WO2021059459A1

WO2021059459A1 - Organic el display device

Info

Publication number: WO2021059459A1
Application number: PCT/JP2019/038017
Authority: WO
Inventors: 克彦岸本
Original assignee: 堺ディスプレイプロダクト株式会社
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2021-04-01

Abstract

An organic EL display device (100) comprises: an element substrate (20) that includes a substrate (1) and a plurality of organic EL elements (3) supported by the substrate; and a thin film sealing structure (10) that covers the plurality of organic EL elements. The thin film sealing structure includes: a first inorganic barrier layer (12); an organic barrier layer (14) formed on the first inorganic barrier layer; and a second inorganic barrier layer (16) formed on the organic barrier layer. The first inorganic barrier layer includes: a first sub-barrier layer (12sa); and a second sub-barrier layer (12sb) that is formed on the first sub-barrier layer and that is in contact with the organic barrier layer. A surface (12S) of the first inorganic barrier layer contacting the organic barrier layer has a plurality of fine protrusions, each having a height of 20-80 nm and a width of 20-80 nm.

Description

Organic EL display device

The present invention relates to an organic EL display device.

Organic EL (Electro Luminescence) display devices have begun to be put into practical use. One of the features of the organic EL display device is that a flexible display device can be obtained. The organic EL display device has at least one organic EL element (Organic Light Emitting Diode: OLED) for each pixel, and at least one TFT (Thin Film Transistor) that controls the current supplied to each OLED. Hereinafter, the organic EL display device will be referred to as an OLED display device. Such an OLED display device having a switching element such as a TFT for each OLED is called an active matrix type OLED display device. Further, the substrate on which the TFT and the OLED are formed is referred to as an element substrate.

OLEDs (particularly organic light emitting layers and cathode electrode materials) are liable to deteriorate under the influence of moisture and are liable to cause display unevenness. Thin Film Encapsulation (TFE) technology has been developed as a technology for protecting the OLED from moisture and providing a sealing structure that does not impair flexibility. The thin film sealing technique attempts to obtain sufficient water vapor barrier properties in a thin film by alternately laminating inorganic barrier layers and organic barrier layers. From the viewpoint of moisture resistance and reliability of the OLED display device, the WVTR (Water Vapor Transmission Rate) of the thin film sealing structure is typically required to be 1 × 10 ^-4 g / m ² / day or less.

The TFE structure used in the OLED display devices currently on the market has an organic barrier layer (polymer barrier layer) having a thickness of about 5 μm to about 20 μm. Such a relatively thick organic barrier layer also plays a role of flattening the surface of the device substrate. A relatively thick organic barrier layer is formed, for example, by using an inkjet method.

On the other hand, recently, a TFE structure having a relatively thin organic barrier layer has been studied. The relatively thin organic barrier layer is discretely formed only around the convex portion (first inorganic barrier layer covering the convex portion) of the lower inorganic barrier layer (first inorganic barrier layer) of the organic resin film (organic barrier layer). It is sometimes called "solid part").

For example,

Patent Documents

1 and 2 describe the following methods. A mist-like organic material (for example, an acrylic monomer) that has been heated and vaporized is supplied onto an element substrate maintained at a temperature of room temperature or lower, and the organic material condenses and drops on the substrate. The droplet-like organic material moves on the substrate due to capillary action or surface tension, and is unevenly distributed at the boundary between the side surface of the convex portion of the first inorganic barrier layer and the surface of the substrate. Then, by curing the organic material, an organic resin film is formed at the boundary portion. Further, Patent Document 3 discloses a method of forming an organic resin film on a flat portion of an element substrate and then ashing to form an organic barrier layer having a plurality of discretely distributed solid portions. Has been done. For reference, all the disclosure contents of Patent Documents 1 to 3 are incorporated herein by reference.

International Publication No. 2014/196137 Japanese Unexamined Patent Publication No. 2016-39120 International Publication No. 2018/003129 Japanese Unexamined Patent Publication No. 2018-181807 Japanese Unexamined Patent Publication No. 2018-181808

According to the study of the present inventor, there is a problem that the light utilization efficiency of the organic EL display device is lowered when the TFE structure is provided. One of the causes is that a part of the light emitted from the OLED (light emitting layer) is reflected at the interface in the TFE structure.

Various technologies have been developed to improve the light utilization efficiency of organic EL display devices. For example, in Patent Documents 4 and 5, a method of forming a concavo-convex structure on the surface of a substrate on which an OLED is formed and using this concavo-convex structure to form regular irregularities on the surface of an anode (reflecting electrode) of the OLED. Is disclosed. According to Patent Documents 4 and 5, the light utilization efficiency of the OLED can be improved by utilizing the surface plasmon resonance at the anode having regular irregularities. Patent Document 4 describes that the height of the convex portion of the concave-convex structure is 10 nm or more and 500 nm or less, the width is 50 nm or more and 800 nm or less, and the interval (pitch) between adjacent convex portions is 100 nm or more and 1200 nm or less. According to Document 5, the height of the convex portion of the concave-convex structure is 100 nm or more and 800 nm or less, the width is 100 nm or more and 250 nm or less, and the interval (pitch) between adjacent convex portions is 520 nm or more and 720 nm or less depending on the color of the pixel. It is described as (red), 435 nm or more and 635 nm or less (green), and 370 nm or more and 570 nm or less (blue).

However, Patent Documents 4 and 5 do not even mention the decrease in light utilization efficiency due to the TFE structure.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an OLED display device that suppresses light reflection in a TFE structure.

According to embodiments of the present invention, the solutions described in the following items are provided.
[Item 1]
An organic EL display device having a plurality of pixels.
It has a substrate, an element substrate having a plurality of organic EL elements supported by the substrate, and a thin film sealing structure covering the plurality of organic EL elements.
The thin film sealing structure has a first inorganic barrier layer, an organic barrier layer formed on the first inorganic barrier layer, and a second inorganic barrier layer formed on the organic barrier layer.
The first inorganic barrier layer has a first sub-barrier layer and a second sub-barrier layer formed on the first sub-barrier layer and in contact with the organic barrier layer.
The surface of the first inorganic barrier layer in contact with the organic barrier layer has a plurality of fine convex portions, and the height of the plurality of fine convex portions is 20 nm or more and 80 nm or less, and the plurality of fine convex portions. An organic EL display device having a width of 20 nm or more and 80 nm or less.
[Item 2]
The organic EL display device according to item 1, wherein the distance between the plurality of fine convex portions is 20 nm or more and 80 nm or less.
[Item 3]
The organic EL display device according to

item

1 or 2, wherein the resin material constituting the organic barrier layer is filled in the gaps between the plurality of fine convex portions.
[Item 4]
The second sub-barrier layer has a plurality of discretely distributed island-shaped portions, and the plurality of island-shaped portions form the plurality of fine convex portions, according to any one of items 1 to 3. Organic EL display device.
[Item 5]
The organic EL display device according to any one of items 1 to 4, wherein the second sub-barrier layer is made of SiN or SiON.
[Item 6]
The organic EL display device according to any one of items 1 to 5, wherein the surface roughness of the first sub-barrier layer is less than 5 nm.
[Item 7]
The organic EL display device according to any one of items 1 to 6, _{wherein the first sub-barrier layer is an Al 2} O ₃ layer having a thickness of 10 nm or more and 30 nm or less.
[Item 8]
The organic EL display device according to any one of items 1 to 6, wherein the first sub-barrier layer is a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less.
[Item 9]
The organic EL display device according to any one of items 1 to 8, wherein the second inorganic barrier layer includes a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less.
[Item 10]
The element substrate further has a bank layer that defines each of the plurality of pixels.
The organic EL display device according to any one of items 1 to 9, wherein the organic barrier layer covers the bank layer and has a flat surface.
[Item 11]
The organic EL display device according to item 10, wherein the thickness of the organic barrier layer is 3 μm or more and 10 μm or less.
[Item 12]
The element substrate further has a bank layer that defines each of the plurality of pixels.
The bank layer has a slope that surrounds each of the plurality of pixels.
The organic barrier layer has a plurality of discretely distributed solid parts.
The organic EL display according to any one of items 1 to 9, wherein the plurality of solid portions have a pixel peripheral solid portion extending from a portion on the slope to the periphery of the pixel of the first inorganic barrier layer. apparatus.
[Item 13]
The organic EL display device according to item 12, wherein the thickness of the organic barrier layer is 50 nm or more and less than 200 nm.
[Item 14]
The first surface of the organic barrier layer in contact with the second inorganic barrier layer has a plurality of fine first convex portions, and the height of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. The organic EL display device according to any one of items 1 to 13, wherein the width of the plurality of fine first convex portions is 20 nm or more and 80 nm or less.
[Item 15]
The organic EL display device according to item 14, wherein the distance between the plurality of fine first convex portions is 20 nm or more and 80 nm or less.
[Item 16]
The second surface of the second inorganic barrier layer, which is opposite to the surface in contact with the first surface, has a plurality of fine second convex portions, and the height of the plurality of fine second convex portions. The organic EL display device according to item 13, wherein the width and the interval are independently 20 nm or more and 80 nm or less.

According to an embodiment of the present invention, an OLED display device that suppresses light reflection in a TFE structure is provided.

It is a schematic partial sectional view of the active area of the OLED display device 100 by embodiment of this invention. FIG. 5 is a partial cross-sectional view of a TFE structure 10A included in the OLED display device according to the first embodiment of the present invention. It is a partial cross-sectional view of the TFE structure 10B included in the OLED display device according to Embodiment 2 of this invention. It is a top view which shows typically the structure of the OLED display device 100 by embodiment of this invention. It is a schematic cross-sectional view of the OLED display device 100A1 of Embodiment 1 provided with a TFE structure 10A1, and is the cross-sectional view including the pixel Pix along the line 4A-4A'in FIG. It is a schematic cross-sectional view of the OLED display device 100A1 of Embodiment 1 which comprises a TFE structure 10A1, and is the cross-sectional view which includes the particle P along the line 4A-4A'in FIG. It is a schematic cross-sectional view of the OLED display device 100A1 of Embodiment 1 provided with a TFE structure 10A1, and is the cross-sectional view along the line 4C-4C'in FIG. FIG. 5 is a schematic cross-sectional view of the OLED display device 100A2 of the first embodiment including the TFE structure 10A2, and is a cross-sectional view including a pixel Pix along the 4A-4A'line in FIG. It is a schematic cross-sectional view of the OLED display device 100A2 of Embodiment 1 provided with a TFE structure 10B, and is the cross-sectional view including the particle P along the line 4A-4A'in FIG. It is a schematic cross-sectional view of the OLED display device 100A2 of Embodiment 1 provided with a TFE structure 10B, and is the cross-sectional view along the line 4C-4C'in FIG. It is a schematic cross-sectional view of the TFE structure 10A1 in the OLED display device 100A1. It is a schematic cross-sectional view of the TFE structure 10A2 in the OLED display device 100A2. It is a schematic cross-sectional view which shows the state of the interface between the 1st inorganic barrier layer 12 and organic barrier layers 14A, 14B in a TFE structure 10A (10A1, 10A2). The state of the interface between the first inorganic barrier layer 12 and the second inorganic barrier layer 16 (surface 12S of the first inorganic barrier layer 12) and the surface 16S of the second inorganic barrier layer 16 in the TFE structure 10A (10A1, 10A2) is shown. It is a schematic cross-sectional view. It is a schematic cross-sectional view of the TFE structure 10B1 in the OLED display device 100B1. It is a schematic cross-sectional view of the TFE structure 10B2 in the OLED display device 100B2. FIG. 5 is a schematic cross-sectional view showing an interface between the

organic barrier layers

14A and 14B and the second inorganic barrier layer 16 and the surface 16S of the second inorganic barrier layer 16 in the TFE structure 10B (10B1, 10B2).

Hereinafter, the OLED display device according to the embodiment of the present invention and the manufacturing method thereof will be described with reference to the drawings. The embodiments of the present invention are not limited to the embodiments exemplified below. For example, the organic EL display device according to the embodiment of the present invention may have, for example, a glass substrate instead of the flexible substrate.

First, the basic configuration of the OLED display device 100 according to the embodiment of the present invention will be described with reference to FIGS. 1, 2A and 2B. FIG. 1 is a schematic partial cross-sectional view of an active region of the OLED display device 100 according to the embodiment of the present invention, and FIGS. 2A and 2B are partial cross-sectional views of a TFE structure 10 formed on the OLED 3. FIG. 2A is a partial cross-sectional view of the TFE structure 10A included in the OLED display device according to the first embodiment, and FIG. 2B is a partial cross-sectional view of the TFE structure 10B included in the OLED display device according to the second embodiment.

The OLED display device 100 has a plurality of pixels, and each pixel has at least one organic EL element (OLED). Here, for the sake of simplicity, a structure corresponding to one OLED will be described.

As shown in FIG. 1, the OLED display device 100 includes a flexible substrate (hereinafter, may be simply referred to as a “board”) 1, a circuit (backplane) 2 including a TFT formed on the substrate 1, and a circuit. It has an OLED 3 formed on the OLED 3 and a TFE structure 10 formed on the OLED 3. OLED3 is, for example, a top emission type. The uppermost portion of the OLED 3 is, for example, an upper electrode or a cap layer (refractive index adjusting layer). An optional polarizing plate 4 is arranged on the TFE structure 10.

The substrate 1 is, for example, a polyimide film having a thickness of 15 μm. The thickness of the circuit 2 including the TFT is, for example, 4 μm, the thickness of the OLED 3 is, for example, 1 μm, and the thickness of the TFE structure 10 is, for example, 1.5 μm or less.

FIG. 2A is a partial cross-sectional view of the TFE structure 10A included in the OLED display device according to the first embodiment. The TFE structure 10A was formed on the first inorganic barrier layer (for example, SiN layer) 12, the organic barrier layer (for example, acrylic resin layer) 14 formed on the first inorganic barrier layer 12, and the organic barrier layer 14. It has a second inorganic barrier layer (for example, SiN layer) 16. The first inorganic barrier layer 12 is formed directly above the OLED 3. The organic barrier layer 14 may be relatively thick and also serve as a flattening layer (see FIG. 4A), or may have a plurality of relatively thin and discretely distributed solid parts (see FIG. 5A). .. The organic barrier layer 14 is preferably formed of a colorless and transparent photocurable resin (for example, acrylic resin or epoxy resin), and for example, when the thickness is 1 μm, the transmittance of visible light is 95% or more. Is preferable. The refractive index of the photocurable resin is, for example, about 1.48 to about 1.61.

Of the light emitted from the OLED 3, (a part of) the light that has passed through the TFE structure 10A is emitted from the OLED display device 100 and used for display. However, a part of the light incident on the TFE structure 10A is reflected at the interface between the first inorganic barrier layer 12 and the organic barrier layer 14. For example, the refractive index of the SiN layer is 1.85, the refractive index of the acrylic resin layer is 1.54, and the refractive index difference (Δn) is as large as 0.31 or more. Therefore, the light emitted from the OLED 3 is reflected at the interface between the first inorganic barrier layer 12 and the organic barrier layer 14, resulting in loss.

The first inorganic barrier layer 12 of the TFE structure 10A included in the OLED display device according to the first embodiment of the present invention is formed on the first sub-barrier layer 12sa and the first sub-barrier layer 12sa, and is in contact with the organic barrier layer 14. The surface 12S having the layer 12sb and in contact with the organic barrier layer 14 of the first inorganic barrier layer 12 has a plurality of fine protrusions, and the height of the plurality of fine protrusions is 20 nm or more and 80 nm or less. The width of the plurality of fine convex portions is 20 nm or more and 80 nm or less (see FIG. 7A). When the surface 12S of the first inorganic barrier layer 12 in contact with the organic barrier layer 14 has such a fine convex portion, reflection due to the refractive index is reduced or eliminated as described below. As a result, the OLED display device according to the embodiment of the present invention can realize higher light utilization efficiency than before.

Generally, if a structure (convex portion) finer than the wavelength of visible light is formed on the surface of an object and air is filled between the fine structures, a region in which a fine structure containing air is formed. The average refractive index (effective refractive index) of (layer) is smaller than the refractive index of the substance itself constituting the fine structure. Furthermore, if the horizontal cross-sectional area of the microstructure is gradually increased with respect to the height direction of the microstructure so that the average refractive index is gradually changed from the air to the bottom of the microstructure, air and an object can be obtained. It is known that the sudden change in the refractive index at the interface with the light can be eliminated and the reflection of light can be reduced.

In the first embodiment of the present invention, the above-mentioned object corresponds to the first sub-barrier layer 12sa, and the surface roughness of the first sub-barrier layer 12sa is less than 5 nm. Immediately above the first sub-barrier layer 12sa, convex portions (second sub-barrier layer 12sb) having a height of 20 nm or more and 80 nm or less and a width of 20 nm or more and 80 nm or less are formed discretely as a microstructure. In order to make the change in the average refractive index as gentle as possible, the lower limit of the height of the second sub-barrier layer 12sb is more preferably 40 nm or more. This is because the higher the height, the slower the change in the refractive index. However, when the height approaches 400 nm, which is the lower limit of visible light, reflection on the side surface of the second sub-barrier layer 12sb cannot be ignored. Therefore, the upper limit of the height of the second sub-barrier layer 12sb is higher than the lower limit wavelength of visible light. It is preferably 80 nm or less, which is sufficiently small. The substance constituting the second sub-barrier layer 12sb is preferably SiN or SiON, and these refractive indexes are about 1.7 to 2.1, although it depends on the film forming method. For example, the refractive index when the SiN layer is formed by the PECVD (Plasma Enhanced Chemical Vapor Deposition) method at a substrate temperature of 100 ° C. or lower is about 1.85. The material constituting the first sub-barrier layer 12sa may be the same as or different from that of the second sub-barrier layer 12sb. The thickness of the first sub-barrier layer 12sa is preferably at least 200 nm or more when a SiN film or a SiON film is used in order to ensure moisture resistance reliability for the organic EL element. _{However, when the Al 2} O ₃ film is formed as the first sub-barrier layer 12sa by using the ALD (Atomic Layer Deposition) method capable of forming a dense thin film, the thickness may be 10 nm or more and 30 nm or less.

In the present embodiment, air is not filled between the plurality of fine protrusions, but a resin material (typically having a refractive index of about 1.5) constituting the organic barrier layer is filled. Is preferable. Refraction between the air and the materials that make up the protrusions when air is filled between the plurality of fine protrusions, or at least when air is present between the organic barrier layer and the plurality of fine protrusions. Since the rate difference is too large, even if the height of the convex portion is set to 20 nm or more and 80 nm or less, reflection may not be sufficiently suppressed.

If the cross-sectional shape of each convex portion of the second sub-barrier layer 12sb (the cross-sectional shape on the surface including the height direction (that is, the surface perpendicular to the substrate)) is a parabolic shape, the surface (that is, the surface orthogonal to the height direction of the convex portion). That is, the cross-sectional area (the cross-sectional shape is almost circular) of the convex portion on the surface parallel to the substrate surface changes linearly along the height direction, and as a result, the average refractive index is the highest along the height direction. It can be changed slowly. Therefore, when forming a convex portion having a specific height, the reflectance can be most effectively reduced by making the cross-sectional shape (the surface including the height direction) a parabolic shape.

If the average refractive index changes gently, the reflectance can be reduced even if a plurality of fine protrusions are not periodically and regularly formed. Therefore, the plurality of fine protrusions do not necessarily have to have a periodic structure. However, if there is a portion having a width equal to or more than the wavelength of light even in at least a part of the plurality of fine convex portions, light reflection (scattering) occurs in that portion. It is not preferable because it is visually recognized as uneven display on the OLED display device. Therefore, the plurality of fine convex portions may have different heights and widths, but it is preferable that all of them are included in the range of 20 nm or more and 80 nm or less.

In order to suppress reflection more effectively, the present inventor has not only the height and width of the plurality of fine protrusions, but also the distance between the plurality of fine protrusions (adjacent fine protrusions). It was found that it is effective to make the interval between them sufficiently small with respect to the wavelength of visible light (400 nm or more and 700 nm or less). That is, it is preferable that the distance between the plurality of fine protrusions is also 20 nm or more and 80 nm or less. The spacing between the plurality of fine protrusions (second sub-barrier layer 12sb), in other words, the width of the flat portion where the surface of the first sub-barrier layer 12sa is exposed is one-fifth of the lower limit of the wavelength of visible light of 400 nm. If it exceeds 80 nm, non-negligible reflection may occur in the flat portion.

Therefore, in the first embodiment of the present invention, the height and width of each of the plurality of fine protrusions and the distance between the adjacent fine protrusions are independently in the range of 20 nm or more and 80 nm or less. Is preferable. As a result, reflection on the surface of the first inorganic barrier layer (the top and side surfaces of the second sub-barrier layer 12sb, and the flat surface where the surface of the first sub-barrier layer 12sa is exposed) can be effectively suppressed. it can.

As another method for preventing reflection at the interface between layers having different refractive indexes, a method using a dielectric multilayer structure in which dielectric layers having a high refractive index and dielectric layers having a low refractive index are alternately laminated is also known. Has been done. However, since this dielectric multilayer structure utilizes interference, it effectively reduces the reflection of light (typically vertically incident light) that is incident on the interface at a particular angle (determined by design). However, the effect of reducing the reflection of light incident at other angles is limited. Further, for the same reason, the reflection of light of a specific wavelength (determined by design) can be effectively reduced, but the effect of reducing the reflection of light of other wavelengths is limited. On the other hand, according to the first embodiment, a high antireflection effect can be obtained for light having a wide incident angle and for light having a wide wavelength range.

If the width of the plurality of fine convex portions is smaller than 20 nm, an elongated convex portion having a large aspect ratio (height / width) will be formed, which increases manufacturing difficulty. In particular, it is difficult to form such an elongated convex portion by the PECVD method. Therefore, the width of the plurality of fine protrusions is preferably 20 nm or more.

As a method other than the PECVD method for forming a plurality of fine convex portions (second sub-barrier layer 12sb), a method for forming a porous low refractive index film by a sol-gel method or a molding method using a mold is used for minute particles. There are a method of forming a row of protrusions, a method of forming a fine structure by patterning by irradiation with a laser beam, and the like. Among these, the PECVD method is preferable from the viewpoint of mass productivity because the first sub-barrier layer 12sa and the second sub-barrier layer 12sb can be continuously formed as described later.

A part of the light incident on the TFE structure 10A is also reflected at the interface between the organic barrier layer 14 and the second inorganic barrier layer 16. Further, on the second inorganic barrier layer 16, for example, an optical film such as a polarizing plate or a touch panel layer may be arranged via an adhesive layer (including an adhesive layer). Since the adhesive layer is made of a polymer material having a refractive index of about 1.5, even at the interface between the second inorganic barrier layer 16 and the adhesive layer, due to the difference in refractive index between these layers, OLED3 Part of the light emitted from is reflected. Further, even when the protective glass or the like is arranged so as to cover the second inorganic barrier layer 16 with the air layer interposed therebetween, the light emitted from the OLED 3 on the surface of the second inorganic barrier layer (the interface with the air layer). Part of is reflected.

In the TFE structure 10B included in the OLED display device according to the second embodiment of the present invention shown in FIG. 2B, the first surface 14S in contact with the second inorganic barrier layer 16 of the organic barrier layer 14 has a plurality of fine first convex portions. The height of the plurality of fine first convex portions is 20 nm or more and 80 nm or less, and the width of the plurality of fine first convex portions is 20 nm or more and 80 nm or less (see FIG. 9). Further, the interval between the plurality of fine first convex portions is also preferably 20 nm or more and 80 nm or less. When the first surface 14S in contact with the second inorganic barrier layer 16 of the organic barrier layer 14 has such a fine convex portion, reflection due to the refractive index is reduced or eliminated. As a result, the OLED display device according to the second embodiment of the present invention can realize a higher light utilization efficiency than the OLED display device according to the first embodiment.

The second surface of the second inorganic barrier layer 16 is affected by a plurality of fine first convex portions (surface roughness) of the first surface 14S of the organic barrier layer 14, and has a plurality of fine second convex portions. Can be done. However, when the height of the plurality of fine first convex portions of the first surface 14S of the organic barrier layer 14 is small, the height of the plurality of fine second convex portions of the second surface 16S of the second inorganic barrier layer 16 is small. The height can be less than 20 nm.

Similar to the first inorganic barrier layer described in the first embodiment, a sub-barrier layer forming a convex portion may be formed on the second surface of the second inorganic barrier layer 16.

As will be described later with reference to FIG. 7B, in the second embodiment, the second surface 16S of the second inorganic barrier layer 16 has a plurality of fine second convex portions, and the plurality of fine second convex portions. The height of the second convex portion may be 20 nm or more and 80 nm or less, and the width of the plurality of fine second convex portions may be 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine second convex portions can be 20 nm or more and 80 nm or less. Since the second surface 16S of the second inorganic barrier layer 16 has such a plurality of fine second convex portions, reflection on the second surface 16S of the second inorganic barrier layer 16 is also reduced.

When the second surface 16S of the second inorganic barrier layer 16 has a plurality of fine second convex portions and a touch panel layer or a cover film is formed on the second surface 16S via an adhesive layer, the adhesive layer is formed. It is preferable that the gap between the plurality of fine second convex portions is filled. With such a configuration, the change in the average refractive index between the second inorganic barrier layer 16 and the adhesive layer can be made slower than when air is filled, so that the second surface can be made gentler. The reflection at 16S can be reduced more effectively.

The second inorganic barrier layer 16 of the organic barrier layer 14 does not have to be provided with a plurality of fine protrusions of the surface 12S in contact with the organic barrier layer 14 of the first inorganic barrier layer 12 in the OLED display device according to the first embodiment. If the first surface 14S in contact with the surface has the above-mentioned fine protrusions, at least the reflection at the interface between the organic barrier layer 14 and the second inorganic barrier layer 16 is reduced, so that the light utilization efficiency is higher than before. It can be realized.

FIG. 3 shows a schematic plan view of the OLED display device 100 according to the embodiment of the present invention. Both the OLED display devices of the first embodiment and the second embodiment may have the same planar structure as the OLED display device 100.

The OLED display device 100 comprises a flexible substrate 1, a circuit (backplane) 2 formed on the flexible substrate 1, a plurality of OLEDs 3 formed on the circuit 2, and a TFE structure 10 formed on the OLED 3. Have. The layer in which a plurality of OLEDs 3 are arranged may be referred to as an OLED layer 3. The circuit 2 and the OLED layer 3 may share some components. An optional polarizing plate (see reference numeral 4 in FIG. 1) may be further arranged on the TFE structure 10. Further, for example, a layer having a touch panel function may be arranged between the TFE structure 10 and the polarizing plate. That is, the OLED display device 100 can be modified into an on-cell type display device with a touch panel.

The circuit 2 has a plurality of TFTs (not shown), and a plurality of gate bus lines (not shown) and a plurality of source bus lines (not shown), each of which is connected to any of the plurality of TFTs (not shown). Have. The circuit 2 may be a known circuit for driving a plurality of OLEDs 3. The plurality of OLEDs 3 are connected to any of the plurality of TFTs included in the circuit 2. The OLED 3 may also be a known OLED.

The OLED display device 100 further includes a plurality of terminals 38 arranged in a peripheral region R2 outside the active region (area surrounded by a broken line in FIG. 3) R1 in which the plurality of OLEDs 3 are arranged, and a plurality of terminals. The TFE structure 10 has a plurality of leader wires 30 connecting the 38 with any of the plurality of gate bus lines or the plurality of source bus lines, and the TFE structure 10 is on the plurality of OLEDs 3 and the active region R1 of the plurality of leader wires 30. It is formed on the side part. That is, the TFE structure 10 covers the entire active region R1 and is selectively formed on the portion of the plurality of drawer wirings 30 on the active region R1 side, and the terminal 38 side and the terminal 38 of the drawer wiring 30 are formed. , Not covered by TFE structure 10.

In the following, an example in which the drawer wiring 30 and the terminal 38 are integrally formed by using the same conductive layer will be described, but they may be formed by using different conductive layers (including a laminated structure).

Next, with reference to FIGS. 4A, 4B, and 4C, the structure of the OLED display device 100A1 according to the first embodiment, which includes the TFE structure 10A1 having a relatively thick organic barrier layer 14A, will be described. 4A is a cross-sectional view including the pixel Pix along the 4A-4A'line in FIG. 3, and FIG. 4B is a cross-sectional view including the particles P along the 4A-4A' line in FIG. 3C. Is a cross-sectional view taken along the line 4C-4C'in FIG.

As shown in FIG. 4A, the thin film sealing structure 10A1 has a first inorganic barrier layer 12, an organic barrier layer 14A formed on the first inorganic barrier layer 12, and a second formed on the organic barrier layer 14A. It has an inorganic barrier layer 16. The organic barrier layer 14A has a relatively thick and flat surface.

The element substrate 20 of the OLED display device 100A1 further has a bank layer 48 that defines each of the plurality of pixels Pix. The bank layer 48 is formed of an insulating material, and is formed between the lower electrode 42 of the OLED 3 and the organic layer (organic EL layer) 44. The OLED 3 includes a lower electrode 42, an organic layer 44 formed on the lower electrode 42, and an upper electrode 46 formed on the organic layer 44, and the lower electrode 42 and the upper electrode 46 are, for example, anodes, respectively. And constitutes the cathode. The upper electrode 46 is a common electrode formed over the entire pixel in the active region, and the lower electrode (pixel electrode) 42 is formed for each pixel. If the bank layer 48 is present between the lower electrode 42 and the organic layer 44, holes are not injected from the lower electrode 42 into the organic layer 44. Therefore, since the region where the bank layer 48 exists does not function as the pixel Pix, the bank layer 48 defines the outer edge of the pixel Pix. The bank layer 48 is sometimes called a PDL (Pixel Defining Layer).

The bank layer 48 has an opening corresponding to the pixel Pix, and the side surface of the opening has a slope having a forward taper side surface portion TSF. The slope of the bank layer 48 surrounds each pixel. The bank layer 48 is formed using, for example, a photosensitive resin (for example, polyimide or acrylic resin). The thickness of the bank layer 48 is, for example, 1 μm or more and 2 μm or less. The inclination angle θb of the slope of the bank layer 48 is 60 ° or less. If the inclination angle θb of the slope of the bank layer 48 is more than 60 °, defects may occur in the layer located above the bank layer 48.

The organic barrier layer 14A covers the bank layer 48 and has a flat surface. The thickness of the organic barrier layer 14A is larger than the thickness of the bank layer 48, for example, 3 μm or more and 20 μm or less. The second inorganic barrier layer 16 is formed on the flat surface of the organic barrier layer 14A. The thickness of the organic barrier layer 14A may be 3 μm or more and 10 μm or less. In order to form the organic barrier layer 14A having a thickness of more than 10 μm, a resin material having a relatively high viscosity is required. The highly viscous resin material may not fill the gaps between the plurality of fine protrusions of the first inorganic barrier layer 12. If the resin material is not filled in the gaps between the plurality of fine protrusions, a sufficient antireflection effect may not be obtained. When the thickness of the organic barrier layer 14A is 3 μm or more and 10 μm or less, it can be formed of a resin material having a relatively low viscosity. Can be filled in. The organic barrier layer 14A having such a thickness can be formed by, for example, an inkjet method or a slit coating method.

As described with reference to FIG. 2A, the first inorganic barrier layer 12 has a first sub-barrier layer 12sa and a second sub-barrier layer 12sb formed on the first sub-barrier layer 12sa and in contact with the organic barrier layer 14. The surface 12S in contact with the organic barrier layer 14 of the first inorganic barrier layer 12 has a plurality of fine convex portions, and the height of the plurality of fine convex portions is 20 nm or more and 80 nm or less, and a plurality of fine protrusions are formed. The width of the fine convex portion is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine protrusions is 20 nm or more and 80 nm or less. As will be described later with reference to FIG. 7A, the second sub-barrier layer 12sb has a plurality of discretely distributed island-shaped portions, and even if the plurality of island-shaped portions form the plurality of fine convex portions. Good. The second sub-barrier layer 12sb is made of, for example, SiN or SiON. At this time, the refractive index of SiN or SiON is preferably 1.70 or more and 2.10 or less.

The surface roughness of the first sub-barrier layer 12sa (for example, arithmetic mean roughness Ra (according to JIS)) is, for example, less than 5 nm. The first sub-barrier layer 12sa is, for example, an Al ₂ O ₃ layer having a thickness of 10 nm or more and 30 nm or less. The first sub-barrier layer 12sa may be, for example, a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less. The second inorganic barrier layer 16 is, for example, a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less.

The first inorganic barrier layer 12 and the second inorganic barrier layer 16 are selectively formed only in a predetermined region so as to cover the active region R1 by, for example, a PECVD method using a mask. The organic barrier layer 14A is formed only in the region surrounded by the inorganic barrier layer joint where the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact with each other. Therefore, the organic barrier layer 14A serves as an intrusion route for moisture, and the moisture does not reach the active region R1 of the OLED display device. The organic barrier layer 14A is formed of a colorless and transparent photocurable resin (for example, an acrylic resin or an epoxy resin) in a predetermined region by using, for example, an inkjet method. The refractive index of the acrylic resin is, for example, 1.48 or more and 1.55 or less. The refractive index of the epoxy resin is, for example, 1.55 or more and 1.61 or less.

The presence of particles (typically 0.5 μm or more and 5 μm or less) P in the active region R1 before or during the formation of the first inorganic barrier layer 12 is schematically shown in FIG. 4B. As shown, cracks (defects) 12c may be formed in the first inorganic barrier layer 12. It is considered that this is caused by the collision (impingement) between the first inorganic barrier layer 12a growing from the surface of the particles P and the first inorganic barrier layer 12b growing from the flat portion of the surface of the OLED 3. The presence of such cracks 12c reduces the barrier property of the TFE structure. By covering the first inorganic barrier layer 12 with an organic barrier layer 14A having a sufficient thickness, the TFE structure 10A1 can suppress a decrease in barrier property.

Next, the structure of the TFE structure 10A1 on the lead-out wiring 30 will be described with reference to FIG. 4C. FIG. 4C is a cross-sectional view taken along the line 4C-4C'in FIG. 3, and is a cross-sectional view of a portion 32 of the drawer wiring 30 on the active region R1 side.

The organic barrier layer 14A is formed only in the active region (region surrounded by the broken line in FIG. 2) R1 in the TFE structure 10 in FIG. 3, and is not formed outside the active region R1. Therefore, outside the active region R1, the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact with each other. That is, as described above, the organic barrier layer 14A is surrounded by the inorganic barrier layer joint portion in which the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact with each other. Therefore, as shown in FIG. 4C, the portion 32 of the drawer wiring 30 on the active region R1 side is covered with the first inorganic barrier layer 12 and the second inorganic barrier layer 16.

Next, the structure of the OLED display device 100A2 according to the first embodiment will be described with reference to FIGS. 5A, 5B and 5C, which comprises a TFE structure 10A2 having a relatively thin organic barrier layer 14B. 5A is a cross-sectional view including the pixel Pix along the 4A-4A'line in FIG. 3, and FIG. 5B is a cross-sectional view including the particles P along the 4A-4A' line in FIG. 3C. Is a cross-sectional view taken along the line 4C-4C'in FIG.

The organic barrier layer 14B of the TFE structure 10A2 shown in FIG. 5A has a plurality of discretely distributed solid parts. The plurality of solid portions have a pixel peripheral solid portion 14Ba extending from the slope of the first inorganic barrier layer 12 on the side surface of the opening of the bank layer 48 to the periphery within the pixel Pix.

The thickness of the organic barrier layer 14B (here, the thickness of the solid portion 14Ba around the pixel) is preferably 50 nm or more and less than 200 nm. When the thickness of the solid portion 14Ba around the pixel increases, the discretely dispersed solid portion becomes a continuous film. The OLED display device 100A2 having a solid portion in which the organic barrier layer 14B is discretely dispersed has an advantage that it is superior in flexibility to the OLED display device 100A having a relatively thick organic barrier layer 14A.

Further, as shown in FIG. 5B, when the particles P are present, the solid portion 14Bb is formed so as to fill the cracks 12c of the first inorganic barrier layer 12, and the surface of the solid portion 14Bb is on the particles P. The surface of the first inorganic barrier layer 12a and the surface of the first inorganic barrier layer 12b on the flat portion of the OLED 3 are continuously and smoothly connected. Since the organic barrier layer 14B is formed by curing a liquid photocurable resin, a concave surface is formed by surface tension. At this time, the photocurable resin exhibits good wettability with respect to the first inorganic barrier layer 12. If the photocurable resin has poor wettability with respect to the first inorganic barrier layer 12, it may become convex on the contrary. The organic barrier layer 14 may also be thinly formed on the surface of the first inorganic barrier layer 12a on the particles P.

The solid portion 14Bb having a concave surface continuously and smoothly connects the surface of the first inorganic barrier layer 12a on the particles P and the surface of the first inorganic barrier layer 12b on the flat portion. On top of this, the second inorganic barrier layer 16 can be formed with a dense film without defects. As described above, the organic barrier layer 14B can maintain the barrier property of the TFE structure 10A2 even in the presence of the particles P.

Next, the structure of the TFE structure 10A2 on the lead-out wiring 30 will be described with reference to FIG. 5C. FIG. 5C is a cross-sectional view taken along the line 4C-4C'in FIG. 3, and is a cross-sectional view of a portion 32 of the leader wiring 30 on the active region R1 side.

As shown in FIG. 5C, the organic barrier layer 14B includes a solid portion 14Bc formed around a convex portion on the surface of the first inorganic barrier layer 12 that reflects the cross-sectional shape of the portion 32 of the lead-out wiring 30. Due to the presence of the solid portion 14Bc, the second inorganic barrier layer 16 can be formed on the step of the first inorganic barrier layer 12 with a dense film having no defects.

The organic barrier layer 14B can be formed, for example, by the method described in

Patent Document

1 or 2 above. For example, in a chamber, a vapor or atomized organic material (eg, acrylic monomer) is supplied onto an element substrate maintained at a temperature below room temperature and condensed on the element substrate to form a liquid capillary tube of the organic material. Due to the phenomenon or surface tension, the first inorganic barrier layer 12 is unevenly distributed at the boundary between the side surface of the convex portion and the flat portion. Then, by irradiating the organic material with, for example, ultraviolet rays, a solid portion of the organic barrier layer (for example, an acrylic resin layer) 14B is formed at the boundary portion around the convex portion. The organic barrier layer 14B formed by this method has substantially no solid portion in the flat portion. At this time, the viscosity of the photocurable resin, the wettability with respect to the slope, and the like are controlled so that the liquid film is also formed on the slope of the bank layer 48. The surface of the slope may be modified. Further, as described in Patent Document 3, the thickness of the resin layer to be first formed is adjusted (for example, less than 100 nm), and / or the ashing conditions (including time) are adjusted. It is also possible to form the organic barrier layer 14B.

For example, when the solid portion 14Bc is formed from the terminal 38 along the lead-out wiring 30, the solid portion 14Bc serves as an intrusion route for moisture, and the moisture reaches the active region R1 of the OLED display device 100A2. There is. In order to prevent this, an inorganic barrier layer joint portion in which the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact is formed in a part of the TFE structure 10A2 formed on the drawer wiring 30. In such an inorganic barrier layer joint, for example, the taper angle of the lead wire 30 is set to 70 ° or less, or the photocurable resin is vaporized by irradiating infrared rays or the like until the photocurable resin is cured. You can let them do it.

The organic barrier layer 14B may be formed by using, for example, a spray method, a spin coating method, a slit coating method, screen printing or an inkjet method. An ashing step may be further included. The organic barrier layer may be formed by using a photosensitive resin and mask exposure may be performed. By mask exposure, a solid portion 14Ba around the pixel may be formed, and an inorganic barrier layer joint portion in which the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact may be formed.

FIG. 6A shows a schematic cross-sectional view of the TFE structure 10A1 in the OLED display device 100A1, and FIG. 6B shows a schematic cross-sectional view of the TFE structure 10A2 in the OLED display device 100A2.

The relatively thick organic barrier layer 14A of the TFE structure 10A1 shown in FIG. 6A covers the bank layer 48 and has a flat surface. The surface 12S of the first inorganic barrier layer 12 in contact with the organic barrier layer 14A has a plurality of fine protrusions. The relatively thin organic barrier layer 14B of the TFE structure 10A2 shown in FIG. 6B has a plurality of discretely distributed solid portions from the slope of the first inorganic barrier layer 12 on the side surface of the opening of the bank layer 48. It has a pixel peripheral solid portion 14Ba that extends to the periphery within the pixel Pix. The surface 12S in contact with the organic barrier layer 14B of the first inorganic barrier layer 12 has a plurality of fine protrusions.

Next, with reference to FIG. 7A, the structure and formation method of the first inorganic barrier layer 12 in the TFE structure 10A1 of the OLED display device 100A1 and the TFE structure 10A2 of the OLED display device 100A2 according to the first embodiment, and the first inorganic barrier layer. It will be explained that the reflection at the interface between 12 and the organic barrier layer 14B is suppressed.

As shown in FIG. 7A, the first inorganic barrier layer 12 has a first sub-barrier layer 12sa and a second sub-barrier layer 12sb formed on the first sub-barrier layer 12sa and in contact with the organic barrier layer 14. The surface 12S in contact with the organic barrier layer 14 of the first inorganic barrier layer 12 has a plurality of fine convex portions, the height of the plurality of fine convex portions is 20 nm or more and 80 nm or less, and the plurality of fine convex portions. The width of is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine protrusions is 20 nm or more and 80 nm or less. As illustrated here, the second sub-barrier layer 12sb may have a plurality of discretely distributed island-shaped portions, and the plurality of island-shaped portions may form the plurality of fine convex portions. At this time, the surface 12S of the first inorganic barrier layer 12 includes the surface of a plurality of discretely distributed island-shaped portions of the second sub-barrier layer 12sb and the second sub-barrier layer 12sb among the surfaces of the first sub-barrier layer 12sa. It will be composed of a plurality of constituent island-shaped portions that are not formed.

The first sub-barrier layer 12sa is, for example, an Al ₂ O ₃ layer (alumina layer) having a thickness of 10 nm or more and 30 nm or less. A dense film-like Al ₂ O ₃ layer having excellent barrier properties can be obtained by forming it by the ALD (Atomic Layer Deposition) method. The first sub-barrier layer 12sa may be a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less. The SiN layer or the SiON layer can be formed by the PECVD method. When formed in this way, the refractive index of SiN or SiON is 1.70 or more and 2.10 or less.

The second sub-barrier layer 12sb is formed of, for example, SiN or SiON. The second sub-barrier layer 12sb can also be formed by the PECVD method. When the first sub-barrier layer 12sa is formed of the SiN layer or the SiON layer, the first sub-barrier layer 12sa and the second sub-barrier layer 12sb can be continuously formed by the PECVD method, so that the throughput is increased and the manufacturing cost is increased. Can be reduced. When continuously formed by the PECVD method, the first sub-barrier layer 12sa is formed and then distributed discretely by increasing the film forming speed and / or adjusting the film forming temperature (element substrate temperature). A second sub-barrier layer 12sb having a plurality of island-shaped portions can be obtained. Regarding the film formation temperature, the temperature may be raised or lowered so as to deviate from the appropriate element substrate temperature, but in consideration of the thermal effect on the organic EL device, the temperature is lowered. It is preferable to adjust with. Further, when the second sub-barrier layer 12sb is formed of the SiON layer, the oxygen concentration to be supplied may be increased. In this way, the first sub-barrier layer 12sa, which is dense and has a high barrier property, and the second sub-barrier layer 12sb, which has a plurality of discretely distributed island-shaped portions, can be formed with desired thicknesses. Compared with the case where the density of the light is continuously changed, it is possible to secure the reliability of moisture resistance and suppress the reflection of light more reliably.

The surface 12S in contact with the organic barrier layer 14 of the first inorganic barrier layer 12 has a plurality of fine convex portions, the height of the plurality of fine convex portions is 20 nm or more and 80 nm or less, and the plurality of fine convex portions. The width of is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine protrusions is 20 nm or more and 80 nm or less. The plurality of fine convex portions having such a configuration and the flat portions between them are sufficiently small even with respect to the lower limit region of visible light (about 400 nm) and do not reflect light. Further, since the organic barrier layer having a refractive index smaller than that is filled between the plurality of fine convex portions, the average refractive index can be gradually lowered. Therefore, the reflection caused by the refractive index can be reduced or eliminated.

As shown in FIG. 7B, the OLED display device 100A1 and the OLED display device 100A2 according to the first embodiment have a region in which the second inorganic barrier layer 16 is directly formed on the first inorganic barrier layer 12. If the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are made of the same material, light will not be reflected at the interface between the first inorganic barrier layer 12 and the second inorganic barrier layer 16. Even when the first sub-barrier layer 12sa is _{formed of the Al 2} O ₃ layer and the second sub-barrier layer 12 sb is formed of the SiN layer or the SiON layer, the refractive index of _{Al 2} O _{3 is about 1.80.} Since the refractive index of SiN is about 1.85 as described above, there is almost no difference in the refractive index and the reflection at the interface is very small. Therefore, since the plurality of fine convex portions act on the organic barrier layer having a smaller refractive index to gradually lower the average refractive index, the reflection caused by the refractive index can be reduced or eliminated.

Since the height of the fine convex portion on the surface of the first inorganic barrier layer 12 is 80 nm or less, even if the second inorganic barrier layer 16 is formed directly on the height, the thickness of the second inorganic barrier layer 16 can be increased. 200 nm or more, more preferably 300 nm or more larger than the height of the fine convex portion on the surface of the first inorganic barrier layer 12 (for example, when the height of the convex portion is 80 nm, the thickness of the second inorganic barrier layer 16 is increased. By setting the diameter to 380 nm or more), a TFE structure having a good barrier property can be obtained without lowering the barrier property of the second inorganic barrier layer 16 against water and oxygen.

Next, the OLED display device 100B1 and the OLED display device 100B2 according to the second embodiment will be described with reference to FIGS. 8A and 8B. FIG. 8A shows a schematic cross-sectional view of the TFE structure 10B1 in the OLED display device 100B1, and FIG. 8B shows a schematic cross-sectional view of the TFE structure 10B2 in the OLED display device 100B2.

The relatively thick organic barrier layer 14A of the TFE structure 10B1 shown in FIG. 8A covers the bank layer 48 and has a flat surface. The surface 12S of the first inorganic barrier layer 12 in contact with the organic barrier layer 14A has a plurality of fine protrusions. Further, the first surface 14AS in contact with the second inorganic barrier layer 16 of the organic barrier layer 14A has a plurality of fine first convex portions, and the height of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. The width of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine first convex portions is 20 nm or more and 80 nm or less. Further, the second surface 16S of the second inorganic barrier layer 16 has a plurality of fine second convex portions, and the height of the plurality of fine second convex portions is 20 nm or more and 80 nm or less, and the plurality of fine parts are present. The width of the second convex portion is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine second convex portions is 20 nm or more and 80 nm or less. It is preferable that the voids between the plurality of fine second convex portions are filled with an adhesive layer having a higher refractive index than air and a lower refractive index than the plurality of fine second convex portions, for example. By forming a plurality of fine first convex portions and a plurality of fine second convex portions in a range sufficiently smaller than the wavelength of visible light in this way, the tops and side surfaces of the respective convex portions, and further adjacent to each other. It is possible to effectively suppress the reflection in the flat portion between the convex portion and the convex portion.

The relatively thin organic barrier layer 14B of the TFE structure 10B2 shown in FIG. 8B has a plurality of discretely distributed solid portions from the slope of the first inorganic barrier layer 12 on the side surface of the opening of the bank layer 48. It has a pixel peripheral solid portion 14Ba that extends to the periphery within the pixel Pix. The surface 12S in contact with the organic barrier layer 14B of the first inorganic barrier layer 12 has a plurality of fine protrusions. Further, the first surface 14BS in contact with the second inorganic barrier layer 16 of the organic barrier layer 14B has a plurality of fine first convex portions, and the height of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. The width of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine first convex portions is 20 nm or more and 80 nm or less. Further, the second surface 16S of the second inorganic barrier layer 16 has a plurality of fine second convex portions, and the height of the plurality of fine second convex portions is 20 nm or more and 80 nm or less, and the plurality of fine parts are present. The width of the second convex portion is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine second convex portions is 20 nm or more and 80 nm or less.

FIG. 9 is a schematic view showing the interface between the organic barrier layer 14A and the second inorganic barrier layer 16 (surface 14AS of the organic barrier layer 14A) and the surface 16S of the second inorganic barrier layer 16 in the TFE structure 10B (10B1, 10B2). It is a cross-sectional view.

As schematically shown in FIG. 9, the first surfaces 14AS and 14BS in contact with the second inorganic barrier layers 16 of the

organic barrier layers

14A and 14B have a plurality of fine first convex portions and a plurality of fine first protrusions. The height of the one convex portion is 20 nm or more and 80 nm or less, and the width of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine first convex portions is 20 nm or more and 80 nm or less. Further, the second surface 16S of the second inorganic barrier layer 16 is affected by a plurality of fine first convex portions (surface roughness) of the first surfaces 14AS and 14BS of the

organic barrier layers

14A and 14B, and a plurality of them. It has a fine second convex portion. The height of the plurality of fine second convex portions is 20 nm or more and 80 nm or less, and the width of the plurality of fine second convex portions is 20 nm or more and 80 nm or less. Further, the distance between the plurality of fine second convex portions is 20 nm or more and 80 nm or less. Since the plurality of fine first convex portions and second convex portions each form a layer having an average refractive index that gradually changes between the organic barrier layer and the adhesive layer, reflection due to the refractive index is caused. It can be reduced or eliminated. Therefore, the reflection at the interface between the organic barrier layer 14A and the second inorganic barrier layer 16 and the reflection at the second surface 16S of the second inorganic barrier layer 16 are also reduced. The OLED display device of the second embodiment can further reduce the reflection in the TFE structure as compared with the OLED display device of the first embodiment.

As a method for forming a fine first convex portion on the surfaces of the

organic barrier layers

14A and 14B, for example, the following method can be exemplified.

After forming the organic resin layers to be the

organic barrier layers

14A and 14B by a known method, O ₂ , O ₃ or N ₂ O gas is turned into plasma to generate oxygen radicals in a high energy state, and the oxygen radicals are converted into the organic resin layer. Irradiate to. The irradiated oxygen radicals combine with the carbon that constitutes the organic resin layer _{to generate CO 2} , and decompose and vaporize the organic resin layer (sometimes called ashing). By adjusting the plasma energy and oxygen radical irradiation conditions at this time, a concavo-convex structure having a height, a width, and an interval of 20 nm or more and 80 nm or less is independently formed on the surface of the organic barrier layer.

When the organic resin film is formed on the flat portion of the element substrate when the solid portion 14Ba around the pixel is formed and then ashed, the third surface of the first inorganic barrier layer 12 existing on the flat portion is formed. It is not necessary to remove all the organic resin filling the fine concave portions (between the fine convex portions) of 12S, and the organic resin filling the fine concave portions may be left.

In the conventional TFE structure described in Patent Documents 1 to 3, etc., the surface of each barrier layer is flat, and the height and width of the convex portions formed on the surface are typically less than 20 nm. Is believed to have been less than 5 nm.

The embodiment of the present invention is suitably used for an OLED display device having a TFE structure, particularly a flexible OLED display device and a method for manufacturing the same.

1: Substrate (flexible substrate)
2: Circuit 3: OLED layer 4: Polarizing

plate

10, 10A, 10A1, 10A2, 10B, 10B1, 10B2: TFE structure 12: First inorganic barrier layer 12S: Surface of first inorganic barrier layer 12sa: First sub-barrier layer 12sb :

Second sub-barrier layer

14, 14A, 14B: Organic barrier layer 14S, 14AS, 14BS: Surface of organic barrier layer 14Ba: Solid part around pixel 16: Second inorganic barrier layer 16S: Surface of second inorganic barrier layer 30: Drawer wiring 38: Terminal 42: Lower electrode 44: Organic layer (organic EL layer)
46: Upper electrode 48: Bank layer 100, 100A1, 100A2, 100B1, 100B2: OLED display device P: Particles

Claims

An organic EL display device having a plurality of pixels.
It has a substrate, an element substrate having a plurality of organic EL elements supported by the substrate, and a thin film sealing structure covering the plurality of organic EL elements.
The thin film sealing structure has a first inorganic barrier layer, an organic barrier layer formed on the first inorganic barrier layer, and a second inorganic barrier layer formed on the organic barrier layer.
The first inorganic barrier layer has a first sub-barrier layer and a second sub-barrier layer formed on the first sub-barrier layer and in contact with the organic barrier layer.
The surface of the first inorganic barrier layer in contact with the organic barrier layer has a plurality of fine convex portions, and the height of the plurality of fine convex portions is 20 nm or more and 80 nm or less, and the plurality of fine convex portions. An organic EL display device having a width of 20 nm or more and 80 nm or less.
The organic EL display device according to claim 1, wherein the distance between the plurality of fine convex portions is 20 nm or more and 80 nm or less.
The organic EL display device according to claim 1 or 2, wherein the resin material constituting the organic barrier layer is filled in the gaps between the plurality of fine convex portions.
The second sub-barrier layer has a plurality of discretely distributed island-shaped portions, and the plurality of island-shaped portions form the plurality of fine convex portions, according to any one of claims 1 to 3. The organic EL display device described.
The organic EL display device according to any one of claims 1 to 4, wherein the second sub-barrier layer is made of SiN or SiON.
The organic EL display device according to any one of claims 1 to 5, wherein the surface roughness of the first sub-barrier layer is less than 5 nm.
The organic EL display device according to any one of claims 1 to 6, wherein the first sub-barrier layer is an Al 2 O 3 layer having a thickness of 10 nm or more and 30 nm or less.
The organic EL display device according to any one of claims 1 to 6, wherein the first sub-barrier layer is a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less.
The organic EL display device according to any one of claims 1 to 8, wherein the second inorganic barrier layer includes a SiN layer or a SiON layer having a thickness of 200 nm or more and 400 nm or less.
The element substrate further has a bank layer that defines each of the plurality of pixels.
The organic EL display device according to any one of claims 1 to 9, wherein the organic barrier layer covers the bank layer and has a flat surface.
The organic EL display device according to claim 10, wherein the thickness of the organic barrier layer is 3 μm or more and 10 μm or less.
The element substrate further has a bank layer that defines each of the plurality of pixels.
The bank layer has a slope that surrounds each of the plurality of pixels.
The organic barrier layer has a plurality of discretely distributed solid parts.
The organic EL according to any one of claims 1 to 9, wherein the plurality of solid portions have a pixel peripheral solid portion extending from a portion on the slope to the periphery of the pixel of the first inorganic barrier layer. Display device.
The organic EL display device according to claim 12, wherein the thickness of the organic barrier layer is 50 nm or more and less than 200 nm.
The first surface of the organic barrier layer in contact with the second inorganic barrier layer has a plurality of fine first convex portions, and the height of the plurality of fine first convex portions is 20 nm or more and 80 nm or less. The organic EL display device according to any one of claims 1 to 13, wherein the width of the plurality of fine first convex portions is 20 nm or more and 80 nm or less.
The organic EL display device according to claim 14, wherein the distance between the plurality of fine first convex portions is 20 nm or more and 80 nm or less.
The second surface of the second inorganic barrier layer, which is opposite to the surface in contact with the first surface, has a plurality of fine second convex portions, and the height of the plurality of fine second convex portions. The organic EL display device according to claim 13, wherein the width and the interval are independently 20 nm or more and 80 nm or less.