacturing method mentioned later, the said metal plate 21 is etched from the 2nd surface 21b side of the metal plate 21 corresponding to the 2nd surface 20b of the deposition mask 20, and the 2nd recessed part When manufacturing (35), the 2nd surface 21b of the metal plate 21 remains between two adjacent 2nd recessed parts 35. As shown in FIG.

On the other hand, as shown in FIGS. 4 to 6 , on one side along the normal direction of the deposition mask, that is, on the side of the first surface 20a of the deposition mask 20, two adjacent first recesses ( 30) is connected. That is, like the manufacturing method mentioned later, the said metal plate 21 is etched from the 1st surface 21a side of the metal plate 21 corresponding to the 1st surface 20a of the deposition mask 20, and the 1st recessed part When forming 30, the 1st surface 21a of the metal plate 21 does not remain|survive between the adjacent two 1st recessed parts 30. As shown in FIG. That is, the first surface 21a of the metal plate 21 is etched over the entire effective region 22 . According to the first surface 20a of the deposition mask 20 formed by the first concave portion 30, the first surface 20a of the deposition mask 20 is formed of a deposition material ( 98), when this deposition mask 20 is used, the utilization efficiency of the deposition material 98 can be effectively improved.

As shown in FIG. 2, when the deposition mask apparatus 10 is accommodated in the deposition apparatus 90, as shown by the dashed-dotted line in FIG. 4, the first surface 20a of the deposition mask 20 is formed of a deposition material ( 98 , the second surface 20b of the deposition mask 20 faces the glass substrate 92 . Therefore, the vapor deposition material 98 passes through the 1st recessed part 30 whose cross-sectional area becomes small gradually, and adheres to the glass substrate 92. As shown in FIG. As indicated by the arrow in FIG. 4 , the vapor deposition material 98 not only moves along the normal direction of the glass substrate 92 from the crucible 94 toward the glass substrate 92 , but also moves in the normal direction of the glass substrate 92 . It may move in a direction that is largely inclined with respect to At this time, when the thickness of the deposition mask 20 is large, most of the deposition material 98 that moves obliquely goes through the through hole 25 and reaches the glass substrate 92 before reaching the wall surface of the first recess 30 . (31) is reached and attached. Moreover, in the area|region which faces the through-hole 25 on the glass substrate 92, the area|region which the vapor deposition material 98 is easy to reach, and the part which is hard to reach will generate|occur|produce. Therefore, in order to increase the utilization efficiency of the deposition material (film formation efficiency: the ratio of adhesion to the glass substrate 92) to save the expensive deposition material, and to stably and uniformly form a film using the expensive deposition material in the desired area, , it becomes important to configure the deposition mask 20 so that the deposition material 98 moving obliquely reaches the glass substrate 92 as much as possible. That is, in the cross-sections of FIGS. 4 to 6 orthogonal to the sheet surface of the deposition mask 20 , the connecting portion 41 serving as a portion having the minimum cross-sectional area of the through hole 25 and the first concave portion 30 It is advantageous that the minimum angle θ1 (refer to FIG. 4 ) formed by the straight line L1 passing through another arbitrary position of the wall surface 31 with respect to the normal direction of the deposition mask 20 is sufficiently large.

As one of the methods for increasing the angle θ1, the thickness of the deposition mask 20 is reduced, whereby the wall surface 31 of the first concave portion 30 or the wall surface of the second concave portion 35 ( 36) can be considered to be small. That is, as the metal plate 21 for constituting the deposition mask 20, it can be said that it is preferable to use the metal plate 21 having a thickness as small as possible within a range that can ensure the strength of the deposition mask 20. .

As another method for increasing the angle [theta]1, it is also conceivable to optimize the outline of the first concave portion 30 . For example, according to the present embodiment, when the wall surfaces 31 of the two adjacent first concave portions 30 join, it is compared with a concave portion having a wall surface (contour) indicated by a dotted line that does not merge with other concave portions. Accordingly, the angle θ1 can be greatly increased. Hereinafter, the reason is demonstrated.

The first concave portion 30 is formed by etching the first surface 21a of the metal plate 21 as described in detail later. Generally, the wall surface of the recessed part formed by etching turns into a curved-surface shape which becomes convex toward an erosion direction. Therefore, the wall surface 31 of the concave portion formed by etching rises steeply in the region serving as the etching start side, and in the region opposite to the etching start side, that is, the deepest side of the concave portion, the normal of the metal plate 21 . relatively large inclination with respect to the direction. On the other hand, in the illustrated deposition mask 20, since the wall surfaces 31 of the two adjacent first recesses 30 are joined at the etching start side, the wall surfaces of the two first recesses 30 ( The outer contour of the portion 43 where the tip edge 32 of 31) joins is not a steeply raised shape, but a chamfered shape. For this reason, the wall surface 31 of the 1st recessed part 30 which forms most of the through-hole 25 can be made to incline effectively with respect to the normal line direction of a deposition mask. That is, the angle θ1 can be increased. Thereby, while effectively improving the utilization efficiency of the vapor deposition material 98, vapor deposition in a desired pattern can be performed stably with high precision.

By the way, in order to obtain the metal plate 21 with small thickness, it is necessary to make large the rolling ratio at the time of rolling a base material and manufacturing the metal plate 21. As shown in FIG. However, the greater the rolling ratio, the greater the degree of non-uniformity of deformation based on rolling. For example, the elongation rate of the metal plate 21 differs according to the position in the width direction (direction orthogonal to the conveyance direction of a base material), As a result, the above-mentioned wave shape may appear in the metal plate 21. Here, consider the case where each vapor deposition mask 20 shown in FIG. 1 is comprised from the metal plate of an elongate shape obtained by respectively cutting|disconnecting the metal plate obtained by rolling a base material along the longitudinal direction. In this case, since the length of each deposition mask 20 is different, the pitch of each through hole 25 of the effective area 22 of each deposition mask 20 is different for each deposition mask 20, as a result. , the positional precision of vapor deposition is reduced, and the case where the utilization efficiency of vapor deposition material falls is considered. Accordingly, in order to obtain an organic EL display device in which the variation in the pitch of each through-hole 25 in the effective region 22 of each deposition mask 20 is suppressed and thereby the size or position of the pixel is small, it will be described later. Thus, it becomes important to select and use the metal plate 21 with a small difference in elongation rate.

Next, the present embodiment including such a configuration and its action and effect will be described. Here, first, the manufacturing method of the metal plate used in order to manufacture a vapor deposition mask is demonstrated. Next, the method of manufacturing a vapor deposition mask using the obtained metal plate is demonstrated. Then, the method of vapor-depositing vapor deposition material on a board|substrate using the obtained vapor deposition mask is demonstrated.

(Method for manufacturing metal plate)

First, with reference to FIGS. 7(a), (b), FIG. 8, (a), (b), (c), (d), and FIG. 10, the manufacturing method of a metal plate is demonstrated. Fig. 7(a) is a view showing a process of obtaining a metal plate having a desired thickness by rolling a base material, and Fig. 7(b) is a diagram showing a process of annealing the metal plate obtained by rolling.

[Rolling process]

First, as shown in Fig. 7(a), a base material 55 made of an invar material is prepared, and the base material 55 is used as a rolling device 56 including a pair of rolling rolls 56a and 56b. ) and conveyed along the conveyance direction shown by arrow D1. The base material 55 reached between the pair of rolling rolls 56a and 56b is rolled by the pair of rolling rolls 56a and 56b, and as a result, the thickness of the base material 55 is reduced and Together they are stretched along the conveying direction. Thereby, the elongate metal plate 64 of _{thickness t 0 can be obtained.} As shown in FIG. 7A , the winding body 62 may be formed by winding the elongated metal plate 64 around the core 61 . Although the specific value of thickness t ₀ is not specifically limited, For example, it is in the range of 0.020 mm or more and 0.100 mm or less.

[annealing process]

Then, in order to remove the residual stress accumulated in the elongate metal plate 64 by rolling, as shown in FIG.7(b), the elongate metal plate 64 is annealed using the annealing apparatus 57. As shown in FIG. The annealing process may be performed, pulling the elongate metal plate 64 in the conveyance direction (longitudinal direction), as shown in FIG.7(b). As a result, it is possible to obtain a long metal plate 64 having a _{thickness t 0} from which residual stress has been removed to some extent. Also, the thickness t ₀ is usually equal to the maximum thickness Tb in the peripheral region 23 of the deposition mask 20 .

In addition, the form of a rolling process and an annealing process is not specifically limited to the form shown to Fig.7 (a), (b). For example, a rolling process may be implemented using several pair of rolling roll 56a, 56b. Moreover, you may produce the elongate metal plate 64 of _{thickness t 0} by repeating a rolling process and an annealing process multiple times. 7B shows an example in which the annealing step is performed while pulling the elongated metal plate 64 in the longitudinal direction, but is not limited thereto. 61) may be carried out in the wound state. In addition, when an annealing process is performed in the state in which the elongate metal plate 64 is wound around the core 61, the bending tendency according to the winding diameter of the winding body 62 may arise in the elongate metal plate 64. Therefore, depending on the winding diameter of the winding body 62 and the material constituting the base material 55 , it is advantageous to perform the annealing step while pulling the elongated metal plate 64 in the longitudinal direction.

[Inspection process]

Then, the inspection process which test|inspects the grade of the difference in elongation of the obtained elongate metal plate 64 is implemented. 8 : is a perspective view which shows the metal plate obtained by the process shown to Fig.7 (a), (b). As shown in FIG. 8 , the elongated metal plate 64 has, at least in part, a wavy shape due to the length in the longitudinal direction D1 being different depending on the position in the width direction D2 . Here, the longitudinal direction D1 is a direction parallel to the conveyance direction at the time of rolling the base material 55, and the width direction D2 is a direction orthogonal to the longitudinal direction D1. In FIG. 8, the edge part of the width direction D2 of the elongate metal plate 64 is represented by the code|symbol 64e.

The wave shape shown in the elongate metal plate 64 is demonstrated. 9(a), (b), (c), and (d) are cross-sectional views taken along lines a-a, b-b, c-c and d-d of FIG. 8, respectively. The line aa in FIG. 8 is a line extending in the longitudinal direction along the central portion 64c in the width direction of the elongated metal plate 64 , and accordingly, FIG. The cross section of the elongate metal plate 64 in (64c) is shown. In addition, the line dd in FIG. 8 is a line extending in the longitudinal direction along the edge part 64e of the width direction of the elongate metal plate 64. Therefore, FIG. 9(d) is the width direction of the elongate metal plate 64. The cross section of the elongate metal plate 64 at the edge part 64e is shown. Central elongation appears in the elongated metal plate 64 according to the present embodiment, and for this reason, the degree of wave shape appearing in the elongated metal plate 64 in the central portion 64c in the width direction is at a position slightly distant from the central portion 64c, For example, it is larger than the degree of the wave shape shown in the elongate metal plate 64 at the position of line bb in FIG. Moreover, ear generation is also shown in the elongate metal plate 64 by this embodiment, and for this reason, the degree of the wave shape which appears in the elongate metal plate 64 at the edge part 64e of the width direction is a position slightly distant from the edge part 64e. , for example, is larger than the degree of wave shape appearing on the elongated metal plate 64 at the position of the line cc in Fig. 8 .

At a test|inspection process, first, the length of the elongate metal plate 64 within the predetermined range of the longitudinal direction D1 is computed at each position of the width direction D2. Here, "length" is the outline of the surface (first surface 64a or second surface 64b) of the elongated metal plate 64 in the longitudinal direction D1 along the wave shape shown in the elongated metal plate 64 . say the length of Specifically, as shown in FIGS. 9(a), (b), (c), and (d), the elongated metal plate at the position indicated by the aa line, the bb line, the cc line and the dd line in FIG. 8 . The lengths la, lb, lc, and ld of (64) are measured in consideration of the wave shape shown in the elongated metal plate 64 as well. The method for calculating the length of the elongate metal plate 64 is not specifically limited. For example, when calculating the length la of the elongated metal plate 64 in the central portion 64c, first, a ranging device capable of measuring the distance between the object and the central portion ( D2) in the width direction D2 In 64c), scanning is performed on the long metal plate 64 along the longitudinal direction D1 of the long metal plate 64, whereby the height position of the surface of the long metal plate 64 is set at predetermined intervals along the longitudinal direction D1. measure This space|interval exists in the range of 1 mm or more and 5 mm or less, for example. Next, a curve connecting each measurement point smoothly is drawn, and then, the length of the curve is calculated. Thereby, the length la of the elongate metal plate 64 in the center part 64c can be obtained. Moreover, the length of the elongate metal plate 64 in each position in the width direction D2 can be obtained by repeating such a measurement while changing the position in the width direction D2.

Next, the minimum value of the length of the elongate metal plate 64 obtained at each position of the width direction D2 is set as reference length. In the present embodiment, the length lb of the elongated metal plate 64 at the position indicated by the line bb in FIG. 8 is set as the reference length. Then, the ratio of the difference of the length of the elongate metal plate 64 at each position in the width direction D2 with respect to the reference length lb is computed as elongation difference ratio. For example, the elongation difference ratio of the elongated metal plate 64 in the central portion 64c is derived by (la-lb)/lb. 10 is a graph showing a curve 80 of the calculated elongation difference ratio. In FIG. 10 , the horizontal axis indicates the position in the width direction D2 of the elongated metal plate 64 , and the vertical axis indicates the elongation difference ratio on the order ^{of 10 −5 .} In the upper end of the horizontal axis of FIG. 10 , the position in the width direction D2 when the central portion 64c in the width direction D2 is taken as the origin is written in the order of mm. Moreover, the ratio with respect to the full width of the elongate metal plate 64 of the position in the width direction D2 is shown by % at the lower end of the horizontal axis of FIG. In addition, in FIG. 10, as the elongate metal plate 64 for manufacturing the vapor deposition mask 20, the case where what has an overall width of 500 mm is used is demonstrated. Therefore, for example, the ratio in the position spaced|separated by +100 mm from the center part 64c of the width direction D2 is +20 %. Also, in Fig. 10, the elongation difference ratios of the elongated metal plate 64 at the positions of the lines aa, bb, cc and dd in Fig. 8 are indicated by symbols A, B, C, and D, respectively.

Then, the elongate metal plate 64 is sorted based on the value of the obtained elongation difference ratio. Here, the elongate metal plate 64 is selected to be used in the manufacturing process of the vapor deposition mask 20 mentioned later, only the elongate metal plate 64 which satisfies all of the following conditions (1) - (3).

(1) the elongation difference ratio in the central portion R1 of the long metal plate 64 is 10×10 ^-5 or less;

(2) the elongation difference ratio at the end 64e of the elongated metal plate 64 in the width direction D2 is 20×10 ^-5 or less; and

(3) the elongation difference ratio at the end portion 64e is greater than the maximum value of the elongation difference ratio at the central portion R1;

Hereinafter, each of the conditions (1) to (3) is examined. Also, in Fig. 10, a central portion of the elongated metal plate 64 is indicated by a reference symbol R1, and a peripheral portion located outside the central portion R1 is indicated by a reference symbol R2. In this embodiment, the central part R1 is defined as a part which occupies 40% of the total width of the elongate metal plate 64 including the central part 64c in the width direction D2 of the elongate metal plate 64. .

In the elongated metal plate 64 in which central elongation and ear generation have occurred, the maximum value of the elongation difference ratio appears in the vicinity of the central portion 64c in the width direction of the elongated metal plate 64 in general, as shown in Fig. 10 (point A). ). Further, the minimum value of the elongation difference ratio appears at a position slightly away from the central portion in the width direction of the elongated metal plate 64 toward the peripheral portion (point B). Further, the elongation difference ratio increases from the point B toward the periphery in the width direction (point C), and the value of the elongation difference ratio becomes the maximum at the edge portion in the width direction (point D). Therefore, as shown by the dashed-dotted line in FIG. 10 , in the central portion R1, the elongation difference ratio = 10×10 ^-5 , and in the peripheral portion R2, the reference line 81 indicating the elongation difference ratio = 20×10 ^-5. When drawn, the fact that the curve 80 of the elongation difference rate is located below the reference line 81 means that the above-described conditions (1) and (2) are satisfied. In the example shown in FIG. 10, the above-mentioned conditions (1) and (2) are satisfied.

For condition (3), the elongation difference ratio at the edge portion 64e in the width direction D2, that is, the elongation difference rate at the point D, is the maximum value of the elongation difference rate at the central portion R1 (in the example shown in Fig. 10, the point It is determined whether it is greater than the elongation difference ratio in A). In the example shown in FIG. 10, the above-mentioned condition (3) is satisfied.

By performing this sorting, even when a wave shape appears in the elongated metal plate 64 due to the large rolling ratio of the elongated metal plate 64, the degree of the wave shape is determined by the subsequent manufacturing process of the deposition mask 20 or It can be determined in advance whether or not there is a problem in the manufacturing process of the organic EL display device. Thereby, it is possible to make the degree of difference in the lengths of the plurality of elongated vapor deposition masks 20 simultaneously produced within the permissible range. For this reason, the variation in the pitch of each through-hole 25 of the effective area 22 of the vapor deposition mask 20 to be manufactured can be reduced, and thereby, the dimensional accuracy and positional accuracy of the pixel of an organic electroluminescent display can be improved. can In addition, the yield in the manufacturing process of the deposition mask 20 may be improved.

In addition, the method of obtaining the elongate metal plate 64 with a total width of 500 mm which has the curve 80 of elongation difference rate as shown in FIG. 10 is not specifically limited.

For example, by rolling the base material 55, an elongated metal plate having a total width exceeding 500 mm, for example, a total width of 700 mm is produced, and then, both ends in the width direction of the elongated metal plate are placed within a predetermined range. By cutting over it, you may produce the long metal plate 64 of width 500mm. In addition, in a long metal plate having an overall width of 700 mm, as shown by a dashed-dotted line in FIG. 10 , there may be a portion in which the ^{elongation difference exceeds 20×10 −5 .} Even in such a case, by cutting both ends over a predetermined range, the elongate metal plate 64 which satisfy|fills the above-mentioned conditions (1) - (3) can be obtained.

Alternatively, the elongated metal plate 64 satisfying the above-described conditions (1) to (3) may be produced by rolling without cutting both ends over a predetermined range.

(Manufacturing method of vapor deposition mask)

Next, the method of manufacturing the vapor deposition mask 20 using the elongate metal plate 64 selected as mentioned above is demonstrated mainly with reference to FIGS. 11-20. In the manufacturing method of the vapor deposition mask 20 demonstrated below, as shown in FIG. 11, the elongate metal plate 64 is supplied, the through hole 25 is formed in this elongate metal plate 64, and also the elongate metal plate. By cutting (64), the deposition mask 20 including the sheet metal plate 21 is obtained.

More specifically, the method for manufacturing the deposition mask 20, the step of supplying the elongated metal plate 64 extending in a band shape, and etching using a photolithography technique are performed on the elongated metal plate 64, ), the process of forming the first recessed portion 30 from the side of the first surface 64a , and etching using a photolithography technique are performed on the elongated metal plate 64 , and the second surface 64b is formed on the elongated metal plate 64 . ) side, forming the second concave portion 35 . And the through-hole 25 is produced in the elongate metal plate 64 by the 1st recessed part 30 and the 2nd recessed part 35 formed in the elongate metal plate 64 communicating with each other. In the example shown in FIG. 11 , the step of forming the second concave portion 35 is performed before the step of forming the first concave portion 30 , and further, the forming step of the second concave portion 35 and the first concave portion are performed. Between the formation process of (30), the process of sealing the produced 2nd recessed part 35 is further provided. Hereinafter, the detail of each process is demonstrated.

11, the manufacturing apparatus 60 for manufacturing the vapor deposition mask 20 is shown. As shown in FIG. 11, first, the winding body 62 which wound the elongate metal plate 64 around the core 61 is prepared. Then, as the core 61 rotates and the winding body 62 is unwound, as shown in FIG. 11 , the elongated metal plate 64 extending in a strip shape is supplied. In addition, in the elongated metal plate 64 , a through hole 25 is formed to form the sheet metal plate 21 , and furthermore, the deposition mask 20 .

The supplied elongate metal plate 64 is conveyed to the etching apparatus (etching means) 70 by the conveyance roller 72 . Each of the processes shown in Figs. 12 to 20 is performed by the etching means 70 .

First, as shown in FIG. 12 , a negative photosensitive resist material is applied on the first surface 64a of the elongated metal plate 64 (on the lower surface in the paper of FIG. 12 ) and on the second surface 64b of the elongated metal plate 64 . Thus, resist films 65c and 65d are formed on the elongated metal plate 64 . Next, exposure masks 85a and 85b in which light is not transmitted to the region to be removed in the resist films 65c and 65d are prepared, and the exposure masks 85a and 85b are respectively formed as resist films as shown in FIG. 13 . Place it on (65c, 65d). As the exposure masks 85a and 85b, for example, a glass dry plate in which light is not transmitted to the region to be removed in the resist films 65c and 65d is used. Thereafter, the exposure masks 85a and 85b are sufficiently brought into close contact with the resist films 65c and 65d by vacuum adhesion.

Moreover, as a photosensitive resist material, a positive type thing may be used. In this case, as the exposure mask, an exposure mask in which light is transmitted through a region to be removed in the resist film is used.

Here, according to this embodiment, as mentioned above, the elongate metal plate 64 whose elongation difference rate at the edge part 64e is larger than the maximum value of the elongation difference rate at the center part R1 is used. That is, the degree of wave shape in the end portion 64e in the width direction D2 of the elongated metal plate 64 is larger than the degree of wave shape in the central portion 64c in the width direction D2 of the elongated metal plate 64 . has been In general, in vacuum adhesion, the air existing between the resist films 65c and 65d provided on the elongated metal plate 64 and the exposure masks 85a and 85b is blown into the elongated metal plate 64 and the resist film 65c, By discharging from the end of the stacked body 65d) to the outside, close contact between the resist films 65c and 65d and the exposure masks 85a and 85b is realized. Here, for example, if the degree of corrugation at the end portion 64e of the elongated metal plate 64 is smaller than the degree of corrugation at the central portion 64c of the elongated metal plate 64, the region near the end of the laminate is , it is conceivably brought into close contact with the exposure masks 85a and 85b before the region near the central portion of the laminate, and as a result, the exhaust path of the air existing in the vicinity of the central portion of the laminate disappears. On the other hand, according to this embodiment, since the degree of corrugation at the end portion 64e of the elongated metal plate 64 is larger than the degree of corrugation at the central portion 64c of the elongated metal plate 64, the central portion of the laminate The exhaust path of the air existing in the vicinity can be reliably secured, and therefore, the exposure masks 85a and 85b can be sufficiently adhered to the resist films 65c and 65d over the entire area.

Thereafter, the resist films 65c and 65d are exposed through the exposure masks 85a and 85b, and the resist films 65c and 65d are further developed. As described above, as shown in FIG. 14 , a resist pattern (simply also referred to as a resist) 65a is formed on the first surface 64a of the elongated metal plate 64 , and the second A resist pattern (referred to simply as a resist) 65b can be formed on the surface 64b.

Next, as shown in FIG. 15 , the resist pattern 65b formed on the elongated metal plate 64 is used as a mask, and an etching solution (eg, ferric chloride solution) is used to form the second layer of the elongated metal plate 64 . Etched from the side 64b. For example, from a nozzle disposed on the side facing the second surface 64b of the elongated metal plate 64 to which the etching solution is conveyed, the second surface 64b of the elongated metal plate 64 over the resist pattern 65b is removed. sprayed toward As a result, as shown in FIG. 15, in the area|region which is not covered with the resist pattern 65b of the elongate metal plate 64, erosion by an etching liquid advances. As mentioned above, many 2nd recessed parts 35 are formed in the long metal plate 64 from the 2nd surface 64b side.

Thereafter, as shown in Fig. 16, the formed second concave portion 35 is covered with the resin 69 having resistance to the etching solution. That is, the second recessed portion 35 is sealed by the resin 69 having resistance to the etching solution. In the example shown in FIG. 16, the film|membrane of the resin 69 is formed so that it may cover not only the formed 2nd recessed part 35 but the 2nd surface 64b (resist pattern 65b).

Next, as shown in FIG. 17 , the second etching is performed on the elongated metal plate 64 . In the second etching, the elongated metal plate 64 is etched only from the first surface 64a side, and the formation of the first concave portion 30 proceeds from the first surface 64a side. This is because the second surface 64b side of the elongated metal plate 64 is coated with a resin 69 resistant to the etching solution. Therefore, the shape of the 2nd recessed part 35 formed in the desired shape by the 1st etching is not impaired.

Erosion by etching is performed in the part of the elongate metal plate 64 which contacted the etching liquid. Accordingly, the erosion proceeds not only in the normal direction (thickness direction) of the elongated metal plate 64 , but also in the direction along the plate surface of the elongated metal plate 64 . As a result, as shown in Fig. 18, etching proceeds in the normal direction of the long metal plate 64 so that the first concave portion 30 is connected to the second concave portion 35 as well as the resist pattern 65a. Two first concave portions 30 respectively formed at positions facing the adjacent two holes 66a are joined at the back side of the bridge portion 67a positioned between the two holes 66a.

As shown in FIG. 19 , etching from the side of the first surface 64a of the elongated metal plate 64 further proceeds. As shown in Fig. 19, a merging portion 43 formed by merging of two adjacent first concave portions 30 is spaced apart from the resist pattern 65a, and the merging portion below the resist pattern 65a. In (43), erosion by etching proceeds also in the normal direction (thickness direction) of the metal plate 64 . As a result, the merging portions 43 pointed toward one side along the normal direction of the deposition mask are etched from one side along the normal direction of the deposition mask, and are chamfered as shown in FIG. 19 . Accordingly, the inclination angle θ1 formed by the wall surface 31 of the first concave portion 30 with respect to the normal direction of the deposition mask can be increased.

In this way, the erosion of the first surface 64a of the elongated metal plate 64 by etching proceeds within the entire region that constitutes the effective region 22 of the elongated metal plate 64 . Accordingly, the maximum thickness Ta along the normal direction of the elongated metal plate 64 in the region constituting the effective region 22 is smaller than the maximum thickness Tb of the elongated metal plate 64 before etching. .

As mentioned above, etching from the 1st surface 64a side of the elongate metal plate 64 advances only by the predetermined amount, and the 2nd etching with respect to the elongate metal plate 64 is complete|finished. At this time, the first concave portion 30 extends along the thickness direction of the elongated metal plate 64 to a position reaching the second concave portion 35 , whereby the first concave portions 30 communicate with each other. and a through hole 25 is formed in the elongated metal plate 64 by the second concave portion 35 .

Thereafter, as shown in FIG. 20 , the resin 69 is removed from the elongated metal plate 64 . The resin film 69 can be removed, for example, by using an alkali-based stripper. Further, when an alkali-based stripper is used, the resist patterns 65a and 65b are also removed simultaneously with the resin 69, as shown in FIG.

In this way, the elongated metal plate 64 having the plurality of through holes 25 formed therein is formed by a cutting device (cutting means) ( 73) is returned. Further, through the tension (tensile force) acting on the elongated metal plate 64 by the rotation of the conveying rollers 72 , 72 , the above-described supply core 61 is rotated, and the elongated metal plate 64 is moved from the winding body 62 . ) is to be supplied.

Thereafter, the long metal plate 64 having the plurality of concave portions 61 formed thereon is cut to a predetermined length and width by a cutting device (cutting means) 73, so that the sheet metal plate in which the plurality of through holes 25 are formed. (21) is obtained.

As described above, the deposition mask 20 including the metal plate 21 having a large number of through holes 25 formed therein is obtained. Here, according to the present embodiment, the first surface 21a of the metal plate 21 is etched over the entire effective region 22 . For this reason, the thickness of the effective area|region 22 of the deposition mask 20 is made small, and the front-end|tip edge 32 of the wall surface 31 of the two 1st recessed parts 30 formed on the 1st surface 21a side is further reduced. ) can be made into a chamfered shape of the outer contour of the part 43 where it joins. Therefore, the above-mentioned angle (theta)1 can be made large, and by this, the utilization efficiency of vapor deposition material and the positional precision of vapor deposition can be improved.

By the way, cutting the elongated metal plate 64 having a wavy shape to a predetermined width along the longitudinal direction means that the length of each deposition mask 20 including the elongated metal plate 21 obtained after cutting is the length of the metal plate ( It means that 21) differs according to the cut out position, ie, the position in the width direction of the elongate metal plate 64. As shown in FIG. Here, according to this embodiment, as mentioned above, the elongate metal plate 64 preselected based on the elongation difference ratio in the width direction D2 is used. For this reason, even when the elongate metal plate 64 has a wavy shape, the degree of difference in the lengths of the some vapor deposition mask 20 produced simultaneously can be made into the thing within a permissible range. Therefore, according to the present embodiment, the thickness of the effective region 22 of the deposition mask 20 is reduced, and the inclination angle θ1 of the wall surface 31 of the first recess 30 of the deposition mask 20 is increased. Enlarging it to improve the utilization efficiency of the deposition material and the positioning accuracy of deposition, reducing the variation in the pitch of each through-hole 25 in the effective area 22 of the deposition mask 20, and the deposition mask manufacturing process It is compatible with improving the adhesiveness in the exposure process in the middle, and improving the yield of the manufacturing process of the vapor deposition mask 20. Accordingly, the deposition mask 20 having excellent characteristics can be stably provided.

(Deposition method)

Next, the method of vapor-depositing vapor deposition material on the board|substrate 92 using the obtained vapor deposition mask 20 is demonstrated. First, as shown in FIG. 2 , the deposition mask 20 is brought into close contact with the substrate 92 . At this time, by installing the deposition mask 20 on the frame 15 , the surface of the deposition mask 20 is parallel to the surface of the substrate 92 . Here, according to this embodiment, the elongate metal plate 64 pre-sorted based on the elongation difference ratio in the width direction D2 is used. For this reason, compared with the case where such sorting is not performed, the variation in the length in each deposition mask 20 and further the variation in the pitch of each through hole 25 in the effective area 22 are uniformly reduced. . Accordingly, the deposition material can be deposited on the substrate 92 with high positioning accuracy. Therefore, when forming the pixel of an organic electroluminescent display by vapor deposition, the dimensional precision and positional precision of the pixel of an organic electroluminescent display can be improved. Thereby, it becomes possible to produce a high-definition organic electroluminescence display.

Moreover, in this embodiment mentioned above, the length of the elongate metal plate 64 at each position in the width direction D2 of the elongate metal plate 64 is an example of calculating without cutting the elongate metal plate 64 in the longitudinal direction. showed However, it is not limited to this, After cut|disconnecting the elongate metal plate 64 to the appropriate length in the longitudinal direction, at each position in the width direction D2, the length of the cut|disconnected metal plate is computed, Based on the result, a metal plate may be selected.

In addition, in this embodiment, the example in which the 1st surface 21a of the metal plate 21 was etched over the whole effective area|region 22 was shown. However, the present invention is not limited thereto, and the first surface 21a of the metal plate 21 may be etched only in a part of the effective area 22 .

Example

Next, although an Example demonstrates this invention more concretely, this invention is not limited to description of the following example, unless the summary is exceeded.

(first sample)

First, by performing the above-mentioned rolling process and annealing process with respect to the base material comprised with the invar material, the winding body (1st winding body) in which the elongate metal plate was wound was manufactured. Then, the 1st sample 100 containing the metal plate of width 500mm and projection length 700mm was obtained as shown in FIG. 21 by cutting out the front-end|tip part of a 1st winding body using a shearing machine. In addition, "projection length" is the length (dimension in a rolling direction) of a metal plate in the case where the metal plate is viewed from directly above, ie, the corrugation shape of a metal plate is disregarded. In addition, the width|variety of the 1st sample 100 means the distance between a pair of edge part 101, 102 of the 1st sample 100 in the width direction. A pair of end portions 101 and 102 of the first sample 100 is a portion formed by passing through a cutting step of cutting both ends in the width direction of the metal plate obtained by the rolling step and the annealing step over a predetermined range, almost straight extended.

Next, as shown in FIG. 21 , the first sample 100 was horizontally loaded on the surface plate 110 . At that time, the first sample 100 was placed still on the surface plate 110 so that a partial concavity did not occur in the first sample 100 . Next, at one end 101 of the first sample 100, the actual length of the first sample 100 in the region of the projection length of 500 mm, that is, the length taking the wave shape into account was measured. In addition, the area|region with a projection length of 500 mm means the area|region excluding the area|region within 100 mm from the both ends 103 and 104 in the longitudinal direction of the sample 1 from the 1st sample 100 of 700 mm of projection length. The region within 100 mm from both ends 103 and 104 is excluded from the measurement target in order to prevent the influence of the distortion of the first sample 100 due to cutting by the shearing machine from affecting the length measurement result. In Fig. 21, a region with a projection length of 500 mm is indicated by a dashed-dotted line.

In the measurement, as indicated by an arrow s in FIG. 21 , the measuring device using a laser beam is moved relative to the first sample 100 along the longitudinal direction of the first sample 100 , and 1 The height position of the surface at one end 101 of the sample 100 was measured at intervals of 1 mm. Further, a curve was drawn to smoothly connect between each measurement point, and then the length of the curve was calculated. As a measuring device for measuring the height position of the surface of the first sample 100, OPTELICS H1200, which is a laser microscope, manufactured by Lasertech Co., Ltd. was used. In addition, the element to be moved at the time of measurement may be any of the measuring device or the first sample 100, but here, by using an auto stage of 500 mm × 500 mm as a surface plate on which the first sample 100 is mounted, the sample ( 100) was moved and the measurement was performed. A laser interferometer was used to control the auto stage in the XY direction. In this way, the length of the first sample 100 at one end 101 was measured.

Next, at a position displaced by 20 mm from one end 101 to the other end 102 side, the length of the first sample 100 was similarly measured. The length of the first sample at each position in the width direction was measured by repeating the above measurement while changing the position of the first sample 100 in the width direction to a predetermined pitch p. Here, the pitch p was set to 20 mm. The obtained measurement results are the length measurement result at one end 101 , the length measurement result at the other end 102 , and the length measurement result at the central portion, and between the central portion and the end portions 101 and 102 . length measurement results. In addition, the central part is a part in which the distance from one edge part 101 is in the range of 150 mm or more and 350 mm or less, when the one edge part 101 is taken as a reference. In addition, the measurement position in the width direction is set so that length measurement may be performed in the center part of the 1st sample 100, ie, at the position where the distance from the one end 101 and the other end becomes equal.

Next, the minimum value of the length of the 1st sample 100 obtained at each position of the width direction was set as reference length. Thereafter, the ratio of the difference in the length of the first sample 100 at each position in the width direction with respect to the reference length was calculated as the elongation difference ratio. As a result, the elongation difference ratio at one end 101 is 79.9×10 ^-5 , the elongation difference ratio at the other end 102 is 71.2×10 ^-5 , and the maximum value of the elongation difference ratio at each position of the central portion is It was 15.8×10 ^-5 .

As a result of comparing the calculation result of the elongation difference ratio in the first sample 100 with the aforementioned conditions (1) to (3), in the first sample 100, condition (3) was satisfied, but condition (1) ) and (2) were not satisfied. Therefore, it is determined that the first sample 100 cannot be used as a material for manufacturing the deposition mask.

In addition, using the metal plate of the first winding body from which the above-described first sample 100 was obtained, a plurality of deposition masks provided with five effective regions along the longitudinal direction were manufactured. In each effective area of each deposition mask, a plurality of through holes are formed in a regular arrangement. Next, in order to evaluate the positional accuracy of the obtained deposition mask, the total pitch of each deposition mask was measured, and the degree of variation of the total pitch was calculated.

Here, the total pitch is the distance between two predetermined points in the deposition mask. As long as the positional accuracy of the deposition mask can be evaluated, the setting location of the two points is not particularly limited, but here, a predetermined mark formed in the vicinity of the effective area located on one end side of the deposition mask, and the other of the deposition mask The distance between a predetermined mark formed in the vicinity of the effective area located on the edge side was measured as a total pitch. The total pitch in this case is set to about 600 mm in design.

As an index of the degree of variation of the total pitch, a value obtained by multiplying the standard deviation (σ) of the total pitch measurement value of each deposition mask by 3, so-called 3σ, was used. The variation (3σ) of the total pitch measurement value of the deposition mask obtained from the first winding body was 35.2 μm. In addition, the number of n when calculating the standard deviation ? was set so that the value of the standard deviation ? has sufficient certainty in comparison with each sample described later. Specifically, the number n was set to 400.

(second sample)

The 2nd sample containing the metal plate of width 500mm and projection length 700mm was obtained by cutting out the front-end|tip part of the 2nd winding body different from the 1st winding body mentioned above. Next, it carried out similarly to the case of the 1st sample mentioned above, at each position in the width direction, the length of the 2nd sample was measured, and also the elongation difference ratio was computed. As a result, the elongation difference ratio at one end was 24.7×10 ^-5 , the elongation difference ratio at the other end was 29.8×10 ^-5 , and the maximum value of the elongation difference ratio at each position in the center was 1.0×10 ^-5 . .

As a result of comparing the calculation result of the elongation difference ratio in the second sample with the aforementioned conditions (1) to (3), in the second sample, conditions (1) and (3) were satisfied, but condition (2) was not satisfied Therefore, it is judged that a 2nd sample cannot be used as a raw material for manufacturing a vapor deposition mask.

Moreover, it carried out similarly to the case of the 1st sample mentioned above, and manufactured many vapor deposition masks in which many through-holes were formed using the metal plate of the 2nd winding body. Next, in the same manner as in the case of the first sample described above, the total pitch of each obtained deposition mask was measured, and the variation (3σ) of the total pitch measurement value was calculated. As a result, the value of 3σ was 16.1 μm.

(3rd sample)

The 3rd sample containing the metal plate of width 500mm and projection length 700mm was obtained by cutting out the front-end|tip part of the 3rd winding body different from the 1st winding body and 2nd winding body mentioned above. Next, it carried out similarly to the case of the 1st sample mentioned above, at each position in the width direction, the length of the 3rd sample was measured, and also the elongation difference rate was computed. As a result, the elongation difference ratio at one end was 18.1×10 ^-5 , the elongation difference ratio at the other end was 19.0×10 ^-5 , and the maximum value of the elongation difference ratio at each position in the center was 13.2×10 ^-5 . .

As a result of comparing the calculation result of the elongation difference ratio in the third sample with the aforementioned conditions (1) to (3), in the third sample, conditions (2) and (3) were satisfied, but condition (1) was not satisfied Therefore, it is determined that the third sample cannot be used as a material for manufacturing the deposition mask.

Moreover, it carried out similarly to the case of the 1st sample mentioned above, and manufactured many vapor deposition masks in which many through-holes were formed using the metal plate of a 3rd winding body. Next, in the same manner as in the case of the first sample described above, the total pitch of each obtained deposition mask was measured, and the variation (3σ) of the total pitch measurement value was calculated. As a result, the value of 3σ was 14.2 mu m.

(4th sample)

The 4th sample containing the metal plate of width 500mm and projection length 700mm was obtained by cutting out the front-end|tip part of the 4th winding body different from the 1st winding body thru|or 3rd winding body mentioned above. Next, it carried out similarly to the case of the 1st sample mentioned above, at each position in the width direction, the length of the 4th sample was measured, and also the elongation difference ratio was computed. As a result, the elongation difference ratio at one end was 26.8×10 ^-5 , the elongation difference ratio at the other end was 18.6×10 ^-5 , and the maximum value of the elongation difference ratio at each position in the center was 3.9×10 ^-5 . .

As a result of comparing the calculation result of the elongation difference ratio in the fourth sample with the aforementioned conditions (1) to (3), in the fourth sample, conditions (1) and (3) were satisfied, but condition (2) was not satisfied Therefore, it is judged that the 4th sample cannot be used as a raw material for manufacturing a vapor deposition mask.

Moreover, it carried out similarly to the case of the 1st sample mentioned above, and manufactured many vapor deposition masks in which many through-holes were formed using the metal plate of a 4th winding body. Next, in the same manner as in the case of the first sample described above, the total pitch of each obtained deposition mask was measured, and the variation (3σ) of the total pitch measurement value was calculated. As a result, the value of 3σ was 13.5 μm.

(5th sample)

The 5th sample containing the metal plate of width 500mm and projection length 700mm was obtained by cutting out the front-end|tip part of the 5th winding body different from the 1st winding body thru|or the 4th winding body mentioned above. Next, it carried out similarly to the case of the 1st sample mentioned above, at each position in the width direction, the length of the 5th sample was measured, and also the elongation difference rate was computed. As a result, the elongation difference ratio at one end was 18.2×10 ^-5 , the elongation difference ratio at the other end was 12.3×10 ^-5 , and the maximum value of the elongation difference ratio at each position in the center was 9.1×10 ^-5 . .

As a result of comparing the calculation result of the elongation difference ratio in the fifth sample with the conditions (1) to (3) described above, in the fifth sample, all of the conditions (1) to (3) were satisfied. Therefore, it is judged that the 5th sample can be used as a raw material for manufacturing a vapor deposition mask.

Moreover, it carried out similarly to the case of the 1st sample mentioned above, and manufactured many vapor deposition masks in which many through-holes were formed using the metal plate of the 5th winding body. Next, in the same manner as in the case of the first sample described above, the total pitch of each obtained deposition mask was measured, and the variation (3σ) of the total pitch measurement value was calculated. As a result, the value of 3σ was 5.6 mu m.

(Sixth sample)

The 6th sample containing the metal plate of width 500mm and projection length 700mm was obtained by cutting out the front-end|tip part of the 6th winding body different from the 1st winding body thru|or 5th winding body mentioned above. Next, it carried out similarly to the case of the 1st sample mentioned above, at each position in the width direction, the length of the 6th sample was measured, and also the elongation difference rate was computed. As a result, the elongation difference ratio at one end was 18.2×10 ^-5 , the elongation difference ratio at the other end was 8.8×10 ^-5 , and the maximum value of the elongation difference ratio at each position in the center was 9.1×10 ^-5 . .

As a result of comparing the calculation result of the elongation difference ratio in the sixth sample with the above-mentioned conditions (1) to (3), in the third sample, conditions (1) and (2) were satisfied, but condition (3) was not satisfied Therefore, it is judged that the 6th sample cannot be used as a raw material for manufacturing a vapor deposition mask.

Moreover, it carried out similarly to the case of the 1st sample mentioned above, and manufactured many vapor deposition masks in which many through-holes were formed using the metal plate of the 6th winding body. Next, in the same manner as in the case of the first sample described above, the total pitch of each obtained deposition mask was measured, and the variation (3σ) of the total pitch measurement value was calculated. As a result, the value of 3σ was 12.6 μm.

(Seventh sample)

The 7th sample containing the metal plate of width 500mm and projection length 700mm was obtained by cutting out the front-end|tip part of the 7th winding body different from the 1st winding body thru|or the 6th winding body mentioned above. Next, it carried out similarly to the case of the 1st sample mentioned above, at each position in the width direction, the length of the 7th sample was measured, and also the elongation difference rate was computed. As a result, the elongation difference ratio at one end was 16.5×10 ^-5 , the elongation difference ratio at the other end was 3.2×10 ^-5 , and the maximum value of the elongation difference ratio at each position in the center was 0.8×10 ^-5 . .

As a result of comparing the calculation result of the elongation difference ratio in the seventh sample with the conditions (1) to (3) described above, in the seventh sample, all of the conditions (1) to (3) were satisfied. Therefore, it is judged that the 7th sample can be used as a raw material for manufacturing a vapor deposition mask.

Moreover, it carried out similarly to the case of the 1st sample mentioned above, and manufactured many vapor deposition masks in which many through-holes were formed using the metal plate of the 7th winding body. Next, in the same manner as in the case of the first sample described above, the total pitch of each obtained deposition mask was measured, and the variation (3σ) of the total pitch measurement value was calculated. As a result, the value of 3σ was 4.3 μm.

As described above, when the metal plates of the 5th and 7th winding bodies from which Samples 5 and 7 from which good judgment was made based on the above-mentioned conditions (1) to (3) were used were used, the variation in the total pitch measurement value of the deposition mask ( 3σ) was able to be small, specifically 10 µm or less. On the other hand, when the metal plates of the first to fourth and sixth winding bodies from which samples 1 to 4 and 6 judged to be defective based on the above-described conditions (1) to (3) were taken out, the total pitch measurement of the deposition mask was used. The value of the variation (3σ) was large, specifically, larger than 10 µm. From this point, it can be said that there exists a strong correlation between the determination result based on the above-mentioned conditions (1) - (3), and the performance of the vapor deposition mask obtained. That is, it can be said that the characteristics of the vapor deposition mask obtained from the metal plate of the said winding body can be predicted with high precision at the stage of a winding body by using the above-mentioned conditions (1) - (3). Therefore, it is considered that the above-mentioned conditions (1) to (3) are a strong judgment method.

20: deposition mask
21: metal plate
21a: the first side of the metal plate
21b: the second side of the metal plate
22: effective area
23: surrounding area
25: through hole
30: first recess
31: wall
35: second recess
36: wall
55: base material
56: rolling device
57: annealing device
61: core
62: winding body
64: long metal plate
64a: the first side of the long metal plate
64b: second side of long metal plate
64c: central part in the width direction of a long metal plate
64e: the end in the width direction of the long metal plate
65a, 65b: resist pattern
65c, 65d: resist film
80: curve of height difference ratio
81: baseline
85a, 85b: exposure mask

Claims (13)

A method for manufacturing a metal plate used for manufacturing a deposition mask by forming a plurality of through holes,
The through hole of the deposition mask is formed by etching the metal plate,
The method of manufacturing the metal plate,
A rolling step of rolling a base material to obtain the metal plate;
A cutting step of cutting both ends in the width direction of the metal plate over a predetermined range;
The metal plate after the cutting step has at least partially a wavy shape due to the length in the longitudinal direction being different depending on the position in the width direction,
The minimum value of the length of the metal plate after the cutting process is referred to as a reference length, and the ratio of the difference between the length of the metal plate at each position in the width direction of the metal plate after the cutting process to the reference length is the elongation difference ratio. In the case of calling, the following conditions (1) to (3) are satisfied,
(1) the elongation difference ratio at the central portion in the width direction of the metal plate after the cutting step is 10×10 ^-5 or less;
(2) the elongation difference ratio at a position 250 mm away from the center of the metal plate in the width direction in the width direction is 20×10 ^-5 or less; and
(3) the elongation difference ratio at a position 250 mm away from the center portion of the metal plate in the width direction in the width direction is greater than a maximum value of the elongation difference ratio at the central portion;
The said central part is a part which occupies 40% of the width of the said metal plate including the central part of the width direction of the said metal plate after the said cutting process, The manufacturing method of a metal plate. The method for manufacturing a metal sheet according to claim 1, further comprising an annealing step of annealing the metal sheet obtained by the rolling step to remove internal stress of the metal sheet. The method for manufacturing a metal sheet according to claim 2, wherein the annealing step is performed while stretching the rolled base material in the longitudinal direction. The method for manufacturing a metal sheet according to claim 2, wherein the annealing step is performed in a state in which the rolled base material is wound around a core. The method for manufacturing a metal plate according to any one of claims 1 to 4, wherein the coefficient of thermal expansion of the base material is a value equal to the coefficient of thermal expansion of the substrate on which the deposition material is formed through a deposition mask manufactured from the metal plate. The method for manufacturing a metal plate according to claim 1, wherein the base material is composed of an invar material. A metal plate used for manufacturing a deposition mask by forming a plurality of through holes,
The metal plate has, at least in part, a wavy shape due to the length in the longitudinal direction being different depending on the position in the width direction,
When the minimum value of the length of the metal plate is referred to as a reference length, and the ratio of the difference in the length of the metal plate at each position in the width direction of the metal plate to the reference length is called the elongation difference ratio, the following conditions (1 ) to (3) are satisfied,
(1) the elongation difference ratio at the central portion in the width direction of the metal plate is 10×10 ^-5 or less;
(2) the elongation difference ratio at a position 250 mm away from the center of the metal plate in the width direction in the width direction is 20×10 ^-5 or less; and
(3) the elongation difference ratio at a position 250 mm away from the center portion of the metal plate in the width direction in the width direction is greater than the maximum value of the elongation difference ratio in the central portion;
The said central part is a metal plate which is a part which occupies 40% of the width|variety of the said metal plate, including the central part of the width direction of the said metal plate. The metal plate according to claim 7, wherein the coefficient of thermal expansion of the metal plate is a value equal to the coefficient of thermal expansion of the substrate on which the deposition material is formed through a deposition mask manufactured from the metal plate. The metal plate according to claim 7, wherein the metal plate is made of an invar material. A method for manufacturing a deposition mask comprising: an effective region in which a plurality of through holes are formed; and a peripheral region positioned around the effective region;
A step of preparing a metal plate, which is a metal plate, and has at least partly a wavy shape due to the length in the longitudinal direction being different depending on the position in the width direction;
a resist pattern forming step of forming a resist pattern on the metal plate;
an etching step of etching the metal plate using the resist pattern as a mask to form a recess for partitioning the through hole in the region of the metal plate constituting the effective region;
When the minimum value of the length of the metal plate is referred to as a reference length, and the ratio of the difference in the length of the metal plate at each position in the width direction of the metal plate to the reference length is called the elongation difference ratio, the following conditions (1 ) to (3) are satisfied,
(1) the elongation difference ratio at the central portion in the width direction of the metal plate is 10×10 ^-5 or less;
(2) the elongation difference ratio at a position 250 mm away from the center of the metal plate in the width direction in the width direction is 20×10 ^-5 or less; and
(3) the elongation difference ratio at a position 250 mm away from the center portion of the metal plate in the width direction in the width direction is greater than the maximum value of the elongation difference ratio in the central portion;
The said central part is a part which occupies 40% of the width of the said metal plate, The manufacturing method of the vapor deposition mask including the central part of the width direction of the said metal plate. The method of claim 10, wherein the resist pattern forming process comprises:
forming a resist film on the metal plate;
a step of vacuum-adhering an exposure mask to the resist film;
and exposing the resist film in a predetermined pattern through the exposure mask. The method for manufacturing a deposition mask according to claim 10 or 11, wherein the coefficient of thermal expansion of the metal plate is a value equal to the coefficient of thermal expansion of the substrate on which the deposition material is formed through the deposition mask manufactured from the metal plate. The method for manufacturing a deposition mask according to claim 10, wherein the metal plate is made of an invar material.

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