JP2000113989A - El element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an EL element easy to manufacture with a simple structure at a low cost and having no short circuit and no defective luminescence on transparent electrode sections and to provide its manufacturing method. SOLUTION: Transparent electrodes 14 are formed with a transparent electrode material such as ITO in the prescribed shape on the surface of a transparent substrate 12 of glass, a resin or the like, a luminescence layer made of an EL material is laminated on the transparent electrodes 14 by a vacuum thin film forming technique such as deposition, and back electrodes of Al-Li or the like having the prescribed shape and facing the transparent electrodes 14 are formed on the surface of the luminescence layer. Insulating layers 15 of the prescribed pattern are provided between the transparent electrodes 14, and the pattern of the transparent electrodes 14 nearly equal in thickness to the insulating layers 15 is provided in contact with the insulating layers 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an EL element used for light-emitting display of a flat light source, a display, and other predetermined patterns, and a method of manufacturing the same.

[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 formed to a thickness of about 500 ° to 1500 ° over up to three layers, and it is preferable that this light emitting layer is thin in order 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) etc. 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 above-mentioned prior art, the ITO stripe-shaped transparent electrodes are formed into stripes of a predetermined pitch by etching. This ITO is an aggregate of large particles, and the etched end face is formed. Is a rough surface with large irregularities. Therefore, when a thin light emitting layer or back electrode of 500 to 1500 degrees is formed on such a rough surface, the film thickness at that portion becomes further thinner, the thickness varies, and a short circuit between the back electrode and the surface electrode occurs. It was easy. In addition, the etching step requires a step such as cleaning or an operation in a clean room, and waste liquid treatment after the cleaning is also a problem.

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, is inexpensive, and does not cause a short circuit or light emission failure at the transparent electrode portion. An object of the present invention is to provide an EL element and a method for manufacturing the same.

[0007]

According to 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 have a predetermined shape, and an EL material is formed on the transparent electrode. Is an organic EL device in which a light-emitting layer made of is laminated by a vacuum thin film forming technique such as vapor deposition, and a back electrode of a predetermined shape, such as Al-Li, is formed on the surface of the light-emitting layer so as to face the transparent electrode. An insulating layer having a predetermined pattern is provided between the transparent electrodes, and a pattern of the transparent electrode having substantially the same thickness as the insulating layer is provided in contact with the insulating layer.
L element.

[0008] The insulating layer is transparent. further,
The transparent electrode is formed in a stripe shape with a predetermined pitch, the insulating layer is provided between the transparent electrodes, and the transparent electrode and the insulating layer are in contact with each other on a smooth surface.

The present invention also provides a method in which a predetermined transparent electrode is formed on a surface of a transparent substrate using a transparent electrode material, and a light emitting layer made of an EL material is laminated on the transparent electrode by a vacuum thin film forming technique. A method for manufacturing an EL element in which a back electrode is formed opposite to the transparent electrode, wherein a vacuum is formed using a first mask having an opening other than the transparent electrode forming part before forming the transparent electrode. Forming an insulating layer of a predetermined pattern by a thin film forming technique, and forming the transparent electrode by using a second mask having an opening in a predetermined pattern except for the insulating layer by a vacuum thin film forming technique to form a transparent electrode of a predetermined pattern. Is formed, and an organic EL light emitting material is laminated by the vacuum thin film forming technique using a third mask opened in a predetermined range of a portion where the transparent electrode is formed.
This is a method for manufacturing an EL element in which a back electrode is formed by the vacuum thin film forming technique through a fourth mask having a predetermined opening facing the transparent electrode.

Further, in each of the above steps, the material of each of the above steps is formed on the substrate while maintaining a vacuum state.

The predetermined patterns of the second mask and the fourth mask are formed in stripes at a predetermined pitch, and are sequentially arranged so as to be orthogonal to each other when forming the vacuum thin film. Further, the fourth mask is the same mask as the second mask, and the longitudinal direction of the stripe-shaped opening of the fourth mask is turned by 90 ° so as to be orthogonal to the pattern formed by the second mask. It is used by moving. The formation of the above-mentioned transparent electrode, organic EL light-emitting material, and back electrode is performed while maintaining a vacuum state using each of the above-mentioned masks.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the organic EL element 10 of this embodiment, as shown in FIG. 3, 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. On the surface of the transparent electrode 14, a light emitting layer 16 made of a hole transporting material of about 500.degree., An electron transporting material of about 500.degree.
Are laminated. The surface of the light emitting layer 16 has Li
Of about 99% purity containing about 0.01 to 0.05%
-A back electrode 18 made of a cathode material such as a Li alloy or other Al-Mg is laminated with an appropriate thickness of about 500 to 1000 mm.

As shown in FIG. 1B, an insulating layer 15 such as SiO ₂ is formed between the transparent electrodes 14. The insulating layer 15 is formed to a thickness substantially equal to the thickness of the transparent electrode 14,
It is formed in a smooth mountain shape. The insulating layer 15 is transparent.

The back electrode 18 is orthogonally opposed to the transparent electrode 14 and is formed in a stripe shape. These substrates 1
The light-emitting portion is formed from the transparent electrode 14 stacked on the substrate 2 to the back electrode 18.

Here, the light emitting layer 16 is formed of a triphenylamine derivative (TP
D), hydrazone derivatives, arylamine derivatives and the like. On the other hand, as electron transport materials, aluminum chelate complexes (Alq3), distyrylbiphenyl derivatives (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.

Next, on the surface of the transparent electrode 14, for example, organic E
A hole transporting layer made of a hole transporting material such as TPD as an L material, an electron transporting layer made of an electron transporting material such as Alq3, and a layer made of other light emitting materials are laminated by vacuum deposition, sputtering, or other vacuum thin film forming techniques to emit light. Tier 1
6 is formed.

In the manufacturing method according to one embodiment of the EL element of the present invention, an insulator such as SiO ₂ is first vacuum-deposited through a first mask 17 as shown in FIG. In the first mask 17, a slit-shaped opening 19 is formed at a position to be an insulating portion between the transparent electrodes 14, and an insulating layer 15 having a predetermined pitch is formed on the substrate 12.

Next, a transparent electrode material such as ITO is provided on the surface of the substrate 12 by vapor deposition or the like. At this time, FIG.
As shown in FIGS. 3A and 3B, a transparent electrode material is vacuum-deposited on the substrate 12 using a second mask 22 in which stripe-shaped openings 20 having a predetermined pitch are formed. At this time, the opening 20 of the second mask 22 is positioned between the insulating layers 15 and vapor deposition is performed.

The first mask 17 is formed on a rectangular plate by about 7 mm.
Slit-shaped openings 19 are formed at a predetermined pitch at a regular interval of 0 μm and about 0.5 mm. As shown in FIG. 2A, the second mask 22 is formed by, for example, attaching a linear material 26 in a striped shape to a rectangular annular frame 24 in a tension state. The linear material 26 is a resin-based single fiber such as a polyimide-based aramid fiber.
The linear material 26 has, for example, a diameter of about 70 μm and a diameter of about 0.7 μm.
They are arranged at equal intervals in the opening of the frame 24 at a pitch of about 5 mm, and are stretched by about 3% in the longitudinal direction and given a predetermined tension. The fixing part with the frame 24 is made of a linear material 26.
Are arranged and fixed in parallel at regular intervals with a predetermined jig via an adhesive in advance.

Next, when depositing the light emitting layer 16, FIG.
As shown in (B), vacuum deposition is performed using a third mask 30 having an opening 28 of the size of the light emitting layer 16.

The deposition conditions are, for example, a degree of vacuum of 6 × 1
At 0-5 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 the above cathode material is provided on the surface of the light emitting layer 16 by a vacuum thin film forming technique such as vacuum deposition. Also at this time, as shown in FIG. 2C, a fourth mask 32 using the same resin-based linear material 26 as in FIG. A back electrode 18 is formed. The back electrode 18 is laminated with a thickness of about 500 to 1000 degrees.

Here, the mask of the resin-based linear material 26 can be used repeatedly about 20 times, and when replacing the mask, the single fiber and the adhesive of the mask are removed.
A new single fiber is adhered to the frame 24 in the same manner as described above to form a mask.

On the entire surface of the light emitting layer and the back electrode, an insulating protective film such as SiO _{2 (} 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 EL device of this embodiment and the method of manufacturing the same, when the light emitting layer 16 is formed, a smooth surface is formed without any irregularities on the surface, and there is no short circuit between the electrodes. Further, since all steps are performed by mask evaporation, there is no etching step, and there is no adverse effect on the light emitting material due to moisture, chemical substances, and the like. In particular, there is no unevenness due to the etching at the side edge of the transparent electrode 14, and the short circuit between the electrodes is reliably prevented.

The insulating layer 15 is formed in a smooth mountain shape, and the transparent electrode 14 is deposited so as to overlap the side edges thereof. However, since the insulating layer 15 is transparent, light emission is not blocked. . Further, all the steps can be performed in one vacuum apparatus, there is no contamination, and the second mask 22 and the fourth mask 32 can be used together, so that more efficient vapor deposition can be performed. Further, it can be manufactured without a clean room, and a complicated pattern can be easily formed.

The EL device of the present invention is not limited to the above embodiment, and the patterns of the electrodes and the like can be appropriately set according to the pattern to be displayed. Further, the mask may be formed by punching or etching a metal plate to form an opening. Further, when a desired pattern is not formed by one-time evaporation, one pattern may be evaporated using a plurality of masks. For forming a thin film, vacuum deposition, sputtering, or the like can be used as appropriate, and a thin film forming method is not limited.

The back electrode is made of Al, Li, Ag, M
A metal such as g or In or an alloy thereof may be used.

[0029]

According to the EL device of the present invention and the method of manufacturing the same, since a series of steps are performed using a mask, there is no adverse effect on the light emitting layer due to etching or the like, and there is no unevenness of the electrode.
No short circuit or poor light emission. In addition, an insulating layer is formed between the transparent electrodes to prevent short circuits between the transparent electrodes, and also to smooth the side surfaces of the transparent electrodes by the smooth side surfaces,
A short circuit with the back electrode is reliably prevented.

According to the method of manufacturing an EL device of the present invention, the manufacturing equipment is simple and the manufacturing is easy.
The cost is also low. Furthermore, there is no waste water and the like, and the processing cost is low. In addition, by performing all the steps in a vacuum, a clean room is not required, and manufacturing equipment can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing each manufacturing process of an EL element according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing each manufacturing step of the EL element according to one embodiment of the present invention.

FIG. 3 is a perspective view showing an EL element according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 organic EL element 12 substrate 14 transparent electrode 15 insulating layer 16 light emitting layer 17 first mask 18 back electrode 19, 20 opening 22 second mask 24 frame 26 linear material 30 third mask 32 fourth mask

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuya Tanbo 3158 Shimo-Okubo, Osawano-cho, Kamishinkawa-gun, Toyama Prefecture Inside Hokuriku Electric Industry Co., Ltd. F term in Industrial Co., Ltd. (reference) 3K007 AB01 AB05 AB18 BA06 CA01 CA02 CA05 CB01 DA00 DB03 EB00 FA00 FA01 FA03

Claims (5)

[Claims] 1. A predetermined transparent electrode is formed of a transparent electrode material on a surface of a transparent substrate, a light emitting layer made of an EL material is laminated on the transparent electrode, and a surface of the light emitting layer is opposed to the transparent electrode. An EL element having a rear electrode formed thereon, wherein an insulating layer having a predetermined pattern is provided between the transparent electrodes, and a pattern of the transparent electrode having substantially the same thickness as the insulating layer is provided in contact with the insulating layer. EL element. 2. The EL device according to claim 1, wherein the insulating layer is transparent. 3. The transparent electrode is formed in a stripe shape with a predetermined pitch, the insulating layer is provided between the transparent electrodes, and the transparent electrode and the insulating layer are in contact with each other on a smooth surface. 2. The EL device according to 2. 4. A predetermined transparent electrode is formed on a surface of a transparent substrate using a transparent electrode material, 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 of manufacturing an EL element in which a back electrode is formed opposite to a transparent electrode, a predetermined thin film is formed by a vacuum thin film forming technique using a first mask having an opening other than a portion where the transparent electrode is formed before forming the transparent electrode. Forming an insulating layer of a pattern, when forming the transparent electrode, forming a transparent electrode of a predetermined pattern by a vacuum thin film forming technique using a second mask having a predetermined pattern other than the insulating layer, An organic EL light emitting material is laminated by the above-mentioned vacuum thin film forming technique using a third mask opened in a predetermined range of a portion where the transparent electrode is formed, and thereafter, the organic EL light emitting material is placed so as to face the transparent electrode. Manufacturing method of an EL element through a fourth mask having a opening and forming a back electrode by the vacuum thin film forming technique. 5. The method according to claim 4, wherein in each of the steps, the material of each of the steps is formed on the substrate while maintaining a vacuum state.