JP2007287346A - Organic EL display device and method of manufacturing organic EL display device - Google Patents

Abstract

An organic EL display device in which the film property of an organic EL layer is stable and a short circuit between a pixel electrode and a counter electrode is suppressed is provided.
An organic EL display device includes a substrate having an electric circuit formed on a surface thereof, and an interlayer insulating film formed on the upper side of the substrate. A pixel electrode formed on the upper side of the interlayer insulating film 11 is provided. A pixel isolation partition wall 21 is provided above the interlayer insulating film 11 and disposed between the respective pixels. The interlayer insulating film 11 has a depression 61 formed so that at least a part thereof is disposed between pixels. The pixel separation partition wall 21 is arranged in the region of the inner surface of the recessed portion 61 at the outer edge portion.
[Selection] Figure 1

Description

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

  An organic EL element using electroluminescence (Electro Luminescence: abbreviated as EL) of an organic material has an organic EL layer in which an organic hole transport layer, an organic light emitting layer, etc. are laminated, sandwiched between an anode and a cathode. Including configurations. An organic EL element has attracted attention as a light emitting element capable of emitting light with high luminance by DC driving at a low voltage.

  Among display devices using an organic EL layer as a display element, an active matrix type display device in which a thin film transistor (hereinafter referred to as TFT for short) for driving the organic EL element is formed for each pixel. An electric circuit such as a TFT or wiring formed on the surface of the substrate is provided.

  On the upper side of the substrate on which the electric circuit such as TFT and wiring is formed, at least one interlayer insulating film is formed in order to flatten the unevenness on the surface of the electric circuit. This interlayer insulating film is also called a planarization insulating film and has electrical insulation. As this planarization insulating film, for example, an organic film is formed. A pixel electrode serving as an anode of the organic EL element is formed on the planarization insulating film. An organic EL layer is formed on the surface of the pixel electrode. The pixel electrode is connected to the TFT through a contact formed in the planarization insulating film.

  On the upper side of the organic EL layer, a counter electrode serving as a cathode of the organic EL element is formed. The counter electrode is grounded, for example. Some organic EL display devices include pixels. The organic EL display device is formed to display a video, an image, and the like by collecting a plurality of pixels. The TFT and the pixel electrode are formed for each pixel, and are formed so as to drive each pixel. The organic EL layer is formed for each pixel, for example. As the counter electrode, for example, a common electrode is formed so as to cover the organic EL layers of a plurality of pixels.

  Each pixel is separated from each other. A pixel separation partition for separating the pixels may be formed between the pixels. The pixel separating partition is formed so as to surround each pixel, and separates adjacent pixels.

  Japanese Patent No. 3691313 discloses a display device in which a light emitting region is formed by laminating an anode, a light emitting element layer, and a cathode, and planarization insulation that separates the anode from the light emitting element layer and the cathode at the end of the anode. A display device comprising a film is disclosed. In this display device, the surface of the cathode is flat by the planarization insulating film, the light emitting element layer is provided to cover the light emitting region and the planarization insulating film, and the light emitting region is formed by the opening of the planarization insulating film. Is stipulated. The planarization insulating film has an end portion on the anode, and the end portion has an inclination. According to this display device, it is disclosed that the cathode can be prevented from being short-circuited with the anode due to the disconnection of the light emitting element layer due to the thickness of the anode, and the deterioration of the light emitting layer due to the electric field concentration at the anode edge can be suppressed. ing.

  Japanese Patent Laid-Open No. 2002-164181 discloses a display device in which an insulating film is formed on an anode, an EL film and a cathode are formed on the insulating film, and the lower end and upper end of the insulating film are curved. It is disclosed. Further, it is disclosed that the taper angle of the central portion of the insulating film is 35 ° or more and 70 ° or less. According to this display device, it is disclosed that disconnection of the EL film and the cathode can be prevented, and an electric field can be prevented from being locally concentrated on the EL film.

  Japanese Patent Application Laid-Open No. 2001-351787 discloses an organic LED element in which a first electrode, an organic LED medium, and a second electrode are sequentially formed on a substrate, and a tapered partition is formed on the substrate or the first electrode. Has been. In this organic LED element, it is disclosed that the partition has a skirt near the substrate or the first electrode, and the surface of the skirt is concave. According to this organic LED element, it is disclosed that there is no short circuit between electrodes, and an organic LED element capable of full color display which is inexpensive and excellent in display quality can be provided.

  Japanese Patent Application Laid-Open No. 2003-217855 discloses an electroluminescence display device in which a planarizing film is formed on a TFT array substrate and an organic EL element is formed on the planarizing film. The organic EL element includes a pixel electrode as an anode, a light emitting layer formed on the pixel electrode, and a cathode formed on the light emitting layer. The peripheral part of the pixel electrode is coated with an insulating member, and the insulating member is formed so that the thickness decreases toward the joint tip with the surface of the pixel electrode. According to this electroluminescence display device, it is disclosed that the lifetime can be improved while the lifetime can be improved.

  Japanese Patent Application Laid-Open No. 2002-83691 discloses an active matrix driving type organic LED display device in which an applied current or applied voltage of an LED element can be controlled by a TFT, and a pixel electrode and a connection wiring are formed independently. Has been. Further, this publication discloses forming a tapered insulating film between pixels. Thereby, deterioration of the element due to electric field concentration at the edge portion of the pixel electrode can be prevented, and when the organic LED layer is formed by a printing method in a later process by forming the insulating film in a tapered shape, It is disclosed that since the transfer substrate of the printing press is completely in close contact with the substrate, it is possible to prevent a portion where the organic LED layer is not transferred.

In Japanese Patent Laid-Open No. 2001-356711, in a display device including an interlayer insulating film provided on a substrate in a state of covering unevenness due to wiring on the substrate, and an organic EL element provided on the interlayer insulating film. In addition, a display device is disclosed in which the interlayer insulating film includes a planarization insulating layer formed in a state in which wiring is embedded and a coat layer formed in a state of covering the surface of the planarization insulating layer. According to this display device, the display element is provided on the interlayer insulating film composed of a multilayer structure of the planarization insulating layer and the coat layer, so that the display characteristics of the display element can be obtained even on a substrate having unevenness due to wiring. It is disclosed that it is possible to stabilize the water and prevent deterioration due to moisture absorption.
Japanese Patent No. 3691313 JP 2002-164181 A JP 2001-351787 A JP 2003-217855 A Japanese Patent Laid-Open No. 2002-83691 JP 2001-356711 A

  For example, in Japanese Patent No. 3691313, Japanese Patent Application Laid-Open No. 2002-164181, Japanese Patent Application Laid-Open No. 2001-351787, or Japanese Patent Application Laid-Open No. 2003-217855, the coating properties of the organic EL layer and the counter electrode are improved. An attempt is made to prevent electrical short circuit between the pixel electrode and the counter electrode or electric field concentration in the organic EL layer. In these patent documents, although the shape of the outer edge of the pixel separation partition and the inclination angle of the outer edge are studied, the method for obtaining the angle depends on the manufacturing method and is structurally No measures were taken.

  In the conventional technique, the surface irregularities caused by wiring and contacts are flattened by forming an interlayer insulating film on the surface of the substrate. However, due to variations in the formation conditions of electrical circuits such as TFTs and the formation conditions of interlayer insulating films, surface irregularities may not be sufficiently flattened.

  In an organic EL display device in which a pixel electrode is formed on the upper side of the interlayer insulating film and a pixel separation partition for separating each pixel is formed, the unevenness caused by the electrical circuit of the substrate and the unevenness caused by the contact May appear on the surface of the interlayer insulating film.

  In the case where the outer edge portion of the pixel separation partition wall is formed in the portion where the unevenness appears, there is a problem that the inclination angle of the outer edge portion of the pixel separation partition wall deviates from the design value. For example, when the outer edge of the pixel separation partition is arranged in the concave and convex portions of the interlayer insulating film, the outer edge becomes thicker. Alternatively, when the outer edge of the pixel separation partition is arranged on the uneven protrusion of the interlayer insulating film, the outer edge becomes thin. As a result, the inclination angle of the outer edge portion of the pixel separation partition is greatly deviated from the design value. For example, the unevenness of the surface after forming the interlayer insulating film has a height difference of at least 0.1 μm or more. Here, when the depth or height of the unevenness on the surface of the interlayer insulating film is changed by 0.1 μm, the inclination angle of the outer edge of the pixel separation partition varies within a range of ± (10 ° to 30 °). End up.

  This variation is, for example, a variation that has a sufficient influence on the inclination angle of the pixel separation partition that is desirably 60 degrees or less, as disclosed in Japanese Patent Application Laid-Open No. 2001-351787. The organic EL layer formed on the upper side of the pixel electrode and the outer edge of the pixel separation partition is a thin film of about 200 nm, for example. When unevenness is generated on the surface of the outer edge of the pixel separation partition wall, the film property of the organic EL layer may deteriorate and the organic EL layer may become thin. As a result, there has been a problem that the pixel electrode and the counter electrode may be short-circuited.

  From the viewpoint of preventing an electrical short circuit between the pixel electrode and the counter electrode, it is preferable to stably form an inclined surface with a small inclination angle at the outer edge portion of the pixel separation partition wall. The inclination angle of the outer edge of the pixel separation partition is sensitively influenced by the conditions for performing the process for forming the pixel separation partition. If it is attempted to stably form the outer edge of the pixel separation partition, the processing conditions for forming the pixel separation partition are limited, resulting in a narrow manufacturing margin. In addition, it is more difficult to form the outer edge of the pixel separation barrier, which is difficult to obtain normally, because irregularities affected by TFTs or similar undulations occur in the underlying film forming the pixel separation barrier. There was a problem with.

  As described above, the conventional technique has a problem that the shape of the outer edge portion of the pixel separation partition cannot be stably obtained.

  It is conceivable that an object having irregularities on the surface of an interlayer insulating film such as a TFT or a wiring is not disposed below the outer edge of the pixel separation partition. However, for example, since the wiring needs to be formed across the pixels in the horizontal and vertical directions in the display area, it is difficult to dispose the wiring below all the outer edge portions of the pixel separation partition wall. There's a problem. Even in the TFT, there is a problem that the area where the TFT is disposed is restricted, and the aperture ratio and the pixel integration rate of the pixel are deteriorated.

  An object of the present invention is to provide an organic EL display device in which the film property of an organic EL layer is stable and a short circuit between a pixel electrode and a counter electrode is suppressed, and a method for manufacturing the organic EL display device.

  The organic EL display device in one aspect based on this invention is equipped with the board | substrate with which the electric circuit was formed in the surface. An insulating film is provided on the upper side of the substrate. A pixel electrode is formed on the insulating film and formed for each pixel. A pixel separation partition is formed on the insulating film and disposed between the pixels. An organic EL layer is provided on the surface of the pixel electrode. A counter electrode is provided on the surface of the organic EL layer. The insulating film has a recess formed so that at least a part thereof is disposed between the pixels. The recess is formed along the pixel. The pixel separation partition has an outer edge arranged in an area on the inner surface of the depression.

  An organic EL display device according to another aspect of the present invention includes a substrate on which an electric circuit is formed. An insulating film is provided on the upper side of the substrate. A pixel electrode is formed on the insulating film and formed for each pixel. A pixel separation partition is formed on the insulating film and disposed between the pixels. An organic EL layer formed on the surface of the pixel electrode is provided. A counter electrode is provided on the surface of the organic EL layer. The insulating film has a raised portion formed so that at least a part thereof is disposed between the pixels. The raised portion is formed along the pixel. The pixel separation partition wall has an outer edge portion disposed in a region on the outer surface of the raised portion.

  The manufacturing method of the organic EL display device in one aspect based on this invention includes the process of forming an electrical circuit on the surface of a board | substrate. An insulating film forming step of forming an insulating film on the upper side of the substrate; A pixel electrode forming step of forming a pixel electrode for each pixel on the upper side of the insulating film is included. A separating partition forming step of forming a pixel separating partition between the pixels on the insulating film. Forming an organic EL layer on the surface of the pixel electrode; Forming a counter electrode on the surface of the organic EL layer; The insulating film forming step includes a step of forming a depression along the pixel so as to include at least a part between the pixels. The separation partition forming step includes a step of forming the pixel separation partition so that an outer edge portion is disposed in a region of the inner surface of the recess.

  The manufacturing method of the organic electroluminescence display in the other situation based on this invention includes the process of forming an electrical circuit on the surface of a board | substrate. An insulating film forming step of forming an insulating film on the upper side of the substrate; A pixel electrode forming step of forming a pixel electrode for each pixel on the upper side of the insulating film is included. A separating partition forming step of forming a pixel separating partition between the pixels on the insulating film. Forming an organic EL layer on the surface of the pixel electrode; Forming a counter electrode on the surface of the organic EL layer; The insulating film forming step includes a step of forming a raised portion along the pixel so as to include at least a part between the pixels. The separation partition forming step includes a step of forming the pixel separation partition so that an outer edge portion is disposed in a region of the outer surface of the raised portion.

  ADVANTAGE OF THE INVENTION According to this invention, the coating property of an organic electroluminescent layer is stabilized, and the manufacturing method of the organic electroluminescence display which suppressed the short circuit with a pixel electrode and a counter electrode, and an organic electroluminescence display can be provided.

(Embodiment 1)
With reference to FIGS. 1 to 16, an organic EL display device and a method for manufacturing the organic EL display device according to the first embodiment of the present invention will be described. The organic EL display device in this embodiment is a so-called top emission structure organic EL display device that takes out light of the emitted organic EL layer from the side opposite to the substrate on which the TFT is formed. In this embodiment, an organic EL display device that performs active matrix driving will be described as an example.

  FIG. 1 is a schematic cross-sectional view of one first organic EL display device in the present embodiment. FIG. 1 is a schematic cross-sectional view taken along a plane substantially perpendicular to the display surface. The organic EL display device in the present embodiment includes a substrate 1. The substrate 1 is made of, for example, a glass material.

  A TFT 4 as an electric circuit is formed on the surface of the substrate 1. Further, wiring 3 as an electric circuit is formed on the surface of the substrate 1. The wiring 3 is electrically connected to the TFT 4. A region indicated by an arrow 154 is a region of each pixel. The TFT 4 is formed to drive each pixel individually.

An interlayer insulating film 11 as an insulating film is formed on the surface of the substrate 1. The interlayer insulating film 11 is formed so as to cover an electric circuit formed on the surface of the substrate 1 such as the TFT 4 and the wiring 3. Interlayer insulating film 11 in the present embodiment is formed of an organic resin. The interlayer insulating film is made of, for example, SiO ₂ (silicon oxide), PSG, BSG (phosphorous silica glass) (boron silica glass), SIN ₄ (in addition to organic materials such as acrylic resin, polyimide resin, and epoxy resin). An inorganic material such as a silicon nitride compound) or Ta ₂ O ₅ (tantalum oxide) can be used. The insulating film is not limited to this form, and may be a stacked body of an organic film and an inorganic film, a stacked body of an organic film and an organic film, or a stacked body of an inorganic film and an inorganic film.

  Interlayer insulating film 11 in the present embodiment has depression 61. The recess 61 is formed to be recessed from the surface of the interlayer insulating film 11. The depression 61 is at least partially disposed between the pixels. The depression 61 is formed so that the cross-sectional shape is substantially trapezoidal. The depression 61 is formed so that the thickness of the interlayer insulating film 11 is gradually reduced toward the center. The recess 61 is formed so as to surround the pixel. The depression 61 is formed along the pixel.

  The recess 61 has an inner surface. The inner surface of the recess 61 in the present embodiment has a side surface 61a and a bottom surface 61b. The side surface 61 a is formed to be inclined with respect to the surface of the substrate 1. The side surface 61 a is formed in a tapered shape so that the opening becomes smaller toward the substrate 1.

  The depression 61 has a contact hole 61c. The contact hole 61 c is formed so that the surface of the wiring 3 is exposed from the inside of the interlayer insulating film 11. The contact hole 61c is formed in the bottom surface 61b. The bottom surface 61b is formed in a planar shape.

  The organic EL display device in the present embodiment has a pixel electrode 41 formed on the surface of the interlayer insulating film 11. The pixel electrode 41 is formed so as to cover the entire pixel region indicated by the arrow 154. The pixel electrode 41 has a discontinuous portion 41a. The discontinuous portion 41a is disposed between the respective pixels. The discontinuous portion 41a is formed so that the pixel electrodes 41 of the respective pixels are electrically discontinuous.

  In the present embodiment, the pixel electrode 41 becomes the anode of the organic EL element. The pixel electrode 41 is formed along the surface of the recess 61. The pixel electrode 41 is formed on the inner surface of the contact hole 61 c and the surface of the wiring 3. The pixel electrode 41 is electrically connected to the wiring 3 by being in contact with the wiring 3, thereby forming the contact 2. .

  The organic EL display device in the present embodiment has a pixel separation partition wall 21 formed on the upper side of the interlayer insulating film 11. The pixel separation partition 21 is formed so as to surround the pixel region indicated by the arrow 154. The pixel separation partition 21 is formed so as to protrude. The pixel separation partition 21 is formed so as to separate the pixel electrode 41 and a counter electrode 51 described later. The pixel separating partition 21 in the present embodiment is formed inside the recess 61 of the interlayer insulating film 11. The pixel separation partition wall 21 is disposed substantially at the center of the recess 61.

  The pixel separation partition 21 includes an outer edge portion. The outer edge portion has an edge 21a. The outer edge portion is formed so as to be arranged in the region of the inner surface of the hollow portion 61. In the pixel separation partition wall 21 in the present embodiment, the edge 21a is disposed in the region of the side surface 61a. In the present embodiment, the entire edge 21 a is disposed in the region of the recessed portion 61 when viewed in plan. The pixel separation partition 21 is formed so that the outer edge portion gradually decreases in thickness toward the edge 21a. That is, the outer edge portion is formed so as to be gradually thinner toward the tip.

  The organic EL display device in the present embodiment includes an organic EL layer 31. The organic EL layer 31 in the present embodiment is formed so as to cover the pixel region indicated by the arrow 154. The organic EL layer 31 is formed on the surface of the pixel electrode 41. The organic EL layer 31 is formed for each pixel.

  The organic EL layer 31 has, for example, a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. When the organic EL display device performs color display, for example, a different organic EL layer is formed for each pixel so that each pixel emits red, green, or blue light. In this case, color display can be performed by combining three pixels.

  The organic EL display device in the present embodiment has a counter electrode 51. The counter electrode 51 is formed on the surfaces of the organic EL layer 31 and the pixel separation partition 21. The counter electrode 51 in the present embodiment is formed across a plurality of pixels. In the present embodiment, the counter electrode 51 serves as the cathode of the organic EL element.

  The organic EL layer 31 is sandwiched between the pixel electrode 41 and the counter electrode 51. In each pixel, when the TFT 4 is driven, a voltage is applied to the pixel electrode 41 through the wiring 3. As a result, the organic EL layer 31 emits light in the pixel region indicated by the arrow 154. Light is emitted in the direction indicated by arrow 153.

  FIG. 2 shows another schematic cross-sectional view of the organic EL display device in the present embodiment. FIG. 2 is a schematic cross-sectional view when cut along a plane substantially parallel to the display surface. 1 is a cross-sectional view taken along the line II in FIG. The organic EL display device in the present embodiment has a plurality of pixels. A region having a length indicated by an arrow 151 and a width indicated by an arrow 152 is a region of one pixel. In FIG. 2, six pixels are described.

  Each pixel is formed so that the planar shape is substantially rectangular. Each pixel is covered with the counter electrode 51. The pixel electrode 41, the counter electrode 51, and the organic EL layer 31 are formed so as to be larger than the pixel.

  In the organic EL display device, members used for sealing the display device such as a sealing film and a sealing substrate may be arranged. Furthermore, a desiccant may be disposed inside the sealed interior. Further, a polarizing plate combining a linear polarizing plate, a (1/4) λ plate, and the like and a film having an optical function equivalent to the polarizing plate may be disposed.

  Here, as for TFTs, pixel electrodes, sealing members, organic EL layers, etc., known materials and production disclosed in Japanese Patent No. 3691313, Japanese Patent Laid-Open No. 2001-351787, or Japanese Patent Laid-Open No. 2002-83691 are disclosed. It can be formed by a method. The interlayer insulating film can be formed by known materials and manufacturing methods disclosed in Japanese Patent Application Laid-Open Nos. 2001-356711 and 2002-83691.

  FIG. 3 shows an enlarged schematic cross-sectional view of a pixel separation partition portion of the first organic EL display device in the present embodiment. The organic EL layer 31 in the present embodiment is formed so that the end portion runs on the outer edge portion including the edge 21 a of the pixel separation partition wall 21. The organic EL layer 31 has a bent portion 31a. The bent portion 31a is formed so that the organic EL layer 31 is bent in the cross section. The bent portion 31 a is formed at the edge 21 a of the pixel separation partition wall 21. The counter electrode 51 has a bent portion 51 a formed at the edge 21 a of the pixel separation partition wall 21.

  In the present embodiment, the width W 1 of the recess 61 of the interlayer insulating film 11 is formed to be larger than the width W 2 of the pixel isolation partition wall 21. The width W1 of the recess 61 is preferably formed to be 0.2 μm or more larger than the width W2 of the pixel separation partition wall 21 from the viewpoint of accuracy when manufacturing.

  By forming an indentation that is many orders of magnitude larger than the irregularities on the surface of the interlayer insulating film and the undulations similar thereto, the irregularities on the surface of the interlayer insulating film and the undulations similar thereto can be substantially absorbed. The influence on the shape at the outer edge of the separation partition wall can be reduced.

  For example, the surface unevenness can be reduced by forming a recess having a depth of 10 times or more the maximum height difference between the surface unevenness of the interlayer insulating film and the swell. Alternatively, for example, the maximum height difference between the unevenness of the surface of the interlayer insulating film and the undulation similar to this when the recess is not formed is 0.1 to 5% of the thickness of the interlayer insulating film. In the interlayer insulating film 11, the thickness in the region of the bottom surface 61b of the recess 61 is preferably 10% or more and 90% or less of the thickness of the portion where the recess 61 is not formed.

  FIG. 4 shows an enlarged schematic cross-sectional view of the outer edge portion of the pixel separation partition of the first organic EL display device in the present embodiment. In the present embodiment, interlayer insulating film 11 is formed such that inclination angle θ1 of side surface 61a with respect to the surface of substrate 1 is 30 °. The inclination angle θ1 of the side surface 61a is preferably formed within a range of 3 ° to 80 °.

  In the pixel separation partition wall 21 in the present embodiment, the surface of the outer edge portion is inclined with respect to the surface of the substrate 1. In the present embodiment, the pixel separation barrier 21 is formed so that the inclination angle θ2 of the surface of the outer edge of the pixel separation barrier 21 with respect to the surface of the substrate 1 is 50 °. The inclination angle θ2 of the surface of the outer edge portion of the pixel separation partition wall 21 is preferably formed within a range of 3 ° to 60 °.

  In the present embodiment, the angle θ3 of the outer edge portion of the pixel separation partition wall 21 is formed to be 80 ° which is the sum of the inclination angle θ1 and the inclination angle θ2.

  With reference to FIG. 5 to FIG. 11, a method for manufacturing the first organic EL display device in the present embodiment will be described. 5 to 11 are schematic cross-sectional views for explaining respective steps of the manufacturing method.

  As shown in FIG. 5, an electric circuit such as TFT 4 and wiring 3 is formed on the surface of the substrate 1. In the present embodiment, an electric circuit is formed so that the wiring 3 is connected to the TFT 4. The surface of the substrate has irregularities in the electric circuit.

Next, an insulating film forming step for forming an insulating film on the upper side of the substrate is performed.
As shown in FIG. 6, an interlayer insulating film 11 is formed so as to cover the entire electric circuit such as the TFT 4 and the wiring 3. The interlayer insulating film 11 is formed by a known method such as a sputtering method, a CVD (Chemical Vapor Deposition) method, or a coating method. As described above, an inorganic material or an organic material can be used for the interlayer insulating film.

  In the present embodiment, a known acrylic resin having photosensitivity is used as the interlayer insulating film 11. The surface of the interlayer insulating film 11 has unevenness corresponding to the unevenness of the electric circuit. In the present embodiment, the convex portion 11a appears.

  Next, as shown in FIG. 7, a recess 61 is formed in the interlayer insulating film 11 by photolithography. In the present embodiment, the depression 61 is formed so that the cross-sectional shape when cut along a plane perpendicular to the extending direction is a trapezoid. A depression 61 is formed so as to surround the pixel. The depression 61 is formed so as to include at least a part between the pixels. Further, a contact hole 61 c is formed in the bottom surface 61 b of the recess 61. The contact hole 61c is formed so that the surface of the wiring 3 is exposed.

  Due to the electric circuit formed on the surface of the substrate 1, irregularities may also appear on the surface of the interlayer insulating film 11. Alternatively, the interlayer insulating film 11 may be formed with a contact (not shown) that connects the TFT and the wiring, or a contact that connects the wiring and the pixel electrode. These electric circuits may cause unevenness on the surface of the interlayer insulating film 11. However, by forming the depression 61 in the interlayer insulating film 11, the height difference of the unevenness can be reduced, and the inner surface of the depression can be flattened. That is, the surface of the side surface 61a and the bottom surface 61b of the hollow portion 61 can be flattened.

  In the present embodiment, the interlayer insulating film 11 is formed using a positive photosensitive resin. In the formation of the depression 61, the area of the depression 61 is exposed more than other areas. In the portion where the exposure amount is large, the development amount of the interlayer insulating film increases. At this time, although the development process proceeds isotropically, the unevenness of the surface is reduced due to an increase in the exposure amount and a longer development time. Thus, the unevenness appearing on the surface of the interlayer insulating film 11 can be reduced. As a result, the unevenness appearing on the surface of the pixel electrode formed in a later process can be reduced.

  The inclined side surface 61a of the depression 61 can be formed by devising a photomask so that it can be formed by a single photolithography process. In the present embodiment, by using a halftone mask, exposure is performed so that a continuously inclined side surface 61 a can be formed from a region substantially parallel to the surface of the substrate 1. Or in the area | region where the hollow part 61 is formed, the hollow part 61 can be formed by adjusting the exposure amount by controlling the exposure conditions which expose photosensitive resin.

  In the formation of the recess portion of the interlayer insulating film, as described above, it is preferable to form a recess portion that is sufficiently deep with respect to small irregularities that appear on the surface of the interlayer insulating film. By this method, small irregularities appearing on the surface can be made sufficiently small.

  Next, the interlayer insulating film 11 that remains thin on the surface of the wiring 3 inside the contact hole 61c formed in the interlayer insulating film 11, the residue of the resist used in the photolithography method, or the reattachment thereof, etc. Residues that obstruct electrical connection between the wiring 3 and the pixel electrode 41 are removed.

  In removing the residue, for example, ashing or cleaning is performed on the entire surface. In the ashing or cleaning treatment, a known method of removing an organic insulator can be mainly employed. For example, oxygen plasma treatment, ultraviolet irradiation ozone treatment, fluorine plasma treatment, argon plasma treatment, alkaline solution treatment, or the like can be used.

Next, a pixel electrode forming step for forming a pixel electrode is performed on the upper side of the interlayer insulating film.
As shown in FIG. 8, the pixel electrode 41 is formed on the surface of the interlayer insulating film 11 and the surface of the wiring 3. After the pixel electrode 41 is formed with a uniform thickness, the pixel electrode 41 is patterned.

  In the present embodiment, the pixel electrode 41 is formed using chromium as a material. The pixel electrode 41 can be formed by, for example, sputtering. The pixel electrode is not limited to this form, and any thin film having conductivity may be used. For example, the pixel electrode 41 may be a metal film or a film in which a light-transmitting conductive film is stacked on the surface of the metal film.

  Next, the pixel electrode 41 is patterned by photolithography. A discontinuous portion 41a is formed in the pixel electrode 41 by patterning. By forming the discontinuous portion 41a, the pixel electrodes 41 in each pixel are electrically separated.

  Next, a separation partition wall forming step for forming a pixel separation partition is performed on the insulating film. The pixel isolation barrier 21 can be formed by the same method as the interlayer insulating film 11.

  As shown in FIG. 9, the pixel separation partition wall 21 having a substantially uniform thickness is formed on the surface of the pixel electrode 41.

  Next, as shown in FIG. 10, patterning is performed to form the pixel isolation barrier 21 in the region where the recess 61 of the interlayer insulating film 11 is formed. Patterning can be performed by a known photolithography method or etching method. The pixel separating partition 21 is formed in a shape protruding outward. The pixel separation partition wall 21 is formed so that the thickness decreases toward the edge 21a that is the tip of the outer edge portion.

  In the present embodiment, patterning is performed so that the edge 21 a of the pixel separation partition wall 21 is disposed in the region of the side surface 61 a of the recess 61. An outer edge portion of the pixel separation partition wall 21 is disposed in a region on the inner surface of the recess portion 61.

  In the formation of the pixel separation partition, each of the organic insulating film and the inorganic insulating film can be formed as a single layer similarly to the interlayer insulating film. Alternatively, an organic insulating film may be stacked on the surface of the inorganic insulating film, or an inorganic insulating film may be stacked on the surface of the organic insulating film. Any laminated film can be formed by a known photolithography method, etching method, or the like.

  Next, as shown in FIG. 11, an organic EL layer 31 is formed. The organic EL layer 31 can be formed by a known vacuum deposition method or the like. In the formation of the organic EL layer 31, the organic EL layer 31 is formed so that the end of the organic EL layer 31 covers the outer edge of the pixel separation partition 21. That is, the organic EL layer 31 is formed so that the end of the organic EL layer 31 runs over the edge 21 a of the pixel separation partition 21. A bent portion 31 a is formed in the organic EL layer 31.

  Next, a counter electrode is formed on the upper side of the organic EL layer 31. In the present embodiment, the organic EL display device shown in FIG. 1 can be manufactured by forming the counter electrode so as to cover the organic EL layer 31 and the pixel separation partition 21.

  In the present embodiment, the insulating film forming step includes a step of forming the depression so that at least a part is disposed between the pixels. In this step, unevenness appearing on the surface of the interlayer insulating film can be reduced. As a result, the unevenness appearing on the surface of the pixel electrode can be reduced to such an extent that the shape of the outer edge portion of the pixel separation partition is not affected.

  For example, in the case where wirings and the like are arranged across the outer edge of the pixel separation partition, unevenness occurs at a portion where the outer edge of the pixel separation partition intersects with the wiring, and the pixel separation partition The angle of the outer edge portion becomes larger (the slope of the outer edge portion becomes steeper), and the film property of the organic EL layer may deteriorate. As a result, the pixel electrode and the counter electrode may be short-circuited to cause a pixel defect. In the present invention, unevenness in the region of the outer edge of the pixel separation partition can be reduced, and pixel defects can be suppressed.

  In the organic EL display device according to the present embodiment, the pixel separation partition includes an outer edge portion formed so that the thickness gradually decreases toward the edge. When the outer edge of the pixel separation partition wall becomes gradually thinner, the influence of the unevenness of the interlayer insulating film is remarkably generated. However, by applying the present invention, pixel defects can be effectively suppressed.

  FIG. 12 is a schematic cross-sectional view of the second organic EL display device in the present embodiment. The second organic EL display device has a pixel separation partition 23. The pixel separation partition wall 23 includes an outer edge portion having an edge 23a. The edge 23 a is disposed at a boundary portion between the side surface 61 a and the bottom surface 61 b in the hollow portion 61 formed in the interlayer insulating film 11. That is, the edge 23 a is formed so as to be disposed at the bent portion 41 b of the pixel electrode 41.

  As described above, in the first organic EL display device, the edge of the pixel separation partition is disposed in the region of the side surface of the recess portion of the interlayer insulating film. However, the present invention is not limited to this configuration, and the edge of the pixel isolation partition is recessed. Similar operations and effects can be obtained as long as the region is formed with the portion. For example, the pixel separation partition may be arranged in the region of the bottom surface of the recessed portion.

  In the present embodiment, the recess of the interlayer insulating film is formed to have a planar bottom surface, but the present invention is not limited to this configuration, and the recess may not have a planar bottom surface. For example, the cross-sectional shape of the recess may be formed in an arc shape.

Next, the test for confirming the effect in this invention is demonstrated.
FIG. 13 shows a schematic plan view of a test panel used in a test for confirming the effect. The test panel 71 has a first area 71a and a second area 71b. In the first region 71a, the first organic EL display device in the present embodiment is formed. That is, in the first region 71a, an organic EL display device in which a depression is formed in the interlayer insulating film is formed. An organic EL display device as a comparative example is formed in the second region 71b.

  FIG. 14 is a schematic cross-sectional view of an organic EL display device as a comparative example. The organic EL display device as a comparative example includes an interlayer insulating film 12 formed on the surface of the substrate 1. A recess is not formed on the surface of the interlayer insulating film 12. The surface of the interlayer insulating film 12 is formed in a planar shape. A pixel electrode 42 is formed on the surface of the interlayer insulating film 12.

  The pixel electrode 42 is connected to the wiring 3 through the contact hole 62c. An arrow 154 indicates a pixel region. A pixel separation partition 22 is formed between the pixel regions. The edge 22 a of the pixel separation partition wall 22 is disposed in a planar portion of the pixel electrode 42. An organic EL layer 32 is disposed on the surface of the pixel electrode 42. The end of the organic EL layer 32 rides on the outer edge of the pixel separation partition wall 22. A counter electrode 52 is formed on the surfaces of the organic EL layer 32 and the pixel separation barrier 22.

  Referring to FIG. 13, the same manufacturing process is performed by manufacturing the first organic EL display device according to the present embodiment in the first region 71a and forming the organic EL display device of the comparative example in the second region 71b. Two types of organic EL display devices to be compared can be manufactured. Moreover, two types of organic EL display devices can be manufactured without being affected by variations in processing in each manufacturing process.

  In the comparison of the two types of organic EL display devices, the lighting test of the organic EL display devices formed in the respective regions was performed, and the ratio of non-lighted pixels was compared. Furthermore, the reliability of each organic EL display device was also confirmed by operating the manufactured test panel continuously for a long time.

  Referring to FIGS. 1, 4, 13 and 14, in the test panel manufacturing method in the present embodiment, an interlayer insulating film is formed on the surface of a substrate on which an electric circuit such as a TFT is formed. The interlayer insulating film was formed using a known photosensitive acrylic resin so as to have a thickness of 2 μm.

  Next, a pattern such as a contact hole for electrically connecting the wiring and the pixel electrode is formed by photolithography. In this photolithography method, in addition to a predetermined pattern, a depression having a trapezoidal cross-sectional shape was formed on the surface of the interlayer insulating film in the first region 71a. In the manufacture of the first region 71a, the depression is optimized by using a halftone mask as a photomask so that the depression of the interlayer insulating film can be formed by a single photolithography process. Formed.

  In the first region 71a, the thickness of the interlayer insulating film in the bottom region of the recess is preferably 10% or more and 90% or less of the thickness of the region where the recess is not formed. The recess was formed such that the thickness of the interlayer insulating film at the bottom of the recess was 50% of the thickness of the region around the recess.

  Referring to FIG. 4, in the first region 71a of the test panel, the inclination angle θ1 formed by the side surface 61a of the recess 61 and the surface (or bottom surface 61b) of the substrate 1 is formed to be 30 °. In the second region 71b, a predetermined pattern such as a contact hole was formed without forming a recess.

  Next, the residue inside the contact hole was removed by an alkali solution treatment. Next, a Cr pixel electrode was formed by sputtering. The thickness of the pixel electrode was 200 nm. When a Cr pixel electrode is formed by sputtering in the first region 71a, a conductive film is formed with a uniform thickness along the shape of the recess of the interlayer insulating film. For this reason, the shape of the hollow part formed in the interlayer insulation film is maintained.

  Next, a pixel separation partition was formed on the surface of the pixel electrode using photosensitive polyimide. In the formation of the pixel separation partition, after the photosensitive polyimide was disposed with a substantially uniform thickness, the pixel separation partition having a substantially trapezoidal cross section was formed by photolithography. In the first region, a pixel separation partition was formed in the substantially central portion of the recess. In the second region 71b of the test panel 71, a pixel electrode, a pixel separation partition, and the like were formed without forming a stepped shape such as a depression in the interlayer insulating film.

  In forming the pixel separation partition, a polyimide film was applied to the surface of the pixel electrode so that the thickness was 2 μm over the entire substrate. In the region of the first region 71a where the recess portion of the interlayer insulating film is formed, the polyimide film is formed while gradually increasing in thickness as it approaches the central portion of the pixel separation partition along the inclined side surface. The thickness of the polyimide film was 3 μm at the substantially central portion of the bottom of the recess.

  Next, the polyimide was pre-baked at 130 ° C. Next, exposure was performed using a photomask. The exposed portion was removed by developing the polyimide film, and a desired pixel separation partition pattern could be obtained.

  In the formation of the pixel separation barrier, an inclined surface can be formed by adjusting conditions such as a photomask and an exposure amount as in the case of the interlayer insulating film. In the first region 71a, the pixel separation partition is formed so that the edge is arranged in the region of the side surface of the recess. Referring to FIG. 4, the pixel separation partition was formed so that the inclination angle θ2 formed by the surface of the substrate 1 and the outer surface of the outer edge of the pixel separation partition 21 was 50 °. The pixel separation partition was formed so that the angle θ3 in the cross section of the outer edge of the pixel separation partition was 80 °.

  Referring to FIG. 3, in the first region 71a, the width W1 of the recess 61 is preferably formed to be 0.2 μm or more larger than the width W2 of the pixel separation partition 21, but in the test panel, Was formed to be 1 μm larger on one side. In other words, the width W1 of the recess 61 was formed to be 2 μm larger than the width W2 of the pixel separation partition 21.

  Here, the test panel manufactured up to the pixel separation partition was observed with a microscope. Observations were made on each area.

  FIG. 15 shows an enlarged schematic plan view of one pixel in the first region of the test panel. FIG. 16 shows an enlarged schematic plan view of one pixel in the second region of the test panel. FIG. 15 and FIG. 16 are schematic plan views of respective pixels in a stage before forming the organic EL layer. That is, it is an enlarged schematic plan view when a pixel separation partition is formed on the surface of the pixel electrode.

  As shown in FIG. 15, in the first region of the test panel, the outer edge portion of the pixel separation partition wall 21 is arranged around the exposed portion of the pixel electrode 41. Even in the region where the TFT 4 and the contact 5 are formed in this region, the shape such as unevenness was not observed.

  On the other hand, as shown in FIG. 16, in the second region of the test panel, no depression is formed in the interlayer insulating film. A similar swell was observed. Irregularities or waviness appeared in the region where the TFT 4 and the contact 5 were formed. Thus, the thickness of the outer edge portion of the pixel separation partition 22 was different from the other portions in the portion where the unevenness was developed in the pixel electrode. That is, the outer edge portion was also uneven.

  By observation with a microscope, in the first organic EL display device according to the present embodiment, it was impossible to observe irregularities at the outer edge of the pixel separation partition, and the shape of the pixel separation partition was stably formed. .

  Next, an organic EL layer is formed on the surface of the pixel electrode. The organic EL layer is formed so as to cover the entire pixel region. The organic EL layer is formed so that the end portion runs over the outer edge portion of the pixel separation partition wall. Next, a counter electrode is formed on the surface of the organic EL layer and the surface of the pixel separation partition wall to manufacture an organic EL display device. Ten identical test panels having the first region and the second region were manufactured by this manufacturing method. In the test panel, 1000 pixels were formed in each region.

  Next, a light emission test was performed. In the light emission test, the number of display defects was counted for each region. Moreover, the detailed cause of the display defect was confirmed.

  In the first region of the test panel in which the depressions were formed in the interlayer insulating film, pixels having display defects of 0.5% or more and 2% or less were confirmed. When these pixels were observed in detail with a microscope, it was found that in all of them, the pixel electrode and the counter electrode were electrically short-circuited by foreign matters remaining on the surface of the pixel electrode. Defects due to the coating properties of the organic EL layer at the outer edge of the pixel separation partition were not observed.

  In the second region of the test panel, display defect pixels of about 10% to 15% were confirmed. Of these display defective pixels, 200 pixels were observed in detail with a microscope. As a result, in 23 locations, foreign matter remaining on the surface of the pixel electrode was confirmed. In other places, foreign matters remaining on the surface of the pixel electrode could not be confirmed.

  Further, a test panel having a display defect in which two foreign substances were not confirmed from the ten test panels was extracted. For each display defect pixel, the cross section was observed in more detail with an electron microscope, centering on the outer edge of the pixel separation partition wall. As a result, there is a portion where the angle at which the outer surface of the outer edge of the pixel separation partition wall is inclined with respect to the surface of the substrate is as large as about 70 °. Further, it was found that the pixel electrode and the counter electrode are short-circuited.

  Thus, in the organic EL display device of the present embodiment, the film property of the organic EL layer was improved, and a short circuit between the pixel electrode and the counter electrode could be suppressed.

  Next, a continuous lighting test for 1000 hours was performed on 8 of 10 manufactured test panels. As a result, in the second region of the test panel, the number of display defect pixels increased from about 20% to 25%. In other words, display defects increased by about 10% by performing continuous lighting. On the other hand, in the first region, even if continuous lighting was performed, display defects other than the cause due to the foreign matter observed with a microscope could not be confirmed. From the result of this continuous lighting test, it was confirmed that the reliability of the organic EL display device was improved.

  In the present embodiment, the active element for performing active matrix driving has been described as an example of an active element that performs TFT driving on the surface of the substrate. However, the present invention is not limited to this form, and any active element for performing active matrix driving may be used. These elements can be used.

  In this embodiment, an organic EL display device having a top emission structure has been described as an example. However, the present invention is not limited to this form, and a so-called bottom emission structure in which light emitted from the organic EL layer is extracted from the lower surface of the substrate. The present invention can also be applied to an organic EL display device having the same.

(Embodiment 2)
With reference to FIGS. 17 to 19, an organic EL display device and a method for manufacturing the organic EL display device according to the second embodiment of the present invention will be described.

  FIG. 17 is a schematic cross-sectional view of the first organic EL display device in the present embodiment. FIG. 17 is a schematic cross-sectional view of a region sandwiched between the pixels. The organic EL display device includes the substrate 1 and an electric circuit such as the TFT 4 and the wiring 3 is formed on the surface of the substrate 1 as in the first embodiment. In the present embodiment, a raised portion is formed in the interlayer insulating film instead of the recessed portion.

  The organic EL display device in the present embodiment has an interlayer insulating film 14 as an insulating film formed on the upper side of the substrate 1. The interlayer insulating film 14 has a raised portion 83 formed so that at least a part thereof is disposed between the pixel regions indicated by the arrows 154.

  The raised portion 83 in the present embodiment is formed so as to include a region between the respective pixels. The raised portion 83 is formed so as to protrude outward. The raised portion 83 has a substantially trapezoidal cross-sectional shape. The raised portion 83 is formed so that the thickness of the interlayer insulating film 11 gradually increases toward the central portion. The raised portion 83 is formed so as to surround the pixel. The raised portion 83 is formed along the pixel.

  The raised portion 83 has an outer surface. The outer surface has a side surface 83a and a top surface 83b. The side surface 83 a is formed to be inclined with respect to the surface of the substrate 1. The raised portion 83 is formed so that the thickness of the side surface 83a gradually increases toward the top surface 83b. The raised portion 83 has a contact hole 83c.

  The organic EL display device has a pixel electrode 44 that is formed on the upper side of the interlayer insulating film 14 and is electrically separated for each pixel.

  The organic EL display device in the present embodiment has a pixel separation partition wall 24 formed on the upper side of the interlayer insulating film 14 and disposed between the respective pixels. The pixel separation partition wall 24 in the present embodiment is formed so that the cross-sectional shape is substantially trapezoidal. The pixel separation partition wall 24 is formed at substantially the center of the raised portion 83. The pixel separation partition 24 is formed within a range where the raised portion 83 is formed.

  The pixel separation partition 24 includes an outer edge portion. The outer edge portion of the pixel separation partition wall 24 is disposed in the region of the outer surface of the raised portion 83. The outer edge portion has an edge 24a. The pixel separation partition 24 is formed so that the outer edge portion gradually decreases in thickness toward the edge 24a. The edge 24 a is disposed in the region of the side surface 83 a of the outer surface of the raised portion 83 of the interlayer insulating film 14.

  The organic EL display device has an organic EL layer 34 formed on the surface of the pixel electrode 44. The organic EL layer 34 is formed from the planar portion of the interlayer insulating film 14 to the region of the side surface 83 a of the raised portion 83. The end of the organic EL layer 34 is on the raised portion 83. A counter electrode 54 is formed on the surfaces of the organic EL layer 34 and the pixel separation partition 24.

  FIG. 18 is an enlarged schematic cross-sectional view of the outer edge portion of the pixel separation partition wall in the present embodiment. The organic EL layer 34 has a bent portion 34a. The raised portion 83 in the present embodiment is formed such that the inclination angle θ4 of the side surface 83a with respect to the main surface of the substrate 1 is 30 °. The inclination angle θ4 with respect to the surface of the substrate 1 is preferably 3 ° or more and 80 ° or less.

  Further, the raised portion 83 in the present embodiment is formed such that the inclination angle θ5 of the outer surface of the outer edge portion of the pixel separation partition wall 24 with respect to the surface of the substrate 1 is 50 °. The inclination angle θ5 of the outer edge portion of the pixel separation partition wall 24 with respect to the surface of the substrate 1 is preferably formed within a range of 3 ° to 50 °. In the present embodiment, the side surface 83 a of the raised portion 83 of the interlayer insulating film 14 is inclined, and the outer surface of the outer edge portion of the pixel isolation partition wall 24 is inclined. An angle θ6 formed by these inclined surfaces is 20 °.

  With reference to FIG. 17, the width W <b> 1 of the raised portion 83 is formed to be larger than the width W <b> 2 of the pixel separation partition 24. Similar to the first embodiment, the width W1 of the raised portion 83 is preferably formed to be 0.2 μm or more larger than the width W2 of the pixel separation partition wall 24 from the viewpoint of manufacturing accuracy.

  In the organic EL display device according to the present embodiment, the raised portion 83 is formed in the interlayer insulating film 14, and the outer edge portion of the pixel separation partition 24 is disposed in the region of the outer surface of the raised portion 83. With this configuration, the film property of the organic EL layer 34 at the outer edge portion of the pixel separation partition 24 can be improved as in the first embodiment. As a result, a short circuit between the pixel electrode 44 and the counter electrode 54 can be suppressed.

  Compared to the unevenness on the surface of the interlayer insulating film and the undulations similar to that, it is possible to substantially absorb the unevenness on the surface of the interlayer insulating film and the similar undulations by forming an extremely large ridge. The influence on the shape at the outer edge of the separation partition wall can be reduced. For example, the surface unevenness can be reduced by forming a raised portion having a height of 10 times or more of the maximum height difference between the surface unevenness of the interlayer insulating film and the undulation similar thereto.

  Alternatively, the unevenness on the surface of the interlayer insulating film and the undulation similar to this when the raised portion is not formed are 0.1% or more and 5% or less of the thickness of the interlayer insulating film. In the raised portion of the interlayer insulating film, the thickness of the top surface 83b of the raised portion 83 is preferably 120% to 190% of the thickness of the region where the raised portion 83 is not formed.

  In the present embodiment, the raised portion has a top surface and a side surface, but the present invention is not limited to this configuration, and the raised portion may not have the top surface. For example, the cross-sectional shape of the raised portion may be formed in an arc shape.

  Further, in the first organic EL display device according to the present embodiment, the edge 24a of the pixel separation partition 24 is disposed in the region of the side surface 83a of the raised portion 83. However, the present invention is not limited to this configuration. The edge may be disposed in the region where the raised portion is formed.

  FIG. 19 is a schematic cross-sectional view of the second organic EL display device in the present embodiment. The second organic EL display device has a pixel separation partition 25. An edge 25a of the pixel separation partition 25 is disposed at a boundary portion between the top surface 83b and the side surface 83a of the raised portion 83. Also by adopting this configuration, the film property of the organic EL layer 34 is improved, and a short circuit between the pixel electrode 44 and the counter electrode 54 can be suppressed.

  In the manufacturing method of the organic EL display device according to the present embodiment, an isolation partition is formed between the insulating film forming step of forming an interlayer insulating film as an insulating film on the upper side of the substrate and the pixels on the upper side of the interlayer insulating film. Separating partition forming step. The insulating film forming step includes a step of forming a raised portion along the pixel so as to include at least a part between the pixels. The separation partition forming step includes a step of forming the pixel separation partition so that the outer edge portion is disposed in the region of the outer surface of the raised portion. By this manufacturing method, a method for manufacturing an organic EL display device in which pixel defects are suppressed can be provided as in the first embodiment.

  In the present embodiment, in the insulating film forming step, a raised portion is formed instead of the recessed portion in the first embodiment. Similar to the first embodiment, the raised portion can be formed by using a halftone mask in, for example, a photolithography method. Further, in the separation partition forming step, the pixel separation partition is formed so that the outer edge portion is disposed on the outer surface of the raised portion.

  Next, a test panel was manufactured and tested in the same manner as in the first embodiment. Referring to FIG. 13, the first organic EL display device according to the present embodiment was formed in first region 71 a of test panel 71. The organic EL display device (see FIG. 14) of the same comparative example as that of the first embodiment was formed in the second region 71b.

  An electric circuit such as a TFT was formed on the surface of the substrate. Next, an insulating film forming step for forming an interlayer insulating film as an insulating film on the surface of the substrate is performed. In the present embodiment, a uniform acrylic resin film is formed so as to have a thickness of 2 μm using a known photosensitive acrylic resin.

  Next, a pattern such as a contact hole is formed in the interlayer insulating film by photolithography. At this time, a raised portion of the interlayer insulating film is formed in the first region 71 a of the test panel 71. In the present embodiment, the raised portion is formed so as to include a region between the pixels. The raised portion forms a portion that continuously rises from the planar portion.

  In the formation of the raised portion, similarly to the first embodiment, the exposure amount can be optimized by using a halftone mask, or the exposure amount can be adjusted by controlling the exposure conditions. In the present embodiment, referring to FIG. 18, interlayer insulating film 14 is formed such that inclination angle θ4 is 30 °.

  Next, the residue remaining inside the contact hole was removed with an acrylic treatment solution. Next, a pixel electrode forming step for forming a pixel electrode was performed. In forming the pixel electrode, a Cr film having a thickness of 200 nm was formed by sputtering. The Cr film was patterned by photolithography to form discontinuities and the like. In this step, a Cr film having a uniform thickness could be formed along the shape of the raised portion.

  Next, a separation partition forming step for forming a pixel separation partition is performed. In this embodiment mode, after forming a photosensitive polyimide film with a uniform thickness, patterning is performed by a photolithography method. Similar to the raised portion formed in the interlayer insulating film, the pixel separating partition is formed such that the outer edge of the pixel separating partition is gradually thinned by adjusting the photomask and processing conditions.

  In the separation partition wall forming step in the present embodiment, a polyimide film was applied on the surface of the pixel electrode so that the thickness was approximately 2 μm. Here, in the first region 71a of the test panel 71, polyimide serving as a pixel separation partition is applied so as to have a thickness of 2 μm, but the polyimide is applied along the cross-sectional shape of the raised portion of the interlayer insulating film. Is gradually thinned toward the center of the pixel separation partition. In the present embodiment, the thickness of the polyimide film at the portion to be the top surface of the raised portion is 1 μm.

  Next, the polyimide film was pre-baked at 130 ° C. Next, exposure was performed using a photomask. Next, the exposed pattern was removed by development processing to obtain a pixel separation partition wall having a desired shape. The pixel separation partition was formed at the substantially central portion of the raised portion.

  Referring to FIG. 18, the first region 71a of the test panel 71 was formed so that the inclination angle θ5 at the outer edge of the pixel separation partition wall was 50 °. In addition, referring to FIG. 17, the protruding portion 83 is formed so that the width W1 is 2 μm larger than the width W2 of the pixel separation partition wall. That is, it was formed so that one side had a difference of 1 μm. Further, the raised portion was formed such that the thickness of the top surface 83b of the raised portion 83 in the first region 71a was 150% of the thickness of the portion around the raised portion 83.

  In the test panel 71 manufactured up to the pixel separation partition as described above, when observed with a microscope as in the first embodiment, the second region 71b corresponds to the unevenness of the electric circuit such as TFT and contact. Unevenness and similar undulations were observed at the outer edge of the pixel separation partition. On the other hand, when the first region 71a of the test panel 71 was observed with a microscope, the unevenness observed in the second region 71b was not observed. The pixel separation partition was formed with a stable shape.

  In this embodiment, since the step on the surface of the interlayer insulating film is larger than the unevenness on the surface of the interlayer insulating film caused by wiring and contact holes, the surface unevenness on the surface of the interlayer insulating film is the same as in the first embodiment. It is thought that the influence of swell was reduced.

  Next, an organic EL display device was manufactured by forming an organic EL layer, a counter electrode, and the like in the first region and the second region of the test panel according to the present embodiment by a known method. Ten same test panels were manufactured by this manufacturing method. In the test panel, 1000 pixels were formed in each region.

  Next, a light emission test was performed. In the light emission test, the number of display defects was counted for each region. Moreover, the detailed cause of the display defect was confirmed.

  In the first region of the test panel in which the raised portion is formed in the interlayer insulating film, pixels having display defects of 1% or more and 3% or less were confirmed. When this pixel was observed in detail with a microscope, it was found that in all of the pixels, the pixel electrode and the counter electrode were electrically short-circuited by foreign matters remaining on the surface of the pixel electrode. Defects due to the coating properties of the organic EL layer at the outer edge of the pixel separation partition were not observed.

  On the other hand, in the second region, display defective pixels were confirmed in about 8% to 14% of the 1000 pixels. Of these display defect pixels, 300 pixels were observed in detail with a microscope. As a result, foreign matter remaining on the surface of the pixel electrode was confirmed in 32 locations, but no foreign matter was confirmed in other locations.

  Further, for the display defective pixel in which no foreign matter was confirmed, a more detailed cross-section was observed with a microscope centering on the outer edge of the pixel separation partition wall. There was a portion where the inclination angle of the outer surface of the outer edge of the pixel separation partition wall was as high as about 70 °. Further, in this portion, the pixel electrode and the counter electrode are in contact with each other because the coating property of the organic EL layer is poor.

  Thus, in the organic EL display device according to the present embodiment, the film property of the organic EL layer was improved, and a short circuit between the pixel electrode and the counter electrode could be suppressed.

  Next, a continuous lighting test for 1000 hours was performed on 8 of 10 manufactured test panels. As a result, the number of display defect pixels in the second region increased to about 20%. On the other hand, in the first region, it was not possible to confirm display defects other than the cause due to the foreign matter observed with a microscope even if continuous lighting was performed.

  From the result of this continuous lighting test, it was confirmed that the reliability of the organic EL display device in this embodiment is improved.

  Since the configuration, operation, effect, and manufacturing method other than those described above are the same as those in the first embodiment, description thereof will not be repeated here.

(Embodiment 3)
With reference to FIGS. 20 to 27, an organic EL display device according to a third embodiment of the present invention will be described. In the present embodiment, an organic EL display device in which various raised portions or recessed portions are formed in an interlayer insulating film will be described. In the present embodiment, a plurality of at least one of the raised portion and the protruding portion is formed between adjacent pixels.

  FIG. 20 is a schematic cross-sectional view of the first organic EL display device in the present embodiment. The first organic EL display device has an interlayer insulating film 15. The interlayer insulating film 15 has a contact hole 65. The interlayer insulating film 15 has a recess 62. The depression 62 is formed so as to sandwich the contact hole 65. The recess 62 is formed on both sides of the contact hole 65 in the cross section. The depression 62 extends along each pixel. The depression 62 has an inclined surface on the pixel side (an inclined surface facing the center of the pixel) and an inclined surface on the side where the depressions 62 face each other. A pixel electrode 45 is formed on the surface of the interlayer insulating film 15.

  The first organic EL display device has a pixel separation partition 26. The pixel separation partition wall 26 is formed in a region sandwiched between the plurality of depressions 62. The pixel separation partition 26 has an edge 26a. The edge 26 a is disposed on the inner surface of the recess 62. The edge 26 a of the pixel separation partition wall 26 is disposed on the inclined surface on the pixel side of the recess 62.

  An organic EL layer 35 is disposed on the surface of the pixel electrode 45. The organic EL layer 35 is formed such that the end portion runs over the surface of the edge 26 a of the pixel separation partition wall 26. A counter electrode 55 is formed on the surfaces of the organic EL layer 35 and the pixel separation partition wall 26.

  FIG. 21 is a schematic cross-sectional view of the second organic EL display device in the present embodiment. The second organic EL display device is different from the first organic EL display device in the position of the edge of the pixel separation partition. The second organic EL display device has an interlayer insulating film 16. The interlayer insulating film 16 has a recess 62.

  The second organic EL display device has a pixel separation partition 27. The pixel separation partition 27 has an edge 27a. The edge 27a is disposed on the inclined surface on the side where the recessed portions 62 are opposed to each other among the inclined surface on the side where the recessed portions 62 are opposed to each other and the inclined surface on the pixel side.

  The second organic EL display device has an organic EL layer 36. The organic EL layer 36 is disposed in a partial region of the recess 62. The organic EL layer 36 is formed so that the end portion runs over the pixel separation partition 27. The second organic EL display device has a counter electrode 56 formed on the surface of the organic EL layer 36.

  In the present invention, as in the first organic EL display device and the second organic EL display device in the present embodiment, a plurality of depressions may be formed between the respective pixels. Further, in the first organic EL display device and the second organic EL display device, the pixel separation partition is formed so that the edge of the pixel separation partition is disposed on the inclined surface of the recess. However, the outer edge portion of the pixel separation partition may be arranged at the bottom or bottom surface of each recess.

  FIG. 22 is a schematic cross-sectional view of the third organic EL display device in the present embodiment. The third organic EL display device has an interlayer insulating film 16. The interlayer insulating film 16 has a raised portion 84. The interlayer insulating film 16 has a contact hole 66. The contact hole 66 is disposed between the respective pixels. Two raised portions 84 are formed between the pixels. The raised portion 84 is disposed in a region between the contact hole 66 and the pixel. A pixel electrode 46 is formed on the surface of the interlayer insulating film 16.

  The third organic EL display device has a pixel separation partition 28. The pixel separation partition 28 is formed in a region sandwiched between the two raised portions 84 in the cross section. The pixel separation partition 28 has an edge 28a. The raised portion 84 has an inclined surface on the pixel side and an inclined surface on the side where the raised portions 84 face each other. The edge 28a of the pixel separation partition 28 is disposed on the inclined surface of the inclined surface on the side where the raised portions 84 face each other.

  An organic EL layer 36 is disposed on the surface of the pixel electrode 46. The organic EL layer 36 is disposed on a part of the inclined surface of the raised portion 84 and the inclined surface on the pixel side and the inclined surface on the side where the raised portions face each other. The end of the organic EL layer 36 is formed so as to run over the outer edge of the pixel separation partition 28. A counter electrode 56 is disposed on the surfaces of the organic EL layer 36 and the pixel separation partition 28.

  FIG. 23 is a schematic cross-sectional view of the fourth organic EL display device in the present embodiment. The fourth organic EL display device is different from the third organic EL display device in the present embodiment in the pixel separation partition.

  The fourth organic EL display device has an interlayer insulating film 17. The interlayer insulating film 17 has a raised portion 84. The fourth organic EL display device has a pixel separation partition 29. The pixel separation partition 29 has an edge 29a at the outer edge. The edge 29a is arranged on the inclined surface on the pixel side among the inclined surface on the pixel side of the raised portion 84 and the inclined surface on the side where the raised portions 84 face each other.

  The fourth organic EL display device has an organic EL layer 37. The organic EL layer 37 is formed so that the end portion runs over the outer edge portion of the pixel separation partition wall 29. A counter electrode 57 is formed on the surfaces of the organic EL layer 37 and the pixel separation partition 29.

  In the present invention, like the third organic EL display device and the fourth organic EL display device, a plurality of raised portions may be formed between the respective pixels. Further, in the third organic EL display device and the fourth organic EL display device, the pixel separation partition is formed so that the edge of the pixel separation partition is disposed on the inclined surface of the raised portion. The outer edge portion of the pixel separation partition may be arranged at the apex or top surface of each raised portion.

  FIG. 24 is a schematic cross-sectional view of the fifth organic EL display device in the present embodiment. The fifth organic EL display device has an interlayer insulating film 18. The interlayer insulating film 18 has a raised portion 84. The interlayer insulating film 18 has a recess 62. In the present embodiment, a raised portion 84 and a depressed portion 62 are formed between adjacent pixels. The raised portion 84 and the depressed portion 62 have an inclined surface on the pixel side and an inclined surface on the side where the depressed portion and the raised portion face each other. The interlayer insulating film 18 has a contact hole 67. A pixel electrode 48 is formed on the surface of the interlayer insulating film 18.

  The fifth organic EL display device has a pixel separation partition 95. The pixel separation partition 95 has edges 95a and 95b. The edge 95a is disposed on the inclined surface of the raised portion 84 on the side where the recessed portion and the raised portion face each other. The edge 95b is disposed on an inclined surface on the pixel side among the inclined surfaces of the recess 62.

  The fifth organic EL display device has an organic EL layer 38. The organic EL layer 38 is formed so that the end portion runs on the outer edge portion including the edges 95 a and 95 b of the pixel separation partition wall 95. A counter electrode 58 is formed on the surfaces of the organic EL layer 38 and the pixel separation partition 95.

  FIG. 25 is a schematic sectional view of a sixth organic EL display device in the present embodiment. The sixth organic EL display device is different from the fifth organic EL display device in the shape of the pixel separation partition.

  The sixth organic EL display device has a pixel separation partition 96. The pixel separation partition 96 has edges 96a and 96b. The edge 96a is disposed on the inclined surface of the raised portion 84 on the side where the recessed portion and the raised portion face each other. The edge 96b is disposed on the inclined surface of the recessed portion 62 on the side where the recessed portion and the raised portion face each other. An organic EL layer 39 is formed on the surface of the pixel electrode 48. A counter electrode 59 is formed on the surfaces of the organic EL layer 39 and the pixel separation partition 96.

  FIG. 26 shows a schematic cross-sectional view of a seventh organic EL display device in the present embodiment. The seventh organic EL display device is different from the fifth organic EL display device in the shape of the pixel separation partition.

  The seventh organic EL display device has a pixel separation partition 97. The pixel separation partition 97 has edges 97a and 97b. The edge 97a is disposed on an inclined surface on the pixel side among the inclined surfaces of the raised portion 84. The edge 97b is disposed on an inclined surface on the pixel side among the inclined surfaces of the recess 62. An organic EL layer 121 is formed on the surface of the pixel electrode 48. A counter electrode 106 is formed on the surfaces of the organic EL layer 121 and the pixel separation partition 97.

  FIG. 27 shows a schematic cross-sectional view of the eighth organic EL display device in the present embodiment. The eighth organic EL display device is different from the fifth organic EL display device in the shape of the pixel separation partition.

  The eighth organic EL display device has a pixel separation partition 98. The pixel separation partition 98 has edges 98a and 98b. The edge 98a is disposed on an inclined surface on the pixel side among the inclined surfaces of the raised portion 84. The edge 98b is disposed on the inclined surface of the recessed portion 62 on the side where the recessed portion and the raised portion face each other. An organic EL layer 122 is formed on the surface of the pixel electrode 48. A counter electrode 107 is formed on the surfaces of the organic EL layer 122 and the pixel separation partition 98.

  In the present invention, as in the fifth to eighth organic EL display devices, recesses and ridges may be formed between the respective pixels.

  Also in each organic EL display device in the present embodiment, it is possible to suppress the occurrence of an image defect due to a short circuit between the pixel electrode and the counter electrode at the outer edge portion of the pixel separation partition.

  Other configurations, functions, effects, and manufacturing methods are the same as those in the first embodiment or the second embodiment, and therefore description thereof will not be repeated here.

  In the respective drawings described above, the same or corresponding parts are denoted by the same reference numerals. In the present invention, descriptions such as “upper” or “lower” do not indicate absolute top and bottom in the vertical direction, but indicate relative positional relationships between components and parts.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

FIG. 3 is a first schematic cross-sectional view of the first organic EL display device in the first embodiment. FIG. 4 is a second schematic cross-sectional view of the first organic EL display device in the first embodiment. FIG. 3 is an enlarged schematic cross-sectional view of a pixel separation partition portion of the first organic EL display device in the first embodiment. 3 is an enlarged schematic cross-sectional view of an outer edge portion of a pixel separation partition of the first organic EL display device in Embodiment 1. FIG. FIG. 4 is a first process explanatory diagram of the manufacturing method of the first organic EL display device in the first embodiment. FIG. 10 is an explanatory diagram of a second step of the method of manufacturing the first organic EL display device in the first embodiment. FIG. 10 is a third process explanatory diagram of the method of manufacturing the first organic EL display device in the first embodiment. FIG. 10 is a fourth process explanatory diagram of the method for manufacturing the first organic EL display device in the first embodiment. FIG. 10 is a fifth process explanatory diagram of the method for manufacturing the first organic EL display device in the first embodiment. FIG. 10 is an explanatory diagram of a sixth step of the method of manufacturing the first organic EL display device in the first embodiment. FIG. 10 is an explanatory diagram of a seventh process of the method for manufacturing the first organic EL display device in the first embodiment. 3 is a schematic cross-sectional view of a second organic EL display device in Embodiment 1. FIG. It is a schematic model top view of a test panel. It is a schematic sectional drawing of the organic electroluminescence display of a comparative example. FIG. 3 is an enlarged schematic plan view of a pixel of the first organic EL display device in the first embodiment. 3 is an enlarged schematic plan view of pixels of an organic EL display device of a comparative example in Embodiment 1. FIG. FIG. 5 is a schematic cross-sectional view of a pixel separation partition portion of a first organic EL display device in a second embodiment. 6 is an enlarged schematic cross-sectional view of an outer edge portion of a pixel separation partition of a first organic EL display device in Embodiment 2. FIG. FIG. 6 is a schematic cross-sectional view of a second organic EL display device in a second embodiment. FIG. 5 is a schematic cross-sectional view of a first organic EL display device in a third embodiment. 10 is a schematic cross-sectional view of a second organic EL display device in a third embodiment. FIG. 6 is a schematic cross-sectional view of a third organic EL display device in Embodiment 3. FIG. 6 is a schematic cross-sectional view of a fourth organic EL display device in Embodiment 3. FIG. 10 is a schematic cross-sectional view of a fifth organic EL display device in Embodiment 3. FIG. 10 is a schematic cross-sectional view of a sixth organic EL display device in Embodiment 3. FIG. 10 is a schematic cross-sectional view of a seventh organic EL display device in Embodiment 3. FIG. It is a schematic sectional drawing of the 8th organic EL display apparatus in Embodiment 3. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Substrate, 2, 5 contact, 3 wiring, 4 TFT, 11, 12, 14-18 interlayer insulation film, 11a Convex part, 21-29, 95-98 Pixel isolation partition, 21a, 22a, 23a, 24a, 25a, 26a, 27a, 28a, 29a, 95a, 95b, 96a, 96b, 97a, 97b, 98a, 98b Edge, 31, 32, 34 to 39, 121, 122 Organic EL layer, 31a, 34a Bent part, 41, 42, 44 to 46, 48 Pixel electrode, 41a Discontinuous part, 41b Bent part, 51, 52, 54 to 59, 106, 107 Counter electrode, 51a Bent part, 61, 62 Depressed part, 61a Side face, 61b Bottom face, 61c, 62c Contact hole, 65-67 Contact hole, 71 Test panel, 71a 1st area | region, 71b 2nd area | region, 83,84 Raised portion, 83a side, 83 b top surface, 83c contact holes, 151-154 arrow.

Claims (10)

A substrate with an electrical circuit formed on the surface;
An insulating film formed on the substrate;
A pixel electrode formed on the insulating film and formed for each pixel;
A pixel separation partition formed on the insulating film and disposed between the pixels;
An organic EL layer disposed on the surface of the pixel electrode;
A counter electrode formed on the surface of the organic EL layer,
The insulating film has a recess formed so that at least a part thereof is disposed between the pixels,
The recess is formed along the pixel,
The pixel separation partition is an organic EL display device in which an outer edge portion is disposed in a region on the inner surface of the recess. The recess is formed so that the cross-sectional shape is substantially trapezoidal,
The organic EL display device according to claim 1, wherein the inner surface includes at least one of a bottom surface and an inclined side surface. A substrate with an electrical circuit formed on the surface;
An insulating film formed on the substrate;
A pixel electrode formed on the insulating film and formed for each pixel;
A pixel separation partition formed on the insulating film and disposed between the pixels;
An organic EL layer formed on the surface of the pixel electrode;
A counter electrode formed on the surface of the organic EL layer,
The insulating film has a raised portion formed so that at least a part thereof is disposed between the pixels,
The raised portion is formed along the pixel,
The pixel separation partition is an organic EL display device in which an outer edge portion is arranged in a region on the outer surface of the raised portion. The raised portion is formed so that the cross-sectional shape is substantially trapezoidal,
The organic EL display device according to claim 3, wherein the outer surface includes at least one of a top surface and an inclined side surface.   5. The organic EL display device according to claim 1, wherein the pixel separation partition includes a tip portion formed such that the outer edge portion gradually decreases in thickness toward the edge. Forming an electrical circuit on the surface of the substrate;
An insulating film forming step of forming an insulating film on the upper side of the substrate;
A pixel electrode forming step of forming a pixel electrode for each pixel on the insulating film;
A separation partition wall forming step of forming a pixel separation partition wall between the pixels on the insulating film;
Forming an organic EL layer on the surface of the pixel electrode;
Forming a counter electrode on the surface of the organic EL layer,
The insulating film forming step includes a step of forming a depression along the pixel so as to include at least a part between the pixels,
The method of forming the separation partition includes a step of forming the pixel separation partition so that an outer edge portion is disposed in a region of the inner surface of the depression. The insulating film forming step includes a step of forming the recess so that a cross-sectional shape is substantially trapezoidal,
The organic EL display according to claim 6, wherein the separation partition forming step includes a step of forming the pixel separation partition so that the outer edge portion is disposed on at least one of a bottom surface and an inclined side surface of the recess portion. Device manufacturing method. Forming an electrical circuit on the surface of the substrate;
An insulating film forming step of forming an insulating film on the upper side of the substrate;
A pixel electrode forming step of forming a pixel electrode for each pixel on the insulating film;
A separation partition wall forming step of forming a pixel separation partition wall between the pixels on the insulating film;
Forming an organic EL layer on the surface of the pixel electrode;
Forming a counter electrode on the surface of the organic EL layer,
The insulating film forming step includes a step of forming a raised portion along the pixel so as to include at least a part between the pixels,
The method for forming an isolation partition includes a step of forming the pixel isolation partition so that an outer edge portion is disposed in an outer surface region of the raised portion. The insulating film forming step includes a step of forming the raised portion so that a cross-sectional shape is substantially trapezoidal,
The organic EL according to claim 8, wherein the separation partition forming step includes a step of forming the pixel separation partition such that the outer edge portion is disposed on at least one of a top surface and an inclined side surface of the raised portion. Manufacturing method of display device.   10. The method of manufacturing an organic EL display device according to claim 6, wherein the separation partition wall forming step includes a step of forming the outer edge portion so that the thickness gradually decreases toward the edge.

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