JP2011076804A - Organic el display device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device eliminating influence of a recess due to a contact hole formed in a planarizing film for forming an excellent light-emitting layer. <P>SOLUTION: The organic EL display device includes: a TFT substrate 10 including a drive element; a planarizing film 11 formed on the TFT substrate 10; a reflection anode 12 formed in the upper part of the planarizing film 11 and the bottom part and the side wall of the contact hole 23 formed in the planarizing film 11 and electrically connected to the drive element through the contact hole 23; an organic light-emitting layer 16 formed on the reflection anode 12; a transparent cathode 18 formed on the organic light-emitting layer 16; and a pixel regulation layer 14 formed between the reflection anode 12 and the organic light-emitting layer 16 to form a non-light-emitting area through which no light emission current flows. The pixel regulation layer 14 is loaded to the upper part of the contact hole 23, and the surface of the pixel regulation layer 14 is planarized. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence (hereinafter referred to as EL) display device and a method for manufacturing the same, and more particularly to an active matrix organic EL display device.

  The organic EL display device is a light emitting display device using an electroluminescence phenomenon of an organic compound, and is configured by disposing an organic EL element that can control light emission independently for each pixel on a substrate. A typical organic EL device is manufactured by laminating a drive circuit, an anode, an organic functional layer, and a cathode on a substrate. In the organic functional layer, one or more of a plurality of functional layers such as an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer are laminated together with an organic light emitting layer made of an organic compound.

  In such a configuration, electric charges are injected from the anode and the cathode into the light emitting layer through a hole injection layer and the like, and light emission is generated by recombination of the injected electric charges in the light emitting layer. It is important that the organic light emitting layer is formed with a uniform film thickness. This is because if the thickness of the light-emitting layer is not uniform, the current distribution in the light-emitting surface is non-uniform, resulting in uneven brightness, and a reduction in device life due to current concentration in a thin part. It is.

  The light emitting layer is formed, for example, by applying a functional liquid containing an organic compound to be an organic light emitting layer to a substrate and drying it. The functional film formed by storing and drying the functional liquid is not limited to the organic light emitting layer of the organic EL element, but is used in various devices, and various types for forming a functional film having excellent thickness uniformity. Technologies are being considered.

  For example, in Patent Document 1, a partition is formed on a substrate, and a functional film that is to be a functional film is stored and dried in a space (called a liquid receiving unit) partitioned by the partition for each pixel to form a functional film. A configuration and a manufacturing method are disclosed. The functional liquid is disposed in the liquid receiving portion by, for example, an ink jet method.

  The drive circuit is composed of thin film transistors (TFTs) that individually drive the organic EL elements. Accordingly, the organic EL display device displays a desired image by applying a desired voltage to the organic EL element and causing a current to flow through the drive circuit.

  As an active matrix organic EL display device, for example, in a top emission method in which light emission is extracted from the cathode side, a sufficient aperture ratio is secured by forming a TFT of a drive circuit between a substrate and an organic EL element. Yes.

  In Patent Document 2, an inorganic insulating film is formed between a driving unit having a TFT as a lower layer and a light emitting unit having a liquid crystal as an upper layer, and the driving unit has a contact hole provided in the inorganic insulating film. The TFT and the pixel electrode of the light emitting unit are electrically connected.

  Patent Document 3 discloses a configuration of an active matrix display device using an organic semiconductor as a light emitting element. A relay electrode formed simultaneously with the data line is electrically connected to one of the source and drain regions of the TFT, which is the lower layer, via a contact hole of the first interlayer insulating film. A transparent pixel electrode made of an ITO film of a thin film light emitting element is electrically connected through a contact hole in the interlayer insulating film.

  In Patent Document 2 and Patent Document 3, a TFT, a planarization film, and a pixel electrode are sequentially formed on a substrate, and a contact hole is formed in the planarization film to electrically connect the TFT and the pixel electrode. It is disclosed that a top emission type display device is configured.

JP 2007-103349 A JP 2003-302917 A JP 2004-177972 A

  However, the structure in which the driving circuit as the lower layer and the pixel electrode of the organic EL element as the upper layer are electrically connected through a contact hole has the following problems.

  FIG. 6A is a plan configuration diagram of a conventional organic EL display device, and FIG. 6B is a cross-sectional configuration diagram of Z-Z ′ of the conventional organic EL display device. The organic EL display device illustrated in FIG. 6A includes a light emitting region, a non-light emitting region, and a partition wall layer 122. The light emitting areas as unit pixels are two-dimensionally arranged, and adjacent light emitting areas are separated by a non-light emitting area or a partition wall layer 122. The partition layer 122 forms a line bank. Therefore, the partition wall layer 122 sandwiches a plurality of light emitting regions arranged in one row or one column. In this case, the contact hole is not provided below the partition layer 122, and for example, the contact hole 123 is provided in a non-light-emitting region in which no light-emitting region exists among regions sandwiched by the same partition layer 122.

  As in the cross-sectional view shown in FIG. 6B, the organic EL display device has a planarization film 111 formed on the TFT substrate 110. The planarizing film 111 is provided with a contact hole 123 for electrically connecting the reflective anode 112 of the upper organic light emitting element and the TFT substrate 110. At this time, since the thickness of the reflective anode 112 is smaller than the thickness of the planarizing film 111, the reflective anode 112 is formed on the surface of the planarizing film 111, the bottom of the contact hole 123, and the side wall. On the reflective anode 112, a transparent metal film 113, a pixel regulating layer 114, a hole injection layer 115, and a partition wall layer 122 are laminated in this order. Thereafter, the organic light emitting layer 116, the electron transport layer 117, the transparent cathode 118, the sealing layer 119, the resin layer 120, and the CF substrate 121 are laminated in this order.

  Here, in the contact hole 123, a depression is generated above the hole injection layer 115. For example, when an organic light emitting layer is formed by a wet film forming method, an organic light emitting layer material is formed in the depression. By flowing in, there is a problem that an extra material for the light emitting layer is required and it is difficult to control the film thickness of the light emitting layer. Further, due to the flow of the organic light emitting layer material into the contact hole 123, the flatness of the organic light emitting layer 116 is not ensured in the vicinity of the contact hole 123. Therefore, for example, there is a problem that the thickness of the organic light emitting layer 116 is reduced at the boundary between the light emitting region and the non-light emitting region, and unevenness in light emission luminance occurs in the light emitting region.

  In addition to the configuration shown in FIG. 6, a configuration in which a contact hole is formed below the partition layer is conceivable. However, when a recess due to the contact hole is covered with the partition layer, a recess is generated above the partition layer. In this case, if the material that is the basis of the organic light emitting layer is dropped from above using an ink jet method or the like, a part of the dripped material may be accumulated in the depression above the partition wall layer and may not flow into the light emitting region. all right. In this case, an extra light emitting material is required, and the dropping amount cannot be controlled with high accuracy, so that the accuracy of the film thickness of the light emitting layer and the like is also lowered.

  In order to solve these problems, an object of the present invention is to form a favorable light emitting layer in an organic EL display device by eliminating the influence of a depression due to a contact hole formed in a planarization film. Furthermore, a simpler manufacturing method for eliminating the influence of the depression due to the contact hole is provided.

  In order to solve the above problems, an organic EL display device according to one embodiment of the present invention is formed over a substrate, a drive circuit layer including a drive element formed over the substrate, and over the drive circuit layer. Formed on the planarizing film, above the planarizing film, and on the bottom and side walls of the contact hole provided in the planarizing film, and electrically connected to the driving element through the contact hole Light emission by being provided between the pixel electrode, the organic light emitting layer formed above the pixel electrode, the counter electrode formed above the organic light emitting layer, and the pixel electrode and the organic light emitting layer A pixel restricting layer that forms a non-light emitting region in which no current flows, the pixel restricting layer is filled in the upper part of the contact hole, and the upper surface of the pixel restricting layer is flattened over the region where the pixel restricting layer is formed It is characterized in that is.

  According to the organic EL display device and the manufacturing method thereof of the present invention, by flattening the depression of the contact hole provided in the planarization film formed between the drive circuit layer and the pixel electrode with the pixel regulation layer. The organic light emitting layer material can be prevented from flowing into the depression. Therefore, the film thickness of the organic light emitting layer can be controlled with high accuracy, the film thickness of the organic light emitting layer is made uniform, and unevenness in light emission luminance can be suppressed.

(A) is a plane block diagram of the organic electroluminescence display which concerns on embodiment of this invention. (B) is a cross-sectional block diagram in X-X 'of the organic electroluminescence display which concerns on embodiment of this invention. (C) is a cross-sectional block diagram in Y-Y 'of the organic electroluminescence display which concerns on embodiment of this invention. (A)-(e) is process sectional drawing explaining the manufacturing method of the organic electroluminescence display which concerns on embodiment of this invention. (A)-(d) is process sectional drawing explaining the manufacturing method of the organic electroluminescence display which concerns on embodiment of this invention. (A)-(c) is process sectional drawing explaining the manufacturing method of the organic electroluminescence display which concerns on embodiment of this invention. 1 is an external view of a TV in which an organic EL display device and a manufacturing method thereof according to the present invention are used. (A) is a plane block diagram of the conventional organic electroluminescence display. (B) is a cross-sectional block diagram in Z-Z 'of the conventional organic electroluminescence display.

  An organic EL display device according to an aspect of the present invention includes a substrate, a drive circuit layer including a drive element formed over the substrate, a planarization film formed over the drive circuit layer, A pixel electrode formed above the planarizing film and at a bottom and a side wall of a contact hole provided in the planarizing film and electrically connected to the driving element through the contact hole; and An organic light-emitting layer formed above, a counter electrode formed above the organic light-emitting layer, and a non-light-emitting region where no light emission current flows is provided between the pixel electrode and the organic light-emitting layer. A pixel restricting layer to be formed, and the pixel restricting layer is filled in an upper part of the contact hole, and an upper surface of the pixel restricting layer is flattened over a region where the pixel restricting layer is formed.

  According to this aspect, the depression generated in the upper portion of the contact hole provided in the non-light emitting region and electrically connecting the driving element and the pixel electrode is flattened by the pixel regulation layer. In other words, since the base layer of the organic light emitting layer is flattened before the organic light emitting layer is formed, the organic light emitting layer material does not flow into the depression, and the increase in the amount of dropped ink is suppressed and organic light emission is achieved. The film thickness of the layer can be controlled with high accuracy. Further, since the organic light emitting layer material does not flow into the contact hole, the flatness of the organic light emitting layer is ensured even in the vicinity of the contact hole. Therefore, the thickness of the organic light emitting layer is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  Further, according to one embodiment of the present invention, a difference between a surface height in a light emitting region of a layer below the pixel restricting layer and in contact with the pixel restricting layer and a surface height of the pixel restricting layer is within 500 nm.

  According to this aspect, a step is generated at the boundary between the light emitting region and the non-light emitting region by the thickness of the flattened pixel regulation layer. The accuracy of layer thickness control is not reduced. Further, the flatness of the organic light emitting layer is ensured even in the vicinity of the step. Therefore, the thickness of the organic light emitting layer is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  Furthermore, according to one aspect of the present invention, the pixel electrode may be formed separately for each light emitting pixel, and the pixel restricting layer may be filled in a region between the adjacent pixel electrodes.

  In a top emission type organic EL display device, the reflective anode formed below the organic light emitting layer is formed separately for each light emitting pixel. A region having a step is generated between the pixel electrodes which are the reflective anodes, and a depression is also generated in the upper portion of the region.

  According to this aspect, the depression generated in the region between the pixel electrodes is filled and flattened by the pixel regulation layer. Therefore, as with the effect of flattening the pixel regulation layer on the contact hole, the underlying layer of the organic light emitting layer is flattened before the organic light emitting layer is formed. Therefore, the increase in the amount of dripped ink can be suppressed and the film thickness of the organic light emitting layer can be controlled with high accuracy. In addition, since the organic light emitting layer material does not flow into the region between the pixel electrodes, the flatness of the organic light emitting layer is ensured even in the vicinity of the region. Therefore, the thickness of the organic light emitting layer is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  In addition, according to an aspect of the present invention, it further includes a partition layer that is formed above a part of the pixel regulation layer and separates a formation region of the organic light emitting layer, and the contact hole includes the partition layer. It may be formed in the non-light emitting region that is not formed.

  According to this aspect, the contact hole is formed not in the partition layer but in the non-light emitting region that separates the light emitting region.

  Furthermore, according to an aspect of the present invention, the partition wall layer may be a linear partition wall layer disposed so as to sandwich a plurality of light emitting regions partitioned by the pixel regulation layer.

  According to this aspect, the bank structure is a bank structure on a line in which the light-emitting pixels in one row or one row are sandwiched, and the same color organic light-emitting layer material is poured into a region sandwiched between the partition layers. In this case, an organic light emitting layer is also formed on the contact hole. Therefore, by flattening the pixel regulation layer that is the base of the organic light emitting layer, the thickness of the organic light emitting layer of the plurality of light emitting pixels sandwiched between the partition layers can be controlled uniformly.

  According to an aspect of the present invention, the plurality of light emitting regions partitioned by the pixel regulation layer and the partition layer are two-dimensionally arranged, and the line-shaped partition layer is formed of the plurality of light emitting regions. You may arrange | position so that the several light emission area | region arrange | positioned one-dimensionally may be pinched | interposed.

  According to this aspect, when the light emitting pixels represented by a light emitting panel used for an organic EL display or the like are two-dimensionally arranged, the film thickness of the organic light emitting layer is extended over all the light emitting pixels arranged two-dimensionally. Can be controlled with high accuracy. Further, in all the light emitting pixels, the film thickness of the organic light emitting layer is made uniform, and unevenness in light emission luminance does not occur in the light emitting region.

  Further, according to one embodiment of the present invention, the plurality of light emitting regions arranged in the region sandwiched between the line-shaped partition layers may have the same color.

  According to this aspect, the plurality of light emitting regions arranged in the region sandwiched between the line-shaped partition layers have the same color. Therefore, the organic light emitting layer material can be poured into the region at a time. In this case, since the pixel restricting layer is flattened, the organic light emitting layer material is not unevenly distributed and does not flow into unnecessary portions. Therefore, the thickness of the organic light emitting layer can be controlled with high accuracy in the above region. it can. Further, in the above region, the thickness of the organic light emitting layer is made uniform, and unevenness in light emission luminance does not occur in the light emitting region.

  In addition, a method for manufacturing an organic EL display device according to one embodiment of the present invention is provided for electrically connecting a driving element and an upper layer of a driving circuit layer above a driving circuit layer formed over a substrate. A first step of forming a planarization film provided with a contact hole; a second step of forming a pixel electrode above the planarization film and on the bottom and side walls of the contact hole; and above the pixel electrode. A third step of forming an insulator layer having a film thickness equal to or greater than the depth of the contact hole depression in a non-light-emitting region including the region where the contact hole is formed; and a convex portion on the surface of the insulator layer Is etched back to form a pixel regulation layer in which the entire surface of the insulator layer is flattened and a light emission current does not flow, and an organic functional layer is formed above the pixel regulation layer. The fifth step and Above the organic functional layer, and a sixth step of forming a counter electrode.

  According to this aspect, the depression generated in the upper portion of the contact hole provided in the non-light emitting region and electrically connecting the driving element and the pixel electrode is flattened by the pixel regulation layer. In other words, since the base layer of the organic light emitting layer is flattened before the organic light emitting layer is formed, the organic light emitting layer material does not flow into the depression, and the increase in the amount of dropped ink is suppressed and organic light emission is achieved. The film thickness of the layer can be controlled with high accuracy. Further, since the organic light emitting layer material does not flow into the contact hole, the flatness of the organic light emitting layer is ensured even in the vicinity of the contact hole. Therefore, the thickness of the organic light emitting layer is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  In addition, the pixel regulation layer can be flattened by a simple process before the formation of the organic light emitting layer which is easily damaged by a process factor such as heating.

  According to an aspect of the present invention, the organic functional layer includes an organic light emitting layer, and further includes a plurality of organic light emitting layer forming regions for separating the organic light emitting layer forming region above a part of the pixel regulating layer. A partition layer may be formed with a predetermined spacing, and after the formation of the plurality of partition layers, the organic light emitting layer may be formed in a region sandwiched between the plurality of partition layers.

  According to this aspect, not only the flatness of the region where the organic light emitting layer is formed is improved by flattening the pixel regulating layer, but also the shape of the upper part of the partition wall layer can be flattened. As a result, when the material that is the basis of the organic light-emitting layer is dropped from above using an inkjet method or the like, a state in which a part of the dripped material accumulates in the depression above the partition wall layer and does not flow into the light emitting region is avoided. it can. Therefore, an extra light emitting material is not required, the amount of dripping can be controlled with high accuracy, and the film thickness of the organic light emitting layer can be controlled with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1A is a plan configuration diagram of an organic EL display device according to an embodiment of the present invention. FIG. 1B is a cross-sectional configuration view taken along the line X-X ′ of the organic EL display device according to the embodiment of the present invention. FIG. 1C is a cross-sectional configuration diagram at Y-Y ′ of the organic EL display device according to the embodiment of the present invention.

  In the organic EL display device 1 illustrated in FIG. 1A, unit pixels are two-dimensionally arranged and have a light emitting region, a non-light emitting region, a partition layer 22, and a contact hole 23. One unit pixel has one light emitting region surrounded by the non-light emitting region and the partition wall layer 22. The partition layer 22 forms a line bank. Therefore, the partition layer 22 sandwiches a plurality of light emitting regions arranged in one row or one column. In FIG. 1A, the contact hole is not provided under the partition layer 22, and for example, the contact hole 23 is provided in a non-light-emitting region in which no light-emitting region exists among regions sandwiched by the same partition layer 22. . The contact hole 23 may be provided below the partition wall layer 22.

  FIG. 1B is a cross-sectional view of a non-light emitting region and a region where a partition layer is formed, and FIG. 1C is a cross-sectional view of the light emitting region and the non-light emitting region. As shown in FIGS. 1B and 1C, the organic EL display device 1 includes a TFT substrate 10, a planarizing film 11, a reflective anode 12, a transparent metal film 13, and a pixel regulating layer. 14, hole injection layer 15, organic light emitting layer 16, electron transport layer 17, transparent cathode 18, sealing layer 19, resin layer 20, CF substrate 21, partition wall layer 22, contact hole. 23.

  The TFT substrate 10 is formed on a glass substrate, for example, and includes a thin film transistor (TFT) that drives an organic EL element.

The planarization film 11 ensures the uniformity of the film thickness of the organic EL element formed in the upper layer by planarizing the unevenness of the surface of the TFT substrate 10. The planarizing film 11 is an insulating film made of an inorganic material or an organic material, and examples thereof include SiN _x , SiO _x , acrylic, polyimide, and sol-gel, and the film thickness is 3.5 μm.

  The contact hole 23 is a region where the planarizing film 11 is formed and is provided so as to penetrate the planarizing film 11.

  The reflective anode 12 is formed on the upper surface of the planarizing film 11 so as to cover the bottom and side walls of the contact hole 23. Thereby, the reflective anode 12 is electrically connected to the driving TFT of the TFT substrate 10 through the contact hole 23. The reflective anode 12 has a function as an anode of the organic EL element, and also has a function of reflecting light emitted from the organic light emitting layer 16 toward the lower reflective anode 12 toward the upper transparent cathode 18. Therefore, the reflective anode 12 is preferably a metal film having high reflectivity and conductivity, and is, for example, APC (Ag, Pd, Cu alloy) and has a film thickness of 150 nm.

  The transparent metal film 13 is formed on the upper surface of the reflective anode 12. The transparent metal film 13 has a function of adjusting the optical distance between the organic light emitting layer and the reflective anode surface by preventing oxidation of the reflective anode 12 and optimizing the film thickness. Therefore, the transparent metal film 13 is preferably a film having high transmittance and conductivity, for example, ITO (Indium Tin Oxide), and the film thickness is 50 nm.

  Due to the film thickness relationship of the planarizing film 11, the reflective anode 12, and the transparent metal film 13 described above, a recess is formed on the contact hole 23 after the transparent metal film 13 is formed.

  The reflective anode 12 and the transparent metal film 13 are separated for each unit pixel.

The pixel regulating layer 14 is between the reflective anode 12 and the organic light emitting layer 16, and is made of an insulator so that a non-light emitting region in which the light emission current between the reflective anode 12 and the transparent cathode 18 is suppressed is unified. Part formation. Examples of the pixel regulation layer 14 include SiN _x , SiO _x , acrylic, polyimide, and sol-gel.

  Here, the pixel regulation layer 14 is filled in the upper part of the contact hole 23, and the surface of the pixel regulation layer 14 is flattened.

  Thereby, since the base layer of the organic light emitting layer 16 is flattened before the organic light emitting layer 16 is formed, the organic light emitting layer material does not flow into the depression, and the increase in the amount of the dropped ink is suppressed. The film thickness of the organic light emitting layer 16 can be controlled with high accuracy. Further, since the organic light emitting layer material does not flow into the contact hole 23, the flatness of the organic light emitting layer 16 is ensured even in the vicinity of the contact hole 23. Therefore, the film thickness of the organic light emitting layer 16 is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  Further, a step is generated at the boundary between the light emitting region and the non-light emitting region by the thickness of the flattened pixel regulating layer 14, but the step height is preferably within 500 nm. Thereby, the precision of the film thickness control of the organic light emitting layer 16 is not lowered. Further, the flatness of the organic light emitting layer 16 is ensured even in the vicinity of the step. Therefore, the film thickness of the organic light emitting layer 16 is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  In addition, the pixel regulation layer 14 is preferably filled in a region between adjacent reflective anodes 12.

  In the top emission type organic EL display device 1 as in the present embodiment, the reflective anode 12 formed below the organic light emitting layer 16 is separately formed for each light emitting pixel. A region having a step is generated between the reflective anodes 12, and a depression is also generated in the upper portion of the region.

  According to the present embodiment, the depression generated in the region between the reflective anodes 12 is filled with the pixel regulation layer 14 and flattened. Therefore, similar to the effect of flattening the pixel regulation layer 14 on the contact hole 23, the base layer of the organic light emitting layer 16 is flattened before the organic light emitting layer 16 is formed. The light emitting layer material does not flow in, the increase in the amount of dropped ink can be suppressed, and the film thickness of the organic light emitting layer 16 can be controlled with high accuracy. Further, since the organic light emitting layer material does not flow into the region between the reflective anodes 12, the flatness of the organic light emitting layer 16 is ensured even in the vicinity of the region. Therefore, the film thickness of the organic light emitting layer 16 is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  The flattening process of the pixel regulating layer 14 will be described in a method for manufacturing the organic EL display device 1 described later.

  The hole injection layer 15 is formed on the upper surface of the transparent metal film 13 in the light emitting region, and on the upper surface of the pixel regulating layer 14 in the non-light emitting region. The hole injection layer 15 is a layer mainly composed of a hole injection material. The hole injecting material is a material having a function of injecting holes injected from the reflective anode 12 side into the organic light emitting layer 16 stably or by assisting the generation of holes. The hole injection layer 15 is, for example, a mixed film of molybdenum oxide and tungsten oxide and has a film thickness of 50 nm.

  Here, since the hole injection layer 15 is formed on the planarized upper surface of the pixel regulation layer 14 in the non-light emitting region, the planarity of the upper surface of the hole injection layer 15 is also ensured.

  The partition layer 22 is formed on the hole injection layer 15, has a function of regulating the formation region of the organic light emitting layer 16 and separating the light emitting region for each light emitting pixel or for each light emitting pixel group. A resin material such as a resin is used.

  In the present embodiment, the partition wall layer 22 is a line-shaped partition wall layer disposed so as to sandwich a plurality of light emitting regions partitioned by the pixel regulation layer 14.

  In the present embodiment, as shown in FIG. 1C, the hole injection layer 15 and the partition layer are formed in the region between the adjacent reflective anodes 12 formed below the partition layer 22. However, the pixel regulation layer 14 may be filled and flattened instead of the partition wall layer 22.

  Thereby, the shape of the upper part of the partition wall layer 22 can be flattened. Therefore, when the material that is the basis of the organic light emitting layer 16 is dropped from above using an ink jet method or the like, a part of the dropped material is accumulated in the depression above the partition wall layer 22 and does not flow into the light emitting region. Can be avoided. Therefore, an extra light emitting material is not required, the dropping amount can be controlled with high accuracy, and the film thickness of the organic light emitting layer 16 can be controlled with high accuracy.

The organic light emitting layer 16 is a layer that emits red light, a layer that emits green light, or a layer that emits blue light. The organic light emitting layer 16 is surrounded by the hole injection layer 15, the electron transport layer 17, and the partition layer 22, and the electrons injected into the organic light emitting layer 16. The light generated by the recombination of holes and holes is emitted from the surface of the transparent cathode 18. The organic light emitting layer 16 can use a low molecular weight or high molecular weight organic light emitting material. As the polymer light-emitting material, for example, a polymer light-emitting material such as polyparaphenylene vinylene (PPV) or polyfluorene can be used. Moreover, as a low molecular weight light emitting material, in addition to Alq ₃ and Be-benzoquinolinol (BeBq ₂ ), 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl)- 1,3,4-thiadiazole, 4,4'-bis (5,7-benzyl-2-benzoxazolyl) stilbene, 4,4'-bis [5,7-di- (2-methyl-2- Butyl) -2-benzoxazolyl] stilbene, 2,5-bis (5,7-di-t-benzyl-2-benzoxazolyl) thiophine, 2,5-bis ([5-α, α- Dimethylbenzyl] -2-benzoxazolyl) thiophene, 2,5-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] -3,4-diphenylthiophene, 2,5-bis (5-methyl-2-benzoxazolyl) thio 4,4'-bis (2-benzoxazolyl) biphenyl, 5-methyl-2- [2- [4- (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazo Benzoxazoles such as ril, 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole, benzothiazoles such as 2,2 ′-(p-phenylenedivinylene) -bisbenzothiazole , 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole, 2- [2- (4-carboxyphenyl) vinyl] benzimidazole, and other fluorescent whitening agents such as Tris, (8-quinolinol) aluminum, bis (8-quinolinol) magnesium, bis (benzo [f] -8-quinolinol) zinc, bis 2-methyl-8-quinolinolate) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinol lithium, tris (5-chloro-8-quinolinol) gallium, bis ( Metal-chelating oxinoid compounds such as 8-hydroxyquinoline-based metal complexes such as 5-chloro-8-quinolinol) calcium and poly [zinc-bis (8-hydroxy-5-quinolinonyl) methane] and dilithium ependridione 1,4-bis (2-methylstyryl) benzene, 1,4- (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, distyrylbenzene, 1,4-bis (2 -Ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) ben , 1,4-bis (2-methylstyryl) 2-methylbenzene and other styrylbenzene compounds, 2,5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine 2,5-bis [2- (1-naphthyl) vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2- (4-biphenyl) vinyl] pyrazine, 2, Distylpyrazine derivatives such as 5-bis [2- (1-pyrenyl) vinyl] pyrazine, naphthalimide derivatives, perylene derivatives, oxadiazole derivatives, aldazine derivatives, cyclopentadiene derivatives, styrylamine derivatives, Coumarin derivatives and aromatic dimethylidin derivatives are used. Furthermore, anthracene, salicylate, pyrene, coronene and the like are also used. Alternatively, a phosphorescent material such as fac-tris (2-phenylpyridine) iridium can be used.

  As described above, since the base layer of the organic light emitting layer 16 is flattened before the organic light emitting layer 16 is formed, the organic light emitting layer material does not flow into the depression such as the contact hole 23, and the dropped ink. The increase in the amount can be suppressed and the thickness of the organic light emitting layer 16 can be controlled with high accuracy.

  The electron transport layer 17 is formed on the upper surface of the organic light emitting layer 16. The electron transport layer 17 is a layer mainly composed of an electron transport material. The electron transporting material has both the property of being an electron acceptor and easily becoming an anion, and the property of transferring generated electrons by a charge transfer reaction between molecules, and the charge from the transparent cathode 18 to the organic light emitting layer 16. A material that is suitable for transportation. Examples of the electron transport layer 17 include oxadiazole derivatives such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7), anthraquinodimethane derivatives, and diphenyl. Polymer materials such as quinone derivatives and silole derivatives, bis (2-methyl-8-quinolinolate)-(para-phenylphenolate) aluminum (BAlq), bathopproin (BCP), and the like are used. At this time, for example, the electron transport layer 17 may be formed after laminating a metal layer mainly composed of at least one of an alkali metal and an alkaline earth metal. In addition, the metal layer may contain two or more kinds of alkali metals and alkaline earth metals.

  The transparent cathode 18 is formed on the upper surface of the electron transport layer 17. The transparent cathode 18 has, for example, a structure in which barium is laminated to 10 nm as a lower layer and ITO is laminated to 100 nm as an upper layer.

  The materials of the hole injection layer 15 and the electron transport layer 17 are not limited in the present invention, and a well-known organic material or inorganic material is used.

  In addition, as a configuration of the organic EL display device 1, there may be a hole transport layer between the hole injection layer 15 and the organic light emitting layer 16, or between the electron transport layer 17 and the transparent cathode 18. There may be an electron injection layer. The hole transport layer is a layer mainly composed of a material having a hole transport property. The hole transporting material has both the property of having an electron donor property and easily becoming a cation (hole) and the property of transferring the generated hole by intermolecular charge transfer reaction. A material that has suitability for charge transport to the layer 16. The electron injection layer is a layer mainly composed of an electron injecting material. The electron injecting material is a material having a function of injecting electrons injected from the transparent cathode 18 into the organic light emitting layer 16 stably or by assisting generation of electrons.

  The sealing layer 19 is formed on the upper surface of the transparent cathode 18 and has a function of blocking the lower organic light emitting layer 16 and the transparent cathode 18 from water vapor and oxygen. This is to prevent the organic light emitting layer 16 itself and the transparent cathode 18 from being deteriorated (oxidized) by being exposed to water vapor or oxygen.

  The resin layer 20 is an acrylic or epoxy resin, and has a function of bonding a layer formed integrally from the TFT substrate 10 to the sealing layer 19 and a CF substrate 21 described later.

  The CF substrate 21 is a substrate that protects the light emitting surface of the light emitting panel, and is, for example, transparent alkali-free glass having a thickness of 0.5 mm.

  Conventionally, since the organic light emitting material flows into the depression of the contact hole, the thickness of the organic light emitting layer is reduced in the vicinity of the contact hole. Therefore, particularly at the boundary between the light emitting region and the non-light emitting region, the film thickness of the organic light emitting layer is smaller than the central portion of the light emitting region, and luminance unevenness occurs in the pixel.

  On the other hand, in the organic EL display device 1 according to the present embodiment, the upper part of the contact hole is flattened by the pixel regulating layer that is the base of the organic light emitting layer. The thickness is made uniform and no brightness unevenness occurs.

  The hole injection layer 15 and the electron transport layer 17 can be omitted depending on the combination of materials of the reflective anode 12, the organic light emitting layer 16, and the transparent cathode 18.

  Further, a hole transport layer may be provided between the hole injection layer 15 and the organic light emitting layer 16, and an electron injection layer may be provided between the electron transport layer 17 and the transparent cathode 18. Further, the transparent metal film 13 may be omitted.

  Next, the manufacturing method of the organic EL display device of the present invention will be described in detail.

  2 to 4 are process cross-sectional views illustrating a method for manufacturing an organic EL display device according to an embodiment of the present invention.

First, as shown in FIG. 2A, a planarizing film 11 is laminated on the TFT substrate 10, for example, 3.5 μm. The material of the planarizing film 11 is an insulating film made of an inorganic material or an organic material, and examples thereof include SiN _x , SiO _x , acrylic, polyimide, and sol-gel. Among these, the insulating film made of SiN _x and SiO _x is formed by, for example, a CVD (Chemical Vapor Deposition) method. Next, in order to electrically connect the driving TFT in the TFT substrate 10 and the upper reflective anode 12, a contact hole 23 penetrating vertically is formed in the planarization film 11. The contact hole 23 is formed by wet etching or dry etching after forming a resist pattern on the planarizing film by photolithography.

  Next, as shown in FIG. 2B, the reflective anode 12 is laminated on the upper surface of the planarizing film 11 so as to cover the bottom and side walls of the contact hole 23. Here, the reflective anode 12 is formed, for example, by first forming a silver alloy APC with a thickness of 150 nm by a sputtering method, and then performing a patterning process by photolithography and wet etching. Thereby, the reflective anode 12 is electrically connected to the driving TFT of the TFT substrate 10 through the contact hole 23, and is separately formed for each unit pixel.

  Next, as shown in FIG. 2C, a transparent metal film 13 is laminated on the upper surface of the reflective anode 12. Here, the transparent metal film 13 is formed, for example, by depositing ITO with a thickness of 50 nm by a sputtering method.

  Due to the film thickness relationship of the planarizing film 11, the reflective anode 12, and the transparent metal film 13 described above, a recess is formed on the contact hole 23 after the transparent metal film 13 is formed.

Next, as shown in FIG. 2 (d), the depth of the depression generated above the contact hole 23 in the non-light emitting region including the region where the contact hole 23 is formed on the upper surface of the transparent metal film 13. The insulator layer 14A having the above thickness is formed. The material of the insulator layer 14A is an insulating film made of an inorganic material or an organic material, and examples thereof include SiN _x , SiO _x , acrylic, polyimide, and sol-gel. Among these, the insulating film made of SiN _x and SiO _x is formed by, for example, CVD.

  Next, as shown in FIG. 2E, a resist 24A is formed on the upper surface of the insulator layer 14A. As the resist 24A, for example, a resist made of an organic material is applied to the upper surface of the insulator layer 14A by using a spin coating method, and then cured by heating or light irradiation. By such a forming method, the surface of the resist 24A is planarized. Further, the etching rate of the resist 24A in the etching method used in the subsequent etch-back step is preferably equal to the etching rate of the insulator layer 14A.

  Next, as shown in FIG. 3A, the resist 24A and the insulator layer 14A are etched back from the upper surface of the resist 24A by dry etching. At this time, the flatness of the surface of the insulator layer 14A is improved as the etching rate of the resist 24A is equal to the etching rate of the insulator layer 14A. When the film thickness in the predetermined region of the insulator layer 14A becomes a predetermined value (for example, 500 nm) or less, the etching is terminated. At this time, a planarized insulator layer 14B is formed.

  Note that after the insulator layer 14A is stacked in FIG. 2D, planarization by a CMP (Chemical Mechanical Planarization) method is used instead of the planarization process described in FIGS. 2E and 3A. A process may be used.

  Next, as shown in FIGS. 3B and 3C, a patterned resist 24B is formed and etched to remove the insulator layer 14B in the region where the partition wall layer 22 is to be formed. At this time, the pixel regulation layer 14 is formed on the upper surface of the transparent metal film 13.

  Next, as shown in FIG. 3D, the hole injection layer 15 is stacked on the upper surface of the resist 24B and the region where the partition layer 22 is formed. The hole injection layer 15 is formed, for example, by forming a mixed film of molybdenum oxide and tungsten oxide to a thickness of 50 nm by, for example, a sputtering method. Here, since the hole injection layer 15 is formed on the planarized upper surface of the pixel regulation layer 14 in the non-light emitting region, the planarity of the upper surface of the hole injection layer 15 is also ensured.

  Next, as shown in FIG. 4A, the partition layer 22 is formed on the upper surface of the hole injection layer 15. Here, the partition wall layer 22 is made of a resin material such as polyimide resin. The partition layer 22 forms a line-shaped partition layer arranged so as to sandwich a plurality of light emitting regions partitioned by the pixel regulating layer 14.

  In addition, you may abbreviate | omit the process described in FIG.3 (b) and FIG.3 (c). In FIG. 4A, the region between the adjacent reflective anodes 12 formed under the partition layer 22 is filled with the hole injection layer 15 and the partition layer 22, but in this case, Instead of the partition wall layer 22, the pixel regulation layer 14 may be filled and planarized. Thereby, the shape of the upper part of the partition wall layer 22 can be flattened. Therefore, when the material that is the basis of the organic light emitting layer 16 is dropped from above using an ink jet method or the like, a part of the dropped material accumulates in the depression above the partition wall layer 22 and does not flow into the light emitting region. Can be avoided. Therefore, an extra light emitting material is not required, the amount of dripping can be controlled with high accuracy, and the film thickness of the organic light emitting layer 16 can be controlled with high accuracy.

  Next, as shown in FIG. 4B, a paste material to be the organic light emitting layer 16 is applied to the region sandwiched between the partition layers 22 by using, for example, an ink jet method. At this time, the paste material to be the organic light emitting layer 16 is applied in a state of rising from the region sandwiched between the partition walls 22 due to surface tension. Thereafter, the paste material is dried, for example, at 80 ° C. for about 30 minutes, and the solvent component of the paste material is volatilized to form the organic light emitting layer 16. At this time, in the case where the light emitting unit is composed of at least three different subpixels such as RGB, the organic light emitting layer 16 that is different for each subpixel is obtained by repeating the paste material applying step and the drying step described above for each subpixel. Is formed. At this time, for example, a plurality of light emitting regions arranged in a region sandwiched between the partition layers 22 emit light in the same color for each line.

  Here, since the base layer of the organic light emitting layer 16 is flattened before the organic light emitting layer 16 is formed, the organic light emitting layer material may flow into the depression above the contact hole in the paste material application step. In addition, the increase in the amount of dropped ink can be suppressed and the film thickness of the organic light emitting layer 16 can be controlled with high accuracy. Further, since the organic light emitting layer material does not flow into the contact hole, the flatness of the organic light emitting layer is ensured even in the vicinity of the contact hole. Therefore, the film thickness of the organic light emitting layer 16 is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  Next, the electron transport layer 17 is formed on the entire surface using, for example, a vacuum deposition method so as to cover the light emitting region, the non-light emitting region, and the partition layer 22. Subsequently, on the electron transport layer 17, for example, ITO is formed using a sputtering method, and the transparent cathode 18 is formed on the entire surface.

  An organic EL element having a function as a light emitting element is formed by the formation process described in FIGS. 2B to 4B.

  Next, as shown in FIG. 4C, 500 nm of silicon nitride is deposited on the transparent cathode 18 by, for example, a plasma CVD method to form a sealing layer 19. Thereafter, a sealing resin to be the resin layer 20 is applied to the surface of the sealing layer 19. Then, the CF substrate 21 including the color filter is disposed on the applied sealing resin. Finally, pressure is applied downward from the upper surface side of the CF substrate 21, and heat or energy rays are applied to form the resin layer 20 that bonds the CF substrate 21 and the sealing layer 19.

  As described above, according to the organic EL display device and the manufacturing method thereof according to the embodiment of the present invention, the upper portion of the contact hole provided in the non-light emitting region and electrically connecting the driving element and the pixel electrode. The dent generated in the step is flattened by the pixel regulation layer. In other words, since the base layer of the organic light emitting layer is flattened before the organic light emitting layer is formed, the organic light emitting layer material does not flow into the depression, and the increase in the amount of dropped ink is suppressed and organic light emission is achieved. The film thickness of the layer can be controlled with high accuracy. Further, since the organic light emitting layer material does not flow into the contact hole, the flatness of the organic light emitting layer is ensured even in the vicinity of the contact hole. Therefore, the thickness of the organic light emitting layer is made uniform over the entire light emitting region, and unevenness in light emission luminance does not occur in the light emitting region.

  The organic EL display device and the manufacturing method thereof according to the present invention are not limited to the above embodiment. Modifications obtained by making various modifications conceivable by those skilled in the art within the scope of the present invention without departing from the spirit of the present invention, and various apparatuses incorporating the display device and display evaluation device according to the present invention are also included in the present invention. include.

  For example, the organic EL display device and the manufacturing method thereof according to the present invention are incorporated in a thin flat TV as shown in FIG. By the organic EL display device and the simplified manufacturing method thereof according to the present invention, a thin flat TV having an organic EL display in which the film thickness of the organic light emitting layer is made uniform and the unevenness of light emission luminance is suppressed is realized. .

  In the organic EL display device 1 according to the embodiment of the present invention, the TFT substrate 10, the planarization film 11, the reflective anode 12, the transparent metal film 13, the hole injection layer 15, the organic light emitting layer 16, and the electron transport layer 17 are used. The materials of the transparent cathode 18, the sealing layer 19, the resin layer 20, and the CF substrate 21 are not limited in the present invention, and a known organic material or inorganic material is used.

  The present invention is particularly useful for an organic EL flat panel display incorporating an organic EL display device, and is optimal for use as an organic EL display device that requires high-quality display performance and a manufacturing method thereof.

DESCRIPTION OF SYMBOLS 1,100 Organic EL display device 10,110 TFT substrate 11,111 Planarization film 12,112 Reflective anode 13,113 Transparent metal film 14,114 Pixel regulation layer 14A, 14B Insulator layer 15,115 Hole injection layer 16, 116 Organic light emitting layer 17, 117 Electron transport layer 18, 118 Transparent cathode 19, 119 Sealing layer 20, 120 Resin layer 21, 121 CF substrate 22, 122 Partition layer 23, 123 Contact hole 24A, 24B Resist

Claims (9)

A substrate,
A drive circuit layer including a drive element formed above the substrate;
A planarization film formed above the drive circuit layer;
A pixel electrode formed above the planarization film and at a bottom and a sidewall of a contact hole provided in the planarization film, and electrically connected to the driving element through the contact hole;
An organic light emitting layer formed above the pixel electrode;
A counter electrode formed above the organic light emitting layer;
A pixel regulating layer that is provided between the pixel electrode and the organic light-emitting layer to form a non-light-emitting region where no light emission current flows;
The organic EL display device, wherein the pixel restricting layer is filled in an upper portion of the contact hole, and an upper surface of the pixel restricting layer is planarized over a region where the pixel restricting layer is formed. The organic EL display device according to claim 1, wherein a difference between a surface height in a light emitting region of a layer below the pixel restricting layer and in contact with the pixel restricting layer and a surface height of the pixel restricting layer is within 500 nm. . The pixel electrode is formed separately for each light emitting pixel,
The organic EL display device according to claim 1, wherein the pixel regulation layer is filled in a region between the adjacent pixel electrodes. further,
A partition layer formed above a part of the pixel regulation layer and separating a formation region of the organic light emitting layer,
The organic EL display device according to claim 1, wherein the contact hole is formed in the non-light-emitting region where the partition layer is not formed. The organic EL display device according to claim 4, wherein the partition layer is a line-shaped partition layer disposed so as to sandwich a plurality of light emitting regions partitioned by the pixel regulating layer. A plurality of light emitting regions partitioned by the pixel regulation layer and the partition layer are two-dimensionally arranged,
The organic EL display device according to claim 5, wherein the line-shaped partition layer is disposed so as to sandwich a plurality of light emitting regions arranged one-dimensionally among the plurality of light emitting regions. The organic EL display device according to claim 6, wherein a plurality of light emitting regions arranged in a region sandwiched between the line-shaped partition walls have the same color. A first step of forming a planarization film provided with a contact hole for electrically connecting a driving element included in the driving circuit layer and an upper layer above the driving circuit layer formed on the substrate;
A second step of forming a pixel electrode above the planarizing film and on the bottom and side walls of the contact hole;
A third step of forming an insulator layer having a thickness equal to or greater than the depth of the contact hole in a non-light emitting region above the pixel electrode and including a region where the contact hole is formed;
A fourth step of forming a pixel regulating layer in which the entire surface of the insulator layer is flattened by etching back the protrusions on the surface of the insulator layer, and the emission current does not flow;
A fifth step of forming an organic functional layer above the pixel regulation layer;
A method for manufacturing an organic EL display device, comprising: a sixth step of forming a counter electrode above the organic functional layer. The organic functional layer includes an organic light emitting layer,
Further, a plurality of partition layers for separating the formation region of the organic light emitting layer are formed at a predetermined interval above a part of the pixel regulation layer, and after the plurality of partition layers are formed, the plurality of partition layers are formed. The method for manufacturing an organic EL display device according to claim 8, wherein the organic light emitting layer is formed in a region sandwiched between partition walls.

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