Display device and method for manufacturing the same

Abstract

A display device (2) comprises: a substrate (4) which has flexibility; protruding parts (22) which are on the substrate and which each have a reverse taper surface (22S) on at least part of a side surface thereof; and a sealing layer (8) which includes a self-repairing material. The display device has a recessed part space (24) which is formed by side surfaces of the protruding parts and a surface (16T) on which the protruding parts are formed. The sealing layer covers upper surfaces (22T) and side surfaces of the protruding parts, and covers a lower surface of the recessed part space. At least part of a side surface of the recessed part space is a reverse taper surface.

Description

[Technical field]

[0001] The present disclosure relates to a display device including a stacked light-emitting element, and a method for manufacturing the display device. [Background technology]

[0002] Patent Document 1 discloses a technique for bending a part of a flexible substrate provided in a display device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-187705 Summary of the Invention [Problem to be solved by the invention]

[0004] In a foldable display device such as the display device disclosed in Patent Document 1, bending the display device may cause defects such as cracks in the members on the flexible substrate. [Means for solving the problem]

[0005] In order to solve the above problems, a display device according to one embodiment of the present disclosure comprises a flexible substrate, a convex portion on the substrate having an inverse tapered surface on at least a portion of a side surface, and a sealing layer containing a self-repairing material, and has a recessed space formed by the side surface of the convex portion and a surface on which the convex portion is formed, the sealing layer covers an upper surface and a side surface of the convex portion and a lower surface of the recessed space, and at least a portion of the side surface of the recessed space is the inverse tapered surface.

[0006] In addition, in order to solve the above problems, a manufacturing method for a display device according to one embodiment of the present disclosure includes a convex portion forming process in which a convex portion, at least a portion of whose side surface is an inverted tapered surface, is formed on a flexible substrate, and the convex portion is formed by the side surface of the convex portion and a surface on which the convex portion is formed, forming a concave space, at least a portion of whose side surface is the inverted tapered surface; and forming a sealing layer that covers the upper surface and side surface of the convex portion and the lower surface of the concave space, and contains a self-repairing material. Effect of the Invention

[0007] This makes it possible to make defects such as cracks less likely to occur in the components on the flexible substrate, and even if such a defect does occur, it is possible to provide the display device with a function for repairing the defect. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a display device according to a first embodiment. [Diagram 2] 1 is a schematic plan view of a display device according to a first embodiment. [Diagram 3] 1 is an enlarged plan view of a display device according to a first embodiment. [Figure 4] 1 is a partially enlarged cross-sectional view of a display device according to a first embodiment. [Diagram 5] 3A to 3C are cross-sectional process views illustrating the repair mechanism of an organic sealing layer by the self-repairing material according to the first embodiment. [Figure 6] 4 is a flowchart showing a method for manufacturing the display device according to the first embodiment. [Figure 7] 3A to 3C are cross-sectional views illustrating steps in a manufacturing process for the display device according to the first embodiment. [Figure 8] 5A to 5C are cross-sectional views illustrating other steps in the manufacturing process of the display device according to the first embodiment. [Figure 9] 5A to 5C are cross-sectional views illustrating other steps in the manufacturing process of the display device according to the first embodiment. [Figure 10] FIG. 11 is a schematic cross-sectional view of a display device according to a second embodiment. [Figure 11]10 is a partially enlarged cross-sectional view of a display device according to a second embodiment. FIG. [Figure 12] 10 is a flowchart showing a method for manufacturing a display device according to the second embodiment. [Figure 13] 10A to 10C are cross-sectional views illustrating steps in a manufacturing process for a display device according to the second embodiment. [Figure 14] 10A to 10C are cross-sectional views illustrating other steps in the manufacturing process of the display device according to the second embodiment. [Figure 15] FIG. 11 is a schematic cross-sectional view of a display device according to a third embodiment. [Figure 16] 11 is a partially enlarged cross-sectional view of a display device according to a third embodiment. FIG. [Figure 17] 10 is a flowchart showing a method for manufacturing a display device according to a third embodiment. [Figure 18] 10A to 10C are cross-sectional views illustrating steps in a manufacturing process for a display device according to embodiment 3. [Figure 19] FIG. 11 is a schematic cross-sectional view of a display device according to a fourth embodiment. [Figure 20] 10 is a flowchart showing a method for manufacturing a display device according to a fourth embodiment. [Figure 21] 10A to 10C are cross-sectional views illustrating steps in a manufacturing process for a display device according to embodiment 4. [Figure 22] 10A to 10C are cross-sectional views illustrating other steps in the manufacturing process of the display device according to embodiment 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Embodiment 1] <Display device overview> Fig. 2 is a schematic plan view of a display device 2 according to this embodiment. As shown in Fig. 2, the display device 2 according to this embodiment includes a display area DA in which display is performed by extracting light emitted from each sub-pixel, which will be described later, and a frame area NA surrounding the periphery of the display area DA. In the frame area NA, terminals T to which signals for driving each light-emitting element of the display device 2 are input are formed.

[0010] Fig. 3 is an enlarged view of region A, which is a part of the display region DA in the schematic plan view shown in Fig. 2. Fig. 1 is a schematic cross-sectional view of a display device 2 according to this embodiment, and in particular, a cross-sectional view taken along line BC in Fig. 3. Note that in Fig. 3, in order to more clearly illustrate the pixels and sub-pixels described in detail later, a sealing layer 8 and a cathode 14, which will be described in detail later, are omitted. Also, in Fig. 3, in order to more clearly illustrate the relationship between the protrusions 22 and the metal layer 26, which will be described in detail later, the metal layer 26 formed on the upper surface 22T of the protrusions 22 is omitted.

[0011] A display device 2 according to this embodiment includes a plurality of pixels at a position overlapping with a display region DA in a plan view. Each pixel includes a plurality of sub-pixels. The schematic cross-sectional view of the display device 2 shown in Fig. 1 shows a pixel P among the plurality of pixels included in the display device 2. In particular, the pixel P includes a red sub-pixel SPR, a green sub-pixel SPG, and a blue sub-pixel SPB.

[0012] The display device 2 according to this embodiment is a flexible display device having a plurality of light-emitting elements on a flexible substrate. For example, as shown in Fig. 1, the display device 2 according to this embodiment includes a flexible substrate 4, a light-emitting element layer 6 on the substrate 4, and a sealing layer 8 covering the light-emitting element layer 6.

[0013] For example, the substrate 4 has a structure in which a TFT (Thin Film Transistor) (not shown) is formed on a flexible film substrate including a PET film or the like. Furthermore, a flexible light emitting element layer 6 and a sealing layer 8 are formed on the substrate 4. Therefore, the display device 2 according to this embodiment realizes a flexible display device that can be folded with at least one of the substrate 4 and the sealing layer 8 facing inward.

[0014] In this specification, the direction from the light-emitting layer 12 of the light-emitting element layer 6 to the anode 10, which will be described later in detail, is described as the "downward direction", and the direction from the light-emitting layer 12 to the cathode 14 is described as the "upward direction".

[0015] <Light emitting element> The light emitting element layer 6 includes, in this order from the substrate 4 side, an anode 10, a light emitting layer 12 as a functional layer, and a cathode 14. In other words, the light emitting element layer 6 includes the light emitting layer 12 between two electrodes, the anode 10 and the cathode 14. The anodes 10 of the light emitting element layer 6 formed on the upper layer of the substrate 4 are formed in an island shape for each of the sub-pixels described above, and are electrically connected to the respective TFTs of the substrate 4.

[0016] In this embodiment, the light-emitting element layer 6 includes a plurality of light-emitting elements, and in particular, each of the sub-pixels includes one light-emitting element. In this embodiment, for example, the light-emitting element layer 6 includes, as light-emitting elements, a red light-emitting element 6R in the red sub-pixel SPR, a green light-emitting element 6G in the green sub-pixel SPG, and a blue light-emitting element 6B in the blue sub-pixel SPB. Hereinafter, in this specification, unless otherwise specified, the term "light-emitting element" refers to any one of the red light-emitting element 6R, the green light-emitting element 6G, and the blue light-emitting element 6B included in the light-emitting element layer 6.

[0017] Here, the anode 10 and the light-emitting layer 12 are formed individually for each sub-pixel. Particularly in this embodiment, the anode 10 includes an anode 10R for the red light-emitting element 6R, an anode 10G for the green light-emitting element 6G, and an anode 10B for the blue light-emitting element 6B. The light-emitting layer 12 includes a red light-emitting layer 12R that emits red light, a green light-emitting layer 12G that emits green light, and a blue light-emitting layer 12B that emits blue light. On the other hand, the cathode 14 is formed in common to the plurality of sub-pixels.

[0018] Therefore, in this embodiment, the red light emitting element 6R is composed of an anode 10R, a red light emitting layer 12R, and a cathode 14. The green light emitting element 6G is composed of an anode 10G, a green light emitting layer 12G, and a cathode 14. The blue light emitting element 6B is composed of an anode 10B, a blue light emitting layer 12B, and a cathode 14.

[0019] Here, blue light is, for example, light having a central emission wavelength in a wavelength band of 400 nm or more and 500 nm or less. Green light is, for example, light having a central emission wavelength in a wavelength band of more than 500 nm and less than 600 nm. Red light is, for example, light having a central emission wavelength in a wavelength band of more than 600 nm and less than 780 nm.

[0020] The light-emitting element layer 6 according to the present embodiment is not limited to the above configuration, and may further include an additional layer in the functional layer between the anode 10 and the cathode 14. For example, the light-emitting element layer 6 may further include at least one of a hole injection layer or a hole transport layer as a functional layer between the anode 10 and the light-emitting layer 12, in addition to the light-emitting layer 12. The light-emitting element layer 6 may further include at least one of an electron transport layer or an electron injection layer between the light-emitting layer 12 and the cathode 14.

[0021] The anode 10 and the cathode 14 contain a conductive material and are electrically connected to the light-emitting layer 12. Of the anode 10 and the cathode 14, the electrode closer to the display surface of the display device 2 is a semi-transparent electrode.

[0022] The anode 10 has a structure in which ITO (Indium Tin Oxide) is laminated on, for example, an Ag-Pd-Cu alloy. The anode 10 having the above structure is, for example, a reflective electrode that reflects light emitted from the light-emitting layer 12. Therefore, of the light emitted from the light-emitting layer 12, the light traveling in a downward direction is reflected by the anode 10.

[0023] In contrast, the cathode 14 is made of, for example, a semi-transparent Mg-Ag alloy. In other words, the cathode 14 is a transmissive electrode that transmits the light emitted from the light-emitting layer 12. Therefore, of the light emitted from the light-emitting layer 12, the light traveling in an upward direction transmits through the cathode 14. In this way, the display device 2 can emit the light emitted from the light-emitting layer 12 in an upward direction.

[0024] As described above, in the display device 2, both the light emitted upward from the light-emitting layer 12 and the light emitted downward can be directed toward the cathode 14 (upward). That is, the display device 2 is configured as a top-emission type display device.

[0025] In this embodiment, the cathode 14, which is a semitransparent electrode, reflects a part of the light emitted from the light-emitting layer 12. In this case, a cavity for the light emitted from the light-emitting layer 12 may be formed between the anode 10, which is a reflective electrode, and the cathode 14, which is a semitransparent electrode. By forming a cavity between the anode 10 and the cathode 14, the chromaticity of the light emitted from the light-emitting layer 12 can be improved.

[0026] The above-mentioned configuration of the anode 10 and the cathode 14 is an example, and the display device 2 may have a different configuration. For example, the electrode close to the display surface of the display device 2 may be the anode 10. In this case, the anode 10 may be a semi-transparent electrode, and the cathode 14 may be a reflective electrode. This allows the display device 2 to direct both the light emitted upward from the light-emitting layer 12 and the light emitted downward toward the anode 10 (downward). In other words, the display device 2 may be configured as a bottom-emission type display device.

[0027] The light-emitting layer 12 is a layer that emits light by recombination of holes transported from the anode 10 and electrons transported from the cathode 14. The light-emitting layer 12 may contain, for example, an organic light-emitting material or an inorganic light-emitting material. When the light-emitting layer 12 contains an organic light-emitting material, each light-emitting element may be an OLED (Organic Light-Emitting Diode) element. Furthermore, when the light-emitting layer 12 contains, for example, an inorganic light-emitting material, the light-emitting layer 12 may include a quantum dot material as a light-emitting body. In this case, each light-emitting element may be a QLED (Quantum dot Light-Emitting Diode) element.

[0028] The display device 2 according to the present embodiment includes a light-emitting element having an anode 10 on the substrate 4 side, but is not limited to this. For example, the light-emitting element layer 6 included in the display device 2 according to the present embodiment may include a cathode 14, a light-emitting layer 12, and an anode 10, which are stacked in this order from the substrate 4 side. In this case, the cathode 14 is a pixel electrode formed in an island shape for each sub-pixel, and the anode 10 is a common electrode formed in common to the multiple sub-pixels.

[0029] The display device 2 according to this embodiment further includes a bank 16 on the upper surface 4T of the substrate 4. The bank 16 includes, for example, a coatable resin material including polyimide, and is formed at a position straddling the boundary between adjacent sub-pixels in a plan view. Therefore, the light-emitting element layer 6 is partitioned by the bank 16 into red light-emitting elements 6R, green light-emitting elements 6G, and blue light-emitting elements 6B. In particular, the anode 10 is separated by the bank 16 into the anode 10R, anode 10G, and anode 10B. The bank 16 may be formed at a position covering each peripheral end of the anode 10, as shown in FIG. 1.

[0030] Moreover, the banks 16 contain a coatable photosensitive resin. Particularly, in this embodiment, the banks 16 contain a positive-type photosensitive resin. The banks 16 each have a side surface 16S. Here, the banks 16 are formed so that the area in a plan view gradually decreases from the substrate 4 side toward the sealing layer 8 side. For this reason, among the normal directions of the side surfaces 16S, the direction toward the inside of the bank 16 is the direction from the sealing layer 8 toward the substrate 4, rather than the planar direction of the upper surface 4T of the substrate 4 on which the bank 16 is formed.

[0031] When a specific member has a side surface and the specific member is formed on a specific surface, the angle between the outer surface of the side surface and the specific surface is assumed to be an obtuse angle. In this case, in this specification, the side surface is assumed to be a forward tapered surface. For example, in a square pyramid in which the area of ​​the lower base is larger than the area of ​​the upper base, all of the side surfaces of the square pyramid are forward tapered surfaces.

[0032] In this embodiment, the bank 16 is formed on the top surface 4T of the substrate 4. The angle between the outer surface of the side surface 16S of the bank 16 and the top surface 4T is an obtuse angle. Therefore, the side surface 16S of the bank 16 is a forward tapered surface. Therefore, in this embodiment, each light-emitting element is partitioned by the bank 16 having a forward tapered surface on its side surface, and each light-emitting element is formed between the side walls of the forward tapered surface.

[0033] <Sealing layer> The sealing layer 8 covers the light-emitting element layer 6 and the banks 16, and seals each light-emitting element included in the display device 2. The sealing layer 8 includes, in order from the light-emitting element layer 6 side, an inorganic sealing film 18 and an organic sealing film 20. The sealing layer 8 reduces the penetration of foreign matter containing moisture and the like from outside the sealing layer 8 side of the display device 2 into the light-emitting element layer 6 and the like.

[0034] The inorganic sealing film 18 is formed by, for example, CVD, and is composed of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminated film of these. The organic sealing film 20 is composed of, for example, a coatable resin material including polyimide or the like. Furthermore, the organic sealing film 20 according to this embodiment includes a self-repairing material, which will be described in detail later. The inorganic sealing film 18 has a thickness of, for example, 1 μm or more and 3 μm or less. The organic sealing film 20 has a thickness of, for example, 1 μm or more and 20 μm or less.

[0035] The sealing layer 8 according to the present embodiment is not limited to the above-mentioned structure, and may further include, for example, a second inorganic sealing film on the organic sealing film 20. In this case, the organic sealing film 20 also functions as a buffer layer that improves the film formability of the second inorganic sealing film.

[0036] <Convex part> The display device 2 according to this embodiment further includes a convex portion 22 between the bank 16 and the sealing layer 8. In particular, the convex portion 22 according to this embodiment is formed outside the pixel P in a plan view. Therefore, the convex portion 22 is formed on the upper surface 16T of the bank 16 located outside the pixel P.

[0037] The protrusions 22 include, for example, a material that absorbs or reflects at least a part of visible light. For example, the protrusions 22 may include a black resin material containing carbon particles. The protrusions 22 also include a coatable photosensitive resin. In particular, in this embodiment, the protrusions 22 include a negative type photosensitive resin. The thickness of the protrusions 22 from the top surface 16T of the bank 16 is, for example, 1 μm or more and 5 μm or less.

[0038] Each of the protrusions 22 has a side surface 22S. Here, the protrusions 22 are formed so that the area in a plan view gradually increases from the substrate 4 side toward the sealing layer 8 side. For this reason, among the normal directions of the side surfaces 22S, the direction toward the outside of the protrusions 22 is the direction from the sealing layer 8 toward the substrate 4, rather than the planar direction of the top surface 16T of the bank 16 on which the protrusions 22 are formed.

[0039] When a specific member has a side surface and the specific member is formed on a specific surface, the angle between the outer surface of the side surface and the specific surface is assumed to be an acute angle. In this case, in this specification, the side surface is assumed to be an inverse tapered surface. For example, in a square pyramid whose lower base area is smaller than the upper base area, all the side surfaces of the square pyramid are inverse tapered surfaces.

[0040] In this embodiment, the protrusion 22 is formed on the top surface 16T of the bank 16. The angle between the outer surface of the side surface 22S of the protrusion 22 and the top surface 16T is an acute angle. Therefore, the side surface 22S of the protrusion 22 is a reverse tapered surface.

[0041] <Recessed space> In this embodiment, a plurality of protrusions 22 are formed. Therefore, a recess space 24 is formed between the protrusions 22 by the upper surface 16T of the bank 16 on which the protrusions 22 are formed and the side surface 22S of the protrusions 22. A more detailed structure of the recess space 24 will be described with reference to Fig. 4. Fig. 4 is a schematic enlarged view of the recess space 24 and the surrounding area of ​​the recess space 24, and is a schematic enlarged view of region D in Fig. 1.

[0042] Since the side surface 22S of the recessed space 24 is an inversely tapered surface, the recessed space 24 gradually becomes wider from the sealing layer 8 side toward the substrate 4 side in a plan view of the substrate 4. For example, as shown in FIG. 4, the recessed space 24 has a structure in which the width gradually becomes wider from the sealing layer 8 side toward the substrate 4 side in its cross section. Furthermore, the display device 2 has a metal layer 26 on the upper surface 16T of the bank 16 located inside the recessed space 24 and on the upper surface 22T of the protrusion 22. In this embodiment, the metal layer 26 contains a single layer or multiple metals, or an alloy of multiple metals, and reflects at least a portion of visible light.

[0043] For example, the metal layer 26 contains the same material as the cathode 14. In this case, when forming the cathode 14, a metal layer containing the material of the cathode 14 is formed over the entire surface of the display area DA of the display device 2, so that the metal layer 26 can be formed simultaneously with the process of forming the cathode 14. In this case, the metal layer 26 located inside the recess space 24 is formed, for example, by cutting the metal layer containing the material of the cathode 14 at an end of the upper surface 22T of the protrusion 22.

[0044] The side surface 22S of the protrusion 22 and the upper surface 16T of the bank 16, which are the side surface and lower surface of the recessed space 24, are covered with the sealing layer 8. In particular, the side surface and lower surface of the recessed space 24 are in contact with the inorganic sealing film 18, and inside the recessed space 24, the inorganic sealing film 18 is in contact with the organic sealing film 20. Therefore, inside the recessed space 24, the outer shapes of the inorganic sealing film 18 and the organic sealing film 20 have a recess shape that follows the internal shape of the recessed space 24.

[0045] For example, the inorganic sealing film 18 in contact with the side and bottom surface of the recessed space 24 can be formed by causing the material of the inorganic sealing film 18 to flow around onto the side surface 22S, which is the side surface of the recessed space 24, when the inorganic sealing film 18 is formed by a CVD method or the like. The organic sealing film 20 in contact with the inorganic sealing film 18 in the recessed space 24 can be formed by depositing the material of the organic sealing film 20 by coating.

[0046] <Reduced breakage of the sealing layer due to the recessed space> As described above, the recess space 24 has a structure that gradually widens from the sealing layer 8 side toward the substrate 4 side. For this reason, when the display device 2 is bent inward at the substrate 4, the protrusions 22 move in a direction in which the sealing layer 8 sides of the protrusions 22 move away from each other, and the recess space 24 widens. Also, when the display device 2 is bent inward at the sealing layer 8, the protrusions 22 move in a direction in which the sealing layer 8 sides of the protrusions 22 move closer to each other, and the recess space 24 becomes smaller.

[0047] Therefore, when the display device 2 is folded, the stress generated in each layer of the display device 2, including the light emitting element layer 6 and the sealing layer 8, is dispersed into the above-mentioned force for realizing the movement of the protrusion 22 around the recessed space 24. Therefore, the display device 2 reduces the stress generated in each layer on the substrate 4, including the light emitting element layer 6 and the sealing layer 8, by the recessed space 24, and reduces the occurrence of defects such as breakage of the layers.

[0048] Furthermore, due to the above-described movement of the protrusions 22, when the display device 2 is folded, the stress generated in the sealing layer 8 is concentrated inside the recessed space 24. Therefore, even if the sealing layer 8 is broken when the display device 2 is folded, the break is concentrated inside the recessed space 24. Therefore, since defects including breaks in the sealing layer 8 are concentrated inside the recessed space 24 located outside each pixel, the defects are less likely to affect the display by the display device 2.

[0049] In this embodiment, the convex portion 22 is formed outside the pixel P in plan view. In other words, each light emitting element according to this embodiment is formed between the banks 16 having forward tapered surfaces on their side surfaces.

[0050] Here, it is assumed that the display device 2 according to this embodiment is a top-emission type display device 2 that extracts light from each light-emitting element toward the sealing layer 8 side rather than the substrate 4 side. In this case, the space between the banks 16 in which the light-emitting elements are formed has a larger area in a plan view on the sealing layer 8 side that extracts light, compared to the substrate 4 side. Therefore, when the display device 2 according to this embodiment is a top-emission type, the bank 16 reduces blocking of light from each light-emitting layer 12, and prevents a decrease in the efficiency of extracting light from each light-emitting element.

[0051] In this embodiment, the angle formed between the side surface 22S of the protrusion 22, which is the side surface of the recessed space 24, and the upper surface 16T of the bank 16, which is the lower surface of the recessed space 24, may be the same in at least one recessed space 24. Specifically, as shown in Fig. 4, a first angle θ1 formed between the side surface 22S of the protrusion 22 located on the left side as you look at Fig. 4 and the upper surface 16T of the bank 16 may be the same as a second angle θ2 formed between the side surface 22S of the protrusion 22 located on the right side as you look at Fig. 4 and the upper surface 16T of the bank 16.

[0052] In this specification, "the two angles are the same" does not mean that the angles are strictly the same, but may be slightly different from each other. For example, the angles that the side surfaces 22S of two different protrusions 22 manufactured from the same material under the same manufacturing conditions form with the upper surface 16T of the bank 16 may be considered to be the same if the difference is within the range of an error that occurs in the manufacturing process of the protrusions 22.

[0053] <Self-healing material> Next, the self-repairing material contained in the organic sealing film 20 according to this embodiment will be described in more detail with reference to Fig. 5. Fig. 5 is a process cross-sectional view for explaining the mechanism by which the broken organic sealing film 20 is repaired by the self-repairing material contained in the organic sealing film 20. In Fig. 5, it is assumed that the organic sealing film 20 is broken into a first organic sealing film 20A and a second organic sealing film 20B, for example, inside the recess space 24.

[0054] 5, the first organic sealing film 20A and the second organic sealing film 20B include a photosensitive polymer as a self-repairing material. The photosensitive polymer includes a plurality of bonding portions 20F formed by, for example, two photosensitive bonding groups bonding to each other, and a bonding chain 20C connecting the bonding portions 20F to each other.

[0055] The two photosensitive bonding groups contained in the bonding portion 20F are radicalized by irradiation with visible light, and break their bonds with each other. Meanwhile, the photosensitive bonding groups contained in the bonding portion 20F rebond with each other when they come into close proximity with other photosensitive bonding groups. The rebonding of the two photosensitive bonding groups also occurs between photosensitive bonding groups different from the two photosensitive bonding groups contained in the original bonding portion 20F.

[0056] For example, the first organic sealing film 20A includes a first photosensitive bonding group 20FA and a second photosensitive bonding group 20FB exposed from a first fracture surface 20AS formed by breaking the first organic sealing film 20A from the second organic sealing film 20B. The first photosensitive bonding group 20FA and the second photosensitive bonding group 20FB are bonded to each other to form a bonding portion 20F exposed from the first fracture surface 20AS. The second organic sealing film 20B includes a third photosensitive bonding group 20FC and a fourth photosensitive bonding group 20FD exposed from a second fracture surface 20BS formed by breaking the first organic sealing film 20A from the second organic sealing film 20B. The third photosensitive bonding group 20FC and the fourth photosensitive bonding group 20FD are bonded to each other to form a bonding portion 20F exposed from the second fracture surface 20BS.

[0057] In the process of repairing the break between the first organic sealing film 20A and the second organic sealing film 20B, visible light VL is irradiated to the bonded portion 20F exposed from the first fractured surface 20AS and the bonded portion 20F exposed from the second fractured surface 20BS, as shown in reaction process R2 in Fig. 5. In practice, the visible light VL may be external light from outside the display device 2.

[0058] The photosensitive bonding groups contained in the bonding portion 20F irradiated with the visible light VL break their bonds by a radical reaction. Therefore, as shown in the reaction process R4 in Fig. 5, the bonding portion 20F exposed from the first fracture surface 20AS is broken into the first photosensitive bonding group 20FA and the second photosensitive bonding group 20FB. In addition, the bonding portion 20F exposed from the second fracture surface 20BS is broken into the third photosensitive bonding group 20FC and the fourth photosensitive bonding group 20FD.

[0059] As a result, the first photosensitive bonding group 20FA and the second photosensitive bonding group 20FB become the cut ends of the bonding portion 20F exposed from the first fracture surface 20AS. Also, the third photosensitive bonding group 20FC and the fourth photosensitive bonding group 20FD become the cut ends of the bonding portion 20F exposed from the second fracture surface 20BS.

[0060] Next, for example, the display device 2 returns from a state in which the substrate 4 side is bent inward to the original substantially flat state, so that the first fracture surface 20AS and the second fracture surface 20BS come into contact with each other and a joint 20J is formed. In this case, for example, as shown in reaction process R6 in Fig. 5, the first photosensitive binding group 20FA and the fourth photosensitive binding group 20FD may come close to each other and recombine with each other. Also, for example, as shown in reaction process R6 in Fig. 5, the second photosensitive binding group 20FB and the third photosensitive binding group 20FC may come close to each other and recombine with each other.

[0061] In this case, as shown in reaction process R6 in Fig. 5, at least one of the bonding chains 20C connecting to the bonding portion 20F formed by the bonding between the first photosensitive bonding group 20FA and the fourth photosensitive bonding group 20FD crosses the bonding portion 20J. Also, as shown in reaction process R6 in Fig. 5, at least one of the bonding chains 20C connecting to the bonding portion 20F formed by the bonding between the second photosensitive bonding group 20FB and the third photosensitive bonding group 20FC crosses the bonding portion 20J.

[0062] As described above, the first organic sealing film 20A and the second organic sealing film 20B are bonded to each other by the bonding chain 20C that crosses the bonding portion 20J. Therefore, the self-repairing material contained in the organic sealing film 20 self-repairs breakage between the first organic sealing film 20A and the second organic sealing film 20B.

[0063] When the angle between the side surface 22S of the protrusion 22 and the top surface 16T of the bank 16 is the same in a certain recessed space 24, the stress generated in the organic sealing film 20 inside the recessed space 24 is concentrated in the central portion of the recessed space 24. Therefore, breaks generated in the organic sealing film 20 inside the recessed space 24 are also concentrated in the central portion of the recessed space 24, so that the above configuration makes it possible to more efficiently repair breaks in the organic sealing film 20.

[0064] The self-repairing material for realizing the above-mentioned repair mechanism of the organic sealing film 20 may be, for example, polyurethane having a thiuram group as a photosensitive bonding group, as shown in the following chemical formula.

[0065] [ka] Alternatively, the self-repairing material for realizing the repair mechanism of the organic sealing film 20 may be, for example, polystyrene having a diselenide group as a photosensitive bonding group, as shown in the following chemical formula.

[0066] [ka] The above-mentioned repair mechanism of the organic sealing film 20 is realized by irradiating the fracture surfaces of the first organic sealing film 20A and the second organic sealing film 20B with visible light and bringing the fracture surfaces into contact with each other. Therefore, for example, the self-repair of the organic sealing film 20 by the self-repairing material occurs naturally in the process of bending the display device 2 and restoring it to its original state.

[0067] In addition, the repair process by the self-repairing material described above is reversible. Therefore, even if defects such as cracks occur multiple times in the organic sealing film 20, the self-repair by the self-repairing material contained in the organic sealing film occurs each time. Therefore, the self-repairing material described above can more efficiently repair defects in the organic sealing film 20.

[0068] In this embodiment, as described above, breakage of the organic sealing film 20 is more likely to occur inside the recessed space 24. Here, the recessed space 24 is provided with a metal layer 26 that reflects at least a part of visible light on its lower surface. Therefore, when breakage of the organic sealing film 20 occurs inside the recessed space 24, the probability that visible light reflected by the metal layer 26 will be irradiated onto the fracture surface formed by the breakage increases. Therefore, the metal layer 26 according to this embodiment allows breakage of the organic sealing film 20 that occurs inside the recessed space 24 to be repaired more efficiently.

[0069] The side surface 22S of the protrusion 22, which is the side surface of the recess space 24, may reflect or scatter at least a part of the visible light. In this case, the visible light reflected or scattered at the side surface 22S of the protrusion 22 is more likely to be irradiated onto the organic sealing film 20 inside the recess space 24. The protrusion 22 according to this embodiment allows a break in the organic sealing film 20 that occurs inside the recess space 24 to be repaired more efficiently.

[0070] <Outline of display device manufacturing method> Next, a method for manufacturing the display device 2 according to this embodiment will be described with reference to Fig. 6 to Fig. 9. Fig. 6 is a flowchart showing the method for manufacturing the display device 2 according to this embodiment. Figs. 7 to 9 are cross-sectional views of the display device 2 for explaining each step shown in the flowchart of Fig. 6. Each of Figs. 7 to 9 shows a cross section corresponding to the cross section of the display device 2 shown in Fig. 1.

[0071] In the method for manufacturing the display device 2 according to this embodiment, first, the substrate 4 is formed (step S2). The substrate 4 is formed, for example, by forming a TFT for each subpixel on a flexible film substrate. It is not necessary to complete the formation of the substrate 4 in step S2. For example, the substrate 4 may be formed by first forming a TFT on a rigid glass substrate, and then forming the light emitting element layer 6 and the sealing layer 8 on the glass substrate according to a formation method described later, followed by peeling off the glass substrate and attaching a film substrate.

[0072] Next, the anode 10 is formed (step S4). The anode 10 may be formed, for example, by forming a film of a conductive material commonly to the sub-pixels by sputtering or the like as described above, and then patterning the thin film of the conductive material for each sub-pixel. In step S4 according to this embodiment, the anode 10R, the anode 10G, and the anode 10B are formed at positions corresponding to the red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB, respectively.

[0073] <Bank formation> Next, a process for forming the bank 16 is performed. In the process for forming the bank 16, first, a bank material 28 containing a positive photosensitive resin is applied onto the upper surfaces of the substrate 4 and the anode 10 (step S6). The bank material 28 may be applied by a coating method such as coating with a coater or coating by spin coating.

[0074] Next, an exposure step is performed in which the applied bank material 28 is irradiated with light (step S8). In step S8, first, a photomask 30 having a shielding portion that blocks ultraviolet light and a transmitting portion that transmits ultraviolet light is placed above the applied bank material 28 on the side opposite to the substrate 4. Here, the photomask 30 has a transmitting portion at a position overlapping each subpixel including each anode 10 in a plan view. For example, the photomask 30 may be a film-like member that blocks ultraviolet light and has openings at positions overlapping each subpixel. The photomask 30 is placed, for example, parallel to the upper surface of the substrate 4.

[0075] After the photomask 30 is placed above the bank material 28, the bank material 28 is irradiated with ultraviolet rays UV from above the photomask 30 side. Here, the ultraviolet rays UV are irradiated in a direction parallel to the directions approximately normal to the upper surface of the substrate 4 and the photomask 30. Therefore, the bank material 28 is irradiated with ultraviolet rays UV only at positions that overlap with the transparent parts of the photomask 30 in a plan view.

[0076] Next, the exposed bank material 28 is developed (step S10) to form the banks 16. Since the bank material 28 contains a positive photosensitive resin, the portions of the bank material 28 irradiated with ultraviolet light UV acquire solubility in a specific developer. Therefore, by washing the exposed bank material 28 with the developer, only the bank material 28 formed in the positions overlapping with the anodes 10 in a plan view is removed, and the remaining bank material 28 becomes the banks 16.

[0077] Here, generally, the light transmitted through the opening of the photomask is scattered at the end of the opening. Therefore, the light transmitted through the opening of the photomask is slightly diffused and irradiated around the opening in the vicinity of the photomask in a plan view. Therefore, when the light is irradiated to the object through the photomask, the light is more strongly irradiated to a position of the object close to the opening of the photomask in a position slightly wider than the opening in a plan view.

[0078] In other words, the area of ​​a specific object irradiated with light transmitted through an opening tends to become smaller as the distance between the opening and the object increases, and the intensity of the irradiated light also tends to decrease. Therefore, in step S8, in a plan view, the area of ​​bank material 28 irradiated with ultraviolet light UV transmitted through the transparent portion of photomask 30 becomes gradually smaller toward the lower side of photomask 30. Furthermore, the exposure intensity of bank material 28 irradiated with ultraviolet light UV also becomes gradually lower toward the lower side of photomask 30.

[0079] Therefore, the portion of bank material 28 irradiated with ultraviolet light UV becomes smaller from the photomask 30 side toward the substrate 4 side of bank material 28. The exposure intensity in that portion also becomes lower from the photomask 30 side toward the substrate 4 side of bank material 28. Therefore, when the portion irradiated with ultraviolet light UV is removed with a developer in step S10, the remaining bank 16 becomes gradually larger from the upper surface 16T toward the substrate 4 side. Under the above circumstances, bank 16 having forward tapered surfaces on its side surfaces can be formed from bank material 28 containing a positive photosensitive material.

[0080] When the bank material 28 is washed with the developer, a small amount of the bank material 28 that was not exposed to light may also be dissolved in the developer. In this case, the thickness of the bank 16 is reduced due to the reduction in the film thickness of the bank material 28. For this reason, the coating thickness of the bank material 28 may be determined taking into consideration the reduction in the thickness of the bank 16.

[0081] Next, the light-emitting layers 12 are formed at positions overlapping with the anodes 10 exposed from the bank 16 (step S12). The light-emitting layers 12 may be formed by forming the light-emitting materials of the red light-emitting layer 12R, the green light-emitting layer 12G, and the blue light-emitting layer 12B by deposition using a metal mask. Alternatively, the light-emitting layers 12 may be formed by depositing and patterning the layers of the light-emitting materials of the light-emitting layers for each emitted color.

[0082] <Formation of protrusions> Next, a step of forming the convex portion 22 is performed. In the step of forming the convex portion 22, first, a convex portion material 32 containing a negative type photosensitive resin is applied onto the upper surfaces of the substrate 4 and the anode 10 (step S14). The convex portion material 32 may be applied by the same method as the bank material 28.

[0083] Next, an exposure process is performed in which the applied convex material 32 is irradiated with light (step S16). In step S16, first, a photomask 34 is placed above the applied convex material 32 on the side opposite to the substrate 4. The photomask 34 may have the same configuration as the photomask 30, for example, except for the position of the transmissive portion. For example, the photomask 34 has a transmissive portion at a position overlapping with the bank 16 located outside the pixel P in a plan view. The photomask 34 is placed, for example, parallel to the upper surface 16T of the bank 16.

[0084] After the photomask 34 is placed above the convex material 32, the convex material 32 is irradiated with ultraviolet light UV from above the photomask 34 side. Here, the ultraviolet light UV is irradiated in a direction parallel to the directions approximately normal to the upper surface of the substrate 4 and the photomask 34. Therefore, the convex material 32 is irradiated with ultraviolet light UV only at positions that overlap with the transparent parts of the photomask 34 in plan view.

[0085] Next, the exposed convex material 32 is developed (step S18) to form the convex portion 22. Since the convex material 32 contains a negative photosensitive resin, the portion of the convex material 32 irradiated with ultraviolet light UV acquires a characteristic of being poorly soluble in a developer. Therefore, by washing the exposed convex material 32 with the developer, only a portion of the convex material 32 formed at a position overlapping with the bank 16 located outside the pixel P in a plan view remains, and the remaining convex material 32 becomes the convex portion 22.

[0086] For the same reason as described above, in step S16, the area of ​​the convex material 32 irradiated with the ultraviolet light UV that has passed through the transparent parts of the photomask 34 in a plan view gradually narrows toward the lower side of the photomask 34, and the intensity of the irradiated light also decreases. Therefore, the part of the convex material 32 irradiated with the ultraviolet light UV becomes smaller from the photomask 34 side of the convex material 32 toward the substrate 4 side. The exposure intensity in that part also decreases from the photomask 34 side of the convex material 32 toward the substrate 4 side.

[0087] Therefore, in step S18, the remaining convex portion 22 is the portion irradiated with ultraviolet light UV, and therefore the convex portion 22 gradually becomes smaller from the upper surface 22T toward the upper surface 16T of the bank 16. Due to the above circumstances, the convex portion 22 having the side surface 22S, which is a reverse tapered surface, can be formed from the convex portion material 32 containing a negative type photosensitive material.

[0088] As a result, in conjunction with the formation of the protrusions 22, a recess space 24 is formed by the bank 16 and the protrusions 22, at least a portion of which is a reverse tapered side surface 22S and the upper surface 16T of the bank 16 is the lower surface. By using a negative photosensitive resin for the protrusion material 32, the side surface 22S of the protrusions 22 can be made into a reverse tapered surface by photolithography using a general method for the protrusion material 32. Therefore, in the manufacturing method for the display device 2 according to this embodiment, no specific operation is required to make the side surface 22S of the protrusions 22 into a reverse tapered surface, and the manufacturing process is simplified.

[0089] Furthermore, in the method for manufacturing the display device 2 according to this embodiment, the protrusions 22 are formed on the banks 16. Therefore, even if there is some deviation in the formation positions of the protrusions 22, this is unlikely to affect the display by the display device 2. Specifically, in the step of forming the protrusions 22, it is not necessary to align the formation positions of the protrusions 22 as precisely as in the step of forming the banks 16. Therefore, in the method for manufacturing the display device 2 according to this embodiment, the step of forming the protrusions 22 is simplified.

[0090] <Formation of cathode and sealing layer> Next, the cathode 14 is formed (step S20). The cathode 14 can be formed by depositing a thin metal film over the entire surface of the display area DA including the pixels P, for example, by a sputtering method, a vapor deposition method, or the like. Here, by depositing a thin metal film even in a position overlapping with the bank 16 on which the protrusion 22 is formed in a plan view, a metal layer 26 located on the upper surface 22T of the protrusion 22 and inside the recess space 24 is formed together with the cathode 14.

[0091] This forms the anode 10, the light-emitting layer 12, and the cathode 14, completing the formation of the light-emitting element layer 6. Accordingly, the red light-emitting element 6R, the green light-emitting element 6G, and the blue light-emitting element 6B are formed at positions corresponding to the red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB, respectively.

[0092] Next, from above the cathode 14 on the side opposite to the substrate 4, an inorganic sealing film 18 is formed by depositing a thin film of an inorganic material by a CVD method or the like (step S22). Here, the inorganic sealing film 18 is deposited by wrapping the thin film of the inorganic material around the side surface 22S of the protrusion 22 and the upper surface 16T of the bank 16, including the side surface and lower surface of the recessed space 24. Thus, in step S22, the inorganic sealing film 18 that covers the side surface and lower surface of the recessed space 24 is formed.

[0093] Next, an organic material containing a self-repairing material is applied from above the inorganic sealing film 18 on the side opposite the substrate 4 by coating with a coater or by spin coating or the like to form an organic sealing film 20 (step S24). By applying the organic sealing film 20, the organic sealing film 20 that covers the side and bottom surfaces of the recessed space 24 can be easily formed. In this manner, the display device 2 shown in FIG. 1 is manufactured.

[0094] In the method for manufacturing the display device 2 according to the present embodiment, an example has been described in which the bank formation step, the light-emitting layer formation step, and then the convex portion formation step are performed in this order. However, the present embodiment is not limited to this, and the method for manufacturing the display device 2 according to the present embodiment may also be performed in this order, in which the bank formation step, the convex portion formation step, and then the light-emitting layer formation step are performed.

[0095] In this case, the convex portion material 32 can be exposed and developed in the convex portion forming step before the formation of the light emitting layer 12. Therefore, according to the above manufacturing method, it is possible to prevent damage to the light emitting layer 12 from occurring during the exposure and development of the convex portion material 32 in the convex portion forming step.

[0096] <Summary and Addendum of First Embodiment> The display device 2 according to this embodiment has a recessed space 24 formed by a protruding portion 22 located on an upper surface 16T of the bank 16. As a result, the display device 2 according to this embodiment can use the recessed space 24 to relieve stress that occurs in each member on the substrate 4 due to bending of the substrate 4, thereby reducing the occurrence of defects in each light-emitting element.

[0097] Furthermore, in the display device 2 according to this embodiment, the sealing layer 8 including the organic sealing film 20 having a self-repairing material covers the upper surfaces 22T of the protrusions 22 and the side and lower surfaces of the recessed space 24 formed by the protrusions 22. Therefore, the display device 2 according to this embodiment self-repairs defects including cracks that occur in the organic sealing film 20 in the recessed space 24, and reduces the intrusion of foreign matter including moisture into the sealing layer 8 and each part below the sealing layer 8.

[0098] The display device 2 according to this embodiment has a protrusion 22 on the upper surface of the bank 16 that divides each light-emitting element. With the above-described configuration, the recessed space 24 formed by the protrusion 22 is not adjacent to each light-emitting element. Therefore, with the above-described configuration, even if a defect such as a crack occurs in the organic sealing film 20 in the recessed space 24, the intrusion of foreign matter including moisture into each light-emitting element is more efficiently reduced.

[0099] [Embodiment 2] <Examples of modified positions of convex portions and modified metal layers> Fig. 10 is a side cross-sectional view of the display device 2 according to this embodiment, and is a cross-sectional view showing a cross section corresponding to the cross section shown in Fig. 1. Fig. 11 is a schematic enlarged view of the recessed space 24 and its surroundings according to this embodiment, and is a schematic enlarged view of the region E shown in Fig. 10. Note that in this specification, members having the same functions are given the same names and reference symbols, and the same description will not be repeated unless there is a difference in configuration.

[0100] Compared to the display device 2 according to the previous embodiment, the display device 2 according to the present embodiment has a convex portion 22 on an upper surface 4T of the substrate 4, instead of on an upper surface 16T of the bank 16. Accordingly, outside the pixels P in a planar view of the display device 2, there are positions where the banks 16 are not formed, and convex portions 22 are formed in part of these positions. Therefore, the display device 2 according to the present embodiment can be considered to have a structure in which the banks 16 located outside the pixels P in a planar view in the display device 2 according to the previous embodiment are replaced with convex portions 22.

[0101] 10, the protrusions 22 may be formed, for example, such that a side surface 22S facing the bank 16 is in contact with a side surface of the bank 16. Furthermore, the protrusions 22 may have, for example, approximately the same thickness as the thickness of the banks 16 with which they come into contact.

[0102] With the above-described configuration, the recessed space 24 formed between the protrusions 22 has, on its side, the side surface 22S of the protrusion 22, and has, on its lower surface, the upper surface 4T of the substrate 4 on which the protrusion 22 is formed. In other words, the recessed space 24 according to this embodiment is formed on the upper surface 4T of the substrate 4.

[0103] Furthermore, compared to the display device 2 according to the previous embodiment, the display device 2 according to the present embodiment further includes a metal layer 36 between the upper surface 4T of the substrate 4 and the metal layer 26 inside the recessed space 24. The metal layer 36 includes, for example, the same material as any of the materials of the anodes 10 of the light-emitting elements.

[0104] Except for the above, the display device 2 according to this embodiment has the same configuration as the display device 2 according to the previous embodiment. For example, the display device 2 according to this embodiment is the same as the display device 2 according to the previous embodiment in that the convex portion 22 is provided outside the pixel P in the plan view of the display device 2. Moreover, the convex portion 22 according to this embodiment has the same configuration as the convex portion 22 according to the previous embodiment, except for the formation position. Therefore, the side surface 22S of the convex portion 22, which is the side surface of the recess space 24, is an inverse tapered surface.

[0105] The display device 2 according to this embodiment includes a protrusion 22 and a recess space 24 on the upper surface 4T of the substrate 4. In other words, the protrusion 22 according to this embodiment is formed at the position where the bank 16 is formed, and can be considered to be a part of the bank 16.

[0106] For this reason, in this embodiment, the bank 16 is not formed in the position where the recessed space 24 is formed, thereby reducing the film thickness of the display device 2. Therefore, the display device 2 according to this embodiment further reduces the stress generated in the recessed space 24 and the surrounding area of ​​the recessed space 24 due to the curvature of the display device 2, and reduces the occurrence of defects, including cracks, around the recessed space 24.

[0107] In this embodiment, in addition to the metal layer 26, a metal layer 36 is provided inside the recessed space 24. The metal layer 36 contains the same material as any of the materials of the anode 10, which is the reflective electrode of each light-emitting element according to this embodiment. Therefore, in this embodiment, it is possible to further increase the probability that visible light is irradiated onto the fracture surface formed by the fracture of the organic sealing film 20 inside the recessed space 24.

[0108] A method for manufacturing the display device 2 according to this embodiment will be described with reference to Figs. 12 to 14. Fig. 12 is a flowchart showing a method for manufacturing the display device 2 according to this embodiment. Figs. 13 and 14 are cross-sectional views of the display device 2 for explaining each step shown in the flowchart of Fig. 12. Each of Figs. 13 and 14 shows a cross section corresponding to the cross section of the display device 2 shown in Fig. 10. Note that in this specification, details of manufacturing steps that can be performed by the same method as the above-mentioned manufacturing steps will not be repeatedly described and may be omitted.

[0109] In the method for manufacturing a display device 2 according to this embodiment, first, a substrate 4 is formed by the same method as in step S2 in the previous embodiment. Then, an anode 10 is formed by the same method as in step S4 in the previous embodiment. Here, in this embodiment, as shown in step S4 in Fig. 13, formation of a metal layer 36 is performed in addition to formation of the anode 10.

[0110] The metal layer 36 may be formed, for example, by leaving a part of the thin film of the conductive material even outside the position where the pixel P is formed in a plan view during patterning of the thin film of the conductive material in the process of forming the anode 10. With this method, the metal layer 36 can be manufactured in the same process as the process of forming the anode 10, and there is no need to form the metal layer 36 separately. Therefore, with the above method, it is possible to reduce the complication of the manufacturing process of the display device 2 and the extension of the takt time in the manufacturing process.

[0111] Next, by the same method as in step S6 in the previous embodiment, a bank material 28 containing a positive photosensitive resin is applied onto the upper surfaces of the substrate 4 and the anode 10. Next, by the same method as in step S8 in the previous embodiment, the applied bank material 28 is exposed to light.

[0112] Here, in step S8 according to this embodiment, exposure of the bank material 28 is performed using a photomask 38 having light-transmitting portions even at positions overlapping the metal layer 36 in a plan view. Thereby, by developing the exposed bank material 28 using the same method as in step S10 in the previous embodiment, the bank material 28 is removed even around the metal layer 36, and the bank 16 according to this embodiment is formed.

[0113] Next, the convex material 32 containing a negative photosensitive resin is applied, exposed, and developed by the same methods as those of steps S14, S16, and S18 in the previous embodiment. Here, in step S16 in this embodiment, the convex material 32 is exposed to light using a photomask 40 having a light-transmitting portion in a position that does not overlap with the bank 16 in a plan view. As a result, the convex material 32 is developed to form the convex portions 22 formed on the upper surface 4T of the substrate 4.

[0114] Next, steps S12, S20, S22, and S24 in the previous embodiment are performed in order to manufacture the display device 2 shown in Fig. 10. For this reason, in the method for manufacturing the display device 2 according to the present embodiment, the step of forming the convex portions 22 is performed prior to the formation of the light-emitting layer 12. Therefore, in the method for manufacturing the display device 2 according to the present embodiment, damage to the light-emitting layer 12 due to development of the convex portion material 32, etc., in the step of forming the convex portions 22 can be prevented.

[0115] [Embodiment 3] <Example where the bank is the same as the protrusion> Fig. 15 is a side cross-sectional view of a display device 2 according to this embodiment, and is a cross-sectional view showing a cross section corresponding to the cross section shown in Fig. 1. Fig. 16 is a schematic enlarged view of a red light emitting element 6R according to this embodiment and the periphery of the red light emitting element 6R, and is a schematic enlarged view of a region F shown in Fig. 15.

[0116] Compared to the display device 2 according to the previous embodiment, the display device 2 according to the present embodiment has convex portions 22 instead of the banks 16 on the upper surface 4T of the substrate 4. In other words, the display device 2 according to the present embodiment can be considered as a display device 2 according to the previous embodiment in which the banks that partition the respective light-emitting elements are the same as the convex portions 22. Therefore, the display device 2 according to the present embodiment has convex portions 22 even inside the pixels P in plan view.

[0117] 15 and 16, the display device 2 according to this embodiment has a recessed space 24 formed between the protruding portions 22 even inside the pixel P in plan view. Furthermore, the display device 2 includes light-emitting elements inside each recessed space 24. In this embodiment, an anode 10, a light-emitting layer 12, and a cathode 14 are provided on the lower surface of each recessed space 24. Therefore, in this embodiment, each recessed space 24 can be considered to include an anode 10 and a cathode 14 instead of the metal layer 26 and the metal layer 36.

[0118] Except for the above, the display device 2 according to this embodiment has the same configuration as the display device 2 according to the previous embodiment. For example, the protrusion 22 according to this embodiment has the same configuration as the protrusion 22 according to the previous embodiment, except for the formation position. Therefore, the side surface 22S of the protrusion 22, which is the side surface of the recess space 24, is an inverse tapered surface.

[0119] The display device 2 according to this embodiment has protrusions 22 as banks that partition each of the light-emitting elements. Moreover, the display device 2 according to this embodiment has each of the light-emitting elements included in the display device 2 inside each of the recessed spaces 24 formed by the protrusions 22. Therefore, in the display device 2 according to this embodiment, even in the region in which each light-emitting element is formed, the recessed spaces 24 can alleviate stress generated in each member on the substrate 4 due to the curvature of the substrate 4, and the occurrence of defects in each light-emitting element can be more efficiently reduced.

[0120] Furthermore, each light-emitting element included in the display device 2 according to this embodiment has, for example, the anode 10, which is a reflective electrode, closer to the substrate 4 than the cathode 14, which is a transmissive electrode. In this case, as is clear from Figs. 15 and 16, in the recessed space 24 that includes any one of the light-emitting elements therein, the anode 10 is located closer to the substrate 4 than the cathode 14.

[0121] With the above configuration, the display device 2 becomes a top-emission type display device that extracts light from each light-emitting element from the substrate 4 side toward the sealing layer 8 side. In this case, if the organic sealing film 20 breaks at a position overlapping with the light-emitting element in a planar view, not only external light but also light from the light-emitting layer 12 of the light-emitting element is irradiated onto the broken surface. Therefore, the display device 2 according to this embodiment can more efficiently repair defects in the organic sealing film 20 at positions overlapping with the light-emitting elements.

[0122] The display device 2 according to the present embodiment has a structure in which all the banks 16 included in the display device 2 according to the previous embodiment are the same as the convex portions 22, but is not limited to this. For example, the display device 2 according to the present embodiment may have a structure in which, among the banks 16 included in the display device 2 according to the previous embodiment, only the banks 16 located on the outermost edge of each pixel P in plan view are the convex portions 22.

[0123] In this case, the red light emitting element 6R, the green light emitting element 6G, and the blue light emitting element 6B formed in the pixel P are positioned between the protrusions 22. Therefore, in the above configuration, a structure including a plurality of light emitting elements is formed inside each recessed space 24. In this manner, the display device 2 according to the present embodiment is not limited to a structure including a single light emitting element inside each recessed space 24, and may include a plurality of light emitting elements.

[0124] Furthermore, the display device 2 according to this embodiment may be a bottom-emission type display device 2 that extracts light from each light-emitting element toward the substrate 4 side rather than the sealing layer 8 side. In this embodiment, the space between the protrusions 22 in which the light-emitting elements are formed has an area larger in plan view on the substrate 4 side than on the sealing layer 8 side. Therefore, when the display device 2 according to this embodiment is a bottom-emission type, the protrusions 22 reduce blocking of light from each light-emitting layer 12, and prevent a decrease in the efficiency of extracting light from each light-emitting element.

[0125] A method for manufacturing a display device 2 according to this embodiment will be described with reference to Fig. 17 and Fig. 18. Fig. 17 is a flowchart showing the method for manufacturing a display device 2 according to this embodiment. Fig. 18 is a process cross-sectional view of the display device 2 for explaining each process shown in the flowchart of Fig. 17. Fig. 18 shows a cross section corresponding to the cross section of the display device 2 shown in Fig. 15.

[0126] In the method for manufacturing the display device 2 according to this embodiment, first, the same manufacturing steps as steps S2 and S4 in the previous embodiment are performed in order to form the substrate 4, the anode 10, and the metal layer 36. Next, in this embodiment, the step of forming the bank 16 is omitted, and the step of forming the protrusion 22 is performed.

[0127] In the process of forming the convex portions 22 according to this embodiment, the convex portion material 32 containing a negative photosensitive resin is applied, exposed, and developed by the same methods as those in steps S14, S16, and S18 in the previous embodiment. Here, in step S16 according to this embodiment, the convex portion material 32 is exposed to light using a photomask 42 having a light-transmitting portion at a position overlapping with each anode 10 and the metal layer 36 in a plan view. As a result, the convex portion material 32 is developed to form the convex portions 22 between each anode 10 and the metal layer 36.

[0128] Next, steps S12, S20, S22, and S24 in the previous embodiment are carried out in order, whereby the display device 2 shown in FIG. 15 can be manufactured.

[0129] The method for manufacturing the display device 2 according to this embodiment omits the step of forming the banks 16. In other words, in the method for manufacturing the display device 2 according to this embodiment, the step of forming the banks 16 can be regarded as being the same as the step of forming the protrusions 22 in each of the embodiments described above.

[0130] As a result, in the method for manufacturing the display device 2 according to this embodiment, the manufacturing process is simpler than in a method in which the step of forming the banks 16 is separately performed, and further, there is no need to consume material used to form the banks 16. Therefore, the method for manufacturing the display device 2 according to this embodiment achieves a reduction in takt time and a reduction in manufacturing costs in the manufacturing process of the display device 2.

[0131] [Embodiment 4] <Convex part with forward tapered surface> FIG. 19 is a side cross-sectional view of a display device 2 according to this embodiment, and is a cross-sectional view showing a cross section corresponding to the cross section shown in FIG.

[0132] The display device 2 according to this embodiment has a structure in which the bank 16 in contact with the protrusion 22 in the display device 2 according to embodiment 2 is replaced with the protrusion 22. Therefore, as shown in Fig. 19, the side surface 22S of the protrusion 22 according to this embodiment has a first side surface 22SA which is a reverse tapered surface and a second side surface 22SB which is a forward tapered surface. In other words, the side surface 22S according to this embodiment has not only a reverse tapered surface but also a forward tapered surface in part.

[0133] 19, in the display device 2 according to this embodiment, the pixel P is formed on the second side surface 22SB of the side surface 22S of the protrusion 22. In other words, the display device 2 according to this embodiment includes each light-emitting element on the forward tapered surface side of the side surface 22S of the protrusion 22. In particular, in this embodiment, the protrusion 22 is adjacent to the blue light-emitting element 6B among the light-emitting elements included in the display device 2, and has the second side surface 22SB on the side of the blue light-emitting element 6B.

[0134] Meanwhile, the side surface 22S of the protrusion 22 has a first side surface 22SA on the side opposite to the forward tapered surface side, in other words, on the outside of the pixel P in plan view. Therefore, the display device 2 according to the present embodiment has a recess space 24 on the first side surface 22SA side of the protrusion 22, in other words, on the outside of the pixel P in plan view.

[0135] Therefore, the recessed space 24 formed in the display device 2 according to this embodiment has a reverse tapered surface including the first side surface 22SA on the side surface, like the recessed space 24 formed in the display device 2 according to each of the above-mentioned embodiments. Therefore, in the display device 2 according to this embodiment, the recessed space 24 can relieve stress generated in each member on the substrate 4 due to bending of the substrate 4, thereby reducing the occurrence of defects in each light-emitting element.

[0136] Additionally, in this embodiment, the side surface 22S of the protrusion 22 further has a second side surface 22SB that is a forward tapered surface, and the second side surface 22SB is on the light-emitting element side. Therefore, the display device 2 according to this embodiment also has the light-emitting element adjacent to the protrusion 22 between the side walls of the forward tapered surface. Therefore, when the display device 2 according to this embodiment is a top-emission type, the display device 2 reduces the blocking of light from the light-emitting layer 12 included in the light-emitting element adjacent to the protrusion 22.

[0137] A method for manufacturing a display device 2 according to this embodiment will be described with reference to Fig. 20 to Fig. 22. Fig. 20 is a flowchart showing the method for manufacturing a display device 2 according to this embodiment. Figs. 21 and 22 are cross-sectional views of the display device 2 for explaining each step shown in the flowchart of Fig. 20. Each of Figs. 21 and 22 shows a cross section corresponding to the cross section of the display device 2 shown in Fig. 19.

[0138] In the method for manufacturing the display device 2 according to this embodiment, first, the same manufacturing steps as steps S2 and S4 in embodiment 2 are performed in order to form the substrate 4, the anode 10, and the metal layer 36. Next, the same methods as steps S6, S8, and S10 in embodiment 2, respectively, are used to apply and form the bank material 28 containing a positive-type photosensitive resin, expose it to light, and develop it.

[0139] Here, in step S8 according to the present embodiment, exposure is performed using a photomask 46 that does not have a light-shielding portion between the anode 10B and the metal layer 36 in a plan view. Therefore, in the step of forming the bank 16 according to the present embodiment, the bank 16 is not formed in a position that covers the peripheral end of the anode 10B on the metal layer 36 side.

[0140] Next, the convex material 32 containing a negative photosensitive material is applied by the same method as step S14 in each of the above-mentioned embodiments. Next, exposure is performed on the convex material 32. Here, in this embodiment, after step S14, for example, a photomask 48 having a light-transmitting portion is placed between the anode 10B and the metal layer 36 in a plan view, and a first exposure is performed on the convex material 32 (step S26). Particularly, in step S26, ultraviolet light UV is irradiated from above the photomask 48 in a direction inclined from the metal layer 36 side toward the anode 10B side with respect to the normal direction of the upper surface 4T of the substrate 4.

[0141] Next, for example, a photomask 50 having a light-transmitting portion is placed on the side opposite the anode 10B from the metal layer 36 in a plan view, and a second exposure is performed on the convex material 32 (step S28). Particularly, in step S28, ultraviolet light UV is irradiated from above the photomask 48 in a direction inclined from the anode 10B side toward the metal layer 36 side with respect to the normal direction of the upper surface 4T of the substrate 4.

[0142] Next, the convex material 32 is developed by the same method as step S18 in each of the above-described embodiments. Here, by steps S26 and S28, the convex material 32 is exposed between the anode 10B and the metal layer 36 and on the side of the metal layer 36 opposite the anode 10B in plan view.

[0143] In addition, a portion of the exposed convex material 32 located between the anode 10B and the metal layer 36 in plan view is exposed to the ultraviolet light UV from above toward the substrate 4, from the metal layer 36 toward the anode 10B. Therefore, by step S18, a convex portion 22 is formed between the anode 10B and the metal layer 36 in plan view, the convex portion 22 having a first side surface 22SA that is a reverse tapered surface on the metal layer 36 side and a second side surface 22SB that is a forward tapered surface on the anode 10B side.

[0144] Furthermore, a portion of the exposed convex material 32 located on the side opposite the anode 10B from the metal layer 36 in plan view is exposed from the upper side where the ultraviolet ray UV is irradiated toward the substrate 4, in a direction from the anode 10B side toward the metal layer 36 side. Thus, by step S18, a convex portion 22 having a first side surface 22SA that is a reverse tapered surface on the metal layer 36 side is formed on the side opposite the anode 10B from the metal layer 36 in plan view. Although omitted in FIG. 22 for simplicity of illustration, the convex portion 22 located on the side opposite the anode 10B from the metal layer 36 in plan view has a second side surface 22SB that is a forward tapered surface on the side opposite the anode 10B from the metal layer 36.

[0145] Next, steps S12, S20, S22, and S24 in the previous embodiment are carried out in order, whereby the display device 2 shown in FIG. 19 can be manufactured.

[0146] In this embodiment, in the step of forming the convex portion 22, the convex portion 22 is formed by photolithography of a photosensitive material. Furthermore, in this embodiment, in the exposure step of the photolithography, ultraviolet light UV is irradiated in a direction tilted from the normal direction of the upper surface 4T of the substrate 4. This makes it possible to form the convex portion 22 having both the first side surface 22SA, which is a reverse tapered surface, and the second side surface 22SB, which is a forward tapered surface, from the same convex portion material 32.

[0147] In this embodiment, the formation of the convex portion 22 having both the first side surface 22SA and the second side surface 22SB is realized by an exposure process in which ultraviolet rays UV are irradiated in a direction inclined from the normal direction of the upper surface 4T of the substrate 4, as described above. Therefore, the convex portion material 32 may be a positive type photosensitive material instead of a negative type photosensitive material. In this case, for example, in steps S26 and S28, the convex portion 22 according to this embodiment can be formed by performing exposure using a photomask in which the light-shielding portion and the light-transmitting portion are inverted from the photomask 48 and the photomask 50, respectively. However, in both steps S26 and S28, it is desirable to appropriately add a light-shielding portion of the photomask in each of steps S26 and S28 so that exposure is not performed on the position of the positive type convex portion material 32 where the convex portion 22 is to be formed.

[0148] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present disclosure also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Furthermore, new technical features can be formed by combining the technical means disclosed in the respective embodiments. [Explanation of symbols]

[0149] 2. Display Device 4. Board 6 Light emitting element layer 8 Sealing layer 10 Anode 12 Emitting layer 14 Cathode 16 Banks 18 Inorganic sealing film 20 Organic sealing film 22 Convex 24 Recessed space 26, 36 metal layer

Claims

1. A flexible substrate; a protrusion having a reverse tapered surface on at least a part of a side surface of the substrate; a sealing layer including a self-repairing material; a recessed space formed by a side surface of the protrusion and a surface on which the protrusion is formed, the sealing layer covers an upper surface and a side surface of the protrusion and a lower surface of the recessed space, A display device in which at least a part of a side surface of the recessed space is the inverse tapered surface.

2. the sealing layer includes, in order from the substrate side, an inorganic sealing film covering an upper surface and a side surface of the protrusion and a lower surface of the recess space, and an organic sealing film on the inorganic sealing film, The display device according to claim 1 , wherein the organic sealing film includes the self-repairing material.

3. the self-repairing material includes a photosensitive polymer having a plurality of photosensitive binding groups bonded to each other; each bond of the plurality of photosensitive binding groups is cleaved by radicalization accompanying irradiation with light, 3. The display device according to claim 1, wherein the photosensitive binding groups are re-bonded to each other by bringing the cut ends of the cut photosensitive binding groups into close proximity to each other.

4. The display device according to claim 2 , further comprising a metal layer formed on a lower surface of the recessed space.

5. The display device according to claim 1 , wherein at least a part of visible light is reflected or scattered by the inversely tapered surface.

6. The display device according to claim 1 , wherein an angle formed between the inverse tapered surface forming the side surface of the recessed space and a bottom surface of the recessed space is the same in at least one of the recessed spaces.

7. Further, a plurality of light-emitting elements each including two electrodes and a functional layer between the two electrodes; 7. The display device according to claim 1, further comprising: a bank formed between the plurality of light-emitting elements to separate each of the light-emitting elements.

8. The display device according to claim 7 , wherein at least a part of the protrusion is provided on an upper surface of the bank.

9. The display device according to claim 7 , wherein at least a part of the convex portion is a part of the bank.

10. At least a part of the side surface of at least one of the protrusions that is different from the reverse tapered surface is a forward tapered surface, The display device according to claim 9 , wherein the light emitting element is provided on a side of the convex portion closer to the forward tapered surface than the convex portion.

11. a convex portion forming step of forming a convex portion on a flexible substrate, at least a part of the side surface of which is an inverse tapered surface, to form a concave space formed by the side surface of the convex portion and a surface on which the convex portion is formed, at least a part of the side surface being the inverse tapered surface; A method for manufacturing a display device comprising the steps of: forming a sealing layer that covers the upper and side surfaces of the convex portion and the lower surface of the concave space, and that contains a self-repairing material.

12. The sealing layer forming step includes: an inorganic sealing film forming step of forming an inorganic sealing film that covers an upper surface and a side surface of the protrusion and a lower surface of the recess space; The method for manufacturing a display device according to claim 11 , further comprising: forming an organic sealing film containing the self-repairing material on an upper layer of the inorganic sealing film.

13. forming a plurality of light emitting devices, each of which includes two electrodes and a light emitting layer between the two electrodes; The method for manufacturing a display device according to claim 11 or 12, further comprising a bank forming step of forming banks between the plurality of light-emitting elements to separate each of the light-emitting elements.

14. After the bank forming step, the convex portion forming step is carried out; The method for manufacturing a display device according to claim 13 , wherein in the convex portion forming step, the convex portion is formed on the bank.

Images