KR20100064868A - Organic electroluminescence device and method for fabricating the same - Google Patents

Abstract

PURPOSE: An organic electroluminescent device and a manufacturing method thereof are provided to reduce total resistance by connecting an anode electrode or a cathode electrode with high resistance to an auxiliary electrode with low resistance. CONSTITUTION: An overcoat layer(103) is formed on the upper side of a substrate(101). A plurality of auxiliary electrodes(105) is formed on the upper side of the overcoat layer with regular intervals. A barrier layer(107) is formed on the upper side of the substrate including the auxiliary electrodes. A plurality of anode electrodes(109) is formed on the upper side of the barrier layer with regular intervals. An insulation layer pattern(113) is formed on the barrier layer between the anode electrodes. The insulation layer pattern comprises a contact hole which exposes a part of the auxiliary electrode. An organic light emitting layer(111) is formed on the upper side of the anode electrode. A cathode electrode(117) is formed to cross the anode electrode on the organic light emitting layer. The cathode electrode is electrically connected in parallel with the auxiliary electrode through the contact hole. A partition(119) is formed to cross the anode electrode. The partition electrically separates each cathode electrode.

Description

Organic electroluminescent device and its manufacturing method {ORGANIC ELECTROLUMINESCENCE DEVICE AND METHOD FOR FABRICATING THE SAME}

The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device and a method of manufacturing the organic electroluminescent device which can eliminate the unevenness of image quality due to the nonuniformity of the resistance by reducing the electrode resistance. .

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such a flat panel display includes a liquid crystal display, a field emission display, a plasma display panel, and an electroluminescent device (hereinafter referred to as "EL"). Element; In particular, the electroluminescent device is basically formed by attaching electrodes to both sides of an organic light emitting layer including a hole transporting layer, a light emitting layer, and an electron transporting layer, and is attracting attention as a next-generation flat panel display due to features such as wide viewing angle, high opening ratio, and high color.

The EL device is largely divided into an inorganic EL device and an organic EL device according to a material used. Dual organic light emitting device emits light when electrons and holes are paired and extinguished when electrons are injected into the organic EL layer formed between the hole injection electrode and the electron injection electrode. There is an advantage.

In addition, the organic light emitting device can be formed on a flexible transparent substrate, such as plastic, and can be driven at a voltage lower than 10V or lower than that of a PDP or an inorganic light emitting device, and consumes power. Is relatively small, and the color is excellent.

Referring to FIG. 1, the organic light emitting diode according to the related art having such a characteristic is as follows.

1 is a cross-sectional view schematically showing an organic light emitting device according to the prior art.

Referring to FIG. 1, in the organic light emitting diode according to the related art, an overcoat layer 13 and a barrier layer 15 are stacked on a substrate 11.

In addition, the anode electrode 17 and the cathode electrode 23 are formed on the barrier layer 15 in a direction crossing each other. Here, a plurality of anode electrodes 17 are spaced apart at predetermined intervals on the substrate 11.

An insulating film 21 having an opening (not shown) is formed in each organic field cell EL region on the substrate 11 on which the anode electrode 17 is formed.

In addition, a partition wall 25 for separating the organic light emitting layer 19 and the cathode electrode 23 to be formed thereon is disposed on the insulating layer 21. Here, the partition wall 25 is formed in a direction crossing the anode electrode 17 and has an inverted taper structure in which the upper end portion has a wider width than the lower end portion.

The organic light emitting layer 19 and the cathode electrode 23, which are made of an organic compound, are sequentially deposited on the anode 17 positioned between the insulating layers 21 on which the barrier ribs 25 are formed.

Although not shown in the drawing, the organic light emitting layer 19 has a hole injection layer (not shown), a hole transport layer (not shown), a light emitting layer (not shown), an electron transport layer (not shown), and electrons on the anode electrode 17. Injection layers (not shown) are stacked and formed.

In the passive type EL device, electrons and holes are emitted when a driving signal is applied to the anode electrode 17 and the cathode electrode 23, and the electrons and holes emitted from the anode electrode 17 and the cathode electrode 23 are organic light emitting layers. Recombination within (19) generates visible light. At this time, the generated visible light comes out through the anode electrode 17 to display a predetermined image or image.

However, in the organic light emitting device according to the related art, since light passes through the cathode electrode, the metal thickness of the cathode electrode must be made very thin, resulting in a large resistance and a deviation of luminance by the panel positions. .

On the other hand, although not described above, in the case of an inverted organic light emitting device, a transparent anode electrode is formed on the organic light emitting layer. In this case, an anode electrode is generally formed using ITO. At this time, since the ITO resistance is also very large, the same problems as in the aforementioned organic light emitting device structure occur.

Accordingly, the present invention has been made to solve the above problems according to the prior art, an object of the present invention is to reduce the overall resistance by lowering the overall resistance by connecting a large resistance electrode in parallel with a metal layer of low resistance in an organic light emitting device It is to provide an organic light emitting device and a method for manufacturing the same that can improve the.

The organic light emitting device according to the present invention for achieving the above object is an overcoat layer formed on a substrate; A plurality of auxiliary electrodes spaced at regular intervals formed on the overcoat layer; A barrier layer formed on the substrate including the plurality of auxiliary electrodes; A plurality of anode electrodes formed on the barrier layer and spaced apart at regular intervals; An insulating layer pattern formed on the barrier layer between the plurality of anode electrodes and having a contact hole exposing a part of the auxiliary electrode; An organic light emitting layer formed on the anode electrode; A cathode electrode formed on the organic light emitting layer to cross the anode electrode and electrically connected in parallel with the auxiliary electrode through the contact hole; And a partition wall formed to intersect the anode electrode and electrically separating the cathode electrodes, respectively.

The organic light emitting device manufacturing method according to the present invention for achieving the above object comprises the steps of forming an overcoat layer on a substrate; Forming a plurality of auxiliary electrodes spaced at regular intervals on the overcoat layer; Forming a barrier layer on the substrate including the plurality of auxiliary electrodes; Forming a plurality of anode electrodes spaced apart at regular intervals on the barrier layer; Forming an insulating layer pattern including a contact hole exposing a part of the auxiliary electrode on a barrier layer therebetween except for the plurality of anode electrodes; Forming an organic light emitting layer on the anode; Forming a partition on the insulating film pattern; And forming a plurality of cathode electrodes electrically connected in parallel with the auxiliary electrode through the contact hole on the organic light emitting layer by using the barrier as a mask.

According to the organic light emitting device and the method of manufacturing the same according to the present invention has the following effects.

The organic light emitting diode and the method of manufacturing the same according to the present invention can improve the image quality by lowering the overall resistance by connecting the cathode or anode electrode with high resistance to the auxiliary electrode with low resistance.

In addition, the organic light emitting device according to the present invention and a method of manufacturing the same in the flexible flexible organic light emitting device using SUS to form an auxiliary electrode of a low resistance metal on the overcoat layer and connect it to the final cathode electrode or anode electrode As a result, the resistance of the cathode or anode can be significantly lowered, thereby reducing power consumption.

Hereinafter, an organic light emitting diode according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a sectional view schematically showing an organic EL display element according to the present invention.

3 is a schematic cross-sectional view of an organic light emitting device according to the present invention, which is a cross-sectional view showing a connection structure of a cathode electrode and an auxiliary electrode.

2 and 3, in the organic light emitting device according to the present invention, an overcoat layer 103 is formed on a flexible substrate 101 such as plastic or SUS. Here, the substrate 101 may be a transparent substrate such as PEN, PET, PES, or an opaque substrate such as SUS or Al.

In addition, a plurality of auxiliary electrodes 105 are spaced at predetermined intervals on the overcoat layer 103. Here, as the metal used as the auxiliary electrode 105, a metal such as Al, Mo, Cu, or Cr is used as the low resistance metal.

In addition, a barrier layer 107 is formed on the overcoat layer 103 including the plurality of auxiliary electrodes 105.

In addition, a plurality of anode electrodes 109 are spaced apart at predetermined intervals on the barrier layer 107. The anode electrode 109 may be formed of indium tin oxide (ITO), IZO, SnO ₂ , or the like.

On the barrier layer 107 where the anode electrode 109 is formed, an insulating layer 113 having an opening (not shown) is formed in each organic field cell EL region.

The barrier rib 119 is formed on the insulating layer 113 to separate the organic light emitting layer 111 and the cathode electrode 117 to be formed on the anode electrode 109. Here, the partition wall 119 is formed in a direction crossing the anode electrode 109, and has a reverse taper structure in which the upper end portion has a wider width than the lower end portion.

The organic light emitting layer 111 and the cathode electrode 117 made of an organic compound are sequentially formed on the anode electrode 109 positioned between the insulating layer 113 on which the partition wall 119 is formed. In this case, the cathode electrode 117 is formed in a direction crossing with the anode electrode 109. In addition, as illustrated in FIG. 3, the cathode electrode 117 is electrically connected to the auxiliary electrode 105 through a contact hole (not shown) formed in the insulating layer 113. In this case, the cathode electrode 117 is formed of a metal material such as Al, Mg, Ca, the thickness is preferably formed in the range of the extent to which light is transmitted, that is, about 10 ~ 500Å.

Although not shown in the drawing, the organic light emitting layer 111 has a hole injection layer (not shown), a hole transport layer (not shown), a light emitting layer (not shown), and an electron transport layer (not shown) on the anode electrode 109, An electron injection layer (not shown) is formed by stacking.

In the passive organic light emitting device, when a driving signal is applied to the anode electrode 109 and the cathode electrode 117, electrons and holes are emitted, and electrons and holes emitted from the anode electrode 109 and the cathode electrode 117 Recombination in the organic light emitting layer 111 generates visible light. At this time, the generated visible light is emitted to the outside through the anode electrode 109 to display a predetermined image or image.

Therefore, in the organic light emitting device according to the present invention, the auxiliary electrode 105 is formed of a metal having low resistance on the overcoat layer 103 in the flexible organic light emitting device using plastic or SUS. By finally connecting 105 to the cathode electrode 117 and in parallel, as shown in FIG. 5, the resistance of the cathode electrode 117 can be significantly lowered as shown in Equation 1 below.

(Equation 1) ----- 1 / R (total) = 1 / r1 + 1 / r2

                       = r1 + r2 / (r1 * r2)

                       = r1 / (r1 * r2) (r1 >> r2)

                       = 1 / r2

Here, r1 is the resistance of the cathode electrode, r2 is the resistance of the auxiliary electrode.

Referring to Figures 3 and 4 with respect to the organic EL device manufacturing method according to the present invention having the configuration as described above are as follows.

4A to 4F are schematic cross-sectional views illustrating a method of manufacturing an organic light emitting diode according to the present invention.

5 is a schematic circuit diagram illustrating a parallel connection relationship between a cathode electrode and an auxiliary electrode in an organic light emitting diode according to the present invention.

As shown in FIG. 4A, the overcoat layer 103 is entirely deposited on a flexible substrate 101 such as plastic or SUS. In this case, the substrate 101 may be a transparent substrate such as PEN, PET, or PES, or an opaque substrate such as SUS or Al.

Next, as shown in FIG. 4B, a metal material film is deposited on the overcoat layer 103 using a sputtering method. In this case, as the metal material used as the metal material film, a metal material such as Al, Mo, Cu, Cr, etc. is used as the low resistance metal.

Subsequently, although not shown in the drawings, a first photoresist film is coated on the metal material layer and then patterned by a photolithography process and an etching process using an exposure mask to form a first photoresist pattern (not shown).

Next, the auxiliary material 105 is formed by selectively removing the metal material layer using the first photoresist pattern (not shown) as a mask.

Subsequently, as illustrated in FIG. 4C, the barrier layer 107 is entirely deposited on the overcoat layer 103 including the auxiliary electrode 105 after removing the first photoresist layer pattern (not shown).

Next, as shown in FIG. 4C, a metal material film is deposited on the overcoat layer 103 using a sputtering method. In this case, indium tin oxide (ITO) or SnO ₂ may be used as the metal material used as the metal material film.

Subsequently, although not shown in the drawings, a second photoresist film is coated on the metal material film and then patterned by a photolithography process and an etching process using an exposure mask to form a second photoresist pattern (not shown).

Next, as illustrated in FIG. 4D, the metal material layer is selectively removed using the second photoresist pattern (not shown) as a mask to form an anode electrode 109.

Subsequently, as shown in FIG. 4E, the second photoresist layer pattern (not shown) is removed, and then a photosensitive organic material is deposited on the barrier layer 107 including the anode electrode 109 and then subjected to a photolithography process. And an insulating pattern 113 including a contact hole 115 exposing a portion of the auxiliary electrode 105 to define a light emitting region in which the organic light emitting layer 111 is to be formed by selectively patterning by an etching process.

Next, after aligning a mask (not shown) for exposing an entire area of the anode electrode 109 which is a light emitting area other than the region of the insulating layer pattern 113 that is the non-light emitting area, an organic light emitting layer 111 is disposed on the anode electrode 109. ). In this case, the organic light emitting layer 111 is formed by sequentially stacking a hole injection layer (not shown), a hole transport layer (not shown), a light emitting layer (not shown) and an electron transport layer (not shown), an electron injection layer (not shown) do. In this case, the hole injection layer (not shown) and the hole transport layer (not shown) are formed using a common mask, and the light emitting layer (not shown) is a light emitting area partitioned by the insulating film pattern 113, that is, the anode electrode 109 Is formed using a shadow (metal) mask that exposes only). In addition, the electron transport layer (not shown) and the electron injection layer (not shown) are formed again using the common mask.

Subsequently, after the organic light emitting layer 111 is formed, a negative photosensitive organic material is coated on the insulating layer pattern 113, and then patterned by a photolithography process and an etching process using an exposure mask, as shown in FIG. 2. The partition 119 is formed.

 Next, as shown in FIG. 4F, a transparent metal material such as Al, Mg, Ca, or the like is sputtered on the organic light emitting layer 111 and the contact hole 115 using the barrier rib 119 as a mask. The thin film is deposited by a thin film to form the cathode electrode 117. At this time, the cathode electrode 117 is electrically separated by the partition 119 at the same time as the deposition. In addition, the cathode electrode 117 is electrically connected to the auxiliary electrode 105 through the contact hole 115. In addition, it is preferable that the thickness of the cathode electrode 117 is formed to be in the range of the extent to which light is transmitted, that is, about 10 to 500 mW.

Therefore, in the flexible organic light emitting device for lighting using plastic or SUS, the auxiliary electrode 105 is formed of a metal having low resistance on the overcoat layer 103, and finally, the cathode electrode 117 and the contact hole 115 are formed. As shown in FIG. 5, the resistance of the cathode electrode 117 having a thin thickness can be greatly reduced by electrically connecting in parallel, thereby reducing power consumption.

On the other hand, as another embodiment of the present invention, the inverted (inverted) type of organic light emitting device, that is, even when the anode electrode and the cathode electrode is changed to each other to electrically connect the anode electrode and the auxiliary electrode in the above-described embodiment, As in the example, the resistance of the anode can be significantly reduced.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

1 is a cross-sectional view schematically showing an organic light emitting device according to the prior art.

2 is a sectional view schematically showing an organic EL display element according to the present invention.

3 is a schematic cross-sectional view of an organic light emitting device according to the present invention, which is a cross-sectional view showing a connection structure of a cathode electrode and an auxiliary electrode.

4A to 4F are schematic cross-sectional views illustrating a method of manufacturing an organic light emitting diode according to the present invention.

5 is a schematic circuit diagram illustrating a parallel connection relationship between a cathode electrode and an auxiliary electrode in an organic light emitting diode according to the present invention.

*** Explanation of symbols on the main parts of the drawing ***

101 substrate 103 overcoat layer

105: auxiliary electrode 107: barrier layer

109: anode electrode 111: organic light emitting layer

113: insulating film pattern 115: contact hole

117: cathode electrode 119: partition wall

Claims (9)

An overcoat layer formed on the substrate; A plurality of auxiliary electrodes spaced at regular intervals formed on the overcoat layer; A barrier layer formed on the substrate including the plurality of auxiliary electrodes; A plurality of anode electrodes formed on the barrier layer and spaced apart at regular intervals; An insulating layer pattern formed on the barrier layer between the plurality of anode electrodes and having a contact hole exposing a part of the auxiliary electrode; An organic light emitting layer formed on the anode electrode; A cathode electrode formed on the organic light emitting layer to cross the anode electrode and electrically connected in parallel with the auxiliary electrode through the contact hole; And And a partition wall formed to intersect the anode electrode and electrically separating the cathode electrodes. The organic light emitting device of claim 1, wherein the auxiliary electrode is formed of Al, Mo, Cu, or Cr, which is a low resistance metal. The organic light emitting device of claim 1, wherein the substrate is a transparent material such as PEN, PET, or PES, or an opaque material such as SUS or Al. The organic light emitting device of claim 1, wherein the cathode is formed of Al, Mg, and Ca, and has a thickness of about 10 to 500 kPa, in a range of light transmission. Forming an overcoat layer on the substrate; Forming a plurality of auxiliary electrodes spaced at regular intervals on the overcoat layer; Forming a barrier layer on the substrate including the plurality of auxiliary electrodes; Forming a plurality of anode electrodes spaced apart at regular intervals on the barrier layer; Forming an insulating layer pattern including a contact hole exposing a part of the auxiliary electrode on a barrier layer therebetween except for the plurality of anode electrodes; Forming an organic light emitting layer on the anode; Forming a partition on the insulating film pattern; And Forming a plurality of cathode electrodes electrically connected in parallel with the auxiliary electrode through the contact hole on the organic light emitting layer by using the barrier as a mask. The method of claim 5, wherein the auxiliary electrode is formed of Al, Mo, Cu, or Cr, which is a low resistance metal. The method of claim 5, wherein the substrate is a transparent material such as PEN, PET, or PES, or an opaque material such as SUS or Al. The method of claim 5, wherein the cathode electrode is formed of Al, Mg, Ca, the thickness of the organic light emitting device manufacturing method, characterized in that formed in the range of about 10 ~ 500Å range of light transmission. The method of claim 5, wherein each of the cathode electrodes is electrically separated by a partition wall.

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