JP2019102417A - Organic el display device - Google Patents

Abstract

To provide an organic EL display device including a thin film encapsulation structure, in which a yield can be improved.SOLUTION: A thin film encapsulation structure (10) of an organic EL display device (100) has a first inorganic barrier layer (12), an organic barrier layer (14) in contact with an upper surface of the first inorganic barrier layer (12) and having a plurality of solid portions discretely dispersed therein, and a second inorganic barrier layer (16) in contact with the upper surface of the first inorganic barrier layer (12) and an upper surface of the solid portion of the organic barrier layer (14). The organic barrier layer (14) shows a black color. The structure also has a bank layer (48) defining each pixel; and the bank layer has an inclined surface enclosing a periphery of the pixel. The solid portion has a pixel peripheral solid portion ranging from a portion on an inclined surface of the first inorganic barrier layer to the periphery in the pixel; the portion on the inclined surface of the first inorganic barrier layer has lyophilicity to a photosensitive resin; and the surface of a flat portion of the first inorganic barrier layer in a region enclosed by the bank layer has liquid repellency to the photosensitive resin.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an organic EL display device and a method of manufacturing the same.

  Organic EL (Electro Luminescence) display devices have begun to be put to 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 light emitting diode (OLED) per pixel and at least one thin film transistor (TFT) that controls the current supplied to each OLED. Hereinafter, the organic EL display device will be referred to as an OLED display device. Thus, an OLED display device having switching elements such as TFTs for each OLED is called an active matrix OLED display device. Further, the substrate on which the TFT and the OLED are formed is referred to as an element substrate.

OLEDs (in particular, organic light emitting layer and cathode electrode materials) are easily deteriorated by the influence of moisture and display unevenness is apt to occur. 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 lose flexibility. The thin film sealing technology is to obtain sufficient water vapor barrier property with a thin film by alternately laminating an inorganic barrier layer and an organic barrier layer. From the viewpoint of the moisture resistance reliability of the OLED display device, typically, 1 × 10 ⁻⁴ g / m ² / day or less is required as a WVTR (Water Vapor Transmission Rate: WVTR) of a thin film sealing structure.

  The thin film encapsulation structure used in OLED displays currently on the market has an organic barrier layer (polymer barrier layer) having a thickness of about 5 μm to about 20 μm. Thus, the relatively thick organic barrier layer also plays a role of planarizing the surface of the element substrate. However, if the organic barrier layer is thick, there is a problem that the flexibility of the OLED display is limited.

  In Patent Document 1, when the first inorganic material layer, the first resin material, and the second inorganic material layer are formed in this order from the element substrate side, the first resin material is used as the first inorganic material. A thin film sealing structure is disclosed which is unevenly distributed around the convex portion of the layer (the first inorganic material layer covering the convex portion). According to Patent Document 1, when the first resin material is unevenly distributed around the convex portion that may not be sufficiently covered by the first inorganic material layer, the penetration of water or oxygen from the portion is suppressed. In addition, the first resin material functions as a base layer of the second inorganic material layer, whereby the second inorganic material layer is properly formed, and the desired thickness of the side surface of the first inorganic material layer is obtained. It becomes possible to coat appropriately. The first resin material is formed as follows. The heated and vaporized mist-like organic material is supplied onto the element substrate maintained at a temperature below room temperature, and the organic material condenses on the substrate and drops. The dropletized organic material moves on the substrate by capillary action or surface tension, and is localized at the boundary between the side surface of the convex portion of the first inorganic material layer and the substrate surface. Thereafter, the first resin material is formed at the boundary portion by curing the organic material. Patent Documents 2 and 3 also disclose an OLED display device having a thin film sealing structure similar to that of Patent Document 2.

  It is considered that the flexibility of the OLED display is improved because the thin film encapsulation structure having an organic barrier layer composed of uneven distribution resin described in Patent Document 1 or 2 does not have a thick organic barrier layer. .

International Publication No. 2014/196137 JP, 2016-39120, A JP, 2015-50022, A

  The yield of an OLED display having a thin film sealing structure including an organic barrier layer having a plurality of discretely distributed solid portions manufactured by the method described in Patent Document 1 or 2 is not necessarily high.

  As described above, when the organic barrier layer is formed by the method described in Patent Document 1 or 2, when the surface of the first inorganic material layer has a convex portion, the convex portion of the surface of the first inorganic material layer The organic barrier layer (solid portion) can be formed only around the However, since the method of forming the organic barrier layer described in Patent Document 1 or 2 only involves uneven distribution using the surface tension of the liquid resin, there is a risk that the organic barrier layer may not be formed reliably in the necessary places. . In addition, there is also a possibility that the organic barrier layer may be formed at unnecessary places. Since the organic barrier layer of the thin film sealing structure of Patent Document 1 or 2 is formed using a transparent photo-curable resin, the organic barrier layer is appropriate around the convex portion on the surface of the first inorganic material layer. It can not be easily checked whether it is formed or not. That is, it takes time and / or cost for checking whether or not the organic barrier layer is formed at the necessary place.

  The convex portion on the surface of the first inorganic material layer is formed, for example, by a step that reflects a wiring such as a gate bus line, a source bus line, or a lead wiring connected thereto. In addition, when particles (fine dust) exist above or below the first inorganic material layer, projections are formed on the surface of the first inorganic material layer.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an organic EL display device having a thin film sealing structure capable of improving the yield, and a method of manufacturing the same.

  An organic EL display device according to an embodiment of the present invention is an organic EL display device having a plurality of pixels, and a substrate and a plurality of organic EL elements supported by the substrate, each of the plurality of pixels And a thin film sealing structure covering the plurality of pixels, the thin film sealing structure comprising: a first inorganic barrier layer; An organic barrier layer having a plurality of solid portions in contact with the top surface of the inorganic barrier layer and discretely distributed, a top surface of the first inorganic barrier layer and a top surface of the plurality of solid portions of the organic barrier layer And a second inorganic barrier layer, and the organic barrier layer has a black color.

  In one embodiment, the organic barrier layer contains a dye or a pigment.

  In one embodiment, a bank layer defining each of the plurality of pixels is further included, the bank layer has a slope surrounding each of the plurality of pixels, and the plurality of solid portions include: It has a pixel peripheral solid portion extending from the portion on the slope of the first inorganic barrier layer to the periphery in the pixel.

  In one embodiment, an inclination angle of the slope of the bank layer is 60 ° or less.

  A manufacturing method according to an embodiment of the present invention is a method of manufacturing any one of the above-described organic EL display devices, and the step of forming the thin film sealing structure is the device in which the first inorganic barrier layer is formed. Step A of preparing a substrate, Step B of forming a liquid film containing a photosensitive resin on the first inorganic barrier layer, and Step C of forming a resin layer by irradiating the liquid film with light And D. forming the organic barrier layer, including partially removing the resin layer by a dry process.

  In one embodiment, the inclined surface of the first inorganic barrier layer is lyophilic with respect to the liquid film, and a region surrounded by the bank layer is liquid repellent with respect to the liquid film. Have.

  In one embodiment, the step D further includes the step of performing plasma treatment and / or corona treatment.

  In one embodiment, the step of forming the thin film sealing structure further includes the step of ashing the surface of the first inorganic barrier layer after the step A and before the step B.

  In one embodiment, the step of forming the thin film sealing structure further includes the step of applying a silane coupling agent to the surface of the first inorganic barrier layer after the step A and before the step B. .

  In one embodiment, the liquid film contains a photocurable resin and a dye or a pigment.

  In one embodiment, the liquid film contains a photopolymerizable dye monomer.

  In one embodiment, the step B is performed by a spray method, a spin coat method, a slit coat method, a screen printing method or an inkjet method.

  In one embodiment, the step B includes, after the step A, disposing the element substrate in a chamber and supplying a photocurable resin in vapor or mist form in the chamber; Forming the liquid film by condensing the photocurable resin on the barrier layer.

  In one embodiment, the manufacturing method may include, after the step of forming the thin film sealing structure, a step of optically acquiring a pattern of the organic barrier layer, and the quality of the thin film sealing structure based on the pattern. And determining.

  According to an embodiment of the present invention, an organic EL display device provided with a thin film sealing structure and a manufacturing method thereof that can improve yield are provided.

(A) is a schematic partial cross-sectional view of the active region of the OLED display device 100 according to an embodiment of the present invention, (b) is a partial cross-sectional view of the TFE structure 10 formed on the OLED 3. FIG. 1 is a plan view schematically showing a structure of an OLED display device 100 according to an embodiment of the present invention. (A)-(c) is typical sectional drawing of the OLED display apparatus 100, (a) is sectional drawing along 3A-3A 'line in FIG. 2, (b) is a cross-sectional view in FIG. FIG. 3C is a cross-sectional view taken along line 3B-3B ′, and FIG. 2C is a cross-sectional view taken along line 3C-3C ′ in FIG. (A) is an enlarged view of a portion including the particle P in FIG. 3 (a), and (b) shows the size of the particle P, the first inorganic barrier layer (SiN layer) covering the particle P, and the organic barrier layer FIG. 6C is a schematic cross-sectional view of the first inorganic barrier layer covering the particle P. FIG. It is a top view which shows typically the several pixel and the bank layer 48 which the OLED display apparatus 100 has. FIGS. 6A and 6B are schematic cross-sectional views of the OLED display device 100, and FIG. 6A is a cross-sectional view along line 6A-6A ′ in FIG. 6 shows a cross-sectional view along line 6B-6B 'in FIG. It is a schematic diagram which shows the foreign material detection apparatus 50 used for the manufacturing method of the OLED display apparatus by embodiment of this invention. FIG. 5 is a schematic view illustrating an inkjet device 60 used in a method of manufacturing an OLED display according to an embodiment of the present invention. It is a schematic diagram for demonstrating the preferable range of the volume of the organic barrier layer formed in the periphery of particle P in the OLED display by embodiment of this invention, (a) is a cross section including the diameter of particle P ((b 9A-9A '), and FIG. 11B is a plan view as viewed in the normal direction.

  Hereinafter, an organic EL display device according to an embodiment of the present invention and a method of manufacturing the same will be described with reference to the drawings. The embodiments of the present invention are not limited to the embodiments exemplified below.

  First, the basic configuration of an OLED display device 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). FIG. 1 (a) is a schematic partial cross-sectional view of the active area of an OLED display 100 according to an embodiment of the present invention, and FIG. 1 (b) is a partial cross-sectional view of TFE structure 10 formed on OLED 3. It is.

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

  As shown in FIG. 1A, the OLED display device 100 includes a flexible substrate (hereinafter sometimes simply referred to as a “substrate”) 1 and a circuit (backplane) 2 including a TFT formed on the substrate 1. And an OLED 3 formed on the circuit 2 and a TFE structure 10 formed on the OLED 3. The OLED 3 is, for example, a top emission type. The top of the OLED 3 is, for example, a top electrode or a cap layer (refractive index adjustment layer). An optional polarizer 4 is disposed 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. 1 (b) is a partial cross-sectional view of TFE structure 10 formed on OLED 3. The TFE structure 10 has a first inorganic barrier layer (for example, a SiN layer) 12, an organic barrier layer (for example, an acrylic resin layer) 14, and a second inorganic barrier layer (for example, SiN layer) 16. The first inorganic barrier layer 12 is formed directly on the OLED 3. The organic barrier layer 14 is in contact with the top surface of the first inorganic barrier layer 12 and has a plurality of solid portions distributed discretely. The second inorganic barrier layer 16 is in contact with the upper surface of the first inorganic barrier layer 12 and the upper surfaces of a plurality of solid portions of the organic barrier layer 14. The organic barrier layer 14 exhibits a black color. The organic barrier layer 14 contains, for example, a dye.

  Since the organic barrier layer 14 has a black color, it can be inspected with less time and / or cost whether or not the organic barrier layer 14 is formed at the required place. Therefore, the yield of the OLED display device 100 can be improved. The manufacturing method and the inspection method of the OLED display device 100 will be described later.

  The organic barrier layer 14 may be colored in black so that it can be visually recognized in an inspection process described later, and does not have to have a light shielding property.

For example, the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are, for example, a SiN layer (for example, Si ₃ N ₄ layer) having a thickness of 400 nm, and the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are The thicknesses are each independently 200 nm or more and 1000 nm or less. The thickness of the TFE structure 10 is preferably 400 nm or more and less than 2 μm, and more preferably 400 nm or more and less than 1.5 μm. The thickness of the organic barrier layer (solid portion) 14 may be about 1 μm at most, although it depends on the size of the projections and particles on the surface of the first inorganic barrier layer 12. The thickness of the organic barrier layer (solid part) 14 is typically 200 nm or more and 500 nm or less.

  The TFE structure 10 is formed to protect the active area (see the active area R1 in FIG. 2) of the OLED display device 100, and at least in the active area, in order from the side closer to the OLED 3, as described above. A first inorganic barrier layer 12, an organic barrier layer 14, and a second inorganic barrier layer 16 are provided. The organic barrier layer 14 does not exist as a film covering the entire surface of the active region, but has an opening. In the organic barrier layer 14, the portion where the organic film actually exists except for the opening is referred to as a “solid portion”. In addition, the “opening” (sometimes referred to as “non-solid portion”) does not have to be surrounded by a solid part, and includes a notch and the like, and the first inorganic barrier layer 12 is not included in the opening. And the second inorganic barrier layer 16 are in direct contact with each other. The opening of the organic barrier layer 14 includes at least an opening formed to surround the active region, and the active region is in direct contact with the first inorganic barrier layer 12 and the second inorganic barrier layer 16. Completely surrounded by the portion (hereinafter referred to as "inorganic barrier layer junction").

  The structure and method of manufacturing an OLED display according to an embodiment of the present invention will be described with reference to FIGS. 2 to 6.

  FIG. 2 shows a schematic plan view of an OLED display device 100 according to an embodiment of the present invention.

  The OLED display device 100 includes 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 the 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 polarizer (see reference numeral 4 in FIG. 1) may be further disposed on the TFE structure 10. Also, for example, a layer having a touch panel function may be disposed between the TFE structure 10 and the polarizing plate. That is, the OLED display device 100 can be modified into a display device with an on-cell touch panel.

  The circuit 2 includes a plurality of TFTs (not shown), a plurality of gate bus lines (not shown) and a plurality of source bus lines (not shown) each 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 disposed in the peripheral region R2 outside the active region (region surrounded by a broken line in FIG. 2) R1 in which the plurality of OLEDs 3 are disposed, and a plurality of terminals The TFE structure 10 has an active region R1 on the plurality of OLEDs 3 and on the plurality of lead wirings 30 and the plurality of lead wirings 30 connecting the plurality of gate bus lines 38 to any one of the plurality of gate bus lines or source bus lines. 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 on the active region R1 side of the plurality of lead interconnections 30, and the terminal 38 side of the lead interconnection 30 and the terminal 38 are , TFE structure 10 is not covered.

  Although an example in which the lead-out wiring 30 and the terminal 38 are integrally formed using the same conductive layer will be described below, they may be formed using different conductive layers (including a stacked structure).

  Next, the TFE structure 10 of the OLED display device 100 will be described with reference to FIGS. 3 (a) to 3 (c). 3 (a) is a cross-sectional view taken along line 3A-3A 'in FIG. 2, and FIG. 3 (b) is a cross-sectional view taken along line 3B-3B' in FIG. 2 shows a cross-sectional view taken along line 3C-3C 'in FIG.

  As shown in FIGS. 3 (a) and 3 (b), the TFE structure 10 includes a first inorganic barrier layer 12 formed on the OLED 3, an organic barrier layer 14, a first inorganic barrier layer 12 and an organic barrier. And a second inorganic barrier layer 16 in contact with the layer 14. The first inorganic barrier layer 12 and the second inorganic barrier layer 16 are, for example, SiN layers, and selectively formed only in predetermined regions so as to cover the active regions R1 by plasma CVD using a mask. Generally, the surface of a layer formed by thin film deposition (for example, CVD, sputtering, vacuum evaporation) reflects the level difference of the base. The organic barrier layer (solid portion) 14 is formed only around the convex portion on the surface of the first inorganic barrier layer 12.

  FIG. 3A is a cross-sectional view taken along the line 3A-3A 'in FIG. 2, and shows a portion including the particle P. As shown in FIG. The particles P are fine dust generated during the manufacturing process of the OLED display device, for example, fine fragments of glass, particles of metal, particles of organic matter. In the case of using the mask vapor deposition method, particles P are particularly likely to be generated.

  As shown in FIG. 3A, the organic barrier layer (solid portion) 14 includes a portion 14 b formed around the particle P. This is because the acrylic monomer applied after the formation of the first inorganic barrier layer 12 is condensed around the surface of the first inorganic barrier layer 12 a on the particle P (the taper angle is more than 90 °) and is localized. is there. The flat portion of the first inorganic barrier layer 12 is an opening (non-solid portion) of the organic barrier layer 14.

  Here, with reference to FIGS. 4A to 4C, the structure of the portion including the particle P will be described. 4 (a) is an enlarged view of a portion including the particle P of FIG. 3 (a), and FIG. 4 (b) is the particle P, a first inorganic barrier layer (SiN layer) 12 covering the particle P, and an organic FIG. 4C is a schematic cross-sectional view of the first inorganic barrier layer 12 covering the particles P. FIG.

  As shown in FIG. 4C, when particles (for example, having a diameter of about 1 μm or more) P exist, cracks (defects) 12 c may be formed in the first inorganic barrier layer 12. This is considered to be caused by the collision (impingement) of the SiN layer 12a grown from the surface of the particle P and the SiN layer 12b grown from the flat portion of the surface of the OLED 3 as described later. The presence of such cracks 12 c reduces the barrier properties of the TFE structure 10.

  In the TFE structure 10 of the OLED display device 100, as shown in FIG. 4A, the organic barrier layer 14 is formed to fill the cracks 12c of the first inorganic barrier layer 12, and the organic barrier layer 14 is formed. The surface continuously and smoothly connects the surface of the first inorganic barrier layer 12 a on the particle P and the surface of the first inorganic barrier layer 12 b on the flat portion of the OLED 3. The organic barrier layer 14 is formed by curing a liquid photocurable resin as described later, and thus forms a concave surface by surface tension. At this time, the photocurable resin exhibits good wettability to the first inorganic barrier layer 12. If the wettability of the photocurable resin to the first inorganic barrier layer 12 is poor, it may be convex. The organic barrier layer 14 may be formed thin also on the surface of the first inorganic barrier layer 12 a on the particle P.

  The surface of the first inorganic barrier layer 12a on the particle P and the surface of the first inorganic barrier layer 12b on the flat portion are continuously and smoothly connected by the organic barrier layer (solid portion) 14 having a concave surface As a result, the second inorganic barrier layer 16 can be formed with a dense film free from defects. Thus, the organic barrier layer 14 can maintain the barrier properties of the TFE structure 10 even if the particles P are present.

The organic barrier layer (solid portion) 14 is formed in a ring shape around the particle P as shown in FIG. 4 (b). The diameter (area equivalent circle diameter) is, for example, 1μm about particles P when viewed from the normal direction, for example, the diameter (area equivalent circle diameter) D _o of the ring-shaped solid portion is 2μm or more.

  Here, for the example in which the organic barrier layer 14 is formed only at the discontinuous portion of the first inorganic barrier layer 12 formed on the particle P, before the particle P forms the first inorganic barrier layer 12 on the OLED 3 The particle P may be present on the first inorganic barrier layer 12. In this case, the organic barrier layer 14 is formed only at the discontinuous portion of the boundary between the particle P present on the first inorganic barrier layer 12 and the first inorganic barrier layer 12, and in the same manner as described above, the TFE structure 10 Maintain the barrier property of The organic barrier layer 14 may be thinly formed also on the surface of the first inorganic barrier layer 12 a on the particle P or the surface of the particle P. In the present specification, the organic barrier layer 14 is said to be present around the particle P for the purpose of including all these aspects.

  The organic barrier layer (solid portion) 14 is not limited to the example shown in FIG. 3A, and is formed only around the convex portion on the surface of the first inorganic barrier layer 12 for the same reason as described above. Another example of the portion where the organic barrier layer (solid portion) 14 is formed is shown below.

  Next, the structure of the TFE structure 10 on the lead wire 30 will be described with reference to FIG. FIG. 3B is a cross-sectional view taken along the line 3B-3B 'in FIG. 2, and is a cross-sectional view of the portion 32 on the active region R1 side of the lead-out wiring 30.

  As shown in FIG. 3B, the organic barrier layer (solid portion) 14 is formed around the convex portion on the surface of the first inorganic barrier layer 12 reflecting the cross-sectional shape of the portion 32 of the lead-out wiring 30. It includes a portion 14c.

  Since the lead interconnection 30 is patterned in the same process as, for example, the gate bus line or the source bus line, here, the gate bus line and the source bus line formed in the active region R1 are also shown in FIG. It has the same cross-sectional structure as the portion 32 on the active region R1 side of the lead-out wiring 30. However, typically, a planarization layer is formed on the gate bus lines and the source bus lines formed in the active region R1, and the surface of the first inorganic barrier layer 12 on the gate bus lines and the source bus lines. There is no level difference on the

  The portion 32 of the lead wire 30 may have, for example, a forward tapered side portion (inclined side portion) in which the side taper angle is less than 90 °. When the lead-out interconnection 30 has a forward tapered side portion, formation of defects in the first inorganic barrier layer 12 and the second inorganic barrier layer 16 formed thereon can be prevented. That is, the moisture resistance reliability of the TFE structure 10 can be improved. The taper angle of the forward tapered side portion is preferably 70 ° or less.

  In the active region R1 of the OLED display device 100, an inorganic barrier layer junction where the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact, except for the portion where the organic barrier layer 14 is selectively formed. Substantially covered by Therefore, the organic barrier layer 14 serves as a moisture penetration path, and moisture does not reach the active region R1 of the OLED display device.

  The OLED display device 100 according to an embodiment of the present invention is suitably used, for example, for high-resolution, medium- and small-sized smartphones and tablet terminals. High-definition (for example, 500ppi), small-sized (for example, 5.7-inch) OLED display devices to form sufficiently low resistance wiring (including gate bus lines and source bus lines) with a limited line width Preferably, the shape of the cross section parallel to the line width direction of the wiring in the active region R1 is close to a rectangle (the taper angle of the side surface is about 90 °). Therefore, in order to form a low resistance wire, the taper angle of the forward tapered side surface portion TSF may be more than 70 ° and less than 90 °, and the forward tapered side surface portion TSF is not provided. It may be 90 degrees.

  Next, FIG. 3 (c) will be referred to. FIG.3 (c) is sectional drawing of the area | region in which the TFE structure 10 is not formed. Here, the terminal 38 also has the same cross-sectional structure as the portion 36 of the lead-out wire 30 shown in FIG. The portion 36 of the lead-out wire 30 shown in FIG. 3C may have, for example, a taper angle of about 90 °.

  Next, with reference to FIGS. 5 and 6, the organic barrier layer 14 formed around the bank structure BS will be described. The organic barrier layer (solid portion) 14 is also formed around the convex portion on the surface of the first inorganic barrier layer 12 constituting the bank structure BS. FIG. 5 is a plan view schematically showing a plurality of pixels and the bank layer 48 which the OLED display device 100 has. 6 (a) and 6 (b) are schematic cross-sectional views of the OLED display device 100, and FIG. 6 (a) shows a cross-sectional view along line 6A-6A 'in FIG. 6 shows a cross-sectional view taken along line 6B-6B 'in FIG.

  As shown in FIGS. 5 and 6 (a), the OLED display device 100 further includes a bank layer 48 that defines each of the plurality of pixels. The bank layer 48 has a slope surrounding each of the plurality of pixels. The plurality of solid portions of the organic barrier layer 14 have pixel peripheral solid portions 14a extending from the portion on the slope S12 of the first inorganic barrier layer 12 to the periphery in the pixel.

  As shown in FIG. 6A, the bank structure BS includes a bank layer (sometimes called "PDL (Pixel Defining Layer)") 48 formed of an insulating material. The bank layer 48 is formed between the lower electrode 42 of the OLED 3 and the organic layer 44. As shown in FIG. 6A, 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. Here, the lower electrode 42 and the upper electrode 46 constitute an anode and a cathode of the OLED 3 respectively. The upper electrode 46 is a common electrode formed over the pixels in the active area. On the other hand, the lower electrode (pixel electrode) 42 is formed for each pixel. When the bank layer 48 exists 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, the region in which the bank layer 48 exists does not function as the pixel Pix, so the bank layer 48 defines the outer edge of the pixel Pix.

  As shown in FIG. 5, each pixel Pix is defined by the opening of the bank layer 48. The bank layer 48 is formed, for example, in a lattice shape. The side of the opening of the bank layer 48 has a bevel with a forward tapered side portion TSF. The slope of the bank layer 48 surrounds the periphery of each pixel. The bank layer 48 is formed using, for example, a photosensitive resin (for example, a polyimide or an acrylic resin). The thickness of the bank layer 48 is, for example, 1 μm to 2 μm. The inclination angle θb of the slope of the bank layer 48 is, for example, 60 ° or less. When 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. A layer located on the bank layer 48 (for example, including the organic layer 44, the upper electrode 46, the first inorganic barrier layer 12, and the second inorganic barrier layer 16) can also constitute the bank structure BS. The layers constituting the bank structure BS may each have a slope surrounding the periphery of each of the plurality of pixels. When the thicknesses of the layers formed on the bank layer 48 are all smaller than the thickness of the bank layer 48, the inclination angle of the slope of the bank structure BS is substantially the same as the inclination angle of the slope of the bank layer 48. It is believed that there is. The first inorganic barrier layer 12 constitutes a bank structure BS and has a slope S12 surrounding the periphery of each of the plurality of pixels. The organic barrier layer (solid portion) 14 includes a pixel peripheral solid portion 14 a extending from the portion on the slope S 12 of the first inorganic barrier layer 12 to the periphery in the pixel.

  For example, as shown in FIG. 6A, the organic barrier layer 14 is formed only at the discontinuous portion of the first inorganic barrier layer 12 formed by the particles P in the central portion in the pixel. That is, as shown in FIG. 6B, the organic barrier layer 14 does not exist in the central portion in the pixel where the particle P does not exist. An OLED display device free of particles P does not have an organic barrier layer at the center of the pixel. Here, the size (sphere equivalent diameter) of the particles P that lowers the moisture resistance reliability of the TFE structure 10 is approximately 0.3 μm to 5 μm. However, particles P having a size of 0.2 μm or more and less than 0.3 μm may also lower the moisture proof reliability. It is considered that there is almost no risk that particles P having a size of less than 0.2 μm will reduce the moisture resistance reliability. The particles having a size of more than 5 μm are removed by washing or the like.

  A G4.5 (730 mm × 920 mm) substrate may have, for example, several tens to about 100 particles having a size of approximately 0.3 μm to 5 μm, and the size of one OLED display device (active area) As for), there may be a few particles or so. Of course, there are also OLED display devices in which particles P do not exist. The organic barrier layer 14 is formed of, for example, a photocurable resin formed by curing a photocurable resin, and a portion where the photocurable resin actually exists is referred to as a “solid portion”. As described above, the organic barrier layer 14 (solid portion) is selectively formed only around the convex portion on the surface of the first inorganic barrier layer 12.

For example, as shown in FIG. 6A, when the particle P is present at the center of the pixel, the organic barrier layer 14 is formed at the discontinuous portion formed by the particle P. As described with reference to FIG. 4B, the organic barrier layer (solid portion) 14 is formed in a ring shape around the particle P. The diameter (area equivalent circle diameter) is, for example, 1μm about particles P when viewed from the normal direction, for example, the diameter (area equivalent circle diameter) D _o of the ring-shaped solid portion is 2μm or more. For example, in the case of a 5.7-inch 2560 × 1440 pixel display (approximately 500 ppi), the pixel pitch is 49 μm. Since the size of the particles P and the organic barrier layer (solid portion) 14 formed around the particles P is sufficiently smaller than the pixel pitch, the organic barrier layer 14 formed around the particles P (solid The change in transmittance due to (1) has little effect on the display.

  Here, with reference to FIGS. 6 (a) and 6 (b), the further advantage obtained by having the organic barrier layer 14 exhibiting a black color will be described.

  Patent Document 3 discloses a thin film sealing structure having an organic barrier layer (sometimes referred to as “planarizing layer”, for example, an acrylic resin layer) selectively formed in the vicinity of the slope of the bank structure. Patent Document 3 does not disclose a colored organic barrier layer. According to the study of the present inventor, when the organic barrier layer is not colored, the light distribution distribution of light emitted from the pixel is formed by the formation of the organic barrier layer (solid portion) in the vicinity of the slope of the bank structure. The viewing angle dependence may change. If the size, shape, and the like of the organic barrier layer are different, the intensity and light distribution of light emitted from the periphery of the pixel are different, and as a result, there arises a problem that the light distribution of emitted light is different for each pixel.

  On the other hand, as shown in FIGS. 6 (a) and 6 (b), the OLED display device 100 according to the embodiment of the present invention is colored black and extends from the slope of the bank structure BS to the periphery in the pixel. Since the organic barrier layer (solid portion) 14 is provided, it is possible to reduce the light emitted from the periphery of the pixel. Thereby, the light distribution of the emitted light between the pixels can be made uniform. Further, as shown in FIG. 6A, the OLED display device 100 also has the organic barrier layer (solid portion) 14 around the particle P, so that light leakage from the periphery of the particle P can be suppressed.

  The organic barrier layer 14 only needs to be able to effectively absorb (for example, 70% or more) light emitted in an oblique direction in order to obtain the above-described effect. As the organic barrier layer 14, for example, a black resist used for a black matrix of a color filter layer of a known display device may be used, but the light shielding property required for the black matrix (for example, about OD value 3 to 4 / μm) Is not necessary.

  Next, a method of manufacturing an OLED display according to an embodiment of the present invention will be described.

  Forming the TFE structure 10 of an OLED display according to an embodiment of the present invention includes the following steps.

Step A: Step of preparing a device substrate on which the first inorganic barrier layer 12 is formed Step B: Step of forming a liquid film containing a photosensitive resin on the first inorganic barrier layer 12 Step C: Light is applied to the liquid film Step of forming the resin layer by irradiation Step D: Step of forming the organic barrier layer 14 including the step of partially removing the resin layer by a dry process However, step D is optional and is omitted You may For example, as described later, the organic barrier layer 14 can be formed by performing mask exposure when curing the photocurable resin.

  As an example, a method of forming the organic barrier layer 14 using the method described in Patent Document 1 or 2 will be described. The disclosures of Patent Documents 1 and 2 are incorporated herein by reference for the method of forming the organic barrier layer.

  In step B, after the step A, the element substrate is placed in a chamber, and a photocurable resin (for example, an acrylic monomer) in vapor or mist form in the chamber, and the first inorganic barrier layer 12 is formed. Forming a liquid film by condensing the photocurable resin. That is, in the chamber, the vapor or mist of the organic material is supplied onto the element substrate maintained at a temperature below room temperature, condensed on the element substrate, and caused by capillary action or surface tension of the liquid organic material The uneven portion is localized at the boundary between the side surface of the convex portion on the surface of the first inorganic barrier layer 12 and the flat portion.

  When the step B is performed by the method described in Patent Document 1 or 2, the liquid film formed in the step B contains, for example, a photocurable resin (for example, an ultraviolet curable resin) and a black dye. Known black dyes can be used. The black dye may comprise a photopolymerizable dye monomer. In addition, a black dye is generally a mixture of dyes (compounds) of a plurality of different colors.

  Subsequently, step C is performed. That is, a photocurable resin layer (for example, an acrylic resin layer) is formed by irradiating the organic material with, for example, ultraviolet light. The photocurable resin layer formed here typically has a plurality of solid portions distributed discretely, and the solid portion is substantially formed on the flat portion of the surface of the first inorganic barrier layer 12 not exist. Even if the organic material is present on the flat portion of the surface of the first inorganic barrier layer 12, the amount (for example, the thickness) of the organic material is smaller than the periphery of the convex portion on the surface of the first inorganic barrier layer 12. Therefore, the organic material on the flat portion of the surface of the first inorganic barrier layer 12 can be removed by subjecting the resin layer once formed to an ashing treatment, for example, in the subsequent step (step D). Thereby, the organic barrier layer (solid portion) 14 unevenly distributed only around the convex portion on the surface of the first inorganic barrier layer 12 is formed. In addition to the above, in order to form such an organic barrier layer 14, the thickness of the liquid film to be formed and / or the ashing conditions (including time) may be appropriately adjusted as necessary.

  Alternatively, when the photocurable resin is cured, selective exposure such as mask exposure may be performed. For example, by performing mask exposure, it is possible to form an inorganic barrier layer bonding portion in which the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact with each other. An opening of the organic barrier layer 14 is formed in a region corresponding to the light shielding portion of the photomask. Therefore, for example, an organic barrier layer having an opening formed so as to surround the active region by exposing the photocurable resin layer through a photomask having a light shielding portion formed so as to surround the active region. 14 can be obtained.

  Thereafter, Step D is performed as necessary to obtain the organic barrier layer (solid portion) 14 which is unevenly distributed only around the convex portion on the surface of the first inorganic barrier layer 12. Step D includes partially removing the photocurable resin layer in a dry process. For example, in the photocurable resin layer, a portion having a relatively large thickness remains without being completely removed. “To remove the organic matter by a dry process” is not limited to ashing, and means to remove the organic matter by a dry process other than ashing (for example, sputtering), and the organic matter is removed from the surface. Not only removing the organic matter completely, but also partially removing it (eg, from the surface to a certain depth). In addition, dry process means that it is not a wet process using liquids, such as stripping solution and a solvent.

  Patent Literatures 1 and 2 neither disclose nor suggest a step of partially removing the photocurable resin layer by a dry process. By performing this step, the margin for forming the organic barrier layer can be increased, that is, the organic barrier layer (photocurable resin layer) is once formed larger (wider) than the region where the organic barrier layer is required, By partially removing this, the organic barrier layer can be formed only in the necessary region, so that the yield can be improved.

Ashing is removed by oxidizing the organic matter. It is also used when removing the organic matter adhering to the surface of the inorganic film. Not only removing the organic matter completely, but also partially removing it (eg, from the surface to a certain depth). Ashing may be performed, for example, in an atmosphere including at least one of N ₂ O, O ₂ and O ₃ . Ashing is roughly classified into plasma ashing (or corona discharge treatment) using any of the above atmosphere gases as high frequency plasma and using the plasma, and light excitation ashing performed by irradiating the atmosphere gas with light such as ultraviolet light. For example, it can be performed using a known plasma ashing apparatus, an ashing treatment apparatus using corona discharge, a light excitation ashing apparatus, a UV ozone ashing apparatus, or the like. When depositing a SiN film as the first inorganic barrier layer 12 and the second inorganic barrier layer 16 by the CVD method, N ₂ O is used as a source gas, so using N ₂ O for ashing can simplify the apparatus. Benefits are obtained.

  When ashing is performed, the surface of the organic barrier layer 14 is almost uniformly scraped, and the surface of the organic barrier layer 14 is oxidized and modified to be hydrophilic. In addition, extremely fine irregularities are formed, and the surface area is increased. The surface area increasing effect when ashing is performed is larger on the surface of the organic barrier layer 14 than on the first inorganic barrier layer 12 which is an inorganic material. Therefore, the surface of the organic barrier layer 14 is modified to be hydrophilic, and the surface area of the surface of the organic barrier layer 14 is increased, so that the adhesion between the organic barrier layer 14 and the second inorganic barrier layer 16 is improved. It is done.

  In order to improve the adhesion between the first inorganic barrier layer 12 and the organic barrier layer 14, plasma ashing treatment (for example, plasma treatment and / or / or the like) is performed on the surface of the first inorganic barrier layer 12 before forming the organic barrier layer 14. It may be subjected to corona treatment) or light excitation ashing treatment. That is, the step of forming TFE structure 10 may further include the step of performing plasma ashing treatment (for example, plasma treatment and / or corona treatment) or light excitation ashing treatment after step A and before step B. . Thereby, the side surface of the convex portion on the surface of the first inorganic barrier layer 12 is modified so as to have lyophilic property to the liquid film applied in step B, or to improve lyophilic property. Preferably. In addition, the surface of the flat portion of the first inorganic barrier layer 12 may be modified to have liquid repellency to the liquid film applied in step B. For example, the slope S12 (see FIGS. 6A and 6B) of the first inorganic barrier layer 12 of the bank structure BS has a lyophilic property to the liquid film applied in step B, and the bank structure The region surrounded by BS may be liquid repellent to the liquid film applied in step B.

  The above surface modification can also be performed using, for example, a silane coupling agent (hydrophilic or hydrophobic). That is, the step of forming TFE structure 10 may further include the step of applying a silane coupling agent to the surface of first inorganic barrier layer 12 after step A and before step B. A step of applying a silane coupling agent or any one of the above ashing treatments may be performed, or after the above ashing treatment is performed on the surface of the first inorganic barrier layer 12, a silane coupling agent is applied to the surface. It is also good. The surface of the first inorganic barrier layer 12 can be modified to be hydrophilic or hydrophobic by applying a silane coupling agent to the surface.

  Also, specific regions of the surface may be modified to be hydrophilic or hydrophobic using a silane coupling agent, for example using a photolithographic process. For example, the slope S12 of the first inorganic barrier layer 12 of the bank structure BS is modified to be lyophilic to the liquid film, and the region surrounded by the bank structure BS is liquid repellent to the liquid film. It may be reformed to have

  Step D may further include a step of performing plasma ashing treatment (for example, plasma treatment and / or corona treatment) or light excitation ashing treatment. Thereby, the organic material on the surface of the flat part of the 1st inorganic barrier layer 12 can be removed more certainly.

  As already mentioned, the active area of the OLED display device 100 according to an embodiment of the present invention is completely surrounded by the inorganic barrier layer junction where the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact. There is. Thus, the OLED display device 100 has excellent moisture resistance and reliability as compared with the OLED display device in which the organic barrier layer is formed by the method described in Patent Document 1 or 2.

  According to the study of the present inventor, when the organic barrier layer is formed by the method described in Patent Document 1 or 2, there is a problem that sufficient moisture resistance reliability can not be obtained. This problem is caused by water vapor in the air reaching the active area (sometimes referred to as "element formation area" or "display area") on the element substrate through the organic barrier layer. I understand.

  When the organic barrier layer is formed using a printing method such as an inkjet method, the organic barrier layer is formed only in the active region (sometimes referred to as “element formation region” or “display region”) on the element substrate, It is possible not to form in the area other than the active area. Therefore, there is a region where the first inorganic material layer and the second inorganic material layer are in direct contact with each other (outside) of the active region, and the organic barrier layer comprises the first inorganic material layer and the second inorganic material. It is completely surrounded by layers and isolated from the surroundings.

  On the other hand, in the method of forming an organic barrier layer described in Patent Document 1 or 2, the resin (organic material) is supplied to the entire surface of the element substrate, and the surface tension of the liquid resin is used to form the surface of the element substrate. The resin is unevenly distributed at the boundary between the side surface of the convex portion and the substrate surface. Therefore, an area outside the active area (sometimes referred to as a "peripheral area"), that is, a terminal area in which a plurality of terminals are arranged, and a lead-out wiring area in which lead lines extending from the active area to the terminal area are formed Organic barrier layers may be formed. Specifically, for example, the resin is unevenly distributed at the boundary between the side surface of the lead wire and the terminal and the substrate surface. Then, the end of the portion of the organic barrier layer formed along the lead-out line is not surrounded by the first inorganic material layer and the second inorganic material layer, and is exposed to the air (the surrounding atmosphere) . Since the organic barrier layer has a lower water vapor barrier property compared to the inorganic material layer (inorganic barrier layer), the organic barrier layer formed along the lead-out wire provides a path for introducing water vapor in the atmosphere into the active region. I will.

  In the manufacturing method according to the embodiment of the present invention, as described above, the opening of the organic barrier layer 14 includes at least an opening formed to surround the active region, and the active region is the first inorganic material. Since the barrier layer 12 and the second inorganic barrier layer 16 are completely surrounded by the direct contact with the inorganic barrier layer junction, the organic barrier layer provides a path for introducing water vapor in the atmosphere into the active region. There is no.

  The organic barrier layer 14 of the OLED display device 100 according to the embodiment of the present invention is not limited to the above method, and may be formed using, for example, a spray method, a spin coat method, a slit coat method, a screen printing method or an inkjet method. it can. That is, the step B may be performed by a spray method, a spin coat method, a slit coat method, a screen printing method or an inkjet method. When using these methods, it is not restricted to photocurable resin (negative type), Photosensitive resin (negative type or positive type) can be used. In the case of using a positive photosensitive resin, a photomask having an opening corresponding to a region where an inorganic barrier layer bonding portion is to be formed is used.

Moreover, when these methods are adopted, the liquid film (sometimes, a material containing a photosensitive resin for forming the liquid film is referred to as a "coating liquid") may contain a pigment without being limited to a dye. The black pigment may be a known one, for example, carbon black. As a photosensitive resin (for example, photocurable resin) in which a black pigment is dispersed, for example, a black resist used for a black matrix of a color filter layer of a liquid crystal display device may be used. In addition, since the organic barrier layer 14 may be colored in black so that it can be visually recognized in an inspection step described later, the light shielding property (for example, an OD value of about 3 to 4 / μm) required for the black matrix is not necessarily required. . As described above, since the thickness of the organic barrier layer 14 is 1 μm or less, typically 200 nm or more and 500 nm or less, even when using a conventional photosensitive resist for black matrix, the exposure amount is 150 mJ / cm ² or less, for example. It can be sufficiently photosensitive (for example, cured). In addition, a mixture of a plurality of different color pigments can also be used as the black pigment.

  In the case of forming the organic barrier layer 14 using the inkjet method, the organic barrier layer (solid portion) can be selectively formed only in a specific region, so that the inorganic barrier layer can be formed without mask exposure. A joint can be formed. Even if screen printing method or printing method such as ink jet method is used, a relatively thick organic barrier layer having a thickness of about 5 μm to about 20 μm, which is used for thin film sealing structure of OLED display devices currently on the market Also, a thin organic barrier layer 14 can be formed. In this case, the photosensitive resin is photocurable (i.e., negative).

  When forming an organic barrier layer using the inkjet method, it is necessary to specify the location which applies a coating liquid. Thus, a method of manufacturing an OLED display according to an embodiment includes a foreign matter detection process and an inkjet process.

  FIG. 7 is a schematic view showing a foreign matter detection apparatus 50 used in the method of manufacturing an OLED display according to an embodiment of the present invention, and FIG. 8 is an inkjet used in the method of manufacturing an OLED display according to an embodiment of the present invention. FIG. 6 is a schematic view showing a device 60.

  The foreign matter detection device 50 shown in FIG. 7 has a controller 52 and a detection head 54. The controller 52 controls the operation of the detection head 54 and also controls the operation of the stage 70. The stage 70 can receive the substrate 100M and transport it in the x-axis and y-axis directions. The stage 70 can, for example, adsorb and fix the substrate 100M and / or carry it up by levitation (non-contact conveyance). The substrate 100M is, for example, an element substrate manufactured using a mother substrate of G4.5, and is formed up to the first inorganic barrier layer.

  The controller 52 has a memory and a processor (both not shown), and operates the detection head 54 and / or the stage 70 according to the information stored in the memory to move the detection head 54 on the substrate 100M. Let it scan. A signal for operating the detection head 54 and / or the stage 70 is generated by a processor and applied to the detection head 54 and / or the stage 70 via an interface (indicated by an arrow in the figure).

  The detection head 54 includes, for example, a laser light source (for example, a semiconductor laser element), an imaging optical system, and an imaging element (all not shown). Laser light is emitted toward a predetermined position of the substrate 100M, and the light scattered by the substrate 100M is imaged on the light receiving surface of the imaging element by the imaging optical system. According to a predetermined algorithm, the processor determines the presence or absence of particles, the size of the particles, and the like according to a predetermined algorithm, and stores the result of imaging by the imaging device in the memory. Such a foreign substance inspection apparatus is described, for example, in JP-A-2016-105052. For reference, the entire disclosure of JP-A-2016-105052 is incorporated herein by reference. As the foreign matter detection device 50, for example, HS-930 manufactured by Toray Engineering Co., Ltd. can be suitably used. The HS-930 can detect 0.3 μm foreign particles (assessed with standard particle scatter), for example, a G4.5 substrate can be inspected in less than 60 seconds.

  The standard particle is a true spherical polystyrene latex particle, and the actual particle P is a fine fragment of glass, a particle of a metal, a particle of an organic substance (organic EL material), and an SiN layer (refractive index: about 1) Because it is covered with the second inorganic barrier layer), it is easier to detect than standard particles, and using the above foreign matter inspection device using laser scattered light, foreign matter with a sphere equivalent diameter of 0.2 μm or more is detected. can do.

  An ink jet apparatus 60 shown in FIG. 8 includes a controller 62, an ink jet head 64, and a UV (ultraviolet light) irradiation head 66.

  The controller 62 has a memory and a processor (all not shown), and operates the inkjet head 64, the UV irradiation head 66 and / or the stage 70 according to the information stored in the memory. The UV irradiation head 66 is moved to a desired position on the substrate 100M.

  Signals for operating the inkjet head 64, the UV irradiation head 66, and / or the stage 70 are generated by the processor, and through the interface (indicated by the arrows in the figure), the inkjet head 64, the UV irradiation head 66, and / or It is given to the stage 70. For example, the controller 62 receives position information (for example, x and y coordinates) at which particles are stored stored in the memory of the controller 52 of the foreign object detection device 50, and based on the position information, a minute liquid of a coating liquid containing a photocurable resin. Drops are applied from the inkjet head 64. For example, the controller 62 receives particle size information stored in the memory of the controller 52 of the foreign object detection device 50 according to the amount of coating liquid applied (the number of microdroplets, ie, the number of shots) applied from the inkjet head 64. Desired.

  Thereafter, the UV irradiation head 66 irradiates the applied photocurable resin with ultraviolet light to cure the photocurable resin, thereby forming an organic barrier layer. Perform this operation for each particle.

  Although the inkjet head 64 and the UV irradiation head 66 are separately described in FIG. 8, they may be provided as one head. In addition, the compact UV irradiation head 66 which mounts light source itself is realizable by using LED and a semiconductor laser element as an ultraviolet light source. Alternatively, only the emission end of the optical fiber and the lens unit provided as needed may be mounted on the UV irradiation head 66. At this time, in addition to LEDs and semiconductor laser elements, various ultraviolet light sources (for example, lamp light sources such as mercury xenon lamps and ultra-high pressure mercury lamps) are used as ultraviolet light source units that emit ultraviolet light toward the incident end of the optical fiber. Can. However, in consideration of coupling efficiency, an LED, a semiconductor laser device, or another light source capable of laser oscillation is preferable. As described above, when the UV irradiation head 66 and the ultraviolet light source are separately disposed, the influence of heat generation of the light source on the OLED 3 of the substrate 100M can be reduced in a series of steps from detection of foreign matter to application of coating liquid and irradiation of ultraviolet light. Benefits are obtained.

  Also, for example, a plurality of inkjet heads may be prepared. For example, two or more inkjet heads having different sizes of the microdroplets to be generated may be prepared and used in accordance with the particle size.

  For example, an inkjet head 64 in which the volume of one microdroplet is on the order of 1 fL (1 fL or more and less than 10 fL) or less than 1 fL can be suitably used. 1 fL corresponds to the volume of a sphere of approximately 1.2 μm in diameter, and 0.1 fL corresponds to the volume of a sphere of approximately 0.6 μm in diameter. For example, an inkjet apparatus (Super Inkjet (registered trademark)) capable of ejecting 0.1 fL of microdroplets manufactured by SIJ Technology, Inc. can be suitably used.

  Here, referring to FIGS. 9A and 9B, the volume of the organic barrier layer (solid portion) formed around the particle P and the preferable size of the microdroplet for forming the same will be described. Do. FIGS. 9A and 9B are schematic diagrams for explaining a preferable range of the volume of the organic barrier layer formed around the particle P in the OLED display according to the embodiment of the present invention. 9 (a) is a cross section taken along line 9A-9A 'of FIG. 9 (b) and is a schematic view of a cross section including the diameter of the particle P, and FIG. 9 (b) is viewed from the normal direction. FIG.

  Here, it is assumed that the first inorganic barrier layer 12a formed to cover the particle P or the particle P (these may be collectively referred to as “convex portions by the particle P”) is spherical. The organic barrier layer 14v around the particle P may be formed to cover the particle P and / or the inorganic barrier layer 12a thereon, but if the organic barrier layer 14v is too thick, the refractive action of the organic barrier layer 14v Due to the (lens effect), there is a possibility that the convex portion by the particle P is visually recognized. Therefore, as shown to Fig.9 (a), it is preferable that the organic barrier layer 14v is formed only below the radius R of the convex part by the particle P. As shown in FIG. Such an organic barrier layer 14v can be obtained by adjusting the volume of the coating solution to be applied (the volume of solid content if the coating solution contains a solvent) and / or the conditions (for example, time) of ashing it can. The ashing will be described later.

Assuming that the concave surface of the organic barrier layer 14v is a curved surface having the same radius of curvature as the radius R of the convex portion of the particle P, the volume V ₀ of the organic barrier layer 14v shown in FIGS. 9 (a) and 9 (b). Is represented by the following formula (1).
V ₀ = (4-π) πR ³ (1)

When the radius R of the convex portion by the particle P is 0.15 μm, V ₀ is about 0.009 fL, and when the radius R is 0.25 μm, V ₀ is about 0.04 fL and V when the radius R is 2.5 μm. ₀ becomes about 42 fL.

The volume of the organic barrier layer 14v is preferably about one-half or more of V _0. If it is smaller than this, there is a possibility that the second inorganic barrier layer 16 can not be formed by the effect of providing the organic barrier layer 14v, that is, a dense film without defects. The upper limit of the volume of the organic barrier layer 14v may be such that the convex portion by the particle P is not visually recognized by the refraction action (lens effect), preferably not exceeding 5 times V ₀ and not exceeding 2 times Is preferred. However, when the radius R of the convex portion due to the particle P is smaller than 2.5 μm (when V ₀ is smaller than about 42 fL), it is not limited to the above, and the volume of the organic barrier layer 14 v should not exceed about 200 fL. Preferably, it is about 100 fL or less.

Preferably, the size of the microdroplet can be appropriately set in accordance with the radius R of the convex portion by the particle P. For example, it is preferable to set 1 to 3 drops so as to satisfy the above V ₀ . In addition, by mixing the solvent in the coating solution, the microdroplet is made larger (for example, more than 1 time to 10 times the solid content in the coating solution (the amount finally remaining as the organic barrier layer 14v) )can do.

  In the case where the diameter of the convex portion by the particles P is less than 0.2 μm (radius R is less than 0.1 μm), it is considered that the influence of the moisture resistance reliability is substantially absent even if the organic barrier layer 14v is not provided. Therefore, at least a convex portion of particles P having a diameter of 0.2 μm or more (radius R of 0.1 μm or more) may be detected to form the organic barrier layer 14v.

  It is inefficient to apply 0.1 fL of microdroplets many times to a particle P having a diameter of 5 μm (radius R of 2.5 μm). Therefore, for example, an inkjet head that generates microdroplets of less than 1 fL (for example, 0.1 fL) and an inkjet head that generates microdroplets of 10 fL or more and less than 0.5 pL (for example, 50 fL) You may make it select according to a magnitude | size. The UV irradiation head 66 can be used in common. Of course, three or more inkjet heads having mutually different microdroplet sizes may be prepared.

  As described above, the portion 14 b formed around the particle P of the organic barrier layer 14 can be formed. On the other hand, the pixel peripheral solid part 14a from the portion of the organic barrier layer 14 on the slope S12 of the first inorganic barrier layer 12 to the periphery in the pixel is an inkjet that generates microdroplets of 10 fL or more and less than 100 pL (eg 200 fL). Using a head is more efficient. Further, since the position of the pixel peripheral solid portion 14a is determined in advance, an inkjet apparatus may be separately prepared to form the pixel peripheral solid portion 14a in accordance with design data.

  The coating liquid containing a photocurable resin (monomer) contains a small amount of additives such as a surfactant in addition to the photopolymerization initiator (radical polymerization initiator or cationic polymerization initiator). The mass fraction of the photocurable resin contained in the coating solution is about 80% by mass to about 90% by mass, and the mass fraction of the photopolymerization initiator is about 5% by mass to about 10% by mass. The coating solution may be mixed with a pigment or a dye. When mixing pigments, dispersing agents may be further mixed. The viscosity is preferably, for example, about 0.5 mPa · s or more and 10 Pa · s. When the dye or pigment is mixed, it can be easily confirmed that the organic barrier layer (solid portion) is formed at the desired position. It is preferable to use a dye because the pigment needs to be finely divided and causes an increase in viscosity. For example, in the case of generating 0.1 fL of microdroplets, it is preferable that neither pigment nor dye be contained. Also, in order to adjust the viscosity or the size (volume) of the microdroplet, a solvent (for example, an organic solvent such as alcohol) may be mixed.

As the photocurable resin, a radical polymerizable monomer having a vinyl group represented by an acrylic resin (acrylate monomer) or a cationic polymerizable monomer having an epoxy group can be used. A photoinitiator is suitably selected according to the kind of resin to be used, and the wavelength range of UV light irradiated. In addition, ultraviolet rays may be irradiated collectively to the photocurable resin on the substrate 100M, for example, using an ultraviolet irradiation device such as a high pressure mercury lamp or an ultrahigh pressure mercury lamp without using the UV irradiation head 66. The ultraviolet radiation dose (exposure dose) depends on the layer thickness of the organic barrier layer 14 to be formed, but it is, for example, 50 mJ / cm ² or more and 200 mJ / cm ² or less and 100 mJ / cm ² or more at i-line of 365 nm. 150 mJ / cm ² or less is preferable.

  Note that the above-described manufacturing method, that is, heating-vaporized vapor or atomized photocurable resin (organic material) is supplied onto the element substrate maintained at a temperature equal to or lower than room temperature, and condensed on the element substrate; In the manufacturing method including the step of unevenly distributing at the boundary portion between the side surface of the convex portion and the flat portion of the surface of the first inorganic barrier layer 12 by the capillary phenomenon or surface tension of the organic material which has become liquid, the photocurable resin It needs to be vaporized once. Therefore, the photocurable resin in this case does not contain a pigment, and the viscosity at room temperature (for example, 25 ° C.) before curing preferably does not exceed 10 Pa · s, and is particularly preferably 1 to 100 mPa · s. . When the viscosity is high, it may be difficult to form a thin liquid film having a thickness of 500 nm or less.

The method may further include the step of partially ashing the photocurable resin layer formed by curing the photocurable resin. The ashing may be performed using a known plasma ashing device, an ashing treatment device using corona discharge, a light excitation ashing device, or a UV ozone ashing device. For example, plasma ashing may be performed using at least one gas of N ₂ O, O ₂ and O ₃ , or these may be further combined with ultraviolet irradiation. When depositing a SiN film as the first inorganic barrier layer 12 and the second inorganic barrier layer 16 by the CVD method, N ₂ O is used as a source gas, so using N ₂ O for ashing can simplify the apparatus. Benefits are obtained.

  When ashing is performed, the surface of the organic barrier layer 14 is oxidized and modified to be hydrophilic. In addition, the surface of the organic barrier layer 14 is almost uniformly scraped, extremely fine asperities are formed, and the surface area is increased. The surface area increasing effect when ashing is performed is larger on the surface of the organic barrier layer 14 than on the first inorganic barrier layer 12 which is an inorganic material. Therefore, the surface of the organic barrier layer 14 is modified to be hydrophilic, and the surface area of the surface of the organic barrier layer 14 is increased, so that the adhesion between the organic barrier layer 14 and the second inorganic barrier layer 16 is improved. It is done.

  In order to improve the adhesion between the first inorganic barrier layer 12 and the organic barrier layer 14, the surface of the first inorganic barrier layer 12 may be ashed before the organic barrier layer 14 is formed. Good.

  Ashing not only adjusts the arrangement and / or volume of the organic barrier layer 14 which finally remains, such as removing the photocurable resin layer formed on the convex part by the particle P, but also the organic barrier layer 14 The adhesion between the second inorganic barrier layer 16 and the second inorganic barrier layer 16 can be improved.

  In the method of manufacturing an OLED display according to an embodiment of the present invention, after the step of forming the thin film sealing structure, the step of optically acquiring the pattern of the organic barrier layer 14 and the quality of the thin film sealing structure based on the pattern And the step of determining By forming the organic barrier layer 14 exhibiting a black color, it is possible to determine the quality of the thin film sealing structure based on the pattern of the organic barrier layer obtained optically. This inspection process can be easily inlined. This can improve the yield.

  Specifically, a pattern (referred to as "design pattern" or "target pattern") of a region where the organic barrier layer (solid portion) of the element substrate on which the first inorganic barrier layer is formed is to be formed is prepared. The pattern of the organic barrier layer (solid part) is optically acquired from the element substrate after forming the organic barrier layer 14 using, for example, an imaging device. By comparing the pattern of the obtained organic barrier layer (solid part) with the design pattern (target pattern), it is determined whether the organic barrier layer (solid part) is formed in a predetermined region. In the method of manufacturing the organic EL display device according to the embodiment of the present invention, since the organic barrier layer has a black color, the pattern of the organic barrier layer can be obtained with high optical precision. Naturally, the design pattern does not include the pattern of the organic barrier layer (solid portion) formed corresponding to the particles. However, in the case where a pattern that matches the design pattern is formed, it can be inferred that, if the particle is present, the organic barrier layer (solid portion) corresponding to the particle is also formed. Therefore, the yield can be improved as compared with the case where the formation state of the organic barrier layer is not inspected at all. Moreover, compared with the case where a transparent organic barrier layer is formed, quality determination can be performed with high precision or in a short time.

  It can also be checked whether an organic barrier layer corresponding to the particles has been formed. For example, the foreign matter detection device detects foreign matter on the element substrate before forming the organic barrier layer, and data including position information (mapping) of the foreign matter and image information (light intensity distribution of light) of a minute region including each foreign matter get. After the organic barrier layer is formed on the element substrate, a foreign substance inspection is similarly performed using a foreign substance inspection device to acquire similar data. Whether or not the organic barrier layer corresponding to each particle is formed may be determined by comparing the data before the formation of the organic barrier layer with the data after the formation of the organic barrier layer. In the method of manufacturing the organic EL display device according to the embodiment of the present invention, since the organic barrier layer has a black color, a change in image information (light intensity distribution) due to the formation of the organic barrier layer is large. The quality determination can be performed with high accuracy or in a short time as compared with the case of forming a transparent organic barrier layer.

  Embodiments of the present invention can be applied to an organic EL display device, in particular, a flexible organic EL display device and a method of manufacturing the same.

1: Flexible board 2: Back plane (circuit)
3: Organic EL element 4: Polarizing plate 10: Thin film sealing structure (TFE structure)
12: first inorganic barrier layer 14: organic barrier layer 16: second inorganic barrier layer 30: lead wiring 42: lower electrode 44: organic layer 46: upper electrode 48: bank layer 50: foreign object detection device 52: controller 54: detection Head 60: Ink jet device 62: Controller 64: Ink jet head 66: UV irradiation head 100: Organic EL display device

Claims (3)

An organic EL display device having a plurality of pixels,
An element substrate including a substrate and a plurality of organic EL elements supported by the substrate, each having a plurality of organic EL elements disposed in each of the plurality of pixels, and a thin film sealing film covering the plurality of pixels Have a stop structure,
The thin film sealing structure includes a first inorganic barrier layer, an organic barrier layer having a plurality of solid portions in contact with the upper surface of the first inorganic barrier layer and distributed discretely, and the first inorganic barrier layer A top surface and a second inorganic barrier layer in contact with the top surfaces of the plurality of solid portions of the organic barrier layer,
The organic barrier layer is formed of a photosensitive resin and has a black color.
It further comprises a bank layer defining each of the plurality of pixels,
The bank layer has a slope surrounding each of the plurality of pixels.
The plurality of solid portions have pixel peripheral solid portions extending from the portion on the slope of the first inorganic barrier layer to the periphery in the pixel,
The portion on the slope of the first inorganic barrier layer is lyophilic with respect to the photosensitive resin,
The surface of the flat part of the said 1st inorganic barrier layer in the area | region enclosed by the said bank layer has liquid repellency with respect to the said photosensitive resin, The organic electroluminescence display device.   The organic EL display device according to claim 1, wherein the organic barrier layer contains a dye or a pigment.   The organic EL display device according to claim 1, wherein an inclination angle of the slope of the bank layer is 60 ° or less.

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