JP2009230953A - Organic el display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display in which a clear interface between an electrode and a protection layer is not formed by installing a mixed film of an electrode material and a protection layer material in the protection layer arranged on the electrode, and its manufacturing method. <P>SOLUTION: This is the organic EL display panel which is equipped with a substrate, a pixel electrode formed on the substrate, an organic medium layer formed on the pixel electrode, the counter electrode formed on the organic medium layer, a first protection layer formed on the counter electrode, and a second protection layer formed on the first protection layer, and in which the first protection layer is a mixed film of the counter electrode and the second protection layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL display panel and a manufacturing method thereof, and more particularly, to an organic EL display panel in which a clear interface between an electrode and a protective layer does not occur and a manufacturing method thereof.

  In the organic EL element, an organic light emitting layer made of an organic light emitting material is formed between two opposing electrodes, and light is emitted by passing a current through the organic light emitting layer. The organic EL element is easily deteriorated by moisture and oxygen in the air, and therefore needs to be sealed so as not to be exposed to the atmosphere.

  Generally as a sealing method for organic EL elements, a cap-shaped sealing substrate made of metal, glass, or the like is bonded by using a substrate on which organic EL elements are formed and an adhesive under dry nitrogen. Methods to prevent exposure are used. However, in this method, the organic EL element is deteriorated by moisture or oxygen passing through the adhesive portion from the outside. For this reason, as a method for preventing the deterioration of the organic EL element, a method is generally employed in which a material having a hygroscopic ability and an oxygen trapping ability is installed inside the cap.

  Alkaline earth metal oxides such as molecular sieves and BaO are used as trap materials for preventing deterioration of organic EL elements. If an alkaline earth metal oxide is installed in the cap, the process becomes complicated, which is disadvantageous in terms of cost. Therefore, instead of alkaline earth metal oxides, oxides and nitrides that are difficult to permeate moisture and oxygen are deposited as protective layers to cover the organic medium layer, thereby blocking moisture and oxygen that have entered from the outside. Is used. A method of laminating different protective layer materials has also been proposed.

Patent Document 1 discloses a method of providing a paraxylene thin film having a thickness of 0.1 μm or more and 20 μm or less as a protective layer on an organic EL element by a gas phase polymerization method. Patent Document 2 discloses a method of providing an organic film such as polybutadiene or an inorganic film such as SiO ₂ on an organic EL element by vacuum deposition or sputtering.

FIG. 8 shows an explanatory diagram of a conventional structure in which the protective layer 83 is provided on the counter electrode 82. In the conventional structure, the initial deterioration can be prevented by providing the protective layer 83, but compared with the organic EL element in which the trap material of oxygen and moisture is installed in the sealed body, the dark spots caused by moisture and oxygen are earlier caused. A non-light-emitting portion called is generated, and further, the luminance efficiency with respect to the current is lowered, and the reliability of the organic EL element is lowered. In the conventional structure, the counter electrode 82 and the protective layer 83 are made of different materials and the film forming process is often different, mainly due to a gas 85 such as moisture or oxygen that reaches the display region through the interface 84 between the layers. It turned out to be. In addition, in order to avoid contact with the organic EL element, it is necessary to install the trap material in the concave portion of the cap-shaped sealing material processed into a concave shape, so that the device shape cannot be thinned. End up.
Japanese Patent Laid-Open No. 4-137383 JP-A-4-73886

  The present invention provides an organic EL display in which a clear interface between the electrode and the protective layer does not occur by providing a mixed film of the electrode material and the protective layer material in the protective layer disposed on the electrode, and a method for manufacturing the same. That is.

  The invention according to claim 1 of the present invention includes a substrate, a pixel electrode formed on the substrate, an organic medium layer formed on the pixel electrode, a counter electrode formed on the organic medium layer, and a counter electrode A first protective layer formed on the first protective layer; and a second protective layer formed on the first protective layer, wherein the first protective layer includes a counter electrode and a second protective layer. The organic EL display panel is a mixed film.

  The invention according to claim 2 of the present invention is the organic EL display panel according to claim 1, wherein the mixed film of the first protective layer has a gradient in the mixing ratio.

  The invention according to claim 3 of the present invention is the organic EL display panel according to claim 1 or 2, wherein the thickness of the first protective layer is 5 nm or more.

  According to a fourth aspect of the present invention, in the organic EL display according to the first or second aspect, the second protective layer is formed so as to cover an upper part or all of the first protective layer. It is a panel.

The invention according to claim 5 of the present invention includes a sealing material having a plate-like member having a water vapor transmission rate of 10 ⁻⁶ g / m ² / day or less, and a resin layer to which the sealing material is adhered. The organic EL display panel according to claim 1, further comprising a body.

  According to a sixth aspect of the present invention, a substrate is prepared, a plurality of pixel electrodes are formed on the substrate, an organic medium layer is formed on the plurality of pixel electrodes, and a counter electrode is formed on the organic medium layer. Forming a first protective layer on the counter electrode and forming a second protective layer on the first protective layer, wherein the first protective layer includes a counter electrode and a second protective layer. The organic EL display panel manufacturing method is characterized by being a mixed film.

  The invention according to claim 7 of the present invention is the method for manufacturing an organic EL display panel according to claim 6, wherein the mixed film of the first protective layer has a gradient in the mixing ratio.

  The invention according to claim 8 of the present invention is the method for manufacturing an organic EL display panel according to claim 6 or 7, wherein the thickness of the first protective layer is 5 nm or more.

  The invention according to claim 9 of the present invention is characterized in that the second protective layer is formed so as to cover the upper part or all of the first protective layer. This is a method for manufacturing a panel.

The invention according to claim 10 of the present invention is a sealing having a sealing material having a plate-like member having a water vapor transmission rate of 10 ⁻⁶ g / m ² / day or less, and a resin layer to which the sealing material is adhered. A method for producing an organic EL display panel according to claim 6, wherein the organic EL display panel comprises a body.

  According to the present invention, an organic EL display in which a clear interface between the electrode and the protective layer does not occur by providing a mixed film of the electrode material and the protective layer material in the protective layer disposed on the electrode, and a method for manufacturing the same. Can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments, the same components are denoted by the same reference numerals, and redundant description among the embodiments is omitted. The present invention is not limited to these.

  As shown in FIG. 1, an organic EL display device 100 according to an embodiment of the present invention includes a substrate 6, an active layer 7, a gate insulating film 8, a gate electrode 9, an interlayer insulating film 10, a drain electrode 11, and a scanning line 12. Source electrode 13, pixel electrode 14, partition 15, hole transport layer 16, interlayer layer 17, organic light emitting layer 18, counter electrode 19, first protective layer 20, and second protective layer 21. Although not shown here, a sealing body 30 having a sealing material and a resin layer is provided. Here, the hole transport layer 16, the interlayer layer 17, and the organic light emitting layer 18 are referred to as the organic medium layer 2, and the pixel electrode 14, the partition wall 15, the hole transport layer 16, the interlayer layer 17, the organic light emitting layer 18, and the counter electrode. The electrode 19 is referred to as the organic EL element 1.

  As shown in FIG. 1, an organic EL display device 100 according to an embodiment of the present invention includes a substrate 6 provided with a thin film transistor (hereinafter, simply referred to as “TFT”), and a thin film transistor electrically connected to each pixel. A pixel electrode 14 connected to the organic medium layer 1, an organic medium layer 1 formed above the pixel electrode 14, and a counter electrode 19 formed above the organic medium layer 1. Furthermore, a first protective layer 20 and a second protective layer 21 are provided.

[Substrate 6]
As shown in FIG. 1, a thin film transistor, a pixel electrode 14, an organic medium layer 1, and a counter electrode 19 are provided on a substrate (backplane) used in the organic EL display device 100 according to the embodiment of the present invention. .

  The thin film transistor and the organic EL element 1 configured above the thin film transistor are supported by the substrate 6. Any material can be used as the substrate 6 as long as the substrate 6 has mechanical strength and insulation and is excellent in dimensional stability.

  Examples of the material of the substrate 6 according to the embodiment of the present invention include glass, quartz, polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, and the like. Films and sheets, or metal oxides such as silicon oxide and aluminum oxide, metal fluorides such as aluminum fluoride and magnesium fluoride, metal nitrides such as silicon nitride and aluminum nitride, oxynitride Translucent base material with a single layer or laminated polymer oxynitride such as silicon, acrylic resin, epoxy resin, silicone resin, polyester resin, etc., metal foil such as aluminum or stainless steel, sheet, plate And Stick films or aluminum sheets, copper, nickel, a metal film such as stainless steel or the like can be used non-translucent substrate as a laminate but are not limited to these.

  What is necessary is just to select the translucency of the board | substrate 6 according to which surface light extraction of the organic electroluminescent display apparatus 100 is performed from. The substrate 6 made of the above-described material is subjected to moisture proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to avoid intrusion of moisture into the organic EL display device 100. Preferably there is. In particular, in order to avoid intrusion of moisture into the organic medium layer 2, it is preferable to reduce the moisture content and gas permeability coefficient in the substrate 6.

  The thin film transistor provided on the substrate 6 includes a drain electrode 11, a source electrode 13, an active layer 7 in which a channel region is formed, a gate insulating film 8, and a gate electrode 9. Examples of the structure of the thin film transistor include a staggered type, an inverted staggered type, a top gate type, and a coplanar type. However, the present invention is not limited to these.

  Examples of the material of the active layer 7 according to the embodiment of the present invention include inorganic semiconductor materials such as amorphous silicon, polycrystalline silicon, microcrystalline silicon, and cadmium selenide, thiophene oligomers, and poly (p-ferylene vinylene). However, the present invention is not limited to these materials.

The active layer 7 according to the embodiment of the present invention is formed by, for example, laminating amorphous silicon by plasma CVD, ion doping, forming amorphous silicon by LPCVD using SiH ₄ gas, and solid-phase growth. After amorphous silicon is crystallized to obtain polysilicon, amorphous silicon is formed by ion doping by ion implantation, LPCVD using Si ₂ H ₆ gas, and PECVD using SiH ₄ gas. After annealing with an excimer laser or the like to crystallize amorphous silicon to obtain polysilicon, a method of ion doping by an ion doping method (low temperature process), a layer of polysilicon by a low pressure CVD method or an LPCVD method, Hot acid above ℃ And forming a gate insulating film 8, the n ⁺ polysilicon gate electrode 9 is formed thereon, then, limitation in a method of ion doping (high temperature process), and the like present invention by ion implantation It is not done.

As the gate insulating film 8 according to the embodiment of the present invention, for example, PECVD method, SiO 2 was formed by the LPCVD method or the _like, SiO ₂ or the like obtained by the polysilicon film by thermal oxidation including but in the present invention However, it is not limited to these.

  Examples of the gate electrode 9 according to the embodiment of the present invention include metals such as aluminum and copper, refractory metals such as titanium, tantalum, and tungsten, polysilicon, silicides of refractory metals, polycides, and the like. The invention is not limited to these.

  The thin film transistor according to the embodiment of the present invention may have a single gate structure, a double gate structure, or a multi-gate structure having three or more gate electrodes 9. 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 thin film transistor according to the embodiment of the present invention needs to be connected so as to function as a switching element, and the drain electrode 11 or the source electrode 13 of the thin film transistor and the pixel electrode 14 of the organic EL element 1 are electrically connected. ing. In the embodiment of the present invention, the active matrix driving type organic EL display device 100 will be described. However, the present invention can also be applied to a passive matrix driving type organic EL display device.

[Pixel electrode 14]
As shown in FIG. 1, the pixel electrode 14 according to the embodiment of the present invention is electrically connected to the source electrode 13 of the thin film transistor on the substrate 6 and is formed by patterning as necessary. The pixel electrode 14 is partitioned by a partition wall 15 and becomes a pixel electrode 14 corresponding to each pixel. Here, the pixel electrode 14 of the passive matrix driving type organic EL display device can be formed on the substrate 6 and patterned as necessary.

  Examples of the material of the pixel electrode 14 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, these metal oxides, Either 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, but the present invention is not limited to these.

  When the pixel electrode 14 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 pixel electrode 14, a metal material such as copper or aluminum may be provided as an auxiliary electrode. Here, in the case of a so-called top emission structure in which light is extracted from above (the direction opposite to the substrate 6), the counter electrode 19 can be stacked on the substrate 6.

  As a method for forming the pixel electrode 14, depending on the material, dry film forming methods such as resistance heating vapor deposition, electron beam vapor deposition, reactive vapor deposition, ion plating, and sputtering, gravure printing, and screen printing are used. A wet film forming method such as a method can be used.

  As a patterning method of the pixel electrode 14, a mask vapor deposition method, a photolithography method, a wet etching method, a dry etching method, or the like can be used depending on a material or a film forming method. In the case of using a substrate on which a thin film transistor is formed as the substrate 6, the substrate 6 is formed so as to be conductive corresponding to the lower pixel.

[Partition 15]
The partition 15 according to the embodiment of the present invention can be formed so as to partition a light emitting region corresponding to a pixel. As shown in FIG. 1, it is preferable to form the pixel electrode 14 so as to cover the end. In the active matrix driving type organic EL display device 100, the pixel electrode 14 is formed for each pixel, and each pixel tries to occupy as wide an area as possible. Therefore, the most preferable shape of the partition 15 formed so as to cover the end of the pixel electrode 14 is basically a lattice shape that divides each pixel electrode 14 by the shortest distance.

  As a method for forming the partition wall 15, an inorganic film is uniformly formed on the substrate (pixel electrode 14), masked with a resist, and then dry-etched, or a photosensitive resin is laminated on the substrate, and photolithography is performed. The method of making a predetermined pattern by a method is mentioned. If necessary, a water repellent can be added, or plasma or UV can be irradiated to impart liquid repellency to the ink after formation.

  A preferable height (thickness) of the partition wall 15 is 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 2 μm or less. If the height of the partition wall 15 is too higher than 10 μm, the formation and sealing of the counter electrode 19 is hindered. If the height of the partition wall 15 is too lower than 0.1 μm, the end of the pixel electrode 14 cannot be covered, or organic When the medium layer 1 is formed, the adjacent pixels are short-circuited or mixed in color.

[Organic medium layer 2]
The organic medium layer 2 according to the embodiment of the present invention includes a hole transport layer 16, an interlayer layer 17, and an organic light emitting layer 18. The light emission auxiliary layer that can be used as the organic medium layer 2 is not limited to the hole transport layer 16 or the interlayer layer 17, but a hole injection layer, an electron transport layer, an electron injection layer, or the like is used although not shown. be able to.

  After the partition wall 15 is formed, the hole transport layer 16 can be formed on the pixel electrode 14. Examples of the organic material of the hole transport layer 16 according to the embodiment of the present invention include polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, poly (3,4-ethylenedioxythiophene) (PEDOT), and the like. The present invention is not limited to these examples. 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.

Examples of the inorganic material of the hole transport layer 16 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, and 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 , MnO _2, etc. Or a sputtering method or a CVD method. However, the material is not limited to these. These metal carbides, nitrides, borides and the like can also be used.

  After the formation of the hole transport layer 16, the interlayer layer 17 can be formed. Examples of the material used for the interlayer layer 17 according to the embodiment of the present invention include aromatic compounds such as polyvinyl carbazole or derivatives thereof, polyarylene derivatives having an aromatic amine in the side chain or main chain, arylamine derivatives, and triphenyldiamine derivatives. Examples thereof include polymers containing a group amine, but the present invention is not limited thereto. 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. When an inorganic material is used as the material for the interlayer layer 17, the metal oxide is formed using a vacuum deposition method, a sputtering method, or a CVD method. As the inorganic material of the interlayer layer 17, the same inorganic material as that of the hole transport layer 16 can be used.

  After the formation of the interlayer layer 17, the organic light emitting layer 18 can be formed. The organic light emitting layer 18 is a layer that emits light when an electric current is applied. The organic light emitting material of the organic light emitting layer 18 is, for example, a coumarin type, a perylene type, a pyran type, an anthrone type, a porphyrene type, a quinacridone type, an N, N′-dialkyl substituted quinacridone type, a naphthalimide type, an N, N′-diaryl substituted. Fluoropyrrole-based and iridium complex-based luminescent dyes dispersed in polymers such as polystyrene, polymethylmethacrylate, and polyvinylcarbazole, and polyarylene-based, polyarylene vinylene-based, and polyfluorene-based polymer materials The present invention is not limited to these examples.

  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.

  FIG. 2 shows a schematic view of a relief printing apparatus 200 when pattern printing is performed on the substrate 28 on which the pixel electrode 14 and the hole transport layer 16 are formed using an organic light emitting ink made of an organic light emitting material. The relief printing apparatus 200 according to the embodiment of the present invention includes a printing plate 27 on which an ink tank 22, an ink chamber 23, an anilox roll 24, and a plate 26 provided with a relief plate are mounted. The ink tank 22 contains an organic light-emitting ink diluted with a solvent, and the organic light-emitting ink is fed into the ink chamber 23 from the ink tank 22. The anilox roll 24 is instructed to rotate in contact with the ink supply section of the ink chamber 23.

  As the anilox roll 24 rotates, the ink layer 25 of the organic light-emitting ink supplied to the surface of the anilox roll 24 is formed with a uniform film thickness. The ink in the ink layer 25 is transferred to the convex portion of the plate 26 mounted on the plate cylinder 27 that is driven to rotate in the vicinity of the anilox roll 24. A printing substrate 28 on which the pixel electrode 14 and the hole transport layer 16 are formed is arranged on the flat table 29, and the ink on the convex portion of the plate 26 is printed on the printing substrate 28, and if necessary. Through the drying process, the interlayer layer 17 or the organic light emitting layer 18 is formed on the substrate 28 to be printed.

[Counter electrode 19]
As shown in FIG. 1, when the counter electrode 19 according to the embodiment of the present invention is used as a cathode, a substance having a high electron injection efficiency into the organic light emitting layer 18 and a low work function can be used.

  For the material of the counter electrode 19, for example, a single metal such as Mg, Al, Yb, or a compound such as Li, oxidized Li, or LiF is sandwiched by about 1 nm at the interface in contact with the organic medium layer 1 and has high stability and conductivity. Al or Cu may be laminated and used. 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 can be used, but the present invention is not limited thereto. Specifically, alloys such as MgAg, AlLi, and CuLi can be used. In the case of a so-called top emission structure in which light is extracted from above, it is necessary to select a light-transmitting material for the counter electrode 19, and a metal composite oxide such as ITO used for the pixel electrode 14 is used as the counter electrode 19. be able to. When ITO is used as the counter electrode 19, a compound such as Li, oxidized Li, or LiF can be used between the counter electrode 19 and the organic medium layer 2.

  The counter electrode 19 can be formed by 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 depending on the material.

[First protective layer 20]
FIG. 3 shows the first protective layer 20 and the second protective layer 21 formed on the organic EL element 1. A mixed layer of an electrode material in contact with the first protective layer 20 and a protective layer material used as the second protective layer 21 can be formed on the first protective layer 20 according to the embodiment of the present invention. . The first protective layer 20 is formed to prevent oxygen, moisture, and the like from entering from the outside through the interface between the sealing material and the counter electrode 19 when the sealing material is provided. As the electrode material of the first protective layer 20, the material of the counter electrode 19 described above can be used. Examples of the protective layer material of the first protective layer 20 include Li, Na, K, Rb, Cs, Cu, Mg, Ba, Ca, Sr, Zn, Cd, Al, Ga, In, Sc, Y, Si, and Ge. Ti, Zr, Hf, Sb, Nb, Ta, Se, Cr, W, Fe, Co, Yb, Eu, Ce, La, Rb, Lu, Ho, Er, Sm or Tm Examples include inorganic compounds such as oxides, nitrides, oxynitrides, sulfides, carbides, and fluorides containing atoms of more than one species, but the present invention is not limited thereto. Furthermore, it is also preferable to use carbon as a constituent material of the first protective layer 20 as an organic compound.

Specifically, as an inorganic compound forming the first protective layer 20, for example, LiOx, LiNx, NaOx, KOx, RbOx, CsOx, BeOx, MgOx, MgNx, CaOx, CaNx, SrOx, BaOx, ScOx, YOx, YNx, LaOx, LaNx, CeOx, PrOx, NdOx, SmOx, EuOx, GdOx, TbOx, DyOx, HoOx, ErOx, TmOx, YbOx, LuOx, TiOx, TiNx, ZrOx, ZrThH NbOx, NbNx, TaOx, TaNx, CrOMnOx, ReOx, FeOx, FeNx, RuOx, OsOx, CoOx, RhOx, IrOx, NiOx, PdOx, PtOx, CuOx, CuNx, AgOx, AuOx, ZnO , CdOx, HgOx, BOx, BNx, AlOx, AlNx, GaOx, GaNx, InOx, SiNx, GeOx, SnOx, PbOx, POx, PNx, AsOx, SbOx, SeOx, TeOx, etc. (each composition) In the formula, x is 1/2 to 2.). _{Further, LiAlO 2, Li 2 SiO 3} , Li 2 TiO 3, Na 2 Al 2 O 3, NaFeO 2, Na 4 SiO 4, K 2 SiO 3, K 2 TiO 3, K 2 WO 4, Rb 2 CrO 4, _{cs 2 CrO 4, MgAl 2 O} 4, MgFe 2 O 4, MgTiO 3, CaTiO 3, CaWO 4, CaZrO 3, SrFe 12 O 19, SrTiO 3, SrZrO 3, BaAl 2 O 4, BaFe 12 O 19, BaTiO 3 _{, Y 3 Al 5 O 12,} Y 3 Fe 5 O 12, LaFeO 3, La 3 Fe 5 O 12, La 2 Ti 2 O 7, CeSnO 4, CeTiO 4, Sm 3 Fe 5 O 12, EuFeO 3, Eu 3 _{Fe 5 O 12, GdFeO 3,} Gd 3 Fe 5 O 12, DyFeO 3, Dy _{Fe 5 O 12, HoFeO 3,} Ho 3 Fe 5 O 12, ErFeO 3, Er 3 Fe 5 O 12, Tm 3 Fe 5 O 12, LuFeO 3, Lu 3 Fe 5 O 12, NiTiO 3, Al 2 TiO 3, _{FeTiO 3, BaZrO 3, LiZrO 3} , MgZrO 3, HfTiO 4, NH 4 VO 3, AgVO 3, LiVO 3, BaNb 2 O 6, NaNbO 3, SrNb 2 O 6, KTaO 3, NaTaO 3, SrTa 2 O 6, _{CuCr 2 O 4, Ag 2 CrO} 4, BaCrO 4, K 2 MoO 4, Na 2 MoO 4, NiMoO 4, BaWO 4, Na 2 WO 4, SrWO 4, MnCr 2 O 4, MnFe 2 O 4, MnTiO 3, _{MnWO 4, CoFe 2 O 4,} ZnFe 2 O 4, F _{WO 4, CoMoO 4, CoTiO 3} , CoWO 4, NiFe 2 O 4, NiWO 4, CuFe 2 O 4, CuMoO 4, CuTiO 3, CuWO 4, Ag 2 MoO 4, Ag 2 WO 4, ZnAl 2 O 4, ZnMoO _{4, ZnWO 4, CdSnO 3,} CdTiO 3, CdMoO 4, CdWO 4, NaAlO 2, MgAl 2 O 4, SrAl 2 O 4, Gd 3 Ga 5 O 12, InFeO 3, MgIn 2 O 4, Al 2 TiO 5, _{FeTiO 3, MgTiO 3, Na 2} SiO 3, CaSiO 3, ZrSiO 4, K 2 GeO 3, Li 2 GeO 3, Na 2 GeO 3, Bi 2 Sn 3 O 9, MgSnO 3, SrSnO 3, PbSiO 3, PbMoO 4 , PbTiO ₃ , SnO ₂ —S Metal composite oxides such as b ₂ O ₃ , CuSeO ₄ , Na ₂ SeO ₃ , ZnSeO ₃ , K ₂ TeO ₃ , K ₂ TeO ₄ , Na ₂ TeO ₃ , Na ₂ TeO ₄ , FeS, Al ₂ S ₃ , MgS Sulfides such as ZnS, fluorides such as LiF, MgF ₂ , SmF ₃ , chlorides such as HgCl, FeCl ₂ , CrCl ₃ , bromides such as AgBr, CuBr, MnBr ₂ , PbI ₂ , CuI, FeI _2, etc. Examples thereof include iodides and metal oxides such as SiAlON, but the present invention is not limited thereto.

Among these inorganic compounds, since the denser first protective layer 20 is obtained, oxides, nitrides containing one or more metal atoms selected from Ca, Al, Si, Ge, and Ce, Oxynitrides, sulfides, carbides or fluorides are preferred. In addition, since the driving voltage does not increase excessively, CaS, Al ₂ O ₃ , AlN, SiO ₂ , SiC, GeO ₂ , and CeO ₂ are more preferable, and because performance and handling are easier, SiO ₂ is the most It is a suitable material. However, when an oxide of Si is used as the constituent material of the first protective layer 20, the material is not limited to SiO ₂ and may be SiO x (x is 1 <x ≦ 2).

The first protective layer 20 is a mixed film of the counter electrode 19 and the second protective layer 21, and the thickness of the first protective layer 20 is 5 nm or more in order to give a gradient in the mixing ratio. preferable.
When the thickness of the first protective layer 20 is less than 5 nm, it passes from the outside through the interface between the first protective layer 20 and the counter electrode 19 and through the interface between the first protective layer 20 and the second protective layer 21. Oxygen, moisture, etc. will invade.

[Second protective layer 21]
In contrast to the first protective layer 20 provided for the purpose of eliminating the interface between the electrode material and the protective layer material and preventing the intrusion of gas from the interface, the second protective layer 21 according to the embodiment of the present invention contains gas. It is provided for the purpose of preventing intrusion through the film formation surface. The second protective layer 21 is formed of the same material as the first protective layer 20 material.

  The second protective layer 21 is formed by a film forming method such as a resistance heating method, an electron beam evaporation method, a sputtering method, an ion plating method, or a CVD method in consideration of the melting point, boiling point, and vapor pressure of the material. Selected.

  The organic EL display panel 100 according to the embodiment of the present invention is a so-called bottom emission type, and a first protective layer 20 and a second protective layer 21 are formed on a counter electrode 19. When the organic EL display panel 100 is a top emission type, the first protective layer 20 and the second protective layer 21 are formed on the pixel electrode 14, and the first protective layer 20 and the second protective layer 21 are formed. The materials described above can be used as appropriate.

[Sealing body 30]
In order to prevent atmospheric gas from reaching the organic EL element 1, normally, a sealing body 30 having a sealing material and a resin layer can be provided in order to shut off from the outside.

The sealing material according to the embodiment of the present invention needs to be a substrate having low moisture and oxygen permeability. Examples of the material for the sealing 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. However, the present invention is not limited thereto. It is not done. 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. When the water vapor transmission rate exceeds 10 ⁻⁶ g / m ² / day, moisture enters the organic EL element and the organic EL element deteriorates. The thickness of the sealing material is preferably 0.7 or less.

  As a material of the resin layer according to the embodiment of the present invention, for example, a photocurable adhesive resin, a thermosetting adhesive resin, a two-component curable adhesive resin made of an epoxy resin, an acrylic resin, a silicone resin, or the like And acrylic resins such as ethylene ethyl acrylate (EEA) polymer, vinyl resins such as ethylene vinyl acetate (EVA), thermoplastic resins such as polyamide and synthetic rubber, and thermoplastic adhesives such as acid-modified products of polyethylene and polypropylene However, the present invention is not limited to these.

  As a method for forming a resin layer on a sealing material, for example, a solvent solution method, an extrusion lamination method, a melting / hot melt method, a calendar method, a nozzle coating method, a screen printing method, a vacuum laminating method, a hot roll laminating method, etc. The present invention is not limited to these examples. A material having a hygroscopic property or an oxygen absorbing property may be contained as necessary. The thickness of the resin layer formed on the sealing material is arbitrarily determined depending on the size and shape of the organic EL display device 100 to be sealed, but is preferably about 5 μm to 500 μm. In addition, although it formed as a resin layer on the sealing material here, it can also form directly in the organic EL element side.

  Finally, the organic EL element and the sealing body 30 are bonded together in a sealing chamber. When the sealing body 30 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.

  In the organic EL display device 100 according to the embodiment of the present invention, the first protective layer 20 and the second protective layer 21 are provided so that a clear interface between the electrode and the protective layer does not occur. The durability of the organic EL display device 100 can be improved by adopting a structure in which moisture and oxygen do not reach the organic medium layer 2 from the outside through the interface. In addition, since it is not necessary to install a trap material for trapping oxygen and moisture in the sealing cap, the process of the organic EL display device 100 can be simplified and the manufacturing cost and the member cost can be reduced. Since it is not necessary to use a sealing material, the organic EL display device 100 can be thinned.

  As shown in FIG. 1, the thickness of the thin film transistor provided on the substrate 6 that functions as a switching element and the pixel electrode 14 formed above the thin film transistor and electrically connected to the source electrode 13 is 0. A 7 mm active matrix substrate 6 was used. The size of the substrate 6 is 5 inches diagonal and the number of pixels is 320 × 240.

  Next, the partition wall 15 was formed in such a shape as to cover the end of the pixel electrode 14 provided on the substrate 6 and partition the pixel. The partition wall 15 was formed by forming a positive resist represented by a trade name “ZWD6216-6” manufactured by Nippon Zeon Co., Ltd. on the entire surface of the substrate 6 with a height (thickness) of 2 μm using a spin coater method. Thereafter, a partition wall 15 having a width of 40 μm was formed by photolithography. As a result, a pixel region having a sub-pixel number of 960 × 240 dots and a pitch of 0.12 mm × 0.36 mm was defined.

  Next, a hole transport layer 16 was formed on the pixel electrode 14. The hole transport layer 16 was patterned using a 50 nm thick molybdenum oxide film by a shadow mask method of vacuum deposition.

  Next, the substrate formed up to the hole transport layer 16 is disposed on the printing substrate 28 of the relief printing apparatus 200, and the interlayer layer 17 is aligned with the line pattern directly above the pixel electrode 14 sandwiched between the partition walls 15. Was printed by letterpress printing. Printing was performed using an ink in which a polyvinyl carbazole derivative, which is a material of the interlayer layer 17, was dissolved in toluene to a concentration of 0.5%. At this time, an anilox roll 24 of 300 lines / inch and a water development type photosensitive resin plate 26 were used. The thickness of the interlayer layer 17 after printing and drying was 10 nm.

  Next, the substrate formed up to the interlayer layer 17 is disposed on the printing substrate 28 of the relief printing apparatus 200, and the organic light emitting layer 18 is formed in line with the line pattern on the pixel electrode 14 sandwiched between the partition walls 15. Printing was performed by letterpress printing. Printing was performed using an organic light-emitting ink in which a polyphenylene vinylene derivative as a material of the organic light-emitting layer 18 was dissolved in toluene so as to have a concentration of 1%. At this time, an anilox roll 24 of 150 lines / inch and a water developing type photosensitive resin plate 26 were used. The thickness of the organic light emitting layer 18 after printing and drying was 80 nm.

  Next, as the counter electrode 19, a calcium film was formed with a thickness of 20 nm using a metal mask by a vacuum deposition method, and an aluminum film was formed with a thickness of 150 nm using a metal mask.

  Next, as shown in FIG. 4, using the same metal mask, the aluminum deposition rate is set to change from 0.5 nm / sec to 0 nm / sec in 10 seconds, and the SiOx deposition rate is set to 0 nm in 10 seconds. The first protective layer 20 was a 5 nm mixed layer obtained by performing film formation at the same time and co-evaporating for 10 seconds. Next, only 150 nm of SiOx was deposited as the second protective layer 21 using the same metal mask.

  Next, as a sealing material, a sealing body 30 having a glass plate having a thickness of 0.3 mm so as to cover the entire organic EL element 1 and a resin layer applied to the entire surface of the glass plate is bonded, and the sealing material is bonded at about 90 ° C. The resin layer was thermally cured for 1 hour for sealing. The total thickness of the organic EL display device 100 was 1.0 mm. When the organic EL display device 100 thus obtained was driven, it was initially in a uniform and favorable light emission state without luminance unevenness and astigmatic areas.

The same procedure as in Example 1 was performed until the counter electrode 19 was formed. Next, as the counter electrode 19, a calcium film was formed to a thickness of 20 nm using a metal mask by a vacuum deposition method, and an aluminum film was formed to a thickness of 150 nm using a metal mask. Next, as shown in FIG. 5, using the same metal mask, the deposition rate of aluminum is set to change from 0.3 nm / sec to 0 nm / sec in 30 seconds, and the deposition rate of Al ₂ O ₃ is set to 30. The first protective layer 20 was a 9 nm mixed layer obtained by setting the film thickness so as to change from 0 nm / sec to 0.3 nm / sec in a second, simultaneously forming a film, and co-evaporating for 30 seconds. Next, a metal mask having an opening 1 mm larger than the opening of the metal mask used when vapor-depositing the first protective layer 20 is used so as to cover all the patterns of the organic EL element 1 and the first protective layer 20. As a second protective layer 21, only Al ₂ O ₃ was deposited to a thickness of 150 nm.

  Next, as a sealing material, a PET film having a thickness of 0.2 mm in which silicon nitride is formed on both sides so as to cover the entire organic EL element 1 and a resin layer applied to the entire surface of the PET film are provided. The sealing body 30 was bonded together, and the resin layer was thermally cured at about 90 ° C. for 1 hour for sealing. The total thickness of the organic EL display device 100 was 0.9 mm. When the organic EL display device 100 thus obtained was driven, it was initially in a uniform and favorable light emission state without luminance unevenness and astigmatic areas.

[Comparative Example 1]
Before the first protective layer 20 was formed, the same procedure as in Example 1 was used. Next, as shown in FIG. 6, a metal mask having an opening 1 mm larger than the opening of the metal mask used when depositing the counter electrode 19 so as to cover the entire pattern of the counter electrode 19 with SiOx as the protective layer 83. Then, a 200 nm film was formed at a deposition rate of 5 nm / sec by a vacuum deposition method.

  Next, as a sealing material, a sealing body 30 having a glass plate covering the entire organic EL element 1 and a resin layer applied to the entire surface of the glass plate is bonded, and the resin layer is formed at about 90 ° C. for 1 hour. Sealing was performed by thermosetting. The total thickness of the organic EL display device 100 was 1.0 mm. When the organic EL display device 100 thus obtained was driven, it was initially in a uniform and favorable light emission state without luminance unevenness and astigmatic areas.

[Comparative Example 2]
Before the sealing, the same procedure as in Comparative Example 1 was used. Next, a concave cap shape that covers the entire organic EL element 1 as a sealing material and a resin layer were applied to the cap-shaped peripheral portion. Next, a sealing body 30 in which a BaO-containing tape having a thickness of 0.2 mm is pasted as a moisture trap material 31 in the concave portion, and the organic EL element 1 is disposed so that the light emitting region of the organic EL element 1 is disposed inside the concave shape. The element 1 was bonded to the substrate 6 and the resin layer was thermally cured at about 90 ° C. for 1 hour for sealing.

  The concave cap-shaped glass was processed by chemical etching, and 0.3 mm was dug into a 0.7 mm thick glass plate to form a concave shape. The total thickness of the organic EL display device 100 was 1.4 mm. When the organic EL display device 100 thus obtained was driven, it was initially in a uniform and favorable light emission state without luminance unevenness and astigmatic areas.

  The organic EL display devices 100 of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were subjected to a constant temperature and humidity test. When an acceleration test was performed in an environment of 60 ° C. and 90%, no dark spots were observed even after 1000 hours in Example 1, Example 2, and Comparative Example 2, but 200 for the sample of Comparative Example 1 After a lapse of time, dark spots started to increase from the outside of the display area, and after 500 hours, dark spots were observed on the entire display area. The favorable panel of Example 1 and Example 2 was able to be obtained from the surface of both the total thickness and reliability of the organic EL display device 100.

It is a schematic sectional drawing which shows the organic electroluminescence display which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the relief printing apparatus which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the organic electroluminescence display which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the organic electroluminescence display which concerns on one Example of this invention. It is a schematic sectional drawing which shows the organic electroluminescence display which concerns on one Example of this invention. 6 is a schematic cross-sectional view showing an organic EL display device according to Comparative Example 1. FIG. 10 is a schematic cross-sectional view showing an organic EL display device according to Comparative Example 2. FIG. It is a schematic sectional drawing which shows the conventional organic EL display apparatus.

Explanation of symbols

1: Organic EL element 2: Organic medium layer 6: Substrate 7: Active layer 8: Gate insulating film 9: Gate electrode 10: Interlayer insulating film 11: Drain electrode 12: Scan line 13: Source electrode 14: Pixel electrode 15: Partition 16: Hole transport layer 17: Interlayer layer 18: Organic light emitting layer 19: Counter electrode 20: First protective layer 21: Second protective layer 22: Ink tank 23: Ink chamber 24: Anilox roll 25: Ink layer 26: Plate 27: Plate cylinder 28: Printed substrate 29: Flat bed 30: Sealing body 31: Trapping material 81: Organic medium layer 82: Counter electrode 83: Protective layer 84: Interface 85: Gas

Claims (10)

A substrate,
A pixel electrode formed on the substrate;
An organic medium layer formed on the pixel electrode;
A counter electrode formed on the organic medium layer;
A first protective layer formed on the counter electrode;
A second protective layer formed on the first protective layer,
The organic EL display panel, wherein the first protective layer is a mixed film of the counter electrode and the second protective layer.   The organic EL display panel according to claim 1, wherein the mixed film of the first protective layer has a gradient in the mixing ratio.   The organic EL display panel according to claim 1, wherein the first protective layer has a thickness of 5 nm or more.   The organic EL display panel according to claim 1, wherein the second protective layer is formed so as to cover an upper portion or all of the first protective layer. A sealing body having a sealing material having a plate-like member having a water vapor transmission rate of 10 ⁻⁶ g / m ² / day or less and a resin layer to which the sealing material is bonded is provided. Item 5. The organic EL display panel according to any one of Items 1 to 4. Prepare the board
Forming a plurality of pixel electrodes on the substrate;
Forming an organic medium layer on the plurality of pixel electrodes;
Forming a counter electrode on the organic medium layer;
Forming a first protective layer on the counter electrode;
Forming a second protective layer on the first protective layer;
The method of manufacturing an organic EL display panel, wherein the first protective layer is a mixed film of the counter electrode and the second protective layer.   7. The method of manufacturing an organic EL display panel according to claim 6, wherein the mixed film of the first protective layer has a gradient in the mixing ratio.   The method of manufacturing an organic EL display panel according to claim 6 or 7, wherein the thickness of the first protective layer is 5 nm or more.   8. The method of manufacturing an organic EL display panel according to claim 6, wherein the second protective layer is formed so as to cover an upper portion or all of the first protective layer. A sealing body having a sealing material having a plate-like member having a water vapor transmission rate of 10 ⁻⁶ g / m ² / day or less and a resin layer to which the sealing material is bonded is provided. Item 10. A method for producing an organic EL display panel according to any one of Items 6 to 9.

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