JP2011210540A - Organic el display device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL display device capable of uniformly printing a resin protecting film, when the surface shape of a substrate is substantially uniform in a forming zone of the resin protection film and attaining a suitable appearance shape of a pixel region boundary section and restraining deterioration in both the image quality and sealing performance.SOLUTION: In the organic EL display device, an element isolation film 6 for separating organic EL display elements is formed at a forming region A of the resin protection film 10 in a pixel region, and an outer rib 12 is formed at a forming region B of the resin protection film 10 outside the pixel region. Projections 8 with a part of their projections projected upward are formed on the element isolation film 6 and the outer rib 12, and overall heights from the surface of the substrate to the tops of the projections 8 are set up to be the same.

Description

  The present invention relates to an organic EL display device including a plurality of organic EL display elements each having an organic compound layer including a light emitting layer between electrodes, and a method for manufacturing the same.

  In recent years, organic EL display devices, which are self-luminous devices, have attracted attention as flat panel displays. However, it is known that the organic EL display elements constituting the organic EL display device are extremely vulnerable to moisture. For example, when moisture enters the organic EL display element from the outside, a non-light emitting region called a dark spot is generated, and the light emitting performance cannot be maintained.

  As one method for preventing moisture from entering the organic EL display element, for example, a method of forming a protective film made of a resin protective film and an inorganic protective film on the organic EL display element is disclosed (patent) Reference 1). The resin protective film covers the surface of the organic EL display element and its surrounding substrate, and the inorganic protective film is a resin protective film and its edge, and the surrounding substrate surface (a transparent material that allows moisture to enter the organic EL display element). Cover the surface with no damp film underneath). With such a sealing configuration, intrusion of moisture can be suppressed and deterioration of the organic EL display element can be prevented. As a method for forming a resin protective film in this sealing configuration, for example, a screen printing method is disclosed (see Patent Document 2).

  On the other hand, in order to reduce non-light emitting defects of the organic EL display device, for example, a part of this insulating film protrudes upward on an insulating film (element isolation film) between pixel openings of the organic EL display element. It is disclosed that a rib is provided (see Patent Document 3). By providing such a rib, when the organic compound layer is vapor deposited in the pixel, the vapor deposition mask is supported on the rib so that the vapor deposition mask does not bend. Therefore, the vapor deposition mask does not contact the organic compound layer and damage the organic compound layer, so that non-light emitting defects can be reduced. In addition, since the vapor deposition mask comes into contact with the protruding portion of the insulating film, the contact area is also reduced, and damage due to transfer of foreign matter attached to the vapor deposition mask to the insulating film can be suppressed.

JP 2003-282240 A Japanese Patent No. 4329740 JP 2005-322564 A

  By the way, when the sealing structure which consists of a resin protective film and an inorganic protective film is employ | adopted like patent document 1 and 2, and a resin protective film is formed by the screen printing method, first, this should be separated on this on a board | substrate. Place a screen printing plate. Then, by moving a rubber blade called a squeegee while applying pressure, the screen printing plate and the substrate are brought into contact with each other, and the resin is transferred from the opening of the screen printing plate to the substrate surface.

  However, it is known that the film thickness of the resin formed by the printing method is largely dependent on the surface shape of the substrate. That is, as in Patent Document 3, when an organic EL display element in which a rib is formed by protruding a part of an insulating film between pixel openings is sealed with a resin protective film and an inorganic protective film, the rib is in the pixel region. Therefore, the surface shape of the substrate is different between the pixel region and the periphery thereof. Therefore, there is a problem in that the thickness of the resin protective film is different between the pixel region and the periphery thereof, resulting in uneven printing shapes, which causes a decrease in image quality and a decrease in sealing performance at the pixel region boundary.

  The object of the present invention is to make the surface shape of the substrate in the resin protective film formation region substantially uniform, to uniformly print the resin protective film uniformly, to have a good appearance shape at the pixel region boundary, An object of the present invention is to provide an organic EL display device capable of suppressing a decrease in sealing performance and a manufacturing method thereof.

  The configuration of the present invention made to achieve the above object is as follows.

That is, the organic EL display device according to the present invention includes a plurality of organic EL display elements having an organic compound layer including a light emitting layer between electrodes on a substrate, and the organic EL display elements are separated by an element separation film. An organic EL display device comprising at least a plurality of organic EL display elements covered with a resin protective film and at least the resin protective film covered with an inorganic protective film,
Forming the element isolation film in the formation region of the resin protective film in the pixel region, and forming an outer rib in the formation region of the resin protective film outside the pixel region;
On the element isolation film and the outer rib, a convex part partially protruding upward is formed,
The organic EL display device is characterized in that all the heights from the substrate surface to the top of the convex portion are set to the same height.

Moreover, the manufacturing method of the organic EL display device according to the present invention is a manufacturing method of an organic EL display device including a plurality of organic EL display elements each having an organic compound layer including a light emitting layer between electrodes on a substrate. ,
Forming an element isolation film for separating the organic EL display element;
Forming a resin protective film so as to cover at least a plurality of organic EL display elements;
Forming an inorganic protective film so as to cover at least the resin protective film;
Have
In the element isolation film forming step, the element isolation film is formed in the resin protection film formation region in the pixel region, and an outer rib is formed in the resin protection film formation region outside the pixel region,
A method of manufacturing an organic EL display device comprising a step of forming convex portions on the element isolation film and the outer rib so that the heights from the substrate surface to the top are all the same. .

  According to the present invention, the element isolation film is formed in the resin protection film formation region in the pixel region, and the outer rib is formed in the resin protection film formation region outside the pixel region, on the element isolation film and the outer rib. The protrusions are formed so that the height from the substrate surface is the same. Therefore, the surface shape of the substrate becomes substantially uniform, and when the resin protective film is formed by using the printing method, the resin protective film can be printed uniformly, the appearance shape of the pixel region boundary is good, and the image quality is deteriorated. And the outstanding effect that the fall of sealing performance can be suppressed is produced.

It is the schematic which shows the cross-sectional shape of one Embodiment in the organic electroluminescence display of this invention. 1 is a schematic diagram illustrating a planar configuration of an organic EL display device of Example 1. FIG. 6 is a schematic diagram illustrating a planar configuration of an organic EL display device according to Example 2. FIG. It is the schematic which shows the cross-sectional shape of the organic electroluminescent display apparatus of the comparative example 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. In the following description, a well-known technique or a well-known technique in the technical field can be applied to a part that is not particularly illustrated or described.

  First, an embodiment of an organic EL display device according to the present invention will be described together with a manufacturing method with reference to FIG. FIG. 1 is a schematic view showing a cross-sectional shape of an embodiment of the organic EL display device of the present invention.

  As shown in FIG. 1, the organic EL display device of this embodiment is an active matrix type organic EL display device, and includes a light emitting layer on a substrate 1 between a first electrode 5 and a second electrode 9. A plurality of organic EL display elements having the organic compound layer 7 are provided. In the organic EL display device of this embodiment, the organic EL display element is separated by the element separation film 6, and at least a plurality of organic EL display elements are covered by the resin protection film 10, and at least the resin protection film 10 is inorganic protected. Covered with a film 11. The resin protective film 10 of this embodiment is formed using a screen printing method.

  In FIG. 1, an area A is a formation area of the resin protective film 10 in the pixel area, and suppresses intrusion of moisture from the upper surface of the organic EL display device together with the inorganic protective film 11 formed thereon. The region B is a region where the resin protective film 10 is formed outside the pixel region, and suppresses moisture intrusion from the side surface of the organic EL display element together with the inorganic protective film 11 formed thereon. In addition, in the A region and the B region, the planarization film 4 and the element isolation film 6 are separated from each other because these also have moisture permeability. This is to suppress the generation of spots as much as possible.

  First, an organic EL display element that is a main component of the organic EL display device will be described.

  In the organic EL display device of the present embodiment, a TFT circuit 2 that is a light emission drive circuit is formed on a substrate 1. Examples of the substrate 1 include an insulating substrate made of a glass substrate or a synthetic resin, a conductive substrate having an insulating layer such as silicon oxide or silicon nitride formed on the surface, or a semiconductor substrate. The substrate 1 may be transparent or opaque.

  On the substrate 1 including the TFT circuit 2, a planarizing film 4 made of, for example, an acrylic resin, a polyimide resin, a norbornene resin, a fluorine resin, or the like is formed in a desired pattern by a photolithography technique or the like. Yes. Here, the flattening film 4 is a film for flattening the uneven shape generated by providing the TFT circuit 2. The material and manufacturing method of the planarizing film 104 are not particularly limited as long as the uneven shape due to the formation of the TFT circuit 2 can be planarized. Note that an insulating layer made of an inorganic material such as silicon nitride, silicon oxynitride, or silicon oxide may be formed between the planarizing film 4 and the TFT circuit 2.

A first electrode 5 is provided on the planarizing film 4 and is electrically connected to a part of the TFT circuit 2. The first electrode 5 may be a transparent electrode or a reflective electrode. When the first electrode 5 is a transparent electrode, examples of the constituent material include ITO (indium tin oxide) and In ₂ O _3, but are not limited thereto. When the first electrode 5 is a reflective electrode, the constituent material thereof is, for example, a single metal such as Au, Ag, Al, Pt, Cr, Pd, Se, or Ir, an alloy combining a plurality of these single metals, or iodine. Examples thereof include metal compounds such as copper chloride. The film thickness of the first electrode 5 is preferably about 0.1 μm to 1 μm.

  An element isolation film 6 for separating the organic EL display element is provided on the peripheral edge of the first electrode 5. Specifically, not only the element isolation film 6 is formed in the resin protection film formation area A in the pixel area, but also in the process of forming the element isolation film 6, the resin protection film formation area B outside the pixel area. The outer rib 12 is also formed. Examples of the constituent material of the element isolation film 6 include, but are not limited to, an inorganic insulating layer made of silicon nitride, silicon oxynitride, silicon oxide, or the like, an acrylic resin, a polyimide resin, or a novolac resin. Not.

  The outer rib 12 of the present embodiment is composed of the planarization film 4 and the element isolation film 6, but may be composed of the planarization film 4 or the element isolation film 6 alone. The film thickness of the element isolation film 6 and the outer rib 12 is preferably about 1 μm to 3 μm.

  Further, on the element isolation film 6 and the outer rib 12, a convex portion 8 is formed with a part protruding upward. The convex portion 8 is preferably formed of a constituent material of the element isolation film 6 or the planarizing film 4. For example, by using a photolithography technique, the planar shape is a stripe shape along the same direction, or a lattice It is arranged vertically and horizontally so as to have a shape. If the protruding height of the convex portion 8 is too high, there is a possibility that uneven resin formation may occur when the resin protective film 10 is formed by using the screen printing method. Therefore, about 0.5 to 3 μm is preferable. . In the present embodiment, the height from the substrate surface to the top of the convex portion 8 (the level of the convex portion 8) is the same height in the resin protection film formation regions A and B inside and outside the pixel region. Has been.

  The organic compound layer 7 provided on the first electrode 5 may be composed of a single layer or a plurality of layers, and the layer configuration is appropriately selected in consideration of the light emitting function of the organic EL display element. it can. Specifically, the structure of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer is mentioned. Moreover, a well-known compound can be used as a constituent material of these layers. The organic compound layer 7 may have a light emitting region in a specific layer or an interface between adjacent layers. The organic compound layer 7 is formed by using, for example, a vacuum deposition method or an inkjet method, but is not limited thereto. In the case of vapor deposition or the like, a high-definition mask is used, while in the case of the ink jet method or the like, high-precision ejection is used to form the organic compound layer 7 in the pixel region.

  A second electrode 9 is formed on the organic compound layer 7. The second electrode 9 may be a transparent electrode or a reflective electrode. Moreover, the material similar to the said 1st electrode 5 can be used for the constituent material of the 2nd electrode 9. FIG.

  An organic EL display element is formed on the substrate 1 through the series of steps described above.

  Next, a protective film having a sealing configuration of the resin protective film 10 and the inorganic protective film 11 is formed on the organic EL display element. Regarding the formation process of the resin protective film 10, first, the substrate on which the organic EL display element is formed is moved to a printing chamber having a low dew point atmosphere. And the resin used as the resin protective film 10 is printed on an organic EL display element using a screen printer.

  In this printing process, as shown in FIG. 1, the element isolation film 6 and the convex portion 8 of the outer rib 12 in the formation regions A and B of the resin protective film 10 inside and outside the pixel region are formed on each convex portion 8 from the substrate surface. By setting the height to the top to be the same, the surface shape of the substrate becomes substantially uniform. Therefore, the resin protective film 10 can be printed evenly, the appearance becomes good in the pixel boundary region, and the deterioration of the image quality and the sealing performance can be suppressed.

  Since the resin protective film 10 is a resin having adhesiveness and covers at least the organic EL display element, an ultraviolet curable resin, a thermosetting resin, or the like can be used as long as it does not include a component that adversely affects the element. Specific examples include, but are not limited to, epoxy resins, acrylic resins, silicon resins, and the like. The viscosity of the resin can be appropriately selected according to the film thickness, but is preferably in the range of 1000 to 10,000 mPa · s. In addition, the thickness of the resin protective film 10 is preferably about 5 to 30 μm in consideration of manufacturing costs and the like.

  Finally, an inorganic protective film 11 is formed on the peripheral substrate so as to cover at least the resin protective film 10, thereby suppressing moisture from entering the organic EL display element. The inorganic protective film 11 is made of silicon nitride, silicon oxide or the like having a low moisture permeability, but is not limited thereto.

  A base protective film made of silicon nitride, silicon oxide, or the like may be formed between the second electrode 9 and the resin protective film 10.

  According to the organic EL display device of the present embodiment, the element isolation film 6 is formed in the resin protective film formation region A in the pixel region, and the outer rib 12 is formed in the resin protective film formation region B outside the pixel region. Is formed. Furthermore, a convex portion 8 is formed on the element isolation film 6 and the outer rib 12 so that the planar shape is a stripe shape or a lattice shape so that the height from the substrate surface is the same. Therefore, the surface shape of the substrate becomes substantially uniform, and when the resin protective film is formed by using the printing method, the resin protective film can be printed uniformly, the appearance shape of the pixel region boundary is good, and the image quality is deteriorated. And the fall of sealing performance can be controlled. Further, when the organic compound layer 7 is formed by a vacuum vapor deposition method, the convex portion 8 of the element isolation film 6 and the vapor deposition mask are in line contact with each other, so that the contact area is also reduced, and the element isolation film of foreign matter attached to the vapor deposition mask is reduced. Damage due to transfer to 6 can be suppressed.

  The preferred embodiment of the present invention has been described above. However, this is merely an example for explaining the present invention, and various embodiments different from the above-described embodiment may be implemented without departing from the gist of the present invention. Can do.

  For example, as long as the height from the substrate surface to the top of the convex portion 8 (the level of the convex portion 8) is set to be the same, the height of each convex portion 8 may be different.

  EXAMPLES Hereinafter, although an Example is given and the organic electroluminescent display apparatus which concerns on this invention, and its manufacturing method are demonstrated in detail, this invention is not limited to a present Example.

[Example 1]
First, the organic EL display device of Example 1 will be described with reference to FIGS. FIG. 2 is a schematic diagram illustrating a planar configuration of the organic EL display device according to the first embodiment.

  As shown in FIG. 2, first, the TFT substrate provided with the first electrode 5 made of Cr was subjected to UV / ozone cleaning treatment. Next, a polyimide resin pattern was formed around the first electrode 5 using a photolithography technique to form an element isolation film 6. In the process of forming the element isolation film 6, not only the element isolation film 6 is formed in the resin protection film formation area A in the pixel area but also the outer rib 12 is formed in the resin protection film formation area B outside the pixel area. (See FIG. 1). At this time, the film thickness of the element isolation film 6 and the outer rib 12 was 1.6 μm.

  Similarly, using a photolithography technique, a convex portion 8 of polyimide resin was formed on the element isolation film 6 and the outer rib 12 so that the planar shape was a stripe shape along the same direction. At this time, the film thickness of the convex part 8 is 1.0 μm, and the height from the substrate surface to the top of each convex part 8 is 2.6 μm, and they are all formed to have the same height.

Next, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer constituting the organic compound layer 7 were sequentially formed by vacuum deposition. Specifically, αNPD was formed on the first electrode 5 to form a hole transport layer. At this time, the thickness of the hole transport layer was 50 nm. Next, an aluminum chelate complex (Alq ₃ ) as a host and coumarin 6 as a guest were co-deposited on the hole transport layer so as to have a weight ratio of 100: 6 to form a light emitting layer. At this time, the thickness of the light emitting layer was 50 nm. Next, a phenanthroline compound (Bphen) was formed on the light-emitting layer to form an electron transport layer. At this time, the thickness of the electron transport layer was 10 nm. Next, a phenanthroline compound (Bphen) and cesium carbonate (Cs ₂ CO ₃ ) were co-evaporated to a weight ratio of 100: 1 on the electron transport layer to form an electron injection layer. At this time, the thickness of the electron injection layer was 40 nm. Next, an ITO film was formed on the electron injection layer by sputtering to form the second electrode 9. At this time, the film thickness of the second electrode 9 was 130 nm. Thus, an organic EL display element was produced.

  Next, the resin protective film 10 was formed in a printing chamber with a low dew point nitrogen atmosphere. A thermosetting epoxy resin was printed on a substrate provided with an organic EL display element by using a screen printer. The stripe-shaped convex portions 8 and the squeegee were printed perpendicularly, that is, the linear direction of the stripe-shaped convex portions 8 and the printing direction were parallel. At this time, by forming the stripe-shaped convex portions 8 in the region A and the region B of the resin protective film 10 inside and outside the pixel region at the same height, the surface shape of the substrate in the region where the resin protective film 10 is formed becomes substantially uniform. The resin protective film 10 could be printed uniformly without unevenness. Thereafter, the resin was cured by heating at a temperature of 100 ° C. for 45 minutes in a vacuum environment to obtain a resin protective film 10 having a thickness of 30 μm.

Next, an inorganic protective film 11 made of silicon nitride was formed by plasma CVD using SiH ₄ gas, N ₂ gas, and H ₂ gas. Here, the film thickness of the inorganic protective film 11 was 1 μm, and was formed so as to cover the entire resin protective film 10.

  In the organic EL display device manufactured as described above, printing unevenness could not be observed in the appearance of the pixel boundary region, and no problem occurred in the appearance inspection and the image quality inspection.

[Example 2]
Next, with reference to FIG. 3, the organic EL display device of Example 1 will be described. FIG. 3 is a schematic diagram illustrating a planar configuration of the organic EL display device according to the second embodiment.

As shown in FIG. 3, in Example 2, the points where the projections 8 were formed vertically and horizontally so that the planar shape was a lattice shape on the element isolation film 6 and the outer rib 12, and the printing direction was not specified. This is different from the first embodiment. In addition, the film thickness of the convex part 8 is 1.0 μm, and the height from the substrate surface to the top of each convex part 8 is 2.6 μm.
It was. Other than that was carried out similarly to Example 1, and produced the organic electroluminescence display.

  In the organic EL display device fabricated as described above, the lattice-shaped convex portions 8 are formed at the same height in the A region and the B region of the resin protective film 10 inside and outside the pixel region, thereby forming the resin protective film 10. The surface shape of the substrate under the region becomes substantially uniform. Therefore, the resin protective film 10 can be printed uniformly without any problem in the appearance inspection and the image quality inspection.

[Comparative Example 1]
Next, an organic EL display device of Comparative Example 1 will be described with reference to FIG. FIG. 4 is a schematic view showing a cross-sectional shape of the organic EL display device of Comparative Example 1.

  As shown in FIG. 4, in the organic EL display device of Comparative Example 1, the outer rib 12 and the convex portion 8 are not provided in the formation region B of the resin protective film 10 outside the pixel region. Further, stripe-shaped convex portions 8 were formed on the element isolation film 6 in the resin protective film region A in the pixel region. Other than that was carried out similarly to Example 1, and produced the organic electroluminescence display.

  In the organic EL display device of Comparative Example 1 manufactured as described above, the surface shape of the substrate under the resin protective film 10 formation region is different between the pixel region and the outside of the pixel region. Therefore, the film thickness of the resin protective film 10 is different between the pixel region and the periphery thereof, resulting in uneven printing formation, and it was determined as a defective product in the appearance inspection and the image quality inspection.

DESCRIPTION OF SYMBOLS 1 Substrate, 5 1st electrode, 6 Element isolation film, 7 Organic compound layer, 8 Convex part, 9 Second electrode, 10 Resin protective film, 11 Inorganic protective film, 12 Outer rib, A Resin protective film area in pixel area , B Resin protective film area outside the pixel area

Claims (6)

A plurality of organic EL display elements each having an organic compound layer including a light emitting layer between electrodes are provided on a substrate, the organic EL display elements are separated by an element separation film, and at least the plurality of organic EL display elements are resin protective films And an organic EL display device in which at least the resin protective film is covered with an inorganic protective film,
Forming the element isolation film in a formation region of the resin protection film in the pixel region, and forming an outer rib in the formation region of the resin protection film outside the pixel region;
On the element isolation film and the outer rib, a convex part partially protruding upward is formed,
An organic EL display device characterized in that the height from the substrate surface to the top of the convex portion is all set to the same height.   The organic EL display device according to claim 1, wherein the convex portions are arranged so that a planar shape thereof is a stripe shape along the same direction.   The organic EL display device according to claim 1, wherein the convex portions are arranged vertically and horizontally so that a planar shape thereof is a lattice shape as a whole. A method for manufacturing an organic EL display device comprising a plurality of organic EL display elements each having an organic compound layer including a light emitting layer between electrodes on a substrate,
Forming an element isolation film for separating the organic EL display element;
Forming a resin protective film so as to cover at least a plurality of organic EL display elements;
Forming an inorganic protective film so as to cover at least the resin protective film;
Have
In the element isolation film forming step, the element isolation film is formed in the resin protection film formation region in the pixel region, and an outer rib is formed in the resin protection film formation region outside the pixel region,
A method of manufacturing an organic EL display device, comprising: forming a convex portion on the element isolation film and the outer rib so that all the heights from the substrate surface to the top portion are the same.   5. The method of manufacturing an organic EL display device according to claim 4, wherein the step of forming the convex portion is performed using a photolithography technique after the step of forming the element isolation film.   The method for manufacturing an organic EL display device according to claim 4, wherein the forming step of the resin protective film is performed using a screen printing method.

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