KR19990046876A - Organic electroluminescent display device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an organic electroluminescent display apparatus and a method of manufacturing the same, and to a plurality of organic electroluminescent devices including a first electrode, a second electrode, and an organic light emitting layer formed between the first and second electrodes. By arranging and bonding on the first casing and separately connecting the first and second electrodes of each organic light emitting element and the corresponding external driving circuit through the contact holes of the second panel having a plurality of conductive contact holes. Therefore, the problem of voltage drop due to the resistance of the electrode can be solved and smooth driving can be performed.

Description

Organic electroluminescent display device and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to an organic electroluminescent display apparatus and a method of manufacturing the same.

Recently, as the size of the display device increases, the demand for a flat display device having less space occupancy is increasing. As one of the flat display devices, an electroluminescent device is attracting attention.

The electroluminescent device is largely divided into an inorganic electroluminescent device and an organic electroluminescent device according to the material used.

In general, an inorganic electroluminescent device is a device that emits light by applying a high electric field to a light emitting part, accelerating electrons in the high electric field, and colliding with the light emitting center to thereby excite the light emitting center.

In addition, the organic light emitting device is based on the exciton generated by combining electrons and holes injected by injecting electrons and holes from the electron injection electrode (cathode) and the hole injection electrode (anode) into the light emitting unit, respectively. It is a device that emits light when falling into a state.

Since the inorganic electroluminescent device having the above operating principle requires a high electric field, a high voltage of 100 to 200 V is required as a driving voltage, whereas the organic electroluminescent device can be driven at a low voltage of about 5 to 20 V. There is an advantage, and research is being actively conducted.

In addition, the organic light emitting display device has excellent characteristics such as wide viewing angle, high speed response and high contrast, so it can be used as a pixel of a graphic display, a TV image display or a surface light source. They are thin, light, and have good color, making them suitable for next-generation flat panel displays.

However, there have been two problems in manufacturing a large area casing display using an organic light emitting display device having such a purpose.

The first is the voltage drop that occurs in the electrode strip direction due to the resistance of the electrode material and thus the difficulty of driving.

That is, in order to manufacture a large-area casing display, the length of the electrode becomes considerably longer, so that the resistance (R) of the electrode increases, the voltage drop increases, and the organic light emitting layer acts as a capacitor (C), thereby increasing the RC. The response time is long.

Second, since the thickness of the organic light emitting layer is not uniform throughout, the brightness is not constant depending on the position.

That is, since the thickness of the organic light emitting layer affects the luminance of the device, the thickness of the organic light emitting layer should be formed to be uniform. However, as the display panel increases, the thickness becomes uneven.

Therefore, conventionally, as a method for solving this problem, first, a plurality of organic light emitting diodes having a small panel of appropriate size are fabricated, and then the elements of the small panel are tiled on a large area casing. By attaching, a method of making a large display panel was used.

1 and 2 are structural cross-sectional views showing an organic light emitting display device according to the prior art, Figure 1 is a cathode 2, an organic light emitting layer 3, the cathode 4 is sequentially stacked on a transparent substrate (1) Attached organic electroluminescent devices on a large-area casing 5, and then electrically connected side surfaces of the anodes 2 adjacent to each other using a conductive adhesive 6, which is shown in FIG. Although the structure is the same as in FIG. 1, instead of electrically connecting the sides of the anodes 2 adjacent to each other as shown in FIG. 1, the bottom surface of the anode 2 is electrically connected instead.

Such a method is known from US Pat. No. 5,302,468.

However, these conventional methods produce a large display panel by attaching a plurality of elements of a small panel, so that the thickness of the organic light emitting layer is uniform, thereby improving the brightness of the device. The voltage drop and thus the difficulty of driving still have not been solved.

The organic light emitting display device according to the prior art has the following problems.

In manufacturing a large area casing display, when the organic light emitting diodes of a small panel are arranged on the large area casing to connect the electrodes of the devices, the length of the electrode becomes considerably longer, so that the resistance (R) of the electrode increases and the voltage drop decreases. The larger the organic light emitting layer acts as a capacitor (C) to increase the RC, the longer the response time (response time).

An object of the present invention is to provide an organic light emitting display device and a method of manufacturing the same, which can reduce a voltage drop occurring in an electrode strip direction.

1 and 2 is a structural cross-sectional view showing an organic light emitting display device according to the prior art

3 is a plan view showing an organic light emitting display device according to the present invention.

FIG. 4 is a cross-sectional view illustrating an organic light emitting display device according to the line I-I of FIG. 3.

FIG. 5 is a structural cross-sectional view of an organic light emitting display device taken along the line II-II of FIG. 4.

6A and 6B are plan views illustrating positions of contact holes connected to electrodes of the organic light emitting diode.

7A to 7D are cross-sectional views illustrating a manufacturing process of an organic light emitting display device according to the present invention.

Explanation of symbols for main parts of the drawings

11: organic light emitting element 12: first casing

13 second casing 14 drive circuit

15 transparent substrate 16 first electrode

17 organic light emitting layer 18 second electrode

19 contact hole 20 insulating layer

The main feature of the organic light emitting display device according to the present invention is to provide a casing between a plurality of organic light emitting diodes arranged in a matrix form and an external driving circuit, and to form conductive contact holes in the casing to form electrodes of the light emitting device. The light emitting device is connected to the driving circuit through the conductive contact hole.

As a result, the length of the driven electrode corresponds to the length of one light emitting device, thereby reducing voltage drop and response time.

Other features of the organic light emitting display device according to the present invention include a plurality of organic light emitting assemblies having light emitting portions including a first electrode, a second electrode, and an organic light emitting layer formed between the first and second electrodes. And a first casing supporting the organic electroluminescent assemblies so that the organic electroluminescent assemblies are array bonded, and a plurality of conductive elements to be electrically connected to the first and second electrodes of each organic electroluminescent assembly and the corresponding external driving circuit. And a second casing having contact holes.

A feature of the method for manufacturing an organic light emitting display device according to the present invention is a laminated structure comprising a first electrode and a second electrode formed on a substrate, and an organic light emitting layer formed between the first electrode and the second electrode. Preparing an organic electroluminescent assemblies of the first and second casings having a first casing and contact holes filled with a conductive material in a predetermined region, and arranging and bonding the organic electroluminescent assemblies on the first casing; Forming an insulating layer between each organic electroluminescent assembly and the organic electroluminescent assembly adjacent thereto, the first electrode and the second electrode of each organic electroluminescent assembly arranged and bonded on the first panel and the corresponding second Bonding the first casing and the second casing to be electrically connected to the conductive contact holes of the casing, and each organic electroluminescence assembly And electrically connecting the conductive contact hole of the second casing electrically connected to the first electrode and the second electrode of the ble and an external driving circuit corresponding thereto.

An organic light emitting display device and a method of manufacturing the same according to the present invention having the above characteristics will be described with reference to the accompanying drawings.

3 is a plan view showing an organic light emitting display device according to the present invention, Figure 4 is a structural cross-sectional view showing an organic light emitting display device along the line I-I of FIG.

First, as shown in FIG. 3, the concept of the present invention is to form the organic light emitting diodes 11 of the small panel so that the voltage drop is within a controllable range, and then the organic light emitting diodes 11 of the small panel are formed. As shown in FIG. 4, the contact holes 19 filled with a conductive material in the predetermined region of the second casing 13 are improved by tiling the first casing 12 to improve the luminance of the device. And the voltage drop due to the resistance of the electrode is reduced by connecting each organic light emitting element 11 to the corresponding driving circuit 14 through the contact holes 19.

Hereinafter, the structure of the present invention having this concept will be described in more detail.

FIG. 5 is a structural cross-sectional view of an organic light emitting display device according to line II-II of FIG. 4. The present invention is shown in FIG. The organic light emitting diode 17 (generally referred to as a hole transporting layer, an organic light emitting layer, an electron transporting layer, etc.) and the organic light emitting diodes having the second electrode 18 sequentially formed and the organic light emitting diodes are arrayed and bonded together. And a plurality of conductive contact holes 19 are formed in a predetermined region, and the first and second electrodes 16 and 18 of the organic light emitting diodes are formed through the first and second casings 12 and the predetermined contact regions 19. ) Is composed of a second casing (13) for separately connecting to the corresponding external driving circuit (14).

Here, the insulating layer 20 is formed therebetween to prevent electrical short between the electrodes of the organic light emitting diodes adjacent to each other.

The conductive contact hole 19 is formed at various positions in the second casing 13 according to the connection portion between the first electrode 16 and the second electrode 18 of the organic light emitting diode.

That is, as an example, assuming that the contact hole 19 connected to the first electrode 16 is X and the contact hole 19 connected to the second electrode 18 is Y, as shown in FIG. 6A, The contact holes 19 formed in the second casing 13 are connected to only one end of the first electrode 16 and the second electrode 18 of the organic light emitting diode 11 and are shown in FIG. 6B. 19 are alternately connected to both ends of the first electrode 16 and the second electrode 18, respectively.

Although a plurality of light emitting devices are tiled and enlarged by the above structure, the first electrode 16 is connected to the driving circuit through conductive contact holes in light emitting devices.

That is, since the length of the first electrode is driven to a length corresponding to one light emitting device (small panel), the voltage drop and response time through the electrode become the same as when driving one small panel.

The production method of the present invention having such a structure is as follows.

7A to 7D are cross-sectional views illustrating a manufacturing process of an organic light emitting display device according to the present invention. First, as shown in FIG. 7A, the first casing 12 and a plurality of conductive contact holes 19 in a predetermined region are shown. To manufacture a second casing 13 and a plurality of organic electroluminescent elements.

Here, organic electroluminescent devices are manufactured in a conventional manner.

That is, after forming the first electrode 16, the organic electroluminescent layer 17 (collectively referred to as the hole transport layer, organic light emitting layer, electron transport layer, etc.), and the second electrode 18 on the transparent substrate 15, A protective film is formed thereon, and care is taken so that the tip of the electrode is not covered with a protective film (not shown).

In addition, the second casing 13 may be manufactured using various materials such as metal, alloy, plastic, and glass, and the second casing 13 made of one of the materials may be positioned by laser processing or etching. Drill a hole in it.

Here, in the case of using a conductive material, an insulating material is coated on the surface by a dipping method after drilling a hole.

The diameter of this hole is formed to be substantially the same as the width of the electrode strip.

Subsequently, the contact hole 19 is formed by filling the hole with a conductive material by electroplating, electroless plating, or the like.

Here, the contact hole 19 to be connected to the first electrode 16 of the organic light emitting diode is formed to protrude slightly.

The reason is that there is a minute step between the first electrode and the second electrode of the organic light emitting display device, so that when the contact hole 19 and the electrode are connected in a later process, the contact hole 19 and the first electrode 16 are connected. This is not done properly.

In the formation of the contact hole 19, when the electroplating method is used, copper, nickel, gold, or the like may be used as the conductive material.

When the first and second casings 12 and 13 and the organic light emitting diodes are completed as described above, as illustrated in FIG. 7B, the organic light emitting diodes are arranged on the first casing 12 and then bonded in a planar direction. do.

In this case, the insulating layer 20 is formed between the organic light emitting diodes to prevent electrical shorts of adjacent organic light emitting diodes.

The insulating layer 20 may be formed in a process before arranging the organic light emitting elements on the first casing 12.

As shown in FIG. 7C, the first casing 12 and the second casing 13 are bonded to each other, and the conductive contact holes 19 of the second casing 13 and the electrodes of the organic light emitting diode corresponding thereto. Allow them to be electrically connected.

Subsequently, as illustrated in FIG. 7D, the organic light emitting diodes connected to the conductive contact holes 19 may be separately connected to the corresponding driving circuits 14 through the conductive contact holes 19 or may vary according to design. In this way, the organic light emitting display device is completed.

The organic electroluminescent display device and its manufacturing method according to the present invention have the following effects.

The electrodes of the organic light emitting diode arrayed on the casing are connected to the driving circuit through the conductive contact hole in the unit of the light emitting device so that the length of the driven electrode is the length corresponding to one light emitting device so that the voltage drop and the response time Can be reduced.

Claims (10)

A plurality of organic electroluminescent assemblies having light emitting portions arranged in a matrix form and having a first electrode, a second electrode, and an organic electroluminescent layer formed between the first and second electrodes; And a casing having a plurality of conductive contact holes to be electrically connected to the first and second electrodes of each of the organic light emitting assemblies and an external driving circuit. The organic light emitting display device according to claim 1, wherein each of the organic light emitting assemblies and the organic light emitting assembly adjacent thereto is isolated by an insulating layer. The organic light emitting display device as claimed in claim 1, wherein each of the organic light emitting assemblies is electrically connected to an external driving circuit corresponding to each of the organic light emitting assemblies through the conductive contact hole of the casing. A plurality of organic electroluminescent assemblies having light emitting portions including a first electrode, a second electrode, and an organic electroluminescent layer formed between the first and second electrodes; A first casing supporting the organic electroluminescent assemblies such that the organic electroluminescent assemblies are array bonded; And a second casing having a plurality of conductive contact holes so as to be electrically connected to the first and second electrodes of the respective organic electroluminescent assemblies and corresponding external driving circuits. The organic electroluminescent display device according to claim 4, wherein each of the organic electroluminescent assemblies and the organic electroluminescent assembly adjacent thereto is isolated by an insulating layer. The organic light emitting display device of claim 4, wherein a diameter of the conductive contact hole is equal to a width of the first and second electrodes. The organic light emitting display device of claim 4, wherein the conductive contact hole is filled with one of copper, nickel, and gold. Organic electroluminescent assemblies of a laminated structure comprising a first electrode and a second electrode formed on a substrate, an organic electroluminescent layer formed between the first electrode and the second electrode, a first casing, And preparing second casings having contact holes filled with a conductive material in a predetermined region. Arranging the organic electroluminescent assemblies on the first casing; Forming an insulating layer between each organic electroluminescent assembly and an organic electroluminescent assembly adjacent thereto; Bonding the first casing and the second casing to be electrically connected to the first electrode and the second electrode of each organic electroluminescent assembly arranged and bonded on the first casing and the conductive contact holes of the second casing corresponding thereto. step; And electrically connecting the conductive contact hole of the second casing electrically connected to the first electrode and the second electrode of each organic light emitting assembly and the external driving circuit corresponding thereto. Display device manufacturing method. The method of claim 8, wherein the conductive material filled in the conductive contact hole of the second casing is formed by any one of electroplating and electroless plating. The method of claim 8, wherein the forming of the insulating layer is performed before the step of arranging the organic electroluminescent assemblies on the first casing.