JP5678455B2 - Method for manufacturing organic EL element and method for manufacturing organic EL panel - Google Patents

Description

  The present invention relates to an organic EL element manufacturing method and an organic EL panel manufacturing method using the electroluminescence (hereinafter abbreviated as EL) phenomenon of an organic thin film.

An organic EL panel 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, and when a voltage is applied between the electrodes, the organic light emitting layer Holes and electrons are injected into the organic light emitting layer, and the holes and electrons recombine in the organic light emitting layer, whereby the organic light emitting layer emits light.
Furthermore, for the purpose of increasing luminous efficiency, a functional layer is also provided between at least one of the anode and the organic light emitting layer and between the organic light emitting layer and the cathode. Between the layer, at least one of a hole injection layer and a hole transport layer is provided as the functional layer, and between the organic light emitting layer and the cathode, an electron transport layer and an electron injection are provided as the functional layer. At least one of the layers is provided, and these are appropriately selected and provided.
Each layer provided as a functional layer between the anode and the organic light emitting layer or between the organic light emitting layer and the cathode is formed of an organic material or an inorganic material, and the organic material includes a low molecular material and a high molecular material. There is.

Examples of using low molecular weight materials include, for example, copper phthalocyanine (CuPc) for the hole injection layer and N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1 for the hole transport layer. , 1'-biphenyl-4,4'diamine (TPD), tris (8-quinolinol) aluminum (Alq3) for the organic light emitting layer, 2- (4-biphenylyl) -5- (4-tert-butyl for the electron transport layer -Phenyl) -1,3,4, -oxadizole (PBD), and those using LiF for the electron injection layer.
Each layer made of these low-molecular materials is generally about 0.1 to 200 nm in thickness, and is formed mainly by a vacuum evaporation method such as a resistance heating method or a dry method (dry process) in a vacuum such as a sputtering method. Yes.
In addition, there are many types of low molecular weight materials, and combinations thereof are expected to improve luminous efficiency, luminous luminance, lifetime, and the like.

  On the other hand, examples of the polymer material include a material in which a low-molecular light-emitting pigment is dissolved in a polymer such as polystyrene, polymethyl methacrylate, and polyvinyl carbazole in an organic light-emitting layer, and a polyphenylene vinylene derivative (hereinafter referred to as PPV). Abbreviated), polymer phosphors such as polyalkylfluorene derivatives (hereinafter abbreviated as PAF), and polymer phosphors such as rare earth metals.

These polymer materials are generally dissolved or dispersed in a solvent and formed into a film with a thickness of about 1 to 100 nm using a wet method such as coating or printing.
When using a wet method, it is possible to form a film in the atmosphere, compared to using a dry method in vacuum such as a vacuum deposition method, the equipment is inexpensive, and the size can be easily increased. There is an advantage that the film can be formed efficiently.
In addition, the organic thin film formed using a polymer material is less likely to crystallize and agglomerate, and further covers pinholes and foreign materials in other layers, thus preventing defects such as short circuits and dark spots. There are also advantages.

  On the other hand, as an inorganic material, an alkali metal element such as Li, Na, K, Rb, Ce, and Fr, an alkaline earth metal element such as Mg, Ca, Sr, and Ba, La, Ce, Lanthanoid elements such as Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, Lu, actinoid elements such as Th, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Al, Ga, In, Sn, Tl, Pb, and Bi Metal elements such as B, Si, Ge, As, Sb, Te and the like, as well as their alloys, inorganic compounds such as oxides, carbides, nitrides, borides, sulfides, halides, etc. It is used.

Many inorganic materials have higher adhesion and thermal stability than organic materials, and are expected to suppress false light emission due to leakage current, reduce non-light emitting areas called dark spots, and improve light emission characteristics and lifetime. The In addition, inorganic materials play an important role in terms of cost reduction when considering application to large displays and mass-produced products that are relatively inexpensive compared to organic materials.
A configuration in which an inorganic hole injection layer using an inorganic material is provided between an organic light emitting layer and an anode that is a hole injection electrode using this feature is known (for example, see Patent Document 1 to Patent Document 4). ).

Moreover, the structure which provides the inorganic electron injection layer using an inorganic material between the organic light emitting layer and the cathode which is an electron injection electrode is known (for example, patent document 2, patent document 3, patent document 5, patent document 6). reference).
As an inorganic material used for the electron injection layer and the electron transport layer, it has been proposed to select a simple substance or a compound of an alkali metal or alkaline earth metal having a small work function. It is known that by providing these materials, the barrier to electrons when the organic light emitting layer is viewed from the cathode electrode is lowered, and the electron injection efficiency is improved.

  In order to remove undesirable impurities from the atmosphere that evaporates during the deposition of the multi-element thin film phosphor composition, for the purpose of increasing the emission luminance of the phosphor material used in the organic EL panel, Immediately before and during deposition of the phosphor film composition, by evaporating one or more getter species in the deposition chamber, impurities in the atmosphere are included in the resulting phosphor film. A method for avoiding this has also been proposed (see, for example, Patent Document 7).

Japanese Patent Laid-Open No. 11-307259 Japanese Patent Laid-Open No. 5-41285 JP 2000-68065 A JP 2006-155978 A JP 2002-367784 A Japanese Patent Application No. 11-191490 Special table 2007-529623 gazette

As described above, when an inorganic material is used as the electron injection layer and the electron transport layer, an electron injection is performed by depositing a simple substance or a compound of alkali metal or alkaline earth metal on the organic light emitting layer in the chamber. Forming a layer and an electron transport layer.
However, when the alkali metal or alkaline earth metal simple substance or compound is deposited on the organic light emitting layer in the chamber, if there is a degradation factor such as water or oxygen in the chamber, the degradation factor is alkalinized. It reacts with a simple substance or compound of a metal or alkaline earth metal, and a reaction film with a deterioration factor is formed, so that the function as an electron injection layer and an electron transport layer cannot be sufficiently exhibited. There is a problem that it leads to deterioration of characteristics such as light emission efficiency, light emission luminance, and life of the organic EL panel.
Therefore, the present invention has been made paying attention to the above-mentioned conventional unsolved problems, and it is possible to improve the light emission efficiency and light emission luminance of the organic EL panel and to improve the lifetime of the organic EL element. It aims at providing the manufacturing method and the manufacturing method of an organic electroluminescent panel.

In order to achieve the above object, an organic EL element manufacturing method according to claim 1 is formed by laminating an organic light emitting layer and a second electrode layer in this order on a substrate on which a first electrode layer is formed. And a method of manufacturing an organic EL element, wherein the organic light emitting layer is laminated on the first electrode layer, and then the second electrode layer is deposited on the organic light emitting layer in a deposition chamber. The substrate is horizontally disposed in the central upper portion of the deposition chamber with the first electrode layer side down, and the substrate is positioned at a position separated from the substrate by a deposition plate in the deposition chamber. The above-described getter material is disposed, and the deposition plate is erected such that the upper end portion thereof is located above the lower surface of the substrate and the whole is located closer to the inner wall side of the deposition chamber than the entire substrate. The deposition plate of the deposition chamber is arranged by Than a delimited area in which the substrate is placed has the getter material as towards the placement area is narrowed, the second electrode layer when deposited within the deposition chamber, performing the deposition The getter material is evaporated in the deposition chamber before and / or during deposition so as not to adhere to the substrate.

Further, in the method for manufacturing an organic EL element according to claim 2, the second electrode layer is formed by a laminated structure of at least one of an electron transport layer and an electron injection layer and a cathode layer, and the organic light emitting layer And at least one of the electron transport layer and the electron injection layer is arranged between the cathode layer and the cathode layer.
Further, in the method for manufacturing an organic EL element according to claim 3, the getter material is any one of an alkali metal, an alkaline earth metal, and a transition metal, a compound, or an alloy system. Yes.
The organic EL device manufacturing method according to claim 4 is characterized in that the organic light emitting layer is formed by a relief printing method.

Furthermore, in the method for manufacturing an organic EL element according to claim 5, the first electrode layer is formed by a laminated structure of at least one of a hole transport layer and a hole injection layer and an anode layer, At least one of the hole transport layer and the hole injection layer is disposed between the light emitting layer and the anode layer.
Moreover, the manufacturing method of the organic EL panel concerning Claim 6 of this invention is a manufacturing method of the organic EL panel provided with the organic EL element as a display element, Comprising: The said organic EL element is Claim 1-5. It is produced using the manufacturing method of the organic EL element of any one of these.

  According to the present invention, the organic light emitting layer is deposited on the substrate on which the first electrode layer is formed. Before forming the second electrode layer on the organic light emitting layer in the chamber, the organic light emitting layer is deposited. And / or evaporating one or more getter materials so that they do not deposit on the substrate during deposition, thereby removing or minimizing degradation factors present in the chamber and affecting the second electrode layer. By forming a good film, high luminous efficiency, high luminance, and long life can be achieved.

It is a schematic sectional drawing of the organic electroluminescent panel concerning embodiment of this invention. It is a schematic sectional drawing of the board | substrate with TFT concerning embodiment of this invention. It is the schematic of the relief printing apparatus concerning embodiment of this invention. It is the schematic of the vacuum chamber concerning embodiment of this invention.

Embodiments of the present invention will be described below.
Here, a case where the present invention is applied to an organic electroluminescence panel (organic EL panel) of an active matrix driving type organic EL display device will be described. However, the present invention is not limited to the active matrix driving type organic EL display device, and can also be applied to a passive matrix driving type organic EL display device.

  As shown in FIG. 1, the organic EL panel is formed on a TFT substrate 101 having at least a thin film transistor TFT (not shown) and the thin film transistor TFT, the anode layer 105, and the anode layer 105 provided for each pixel. A first electrode layer 102 (anode side) composed of the positive hole transport layer (or hole injection layer) 106, an insulating layer 103 serving as a partition formed so as to cover an end of the first electrode layer 102, An organic light emitting layer 104 formed on the first electrode layer 102, an electron injection layer (or electron transport layer) 108 formed on the organic light emitting layer 104, and a cathode formed on the electron injection layer 108 A second electrode layer 107 (cathode side) including the layer 109. Note that only the hole transport layer 106 (or hole injection layer) is provided here, but it is also possible to provide both the hole transport layer 106 and the hole injection layer. Similarly, only the electron injection layer 108 (or the electron transport layer) is provided, but it is also possible to provide both the electron injection layer 108 and the electron transport layer.

  As shown in FIG. 2, on the upper surface of the TFT substrate (back plane) 101 applied to an active matrix drive type organic EL display device (hereinafter also referred to as an organic EL display device), a thin film transistor TFT and an organic EL display device are provided. An anode layer 201 (corresponding to the anode layer 105 in FIG. 1) is provided, and the source electrode 206 of the thin film transistor TFT and the anode layer 201 are electrically connected.

  The thin film transistor TFT and the organic EL panel formed thereon are supported by the support 202. Any material can be used for the support 202 as long as it 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-proof treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to prevent moisture from entering the organic EL display device. Preferably there is. In particular, in order to prevent moisture from entering the organic light emitting layer, it is preferable to reduce the moisture content and gas permeability coefficient of the support 202.
As the thin film transistor TFT provided on the support 202, a known thin film transistor can be used. Specifically, a thin film transistor including an active layer 203 in which a source / drain region and a channel region are formed, a gate insulating film 204, and a gate electrode 205 is mainly mentioned. 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 203 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 203 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 using 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 Game The insulating film 204 is formed, 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 a gate insulating film can be used. For example, SiO ₂ formed by PECVD, LPCVD, or the like; SiO ₂ obtained by thermally oxidizing a polysilicon film Etc. can be used.
As the gate electrode 205, those normally used as a gate electrode can be used. For example, metals such as aluminum and copper; refractory metals such as titanium, tantalum and tungsten; polysilicon; silicide of refractory metals; Polycide; and the like.

The thin film transistor TFT may have a single gate structure, a double gate structure, or a multi-gate structure having three or more gate electrodes 205. Moreover, you may have a LDD structure and an offset structure. Further, two or more thin film transistors may be arranged in one pixel.
In the organic EL display device of the present invention, the thin film transistor TFT needs to be connected so as to function as a switching element of the organic EL panel, and the source electrode 206 of the thin film transistor TFT and the pixel electrode (anode layer 201) of the organic EL panel And are electrically connected.
In FIG. 2, reference numeral 207 denotes a drain electrode of the thin film transistor TFT, 208 denotes a scanning line, 209 denotes an interlayer insulating film, and 210 denotes an insulating layer (corresponding to the insulating layer 103 in FIG. 1) serving as a partition partitioning pixels.

Next, a method for forming the anode layer 105 in FIG. 1 will be described.
An anode layer 105 is formed on the TFT substrate 101 and patterned according to the pixel to be formed. The patterned anode layer 105 is partitioned by the insulating layer 103 as will be described later, and becomes the anode layer 105 corresponding to each pixel.
As the material of the anode layer 105, 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.

When the anode layer 105 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 anode layer 105, a metal material such as copper or aluminum may be provided as an auxiliary electrode.
As a method for forming the anode layer 105, depending on the material of the anode layer 105, 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, a sputtering method, or gravure printing is used. For example, a wet film forming method such as a screen printing method or the like can be used.

As a patterning method for the anode layer 105, 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 or a film forming method.
Note that in the case where a substrate on which a thin film transistor TFT is formed is used as the TFT substrate 101, the TFT substrate 101 is formed so as to be conductive corresponding to the lower pixel.

  The insulating layer 103 serving as a partition is formed so as to partition a light emitting region corresponding to a pixel. As shown in FIG. 1, the anode layer 105 is preferably formed so as to cover the end portion. If the end portion of the anode layer 105 is exposed, an electric field concentrates on the end portion, and there is a possibility that performance deterioration such as a short circuit of the element may occur. However, the insulating layer 103 as a partition wall is the end of the anode layer 105 that is an electrode. This can be suppressed by covering the part.

In general, an active matrix drive type display device has an anode layer 105 formed for each pixel, and each pixel occupies as wide an area as possible. Therefore, the most preferable shape of the insulating layer 103 as a partition wall formed so as to cover the end portion of the anode layer 105 to be the pixel electrode is basically a lattice shape that divides the pixel electrode, that is, the anode layer 105 by the shortest distance.
As a method of forming the insulating layer 103 as a partition wall, a method of forming an inorganic film uniformly on the TFT substrate 101, masking with a resist, and then performing dry etching, or photosensitive on the TFT substrate 101, as in the past. There is a method of laminating a resin and forming a predetermined pattern by a photolithography method. Adding water repellent as necessary, or imparting liquid repellency to the ink for forming the organic light emitting layer in the subsequent step of generating the organic light emitting layer by irradiating with plasma or UV. You can also.

  A preferable height of the insulating layer 103 as a partition wall is 0.1 μm to 10 μm, and more preferably about 0.5 μm to 2 μm. If the insulating layer 103 is too high, the formation and sealing of the second electrode layer 107 is hindered, and if it is too low, the end of the anode layer 105 (201) as the pixel electrode cannot be covered, or the pixel adjacent to the organic light emitting layer is formed. This is because they are short-circuited or mixed colors.

Next, a method for forming the hole transport layer 106 will be described.
After the partition wall 103 is formed, the hole transport layer 106 is formed. Examples of the hole transporting material that forms the hole transporting layer 106 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 letterpress printing methods.

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 ≧ 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 , MnO _2, etc. are used. It is formed by vapor deposition. However, the material is not limited to these.

  After forming the hole transport layer 106, an interlayer layer (not shown) is formed at a position immediately above the hole transport layer 106 facing the anode layer 105. Examples of materials used for the interlayer layer include 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, and triphenyldiamine derivatives. . These materials are dissolved or dispersed in a solvent and formed by a wet method such as various coating methods using a spin coater or the like, a known printing method such as a relief printing method, a flexographic printing method, and the like.

After forming the interlayer layer, the organic light emitting layer 104 is formed. The organic light emitting layer 104 is a layer that emits light by passing a current.
Examples of the organic light-emitting material forming the organic light-emitting layer 104 include coumarin-based, perylene-based, pyran-based, anthrone-based, porphyrene-based, quinacridone-based, N, N′-dialkyl-substituted quinacridone-based, naphthalimide-based, N, N′-. Diaryl-substituted pyrrolopyrrole, iridium complex, and other luminescent dyes dispersed in polymers such as polystyrene, polymethyl methacrylate, polyvinylcarbazole, and polyarylene, polyarylene vinylene, and polyfluorene polymers Materials. These materials are also formed using a wet method similar to the interlayer layer.

These organic light emitting materials are dissolved or stably dispersed in a solvent to obtain 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. 3 shows an example of a relief printing apparatus using a relief printing method as an organic light emitting ink coating method.

The relief printing method is suitable for the production of an organic EL panel from the viewpoint that the viscosity characteristic of the coating liquid can be printed without damaging the substrate and the utilization efficiency of the coating liquid material is good.
A relief printing apparatus using the relief printing method shown in FIG. 3 includes a printing copper on which an ink tank 301, an ink chamber 302, an anilox roll 303, and a printing plate 305 made of a relief printing plate having an image line portion formed in a convex shape are mounted. 306. The ink tank 301 contains the 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 rotatably supported in contact with the ink supply unit of the ink chamber 301.

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 by the ink chamber 302 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.
On the plate 305, a convex portion serving as an image line portion is formed in advance according to the pattern of the anode layer 105 as a pixel electrode formed on the TFT substrate 101 in advance.

  On the other hand, on the flat table 308, the TFT substrate 101 on which the anode layer 105, the interlayer layer, and the hole transport layer 106 are formed is placed as a printing substrate 307. After the alignment of the printing substrate 307 and the plate 305 is performed, the ink on the top surface of the convex portion of the plate 305 is printed on the printing substrate 307, so that the organic light emitting ink is covered. The organic light emitting layer is formed on the substrate to be printed 307 by being transferred to the printed substrate 307 and passing through a drying process as necessary. Thus, the organic light emitting layer 104 made of organic light emitting ink is formed on the hole transport layer 106 between the insulating layers 103 of the TFT substrate 101 which is the substrate to be printed 307.

Next, a method for forming the second electrode layer 107 including the electron injection layer (or electron transport layer) 108 and the cathode layer 109 shown in FIG. 1 will be described.
An inorganic material is used for the electron injection layer (or electron transport layer) 108, and an alkali metal or alkaline earth metal simple substance or compound or alloy system having a low work function that can achieve both electron injection efficiency and stability. This is selected, and this is formed to several nm on the entire surface including the organic light emitting layer. Further, for the cathode layer 109, an inorganic material having a low work function is made of a single metal such as Mg, Al, Yb or the like, and in order to achieve both electron injection efficiency and stability, Li, Mg, Ca, An alloy system of one or more metals such as Sr, La, Ce, Er, Eu, Sc, Y, Yb and a stable metal element such as Ag, Al, or Cu is used. Specifically, an alloy system such as MgAg, AlLi, or CuLi can be used.

As a method for forming the second electrode layer 107, 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 in a chamber depending on the material.
Here, in the method of depositing the cathode layer material and the electron injection layer material constituting the second electrode layer 107 in the chamber according to the present invention, the reaction with the deterioration factor such as water and oxygen existing in the chamber is performed. Including minimization and removal steps. The step is a method of evaporating or vaporizing a getter material capable of removing the deterioration factor immediately before or during the deposition of the cathode layer material by an evaporation method or a sputtering method. Therefore, a good film is formed by not reacting with the deterioration factor in the cathode layer material to be deposited or by minimizing it.

The step of evaporating or vaporizing the getter material is preferably performed after the substrate is introduced into the chamber until the cathode layer is deposited, or during the deposition of the cathode layer, and may be performed continuously. . Further, it may be performed before the substrate is introduced into the chamber.
As the getter material, an alkali metal or alkaline earth metal, a transition metal such as titanium or molybdenum, a compound, or an alloy type material having a getter action is selected. Degradation factors include, but are not limited to, oxygen, water, carbon monoxide, carbon dioxide, and hydrogen-containing molecules. Therefore, as a deterioration factor, a getter material having a getter action with respect to the deterioration factor to be removed is used.

As an apparatus for depositing the second electrode layer 107, an example of a vapor deposition chamber is shown in FIG.
As an evaporation source for resistance heating for forming the electron injection material (electron transport material when forming the electron transport layer) and the cathode layer 109 for forming the electron injection layer 108 in the vacuum chamber of the vapor deposition chamber Two electrode deposition evaporation sources 401 were installed. A substrate holder 402 was provided at a position above the two electrode deposition evaporation sources 401. The TFT substrate 101 formed up to the organic light emitting layer 104 is set on the substrate holder portion 402. Further, one or more getter material evaporation sources 404 for evaporating the getter material are provided around the electrode deposition evaporation source 401. However, an adhesion preventing plate 405 is disposed between the getter material evaporation source 404 and the TFT substrate 101 so that the evaporated getter material does not accumulate on the TFT substrate 101. Note that although an apparatus using the resistance heating vapor deposition method is described here, an ion plating method or a sputtering method can also be used to evaporate the second electrode material or the getter material.
A partial pressure measuring device 406 is attached to the vacuum chamber in order to measure the partial pressure of oxygen, water, etc. in the chamber. As the partial pressure measuring device 406, a quadrupole mass spectrometer (Q-MASS) or a partial pressure vacuum gauge is used.

Next, the sealing body will be described.
As an organic EL display device, it is possible to emit light by sandwiching a light emitting material between electrodes and passing an electric current. However, since an organic light emitting material is easily deteriorated by moisture or oxygen in the atmosphere, it 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 5-500 micrometers is 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 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.

  In the organic EL panel generated by the above procedure, the organic light emitting layer 104 is deposited on the TFT substrate 101 on which the first electrode layer 102 is formed, and the second electrode layer 107 is formed on the organic light emitting layer 104 in the chamber. When forming the film, one or two or more getter materials are evaporated so as not to be deposited on the substrate immediately before and during the deposition. Therefore, the deterioration factor that exists in the chamber and affects the second electrode layer 107 can be removed or minimized, and a favorable layer can be formed as the second electrode layer 107. Accordingly, it is possible to avoid a decrease in light emission efficiency and luminance or a reduction in lifetime due to the second electrode layer 107 containing impurities, and to realize high light emission efficiency, high luminance, and long life. it can.

Examples of the present invention and comparative examples are shown below.
(Example)
As the TFT substrate 101 shown in FIG. 1, an active matrix substrate provided with a thin film transistor functioning as a switching element provided on a support 202 was used. The substrate size was 200 mm × 200 mm, and a 5-inch diagonal display was installed in the center of the substrate. An anode layer 105 was formed on the TFT substrate 101.
First, an ITO film is formed to a thickness of 100 nm using a sputtering method, and the ITO film is patterned to have a width of 25 μm by photolithography and etching with an acid solution to form an anode layer (pixel electrode). 105 was formed. The number of pixels was 320 × 240.

Next, an insulating layer 103 serving as a partition is formed on the TFT substrate 101 on which the anode layer 105 is formed.
That is, first, an acrylic photoresist material was spin coated on the entire surface. At this time, the spin coating conditions were rotated at 150 rpm for 5 seconds and then rotated at 500 rpm for 20 seconds to obtain a coating film having a height of 1.5 μm. Thereafter, a line-shaped insulating layer 103 was formed between the electrodes by photolithography.

Next, molybdenum oxide (MoOx) having a thickness of 20 nm was stacked over the anode layer 105 and the insulating layer 103 as the hole transport layer 106 by a vacuum evaporation method. The distance between the electrode deposition evaporation source 401 and the TFT substrate 101 was 300 mm, and the angle between the vapor deposition source direction and the normal direction of the substrate surface from the center of the substrate surface was set to 0 degrees.
Next, using an ink obtained by dissolving polyvinyl carbazole derivative, which is an interlayer material, in toluene so as to have a concentration of 0.5%, the TFT substrate 101 is placed on a flat plate 308 as a printing substrate 307 of the relief printing apparatus of FIG. The interlayer layer was printed by a relief printing method in accordance with the line pattern just above the anode layer 105 sandwiched between the insulating layers 103 as the partition walls. The film thickness of the interlayer layer after printing and drying was 10 nm.

  Next, an organic light emitting ink in which a polyphenylene pinylene derivative, which is an organic light emitting material, is dissolved in toluene to a concentration of 1% is used, and the TFT substrate 101 after forming the interlayer layer is used as a printing substrate 307 in a relief printing apparatus. Setting was performed, and printing was performed by a relief printing method with a target film thickness of 80 nm in accordance with the line pattern of the anode layer 105 sandwiched between the insulating layers 103 as partition walls.

Next, the second electrode layer 107 is deposited by an evaporation chamber using the vacuum evaporation method shown in FIG. Selection of the material used Ba as an electron injection material, Al as a cathode material, and Mo as a getter material.
One electrode deposition evaporation source 401 is operated, and Ba, which is an electron injection material, is deposited with a film thickness of 4 nm using a metal mask. Then, the other electrode deposition evaporation source 401 is operated, and the cathode material Al is Deposition was performed with a thickness of 150 nm using a metal mask. Note that Li as the getter material is evaporated by the getter material evaporation source 404 immediately before and during the deposition of the second electrode layer 107, and the getter material removes deterioration factors such as water and oxygen existing in the chamber. Or reduced.
As a result, a high vacuum environment with a moisture pressure of 1.0 × 10 ⁻⁶ and an oxygen partial pressure of 6 × 10 ⁻⁷ can be realized, and the manufacturing environment of the electron injection layer 108 and the cathode layer 109 can be improved. As a result, a good film could be formed as the second electrode layer 107.

Next, a cap type sealing glass and an adhesive are placed so as to cover the light emitting region, and the adhesive is thermally cured at about 90 ° C. for 1 hour, and hermetically sealed to produce an active matrix driving type organic EL panel. did.
The active matrix driving type organic EL panel manufactured by using such a manufacturing method has a good first effect because the reaction between the second electrode layer 107 and the deterioration factor that affects the characteristics of the second electrode layer 107 is suppressed. The two-electrode layer 107 can be formed, the electron injection efficiency is improved, the luminance is 600 cd / m 2 when the applied voltage is 7 V, and the luminance half time at the initial luminance of 500 cd / m 2 is 280 hours. Luminous efficiency, high luminance, and long life were obtained.

(Comparative Example 1)
As a comparative example with respect to the example, an organic EL panel was produced by a procedure different from the example. Specifically, the getter material was not evaporated immediately before and during the deposition of the second electrode layer 107, and the organic EL panel was fabricated under the same conditions as in the above examples for the other steps.
As a result, the deterioration factor in the vapor deposition chamber cannot be removed, and the second electrode layer is in an environment with a low degree of vacuum such as a moisture pressure of 1.0 × 10 ⁻⁴ and an oxygen partial pressure of 9 × 10 ^−5. Was made.
The selected material and film thickness were the same as in the example. Other processes were the same as those in the example.

Then, an organic EL panel was manufactured using the TFT substrate 101 on which the second electrode layer 107 deteriorated by reacting with oxygen, water, etc. existing in the vapor deposition chamber was formed.
The active matrix driving type organic EL panel of the comparative example manufactured by such a manufacturing method has an electron injection efficiency worse than that of the example, and the applied voltage is 7 V, the luminance is 200 cd / m2, and the initial luminance is 500 cd / m2. The luminance half-life at 90 was 90 hours, and the luminous efficiency and lifetime were reduced.

As described above, by evaporating the getter material immediately before and during the deposition of the second electrode layer 107, a favorable second electrode layer 107 can be formed, and an organic material with high emission efficiency, high emission luminance, and long life can be obtained. An EL panel could be obtained.
In the above embodiment, the case where the present invention is applied to an organic EL panel of an organic EL display device has been described. However, the present invention is not limited thereto, and can be applied to, for example, a light emitting panel for illumination. It is.

101 TFT substrate 102 First electrode layer 103, 210 Insulating layer 104 Organic light emitting layer 105, 201 Anode layer 106 Hole transport layer 107 Second electrode layer 108 Electron injection layer (or electron transport layer)
109 Cathode layer 202 Support 203 Active layer 204 Gate insulating film 205 Gate electrode 206 Source electrode 207 Drain electrode 208 Scan line 301 Ink tank 302 Ink chamber 303 Anilox roll 305 Plate 306 Plate cylinder 307 Printed substrate 401 Electrode deposition evaporation source 402 Substrate holder 404 Evaporation source 405 for getter material Adhering plate 406 Partial pressure measuring device

Claims (6)

An organic light emitting layer and a second electrode layer are laminated in this order on the substrate on which the first electrode layer is formed, and after the organic light emitting layer is laminated on the first electrode layer, the second A method of manufacturing an organic EL element, wherein an electrode layer is deposited on the organic light emitting layer in a deposition chamber,
The substrate is horizontally disposed in the central upper part in the deposition chamber with the first electrode layer side down,
Placing one or more getter materials in the deposition chamber at a position separated from the substrate by a deposition plate;
The deposition plate is disposed in a state in which the upper end portion is positioned above the lower surface of the substrate and the whole is positioned so as to be positioned closer to the inner wall side of the deposition chamber than the entire substrate. The region in which the getter material is disposed is narrower than the region in which the substrate, which is separated by the deposition plate, is disposed in the chamber,
When the second electrode layer is deposited in the deposition chamber, the getter material is evaporated so as not to adhere to the substrate in the deposition chamber before and / or during the deposition. A method for manufacturing an organic EL element.   The second electrode layer is formed of a stacked structure of at least one of an electron transport layer and an electron injection layer and a cathode layer, and the electron transport layer and the electron are interposed between the organic light emitting layer and the cathode layer. 2. The method of manufacturing an organic EL element according to claim 1, wherein at least one of the injection layers is disposed.   3. The organic EL device manufacturing method according to claim 1, wherein the getter material is any one of an alkali metal, an alkaline earth metal, and a transition metal, a compound, or an alloy. Method.   The method for producing an organic EL element according to any one of claims 1 to 3, wherein the organic light emitting layer is formed by a relief printing method.   The first electrode layer is formed by a laminated structure of at least one of a hole transport layer and a hole injection layer and an anode layer, and the hole transport is between the organic light emitting layer and the anode layer. 5. The method of manufacturing an organic EL element according to claim 1, wherein at least one of a layer and a hole injection layer is disposed. A method for producing an organic EL panel including an organic EL element as a display element,
The method for producing an organic EL panel, wherein the organic EL element is produced using the method for producing an organic EL element according to any one of claims 1 to 5.

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