JP2008235178A - Organic el display and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an organic EL display which method well suppresses damage caused by laser repairing and enables laser repairing without carrying out atmosphere control following a sealing process, and an organic EL display manufactured by the method. <P>SOLUTION: According to the manufacturing method for the organic EL display, an organic EL element is provided, which includes a laminated structure made by laminating a substrate, a first electrode, an organic layer having a light-emitting layer, and a second electrode in increasing order, and a defective portion inside the laminated structure. Laser light is emitted on a given layer in the organic layer that corresponds to a luminescent spot defective portion of the organic EL element. This causes multiphoton absorption to form nonluminous portion made up of a fracture portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In recent years, with the advancement of information technology, there is an increasing demand for a flat panel display (FPD) that is thin, low power consumption, and lightweight. Among them, an organic electroluminescence (hereinafter, also referred to as “EL”) display using an organic light emitting material is attracting attention because it can be driven at a low voltage and can realize a high luminance display. In particular, due to recent research and development, the luminous efficiency of organic EL elements has been remarkably improved, and the practical use of organic EL displays equipped with organic EL elements has begun.

  The structure of the organic EL element in the organic EL display is basically an organic layer (EL layer) including at least one light emitting layer between a pair of electrodes of an anode and a cathode as disclosed in Patent Document 1. ), And is basically a laminated structure of “anode electrode / hole injection layer / light emitting layer / cathode electrode” such as Tang et al. The organic EL element emits light by applying an electric field between the electrodes and passing an electric current through the EL layer.

  When an organic EL element is used as a panel for a display, it is roughly divided into a passive matrix system and an active matrix system according to an electrode configuration and a driving method, similarly to an LCD. In such a panel, organic EL elements are used to achieve colorization, and the most basic three colors of organic EL materials of R 1, G 2, and B 3 are precisely arranged for each pixel of the display device. In addition to the side-by-side method, a CF method that combines a white light emitting layer and a color filter layer (also referred to as a CF layer) of R 1, G 2, and B 3, and a CCM (Color Changing) that combines a blue light emitting layer and a fluorescent conversion dye filter of R 1 and G 2. Medium) method.

  Such a conventional organic EL element has a problem that when considering application to an actual product, leakage of the upper and lower electrodes occurs, resulting in non-luminous pixels. This vertical leak may be caused by various factors such as particles and dust mixed during the device fabrication process, and splash of the organic film formed. In any case, if such vertical leak occurs, non-luminous pixels As a result, defective pixels are generated in the display of the display, and not only luminance unevenness and display uniformity are impaired, but also the current that does not contribute to light emission increases, so the light emission efficiency and power efficiency are significantly reduced, and the power consumption is increased. It will cause. Therefore, as a method for dealing with such a leak, the laser repair method for the non-light emitting pixels as described above is widely used. This method is a method in which particles and dust existing in the non-light-emitting pixels are irradiated with laser and burned out.

  However, the organic EL element has the following problems when a defective portion is burned out by such high-energy laser irradiation.

  In other words, peeling occurs due to the difference in thermal conductivity between the organic layer and the electrode layer, or a lump containing the organic layer or electrode layer is scattered around the laser irradiation part, or the thermal energy is transferred to the surrounding layers by laser irradiation. May suffer damage such as contracting and shrinking. Due to the damage caused by such laser repair, oxygen or moisture enters from the place where laser repair has been performed, resulting in a dark spot, or leakage between the upper electrode and the lower electrode during aging. The problem arises that recurrence and spread occur. Therefore, as a laser repair method for organic EL elements, there is a problem of developing a low-damage laser repair method that does not cause damage to the periphery of the repair location and does not cause recurrence or spread of defective locations during aging.

  In response to the above problem, Patent Document 2 discloses a leak prevention functional layer that evaporates a layer in contact with a transparent substrate among a plurality of organic material layers of an organic EL element by absorption of laser light, and an upper metal electrode. A structure for forming a sealing film having elasticity is disclosed. And according to this, by evaporating and expanding the leak prevention functional layer of the defective part by laser irradiation, the organic material layer, the metal electrode and the sealing film are pushed up and separated from the transparent electrode, and the leak is suppressed. Are listed.

Patent Document 3 discloses a method of correcting a defect by removing a second electrode at a defective portion by laser repair with respect to an organic EL element having a simple matrix structure.
Japanese Patent No. 1526026 JP 2000-331782 A JP 2004-228096 A

  However, in the technique disclosed in Patent Document 2, when the upper layer of the laser irradiation unit is pushed up, the film profile of the upper layer may change around the laser irradiation unit and affect the light emission characteristics. Moreover, the part pushed up during aging falls, and a defective part may recur because an organic material layer touches the transparent electrode on a transparent substrate again.

  Moreover, in patent document 3, it does not describe about the cross-sectional shape of the layer around a laser irradiation part.

  Further, in a future organic EL element, a laminated structure in which a sealing film is directly formed on the second electrode with a top emission (TE) structure is generally used. When the second electrode is removed with this TE structure and repair is attempted, the second electrode removed by laser irradiation affects the upper and lower layers. In particular, since the sealing layer formed on the upper part of the second electrode is damaged, there is a case where normal light emission cannot be obtained around the irradiated part during aging due to the influence of oxygen and moisture. For this reason, the repair aimed at the second electrode is affected by oxygen and moisture due to re-leakage and damage to the sealing layer, and normal light emission cannot be obtained around the irradiated part during aging. There is.

  The present invention has been made in view of the above points, and the object of the present invention is to satisfactorily suppress damage during laser repair and to perform laser repair without performing atmosphere control after performing a sealing process. It is providing the manufacturing method of the organic electroluminescent display which can be performed, and the organic electroluminescent display manufactured by it.

  The inventors of the present invention have made extensive studies in order to prevent damage to the periphery of the defect due to laser repair, and to prevent an increase in the number of defective parts due to aging after laser repair. We found that there is a strong correlation with the phenomenon of increasing defects due to aging, and succeeded in solving the above problems.

  That is, the organic EL display manufacturing method according to the present invention includes a laminated structure in which a substrate, a first electrode, an organic layer having a light emitting layer, and a second electrode are laminated in this order, and has a bright spot inside the laminated structure. Non-light-emitting composed of defective parts by preparing an organic EL element having a defective part and irradiating a predetermined layer in the organic layer corresponding to the bright spot defective part of the organic EL element with laser light to cause multiphoton absorption Forming a portion.

  The organic EL device of the present invention has a structure in which a light emitting layer is sandwiched between electrodes. The light emitting layer constituting such an organic EL element is a layer including an organic material that emits light when an electric field is applied. The organic layer has a structure in which layers composed of an organic material such as a light-emitting layer are stacked, and usually includes a hole injection layer, a hole transport layer, an electron transport layer, and the like in addition to the light-emitting layer. As a preferable form of the organic EL device of the present invention, for example, a form in which a substrate, an anode, a hole transport layer, a light emitting layer and a cathode are laminated in this order can be mentioned. At this time, it is preferable that at least one of the anode and the cathode has translucency.

  The organic EL element may cause pixel defects (bright spot defects) due to dust or particles. In such a pixel defect, by irradiating the dust or particles present in the pixel with laser, a non-light emitting region is generated in the pixel due to laser irradiation, but the entire pixel emits light. There are various types of laser light used here, such as YAG lasers, solid-state lasers, and excimer lasers. The inventors of the present application perform laser repair using multiphoton absorption (multiphoton absorption). The present inventors have succeeded in producing an organic EL element in which a non-light-emitting portion composed of a defect portion is formed in a predetermined layer in an organic layer, and the peripheral layer and the peripheral region are not damaged in that region. Further, since the upper and lower layers are electrically separated in that region, it is possible to prevent the vertical leak.

  By having the above cross-sectional shape, even if laser irradiation is performed aiming at a specific layer, re-leakage due to destruction of surrounding layers and spread of non-light emitting parts due to repair can be suppressed, and leakage is not particularly caused without damaging the sealing layer. Reduction can be performed. For this reason, it is difficult to be influenced by oxygen and moisture due to aging after repair, and the probability of leaking is remarkably reduced, so that a long-life organic EL element can be produced.

  Further, it is desirable that the focal point of the laser beam to be irradiated is focused on one specific layer. Multi-photon absorption (multi-photon absorption) is focused on a specific layer of interest by laser irradiation due to the locally high energy density of the focus of the laser beam. Enables ultra-fine processing. For this reason, it is possible to repair only the target specific layer. Further, even when damage is applied to layers other than the specific layer, laser repair can be performed with the damage range being suppressed to a lower level.

  Furthermore, in the method for manufacturing an organic EL display according to the present invention, a color filter layer is provided outside the first or second electrode, and the bright spot defect portion is irradiated with laser light through the color filter layer. May be.

  In the organic EL element configuration, when the color filter layer is provided, the effect is particularly exerted. Even when the color filter layer is included in the element structure by laser repair using multiphoton absorption, repair through the color filter layer and the sealing resin can be realized, and the spread of heat by laser irradiation can be realized. By suppressing, it is possible to realize a repair in which the spread of the irradiation part is suppressed. Further, since there is almost no damage to the color filter layer, there is no influence on optical characteristics such as light leakage. Furthermore, there is almost no damage to the sealing layer. Therefore, it is possible to realize a repair that does not cause deterioration or re-leakage of a light emitting pixel affected by oxygen or moisture due to deterioration of sealing performance due to aging.

  In the organic EL display manufacturing method according to the present invention, the organic EL element may be formed by laminating the sealing layer, the color filter layer, and the counter substrate in this order on the second electrode of the multilayer structure.

  In an organic EL element, sealing with glass, metal, and a desiccant is generally performed to prevent deterioration due to external moisture or oxygen. However, recently, a structure for taking out the light emission of the organic EL from the direction of the second electrode has been actively studied. In this case, not a conventional sealing method but a resin sealing method in which the entire organic EL layer is covered with inorganic and organic resins is often used. Even in such an element configuration, by performing laser repair using multiphoton absorption, repair via a sealing resin or a color filter layer, which has been impossible in the past, becomes possible.

  Furthermore, in the method for manufacturing an organic EL display according to the present invention, the laser beam to be irradiated may be a femtosecond laser beam.

  The above cross-sectional structure is formed by laser repair using multiphoton absorption (multiphoton absorption), and the laser repair method is not particularly limited, but multiphoton absorption (multiphoton absorption) is efficiently expressed. It is desirable to use femtosecond lasers that can do this. By using femtosecond laser light, the energy density at the focal point of the laser light is locally high, so that the target specific layer is focused and laser irradiation is performed, and the focal position of the laser light is moved. The vertical direction can also be controlled, and laser repair with lower damage can be performed.

  The multiphoton absorption (multiphoton) method, which is a feature of this laser repair method, will be described below.

  Physical phenomena that occur at the laser focusing point can be broadly divided into three types: thermal processing, plasma processing, and photoionization processing. Carbon dioxide laser is divided into thermal processing, YAG laser is divided into plasma processing, and UV laser and femtosecond laser are divided into photoionization processing. In reality, any laser is used to develop three processes simultaneously, and the dominant process is determined not only by the type of laser but also by the optical absorption characteristics of the material. Unlike other processes, the process of photoionization is very clean around the processed part. This is because the surface is directly decomposed by the laser beam, so that there is no influence of heat or plasma. In order to realize the photoionization processing, a UV laser or a femtosecond laser is required. The UV laser is processing using linear absorption, and the femtosecond laser is processing using multiphoton absorption (multiphoton absorption).

  Here, multiphoton absorption (multiphoton absorption) induces a light absorption effect equivalent to a wavelength shorter than the incident wavelength by simultaneously absorbing a plurality of photons. The absorption factor of multiphoton absorption (multiphoton absorption) can be expressed by the product of the nth-order nonlinear absorption coefficient and the nth power of the beam electric field. Since this coefficient is small, it is an absolute requirement that the laser irradiation intensity be high It becomes.

  Multiphoton absorption that suppresses thermal processing better as the pulse width is shorter than the threshold value of each function of fluence (light energy density) required for multiphoton absorption (multiphoton absorption) and pulse width of pulse energy generated by thermal processing It can be seen that (multiphoton absorption) appears. Therefore, photoionization processing by multiphoton absorption (multiphoton absorption) is realized by irradiating a laser whose pulse energy is adjusted. In addition, since multiphoton absorption (multiphoton absorption) is an intensity-dependent process, it is possible to perform internal processing only at the focal point or ultra-fine processing below the spot size.

  Next, physical phenomena that occur in nanosecond lasers, picosecond lasers, and femtosecond lasers with short pulse widths will be described.

  When the pulse width is on the order of nanoseconds and the linear absorption is small, dielectric breakdown occurs due to the high intensity, resulting in the generation of plasma. When plasma is generated, there is a complex interaction between the laser and the plasma, and the plasma and the material surface. In this case, the processing threshold is calculated as a dielectric breakdown threshold.

  Furthermore, if the pulse width is reduced to picoseconds and the material has little linear absorption, the situation is different from nanosecond processing. Since generation of plasma starts from 100 ps to 1 ns after energy input, there is no interaction between plasma and laser in this pulse width region. In this case, the cause of deterioration of processing is phonon coupling (interaction between electrons and lattices). Phonon coupling occurs on a time scale of 1 to 2 ps after laser irradiation.

  In the case of laser irradiation with femtosecond laser light, phonon coupling can be avoided. As a result, thermal denaturation induced by phonon coupling can be minimized. By applying sufficient energy in a short time, ionization is possible without going through the phonon coupling process.

  Multiphoton absorption (multiphoton absorption) is a phenomenon that can be observed not only in femtoseconds but also in nanoseconds. However, in the case of nanoseconds, plasma is generated at a lower intensity level than the multiphoton absorption (multiphoton absorption). As a result, processing by multi-photon absorption is difficult to develop with nanosecond lasers, and such reports are very few.

  Therefore, only a femtosecond laser pulse easily realizes a special situation in which the multiphoton absorption (multiphoton absorption) processing threshold is lower than the dielectric breakdown threshold.

  In the method for manufacturing an organic EL display according to the present invention, laser light may be irradiated at an oscillation wavelength in an absorption wavelength band of a predetermined layer.

  According to such a configuration, the absorption of the laser beam in the specific layer that irradiates the laser beam increases, and multiphoton absorption can be generated with a smaller irradiation energy. Laser repair that suppresses damage can be performed.

  Furthermore, in the method for manufacturing an organic EL display according to the present invention, the non-light emitting portion may be formed in the first electrode.

  According to such a configuration, when laser light is irradiated, fine particles due to ablation are generated in the irradiated portion, but the fine particles are absorbed by the surrounding layers and the periphery. In the case where the organic EL element has a drive unit such as an active matrix, there is a relatively thick insulating film such as a JAS film between the drive unit and the first electrode. This insulating film can be absorbed. Further, when the organic EL element does not have a driving unit, the lower portion of the first electrode is, for example, a glass substrate. Even in the case of a glass substrate, fine particles generated by ablation can be absorbed by the glass substrate. For this reason, the laser repair which suppresses the damage to a surrounding layer and a surrounding area | region favorably can be performed.

  Moreover, the manufacturing method of the organic EL display which concerns on this invention may form a non-light-emission part in a light emitting layer.

  According to such a configuration, by adjusting the oscillation wavelength of the laser light to the absorption wavelength of the light emitting layer, absorption to the inorganic layer such as an electrode can be suppressed, and multiphoton absorption can be generated with smaller irradiation energy. Can do. Moreover, although the microparticle by ablation arises in an irradiation part, the microparticle is absorbed by the surrounding layer and the periphery. In the case where the organic EL element has a driving unit such as an active matrix, since the first electrode and the insulating film having a relatively large thickness exist below the light emitting layer, fine particles generated by ablation are removed from the first electrode. Alternatively, it can be absorbed by the insulating film. Further, when the organic EL element does not have a driving unit, the lower portion of the first electrode is, for example, a glass substrate. Even in the case of a glass substrate, fine particles generated by ablation can be absorbed by the glass substrate. For this reason, the laser repair which suppresses the damage to a surrounding layer and a surrounding area | region favorably can be performed.

  The organic EL display according to the present invention has a laminated structure in which a substrate, a first electrode, an organic layer having a light emitting layer, and a second electrode are laminated in this order, and is configured with a defect in a predetermined layer in the organic layer. It is characterized by having a non-light emitting portion.

  According to such a configuration, the organic EL display has a non-light-emitting portion composed of a defect portion in a predetermined layer in the organic layer of the laminated structure. Therefore, the bright spot defect portion corresponds to the non-light-emitting portion. It is possible to satisfactorily suppress bright spot defects due to leakage.

  According to the present invention, a method for manufacturing an organic EL display capable of satisfactorily suppressing damage at the time of laser repair and performing laser repair without performing atmosphere control after performing a sealing process, and an organic EL manufactured thereby A display can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

(Embodiment 1)
(Configuration of organic EL display 10)
As shown in FIG. 1, an organic EL display 10 according to Embodiment 1 of the present invention includes a substrate 11, an anode (first electrode) 12, an organic layer 13, a cathode (second electrode) 14, a sealing layer 15, and a color. The organic EL element 20 includes a laminated structure 25 in which the filter layer 16 and the sealing substrate 17 are laminated in this order, and further includes a control unit (not illustrated) that drives the organic EL element 20. Here, in the present embodiment, the organic EL display 10 having a top emission (TE) structure will be described as an example.

The substrate 11 is preferably constructed so that at least the surface thereof is insulative, for example, a substrate formed of an inorganic material such as glass or quartz, a substrate formed of a plastic such as polyethylene terephthalate, or a ceramic such as alumina. Wide range of substrates to be formed, substrates in which a metal substrate such as aluminum or iron is coated with an insulator such as SiO ₂ or an organic insulating material, and substrates in which the surface of the metal substrate is subjected to an insulation process by an anodic oxidation method or the like Can be used. On the substrate 11, for example, a TFT circuit having a two-transistor and one-capacitor configuration necessary for driving the organic EL element 20 is formed.

The anode 12 is formed on the substrate 11 and is formed using a known electrode material. Materials for the anode 12 for injecting holes into the organic layer 13 include metals having a high work function such as Au, Pt, Ni, ITO, IDIXO [indium oxide-indium zinc oxide; In ₂ O ₃ (ZnO) _n ]. And transparent conductive materials such as SnO ₂ . In the organic EL display 10 according to the embodiment of the present invention, a defect portion 21 (non-light emitting portion) is formed in the anode 12 as a repair of a bright spot defect portion.

  In addition, although the defect | deletion part 21 (non-light-emission part) is formed in the anode 12 in this embodiment, it is not restricted to this, For example, other layers, such as the cathode 14 and the organic layer 13, or crossing them. As such, it may be formed in a plurality of layers.

The cathode 14 is formed on the organic layer 13 and is formed using a known electrode material. The cathode 14 for injecting electrons into the organic layer 13 includes a metal electrode in which a metal having a low work function such as Ca / Al, Ce / Al, Cs / Al, Ba / Al and a stable metal are laminated, and a Ca: Al alloy. A metal electrode containing a metal having a low work function such as Mg: Ag alloy, Li: Al alloy, an insulating layer (thin film) such as LiF / Al, LiF / Ca / Al, BaF ₂ / Ba / Al, and a metal electrode Combination electrodes and the like can be mentioned. As a method of forming the anode 12 and the cathode 14, a vapor deposition method, an electron beam (EB) method, a molecular beam epitaxy (MBE) method, a dry process such as a sputtering method, a spin coating method, A wet process such as a printing method or an inkjet method can be used.

  The organic layer 13 has at least one light emitting layer 23. The organic layer 13 (or the light emitting layer 23 included therein) may have a single layer structure or a multilayer structure.

  As the light emitting material of the light emitting layer 23, a known light emitting material for the organic EL element 20 can be used, but it is not particularly limited thereto. Specifically, a low molecular light emitting material, a polymer light emitting material, a precursor of a polymer light emitting material, or the like can be used.

Examples of the low-molecular light emitting material include aromatic dimethylidene compounds such as 4,4′-bis (2,2′-diphenylvinyl) -biphenyl (DPVBi), 5-methyl-2- [2- [4- (5 Oxadiazole compounds such as -methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 3- (4-biphenylyl) -4-phenyl-5-t-butylphenyl-1,2,4-triazole (TAZ) and other triazole derivatives, 1,4-bis (2-methylstyryl) benzene and other styrylbenzene compounds, thiopyrazine dioxide derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, diphenoquinone derivatives, fluorenone derivatives, etc. Fluorescent organic material, azomethine zinc complex, (8-hydroxyquinolinato) aluminium Complex (Alq3) fluorescent organic metal compound such as and the like. Examples of the polymer light emitting material include poly (2-decyloxy-1,4-phenylene) (DO-PPP), poly [2,5-bis- [2- (N, N, N-triethylammonium) ethoxy]. -1,4-phenyl-alt-1,4-phenylylene] dibromide (PPP-NEt ³⁺ ), poly [2- (2′-ethylhexyloxy) -5-methoxy-1,4-phenylenevinylene] (MEH -PPV), poly [5-methoxy- (2-propanoxysulfonide) -1,4-phenylenevinylene] (MPS-PPV), poly [2,5-bis- (hexyloxy) -1,4- And fluorescent organometallic compounds such as phenylene- (1-cyanovinylene)] (CN-PPV) and poly (9,9-dioctylfluorene) (PDAF). Examples of the precursor of the polymer light emitting material include a PPV precursor, a PNV precursor, a PPP precursor, and the like.

  In the sealing layer 15, the color filter layer 16 and the sealing substrate 17 are formed on the cathode 14 in this order, and each is formed using a known material.

(Method for manufacturing organic EL display 10)
Next, a method for manufacturing the organic EL display 10 according to Embodiment 1 of the present invention will be described.

  First, an Al electrode electrically connected through a through hole is formed on a substrate 11 having a TFT circuit to a thickness of 100 nm by sputtering, and patterned to a pixel size by a photolithography process.

  Next, an ITO transparent electrode to be the anode 12 is formed thereon. The ITO film is formed by a sputtering method, and patterned to a pixel size by a photolithography process. For example, both the Al electrode and the ITO electrode are patterned with a pixel width of 200 μm and an extraction width of 30 μm.

Next, on the transparent substrate 11 on which the anode 12 is formed, a hole injection layer (Cupc is 35 nm), a hole transport layer (TPD is 45 nm), a light emitting layer 23 (white light emitting material 55 nm), an electron injection layer ( LI ₂ O (1 nm) and cathode 14 (Al 5 nm) are sequentially deposited by vacuum evaporation or the like.

  Next, in order to maintain transparency, an ITO electrode is formed thereon by an ion plating method.

Next, a SiNx film of 2 μm is formed by a CVD method to form a sealing film, and finally a UV curable resin is used to bond the sealing substrate 17 to the inside on which the CF ₆ is formed, thereby forming an organic EL. Element 20 is formed.

  The present embodiment shows an example of a method for producing the organic EL element 20, and the organic material, the sealing film, and the like to be used are not limited thereto. In addition, regarding the method of forming the organic layer 13, an example of a process according to the low molecular light emitting element is shown here, but the method is not limited to this. For example, a high molecular organic EL material is printed using an inkjet process or the like. You may form into a film.

  Next, a repair method when a bright spot defect portion (pixel defect or the like) such as a foreign substance is generated in the organic EL element 20 formed as described above will be described with reference to FIG.

  First, a voltage is applied to the organic EL element 20 having a bright spot defect portion so as to light the entire surface. This confirms the presence of non-light emitting pixels. The position of the non-light emitting pixel corresponds to a bright spot defect site inside the element.

  Next, laser repair is performed on the bright spot defect using the femtosecond laser repair device 30. The femtosecond laser repair device 30 includes a femtosecond laser oscillator 31, a diaphragm 32, a mirror 33, and a lens 34.

  The femtosecond laser light is a microscope-mounted pulse variable excitation laser light, and the oscillation wavelength can be arbitrarily selected. Irradiation with femtosecond laser light is performed from the color filter layer 16 side, for example, so that the pulse time width is 100 femtoseconds or less, preferably 1 femtosecond or less. Further, the wavelength of the femtosecond laser light may be any, but it is particularly preferable that it be a medium wavelength (700 to 900 nm, preferably 780 nm). Moreover, it is preferable to irradiate femtosecond laser light at an oscillation wavelength in the absorption wavelength band of the anode.

  The focus of repair is adjusted to the anode 12 corresponding to the bright spot defect site in order to realize repair with low damage. The laser beam is focused by adjusting a diaphragm 32 and a lens 34 mounted on the femtosecond laser repair device 30.

  By irradiating femtosecond laser light in this way, multiphoton absorption occurs in a region corresponding to the bright spot defect portion of the anode 12 to form a defect portion 21, thereby suppressing leakage.

  Further, the focus of repair is not limited to the anode 12. For example, the defect portion 21 may be formed in the light emitting layer 23 in accordance with the light emitting layer 23.

(Embodiment 2)
(Configuration of organic EL display 40)
Next, the configuration of the organic EL display according to Embodiment 2 of the present invention will be described in detail with reference to the drawings. Hereinafter, the same components as those of the organic EL display 10 according to Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 3, the organic EL display 40 according to Embodiment 2 of the present invention includes a substrate 11, an anode (first electrode) 12, an organic layer 43, a cathode (second electrode) 14, a sealing layer 15, and a sealing layer. An organic EL element 44 having a laminated structure 45 in which the stop substrate 17 is laminated in this order, and a control unit (not shown) that drives the organic EL element 44 are configured. In this embodiment, an organic EL display having a top emission (TE) structure will be described as an example.

  The organic EL display 40 according to the second embodiment has a configuration in which the organic layer 43 itself including the light emitting layer 46 has a function of a color filter, and is not provided with a color filter layer on the sealing layer 15. 1 is different from the organic EL display 10 according to 1.

  The organic layer 43 has at least one light emitting layer 46. The organic layer 43 (or the light emitting layer 46 included therein) may have a single layer structure or a multilayer structure. The organic layer 43 is provided with a light emitting layer 46 for each of RED, Green, and Blue pixels.

  In the organic EL display 40 according to the embodiment of the present invention, the defective portion 47 (non-light emitting portion) is formed in the anode 12 in the portion corresponding to each of the RED, Green, and Blue pixels as the repair of the bright spot defect portion. Yes.

  In addition, although the defect | deletion part 47 (non-light-emission part) is formed in the anode 12 in this embodiment, it is not restricted to this, For example, other layers, such as the organic layer 43 and the cathode 14, or crossing them As such, it may be formed in a plurality of layers.

(Method for manufacturing organic EL display 40)
Next, a method for manufacturing the organic EL display 40 according to Embodiment 2 of the present invention will be described.

  First, an Al electrode electrically connected through a through hole is formed on a substrate 11 having a TFT circuit to a thickness of 100 nm by sputtering, and patterned to a pixel size by a photolithography process.

  Next, an ITO transparent electrode to be the anode 12 is formed thereon. The ITO film is formed by a sputtering method, and patterned to a pixel size by a photolithography process. For example, both the Al electrode and the ITO electrode are patterned with a pixel width of 200 μm and an extraction width of 30 μm.

  Next, a hole injection layer (Cupc is 35 nm) and a hole transport layer (TPD is 45 nm) are sequentially deposited on the transparent substrate 11 on which the anode 12 is formed by vacuum evaporation or the like. The light-emitting layer 46 (light-emitting material 55 nm) is formed by depositing a light-emitting material for each color of RED, Green, and Blue by a vacuum vapor deposition method or the like using a mask, and separately applying each color.

Thereafter, an electron injection layer (LI ₂ O of 1 nm) and a cathode 14 (Al of 5 nm) are sequentially deposited by vacuum evaporation or the like.

  Next, in order to maintain transparency, an ITO electrode is formed thereon by an ion plating method.

Next, a SiNx film of 2 μm is formed by a CVD method to form a sealing film, and finally, a UV curable resin is used to bond the sealing substrate 17 to the inside where the CF ₆ is formed (UV curing). The thickness of the resin film is 20 μm), and the organic EL element 44 is formed.

  This embodiment shows an example of a method for producing the organic EL element 44, and the organic material, sealing film, and the like to be used are not limited thereto. In addition, regarding the film formation method of the organic layer 43, an example of a process according to the low molecular light emitting element is shown here, but the present invention is not limited to this. For example, a high molecular organic EL material is printed using an inkjet process or the like. You may form into a film.

  Next, a repair method when a bright spot defect portion (pixel defect or the like) such as a foreign substance is generated in the organic EL element 44 formed as described above will be described with reference to FIG.

  First, a voltage is applied to the organic EL element 44 having a bright spot defect portion so as to light the entire surface. This confirms the presence of non-light emitting pixels. The position of the non-light emitting pixel corresponds to a bright spot defect site inside the element.

  Next, laser repair is performed on the bright spot defect using the femtosecond laser repair device 30.

  The focus of repair is adjusted to the anode 12 corresponding to the bright spot defect site. The laser beam is focused by adjusting a diaphragm 32 and a lens 34 mounted on the femtosecond laser repair device 30.

  By irradiating the femtosecond laser light in this way, multiphoton absorption occurs in a region corresponding to the bright spot defect portion of the anode 12 to form a defect portion 47, thereby suppressing leakage.

  Further, the focus of repair is not limited to the anode 12. For example, the defect 47 may be formed in the light emitting layer 46 in accordance with the light emitting layer 46 of each color of RED, Green, and Blue.

  In order to investigate the effect of pixel defect repair using the laser repair method according to the first embodiment of the present invention, the following experiment was performed.

  First, when two organic EL elements having the top emission (TE) structure of the above-described embodiment are prepared and voltages are applied so as to light them all over, there are ten non-light emitting pixels for each element. It was confirmed. Here, let these two organic EL elements be element A and element B. When the non-light-emitting pixels were observed with a microscope in both the elements A and B, it was found that minute particles of about 1 to 3 microns were contained inside the pixels.

  Next, as shown in FIG. 5, laser repair is performed on the particles in the defective pixel of the element A using a repair device using the YAG laser 60, and the organic EL element after being repaired (comparative example) is obtained. Obtained. The YAG laser 60 is a microscope-mounted pulse excitation Q-switched Nd: YAG laser, and has an oscillation wavelength of 532 nm.

  Further, laser repair was performed on the particles in the defective pixel of the element B using the femtosecond laser repair apparatus according to the embodiment of the present invention, and an organic EL element after repair (Example 1) was obtained. Further, the oscillation wavelength of the femtosecond laser light is 780 nm, and this wavelength has an absorptance of 10% or less for any of the films constituting the element B. When the normal absorptance is about 10%, the film cannot be damaged no matter how much irradiation is performed with laser light that is not multiphoton absorption.

  In Comparative Example and Example 1, the laser beam was irradiated from the sealing substrate side through the color filter layer. Further, the repair was focused on the vicinity of Al as the anode in any laser beam. The focus of the laser light was adjusted using a microscope mounted on the laser device. The irradiation spot was circular and had a diameter of 10 μm.

(Evaluation result of comparative example)
When laser repair processing was performed under such conditions, the element B using the YAG laser 60 was absorbed by the color filter layer and the organic layer, and the defective pixel could not be repaired. This is thought to be because the power of the laser beam did not reach the organic layer because the wavelength of 532 nm of the YAG laser beam was strongly absorbed by the color filter layer and the like. For this reason, only the color filter layer has been extinguished by the laser.

  Therefore, in the comparative example, when the intensity of the YAG laser light is further increased and the number of times of irradiation is increased, as shown in FIG. The hole was opened. This is because although the electrodes could be burned out by the laser light, very large heat was generated at that time, affecting not only the focused electrodes but also the surroundings. As a result, the defective pixel cannot be repaired, and a larger leak current flows than before the repair. Thus, normal laser light is absorbed by the color filter layer and the resin sealing film. The discoloration part 70 of FIG. 5 shows the site | part which discolored because the color filter layer absorbed the laser beam. For this reason, it is difficult to irradiate the light to the back of the element, and even if the intensity is increased and the light penetrates deeply, the generation of heat cannot be prevented. For this reason, it turned out that there exists a possibility of damaging an element instead of repair as a result.

(Evaluation result of Example 1)
Regarding the element B using the femtosecond laser beam, all the ten non-light emitting pixels are turned on, and the repair was successful.

  In the element B, a non-light emitting region having a diameter of about 5 μm was generated with respect to the laser irradiation region, and the leakage of the non-lighted pixel was improved to become a light emitting pixel. Further, since no light leakage was observed from the irradiated portion, it was confirmed that there was little damage to the color filter layer and the organic layer, and there was no problem on the optical characteristics.

  When the cross section of the repaired portion was observed with a scanning electron microscope (SEM), the specific part of the anode was mainly removed, and the fine particles generated by ablation were absorbed by the insulating film, and the sealing layer, color filter layer No damage was seen. An aging test was performed on nine defective portions of the element B. As a result, the defective pixels were not formed again without leaking again at all the portions.

  Next, a TE structure organic EL element C having a light emitting layer for each of RED, Green, and Blue pixels having the same configuration as that of the second embodiment is repaired by irradiation with femtosecond laser light. 2. The repair method is the same as that of the second embodiment, and the focus of repair is aligned with the anode that is the first electrode, and the leak is corrected by burning the anode.

(Evaluation result of Example 2)
The defective pixels of the element C used in Example 2 were formed at 10 locations for each of the RED, Green, and Blue pixels (a total of 30 locations). The anode was removed, and no damage was seen on the surrounding layers at all points, so the repair was successful.

  Moreover, since no light leakage was observed from the irradiated part, it was confirmed that there was little damage to the organic layer and no problem on the optical characteristics.

  Furthermore, when the cross-sectional shape of the laser irradiated portion was observed using a scanning electron microscope (SEM), the anode was mainly removed, and the fine particles generated by ablation were absorbed by the insulating film, resulting in damage to the sealing layer. Was not seen.

  Further, when these repair locations were aged, no re-leakage occurred. Thus, in the organic EL element C having a top emission structure in which a light emitting part is formed with a different light emitting material for each pixel of RED, Green, and Blue, even if laser repair is performed with the focus on the anode, re-leakage or sealing It was possible to realize repair that removes the target layer with low damage that does not cause deterioration of the sealing performance of the stopper layer.

  Next, in the organic EL element D having the TE structure as in Example 1, as shown in FIG. 6, repair was performed by irradiation with femtosecond laser light. The repair method was the same as in Embodiment 1, and the focus of repair was adjusted to the light emitting layer (for example, Alq3). Furthermore, it was decided to correct the leak by matching the oscillation wavelength of the laser light with the light emitting layer, which is an organic layer, and burning the light emitting layer.

(Evaluation result of Example 3)
Although there were 10 defective pixels in the element D used in Example 3, no damage to the surrounding layers was observed at all locations, and the target light emitting layer was removed by condensing the laser light. The repair was successful.

  In addition, since no light leakage is observed from the irradiated part, there is little damage to the anode and cathode, the color filter layer, and the resin layer, which are inorganic layers with little absorption of the oscillation wavelength of the laser light, and the optical characteristics are also affected. It was confirmed that there was no problem.

  Furthermore, when the cross-sectional shape of one place of the laser irradiation place was observed using a scanning electron microscope (SEM), the light emitting layer was mainly removed, and the fine particles generated by ablation were applied to the anode and the insulating film. Absorbed and no damage to the sealing layer and the color filter layer was observed.

  Further, when these repair locations were aged, no re-leakage occurred. In this way, it is possible to realize a repair that removes the target layer with low damage that does not cause re-leakage or deterioration of the sealing performance of the sealing layer even if laser repair is performed with the focus on the light emitting layer. did it.

  Next, the organic EL element having the same TE structure as in Example 1 was repaired by irradiation with femtosecond laser light as shown in FIG. Here, in Example 4, organic EL elements E and F, each of which constitutes each pixel, were prepared by arranging three-color picture elements of RED, Green, and Blue on the color filter layer in a matrix.

  The repair method was the same as that of the first embodiment, and the focus of repair was adjusted to the anode and the leak was corrected by burning off the anode.

  In addition, the wavelength of the laser light applied to the organic EL element E was set to 780 nm, and the wavelength of the laser light applied to the organic EL element F was set to 490 nm.

(Evaluation result of Example 4)
The defective pixels of the element E were formed at 10 locations for each of the RED, Green, and Blue pixels (a total of 30 locations). The anode targeted by condensing and irradiating laser light (wavelength 780 nm) The repair was successful with no damage to the surrounding layers at all points.

  In addition, the defective pixels of the element F are also formed at 10 locations (30 locations in total) for each of the RED, Green, and Blue pixels. However, the laser beam (wavelength 490 nm) is focused and irradiated. The anode was removed, and no damage was seen on the surrounding layers at all points, so the repair was successful.

  In addition, it was confirmed that both the elements E and F did not cause light leakage from the irradiated portion, so that there was little damage to the color filter layer and the resin layer, and there was no problem on the optical characteristics.

  However, when comparing the pixels of each color of the elements E and F, it is better to use a wavelength with a high transmittance (RED, Green is an element E using a wavelength of 780 nm, and Blue is an element F using a wavelength of 490 nm). Since the repair can be performed with low energy, the spread of the irradiated part was suppressed.

  Further, when the cross-sectional shape of the laser irradiation locations of the elements E and F was observed using a scanning electron microscope (SEM), both elements correspond to the RED, Green, and Blue pixels, respectively, and the anode mainly It was removed. Further, fine particles generated by ablation were absorbed by the insulating film, and no damage to the sealing layer and the color filter layer was observed. However, when the spread to the surroundings is compared, it is better to use a wavelength having a high transmittance (RED, Green is an element E using a wavelength of 780 nm, and Blue is an element F using a wavelength of 490 nm). The spread was suppressed.

  In addition, when both of the elements E and F were aged at these repair locations, no re-leakage occurred. As described above, it was confirmed that by selecting a wavelength having a high transmittance of each color of the color filter layer and performing laser repair, a repair with less damage and a small irradiation area can be realized.

  The various repair conditions used in Examples 1 to 4 have optimum values depending on differences in pixel size, panel size, constituent material, and the like of the organic EL element to be tested. Therefore, the repair conditions used in Examples 1 to 4 are examples, and the present invention is not limited to these.

(Function and effect)
Next, the function and effect will be described.

  In the method for manufacturing an organic EL display according to Embodiment 1 of the present invention, a substrate 11, an anode (first electrode) 12, an organic layer 43 having a light emitting layer 23, and a cathode (second electrode) 14 are laminated in this order. An organic EL element 20 having a laminated structure 25 and having a bright spot defect portion inside the laminated structure 25 is prepared, and laser light is applied to a predetermined layer in the organic layer corresponding to the bright spot defect portion of the organic EL element 20. Irradiation is performed to cause multiphoton absorption to form a non-light-emitting portion 21 composed of a defect portion.

  According to such a configuration, by performing laser repair using multiphoton absorption (multiphoton absorption), repair of a bright spot defect portion with no recurrence of leakage and less damage to the periphery of the repair portion is performed. be able to. For this reason, the aging after repair is less susceptible to the influence of oxygen and moisture, and the probability of leakage again is remarkably reduced, thereby providing an organic EL element having a long element lifetime.

  As described above, the present invention relates to an organic EL display manufacturing method and an organic EL display.

1 is a cross-sectional view of an organic EL display 10 according to Embodiment 1. FIG. It is a schematic diagram which shows the mode of the repair of the pixel defect part of the organic EL display 10 which concerns on Embodiment 1, and the organic EL display which concerns on Example 1. FIG. It is sectional drawing of the organic electroluminescent display 40 which concerns on Embodiment 2. FIG. FIG. 10 is a schematic diagram illustrating a state of repair of a pixel defect portion of an organic EL display according to Example 2. It is a schematic diagram which shows the mode of the repair of the pixel defect part of the organic electroluminescent display which concerns on a comparative example. It is a schematic diagram which shows the mode of the repair of the pixel defect part of the organic electroluminescent display which concerns on Example 3. FIG. It is a schematic diagram which shows the mode of the repair of the pixel defect part of the organic electroluminescent display which concerns on Example 4. FIG.

Explanation of symbols

10,40 Organic EL display
11 Substrate
12 Anode
13,43 Organic layer
14 Cathode
15 Sealing layer
16 Color filter layer
17 Sealing substrate
20, 44 Organic EL device
21, 47 Deficient part (non-light emitting part)
23, 46 Light emitting layer
25,45 Laminated structure
30 femtosecond laser repair equipment
31 femtosecond laser oscillator
33 Mirror
34 lenses
60 YAG laser
70 Discoloration part

Claims (8)

  A substrate, a first electrode, an organic layer having a light emitting layer, and a second electrode are laminated in this order, and an organic EL element having a bright spot defect is prepared inside the laminated structure, A method for manufacturing an organic EL display in which a predetermined layer in an organic layer corresponding to a bright spot defect portion of an organic EL element is irradiated with a laser beam to cause multiphoton absorption to form a non-light emitting portion constituted by a defect portion . In the manufacturing method of the organic electroluminescent display described in Claim 1,
A color filter layer is provided outside the first or second electrode,
The manufacturing method of the organic electroluminescent display which irradiates the said bright spot defect part through the said color filter layer with the said laser beam. In the manufacturing method of the organic electroluminescent display described in Claim 2,
The organic EL element is a method for manufacturing an organic EL display in which a sealing layer, the color filter layer, and a counter substrate are laminated in this order on the second electrode of the laminated structure. In the manufacturing method of the organic electroluminescent display described in Claim 1,
The said laser beam is a manufacturing method of the organic electroluminescent display which is femtosecond laser beam. In the manufacturing method of the organic electroluminescent display described in Claim 1,
A method for manufacturing an organic EL display, which irradiates the laser beam at an oscillation wavelength in an absorption wavelength band of the predetermined layer. In the manufacturing method of the organic electroluminescent display described in Claim 1,
A method for manufacturing an organic EL display, wherein the non-light-emitting portion is formed in the first electrode. In the manufacturing method of the organic electroluminescent display described in Claim 1,
The manufacturing method of the organic electroluminescent display which forms the said non-light-emitting part in the said light emitting layer.   An organic layer having a laminated structure in which a substrate, a first electrode, an organic layer having a light emitting layer, and a second electrode are laminated in this order, and having a non-light emitting portion composed of a defective portion in a predetermined layer in the organic layer EL display.

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