Vapor deposition mask and method for manufacturing the same

Abstract

This invention provides a high-definition vapor deposition mask that is less prone to defects in the openings and suppresses the generation of foreign matter caused by the vapor-deposited film. [Solution] In a metal mask (1), the sidewall of an opening (3) has a boundary (P3) in the thickness direction, and exhibits a tapered shape from the boundary (P3) toward the first surface (4) and the second surface (5), and the taper angle (θ1) on the first surface (4) side, which is located on the deposition source side, and the taper angle (θ2) on the second surface (5) side, which is located on the non-deposition substrate side, are both acute angles, with θ1 > θ2.

Description

[Technical Field]

[0001] The present invention relates to a high-definition metal deposition mask and a method for manufacturing the same. [Background technology]

[0002] In recent years, the range of applications for organic EL panels, which use organic electroluminescence elements (hereinafter referred to as "organic EL elements") as light-emitting elements, has expanded beyond large-screen televisions to include VR headsets and dedicated goggles required for VR (virtual reality), AR (augmented reality), and MR (mixed reality). These require extremely high pixel densities (ppi), for example, of 3000 ppi or more, but because organic EL panels are generally manufactured through a vacuum deposition process of organic materials using a deposition mask, a high-resolution deposition mask that can accommodate such high pixel densities is required. Known technology relating to such high-definition deposition masks is that described in Patent Document 1. Patent Document 1 discloses a deposition mask used to form a thin film pattern by vacuum deposition and having openings corresponding to the thin film pattern, the deposition mask being made of single-crystal silicon instead of metal, and the mask openings being formed by anisotropic wet etching utilizing crystal orientation dependency. Single-crystal silicon deposition masks are manufactured using photolithography and anisotropic wet etching, allowing for highly accurate processing of openings. However, as pixel density increases, the thin silicon portion where the openings are located becomes extremely thin, and silicon, being a brittle material, is prone to cracking and chipping due to scratches and other defects. Patent Document 1 describes a method for reducing chipping by providing tapered structures in opposite directions on the deposition source side and the deposition substrate side of the openings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-305079 Summary of the Invention [Problem to be solved by the invention]

[0004] When vapor deposition is performed on a substrate with high pixel density using a high-resolution vapor deposition mask, the vapor deposition mask and the substrate are sometimes brought into contact with each other to reduce vapor deposition blurring on adjacent pixels. However, the thickness of the vapor deposition mask corresponding to the high pixel density is too thin, and the tapered structure alone may not be sufficient to prevent defects that occur in the openings when the mask comes into contact. Furthermore, repeated deposition processes can result in unintended foreign matter being generated on the substrate, and foreign matter adhering to the mask during the process can not only cause pixel defects and reduce production yields, but can also become a point of stress concentration on the mask when it comes into contact, potentially causing mask damage. One aspect of the present disclosure provides a high-definition deposition mask in which defects at openings are unlikely to occur and in which the generation of foreign matter resulting from a deposition film is suppressed. [Means for solving the problem]

[0005] One aspect of the present disclosure is a deposition mask made of metal, the deposition mask having a first surface, a second surface located on the opposite side of the first surface, and an opening penetrating from the first surface to the second surface, a sidewall surrounding the opening has a boundary between the first surface and the second surface, and is tapered from the boundary toward the first surface and the second surface, respectively; In a cross section passing through the first surface, the second surface, and the opening, when a taper angle formed by an extension line drawn from the first surface onto the opening and the side wall is θ1 and a taper angle formed by an extension line drawn from the second surface onto the opening and the side wall is θ2, Both θ1 and θ2 are acute angles and relate to different deposition masks. Another aspect 2 of the present disclosure is providing a seed layer on the substrate; forming a first resist pattern having a taper of θ2 on the substrate; forming a second resist pattern having a taper of θ1 on the first resist pattern; electrolytically depositing a metal film in the gap between the first and second resist patterns; removing the first and second resist patterns to form an opening in the metal film; removing the substrate and the seed layer from the metal film in which the opening is formed; The present invention relates to a method for manufacturing a deposition mask having the above structure. [Effects of the Invention]

[0006] According to the present disclosure, defects are less likely to occur in the openings of the deposition mask, and the generation of foreign matter is prevented, making it possible to form a deposition film that corresponds to high-density pixels. [Brief explanation of the drawings]

[0007] [Figure 1] 2 is a schematic end view of a cross section in a thickness direction of the vapor deposition mask according to the embodiment. FIG. [Figure 2] FIG. 2 is an enlarged view of an opening in the deposition mask of FIG. [Figure 3] FIG. 1 is a schematic plan view of an example of a high-definition metal vapor deposition mask. [Figure 4] FIG. 1 is a schematic end view of a vapor deposition process using a high-definition metal vapor deposition mask. [Figure 5] This is an explanatory diagram of the deposition angle. [Figure 6] 1A is a schematic end view showing vapor deposition using the vapor deposition mask of the embodiment, and FIG. 1B is a schematic end view showing vapor deposition using a conventional vapor deposition mask. [Figure 7] 5A and 5B are explanatory diagrams of the thickness of a tapered portion in the vapor deposition mask according to the embodiment. [Figure 8] 10A and 10B are explanatory diagrams of taper angles in another embodiment of the vapor deposition mask according to the embodiment. [Figure 9] 5A to 5C are schematic end surface views in the thickness direction illustrating a manufacturing process of the vapor deposition mask according to the embodiment. [Figure 10] 1 is a schematic cross-sectional view in the thickness direction of an example of an organic light-emitting device. [Figure 11] FIG. 1 is a schematic diagram illustrating an example of a display device. [Figure 12]1A is a schematic diagram illustrating an example of an imaging device, and FIG. 1B is a schematic diagram illustrating an example of an electronic device. [Figure 13] 1A is a schematic diagram illustrating an example of a display device, and FIG. 1B is a schematic diagram illustrating an example of a foldable display device. [Figure 14] FIG. 1( a ) is a schematic diagram showing an example of a lighting device. [Figure 15] 1A and 1B are schematic diagrams showing an example of an automobile having a vehicle lamp; [Figure 16] 1A is a schematic diagram showing an example of a wearable device, and FIG. 1B is a schematic diagram showing an example of a wearable device having an imaging device. [Figure 17] 1A is a schematic diagram showing an example of an image forming apparatus, and FIGS. 1B and 1C are schematic diagrams showing an embodiment in which a plurality of light-emitting units of an exposure light source are arranged on a long substrate. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, specific embodiments of a deposition mask and a deposition process using the deposition mask according to the present disclosure will be described with reference to the accompanying drawings. In the following description and drawings, common reference numerals are used to designate components common to multiple drawings. Therefore, the common components will be described with mutual reference to multiple drawings, and descriptions of the components with common reference numerals will be omitted as appropriate. The deposition mask of this embodiment is made of metal and has a first surface, a second surface, and an opening that penetrates from the first surface to the second surface, and a sidewall surrounding the opening has a boundary between the first surface and the second surface and exhibits a tapered shape from the boundary toward the first surface and the second surface, respectively. The deposition mask is characterized in that the taper angle on the first surface side and the taper angle on the second surface side are both acute angles and different from each other. First, a high-definition gold deposition mask and a deposition process using the mask will be described. Figure 3 shows a schematic plan view of an example of a high-resolution metal deposition mask. As shown in Figure 3, a plurality of apertures 13 are arranged in the mask 11. Reference numeral 12 denotes a mask frame attached to the periphery of one surface of the mask 11. The position, diameter, pitch, and shape of the apertures 13 are determined appropriately based on the pixel position, size, pitch, and shape of the substrate to be deposited. Generally, multiple organic EL panels are manufactured from a substrate to be deposited, so apertures 13 are arranged for each chip corresponding to each panel size. In Figure 3, each chip is separated by cutting along the dashed lines. Although the shape of the apertures 13 is depicted as a circle in Figure 3, they may also be rectangular or polygonal depending on the corresponding pixel shape. The arrangement of the apertures 13 can also be appropriately selected based on the pixel arrangement of the substrate to be deposited, such as a delta or staggered arrangement. When there are no apertures 13 in the inter-chip regions, they may be thicker than the areas around the apertures 13 to enhance the mechanical strength of the high-resolution metal deposition mask.

[0009] Next, Fig. 4 shows a schematic cross-sectional view of a substrate to be vapor-deposited in the thickness direction. The vapor deposition process includes the steps of: placing a mask 11 having a plurality of openings and a substrate (substrate to be vapor-deposited) 15 having pixels opposite each other in a vapor deposition chamber; aligning the substrate 15 with the mask 11; and depositing a vapor deposition material onto the substrate 15 through the openings (not shown) in the mask 11.

[0010] First, as shown in Figure 4(a), the substrate 15 held by the substrate holding arm 16 and the mask 11 held by the mask stage 17 are placed facing each other. Next, for example, either or both of the substrate 15 and the mask 11 are moved, and the substrate 15 and the mask 11 are aligned by looking at an alignment mark (not shown) provided on the substrate 15 and an alignment mark (not shown) provided on the mask 11.

[0011] After alignment, as shown in Figure 4(b), the mask 11 is attracted by a magnet 18 located above the substrate 15, bringing the substrate 15 and the mask 11 into contact.

[0012] Thereafter, as shown in FIG. 4(c), a deposition material 19 is deposited on the substrate 15 through the multiple openings in the mask 11.

[0013] After deposition, as shown in FIG. 4(d), the magnet 18 is moved away from the substrate 15 to weaken the magnetic force, cutting off the attraction to the mask 11, and separating the substrate 15 and the mask 11.

[0014] The deposition mask of this embodiment is preferably used in the deposition process described above. Hereinafter, the embodiment will be described with reference to the drawings. It should be noted that the dimensions, materials, shapes, relative positions, and the like of the components described below are not intended to limit the scope of the present disclosure unless otherwise specified.

[0015] Fig. 1 shows an end view of a thickness direction cross section including the first surface, the second surface, and the center of an opening of one embodiment of the deposition mask of this embodiment. In the figure, 1 is a deposition mask, one main surface of which is the first surface 4, and the surface located opposite the first surface 4 is the second surface 5. 3 is an opening that penetrates from the first surface 4 to the second surface 5. 2 is a mask frame that is joined to the outer periphery of the second surface as necessary to suppress distortion or bending of the mask 1. Fig. 2(a) is an enlarged view of the vicinity of the opening 3, and Fig. 2(b) is a schematic plan view of the opening 3 as viewed from the second surface 5 side.

[0016] In FIG. 2 , P1 denotes the boundary between the sidewall of the opening 3 and the first surface 4, and P2 denotes the boundary between the sidewall and the second surface 5. In this embodiment, as shown in FIG. 1 , in a cross section including the first surface 4, the second surface 5, and the center of the opening 3, the sidewall surrounding the opening 3 has a boundary P3 at a predetermined distance from the first surface 4 and the second surface 5 in the thickness direction, and exhibits a tapered shape from the boundary P3 toward the first surface 4 and the second surface 5, respectively. At the boundary P1 between the first surface 4 and the sidewall, the taper angle formed by the sidewall and an extension line drawn from the first surface 4 onto the opening is defined as θ1, and at the boundary P2 between the second surface 5 and the sidewall, the taper angle formed by the second surface 5 drawn onto the opening 3 is defined as θ2. θ1 and θ2 are both acute angles and are different from each other. The taper directions from the boundary P3 toward the first surface 4 and the second surface 5 are opposite to each other.

[0017] Furthermore, in the deposition process, the mask 1 shown in Figures 1 and 2 is used with the first surface 4 facing the deposition source and the second surface 5 facing the substrate to be deposited, and in this case, θ1 > θ2.

[0018] Here, the contact portion between the mask opening and the substrate to be vapor-deposited, the taper angle of the mask opening, and the vapor deposition angle will be described with reference to FIGS. Figure 5 is a schematic vertical cross-sectional view showing the deposition process in the deposition chamber 20. Figure 6 is a schematic cross-sectional view showing the state in which the mask is attracted by the aforementioned magnet (not shown) and the substrate 15 to be deposited on and the mask are in contact. Figure 6(a) shows the state in which deposition is performed using the mask 1 of this embodiment, and Figure 6(b) shows the state in which deposition is performed using the conventional mask 11.

[0019] As shown in Fig. 5, a deposition source 21 such as a crucible is provided at the bottom of a deposition chamber 20. The deposition apparatus is composed of multiple deposition chambers corresponding to the multiple functional layers. In addition to the deposition chambers, the apparatus may also include multiple process chambers such as a load lock chamber for loading and unloading a deposition target substrate 15, a pre-processing chamber, a transfer chamber, a relay chamber, a substrate stock chamber, and a sealing chamber.

[0020] To obtain the desired film thickness uniformity, the deposition angle of the deposition particles 22 incident from the deposition source 21 onto the deposition substrate 15 is determined by design factors such as the distance between the deposition substrate 15 and the deposition source 21 (Target-Source; TS distance), the offset position of the substrate from the central axis of the deposition source 21, and the substrate size. This deposition angle also differs depending on the position on the deposition substrate 15, and varies depending on the relative positional relationship between the deposition source 21 and each position on the deposition substrate 15. For example, the deposition angle is approximately 90° at a portion of the deposition substrate 15 located directly above the deposition source 21, but the deposition angle becomes shallower, i.e., smaller, toward the edge of the deposition substrate 15. When the TS distance is 400 mm to 600 mm, depending on the offset position, if the deposition substrate 15 is a 12-inch silicon substrate, the deposition angle (θ ev The smallest deposition angle (θ) at the edge of the substrate is generally around 50° to 70°. Therefore, in order to increase the number of elements on the substrate 15 for production efficiency, the smallest deposition angle (θ) at the edge of the substrate is generally set.ev ) The taper angle θ of the opening 13 of the mask 11 c 6(a) and 6(b), it is preferable to reduce the vignetting of the vapor deposition particles 22 by the opening 13 which hinders deposition of the film on the substrate. c The deposition angle (θ ev ) or smaller.

[0021] Also, the taper angles θ1 and θ c In order to reduce the thickness of the mask, it is necessary to reduce the thickness of the mask. c When the apertures 3 and 13 are reduced in size, the adjacent apertures 3 and 13 come into contact with each other on the first surface side. In particular, in a high-resolution organic EL panel of 3000 ppi or more, the pixel pitch and the center-to-center distance of the corresponding mask apertures are about 8 μm or less. At this time, the thickness of the thin-walled portion where the apertures 3 and 13 are present is determined by the taper angles θ1 and θ2. c At 70°, the taper angle is 8.8μm or less, and the taper angle is θ1, θ c For the above reasons, a thickness of 3.8 μm or less is required at an angle of 50°. These film thicknesses are very thin, and if silicon is used as the mask material, cracks and other defects are likely to occur. Therefore, when the thin-walled portion of the mask is 8.8 μm or less in thickness, it is preferable to use a metal mask film made of metal.

[0022] Here, we will explain high-resolution masks for manufacturing light-emitting devices with high-resolution pixels. For example, at pixel densities of 3000 ppi or higher, the pixel-to-pixel distance is approximately 8 μm or less. In this case, the thin-walled portion of a silicon deposition mask is very thin, approximately 2 μm to 3 μm thick. When using a high-resolution deposition mask to deposit on a substrate with high pixel density, it is preferable to bring the deposition mask into contact with the substrate to reduce deposition blurring on adjacent pixels. However, the deposition mask is too thin for a thickness corresponding to high pixel density, and a tapered structure alone may not be sufficient to prevent defects that occur at the openings when the mask comes into contact.

[0023] Furthermore, repeated deposition processes can result in unintended foreign matter being generated on the substrate. Foreign matter can also adhere to the mask during the process, affecting deposition. For example, if a deposition film is formed while the deposition substrate is in contact with the deposition mask, a continuous film is formed that straddles the deposition mask and the deposition substrate. After deposition, when the deposition mask is peeled off from the deposition substrate, this continuous film may peel off or break into fragments, potentially becoming a source of foreign matter. Since these foreign matters occur near pixels, they not only cause pixel defects and reduced production yields, but also become stress concentration points on the mask upon contact, potentially causing mask damage.

[0024] For example, in the case where the opening 13 has a straight structure as shown in FIG. 6(b), the opening 13 does not have a taper on the deposition substrate 15 side in the opposite direction to the deposition source side, and the taper angle θ c Some of the vapor deposition particles incident at this angle are deposited at the contact line between the substrate 15 and the mask 11. This deposited vapor deposition film 23 is a continuous film that straddles the substrate 15 and the mask 11. Therefore, after vapor deposition, when the attraction from the magnet to the mask 11 is stopped and the substrate 15 and the mask 11 are separated, a break occurs in this continuous film. This break can cause film peeling and the generation of foreign matter near the pixels, resulting in a decrease in yield.

[0025] 6(a), by providing a tapered structure on the deposition substrate 15 side as well, a continuous film is not formed across the deposition substrate 15 and the mask 1, thereby reducing film peeling and the generation of foreign matter due to the continuous film. Furthermore, if the taper angle θ1 on the deposition source side and the taper angle θ2 on the deposition substrate 15 side satisfy the relationship θ1>θ2, the tapered structure on the deposition source side suppresses vignetting of deposition particles from the deposition source.

[0026] Next, a more preferable range of the taper angle θ2 on the deposition substrate side in the mask of this embodiment will be exemplified. 6(a), if the taper angle θ1 on the deposition source side and the taper angle θ2 on the deposition substrate side satisfy the relationship θ1 > θ2, vignetting of the deposition particles and breakage of the continuous film can be reduced, but it is preferable to make the taper angle θ2 on the deposition substrate 15 side small. This is because if θ2 can be reduced, θ1 can be made smaller accordingly, and therefore vignetting can be reduced and continuous film formation can be suppressed even when the deposition substrate, mask, and deposition source are arranged in such a way that deposition particles are incident at a smaller deposition angle.

[0027] However, there are certain taper angles θ2 on the deposition substrate 15 side that cause structural problems for high-resolution metal deposition masks. Figure 7 shows a schematic end view of the cross section near the opening 3 when θ2 is reduced. Here, the opening on the deposition source side is referred to as the lower opening, with its diameter B, and the opening on the deposition substrate side is referred to as the upper opening, with its diameter A. The opening 3 is a through hole for the passage of deposition particles, but can be characterized by tapered portions on the deposition source side and the deposition substrate side, each tapered in the opposite direction. The thickness of the tapered portion on the deposition source side is referred to as the lower thickness t1, and the thickness of the tapered portion on the deposition substrate side is referred to as the upper thickness t2. The sum of t1 and t2 is the mask film thickness t at the opening 3 of the mask 1. In other words, if the direction parallel to the second surface 5 is referred to as the first direction and the direction perpendicular to the second surface is referred to as the second direction, then in the second direction, the length from the boundary P3 to the first surface 4 is referred to as t1, and the length from the boundary P3 to the second surface 5 is referred to as t2. The center-to-center distance between these openings 3 in the first direction corresponds to the pixel pitch of the substrate, and is defined as D. Furthermore, the length of the sidewall separating adjacent openings 3, 3 in the first direction (sidewall width) at boundary P3 where the taper direction is reversed is defined as W.

[0028] If θ2 is reduced while the upper thickness t2 of the mask 1 is fixed, the upper sidewalls will have a sharply pointed shape. Finally, below a specific angle, the inner sidewall height of the opening 3 closest to the chip edge, i.e., the sidewall of the rib, will be lower than the outer side of the opening 3 in the mask 1. With this type of mask, when the deposition substrate and the mask 1 are magnetically attracted to each other, the shape of the opening 3 will be distorted due to the insufficient height, resulting in the problem of not being able to deposit the desired film shape on the non-deposition substrate. To avoid this, θ2 should be increased beyond the specific angle at which the upper sidewalls have a sharply pointed shape. In other words, θ2 ≥ Arctan(2t2 / W) should be satisfied.

[0029] Next, a preferred range of the upper thickness t2, which is the thickness of the tapered portion on the deposition substrate side, in the mask of this embodiment will be exemplified. As mentioned above, the tapered portion on the substrate side prevents the formation of a continuous film spanning both the substrate and the mask. However, there is a preferred range for the upper thickness t2. As shown in Figure 6(a), the deposited film accumulates on the substrate 15 above the boundary P1 where the taper inverts. If the desired thickness of the deposited film is greater than the upper thickness t2, the deposited film will reach the boundary P1 and form a continuous film spanning both the substrate 15 and the mask 1. Therefore, the upper thickness t2 should be set to be equal to or greater than the desired thickness of the deposited film. Since the thickness of the emissive layer of an organic EL device is typically approximately 0.01 μm, it is preferable that the upper thickness t2 exceed at least 10 nm. Furthermore, if a hole injection layer or hole transport layer is formed between the emissive layer and the anode, the upper thickness t2 may be increased by the thickness of these layers.

[0030] If the upper thickness t2 is sufficiently large, the deposition of the deposited film will not reach the boundary P1 during film formation. However, as mentioned above, increasing the upper thickness t2 will cause problems due to the structure of the mask 1. As shown in Figure 7, when the taper angle θ2 of the tapered portion on the substrate side is fixed at a certain angle, increasing the upper thickness t2 relative to the opening 3 will result in a sharp-pointed upper portion of the sidewall. Ultimately, if the upper thickness t2 exceeds a certain upper thickness, the inner sidewall of the opening 3 closest to the chip edge will be lower than the outer side, i.e., the sidewall of the rib. With this type of mask 1, when the substrate and the mask 1 are magnetically attracted to each other, the insufficient height distorts the shape of the opening 3, preventing the desired film shape from being deposited on the substrate.

[0031] To avoid this, the upper thickness t2 should be set to a specific upper thickness or less at which the upper part of the side wall becomes sharp, i.e., θ2 should be set so that t2≦(W / 2) tan θ2.

[0032] In this embodiment, we will describe the case where the side wall of the opening of the mask is not a straight line in the cross-sectional view, but a curve or a bent line. Figure 8(a) shows the case where the side wall of the opening 3 is curved in the thickness direction of the mask, and Figure 8(b) shows the case where it is a bent line.

[0033] 8(a), θ1 and θ2 can be defined using boundary P1 on the deposition source side of opening 3, boundary P3 where the taper direction is reversed, and boundary P2 on the deposition substrate side. That is, the effect of this embodiment can be obtained by defining the angle between the line connecting P1 and P3 and an extension of first surface 4 of mask 1 as θ1, and the angle between the line connecting P2 and P3 and an extension of second surface 5 of mask 1 as θ2.

[0034] 8(b), even if there are multiple bending points in the linear portion, the angles θ1 and θ2 can be defined using the boundary P1 on the deposition source side of the opening 3, the boundary P3 where the taper direction is reversed, and the boundary P2 on the deposition substrate side. That is, the effect of this embodiment can be obtained by defining the angle between the line connecting P1 and P3 and an extension of the first surface 4 of the mask 1 as θ1, and the angle between the line connecting P2 and P3 and an extension of the second surface 5 of the mask 1 as θ2.

[0035] Next, a method for manufacturing the mask of this embodiment will be described. The mask of this embodiment can be manufactured by the following steps. Process of forming a seed layer on a substrate forming a first resist pattern having a taper of θ2 on the substrate; forming a second resist pattern having a taper of θ1 on the first resist pattern; A step of electrolytically depositing a metal film in the gap between the first and second resist patterns. removing the first and second resist patterns to form openings in the metal film; Removing the substrate and the seed layer from the metal film in which the openings are formed.

[0036] The present invention will be specifically described below with reference to an embodiment.

[0037] Figure 9 shows the manufacturing process of the mask shown in Figure 1. Figure 9 is a schematic cross-sectional view of the mask in the thickness direction. First, as shown in Figure 9(a), a glass substrate 31 is prepared, and a chromium film 32 is deposited on this glass substrate 31 by sputtering. Note that this chromium film 32 is a seed layer to provide conductivity in the subsequent plating process, so it is not limited to chromium as long as it can provide conductivity.

[0038] Next, as shown in Figure (b), a first resist pattern 33a with a taper angle θ2 is formed. Specifically, first, a positive resist is applied by spin coating and pre-baked. Exposure and development are performed through a photomask, and after development, post-baking is performed to cure. At this time, the exposure and development conditions and the use of a grayscale mask as the photomask can be controlled to create a first resist pattern 33a with a predetermined taper angle θ2.

[0039] Next, as shown in Figure 9(c), a second resist pattern 33b having a taper angle θ1 is formed. Specifically, a negative resist is applied to the first resist pattern 33a by spin coating and pre-baking is performed. Note that if the thickness of the first resist pattern 33a is large, striations caused by the resist pattern may occur depending on the spin coating rotation conditions. In such cases, the negative resist may be applied by spray coating instead of spin coating. Exposure and development are performed through a photomask, and after development, post-baking is performed to cure. At this time, the exposure and development conditions can be controlled to create a second resist pattern 33b having a predetermined taper angle θ1. As a result, a resist pattern 33 is obtained in which the first resist pattern 33a and the second resist pattern 33b are connected in the film thickness direction.

[0040] Next, as shown in FIG. 9(d), electroplating is performed on the gaps in the resist pattern 33 using the underlying chromium film 12 as an electrode, and the gaps are filled with the deposited metal film 36. Iron-nickel alloys and nickel-cobalt alloys are preferred for plating because they have a low thermal expansion coefficient. A plating bath with a typical plating composition containing nickel sulfate, cobalt sulfate, and iron sulfate as its main components can be used. The thickness of the metal film 36 is preferably less than that of the resist pattern 33. If the thickness of the metal film 36 exceeds that of the resist pattern 33, the top surface of the resist pattern 33 will be covered with the metal film 36, making it difficult to remove the resist later. Furthermore, this electroforming method using resist and plating can avoid the dimensional limitations on opening diameter and thickness that arise from the unique taper angle determined by the crystal orientation when anisotropic wet etching of single-crystal silicon is used.

[0041] Next, as shown in Figure 9(e), the resist pattern 33 is removed with a resist stripping solution, and a metal film 36 is obtained where the resist pattern 33 was previously an opening 3. If any residue remains after removing the resist stripping solution, the resist residue may be removed by plasma treatment with oxygen or argon.

[0042] Finally, as shown in Figure 9(f), the metal film 36 is peeled off from the chromium film 32 and the glass substrate 31 to obtain the mask 1. Furthermore, if necessary, a mask frame (not shown) is bonded to the outer periphery of the mask 1 so that it can be set in a deposition apparatus. When bonding the mask frame, it is sufficient to appropriately fix it by welding or screwing while applying a general tension.

[0043] In this way, a mask 1 made of metal is obtained, which has openings 3 tapered in opposite directions on both the deposition source side (first surface 4) and the substrate side (second surface 5). This mask 1 is a high-definition metal deposition mask that is compatible with high pixel densities of, for example, 3000 ppi or more, in which the film thickness is thin where the openings 3 are present and the spacing between the openings is very narrow.

[0044] Next, a method for manufacturing an organic light-emitting device using the mask of this embodiment will be described. An organic light-emitting device is fabricated through multiple processes. First, a substrate is prepared on which a driving circuit consisting of transistors and capacitors for controlling the light emission of each pixel corresponding to red, green, and blue is formed. Next, a hole injection layer and a hole transport layer are formed on each pixel as needed. Next, light-emitting layers are formed for each color by vacuum deposition. Next, an electron transport layer, an electron injection layer, and a cathode are formed. Here, the hole injection layer, the hole transport layer, or the electron transport layer and the electron injection layer may be formed as a common layer so that it is the same thickness for all colors, taking productivity into consideration. Alternatively, to achieve an optical interference effect, the hole transport layer and the electron transport layer may be formed with different thicknesses for each color. Each element is explained using Figure 10.

[0045] FIG. 10 is a schematic cross-sectional view in the thickness direction of a substrate of an example of an organic light-emitting device having light-emitting layers of multiple colors. In the device shown in FIG. 10, an insulating layer 42, a first electrode 43 serving as a pixel electrode, a contact region 44 for applying current to the second electrode 49, a pixel separation layer 45, a first organic layer 46, a first light-emitting layer 47a, a second light-emitting layer 47b, a third light-emitting layer 47c, a second organic layer 47, and a second electrode 49 are formed on a substrate 41. Typically, the first, second, and third light-emitting layers 47a, 47b, and 47c emit red, green, and blue light, respectively. A protective layer 50, as well as color filters and microlenses (not shown) may be provided on the second electrode 49. If the light-emitting layers 47a to 47c, which emit light for each pixel corresponding to red, green, and blue, are individually painted using a high-resolution metal vapor deposition mask, color filters are not necessarily required. However, if color filters are used to improve color purity, a planarization layer may be provided between the protective layer and the first electrode 49. The planarization layer may be made of acrylic resin or the like. The same applies to the case where a planarizing layer is provided between the color filter and the microlens.

[0046] Each component will be described below. [substrate] Examples of materials for the substrate 41 include quartz, glass, a silicon wafer, resin, and metal. Furthermore, switching elements such as transistors and wiring may be provided on the substrate 41, with an insulating layer 42 provided thereon. Any material can be used for the insulating layer 42 as long as it allows contact holes to be formed so that wiring can be formed between the first electrode 43 and the insulating layer 42, and ensures insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used. A silicon substrate is preferable, particularly when high pixel density is desired.

[0047] [electrode] One of the first electrode 43 and the second electrode 49 may be an anode and the other a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with the higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0048] The anode material should have as high a work function as possible. Examples include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0049] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0050] When used as a reflective electrode, materials such as chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. These materials can also function as a reflective film without serving as an electrode. Furthermore, when used as a transparent electrode, oxide transparent conductive layers such as indium tin oxide (ITO) or indium zinc oxide can be used, but are not limited to these. Photolithography can be used to form the electrodes.

[0051] On the other hand, materials with a small work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and elemental metals or mixtures containing these, such as aluminum, titanium, manganese, silver, lead, and chromium. Alternatively, alloys combining these elemental metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used individually or in combination of two or more. The cathode may also be a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to reduce silver aggregation. The alloy ratio is not important as long as silver aggregation is reduced. For example, the ratio of silver to other metals may be 1:1, 3:1, etc.

[0052] The cathode may be a top-emission element using an oxide conductive layer such as ITO or silver with a thickness sufficient to be semi-permeable, or it may be a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but using DC and AC sputtering methods is more preferable because it provides good film coverage and makes it easier to reduce resistance.

[0053] [Pixel isolation layer] The pixel separation layer 45 is formed of a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, or a silicon oxide (SiO) film formed using a chemical vapor deposition (CVD) method. To increase the in-plane resistance of the organic compound layer, it is preferable that the organic compound layer, particularly the hole transport layer, be formed thin on the sidewalls of the pixel separation layer 45. Specifically, the thickness of the sidewalls can be made thin by increasing the taper angle of the sidewalls of the pixel separation layer 45 or the thickness of the pixel separation layer 45, thereby increasing vignetting during deposition.

[0054] On the other hand, it is preferable to adjust the sidewall taper angle of the pixel separation layer 45 and the film thickness of the pixel separation layer 45 to such an extent that voids are not formed in the protective layer 50 formed thereon. Since voids are not formed in the protective layer 50, it is possible to reduce the occurrence of defects in the protective layer 50. Since the occurrence of defects in the protective layer 50 is reduced, it is possible to reduce deterioration in reliability such as the occurrence of dark spots and poor conduction of the second electrode 49.

[0055] Even if the taper angle of the sidewall of the pixel separation layer 45 is not steep, charge leakage to adjacent pixels can be effectively suppressed as long as the taper angle is in the range of 60° to 90°. The thickness of the pixel separation layer 45 is desirably 10 nm to 150 nm. Similar effects can also be achieved by using only the first electrode 43 without the pixel separation layer 45. In this case, however, it is preferable that the thickness of the first electrode 43 be half or less than that of the organic compound layers (46, 47a, 47b, 47c, 48) or that the edge of the first electrode 43 be forward tapered at less than 60°, since this reduces short circuits in the organic light-emitting element.

[0056] [Organic compound layer] A laminate having a first organic layer 46, light-emitting layers 47a to 47c, and a second organic layer 48 sandwiched between a first electrode 43 and a second electrode 49 is called an organic compound layer. The first organic layer 46 and the second organic layer 48 have one or more of the following functions: a hole implantation layer, a hole transport layer, an electron blocking layer, a Hole element layer, an electron transport layer, or an electron implantation layer. Each layer of the organic compound layer is mainly composed of organic compounds, but may also contain inorganic atoms or inorganic compounds. For example, it may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. When multiple light-emitting layers are stacked, a charge generation layer may be placed between the upper and lower light-emitting layers. The charge generation layer may contain an organic compound with a lowest unoccupied orbital energy (LUMO) of -5.0 eV or less. Furthermore, the charge generation layer may be composed of a compound whose LUMO is lower than that of the hole transport layer, and the LUMO of the charge generation layer may be lower than the highest occupied orbital energy (HOMO) of the hole transport layer. Here, the orbital energy of the organic compound layer may be the orbital energy of the organic compound with the largest mass ratio in the organic compound layer.

[0057] Here, the closer the HOMO and LUMO are to the vacuum level, the higher they are described as being. The LUMO of the charge generation layer being lower than the HOMO of the hole transport layer means that the LUMO of the charge generation layer is closer to the vacuum level than the HOMO of the hole transport layer.

[0058] In this specification, the HOMO and LUMO can be calculated using molecular orbital calculations. The molecular orbital calculations may be performed using density functional theory (DFT) or the like, using B3LYP as the functional and 6-31G* as the basis function.Gaussian09(Gaussian09,RevisionC.01,MJFrisch,GWTrucks,HBSchlegel,GEScuseria,MARobb, JRCheeseman,G.Scalmani,V.Barone,B.Mennucci,GAPetersson,H.Nakatsuji,M.Caricato,X.Li,HPHratchian,AF Izmailov,J.Bloino,G.Zheng,JLSonnenberg,M.Hada,M.Ehara,K.Toyota,R.Fukuda,J.Hasegawa,M.Ishida,T.Nak ajima,Y.Honda,O.Kitao,H.Nakai,T.Vreven,JAMontgomery,Jr.,JEPeralta,F.Ogliaro,M.Bearpark,JJHeyd,E.B rothers,KNKudin,VNStaroverov,T.Keith,R.Kobayashi,J.Normand,K.Raghavachari,A.Rendell,JCBurant,SSIy engar,J.Tomasi,M.Cossi,N.Rega,JMMillam,M.Klene,JEKnox,JBCross,V.Bakken,J.Adamo,J.Jaramillo,R.Gomp erts,RESstratmann,O.Yazyev,AJAustin,R.Cammi,J.Pomelli,JWOchterski,RLMartin,K.Morokuma,VGZakrzewski,GAVoth,P.Salvador,JJDannenberg,S.Dapprich,ADDaniels,O.Farkas,JBForesman,JVOrtizski,J.Condizski DJFox,Gaussian,Inc.,Wallingford CT,2010.)

[0059] In this specification, HOMO and LUMO can be calculated using the ionization potential and band gap. The HOMO can be estimated by measuring the ionization potential. The ionization potential can be measured by dissolving the compound to be measured in a solvent such as toluene and measuring it with a measuring device such as AC-3. The band gap can be measured by dissolving the compound to be measured in a solvent such as toluene and irradiating it with excitation light. The band gap can be measured by measuring the absorption edge of the excitation light. Alternatively, the compound to be measured can be deposited on a substrate such as glass and the deposited film can be irradiated with excitation light to measure the band gap. The measurement can be performed by measuring the absorption edge of the absorption spectrum at which the deposited film absorbs the excitation light.

[0060] The LUMO can be calculated using the band gap and ionization potential: subtracting the ionization potential from the band gap gives the LUMO.

[0061] The LUMO can also be estimated from the reduction potential. For example, the one-electron reduction potential can be estimated using CV (cyclic volmetry) measurements. CV measurements are performed, for example, in a 0.1 M tetrabutylammonium perchlorate solution in DMF, with an Ag / Ag reference electrode. + The LUMO can be estimated by adding -4.8 eV, the difference between the reduction potential of the compound and that of ferrocene, to the reduction potential of the compound obtained.

[0062] The organic compound layer can be formed using dry processes such as vacuum deposition, ionization deposition, sputtering, or plasma deposition. Alternatively, a wet process can be used, in which the compound is dissolved in a suitable solvent and the layer is formed by a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0063] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining with an appropriate binder resin.

[0064] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0065] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0066] The deposition mask of this embodiment is preferably used in the deposition process of the light-emitting layers 47a to 47c in the organic compound layer. When the deposition material is a light-emitting layer, for example, it is a light-emitting material corresponding to red, green, and blue. If red is selected as the first color, then for example, the second color should be green, the third color blue, and so on, and so on, and the films can be deposited sequentially. Furthermore, each color of light-emitting material may consist of a single material, or it may be a multi-component material consisting of a so-called host and a light-emitting dopant. There are also two methods for deposition of the second and third colors.

[0067] One method involves preparing and using masks with different aperture positions for each color. In this case, the mask is simply replaced for the second and subsequent colors, and the same process as for the first color is repeated. Another method involves preparing only one mask for each color and shifting the mask's position for the second, third, and subsequent colors to paint each pixel. This method eliminates the need to replace masks and reduces the number of masks if the pixel size and pitch of each color are the same and repeatedly arranged. However, since a vapor-deposited film accumulates on the back of each mask for each color, the frequency of mask cleaning increases. Therefore, considering productivity, these two methods should be selected as appropriate.

[0068] Luminescent materials primarily involved in light emission include fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolate)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives.

[0069] [Protective layer] A protective layer 50 may be provided on the second electrode 49. For example, by bonding a glass with a desiccant onto the second electrode 49, the intrusion of water and other substances into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. Alternatively, a passivation film of silicon nitride or the like may be provided on the cathode to reduce the intrusion of water and other substances into the organic compound layer. For example, after forming the cathode, the material may be transported to another chamber without breaking the vacuum, and a silicon nitride film with a thickness of 2 μm may be formed by the CVD method to serve as the protective layer 50. A protective layer 50 may also be provided using atomic deposition (ALD) after the CVD film formation. The material of the film formed by the ALD method is not limited, but may be silicon nitride, silicon oxide, aluminum oxide, etc. A silicon nitride film may be further formed on the film formed by the ALD method using the CVD method. The film formed by the ALD method may have a thinner film thickness than the film formed by the CVD method. Specifically, it may be 50% or less, or even 10% or less.

[0070] [Color Filter] A color filter (not shown) may be provided on the protective layer 50. For example, a color filter that takes into account the size of the organic light-emitting element may be provided on a separate substrate and bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer as described above using photolithography technology. The color filter may be made of polymer.

[0071] [Planarization layer] A planarization layer (not shown) may be provided between the color filter (not shown) and the protective layer 50. The planarization layer is provided for the purpose of reducing unevenness of the underlying layer. It may also be called a material resin layer without limiting its purpose. The planarization layer may be made of an organic compound, and may be either a low molecular weight or a high molecular weight, but is preferably a high molecular weight.

[0072] The planarizing layer may be provided above or below the color filter, and may be made of the same or different materials, such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0073] [Microlens] The organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be used to increase the amount of light extracted from the organic light-emitting device and to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the hemisphere is the vertex of the microlens. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the semicircle is the vertex of the microlens.

[0074] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0075] A microlens has a first surface with a convex portion and a second surface opposite to the first surface. It is preferable that the second surface is positioned closer to the functional layer than the first surface. To adopt such a configuration, it is necessary to form the microlens on the light-emitting device. If the functional layer is an organic layer, it is preferable to avoid processes that involve high temperatures during the manufacturing process. Furthermore, when adopting a configuration in which the second surface is positioned closer to the functional layer than the first surface, it is preferable that the glass transition temperatures of all organic compounds constituting the organic layer are 100°C or higher, and more preferably 130°C or higher.

[0076] [Counter substrate] An opposing substrate may be provided on the planarization layer. The opposing substrate is called the opposing substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the opposing substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate 41 is the first substrate, the opposing substrate may be the second substrate.

[0077] [Pixel circuit] The organic light-emitting device may have a pixel circuit connected to an organic EL element. The pixel circuit may be an active-matrix type that independently controls the light emission of a first light-emitting element and a second light-emitting element. The active-matrix type circuit may be voltage-programmed or current-programmed. The driving circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the light emission brightness of the light-emitting element, a transistor that controls the light emission timing, a capacitor that holds the gate voltage of the transistor that controls the light emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0078] The light-emitting device has a display region and a peripheral region arranged around the display region. The display region has pixel circuits, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be lower than the mobility of a transistor constituting the display control circuit. The slope of the current-voltage characteristics of the transistors that make up the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors that make up the display control circuit. The slope of the current-voltage characteristics can be measured using the so-called Vg-Ig characteristics. The transistors that make up the pixel circuit are transistors connected to light-emitting elements such as the first light-emitting element.

[0079] [Pixels] An organic light emitting device includes a plurality of pixels, each of which includes sub-pixels that emit different colors, for example, RGB colors. The pixel emits light from an area called the pixel aperture. This area is the same as the first area. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. The distance between the subpixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, or 6.4 μm.

[0080] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0081] An example of an organic light-emitting device is given. A silicon substrate is used for the substrate 41. For the anode, i.e., the first electrode 43, a Ti / TiN / AlCu (65 nm thick) laminated structure is used, with a hole injection layer (8 nm thick) and a hole transport layer (37 nm thick) laminated as the first organic layer 46. After sequentially depositing each layer of the light-emitting layers 47a to 47c (10 nm thick) using the deposition mask of this embodiment by vacuum deposition, a hole blocking layer (34 nm), an electron transport layer (20 nm), and an electron injection layer (0.5 nm) are laminated as the second organic layer 48. Finally, a magnesium and silver laminated structure (total thickness 15 nm) is laminated as the cathode, i.e., the second electrode 49. Furthermore, the protective layer 50 may be used as a protective layer to prevent moisture permeability by transporting the cathode to another chamber without breaking the vacuum after formation and forming a silicon nitride film with a thickness of 2 μm by CVD. In this example, only the light-emitting layers 47a to 47c are deposited for each pixel using the mask of this embodiment, and the other functional layers may be deposited as common layers on all the first electrodes 43 using a general deposition mask.

[0082] [Applications of organic light-emitting devices] The organic light-emitting device manufactured using the deposition mask of this embodiment can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, a light-emitting device having a white light source and a color filter, etc.

[0083] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, linear CCD, memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

[0084] Furthermore, the display unit of the imaging device or inkjet printer may have a touch panel function. The driving method for this touch panel function may be infrared, capacitive, resistive, or electromagnetic induction, and is not particularly limited. The display device may also be used as the display unit of a multifunction printer.

[0085] Next, a display device using an organic light-emitting device will be described with reference to the drawings. 11 is a schematic diagram showing an example of a display device. The display device 1000 has a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0086] The display device of this example may have color filters having red, green, and blue colors, and the red, green, and blue colors may be arranged in a delta configuration in the color filters.

[0087] The display device of this example is used as a display unit of a mobile terminal. In this case, it may have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0088] The display device of this example is used in the display unit of an imaging device having an optical unit with multiple lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit located within the viewfinder. The imaging device may be a digital camera or a digital video camera.

[0089] 12(a) is a schematic diagram showing an example of an imaging device. The imaging device 1100 has a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 has a display device. In this case, the display device may display not only the captured image but also environmental information, imaging instructions, etc. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, etc.

[0090] Since the optimum timing for capturing an image is very short, it is better to display information as quickly as possible. Therefore, it is preferable to use a display device using an organic light-emitting device, because organic light-emitting devices have a fast response speed. A display device using an organic light-emitting device is more suitable than a liquid crystal display device, which requires a high display speed.

[0091] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may also be called a photoelectric conversion device. Instead of sequentially capturing images, the photoelectric conversion device can include an imaging method that detects the difference from the previous image, or a method of cutting out an image from a constantly recorded image, etc.

[0092] FIG. 12(b) is a schematic diagram showing an example of an electronic device. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform operations such as unlocking. An electronic device having a communication unit can also be called a communication device. The electronic device may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit. Examples of the electronic device include a smartphone and a laptop computer.

[0093] FIG. 13 is a schematic diagram showing an example of a display device. FIG. 13(a) shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 uses an organic light-emitting device. The display device 1300 has the frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in FIG. 13(a). The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0094] FIG. 13(b) is a schematic diagram showing another example of a display device. The display device 1310 in FIG. 13(b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 have organic light-emitting devices. The first display unit 1311 and the second display unit 1312 may be a single seamless display unit. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may display a single image.

[0095] FIG. 14 is a schematic diagram showing an example of a lighting device. The lighting device 1400 has a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404, and a light diffusion unit 1405. The light source 1402 has an organic light-emitting device. The optical filter 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse light from the light source 1402, such as for lighting up, and deliver the light over a wide area. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light output side of the lighting. If necessary, a cover may be provided on the outermost part.

[0096] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit to adjust the brightness. The lighting device has an organic light-emitting device and a power supply circuit connected to it. The power supply circuit is a circuit that converts AC voltage to DC voltage. White has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter. The lighting device may also have a heat dissipation unit that dissipates heat from within the device to the outside, and examples of the heat dissipation unit include metals with high specific heat, liquid silicone, and the like.

[0097] Fig. 15(a) is a schematic diagram of an automobile, which is an example of a moving body. As shown in Fig. 15(a), the automobile has tail lamps, which are an example of lighting fixtures. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed. Tail lamp 1501 has an organic light-emitting device. Tail lamp 1501 may have a protective member that protects the organic light-emitting device. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but it is preferable that the protective member be made of polycarbonate or the like. Polycarbonate may also be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0098] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display, as long as it is not a window for checking the front and rear of the automobile. The transparent display has an organic light-emitting device. In this case, constituent materials of the electrodes and the like of the organic light-emitting device are made of transparent materials.

[0099] 15(b), the automobile 1500 has a handle 1504 for controlling the direction of travel of the vehicle, a display unit 1505 for displaying a map, the position of the vehicle, turning directions, etc., and is mounted on the vehicle body 1503. The display unit 1505 has an organic light-emitting device. Here, an example of a moving body is an automobile, but the moving body may also be a ship, an airplane, a drone, etc. The moving body has a body and a lighting device and a display unit provided on the body. The lighting device emits light to indicate the position of the body. Either the lighting device or the display unit has an organic light-emitting device.

[0100] An application example of the above-mentioned display device will be described with reference to Fig. 16. The display device can be applied to a system that can be attached as a wearable device, such as smart glasses, HMD, or smart contact lenses. The image capturing and display device used in such an application example has an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0101] 16(a) is a schematic diagram of glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, a display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0102] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0103] Figure 16(b) illustrates a pair of glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 in Figure 16(a) and a display device. The lens 1611 has an optical system formed therein for projecting light emitted from the imaging device and the display device within the control device 1612, and an image is projected onto the lens 1611. The control device 1612 functions as a power supply to provide power to the imaging device and the display device, and also controls the operation of the imaging device and the display device. The control device 1612 may have a gaze detection unit that detects the wearer's gaze. Gaze detection may use infrared light. The infrared light emitter emits infrared light towards the eyeball of the user who is fixating on the displayed image. The imaging unit, which has a photodetector, detects the reflected light from the eyeball of the emitted infrared light, thereby obtaining an image of the eyeball. By having a reduction means that reduces the light from the infrared light emitter to the display unit in planar view, the deterioration of image quality is reduced.

[0104] The user's gaze towards a displayed image is detected from an image of the eyeball obtained by imaging with infrared light. Any known method can be applied to gaze detection using an image of the eyeball. As an example, a gaze detection method based on the Purkinje image obtained by the reflection of the irradiated light from the cornea can be used. More specifically, gaze detection processing based on the pupil-corneal reflection method is performed. Using the pupil-corneal reflection method, the user's gaze is detected by calculating a gaze vector representing the orientation (rotation angle) of the eyeball based on the pupil image and the Purkinje image contained in the image of the eyeball.

[0105] The display device of this example may have an imaging device with a light receiving element, and may control the display image of the display device based on user line-of-sight information from the imaging device. Specifically, the display device determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be received from an external control device. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0106] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0107] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from an image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in an external device, it is transmitted to the display device via communication. When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0108] FIG. 17(a) is a schematic diagram showing an example of an image forming apparatus. The image forming apparatus 1700 is an electrophotographic image forming apparatus and includes a photoconductor 1707, an exposure light source 1708, a charging unit 1710, a developing unit 1711, a transfer unit 1712, transport rollers 1713, and a fixing unit 1715. Light 1709 is irradiated from the exposure light source 1708, and an electrostatic latent image is formed on the surface of the photoconductor 1707. The exposure light source 1708 includes an organic light-emitting device. The developing unit 1711 includes toner and the like. The charging unit 1710 charges the photoconductor 1707. The transfer unit 1712 transfers the developed image to a recording medium 1714. The transport rollers 1713 transport the recording medium 1714. The recording medium 1714 is, for example, paper. The fixing unit 1715 fixes the image formed on the recording medium 1714.

[0109] 17(b) and 17(c) are diagrams showing an exposure light source 1708 and are schematic diagrams illustrating a state in which multiple light-emitting units 1726 are arranged on a long substrate. Arrow 1727 indicates the direction parallel to the axis of the photoconductor, representing the column direction in which the organic light-emitting devices are arranged. This column direction is the same as the axis direction about which the photoconductor 1707 rotates. This direction can also be referred to as the long axis direction of the photoconductor 1707. FIG. 17(b) shows a configuration in which the light-emitting units 1726 are arranged along the long axis direction of the photoconductor 1707. The light-emitting units 1726 include organic light-emitting devices. FIG. 17(c) shows a configuration different from FIG. 17(b), in which the light-emitting units 1726 are arranged alternately in the column direction in the first and second columns. The first and second columns are arranged at different positions in the row direction. In the first column, multiple light-emitting units 1726 are arranged at intervals. The second column has light-emitting units 1726 at positions corresponding to the spacing between the light-emitting units 1726 in the first column. That is, multiple light-emitting units 1726 are also arranged at intervals in the row direction. The arrangement in Figure 17(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0110] As described above, by using an organic light-emitting device, it is possible to provide a stable display with good image quality even over a long period of time.

[0111] [Included components] The disclosure of this embodiment includes the following configuration. (Configuration 1) A vapor deposition mask made of metal, having a first surface, a second surface located on the opposite side of the first surface, and an opening that penetrates from the first surface to the second surface, a sidewall surrounding the opening has a boundary between the first surface and the second surface, and is tapered from the boundary toward the first surface and the second surface, respectively; In a cross section passing through the first surface, the second surface, and the opening, when a taper angle formed by an extension line drawn from the first surface onto the opening and the side wall is θ1 and a taper angle formed by an extension line drawn from the second surface onto the opening and the side wall is θ2, A vapor deposition mask characterized in that both θ1 and θ2 are acute angles and are distinct from each other. (Configuration 2) The first surface is the surface located on the deposition source side, The second surface is the surface that is positioned opposite the substrate to be deposited on, The vapor deposition mask according to configuration 1, characterized in that θ1 > θ2. (Configuration 3) In the cross section, when the length of the side wall at the boundary in a first direction parallel to the second surface is W, and the length from the boundary to the second surface in a second direction perpendicular to the second surface is t2, θ² ≥ Arctan(2t² / W) A vapor deposition mask according to configuration 1 or 2, characterized in that it is the same as the one described above. (Configuration 4) In the cross section, when the length of the sidewall at the boundary in a first direction parallel to the second surface is W [μm] and the length from the boundary to the second surface in a second direction perpendicular to the second surface is t2, 0.01 [μm] <t2≦(W / 2)tanθ2 A vapor deposition mask according to any one of configurations 1 to 3, characterized in that it is such. (Configuration 5) 5. The deposition mask according to any one of structures 1 to 4, wherein the sidewall surrounding the opening has a length of 8.8 μm or less in a direction perpendicular to the second surface. (Configuration 6) 6. The deposition mask according to any one of structures 1 to 5, wherein the metal is an alloy selected from the group consisting of iron, nickel, and cobalt. (Configuration 7) 7. The deposition mask according to any one of Structures 1 to 6, wherein the deposition mask has a mask frame on the outer periphery of the second surface. (Configuration 8) A method for manufacturing a deposition mask according to any one of configurations 1 to 7, comprising: providing a seed layer on the substrate; forming a first resist pattern having a taper of θ2 on the substrate; forming a second resist pattern having a taper of θ1 on the first resist pattern; electrolytically depositing a metal film in the gap between the first and second resist patterns; removing the first and second resist patterns to form an opening in the metal film; removing the substrate and the seed layer from the metal film in which the opening is formed; 1. A method for manufacturing a deposition mask, comprising: [Explanation of symbols]

[0112] 1: deposition mask, 2: mask frame, 3: opening, 4: first surface, 5: second surface, 33, 33a, 33b: resist pattern

Claims

1. a deposition mask made of metal, the deposition mask having a first surface and a second surface located on the opposite side to the first surface, and an opening penetrating from the first surface to the second surface, a sidewall surrounding the opening has a boundary between the first surface and the second surface, and is tapered from the boundary toward the first surface and the second surface, respectively; In a cross section passing through the first surface, the second surface, and the opening, a taper angle formed between an extension line drawn from the first surface onto the opening and the side wall is defined as θ 1 The taper angle formed by the extension line drawn from the second surface onto the opening and the side wall is θ 2 When θ 1 and θ 2 are all acute angles and are different from each other.

2. the first surface is a surface disposed on a deposition source side, the second surface is a surface disposed opposite to a substrate to be deposited, θ 1 >θ 2 2. The deposition mask according to claim 1, wherein

3. In the cross section, the length of the side wall at the boundary in a first direction parallel to the second surface is defined as W, and the length from the boundary to the second surface in a second direction perpendicular to the second surface is defined as t 2 When θ 2 ≧Arctan(2t 2 / W) 2. The deposition mask according to claim 1, wherein

4. In the cross section, the length of the side wall at the boundary in a first direction parallel to the second surface is defined as W [μm], and the length from the boundary to the second surface in a second direction perpendicular to the second surface is defined as t 2 When 0.01[μm]<t 2 ≦(W / 2)tanθ 2 2. The deposition mask according to claim 1, wherein

5. 2. The deposition mask according to claim 1, wherein the sidewall surrounding the opening has a thickness of 8.8 [mu]m or less in a direction perpendicular to the second surface.

6. 2. The deposition mask according to claim 1, wherein the metal is an alloy selected from the group consisting of iron, nickel, and cobalt.

7. The deposition mask according to claim 1 , wherein the deposition mask has a mask frame on the outer periphery of the second surface.

8. A method for manufacturing the deposition mask according to any one of claims 1 to 7, comprising the steps of: providing a seed layer on the substrate; On the substrate, 2 forming a first resist pattern having a taper of The θ 1 forming a second resist pattern having a taper of a step of electrolytically depositing a metal film in the gap between the first and second resist patterns; removing the first and second resist patterns to form an opening in the metal film; removing the substrate and the seed layer from the metal film in which the opening is formed; 1. A method for manufacturing a deposition mask, comprising:

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