JP2002170669A - Organic el display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a coating distinction of organic layers in a substrate with an organic EL display device, especially one of which organic layers are formed by coating, and to provided a novel process of colorification in which an outer electrode lead-out part and a sealing adhesion area are secured and organic EL elements with different luminescent colors are arranged in one and the same substrate. SOLUTION: The organic EL display device is provided with a substrate, a first electrode formed on the substrate, one or more organic layers at least involved in luminescent function, and a second electrode formed on the organic layer, and it is so structured in the manufacturing method that at least one of the above layers is formed by a method of application and patterned by a lift-off method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL display device characterized by forming an organic layer by a coating method, and more particularly, to a method using a material and a solvent which are inert to the organic EL material. The present invention relates to a process for selectively disposing an organic substance by a lift-off method.

[0002]

2. Description of the Related Art As described in JP-A-59-194393, a laminated organic EL device using a vacuum deposition method is disclosed.
Since the development of the element, the development of the organic EL display has been actively carried out, and an element at a practical level has been created and is currently being put to practical use.

On the other hand, since the development of a device forming technique by a coating method as described in Japanese Patent Application Laid-Open No. 4-500582, the development of an organic EL device by a coating method has become active, and the element by a vapor deposition method has been developed. The same characteristics can be obtained.

By the way, in order to make an organic EL device into a device, an organic EL material is formed such as an electrode extraction portion for connecting to a circuit and an adhesion region for performing sealing for keeping the device under low humidity. It is necessary to secure an unoccupied area.

[0005] In a stacked organic EL device using a vacuum deposition method, it is possible to accurately separate a deposited portion and a non-deposited portion by a metal mask deposition, similarly to the colorization process. On the other hand, an organic EL prepared using a coating method
There is no effective method for the element, and there is almost no report on a method of applying differently, except for a method using ink jet.

[0006] When a color device is used by using an organic EL element, elements having different emission colors must be arranged on the same substrate. In a stacked organic EL display by vacuum evaporation, it is possible to arrange each element in a delicate pattern by evaporation through a metal mask, and several companies have already announced full-color displays at the '99 Electronics Show. .

On the other hand, at present, there is no definitive method for colorizing an organic EL element using coating.
Only SID99 DIGEST (1999) 372 has announced a full-color display in which materials are separately applied by an ink-jet method, but has solved the problem of ink landing accuracy due to flight bending and the problem of dot size due to uneven application amount. Absent. In addition, since a process of applying a small amount of ink is basically used, there is a problem that unevenness occurs when applied to a pixel having a relatively large area such as a part color display.

As another possible method of forming the uncoated portion, a method of simply masking with an adhesive sheet and peeling the sheet after applying the organic material can be considered. In this method, however, the uncoated portion is formed on a substrate. The internal structure such as the insulating film and the partition for separating the negative electrode is also peeled off at the same time, so that it cannot be put to practical use. In addition, the accuracy is too low to be used for different coating of the light emitting layer.

[0009] In addition, the technique of peeling the organic film using the adhesive sheet after the application of the organic layer also causes problems of destruction of the internal structure and poor accuracy.

[0010] In the lift-off method using a resist, which is often used in inorganic EL and the like, the solvent cannot simultaneously remove the necessary organic layer during the lift-off, so that the purpose cannot be achieved.

Until now, as a lift-off method which does not affect the organic layer, Japanese Patent Application Laid-Open Nos. Hei 10-261486 and Hei 10-261490 disclose counter electrode separation methods using a fluorine-based resin. But organic EL
There is no example used to pattern an organic layer of a display device.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic EL display device, in particular, an organic EL display device in which an organic layer is formed by coating, so that the organic layers can be separately coated on the same substrate. It is an object of the present invention to provide a novel process in a colorization process for securing an electrode extraction portion, a sealing adhesive region, and arranging organic EL elements having different emission colors on the same substrate.

[0013]

That is, the above object is achieved by the following constitutions. (1) a substrate, a first electrode formed on the substrate, at least one or more types of organic layers involved in a light emitting function, and a second electrode formed on the organic layer; An organic EL in which at least one of the organic layers is formed by a coating method and is patterned by a lift-off method
Display device. (2) The organic EL display device according to (1), wherein the patterning material used in the lift-off method is a fluorine-based material. (3) The organic EL display device according to the above (1) or (2), wherein the region from which the patterned organic layer is removed is at least an external electrode extraction portion or a sealing adhesive region. (4) The organic EL display device according to any one of (1) to (3), wherein the area where the patterned organic layer remains is a light emitting area. (5) An organic EL including a substrate, a first electrode formed on the substrate, at least one kind of organic layer involved in at least a light emitting function, and a second electrode formed on the organic layer. A method for manufacturing a display device, wherein at least one of the organic layers is formed by a coating method and patterned by a lift-off method. (6) The method for manufacturing an organic EL display device according to the above (5), wherein the patterning material used in the lift-off method is a fluorine-based material, which is dissolved in a fluorine-based solvent. (7) The method for producing an organic EL display device according to the above (5) or (6), wherein the region from which the patterned organic layer is removed is at least an external electrode extraction portion or a sealing adhesive region. (8) The method for manufacturing an organic EL display device according to any one of the above (5) to (7), wherein the region where the patterned organic layer remains is a light emitting region. (9) A method for manufacturing an organic EL display device in which organic EL elements having different emission colors are formed on the same substrate by repeating the steps of claim 5.

[0014]

The organic EL element is a device using an organic material, and is eroded by most organic solvents.
Even if an organic solvent having low solubility and being difficult to dissolve is used, desired characteristics cannot be obtained due to a change in film quality or the like.
Further, it is very sensitive to moisture, and the moisture easily causes destruction. For this reason, it was not possible to pass through a process such as ordinary photolithography, and patterning of the organic layer was extremely difficult.

By the way, in order to make an organic EL device into a device, an electrode extraction portion for connecting to a drive circuit or the like, an adhesion region for performing sealing for keeping the device under low humidity, and the like are provided.
It is necessary to secure a region where the organic EL material layer is not formed. In a stacked organic EL element using a vacuum evaporation method, it is possible to accurately perform deposition of an evaporation part and a non-evaporation part by mask evaporation, but in an organic EL element created using a coating method, At present, there is no effective method.

Further, when a color device is used by using an organic EL element, elements having different emission colors must be arranged on the same substrate. In a stacked organic EL device using a vacuum evaporation method, similarly, it was possible to accurately and separately apply a deposited portion and a non-deposited portion by mask deposition, but an organic EL device formed using a coating method was used. However, there is no effective method, and there are many disadvantageous elements in making a device as compared with a vacuum evaporation system.

As a result of repeated studies by the present inventors on this problem, it has been found that the problem can be solved by a lift-off method using a solvent inert to the organic EL material, specifically, a fluorine-based solvent. I found it. Fluorine-based materials can be made into a thin film by vacuum evaporation. After applying an organic material on this thin film, the organic material is removed from the organic material by removing the fluorine-based material together with the upper organic material in a fluorine-based solvent. A part can be formed. Since a fluorine-based material is formed by an evaporation method via a metal mask, an organic EL using coating is used.
Also in the element, it is possible to separately apply the coated part and the non-coated part with the same accuracy as the stacked organic EL element.

The lift-off layer made of a fluorine-based material can also be formed by ordinary photolithography. In this case, after forming a photoresist film on the fluorine-based material layer, the resist may be exposed and developed, and the fluorine-based material layer may be separated by various etching methods. After the application of the organic EL material, the organic E
The L material and the resist film can be removed at the same time. Otherwise, a photosensitive fluororesin may be used.

By using a similar method, it is possible to arrange organic EL elements having different emission colors on the same substrate. Specifically, a fluorine-based material is thinned by vacuum evaporation, an organic material is applied on the thin film, and then the fluorine-based material is removed together with the upper organic material in a fluorine-based solvent, so that the fluorine-based material is not applied. A part can be formed. Since the fluorine-based material is formed by a vapor deposition method via a metal mask, even in an organic EL element using coating, it is possible to separately apply the coated part and the non-coated part with the same accuracy as the stacked organic EL element. . According to this method, even in an organic EL element using coating, it is possible to separately apply the coated portion and the non-coated portion with the same accuracy as that of the stacked organic EL device.

Further, this process is repeated for each of the blue, green and red organic E
Coloring can be achieved by performing the processing on the L material.
The organic EL material layer formed first is a subsequent step,
Since it does not touch anything other than the fluorine-based solvent, it does not deteriorate.

The lift-off layer may be formed from a fluorine-based material by other methods such as using a photosensitive fluororesin.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An organic EL display device according to the present invention comprises a substrate, a first electrode formed on the substrate, at least one or more types of organic layers involved in at least a light emitting function, and And at least one of the organic layers is formed by a coating method and patterned by a lift-off method.

As described above, by forming the organic layer by the coating method and using the lift-off method for patterning, the organic layer formed by the coating method can be patterned in the same manner as in the vapor deposition method using a metal mask. This makes it possible to very easily form and pattern an organic layer. In addition, since the patterning material used for patterning preferably uses an organic layer, an inert fluorine-based material, and a fluorine-based solvent, damage to the organic layer can be minimized.

As the patterning material, an organic material and an inert fluorine-based material are preferable. Specifically, (1) fluorinated polyolefins such as polychlorotrifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, and (2) tetrafluoroethylene with the following formula

[0025]

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(3) a copolymer of tetrafluoroethylene and perfluoroallyl vinyl ether, a copolymer of chlorotrifluoroethylene and perfluoroallyl vinyl ether, and the like. , Copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether,
Fluorinated polyethers such as copolymers of chlorotrifluoroethylene and perfluoroalkyl vinyl ether,
And (4) fluorinated resins such as fluorinated polysiloxanes. Among these resins, a polymer of tetrafluoroethylene and a perfluoroallyl vinyl ether having 4 to 8 carbon atoms or a copolymer of tetrafluoroethylene and a perfluoroalkyl vinyl ether having 4 to 8 carbon atoms is preferable.

More specifically, 2,2-bis (trifluoromethyl) -4,5-difluoro-1,3-dioxole / tetrafluoroethylene copolymer (2,2-Bis (trifluoromethyl) -4,
5-difluoro-1,3-dioxole / tetrafluoroethylene copolym
er), commercially available products, such as Cytop CTX809A (trade name, manufactured by Asahi Glass Co., Ltd.).
In particular, 2,2-bis (trifluoromethyl) -4,5-difluoro-1,3-dioxole / tetrafluoroethylene copolymer is preferable because vapor deposition is possible.

The solvent for dissolving the patterning material is particularly preferably one in which the solubility of the organic material used in the organic layer (light-emitting layer) of the organic EL element is 0.001% or less. Of fluorinated hydrocarbons. That is, a fluorinated lower paraffin (having a carbon number of 50 or less) such as a linear perfluoroalkane (having a kinematic viscosity of about 0.1 to 1 cSt) or a fluorinated lower amine (having a carbon number of 50 or less) such as perfluoroamine Is 20 or less), perfluoropolyether (molecular weight of 1,000 to
Fluorinated polyethers and the like. Further, a fluorinated silicone oil can be used as the solvent. More specifically, Fluorinert manufactured by Sumitomo 3M, Demnum S20 manufactured by Daikin, and the like can be mentioned. Particularly, those having a boiling point of 100 ° C. or less are preferable because they are easy to handle.

The patterning layer is formed at least before forming an organic layer formed by a coating method. For forming the patterning layer, an evaporation method, particularly a mask evaporation method, is preferable.

In addition, a coating liquid (including a prepolymer) capable of forming a resin layer serving as a material of a release layer is prepared, and a spin coating method and a dipping using the coating liquid are prepared. It can also be formed by a method such as a bar coating method. In this case, the uncured resin layer is cured by heat, ultraviolet light, or the like to obtain a resin layer serving as a material for the patterning layer. Thereafter, the resin layer is patterned into a desired shape by a method such as lithography, laser beam processing, electron beam drawing, or the like, whereby a desired patterning layer can be obtained.

The thickness of the patterning layer is preferably 10 to 300 nm, more preferably 50 to 200 nm. If the thickness of the patterning layer is too large, peeling may occur in areas other than the area to be patterned, or it may take time to dissolve the patterning layer, which unnecessarily increases the manufacturing process time. If the thickness of the patterning layer is too small, lift-off becomes difficult.

The patterning of the organic layer, particularly the organic layer formed by the coating method, is performed by a lift-off method.

In the patterning step, first, a patterning layer is formed on the substrate on which the first electrode has been formed. In this case, when the patterning layer is formed by a vacuum evaporation method, by a mask evaporation method, at the same time as the formation of the patterning layer,
It is preferable to perform pattern formation of the patterning layer.
When the patterning layer is formed by a coating method, a patterning process is performed after performing a curing process and a polymerization process as necessary.

Next, an organic layer is formed on the substrate having the patterned layer subjected to the patterning process. At least one of the organic layers is formed by a coating method. As a coating method, any method such as a spin coating method, a dipping method, and a bar coating method may be used.

After the organic layer is formed, the organic layer is patterned by dissolving the patterning layer with a fluorine-based solvent. The patterning layer may be dissolved by dipping the substrate on which the organic layer is formed in a solvent. The time required for dissolution depends on the thickness of the patterning layer, but is usually 10 sec.
It is about 10 min, especially about 1 to 5 min.

When performing the dissolution treatment, ultrasonic irradiation may be performed as necessary. By performing ultrasonic irradiation, dissolution is promoted, and the organic layer can be peeled off without unevenness.

The effect of the ultrasonic wave depends on the distance between the oscillator and the substrate. If the distance is kept constant, an ultrasonic effect corresponding to the output intensity can be obtained. Actually, there is no problem if the distance between the oscillator (vibrator) and the substrate is set to 20 cm or less, preferably 10 cm or less.

The output of the oscillator is not particularly limited, but is usually about 100 to 1000 W. The transmission frequency is about 30 to 50 kHz.

The region from which the organic layer is removed by patterning is at least a portion from which an external electrode is taken out or an adhesive region for sealing.
Non-light-emitting regions such as wiring electrode portions are also removed. Wiring can be secured by removing the organic layer from the external electrode extraction portion, and the sealing plate can be securely bonded and fixed by removing the organic layer from the sealing adhesive region.

The above patterning step may be performed a plurality of times for a plurality of organic layers. By performing the patterning process a plurality of times, for example, R, G, B, and the like can be separately applied.

If necessary, an organic layer such as a charge injection layer or an inorganic layer may be formed by a vapor deposition method.

Next, a second electrode is formed and patterned on the substrate on which the organic layer is formed and patterned.
Further, if necessary, a wiring electrode is formed and sealed to obtain a display device.

In the present invention, as an organic material for forming an organic layer, a fluorescent material and a charge transporting material (general terms of an electron transporting material and a hole transporting material) as generally used in an organic EL device are used. ) Can be used.

For example, a light emitting layer using a polymer fluorescent substance having high solubility, a mixed light emitting layer of a polymer fluorescent substance and a charge transport material, or a light emitting layer of such a light emitting layer and an electron injection electrode (negative electrode) An electron injection / transport layer containing an electron injection / transport material may be provided therebetween, or a hole injection / transport layer containing a hole injection / transport material may be provided between the light emitting layer and the hole injection electrode. Further, instead of the electron injection / transport layer and the hole injection / transport layer, a high resistance electron injection / transport layer or a hole injection / transport layer made of an inorganic material may be provided.

As such a polymeric fluorescent substance, polyethylene dioxythiophene polystyrene sulphonate (Polyethlene dioxytiophene polystyrene sulphonate) is used.
: PEDOT / PSS), polyvinyl carbazole (PVK),
Metal phthalocyanine compound, polyaniline / polystyrene sulfonate (Pani / PSS), polyparaphenylenevinylene derivative (PPV derivative) having the following structure,

[0046]

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And any one or a mixture of polyallylfluorene derivatives having the following structure.

[0048]

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The metal phthalocyanine compound is not particularly limited and may be any known one. As the central metal, Cu, Fe, Zn, Co, Pt, Cr, Ni, Pd
And the like, and Cu and Zn are preferable, and Cu is particularly preferable.

The light emitting layer may be a single layer or two or more layers, and a plurality of light emitting layers and a charge transport layer may be formed. Further, the light emitting layer may contain the following fluorescent material and charge transporting material in addition to the polymer fluorescent material. Further, the polymeric fluorescent substance and / or the charge transport material may be dispersed in a polymeric compound.

The known luminescent material that can be used together with the polymeric fluorescent substance of the present invention is not particularly limited. Examples thereof include a naphthalene derivative, anthracene and its derivative, perylene and its derivative, polymethine, xanthene,
Coumarin-based, cyanine-based dyes, metal complexes of 8-hydroxyquinoline and its derivatives, aromatic amines,
Tetraphenylcyclopentadiene and derivatives thereof,
Tetraphenylbutadiene and derivatives thereof can be used. Specifically, for example, Japanese Patent Application Laid-Open No. 57-5
Known ones such as those described in JP-A Nos. 1781 and 59-194393 can be used.

As the charge transporting material that can be used in the present invention, various electron transporting materials and hole transporting materials can be used and are not particularly limited.

Examples of the hole transporting material include pyrazoline derivatives, arylamine derivatives, stilpene derivatives, triphenyldiamine derivatives and the like.

Examples of the electron transporting material include oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyanoanthraquinodimethane and its derivatives, fluorene and Metal complexes such as derivatives thereof, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, and 8-hydroxyquinoline and derivatives thereof can be given.

Specifically, JP-A-63-70257, JP-A-63-175860, and JP-A-2-1353
Nos. 59, 2-135361, 2-209
988, 3-37992, 3-152
No. 184, for example.

Particularly, as a hole transporting material, 4,4-bis (N (3-methylphenyl) -N-phenylamino)
Biphenyl and 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,3 as an electron transporting material
4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum are preferred.

Of these, one or both of the electron transport compound and the hole transport compound may be used simultaneously. These may be used alone or as a mixture.

The amount of the charge transporting material varies depending on the type of the compound used and the like. Therefore, the optimum amount of the charge transporting material may be determined within a range that does not impair the sufficient film-forming property and the light emitting characteristics. Usually, it is 1 to 40% by mass, more preferably 2 to 30% by mass, based on the fluorescent material (light emitting material).

The organic layer may have an electron injecting and transporting layer, a hole injecting and transporting layer, and the like in addition to the light emitting layer. The electron transporting material and the hole transporting material used for the electron injecting and transporting layer and the hole injecting and transporting layer made of an organic material may be any of the above-mentioned materials that are suitable in relation to the light emitting layer, the electrode, and the like.

When the polymer fluorescent substance is used, the light emitting layer has a thickness of 0.5 nm to 10 μm, preferably 1 nm to 1 μm.
μm. In order to increase the current density and the luminous efficiency, the range of 10 to 500 nm is preferable. When the film is formed into a thin film by a coating method, it is desirable to heat and dry at a temperature of 30 to 200 ° C., preferably 60 to 100 ° C. under reduced pressure or an inert atmosphere in order to remove the solvent.
When such a heating and drying step is required, it is preferable to form an inorganic charge injection layer shown below between the electrodes.

When the charge injection / transport layer is formed below the light emitting layer, a certain degree of heat resistance is required when a heat polymerization step is required for forming the light emitting layer. In this case, the glass transition temperature is preferably 200 ° C. or higher, more preferably 3 ° C.
Compounds having a temperature of at least 00 ° C, especially at least 350 ° C, are preferred.

The thickness of the organic hole injecting and transporting layer and the thickness of the electron injecting and transporting layer are not particularly limited and vary depending on the forming method, but are usually about 5 to 500 nm, especially 10 to 300 nm. Is preferred. When a hole injection layer and a transport layer are provided, it is preferable that the thickness of the injection layer is 1 nm or more and the thickness of the transport layer is 1 nm or more. The injection layer at this time,
The upper limit of the thickness of the transport layer is usually about 500 nm in the injection layer,
The thickness is about 500 nm in the transport layer.

The solvent used for forming the organic layer of the present invention is not particularly limited as long as it dissolves the organic material and does not cause any trouble during coating. Specifically, those generally used such as alcohols, hydrocarbons, ketones, and ethers can be used.
Among them, chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene and the like are preferable. Although it depends on the structure and molecular weight of the phosphor, it can be usually dissolved in these solvents in an amount of 0.1% by mass or more.

The negative electrode (electron injection electrode) is not particularly limited because it does not need to have a low work function and an electron injection property when combined with an electron injection layer such as an inorganic electron injection layer. Ordinary metals can be used. Among them, Al, Ag, In, T in terms of conductivity and ease of handling.
One, two or more metal elements selected from i, Cu, Au, Mo, W, Pt, Pd and Ni, particularly Al and Ag are preferable.

The thickness of these negative electrode thin films may be a certain thickness or more that can provide electrons to the high-resistance inorganic electron injecting and transporting layer, and may be 50 nm or more, preferably 100 nm or more. Although the upper limit is not particularly limited, the film thickness may be generally about 50 to 500 nm.

The following may be used as the electron injection electrode, if necessary. For example, K, Li, Na, M
g, La, Ce, Ca, Sr, Ba, Sn, Zn, Zr
Or a two-component or three-component alloy system containing them for improving stability, for example, Ag.Mg.
(Ag: 0.1 to 50 at%), Al.Li (Li: 0.
01 to 14 at%), In.Mg (Mg: 50 to 80 at%)
%), Al.Ca (Ca: 0.01 to 20 at%), Li
F (F: 0.01 to 40 at%) and the like.

The thickness of the electron injecting electrode thin film may be a certain thickness or more for sufficiently injecting electrons.
The thickness is preferably 0.5 nm or more, particularly 1 nm or more.
The upper limit is not particularly limited.
It may be about 500 nm. On the electron injection electrode,
Further, an auxiliary electrode (protection electrode) may be provided.

The thickness of the auxiliary electrode may be a certain thickness or more, preferably 50 nm or more, more preferably 100 nm or more, in order to secure electron injection efficiency and to prevent entry of moisture, oxygen or an organic solvent. A range from 100 to 500 nm is preferred. If the auxiliary electrode layer is too thin, the effect cannot be obtained, and the step coverage of the auxiliary electrode layer is reduced, and the connection with the terminal electrode is not sufficient. On the other hand, if the auxiliary electrode layer is too thick, the stress of the auxiliary electrode layer increases, which causes adverse effects such as an increase in the growth rate of dark spots.

As the auxiliary electrode, an optimum material may be selected and used depending on the material of the electron injection electrode to be combined. For example, if importance is placed on ensuring electron injection efficiency, a low-resistance metal such as Al may be used, and if importance is placed on sealing properties, a metal compound such as TiN may be used.

The total thickness of the electron injection electrode and the auxiliary electrode is not particularly limited, but is usually 50 to 500 nm.
It should be about the degree.

The hole injection electrode material is inorganic hole injection transport.
Efficient holes in the transport layer or organic hole injection transport layer
3. It is preferable that the work function be able to be injected well.
Substances between 5 eV and 5.5 eV are preferred. Specifically, tin do
Indium oxide (ITO), zinc-doped indium oxide
(IZO), indium oxide (In)_TwoO_Three), Oxide
(SnO_Two) And zinc oxide (ZnO)
Those having a main composition are preferred. These oxides are
There may be some deviation from the stoichiometric composition. In _TwoO_ThreeTo
SnO_TwoIs 1 to 20% by mass, and
5-12 mass% is preferred. In addition, In in IZO_TwoO
_ThreeIs usually 12 to 32% by mass.
It is about.

The hole injection electrode may contain silicon oxide (SiO ₂ ) in order to adjust the work function.
The content of silicon oxide (SiO ₂ ) is preferably about 0.5 to 10% by mol ratio of SiO _{2 to} ITO. S
The inclusion of iO ₂ increases the work function of ITO.

The electrode on the light extraction side has an emission wavelength band,
The light transmittance is usually 400 to 700 nm, particularly preferably 50% or more, more preferably 80% or more, and particularly preferably 90% or more for each emitted light. If the transmittance is too low, the light emission itself from the light emitting layer is attenuated, and it becomes difficult to obtain the luminance required for the light emitting element.

The thickness of the electrode is 50 to 500 nm, especially 50 to 500 nm.
The range of -300 nm is preferred. The upper limit is not particularly limited. However, if the thickness is too large, there is a fear that the transmittance is reduced or the layer is peeled off. If the thickness is too small, a sufficient effect cannot be obtained, and there is a problem in film strength at the time of production and the like.

Further, in order to prevent deterioration of the organic layers and electrodes of the device, it is preferable to seal the device with a sealing plate or the like. The sealing plate adheres and seals the sealing plate using an adhesive resin layer in order to prevent moisture from entering. The sealing gas is A
An inert gas such as r, He, and N ₂ is preferable. Further, the moisture content of the sealing gas is preferably 100 ppm or less, more preferably 10 ppm or less, and particularly preferably 1 ppm or less. Although there is no particular lower limit for the water content, it is usually about 0.1 ppm.

The material of the sealing plate is preferably a flat plate, and may be a transparent or translucent material such as glass, quartz, resin, etc., and glass is particularly preferred. As such a glass material, an alkali glass is preferable from the viewpoint of cost, and in addition, a glass composition such as soda lime glass, lead alkali glass, borosilicate glass, aluminosilicate glass, and silica glass is also preferable. In particular, soda glass, a glass material without surface treatment can be used at low cost,
preferable. As the sealing plate, other than a glass plate, a metal plate, a plastic plate, or the like can be used.

The height of the sealing plate may be adjusted by using a spacer, and may be maintained at a desired height. Examples of the material of the spacer include resin beads, silica beads, glass beads, and glass fibers, and glass beads are particularly preferable.

When a recess is formed in the sealing plate,
Spacers may or may not be used. The preferred size when used is within the above range,
Particularly, the range of 2 to 8 μm is preferable.

The adhesive is not particularly limited as long as it can maintain stable adhesive strength and has good airtightness, but it is preferable to use a cationic curing type ultraviolet curing epoxy resin adhesive. .

In the present invention, the substrate on which the organic EL structure is formed is an amorphous substrate such as glass or quartz, or a crystalline substrate such as Si, GaAs, ZnSe, or Z.
Examples thereof include nS, GaP, and InP, and a substrate in which a crystalline, amorphous, or metal buffer layer is formed on these crystalline substrates can also be used. As the metal substrate, Mo, Al, Pt, Ir, Au, Pd, or the like can be used, and a glass substrate is preferably used. When the substrate is on the light extraction side, it is preferable that the substrate has the same light transmittance as the above-mentioned electrodes.

Further, a large number of the elements of the present invention may be arranged on a plane. By changing the emission color of each element arranged on a plane, a color display can be obtained.

The emission color may be controlled by using a color filter film, a color conversion film containing a fluorescent substance, or a dielectric reflection film on the substrate.

As the color filter film, a color filter used in a liquid crystal display or the like may be used.
The characteristics of the color filter may be adjusted in accordance with the light emitted from the organic EL element to optimize the extraction efficiency and the color purity.

When a color filter capable of cutting off short-wavelength external light that is absorbed by the EL element material or the fluorescence conversion layer is used, the light resistance of the element and the display contrast are improved.

An optical thin film such as a dielectric multilayer film may be used in place of the color filter.

The fluorescence conversion filter film absorbs EL light and emits light from the phosphor in the fluorescence conversion film to convert the color of emitted light. The composition includes a binder, It is formed from a fluorescent material and a light absorbing material.

As the fluorescent material, basically, a material having a high fluorescence quantum yield may be used, and it is desirable that the fluorescent material has strong absorption in the EL emission wavelength region. In practice, laser dyes and the like are suitable, and rhodamine compounds, perylene compounds, cyanine compounds, phthalocyanine compounds (including subphthalocyanines, etc.) naphthalimide compounds, condensed ring hydrocarbon compounds, condensed heterocyclic compounds A styryl compound, a coumarin compound or the like may be used.

As the binder, basically, a material that does not quench the fluorescence may be selected, and a binder that can be finely patterned by photolithography, printing, or the like is preferable. In the case where the hole injection electrode is formed on the substrate in contact with the hole injection electrode, a material which is not damaged when the hole injection electrode (ITO, IZO) is formed is preferable.

The light absorbing material is used when the light absorption of the fluorescent material is insufficient, but may be omitted when unnecessary. As the light absorbing material, a material that does not quench the fluorescence of the fluorescent material may be selected.

The organic EL display device of the present invention is usually used as a DC drive type or pulse drive type EL element.
AC drive can also be used. The applied voltage is usually
It is about 30V.

The organic EL display device of the present invention includes, for example, a substrate / first electrode (hole injection electrode) / organic layer (light emitting layer).
/ The second electrode (negative electrode) may be sequentially laminated, or the reverse lamination structure may be adopted. The lamination structure may be appropriately determined according to, for example, the specifications of the display and the manufacturing process.

The organic EL display device of the present invention can be used not only as a display but also for various optical devices such as an optical pickup used for memory reading / writing, a relay device in a transmission line of optical communication, and a photocoupler. It can be used for application devices.

[0093]

Embodiment 1 Next, an embodiment of the organic EL display device of the present invention will be described with reference to FIGS.

On a 7059 glass substrate 1 manufactured by Corning Incorporated, an ITO transparent electrode 2 was patterned as a hole injection electrode by photolithography into a stripe shape having a width of 2 mm and an electrode interval of 1 mm. Also, an aluminum electrode 3 was formed as an extraction electrode at the end in the 90 ° direction (FIG. 1). IT
An edge cover 4 was formed using polyimide in order to prevent leakage due to unevenness of the edge portion of ITO between the O electrodes, and a test substrate was formed (FIG. 2).

Next, a fluorine resin 5 (2,2-Bis (trifluoromethyl)-
4,5-difluoro-1,3-dioxole / tetrafluoroethylene copol
ymer) was formed to a thickness of 200 nm by a vacuum evaporation method to secure a lift-off region (FIG. 3). The substrate was subjected to ultrasonic cleaning neutral detergent, acetone, in the order of ethanol, ethanol vapor washing, was used to perform experiments UV / 0 ₃ wash.

Polyethlene dioxytiophene polystyrene
sulphonate (PEDOT / PSS) is applied from a mixed solution of water and isopropanol to a thickness of 50 nm by a spin coating method,
After drying by heating under vacuum, polyvinyl carbazole (PV
100 mm of K) was applied from a toluene solution to form an organic layer 6. In this PVK solution, 2- (4-Bip
henylyl) -5- (4-tert-butylphenyl) -1-3,4-oxadiazole
(Butyl-PBD) 3% by mass, teraphe as doping material
It contains 3 mol% of nylbutadiene (TPB) (FIG. 4).

Next, the above-mentioned substrate was immersed in a fluorine-based solvent (Fluorinert manufactured by Sumitomo 3M), and ultrasonic waves were applied for 1 minute to peel off the fluororesin together with the upper organic layer, and to take out the electrode extraction area and the sealing area. An adhesion area was secured (FIG. 5).

Next, using a metal mask, the I
A negative electrode 7 was formed by vacuum deposition of 0.5 nm thick lithium fluoride and a 200 nm thick aluminum electrode in a 90 ° direction with a pattern of TO having a width of 2 mm and an interval of 1 mm. The end of this aluminum electrode functions as a cathode by coming into contact with an extraction electrode provided on the substrate in advance (FIG. 6).

Next, this substrate was transferred into a glove box filled with dry N _2, and sealed with a Corning 7059 glass 8 coated with an ultraviolet-curable epoxy adhesive to perform sealing. (Fig. 7).

By applying an electric field with the ITO electrode of the produced display device as the anode and the aluminum electrode as the cathode, the selected element was able to emit light without any problem.

<Embodiment 2> Next, a second embodiment of the present invention will be described with reference to FIG.

After the substrate was formed in the same manner as in Example 1 up to the edge cover, a negatively tapered negative electrode separating partition 9 was formed on the edge cover using a resist (FIG. 8). Next, in the same manner as in Example 1, formation of a fluororesin layer, PEDO
After the formation of the T layer and the formation of the PVK layer, the fluorine material and fat were similarly peeled off to secure an electrode take-out region and a sealing adhesion region.

Next, a metal mask is applied to a region where there is no partition, and a lithium fluoride layer having a thickness of 0.5 is formed by a vacuum evaporation method.
nm, and an aluminum electrode layer was formed to a thickness of 200 nm. The aluminum electrode separated by the negative electrode separation wall functions as a cathode when it comes into contact with an extraction electrode provided on the substrate in advance. Finally, sealing was performed in the same manner as in the example, to obtain a simple matrix display device.

When the obtained display device was driven in the same manner as in Example 1, it was possible to emit light without any problem.

<Embodiment 3> Next, a third embodiment of the present invention will be described with reference to FIGS.

On a 7059 glass substrate 1 manufactured by Corning Incorporated, an ITO transparent electrode 2 as a hole injection electrode was patterned in a stripe shape by photolithography.
Further, an aluminum electrode (not shown) was formed as an extraction electrode at the end in the 90 ° direction (FIG. 9: a partial plan view, the same applies to FIG. 14 below). In order to prevent leakage due to unevenness of the edge portion of the ITO between the ITO electrodes, an edge cover 4 was formed by photolithography using polyimide to prepare a test substrate having a 2 mm square ITO portion (FIG. 10).

Next, a fluorine resin (2,2-Bis (trifluoromethyl)-
4,5-difluoro-1,3-dioxole / tetrafluoroethylene copol
ymer) 5 was formed to a thickness of 200 nm by a vacuum evaporation method to secure a lift-off region (FIG. 11). The substrate was subjected to ultrasonic cleaning neutral detergent, acetone, in the order of ethanol, ethanol vapor washing, was used to perform experiments UV / 0 ₃ wash.

Polyvinyl carbazole (PVK) was applied 100 mm from a toluene solution by a spin coating method to obtain a blue organic layer 6a. In this PVK solution, 2- (4-Biphenylyl) -5- (4-tert-butylphenyl) -1- was used as an electron transport material.
3% by mass of 3,4-oxadiazole (Butyl-PBD), 3% by mol of teraphenylbutadiene (TPB) as blue doping material
include.

Next, the above-mentioned substrate was immersed in a fluorinated solvent (Fluorinert manufactured by Sumitomo 3M Limited) and irradiated with ultrasonic waves for 1 minute to peel off the fluororesin together with the upper organic layer, and the organic layer of the blue light emitting portion was removed. Only (FIG. 12).

Next, by repeating the above-mentioned method, a PV mixed with coumarin 6 which is a light emitting dove for color recording was obtained.
A green organic layer 6b was formed using the K solution, a yellow organic layer 6c was similarly formed using DCM1, which is a yellow light-emitting dopant, and an orange organic layer 6d was formed using rubrene, which was an orange light-emitting dopant (FIG. 13).

Next, using a metal mask, the I
A negative electrode 7 was formed by vacuum deposition of 0.5 nm thick lithium fluoride and a 200 nm thick aluminum electrode in a 90 ° direction with a pattern of TO having a width of 2 mm and an interval of 1 mm. The end of this aluminum electrode functions as a cathode by being brought into contact with an extraction electrode previously provided on the substrate (FIG. 14).

Next, this substrate was transferred into a glove box filled with dry N ₂ and sealed by bonding with Corning 7059 glass coated with an ultraviolet-curing epoxy adhesive to form a multicolor organic EL display device. And

By applying a voltage with the ITO electrode of the produced display device as the anode and the aluminum electrode as the cathode, uniform surface light emission was obtained from the elements of each color formed on the same substrate.

<Comparative Example 1> The procedure of Example 1 was repeated, except that the steps of forming and removing the fluororesin layer were not performed. In this display device, contact cannot be made because the organic layer remains between the external extraction electrode and the aluminum negative electrode,
The device could not emit light. In addition, the adhesion between the organic layer and the sealing adhesive could not be obtained, and the sealing plate was easily peeled off.

<Comparative Example 2> Instead of the fluororesin layer, a polyimide tape was used to mask the electrode take-out area and the sealing adhesive area, and peeled off after forming the organic layer. Otherwise, the procedure was the same as in Example 1. In this display device, along with the organic layer, the edge cover portion formed on the substrate was also peeled off at the same time. Therefore, a leak occurred from the ITO end portion, and the display device did not function. Further, the adhesive strength of the sealing plate could not be secured because the adhesive material of the polyimide tape remained.

<Comparative Example 3> Comparative Example 1 was performed until the organic layer was formed.
After that, the organic layer in the electrode take-out area and the sealing adhesive area was peeled off using an adhesive tape, and a negative electrode was formed and sealed in the same manner as in Example 1. In this display device as well, the edge cover portion formed on the substrate together with the organic layer was peeled off at the same time, and the device did not function as a display device due to leakage.

<Comparative Example 4> After the steps up to the creation of the edge cover were performed in the same manner as in Example 1, application, exposure, and development were performed using a photoresist to form an electrode take-out area and a sealing adhesive area. A resist was formed.

After the formation of the organic layer, the organic layer was removed together with the resist layer using an N-methylpyrrolidone solution. However, the region where only the organic layer was formed also peeled off at the same time, and a display device could not be manufactured.

Comparative Example 5 The same material as in Example 3 was applied using an ink jet printer (modified M830C manufactured by Seiko Wepson) after the edge cover was formed in the same manner as in Example 3. Next, a negative electrode was formed and sealed in the same manner as in Example 3 to obtain a multicolor organic EL display device.

In this display device, since the application surface was an aggregate of dots, a non-application portion was apt to occur between the applied dots, and the leakage between the ITO and the negative electrode was severe and only low-frequency light emission was obtained. Further, uniform light emission could not be obtained due to unevenness in film thickness generated during dot formation.

<Comparative Example 6> An attempt was made to apply each element by the same process as in Example 3 except that a photoresist and N-methylpyrrolidone were used instead of the combination of the fluororesin and the fluorine-based solvent. .

However, when the photoresist was peeled off with N-methylpyrrolidone, the PVK layer was peeled off at the same time, and a display device was not produced.

The effects of the present invention are clear from the above embodiments.

[0124]

As described above, according to the present invention, the organic EL
Display device, in particular, organic E in which an organic layer is formed by coating
In the L display device, it is possible to separately color the organic eyebrows in the same substrate, secure a portion for taking out external electrodes, secure a bonding area, and further arrange a color in which organic EL elements having different emission colors are arranged in the same substrate. In the conversion process, a new process can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first manufacturing process of an organic EL display device of the present invention.

FIG. 2 is a plan view showing a first manufacturing process of the organic EL display device of the present invention.

FIG. 3 is a plan view showing a first manufacturing process of the organic EL display device of the present invention.

FIG. 4 is a plan view showing a first manufacturing step of the organic EL display device of the present invention.

FIG. 5 is a plan view showing a first manufacturing process of the organic EL display device of the present invention.

FIG. 6 is a plan view showing a first manufacturing step of the organic EL display device of the present invention.

FIG. 7 is a plan view showing a first manufacturing step of the organic EL display device of the present invention.

FIG. 8 is a plan view showing a second manufacturing process of the organic EL display device of the present invention.

FIG. 9 is a partial plan view showing a third manufacturing step of the organic EL display device of the present invention.

FIG. 10 is a partial plan view showing a third manufacturing step of the organic EL display device of the present invention.

FIG. 11 is a partial plan view showing a third manufacturing step of the organic EL display device of the present invention.

FIG. 12 is a partial plan view showing a third manufacturing step of the organic EL display device of the present invention.

FIG. 13 is a partial plan view showing a third manufacturing step of the organic EL display device of the present invention.

FIG. 14 is a partial plan view showing a third manufacturing step of the organic EL display device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 ITO transparent electrode 3 Aluminum extraction electrode 4 Edge cover 5 Fluororesin 6 Organic layer 7 Negative electrode 8 Sealing plate 9 Negative electrode separation wall

Claims (9)

[Claims] 1. A semiconductor device comprising: a substrate; a first electrode formed on the substrate; at least one kind of organic layer involved in at least a light emitting function; and a second electrode formed on the organic layer. And at least one of the organic layers is formed by a coating method,
And organic E patterned by a lift-off method
L display device. 2. The organic EL device according to claim 1, wherein the patterning material used in the lift-off method is a fluorine-based material.
Display device. 3. The organic EL display device according to claim 1, wherein the region from which the organic layer has been removed by patterning is at least an external electrode extraction portion or a sealing adhesive region. 4. The organic EL display device according to claim 1, wherein the region where the organic layer remains after being patterned is a light emitting region. 5. A semiconductor device comprising: a substrate; a first electrode formed on the substrate; at least one kind of organic layer involved in at least a light emitting function; and a second electrode formed on the organic layer. A method for manufacturing an organic EL display device, wherein at least one of the organic layers is formed by a coating method and patterned by a lift-off method. 6. The method according to claim 5, wherein the patterning material used in the lift-off method is a fluorine-based material, which is dissolved in a fluorine-based solvent. 7. The method for manufacturing an organic EL display device according to claim 5, wherein the region from which the organic layer is removed by patterning is at least an external electrode extraction portion or a sealing adhesive region. 8. The method for manufacturing an organic EL display device according to claim 5, wherein the region where the patterned organic layer remains is a light emitting region. 9. A method for manufacturing an organic EL display device in which organic EL elements having different emission colors are formed on the same substrate by repeating the steps according to claim 5.