JP2008159321A - Organic el display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display panel in which a lead wire connecting an extraction electrode and a mother board and a contact area to the plug can be taken large, and a trouble such as reduction of contact resistance and disconnection is reduced. <P>SOLUTION: The organic EL display panel for forming a large panel by mutually joining together has an organic EL element formed on a substrate by including a first electrode and a second electrode and an organic luminous layer interposed between these on a display part, a passivation layer formed so as to cover the organic EL element on the display part, and a lead wire which is formed so as to extend from the passivation layer to the substrate outside of the passivation layer. The first electrode and the second electrode respectively extend from the display part to the substrate end to constitute an extraction electrode at the substrate end, and the lead wire and the extraction electrode are laminated at the portion outside of the passivation layer, and a bump is formed at the tip part on the opposite side to the extraction electrode side of the lead wire. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic EL display panel for connecting a plurality of panels to increase the size and a method for manufacturing the same.

  In 1987, Eastman Kodak's C.I. W. Since Tang announced a highly efficient organic EL element in a two-layer device by Tang, various organic EL elements have been developed up to the present, and some of them have begun to be put into practical use in portable terminals and the like. Furthermore, since the viewing angle dependency is smaller than that of liquid crystal, application to a large panel is also being studied.

In addition, in order to meet diversifying social needs, organic EL elements have long-term stability and high-speed response, and there is an urgent need for practical use of organic EL displays capable of multicolor display or high-definition full-color display. ing.
Coloring methods include a three-color painting method, a color conversion method (CCM method), a color filter method, and the like. Among these methods, the CCM method and the color filter method do not require the use of a metal mask at the time of film formation, and the color conversion layer and the color filter may be formed on a substrate using a photo process. This is advantageous for high definition.

  In addition, display devices using organic EL elements include a passive matrix display device and an active matrix device. In the former, a plurality of anode lines and a plurality of cathode lines are provided, and a light emitting layer is formed at a position (pixel position) where the anode lines and the cathode lines intersect, and each pixel has a selected time during one frame period. Light. The structure is simple, the manufacturing cost is low, and it can be provided at low cost. However, since the selection time becomes shorter as the number of pixels increases, it is necessary to increase the driving voltage and increase the instantaneous luminance. In addition, since the organic EL element is current driven, the voltage drop due to the wiring resistance is large when the screen is large, and it is necessary to increase the driving voltage.

On the other hand, since the TFT switching element is connected to each pixel, the active matrix display device can continue to be lit for one frame period. Therefore, since it is not necessary to increase the instantaneous luminance, the current can be suppressed, and the life can be extended. However, since the TFT is used, there is a problem that the manufacturing cost is increased.
From the above, in order to manufacture a large panel at low cost, it is preferable to employ a method of joining small passive matrix panels.

  When connecting small display panels to make a large panel, if a drive circuit board is provided on the outer periphery of the small display panel, the area of this drive circuit becomes a non-display area that cannot display the screen, The image quality will be degraded. Further, the connection between the drive circuit and the small display panel is usually electrically connected by a flexible wiring board or the like, but there is a problem that migration occurs in this wiring and disconnection occurs.

  In the case of a display device in which a drive circuit board is mounted on a display panel, bumps are provided on the drive board, and the bumps and the display panel are electrically connected. As such a display device, a display panel having a structure in which an electrode and a display material are laminated, and a bump that is electrically connected to the electrode of the display panel, and a wiring board that performs drive control of the display panel is UV-cured. There is a proposal of a display device bonded with a mold adhesive (for example, see Patent Document 1). In this proposal, through holes are provided near the end portions of a plurality of cathodes and anodes each having a plurality of stripes, and bumps are provided so as to connect the through holes and the electrode end portions. It is connected to the drive control part via.

  In addition, a passivation layer is provided on the entire surface of the substrate opposite to the display portion of the organic EL display body, and a first wiring and a second wiring are formed on the passivation layer, and the first and second wirings of the organic EL display body are formed. There is also a proposal of a display body in which the electrode and the first and second wirings are connected through through holes, and these through holes are provided at the end of the substrate (for example, see Patent Document 2). In this proposal, the driving semiconductor element is provided on the passivation layer.

JP 2002-207436 A JP 2004-355998 A

  When connecting a small display panel to make a large panel, if the joint between the small panels is enlarged to provide an electrode take-out portion from the end of the small panel, there is a problem that the boundary of the panel is conspicuous. For this reason, the small panel has to be a narrow frame panel in which the peripheral area where wiring is required is reduced, and there is a problem that the electrodes must be wired in the reduced peripheral area.

  In the display device of Patent Document 1, bumps are formed on the electrodes at the end of the small panel, and as the number of electrodes increases, the bumps become smaller accordingly, so that contact resistance increases and problems such as disconnection are likely to occur. .

  In addition, the organic EL display of Patent Document 2 is also connected to the driving element provided on the passivation layer and the ends of the first and second electrodes of the display through a through hole and first and second wirings. Since the connection between the through hole and the electrode end is performed by spotting the through hole portion and the vicinity thereof, the same problem as described above that the connection area decreases and the connection resistance increases as the number of electrodes increases. Have.

  In view of such circumstances, the present inventors can increase the contact area between the lead electrode connecting the extraction electrode and the mother substrate, the contact area to the plug, reducing defects such as contact resistance reduction and disconnection, and yield. An object of the present invention is to provide an organic EL display panel with improved performance.

  In order to achieve the above-described object, the organic EL display panel of the present invention is an organic EL display panel that is connected to each other to form a large panel, and the organic EL display panel is a display formed on a substrate. Part, an organic EL element formed including a first electrode and a second electrode in the display part, and an organic light emitting layer sandwiched between them, and a passivation layer formed so as to cover the organic EL element in the display part And lead wires formed so as to extend from the passivation layer to the substrate outside the passivation layer, and the first electrode and the second electrode each extend from the display portion to the substrate end portion to form the substrate. An extraction electrode is formed at the end, and the lead wire and the extraction electrode are laminated in a portion outside the passivation layer, and the lead wire is drawn out. The by electrode side, characterized in that the bump on the tip portion of the opposite side.

  The organic EL display panel manufacturing method of the present invention also includes a color conversion filter layer forming step of forming a color conversion filter layer on the substrate in the display unit, and extending from the display unit to the substrate end to provide an extraction electrode at the substrate end. Organic EL element forming step for forming an organic EL element on the color conversion filter layer, including the electrode to constitute, a passivation layer forming step for forming a passivation layer on the portion other than the extraction electrode portion including the back surface of the display portion on the substrate, lead The lead wire and the extraction electrode are formed so as to be laminated in a portion outside the passivation layer so as to extend from the passivation layer to the substrate outside the passivation layer, and on the side opposite to the extraction electrode side It has at least a lead wire forming step for forming a bump at the tip.

According to the present invention, it is possible to increase the contact area between the lead electrode that connects the lead electrode and the plug of the mother substrate, and the contact area with the plug, and even in a so-called narrow frame organic EL display panel with a narrow peripheral portion. In addition, problems such as reduction in contact resistance and disconnection can be reduced, and the yield of manufacturing an organic EL display panel can be improved.

Hereinafter, the present invention will be described with reference to the drawings.
Although the present invention can be applied to a top emission type organic EL element, a bottom emission type color conversion type organic EL display will be described.
FIG. 1 is a schematic sectional view showing one embodiment of a bottom emission type organic EL display panel of the present invention, and FIG. 2 is a view showing an arrangement example of lead electrodes and lead wires.

In the organic EL display panel of the present invention shown in FIG. 1, a display unit is formed on a substrate 1.
The display unit is a pixel display unit that emits a predetermined color from the substrate 1 side by converting light emitted from the organic light emitting layer 8 by the color conversion filter layer 2 when energized, and the display unit is disposed on the substrate 1. The formed color conversion filter layer 2, the overcoat layer 3 for covering and flattening the color conversion filter layer 2, the barrier layer 4 for preventing diffusion of moisture remaining in the overcoat layer 3, and the overcoat layer 3 are formed thereon. A first electrode 5 composed of a plurality of stripes, an insulating layer 6 formed in a lattice shape on the first electrode 5 in order to prevent short-circuit leakage of the display portion, and an organic light emitting layer 8 formed in an opening of the lattice-shaped insulating layer 6 At least a second electrode 9 made of a plurality of stripes extending in a direction perpendicular to the stripes of the first electrode is formed. That is, in the display unit, the organic light emitting layer 8 is sandwiched between the first electrode 5 and the second electrode 9 to form an organic EL element. Here, the color conversion filter layer is a general term for a color filter layer, a color conversion layer, and a laminate of a color filter layer and a color conversion layer.

  The substrate 1 needs to be transparent to the light converted by the color conversion filter layer. The substrate 1 should be able to withstand the conditions (solvent, temperature, etc.) used for forming the color conversion filter layer and the black mask, and is preferably excellent in dimensional stability. The substrate 1 preferably has a transmittance of 50% or more with respect to light having a wavelength of 400 to 800 nm. Preferred materials for the substrate 1 include resins such as glass, polyethylene terephthalate, and polymethyl methacrylate. Borosilicate glass or blue plate glass is particularly preferable. In the case where a glass substrate is used as the substrate 1, the thickness is preferably 0.3 to 1.0 mm in order to maintain rigidity and make a cut.

  The color conversion layer in the color conversion filter layer 2 is a layer made of a color conversion dye and a matrix resin. The color conversion dye is a dye that converts the wavelength distribution of incident light and emits light in different wavelength ranges, and preferably converts the wavelength distribution of near-ultraviolet light or blue to blue-green light from the organic light emitting layer. Thus, it is a pigment that emits light in a desired wavelength band (for example, blue, green, or red).

  The color conversion dye absorbs light in the near ultraviolet region or visible region emitted from the illuminant, particularly light in the blue or blue-green region, and emits visible light having a different wavelength as fluorescence. Preferably, at least one fluorescent dye that emits fluorescence in the red region may be used, and may be combined with one or more fluorescent pigments that emit fluorescence in the green region.

  The color filter layer can be formed using a material (for example, a color filter material for a liquid crystal display) in which any pigment known in the art is dispersed in a matrix resin. In order to enable full color display, it is desirable to have at least a blue (B) conversion filter layer, a green (G) conversion filter layer, and a red (R) conversion filter layer.

  The red conversion filter layer is preferably a laminate of a red conversion layer and a red color filter layer. This is because when the organic EL layer 110 that emits light in the blue or blue-green region is used as the light source, if light from the organic light-emitting layer 8 is passed through a simple red filter to obtain light in the red region, This is because the output light becomes extremely dark due to the small amount of light of the wavelength. By converting the wavelength distribution of light in the blue or blue-green region into red light by the red conversion layer, it is possible to output light in the red region having sufficient intensity.

  The green conversion filter layer is preferably a laminate of a green conversion layer and a green color filter layer. However, when the light emitted from the organic light emitting layer 8 contains a sufficiently strong green component, only the green color filter layer may be used.

The blue conversion filter layer may include a blue conversion layer that performs wavelength distribution conversion of near-ultraviolet light or blue-green light emitted from the organic light emitting layer 8 and outputs blue light, and a blue color filter layer. However, when the organic light emitting layer 8 emits blue to blue-green light, it is preferable to use only the blue color filter layer.
The color conversion filter layers for red, green, and blue are preferably about 12 μm thick in order to efficiently convert the light from the organic light emitting layer 8 into each color.

  Examples of fluorescent dyes that absorb blue to blue-green light emitted from the luminescent material and emit fluorescence in the red region include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11 Pyridine dyes such as rhodamine dyes such as basic red 2, cyanine dyes, 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1) Or oxazine dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

  Examples of fluorescent dyes that absorb blue to blue-green light emitted from a light emitter and emit green light include 3- (2′-benzothiazolyl) -7-diethylamino-coumarin (coumarin 6), 3- (2′-Benzimidazolyl) -7-diethylamino-coumarin (coumarin 7), 3- (2′-N-methylbenzimidazolyl) -7-diethylamino-coumarin (coumarin 30), 2,3,5,6-1H, 4H -Coumarin-based dyes such as tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), or basic yellow 51 which is a coumarin dye-based dye, solvent yellow 11, solvent yellow 116 And naphthalimide dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

  In addition, the color conversion dye is previously added to polymethacrylic acid ester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and a mixture of these resins. It may be kneaded to form a pigment to obtain an organic color conversion pigment. In addition, these color conversion dyes and organic color conversion pigments (in the present specification, the above two are collectively referred to as color conversion dyes) may be used singly, and two kinds may be used to adjust the hue of fluorescence. A combination of the above may also be used.

  The matrix resin used in the color conversion layer is a photocurable or photothermal combination type curable resin (resist) that is subjected to light and / or heat treatment to generate radical species or ionic species to be polymerized or crosslinked to be insoluble and infusible. It is a thing. In order to perform patterning of the color conversion layer, it is desirable that the photocurable or photothermal combination type curable resin is soluble in an organic solvent or an alkaline solution in an unexposed state.

  Specifically, the matrix resin is obtained by subjecting a composition film comprising (1) an acrylic polyfunctional monomer and oligomer having a plurality of acryloyl groups and methacryloyl groups, and light or thermal polymerization initiator to light or heat treatment, Or a polymer obtained by generating thermal radicals, (2) a composition comprising a polyvinylcinnamic acid ester and a sensitizer dimerized by light or heat treatment, and (3) a chain or cyclic olefin A composition film composed of bisazide is irradiated with light or heat to generate nitrene and crosslinked with olefin, and (4) a composition film composed of a monomer having an epoxy group and an acid generator is subjected to light or heat treatment, Including those polymerized by generating an acid (cation). In particular, a polymer obtained by polymerizing a composition comprising the acrylic polyfunctional monomer and oligomer (1) and light or a thermal polymerization initiator is preferred. This is because the composition can be patterned with high definition and has high reliability such as solvent resistance and heat resistance after polymerization.

  The photopolymerization initiator, sensitizer, and acid generator that can be used here are preferably those that initiate polymerization by light having a wavelength that is not absorbed by the fluorescent conversion dye contained therein. In the fluorescence conversion filter layer of the present invention, a photopolymerization initiator and a thermal polymerization initiator are added when the resin itself in the photocurable or photothermal combination type curable resin can be polymerized by light or heat. It is also possible not to.

  A black matrix is preferably formed in a region between the color conversion filter layers corresponding to each color. By providing the black matrix, it is possible to prevent leakage of light to the color conversion filter layer of the adjacent subpixel and obtain only a desired fluorescence conversion color without blur.

  An overcoat layer 3 is preferably provided on the color conversion filter layer 2 so as to cover the color conversion filter layer 2. The overcoat layer 3 can be formed without impairing the function of the color conversion filter layer 2 and is formed from a material having appropriate elasticity. A preferable material has a pencil hardness of 2H or more and a Young's modulus of 0.3 MPa or more, and can form a smooth coating film on the color conversion filter layer. It is a polymer material that does not decrease. More preferably, the material is a polymer material having high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm), electrical insulation, and barrier properties against moisture, oxygen, and low molecular components. It is. The overcoat layer 3 is an optional layer, but is preferably a layer provided for the above purpose.

Examples of such polymer materials include imide-modified silicone resins, materials in which inorganic metal compounds (TiO, Al ₂ O ₃ , SiO _2, etc.) are dispersed in acrylic, polyimide, silicone resins, etc., acrylate monomers / oligomers / polymers And a photocurable resin and / or a thermosetting resin such as a resin having a reactive vinyl group, a resist resin, a fluorine resin, or an epoxy resin having a mesogenic structure having a high thermal conductivity.

  The barrier layer 4 formed on the overcoat layer 3 has excellent moisture / oxygen barrier properties, and therefore prevents moisture and oxygen from being transmitted from the overcoat layer 3 and the color conversion filter layer 2. It is. In order to transmit light from the organic EL element to the color conversion filter layer, the barrier layer 3 preferably has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm). Moreover, since it is necessary to form the 1st electrode 5 which consists of a several electrically independent part on the barrier layer 4, the barrier layer 4 is requested | required to have electrical insulation at least in the upper surface. Moreover, it is preferable that the barrier layer 4 has a film hardness of 2H or higher.

The barrier layer 4 is composed of an inorganic film such as an oxide, nitride, carbide, or oxynitride. The barrier layer 4 may be a laminate or mixture of the above compounds. Specific examples thereof include silicon oxide and silicon nitride. The barrier layer 4 is preferably configured to completely cover the overcoat layer 3 as shown in FIG. By doing so, it is possible to prevent the overcoat layer 3 from coming into contact with the atmosphere and adsorbing a gas such as water vapor after the barrier layer 4 is formed, and to prevent degassing from the barrier layer 4 itself after the organic EL element is formed. it can.
In addition, since the barrier layer 4 is made of an inorganic film, it is possible to improve moisture and oxygen trapping properties and to prevent moisture and oxygen from being transferred from the color conversion filter layer 2 to the organic EL element.

In the display unit, an organic EL element is formed on the barrier layer 4. The organic EL element is obtained by holding the organic light emitting layer 8 between at least a pair of electrodes (first electrode and second electrode) in the display unit, and if necessary, a hole transport layer, a hole injection layer, and / or Alternatively, it has a structure in which an electron injection layer is interposed. Each of these layers has a film thickness sufficient to achieve the desired characteristics. For example, the following layer structure is adopted.
(1) First electrode / organic light emitting layer / second electrode (2) First electrode / hole injection layer / organic light emitting layer / second electrode (3) First electrode / organic light emitting layer / electron injection layer / second Electrode (4) First electrode / hole injection layer / organic light emitting layer / electron injection layer / second electrode (5) First electrode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / second Two electrodes The first electrode 5 includes a plurality of stripes, and the second electrode 9 includes a plurality of stripes extending in a direction orthogonal to the stripes of the first electrode. The first electrode 5 is made of ITO (In—Sn oxide), NESA film, Sn oxide, In oxide, IZO (In—Zn oxide), Zn oxide, Zn—Al oxide, Zn—Ga oxide. Alternatively, a conductive transparent metal oxide in which a dopant such as F or Sb is added to these oxides can be used.

  Each stripe of the first electrode 5 is formed so as to cross the substrate, and constitutes an extraction electrode 16 at one end of the substrate. Further, each stripe of the second electrode 9 is also formed so as to cross the substrate, and an extraction electrode 17 is configured at one substrate end. That is, the first electrode and the second electrode respectively extend from the display portion to the substrate end portion, and constitute an extraction electrode at the substrate end portion.

Any known material can be used as the material of the organic light emitting layer. For example, in order to obtain light emission from blue to blue-green, for example, a condensed aromatic ring compound, a ring assembly compound, a metal complex (such as an aluminum complex such as Alq ₃ ), a styrylbenzene compound (4,4′-bis (diphenyl) (Vinyl) biphenyl (DPVBi), etc.), porphyrin compounds, benzothiazole compounds, benzimidazole compounds, benzoxazole compounds and the like, and materials such as aromatic dimethylidin compounds are preferably used. Or you may form the organic light emitting layer which emits the light of a various wavelength range by adding a dopant to a host compound. Examples of host compounds include distyrylarylene compounds (for example, IDE-120 manufactured by Idemitsu Kosan Co., Ltd.), N, N′-ditolyl-N, N′-diphenylbiphenylamine (TPD), aluminum tris (8-quinolinolate) (Alq ₃ ). ) Etc. can be used. As dopants, perylene (blue purple), coumarin 6 (blue), quinacridone compounds (blue green to green), rubrene (yellow), 4-dicyanomethylene-2- (p-dimethylaminostyryl) -6-methyl- 4H-pyran (DCM, red), platinum octaethylporphyrin complex (PtOEP, red), or the like can be used.

  As a material for the hole injection layer, Pc (including CuPc) or indanthrene compounds can be used. The hole transport layer can be formed using a material having a triarylamine partial structure, a carbazole partial structure, or an oxadiazole partial structure. Materials that can be used preferably include TPD, [alpha] -NPD, MTDAPB (o-, m-, p-), m-MTDATA, and the like.

As the material for the electron injection layer, an aluminum complex such as Alq ₃ or an aluminum quinolinol complex doped with an alkali metal or an alkaline earth metal can be used.

  A passivation layer 10 is provided to cover each layer below the second electrode 9 formed as described above. The passivation layer 10 is not formed on the extraction electrodes of the first electrode and the second electrode. Further, in the vicinity of the end of the passivation layer 10 on the extraction electrode side, it is preferable that an inclination is formed so that the thickness increases as the distance from the extraction electrode increases. The passivation layer 10 is effective in preventing permeation of oxygen, low molecular components, and moisture from the external environment, and preventing functional degradation of the organic EL element due to them. The passivation layer 10 is preferably transparent in the emission wavelength region in order to transmit the light emitted from the organic light emitting layer 8 to the color conversion filter layer 2.

In order to satisfy these requirements, the passivation layer 10 has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm), electrical insulation, and a barrier against moisture, oxygen, and low molecular components. Preferably, it is formed of a material having a film hardness of pencil hardness 2H or more. For example, materials such as inorganic oxides and inorganic nitrides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , and ZnO _x can be used.

In addition, various polymer materials can be used for the passivation layer. Imide-modified silicone resin, materials in which inorganic metal compounds (TiO, Al ₂ O ₃ , SiO ₂ etc.) are dispersed in acrylic, polyimide, silicone resin, etc., resin having reactive vinyl group of acrylate monomer / oligomer / polymer And a photocurable resin and / or a thermosetting resin such as a resist resin, a fluorine resin, or an epoxy resin having a mesogenic structure having high thermal conductivity.

As shown in FIG. 2, a lead wire 11 is provided on the passivation layer 10 so as to extend from there to the substrate 1 outside the passivation layer. The lead wire 11 is laminated with the extraction electrode 16 of the first electrode 5 in a portion outside the passivation layer. By this lamination, the contact area between the first electrode and the lead wire is remarkably larger than the conventional point contact, and the contact resistance can be greatly reduced. The lead wires 11 are provided as many as the extraction electrodes 16 corresponding to the respective extraction electrodes 16.
As shown in FIG. 2, the lengths of the lead wires on the passivation layer 10 are different from each other in the length of the adjacent lead wires, and are repeated as long and short. Thereby, the danger of the short circuit of adjacent lead wires can be reduced.

  A bump 12 is formed on the end of the lead wire 11 opposite to the lead electrode side, and the thickness of the bump 12 is greater than the thickness of the lead wire 11. As a result, when the motherboard 15 is crimped to the substrate 1 to connect the substrate 1 on which the lead wire 11 is provided and the plug 13 of the motherboard 15, the plug 13 contacts only the bump 12 and contacts the lead wire body. There is nothing to do. Accordingly, the lead wires are not connected to each other via the plug, and therefore, pixels other than the target pixel do not shine. This lead wire can be formed by a printing method.

  The mother board 15 is provided to hold and reinforce the panel and through electrodes provided on the board. FIG. 1 shows a part of the board and the mother board showing one pixel, but FIG. As estimated from the number of extraction electrodes of the first electrode and the number of extraction electrodes of the second electrode, the pixel is provided at the intersection of the first electrode and the second electrode, so that the substrate is a large number of pixels. have. In addition, since the mother board forms a large panel, a large number of panels are mounted thereon.

  The motherboard 15 is provided with contact holes 14 at positions corresponding to the bumps 12 of the lead wires 11, and plugs 13 that are electrically connected to each other are provided on both sides of the motherboard at the contact hole positions. The plug on the surface opposite to the board of the motherboard is connected to the drive IC.

Next, the manufacturing method of the organic EL display panel of the present invention will be described.
Although it is possible to make this panel one by one, in order to improve productivity, a plurality of small panels are formed on a large substrate 1 as shown in the upper part of FIG. 3 and cut after sealing with a passivation layer, After forming the lead wire, it is unitized with the mother board 15 again, and a large panel is manufactured by connecting a plurality of panels as shown in the lower part of FIG.
First, an organic EL element is formed on a substrate. In forming an organic EL element, a black matrix is formed on a substrate in a lattice shape by a photo process, and then 3 colors for emitting three colors of red (R), green (G), and blue (B) are formed thereon. A seed color conversion filter layer is formed by a photo process.

  The color conversion filter layer 2 uses a spin coating method, a roll coating method, a casting method, a dip coating method, or the like using a solution or dispersion containing a photocurable or photothermal combination type curable resin, a color conversion dye and an additive. Then, it is formed on the substrate 1 by coating the substrate 1 to form a resin layer, and then exposing the desired portion of the photocurable or photothermal combination type curable resin to polymerization. Patterning is performed after exposing the desired portion to insolubilize the photocurable or photothermal combination type curable resin. The patterning can be performed by a conventional method such as removing the resin in the unexposed portion using an organic solvent or an alkali solution in which the resin in the unexposed portion is dissolved or dispersed.

  Next, it is preferable to form an overcoat layer on the substrate 1 on which the color conversion filter layer 2 is formed and form a barrier layer thereon. The method for forming the overcoat layer is not particularly limited. For example, a dry method (sputtering method, vapor deposition method, CVD method, etc.) or a wet method (spin coating method, roll coating method, cast method, etc.) is used. It can be formed by a conventional method. In the case of forming an inorganic film as the barrier layer, this inorganic film can be formed by vapor deposition, sputtering (including reactive sputtering), or chemical vapor deposition (CVD). In particular, when an oxide film is formed, it is preferable to use a sputtering method (including a reactive sputtering method) from the viewpoints of adhesion, film thickness uniformity, and productivity.

  An organic EL element is formed by sequentially laminating at least the first electrode, the organic EL layer, and the second electrode on the substrate on which the color conversion filter thus obtained is mounted.

The first electrode can be formed by vapor deposition, sputtering (including reactive sputtering) or chemical vapor deposition (CVD), and preferably using sputtering (including reactive sputtering). Form.
The first electrode 5 is formed of a plurality of stripes formed so as to cross the substrate, and the extraction electrode 16 is configured at one substrate end.

Next, an insulating layer (SM1) 6 for preventing a short circuit leak in the display portion is formed on the black matrix in a lattice shape. A cathode separation wall 7 is preferably formed on the insulating layer 6. The cathode separation wall 7 is made of a photoresist such as acrylic or novolac resin, and a linear pattern orthogonal to the stripe of the first electrode is formed by a photo process and etching. The cathode separation wall 7 has a reverse taper shape and has a patterning function of the cathode (second electrode). That is, when the conductor layer is formed between the upper portion of the cathode separation wall and the adjacent cathode separation wall in order to form the second electrode between the adjacent cathode separation walls, the reverse tapered shape of the cathode separation wall is formed. Therefore, the conductive layer provided on the cathode separation wall and the conductor layer between the cathode separation walls are not electrically connected, and the stripe-shaped second electrode pattern is formed between the adjacent cathode separation walls. It is formed.
You may form the reflective electrode which consists of a some partial electrode using the mask which gives a desired shape. In this case, it is not necessary to provide a cathode separation wall.

A layer including at least an organic light emitting layer is formed on the substrate on which the first electrode 5 is formed and the insulating layer 6 and the cathode separation wall 7 are formed.
Each layer of the hole injection layer / hole transport layer / organic light emitting layer / electron injection layer can be formed by vapor deposition.

  A second electrode is formed on the substrate on which these layers are formed. The second electrode 9 is also formed of a plurality of stripes formed so as to cross the substrate, and the extraction electrode 17 is configured at one substrate end. The second electrode can be formed using any means known in the art such as vapor deposition (resistance heating or electron beam heating), sputtering, ion plating, laser ablation, etc., depending on the material used. .

  A passivation layer 10 is formed on the substrate on which the organic EL element thus formed is formed. The passivation layer is formed so as to cover portions other than the extraction electrode 16 of the first electrode and the extraction electrode 17 of the second electrode. There is no restriction | limiting in particular as a formation method of the passivation layer 10. FIG. When the passivation layer is made of an inorganic compound, it can be formed by a conventional method such as a sputtering method, a CVD method, a vacuum deposition method, a dip method, or a sol-gel method. In addition, when the passivation layer is made of a polymer material, the formation method is not particularly limited. For example, a dry method (sputtering method, vapor deposition method, CVD method, etc.) or a wet method (spin coating method, roll coating method, cast method) For example). The thickness of the passivation layer is preferably 5 to 10 μm at the thickest part.

  At this stage, a diamond cutter, a carbide wheel cutter or a laser cutter is used to cut and cut at a predetermined position where the large substrate 1 is divided.

Next, the lead wire is formed so as to extend from the passivation layer to the substrate outside the passivation layer, and the lead wire and the extraction electrode are laminated in a portion outside the passivation layer. The lead wire is preferably formed by printing using a conductive paste. Examples of the printing method include an inkjet method and a screen printing method.
A bump that is thicker than other portions of the lead wire is formed at the tip of the lead wire opposite to the lead electrode side. This bump can be formed, for example, by overprinting. This overprinting may be repeated until a predetermined thickness is reached.

  In this way, the small panel on which the lead wire is printed and the mother board 15 are bonded. The motherboard is provided with a plug 13 that is electrically connected to the driving IC arranged on the back surface through a contact hole. The plug of the motherboard is attached so that the bumps 12 of the corresponding lead wires 11 are aligned. And make them electrically conductive. In order to make this conduction good, it is preferable that the plug 13 is also formed by printing using conductive ink and fired in a state of being bonded as described above. If the lead wires, bumps and plugs are formed by printing and firing is performed after the mother board and the small panel are bonded together, there is an advantage that the number of man-hours can be reduced.

The present invention will be further described below using examples.
<Example 1>
A plurality of small panels of 8 lines × 16 pixels were formed on a glass substrate having a thickness of 0.8 mm. The pixel is set to one pixel by three sub-pixels corresponding to three kinds of color conversion layers of red, green, and blue.

  After depositing low-reflection chrome on a glass substrate, a black matrix was formed in a lattice shape by a photo process. Next, red, green, and blue color conversion filter layers were formed with a thickness of 12 μm. Next, an acrylic resist material (manufactured by Tokyo Ohka Kogyo Co., Ltd., NN810) is spin-coated to fill and flatten the grooves formed by the color conversion layer filter formation, and an overcoat layer that covers the color conversion filter layer and the black mask by a photo process A silicon nitride film having a thickness of 1 μm was formed thereon by CVD to form a barrier layer.

  On the barrier layer thus formed, IZO (In—Zn oxide) was deposited at room temperature by sputtering, and patterned by a photo process to form a first electrode. The first electrode is composed of a plurality of stripes, and each stripe is formed so as to cross the substrate, and the extraction electrode 16 is formed at one end of the substrate.

Next, in order to prevent short-circuit leakage in the display portion, an insulating layer is formed on the black matrix using a phenol-based positive resist JEM700 (manufactured by JSR), a novolac resin is used on the insulating film, and a photo process is performed. A reverse-tapered cathode separation wall perpendicular to the stripe of one electrode was formed.
The substrate thus obtained was subjected to UV / ozone treatment using an excimer lamp. By performing UV / ozone treatment on the IZO surface, the resist residue on the IZO was decomposed and removed, and the work function was increased to about 5.1 eV.

Next, the substrate on which the first electrode is formed is mounted in a resistance heating vapor deposition apparatus, and the organic EL layer composed of four layers of the hole injection layer / hole transport layer / organic light emitting layer / electron injection layer is not broken. Were sequentially formed. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. Copper phthalocyanine (CuPc) with a film thickness of 100 nm is used as the hole injection layer, and 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α with a film thickness of 20 nm is used as the hole transport layer. -NPD) as the organic light-emitting layer, 30 nm-thick 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi), and as the electron injection layer, 20 nm-thick tris (8-hydroxy) A quinoline) aluminum complex (Alq ₃ ) was laminated.

  Subsequently, aluminum was vapor-deposited thereon as a cathode (second electrode). Since the cathode separation wall has a reverse taper shape, the adjacent stripes are not short-circuited in the second electrode formed in a stripe shape between the adjacent cathode separation walls. Similar to the stripe of the first electrode, this stripe was formed so as to cross the substrate, and the extraction electrode 17 was configured at one end of the substrate.

Next, after the extraction electrode portions 16 and 17 were covered with a metal mask as a passivation layer, a silicon nitride film having a thickness of 10 μm was formed by a CVD method.
Next, a cut was made at a position where the substrate was divided using a diamond cutter, and the substrate was divided into individual small panels. In order to remove the glass scrap generated by the division, it was subjected to ultrasonic cleaning for 3 minutes, then washed with running water for 3 minutes, and dried by IPA vapor drying.

  Next, a lead wire was printed by a piezoelectric element-driven ink jet using a nanometal ink having a viscosity of 5 cP in which Ag nanoparticles were dispersed as a conductive ink. This conductive ink can be baked at 120 ° C., and exhibits a specific resistance of about 3 μΩ · cm after baking. The ink jet head used had a nozzle diameter of 50 μm, had 128 nozzles, and could print 50 to 80 pL per dot, and the print dot diameter was about Φ100 μm.

  The lead wire is formed to have a width of 600 μm and a thickness of 5 μm so as to extend from the passivation layer to the substrate outside the passivation layer, and overlaps with the extraction electrode of the first electrode in a portion outside the passivation layer. Then, it was formed to be in a laminated state. As shown in FIG. 2, the lengths of the lead wires on the passivation layer are such that the lengths of the adjacent lead wires are different from each other, and the length is short and long. The total length of the lead wire was 6 mm for the longer side and 3 mm for the shorter side. Overprinting was performed on the portion of the lead wire on the passivation layer that was in contact with the plug of the mother board to form a bump having a thickness of 30 μm.

  Next, a small panel in which the lead wires are formed, and a mother board having a driver IC on a separately prepared back surface and a plug formed of conductive ink so as to be electrically connected to the driver IC through a contact hole. The plugs and the bumps were bonded so that they were in contact with each other and baked at 120 ° C. for 60 minutes. This conductive ink exhibited a specific resistance of about 3 μΩ · cm upon firing. As a result, an electrical connection between the driving IC and the first electrode was obtained, and an organic EL display panel having excellent reliability and productivity without disconnection even in a narrow frame panel having a small portion other than the display portion could be manufactured.

  The lead wire of the present invention makes it possible to increase the area of the contact portion between the lead electrode and the plug of the motherboard, and also to increase the contact between the lead wire and the first electrode, thereby reducing the contact resistance. As a result, it is possible to reduce the trouble at the head of the stage and improve the yield.

1 is a schematic cross-sectional view showing an embodiment of a bottom emission type organic EL display panel of the present invention. It is a figure which shows the example of arrangement | positioning of an extraction electrode and a lead wire. It is the figure which shows the some organic display panel formed on a board | substrate, and the figure which shows the state which cut out each organic display panel and connected the organic display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Color conversion filter layer 3 Overcoat layer (flattening layer) 4 Barrier layer 5 First electrode (anode) 6 Insulating layer (SM1)
7 Cathode separation wall 8 Organic light emitting layer 9 Second electrode (cathode) 10 Passivation layer 11 Lead wire 12 Bump 13 Plug 14 Contact hole 15 Motherboard 16 Lead electrode (first electrode)
17 Extraction electrode (second electrode)

Claims (6)

  An organic EL display panel connected to each other to form a large panel, wherein the organic EL display panel includes a first electrode, a second electrode, and an organic light emitting layer sandwiched between them in a display unit The organic EL element formed above, the passivation layer formed so as to cover the organic EL element in the display unit, and the lead formed so as to extend from the passivation layer to the substrate outside the passivation layer Each of the first electrode and the second electrode extends from the display portion to the end of the substrate to form an extraction electrode at the end of the substrate, and the lead wire and the extraction electrode are in a portion outside the passivation layer. An organic EL display characterized in that it is laminated and bumps are formed at the tip of the lead wire opposite to the lead electrode side. Ipaneru.   A plurality of the extraction electrodes are provided, the lead wires extending from the extraction electrodes are alternately different in length, and the thickness of the bump formed at the tip of each lead wire is thicker than the thickness of the lead wire. The organic EL display panel according to claim 1.   3. The organic EL display panel according to claim 1, wherein the lead wire is formed by printing.   A color conversion filter layer forming step for forming a color conversion filter layer on the substrate in the display unit, including an electrode extending from the display unit to the substrate end and constituting an extraction electrode at the substrate end, and an organic EL on the color conversion filter layer Organic EL element forming process for forming elements, passivation layer forming process for forming a passivation layer in a portion other than the extraction electrode part including the display part on the substrate, and extending the lead wire from the passivation layer to the substrate outside the passivation layer. And at least a lead wire forming step in which the lead wire and the lead electrode are formed so as to be laminated in a portion outside the passivation layer, and a bump is formed at a tip portion opposite to the lead electrode side. The manufacturing method of the organic electroluminescent display panel characterized by these.   5. The method of manufacturing an organic EL display panel according to claim 4, wherein the lead wire is formed by printing or inkjet.   A plurality of the extraction electrodes are provided, the lead wires extending from the extraction electrodes are alternately different in length, and the thickness of the bump formed at the tip of each lead wire is thicker than the thickness of the lead wire. The method for producing an organic EL display panel according to claim 4 or 5, wherein

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