WO2011158291A1 - Organic light-emitting element production method - Google Patents
Organic light-emitting element production method Download PDFInfo
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- WO2011158291A1 WO2011158291A1 PCT/JP2010/004009 JP2010004009W WO2011158291A1 WO 2011158291 A1 WO2011158291 A1 WO 2011158291A1 JP 2010004009 W JP2010004009 W JP 2010004009W WO 2011158291 A1 WO2011158291 A1 WO 2011158291A1
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/10—Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
- H10K59/10—OLED displays
- H10K59/12—Active-matrix OLED [AMOLED] displays
- H10K59/122—Pixel-defining structures or layers, e.g. banks
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
- H10K59/10—OLED displays
- H10K59/17—Passive-matrix OLED displays
- H10K59/173—Passive-matrix OLED displays comprising banks or shadow masks
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
- H10K59/30—Devices specially adapted for multicolour light emission
- H10K59/35—Devices specially adapted for multicolour light emission comprising red-green-blue [RGB] subpixels
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
- H10K71/10—Deposition of organic active material
- H10K71/12—Deposition of organic active material using liquid deposition, e.g. spin coating
- H10K71/13—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing
- H10K71/135—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing using ink-jet printing
Definitions
- the present invention relates to a method for manufacturing an organic light emitting device, and more particularly to a method for manufacturing an organic light emitting device by applying an ink for forming a functional layer and a light emitting layer between banks.
- organic electroluminescence element (hereinafter referred to as “organic EL element”), which has been researched and developed in recent years, is a light-emitting element utilizing an electroluminescence phenomenon of an organic material, and includes a lower electrode (anode) and an upper part. A light emitting layer is interposed between the electrode (cathode). Such organic EL elements are arranged in a matrix to form an organic EL display.
- pixels are partitioned by a bank made of an insulating material, and the shape of the light emitting layer is defined by the bank.
- a hole injection layer, a hole transport layer, or a hole injection / transport layer is interposed between the lower electrode and the light emitting layer as necessary, and electrons are also inserted between the upper electrode and the light emitting layer as necessary.
- An injection layer, an electron transport layer, or an electron injection / transport layer is interposed.
- the lower electrode, the hole injection layer, the electron injection layer, and the upper electrode perform specific functions of injecting charges, these layers are referred to as “functional layers”.
- Such an organic EL display includes a step of forming a functional layer including a lower electrode, a bank forming step of forming a bank that partitions adjacent pixel portions on the functional layer, and an ink including an organic light emitting material. It is produced through a step of forming a light emitting layer for forming an organic light emitting layer and a step of forming an upper electrode above the organic light emitting layer.
- the ink (coating liquid) in which the material is dissolved in a solvent is filled between the banks by an inkjet method or the like. Many wet methods for drying ink are also used.
- a solvent having a relatively high boiling point is used as a solvent so that each opening is filled with an equal amount of ink, and when the filled ink is dried, the solvent having a high boiling point is evaporated. Therefore, the substrate filled with ink is dried under reduced pressure in a dryer.
- the driving voltage of the organic light emitting device is increased or the light emission efficiency is decreased because the residue of the bank material remains on the bottom surface of the opening between the banks, and the charge injection characteristic of the functional layer is the residue of the bank material. It is thought that it is inhibited by.
- Patent Documents 2 and 3 by forming a bank and then treating with O2 plasma or irradiating with UV light, the bottom of the opening between the banks is formed. There is also a method of removing the residue remaining in the substrate, but O2 plasma treatment and UV light irradiation have a problem that the contact angle of the bank is lowered and the ink overflows, making it difficult to form the light emitting layer with a wet method with high accuracy. .
- the present invention can stably produce an organic light emitting device having a low driving voltage and good luminous efficiency by reducing the residue of the bank material while ensuring the liquid repellency of the bank surface. It aims to provide a method.
- a first step of preparing a substrate, and a second step of forming a functional layer including a lower electrode above the substrate A photosensitive resist material containing a fluorine component and a resin component is applied above the functional layer, and the photosensitive resist material is exposed and patterned to form openings corresponding to the pixel portions and adjacent pixels.
- a fifth step of forming an organic light emitting layer and a sixth step of forming an upper electrode above the organic light emitting layer are formed in the fourth step.
- the vibration energy of light is 458 to 472 kJ / mol.
- the sum of the amount of light to be irradiated is decided to irradiation so that 690 ⁇ 1035mJ / cm 2.
- vibration energy of light refers to the energy E of photons and is obtained from the wavelength of light.
- the total amount of light to be irradiated (integrated light amount) is 690 to 1035 mJ / cm 2 using ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol. Since the opening and the bank are irradiated, the residue of the bank material can be reduced while ensuring the liquid repellency of the bank surface.
- the organic light emitting layer can be accurately formed in the fifth step, and the bank residue is reduced.
- favorable light emission characteristics an improvement in light emission efficiency, a decrease in driving voltage, and a longer life
- uniform light emission characteristics can be obtained throughout the panel, and good light emission characteristics as an organic light emitting device can be obtained.
- a part of the bank constituent materials (fluorine component and resin material) remains as a residual component on the functional layer in the opening between the banks. If the light emitting layer is formed in the opening between the banks while the residual component remains, the charge injection characteristic of the functional layer is deteriorated.
- the resin is mainly used as a residual component remaining on the functional layer of the opening by irradiating the opening and the bank with the ultraviolet light having the vibration energy in the specific range.
- the binding of the components is dissociated and the residual components are reduced.
- a light emitting layer is formed in the opening part between banks in the state in which the residual component was reduced, the fall of a charge injection characteristic is suppressed.
- the ultraviolet rays irradiated in the fourth step have energy in the above range and the integrated light amount is also irradiated in the above range, the bond of the fluorine component is not actively dissociated. Therefore, the bond of fluorine components on the bank surface is not damaged by ultraviolet rays, and the liquid repellency of the bank surface is maintained.
- the opening is filled with ink containing an organic light emitting material in the fifth step, the ink does not overflow from the opening, and the organic light emitting layer can be formed satisfactorily.
- a first step of preparing a substrate a second step of forming a functional layer including a lower electrode above the substrate, and above the functional layer, By applying a photosensitive resist material containing a fluorine component and a resin component, and exposing and patterning the photosensitive resist material, an opening corresponding to the pixel portion is formed and a bank that partitions adjacent pixel portions is formed.
- the fourth step of irradiating the opening and the bank with ultraviolet rays and after the fourth step, the organic light emitting layer is coated with an ink containing an organic light emitting material and dried.
- a sixth step of forming the upper electrode above the organic light emitting layer is one embodiment of the present invention.
- ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol is used.
- Sum morphism that amount (integrated light quantity) is decided to irradiation so that 690 ⁇ 1035mJ / cm 2.
- the organic light emitting layer can be formed with high accuracy and the residue of the bank material is reduced, so that the organic light emitting device has good light emission characteristics (improvement of light emission efficiency, decrease in driving voltage, and longer life). can get.
- the vibration energy of the ultraviolet light irradiated in the fourth step is set to be larger than the maximum value of the bond dissociation energy of the resin component and smaller than the minimum value of the bond dissociation energy of the fluorine component.
- the integrated light quantity in the fourth step is represented by the product of the illuminance and the irradiation time.
- the illuminance is set in the range of 5 to 150 mW / cm 2 and the irradiation time is set to 5 to 200 seconds.
- a hole injection layer (HIL) containing tungsten oxide (WOx) is used as the functional layer, and the normalized ionic strength of the fluorine component on the functional layer after the fourth step (standardized with reference to the tungsten oxide component). Value) is 3.0 ⁇ 10 0 or more and 1.0 ⁇ 10 1 or less.
- the normalized ionic strength of the fluorine component in the bank after the fourth step is 0.3 or more and less than 1 with respect to the normalized ionic strength of the fluorine component in the bank after the third step. To do. By doing so, the residual amount of the fluorine component does not change greatly before and after the UV irradiation, so that the liquid repellency of the bank surface is maintained.
- the contact angle of the ink containing the organic light emitting material with respect to the bank after being irradiated with ultraviolet rays is set to 35 ° to 60 °. If it does so, in an 5th process, since an ink does not overflow easily from an opening part, an organic light emitting layer can be formed favorably.
- the resin material diffused from the bank to the hole injection layer in the third step by irradiating the opening with ultraviolet rays in the fourth step. Remove.
- An organic light emitting display device can be constituted by the organic light emitting device manufactured by the above manufacturing method and a drive circuit for driving the organic light emitting device.
- a first step of preparing a substrate a second step of forming a functional layer including a lower electrode above the substrate, and an upper portion of the functional layer
- a photosensitive resist material containing a fluorine component and a resin component is applied, and the photosensitive resist material is exposed and patterned to form an opening corresponding to the pixel portion and to partition adjacent pixel portions.
- an ink containing an organic light-emitting material is applied to the opening and dried.
- a fifth step of forming the light emitting layer and a sixth step of forming the upper electrode are provided above the organic light emitting layer.
- the vibration energy of the ultraviolet light is determined from the dissociation energy of the resin component used. The value is larger and smaller than the dissociation energy of the fluorine component to be used. Further, the total amount of light to be irradiated (integrated light amount) is the normalized ion intensity of the fluorine component in the bank after the fourth step. The ratio value was 0.3 or more and less than 1 with respect to the normalized ionic strength of the fluorine component in the later bank.
- uniform light emission characteristics can be obtained throughout the panel, and good light emission characteristics as an organic light emitting device can be obtained.
- the dissociation energy of the resin material is 335 to 457 kJ / mol
- the dissociation energy of the fluorine component is 472 to 524 kJ / mol
- the vibration energy of the ultraviolet light is 458 to 472 kJ / mol
- the integrated light quantity is 690 to 1035 mJ / cm 2. It is preferable that
- the energy of the UV light for removing the resin component is smaller than the energy of the UV light for removing the fluorine component.
- the fluorine component contained in the bank can be left by setting the irradiation time appropriately.
- the TFT substrate 1 includes, for example, alkali-free glass, soda glass, non-fluorescent glass, phosphoric acid glass, boric acid glass, quartz, acrylic resin, styrene resin, polycarbonate resin, epoxy resin, polyethylene, polyester, and silicone.
- An amorphous TFT (EL element drive circuit) is formed on a base substrate made of an insulating material such as a resin or alumina.
- the protective resist covering the TFT substrate 1 is peeled off, an organic resin is spin-coated on the TFT substrate 1, and patterned by PR / PE (photoresist / photoetching).
- PR / PE photoresist / photoetching
- a planarizing film 1a thickness 4 ⁇ m is formed.
- An anode electrode as a lower electrode is formed on the planarizing film 1a.
- a first anode electrode 2 made of silver-palladium-copper alloy (APC) is formed on the planarizing film 1a.
- the first anode electrode 2 is formed, for example, by forming a thin film by APC by sputtering and patterning the thin film in a matrix form by PR / PE (thickness 150 nm).
- the first anode electrode 2 may be formed by vacuum deposition or the like.
- the second anode electrode 3 is formed in a matrix.
- the second anode electrode 3 is formed, for example, by forming an ITO thin film by a plasma vapor deposition method and patterning the ITO thin film by PR / PE (thickness 110 nm).
- a hole injection layer 4 is formed on the second anode electrode 3.
- the hole injection layer 4 is formed by sputtering a material that performs a hole injection function, such as metal oxide, metal nitride, or metal nitride, for example, WOx (tungsten oxide) and patterning it with PR / PE (thickness). 40 nm).
- the hole injection layer 4 is formed not only on the anode electrode but over the entire upper surface of the substrate 1.
- the anode electrode and hole injection layer 4 formed as described above correspond to a functional layer.
- the second anode electrode 3 is interposed between the first anode electrode 2 and the hole injection layer 4 and has a function of improving the bonding property between the layers.
- Bank formation process As shown in FIG. 1G, a bank 5 is formed on the hole injection layer 4.
- a region where the bank 5 is formed on the hole injection layer 4 is a region corresponding to a boundary between adjacent light emitting layer formation scheduled regions.
- the bank 5 is formed by forming a bank material layer so as to cover the whole of the hole injection layer 4 and removing a part of the formed bank material layer by PR / PE (thickness: 1 ⁇ m).
- FIG. 1 shows a cross-sectional shape of the substrate 1 cut in the horizontal direction
- the bank 5 extends along the top surface of the substrate 1 in the vertical direction (the front and back direction in FIG. 1).
- a plurality of banks 5 are arranged over the entire top surface of the substrate 1.
- the bank 5 may be a striped line bank that extends only in the vertical direction, or may be a pixel bank that extends in the vertical and horizontal directions and has a planar shape in the form of a cross.
- FIG. 2 is a diagram for specifically explaining the bank formation process.
- a substrate on which a hole injection layer is formed is put, and a bank material is applied thereon by spin coating as shown in FIG. 2 (b), thereby forming a bank material layer 5a.
- the bank material a photosensitive resist material containing a fluorine component compound and a resin component material is used.
- this bank material is subjected to an etching process, a baking process, etc. after application, and ink is applied to the bank surface in the next process, so that it has resistance to organic solvents, It is desirable to use a material that does not easily cause alteration.
- a photosensitive resist containing a fluororesin such as a fluorinated polyolefin resin, a fluorinated polyimide resin, or a fluorinated polyacrylic resin
- a fluororesin such as a fluorinated polyolefin resin, a fluorinated polyimide resin, or a fluorinated polyacrylic resin
- the fluororesin include a fluorine-containing polymer described in JP-T-2002-543469; LUMIFLON (registered trademark, Asahi Glass) which is a copolymer of fluoroethylene and vinyl ether.
- a photomask having an opening corresponding to the bank formation scheduled region is overlaid on the bank material layer 5a. Then, when UV exposure is performed, only the portion of the bank material layer 5a irradiated with UV light is polymerized and cured.
- the bank material layer 5a is patterned into a bank shape because the uncured portion is removed and the cured portion remains.
- a forward-tapered bank 5 is formed as shown in FIG.
- a recess is formed between the banks 5, and the hole injection layer 4 is exposed on the bottom surface of the recess.
- the uncured portion of the bank material layer 5a is basically removed, but usually a portion of the bank material layer 5a remains on the bottom surface of the recess as a residue 5c.
- the next UV cleaning step is performed.
- UV cleaning process Ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol is irradiated from the substrate on which the bank 5 is formed.
- a low-pressure mercury lamp having a main radiation intensity at a main wavelength of 254 nm is used.
- a wavelength of 254 nm corresponds to vibration energy of 472 kJ / mol.
- the illuminance when the substrate is irradiated with UV light is preferably set in the range of 5 to 150 mW / cm 2 .
- the irradiation time is set so that the total amount of UV light to be irradiated (integrated light amount) is 690 to 1035 mJ / cm 2 .
- Hole transport layer formation process The hole transport layer 6 is formed as shown in FIG. 3A by filling the recesses between the banks 5 with ink containing the material of the hole transport layer and drying.
- Examples of the material for the hole transport layer 6 include poly (3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSS) and derivatives thereof (such as copolymers).
- the thickness of the hole transport layer 6 is usually 10 nm or more and 100 nm or less, for example, 20 nm.
- Light emitting layer forming process The recesses between the banks 5 are filled with ink containing an organic light emitting material. That is, ink is printed by a droplet discharge method (inkjet method) between the plurality of banks 5 over the entire substrate 1.
- a dispenser method As a method for filling the ink between the banks, a dispenser method, a nozzle coating method, a spin coating method, intaglio printing, letterpress printing, or the like may be used.
- the thickness of the light emitting layer 7 is 60 to 90 nm.
- organic light-emitting materials include, for example, oxinoid compounds, perylene compounds, coumarin compounds, azacoumarin compounds, oxazole compounds, oxadiazole compounds, perinone compounds, pyrrolopyrrole compounds, naphthalene compounds, anthracene compounds described in JP-A-5-163488 , Fluorene compounds, fluoranthene compounds, tetracene compounds, pyrene compounds, coronene compounds, quinolone compounds and azaquinolone compounds, pyrazoline derivatives and pyrazolone derivatives, rhodamine compounds, chrysene compounds, phenanthrene compounds, cyclopentadiene compounds, stilbene compounds, diphenylquinone compounds, styryl compounds , Butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound , Pyrylium compounds, thiapyrylium compounds, ser
- the ink is manufactured by dissolving the organic light emitting material constituting the light emitting layer 7 as a solute and dissolving it in a solvent containing a solvent having a relatively high boiling point (boiling point: 170 to 300 ° C.).
- the high boiling point solvent examples include cyclohexylbenzene, diethylbenzene, decahydronaphthalene, methylbenzoate, acetophenone, phenylbenzene, benzyl alcohol, tetrahydronaphthalene, isophorone, n-dodecane, dicyclohexyl, and p-xylene glycol dimethyl ether.
- These solvents may be used alone, or may be a mixture of a plurality of solvents, or a mixture of the above high boiling point solvent and a low boiling point solvent.
- Electron injection layer, upper electrode, sealing layer formation process As shown in FIGS. 3C to 3E, an electron transport layer 8, a cathode electrode 9 as an upper electrode, and a sealing layer 10 are sequentially formed so as to cover the bank 5 and the light emitting layer 7.
- the electron transport layer 8, the cathode electrode 9, and the sealing layer 10 are formed so as to be continuous with the pixel planned region of the adjacent organic EL element beyond the pixel planned region defined by each bank 5.
- the electron transport layer 8 is formed by, for example, ETL vapor deposition (thickness 20 nm) using barium, lithium fluoride, or a combination thereof.
- the electron transport layer 8 has a function of transporting electrons injected from the cathode electrode 9 to the light emitting layer 7.
- the cathode electrode 9 is formed by plasma deposition of a light transmissive material, for example, ITO, IZO (indium zinc oxide) or the like (thickness: 100 nm).
- a light transmissive material for example, ITO, IZO (indium zinc oxide) or the like (thickness: 100 nm).
- the sealing layer 10 is formed of a material such as SiN (silicon nitride) or SiON (silicon oxynitride) by CVD (thickness: 1 ⁇ m).
- the sealing layer 10 has a role of suppressing the light emitting layer 7 and the like from being exposed to moisture or being exposed to air.
- an organic EL display panel in which top emission type organic EL elements are arranged in a matrix is manufactured.
- the color filter substrate is bonded to the panel produced as described above via a sealing material.
- the panel is divided into a predetermined size.
- the drive circuit is mounted.
- an organic light emitting display device is manufactured.
- FIG. 4 is a chart showing the binding energy of various molecules and the vibration energy (kJ / mol) of light of various lamps.
- the CF bond dissociation energy in fluorobenzene is 524 kJ / mol
- the CF bond energy in fluoromethane is 472 kJ / mol
- the UV light (254 nm) of a low-pressure mercury lamp Is less than or equal to the C—F bond energy because its vibrational energy is 472 kJ / mol. Therefore, the C—F bond is not dissociated by the vibrational energy of the UV light (254 nm).
- FIG. 4 shows methyl group, CH bond energy (457 kJ / mol, 432 kJ / mol) of methane, etc.
- the vibration energy (458 to 472 kJ / mol) of the UV light is larger than the bond energy of the CH bond in a general resin component. Therefore, irradiation with UV light having vibration energy of 458 to 472 kJ / mol can dissociate the C—H bond and decompose the resin component.
- FIG. 6 schematically shows a state in which when the UV light (wavelength 254 nm) is irradiated from above the bank, the residue and the CH bond on the bank surface are dissociated and the CF bond remains without dissociation.
- the total sum of UV light (integrated light amount) is also set within the range of 690 to 1035 mJ / cm 2 .
- the resin component in the residue is decomposed while reliably suppressing the decomposition of the fluorine component present on the surface of the bank 5 and ensuring the liquid repellency of the surface of the bank 5.
- the area occupied by the bank residue on the hole injection layer 4 can be reduced.
- Experiment 1 Residual amount of fluorine A bank was formed on a substrate by spin-coating a bank material on a flat glass and patterning it with a photolithographic technique. Here, it was formed on a substrate (a bank having a width of 30 ⁇ m with a gap of 60 ⁇ m).
- the illuminance for irradiating the UV light (wavelength 254 nm) from above the bank is constant at 23 mW / cm 2 , and the irradiation time of the UV light is 0 seconds, 10 It was examined how the residual amount of fluorine on the surface of the hole injection layer 4 was changed by changing the seconds, 30 seconds, and 60 seconds.
- the measurement of the residual amount of fluorine was performed by measuring the negative ion intensity on the surface of the hole injection layer 4 under the following analysis conditions using a time-of-flight secondary ion mass spectrometry (TOF-SIMS) method.
- TOF-SIMS time-of-flight secondary ion mass spectrometry
- FIG. 7 is a graph showing the measurement results, in which the negative ionic strength measurement value before UV irradiation is normalized as the reference value 10.
- Rf is a measured value when the bank 5 is not formed on the hole injection layer 4.
- the normalized ion intensity is 3.0 ⁇ 10 0 to 1 It is within the range of 0.0 ⁇ 10 0 and is smaller in the range of 0.3 or more and less than 1 compared with the normalized fluorine ion intensity (1.0 ⁇ 10 1 ) before irradiation (0 second). However, it can be seen that about 100 times as much fluorine remains as compared with Rf.
- the ink used was butyl benzoate as solvent, polyfluorene polymer (product name: Poly (9,9-di-n-dodecylfluorenyl-2,7-diyl), manufactured by Aldrich), and the concentration was 1.0 wt% It is.
- FIG. 8 is a diagram and a table showing the results.
- the contact angle is 45 ° in the initial stage (0 seconds), the contact angle gradually decreases as the irradiation time elapses, and the contact angle decreases to 35 ° when 45 seconds elapse. Yes.
- the printability of the ink is good when the contact angle of the ink with respect to the bank surface is 35 ° or more. That is, if the contact angle is in the range of 35 ° or more and 60 ° or less, the ink is unlikely to overflow from between the banks when the ink is filled in the openings between the banks as shown in FIG. 6C. Experience has shown that the light emitting layer 7 can be satisfactorily formed over the entire panel.
- the contact angle of the ink with respect to the banks is maintained at 35 ° or more, and ink can be printed favorably between the banks (inkjet It can be filled with.
- the contact angle of the ink with respect to the bank surface varies somewhat depending on the type of the bank material used and the solvent of the ink, but if a bank material and an ink solvent containing a fluorine component and a resin component that are generally used in an organic EL element are used. It is considered that a result almost similar to the result shown in FIGS.
- the second anode electrode 3 (ITO layer, thickness 100 nm), the hole injection layer 4 (WOx layer, thickness 30 nm), and the bank 5 are formed on the substrate. Then, after irradiating UV light (wavelength 254 nm) at an illuminance of 23 mW / cm 2 for 0 seconds, 30 seconds, and 45 seconds, the ink is applied between the banks and dried, the hole transport layer 6 (thickness 30 nm), A light emitting layer 7 (thickness 95 nm) is formed, and an electron transport layer 8 (Ba layer, thickness 5 nm) and a cathode electrode 9 (Al layer, thickness 120 nm) are formed in this order to form a device sample for testing. did.
- FIG. 9 is a graph of J- ⁇ characteristics showing the result.
- FIG. 10 is a graph of VJ characteristics showing the result.
- the drive voltage required to obtain the same current density is higher than that when the UV light is not irradiated (0 seconds). It is low.
- the degree of decrease in the drive voltage is about 2 V at a current density of 10 mA / cm 2 .
- FIG. 11 is a graph showing the results. It can be seen that the element sample irradiated with UV light has less decrease in luminance over time.
- FIG. 12 is a graph showing the results.
- the element sample irradiated with UV light has a smaller initial driving voltage and a smaller increase in driving voltage over time than the element sample not irradiated with UV light.
- the light emission color of the light emitting layer in the organic EL display is not mentioned, but the present invention can be applied not only to a single color display but also to a full color display organic EL display.
- the organic EL element corresponds to a subpixel of each RGB color, and adjacent RGB subpixels are combined to form one pixel, and this pixel is arranged in a matrix to form an image display area Is formed.
- the top emission type organic EL display has been described as an example.
- the present invention can be similarly applied to the case where the light emitting layer of the bottom emission type organic EL display is formed.
- the present invention can also be applied to an organic TFT (Thin Film Transistor).
- the present invention is effective for manufacturing an organic EL panel such as an organic EL display as well as an organic EL light source by a method of forming a light emitting layer by a wet method.
- the light emission characteristics are good and uniform light emission characteristics can be obtained in the image display surface, which contributes to the improvement of the image quality.
Abstract
Disclosed is a method for stable production of an organic light-emitting element with low drive voltage and good luminous efficiency, by reducing bank material residue while ensuring liquid repellency of bank surfaces. To achieve this, a photosensitive resist material that has a fluorine component and a resin component is used as the bank material, and banks (5) are formed on a hole injection layer. An ultra-violet light with a light vibration energy of 458 to 472 kJ/mol is irradiated from the top of a substrate where the banks (5) are formed. The irradiation time is set such that the total irradiated UV light volume (cumulative light volume) is 690 to 1,035 mJ/cm2. Hole transport layers are formed in concave sections between the banks (5) by filling the concave sections with an ink that includes a hole transport layer material, and drying same. The concave sections between the banks (5) are also filled with an ink that includes an organic light-emitting material, which is then dried under reduced pressure and baked to form a light-emitting layer.
Description
本発明は、有機発光素子の製造方法に関し、特に、バンク間に機能層、発光層を形成するインクを塗布することによって有機発光素子を製造する方法に関する。
The present invention relates to a method for manufacturing an organic light emitting device, and more particularly to a method for manufacturing an organic light emitting device by applying an ink for forming a functional layer and a light emitting layer between banks.
近年、研究・開発が進んでいる有機エレクトロルミネッセンス素子(以下、「有機EL素子」と記載する。)は、有機材料の電界発光現象を利用した発光素子であって、下部電極(陽極)と上部電極(陰極)との間に発光層が介挿された構造を有している。そして、このような有機EL素子がマトリックス状に配列されて有機ELディスプレイが構成されている。
An organic electroluminescence element (hereinafter referred to as “organic EL element”), which has been researched and developed in recent years, is a light-emitting element utilizing an electroluminescence phenomenon of an organic material, and includes a lower electrode (anode) and an upper part. A light emitting layer is interposed between the electrode (cathode). Such organic EL elements are arranged in a matrix to form an organic EL display.
このような有機ELディスプレイの構造は、一般に、画素同士が絶縁材料からなるバンクで仕切られていて、このバンクによって発光層の形状が規定されている。また、下部電極と発光層との間に、必要に応じてホール注入層、ホール輸送層またはホール注入兼輸送層が介挿され、上部電極と発光層との間にも、必要に応じて電子注入層、電子輸送層または電子注入兼輸送層が介挿される。以下、下部電極、ホール注入層、電子注入層、上部電極は、電荷を注入する固有の機能を果たすので、これらの層を「機能層」という。
In such an organic EL display structure, generally, pixels are partitioned by a bank made of an insulating material, and the shape of the light emitting layer is defined by the bank. In addition, a hole injection layer, a hole transport layer, or a hole injection / transport layer is interposed between the lower electrode and the light emitting layer as necessary, and electrons are also inserted between the upper electrode and the light emitting layer as necessary. An injection layer, an electron transport layer, or an electron injection / transport layer is interposed. Hereinafter, since the lower electrode, the hole injection layer, the electron injection layer, and the upper electrode perform specific functions of injecting charges, these layers are referred to as “functional layers”.
このような有機ELディスプレイは、下部電極を含む機能層を形成する工程、その機能層の上に、隣り合う画素部を区画するバンクを形成するバンク形成工程、有機発光材料を含むインクを、バンク間の開口部に塗布して乾燥させ、有機発光層を形成する発光層形成工程、有機発光層の上方に上部電極を形成する工程を経て作製される。
Such an organic EL display includes a step of forming a functional layer including a lower electrode, a bank forming step of forming a bank that partitions adjacent pixel portions on the functional layer, and an ink including an organic light emitting material. It is produced through a step of forming a light emitting layer for forming an organic light emitting layer and a step of forming an upper electrode above the organic light emitting layer.
発光層を形成する工程においては、低分子材料を真空プロセスで成膜する方式以外に、材料を溶剤に溶解させたインク(塗布液)を、インクジェット法などでバンク間に充填して、充填されたインクを乾燥するウェット方式も多く用いられている。
In the process of forming the light-emitting layer, in addition to the method of forming a low molecular material by a vacuum process, the ink (coating liquid) in which the material is dissolved in a solvent is filled between the banks by an inkjet method or the like. Many wet methods for drying ink are also used.
そして、このウェット方式では、各開口部にインクが均等量充填されるように、溶剤として比較的沸点の高い溶剤が用いられ、充填されたインクを乾燥する時には、その沸点の高い溶剤を蒸発させるために、インクを充填した基板を乾燥器内で減圧乾燥している。
In this wet method, a solvent having a relatively high boiling point is used as a solvent so that each opening is filled with an equal amount of ink, and when the filled ink is dried, the solvent having a high boiling point is evaporated. Therefore, the substrate filled with ink is dried under reduced pressure in a dryer.
また、発光層を精度よく形成するために、インクに対するバンク表面の撥液性を高くすること、すなわちバンク表面に対するインクの接触角度を大きくすることも重要である。そのために、例えば、フッ素化フォトレジストを用いてバンクを形成することも提案されている(特許文献1)。このように、フッ素化フォトレジストを塗布し、現像,洗浄,焼成といったフォトリソグラフィープロセスでバンクを形成すると、バンク表面の撥液性が高くなるので、パネル全体に均一的に発光層を形成することができる。
It is also important to increase the liquid repellency of the bank surface with respect to the ink, that is, to increase the contact angle of the ink with respect to the bank surface, in order to form the light emitting layer with high accuracy. Therefore, for example, it has also been proposed to form a bank using a fluorinated photoresist (Patent Document 1). In this way, when a bank is formed by applying a fluorinated photoresist and a photolithographic process such as development, washing, and baking, the liquid repellency of the bank surface is increased, so that the light emitting layer is uniformly formed on the entire panel. Can do.
このような有機EL素子において、その駆動電圧を低くし、発光効率を良好なものとすることが望まれている。
In such an organic EL element, it is desired to lower the driving voltage and to improve the luminous efficiency.
しかしながら、上記のようにして、感光性のバンク材料を塗布し、塗付した感光性バンク材料を露光してパターニングするフォトレジスト法でバンクを形成すると、有機発光素子の駆動電圧が高くなったり、発光効率が低下する傾向があり、駆動電圧が低く発光効率が良好な有機発光素子を安定して得ることがなかなか難しい。
However, as described above, when a bank is formed by a photoresist method in which a photosensitive bank material is applied, and the applied photosensitive bank material is exposed and patterned, the driving voltage of the organic light emitting element is increased, Luminous efficiency tends to decrease, and it is difficult to stably obtain an organic light emitting device having low driving voltage and good luminous efficiency.
このように、有機発光素子の駆動電圧が高くなったり発光効率が低下するのは、バンク間の開口部の底面にバンク材料の残渣が残り、機能層の電荷注入特性が、そのバンク材料の残渣によって阻害されるためと考えられる。
As described above, the driving voltage of the organic light emitting device is increased or the light emission efficiency is decreased because the residue of the bank material remains on the bottom surface of the opening between the banks, and the charge injection characteristic of the functional layer is the residue of the bank material. It is thought that it is inhibited by.
このような課題に対して、例えば、特許文献2、3に開示されているように、バンクを形成した後に、O2プラズマで処理したりUV光を照射することによって、バンク間の開口部の底部に残る残渣を除去する方法もあるが、O2プラズマ処理やUV光の照射はバンクの接触角が低下するのでインクがあふれてしまい、発光層をウェット方式で精度よく形成しにくくなるという問題がある。
To solve such a problem, for example, as disclosed in Patent Documents 2 and 3, by forming a bank and then treating with O2 plasma or irradiating with UV light, the bottom of the opening between the banks is formed. There is also a method of removing the residue remaining in the substrate, but O2 plasma treatment and UV light irradiation have a problem that the contact angle of the bank is lowered and the ink overflows, making it difficult to form the light emitting layer with a wet method with high accuracy. .
本発明は、このような課題に鑑み、バンク表面の撥液性を確保しながらバンク材料の残渣を少なくすることによって、駆動電圧が低く且つ発光効率の良好な有機発光素子を安定して製造できる方法を提供することを目的とする。
In view of such a problem, the present invention can stably produce an organic light emitting device having a low driving voltage and good luminous efficiency by reducing the residue of the bank material while ensuring the liquid repellency of the bank surface. It aims to provide a method.
上記課題を解決するため、本発明の一態様である有機発光素子の製造方法においては、基板を準備する第1工程と、基板の上方に、下部電極を含む機能層を形成する第2工程と、機能層の上方に、フッ素成分および樹脂成分を含む感光性レジスト材料を塗布し、感光性レジスト材料を露光してパターニングすることにより、画素部に対応する開口部を形成すると共に、隣り合う画素部を区画するバンクを形成する第3工程と、開口部およびバンクに対し、紫外線を照射する第4工程と、第4工程の後、有機発光材料を含むインクを前記開口部に対して塗布して乾燥させ、有機発光層を形成する第5工程と、有機発光層の上方に、上部電極を形成する第6工程とを設け、第4工程において、光の振動エネルギーが458~472kJ/molの範囲となる紫外線を用い、照射する光量の総和(積算光量)が690~1035mJ/cm2となるように照射することとした。
In order to solve the above-described problem, in the method for manufacturing an organic light-emitting element which is one embodiment of the present invention, a first step of preparing a substrate, and a second step of forming a functional layer including a lower electrode above the substrate, A photosensitive resist material containing a fluorine component and a resin component is applied above the functional layer, and the photosensitive resist material is exposed and patterned to form openings corresponding to the pixel portions and adjacent pixels. A third step of forming a bank for partitioning the part, a fourth step of irradiating the opening and the bank with ultraviolet light, and after the fourth step, an ink containing an organic light emitting material is applied to the opening. A fifth step of forming an organic light emitting layer and a sixth step of forming an upper electrode above the organic light emitting layer. In the fourth step, the vibration energy of light is 458 to 472 kJ / mol. Using ultraviolet as the circumference, the sum of the amount of light to be irradiated (integrated light quantity) is decided to irradiation so that 690 ~ 1035mJ / cm 2.
上記「光の振動エネルギー」は、光子のエネルギーEを指し、光の波長から求められる。
The above "vibration energy of light" refers to the energy E of photons and is obtained from the wavelength of light.
E=h×c/λ(cは真空中の光速、h:プランク定数6.626×10-34[J s])
E = h × c / λ (c is the speed of light in vacuum, h: Planck's constant 6.626 × 10 −34 [J s])
上記態様によれば、第4工程において、光の振動エネルギーが458~472kJ/molの範囲にある紫外線を用いて、照射する光量の総和(積算光量)が690~1035mJ/cm2となるように、開口部およびバンクを照射しているので、バンク表面の撥液性を確保しながらバンク材料の残渣を少なくすることができる。
According to the above aspect, in the fourth step, the total amount of light to be irradiated (integrated light amount) is 690 to 1035 mJ / cm 2 using ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol. Since the opening and the bank are irradiated, the residue of the bank material can be reduced while ensuring the liquid repellency of the bank surface.
従って、第5工程で有機発光層を精度よく形成することができ、且つバンク残渣が少なくなる。それによって、有機発光素子として良好な発光特性(発光効率の向上、駆動電圧の低下、長寿命化)が得られる。すなわち、パネル全体で均一な発光特性が得られる共に、有機発光素子として良好な発光特性が得られる。
Therefore, the organic light emitting layer can be accurately formed in the fifth step, and the bank residue is reduced. As a result, favorable light emission characteristics (an improvement in light emission efficiency, a decrease in driving voltage, and a longer life) can be obtained as an organic light emitting device. That is, uniform light emission characteristics can be obtained throughout the panel, and good light emission characteristics as an organic light emitting device can be obtained.
上記効果が得られるメカニズムは、以下のように推定される。
The mechanism by which the above effect can be obtained is estimated as follows.
第1~第3工程を通じて、バンクの構成材料(フッ素成分および樹脂材料)の一部が、バンク間の開口部の機能層上に残渣成分として残る。そして、この残渣成分が残ったまま、バンク間の開口部に発光層が形成されると、機能層の電荷注入特性が低下する原因となる。
Through the first to third steps, a part of the bank constituent materials (fluorine component and resin material) remains as a residual component on the functional layer in the opening between the banks. If the light emitting layer is formed in the opening between the banks while the residual component remains, the charge injection characteristic of the functional layer is deteriorated.
これに対して上記態様によれば、第4工程で、上記特定範囲の振動エネルギーを有する紫外線で開口部及びバンクを照射することにより、開口部の機能層上に残る残渣成分の中、主として樹脂成分の結合が解離されて、残渣成分が低減される。そして、残渣成分が低減された状態で、バンク間の開口部に発光層が形成されるので、電荷注入特性の低下は抑えられる。
On the other hand, according to the aspect, in the fourth step, the resin is mainly used as a residual component remaining on the functional layer of the opening by irradiating the opening and the bank with the ultraviolet light having the vibration energy in the specific range. The binding of the components is dissociated and the residual components are reduced. And since a light emitting layer is formed in the opening part between banks in the state in which the residual component was reduced, the fall of a charge injection characteristic is suppressed.
また、第4工程において照射する紫外線は、上記範囲のエネルギーを有し且つその積算光量も上記の範囲内で照射されるので、フッ素成分の結合は積極的には解離されない。従って、バンク表面におけるフッ素成分の結合が紫外線で損傷することがなく、バンク表面の撥液性は維持される。
Moreover, since the ultraviolet rays irradiated in the fourth step have energy in the above range and the integrated light amount is also irradiated in the above range, the bond of the fluorine component is not actively dissociated. Therefore, the bond of fluorine components on the bank surface is not damaged by ultraviolet rays, and the liquid repellency of the bank surface is maintained.
以上より、第5工程において開口部に有機発光材料を含むインクを充填する際に、インクが開口部から溢れることがなく、有機発光層を良好に形成できる。
As described above, when the opening is filled with ink containing an organic light emitting material in the fifth step, the ink does not overflow from the opening, and the organic light emitting layer can be formed satisfactorily.
なお、上記のようにフッ素成分物の結合は積極的には解離されないので、残渣成分中のフッ素成分は残存するが、樹脂成分が低減されることによって、機能層の特性低下を防止する効果は十分に得られる。
In addition, since the bond of the fluorine component is not actively dissociated as described above, the fluorine component in the residual component remains, but the effect of preventing the functional layer from being deteriorated by reducing the resin component is Fully obtained.
本発明の一態様である有機発光素子の製造方法においては、基板を準備する第1工程と、基板の上方に、下部電極を含む機能層を形成する第2工程と、機能層の上方に、フッ素成分および樹脂成分を含む感光性レジスト材料を塗布し、感光性レジスト材料を露光してパターニングすることにより、画素部に対応する開口部を形成すると共に、隣り合う画素部を区画するバンクを形成する第3工程と、開口部およびバンクに対し、紫外線を照射する第4工程と、第4工程の後、有機発光材料を含むインクを前記開口部に対して塗布して乾燥させ、有機発光層を形成する第5工程と、有機発光層の上方に、上部電極を形成する第6工程とを設け、第4工程において、光の振動エネルギーが458~472kJ/molの範囲となる紫外線を用い、照射する光量の総和(積算光量)が690~1035mJ/cm2となるように照射することとした。
In the method for manufacturing an organic light-emitting element which is one embodiment of the present invention, a first step of preparing a substrate, a second step of forming a functional layer including a lower electrode above the substrate, and above the functional layer, By applying a photosensitive resist material containing a fluorine component and a resin component, and exposing and patterning the photosensitive resist material, an opening corresponding to the pixel portion is formed and a bank that partitions adjacent pixel portions is formed. After the third step, the fourth step of irradiating the opening and the bank with ultraviolet rays, and after the fourth step, the organic light emitting layer is coated with an ink containing an organic light emitting material and dried. And a sixth step of forming the upper electrode above the organic light emitting layer. In the fourth step, ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol is used. Sum morphism that amount (integrated light quantity) is decided to irradiation so that 690 ~ 1035mJ / cm 2.
本態様により、有機発光層を精度よく形成することができ、且つバンク材料の残渣が少なくなるので、有機発光素子として良好な発光特性(発光効率の向上、駆動電圧の低下、長寿命化)が得られる。
According to this aspect, the organic light emitting layer can be formed with high accuracy and the residue of the bank material is reduced, so that the organic light emitting device has good light emission characteristics (improvement of light emission efficiency, decrease in driving voltage, and longer life). can get.
上記態様において、以下のようにすることが好ましい。
In the above aspect, the following is preferable.
第4工程で照射する紫外線の光の振動エネルギーを、樹脂成分の結合解離エネルギーの最高値よりも大きく、且つ、フッ素成分の結合解離エネルギーの最低値よりも小さく設定する。
The vibration energy of the ultraviolet light irradiated in the fourth step is set to be larger than the maximum value of the bond dissociation energy of the resin component and smaller than the minimum value of the bond dissociation energy of the fluorine component.
第4工程における積算光量は、照度と照射時間の積で表されるが、照度は5~150mW/cm2の範囲内とし、照射時間は5~200秒に設定する。
第2工程において、機能層として酸化タングステン(WOx)を含む正孔注入層(HIL)を用い、前記第4工程後の機能層上におけるフッ素成分の規格化イオン強度(酸化タングステン成分を基準として規格化した値)を、3.0×100以上であって1.0×101以下とする。 The integrated light quantity in the fourth step is represented by the product of the illuminance and the irradiation time. The illuminance is set in the range of 5 to 150 mW / cm 2 and the irradiation time is set to 5 to 200 seconds.
In the second step, a hole injection layer (HIL) containing tungsten oxide (WOx) is used as the functional layer, and the normalized ionic strength of the fluorine component on the functional layer after the fourth step (standardized with reference to the tungsten oxide component). Value) is 3.0 × 10 0 or more and 1.0 × 10 1 or less.
第2工程において、機能層として酸化タングステン(WOx)を含む正孔注入層(HIL)を用い、前記第4工程後の機能層上におけるフッ素成分の規格化イオン強度(酸化タングステン成分を基準として規格化した値)を、3.0×100以上であって1.0×101以下とする。 The integrated light quantity in the fourth step is represented by the product of the illuminance and the irradiation time. The illuminance is set in the range of 5 to 150 mW / cm 2 and the irradiation time is set to 5 to 200 seconds.
In the second step, a hole injection layer (HIL) containing tungsten oxide (WOx) is used as the functional layer, and the normalized ionic strength of the fluorine component on the functional layer after the fourth step (standardized with reference to the tungsten oxide component). Value) is 3.0 × 10 0 or more and 1.0 × 10 1 or less.
第4工程後のバンク中におけるフッ素成分の規格化イオン強度が、第3工程後のバンク中におけるフッ素成分の規格化イオン強度に対し、その比の値を0.3以上であって1未満とする。そうすれば、UVを照射する前後で、フッ素成分の残存量は大きくは変わらないので、バンク表面の撥液性が維持されることになる。
The normalized ionic strength of the fluorine component in the bank after the fourth step is 0.3 or more and less than 1 with respect to the normalized ionic strength of the fluorine component in the bank after the third step. To do. By doing so, the residual amount of the fluorine component does not change greatly before and after the UV irradiation, so that the liquid repellency of the bank surface is maintained.
第4工程によって、紫外線が照射された後のバンクに対する有機発光材料を含むインクの接触角度を35°~60°とする。そうすれば、第5工程において、インクが開口部から溢れにくいので、有機発光層を良好に形成できる。
In the fourth step, the contact angle of the ink containing the organic light emitting material with respect to the bank after being irradiated with ultraviolet rays is set to 35 ° to 60 °. If it does so, in an 5th process, since an ink does not overflow easily from an opening part, an organic light emitting layer can be formed favorably.
機能層が、ホール注入層(正孔注入層)を備える場合、第4工程において、紫外線を開口部に対して照射することにより、第3工程に伴ってバンクからホール注入層に拡散した樹脂材料を除去する。
When the functional layer includes a hole injection layer (hole injection layer), the resin material diffused from the bank to the hole injection layer in the third step by irradiating the opening with ultraviolet rays in the fourth step. Remove.
以上の製造方法により製造された有機発光素子と、有機発光素子を駆動するための駆動回路とによって有機発光表示装置を構成することができる。
An organic light emitting display device can be constituted by the organic light emitting device manufactured by the above manufacturing method and a drive circuit for driving the organic light emitting device.
また、本発明の一態様である有機発光素子の製造方法においては、基板を準備する第1工程と、基板の上方に、下部電極を含む機能層を形成する第2工程と、機能層の上方に、フッ素成分および樹脂成分を含む感光性レジスト材料を塗布し、感光性レジスト材料を露光してパターニングすることにより、画素部に対応する開口部を形成すると共に、隣り合う画素部を区画するバンクを形成する第3工程と、開口部および前記バンクに対し、紫外線を照射する第4工程と、第4工程の後、有機発光材料を含むインクを開口部に対して塗布して乾燥させ、有機発光層を形成する第5工程と、有機発光層の上方に、上部電極を形成する第6工程とを設け、第4工程において、紫外光の振動エネルギーを、用いられる樹脂成分の解離エネルギーよりも大きく、且つ、用いられるフッ素成分の解離エネルギーよりも小さい値とし、さらに、照射する光量の総和(積算光量)を、第4工程後のバンク中におけるフッ素成分の規格化イオン強度が、第3工程後のバンク中におけるフッ素成分の規格化イオン強度に対し、その比の値が0.3以上であって1未満となるようにした。
In the method for manufacturing an organic light-emitting element which is one embodiment of the present invention, a first step of preparing a substrate, a second step of forming a functional layer including a lower electrode above the substrate, and an upper portion of the functional layer In addition, a photosensitive resist material containing a fluorine component and a resin component is applied, and the photosensitive resist material is exposed and patterned to form an opening corresponding to the pixel portion and to partition adjacent pixel portions. After the fourth step of irradiating the opening and the bank with ultraviolet light, and after the fourth step, an ink containing an organic light-emitting material is applied to the opening and dried. A fifth step of forming the light emitting layer and a sixth step of forming the upper electrode are provided above the organic light emitting layer. In the fourth step, the vibration energy of the ultraviolet light is determined from the dissociation energy of the resin component used. The value is larger and smaller than the dissociation energy of the fluorine component to be used. Further, the total amount of light to be irradiated (integrated light amount) is the normalized ion intensity of the fluorine component in the bank after the fourth step. The ratio value was 0.3 or more and less than 1 with respect to the normalized ionic strength of the fluorine component in the later bank.
本態様によっても、パネル全体で均一な発光特性が得られると共に、有機発光素子として良好な発光特性が得られる。
Also according to this embodiment, uniform light emission characteristics can be obtained throughout the panel, and good light emission characteristics as an organic light emitting device can be obtained.
ここで、樹脂材料の解離エネルギーを335~457kJ/mol、フッ素成分の解離エネルギーを472~524kJ/molとし、紫外線光の振動エネルギーを458~472kJ/molとし、積算光量を690~1035mJ/cm2とすることが好ましい。
Here, the dissociation energy of the resin material is 335 to 457 kJ / mol, the dissociation energy of the fluorine component is 472 to 524 kJ / mol, the vibration energy of the ultraviolet light is 458 to 472 kJ / mol, and the integrated light quantity is 690 to 1035 mJ / cm 2. It is preferable that
[実施の形態]
[本発明の一態様を得るに至った経緯]
以下、本発明の態様を具体的に説明するに先立ち、本発明の態様を得るに至った経緯について説明する。
(i)従来:
従来、上記[背景技術]において述べたように、フッ素成分を含む感光性のバンク材料を塗布し、塗付したバンク材料を露光してパターニングするフォトレジスト法でバンクを形成すると、有機発光素子の駆動電圧が高くなったり、発光効率が低下する傾向があった。
この原因としては、バンク間の開口部の底面にバンク材料の残渣が残って機能層の表面に付着し、機能層の電荷注入特性が、そのバンク材料の残渣によって阻害されるためと考えられている。
そして、その原因の1つとして、バンク材料の残渣成分のうち,反応性が高く強力な酸化作用を有するフッ素成分が、機能層を化学的に変性させ、電荷注入特性に影響を及ぼしていることが考えられている。
このため、例えばUV光(紫外線)を照射することにより、残渣成分中のフッ素成分を積極的に除去する試みが図られていた。
(ii)考察:
本発明者は上記の点に関して検討した結果、機能層に付着したフッ素成分を確実に除去すべく、UV光のエネルギーを大きくした場合、機能層に付着したフッ素成分は除去できるものの、バンクに含有されているフッ素成分も併せて除去されてしまい、バンクの溌液性が低下するおそれがあることを見い出した。
一方、バンク中のフッ素成分の含有量を維持するため、UV光のエネルギーを小さくした場合、機能層に付着したフッ素成分は十分には除去できず、依然として電荷注入特性が低下してしまうおそれがある。
以上の通り、機能層に付着したフッ素成分を確実に除去することを目的とする限り、UV光を用いる解決手段に関し、有効な打開策を見い出すに至らなかったのである。
ここに及んで、本発明者は、発想の転換を図り、機能層の電荷注入特性の低下は、残渣成分中のフッ素成分自体に主な原因があるというよりも、残渣成分全体(フッ素のほか樹脂成分)の付着量に主な原因があると推定したのである。
そして具体的には、機能層に付着した残渣成分中の樹脂成分(C-H)に着眼し、この樹脂成分を除去することにより、残渣成分の全体の付着量を減少させ、電荷注入特性の低下を防止できると推察したのである。この場合、樹脂成分を除去するためのUV光のエネルギーは、フッ素成分を除去するためのUV光のエネルギーに較べて小さくて済むことを確認し、このことにより、エネルギーの小さいUV光を照射して樹脂成分を除去する場合、照射時間を適切に設定することにより、バンクに含有されるフッ素成分を残存させることができると考えたのである。 [Embodiment]
[Background of obtaining one embodiment of the present invention]
Hereinafter, prior to specific description of the embodiments of the present invention, the background for obtaining the embodiments of the present invention will be described.
(i) Conventional:
Conventionally, as described in [Background Art] above, when a bank is formed by a photoresist method in which a photosensitive bank material containing a fluorine component is applied, and the applied bank material is exposed and patterned, the organic light emitting device There was a tendency for the drive voltage to increase and the luminous efficiency to decrease.
This is thought to be because the residue of the bank material remains on the bottom of the opening between the banks and adheres to the surface of the functional layer, and the charge injection characteristics of the functional layer are hindered by the residue of the bank material. Yes.
One of the causes is that among the residual components of the bank material, a highly reactive and strong oxidizing fluorine component chemically modifies the functional layer and affects the charge injection characteristics. Is considered.
For this reason, for example, attempts have been made to positively remove the fluorine component in the residual component by irradiating with UV light (ultraviolet light).
(ii) Consideration:
As a result of studying the above points, the present inventor has found that when the energy of UV light is increased in order to reliably remove the fluorine component adhering to the functional layer, the fluorine component adhering to the functional layer can be removed, but it is contained in the bank. It has also been found that the fluorine component that has been removed is also removed and the liquid spillability of the bank may be reduced.
On the other hand, if the energy of the UV light is reduced in order to maintain the content of the fluorine component in the bank, the fluorine component adhering to the functional layer cannot be removed sufficiently, and the charge injection characteristics may still be deteriorated. is there.
As described above, as long as the purpose is to surely remove the fluorine component adhering to the functional layer, an effective solution for the solution using UV light has not been found.
At this point, the present inventor tried to change the idea, and the decrease in the charge injection characteristics of the functional layer was not caused mainly by the fluorine component itself in the residue component, but the entire residue component (in addition to fluorine). It was estimated that there was a main cause for the amount of resin component) attached.
Specifically, by focusing on the resin component (CH) in the residual component adhering to the functional layer and removing this resin component, the total amount of the residual component is reduced and the charge injection characteristics are reduced. I guessed it could be prevented. In this case, it is confirmed that the energy of the UV light for removing the resin component is smaller than the energy of the UV light for removing the fluorine component. In the case of removing the resin component, it was thought that the fluorine component contained in the bank can be left by setting the irradiation time appropriately.
[本発明の一態様を得るに至った経緯]
以下、本発明の態様を具体的に説明するに先立ち、本発明の態様を得るに至った経緯について説明する。
(i)従来:
従来、上記[背景技術]において述べたように、フッ素成分を含む感光性のバンク材料を塗布し、塗付したバンク材料を露光してパターニングするフォトレジスト法でバンクを形成すると、有機発光素子の駆動電圧が高くなったり、発光効率が低下する傾向があった。
この原因としては、バンク間の開口部の底面にバンク材料の残渣が残って機能層の表面に付着し、機能層の電荷注入特性が、そのバンク材料の残渣によって阻害されるためと考えられている。
そして、その原因の1つとして、バンク材料の残渣成分のうち,反応性が高く強力な酸化作用を有するフッ素成分が、機能層を化学的に変性させ、電荷注入特性に影響を及ぼしていることが考えられている。
このため、例えばUV光(紫外線)を照射することにより、残渣成分中のフッ素成分を積極的に除去する試みが図られていた。
(ii)考察:
本発明者は上記の点に関して検討した結果、機能層に付着したフッ素成分を確実に除去すべく、UV光のエネルギーを大きくした場合、機能層に付着したフッ素成分は除去できるものの、バンクに含有されているフッ素成分も併せて除去されてしまい、バンクの溌液性が低下するおそれがあることを見い出した。
一方、バンク中のフッ素成分の含有量を維持するため、UV光のエネルギーを小さくした場合、機能層に付着したフッ素成分は十分には除去できず、依然として電荷注入特性が低下してしまうおそれがある。
以上の通り、機能層に付着したフッ素成分を確実に除去することを目的とする限り、UV光を用いる解決手段に関し、有効な打開策を見い出すに至らなかったのである。
ここに及んで、本発明者は、発想の転換を図り、機能層の電荷注入特性の低下は、残渣成分中のフッ素成分自体に主な原因があるというよりも、残渣成分全体(フッ素のほか樹脂成分)の付着量に主な原因があると推定したのである。
そして具体的には、機能層に付着した残渣成分中の樹脂成分(C-H)に着眼し、この樹脂成分を除去することにより、残渣成分の全体の付着量を減少させ、電荷注入特性の低下を防止できると推察したのである。この場合、樹脂成分を除去するためのUV光のエネルギーは、フッ素成分を除去するためのUV光のエネルギーに較べて小さくて済むことを確認し、このことにより、エネルギーの小さいUV光を照射して樹脂成分を除去する場合、照射時間を適切に設定することにより、バンクに含有されるフッ素成分を残存させることができると考えたのである。 [Embodiment]
[Background of obtaining one embodiment of the present invention]
Hereinafter, prior to specific description of the embodiments of the present invention, the background for obtaining the embodiments of the present invention will be described.
(i) Conventional:
Conventionally, as described in [Background Art] above, when a bank is formed by a photoresist method in which a photosensitive bank material containing a fluorine component is applied, and the applied bank material is exposed and patterned, the organic light emitting device There was a tendency for the drive voltage to increase and the luminous efficiency to decrease.
This is thought to be because the residue of the bank material remains on the bottom of the opening between the banks and adheres to the surface of the functional layer, and the charge injection characteristics of the functional layer are hindered by the residue of the bank material. Yes.
One of the causes is that among the residual components of the bank material, a highly reactive and strong oxidizing fluorine component chemically modifies the functional layer and affects the charge injection characteristics. Is considered.
For this reason, for example, attempts have been made to positively remove the fluorine component in the residual component by irradiating with UV light (ultraviolet light).
(ii) Consideration:
As a result of studying the above points, the present inventor has found that when the energy of UV light is increased in order to reliably remove the fluorine component adhering to the functional layer, the fluorine component adhering to the functional layer can be removed, but it is contained in the bank. It has also been found that the fluorine component that has been removed is also removed and the liquid spillability of the bank may be reduced.
On the other hand, if the energy of the UV light is reduced in order to maintain the content of the fluorine component in the bank, the fluorine component adhering to the functional layer cannot be removed sufficiently, and the charge injection characteristics may still be deteriorated. is there.
As described above, as long as the purpose is to surely remove the fluorine component adhering to the functional layer, an effective solution for the solution using UV light has not been found.
At this point, the present inventor tried to change the idea, and the decrease in the charge injection characteristics of the functional layer was not caused mainly by the fluorine component itself in the residue component, but the entire residue component (in addition to fluorine). It was estimated that there was a main cause for the amount of resin component) attached.
Specifically, by focusing on the resin component (CH) in the residual component adhering to the functional layer and removing this resin component, the total amount of the residual component is reduced and the charge injection characteristics are reduced. I guessed it could be prevented. In this case, it is confirmed that the energy of the UV light for removing the resin component is smaller than the energy of the UV light for removing the fluorine component. In the case of removing the resin component, it was thought that the fluorine component contained in the bank can be left by setting the irradiation time appropriately.
以上の考察を積み重ねた結果、本発明者は、「所定のエネルギー範囲」を有するUV光を用いることにより、機能層に付着した樹脂成分を除去し、機能層の電荷注入特性の低下を防止すると共に、このUV光を「所定時間」照射することにより、バンクに含まれるフッ素成分を残存させ、バンクの溌液性を維持するという本発明の技術的思想に辿り着くことができたのである。そして、さらなる実験確認を通じ、本発明に係る具体的な解決手段を知得し、その効果を確認したのである。
〈有機ELディスプレイの製造方法〉
図1~3は、本発明の一実施形態にかかる有機ELディスプレイの製造方法を説明する工程図である。 As a result of accumulating the above considerations, the present inventor removes the resin component adhering to the functional layer by using UV light having a “predetermined energy range” and prevents the charge injection characteristics of the functional layer from deteriorating. At the same time, by irradiating this UV light for “predetermined time”, the inventors have reached the technical idea of the present invention in which the fluorine component contained in the bank is left and the lyophobicity of the bank is maintained. Through further experimental confirmation, the specific solution means according to the present invention was obtained and the effects were confirmed.
<Method for manufacturing organic EL display>
1 to 3 are process diagrams illustrating a method for manufacturing an organic EL display according to an embodiment of the present invention.
〈有機ELディスプレイの製造方法〉
図1~3は、本発明の一実施形態にかかる有機ELディスプレイの製造方法を説明する工程図である。 As a result of accumulating the above considerations, the present inventor removes the resin component adhering to the functional layer by using UV light having a “predetermined energy range” and prevents the charge injection characteristics of the functional layer from deteriorating. At the same time, by irradiating this UV light for “predetermined time”, the inventors have reached the technical idea of the present invention in which the fluorine component contained in the bank is left and the lyophobicity of the bank is maintained. Through further experimental confirmation, the specific solution means according to the present invention was obtained and the effects were confirmed.
<Method for manufacturing organic EL display>
1 to 3 are process diagrams illustrating a method for manufacturing an organic EL display according to an embodiment of the present invention.
TFT基板1を準備する。
Prepare the TFT substrate 1.
このTFT基板1は、例えば、無アルカリガラス、ソーダガラス、無蛍光ガラス、燐酸系ガラス、硼酸系ガラス、石英、アクリル系樹脂、スチレン系樹脂、ポリカーボネート系樹脂、エポキシ系樹脂、ポリエチレン、ポリエステル、シリコーン系樹脂、又はアルミナ等の絶縁性材料からなるベース基板上に、アモルファスTFT(EL素子ドライブ回路)が形成されたものである。
The TFT substrate 1 includes, for example, alkali-free glass, soda glass, non-fluorescent glass, phosphoric acid glass, boric acid glass, quartz, acrylic resin, styrene resin, polycarbonate resin, epoxy resin, polyethylene, polyester, and silicone. An amorphous TFT (EL element drive circuit) is formed on a base substrate made of an insulating material such as a resin or alumina.
図1(b)に示すように、TFT基板1を覆っている保護レジストを剥離し、TFT基板1上に、有機樹脂をスピンコートし、PR/PE(フォトレジスト/フォトエッチングでパターニングすることによって、図1(c)に示すように、平坦化膜1a(厚さ4μm)を形成する。
As shown in FIG. 1B, the protective resist covering the TFT substrate 1 is peeled off, an organic resin is spin-coated on the TFT substrate 1, and patterned by PR / PE (photoresist / photoetching). As shown in FIG. 1C, a planarizing film 1a (thickness 4 μm) is formed.
この平坦化膜1a上に、下部電極としてのアノード電極を形成する。
An anode electrode as a lower electrode is formed on the planarizing film 1a.
まず、図1(d)に示すように、平坦化膜1a上に銀-パラジウム-銅合金(APC)からなる第一アノード電極2を形成する。この第一アノード電極2は、例えば、スパッタリングによりAPCで薄膜を形成し、当該薄膜をPR/PEでマトリックス状にパターニングすることによって形成する(厚さ150nm)。なお、第一アノード電極2は真空蒸着等で形成しても良い。
First, as shown in FIG. 1D, a first anode electrode 2 made of silver-palladium-copper alloy (APC) is formed on the planarizing film 1a. The first anode electrode 2 is formed, for example, by forming a thin film by APC by sputtering and patterning the thin film in a matrix form by PR / PE (thickness 150 nm). The first anode electrode 2 may be formed by vacuum deposition or the like.
次に、図1(e)に示すように、第二アノード電極3をマトリックス状に形成する。第二アノード電極3は、例えばプラズマ蒸着法でITO薄膜を形成し、当該ITO薄膜をPR/PEによりパターニングすることにより形成する(厚さ110nm)。
Next, as shown in FIG. 1 (e), the second anode electrode 3 is formed in a matrix. The second anode electrode 3 is formed, for example, by forming an ITO thin film by a plasma vapor deposition method and patterning the ITO thin film by PR / PE (thickness 110 nm).
次に、図1(f)に示すように、第二アノード電極3の上からホール注入層4を形成する。
Next, as shown in FIG. 1 (f), a hole injection layer 4 is formed on the second anode electrode 3.
ホール注入層4は、金属酸化物、金属窒化物又、金属窒化物などホール注入機能を果たす材料、例えば、WOx(酸化タングステン)をスパッタリングし、PR/PEによりパターニングすることで形成する(厚さ40nm)。なお、ホール注入層4は、アノード電極上だけでなく、基板1の上面全体に亘って形成する。
The hole injection layer 4 is formed by sputtering a material that performs a hole injection function, such as metal oxide, metal nitride, or metal nitride, for example, WOx (tungsten oxide) and patterning it with PR / PE (thickness). 40 nm). The hole injection layer 4 is formed not only on the anode electrode but over the entire upper surface of the substrate 1.
以上のように形成されたアノード電極及びホール注入層4が、機能層に相当する。そして、第二アノード電極3は、第一アノード電極2とホール注入層4の間に介在し、各層間の接合性を良好にする機能を有する。
The anode electrode and hole injection layer 4 formed as described above correspond to a functional layer. The second anode electrode 3 is interposed between the first anode electrode 2 and the hole injection layer 4 and has a function of improving the bonding property between the layers.
バンク形成工程:
図1(g)に示すように、ホール注入層4上にバンク5を形成する。ホール注入層4上においてバンク5を形成する領域は、隣り合う発光層形成予定領域どうしの境界に相当する領域である。 Bank formation process:
As shown in FIG. 1G, abank 5 is formed on the hole injection layer 4. A region where the bank 5 is formed on the hole injection layer 4 is a region corresponding to a boundary between adjacent light emitting layer formation scheduled regions.
図1(g)に示すように、ホール注入層4上にバンク5を形成する。ホール注入層4上においてバンク5を形成する領域は、隣り合う発光層形成予定領域どうしの境界に相当する領域である。 Bank formation process:
As shown in FIG. 1G, a
このバンク5は、ホール注入層4上の全体を覆うようにバンク材料層を形成し、形成したバンク材料層の一部をPR/PEで除去することによって形成する(厚さ1μm)。
The bank 5 is formed by forming a bank material layer so as to cover the whole of the hole injection layer 4 and removing a part of the formed bank material layer by PR / PE (thickness: 1 μm).
なお、図1では、基板1を横方向に切断した断面形状を示しているが、バンク5は、基板1の上面に沿って縦方向(図1では紙面表裏方向)に伸長している。そして、複数本のバンク5が、基板1の上面全体に亘って配列されている。
Although FIG. 1 shows a cross-sectional shape of the substrate 1 cut in the horizontal direction, the bank 5 extends along the top surface of the substrate 1 in the vertical direction (the front and back direction in FIG. 1). A plurality of banks 5 are arranged over the entire top surface of the substrate 1.
なお、バンク5は、縦方向にだけ伸長するストライプ状のラインバンクであってもよいし、縦と横に伸長し平面形状が井桁状のピクセルバンクであってもよい。
The bank 5 may be a striped line bank that extends only in the vertical direction, or may be a pixel bank that extends in the vertical and horizontal directions and has a planar shape in the form of a cross.
図2は、バンク形成工程を具体的に説明する図である。
FIG. 2 is a diagram for specifically explaining the bank formation process.
図2(a)に示すように、ホール注入層を形成した基板を投入し、その上に、図2(b)に示すように、バンク材料をスピンコート法で塗布することによってバンク材料層5aを形成する。
As shown in FIG. 2 (a), a substrate on which a hole injection layer is formed is put, and a bank material is applied thereon by spin coating as shown in FIG. 2 (b), thereby forming a bank material layer 5a. Form.
バンク材料としては、フッ素成分化合物および樹脂成分材料を含む感光性レジスト材料を用いる。また、このバンク材料は、塗付後にエッチング処理、ベーク処理等が施され、次の工程でもバンク表面にインクが塗布されるので、有機溶剤に対する耐性を有し、これらの処理に対して変形や変質を生じにくい材料を用いることが望ましい。
As the bank material, a photosensitive resist material containing a fluorine component compound and a resin component material is used. In addition, this bank material is subjected to an etching process, a baking process, etc. after application, and ink is applied to the bank surface in the next process, so that it has resistance to organic solvents, It is desirable to use a material that does not easily cause alteration.
例えば、フッ素化ポリオレフィン系樹脂、フッ素化ポリイミド樹脂、フッ素化ポリアクリル樹脂などのフッ素樹脂を含む感光性レジストが挙げられる。フッ素樹脂の具体例としては、特表2002-543469号公報に記載されているフッ素含有ポリマー;フルオロエチレンとビニルエーテルとの共重合体であるルミフロン(LUMIFLON、登録商標、旭硝子)が挙げられる。
For example, a photosensitive resist containing a fluororesin such as a fluorinated polyolefin resin, a fluorinated polyimide resin, or a fluorinated polyacrylic resin can be used. Specific examples of the fluororesin include a fluorine-containing polymer described in JP-T-2002-543469; LUMIFLON (registered trademark, Asahi Glass) which is a copolymer of fluoroethylene and vinyl ether.
図2(c)に示すように、バンク材料層5aの上に、バンク形成予定領域に合わせた開口を有するフォトマスクを重ねる。そして、UV露光すると、バンク材料層5aにおけるUV光が照射された部分だけが重合反応して硬化する。
As shown in FIG. 2C, a photomask having an opening corresponding to the bank formation scheduled region is overlaid on the bank material layer 5a. Then, when UV exposure is performed, only the portion of the bank material layer 5a irradiated with UV light is polymerized and cured.
そして、図2(d)に示すように現像すると、バンク材料層5aは、未硬化部分が除去されて、硬化部分が残るので、バンク形状にパターニングされる。
Then, when developed as shown in FIG. 2D, the bank material layer 5a is patterned into a bank shape because the uncured portion is removed and the cured portion remains.
さらに、べーク(加熱処理)を施すことによって、図2(e)に示されるように順テーパ状のバンク5が形成される。
Further, by performing baking (heat treatment), a forward-tapered bank 5 is formed as shown in FIG.
図1(g)に示すように、バンク5間には、凹部が形成され、凹部の底面にはホール注入層4が露出している。
As shown in FIG. 1G, a recess is formed between the banks 5, and the hole injection layer 4 is exposed on the bottom surface of the recess.
以上の現像、ベーク工程において、バンク材料層5aの未硬化部分は基本的に除去されるが、通常は、その一部分が残渣5cとして凹部の底面上に残るので、この残渣を低減させるために、次のUV洗浄工程を行う。
In the development and baking processes described above, the uncured portion of the bank material layer 5a is basically removed, but usually a portion of the bank material layer 5a remains on the bottom surface of the recess as a residue 5c. The next UV cleaning step is performed.
UV洗浄工程:
バンク5を形成した基板上から、光の振動エネルギーが458~472kJ/molの範囲にある紫外線を照射する。例えば、主な波長254nmに主な放射強度を持つ低圧水銀ランプを用いる。波長254nmは、振動エネルギー472kJ/molに相当する。 UV cleaning process:
Ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol is irradiated from the substrate on which thebank 5 is formed. For example, a low-pressure mercury lamp having a main radiation intensity at a main wavelength of 254 nm is used. A wavelength of 254 nm corresponds to vibration energy of 472 kJ / mol.
バンク5を形成した基板上から、光の振動エネルギーが458~472kJ/molの範囲にある紫外線を照射する。例えば、主な波長254nmに主な放射強度を持つ低圧水銀ランプを用いる。波長254nmは、振動エネルギー472kJ/molに相当する。 UV cleaning process:
Ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol is irradiated from the substrate on which the
UV光を基板に照射するときの照度は5~150mW/cm2の範囲内に設定することが好ましい。
The illuminance when the substrate is irradiated with UV light is preferably set in the range of 5 to 150 mW / cm 2 .
照射するUV光量の総和(積算光量)は、690~1035mJ/cm2となるように照射時間を設定する。この積算光量は、照度と照射時間の積(積算光量=照度×照射時間)で表される。
The irradiation time is set so that the total amount of UV light to be irradiated (integrated light amount) is 690 to 1035 mJ / cm 2 . This integrated light quantity is represented by the product of illuminance and irradiation time (integrated light quantity = illuminance x irradiation time).
上記のように照度5~150mW/cm2で、積算光量を690~1035mJ/cm2に設定する場合、照射時間は最低で690/150=4.6(秒)、最長で1035/5=207(秒)となる。従って、照射時間は約5~200秒の範囲内で設定されることになる。
As described above, when the illuminance is 5 to 150 mW / cm 2 and the integrated light quantity is set to 690 to 1035 mJ / cm 2 , the irradiation time is at least 690/150 = 4.6 (seconds), and the longest is 1035/5 = 207. (Seconds). Therefore, the irradiation time is set within a range of about 5 to 200 seconds.
なお、このUV洗浄工程については後で詳細を説明する。
The details of the UV cleaning process will be described later.
ホール輸送層形成工程:
バンク5間の凹部に、ホール輸送層の材料を含むインクを充填し、乾燥することによって、図3(a)に示すように、ホール輸送層6を形成する。 Hole transport layer formation process:
The hole transport layer 6 is formed as shown in FIG. 3A by filling the recesses between thebanks 5 with ink containing the material of the hole transport layer and drying.
バンク5間の凹部に、ホール輸送層の材料を含むインクを充填し、乾燥することによって、図3(a)に示すように、ホール輸送層6を形成する。 Hole transport layer formation process:
The hole transport layer 6 is formed as shown in FIG. 3A by filling the recesses between the
ホール輸送層6の材料として、ポリスチレンスルホン酸をドープしたポリ(3,4-エチレンジオキシチオフェン)(PEDOT-PSS)や、その誘導体(共重合体など)が挙げられる。ホール輸送層6の厚さは、通常10nm以上100nm以下であって、例えば20nmである。
Examples of the material for the hole transport layer 6 include poly (3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSS) and derivatives thereof (such as copolymers). The thickness of the hole transport layer 6 is usually 10 nm or more and 100 nm or less, for example, 20 nm.
発光層形成工程:
バンク5間の凹部に、有機発光材料を含むインクを充填する。すなわち、基板1上の全体に亘って、複数本のバンク5どうしの間に、液滴吐出法(インクジェット法)でインクを印刷する。インクをバンク間に充填する方法として、ディスペンサー法、ノズルコート法、スピンコート法、凹版印刷、凸版印刷等を用いてもよい。 Light emitting layer forming process:
The recesses between thebanks 5 are filled with ink containing an organic light emitting material. That is, ink is printed by a droplet discharge method (inkjet method) between the plurality of banks 5 over the entire substrate 1. As a method for filling the ink between the banks, a dispenser method, a nozzle coating method, a spin coating method, intaglio printing, letterpress printing, or the like may be used.
バンク5間の凹部に、有機発光材料を含むインクを充填する。すなわち、基板1上の全体に亘って、複数本のバンク5どうしの間に、液滴吐出法(インクジェット法)でインクを印刷する。インクをバンク間に充填する方法として、ディスペンサー法、ノズルコート法、スピンコート法、凹版印刷、凸版印刷等を用いてもよい。 Light emitting layer forming process:
The recesses between the
そして、充填したインクを減圧下で乾燥し、ベークすることによって、図3(b)に示すように発光層7を形成する。発光層7の厚さは60~90nmである。
Then, the filled ink is dried under reduced pressure and baked to form the light emitting layer 7 as shown in FIG. The thickness of the light emitting layer 7 is 60 to 90 nm.
有機発光材料として、例えば、特開平5-163488号公報に記載されたオキシノイド化合物、ペリレン化合物、クマリン化合物、アザクマリン化合物、オキサゾール化合物、オキサジアゾール化合物、ペリノン化合物、ピロロピロール化合物、ナフタレン化合物、アントラセン化合物、フルオレン化合物、フルオランテン化合物、テトラセン化合物、ピレン化合物、コロネン化合物、キノロン化合物及びアザキノロン化合物、ピラゾリン誘導体及びピラゾロン誘導体、ローダミン化合物、クリセン化合物、フェナントレン化合物、シクロペンタジエン化合物、スチルベン化合物、ジフェニルキノン化合物、スチリル化合物、ブタジエン化合物、ジシアノメチレンピラン化合物、ジシアノメチレンチオピラン化合物、フルオレセイン化合物、ピリリウム化合物、チアピリリウム化合物、セレナピリリウム化合物、テルロピリリウム化合物、芳香族アルダジエン化合物、オリゴフェニレン化合物、チオキサンテン化合物、アンスラセン化合物、シアニン化合物、アクリジン化合物、8-ヒドロキシキノリン化合物の金属錯体、2-ビピリジン化合物の金属錯体、シッフ塩とIII族金属との鎖体、オキシン金属錯体、希土類錯体等が挙げられる。
Examples of organic light-emitting materials include, for example, oxinoid compounds, perylene compounds, coumarin compounds, azacoumarin compounds, oxazole compounds, oxadiazole compounds, perinone compounds, pyrrolopyrrole compounds, naphthalene compounds, anthracene compounds described in JP-A-5-163488 , Fluorene compounds, fluoranthene compounds, tetracene compounds, pyrene compounds, coronene compounds, quinolone compounds and azaquinolone compounds, pyrazoline derivatives and pyrazolone derivatives, rhodamine compounds, chrysene compounds, phenanthrene compounds, cyclopentadiene compounds, stilbene compounds, diphenylquinone compounds, styryl compounds , Butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound , Pyrylium compounds, thiapyrylium compounds, serenapyrylium compounds, telluropyrylium compounds, aromatic aldadiene compounds, oligophenylene compounds, thioxanthene compounds, anthracene compounds, cyanine compounds, acridine compounds, metal complexes of 8-hydroxyquinoline compounds, 2-bipyridine compounds Metal complexes, Schiff salts and group III metal chains, oxine metal complexes, rare earth complexes, and the like.
発光層7を構成する有機発光材料を溶質とし、比較的沸点が高い溶剤(沸点170~300℃)を含む溶剤に溶解してインクを製造する。
The ink is manufactured by dissolving the organic light emitting material constituting the light emitting layer 7 as a solute and dissolving it in a solvent containing a solvent having a relatively high boiling point (boiling point: 170 to 300 ° C.).
高沸点溶剤としては、シクロヘキシルベンゼン、ジエチルベンゼン、デカハイドロナフタレン、メチルベンゾエート、アセトフェノン、フェニルベンゼン、ベンジルアルコール、テトラハイドロナフタレン、イソフォロン、n-ドデカン、ジシクロヘキシル、p-キシレングリコールジメチルエーテルが挙げられる。これら溶剤は、単独で用いてもよいし、複数の溶剤を混合したもの、あるいは上記の高沸点溶剤と、低沸点溶剤とを混合して用いてもよい。
Examples of the high boiling point solvent include cyclohexylbenzene, diethylbenzene, decahydronaphthalene, methylbenzoate, acetophenone, phenylbenzene, benzyl alcohol, tetrahydronaphthalene, isophorone, n-dodecane, dicyclohexyl, and p-xylene glycol dimethyl ether. These solvents may be used alone, or may be a mixture of a plurality of solvents, or a mixture of the above high boiling point solvent and a low boiling point solvent.
電子注入層、上部電極、封止層形成工程:
図3(c)~(e)に示すように、バンク5及び発光層7を覆うように、電子輸送層8、上部電極としてのカソード電極9、封止層10を順次形成する。 Electron injection layer, upper electrode, sealing layer formation process:
As shown in FIGS. 3C to 3E, anelectron transport layer 8, a cathode electrode 9 as an upper electrode, and a sealing layer 10 are sequentially formed so as to cover the bank 5 and the light emitting layer 7.
図3(c)~(e)に示すように、バンク5及び発光層7を覆うように、電子輸送層8、上部電極としてのカソード電極9、封止層10を順次形成する。 Electron injection layer, upper electrode, sealing layer formation process:
As shown in FIGS. 3C to 3E, an
これら電子輸送層8,カソード電極9,封止層10は、各バンク5で規定された画素予定領域を超えて、隣接する有機EL素子の画素予定領域と連続するように形成する。
The electron transport layer 8, the cathode electrode 9, and the sealing layer 10 are formed so as to be continuous with the pixel planned region of the adjacent organic EL element beyond the pixel planned region defined by each bank 5.
電子輸送層8は、例えば、バリウム、フッ化リチウム、あるいはこれらの組み合わせで、ETL蒸着して形成する(厚さ20nm)。この電子輸送層8は、カソード電極9から注入される電子を発光層7へ輸送する機能を持つ。
The electron transport layer 8 is formed by, for example, ETL vapor deposition (thickness 20 nm) using barium, lithium fluoride, or a combination thereof. The electron transport layer 8 has a function of transporting electrons injected from the cathode electrode 9 to the light emitting layer 7.
カソード電極9は、光透過性の材料、例えば、ITO、IZO(酸化インジウム亜鉛)等を、プラズマ蒸着することによって形成する(厚さ100nm)。
The cathode electrode 9 is formed by plasma deposition of a light transmissive material, for example, ITO, IZO (indium zinc oxide) or the like (thickness: 100 nm).
封止層10は、SiN(窒化シリコン)、SiON(酸窒化シリコン)等の材料をCVDで形成する(厚さ1μm)。この封止層10は、発光層7等が水分に晒されたり、空気に晒されたりすることを抑制する役割を有する。
The sealing layer 10 is formed of a material such as SiN (silicon nitride) or SiON (silicon oxynitride) by CVD (thickness: 1 μm). The sealing layer 10 has a role of suppressing the light emitting layer 7 and the like from being exposed to moisture or being exposed to air.
以上で、トップエミッション型の有機EL素子がマトリックス状に配列された有機ELディスプレイパネルが作製される。
Thus, an organic EL display panel in which top emission type organic EL elements are arranged in a matrix is manufactured.
このように作製したパネルに対して、図4に示す以下の工程を行う。
The following steps shown in FIG. 4 are performed on the panel thus manufactured.
貼り合わせ工程では、上記のように作製したパネル上に、シール材を介してカラーフィルター基板を貼り合わせる。
In the bonding step, the color filter substrate is bonded to the panel produced as described above via a sealing material.
スクライブ・ブレーク工程では、パネルを所定サイズに分断する。
In the scribe and break process, the panel is divided into a predetermined size.
実装工程では、駆動回路を実装する。
In the mounting process, the drive circuit is mounted.
以上で、有機発光表示装置が作製される。
Thus, an organic light emitting display device is manufactured.
〈UV洗浄工程の詳細と効果〉
上記UV光の振動エネルギー(458~472kJ/mol)は、樹脂成分のC-H結合エネルギーの最高値よりも大きいので、基本的に、樹脂成分のC-H結合は当該UV光照射によって解離されるが、フッ素成分のC-F結合エネルギーの最低値よりも小さいので、C-F結合は当該UV光照射によって解離されない。 <Details and effects of UV cleaning process>
Since the vibration energy (458 to 472 kJ / mol) of the UV light is larger than the maximum value of the C—H bond energy of the resin component, basically, the C—H bond of the resin component is dissociated by the UV light irradiation. However, since it is smaller than the minimum value of the C—F bond energy of the fluorine component, the C—F bond is not dissociated by the UV light irradiation.
上記UV光の振動エネルギー(458~472kJ/mol)は、樹脂成分のC-H結合エネルギーの最高値よりも大きいので、基本的に、樹脂成分のC-H結合は当該UV光照射によって解離されるが、フッ素成分のC-F結合エネルギーの最低値よりも小さいので、C-F結合は当該UV光照射によって解離されない。 <Details and effects of UV cleaning process>
Since the vibration energy (458 to 472 kJ / mol) of the UV light is larger than the maximum value of the C—H bond energy of the resin component, basically, the C—H bond of the resin component is dissociated by the UV light irradiation. However, since it is smaller than the minimum value of the C—F bond energy of the fluorine component, the C—F bond is not dissociated by the UV light irradiation.
そのため、(1)バンク表面の撥液性を確保しながら、(2)ホール注入層4上においてバンク残渣の占める面積を少なくすることができる。
Therefore, (1) while ensuring the liquid repellency of the bank surface, (2) the area occupied by the bank residue on the hole injection layer 4 can be reduced.
そして、(1)バンク表面の撥液性を確保することによって、バンク5間にホール輸送層6、発光層7のインクを印刷するときに、バンク5間に充填されたインクがバンク5の外に流れ出ることなく、良好な印刷性が得られる。
(1) By ensuring the liquid repellency of the bank surface, when the ink of the hole transport layer 6 and the light emitting layer 7 is printed between the banks 5, the ink filled between the banks 5 is outside the banks 5. Good printability can be obtained without flowing out.
また、(2)ホール注入層4上においてバンク残渣の占める面積が少なくなることによって、素子におけるホール注入性が良好となる。
(2) Since the area occupied by the bank residue on the hole injection layer 4 is reduced, the hole injection property in the device is improved.
この点について、図4を参照しながら説明する。
This point will be described with reference to FIG.
図4は、各種分子の結合エネルギー、並びに各種ランプの光の振動エネルギー(kJ/mol)を示す図表である。
FIG. 4 is a chart showing the binding energy of various molecules and the vibration energy (kJ / mol) of light of various lamps.
図4に示されるように、フルオロベンゼンにおけるC-F結合解離エネルギーが524kJ/mol、フルオロメタンにおけるC-F結合エネルギーは472kJ/molであるのに対して、低圧水銀ランプのUV光(254nm)は、その振動エネルギーが472kJ/molであるので、C-F結合エネルギー以下である。従って、このUV光(254nm)の振動エネルギーではC-F結合は解離しない。
As shown in FIG. 4, the CF bond dissociation energy in fluorobenzene is 524 kJ / mol, and the CF bond energy in fluoromethane is 472 kJ / mol, whereas the UV light (254 nm) of a low-pressure mercury lamp. Is less than or equal to the C—F bond energy because its vibrational energy is 472 kJ / mol. Therefore, the C—F bond is not dissociated by the vibrational energy of the UV light (254 nm).
一方、図4において、メチル基、メタンのC-H結合エネルギー(457kJ/mol、432kJ/mol)などが示されているが、一般に樹脂成分におけるC-H結合の結合エネルギーはこの値に近いと見ることができるので、上記UV光の振動エネルギー(458~472kJ/mol)は、一般的な樹脂成分におけるC-H結合の結合エネルギーよりも大きい。従って、振動エネルギー458~472kJ/molのUV光を照射することによって、C-H結合を解離して樹脂成分を分解することができる。
On the other hand, FIG. 4 shows methyl group, CH bond energy (457 kJ / mol, 432 kJ / mol) of methane, etc. Generally, when the bond energy of CH bond in the resin component is close to this value, As can be seen, the vibration energy (458 to 472 kJ / mol) of the UV light is larger than the bond energy of the CH bond in a general resin component. Therefore, irradiation with UV light having vibration energy of 458 to 472 kJ / mol can dissociate the C—H bond and decompose the resin component.
なお、図6は、UV光(波長254nm)をバンク上から照射したときに、残渣及びバンク表面におけるC-H結合が解離し、C-F結合が解離せずに残る様子を模式的に示す図である。
FIG. 6 schematically shows a state in which when the UV light (wavelength 254 nm) is irradiated from above the bank, the residue and the CH bond on the bank surface are dissociated and the CF bond remains without dissociation. FIG.
また、本実施形態のUV洗浄工程においては、上記のようにUV光の総和(積算光量)も、690~1035mJ/cm2の範囲内に設定している。
Further, in the UV cleaning process of the present embodiment, as described above, the total sum of UV light (integrated light amount) is also set within the range of 690 to 1035 mJ / cm 2 .
従って、本実施形態の製造方法によれば、確実に、バンク5の表面に存在するフッ素成分の分解を抑えてバンク5表面の撥液性を確保しながら、残渣中の樹脂成分を分解してホール注入層4上におけるバンク残渣の占める面積を少なくすることができる。
Therefore, according to the manufacturing method of the present embodiment, the resin component in the residue is decomposed while reliably suppressing the decomposition of the fluorine component present on the surface of the bank 5 and ensuring the liquid repellency of the surface of the bank 5. The area occupied by the bank residue on the hole injection layer 4 can be reduced.
〈実験〉
実験1:フッ素残存量
平らなガラス上に、バンク材料をスピン塗布して、フォトリソグラフィー技術でパターンニングすることによって、基板上にバンクを形成した。ここでは、基板上に(幅30μのバンクを間隙60μm)で形成した。 <Experiment>
Experiment 1: Residual amount of fluorine A bank was formed on a substrate by spin-coating a bank material on a flat glass and patterning it with a photolithographic technique. Here, it was formed on a substrate (a bank having a width of 30 μm with a gap of 60 μm).
実験1:フッ素残存量
平らなガラス上に、バンク材料をスピン塗布して、フォトリソグラフィー技術でパターンニングすることによって、基板上にバンクを形成した。ここでは、基板上に(幅30μのバンクを間隙60μm)で形成した。 <Experiment>
Experiment 1: Residual amount of fluorine A bank was formed on a substrate by spin-coating a bank material on a flat glass and patterning it with a photolithographic technique. Here, it was formed on a substrate (a bank having a width of 30 μm with a gap of 60 μm).
バンクを形成した基板に対して、UV洗浄工程を行う際に、UV光(波長254nm)をバンク上から照射する照度を23mW/cm2で一定とし、UV光の照射時間を、0秒,10秒,30秒,60秒と変えて、ホール注入層4の表面におけるフッ素残存量がどのように変化するかを調べた。
When performing the UV cleaning process on the substrate on which the bank is formed, the illuminance for irradiating the UV light (wavelength 254 nm) from above the bank is constant at 23 mW / cm 2 , and the irradiation time of the UV light is 0 seconds, 10 It was examined how the residual amount of fluorine on the surface of the hole injection layer 4 was changed by changing the seconds, 30 seconds, and 60 seconds.
バンク材料としては、フルオロエチレンとビニルエーテルとの共重合体を用いた。
As the bank material, a copolymer of fluoroethylene and vinyl ether was used.
フッ素残存量の測定は、飛行時間型二次イオン質量分析(TOF-SIMS)法を用い、以下の分析条件で、ホール注入層4の表面におけるNegativeイオン強度を測定することによって行った。
The measurement of the residual amount of fluorine was performed by measuring the negative ion intensity on the surface of the hole injection layer 4 under the following analysis conditions using a time-of-flight secondary ion mass spectrometry (TOF-SIMS) method.
照射イオン Ga+
一次イオンエネルギー (Negative)18keV
イオン照射面積 (Negative)30×30μm
分析・解析領域 (Negative)15×30μm
図7は、その測定結果を示すグラフであって、UV照射する前のNegativeイオン強度測定値を基準値10として規格化したものである。Rfは、ホール注入層4上にバンク5を形成していない場合における測定値である。 Irradiated ion Ga +
Primary ion energy (Negative) 18 keV
Ion irradiation area (Negative) 30 × 30μm
Analysis / Analysis Area (Negative) 15 × 30μm
FIG. 7 is a graph showing the measurement results, in which the negative ionic strength measurement value before UV irradiation is normalized as thereference value 10. Rf is a measured value when the bank 5 is not formed on the hole injection layer 4.
一次イオンエネルギー (Negative)18keV
イオン照射面積 (Negative)30×30μm
分析・解析領域 (Negative)15×30μm
図7は、その測定結果を示すグラフであって、UV照射する前のNegativeイオン強度測定値を基準値10として規格化したものである。Rfは、ホール注入層4上にバンク5を形成していない場合における測定値である。 Irradiated ion Ga +
Primary ion energy (Negative) 18 keV
Ion irradiation area (Negative) 30 × 30μm
Analysis / Analysis Area (Negative) 15 × 30μm
FIG. 7 is a graph showing the measurement results, in which the negative ionic strength measurement value before UV irradiation is normalized as the
図7の結果から、UV光(波長254nm)を10秒~60秒照射(積算光量230m~1380J/cm2)すると、規格化イオン強度は、規格化イオン強度は3.0×100~1.0×100の範囲内になっていて、照射前(0秒)の規格化フッ素イオン強度(1.0×101)と比べると、0.3以上1未満の範囲で小さくなっているが、Rfと比べると100倍程度は多くフッ素が残存していることがわかる。
From the results shown in FIG. 7, when UV light (wavelength 254 nm) is irradiated for 10 seconds to 60 seconds (integrated light amount 230 m to 1380 J / cm 2 ), the normalized ion intensity is 3.0 × 10 0 to 1 It is within the range of 0.0 × 10 0 and is smaller in the range of 0.3 or more and less than 1 compared with the normalized fluorine ion intensity (1.0 × 10 1 ) before irradiation (0 second). However, it can be seen that about 100 times as much fluorine remains as compared with Rf.
これは、UV光(波長254nm)を積算光量で230mJ/cm2以上照射すると、ある程度フッ素成分が分解されるものの、積算光量が1380mJ/cm2以下では、フッ素成分が多く残存していることを示している。
This is because, when UV light (wavelength 254 nm) is irradiated with an integrated light amount of 230 mJ / cm 2 or more, the fluorine component is decomposed to some extent, but when the integrated light amount is 1380 mJ / cm 2 or less, a large amount of fluorine component remains. Show.
実験2:インクの接触角
UV洗浄工程において、UV光をバンク間に照射する照度を23mW/cm2で一定とし、照射時間を0秒,30秒,45秒,60秒と変えて、バンク表面に、有機EL素子の発光層形成用インクの液滴を滴下して、インクのバンク表面に対する接触角を測定した。 Experiment 2: Ink contact angle In the UV cleaning process, the illuminance for irradiating UV light between banks is constant at 23 mW / cm 2 , and the irradiation time is changed to 0 seconds, 30 seconds, 45 seconds, and 60 seconds to change the bank surface. Then, a drop of ink for forming a light emitting layer of the organic EL element was dropped, and the contact angle of the ink with respect to the bank surface was measured.
UV洗浄工程において、UV光をバンク間に照射する照度を23mW/cm2で一定とし、照射時間を0秒,30秒,45秒,60秒と変えて、バンク表面に、有機EL素子の発光層形成用インクの液滴を滴下して、インクのバンク表面に対する接触角を測定した。 Experiment 2: Ink contact angle In the UV cleaning process, the illuminance for irradiating UV light between banks is constant at 23 mW / cm 2 , and the irradiation time is changed to 0 seconds, 30 seconds, 45 seconds, and 60 seconds to change the bank surface. Then, a drop of ink for forming a light emitting layer of the organic EL element was dropped, and the contact angle of the ink with respect to the bank surface was measured.
用いたインクは、溶媒が安息香酸ブチル、溶質はポリフルオレンポリマー(品名:Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl)、アルドリッチ製)であり、濃度は1.0wt%である。
The ink used was butyl benzoate as solvent, polyfluorene polymer (product name: Poly (9,9-di-n-dodecylfluorenyl-2,7-diyl), manufactured by Aldrich), and the concentration was 1.0 wt% It is.
図8は、その結果を示す図及び表である。
FIG. 8 is a diagram and a table showing the results.
図8に示されるように、初期(0秒)には接触角が45°であり、照射時間経過に伴って接触角は徐々に低下し、45秒経過時に接触角が35°まで低下している。この45秒経過時における積算光量は45×23=1035mJ/cm2である。
As shown in FIG. 8, the contact angle is 45 ° in the initial stage (0 seconds), the contact angle gradually decreases as the irradiation time elapses, and the contact angle decreases to 35 ° when 45 seconds elapse. Yes. The accumulated light quantity after 45 seconds is 45 × 23 = 1035 mJ / cm 2 .
ところで、インクの印刷性は、バンク表面に対するインクの接触角が35°以上のときに良好である。すなわち、この接触角が35°以上、60°以下の範囲内あれば、図6(c)のようにインクをバンク間の開口部に充填するときに、インクがバンク間から外に溢れにくいので、パネル全体にわたって発光層7を良好に形成できることが経験上わかっている。
Incidentally, the printability of the ink is good when the contact angle of the ink with respect to the bank surface is 35 ° or more. That is, if the contact angle is in the range of 35 ° or more and 60 ° or less, the ink is unlikely to overflow from between the banks when the ink is filled in the openings between the banks as shown in FIG. 6C. Experience has shown that the light emitting layer 7 can be satisfactorily formed over the entire panel.
従って、UV光をバンクに照射するときの積算光量を1035mJ/cm2以下に設定することによって、インクのバンクに対する接触角が35°以上に保たれ、バンク間にインクを良好に印刷できる(インクジェットなどで充填できる)ことがわかる。
Therefore, by setting the integrated light amount when irradiating the banks with UV light to 1035 mJ / cm 2 or less, the contact angle of the ink with respect to the banks is maintained at 35 ° or more, and ink can be printed favorably between the banks (inkjet It can be filled with.
なお、バンク表面に対するインクの接触角は、使用するバンク材料及びインクの溶剤の種類によって多少変わるが、一般的に有機EL素子に用いられるフッ素成分および樹脂成分を含むバンク材料及びインク溶剤を用いれば、図7,8に示す結果とほぼ同様の結果が得られると考えられる。
The contact angle of the ink with respect to the bank surface varies somewhat depending on the type of the bank material used and the solvent of the ink, but if a bank material and an ink solvent containing a fluorine component and a resin component that are generally used in an organic EL element are used. It is considered that a result almost similar to the result shown in FIGS.
実験3:V-J特性
上記実施の形態に基づいて、基板上に、第二アノード電極3(ITO層,厚さ100nm)、ホール注入層4(WOx層,厚さ30nm)、バンク5を形成し、UV光(波長254nm)を照度23mW/cm2で0秒,30秒,45秒照射した後、バンク間にインクを塗布して乾燥する方法で、ホール輸送層6(厚さ30nm)、発光層7(厚さ95nm)を形成し、さらに電子輸送層8(Ba層,厚さ5nm)、カソード電極9(Al層,厚さ120nm)を順に形成して、試験用の素子サンプルを形成した。 Experiment 3: VJ characteristics Based on the above embodiment, the second anode electrode 3 (ITO layer,thickness 100 nm), the hole injection layer 4 (WOx layer, thickness 30 nm), and the bank 5 are formed on the substrate. Then, after irradiating UV light (wavelength 254 nm) at an illuminance of 23 mW / cm 2 for 0 seconds, 30 seconds, and 45 seconds, the ink is applied between the banks and dried, the hole transport layer 6 (thickness 30 nm), A light emitting layer 7 (thickness 95 nm) is formed, and an electron transport layer 8 (Ba layer, thickness 5 nm) and a cathode electrode 9 (Al layer, thickness 120 nm) are formed in this order to form a device sample for testing. did.
上記実施の形態に基づいて、基板上に、第二アノード電極3(ITO層,厚さ100nm)、ホール注入層4(WOx層,厚さ30nm)、バンク5を形成し、UV光(波長254nm)を照度23mW/cm2で0秒,30秒,45秒照射した後、バンク間にインクを塗布して乾燥する方法で、ホール輸送層6(厚さ30nm)、発光層7(厚さ95nm)を形成し、さらに電子輸送層8(Ba層,厚さ5nm)、カソード電極9(Al層,厚さ120nm)を順に形成して、試験用の素子サンプルを形成した。 Experiment 3: VJ characteristics Based on the above embodiment, the second anode electrode 3 (ITO layer,
そして、作製した各素子サンプルについて、電流密度(J)を変化させながら発光効率(η)を測定した。
And about each produced element sample, luminous efficiency ((eta)) was measured changing current density (J).
図9は、その結果を示すJ-η特性のグラフである。
FIG. 9 is a graph of J-η characteristics showing the result.
図9に示すように、UV光の照射時間が30秒、45秒のもの(積算光量が690~1035mJ/cm2)では、UV光を照射していないもの(0秒)と比べて、発光効率が40%程度向上した。
As shown in FIG. 9, when the irradiation time of the UV light is 30 seconds and 45 seconds (integrated light amount is 690 to 1035 mJ / cm 2 ), the light emission is larger than that when the UV light is not irradiated (0 seconds). Efficiency improved by about 40%.
また、作製した各素子サンプルについて、駆動電圧(V)と電流密度(J)との関係も測定した。
Moreover, the relationship between the drive voltage (V) and the current density (J) was also measured for each of the fabricated element samples.
図10は、その結果を示すV-J特性のグラフである。
FIG. 10 is a graph of VJ characteristics showing the result.
図10からわかるように、UV光の照射時間が30秒、45秒のものでは、UV光を照射していないもの(0秒)と比べて、同じ電流密度を得るのに必要な駆動電圧が低くなっている。その駆動電圧の低下度は、電流密度10mA/cm2において2V程度である。
As can be seen from FIG. 10, when the UV light irradiation time is 30 seconds and 45 seconds, the drive voltage required to obtain the same current density is higher than that when the UV light is not irradiated (0 seconds). It is low. The degree of decrease in the drive voltage is about 2 V at a current density of 10 mA / cm 2 .
実験4:寿命特性
UV光(波長254nm)を照度23mW/cm2で30秒照射した素子サンプルと、UV照射していない素子サンプルについて、初期輝度が8000cd/m2となるような一定の駆動電圧で駆動したときの輝度を経時的に測定した。 Experiment 4: Lifetime characteristics A constant driving voltage such that the initial luminance is 8000 cd / m 2 for an element sample irradiated with UV light (wavelength 254 nm) at an illuminance of 23 mW / cm 2 for 30 seconds and an element sample not irradiated with UV light. The luminance when driven by was measured over time.
UV光(波長254nm)を照度23mW/cm2で30秒照射した素子サンプルと、UV照射していない素子サンプルについて、初期輝度が8000cd/m2となるような一定の駆動電圧で駆動したときの輝度を経時的に測定した。 Experiment 4: Lifetime characteristics A constant driving voltage such that the initial luminance is 8000 cd / m 2 for an element sample irradiated with UV light (wavelength 254 nm) at an illuminance of 23 mW / cm 2 for 30 seconds and an element sample not irradiated with UV light. The luminance when driven by was measured over time.
図11はその結果を示すグラフである。UV光を照射した素子サンプルの方が経時的な輝度の低下が少ないことがわかる。
FIG. 11 is a graph showing the results. It can be seen that the element sample irradiated with UV light has less decrease in luminance over time.
また、UV光(波長254nm)を照度23mW/cm2で30秒照射した素子サンプルと、UV照射していない素子サンプルについて、一定の輝度8000cd/m2で駆動させて、駆動電圧を経時的に測定した。図12はその結果を示すグラフである。
In addition, an element sample irradiated with UV light (wavelength 254 nm) at an illuminance of 23 mW / cm 2 for 30 seconds and an element sample not irradiated with UV were driven at a constant luminance of 8000 cd / m 2 , and the drive voltage was changed over time. It was measured. FIG. 12 is a graph showing the results.
図12に示すように、UV光を照射した素子サンプルは、UV光を照射していない素子サンプルと比べて、初期の駆動電圧も小さく、経時的な駆動電圧の上昇も小さいことがわかる。
As shown in FIG. 12, it can be seen that the element sample irradiated with UV light has a smaller initial driving voltage and a smaller increase in driving voltage over time than the element sample not irradiated with UV light.
〈変形例〉
以上、実施の形態を説明したが、以下のような変形例が考えられる。 <Modification>
Although the embodiment has been described above, the following modifications can be considered.
以上、実施の形態を説明したが、以下のような変形例が考えられる。 <Modification>
Although the embodiment has been described above, the following modifications can be considered.
(1)上記実施の形態では、有機ELディスプレイにおける発光層の発光色については言及しなかったが、単色表示に限らず、フルカラー表示の有機ELディスプレイにも適用できる。フルカラー表示の有機ELディスプレイにおいては、有機EL素子が、RGB各色のサブピクセルに相当し、隣り合うRGBのサブピクセルが合わさって一画素が形成され、この画素がマトリックス状に配列されて画像表示領域が形成される。
(1) In the above embodiment, the light emission color of the light emitting layer in the organic EL display is not mentioned, but the present invention can be applied not only to a single color display but also to a full color display organic EL display. In an organic EL display of full color display, the organic EL element corresponds to a subpixel of each RGB color, and adjacent RGB subpixels are combined to form one pixel, and this pixel is arranged in a matrix to form an image display area Is formed.
(2)上記実施の形態では、トップエミッション型有機ELディスプレイを例に説明したが、ボトムエミッション型有機ELディスプレイの発光層を形成する場合にも同様に実施可能である。
(3)なお、本発明は有機TFT(Thin Film Transistor)にも適用できる。 (2) In the above embodiment, the top emission type organic EL display has been described as an example. However, the present invention can be similarly applied to the case where the light emitting layer of the bottom emission type organic EL display is formed.
(3) The present invention can also be applied to an organic TFT (Thin Film Transistor).
(3)なお、本発明は有機TFT(Thin Film Transistor)にも適用できる。 (2) In the above embodiment, the top emission type organic EL display has been described as an example. However, the present invention can be similarly applied to the case where the light emitting layer of the bottom emission type organic EL display is formed.
(3) The present invention can also be applied to an organic TFT (Thin Film Transistor).
本発明は、発光層をウェット方式で形成する方法で有機ELディスプレイをはじめ有機EL光源など有機ELパネルを製造するのに有効である。
The present invention is effective for manufacturing an organic EL panel such as an organic EL display as well as an organic EL light source by a method of forming a light emitting layer by a wet method.
有機ELディスプレイにおいては、画像表示面内において、発光特性が良好で、均一的な発光特性が得られるので画質の向上にも寄与する。
In the organic EL display, the light emission characteristics are good and uniform light emission characteristics can be obtained in the image display surface, which contributes to the improvement of the image quality.
1 TFT基板
1a 平坦化膜
2 第一アノード電極
3 第二アノード電極
4 ホール注入層
5 バンク
5a バンク材料層
5c 残渣
6 ホール輸送層
7 発光層
8 電子輸送層
9 カソード電極
10 封止層 DESCRIPTION OFSYMBOLS 1 TFT substrate 1a Planarization film 2 1st anode electrode 3 2nd anode electrode 4 Hole injection layer 5 Bank 5a Bank material layer 5c Residue 6 Hole transport layer 7 Light emitting layer 8 Electron transport layer 9 Cathode electrode 10 Sealing layer
1a 平坦化膜
2 第一アノード電極
3 第二アノード電極
4 ホール注入層
5 バンク
5a バンク材料層
5c 残渣
6 ホール輸送層
7 発光層
8 電子輸送層
9 カソード電極
10 封止層 DESCRIPTION OF
Claims (10)
- 基板を準備する第1工程と、
前記基板の上方に、下部電極を含む機能層を形成する第2工程と、
前記機能層の上方に、フッ素成分および樹脂成分を含む感光性レジスト材料を塗布し、前記感光性レジスト材料の一部を露光してパターニングすることにより、画素部に対応する開口部を形成すると共に、隣り合う画素部を区画するバンクを形成する第3工程と、
前記開口部および前記バンクに対し、紫外線を照射する第4工程と、
前記第4工程の後、有機発光材料を含むインクを前記開口部に対して塗布して乾燥させ、有機発光層を形成する第5工程と、
前記有機発光層の上方に、上部電極を形成する第6工程と、
を有し、
前記第4工程において、光の振動エネルギーが458~472kJ/molの範囲となる紫外線を用い、照射する光量の総和(積算光量)が690~1035mJ/cm2となるように照射することを特徴とする有機発光素子の製造方法。 A first step of preparing a substrate;
A second step of forming a functional layer including a lower electrode above the substrate;
A photosensitive resist material containing a fluorine component and a resin component is applied above the functional layer, and a part of the photosensitive resist material is exposed and patterned to form an opening corresponding to the pixel portion. A third step of forming a bank that partitions adjacent pixel portions;
A fourth step of irradiating the opening and the bank with ultraviolet rays;
After the fourth step, a fifth step of forming an organic light emitting layer by applying an ink containing an organic light emitting material to the opening and drying it;
A sixth step of forming an upper electrode above the organic light emitting layer;
Have
In the fourth step, irradiation is performed using ultraviolet light having a vibration energy of light in the range of 458 to 472 kJ / mol, so that the total amount of light to be irradiated (integrated light amount) is 690 to 1035 mJ / cm 2. A method for manufacturing an organic light emitting device. - 前記光の振動エネルギーは、
前記樹脂成分の解離エネルギーよりも大きく、且つ、前記フッ素成分の解離エネルギーよりも小さい値であることを特徴とする請求項1記載の有機発光素子の製造方法。 The vibration energy of the light is
2. The method of manufacturing an organic light emitting element according to claim 1, wherein the organic light emitting element has a value larger than the dissociation energy of the resin component and smaller than the dissociation energy of the fluorine component. - 前記第4工程における積算光量は、照度と照射時間の積で表され、
前記照度は5~150mW/cm2の範囲内であり、
且つ、前記照射時間は5~200秒の範囲内であることを特徴とする請求項1記載の有機発光素子の製造方法。 The integrated light quantity in the fourth step is represented by the product of illuminance and irradiation time,
The illuminance is in the range of 5 to 150 mW / cm 2 ;
2. The method of manufacturing an organic light-emitting element according to claim 1, wherein the irradiation time is in the range of 5 to 200 seconds. - 前記第2工程において、機能層として酸化タングステン(WOx)を含む正孔注入層(HIL)を用い、
前記第4工程後の機能層上におけるフッ素成分の規格化イオン強度(酸化タングステン成分を基準として規格化した値)は、3.0×100以上であって1.0×101以下であることを特徴とする請求項1記載の有機発光素子の製造方法。 In the second step, a hole injection layer (HIL) containing tungsten oxide (WOx) is used as a functional layer,
The normalized ionic strength (value normalized based on the tungsten oxide component) of the fluorine component on the functional layer after the fourth step is 3.0 × 10 0 or more and 1.0 × 10 1 or less. The manufacturing method of the organic light emitting element of Claim 1. - 前記第4工程後の機能層上におけるフッ素成分の規格化イオン強度は、前記第3工程後の機能層上におけるフッ素成分の規格化イオン強度に対し、その比の値が0.3以上であって1未満であることを特徴とする請求項1記載の有機発光素子の製造方法。 The normalized ionic strength of the fluorine component on the functional layer after the fourth step is 0.3 or more relative to the normalized ionic strength of the fluorine component on the functional layer after the third step. The method for producing an organic light emitting device according to claim 1, wherein the organic light emitting device is less than 1.
- 前記第4工程により、紫外線が照射された後の前記バンクに対する前記有機発光材料を含むインクの接触角度は35°~60°であることを特徴とする請求項1記載の有機発光素子の製造方法。 2. The method of manufacturing an organic light-emitting element according to claim 1, wherein the contact angle of the ink containing the organic light-emitting material with respect to the bank after being irradiated with ultraviolet rays in the fourth step is 35 ° to 60 °. .
- 前記機能層は、正孔注入層を備え、
前記第4工程では、紫外線を前記開口部に対して照射することにより、第3工程に伴って前記バンクから前記正孔注入層の表面に付着した樹脂成分を除去することを特徴とする請求項1記載の有機発光素子の製造方法。 The functional layer includes a hole injection layer,
The resin component attached to the surface of the hole injection layer from the bank in the third step is removed by irradiating the opening with ultraviolet rays in the fourth step. 2. A method for producing an organic light emitting device according to 1. - 前記請求項1~7のいずれかの製造方法により製造された有機発光素子と、
前記有機発光素子を駆動するための駆動回路とを有する有機発光表示装置。 An organic light emitting device manufactured by the manufacturing method according to any one of claims 1 to 7,
An organic light emitting display device having a drive circuit for driving the organic light emitting element. - 基板を準備する第1工程と、
前記基板の上方に、下部電極を含む機能層を形成する第2工程と、
前記機能層の上方に、フッ素成分および樹脂成分を含む感光性レジスト材料を塗布し、前記感光性レジスト材料を露光してパターニングすることにより、画素部に対応する開口部を形成すると共に、隣り合う画素部を区画するバンクを形成する第3工程と、
前記開口部および前記バンクに対し、紫外線を照射する第4工程と、
前記第4工程の後、有機発光材料を含むインクを前記開口部に対して塗布して乾燥させ、有機発光層を形成する第5工程と、
前記有機発光層の上方に、上部電極を形成する第6工程とを有し、
前記第4工程において、前記紫外線の光の振動エネルギーは、前記用いられる樹脂材料の解離エネルギーよりも大きく、且つ、前記用いられるフッ素成分の解離エネルギーよりも小さい値であり、
さらに、照射する光量の総和(積算光量)は、前記第4工程後の機能層上におけるフッ素成分の規格化イオン強度が、前記第3工程後の機能層上におけるフッ素成分の規格化イオン強度に対し、その比の値が0.3以上であって1未満であることを特徴とする有機発光素子の製造方法。 A first step of preparing a substrate;
A second step of forming a functional layer including a lower electrode above the substrate;
A photosensitive resist material containing a fluorine component and a resin component is applied above the functional layer, and the photosensitive resist material is exposed and patterned to form openings corresponding to the pixel portions and adjacent to each other. A third step of forming a bank for partitioning the pixel portion;
A fourth step of irradiating the opening and the bank with ultraviolet rays;
After the fourth step, a fifth step of forming an organic light emitting layer by applying an ink containing an organic light emitting material to the opening and drying it;
A sixth step of forming an upper electrode above the organic light emitting layer;
In the fourth step, the vibration energy of the ultraviolet light is larger than the dissociation energy of the resin material used, and smaller than the dissociation energy of the fluorine component used.
Further, the total amount of light to be irradiated (integrated light amount) is such that the normalized ionic strength of the fluorine component on the functional layer after the fourth step is the normalized ionic strength of the fluorine component on the functional layer after the third step. On the other hand, the value of the ratio is 0.3 or more and less than 1, The manufacturing method of the organic light emitting element characterized by the above-mentioned. - 前記樹脂材料の解離エネルギーは335~457kJ/molであり、前記フッ素成分の解離エネルギーは472~524kJ/molであり、前記紫外線の光の振動エネルギーは、458~472kJ/molであり、
前記積算光量は690~1035mJ/cm2であることを特徴とする請求項9記載の有機発光素子の製造方法。 The dissociation energy of the resin material is 335 to 457 kJ / mol, the dissociation energy of the fluorine component is 472 to 524 kJ / mol, and the vibration energy of the ultraviolet light is 458 to 472 kJ / mol,
10. The method of manufacturing an organic light emitting device according to claim 9, wherein the integrated light quantity is 690 to 1035 mJ / cm 2 .
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006073222A (en) * | 2004-08-31 | 2006-03-16 | Asahi Glass Co Ltd | Organic el display device and manufacturing method of organic el display device |
JP2006185869A (en) * | 2004-12-28 | 2006-07-13 | Asahi Glass Co Ltd | Organic electroluminescent element and method of manufacturing the same |
JP2009117392A (en) * | 2007-05-31 | 2009-05-28 | Panasonic Corp | Organic el display panel and its manufacturing method |
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006073222A (en) * | 2004-08-31 | 2006-03-16 | Asahi Glass Co Ltd | Organic el display device and manufacturing method of organic el display device |
JP2006185869A (en) * | 2004-12-28 | 2006-07-13 | Asahi Glass Co Ltd | Organic electroluminescent element and method of manufacturing the same |
JP2009117392A (en) * | 2007-05-31 | 2009-05-28 | Panasonic Corp | Organic el display panel and its manufacturing method |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110164948A (en) * | 2019-06-13 | 2019-08-23 | 京东方科技集团股份有限公司 | A kind of pixel defining layer, production method and display panel |
CN110164948B (en) * | 2019-06-13 | 2021-12-28 | 京东方科技集团股份有限公司 | Pixel defining layer, manufacturing method and display panel |
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