JP2009301910A - Organic el display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply material liquid for hole injection layers to the whole anode electrodes. <P>SOLUTION: The method for manufacturing an organic EL display panel comprises a step of preparing a substrate including banks for specifying bank opening portions arranged in a matrix shape and the anode electrodes each having a minor axis and a major axis and arranged in the bank opening portions, and a step of applying the water solution to the anode electrodes while dropping a plurality of droplets of water solution containing polyethylene dioxythiophene along the major axis into one bank opening portion to form the hole injection layers. The bank opening portions each have a clearance between the end of the anode electrode on the downstream side in the applying direction and the bank. The water solution is also applied to the clearances. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL display panel and a manufacturing method thereof.

  An organic EL display panel is a display panel having a light emitting element utilizing electroluminescence of an organic compound. In other words, the organic EL display panel has an organic EL element including an anode electrode and a cathode electrode, and an organic EL layer that is disposed between the electrodes and emits electroluminescence. Electroluminescent organic EL layer materials can be broadly classified into low molecular organic compound combinations (host material and dopant material) and high molecular organic compounds. Examples of the polymer organic compound that emits electroluminescence include polyphenylene vinylene called PPV and derivatives thereof.

  An organic EL layer made of a polymer organic compound can be driven at a relatively low voltage, consumes little power, and is easy to cope with an increase in the screen size of a display panel. In addition, an organic EL layer made of a polymer organic compound can be manufactured by a coating method such as an inkjet method. Therefore, the productivity of the polymer organic EL display is significantly higher than that of the low molecular organic EL display using the vacuum process.

  The polymer organic EL display usually has a hole injection layer disposed between the anode electrode and the organic EL layer in order to efficiently transport holes from the anode electrode to the organic EL layer. As a material for the hole injection layer, poly (3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PSS) (referred to as PEDOT-PSS), which can be produced by a coating method, or a derivative thereof Water-soluble polymers such as (copolymers) are used. The hole injection layer was formed by dropping and applying an aqueous solution containing such a material on the anode electrode in the opening in each subpixel.

  Patent Document 1 shows a plan view of a conventional organic EL display panel. FIG. 1A shows a plan view of an organic EL display panel described in Patent Document 1. FIG. FIG. 1B shows a cross-sectional view along line III of FIG. 1A. As shown in FIG. 1, the organic EL display panel includes a glass substrate 1, a first electrode layer 2, a first bank 3, a second bank 4, a hole injection layer 5, and an organic EL layer 6 ( Patent Document 1).

  The first bank 3 defines a groove 20. A plurality of openings 10 arranged in a row are arranged in the groove 20. The groove 20 defines a region of the organic EL layer 6. The second bank 4 defines an opening 10. The opening 10 defines a region of the hole injection layer 5. Thus, in the conventional organic EL display panel, the hole injection layer may be disposed independently for each opening (subpixel).

  As described above, the hole injection layer is formed by dropping and applying, for each subpixel, an aqueous solution in which PEDOT-PSS is dissolved in water. However, since the aqueous solution has a strong surface tension, there has been a problem that the dropped material liquid of the hole injection layer does not spread to a desired region. Therefore, when the hole injection layer is arranged for each opening as shown in FIG. 1, the material liquid for the hole injection layer may not be applied, and the anode electrode may be exposed. Since the cathode electrode comes into contact with the exposed anode electrode, a short circuit occurs and the sub-pixel does not emit light, and the quality of the organic EL display panel is significantly deteriorated.

On the other hand, there is a technique described in Patent Document 2 as a technique for spreading the dropped functional layer material liquid to a desired region.
FIG. 2 shows an opening in a sub-pixel of the organic EL display device disclosed in Patent Document 2. As shown in FIG. 2, the opening 10 has a liquid reservoir 40 having a liquid inlet 30 on all four sides thereof. When the material liquid of the organic EL layer 6 is dropped onto the pixel having such a shape, the material liquid flows into the liquid reservoir 40 due to a capillary phenomenon. As a result, the organic EL layer 6 is disposed over the entire opening 10 (see Patent Document 2).
US Pat. No. 7,091,660 JP 2007-128690 A

  However, the technique described in Patent Document 2 is a technique aiming to spread a material solution (solution containing an organic solvent and a light emitting material) of a light emitting layer having a low surface tension in a desired region. Therefore, as shown in FIG. 2, even if the liquid reservoirs are provided on the four sides of the opening, the material liquid (aqueous solution) of the hole injection layer having a high surface tension does not spread over the entire opening. In some cases, the layer material liquid was not applied to the entire anode electrode, and the anode electrode was exposed.

On the other hand, a method may be considered in which the material liquid for the hole injection layer necessary for one opening is not dropped at a time, but is dropped in multiple portions at different locations in the opening.
FIG. 3 shows a method in which a hole injection layer material liquid is applied on the anode electrode by dropping a plurality of droplets of the hole injection layer along the long axis of the anode electrode 103 into the opening 105. It is shown. In the method shown in FIG. 3, the material liquid for the hole injection layer 109 is applied in the direction of arrow X in FIG. 3A. Thus, it is considered that the anode electrode can be prevented from being exposed by dropping the material liquid of the hole injection layer into a plurality of different portions in the opening in a plurality of times.

  However, even in the method shown in FIG. 3, the material liquid droplet of the hole injection layer first dropped into the opening portion causes the material liquid droplet of the hole injection layer subsequently dropped into the opening portion. It was found that the material liquid of the hole injection layer 109 was not applied to the entire anode electrode, and an exposed region 103 ′ of the anode electrode might be generated (see FIG. 3C).

  In the present invention, even when a hole injection layer containing PEDOT-PSS is arranged for each opening in the subpixel, the material liquid of the hole injection layer is applied to the entire anode electrode, and an exposed area of the anode electrode is generated. An object of the present invention is to provide an organic EL display panel that does not.

1st of this invention is related with the manufacturing method of the organic display panel shown below.
[1] preparing a substrate including a bank defining openings arranged in a matrix and an anode electrode having a short axis and a long axis arranged in the opening; and the long axis in one opening And a step of dropping a plurality of droplets of an aqueous solution containing polyethylene dioxythiophene and applying the aqueous solution to the anode electrode to form a hole injection layer. The organic EL display panel manufacturing method, wherein the opening has a gap between an end of the anode electrode downstream in the application direction and the bank, and the aqueous solution is also applied to the gap.
[2] A step of preparing a substrate including a bank defining openings arranged in a matrix and an anode electrode having a short axis and a long axis arranged in the opening, and the long axis in one opening And a step of dropping a plurality of droplets of an aqueous solution containing polyethylene dioxythiophene and applying the aqueous solution to the anode electrode to form a hole injection layer. The method for producing an organic EL display panel, wherein the end of the anode electrode downstream in the application direction is narrowed down from the end of the anode electrode upstream in the application direction.

The second aspect of the present invention relates to the organic display panel shown below.
[3] Openings arranged in a matrix on the substrate, banks defining the openings, anode electrodes having a major axis and a minor axis arranged in the openings, and arranged independently for each of the openings. An organic EL display panel comprising: a hole injection layer disposed on the anode electrode; an organic EL layer disposed on the hole injection layer; and a cathode electrode disposed on the organic EL layer. The opening has an air gap between one end of the major axis of the anode electrode and the bank.
[4] Openings arranged in a matrix on the substrate, banks defining the openings, anode electrodes having a major axis and a minor axis arranged in the openings, and arranged independently for each of the openings. An organic EL display panel comprising: a hole injection layer disposed on the anode electrode; an organic EL layer disposed on the hole injection layer; and a cathode electrode disposed on the organic EL layer. The organic EL display panel, wherein one end of the major axis of the anode electrode is narrower than the other end of the major axis of the anode electrode.

  According to the present invention, even when a hole injection layer containing PEDOT-PSS is disposed for each opening of a subpixel, the entire anode electrode in the opening can be covered with the hole injection layer. Therefore, according to the present invention, each organic EL element is prevented from being short-circuited, so that a high-quality organic EL display panel can be provided.

1. About the manufacturing method of an organic EL display panel The manufacturing method of the organic EL display panel of the present invention includes: 1) a bank defining openings arranged in a matrix, and an anode electrode having a short axis and a long axis arranged in the openings (See FIG. 4), and 2) a plurality of droplets of the material liquid of the hole injection layer are dropped in the opening of 1 along the long axis of the anode electrode to make the aqueous solution into the anode electrode. Applying and forming a hole injection layer.

  Each pixel in the organic EL display panel is composed of three “sub-pixels” of RGB. That is, three subpixels of RGB constitute one pixel. In the organic EL display panel of the present invention, the major axis of each subpixel is 270 to 480 μm, and the minor axis is 90 to 160 μm.

  In addition, the “opening” means a region where the material liquid of the hole injection layer defined by the bank is applied in each sub-pixel. Hereinafter, the “opening” defined by the bank is referred to as “bank opening”.

  As shown in FIG. 4, in the method for manufacturing an organic EL display panel according to the present invention, a nozzle head 203 having a plurality of nozzles 201 for discharging a material liquid for a hole injection layer is prepared. Then, by moving the substrate 101 in which the bank openings 105 are arranged in a matrix in the direction of the arrow Y, the material liquid for the hole injection layer is applied onto the anode electrode 103 in each bank opening 105.

The amount of the material liquid of the hole injection layer dropped into the bank opening is preferably 240 pl to 360 pl per one bank opening (9600 μm ² ).

  Moreover, it is preferable that the capacity | capacitance of one drop of the material liquid droplet of the hole inflow layer dripped is 2-20pl.

  The interval at which the droplet of the material liquid of the hole injection layer is dropped along the long axis of the anode electrode is preferably 5 to 12 μm.

The manufacturing method of the organic EL display of the present invention includes a preferred first example and a preferred second example. Hereinafter, the manufacturing method of the organic EL display of the present invention will be described by dividing into (A) a first example and (B) a second example with reference to the drawings.
In the following description of the first and second examples of the manufacturing method of the present invention, a method of manufacturing one organic EL element (subpixel) included in the organic EL display panel of the present invention will be described.

(A) First Example FIG. 5 shows a first example of a method for producing an organic EL display panel of the present invention. The first example of the manufacturing method of the present invention is as follows: 1) First step of preparing a substrate (FIG. 5A), 2) Second step of forming an anode electrode on the substrate (FIG. 5B), 3) Bank on the substrate A third step (FIG. 5C) for forming a bank opening having a gap between the anode electrode and the bank, and 4) along the major axis of the anode electrode in the bank opening of 1, There is a fourth step (see FIGS. 5D and 5E) for forming a hole injection layer by dropping a plurality of droplets of an aqueous solution containing oxythiophene and applying the aqueous solution to the anode electrode.

  In addition, an insulating inorganic film may be formed between the first step and the second step.

  1) In the first step (FIG. 5A), the substrate 101 is prepared. The material of the substrate 101 differs depending on whether the organic EL display panel is a bottom emission type or a top emission type. Specifically, in the case of the bottom emission type, since the substrate 101 is required to be transparent, examples of the material of the substrate 101 include glass, transparent resin, and the like. In the case of the top emission type, since the substrate 101 does not need to be transparent, the material of the substrate 101 is arbitrary as long as it is insulative.

2) In the second step (FIG. 5B), an anode electrode 103 (thickness 10 to 100 nm) is disposed on the substrate 101. The anode electrode 103 is formed by, for example, forming a film of an electrode material on the substrate 101 by sputtering or the like; masking the film of the electrode material with a resist; and etching and patterning.
In the case of the bottom emission type, since the anode electrode 103 is required to be a transparent electrode, examples of the material of the anode electrode 103 include ITO (indium tin oxide), IZO (indium oxide zinc), and ZnO (oxide oxidation). Zinc) and the like.
In the case of the top emission type, since the anode electrode 103 is required to have light reflectivity, an example of the material of the anode electrode 103 is an alloy containing silver, more specifically, a silver-palladium-copper alloy (also referred to as APC), Including silver-ruthenium-gold alloy (also referred to as ARA), MoCr (molybdenum chromium), NiCr (nickel chromium) and the like.

  In addition, an ITO film covering the anode electrode may be formed so that the material liquid for the hole injection layer described later is well adapted to the anode electrode surface.

  3) In the third step (FIG. 5C), the bank 106 that defines the bank opening 105 for each sub-pixel 104 is formed by, for example, photolithography, intaglio printing, letterpress printing, or the like. The height of the bank is preferably 0.5 to 1 μm. The material of the bank is arbitrary as long as it is insulative, but is preferably an insulating resin (polyimide or the like). Furthermore, it is preferable that the surface of the first bank has low wettability (for example, water repellency). Therefore, the bank material is preferably an insulating resin containing a fluororesin. The wettability may be lowered by fluorinating the surface of the bank with fluorine-based gas plasma.

  The major axis length of the bank opening is preferably 230 to 415 μm, and the minor axis length of the bank opening is preferably 70 to 175 μm.

  The anode electrode in the bank opening preferably has a major axis and a minor axis. The anode electrode may have a vertically long shape and does not necessarily have an “ellipse” shape. The length of the major axis of the anode electrode is 220 to 390 μm, and the length of the minor axis of the anode electrode is preferably 70 to 125 μm.

As shown in FIG. 5C, the first example of the manufacturing method of the present invention is to make the bank opening 105 defined by the bank 106 longer than the anode electrode 103 downstream in the coating direction, which will be described later. A gap 107 is formed between the bank 103 and the downstream end of the coating direction 103. Here, the “air gap” means a region where the base layer of the anode electrode formed between the anode electrode and the bank is exposed. The distance d between the downstream end of the anode electrode 103 in the coating direction and the bank 106 is preferably 10 to 25 μm. The area of the gap is preferably 270 to 690 μm ² .
Further, a gap may be formed between the bank and the end in the minor axis direction at the downstream end of the anode electrode in the application direction (FIG. 7B).

  4) In the fourth step (FIG. 5D), an aqueous solution containing the hole injection material (the material liquid of the hole injection layer) in the bank opening 105 along the long axis of the anode electrode 103 in the direction of the arrow X in FIG. A plurality of droplets are dropped and an aqueous solution is applied to the anode electrode to form the hole injection layer 109. The material liquid for the hole injection layer may be applied by, for example, an ink jet method. Examples of the hole injection material include poly (3,4-ethylenedioxythiophene) doped with polyethylene sulfonic acid (referred to as PEDOT-PSS) and derivatives thereof (such as copolymers). As shown in FIG. 5D, in the present invention, the hole injection layer is formed for each bank opening.

  As shown in FIG. 5D, in the first example of the manufacturing method of the present invention, the material liquid for the hole injection layer is applied to the gap 107.

  Thus, by providing a gap between the bank downstream of the anode electrode application direction and the bank and applying the hole injection layer material liquid to the gap, the anode electrode is prevented from being exposed (see FIG. 5E). ), The organic EL element (subpixel) can be prevented from being short-circuited. That is, as shown in FIG. 5E, in the first example of the manufacturing method of the present invention, the material liquid for the hole injection layer cannot be applied to a part of the gap 107, and the gap 107 may be exposed. In addition, since the anode electrode 103 is not disposed in the gap 107, there is no possibility that the organic EL element is short-circuited even if the gap 107 is exposed.

  In addition to the above steps, the method for producing an organic EL display panel of the present invention may have a step of forming an intermediate layer and an organic EL layer, and a step of forming a cathode electrode on the organic EL layer.

  The intermediate layer and the organic EL layer are formed, for example, by applying a material liquid for the intermediate layer and the organic EL layer on the hole injection layer using an inkjet method or the like.

  The intermediate layer has a role of blocking the transport of electrons to the hole injection layer and a role of efficiently transporting holes to the organic EL layer, and is a layer made of, for example, a polyaniline material. The intermediate layer material liquid (ink in which the intermediate layer material is dissolved in an organic solvent such as anisole or cyclobenzene) is applied to the bank openings. The thickness of the intermediate layer is preferably 10 to 40 nm.

  The material of the organic EL layer may be a high molecular weight organic EL material or a low molecular weight organic EL material, but an organic EL layer made of a high molecular weight organic EL material can be easily and other materials. It is preferable because it can be formed without damaging.

  Examples of the polymer organic EL material include polyphenylene vinylene and its derivatives, polyacetylene and its derivatives, polyphenylene and its derivatives, polyparaphenylene ethylene and its derivatives. , Poly 3-hexyl thiophene (P3HT) and derivatives thereof, polyfluorene (PF) and derivatives thereof, and the like. The thickness of the organic EL layer is preferably about 50 to 100 nm.

  The cathode electrode may be formed using, for example, a vapor deposition method or a sputtering method. The material of the cathode electrode differs depending on whether it is a bottom emission type or a top emission type. In the case of the top emission type, since the cathode electrode needs to be transparent, it is preferably formed of a material including an ITO electrode or an IZO electrode. Moreover, you may comprise with Ba, Al, and WOx.

  In the case of the bottom emission type, the cathode electrode does not need to be transparent, and the cathode electrode may be formed of an arbitrary material. For example, the cathode electrode is preferably formed of a material containing Ba, BaO, Al, or the like.

  A cover material (sealing material) may be further provided on the surface on which the cathode electrode is formed to seal the organic EL display panel of the present invention. Intrusion of moisture and oxygen is suppressed by the cover material.

(B) Second Example FIG. 6 shows a second example of the method for producing an organic EL display panel of the present invention. The second example of the manufacturing method of the present invention is as follows: 1) First step of preparing a substrate (FIG. 6A), 2) Second step of forming an anode electrode on the substrate (FIG. 6B), 3) Bank on the substrate A third step (FIG. 6C) for forming a bank opening in which the downstream end in the coating direction is narrowed, and 4) along the major axis of the anode electrode in the bank opening of 1, the polyethylene dioxy There is a fourth step (see FIGS. 6D and 6E) in which a plurality of droplets of an aqueous solution containing thiophene are dropped and the aqueous solution is applied to the anode electrode to form a hole injection layer.

  Further, an insulating inorganic film may be formed between step 1) and step 2).

  The substrate in the second example of the manufacturing method of the present invention may be the same as the substrate described in the first example.

2) In the second step (FIG. 6B), the anode electrode 103 is formed.
The anode electrode forming means and material may be the same as those in the first example of the manufacturing method of the present invention described above.

  3) In the third step (FIG. 6C), a bank 106 that defines a bank opening 105 for each sub-pixel 104 is formed. The formation means and material of the bank 106 may be the same as those in the first example described above. The major axis length of the bank opening is preferably 195 to 365 μm, and the minor axis length of the bank opening is preferably 70 to 125 μm.

  The anode electrode in the bank opening preferably has a major axis and a minor axis. The length of the major axis of the anode electrode is 195 to 365 μm, and the minor axis of the anode electrode is preferably 70 to 125 μm.

  The second example of the manufacturing method of the present invention is characterized in that the end of the anode electrode 103 in the bank opening 105 downstream in the coating direction is narrowed down. Here, “narrowing” means that the end of the anode electrode downstream in the application direction is contracted in the longer axis direction than the end upstream of the application direction (see FIG. 8A) or the end of the anode electrode downstream in the application direction is applied in the application direction This includes narrowing in the minor axis direction than the upstream end and increasing the curvature of the end downstream of the anode electrode in the coating direction (see FIG. 8B). Thus, in the second example of the manufacturing method of the present invention, the anode electrode in the bank opening is asymmetric with respect to the minor axis passing through the midpoint of the major axis of the anode electrode. In the second example of the manufacturing method of the present invention, the downstream end of the bank opening 105 defined by the bank 106 in the application direction is also narrowed down.

  When the end of the anode electrode downstream in the coating direction is contracted in the longer axis direction than the end upstream of the coating direction (see FIG. 8A), the downstream end of the anode electrode in the coating direction is 10-25 μm from the upstream end of the coating direction. It is preferable to shorten.

  When the end portion of the anode electrode downstream in the application direction is narrower than the end portion upstream of the application direction in a short axis method (see FIG. 8B), the end portion of the anode electrode downstream in the application direction is 10 It is preferable to narrow in the direction of the short axis of ˜25 μm.

  In order to narrow down the downstream end of the anode electrode 103 in the coating direction, the anode electrode itself may be patterned so that the downstream end in the coating direction is narrowed, or the anode electrode itself may be patterned into an arbitrary shape, Further, the patterning may be performed so that the downstream end of the anode electrode exposed in the bank opening is narrowed down.

  4) In the fourth step (FIG. 6D), a plurality of droplets of the material liquid of the hole injection layer are dropped in the bank opening 105 along the long axis of the anode electrode 103 in the direction of arrow X in FIG. The hole injection layer 109 is formed by applying to the anode electrode. The material liquid for the hole injection layer may be applied by, for example, an ink jet method.

  In the conventional organic EL display panel, when the material liquid for the hole injection layer is applied on the anode electrode by such a method, the material liquid for the hole injection layer is applied to the entire anode electrode downstream in the application direction of the anode electrode. In some cases, the anode electrode was exposed (see FIG. 3C). However, since the end downstream of the anode electrode in the application direction is narrowed down as compared with the end upstream of the anode electrode in the application direction as described above, the dropped holes at the end downstream of the anode electrode in the application direction. The area of the anode electrode per drop of the material liquid of the injection layer is reduced. Therefore, even when a plurality of material liquids for the hole injection layer are dropped along the major axis of the anode electrode, the anode electrode is hardly exposed. Thereby, it is possible to prevent the organic EL element (subpixel) from being short-circuited.

  In addition to the above steps, the second example of the production method of the present invention may include a step of forming an intermediate layer and an organic EL layer, and a step of forming an electron injection layer and a cathode electrode on the organic EL layer. An electron injection layer may be formed between the cathode electrode and the organic EL layer.

As described above, both the first example and the second example of the manufacturing method of the present invention may further include a step of forming an insulating inorganic film (hereinafter referred to as “inorganic insulating film”). . The inorganic insulating film is of course electrically insulating, but it is also preferable that the wettability is high. Examples of the material of the inorganic insulating film include silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), silicon oxynitride (SiON), and the like. The thickness of the inorganic insulating film is preferably 10 nm to 200 nm.

  The inorganic insulating film preferably protrudes from the bank to the bank opening (see FIG. 9). Preferably, the inorganic insulating film protrudes from the bank to the bank opening by 5 to 10 μm.

  FIG. 9A shows the shape of the inorganic insulating film 108 in the first example. As shown in FIG. 9A, a gap 107 is provided between the downstream end of the anode electrode 103 in the coating direction and the inorganic insulating film 108.

  FIG. 9B shows the shape of the inorganic insulating film 108 in the second example. As shown in FIG. 9B, the inorganic insulating film 108 may be disposed so as to surround the edge of the anode electrode 103.

  The material liquid of the hole injection layer is uniformly applied to the entire bank opening by the inorganic insulating film, and a functional layer having a uniform film thickness can be obtained.

Further, as described above, the bank surface may be fluorinated by fluorine-based gas plasma. In this case, fluorine may adhere not only to the bank but also to the anode electrode surface. Since fluorine has a function of lowering wettability, the wettability of the surface of the anode electrode to which fluorine has adhered is lowered, and there is also a problem that the material liquid for the hole injection layer is more difficult to be applied onto the anode electrode. However, as in the present invention, fluorine is deposited on the anode electrode by providing a gap between the bank and the downstream end of the anode electrode in the coating direction or by narrowing the downstream end of the anode electrode in the coating direction. However, the material liquid for the hole injection layer is applied to the entire anode electrode, and the anode electrode is prevented from being exposed.
Therefore, the present invention is particularly effective when the bank surface is fluorinated with fluorine-based gas plasma.

2. About the organic EL display panel of the present invention The organic EL display panel of the present invention has a substrate, an anode electrode, a cathode electrode, and an organic EL element having a hole injection layer and an organic EL layer sandwiched between both electrodes. In the organic EL display panel of the present invention, such organic EL elements are arranged in a matrix on the substrate and function as subpixels.

  An anode electrode is formed on the substrate. When the organic EL display panel is a passive matrix type, a plurality of anode electrodes are formed in a line shape. The line-like anode electrodes are preferably parallel to each other. When the organic EL display panel is an active matrix type, the anode electrode is independently arranged for each subpixel on the substrate.

  The hole injection layer is independently disposed on the anode electrode for each bank opening defined by the bank.

  The organic EL layer may be disposed on the hole injection layer, and an intermediate layer may be disposed between the hole injection layer and the organic EL layer.

  The organic EL display panel of the present invention has a cathode electrode on the organic EL layer. An electron injection layer may be disposed between the cathode electrode and the organic EL layer.

  A cover material (sealing material) may be provided on the surface on which the cathode electrode is formed to seal the organic EL display panel. Intrusion of moisture and oxygen is suppressed by the cover material.

  The structure of the organic EL element included in the organic EL display panel according to the present invention differs depending on whether it is manufactured according to the first example or the second example. Hereinafter, the structure of the organic EL element included in the organic EL display panel of the present invention is manufactured by (A) the manufacturing method of the first example, and (B) manufactured by the manufacturing method of the first example. This will be explained separately for each case.

(A) When manufactured by the manufacturing method of the first example FIG. 5E shows an organic EL element included in the organic EL display panel manufactured by the manufacturing method of the first example, in which the cathode electrode and the organic EL layer are removed. FIG. FIG. 10 is a cross-sectional view along the major axis of the organic EL element shown in FIG. 5E. As shown in FIG. 10, a gap 107 is formed between one end of the long axis of the anode electrode 103 and the bank 106. Since the base layer of the anode electrode 103 is exposed in the gap 107, the hole injection layer 109 is in contact with the base layer of the anode electrode 103.

(B) When manufactured by the manufacturing method of the second example FIG. 6E shows the organic contained in the organic EL display panel of the present invention manufactured by the manufacturing method of the second example, in which the cathode electrode and the organic EL layer are removed. It is a top view of EL element. As shown in FIG. 6E, one end (downstream in the application direction) of the long axis of the hole injection layer 109 is more than the other end (upstream in the application direction) of the long axis of the hole injection layer 109. It is narrowed down.

  FIG. 6C is a plan view of the organic EL element obtained by removing the hole injection layer from the organic EL element of FIG. 6E. As shown in FIG. 6C, one end (downstream in the application direction) of the long axis of the anode electrode 103 is narrowed more than the other end (upstream in the application direction) of the long axis of the anode electrode 103. That is, in FIG. 6C, the anode electrode 103 is asymmetric with respect to the minor axis passing through the midpoint of the major axis of the anode electrode 103.

  According to the present invention, there is provided an organic EL display panel in which the whole anode electrode in the opening is covered with the hole injection layer even when the hole injection layer including PEDOT-PSS is arranged for each opening of the subpixel. Is done. That is, according to the present invention, since each organic EL element is prevented from being short-circuited, a high-quality organic EL display panel can be provided. Also, the yield is improved.

The figure which shows the conventional organic EL display panel. The top view of the conventional organic electroluminescent display panel. The figure which shows one example of the formation method of a positive hole injection layer. The figure which shows the manufacturing method of the organic electroluminescent display panel of this invention. The figure which shows the 1st example of the manufacturing method of the organic electroluminescent display panel of this invention. The figure which shows the 2nd example of the manufacturing method of the organic electroluminescent display panel of this invention. The top view of the subpixel contained in the organic electroluminescence display panel of this invention. The top view of the subpixel contained in the organic electroluminescence display panel of this invention. The top view of the subpixel which has an insulating inorganic film. Sectional drawing of the organic EL element contained in the organic EL display panel of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 1st electrode layer 3 1st bank 4 2nd bank 5 Hole injection layer 6 Organic EL layer 10 Opening 20 Groove 30 Liquid inlet 40 Liquid reservoir 101 Substrate 103 Anode electrode 104 Subpixel 105 Bank opening Part 106 bank 107 gap 108 inorganic insulating film 109 hole injection layer 201 nozzle 203 nozzle head

Claims (6)

Providing a substrate including banks defining openings arranged in a matrix, and an anode electrode having a short axis and a long axis arranged in the openings;
Forming a hole injection layer by dropping a plurality of droplets of an aqueous solution containing polyethylenedioxythiophene along the major axis in the opening of 1 and applying the aqueous solution to the anode electrode; and
An organic EL display panel manufacturing method comprising:
The opening has a gap between the bank and the downstream end in the application direction of the anode electrode,
The method for producing an organic EL display panel, wherein the aqueous solution is also applied to the gap. Providing a substrate including banks defining openings arranged in a matrix, and an anode electrode having a short axis and a long axis arranged in the openings;
Forming a hole injection layer by dropping a plurality of droplets of an aqueous solution containing polyethylenedioxythiophene along the major axis in the opening of 1 and applying the aqueous solution to the anode electrode; and
An organic EL display panel manufacturing method comprising:
The downstream end of the anode electrode in the application direction is narrowed down from the upstream end of the anode electrode in the application direction.
A method for producing an organic EL display panel. Openings arranged in a matrix on the substrate banks defining the openings;
An anode electrode having a major axis and a minor axis disposed in the opening,
A hole injection layer disposed independently on each of the openings and disposed on the anode electrode;
An organic EL display panel having an organic EL layer disposed on the hole injection layer, and a cathode electrode provided on the organic EL layer,
The organic EL display panel, wherein the opening has a gap between one end of the major axis of the anode electrode and the bank. Openings arranged in a matrix on the substrate banks defining the openings;
An anode electrode having a major axis and a minor axis disposed in the opening,
A hole injection layer disposed independently on each of the openings and disposed on the anode electrode;
An organic EL display panel having an organic EL layer disposed on the hole injection layer, and a cathode electrode provided on the organic EL layer,
The organic EL display panel, wherein one end of the major axis of the anode electrode is narrowed down more than the other end of the major axis of the anode electrode. An insulating inorganic film that protrudes from the bank into the opening;
The organic EL display panel according to claim 3, wherein the opening has a gap between one end of the major axis of the anode electrode and the insulating inorganic film. The organic EL display panel according to claim 4, further comprising an insulating inorganic film that protrudes from the bank into the opening.

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