JPH10162954A - Manufacturing method of organic EL element - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing an organic EL device with a simple structure, with no short circuit between a transparent electrode and a back electrode and with a good yield. A transparent substrate made of glass, quartz, resin, or the like is provided.
A transparent electrode 12 having a predetermined shape is formed on the surface of the substrate by etching or mask evaporation using a transparent electrode material such as ITO. When the light emitting layer 15 made of an organic EL material made of a hole transporting material 14, an electron transporting material 16 and other light emitting materials is laminated on the surface of the transparent electrode 12, the direction of vapor deposition of the light emitting layer 15 on the substrate 10 on which the transparent electrode 12 is formed. Is deposited in such a manner that the incidence on the transparent electrode 12 is set to be opposite to each other for each layer, and thereafter, the back electrode 18 is deposited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flat light source, a display, and an organic EL device used for light emission display of a predetermined pattern.

[0002]

2. Description of the Related Art Conventionally, for example, an organic EL (electroluminescence) element for emitting dot matrix light is shown in FIG.
As shown in FIG. 1, a light-transmitting ITO film is formed on one surface of a glass substrate 10, this ITO film is etched in a stripe shape to form a transparent electrode 12, and a triphenylamine derivative (TPD) or the like is formed on the surface. A hole transport material 14 is provided,
On top of that, an aluminum chelate complex (Al
q ₃ ) and the like. On the surface thereof, a back electrode 18 of Al, Li, Ag, Mg, In or the like is formed by being attached in a stripe shape in a direction orthogonal to the pattern of the transparent electrode 12 by vapor deposition or the like. In this organic organic EL element, a predetermined current is applied to the intersection of the transparent electrode 12 and the back electrode 18 to emit light. And
This organic EL device is manufactured by etching a glass substrate 10 on which a transparent electrode 12 is formed in a stripe shape by etching.
The electrode material and the EL material are sequentially formed by vacuum evaporation.

[0003]

Here, the organic EL element is an element through which a current flows, and it is necessary to reduce the loss due to the conductor path. It must be prevented as much as possible from being different. Therefore, in order to suppress the resistance value of the conductor path as much as possible, the thickness of the ITO film was about 1 μm. On the other hand, if the material of the light emitting layer is thick because of semiconductor characteristics, no current flows, and both TPD and Alq ₃ are 500Å
It is formed in a thin layer.

[0004] Therefore, since the difference between the thickness of the transparent electrode 12 and the thickness of the light emitting layer is extremely large, a thin portion or a non-existent portion of the EL material is generated at the corners and side portions of the transparent electrode 12. The deposition source of the back electrode 18 is located at a position different from the deposition source of the EL material, and the deposition thickness of the back electrode is 100
Since it is relatively thick at 0 [deg.] Or more, it adheres to a part of the transparent electrode 12 where the vapor deposition material is thin or not provided, and the back electrode 1
In the case of No. 8, a short circuit may occur between the EL and the transparent electrode 12.

The present invention has been made in view of the above-mentioned conventional technology, and provides a method of manufacturing an organic EL device having a simple structure, which has no short circuit between a transparent electrode and a back electrode and has a good yield. With the goal.

[0006]

According to the present invention, a transparent electrode of a predetermined shape is formed on a transparent substrate surface such as glass, quartz or resin by etching or mask vapor deposition using a transparent electrode material such as ITO. When a light emitting layer made of an organic EL material made of a hole transporting material, an electron transporting material, or another light emitting material is laminated on the surface of the electrode, the direction of vapor deposition of the light emitting layer on the substrate on which the transparent electrode is formed is changed by the transparent This is a method for manufacturing an organic EL element in which vapor deposition is performed so that incident light on the electrodes is in opposite directions, and then a back electrode is vapor deposited. The direction of vapor deposition when each light emitting layer is vapor-deposited on the substrate is such that each material is incident on the substrate at a substantially symmetrical angle with respect to a perpendicular to the substrate.

In order for the EL material of the light emitting layer to be incident at substantially symmetrical angles with respect to a vertical line standing on the substrate,
An evaporation source is moved with respect to the substrate, a substrate is moved or swung with respect to the evaporation source, or a plurality of evaporation sources under the same conditions are provided to perform evaporation under the same conditions.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an embodiment of the organic EL device of the present invention. As shown in FIG.
A transparent electrode 12 made of a transparent electrode material such as ITO is formed on one side of a transparent substrate 10 such as a resin. The transparent electrode 12 is formed in a stripe shape, and has a surface
A hole transporting material 14 of about 00 °, an electron transporting material 16 of about 500 °, and a light emitting layer 15 made of an organic EL material made of a light emitting material are laminated. And the light emitting layer 1
On the surface of the electron transport material 16 of No. 5, for example, Li
A back electrode 18 of an Al-Li alloy having a purity of about 99% containing about 1 to 0.05% is formed in a stripe shape in a direction perpendicular to the transparent electrode 12 at an appropriate thickness of about 500 to 1000 °.

Further, a conductive pattern made of Al or the like having a purity of 99.999% or more may be appropriately formed on the surface of the back electrode 18. On the surface of the back electrode 18,
Further, a protective layer 20 is laminated. The protective layer 20
It is formed of a metal thin film such as Ag or Al, a resin such as phenol or epoxy, or a conductive paint, and shields the back electrode 18 and the light emitting layer 15 from the outside air.

The light-emitting layer 15 is formed of a triphenylamine derivative (TP
D), hydrazone derivatives, arylamine derivatives and the like. The electron transporting material 16 includes an aluminum chelate complex (Alq ₃ ), a distyrylbiphenyl derivative (DP
VBi), an oxadiazole derivative, a bistyrylanthracene derivative, a benzoxazolethiophene derivative,
Perylenes, thiazoles and the like are used. Further, an appropriate light emitting material may be mixed, and a light emitting layer 15 in which the hole transport material 14 and the electron transport material 16 are mixed may be formed.
In that case, the ratio of the hole transporting material 14 to the electron transporting material 16 can be changed as appropriate within the range of 10:90 to 90:10.

In the method of manufacturing an organic EL device according to this embodiment, an electrode material for a transparent electrode 12 such as ITO is formed on the entire surface of a substrate 10 by a vacuum thin film forming technique. The transparent electrode material is formed to a thickness of about 1 μm so that the resistivity is about 10 Ω / □. Thereafter, an etching material is applied in a stripe shape, and the transparent electrode material is etched in a stripe shape to form a transparent electrode 12. Then, the hole transport material 1 is applied to the surface of the transparent electrode 12.
4 and an electron transporting material 16 including a light emitting material are sequentially laminated on one surface by a vacuum thin film forming technique.

At the time of depositing the light emitting layer 15, the direction in which the hole transporting material 14 and the electron transporting material 16 are deposited on the substrate is set so that they are incident at substantially symmetric angles with respect to a perpendicular line on the substrate 10. I do. For this purpose, as shown in FIG. 2, when the hole transport material 14 is deposited, about half of the deposition is performed by installing the deposition source 24 on one side of the substrate 10, and the other half of the deposition is performed by the deposition This is done by moving the source 24 to the opposite side. The vapor deposition range is regulated by the shutter 26, and the shutter 26 is closed during movement and during temperature rise. The vapor deposition of the electron transporting material 16 including the light emitting material is performed in the same manner. In addition, this movement is performed by heating the shutter 2
6 may be opened and moved.

After the deposition of the light emitting layer 15, the Li content is set to 0.01 to
A back electrode material made of an Al-Li alloy having a purity of about 99% containing about 0.05% is formed in a stripe shape by a vacuum thin film forming technique to an appropriate thickness of about 500 to 1000 °. A conductive pattern of Al or the like is formed on the surface of the back electrode 18 in a direction perpendicular to the conductive layer 24 by, for example, mask evaporation. Alternatively, a stripe pattern may be formed by etching after vapor deposition of Al on the entire surface. Then, the protective layer 20 is appropriately laminated. The protective layer 20 is made of Ag,
It is made of a metal thin film such as Al, a resin such as phenol or epoxy, or a conductive paint, and shields the back electrode 18 and the light emitting layer 15 from the outside air.

Here, the deposition conditions are, for example, that the degree of vacuum is 6 ×
At 10 ⁻⁶ Torr, a film is formed at a deposition rate of 50 ° / sec in the case of an EL material. Further, the light emitting layer 15 and the like may be formed by flash evaporation. In the flash evaporation method, an organic EL material mixed in a predetermined ratio in advance is used for 300 to 600 times.
C. Preferably, the organic EL material is dropped at a deposition source heated to 400 to 500.degree. C. to evaporate the organic EL material at a stretch.
Alternatively, the organic EL material may be housed in a container, and the container may be rapidly heated and vapor-deposited at once.

As a method of causing the EL material of the light-emitting layer 15 to enter at an angle substantially symmetrical with respect to a perpendicular set on the substrate 10, a method of moving the evaporation source 24 relative to the substrate 10 or a method of depositing the substrate 10 The material may be deposited on the sides and corners of the transparent electrode 12 by translating or swinging with respect to the source 24. This parallel movement or swing may be performed only once for the anisotropic light, or may be reciprocated. Further, a plurality of evaporation sources 24 under the same conditions may be provided, and the evaporation may be performed under the same conditions. In that case, it is preferable to connect heating devices of the evaporation source 24 in series so that heating is performed under the same conditions.

The organic EL device according to the present invention may be any device as long as the organic EL material to be deposited on the transparent electrode is located on the opposite side substantially symmetrically to each other and is deposited on the substrate. And arrangement means does not matter. In addition, the vapor deposition method may be a method using a thin film forming method in which atomic or molecular particles are skipped and adhered in a vacuum or by sputtering in addition to ordinary vacuum vapor deposition.

[0017]

The method for manufacturing an organic EL device according to the present invention comprises:
The EL material is surely deposited on the side surface of the transparent electrode, and no short circuit occurs between the back electrode and the transparent electrode, so that the production yield is improved and the quality is good. Further, since the light emitting layer is also formed on the side surface of the transparent electrode, the light emitting efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an organic EL device according to an embodiment of the present invention.

FIG. 2 is a schematic view of a manufacturing process of the organic EL device according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional organic EL device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 12 Transparent electrode 14 Hole transport material 15 Light emitting layer 16 Electron transport material 18 Back electrode

Claims (5)

[Claims] 1. A transparent electrode having a predetermined shape is formed on a transparent substrate surface with a transparent electrode material, and a light emitting layer made of a hole transporting material, an electron transporting material, or another organic EL material made of a light emitting material is laminated on the surface of the transparent electrode. At this time, the direction of vapor deposition of the light emitting layer with respect to the substrate on which the transparent electrode is formed is such that the incidence on the transparent electrode is opposite to each other for each layer. Manufacturing method of EL element. 2. The organic EL device according to claim 1, wherein the respective light emitting layers are deposited at a substantially symmetric angle with respect to a vertical line formed on the substrate in a deposition direction when the respective light emitting layers are deposited on the substrate. element. 3. An organic material according to claim 1, wherein an evaporation source is moved with respect to the substrate so that the EL material of the light emitting layer is incident on the perpendicular to the substrate at substantially symmetrical angles. Manufacturing method of EL element. 4. The method according to claim 1, wherein the substrate is translated or swung with respect to the vapor deposition source so that the EL material of the light emitting layer is incident on the perpendicular to the substrate at substantially symmetrical angles with respect to each other. Or the method for producing an organic EL device according to 2. 5. A method according to claim 1, wherein a plurality of vapor deposition sources under the same condition are provided, and vapor deposition is performed under the same condition, in order to cause the EL material of the light emitting layer to be incident at a substantially symmetrical angle with respect to a perpendicular to the substrate. Or the method for producing an organic EL device according to 2.