JP5963342B2 - Manufacturing method of organic EL element - Google Patents

Description

  The present invention relates to a method for manufacturing an organic electroluminescence element.

  Conventionally, in an organic electroluminescence (hereinafter referred to as “organic EL”) element in which an organic layer is interposed between an anode (anode) and a cathode (cathode), conductive foreign matters are attached or mixed in the manufacturing process. The anode and the cathode may be short-circuited. In this case, there is a method of repairing (resolving) the short-circuited portion by performing laser irradiation on the short-circuited portion (see, for example, Patent Documents 1 and 2).

  In Patent Document 1, an organic EL element including a first electrode formed on a substrate and a second electrode provided so as to face the first electrode through a light emitting layer and having a bright spot defect portion therein. The manufacturing method including the process of repairing is disclosed. Specifically, the pixel having the bright spot defect portion is repaired by irradiating the bright spot defect portion with a laser beam to cause multiphoton absorption to form a non-light emitting portion. According to this manufacturing method, it is not necessary to match the absorption wavelength of the film to be repaired with the oscillation wavelength of the laser by using a multiphoton absorption mode different from that of normal laser repair. It can be repaired by multiphoton absorption. In addition, if a specific layer has absorption by multiphoton absorption, only a specific film in the laminated film is repaired, and it may be impossible to repair properly, so half of the light absorption wavelength of the light emitting layer is assumed. By irradiating an oscillation wavelength outside the value band, reliable repair is performed on the target layer or the entire laminated film. In order to avoid repair unevenness due to the difference in intensity between the laser irradiation center and the surrounding area, the above-mentioned bright spot defect portion is irradiated through a mask having a laser light passage hole, and the effect of the multiphoton absorption mode is more remarkably extracted. Yes. By irradiating the laser according to the above embodiment, the bright spot defect portion and the anode, organic layer, color filter layer, etc. in the vicinity thereof are extinguished and a non-light emitting portion is formed, thereby causing a bright spot with little damage to the repair area. It is said that repair of a defective part can be performed.

  Moreover, in patent document 2, with respect to the organic EL element which has the same laminated structure and bright spot defect part as patent document 1, a predetermined layer in the organic layer corresponding to the bright spot defect part is irradiated with laser light, A method of manufacturing an organic EL display that causes multiphoton absorption and has a defect portion as a non-light emitting portion is disclosed. According to this manufacturing method, by performing laser repair using multiphoton absorption, a non-light-emitting portion composed of a defect portion is formed in a predetermined layer in the organic layer, and in that region, a peripheral layer or a peripheral portion is formed. It is possible to produce an organic EL element that does not damage this region.

JP 2008-235177 A JP 2008-235178 A

  In the manufacturing method of the organic EL element described in Patent Document 1, at least dust and particles constituting the bright spot defect portion are focused and irradiated with a laser, and an anode and an organic layer that are close to the bright spot defect portion. The non-light emitting portion is formed by eliminating or modifying the color filter layer and the like. However, the laser component that does not absorb light in the non-light-emitting part is absorbed in the vicinity of the non-light-emitting part and causes thermal damage, the non-light-emitting part expands to the vicinity, the non-lighting area is enlarged, and the repair quality is deteriorated. There is a fear that it will end.

  Moreover, in the manufacturing method of the organic EL element described in Patent Document 2, the predetermined layer of the organic layer including the anode is irradiated with a laser so that the predetermined layer is denatured or extinguished to form a non-light emitting portion. . However, an intensity component less than the energy for processing the predetermined layer by multiphoton absorption transmits the predetermined layer and causes energy absorption in other organic layers. This causes thermal damage in other organic layers. Furthermore, even if the intensity component has energy to process the predetermined layer by multiphoton absorption, if the variation of the intensity component is large, the predetermined layer to be processed is also thermally damaged. Due to the thermal damage of the organic layer and the predetermined layer, there is a concern that the non-light emitting portion expands to the periphery of the organic layer and the predetermined layer, the non-lighting area is expanded, and the repair quality is deteriorated.

  In view of the above problems, an object of the present invention is to provide an organic EL element manufacturing method that eliminates a short-circuited portion between electrodes without causing laser damage to an organic layer made of an organic material and a predetermined layer to be processed. To do.

  In order to solve the above problems, a method for manufacturing an organic EL element according to one embodiment of the present invention includes a lower electrode layer, an organic layer including a light emitting layer, and an upper electrode layer, which are stacked in this order. A preparation step of preparing an organic EL device having at least one of layers made of a transparent material and having a defect portion, and selecting a laser beam having an intensity distribution of a top flat distribution, and selecting the selected laser beam, An irradiation step of irradiating at least one of the defect portion and the periphery of the defect portion to eliminate a defect caused by the defect portion.

  According to the method of manufacturing an organic electroluminescent element according to the present invention, only laser light having a top flat (top hat) distribution is selected from laser beams having an intensity distribution, and the electrode layer region of the defective portion or the same layer is selected. Irradiate around the area. Therefore, thermal damage to the organic layer adjacent to the electrode layer can be reduced by a strength component less than the energy for processing the electrode layer, and thermal damage is also applied to the electrode layer to be processed by a uniform strength component. Since it can be reduced, it is possible to minimize the non-lighting area that has become a dark spot, and to improve the repair accuracy.

It is a section schematic diagram of an organic EL device concerning an embodiment of the invention. It is a top view of the organic EL element showing the shape of the cathode made high resistance. It is a flowchart explaining the manufacturing method of the organic EL element which concerns on this invention. It is a section schematic diagram of an organic EL element prepared at the 1st process of the present invention. It is an operation | movement flowchart for demonstrating step S20 which concerns on embodiment of this invention. It is an operation | movement flowchart for demonstrating step S30 which concerns on embodiment of this invention. It is a system configuration figure for carrying out laser repair concerning an embodiment of the invention. It is the graph showing the intensity distribution of the laser beam in the organic EL element surface which concerns on embodiment, and the graph which expanded the top flat distribution. It is the graph showing the intensity distribution of the laser beam in the organic EL element surface which concerns on embodiment, and the graph which expanded the distribution with a large dispersion | variation in an intensity component. It is a cross-sectional schematic diagram of the organic EL element during laser irradiation. It is a figure showing the pixel light emission state at the time of irradiating the laser beam which passed the slit which has a slit width of 50 micrometers square. It is a figure showing the pixel light emission state at the time of irradiating the laser beam which passed the slit which has a slit width of 200 micrometers phi. It is a figure showing the pixel light emission state at the time of irradiating the laser beam which passed the slit which has a 300 micrometers square slit width. It is a figure showing the light emission state of the pixel at the time of laser drawing and recovery lighting confirmation. It is a cross-sectional schematic diagram of the organic EL element which concerns on the 1st modification of embodiment of this invention. It is a section schematic diagram of the organic EL element concerning the 2nd modification of an embodiment of the invention. It is an external view of the television system provided with the organic EL element of this invention.

  In the method for manufacturing an organic EL element according to one embodiment of the present invention, a lower electrode layer, an organic layer including a light emitting layer, and an upper electrode layer are stacked in this order, and at least one of the lower electrode layer and the upper electrode layer is a transparent material. A preparation step of preparing an organic EL element having a defect portion, and selecting a laser beam having an intensity distribution of a top flat distribution, and applying the selected laser beam around the defect portion and the defect portion Irradiating at least one of them and irradiating the defect caused by the defective part.

  According to this aspect, only the laser beam having the top flat distribution is selected and irradiated to the defect portion and the periphery of the defect portion. Therefore, thermal damage to the organic layer adjacent to the electrode layer can be reduced by a strength component less than the energy for processing the electrode layer, and thermal damage is also applied to the electrode layer to be processed by a uniform strength component. Since it can be reduced, it is possible to minimize the non-lighting area that has become a dark spot, and to improve the repair accuracy.

  In one embodiment of the present invention, in the irradiation step, laser light having a Gaussian intensity distribution is disposed between a light source that emits the laser light and the organic EL element. It is preferable to irradiate a laser beam whose intensity distribution is a top flat distribution obtained by passing through a slit having a slit width smaller than the beam diameter of the light and an imaging optical system.

  According to this aspect, it is possible to select only the intensity component of the top flat (top hat) distribution from the laser light having the Gaussian distribution with a simple configuration.

  Further, according to one embodiment of the present invention, in the irradiation step, the laser light is irradiated with a region of the lower electrode layer or the upper electrode layer made of the transparent material in the defect portion and a periphery of the region in the same layer. It is preferable to irradiate at least one of them.

  According to this aspect, only the laser beam having the top flat distribution is selected and irradiated to the defect portion and the electrode layer region of the defect portion or the periphery of the region in the same layer. Therefore, thermal damage to the organic layer adjacent to the electrode layer can be reduced by a strength component less than the energy for processing the electrode layer, and thermal damage is also applied to the electrode layer to be processed by a uniform strength component. Since it can be reduced, it is possible to minimize the non-lighting area that has become a dark spot, and to improve the repair accuracy.

  In one embodiment of the present invention, the slit width of the slit is preferably 10 to 200 μm.

  According to this aspect, it is possible to select a laser having only an intensity component of a top flat distribution in which mutual interference is suppressed in visible light to near-infrared laser light.

  In one embodiment of the present invention, the laser light is preferably an ultrashort pulse laser.

  According to this embodiment, the resistance of an anode or cathode in an amorphous state can be easily increased by irradiation with an ultrashort pulse laser. Furthermore, it is possible to increase the resistance of a transparent conductive material that is not easily processed by other lasers.

  In one embodiment of the present invention, the transparent material may be a metal oxide.

  Thereby, since the constituent material of the electrode is a transparent metal oxide, the resistance can be more reliably increased by irradiation with an ultrashort pulse laser.

  Further, according to one aspect of the present invention, in the irradiation step, a laser beam whose intensity distribution is a top flat distribution is a region of the lower electrode layer or the upper electrode layer made of the transparent material in the defect portion, and At least one of the surroundings in the same layer of the region is multiphoton absorbed, so that at least one of the regions has a high resistance.

  As a result, the intensity component that is less than the energy to increase the resistance of the cathode or anode by multiphoton absorption may pass through the cathode or anode and cause thermal damage to the organic layer, and laser light with large intensity variation. Can suppress thermal damage to the electrode layer, so that the area to be darkened by repair can be suppressed to a minimum, and repair accuracy can be improved.

  Hereinafter, the manufacturing method of the organic EL element concerning embodiment of this invention is demonstrated based on drawing. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout all the drawings, and redundant description thereof is omitted.

(Embodiment 1)
<Element structure>
FIG. 1 is a schematic cross-sectional view of an organic EL element 1 according to an embodiment of the present invention. The organic EL element 1 shown in the figure is an organic functional device having an organic layer including an anode, a cathode, and a light emitting layer sandwiched between the two electrodes.

  As shown in FIG. 1, the organic EL element 1 includes a planarizing film 10, an anode 11, a hole injection layer 12, a light emitting layer 13, a partition wall 14, and an electron injection layer 15 on a transparent glass 9. And a cathode 16, a thin film sealing layer 17, a sealing resin layer 19, and a transparent glass 18.

  The anode 11 and the cathode 16 correspond to the lower electrode layer and the upper electrode layer in the present invention, respectively. Moreover, the hole injection layer 12, the light emitting layer 13, and the electron injection layer 15 correspond to the organic layers in the present invention.

  The transparent glasses 9 and 18 are substrates that protect the light emitting surface of the light emitting panel, and are, for example, transparent alkali-free glass having a thickness of 0.5 mm.

  For example, the planarization film 10 is made of an insulating organic material, and is formed on a substrate including, for example, a driving thin film transistor (TFT).

  The anode 11 is an anode to which holes are supplied, that is, an electric current flows from an external circuit, and has a structure in which a reflective electrode made of, for example, Al or silver alloy APC is laminated on the planarizing film 10. Yes. The thickness of the reflective electrode is 10 to 40 nm as an example. The anode 11 may have a two-layer structure made of, for example, ITO (Indium Tin Oxide) and silver alloy APC. In this way, the anode 11 is formed of a metal having a high reflectance such as APC, so that the irradiated laser light is reflected by the metal having a high reflectance. Therefore, the laser light is collected on a layer to be focused more efficiently. It becomes possible to shine.

  The hole injection layer 12 is a layer mainly composed of a hole injecting material. The hole injecting material is a material having a function of injecting holes injected from the anode 11 side into the light emitting layer 13 stably or by assisting the generation of holes. For example, PEDOT (polyethylene Compounds such as dioxythiophene) and aniline are used.

  The light emitting layer 13 is a layer that emits light when a voltage is applied between the anode 11 and the cathode 16. For example, α-NPD (Bis [N- (1-naphthyl) -N-phenyl] benzidine), As the upper layer, Alq3 (tris- (8-hydroxyquinoline) aluminum) is laminated.

  The electron injection layer 15 is a layer mainly composed of an electron injecting material. The electron injecting material is a material having a function of injecting electrons injected from the cathode 16 into the light emitting layer 13 in a stable manner or assisting the generation of electrons. For example, polyphenylene vinylene (PPV) is used. Is done.

  The cathode 16 is a cathode to which electrons are supplied, that is, a current flows out to an external circuit, and has a structure in which, for example, ITO is laminated as a transparent metal oxide. It can also be formed as a transparent electrode using a material such as Mg or Ag. Moreover, the thickness of an electrode is 10-40 nm as an example.

  The partition wall 14 is a wall for separating the light emitting layer 13 into a plurality of light emitting regions, and is made of, for example, a photosensitive resin.

  The thin film sealing layer 17 is made of, for example, silicon nitride and has a function of blocking the light emitting layer 13 and the cathode 16 from water vapor and oxygen. This is to prevent the light emitting layer 13 itself or the cathode 16 from being deteriorated (oxidized) by being exposed to water vapor or oxygen.

  The sealing resin layer 19 is an acrylic or epoxy resin, and joins the transparent glass 18 and the integrally formed layer from the planarization film 10 to the thin film sealing layer 17 formed on the substrate. It has the function to do.

  The configuration of the anode 11, the light emitting layer 13, and the cathode 16 described above is a basic configuration of the organic EL element. With such a configuration, when an appropriate voltage is applied between the anode 11 and the cathode 16, the anode 11 side To holes and electrons from the cathode 16 side are respectively injected into the light emitting layer 13. By the energy generated by recombination of these injected holes and electrons in the light emitting layer 13, the light emitting material of the light emitting layer 13 is excited and emits light.

  The materials of the hole injection layer 12 and the electron injection layer 15 are not limited in the present invention, and a known organic material or inorganic material is used.

  Moreover, as a structure of the organic EL element 1, there may be a hole transport layer between the hole injection layer 12 and the light emitting layer 13, or an electron transport layer between the electron injection layer 15 and the light emitting layer 13. There may be. In addition, a hole transport layer may be disposed instead of the hole injection layer 12, and an electron transport layer may be disposed instead of the electron injection layer 15. The hole transport layer is a layer mainly composed of a material having a hole transport property. Here, the hole transporting material has both the property of having an electron donor property and easily becoming a cation (hole) and the property of transferring the generated hole by intermolecular charge transfer reaction. It is a material having appropriateness for charge transport to the light emitting layer 13. The electron transport layer is a layer mainly composed of an electron transport material. Here, the material having an electron transporting property has a property of having an electron acceptor property and easily becoming an anion, and a property of transmitting generated electrons by a charge transfer reaction between molecules, and from the cathode 16 to the light emitting layer 13. A material that has suitability for charge transport.

  The organic EL element 1 further includes a color filter (light control layer) that performs red, green, and blue color adjustment on the lower surface of the transparent glass 18 so as to cover each light emitting region separated by the partition wall 14. It may be a configuration.

  In the present invention, the hole injection layer 12, the light emitting layer 13, and the electron injection layer 15 are collectively referred to as an organic layer 30. In addition, when the hole transport layer and the electron transport layer are included, these layers are also included in the organic layer 30. As an example, the thickness of the organic layer 30 is 100 nm to 200 nm. Further, the planarization film 10, the anode 11, the organic layer 30, the cathode 16, the thin film sealing layer 17, and the transparent glass 18 arranged in the light emitting region separated by the partition wall 14 are referred to as a pixel 2.

  Furthermore, in the organic EL element 1 shown in FIG. 1, in the manufacturing process, conductive foreign matter 20 is mixed between the anode 11 and the cathode 16, and the anode 11 and the cathode 16 are short-circuited via the foreign matter 20. Yes. Then, by increasing the resistance of the cathode portion 16a around the foreign material 20, the short circuit between the anode 11 and the cathode 16 short-circuited by the foreign material 20 is eliminated (repaired). The repair process for the shorted part will be described later.

  FIG. 2 is a top view of the organic EL element showing the shape of the cathode having a high resistance. As shown in the figure, in the present embodiment, the laser focus is focused on the cathode 16 in a predetermined area around the foreign material 20 and the laser is irradiated. For example, the peripheral cathode 16 that is about 10 μm away from the foreign material 20 is irradiated with a laser with high efficiency in a square shape of a square of 20 μm × 20 μm, and a part 16a of the cathode with high resistance is formed.

<Manufacturing method>
Next, a method for manufacturing the organic EL element 1 will be described.

  FIG. 3 is a flowchart illustrating a method for manufacturing an organic EL element according to the present invention.

  First, an organic EL panel is prepared (S10). In the organic EL panel, pixels in which an organic EL element and a drive circuit for driving the organic EL element are formed are arranged in a matrix. This step is a step of stacking and forming organic EL elements included in a plurality of pixels arranged in a matrix, and corresponds to a preparation step.

  Next, in the organic EL panel included in the plurality of pixels formed in step S10, the short-circuit state of the organic EL element included in each pixel is inspected, and the short-circuit defect portion in the short-circuit state is specified (S20).

  Finally, the short-circuit defect detected in step S20 is repaired by laser irradiation (S30). The process in step S30 is a characteristic process of the present invention.

  Through the above steps, an organic EL panel having a high-quality organic EL element with a high yield is completed.

  Hereinafter, the three steps described above will be described in detail.

  First, the step (S10) of preparing an organic EL element will be described.

  FIG. 4 is a schematic cross-sectional view of the organic EL element prepared in the first step of the present invention. In the drawing, a cross-sectional structure of the organic EL element 1A in which the anode 11 and the cathode 16 are short-circuited by the foreign matter 20 is shown.

  First, a planarizing film 10 made of an insulating organic material is formed on a substrate including a TFT, and then an anode 11 is formed on the planarizing film 10. The anode 11 is formed by, for example, sputtering, depositing Al with a thickness of 30 nm on the planarizing film 10, and then performing a patterning process by photolithography and wet etching.

  Next, the hole injection layer 12 is formed on the anode 11 by, for example, dissolving PEDOT in a solvent made of xylene and spin-coating this PEDOT solution.

  Next, α-NPD and Alq3 are stacked on the hole injection layer 12 by, for example, a vacuum deposition method, and the light emitting layer 13 is formed.

  Next, the electron injection layer 15 is formed on the light emitting layer 13 by, for example, polyphenylene vinylene (PPV) dissolved in a solvent made of xylene or chloroform and spin-coated.

  Subsequently, the cathode 16 is formed without exposing the substrate on which the electron injection layer 15 is formed to the atmosphere. Specifically, the cathode 16 is formed by depositing 35 nm of ITO (Indium Tin Oxide) on the electron injection layer 15 by sputtering. At this time, the cathode 16 is in an amorphous state.

  By the manufacturing process, an organic EL element having a function as a light emitting element is formed. In addition, the partition 14 which consists of surface photosensitive resin is formed in a predetermined position between the formation process of the anode 11, and the formation process of the positive hole injection layer 12. FIG.

Next, 500 nm of silicon nitride is laminated on the cathode 16 by, for example, plasma CVD (Chemical Vapor Deposition) to form the thin film sealing layer 17. Since the thin film sealing layer 17 is formed in contact with the surface of the cathode 16, it is particularly preferable that the necessary conditions as a protective film are tightened. Non-oxygen-based inorganic materials such as the above-described silicon nitride are preferably used. preferable. Further, for example, an oxygen-based inorganic material such as silicon oxide (Si _X O _Y ) or silicon oxynitride (Si _X O _Y N _Z ), or a structure in which a plurality of these inorganic materials are formed may be used. Further, the forming method is not limited to the plasma CVD method, and may be other methods such as a sputtering method using argon plasma.

  Next, a sealing resin layer 19 is applied to the surface of the thin film sealing layer 17. Thereafter, the transparent glass 18 is disposed on the applied sealing resin layer 19. Here, a color filter (light control layer) may be formed in advance on the main surface of the transparent glass 18. In this case, the transparent glass 18 is disposed on the applied sealing resin layer 19 with the surface on which the color filter is formed facing downward. The thin film sealing layer 17, the sealing resin layer 19, and the transparent glass 18 correspond to the protective layer in the present invention.

  Finally, heat or energy rays are applied while pressing the transparent glass 18 downward from the upper surface side to cure the sealing resin layer 19, and the transparent glass 18 and the thin film sealing layer 17 are bonded.

  By such a forming method, the organic EL element 1A shown in FIG. 4 is formed.

  In addition, the formation process of the anode 11, the hole injection layer 12, the light emitting layer 13, the electron injection layer 15, and the cathode 16 is not limited by this invention.

  Next, the process (S20) which specifies the short circuit defect part of an organic EL element is demonstrated.

  In FIG. 4, the foreign material 20 includes, for example, Al, which is a material of the anode 11, and adheres to the anode 11 after the formation of the anode 11, followed by the hole injection layer 12, the light emitting layer 13, the electron injection layer 15, This is because the cathode 16 is laminated. As an example, the size of the foreign material 20 is about 200 nm in diameter and about 500 nm in height. Since the anode 11 and the cathode 16 are short-circuited by the foreign matter 20, the organic EL element does not emit light in this pixel 2 and becomes a dark spot pixel.

  FIG. 5 is an operation flowchart for explaining step S20 according to the embodiment of the present invention.

  First, a lighting inspection of the organic EL panel formed in step S10 is performed (S21). Specifically, a forward bias voltage is applied simultaneously to all the pixels of the organic EL panel by a drive circuit provided in the organic EL panel or by an externally connected source meter. At this time, all pixels are imaged with a CCD camera or the like.

  Then, the light emission luminance of each pixel is calculated from the captured image in the forward bias voltage application period, and a pixel whose light emission luminance is equal to or lower than a predetermined threshold, that is, a so-called dark spot pixel is detected (S22).

  Next, the detected dark spot pixel is enlarged and observed (S23). Specifically, for example, a dark spot pixel is observed using a camera microscope.

  At this time, the foreign object 20 is specified in the area of the dark spot pixel observed to be enlarged (S24).

  Next, a reverse bias voltage is applied to the dark spot pixel detected in step S22 to specify a light emission point that emits leak light (S25). In a normal pixel, no current flows through the organic EL element due to the reverse bias voltage, but in an organic EL element having a short-circuit defect portion, leak light emission due to a leak current is observed at the short-circuit portion. A leak light emission point in the light emitting pixel is specified by an image obtained by imaging the leak light emission state. Specifically, a predetermined reverse bias voltage is applied to the pixel to be inspected by a drive circuit provided in the organic EL panel or by an externally connected source meter. Then, a light emitting point that emits leak light having a threshold intensity or higher during the period in which the reverse bias voltage is applied is specified. Since leak light emission due to reverse bias voltage application is weak, it is preferable that imaging by a CCD camera or the like is performed in a completely light-shielded environment. Then, the light emission intensity at each imaging point is binarized with the threshold intensity to determine whether or not the leak light emission point is correct. In this way, the leak emission point is specified.

  The CCD camera is preferably a cooled CCD camera. Thereby, a predetermined S / N ratio can be ensured even in the imaging of leak light emission of a weak organic EL element. Therefore, noise during inspection is eliminated, and the detection accuracy of defective pixels is improved.

  Next, by synthesizing the image of the dark spot pixel in the forward bias voltage application observed in step S24 and the image of the leak light emission point in the reverse bias voltage application observed in step S25, in the dark spot pixel. The position of the short-circuit defect portion is determined (S26).

  In the determination process of the short-circuit defect portion position in step S26 described above, the short-circuit defect portion position is determined based on the degree of coincidence between the foreign matter specified in the forward bias voltage application and the leak emission point specified in the reverse bias voltage application. However, the position of the short-circuit defect portion may be determined by specifying the foreign matter when applying the forward bias voltage or specifying the leak emission point when applying the reverse bias voltage.

  In addition, the detection of the pixel having the short-circuit defect portion is not limited to the above-described method. For example, the current value flowing between the anode 11 and the cathode 16 of the organic EL element is measured and detected based on the magnitude of the current value. May be. In this case, a pixel having a current value equivalent to that of a normal pixel when a forward bias voltage is applied and a leak light emission observed when a reverse bias voltage is applied may be determined as a dark spot pixel.

  Next, the process (S30) which repairs the short circuit defect part of the organic EL element which is the principal part of this invention by laser irradiation is demonstrated.

  In this step, instead of monitoring the reflected light having the same wavelength as the laser irradiation wavelength, by monitoring the emitted light from a certain layer of the multilayer film constituting the organic EL element, The laser focus is adjusted. The emitted light is generated by multiphoton absorption in the specific layer, and may have a wavelength range unique to the specific layer. Therefore, when irradiating a specific layer with a laser with high efficiency, the distance between the laser source and the specific film is adjusted while monitoring the radiation corresponding to the specific layer. Can be combined.

  In addition, although the radiated light radiated | emitted through the multiphoton absorption process mentioned above is matched with each layer based on the band gap etc. of the material which comprises each layer, the said radiated light is not restricted to this. Even radiated light that has not been determined to have undergone a multiphoton absorption process may be radiated light that has a shorter wavelength than the laser light wavelength to be irradiated and can be associated with each layer.

  FIG. 6 is an operation flowchart for explaining step S30 according to the embodiment of the present invention. FIG. 7 is a system configuration diagram for carrying out laser repair according to the embodiment of the present invention. The system described in FIG. 7 includes a laser oscillator 101, a slit 102, a stage 103, an imaging lens 104, and an objective lens 105. In addition, an organic EL panel having the organic EL element 1 </ b> A, which is a work-in-process, is fixedly disposed on the stage 103.

  For example, the laser oscillator 101 can oscillate an ultrashort pulse laser having a wavelength of 532 nm to 1600 nm, an output energy of 1 to 30 μJ, and a pulse width of the order of several femtoseconds to several picoseconds. Such ultrashort pulse lasers include, for example, femtosecond lasers, and a suitable pulse width range is 100 fs to 20 ps. By irradiating with an ultrashort pulse laser, it is possible to easily increase the resistance of the constituent material of the anode or cathode in an amorphous state. Furthermore, it is possible to increase the resistance of a transparent conductive material that is not easily processed by other lasers.

  In the present embodiment, a laser focus is set on the cathode 16 to increase the resistance of a part of the cathode 16. At this time, the range of output energy that can increase the resistance of a part of the cathode 16 depends on the wavelength of the laser to be irradiated. If the cathode 16 is irradiated with a laser having excessive output energy, the laser reaches the organic layer 30 provided below the cathode 16 and the organic layer 30 is damaged. Further, when the cathode 16 is irradiated with a laser having an excessive output energy, the cathode 16 is not increased in resistance. Further, when the laser having a pulse width of 20 psec or more is irradiated, the organic layer 30 is damaged. By combining these and irradiating the organic EL element with a laser having a pulse width in the above-mentioned laser wavelength range and in the above-mentioned pulse width range, a part of the cathode 16 can be easily increased in resistance.

  The stage 103 is movable in the height direction Z and the plane directions X and Y, and has a function of fixing an object to be repaired.

  Hereinafter, the repair process (S30) will be described in detail with reference to the flowchart of FIG.

  First, in order to increase the resistance of the peripheral portion by irradiating the peripheral portion of the short-circuit region of the cathode 16 with the foreign material 20 to increase the resistance, the laser irradiation position and the drawing line are set (S31). Specifically, as shown in FIG. 2, in the present embodiment, 20 μm is applied to the surrounding cathode 16, which is about 10 μm away from the foreign material 20, so as to irradiate the cathode 16 in a predetermined region around the foreign material 20. The drawing line in the plane direction is set so that the laser is irradiated in a square shape of a square of 20 μm.

  Next, from the laser light having the intensity distribution, an intensity component whose intensity distribution is a top flat distribution is selected, and only the selected intensity component is placed around the short-circuit portion of the cathode 16 that is in contact with the foreign material 20. Irradiate to eliminate the short-circuit failure caused by the foreign matter 20 (S32). Step S32 corresponds to an irradiation step.

  FIG. 8A is a graph showing the intensity distribution of laser light on the surface of the organic EL element according to the embodiment and a graph in which the top flat distribution is enlarged. 8A shows the intensity distribution of the laser light emitted from the laser oscillator 101. The horizontal axis represents the distance from the beam center, and the vertical axis represents the normalized beam energy of the laser beam. 8A shows the intensity distribution of the top flat portion of the laser light emitted from the laser oscillator 101. In the same figure, the intensity range selected by the slit width of the slit 102 is also shown.

  In the intensity distribution of the laser light output from the laser oscillator 101, the intensity absorbed by the multiphoton absorption process at the cathode 16 needs to be equal to or higher than a predetermined intensity. Therefore, when the organic EL element 1A is irradiated with an intensity component having a large distance from the beam center and having a predetermined intensity or less, the component passes through the cathode 16 and thermally damages and denatures the electron injection layer 15 and the light emitting layer 13. End up. Further, even when only the intensity component having the predetermined intensity or higher is focused on the cathode 16 and the intensity component having the predetermined intensity or higher is greatly varied, the cathode 16 to be processed is also heated. It will cause damage. Due to thermal damage to the electron injection layer 15, the light emitting layer 13 and the cathode 16 described above, the non-light emitting portion after repair expands to the periphery of the organic layer and the cathode 16, the non-lighting area expands, and the repair quality deteriorates. There is a fear that it will end. For example, when the beam diameter of the laser light output from the laser oscillator 101 is 4 mm and the objective lens 105 is 20 times, when the slit 102 is not provided, the beam condensing diameter is 5 mm on the surface of the organic EL element 1A. It becomes. This includes a strength component that modifies the electron injection layer 15 and the light emitting layer 13 and does not denature the cathode 16.

  On the other hand, by providing, for example, a slit 102 having a slit width smaller than the beam condensing diameter and an imaging lens 104 which is an imaging system between the laser oscillator 101 and the objective lens 105, the top. Laser light having only an intensity component having a flat distribution can be obtained. Here, the laser beam having only the intensity component of the top flat distribution is a laser beam having an intensity distribution of the Gaussian distribution, and only an intensity component of 60% or more with respect to the maximum intensity at the beam center can be obtained. Laser light that is in the beam range.

  In the present embodiment, among the intensity distributions that are Gaussian distributions emitted from the laser oscillator 101, only the intensity distribution for uniformly increasing the resistance of the portion of the cathode 16 to be processed is transmitted through the slit 102. The transmitted intensity component is condensed to a desired beam condensing diameter (˜10 μm) by the imaging lens 104. If the top flat distribution is to be realized using only the slit 102 without using the imaging lens 104, the slit width must be set to a size equal to or smaller than the beam diameter to be irradiated on the surface of the organic EL element 1A. In this case, the mutual interference between the laser beams transmitted through the slit 102 is strong, and the top flat distribution cannot be obtained. Therefore, it is preferable to set the slit width (10 to 200 μm) so that the laser beams transmitted through the slit 102 do not interfere with each other, and to dispose the imaging lens 104 in order to avoid diffusion of the laser beam transmitted through the slit 102. . When the slit width is smaller than 10 μm, the top flat distribution cannot be obtained due to the mutual interference of the laser beams as described above. On the other hand, when the slit width is larger than 200 μm, the variation in the intensity component of the transmitted light in the visible light to near-infrared laser light becomes large, and the top flat distribution cannot be obtained.

  FIG. 8B is a graph showing the intensity distribution of the laser light on the surface of the organic EL element according to the embodiment and an enlarged graph of the distribution with a large variation in intensity components. 8B shows the intensity distribution of the laser light emitted from the laser oscillator 101. The horizontal axis represents the distance from the beam center, and the vertical axis represents the normalized beam energy of the laser beam. Further, the lower diagram of FIG. 8B shows the intensity distribution of a portion shifted by 1 μm from the beam center of the laser beam emitted from the laser oscillator 101. In the intensity distribution shown in the figure below, the laser beam having a beam diameter of ± 150 μm that has passed through the slit 102 has an intensity variation of 15 to 20%. When this laser light is condensed using the imaging lens 104 and irradiated to the organic EL element 1A, an absorption mode other than multiphoton absorption occurs in the cathode 16 to be processed, and the cathode 16 is thermally damaged. The non-light emitting portion after repair expands to the periphery of the organic layer and the cathode 16 and the non-lighting area expands, and the repair quality deteriorates.

  The method of irradiating the cathode 16 with the laser light having only the intensity component of the top flat distribution among the laser light irradiating the organic EL element is not limited to the method of passing through the slit 102 and the imaging lens 104 described above. .

  Here, the multiphoton absorption process caused by laser light irradiation on the cathode 16 will be described. The peak wavelengths observed in the spectrum of the emitted light emitted from the cathode 16 are all located on the shorter wavelength side than the laser incident wavelength. This is presumed that the cathode 16 emits light having a shorter wavelength than the incident laser by being excited by multiphoton absorption by the incident laser. Incidentally, the wavelength of the emitted light from the laminated film to be irradiated differs depending on the band gap of each laminated film. Thus, by monitoring the radiated light having a wavelength unique to each laminated film, it is possible to cause excitation by multiphoton absorption in the laminated film to be processed.

  FIG. 9 is a schematic cross-sectional view of an organic EL element during laser irradiation. As shown in the figure, the laser 125 having only the intensity component of the top flat distribution shown in FIG. 8A is irradiated around the defect portion so as to surround the short-circuit defect portion where the foreign matter 20 exists. That is, the specified laser beam is irradiated around the same layer in the cathode 16 region of the short-circuit defect portion. Thus, the cathode region that is electrically short-circuited with the foreign material 20, that is, the cathode region surrounded by the cathode part 16 a is insulated from the other cathode regions and short-circuited to the anode 11 via the foreign material 20. The Thereby, the current path flowing between the anode 11 and the cathode 16 does not occur in the cathode region surrounded by the cathode part 16a, but normally occurs in the cathode region other than the cathode region.

  FIG. 10A is a diagram illustrating a pixel light emission state when a laser beam that has passed through a slit having a slit width of 50 μm square is irradiated. FIG. 10B is a diagram illustrating a pixel light emission state when a laser beam that has passed through a slit having a slit width of 200 μmφ is irradiated. FIG. 10C is a diagram illustrating a pixel light emission state when a laser beam that has passed through a slit having a slit width of 300 μm square is irradiated. In any case, the laser light emitted from the laser oscillator 101 passes through the slit 102 and then passes through the imaging lens 104 and the objective lens 105 as shown in the system configuration diagram of FIG. The surface of the EL element 1A is irradiated. FIG. 10A to FIG. 10C show pixel emission states when a laser beam that has passed through the slit and the imaging lens described above is irradiated linearly on the pixel center portion.

  In FIG. 10A and FIG. 10B showing the results of using the method for manufacturing the organic EL element of the present invention, the intensity distribution of the laser beam that has passed through the slits 102 of 50 μm square and 200 μmφ causes multiphoton absorption in the uniform cathode 16. Top flat distribution. Thereby, in the pixel light emission state, only the light emission luminance is lowered only at the laser irradiation portion, and the peripheral portion of the laser irradiation portion is not affected by the laser irradiation in the light emission state. This is because only the laser-irradiated portion of the cathode 16 has been increased in resistance, and the layers adjacent to the top and bottom of the portion and the in-plane peripheral portion of the portion are not modified. It is.

  On the other hand, in FIG. 10C, the intensity distribution of the laser beam that has passed through the 300 μm square slit has a large intensity variation although it has an intensity component that causes multiphoton absorption in the uniform cathode 16. As a result, in the pixel emission state, not only the laser irradiation portion but also the non-light emitting region diffuses not only in the peripheral portion of the laser irradiation portion. This is because, in addition to multiphoton absorption at the cathode 16, the cathode 16 is thermally damaged at the periphery of the irradiated portion by irradiating the cathode 16 with an intensity component that causes thermal damage. Is.

  Returning to FIG. 6 again, the laser repair process will be described.

  Finally, it is confirmed whether or not the pixel having the short-circuit defect portion has been recovered by the laser repair described above (S33).

  FIG. 11 is a diagram illustrating the light emission state of the pixel at the time of laser drawing and at the time of recovery lighting confirmation. During laser drawing in step S32, pixels having a short-circuit defect do not emit light even when a forward bias voltage is applied unless the drawing line is connected. On the other hand, when the recovery lighting is confirmed after the drawing line is completed, it is confirmed that, by applying the forward bias voltage, the area surrounded by the drawing line does not emit light, but the other areas emit light. When this is confirmed as the whole organic EL light emitting panel, even if a 20 μm × 20 μm square region does not emit light, the non-emitting portion is not visually recognized, and the image quality of the organic EL panel is improved.

  Conventionally, laser irradiation using multiphoton absorption is performed by focusing on the dust and particles that make up the bright spot defect, and the anode, organic layer, color filter layer, etc. close to the bright spot defect are also extinguished. Or it modified | denatured and the non-light-emission part was formed. Further, by irradiating a predetermined layer of the organic layer including the anode with a laser, the predetermined layer is modified or extinguished to form a non-light emitting portion. However, as shown in the experimental results shown in FIG. 10C, even if the intensity component has energy for processing the cathode 16 by multiphoton absorption, if the intensity component varies greatly, The target cathode 16 is also thermally damaged. Due to the above-described thermal damage of the organic layer and the cathode 16, there is a concern that the non-light emitting portion expands to the periphery of the organic layer and the cathode 16, the non-lighting area is expanded, and the repair quality is deteriorated.

  On the other hand, according to the method for manufacturing the organic EL element described above, only the laser light having the top flat (top hat) distribution is selected from the laser lights having the intensity distribution, and the electrode layer region of the defect portion or Irradiate around the area in the same layer. In other words, in the Gaussian distribution of the laser, the energy component outside the energy range necessary for increasing the resistance of the cathode or anode is optically cut, and the laser is applied to the organic layer and electrode layer by having a uniform intensity component. Suppresses absorption. Therefore, thermal damage to the organic layer adjacent to the electrode layer can be reduced by a strength component less than the energy for processing the electrode layer, and thermal damage is also applied to the electrode layer to be processed by a uniform strength component. Since it can be reduced, it is possible to minimize the non-lighting area that has become a dark spot, and to improve the repair accuracy.

<First Modification>
FIG. 12 is a schematic cross-sectional view of an organic EL element according to a first modification of the embodiment of the present invention. The organic EL element 50 according to this modification is different from the organic EL element 1 according to the above-described embodiment only in the laser irradiation region, and the stacked structure of the elements and the generation state of foreign matters are the same. Hereinafter, description of the same points as in the above embodiment will be omitted, and only different points will be described. In the above embodiment, the laser light from which the electron injection layer 15 and the light-emitting layer 13 are denatured through the cathode 16 and from which the intensity component that does not denature the cathode 16 is removed is square-shaped so as to surround the foreign material 20. In this modification, the entire rectangular area including the foreign material 20 is irradiated with the laser.

  In this modification as well, steps S31 to S33 shown in FIG. 6 are executed in order to increase the resistance of the rectangular region by laser irradiation. Thereby, it is possible to reliably eliminate the short circuit between the anode and the cathode while suppressing the occurrence of damage due to laser irradiation.

  Also by laser irradiation in this modification, the cathode region including the foreign material 20 is increased in resistance and insulated from other cathode regions. As a result, the current path flowing between the anode 11 and the cathode 16 does not occur in the cathode region including the foreign material 20, but normally occurs in the cathode region other than the cathode region.

<Second Modification>
Next, a second modification of the embodiment of the present invention will be described. The difference between the organic EL element 60 according to this modification and the organic EL element 1 according to the above-described embodiment is that in the pixel 52, the anode and the cathode are directly in contact with each other without a conductive foreign substance and short-circuited. The point where the short-circuited portion is repaired.

  FIG. 13 is a schematic cross-sectional view of an organic EL element according to a second modification of the embodiment of the present invention. Since the laminated structure of the organic EL element 60 shown in the figure is the same as that of the first embodiment, description thereof is omitted. In FIG. 14, the anode 11 and the cathode 16 are in direct contact with each other at a part 116a of the cathode. This is because, for example, a pinhole is formed at the position of the short-circuit portion in the formation process of the organic layer 30, and then the material constituting the cathode 16 is introduced into the pinhole in the formation process of the cathode 16 to form the cathode 16. Therefore, they are in direct contact in this way. And it has the structure which eliminated the short circuit of the anode 11 and the cathode 16 which were short-circuited by making high resistance the part 116a of a cathode. In the above embodiment, the laser light from which the electron injection layer 15 and the light-emitting layer 13 are denatured through the cathode 16 and from which the intensity component that does not denature the cathode 16 is removed is square-shaped so as to surround the foreign material 20. In this modification, the laser is irradiated to the entire square area including the pinhole portion.

  In this modification as well, steps S31 to S33 shown in FIG. 6 are executed in order to increase the resistance of the rectangular region by laser irradiation. Thereby, it is possible to reliably eliminate the short circuit between the anode and the cathode while suppressing the occurrence of damage due to laser irradiation.

  The cathode region including the pinhole portion is also insulated from the anode 11 by the laser irradiation in this modification. As a result, the current path flowing between the anode 11 and the cathode 16 does not occur in the cathode region including the pinhole portion, but normally occurs in the cathode region other than the cathode region.

  In addition, this invention is not limited to above-described embodiment and its modification, You may perform a various improvement and deformation | transformation within the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the configuration in which the lower electrode is an anode and the upper electrode is a cathode is shown, but the lower electrode may be a cathode and the upper electrode may be an anode. Further, the planarization film, anode, hole injection layer, light emitting layer, partition wall, electron injection layer, cathode, thin film sealing layer, sealing resin layer and transparent glass, which are the constitution of the organic EL element, are as described above. Not only the configuration shown in the embodiment but also the material, configuration, and formation method may be changed. For example, a hole transport layer may be provided between the hole injection layer and the light emitting layer, or an electron transport layer may be provided between the electron injection layer and the light emitting layer. Moreover, the structure provided with the color filter which adjusts the color of red, green, and blue on the lower surface of transparent glass so that each light emission area | region isolate | separated by the partition may be covered may be sufficient. Since the femtosecond laser described above can pass through the color filter, a short circuit can be eliminated through the color filter.

  Further, the laser irradiation position is not limited to the above-described embodiment, and may be set to a predetermined range including a foreign object or a short-circuit portion, or may be set only to the foreign object or the short-circuit portion. Moreover, you may set so that the circumference | surroundings of a foreign material and a short circuit part may be enclosed. Laser irradiation is not limited to the cathode and may be performed on the anode.

  In addition, various modifications conceived by those skilled in the art can be made in the present embodiment, or forms constructed by combining the components in different embodiments and modifications thereof without departing from the spirit of the present invention. It is included in the range. The present invention is suitable for manufacturing a thin flat TV system having an organic EL element as shown in FIG. 14, for example.

  The method for producing an organic EL device according to the present invention is particularly useful in technical fields such as thin televisions and personal computer displays that require a large screen and high resolution.

DESCRIPTION OF SYMBOLS 1, 1A, 50, 60 Organic EL element 2, 52 Pixel 9 Transparent glass 10 Flattening film 11 Anode 12 Hole injection layer 13 Light emitting layer 14 Partition 15 Electron injection layer 16 Cathode 16a, 116a Part of cathode 17 Thin film sealing Layer 18 Transparent glass 19 Sealing resin layer 20 Foreign material 30 Organic layer 101 Laser oscillator 102 Slit 104 Imaging lens 103 Stage 125 Laser

Claims (7)

A preparation step of preparing an organic EL element having a defective portion, wherein a lower electrode layer, an organic layer including a light emitting layer, and an upper electrode layer are laminated in this order, and at least one of the lower electrode layer and the upper electrode layer is made of a transparent material. When,
Intensity distribution by selecting a laser beam of a top flat distribution, the said selected laser beam is irradiated on the periphery of the defect portion, seen containing an irradiation step to eliminate the defect due to the defect ,
In the irradiation step,
Laser light whose intensity distribution is a top flat distribution irradiates the periphery in the same layer of the region of the lower electrode layer or the upper electrode layer made of the transparent material in the defect portion, and the periphery has high resistance. A method for producing an organic EL element to be converted. In the irradiation step,
A laser beam having a Gaussian intensity distribution is arranged between a light source that emits the laser beam and a slit having a slit width smaller than the beam diameter of the laser beam from the light source, and a connection. The method for manufacturing an organic EL element according to claim 1, wherein the laser light having the intensity distribution obtained by passing through an image optical system is a top flat distribution. Wherein the irradiation step, organic according to claim 1, the laser beam is irradiated to the ambient in the same layer of realm of the lower electrode layer or the upper electrode layer made of the transparent material of said defect Manufacturing method of EL element. The manufacturing method of the organic EL element according to claim 2, wherein a slit width of the slit is 10 to 200 μm. The method for producing an organic EL element according to claim 1, wherein the laser light is an ultrashort pulse laser. The method for producing an organic EL element according to claim 1, wherein the transparent material is a metal oxide. In the irradiation step,
The intensity distribution is a top-flat profile laser beam, by being multiphoton absorption before Symbol periphery, a method of manufacturing an organic EL element according to claim 1 in which the surrounding is high resistance.