JP2001291587A - Manufacturing method of organic light emission device and organic light emission device manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic light emission device of inexpensive and highly functional full color organic EL display body or the like and its manufacturing method, by homogeneously patterning low molecular (monomer) organic luminous layer for each pigment with a high accuracy by means of a wet patterning method. SOLUTION: In a manufacturing method of an organic light emission device in which a layer which consists of at least an organic material between a pair of electrodes is arranged and in which a voltage is applied between the electrodes and light emission is obtained, the organic material layer is formed by the wet patterning method in which an ink containing the organic material in an hydrophobic organic solvent that has not more than 5 wt.% of solubility in water at the room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for manufacturing an organic light emitting device using a wet patterning method, and an organic light emitting device manufactured by the method.

[0002]

2. Description of the Related Art An organic light-emitting device (organic EL device) has a structure in which a thin film containing a fluorescent organic compound is sandwiched between a cathode and an anode, and electrons and holes are injected into the thin film. The recombination produces excitons (excitons), which emit light when the excitons are deactivated (fluorescence,
This is an element that emits light using phosphorescence.

[0003] The features of this organic EL device are that it can emit a high-luminance surface light of about 100 to 100,000 cd / m ² at a low voltage of 10 V or less, and can change the color from blue to red by selecting the type of fluorescent substance. Light emission is possible.

[0004] Organic EL elements have attracted attention as realizing inexpensive large-area full-color display elements (IEICE Technical Report, Vol. 89, Nos. 106, 49).
1989). According to reports, organic dyes that emit strong fluorescence are used in the light-emitting layer, and bright blue, green, and red light is emitted. It is thought that a high-luminance full-color display could be realized by using an organic dye which emits strong fluorescence in a thin film state and has few pinhole defects.

Further, Japanese Patent Application Laid-Open No. 5-78655 discloses a thin film layer in which the components of the organic light emitting layer are made of a mixture of an organic charge material and an organic light emitting material, thereby preventing concentration quenching and expanding the range of light emitting material selection. It has been proposed to use a high-luminance full-color element.

For a polymer organic EL material, an actual manufacturing method, and in particular, a structure and a manufacturing method of a full-color display panel are disclosed in Japanese Unexamined Patent Publication (Kokai) No. 3-269999.
In this publication, a manufacturing method by printing is disclosed, but there is no detailed disclosure. Further, Japanese Unexamined Patent Application Publication No. 10-1237
In Japanese Patent Application Publication No. 7 (Kokai) No. 7 (Kokai), a manufacturing method using an ink jet is disclosed.

On the other hand, for a low molecular (monomer) organic EL material, a method for producing a full-color display panel is disclosed in US Pat. No. 5,294,869, JP-A-5-258869, JP-A-5-258860 and JP-A-5-275172. As disclosed in the gazette, a method of patterning using a shadow mask in vacuum deposition is general.
With this method, there are limitations on the positional accuracy of the mask, the opening width, and the like, and it is difficult to produce a high-definition full-color display panel.

As a method for solving these problems, a patterning method using a donor sheet as disclosed in Japanese Patent Application Laid-Open No. 9-167684 has been proposed.
Even in this method, the light emitting layer needs to be vacuum-deposited, which is a very complicated manufacturing process.

[0009]

The organic thin-film EL device using the above-mentioned monomer organic dye can emit blue, green and red light. However, as is well known, in order to realize a full-color display, it is necessary to arrange an organic light-emitting layer for emitting three primary colors for each pixel.

Heretofore, a technique for patterning an organic light emitting layer has been extremely difficult. The first cause is that the metal surface of the reflective electrode material is unstable and the patterning accuracy of vapor deposition is not high. Second, polymers and precursors forming the hole injection layer and the organic light emitting layer are not resistant to a patterning step such as photolithography. Third, the organic light-emitting layer used in conventional printing and patterning by the ink-jet method is dissolved by a hydrophilic solvent. In these solvents, material deterioration due to solvent-containing moisture occurs, the light emission luminance is weak, and the light emission lifetime is low. Is short.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to pattern a low-molecular (monomer) organic light-emitting layer with high precision and uniformity for each dye by a wet patterning method. It is an object of the present invention to provide an inexpensive organic light emitting device such as a high-performance full-color organic EL display and a method for manufacturing the same.

[0012]

That is, according to a method of manufacturing an organic light emitting device of the present invention, a layer made of at least an organic material is arranged between a pair of electrodes, and a voltage is applied between the electrodes to emit light. In the method for manufacturing an organic light emitting device to be obtained, the organic material layer is formed by a wet patterning method using an ink containing an organic material in a hydrophobic organic solvent having a water solubility of 5 wt% or less at room temperature.

In the method for manufacturing an organic light-emitting device according to the present invention, it is preferable that the wet patterning method is an offset printing method in which the ink is transferred from an intaglio to a blanket and then transferred to a substrate. The viscosity of the ink is 5,000 CP or less, and the surface energy of the ink is 20 to 60 d.
More preferably, it is in the range of yne / cm.

Further, it is preferable that the wet patterning method is an ink jet printing method in which fine droplets of the ink are ejected and fixed, wherein the ink has a viscosity of 100 CP or less.
More preferably, the surface energy is in the range of 20 to 60 dyne / cm.

Further, it is preferable to form a light emitting layer having a light emitting color corresponding to each of the red, green and blue pixels by the wet patterning method. At this time, a partition for separating each of the red, green and blue pixels is formed. It is more preferable to have a step of forming.

The molecular weight of the organic material is preferably 5,000 or less.

Preferably, the organic material layer formed by the wet patterning method is an amorphous layer. Further, the difference between the melting point mp of the organic material and the glass transition point Tg is preferably 50 ° C. or more.

It is preferable that the organic material functions as at least one selected from a luminescent material, a hole injection material, an electron injection material, a hole transport material, and an electron transport material.

The organic material may be formed by doping a hole-injecting material or a hole-transporting material with a light-emitting material, by doping an electron-injecting material or an electron-transporting material with a light-emitting material, It is preferable that a material capable of transporting both electrons is doped with a light emitting material.

It is preferable that a plurality of the organic material layers are arranged between the pair of electrodes.

The method may further include, after forming the one electrode on the substrate, forming a plurality of layers including the organic material layer on the electrode, and forming the other electrode on the plurality of layers. Preferably, at this time, it is more preferable to form a passive matrix wiring structure using the above steps.

Also, a plurality of thin film transistors on a substrate,
And forming the one electrode connected to the transistor, forming a plurality of layers including the organic material layer on the electrode, and forming the other electrode on the plurality of layers. In this case, it is more preferable to form an active matrix wiring structure using the above-described steps.

Further, the thickness of the organic material layer is 0.005.
It is preferable to set it in the range of 0.3 μm.

The hydrophobic organic solvents include chloroform, toluene, carbon tetrachloride, dichloroethane, tetrachloroethane, xylene, cymene, cyclohexanone, octylbenzene, dodecylbenzene, decalin, quinoline, chlorobenzene, dichlorobenzene, trichlorobenzene, thymol. Nitrobenzaldehyde, nitrobenzene, carbon disulfide, 2-heptanone, benzene, terpineol, butyl carbitol acetate, and cellosolves.

Further, an organic light emitting device according to the present invention is characterized by being manufactured by the above method.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a partial top view showing an example of an active matrix type organic EL full-color display obtained by the present invention.

An active matrix type organic EL full-color display as shown in FIG. 3 has red, green and blue organic light-emitting elements on a signal line 301, a gate line 302, a pixel electrode 303 and a thin film transistor 304 formed on a substrate. Layer 3
05, 306, and 307. here,
The signal line 301 is connected to the source of the thin film transistor 304,
The gate line 302 is connected to the gate of the thin film transistor 304, and the pixel electrode 303 is connected to the drain of the thin film transistor 304. Organic light emitting layers 305, 3
Reference numerals 06 and 307 are formed by dissolving a luminescent organic material in a hydrophobic organic solvent and patterning it by a wet patterning method, that is, a printing method.

As the organic material, a low molecular (monomer) organic material is preferable. Among them, those having a molecular weight of 5,000 or less are preferable because the purity is increased and the characteristics are stabilized. Materials, electron injection materials,
At least one selected from a hole transport material and an electron transport material
Seeds can be used. Then, a light-emitting material can be doped into the hole-injection material or the hole-transport material, or the light-emitting material can be doped into the electron-injection material or the electron-transport material, so that a wider range of colors can be selected. . Further, a light-emitting device can be formed by disposing a plurality of organic material layers between a pair of electrodes.

In order to improve the luminous efficiency of the organic material layer, especially the organic light emitting layer, it is conceivable to configure the organic material layer as an amorphous layer.
It is preferable to use a material having a difference between p and the glass transition point Tg of 50 ° C. or more.

Organic light-emitting materials of each color include triarylamine derivatives, stilbene derivatives, polyarylenes, aromatic condensed polycyclic compounds, aromatic heterocyclic compounds, aromatic heterocondensed ring compounds, metal complex compounds and the like, and single oligos thereof. It can be adopted from a complex or a complex oligo, but is not limited thereto.

As the hole injecting / transporting material, a soluble phthalocyanine compound, a triarylamine compound, a conductive polymer, a perylene-based compound, an Eu complex, or the like can be used, but is not limited thereto.

As an electron injecting / transporting material, aluminum having a trimer of 8-hydroxyquinoline coordinated with aluminum is used.
q ₃ , azomethine zinc complex, distyrylbiphenyl derivative and the like can be used, but are not limited thereto.

In forming the organic material layer by the wet patterning method, the organic material is used by dissolving it in a hydrophobic organic solvent having a water solubility of 5 wt% or less at room temperature. At this time, a small amount of a hydrophilic solvent may be used in addition to the hydrophobic organic solvent. In this case, however, the mixture is mixed so that the water solubility at room temperature is 5 wt% or less at room temperature.

As the hydrophobic organic solvent, chloroform,
Toluene, carbon tetrachloride, dichloroethane, tetrachloroethane, xylene, cymene, cyclohexanone, octylbenzene, dodecylbenzene, decalin, quinoline,
Single or mixed solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, thymol, nitrobenzaldehyde, nitrobenzene, carbon disulfide, 2-heptanone, benzene, terpineol, butyl carbitol acetate and cellosolves can be suitably used. It is not limited.

An organic light emitting layer, an electron injection and transport layer,
In any of the hole injecting and transporting layers, it is also possible to disperse and use each functional substance in an appropriate binder resin.

The organic light-emitting layer may be a layer having a single function such as hole transport or a layer having a composite function. Further, separately from the organic light-emitting layer, a layer having a function of transporting holes and the like may be formed separately. In this case, the layer provided separately is also formed by a wet patterning method, and the organic material layer has a laminated structure. Thereby, the luminous efficiency can be improved and the manufacturing process can be simplified.

The thickness of the organic light emitting layer is 0.005 to 0.3 μm.
m, preferably 0.005 to 0.15 μm
m. In the case where the organic material layers have a laminated structure, each layer preferably has a thickness in the above range.

Examples of the wet patterning method employed in the present invention include an offset printing method capable of stably forming high-precision, high-definition patterning at low cost and an inkjet printing method suitable for patterning low-viscosity ink. Although it is mentioned, it is not necessarily limited to these.

The offset printing press is basically a sheet-fed proof printing press, but the printing position accuracy and the printing conditions can be set with higher accuracy than a general waterless lithographic printing press or intaglio printing press for printing on paper. It is better to improve it.

A method for forming an organic material layer using an offset printing machine will be described with reference to FIG. FIG. 4 is a schematic view showing the steps of the offset printing method. 4, reference numeral 401 denotes a printing stage; 402, an intaglio; 403, an ink (organic material) ejector; 404, an ink reservoir;
Is a doctor blade, 406 is a blanket cylinder, 407 is a blanket made of silicon, 408 is a receiving ink, 40
Reference numeral 9 denotes a blanket cylinder rotation direction, 410 denotes a printing stage moving direction, 411 denotes a substrate to be printed, and 412 denotes a transfer ink.

As shown in FIG. 4A, first, an intaglio 40
2, ink composed of an organic material dissolved in a hydrophobic solvent is dropped from an ink ejector 403. Next, ink is filled into the concave portions of the intaglio 402 while scraping with the doctor blade 405. The blanket 407 attached to the blanket cylinder 406 is brought into contact with the intaglio 402 at a constant pressure, and the ink filled in the intaglio 402 is received on the surface of the blanket 407. Then, as shown in FIG. 4B, the blanket 407 is brought into contact with the substrate 411 of the organic EL display, which is the substrate to be printed, at a constant printing pressure to transfer ink from the blanket surface to the substrate surface.

The ink used for offset printing is 5000
The viscosity is preferably equal to or less than CP. The ink viscosity cannot be determined unequivocally depending on the film thickness and pattern shape, as well as the surface properties of the blanket and the intaglio.
In general, when the viscosity is high, the filling property of the intaglio plate is impaired, and air bubbles are easily entrained. In particular, when the film thickness (WET) is thin, the viscosity is more preferably lower, and preferably 100 CP or less.

The delivery of printing ink is determined by the balance of the surface energy of the intaglio, blanket, and printing medium (substrate). The higher the surface energy is, the better, and the surface energy may be increased by activating the surface using ozone generated on the substrate surface using ultraviolet light or plasma. Therefore, the surface energy of the ink also needs to be a value within a range having a certain wettability on these surfaces, and generally 20 to 60 dyne / cm.
, Preferably in the range of 28 to 50 dyne / cm.

Next, a method of forming an organic material layer using an ink jet printer will be described with reference to FIG. FIG.
1 is a schematic diagram of an inkjet drawing apparatus. 6, reference numeral 601 denotes an inkjet head; 602, an XY stage; 603, a discharge ink (organic material); 604, a substrate such as glass; 605, a partition; 606, an X-axis drive system;
Reference numeral 07 denotes a Y-axis drive system.

The ink jet drawing apparatus shown here is:
It is configured on the basis of a stepper which is a semiconductor manufacturing apparatus. By driving the X-axis drive system 606 and the Y-axis drive system 607, the substrate 604 can be precisely moved, and the organic material can be moved to a desired position. Can be ejected. Inkjet head 601
As a method, a so-called bubble jet (registered trademark) method, which is a discharge method using thermal energy, or a piezo jet method using a piezoelectric element can be adopted. .

The ink used for ink-jet printing preferably has a viscosity of 100 CP or less in order to stably perform ejection and fixing. Although there is a difference in the usable viscosity range depending on the ejection method, in general, a high-viscosity ink cannot be ejected by an inkjet method having a small ejection energy. In particular, when the film thickness (WET) with a small discharge amount is small, the viscosity is more preferably lower, and preferably 20 CP or less. In addition, since a method of obtaining printing shape accuracy using a surface energy difference between a printed portion of a pixel portion and a non-printed portion such as a partition wall is generally used, the surface energy difference between the printed portion and the non-printed portion is increased. Is also good. In consideration of the surface energy of the ink, the surface energy is generally 20 to 60 dyn.
e / cm, preferably 28 to 50 dyne / cm
It is good to be in the range of.

In the ink jet printing method,
From the viewpoint of high precision and high definition, red, green,
It is preferable to form the partition 605 for separating each blue pixel by offset printing, photolithography, or the like. The ink for the partition 605 is preferably a resin that is durable to an organic material or a solvent added thereto, and is polymerized by heat or light. For example, an epoxy resin, an acrylic resin, or the like can be used. Although the color is not particularly limited, for example, when black is used, it can be used instead of or complement the black matrix.

[0049]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

Example 1 This example is an example in which an active matrix type organic EL full-color display as shown in FIG. 3 was manufactured.

As shown in FIG. 1, a signal line 109, a gate line 110, and a thin film transistor 10 are formed on a glass substrate 101.
After forming No. 2, an ITO transparent pixel electrode 103 was formed. Here, the source of the thin film transistor is connected to the signal line 10.
9, the gate is connected to the gate line 110, and the drain is connected to the pixel electrode 103.

Next, triphenylamine hexamer (TPA-6: molecular weight 1461, melting point 277) was used as a hole injection material.
(Tg, 156 ° C) in toluene to prepare a 0.5% solution. The solution thus obtained was coated on the substrate 101 by spin coating. Heat drying (80
C. for 10 minutes) to form a hole injection layer 104 having a thickness of 0.05 μm.

Next, using an offset printing apparatus shown in FIG. 4, a luminescent material for emitting red, green, and blue light was deposited at a depth of 15 μm.
After filling the intaglio 402 with the doctor blade 405,
A pattern was printed by receiving a silicon blanket 407 from the intaglio 402 at a printing pressure of 50 μm in indentation at a speed of 20 mm / s at a speed of 20 mm / s and transferring the pattern to the substrate 411 at the same speed and printing pressure to print a pattern having a thickness of 0.05 μm. Organic light emitting layers 105, 106 and 107 were formed (drying conditions: 80)
° C, 10 minutes).

A pentamer of 9,9-dioctylfluorene (DOFL-5: molecular weight 1945, melting point 210 ° C., Tg 123 ° C.) is used for a blue light emitting material, and 1.0 watts for a green light emitting material.
DOFL-5 doped with t% coumarin, 1.0% by weight of 4-wt.
(Dicyanomethylene) -2-methyl-6- (4-dimethylaminostyryl) -4-H-pyran (DCM)
What was doped into FL-5 was used. Each color light emitting material was dissolved in toluene at a concentration of 1.0 wt% using a solvent, and then diluted with terpineol at the same magnification to obtain a 0.5 wt% solution.

Finally, a 0.1-0.2 μm thick MgA
g reflective electrode (Mg: Ag = 10: 1) 108 is vapor-deposited (rate: 10 ° / s, degree of vacuum: 10 ^-5 to 10 ^-6 Torr)
r). Thus, an active full-color organic EL display (overall dimensions: 40 mm × 40 mm, overall dimensions: 0.4 mm × 0.4 mm) was completed. When the obtained organic EL display was driven at a constant current (1/80 duty, low voltage: 6 V), stable light emission was obtained over a long period of time.

(Embodiment 2) In this embodiment, an active matrix type organic EL full-color display as shown in FIG. 3 is manufactured.

As shown in FIG. 2, a signal line 209, a gate line 210, and a thin film transistor 20 are formed on a glass substrate 201.
2 and then forming an AlLi reflective pixel electrode (Li1wt
%) 203 was formed by mask evaporation (rate: 10 ° / s, degree of vacuum: 10 ^-5 to 10 ^-6 Torr). The connection between the transistor and the wiring is the same as in the first embodiment.

Next, using the offset printing machine shown in FIG. 4, the light-emitting material emitting red, green, and blue colors used in Example 1 was dissolved in toluene at a concentration of 1.0 wt% using toluene as a solvent.
A 0.5 wt% solution diluted 1: 1 with terpineol was prepared. The solution thus obtained was pattern-printed in the same manner as in Example 1, and the organic light-emitting layer 205 having a thickness of 0.05 μm was printed.
206 and 207 were formed.

Next, as a hole injection material, a 0.5% solution of TPA-6 dissolved in toluene as in Example 1 was coated by an extrusion method. By heating and drying, a hole injection layer 204 having a thickness of 0.05 μm was formed.

Finally, an ITO transparent electrode 208 was formed by DC sputtering. Thus, an active full-color organic EL display having the same size as that of Example 1 was completed.
When the obtained organic EL display was driven at a constant current under the same conditions as in Example 1, stable light emission was obtained over a long period of time.

Embodiment 3 In this embodiment, an active matrix type organic EL full-color display as shown in FIG. 3 is manufactured.

As shown in FIG. 8, a signal line 809, a gate line 810, and a thin film transistor 80 are formed on a glass substrate 801.
After forming No. 2, an ITO transparent pixel electrode 803 was formed.

Next, a partition pattern is printed by the offset printing apparatus shown in FIG.
A partition 811 having a height of 0.1 μm was formed. A thermosetting acrylic resin (Optmer SS high viscosity type (4000 CPS) manufactured by JSR) was used as a partition wall material.

As the organic light emitting material constituting the organic light emitting layer, tetraphenylbutadiene (TPB: molecular weight: 516, melting point: 175.6 ° C., Tg: 63 ° C.) was used to prepare a 0.5 wt% solution using toluene as a solvent. A 0.5 wt% solution of TPA-6 in toluene was prepared as a hole injection material.
A blue light-emitting material was obtained by stacking two layers using these solutions.

Similarly, DPVBi is used as an organic light emitting material.
(Molecular weight 952, melting point 352.8 ° C., Tg 168.8)
C), and a 0.5 wt% solution of toluene doped with lumogen red (5 mol%) is prepared.
0.5wt% of TPA-6 toluene as hole injection material
The solution was prepared. Using these solutions, a red light-emitting material was obtained by laminating two layers.

Further, as an organic light emitting material, a 0.5 wt% toluene solution of Alq ₃ (molecular weight 459.44, melting point 300 ° C. or more, Tg 300 ° C. or more) doped with a quinacridone derivative (QD) was prepared, and hole injection was performed. A 0.5 wt% solution of TPA-6 in toluene was prepared as a material. Using these solutions, a green light-emitting material was obtained by laminating two layers.

Next, the above-mentioned solution containing a light-emitting material emitting red, green, and blue colors was placed in a cell partitioned by a partition 811 using a Canon drawing apparatus equipped with a Canon BJ head shown in FIG. Two layers are laminated and ejected, thickness 0.05μm
Organic light emitting layers 805, 806 and 807 (hole injection layer 0.03 μm, coloring layer 0.02 μm) were formed.

Further, A as an electron injection material and a transport material
A 0.5 wt% solution of lq ₃ in toluene was coated by the extrusion method. By the heat treatment, an electron injection and transport layer 804 having a thickness of 0.05 μm was formed.

Finally, in the same manner as in the first embodiment, the thickness
A MgAg reflective electrode 808 having a thickness of 1 to 0.2 μm was formed by an evaporation method. Thus, an active full-color organic EL display having the same size as that of Example 1 was completed. When the obtained organic EL display was driven at a constant current under the same conditions as in Example 1, stable light emission was obtained over a long period of time.

(Embodiment 4) In this embodiment, an active matrix type organic EL full-color display as shown in FIG. 3 is manufactured.

As shown in FIG. 7, a signal line 709, a gate line 710, and a thin film transistor 70 are formed on a glass substrate 701.
2 was formed, and then an AlLi reflective pixel electrode 703 was formed in the same manner as in Example 2. Next, in the same manner as in Example 3, a partition wall 711 having a height of 0.1 μm was formed.

Further, as in Example 3, a 0.5 wt% solution of Alq ₃ in toluene was coated as an electron injecting material and a transporting material by an extrusion method. After the material is filled into the cell by the partition wall 711 by sufficient leveling, the solvent is removed by a heat treatment, and the thickness is reduced to 0.
A 05 μm electron injection and transport layer 704 was formed.

The blue, green, and red organic light-emitting materials similar to those in the third embodiment emit red, green, and blue in the cells divided by the partition 711 by the drawing apparatus shown in FIG. Two layers of light emitting materials are discharged and laminated, and an organic light emitting layer 7 having a thickness of 0.05 μm (a hole injection layer 0.03 μm, a color forming layer 0.02 μm) is formed.
05, 706 and 707 were formed.

Finally, an ITO transparent electrode 708 was formed by DC sputtering. Thus, an active full-color organic EL display having the same size as that of Example 1 was completed.
When the obtained organic EL display was driven at a constant current under the same conditions as in Example 1, stable light emission was obtained over a long period of time.

Embodiment 5 This embodiment is an example in which a passive matrix type organic EL full-color display is manufactured.

As shown in FIG. 5, a plurality of transparent lower wirings 502 were formed on the surface of a glass substrate 501 by using ITO, and black stripes 503 were formed in the gaps between them. As a black stripe material, a material obtained by adding carbon black to a UV curable acrylic resin (Optmer CR (black) manufactured by JSR Corporation, a high-viscosity type (4000CP)
S)) was used.

Here, the transparent lower wiring 502 and the MgAg reflective electrode (upper wiring) 507 are stripes orthogonal to each other, and the organic light emitting layers 504, 505, and 506 are square dot patterns.

Further, TPA-6 was used as a hole injection material.
Was coated by a spin coating method. By heating and drying (80 ° C., 10 minutes), a hole injection layer 508 having a thickness of 0.05 μm was formed.

Next, using the offset printing apparatus shown in FIG. 4, the luminescent material for emitting red, green, and blue colors used in Example 1 was printed in a pattern in the same manner as in Example 1, and the thickness was adjusted to 0.05.
Organic light emitting layers 504, 505, and 506 having a thickness of μm were formed.

Finally, in the same manner as in the first embodiment, the thickness
An MgAg reflective electrode (upper wiring) 507 having a thickness of 1 to 0.2 μm was formed by a mask evaporation method. Thus, a passive full-color organic EL display having the same size as that of Example 1 was completed. When the obtained organic EL display was driven at a constant current under the same conditions as in Example 1, stable light emission was obtained over a long period of time.

(Embodiment 6) This embodiment is an example in which a passive matrix type organic EL full-color display is manufactured.

As shown in FIG. 9, a plurality of transparent lower wirings 902 were formed on the surface of a glass substrate 901 by using ITO.

Here, the transparent lower wiring 902 and the MgAg reflection electrode (upper wiring) 907 are orthogonal stripes, and the organic light emitting layers 904, 905 and 906 are square dot patterns.

Next, a partition pattern is printed using an offset printing apparatus shown in FIG. 4, and heated at 60 ° C. for 30 minutes to form a partition (black stripe) 90 having a height of 0.1 μm.
9 was formed. Partition material is made by JSR Optmer CR
A (black) high viscosity type (4000 CPS) was used.

Further, T is used as a hole injection and transport material.
A 0.5 wt% solution of PA-6 in toluene was coated by an extrusion method. After the cells were filled with the partition wall 909 by sufficient leveling, a hole injection layer 908 having a thickness of 0.05 μm was formed by heat treatment.

Next, the blue, green, and red organic light-emitting materials used in Example 1 were placed in the cells divided into partitions 909 by the drawing apparatus shown in FIG. A light emitting material that emits blue light was discharged to form organic light emitting layers 904, 905, and 906 having a thickness of 0.05 μm.

Finally, in the same manner as in the first embodiment, the thickness
A MgAg reflective electrode 907 of 1 to 0.2 μm was formed by a mask evaporation method. Thus, a passive full-color organic EL display having the same size as that of Example 1 was completed. When the obtained organic EL display was driven at a constant current under the same conditions as in Example 1, stable light emission was obtained over a long period of time.

Embodiment 7 This embodiment is an example in which a passive matrix type organic EL full-color display is manufactured.

As shown in FIG. 9, a plurality of transparent lower wirings 902 were formed on the surface of a glass substrate 901 by using ITO.

Next, in the same manner as in the sixth embodiment, a height of 0.1
A μm partition (black stripe) 909 was formed.

Further, T is used as a hole injection and transport material.
A 0.5 wt% solution of PA-6 in toluene was coated by an extrusion method. After the material was filled into the cells by the partition walls 909 by sufficient leveling, the cells were heated to form a hole injection layer 908 having a thickness of 0.05 μm.

Next, the same blue, green, and red organic light emitting materials as in Example 3 were discharged and laminated in two layers in the same manner as in Example 3, and the thickness of the organic light emitting material was reduced to 0. Organic light emitting layers 904, 905 and 906 each having a thickness of 05 μm (hole injection layer 0.03 μm, coloring layer 0.02 μm) were formed.

Finally, in the same manner as in the first embodiment, the thickness
A MgAg reflective electrode 907 of 1 to 0.2 μm was formed by a mask evaporation method. Thus, a passive full-color organic EL display having the same size as that of Example 1 was completed. When the obtained organic EL display was driven at a constant current under the same conditions as in Example 1, stable light emission was obtained over a long period of time.

Comparative Example 1 This example is an example in which an active matrix type organic EL full-color display as shown in FIG.

However, in this example, the hole transport material and blue,
After preparing a solution having a concentration of 1.0 wt% using toluene as a solvent as a solution containing green and red organic light emitting materials,
Isopropyl alcohol was added at an equal volume to obtain a 0.5 wt% solution.

The obtained organic EL display having the same size as in Example 1 was driven at a constant current under the same conditions as in Example 1, but hardly emitted light.

(Comparative Example 2) In this example, as in Comparative Example 1,
This is an example in which an active matrix type organic EL full-color display as shown in FIG. 3 is manufactured.

However, as a solution containing the hole transport material and the blue, green, and red organic light emitting materials, a 0.75 wt% solution was prepared using toluene as a solvent, and イ ソ プ ロ ピ ル equivalent of isopropyl alcohol was added. A 0.5 wt% solution was used.

The obtained organic EL display having the same size as in Example 1 was driven at a constant current under the same conditions as in Example 1, but the initial luminance was about １ ／, and the emission luminance was deteriorated (half-time).
Was as fast as 1/10 of Example 1.

[0100]

As described above, according to the present invention, a monomer organic EL material which is conventionally considered to have good shape reproduction accuracy and not be able to be patterned with uniform film thickness is used.
By forming by wet patterning method,
An organic EL display of full color display can be realized. This makes it possible to manufacture a large-screen full-color display that is inexpensive, high-quality, high-functional, and long-lived.

Further, since the organic material layer, especially the organic light emitting layer is amorphous, the luminous efficiency is improved.

When the difference between the melting point of the organic material and the glass transition point is 50 ° C. or more, the efficiency of forming an amorphous layer is good.

Further, the luminous efficiency is improved by each organic material exhibiting functionality.

By doping the hole transporting material with a light emitting material or doping the electron transporting material with a light emitting material, the range of selection of each color is expanded.

Further, by forming the organic material layers in an overlapping manner, the luminous efficiency is improved and the manufacturing process can be simplified.

In addition, high-precision, high-definition patterning can be stably formed by offset printing using an intaglio plate and a blanket.

Further, the range of use of the low-viscosity ink is expanded by ink jet printing, and the performance can be improved. At this time, the use of the partition walls enables high-precision and high-definition inkjet printing.

Further, power consumption in a large area can be reduced by the active matrix structure. Further, an inexpensive display body can be manufactured by the passive matrix structure.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a cross section of an active matrix type organic EL display according to Example 1. FIG.

FIG. 2 is a schematic view showing a cross section of an active matrix organic EL display according to Example 2.

FIG. 3 is a partial top view showing an example of an active matrix type organic EL full-color display obtained by the present invention.

FIG. 4 is a process sectional view of an offset printing method that can be adopted in the present invention.

FIG. 5 is a passive matrix organic EL according to a fifth embodiment.
It is a schematic diagram which shows the cross section of a display body.

FIG. 6 is a schematic diagram of an inkjet drawing apparatus that can be employed in the present invention.

FIG. 7 is a schematic diagram showing a cross section of an active matrix type organic EL display according to Example 4.

FIG. 8 is a schematic diagram showing a cross section of an active matrix organic EL display according to Example 3.

FIG. 9 is a schematic view showing a cross section of a passive matrix type organic EL display according to Examples 6 and 7.

[Explanation of symbols]

 101 glass substrate 102 thin film transistor 103 transparent pixel electrode 104 hole injection layer 105 organic light emitting layer (red) 106 organic light emitting layer (green) 107 organic light emitting layer (blue) 108 reflective electrode 109 signal line 110 gate line 201 glass substrate 202 thin film transistor 203 Reflective pixel electrode 204 hole injection layer 205 organic light emitting layer (red) 206 organic light emitting layer (green) 207 organic light emitting layer (blue) 208 transparent electrode 209 signal line 210 gate line 301 signal line 302 gate line 303 pixel electrode 304 thin film transistor 305 Organic light emitting layer (red) 306 Organic light emitting layer (green) 307 Organic light emitting layer (blue) 401 Printing stage 402 Intaglio 403 Ink ejector 404 Ink reservoir 405 Doctor blade 406 Blank cylinder 407 Blanket 408 Receiving ink 40 9 Blank rotation direction 410 Printing stage movement direction 411 Substrate to be printed 412 Transfer ink 501 Glass substrate 502 Transparent lower wiring 503 Black stripe 504 Organic light emitting layer (red) 505 Organic light emitting layer (green) 506 Organic light emitting layer (blue) 507 Reflection Pixel electrode 508 Hole injection layer 601 Ink jet head 602 XY stage 603 Discharged ink (light emitting material) 604 Substrate 605 Partition wall 606 X axis drive system 607 Y axis drive system 701 Glass substrate 702 Thin film transistor 703 Transparent pixel electrode 704 Electron injection and transport layer 705 Organic light emitting layer (red) 706 Organic light emitting layer (green) 707 Organic light emitting layer (blue) 708 Reflecting electrode 709 Signal line 710 Gate line 711 Partition 801 Glass substrate 802 Thin film transistor 803 Reflecting pixel electrode 804 Electron injection And transport layer 805 organic light emitting layer (red) 806 organic light emitting layer (green) 807 organic light emitting layer (blue) 808 transparent electrode 809 signal line 810 gate line 811 partition 901 glass substrate 902 transparent lower wiring 904 organic light emitting layer (red) 905 Organic light emitting layer (green) 906 Organic light emitting layer (blue) 907 Reflective pixel electrode 908 Hole injection layer 909 Black stripe

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41M 3/00 G09F 9/30 338 G09F 9/30 338 365Z 365 H05B 33/12 B H05B 33/12 33 / 14 A 33/14 33/22 D 33/22 B Z B41J 3/04 101Z

Claims (24)

[Claims] 1. A method for manufacturing an organic light-emitting device in which a layer made of at least an organic material is disposed between a pair of electrodes and a voltage is applied between the electrodes to emit light, the water solubility at room temperature is 5 wt% or less. Forming the organic material layer by a wet patterning method using an ink containing an organic material in a hydrophobic organic solvent. 2. The organic light emitting device according to claim 1, wherein the wet patterning method is an offset printing method of transferring the ink to a substrate after receiving the ink from the intaglio to a blanket. Production method. 3. The method according to claim 2, wherein the viscosity of the ink is 5000 CP or less. 4. The method according to claim 1, wherein the surface energy of the ink is 20 to 20.
The method for manufacturing an organic light emitting device according to claim 2 or 3, wherein the range is 60 dyne / cm. 5. The method according to claim 1, wherein the wet patterning method is an inkjet printing method in which fine droplets of the ink are ejected and fixed. 6. The method according to claim 5, wherein the ink has a viscosity of 100 CP or less. 7. The ink has a surface energy of 20.
The method for manufacturing an organic light emitting device according to claim 5, wherein the thickness is in the range of 60 dyne / cm to 60 dyne / cm. 8. The method according to claim 1, wherein the wet patterning method comprises:
The method for manufacturing an organic light-emitting device according to claim 1, wherein a light-emitting layer having a light-emitting color corresponding to each of green and blue pixels is formed. 9. The method for manufacturing an organic light emitting device according to claim 8, further comprising a step of forming a partition for separating each of red, green, and blue pixels. 10. The method according to claim 1, wherein the organic material has a molecular weight of 5,000 or less. 11. The method according to claim 1, wherein the organic material layer formed by the wet patterning method is an amorphous layer. 12. The method according to claim 1, wherein a difference between the melting point mp of the organic material and the glass transition point Tg is 50 ° C. or more. 13. The method according to claim 1, wherein the organic material functions as at least one selected from a light emitting material, a hole injection material, an electron injection material, a hole transport material, and an electron transport material. A method for manufacturing an organic light-emitting device according to any one of the above. 14. The method according to claim 1, wherein the organic material is obtained by doping a hole injection material or a hole transport material with a light emitting material. 15. The method for manufacturing an organic light emitting device according to claim 1, wherein the organic material is obtained by doping an electron injection material or an electron transport material with a light emitting material. 16. The method for manufacturing an organic light emitting device according to claim 1, wherein the organic material is obtained by doping a light emitting material into a material capable of transporting both holes and electrons. . 17. The method for manufacturing an organic light emitting device according to claim 1, wherein a plurality of the organic material layers are arranged between the pair of electrodes. 18. The method according to claim 18, further comprising: after forming the one electrode on the substrate, forming a plurality of layers including the organic material layer on the electrode; and forming the other electrode on the plurality of layers. The method for manufacturing an organic light-emitting device according to claim 1, wherein: 19. The method according to claim 18, wherein a passive matrix wiring structure is formed using the steps. 20. A step of forming a plurality of thin film transistors on a substrate and the one electrode connected to the transistor; a step of forming a plurality of layers including the organic material layer on the electrodes; 18. The method according to claim 1, further comprising the step of forming the other electrode. 21. The method according to claim 20, wherein an active matrix wiring structure is formed using the steps. 22. The organic material layer having a thickness of 0.005 to 0.005.
3. The range of 0.3 .mu.m.
2. The method for manufacturing an organic light-emitting device according to any one of 1. 23. The hydrophobic organic solvent includes chloroform, toluene, carbon tetrachloride, dichloroethane, tetrachloroethane, xylene, cymene, cyclohexanone, octylbenzene, dodecylbenzene, decalin, quinoline, chlorobenzene, dichlorobenzene, trichlorobenzene, thymol. 23. The method for manufacturing an organic light-emitting device according to claim 1, wherein the organic light-emitting device is selected from nitrobenzaldehyde, nitrobenzene, carbon disulfide, 2 heptanone, benzene, terpineol, butyl carbitol acetate, and cellosolves. . 24. An organic light-emitting device manufactured by the method according to claim 1. Description: