JP2000100565A - Manufacture of el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an EL element having a simple structure, easy to manufacture and causing no short circuit and no defective luminescence on a transparent electrode section. SOLUTION: Transparent electrodes 14 are formed in a stripe shape at the prescribed pitch with a transparent electrode material such as ITO on the surface of a transparent substrate 12 made of glass or a resin, and a luminescent layer made of an EL material is laminated on the transparent electrodes 14 by the vacuum thin film forming technique such as deposition. After the transparent electrodes 14 are formed, multiple single-fiber-shaped linear materials 20 applied with the prescribed tension in advance are arranged along the transparent electrodes 14 to cover the transparent electrodes 14. Gaps 22 are formed between the linear materials 20 at the prescribed pitch at positions corresponding to the space portions between the transparent electrodes 14. Cover materials 16 covering the side edge sections in the longitudinal direction of the transparent electrodes 14 via the linear materials 20 are formed by the vacuum thin film forming technique.

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 an EL element used for light-emitting display such as a flat light source, a display, and other predetermined patterns.

[0002]

2. Description of the Related Art Conventionally, an organic EL (electroluminescence) element is formed by forming a translucent ITO film on one surface of a transparent substrate made of glass or the like and etching it into a predetermined stripe to form a transparent electrode. I was 500 transparent electrodes
It is preferably formed to a thickness of {3000} and thick to reduce the resistance value. Then, a light emitting layer is formed on the transparent electrode. The light emitting layer is usually made of an organic EL material.
It is preferably formed to a thickness of about 500 ° to 1500 ° over up to three layers, and thinner to reduce the applied voltage. Further, a back electrode material is provided on the surface of the light emitting layer by vapor deposition or the like to form a back electrode.

Here, an organic EL material constituting a light emitting layer includes a hole transport material such as a triphenylamine derivative (TPD) and an aluminum chelate complex (Alq) as a light emitting material.
₃ ) The electron transporting material as described above. The light emitting layer is composed of a layer in which an electron transporting material is laminated on a hole transporting material, or a mixed layer thereof. The back electrode material is Al, Li, A
It is made of a metal such as g, Mg, In, or an alloy thereof.

The light emitting section thus formed is driven by a so-called dot matrix method in which a predetermined current is applied to a predetermined intersection between the transparent electrode and the back electrode to cause the light emitting layer to emit light.

[0005]

In the case of the above-mentioned prior art, the transparent electrode of ITO is an aggregate of large particles, and the etched end face is a rough surface having large irregularities. Therefore, when a thin light-emitting layer or a back electrode is formed on such a rough surface, the film thickness at that portion becomes thin and varies, and a short circuit between the back electrode and the surface electrode is likely to occur.

Therefore, as shown in FIG. 4, an organic material 2 such as a photoresist is formed in a stripe shape along the transparent electrode 4 by photoetching so as to cover the irregularities on the side edges of the transparent electrode 4. Some have done it. However, in this case, a photosensitive material must be used for the organic material 2, and the residue of the etching process may adversely affect the light emitting layer, which also causes a reduction in product yield. . Moreover, in practice, the organic material 2 has a thickness of about several μm, which is ten times or more the thickness of the transparent electrode, and there is a risk of short-circuit or disconnection at the step.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has a simple structure, is easy to manufacture, and has an EL element in which a short circuit or a light emission failure does not occur in a transparent electrode portion. It is intended to provide a manufacturing method.

[0008]

According to a method of manufacturing an EL device of the present invention, a transparent electrode is formed on a transparent substrate surface such as glass or resin by a transparent electrode material such as ITO so as to form a stripe at a predetermined pitch. A light emitting layer made of an EL material is laminated on the transparent electrode by a vacuum thin film forming technique such as vapor deposition, and is formed on the surface of the light emitting layer at a predetermined pitch in a stripe shape facing the transparent electrode in a direction orthogonal to the transparent electrode. A back electrode of Al-Li or the like is formed. Here, after the transparent electrode is formed, a plurality of single fiber-shaped linear materials in a state where a predetermined tension is applied in advance are arranged along the transparent electrode so as to cover the transparent electrode, and the linear material is formed. Are arranged such that a gap is formed between the linear materials at a predetermined pitch, and a space portion between the transparent electrodes corresponds to the gap. Then, a coating material for coating the longitudinal side edges of the transparent electrode through the linear material is provided by a vacuum thin film forming technique,
Thereafter, the EL material and the back electrode are formed.

Further, the linear material is a resin, and a plurality of the resin linear materials are provided in close contact with the transparent electrode, and a predetermined gap is formed for each of the plurality of linear materials. I have. The coating material is provided with an insulating material by a vacuum thin film forming technique.

Further, another linear material is opposed to the space between the transparent electrodes so as not to cover the longitudinal side edges of the transparent electrode. It may be coated with a conductive coating material. At this time, the conductive coating material does not adhere to the portion corresponding to the other linear material, and the adjacent coating materials are insulated from each other.

Further, when the coating material is applied by the vacuum thin film forming technique, a coating material is applied to the plurality of closely-connected linear materials in advance to fill the gaps between the closely-connected linear materials. Is the way. Further, the coating material is provided by using a black or dark material by a vacuum thin film forming technique. The linear material is a single fiber of an imide-based resin, and is fixed to the frame with an adhesive.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the organic EL element 10 of this embodiment, a transparent electrode 14 made of a transparent electrode material such as ITO is formed on one surface of a transparent substrate 12 made of glass, quartz, resin or the like. The transparent electrodes 14 are formed on the substrate 12 in a stripe pattern at a predetermined pitch. A coating material 16 is provided on a side edge in the longitudinal direction of the transparent electrode 14 so as to cover an edge of the side edge formed by etching. The coating material 16 has the structure shown in FIG.
It is an insulating material, such as a resin material such as SiO ₂ , SiO, or polyimide thereof.

Further, the surface of the transparent electrode 14
A light emitting layer made of an EL material of a hole transporting material, an electron transporting material of about 500 °, and other light emitting materials is laminated. Then, on the surface of the light emitting layer, Li
Al-Li alloy of about 99% purity containing about 0.05%,
In addition, a back electrode made of a cathode material such as Al-Mg is laminated with an appropriate thickness of about 500 to 1000 mm. The back electrode is orthogonally opposed to the transparent electrode and is formed in a stripe shape. The area from the transparent electrode 14 laminated on the substrate 12 to the back electrode forms a light emitting section.

Here, the light-emitting layer is formed of a triphenylamine derivative (TP
D), hydrazone derivatives, arylamine derivatives and the like. On the other hand, as electron transporting materials, aluminum chelate complex (Alq ₃ ), distyrylbiphenyl derivative (DPVB
i), oxadiazole derivatives, bistyrylanthracene derivatives, benzoxazolethiophene derivatives, perylenes, thiazoles and the like are used. Further, an appropriate light emitting material may be mixed, or a light emitting layer in which a hole transport material and an electron transport material are mixed may be formed. In this case, the ratio of the hole transport material to the electron transport material is 10:90 to 90. : 1
It can be changed appropriately within the range of 0.

In the manufacturing method according to one embodiment of the EL element of the present invention, a transparent electrode material such as ITO is provided on the entire surface of a transparent substrate 12 made of glass, quartz, resin, or the like by vapor deposition or the like.
A resist is applied to this surface, and a stripe pattern having a predetermined pitch is overlaid. Next, the resist is exposed and developed to leave a resist in a shape corresponding to the stripe pattern. Then, the transparent electrode material is etched to form a desired striped transparent electrode 14.

Before forming the light emitting layer on the surface of the transparent electrode 14, a plurality of linear materials 20 in the form of a resin single fiber to which a predetermined tension is applied in advance are applied along the transparent electrode. 5 each so as to cover. In the linear material 20, gaps 22 are formed between the set of five linear materials 20 at a predetermined pitch, and the space portions between the transparent electrodes 14 are arranged so as to correspond to the gaps 22. Then, a coating material 16 for covering the longitudinal side edge of the transparent electrode 14 via the linear material 20 is provided by a vacuum thin film forming technique such as vacuum deposition.

The linear material 20 is fixed to a frame (not shown). The frame is a rectangular ring-shaped frame made of an alloy such as stainless steel, a metal, a resin, or the like, which is hardly deformed.
0 is provided. The linear material 20 is one in which five resin-based single fibers such as polyimide-based aramid fibers are arranged at equal intervals in the opening of the frame. The single fibers have a diameter of, for example, about 70 μm, are arranged at equal intervals in the opening of the frame at a pitch of about 0.5 mm, and are stretched about 3% in the longitudinal direction to give a predetermined tension. In the fixing portion to the frame, the single fibers are arranged and fixed in parallel at equal intervals in advance with a predetermined jig via an adhesive.

When the coating material 16 is deposited, the linear material 2
0 is superimposed on the transparent electrode 14, and as shown in FIG. 1, the longitudinal direction of the linear material 20 is
Overlaid. At this time, a set of five linear materials 20 faces the surface of the transparent electrode 14, and a gap 22 of each set of five linear materials 20 is located in a space between the transparent electrodes 14.

The mask provided with the linear material 20 is located on the side of the vapor deposition source with respect to the substrate 12, and the linear material 20 of the mask is provided.
Is pressed against the transparent electrode 14. Prior to the vapor deposition, the coating material 16 is applied to the linear material 20 in advance.
Is deposited, the gaps between the five linear materials 20 are filled, and when the coating material 16 is deposited on the transparent electrode 14, the coating material 16 does not adhere to portions other than the side edges of the transparent electrode 14.

After the deposition, the linear material 20 is removed from the transparent electrode 14. As a result, the coating material 16 deposited on the space between the transparent electrodes 14 from the gaps 22 between the linear materials 20 covers the etched side surfaces of the transparent electrodes 14 and smoothes them. In this case, the coating material 16 is an insulator.

[0021] Then the surface of the transparent electrode 14 and the covering material 16, for example, a hole transport layer made of a hole transporting material TPD such as EL material, an electron transporting layer or other light-emitting material formed of an electron transporting material such as Alq ₃ The layers are stacked by vacuum deposition, sputtering, or other vacuum thin film forming techniques to form a light emitting layer.

The deposition conditions include, for example, a degree of vacuum of 6 × 1
At 0-6 Torr, a film is formed at a deposition rate of 50 ° / sec in the case of an EL material. The light emitting layer 14 and the like may be formed by flash evaporation. In the flash evaporation method, an EL material previously mixed at a predetermined ratio is heated to 300 ° C. to 600 ° C.
Preferably, the EL material is dropped onto a deposition source heated to 400 ° C. to 500 ° C. to evaporate the EL material at a stretch. Alternatively, the EL material may be housed in a container, and the container may be rapidly heated and vapor-deposited at once.

Next, an Al-Li alloy containing about 0.01 to 0.05% of Li and having a purity of about 99%, other Al-Mg
A back electrode material made of a cathode material is provided on the surface of the light emitting layer and the mask by a vacuum thin film forming technique such as vacuum deposition. Also at this time, the back electrode can be formed in a direction perpendicular to the transparent electrode 14 using a mask using a resin-based linear material.

The mask made of the resin-based linear material 20 can be used repeatedly about 20 times. When replacing the mask, the single fiber and the adhesive of the mask are removed, and a new one is formed on the frame 18 in the same manner as described above. The mask 22 is provided by bonding single fibers.

On the entire surface of the light emitting layer and the back electrode, an insulating protective film such as SiO (not shown) may be formed by vacuum evaporation, sputtering, or other vacuum thin film forming techniques. Further, a water repellent film, a resin protective film, or the like may be provided.

According to the manufacturing method of the EL element of this embodiment, the etching cross section of the side edge of the transparent electrode 14 is covered with the coating material 16 using the resin-based single fiber mask. Short-circuiting and poor light emission can be reliably prevented. Further, since there is no chemical process such as etching, there is no adverse effect on the light emitting layer, and the manufacturing process is simple.

As shown in FIG. 2, a linear material 24 similarly serving as a mask is
May be arranged so that the coating material 16 is deposited between the linear material 20 and the linear material 24. This covers the longitudinal side edges of the transparent electrodes 14 and the coating material 16 between the transparent electrodes 14 is not continuous, so that a conductive material can be used as the coating material 16. The coating material of the conductive material used here is Al or carbon. In the case of Al, light emission unevenness due to electric resistance of the transparent electrode can be suppressed, and since the reflectance is high, light emission in a planar direction can be reflected and reflected to the transparent substrate side. Further, by using carbon as a coating material, bleeding of light between the light emitting elements by the transparent electrode is prevented, and the contrast is improved.

The method of manufacturing an EL element according to the present invention is not limited to the above embodiment, and the number, interval, and size of the linear material of the mask can be appropriately set in accordance with a transparent electrode or the like. It is possible to use metals and other fibers in addition to resin. Further, the shape of the frame may be any shape as long as it has an internal space larger than that of the substrate and does not cause distortion by the mask, or may be fixed to the frame using a material other than the adhesive. The back electrode is A
A metal such as 1, Li, Ag, Mg, In, or an alloy thereof may be used.

Further, as the coating material, in addition to the above, a black or dark insulating material may be used, and a metal other than Al may be used as the conductive material.

[0030]

According to the method for manufacturing an EL device of the present invention, the side edges of the transparent electrodes are covered with the coating material using the mask of the linear material, and the short circuit between the electrodes can be reliably prevented. Things. In addition, its manufacture is easy, there is no treatment such as etching or a subsequent cleaning step, the adverse effect on the light emitting layer is extremely small, and the manufacturing cost is low.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one manufacturing step of an EL element according to an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is an enlarged sectional view of an edge portion of a transparent electrode according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing one manufacturing process of a conventional EL element.

[Explanation of symbols]

 12 Substrate 14 Transparent electrode 16 Coating material 20, 24 Linear material 22 Gap

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shigeru Fukumoto 3158, Shimo-Okubo, Osawano-cho, Kamishinkawa-gun, Toyama Prefecture Inside (72) Inventor Hajime Yamamoto 3158, Shimo-Okubo, Osawano-cho, Kamishinkawa-gun, Toyama Hokuriku Electric Industry F term in the company (reference) 3K007 AB01 AB05 AB08 AB18 CA01 CA02 CA05 CB00 CB01 DA00 DB03 EB00 FA01

Claims (6)

[Claims] 1. A transparent electrode is formed on a transparent substrate surface with a transparent electrode material so as to form a stripe at a predetermined pitch, and a light emitting layer made of an EL material is laminated on the transparent electrode by a vacuum thin film forming technique. In a method for manufacturing an EL element, on a surface of the light emitting layer, a back electrode is formed at a predetermined pitch in a stripe shape in a direction orthogonal to the transparent electrode in a direction orthogonal to the transparent electrode, a predetermined tension is applied in advance after forming the transparent electrode. A plurality of linear materials in a single fiber shape in the state of being arranged are arranged along the transparent electrode so as to cover the transparent electrode, and the linear material is
A gap is formed between the linear materials at a predetermined pitch, a space between the transparent electrodes is arranged so as to correspond to the gap, and a longitudinal side edge of the transparent electrode is interposed through the linear material. A method for manufacturing an EL element, comprising: providing a coating material to be coated by a vacuum thin film forming technique, and thereafter forming the EL material and the back electrode. 2. The method according to claim 1, wherein the linear material is a resin, and a plurality of the resin linear materials are provided in close contact with the transparent electrode. 3. The method for manufacturing an EL element according to claim 1, wherein said coating material is provided by using an insulating material by a vacuum thin film forming technique. 4. A linear material is opposed to a space between the transparent electrodes so as not to cover a longitudinal side edge of the transparent electrode, and the longitudinal side edge of the transparent electrode is electrically conductive. 3. The method for manufacturing an EL element according to claim 1, wherein the EL element is coated with a coating material. 5. The method according to claim 2, wherein when the coating material is applied by the vacuum thin film forming technique, the coating material is applied to the plurality of closely-connected linear materials in advance to fill gaps between the closely-connected linear materials. Method for manufacturing an EL element. 6. The method for manufacturing an EL element according to claim 1, wherein said coating material is a black or dark color material provided by a vacuum thin film forming technique.