JP5663853B2 - Organic EL panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to an organic EL panel and a method for manufacturing the same, and more particularly to an organic EL panel utilizing an electroluminescence (hereinafter abbreviated as EL) phenomenon of an organic thin film and a method for manufacturing the same.

  An organic EL element has a structure in which an organic light emitting layer exhibiting at least an EL phenomenon is sandwiched between an electrode as an anode and an electrode as a cathode. When a voltage is applied between the electrodes, organic light emission occurs. Holes and electrons are injected into the layer, and the holes and electrons are recombined in the organic light emitting layer, whereby the organic light emitting layer emits light. Further, in the organic EL device, for the purpose of increasing the light emission efficiency, a hole injection layer, a hole transport layer, or an electron transport layer between the organic light emitting layer and the cathode is provided between the anode and the organic light emitting layer. An electron injection layer and the like are appropriately selected and provided. The organic light emitting layer and these hole injection layer, hole transport layer, electron transport layer, electron injection layer and the like are collectively called an organic light emitting medium layer.

  Organic light emitting materials for forming the organic light emitting layer include low molecular materials and high molecular materials. In general, a low molecular material is formed into a thin film by a vacuum deposition method or the like, and patterning is performed using a fine pattern mask at this time. However, this method has a problem that the patterning accuracy becomes difficult as the substrate becomes larger. In addition, since the film is formed in a vacuum, there is a problem that the throughput is poor. Therefore, recently, a method in which a polymer material is dissolved in a solvent to form a coating solution and a thin film is formed by a wet coating method has been tried. In the case of forming an organic light emitting medium layer including an organic light emitting layer by a wet coating method using a coating liquid of a polymer material, a two-layer structure in which a hole transport layer and an organic light emitting layer are laminated from the anode side is generally used. Is. At this time, the organic light emitting layer is formed by dissolving or stably dispersing organic light emitting materials having respective emission colors of red (R), green (G), and blue (B) in a solvent in order to form a color panel. It is necessary to paint with organic luminescent ink.

  However, when the film is formed by the wet coating method, the film becomes thicker along the shape of the partition provided to insulate each pixel electrode, resulting in poor flatness. For this reason, the light emission in the pixel is non-uniform, and the total luminance in the pixel is reduced with respect to the peak luminance in one pixel. Therefore, there is a problem that affects the light emission efficiency and the lifetime. Furthermore, when the thickness of the organic light emitting layer is increased to some extent, the conductivity of the organic light emitting layer is poor and a portion that does not emit light is generated. Therefore, when considering the aperture ratio, there is a problem that the non-light emitting portion in the pixel must also be considered. It was.

  In the case of applying an organic light emitting material using a wet coating method, Patent Documents 1 and 2 propose a pattern forming method using an ink jet method. In Patent Document 1, for example, a bank is formed in advance on a substrate with a material having ink repellency by using a photolithography method or the like, and ink droplets are landed on the bank, whereby the ink repels according to the shape of the bank. A method of obtaining a linear pattern is disclosed. However, when the repelled ink returns to the inside of the pixel, the ink swells inside the pixel, and there remains a problem that the film thickness of the organic light emitting layer in the pixel varies.

  On the other hand, in Patent Document 2, for example, a structure in which a first insulating layer having a lyophilic property on a partition and a second insulating layer having a lyophobic property is stacked on the first insulating layer is formed, and an inkjet is formed there. There is disclosed a method for suppressing variation in film thickness of an organic light emitting layer in a pixel by forming an organic light emitting layer using a method. However, in the step of forming a hole transport layer or a hole injection layer between the first electrode and the organic light emitting layer, when a solid film is formed by a sputtering method, a vacuum deposition method, or the like, the second insulation having a lyophobic property Since the layer is also covered, there is a problem that the effect of suppressing the nonuniformity of the film thickness of the organic light emitting layer is lost.

  Here, a conventional organic EL panel 400 will be described with reference to FIG. In FIG. 4, a conventional organic EL panel 400 includes a first electrode 402 patterned on one surface of a TFT (Thin Film Transistor) substrate 401 corresponding to a pixel to be formed, and a periphery of the first electrode 402. A partition 403 formed on one surface of the TFT substrate 401 so as to surround, and an upper surface of the first electrode 402 surrounded by the partition 403 and a hole transport layer 404 made of inorganic or organic formed on the upper surface of the partition 403, The organic light emitting layer 405 made of a polymer formed on the upper surface of the hole transport layer 404 and the second electrode 406 formed on the upper surface of the organic light emitting layer 405 facing the first electrode 401.

JP 2002-305077 A Japanese Patent Application No. 2003-107840

  In such a conventional polymer type organic EL panel 400, as shown in FIG. 4, when the organic light emitting layer 405 is formed by wet coating, the shape of the partition 403 provided to insulate each pixel electrode is formed. Accordingly, the flatness is deteriorated because the film is thickened. For this reason, the light emission in the pixel becomes non-uniform, and the total luminance in the pixel is reduced with respect to the peak luminance in one pixel, which has a problem of affecting the light emission efficiency and life. Furthermore, when the thickness of the organic light emitting layer is increased to some extent, the conductivity of the organic light emitting layer is poor and a portion that does not emit light is generated. Therefore, when considering the aperture ratio, there is a problem that the non-light emitting portion in the pixel must also be considered. It was.

  The present invention provides an organic EL panel that can suppress an increase in film thickness within a pixel, improve light emission efficiency and lifetime reduction, and improve an aperture ratio by reducing a non-light emitting region, and a method for manufacturing the same. is there.

According to a first aspect of the present invention, there is provided a substrate, a first electrode patterned corresponding to a pixel formed on one surface of the substrate, and a first electrode formed so as to cover an end portion of the first electrode. A barrier including a first insulating layer and a second insulating layer formed on the first insulating layer, an organic light emitting layer formed on the first electrode and the barrier, and a second electrode formed to cover the organic light emitting layer When provided with, in forming the organic light-emitting layer, the edge of the width of the end portion of the organic light-emitting layer to the center of the first electrode respectively with L1, L2 (L1> L2) , L 1 side of the organic light-emitting layer The portion is on the second insulating layer, and is formed so that D / 4 ≦ | L1-L2 | <D / 2, where D is the width of the second insulating layer. This is an EL panel.

According to a first aspect of the present invention, a substrate including a thin film transistor is prepared, a first electrode is formed by patterning on one surface of the substrate corresponding to a pixel, and an end portion of the first electrode is covered. A first insulating layer is formed, a second insulating layer is formed on the first insulating layer, and the width from the end of the organic light emitting layer to the center of the first electrode is set on each of the first electrode and the first insulating layer. When L1 and L2 (L1> L2) and the end of the organic light emitting layer on the L2 side is on the second insulating layer and the width of the second insulating layer is D, D / 4 ≦ | L1−L2 | < A method for producing an organic EL panel, wherein an organic light emitting layer is formed using a relief printing method so as to be in a range of D / 2, and a second electrode is formed so as to cover the organic light emitting layer It is.

According to a second aspect of the present invention, in the organic EL panel according to the first aspect, the end portion of the second insulating layer recedes 0.5 μm or more from the end portion of the first insulating layer. This is a manufacturing method.

The invention according to claim 3 of the present invention is the method for manufacturing an organic EL panel according to claim 1 or 2 , wherein the height of the partition wall is 0.5 μm or more and 2 μm.

The invention according to claim 4 of the present invention, production of an organic EL panel according to claim 1, characterized in that to form the hole transport layer or a hole injection layer between the first electrode and the organic light-emitting layer It is a method.

The invention according to claim 5 of the present invention is characterized in that an electron transport layer or an electron injection layer is formed between the second electrode and the organic light emitting layer, and the method for producing an organic EL panel according to claim 1 , It is a thing.

  According to the present invention, it is possible to provide an organic EL panel that can suppress an increase in film thickness within a pixel, improve a reduction in luminous efficiency and lifetime, and improve an aperture ratio by reducing a non-light emitting region, and a method for manufacturing the same. be able to.

It is a schematic sectional drawing which shows the organic electroluminescent panel which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the board | substrate with TFT which concerns on embodiment of this invention. It is the schematic which shows the relief printing apparatus which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the conventional organic EL panel.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the same components are denoted by the same reference numerals between the embodiments.

  As an example of the organic EL panel (organic EL panel) according to the embodiment of the present invention, an active matrix driving type organic EL panel will be described. However, the embodiment of the present invention is not limited to the active matrix driving type organic EL panel, but can be applied to a passive matrix driving type organic EL panel.

  Hereinafter, an active matrix driving type organic EL panel 100 according to an embodiment of the present invention will be described with reference to FIG. An active matrix driving type organic EL panel 100 shown in FIG. 1 covers a substrate 101 provided with a thin film transistor (TFT), a thin film transistor and a first electrode 102 (anode) provided for each pixel, and an end of the first electrode 102. The first insulating layer 104 formed as described above, the second insulating layer 105 stacked on the first insulating layer 104, the hole transport layer 106 formed above the first electrode 102, and the hole transport layer 106. An organic light emitting layer 107 formed above the organic light emitting layer 107 and a second electrode 108 (cathode) formed above the organic light emitting layer 107.

  A substrate (back plane) 101 used in the active matrix driving type organic EL panel 100 according to the embodiment of the present invention will be described with reference to FIG. A substrate (back plane) 101 used in the active matrix driving type organic EL panel 100 of the embodiment of the present invention is provided with the TFT shown in FIG. 2 and the first electrode 102 of the organic EL panel 100. The source electrode 206 of the TFT and the first electrode 102 of the organic EL panel 100 are electrically connected.

  The substrate (backplane) 101 is supported by a support 202 in the TFT and the active matrix driving organic EL panel 100 formed above the TFT. As the support 202, any material can be used as long as the support 202 has mechanical strength and insulation and is excellent in dimensional stability. For example, plastic films and sheets such as glass, quartz, polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, etc., or oxidation to these plastic films and sheets Metal oxides such as silicon and aluminum oxide, metal fluorides such as aluminum fluoride and magnesium fluoride, metal nitrides such as silicon nitride and aluminum nitride, metal oxynitrides such as silicon oxynitride, acrylic resins and epoxy resins Translucent base material with a single layer or laminated polymer resin film such as silicon resin or polyester resin, metal foil such as aluminum or stainless steel, sheet or plate, and aluminum film on the plastic film or sheet. It can be used beam, copper, nickel, stainless steel and metal film non-translucent substrate as a laminate of such. What is necessary is just to select the translucency of the support body 202 according to which surface light extraction is performed from. The support 202 made of these materials is subjected to moisture-proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to prevent moisture from entering the organic EL panel 100. Preferably there is. In particular, it is preferable to reduce the moisture content and gas permeability coefficient of the support 202 in order to prevent moisture from entering the organic light emitting medium layers (the hole transport layer 106 and the organic light emitting layer 107).

  As the thin film transistor provided over the support 202, a thin film transistor having a known structure can be used. Specifically, a thin film transistor mainly including a source electrode region 206 / drain electrode region 207, an active layer 203 in which a channel region is formed, a gate insulating film 204, and a gate electrode 205 can be given. The structure of the thin film transistor is not particularly limited, and examples thereof include a staggered type, an inverted staggered type, a top gate type, and a coplanar type.

The active layer 303 is not particularly limited, and examples thereof include inorganic semiconductor materials such as amorphous silicon, polycrystalline silicon, microcrystalline silicon, cadmium selenide, thiophene oligomers, poly (p-ferylene vinylene), and the like. The organic semiconductor material can be used. These active layers 303 are formed by, for example, laminating amorphous silicon by plasma CVD and ion doping; forming amorphous silicon by LPCVD using SiH ₄ gas, and crystallizing amorphous silicon by solid phase growth. After obtaining polysilicon, a method of ion doping by ion implantation; amorphous silicon is formed by LPCVD using Si ₂ H ₆ gas and PECVD using SiH ₄ gas, and by a laser such as an excimer laser After annealing and crystallizing amorphous silicon to obtain polysilicon, a method of ion doping by ion doping (low temperature process); polysilicon is deposited by low pressure CVD or LPCVD, and thermally oxidized at 1000 ° C. or higher Gate break Forming a film 204, a gate electrode 205 of the n ⁺ polysilicon is formed thereon, then, a method of ion doping (high temperature process), and the like by an ion implantation method.

As the gate insulating film 204, a film normally used as the gate insulating film 204 can be used. For example, SiO ₂ formed by PECVD method, LPCVD method or the like; obtained by thermally oxidizing a polysilicon film. SiO ₂ or the like can be used.

  As the gate electrode 205, those usually used as the gate electrode 205 can be used. For example, a metal such as aluminum or copper, a refractory metal such as titanium, tantalum, or tungsten, polysilicon, or a refractory metal. Examples thereof include silicide and polycide.

  As the source electrode 206 and the drain electrode 207, those normally used as the source electrode 206 and the drain electrode 207 can be used. For example, a metal such as aluminum or copper, titanium, tantalum, tungsten, or the like can be used. it can.

  The thin film transistor may have a single gate structure, a double gate structure, or a multi-gate structure having three or more gate electrodes 305. Moreover, you may have a LDD structure and an offset structure. Further, two or more thin film transistors may be arranged in one pixel.

  The organic EL panel 100 according to the embodiment of the present invention needs to be connected so that the thin film transistor functions as a switching element of the organic EL panel 100, and the source electrode 206 of the thin film transistor and the pixel electrode ( The first electrode 102) is electrically connected.

  Next, the first electrode 102 of the organic EL panel 100 that electrically connects the source electrode 206 of the thin film transistor will be described. The first electrode 102 is formed on the substrate 101, and patterning is performed according to the pixel to be formed. The patterned first electrode 102 is partitioned by a partition wall 210 and becomes the first electrode 102 corresponding to each pixel. Examples of the material of the first electrode 102 include metal composite oxides such as ITO (indium tin composite oxide), indium zinc composite oxide, and zinc aluminum composite oxide, metal materials such as gold and platinum, and these metal oxides. Alternatively, a single layer or a laminate of fine particle dispersion films in which fine particles of a metal material are dispersed in an epoxy resin or an acrylic resin can be used. When the first electrode 102 is used as an anode, it is preferable to select a material having a high work function such as ITO. In the case of a so-called bottom emission structure in which light is extracted from below, it is necessary to select a light-transmitting material. If necessary, in order to reduce the wiring resistance of the first electrode 102, a metal material such as copper or aluminum may be provided as an auxiliary electrode.

  The first electrode 102 can be formed by a dry film forming method such as a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method, a gravure printing method, a screen depending on the material. A wet film forming method such as a printing method can be used. As a patterning method of the first electrode 102, an existing patterning method such as a mask vapor deposition method, a photolithography method, a wet etching method, or a dry etching method can be used depending on a material and a film forming method. In the case of using a substrate on which a TFT is formed as a substrate, it is formed so that conduction can be achieved corresponding to a lower pixel.

  Next, a method for forming the partition wall 103 of the organic EL panel 100 according to the embodiment of the present invention will be described. The partition 103 of the organic EL panel 100 according to the embodiment of the present invention is formed so as to partition the light emitting region corresponding to the pixel (first electrode 102). In this partition wall 103, a first insulating layer 104 is formed so as to cover an end portion of the first electrode 102, and a second insulating layer 105 is formed so as to recede 0.5 μm or more from the end portion of the first insulating layer 104. And the shape of a two-stage partition wall. By forming the second insulating layer 105 so as to recede by 0.5 μm or more from the end portion of the first insulating layer 104, the hole transport layer 106 formed on the first insulating layer 104 and the second insulating layer 105 is flattened. Can be formed.

  As a method for forming the partition wall 103, as in the past, an inorganic film is uniformly formed on a substrate, masked with a resist, and then dry etching is performed, or a photosensitive resin is laminated on the substrate, and a photolithography method is used. The method of setting to a predetermined pattern is mentioned. In the case where the two-step partition wall according to this embodiment is formed, the second insulating layer 105 is formed using a different etching method by using an inorganic material for the first insulating layer 104 and a photosensitive resin for the second insulating layer 105. Is recessed from the end of the first insulating layer 104 by 0.5 μm or more to form a stepped shape.

  A preferable height of the partition wall 103 is about 0.5 μm or more and 2 μm or less. When the height of the partition wall 103 is higher than 2 μm, the formation and sealing of the second electrode 108 is hindered. When the height is lower than 0.5 μm, the periphery of the pixel electrode (first electrode 102) cannot be covered, or organic light emission is performed. This is because when forming a layer or the like, the adjacent pixels are short-circuited or mixed in color. In the case of the two-step partition wall 103, the height of the first insulating layer 104 is 50 nm or less, and the height of the second insulating layer 105 is about 0.5 μm to 2 μm.

Next, a method for forming an organic light emitting medium layer such as an organic light emitting layer of the organic EL panel 100 according to the embodiment of the present invention will be described. After the partition wall 103 is formed, the hole transport layer 106 is formed. When an organic material is used as a hole transport material for forming the hole transport layer 106, examples of the organic material include polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, poly (3,4-ethylenedioxythiophene) (PEDOT). ) And the like. These materials are dissolved or dispersed in a solvent, and are formed using various coating methods using a spin coater or the like and a relief printing method. In addition, when an inorganic material is used as the hole transport material, examples of the inorganic material include Cu ₂ O, Cr ₂ O ₃ , Mn ₂ O ₃ , FeOx (x to 0.1), NiO, CoO, Pr ₂ O ₃ , Ag. _{2 O, MoO 2, Bi 2} O 3, ZnO, TiO 2, SnO 2, ThO 2, V 2 O 5, Nb 2 O 5, Ta 2 O 5, MoO 3, WO 3, vacuum by using a MnO ₂ It is formed by vapor deposition. However, the material is not limited to these.

  An interlayer layer (not shown) may be formed after the hole transport layer 106 is formed. Polymers containing aromatic amines such as polyvinyl carbazole or derivatives thereof, polyarylene derivatives having aromatic amines in the side chain or main chain, arylamine derivatives, triphenyldiamine derivatives, etc. as materials used in forming the interlayer layer Etc. These materials are dissolved or dispersed in a solvent, and are formed using various coating methods using a spin coater or the like and a relief printing method.

  After forming the interlayer layer, the organic light emitting layer 207 is formed. The organic light emitting layer 207 is a layer that emits light when an electric current is passed. The organic light emitting material forming the organic light emitting layer 207 is, for example, a coumarin type, a perylene type, a pyran type, an anthrone type, a porphyrene type, a quinacridone type, N, N Dispersing luminescent dyes such as' -dialkyl-substituted quinacridone, naphthalimide, N, N'-diaryl-substituted pyrrolopyrrole, iridium complex in polymers such as polystyrene, polymethylmethacrylate, polyvinylcarbazole, , Polyarylene-based, polyarylene vinylene-based, and polyfluorene-based polymer materials.

  These organic light emitting materials are dissolved or stably dispersed in a solvent to form an organic light emitting ink. Examples of the solvent for dissolving or dispersing the organic light emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, or a mixed solvent thereof. Among them, aromatic organic solvents such as toluene, xylene, and anisole are preferable from the viewpoint of the solubility of the organic light emitting material. Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to organic luminescent ink as needed.

  Here, in the embodiment of the present invention, the hole transport layer 106 and the interlayer layer are formed between the first electrode 102 and the organic light emitting layer 107, but between the first electrode 102 and the hole transport layer 106. In addition, a hole injection layer may be formed. These layer structures are preferably selected as appropriate according to the materials used.

  Next, a relief printing apparatus 300 according to the embodiment of the present invention used when forming the hole transport layer 106, the interlayer, and the organic light emitting layer 107 when using an organic material will be described with reference to FIG. . FIG. 3 shows a case where an organic light emitting ink made of an organic light emitting material is subjected to pattern printing on a pixel substrate (first electrode 102), a partition 103, for example, a substrate to be printed 307 on which a hole transport layer made of an inorganic material is formed. The manufacturing apparatus includes an ink tank 301, an ink chamber 302, an anilox roll 303, and a plate cylinder 306 on which a plate 305 provided with a relief plate is mounted. The ink tank 301 contains an organic light emitting ink diluted with a solvent, and the organic light emitting ink is fed into the ink chamber 302 from the ink tank 301. The anilox roll 303 is instructed to rotate in contact with the ink supply unit of the ink chamber 302.

  As the anilox roll 303 rotates, the ink layer 304 of the organic light-emitting ink supplied to the surface of the anilox roll 303 is formed with a uniform film thickness. The ink of the ink layer 304 is transferred to the convex portion of the plate 305 mounted on the plate cylinder 306 that is driven to rotate in the vicinity of the anilox roll 303, and the pattern is transferred to the pixel portion of the printing substrate 307 installed on the flat table 308. Printed.

  In the embodiment of the present invention, as shown in FIG. 1, the method of forming the organic light emitting layer 107 to be printed is such that the width from the edge of the organic light emitting layer 107 to the center of the first electrode 102 is L1, L2 ( When L1> L2) and L2 is from the center of the first electrode 102 to the end of the second insulating layer 105, and the width of the second insulating layer 105 is D, D / 4 ≦ | L1-L2 | It is formed by shifting the center of the convex portion of the plate 307 from the pixel center position so as to be in the range of <D / 2. In other words, when a striped plate is used, printing is performed by shifting | L1-L2 | / 2 from the position where the center of the pixel and the center of the plate coincide with each other in the direction orthogonal to the stripe direction. Thereby, thickening can be suppressed at one end portion of the formed organic light emitting layer 107, and the non-light emitting portion is reduced, so that the aperture ratio can be improved. Further, since one end of the organic light emitting layer 107 has a thin film shape, there is a possibility of short-circuiting, but this can be solved by forming the end of the organic light emitting layer 107 in the first insulating layer 104 of the two-step partition wall. Moreover, the organic light emitting layer 107 is formed on the to-be-printed board | substrate 307 through a drying process as needed.

  Next, the second electrode 108 is formed. When the second electrode 108 is a cathode, a substance having a high electron injection efficiency into the organic light emitting layer 107 and a low work function is used. Specifically, a single metal such as Mg, Al, or Yb is used, or a compound such as Li, oxidized Li, or LiF is sandwiched by several nanometers at the interface in contact with the light emitting medium, and Al or Cu having high stability and conductivity is laminated. You may use it. Alternatively, in order to achieve both electron injection efficiency and stability, one or more metals such as Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, and Yb having a low work function and stable Ag, Al An alloy system with a metal element such as Cu or Cu may be used. Specifically, alloys such as MgAg, AlLi, and CuLi can be used.

  As a method for forming the second electrode 108, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used depending on the material.

  The organic EL panel 100 can emit light by sandwiching a light emitting material between electrodes and passing an electric current. However, since the organic light emitting material is easily deteriorated by moisture or oxygen in the atmosphere, the organic EL panel is usually externally connected. A sealing body (not shown) for blocking is provided. The sealing body can be manufactured, for example, by providing a resin layer on a sealing material.

The sealing material needs to be a base material having low moisture and oxygen permeability. Examples of the material include ceramics such as alumina, silicon nitride, and boron nitride, glass such as alkali-free glass and alkali glass, quartz, and moisture resistant film. Examples of moisture-resistant films include films formed by CVD of SiOx on both sides of plastic substrates, films with low permeability and water-absorbing films, or polymer films coated with a water-absorbing agent. The water vapor transmission rate is preferably 10 ⁻⁶ g / m ² / day or less.

  As an example of the material of the resin layer, a photo-curing adhesive resin, a thermosetting adhesive resin, a two-component curable adhesive resin, or an ethylene ethyl acrylate (EEA) made of epoxy resin, acrylic resin, silicon resin, or the like Examples thereof include acrylic resins such as polymers, vinyl resins such as ethylene vinyl acetate (EVA), thermoplastic resins such as polyamide and synthetic rubber, and thermoplastic adhesive resins such as acid-modified products of polyethylene and polypropylene. Examples of methods for forming a resin layer on a sealing material include solvent solution method, extrusion lamination method, melting / hot melt method, calendar method, nozzle coating method, screen printing method, vacuum laminating method, hot roll laminating method, etc. Can be mentioned. A material having a hygroscopic property or an oxygen absorbing property may be contained as necessary. Although the thickness of the resin layer formed on a sealing material is arbitrarily determined by the magnitude | size and shape of the organic electroluminescent panel to seal, about 5 micrometers-about 500 micrometers are desirable. In addition, although it formed as a resin layer on the sealing material here, it can also form directly in the organic EL panel side.

  Finally, the organic EL panel 100 and the sealing body are bonded together in a sealing chamber. When the sealing body has a two-layer structure of a sealing material and a resin layer, and a thermoplastic resin is used for the resin layer, it is preferable to perform only pressure bonding with a heated roll. When a thermosetting adhesive resin is used, it is preferable to perform heat curing at a curing temperature after pressure bonding with a heated roll. In the case where a photocurable adhesive resin is used, curing can be performed by further irradiating light after pressure bonding with a roll.

  As described above, when the organic EL panel 100 according to the embodiment of the present invention forms the organic light emitting layer 107, the width from the end of the organic light emitting layer 107 to the center of the first electrode 102 is set to L1, respectively. When L2 (L1> L2) and L2 are from the center of the first electrode 102 to the end of the second insulating layer 105, and the width of the second insulating layer 105 is D, D / 4 ≦ | L1− By making the range L2 | <D / 2, it is possible to suppress an increase in film thickness within the pixel, improve the light emission efficiency and lifetime, and improve the aperture ratio by reducing the non-light emitting region. . Note that the direction of the light emitting layer shifted from the center of the first electrode 102 is at least one direction, but in the case of a rectangular pixel shape having a long side and a short side, the light emitting layer is within the above-described range in the short side direction. The position and width are preferably defined. This is because the non-light emitting area that can be reduced is larger than that in the case of shifting in the long side direction.

  Next, an embodiment of the present invention will be described with reference to FIG.

  As the substrate, an active matrix substrate provided with a thin film transistor functioning as a switching element provided on a support was used. The size of the substrate was 200 mm × 200 mm, and a 5-inch diagonal display was installed in the center. The first electrode 202 was formed above the active matrix substrate. As a forming method, first, an ITO film is formed to a thickness of 100 nm by using a sputtering method, and the ITO film is patterned to have a width of 25 μm by etching using a photolithography method and an acid solution, thereby forming a transparent electrode (pixel electrode). The number of pixels was 320 × 240.

  Next, a two-stage partition was formed so as to cover the first electrode 202 provided on the active matrix substrate and partition the pixels. First, the first insulating layer 104 is formed by uniformly forming an inorganic material with a thickness of 30 nm on the active matrix substrate by a vacuum deposition method, masking it with a resist, and then covering the end portion of the first electrode 102 by 0.5 μm. As described above, a line pattern having a width of 40 μm was formed between the first electrodes 102 by dry etching. The second insulating layer 105 was formed by spin coating a photoresist material with a thickness of 2 μm. The applied photoresist material was formed to recede by 0.5 μm from the end of the first insulating layer 104 by photolithography.

  Next, molybdenum oxide (MoOx) having a thickness of 20 nm was stacked as a hole transport material on the surfaces of the first electrode 102 and the partition wall 103 by a vacuum evaporation method. The distance between the evaporation source and the substrate was set at a position of 300 mm and an angle of 0 degree.

  Next, using the ink in which the polyvinyl carbazole derivative, which is an interlayer material, is dissolved in toluene so as to have a concentration of 0.5%, the substrate on which the above-described hole transport layer 106 is formed is set in the relief printing apparatus 300. Then, the interlayer layer was printed by the relief printing method in accordance with the line pattern just above the first electrode 102 sandwiched between the partition walls 103. The film thickness of the interlayer layer after printing and drying was 10 nm.

  Next, using an organic light emitting ink in which a polyphenylene pinylene derivative, which is an organic light emitting material, is dissolved in toluene so as to have a concentration of 1%, the substrate on which the above-described interlayer layer is formed is set in the relief printing apparatus 300, In accordance with the line pattern of the partition wall 103 and the first electrode 102 sandwiched between the partition walls 103, printing was performed with a target film thickness of 80 nm by a relief printing method. When printing, the center of the convex portion of the plate 305 on which the organic light emitting ink is mounted on the plate cylinder 306 is shifted from the center position of the pixel electrode 102, so that the edge of the organic light emitting layer 107 formed from the center of the pixel electrode 102 is obtained. Up to a portion having a width of 14.5 μm (L1) and 12.5 μm (L2), and a shape within a range of D / 4 ≦ | L1−L2 | <D / 2.

  Next, as a second electrode 108, a Ba film was formed to a thickness of 4 nm using a metal mask by a vacuum evaporation method, and then an Al film was formed to a thickness of 150 nm using a metal mask by a vacuum evaporation method. Then, a cap-type sealing glass and an adhesive were placed so as to cover the light emitting region, and the adhesive was thermally cured at about 90 ° C. for 1 hour to be hermetically sealed, thereby producing an active matrix driving type organic EL panel.

The active matrix driving type organic EL panel manufactured in this way can suppress the increase in thickness at one end of the formed organic light emitting layer 107, and can improve the aperture ratio because the non-light emitting portion is reduced. When the applied voltage was 7 V, the luminance was 600 cd / m ² and the luminous efficiency could be improved.

[Comparative Example 1]
An organic EL panel having a configuration not corresponding to the organic EL panel according to the present invention was produced as Comparative Example 1 with respect to Example 1. In this comparative example, the organic light emitting layer formed in Example 1 does not have a shape within the range of D / 4 ≦ | L1−L2 | <D / 2, but is thick along the partition walls at both ends of the organic light emitting layer. In the same manner as in Example 1, the film thickness was printed at 80 nm. The formation process other than the organic light emitting layer was the same as in Example 1. Therefore, since the region of the thick film expanded with respect to the target thick film, an active matrix driving type organic EL panel not corresponding to the present invention was manufactured.

The active matrix driving type organic EL panel of Comparative Example 1 manufactured in this way has a non-light emitting portion increased with respect to Example 1, and when the applied voltage is 7 V, the luminance is 300 cd / m ² . Luminous efficiency has also decreased.

  In the organic EL panel according to this example, the organic light emitting layer is formed within the range of D / 4 ≦ | L1-L2 | <D / 2, so that the thick film in the pixel can be suppressed and the light emission efficiency is improved. did it.

  201 ... TFT substrate, 202, 301 ... first electrode, 203, 310 ... partition, 204 ... first insulating layer, 205 ... second insulating layer, 206 ... hole transport layer, 207 ... organic light emitting layer, 208 ... second Electrode 302... Support 303 303 Active layer 304 Gate insulating film 305 Gate electrode 306 Source electrode 307 Drain electrode 308 Scan line 401 Ink tank 402 Ink chamber 403 Anilox roll, 406... Plate cylinder, 407.

Claims (5)

Preparing a substrate with thin film transistors;
A first electrode is formed by patterning on one surface of the substrate corresponding to the pixels,
Covering the end of the first electrode to form a first insulating layer;
Forming a second insulating layer on the first insulating layer;
On the first electrode and the first insulating layer, the width from the end of the organic light emitting layer to the center of the first electrode is L1 and L2 (L1> L2), respectively, and the end of the organic light emitting layer on the L2 side The portion is on the first insulating layer , and when the width of the second insulating layer is D, the organic light-emitting layer is formed by letterpress printing so that D / 4 ≦ | L1-L2 | <D / 2. Formed using
A method of manufacturing an organic EL panel, wherein the second electrode is formed so as to cover the organic light emitting layer.   2. The method of manufacturing an organic EL panel according to claim 1, wherein an end portion of the second insulating layer recedes 0.5 μm or more from an end portion of the first insulating layer.   3. The method of manufacturing an organic EL panel according to claim 1, wherein a height of the partition wall is 0.5 μm or more and 2 μm.   The method for producing an organic EL panel according to claim 1, wherein a hole transport layer or a hole injection layer is formed between the first electrode and the organic light emitting layer.   The method for producing an organic EL panel according to claim 1, wherein an electron transport layer or an electron injection layer is formed between the second electrode and the organic light emitting layer.