KR20030042074A - Organic electroluminescence device and method of making the same - Google Patents

Abstract

PURPOSE: An organic electroluminescence device and a manufacturing method thereof are provided to reduce the manufacturing process and cost by inserting an insulating layer between two electrode layers and an organic luminescent layer to divide the organic electroluminescence device. CONSTITUTION: A plurality of first striped-type electrodes(22) are formed on a transparent substrate(21). The first insulating layer pattern, which is made of an inorganic material, is deposited on the first region that is perpendicular to the plurality of first electrodes(22) and the second region in parallel to the plurality of first electrodes(22). A plurality of organic luminescent layers are formed on the plurality of first electrodes(22). A plurality of second electrodes are deposited on the organic luminescent layers and perpendicular to the plurality of first electrodes(22).

Description

Organic electroluminescent device and method of manufacturing the same {Organic electroluminescence device and method of making the same}

The present invention relates to an organic electroluminescent device and a method of manufacturing the same. In particular, the organic electroluminescent light emitting device can be separated by a single insulating layer pattern between the positive electrode layer and the organic light emitting layer, thereby simplifying the manufacturing process and reducing the manufacturing cost. A device and a method of manufacturing the same.

In general, an organic electroluminescent device is one of the flat panel display devices, and is formed between the positive electrode layer and the negative electrode layer on a transparent substrate through an organic electroluminescent layer, and can be formed in a very thin and matrix form. It can be driven with a low voltage below 15V and shows excellent characteristics in brightness, viewing angle, response speed and power consumption compared to TFT-LCD. In particular, due to the fast response speed of the organic electroluminescent device superior to other display devices, it is a very suitable device for the mobile phone for IMT-2000 where video is essential.

However, such an organic electroluminescent device has many difficulties in the manufacturing process, the most difficult process is the pixelation (patterning) or patterning (patterning) process. In addition, the organic light emitting layer material is very vulnerable to oxygen, moisture and the like to prevent degradation of the organic light emitting layer by blocking and sealing the device to the outside in order to ensure reliability.

In addition, since the organic material is very vulnerable to oxygen, moisture, etc., all the processes after the formation of the positive electrode layer are difficult to form a pattern through the photolithography technique. Therefore, the direct pixelation method using a shadow mask is widely used, but this method also implements a pitch between pixels, i.e., each organic layer line formed between the lines to form a high resolution. When the gap was reduced, it was difficult to use.

Another method of forming patterns of organic material layers that do not use photolithography techniques, including masks and etching processes that are easy to expose to oxygen or moisture, is to form barrier ribs with materials that can be electrically insulated, The organic material layer patterns separated from each other can be obtained.

The partition wall is orthogonal to the positive electrode layer and arranged at regular intervals, and the negative electrode layer is formed to have an overhang structure so that the negative electrode layer is not short-circuited with adjacent components. However, unlike the general patterning process, the process of forming the partition wall must maintain a negative profile at all times, and if the partition wall is missing, there may be a short circuit between adjacent pixels.

An insulating layer is formed below the partition wall. When the organic layer is laminated on the positive electrode, the thickness of the organic layer becomes thin due to the shadow effect caused by the partition wall near the partition wall. That is, without the insulating layer, the negative electrode layer stacked on the organic layer may be shorted with the positive electrode layer. In particular, in the case of a large substrate having difficulty in securing the uniformity of the thickness of the organic layer, the yield may be reduced if the insulating layer is not formed.

In addition, since the isolation of the device is required only when both the insulating layer and the partition wall are formed, the process is complicated and the manufacturing cost increases.

Hereinafter, the organic electroluminescent device manufacturing method according to the related art will be described in detail with reference to the accompanying drawings.

1 is a plan view of an organic electroluminescent device of the prior art.

On the transparent substrate 1, a plurality of first electrodes 2 made of indium tin oxide (ITO) or the like are arranged in a stripe type, between the first electrodes 2 and the first electrodes 2. ), A lattice-shaped insulating layer pattern 3 is laminated on the transparent substrate 1 including the first electrode 2 on a region orthogonal thereto. An organic light emitting layer is formed on the insulating layer pattern 3 orthogonal to the first electrode 2 and the partition 4 is stacked on the transparent substrate 1 including the insulating layer pattern 3 and the partition 4, The second electrode (negative electrode layer) is not shown.

FIG. 2 is a cross-sectional view of a method of manufacturing an organic light emitting device according to the related art, taken along the line AA ′ of FIG. 1.

As shown in FIG. 2A, a positive electrode material layer (not shown) made of indium tin oxide (ITO) or the like is laminated on the transparent substrate 1 in a thickness using a sputtering method. A photosensitive film (not shown) is applied on the positive electrode material layer, and exposed and developed to form a stripe type photosensitive film pattern (not shown). When the positive electrode material layer is etched using the photoresist pattern as a mask, the first electrode 2 having a stripe shape is formed.

As shown in FIG. 2B), an insulating layer (not shown) that can be electrically insulated is laminated on the transparent substrate 1 including the first electrode 2. Organic or inorganic materials can be used as the insulating layer. As an organic material, an acrylic resin or a photosensitive film is used, and as an inorganic material, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like is used. The insulating layer is patterned to form an insulating layer pattern 3 arranged at regular intervals between the plurality of first electrodes 2 and perpendicular to the first electrode.

As shown in FIG. 2C, a partition 4 having a reverse slope is formed by stacking and patterning a negative type organic photosensitive film (not shown) with an electrically insulating material on the insulating layer pattern 3. To form. The organic light emitting layer 5 and the second electrode 6 are sequentially stacked using a shadow mask (not shown). The partition wall 4 is orthogonal to the first electrode 2 and arranged at regular intervals, and has an overhang structure so that the second electrode 6 is not shorted to an adjacent component.

The organic light emitting layer 5 and the second electrode 6 are sequentially deposited on the first electrode 2. At this time, when the organic light emitting layer 5 is laminated on the first electrode 2, the thickness of the organic light emitting layer 5 becomes thin due to a shadow effect caused by the partition wall near the partition 4. That is, without the insulating layer pattern 3, the second electrode 6 stacked on the organic light emitting layer 5 may short the first electrode 2.

Thereafter, an outer encapsulation cap made of metal or glass is provided on the front surface including the second electrode 6 to compensate for the weakness of the organic light emitting layer 5 in moisture, gas, and the like. To isolate from outside.

3 is a plan view of another conventional organic electroluminescent device.

As shown in FIG. 3A, a plurality of first electrodes 2 made of indium tin oxide (ITO) or the like are arranged in a stripe type on the transparent substrate 1, and the transparent substrate 1 and the first substrate are arranged in a stripe type. A stripe-shaped insulating layer pattern 3 is laminated on a region orthogonal to the first electrode 2 on the first electrode 2.

As shown in FIG. 3B, a photosensitive film 7 is laminated on the transparent substrate 1 including the first electrode 2 and the insulating layer pattern 3. The photosensitive film 7 exposes the opening 8 exposing the first electrode 2 and the central portion of the insulating layer pattern 3 having the same direction as the insulating layer pattern 3. In the center portion of the insulating layer pattern 3, a trench 9 is formed by etching a predetermined thickness of the insulating layer pattern 3. In general, the photosensitive film 7 is formed in a lattice shape that exposes the first electrode 2. The organic light emitting layer and the second electrode (negative electrode layer) stacked on the transparent substrate 1 including the opening 8 are not shown.

FIG. 4 is a cross-sectional view of another method of manufacturing an organic EL device according to another art taken along the line AA ′ of FIG. 3.

As shown in FIG. 4A, a positive electrode material layer (not shown) made of indium tin oxide (ITO) or the like is laminated on the transparent substrate 1 in a thickness using a sputtering method. A photoresist film (not shown) is applied on the positive electrode material layer, and exposed and developed to form a stripe type photoresist pattern (not shown). When the positive electrode material layer is etched using the photoresist pattern as a mask, the first electrode 2 having a stripe shape is formed.

Then, an insulating layer (not shown) that can be electrically insulated is laminated on the transparent substrate 1 including the first electrode 2. As the insulating layer material, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like is used, and is deposited using a chemical vapor deposition method. The insulating layer is patterned to form an insulating layer pattern 3 that is orthogonal to the plurality of first electrodes and is arranged at regular intervals.

As shown in FIG. 4B), a positive type photosensitive film 7 is laminated on the insulating layer pattern 3 with an electrically insulating material and subjected to an exposure and development process and patterned. An opening 8 through which the first electrode 2 is exposed is formed by patterning the photosensitive film 7, and the center portion of the insulating layer pattern 3 is exposed in parallel with the insulating layer pattern 3.

As shown in FIG. 4C, a trench 9 is formed by etching a central portion of the insulating layer pattern 3 to a predetermined depth using the photosensitive film 7 having the pattern as an etching mask. The cross section of the sphere 9 looks square but generally trapezoidal or semicircular. And it functions to prevent the short circuit of the 2nd electrode (negative electrode layer) which adjoins with the structure of the sphere 9 mutually.

Subsequently, the organic light emitting layer 10 and the second electrode 11 are sequentially stacked. Then, an encapsulation cap (not shown in the figure) made of metal or glass, etc., to compensate for the organic light emitting layer vulnerable to moisture, gas, etc. on the front surface including the second electrode 11. ) To cut off from the outside.

Such a conventional method of manufacturing an organic EL device has the following problems.

A partition wall is formed on the insulating layer and the insulating layer to separate the device. When the insulating layer is laminated on the positive electrode, the thickness of the organic light emitting layer becomes thin due to a shadow effect caused by the partition wall near the partition wall. In other words, if the insulating layer pattern is not present, the negative electrode layer stacked on the organic light emitting layer may have a positive electrode layer short, so an insulating layer pattern should be formed. In addition, the bulkhead also has a problem to pay attention to the angle of the reverse slope, unlike the general patterning.

In addition, since both the insulating layer and the partition wall must be formed, the process is complicated and the manufacturing cost increases.

The present invention is to solve the problems of the prior art organic electroluminescent device manufacturing method to simplify the manufacturing process and reduce the manufacturing cost by enabling the device separation in a single insulating layer pattern between the positive electrode layer and the organic light emitting layer It is an object of the present invention to provide an organic electroluminescent device and a method of manufacturing the same.

1 is a plan view of an organic electroluminescent device of the prior art

FIG. 2 is a cross-sectional view of a method of manufacturing an organic EL device according to the related art, taken along line AA ′ of FIG. 1.

3 is a plan view of another conventional organic electroluminescent device

4 is a cross-sectional view of a method of manufacturing an organic light emitting diode according to the related art, taken along line AA ′ of FIG. 3.

5 is a plan view of an organic electroluminescent device according to the present invention.

6 is a cross-sectional view of a method of manufacturing an organic EL device according to the present invention, taken along line AA ′ of FIG. 5.

7 is a cross-sectional view of a method of manufacturing an organic EL device according to the present invention, taken along line BB ′ in FIG. 5.

Explanation of symbols for the main parts of the drawings

21 transparent substrate 22 first electrode

23: first insulating layer 24: first photosensitive film pattern

25: first opening 26: first insulating layer pattern

27 second photosensitive film pattern 28 second opening

29 organic light emitting layer 30 second electrode

31 second insulating layer 40 first region of first insulating layer pattern

41: second region of the first insulating layer pattern

The organic electroluminescent device according to the present invention for achieving the above object is

A plurality of first electrodes having a stripe shape on the transparent substrate; A first insulating layer pattern of an inorganic material stacked in a first region in a direction orthogonal to the plurality of first electrodes and a second region in a direction parallel to the plurality of first electrodes; A plurality of organic light emitting layers on the plurality of first electrodes; The second electrode may be stacked on the plurality of organic light emitting layers, and includes a second number of north electrodes orthogonal to the plurality of first electrodes.

The organic electroluminescent device manufacturing method according to the present invention for achieving the above object comprises the steps of forming a plurality of first electrode of the stripe shape on the transparent substrate; Stacked in a first region in a direction orthogonal to the plurality of first electrodes and a second region in a direction parallel to the plurality of first electrodes, wherein the film thickness in the second region is a film thickness in the first region. Forming a first insulating layer pattern of a lower thickness inorganic material; Forming a plurality of organic light emitting layers on the plurality of first electrodes; And forming a plurality of second electrodes on the plurality of organic light emitting layers.

Hereinafter, the organic electroluminescent device manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings.

5 is a plan view of an organic EL device according to the present invention.

As shown in FIG. 5A, a plurality of first electrodes 22 made of indium tin oxide (ITO) or the like is arranged on a transparent substrate 21 in a stripe type.

As illustrated in FIG. 5B, a lattice-shaped first insulating layer pattern 26 is transparent to the first electrode 22 between the plurality of first electrodes 22 and on a region orthogonal to the plurality of first electrodes 22. A first opening 25 is formed on the substrate 21 and exposes a region where pixels are formed on the plurality of first electrodes 22. The first insulating layer pattern 26 in which the first opening 25 in which the pixel is formed is exposed is in a lattice shape.

The first insulating layer pattern 26 stacked in a direction perpendicular to the plurality of first electrodes 22 is defined as the first region 40, and is stacked between the plurality of first electrodes 22 and formed of a plurality of first electrodes. The first insulating layer pattern 26 parallel to the first electrode is defined as the second region 41. Here, the second region 41 of the first insulating layer pattern 26 is formed to have a lower thickness than the first region 40 of the first insulating layer pattern 26. The reason is that a plurality of second electrodes (not shown in the figure) pass through the opening 25 in which the organic light emitting layer (not shown in the figure) is formed, and are formed perpendicular to the plurality of first electrodes 22. This is to exclude the possibility of breakage due to a thin film thickness when the second electrode is deposited at the boundary of the first electrode 22.

As shown in FIG. 5C, a second opening 28 is formed in the center of the first region 40 of the first insulating layer pattern 26 stacked in a direction perpendicular to the plurality of first electrodes 22. The second opening 28 serves to prevent shorting of the second electrodes adjacent to each other. The organic light emitting layer and the second electrode (negative electrode layer) stacked on the transparent substrate 21 including the first opening 25 are not shown.

6 is a cross-sectional view of a method of manufacturing an organic EL device according to the present invention, taken along line AA ′ of FIG. 5.

As shown in Fig. 6A, a transparent substrate 21 is prepared. In the present invention, a substrate such as transparent glass is used as the transparent substrate 21. On the transparent substrate 21, a positive electrode material layer (not shown) made of indium tin oxide (ITO) or the like is laminated to a thickness of 1,500 to 2,000 mW. The sheet resistance of the positive electrode material layer should be 10 Ω / □ or less. The positive electrode material layer is laminated on the cleaned transparent substrate 21 using a sputtering method. A photoresist film (not shown) is applied on the positive electrode material layer, and exposed and developed to form a stripe type photoresist pattern (not shown). When the positive electrode material layer is etched using the photoresist pattern as a mask, the first electrode 22 having a stripe shape is formed.

As shown in FIG. 6B, a process of suppressing a leakage current at an edge of the first electrode 22 and forming a first insulating layer 23 for separating pixels is performed. An inorganic material layer having an insulating property is used as the device isolation layer that prevents electrical connection between the first electrode 22 and the second electrode 30 formed later.

The first insulating layer 23 is formed of a single layer or a plurality of layers of a silicon oxide film (SiO ₂ ), a silicon nitride film (SiNx), a silicon oxynitride film (SiON), and a germanium oxide film (GeO) by sputtering or chemical vapor deposition. Laminate about 3 ㎛.

As shown in FIG. 6C, a first photosensitive film (not shown) is applied on the first insulating layer 23 by about 1 to 2 μm, the first photosensitive film is exposed and developed, and the first photosensitive film pattern 24 is applied. Form. Here, the first photosensitive film pattern 24 stacked in the region between the first electrodes 22 and parallel to the first electrode 22 has a halftone shape. The halftone-shaped first photoresist pattern 24 has a lattice or chevron shape. Then, the first photoresist film in the region outside the first photoresist pattern 24 is removed.

As illustrated in FIG. 6D, the first insulating layer 23 is dry-etched using the first photoresist pattern 24 as a mask to form a first insulating layer pattern 26. The side surface of the first insulating layer pattern 26 is to maintain the inclination angle of about 45 degrees.

5B, the second region 41 of the first insulating layer pattern 26 in a portion parallel to the first electrode 22 is lower than the first region 40 of the first insulating layer pattern 26. It is formed in thickness. Here, the first insulating layer 23 perpendicular to the first electrode 22 and corresponding to the first electrode 22 is removed to form the first opening 25. The reason why the second region 41 of the first insulating layer pattern 26 in a portion parallel to the first electrode 22 is lower than the first region 40 of the first insulating layer pattern 26 is that An organic light emitting layer (not shown) and a second electrode (not shown) formed in a direction perpendicular to the plurality of first electrodes 22 are formed at both ends of the first insulating layer pattern 26 and the first. This is to exclude the possibility of breakage due to a thin film thickness when the second electrode is deposited at the boundary of the electrode 22.

After the formation of the first insulating layer pattern 26 is completed, the first photoresist layer pattern 24 is removed.

As shown in FIG. 6E, a second photosensitive film (not shown) is applied on the transparent substrate 21 including the first insulating layer pattern 26 to a thickness of about 1 to 2 μm. The second photosensitive film is exposed and developed to form a second photosensitive film pattern 27 exposing a central portion of the first insulating layer pattern 26 in a direction perpendicular to the first electrode 22 to a width of about 5 μm. . Using the second photoresist pattern 27 as a mask, dry etching is performed on the center of the first region 40 of the first insulating layer pattern 26 to form a second opening 28 for device isolation as shown in FIG. 5C. .

The depth of the second opening 28 is greater than the sum of the thicknesses of the organic light emitting layer 29 and the second electrode 30 formed later. In addition, the opening of the second opening 28 is narrow and the bottom thereof is wide so that a short circuit with the second electrode 30 of the adjacent pixel does not occur.

As shown in FIG. 6F, the second photoresist layer pattern 27 is removed, and the transparent substrate 21 is moved into a vacuum deposition apparatus for forming the organic emission layer 29, and the transparent layer including the first insulating layer pattern 26 is formed. The organic light emitting layer 29 is laminated on the substrate 21.

The organic electroluminescent layer is made of monomolecular organic materials such as Alq ₃ , Anthrancene, PPV ((p-phenylenevinylene)), PT (polythiophene), and polymer organic light emitting materials thereof. The low molecular weight organic material uses an evaporation method, and the high molecular weight organic material uses a spin coating, a transfer method, and an ink jet method like a photosensitive film.

Here, the hole transport layer may be formed on the hole injection layer and the hole injection layer before the organic light emitting layer is formed. In addition, an electron transport layer and an electron injection layer may be formed on the organic emission layer. In the hole injection layer, when a hole injection electrode having a large work function is used, a large amount of holes can be injected and the injected holes must be able to move in the layer. It is a thin film layer having a property of being hard to move. In addition, the electron transport layer is capable of injecting a large amount of electrons when using an electron injection electrode having a low work function, and the injected electrons must be able to move in the layer, and the hole injection is difficult and difficult to move even if the injection is possible. It is a thin film layer having.

As shown in FIG. 6G, the second electrode 30 is formed on the transparent substrate 21 including the organic emission layer 29. The second electrode 30 mainly uses a metal having good electrical conductivity, such as Al, and is laminated by vacuum deposition or sputtering. Separation of the second electrode 30 is made by the second opening 28 formed in the central portion of the first insulating film pattern 26.

As shown in FIG. 6H), the organic light emitting layer 29 and the second electrode 30 are formed as a protective layer so that an external encapsulation cap for preventing deterioration due to external moisture or oxygen is unnecessary. ). The second insulating layer 31 is formed of a single layer or a plurality of layers of the second electrode by sputtering or chemical vapor deposition using a silicon oxide film (SiO ₂ ), a silicon nitride film (SiNx), a silicon oxynitride film (SiON), and a germanium oxide film (GeO). 50-1200 nm is laminated | stacked so that 30 may fully cover.

FIG. 7 is a cross-sectional view of the organic electroluminescent device manufacturing method of the present invention, taken along line BB ′ in FIG. 5.

FIG. 7A shows a first photosensitive film pattern 24 stacked in an area perpendicular to the first electrode 22 and in an area parallel to the first electrode 22. The first photoresist pattern 24 in a region parallel to the first electrode 22 has a halftone shape, and is formed to have a thickness lower than that of the first photoresist pattern 24 in a region perpendicular to the first electrode 22.

FIG. 7B is a dry etching of the first insulating layer 23 using the first photoresist pattern 24. The first insulation under the first photoresist pattern 24 in an area parallel to the halftone-shaped first electrode 22 is illustrated. Layer 23 is more etched. Therefore, as shown in FIG. 5B, the first insulating layer pattern 26 having a lower thickness than the first region 40 of the first insulating layer pattern 26 and the first region 40 of the first insulating layer pattern 26 is formed. The second region 41 is formed.

Such an organic EL device and a method of manufacturing the same according to the present invention has the following effects.

A single layer insulating film having an insulating property between the positive electrode layer and the organic light emitting layer is capable of separating the device, thereby simplifying the manufacturing process and reducing the manufacturing cost.

The insulating layer pattern formed on the transparent substrate and the insulating layer pattern orthogonal to the positive electrode layer is lower than the thickness of the other insulating layer pattern to prevent the possibility of disconnection of the negative electrode layer.

An opening deeper than the thickness of the organic light emitting layer and the negative electrode layer is formed in the center of the insulating layer pattern to allow device isolation.

Claims (9)

A plurality of first electrodes having a stripe shape on the transparent substrate; A first insulating layer pattern of an inorganic material stacked in a first region in a direction orthogonal to the plurality of first electrodes and a second region in a direction parallel to the plurality of first electrodes; A plurality of organic light emitting layers on the plurality of first electrodes; An organic electroluminescent device, which is stacked on the plurality of organic light emitting layers and includes a second number of north electrodes orthogonal to the plurality of first electrodes. The organic electroluminescent device according to claim 1, further comprising a protective layer formed on the transparent substrate including the plurality of second electrodes as a second insulating layer which is an insulating film. The organic electroluminescent device according to claim 1, wherein an opening is formed in a central portion of the first region of the first insulating layer pattern. The organic electroluminescent device according to claim 3, wherein a depth of the opening is greater than a sum of thicknesses of the plurality of organic light emitting layers and the plurality of second electrodes. The method according to any one of claims 2 to 3, wherein the first insulating layer pattern and the second insulating layer are used as one or two or more composite layers of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a germanium oxide film. An organic electroluminescent device, characterized in that. Forming a plurality of first electrodes having a stripe shape on the transparent substrate; Stacked in a first region in a direction orthogonal to the plurality of first electrodes and a second region in a direction parallel to the plurality of first electrodes, wherein the film thickness in the second region is a film thickness in the first region. Forming a first insulating layer pattern of a lower thickness inorganic material; Forming a plurality of organic light emitting layers on the plurality of first electrodes; And forming a plurality of second electrodes on the plurality of organic light emitting layers. The method of claim 6, wherein the forming of the insulating layer pattern is performed. Forming an insulating film of an inorganic material electrically on the transparent substrate including the plurality of first electrodes; Applying a first photosensitive film on the insulating film; Exposing and developing the first photosensitive film to form a first photosensitive film and a halftone pattern of the first photosensitive film between the plurality of first electrodes in an isolation region of the transparent substrate orthogonal to the plurality of first electrodes; ; Etching the first insulating layer using the first photoresist film and the halftone pattern as a mask to form the first region of the first insulating layer pattern and the second region of the first insulating layer pattern. The manufacturing method of the organic electroluminescent element characterized by the above-mentioned. The method according to claim 6 or 7, And etching the central portion of the first region of the first insulating layer pattern to form an opening deeper than the thickness of the organic light emitting layer and the second electrode. 9. The method of claim 6, further comprising forming a second insulating layer, which is a protective layer, of an inorganic insulating material on the transparent substrate including the plurality of second electrodes. Method for producing an organic electroluminescent device.