JP2013069615A - Organic el display and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL display in which extraneous materials can be removed by laser repair method, even for an organic EL element where a protective film covers a cathod.SOLUTION: An organic EL element substrate consisting of a first patterned electrode on one surface of a first substrate, a barrier covering the peripheral end of the first electrode, an organic light-emitting medium layer provided on the first electrode in the barrier, and a second electrode provided on the organic light-emitting medium layer at a position facing the first electrode, and a counter substrate on which a sheet-like adhesive layer formed entirely on one surface of a second substrate, and a protective layer formed in a region on the inside thereof are laminated sequentially are stuck on one sides thereof thus obtaining an organic EL display, where (a) a gap layer is formed between the second electrode and the protective layer, and (b) the organic EL element substrate and the counter substrate are bonded via a sheet-like adhesive layer interposed therebetween. A manufacturing method of the organic EL display is also provided.

Description

  The present invention relates to an organic EL display and a manufacturing method thereof, and more particularly to an organic EL display capable of removing adhesion of foreign matters generated in forming an organic EL layer and a cathode by laser repair.

  In recent years, with the diversification of information equipment, there has been an increasing need for flat display elements that consume less power than commonly used CRTs (cathode ray tubes). As one of such flat display elements, organic electroluminescence (hereinafter abbreviated as “organic EL”) elements having features such as high efficiency, thinness, light weight, and low viewing angle dependence have been attracting attention. The development of the existing display is underway.

  An organic EL element is formed on a substrate provided with a thin film transistor (TFT), an organic layer such as a first electrode (anode), a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a second electrode ( A cathode in which cathodes are stacked in order is known. When a potential difference is applied between the anode and the cathode, and a drive current is passed through the organic EL element, holes injected from the anode and electrons injected from the cathode are recombined inside the light emitting layer to form a light emitting layer. Excitons are generated by exciting organic molecules. Light is emitted from the light emitting layer in the process of radiation deactivation of the excitons, and the light is emitted from the transparent anode through the transparent insulating substrate to emit light.

  The organic EL layer and the cathode are formed by, for example, a vacuum evaporation method using a metal mask. There is a problem that foreign matters adhere to the formation region of the organic EL element in this vapor deposition process. Due to this adhesion, the anode and the cathode are short-circuited to eliminate the potential difference. As a result, the drive current does not flow through the organic EL element, and the pixel does not emit light. Therefore, as in Patent Document 1, a laser beam having a predetermined wavelength (for example, 1056 nm) is irradiated on the foreign matter, and the foreign matter is burned off and blown off to emit light (hereinafter referred to as laser repair).

  However, in the structure having a protective layer on the cathode as in Patent Documents 2 and 3 (see FIG. 4), since the protective layer covers the cathode, foreign matter is hardly scattered and laser repair is difficult. If the laser intensity (energy) is increased in order to scatter foreign matter, the foreign matter can penetrate the protective layer and scatter, but the barrier property of the protective layer is eventually lost, and moisture penetrates from this through hole. Display defects called dark spots (non-light emitting points) are enlarged. Further, when the laser intensity is increased, the organic EL layer around the foreign matter is also deteriorated, and the area of the dark spot is increased from the beginning.

JP 2000-195567 A JP 2005-347204 A JP 2007-184251 A

  The present invention has been made in view of the above problems, and even with an organic EL element having a structure in which a protective layer covers a cathode, laser repair can be performed as removal of the foreign matter, and luminance with the lapse of driving time. An object of the present invention is to provide an organic EL display capable of suppressing the deterioration phenomenon of the display, such as a decrease in brightness and an expansion of dark spots.

According to a first aspect of the present invention, there is provided a first electrode provided in a pattern on one surface of a first substrate, a partition covering a peripheral edge of the first electrode, and a first electrode in the partition. An organic light emitting medium layer provided on one electrode, an organic EL element substrate comprising a second electrode provided on the organic light emitting medium layer at a position facing the first electrode, and an entire surface of one surface of the second substrate It is an organic EL display in which a sheet-like adhesive layer and a counter substrate formed by sequentially laminating a protective layer in an inner region of the sheet-like adhesive layer are bonded to one surface side,
(A) a void layer is formed between the second electrode and the protective layer;
(B) An organic EL display in which an organic EL element substrate and a counter substrate are bonded via a sheet-like adhesive layer. That is, by forming a gap layer between the second electrode and the protective layer, when repairing a pixel that has been short-circuited due to a foreign matter generated during the formation of the organic EL element substrate, the space on the second electrode is a space. Since it is covered with a protective layer, it can be repaired easily and with low energy. Moreover, since the edge part of a sheet-like adhesive bond has adhere | attached with the organic EL element substrate, the moisture-permeable component from the outside can be suppressed.

  In the invention according to claim 2 of the present invention, the counter substrate includes a second adhesive layer on one whole surface of the second substrate, the sheet-like adhesive layer on an inner region, and The organic EL display according to claim 1, wherein the protective layer is sequentially laminated in an inner region. That is, since the second adhesive layer is formed so as to cover the sheet-like adhesive layer, moisture-permeable components from the outside can be further suppressed.

  In the invention according to claim 3 of the present invention, the counter substrate includes the second adhesive layer on one whole surface of the second substrate, a second protective layer in an inner region, and 3. The organic EL display according to claim 1, wherein the sheet-like adhesive layer is laminated in an inner region, and the protective layer is laminated in an inner region. That is, the second adhesive layer is formed so as to cover the sheet-like adhesive layer, and further, the second protective layer is formed in the inner region, so that moisture permeation components from the outside can be at a very high level. Can be suppressed.

  According to a fourth aspect of the present invention, there is provided an organic EL element substrate forming step comprising a step of forming a first electrode, a step of forming a partition, and a step of forming an organic light emitting medium layer, and at least a sheet 2. The method according to claim 1, further comprising a step of forming a counter substrate comprising a step of forming an adhesive layer, a step of forming a protective layer, and a step of bonding the organic EL element substrate and the counter substrate. It is a manufacturing method of the organic EL display in any one of -3.

  In the present invention, since a void layer (space) is formed between the second electrode partitioned by the partition and the protective layer, the pixel is short-circuited due to a foreign matter generated when the organic EL element substrate is formed. When the laser is repaired, since the second electrode is covered with a protective layer through a space, the repair can be easily performed with low energy. Therefore, the dark spot generated by laser repair can be suppressed to the minimum necessary size. In addition, since it is possible to repair without damaging the protective layer, moisture does not enter from the protective layer and the dark spot does not expand. Moreover, since the protective layer is formed on the sheet-like adhesive layer side, the EL element is not damaged by the formation of the protective layer. The edge of the sheet-like adhesive layer is bonded to the organic EL element substrate, and further, a second adhesive layer, a second protective layer, and a second adhesive layer are provided so as to cover the sheet-like adhesive layer. The moisture-permeable component from the outside can be suppressed. Therefore, it is possible to suppress the expansion of dark spots generated by laser repair.

ADVANTAGE OF THE INVENTION According to this invention, even if it performs laser repair, the organic EL display which can suppress the deterioration phenomenon of a display, such as the fall of the brightness | luminance accompanying progress of drive time and the expansion of a dark spot, can be provided.

It is a cross-sectional schematic diagram which shows the organic electroluminescent display which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram which shows the organic electroluminescent display which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram which shows the organic electroluminescent display which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram which shows the organic electroluminescent display which concerns on one Embodiment of a prior art.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. Note that the drawings referred to in the following description of the embodiments are for explaining the configuration of the present invention, and the size, thickness, dimensions, and the like of each part shown in the drawings are different from the actual ones. The present invention is not limited to these.

  The organic EL display of the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view of an organic EL display according to an embodiment of the present invention, in which a substrate 1, a thin film transistor (TFT) 2, a planarizing film layer 3, a first electrode 4, a partition wall 5, an organic light emitting medium layer 6, A second electrode 7, a sealing substrate 10, a sheet-like adhesive layer 11, and a protective layer 12 are included.

  FIG. 2 is a cross-sectional view of an organic EL display according to an embodiment of the present invention, which includes a second adhesive layer 13 in addition to the substrate shown in FIG.

  FIG. 3 is a cross-sectional view of an organic EL display according to an embodiment of the present invention, and includes a second protective layer 14 in addition to the substrate shown in FIG.

  As shown in FIGS. 1 to 3, the feature of the present invention is that a gap layer 20 is provided between the protective layer 12 and the second electrode 7. Repair is possible. That is, foreign matters existing in the organic light emitting medium layer 6 by laser repair can be scattered in the gap layer without damaging the protective layer 12 due to low energy.

  In the manufacturing process of the organic EL display of the present invention, a thin film transistor (TFT) 2 and a planarizing film layer 3 are formed on a substrate 1, and a first electrode 4 and a partition wall 5 are formed thereon. Next, the organic light emitting medium layer 6 and the second electrode 7 are sequentially formed on the first electrode 4 in the section surrounded by the partition walls 5. The height of the partition wall 5 needs to be higher than the uppermost surface of the second electrode 7.

  On the other hand, at least a sheet-like adhesive layer 11 and a protective layer 12 are sequentially formed on the sealing substrate 10. Thereafter, the surface on the second electrode 7 side of the uppermost layer formed on the former substrate 1 and the surface on the protective layer 12 side on the latter sealing substrate 10 are bonded together to obtain an organic EL display. By making the height of the partition wall 5 higher than the uppermost surface of the second electrode 7 as described above, the void layer 20 that is a feature of the present invention can be formed at the time of bonding.

  Hereinafter, the material of each part constituting the organic EL display will be described.

(1) Substrate 1
Any substrate can be used as the substrate 1 as long as it has insulating properties and excellent 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 silicone resin or polyester resin, metal foil such as aluminum or stainless steel, sheet, plate, aluminum on the plastic film or sheet It can be used um, 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 a base material according to which surface light extraction is performed from. The substrate made of these materials may have been subjected to moisture-proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to avoid moisture intrusion into the organic EL element. preferable. In particular, in order to avoid intrusion of moisture into the organic light emitting medium, it is preferable to reduce the moisture content and gas permeability coefficient in the substrate.

(2) Thin film transistor 2 (TFT)
Further, as the substrate 1, a driving substrate on which a thin film transistor (TFT) is formed may be used as necessary. In the case of an active drive organic EL element, the planarization film layer 3 is formed on the TFT, the first electrode 4 of the organic EL element is provided on the planarization film layer, and The TFT and the first electrode are preferably electrically connected via a contact hole provided in the planarizing film layer. By comprising in this way, the outstanding electroconductivity can be obtained between TFT and an organic EL element. As the thin film transistor provided over the substrate, a known thin film transistor can be used. Specifically, a thin film transistor mainly including an active layer in which a source / drain region and a channel region are formed, a gate insulating film, and a gate electrode can be given. The structure of the thin film transistor is not particularly limited, and examples thereof include a staggered type, an inverted staggered type, a top gate type, and a coplanar type.

(3) Planarization film layer 3
As for the material of the planarizing film layer 3, inorganic materials such as SiO ₂ , spin-on glass, SiN (Si ₃ N ₄ ), TaO (Ta ₂ O ₅ ), polyimide resin, acrylic resin, photoresist material, black matrix material, etc. An organic material or the like can be used. Spin coating, CVD, vapor deposition, etc. can be selected according to these materials. If necessary, contact holes can be formed by dry etching, wet etching, or the like at a position corresponding to the lower layer thin film transistor 120 by photolithography using a photosensitive resin as a planarizing film layer, or once a planarizing layer is formed on the entire surface. Form. The contact hole is then filled with a conductive material to establish conduction with the pixel electrode formed in the upper layer of the planarization layer. The thickness of the planarizing layer is not limited as long as it can cover the lower TFT, capacitor, wiring, etc., and the thickness may be several μm, for example, about 3 μm.

(4) First electrode 4
The first electrode 4 is formed on the substrate 1 and patterned as necessary. In the present invention, the first electrode is partitioned by a partition wall and becomes a pixel electrode corresponding to each pixel. As materials for the first electrode, 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 first electrode 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, a metal material such as copper or aluminum may be provided as an auxiliary electrode in order to reduce the wiring resistance of the first electrode. Depending on the material, the first electrode 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, a sputtering method, a dry film forming method, a gravure printing method, or a screen printing method. A wet film forming method such as a method can be used. As a patterning method for the first electrode, 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 the material and the film forming method. In the case of using a substrate on which a TFT is formed as a substrate, it is formed so that conduction can be achieved corresponding to a lower pixel.

(5) Bulkhead 5
Next, the partition walls 5 are formed in a lattice shape so as to partition the light emitting regions corresponding to the pixels. Further, the partition wall is preferably formed so as to cover the end portion of the first electrode 4 which is a pixel electrode. In general, in an active matrix drive type display device, a pixel electrode is formed for each pixel (sub-pixel), and each pixel tries to occupy as large an area as possible so that it covers the end of the pixel electrode. The most preferable shape of the partition wall 5 is basically a lattice shape that divides each pixel electrode by the shortest distance. As a method for forming the partition walls 5, as in the past, an inorganic film is uniformly formed on a substrate, masked with a resist, and then dry etching is performed, or a photosensitive resin is laminated on the substrate, and a photolithographic method is used. There is a method of making a predetermined pattern. If necessary, a water repellent can be added, or plasma or UV can be irradiated to impart liquid repellency to the ink after formation. The preferable height of the partition wall 5 is 0.1 μm to 10 μm, and more preferably 0.5 μm to 2 μm.

(6) Organic light emitting medium layer 6
Next, the organic light emitting medium layer 6 is formed. The organic light emitting medium layer 6 in the present invention can be formed of a single layer film or a multilayer film containing a light emitting substance. Examples of the configuration in the case of forming a multilayer film include a hole transport layer, an electron transporting light emitting layer or a hole transporting light emitting layer, a two-layer structure comprising an electron transport layer, a hole transport layer, a light emitting layer, and an electron transport layer. By further separating the hole (electron) injection function and the hole (electron) transport function as necessary, or by inserting a layer that blocks the transport of holes (electrons), if necessary, It is more preferable to form a multilayer. In addition, the organic light emitting layer in the present invention refers to a layer containing an organic light emitting material, and the charge transport layer refers to a layer formed to increase other light emission efficiency such as a hole transport layer.

Examples of the hole transport material used for the organic light emitting medium layer 6 include metal phthalocyanines and metal-free phthalocyanines such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, quinacridone compounds, 1,1-bis (4-di -P-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine, N, N'-di ( 1-naphthyl) -N, N′-diphenyl-1,1′-biphenyl-4,4′-diamine and other aromatic amine-based low-molecular hole injection / transport materials, polyaniline, polythiophene, polyvinylcarbazole, poly (3 , 4-ethylenedioxythiophene) and a mixture of polystyrene sulfonic acid and other polymer hole transport materials, polythiophene oligomer materials, Cu ₂ O, C _{r 2 O 3, Mn 2 O} 3, FeOx, 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 It can be selected from inorganic materials such as ₂ O ₅ , Ta ₂ O ₅ , MoO ₃ , WO ₃ and MnO ₂ and other existing hole transport materials.

  When the light emitting material of the organic light emitting medium layer 6 is a polymer material, the hole transport property is increased between the light emitting layer and the hole transport layer or between the hole transport layer and the electron transport layer, It is preferable to form an interlayer layer having a function of blocking electrons. 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 can be dissolved or dispersed in a solvent and formed using various coating methods such as spin coating or letterpress printing.

  The light emitting material used for the organic light emitting medium layer 6 includes 9,10-diarylanthracene derivatives, pyrene, coronene, perylene, rubrene, 1,1,4,4-tetraphenylbutadiene, tris (8-quinolinolato) aluminum complex, tris. (4-methyl-8-quinolinolato) aluminum complex, bis (8-quinolinolato) zinc complex, tris (4-methyl-5-trifluoromethyl-8-quinolinolato) aluminum complex, tris (4-methyl-5-cyano-) 8-quinolinolato) aluminum complex, bis (2-methyl-5-trifluoromethyl-8-quinolinolato) [4- (4-cyanophenyl) phenolate] aluminum complex, bis (2-methyl-5-cyano-8-quinolinolato) ) [4- (4-Cyanophenyl) phenolate Aluminum complex, tris (8-quinolinolato) scandium complex, bis [8- (para-tosyl) aminoquinoline] zinc complex and cadmium complex, 1,2,3,4-tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, poly- 2,5-diheptyloxy-para-phenylene vinylene, coumarin phosphor, perylene phosphor, pyran phosphor, anthrone phosphor, porphyrin phosphor, quinacridone phosphor, N, N′-dialkyl substitution Low molecular weight light emitting materials such as quinacridone phosphors, naphthalimide phosphors, N, N′-diaryl-substituted pyrrolopyrrole phosphors, phosphorescent phosphors such as Ir complexes, polyfluorenes, polyparaphenylene vinylenes, Polymer materials such as polythiophene and polyspiro, and these polymers The materials and dispersed or copolymerization of low molecular weight material, it is possible to use other conventional fluorescent light emitting material or phosphorescent material cost.

  Examples of the electron transport material used for the organic light emitting medium layer 6 include 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole, 2,5-bis. (1-naphthyl) -1,3,4-oxadiazole, an oxadiazole derivative, a bis (10-hydroxybenzo [h] quinolinolato) beryllium complex, a triazole compound, or the like can be used. Alternatively, these electron transport materials may be used as an electron injection layer by doping a small amount of alkali metal or alkaline earth metal having a low work function such as sodium, barium, or lithium.

  The thickness of the organic light emitting medium layer 6 is 1 μm or less, preferably about 0.05 to 0.2 μm, even when formed by a single layer or a stacked layer. Depending on the material, the organic luminescent medium layer can be formed by vacuum deposition, coating, printing such as slit coating, spin coating, spray coating, nozzle coating, flexo, gravure, micro gravure, intaglio offset, inkjet, etc. The method etc. can be used.

(7) Second electrode 7
Next, the second electrode 7 is formed. When the second electrode is used as a cathode, a substance having a high work efficiency of electron injection into the organic light emitting medium layer 6 and a low work function is used. Specifically, a single metal such as Mg, Al, or Yb is used, or a compound such as Li, oxidized Li, or LiF is sandwiched by about 1 nm at the interface contacting the light emitting medium, and Al or Cu having high stability and conductivity is laminated. May be 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 or Cu may be used. 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 the second electrode side, it is preferable to select a light-transmitting material. As a method for forming the second electrode 7, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used depending on the material. Although there is no restriction | limiting in particular in the thickness of a 2nd electrode, About 50 nm-1000 nm are desirable.

(10) Sealing substrate 10
The sealing substrate 10 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, metal foil such as quartz, aluminum, and stainless steel, 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.

(11) Sheet adhesive layer 11
The sheet-like adhesive layer 11 is non-flowable at room temperature (about 25 ° C.) and exhibits a softening point and fluidity in the range of 50 ° C. to 100 ° C. when heated, and is formed into a sheet shape. Refers to an encapsulating composition. As the sheet adhesive layer 11, for example, an adhesive encapsulating composition in which a latent curing agent such as dicyandiamide, diaminodiphenylsulfone, polyhydric phenol, and imidazole is mixed with an epoxy resin, a hydrogenated cyclic olefin-based polymer, a polyisobutylene resin, a photocurable type Examples thereof include an adhesive encapsulating composition containing a resin and a photopolymerization initiator. The sheet-like adhesive layer can be coated on a suitable substrate as a film, for example. The substrate may be temporarily used for molding, or the substrate may be integrated until the adhesive encapsulating composition is used. In either case, it is possible to release the surface of the substrate with, for example, a silicone resin. The coating process can be performed using known techniques such as die coating, spin coating, doctor blade coating, calendering, extrusion and the like. The sheet-like adhesive layer forms a protective layer 12 which will be described later in a region facing the second electrode on the organic EL element substrate, and does not form the protective layer 12 at the end bonded to the organic EL element substrate. . The sheet-like adhesive layer on which the protective layer is patterned is laminated and transferred onto the organic EL element substrate so that the protective layer faces the second electrode. Alternatively, vacuum lamination may be performed by picking and placing.

(12) Protective layer 12
The protective layer 12 has an electrical insulating property and is formed of a material having a barrier property against moisture, oxygen, and low molecular components. For example, at least one inorganic material selected from the group consisting of silicon oxide, aluminum oxide, magnesium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), and silicon nitride can be used. As a method for forming the protective layer, sputtering, CVD, vapor deposition, or the like can be used. In the present invention, since the protective layer (inorganic film) is formed on the sheet-like adhesive layer, the protective layer can be formed at a low temperature in a short time, and in order to ensure gas barrier performance, 1 μm It is necessary to obtain a sufficient film thickness as described above. Therefore, in the present invention, a protective layer containing silicon oxide or silicon nitride formed by low-temperature CVD is preferable.

(13) Second adhesive layer 13
The second adhesive layer 13 is formed so as to cover the sheet-like adhesive layer, and the organic EL element substrate and the counter substrate are bonded to each other through the second adhesive layer. The second adhesive layer may be, for example, an acrylic acid oligomer, a photocuring and thermosetting sealant having a reactive vinyl group of a methacrylic acid oligomer, or a moisture curable adhesive layer such as 2-cyanoacrylate. An epoxy-based heat- and chemical-curing type (two-component mixture) adhesive layer, a cationic curing type ultraviolet-curing epoxy resin adhesive layer, and the like. When bonding the sealing substrate and the organic EL element substrate using the second adhesive layer, the bonding stability, the prevention of air bubbles from being mixed into the bonding portion, the flatness of the flexible sealing substrate, etc. Considering this, it is preferable to carry out under reduced pressure conditions of 10 to 1 × 10 ⁻⁵ Pa.

(14) Second protective layer 14
The second protective layer is formed so as to cover the sheet-like adhesive layer 11, and the organic EL element substrate and the counter substrate are bonded together via the second adhesive layer 13. The second protective layer 14 can use the same material as the first protective layer. Also, the film thickness is desirably 1 μm or more in order to ensure the gas barrier performance as in the first protective layer.

  Hereinafter, the present invention will be described in detail by way of examples.

<Example 1>
An active matrix substrate having a thickness of 0.7 mm provided with a thin film transistor provided on the substrate 1 and a pixel electrode (first electrode 4) was used. The substrate size is 5 inches diagonal and the number of pixels is 320 × 240. A partition wall 5 was formed so as to cover the end of the pixel electrode and partition the pixel. The partition wall 5 was formed by forming a positive resist represented by a trade name “ZWD 6216-6” manufactured by Nippon Zeon Co., Ltd. with a height (thickness) of 2 μm on the entire surface of the substrate using a spin coater method. Thereafter, a partition wall 5 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 was formed on the pixel electrode. For the hole transport layer, a 50 nm thick molybdenum oxide film was used to form a pattern by a shadow mask method using a vacuum deposition method.

  Next, the interlayer layer was printed by a relief printing method in line with the line pattern, directly above the pixel electrode sandwiched between the partition walls. Printing was performed using an ink in which a polyvinyl carbazole derivative, which is a material of the interlayer layer, was dissolved in toluene so as to have a concentration of 0.5%. The film thickness of the interlayer layer after printing and drying was 10 nm.

  Next, an organic light emitting layer was printed by a relief printing method in accordance with the line pattern directly above the pixel electrode sandwiched between the partition walls. Printing was performed using an organic light-emitting ink in which a polyphenylene vinylene derivative, which is a material of the organic light-emitting layer, was dissolved in toluene to a concentration of 1%. The thickness of the organic light emitting layer after printing and drying was 80 nm.

  Next, as a counter electrode (second electrode 7), 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 the sheet-like adhesive layer 11, an ultraviolet curable sheet-like adhesive layer (TB1630, manufactured by Three Bond Co., Ltd.) having a thickness of 20 μm was used. The sheet-like adhesive layer consists of three layers: base film / adhesive layer / separate film. After the separation film is peeled off, it is loaded into a CVD device and SiNx is formed to 1 μm with the metal mask floating 2 mm above the adhesive layer surface. Filmed. The opening of the metal mask was 1 mm larger than the opening of the second electrode. The SiNx film was formed under the conditions of total pressure: 300 Pa, power: 1.2 kW, SiH ₄ gas: 100 sccm, NH ₃ gas: 0.02 sLm, N ₂ gas: 0.8 sLm.

Next, the organic EL element substrate formed up to the second electrode and the sheet-like adhesive layer formed by patterning the SiNx film are bonded together in an N ₂ atmosphere, and the temperature is 85 ° C., the pressure is 0.1 MPa, the speed is set using a heat roller. Thermocompression bonding was performed under the condition of 5 mm / sec.

  Next, after peeling off the base film of the sheet-like adhesive layer, it was bonded to a non-alkali glass (OA10G, manufactured by Nippon Electric Glass Co., Ltd.) having a thickness of 0.7 mm used as a sealing substrate. For the bonding, a diaphragm type vacuum laminator was used, and the temperature was 90 ° C. and the pressure was 5 minutes.

Finally, 30 kJ / m ² was irradiated with ultraviolet rays (365 nm wavelength measurement) from the sealing substrate side.

<Example 2>
The organic EL element substrate formed up to the second electrode in Example 1 and the sheet-like adhesive layer formed by patterning the SiNx film were bonded together in an N ₂ atmosphere, and the base film was peeled off, followed by ultraviolet light (365 nm wavelength measurement). ) 30 kJ / m ² was irradiated. Thereafter, vacuum sealing was performed on a sealing substrate (non-alkali glass, 0.7 mm thick) with a 30 μm-thick UV curable adhesive layer (XNR5516Z, manufactured by Nagase Sangyo Co., Ltd.) formed by screen printing. Then, ultraviolet rays 6000 mJ / cm ² (365 nm wavelength measurement) was irradiated.

<Example 3>
The organic EL element substrate formed up to the second electrode in Example 1 and the sheet-like adhesive layer formed by patterning the SiNx film were bonded together in an N ₂ atmosphere, and the base film was peeled off, followed by ultraviolet light (365 nm wavelength measurement). ) 30 kJ / m ² was irradiated. Thereafter, a SiNx film having a thickness of 2 μm was formed using a CVD apparatus. The SiNx film was formed under the conditions of total pressure: 300 Pa, power: 1.2 kW, SiH ₄ gas: 100 sccm, NH ₃ gas: 0.02 sLm, N ₂ gas: 0.8 sLm. Next, vacuum sealing was performed on a sealing substrate (non-alkali glass, 0.7 mm thick) having a 30 μm-thick UV-curable adhesive layer (XNR5516Z, manufactured by Nagase Sangyo Co., Ltd.) formed by screen printing. Then, ultraviolet rays 6000 mJ / cm ² (365 nm wavelength measurement) was irradiated.

<Comparative Example 1>
After forming up to the second electrode in Example 1, a SiNx film having a thickness of 2 μm was formed by a CVD apparatus so as to cover the second electrode. The SiNx film was formed under the conditions of total pressure: 300 Pa, power: 1.2 kW, SiH ₄ gas: 100 sccm, NH ₃ gas: 0.02 sLm, N ₂ gas: 0.8 sLm. Next, vacuum sealing was performed on a sealing substrate (non-alkali glass, 0.7 mm thick) having a 30 μm-thick UV-curable adhesive layer (XNR5516Z, manufactured by Nagase Sangyo Co., Ltd.) formed by screen printing. Then, ultraviolet rays 6000 mJ / cm ² (365 nm wavelength measurement) was irradiated.

<Evaluation>
Laser repair of the organic EL displays obtained in Examples 1 to 3 and Comparative Example 1 was performed. Laser repair was performed on the dark spot pixels having foreign matters of 5 μm or less. As a result of laser irradiation with increased intensity until repair was possible, the dark spot (non-light emitting portion) size was as shown in Table 1. Further, after laser repair, the sample was left in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 1500 hours, and the degree of expansion of dark spots was examined. The results are also shown in Table 1.

<Comparison result>
In the organic EL displays that are the products of the present invention of Examples 1 to 3, the initial dark spot size is small, and even when left in a constant temperature and humidity layer, the result that the width of the dark spot size is small is obtained, and laser repair is effective. I was able to do it. On the other hand, the comparative product obtained in Comparative Example 1 had a large initial dark spot size and was unable to perform practical laser repair.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... Thin-film transistor 3 ... Planarization film layer 4 ... 1st electrode 5 ... Partition 6 ... Organic light emission medium layer 7 ... 2nd electrode 10 ... Sealing substrate 11 ... Sheet-like adhesive layer 12 ... Protective layer 13 ... 1st Second adhesive layer 14 ... second protective layer 20 ... void layer

Claims (4)

A first electrode provided in a pattern on one surface of the first substrate, a partition covering the peripheral edge of the first electrode, and an organic light emitting medium layer provided on the first electrode in the partition An organic EL element substrate comprising a second electrode provided at a position facing the first electrode on the organic light emitting medium layer, a sheet-like adhesive layer on the entire surface of one surface of the second substrate, and An organic EL display in which a counter substrate formed by sequentially laminating a protective layer in an inner region is bonded to one of the surfaces,
(A) a void layer is formed between the second electrode and the protective layer;
(B) The organic EL element substrate and the counter substrate are bonded via a sheet-like adhesive layer.
This is an organic EL display.   The counter substrate is formed by sequentially laminating a second adhesive layer on one whole surface of the second substrate, the sheet-like adhesive layer in an inner area, and the protective layer in an inner area. The organic EL display according to claim 1.   The counter substrate includes the second adhesive layer on one whole surface of the second substrate, a second protective layer in an inner region, the sheet-like adhesive layer in an inner region, The organic EL display according to claim 1, wherein the protective layer is sequentially laminated in an inner region.   Forming a first electrode; forming a partition; forming an organic light emitting medium layer; forming an organic EL element substrate; forming at least a sheet-like adhesive layer; and a protective layer. The manufacturing process of the organic EL display according to claim 1, comprising: a counter substrate forming step including a forming step; and a step of bonding the organic EL element substrate and the counter substrate. Method.