KR101779475B1 - Organic electro-luminescence device and method for fabricating of the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device and a method of manufacturing the same, and more particularly, to an organic electroluminescent device and a method of manufacturing the same that prevent voltage drop of a second electrode and improve process efficiency.
A feature of the present invention is to further prevent an occurrence of a voltage drop of the second electrode through the auxiliary electrode by further forming an auxiliary electrode between the upper side of the bank and the neighboring banks.
In addition, in the process of forming the organic light emitting layer, the organic light emitting layer may be coated or deposited on the entire surface of the substrate, and then the organic light emitting layer may be separated for each pixel region through the auxiliary electrode, thereby improving the efficiency of the process.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic electroluminescent device and a method for fabricating the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device and a method of manufacturing the same, and more particularly, to an organic electroluminescent device and a method of manufacturing the same that prevent voltage drop of a second electrode and improve process efficiency.

Until recently, CRT (cathode ray tube) was mainly used as a display device. However, in recent years, flat panel displays such as a plasma display panel (PDP), a liquid crystal display device (LCD), and an organic luminescence emitting device (OLED) Devices have been widely studied and used.

Of the above flat panel display devices, an organic electroluminescent element (hereinafter referred to as OLED) is a self-luminous element and can be lightweight and thin because it does not require a backlight used in a liquid crystal display device which is a non-light emitting element.

In addition, it has a better viewing angle and contrast ratio than liquid crystal display devices, is advantageous in terms of power consumption, can be driven by DC low voltage, has a fast response speed, is resistant to external impacts due to its solid internal components, It has advantages.

Particularly, since the manufacturing process is simple, it is advantageous in that the production cost can be saved more than the conventional liquid crystal display device.

FIG. 1 schematically shows a cross section of a general OLED, wherein the OLED is a top emission type.

As shown, the OLED 10 comprises a first substrate 1 and a second substrate 2 facing the first substrate 1, and the first and second substrates 1, So that the edges thereof are sealed and adhered to each other through a seal pattern (20).

In more detail, a driving thin film transistor DTr is formed for each pixel region P on the first substrate 1, a first electrode 11 connected to each driving thin film transistor DTr, An organic light emitting layer 13 for emitting light of a specific color is formed on the first electrode 11 and a second electrode 15 is formed on the organic light emitting layer 13.

The first and second electrodes 11 and 15 and the organic light emitting layer 13 formed therebetween form an organic light emitting diode E.

Here, the first electrode 11 is made of a conductive material having a relatively large work function value and serves as an anode electrode, and the second electrode 15 is a conductive material having a lower work function value than the first electrode 11 And serves as a cathode electrode.

In this case, the top emission type and the bottom emission type are divided according to the transmission direction of the light emitted through the organic electroluminescent diode E, The upper light emitting method is mainly used.

Accordingly, in the case of the upper emission type, light emitted from the organic light emitting layer 13 must be transmitted through the second electrode 15, while the second electrode 15 is made of a metal material having a low work function value. .

The second electrode 15 is formed by depositing a transparent conductive material thick on the semitransparent metal film thinly deposited on the second electrode 15. The second electrode 15 may be damaged by damage to the organic light- Temperature deposition is performed to minimize the thickness of the film.

In this case, when the second electrode 15 is formed by low-temperature deposition, the film quality of the second electrode 15 is poor and the same negative voltage is not applied to each pixel region P, A voltage difference is generated in a region close to and in a region where a voltage is input.

In addition, the second electrode 15 has a high resistivity. When the specific resistance is increased, the voltage drop is further intensified. As a result, the brightness and the image characteristics are unevenly generated. Causing problems.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide an organic electroluminescent device capable of preventing a voltage drop.

It is a second object of the present invention to provide a uniform signal to improve luminance and image characteristics.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a first substrate on which a driving thin film transistor is formed for each pixel region; An organic light emitting diode electrically connected to each of the driving thin film transistors, the organic light emitting diode comprising first and second electrodes and an organic light emitting layer provided between the first and second electrodes; And an auxiliary electrode electrically patterning the organic light emitting layer for each pixel region and electrically contacting the second electrode.

At this time, the auxiliary electrode overlaps the edge of the first electrode, and is positioned between the upper or adjacent banks formed at the boundary of each pixel region, and the auxiliary electrode is made of a conductor through which a current can flow .

The auxiliary electrode is made of a double layer and the first layer in contact with the second electrode is made of Ag, Al, Au, indium-tin-oxide (ITO) (IZO), and the second layer located under the first layer is one of molybdenum (Mo), tungsten (W), and chromium (Cr), and the auxiliary electrode is a matrix of a lattice structure Type, or formed in a linear structure along the row direction or the column direction of each pixel region.

The first substrate may further include a second substrate facing the first substrate.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display, comprising: forming a driving thin film transistor on a first substrate on which a pixel region is defined; Forming a first electrode in contact with the driving thin film transistor; Forming an auxiliary electrode on the boundary of the pixel region above the first electrode; Forming an organic light emitting material layer on the entire surface of the first substrate including the auxiliary electrode; Applying an electric current to the auxiliary electrode to remove the organic light emitting material layer located above the auxiliary electrode by heating to form an organic light emitting layer for each pixel region; And forming a second electrode on the entire surface of the first substrate including the organic light emitting layer, the second electrode being in contact with the auxiliary electrode.

Forming a bank at a boundary of the pixel region so as to overlap the edge of the first electrode after the first electrode is formed, and the auxiliary electrode is formed on the bank.

And forming a bank so that the auxiliary electrode is exposed after the auxiliary electrode is formed and the edge of each of the pixel regions is formed, and the auxiliary electrode is heated to 100 to 1000 ° C. or more.

The auxiliary electrode is made of a conductor through which a current can flow, the auxiliary electrode is made of a double layer, and the first layer in contact with the second electrode is made of silver (Ag), aluminum (Al) (Mo), tungsten (W), chromium (W), or the like. The first layer is formed of one of indium, tin, indium-tin- Cr).

The auxiliary electrode may be formed in a matrix structure of a lattice structure or may have a linear structure along a row direction or a column direction of each pixel region, and the auxiliary electrode may be formed of the same material as the first electrode.

The auxiliary electrode is made of one of indium-tin-oxide (ITO) and indium-zinc-oxide (IZO), and after the second electrode is formed, And attaching the second substrate.

As described above, according to the present invention, the auxiliary electrode is further formed between the upper side of the bank and the neighboring banks, thereby preventing the voltage drop of the second electrode from occurring through the auxiliary electrode.

Therefore, a uniform signal can be applied to the organic electroluminescent device, and the brightness and image characteristics can be made uniform.

In addition, in the process of forming the organic light emitting layer, the organic light emitting layer may be applied or deposited on the entire surface of the substrate, and then the organic light emitting layer may be separated for each pixel region through the auxiliary electrode, .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a cross section of a typical OLED. FIG.
2 is a cross-sectional view schematically illustrating an OLED according to a first embodiment of the present invention.
FIGS. 3A to 3G are cross-sectional views illustrating steps of manufacturing a first substrate of an OLED according to a first embodiment of the present invention;
4A to 4C are plan views schematically showing a state in which auxiliary electrodes are formed;
5 is a cross-sectional view schematically illustrating an OLED according to a second embodiment of the present invention.
6A to 6F are cross-sectional views of a first substrate of an OLED according to a second embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

- First Embodiment

2 is a cross-sectional view schematically showing an OLED according to a first embodiment of the present invention.

The OLED 100 according to the first embodiment of the present invention includes a first substrate 101 on which a driving thin film transistor DTr and an organic light emitting diode E are formed and a second substrate 101 for encapsulation The first and second substrates 101 and 102 are spaced apart from each other. The edge portions of the first and second substrates 101 and 102 are sealed and adhered to each other through a seal pattern 120.

A semiconductor layer 201 is formed on the pixel region P on the first substrate 101. The semiconductor layer 201 is made of silicon and has a central portion as an active region 201a forming a channel, And source and drain regions 201b and 201c doped with high-concentration impurities on both sides of the region 201a.

A gate insulating layer 203 is formed on the semiconductor layer 201.

The gate electrode 205 corresponding to the active region 201a is formed on the gate insulating film 203 and a gate wiring extending in one direction although not shown in the figure is formed.

A first interlayer insulating film 207a is formed on the entire upper surface of the gate electrode 205 and the gate wiring (not shown). At this time, the first interlayer insulating film 207a and the gate insulating film 203, And first and second semiconductor layer contact holes 209a and 209b that respectively expose the source and drain regions 201b and 201c located on both sides of the semiconductor layer 201a.

Next, upper portions of the first interlayer insulating film 207a including the first and second semiconductor layer contact holes 209a and 209b are separated from each other by the source and the drain, which are exposed through the first and second semiconductor layer contact holes 209a and 209b, And source and drain electrodes 211 and 213 which are in contact with the drain regions 201b and 201c, respectively.

A second interlayer insulating film 207b is formed on the first interlayer insulating film 207a exposed between the source and drain electrodes 211 and 213 and the two electrodes 211 and 213. The second interlayer insulating film 207b And a drain contact hole 215 exposing the drain electrode 213.

At this time, the semiconductor layer 201 including the source and drain electrodes 211 and 213 and the source and drain regions 201b and 201c in contact with the electrodes 211 and 213 and the gate insulating film 201 formed on the semiconductor layer 201 The gate electrode 203 and the gate electrode 205 constitute a driving thin film transistor DTr.

On the other hand, although not shown in the drawing, data lines (not shown) are formed which cross the gate wiring (not shown) and define the pixel region P. The switching thin film transistor (not shown) has the same structure as the driving thin film transistor DTr and is connected to the driving thin film transistor DTr.

In the drawing, the switching thin film transistor (not shown) and the driving thin film transistor DTr are shown as a top gate type in which the semiconductor layer 201 is formed of a polysilicon semiconductor layer. As a variation thereof, It may be formed as a bottom gate type of impurity amorphous silicon.

The first electrode 111, the organic light emitting layer 113 and the second electrode 115 constituting the organic electroluminescent diode E are sequentially formed on the second interlayer insulating film 207b, Respectively.

Here, the first electrode 111 and the organic light emitting layer 113 are formed for each pixel region P, and the second electrode 115 is formed on the entire surface of the first substrate 101 including the organic light emitting layer 113 .

A bank 119 is located in a non-pixel region (not shown) between the first electrode 111 and the organic light emitting layer 113 formed for each pixel region P.

That is, the banks 119 are formed in the matrix type of the lattice structure as a whole on the first substrate 101, and the first electrodes 111 are formed in the pixel regions P with the banks 119 as boundaries for the respective pixel regions P, Are formed in a separated structure.

The OLED 100 according to the first embodiment of the present invention is further characterized in that an auxiliary electrode 200 is further formed on the bank 119. The auxiliary electrode 200 is electrically connected to the second electrode 115 It serves to prevent voltage drop.

The organic light emitting layer 113 is formed separately for each pixel region P by the auxiliary electrode 200. Accordingly, the OLED 100 according to the first embodiment of the present invention can improve the process efficiency in the process of forming the organic light emitting layer 113. Let me take a closer look at this later.

The first electrode 111 is connected to the drain electrode 213 of the driving thin film transistor DTr through the drain contact hole 215 of the second interlayer insulating film 207b.

In this case, the first electrode 111 is formed of indium-tin-oxide (ITO), which is a relatively high work function value, to serve as an anode electrode, and the second electrode 115 is formed of a cathode cathode is made of a metal material having a relatively low work function value.

The light emitted from the organic light emitting layer 113 is driven by the upper light emitting method that is emitted toward the second electrode 115.

Here, the organic light emitting layer 113 may be a single layer made of a light emitting material. In order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, an emitting material layer ), An electron transporting layer, and an electron injection layer.

When a predetermined voltage is applied to the first electrode 111 and the second electrode 115 according to a selected color signal, the OLED 100 emits light from the first electrode 111 and the second electrode 115, Electrons are transported to the organic light emitting layer 113 to form an exciton. When the excitons are transited from the excited state to the ground state, light is emitted and emitted in the form of visible light.

At this time, the emitted light passes through the transparent second electrode 115 and exits to the outside, so that the OLED 100 realizes an arbitrary image.

Since the light emitted from the organic light emitting layer 113 must pass through the second electrode 115, the second electrode 115 must be made of a transparent conductive material. The transparent conductive material may be indium-tin-oxide (ITO) Indium-zinc-oxide (IZO). However, since the transparent conductive material has a high work function, it is difficult to use the transparent electrode as the second electrode 115.

Therefore, the second electrode 115 is formed by depositing a thick transparent conductive material on a semitransparent metal film thinly deposited with a metal material having a low work function. The second electrode 115 is formed by using an organic light emitting layer 113), the film quality is poor and the resistivity is high.

In this way, as the film quality of the second electrode 115 becomes poor and the specific resistance increases, the same negative voltage is not applied to each pixel region P, but a voltage drop due to an IR drop A voltage difference occurs in a region far from the OLED 100. This causes unevenness in luminance and image characteristics and raises a problem of increasing the power consumption of the OLED 100. [

The OLED 100 according to the first embodiment of the present invention further includes an auxiliary electrode 200 on the bank 119 and prevents the voltage drop of the second electrode 115 through the auxiliary electrode 200 , Thereby preventing such a problem.

At this time, as the thickness of the auxiliary electrode 200 becomes thicker, the voltage drop of the second electrode 115 can be more effectively prevented.

Particularly, the OLED 100 according to the first embodiment of the present invention can further improve the efficiency of the process by further forming the auxiliary electrode 200 on the bank 119.

Hereinafter, the manufacturing method of the OLED (100 of FIG. 2) according to the first embodiment of the present invention will be described in more detail. The OLED 100 according to the first embodiment of the present invention has a structural feature in the first substrate 101 on which the organic light emitting diode E is formed so that only the manufacturing method of the first substrate 101 is described would.

3A to 3G are cross-sectional views illustrating steps of manufacturing a first substrate of an OLED according to a first embodiment of the present invention.

3A, a driving thin film transistor DTr is formed on a substrate 101. The driving thin film transistor DTr includes a semiconductor layer 201 and a gate insulating film 203 formed on the semiconductor layer 201, And a gate electrode 205, a first interlayer insulating film 207a formed on the gate electrode 205, and source and drain electrodes 211 and 213.

A second interlayer insulating film 207b is formed on the source and drain electrodes 211 and 213. [

Although not shown in the drawing, a method of forming the amorphous silicon layer will be described in more detail. After deposition of the amorphous silicon layer, the photoresist layer may be formed by applying a photoresist, exposing through a mask, developing the exposed photoresist, A series of processes called patterning through a mask process such as etching of the silicon layer and ashing or strip of the remaining photoresist is performed to form the semiconductor layer 201. [

At this time, the semiconductor layer 201 is further subjected to a dehydrogenation process and then crystallized into polysilicon by heat treatment.

Next, a first insulating material is deposited on the substrate 101 on which the semiconductor layer 201 is formed to form a gate insulating layer 203, a first metal layer is deposited on the gate insulating layer 203, A first metal layer is formed as a gate electrode 205 at a central portion of the semiconductor layer 201 through a mask process.

Here, the first insulating material is preferably any one of silicon nitride (SiNx) and silicon oxide (SiO2), which are inorganic insulating materials.

The first metal layer may be formed by depositing one or more materials selected from metal materials such as aluminum (Al) or an aluminum alloy (AlNd), molybdenum (Mo), nickel (Ni), tungsten .

Next, the gate electrode 205 and the gate insulating film 203 exposed to the outside of the gate wiring (not shown) are etched and removed on the substrate 101 on which the semiconductor layer 201 is formed, N + or p + doping is performed by ion implantation with a dose amount.

At this time, in the semiconductor layer 201, the portion where the ion implantation is blocked by the gate electrode 205 forms the active layer 201a, and the other ion-implanted active region is the source and drain regions 201b and 201c. .

As a result, the semiconductor layer 201 including the active region 201a and the source and drain regions 201b and 201c is completed.

Next, the inorganic insulating material is deposited on the exposed source and drain regions 201b and 201c including the gate electrode 205, and the mask process is performed to pattern the source and drain regions 201b and 201c on both sides of the gate electrode 205 The first interlayer insulating film 207a having the first and second semiconductor layer contact holes 209a and 209b exposing a part of the first and second semiconductor layer contact holes 209a and 209b is formed.

Next, a metal material is deposited on the entire surface of the substrate 101 on which the first interlayer insulating film 207a having the first and second semiconductor layer contact holes 209a and 209b is formed, and the mask process is performed to perform patterning, The source and drain electrodes 211 and 213 are formed to contact the source and drain regions 201b and 201c through the layer contact holes 209a and 209b, respectively.

At this time, the source and drain electrodes 211 and 213 are spaced apart from each other with the gate electrode 205 therebetween.

Next, an organic insulating material such as photo acryl or benzocyclobutene (BCB) is applied to the entire surface of the substrate 101 on which the source and drain electrodes 211 and 213 are formed, An insulating film 207b is formed.

At this time, the second interlayer insulating film 207b has a drain contact hole 215 exposing the drain electrode 213.

Next, as shown in FIG. 3B, on the second interlayer insulating film 207b having the drain contact hole 215, indium-tin-oxide (ITO) or indium-zinc- (IZO) is deposited to have a thickness of several thousand angstroms and is patterned to form a plurality of pixel regions (P in FIG. 2) which are in contact with the drain electrodes 213 of the driving thin film transistor DTr through the drain contact holes 215, Thereby forming one electrode 111.

Next, as shown in FIG. 3C, a photosensitive organic insulating material such as black resin, graphite powder, gravure ink, black spray, or black enamel is coated on the first electrode 111 And the banks 119 are formed on the first electrodes 111 by patterning them.

The banks 119 are formed as a matrix type of a lattice structure as a whole on the substrate 101, and distinguish between the pixel regions (P in Fig. 2).

Next, as shown in FIG. 3D, a low resistance metal material such as Ag, Al, Au, Indium-Tin-oxide (ITO) -Oxide (IZO) material is deposited to form the auxiliary electrode 200.

At this time, the auxiliary electrode 200 may have a single layer structure made of the above-described low resistance metal material, or may have a double layer structure, though not shown in the drawing.

When the auxiliary electrode 200 is made of a double layer, the first layer (not shown) contacting the bank 119 is made of a metal material such as molybdenum (Mo), tungsten (W), chromium (Cr) ) And titanium (Ti), and the second layer (not shown) formed to cover the first layer (not shown) may be made of the above-described low resistance metal material.

In addition, the auxiliary electrode 200 can be any material that can conduct current.

Next, as shown in FIG. 3E, an organic light emitting material layer 113a is formed by applying or depositing an organic light emitting material on the entire surface of the substrate 101 including the auxiliary electrode 200.

The organic luminescent material layer 113a is formed on the entire surface of the substrate 101 by coating or spraying using a nozzle coating apparatus (not shown), a dispensing apparatus (not shown), or an ink jet apparatus (not shown) Alternatively, the organic light emitting material layer 113a may be formed by a vacuum thermal deposition method.

In this case, in the vacuum thermal deposition method, heat is applied to a crucible (not shown) in which an organic light emitting material for forming an organic light emitting material layer is contained in a powder state in a vacuum chamber (not shown) do.

Although not shown in the figure, the organic light emitting material layer 113a may be a single layer made of a light emitting material. In order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, emitting material layer, an electron transporting layer, and an electron injection layer.

Next, as shown in FIG. 3F, by removing the organic light emitting material layer (113a in FIG. 3E) located above the auxiliary electrode 200 by the heat generated by applying the current to the auxiliary electrode 200, (P in FIG. 2) are formed.

This is a joule heating method in which heat is generated when an electric current is applied to the auxiliary electrode 200 made of a metal material. The generated heat heats the organic light emitting material layer (113a in FIG. 3E) located above the auxiliary electrode 200. The heated organic light emitting material layer (113a in FIG. 3E) contacts the auxiliary electrode 200 Only the area that has been heated is heated. Accordingly, the organic light emitting material layer (113a in FIG. 3E) which is in contact with the auxiliary electrode is heated and sublimated and removed on the auxiliary electrode 200.

As a result, the auxiliary electrode 200 is exposed and the organic light emitting material layer 113a of FIG. 3E has a structure separated by each pixel region (P in FIG. 2).

Such a row heating method is caused by the Joule's law, and the amount of heat generated in the auxiliary electrode 200 is proportional to the square of the applied current or voltage and the resistance of the auxiliary electrode 200.

At this time, it is preferable that the auxiliary electrode 200 is heated to 350 to 500 ° C at which the organic light emitting material can be sublimated by heating.

Next, as shown in 3g, a metal material having a relatively low work function value such as aluminum (Al) is deposited on the organic light emitting layer 113 formed by the auxiliary electrode 200 for each pixel region (P in FIG. 2) (Al), aluminum (Ag), magnesium (Mg), and gold (Au) is deposited on the entire surface of the substrate 101 by thermal deposition or ion beam deposition, (115).

At this time, it is preferable that the second electrode 115 is formed at a low temperature to minimize the damage of the organic light emitting layer 113.

Although not shown in the drawing, in order to protect the second electrode 115 having a relatively thin thickness and to prevent moisture from penetrating into the organic light emitting layer 113, a transparent conductive material such as indium An auxiliary second electrode (not shown) having a thickness of about 500 Å to 2000 Å may be further formed of tin oxide (ITO) or indium-zinc-oxide (IZO).

At this time, the second electrode 115 is brought into contact with the exposed auxiliary electrode 200, so that the voltage drop due to the internal resistance of the second electrode 115 hardly occurs, It is possible to prevent a luminance non-uniformity phenomenon within the display panel.

The OLED 100 according to the first embodiment of the present invention is not separately formed for each pixel region (P in FIG. 2) in the process of forming the organic light emitting layer 113, By coating or vapor-depositing on the entire surface, the efficiency of the process can be improved.

That is, when the organic light emitting material is formed by coating or spraying each pixel region (P in FIG. 2) using a nozzle coating apparatus (not shown), a dispensing apparatus (not shown), or an inkjet apparatus It is necessary to consider the quantification of the organic luminescent material to be coated or injected into the pixel region (P in FIG. 2), the position of coating or injection, and the like, so that the process is very difficult.

In addition, when the organic light emitting materials are deposited for each pixel region (P in FIG. 2) through a vacuum thermal deposition method, a shadow mask (not shown) having openings is required for each pixel region (P in FIG. 2) The process cost is increased and the additional process such as the alignment process of the shadow mask (not shown) and the substrate 101 is also required, which causes a problem that the process time is also increased.

In contrast, according to the present invention, the organic luminescent material is formed on the entire surface of the substrate 101 without being formed for each pixel region (P in FIG. 2) Are separated for each pixel region (P in Fig. 2), it is possible to prevent the above-described problems from occurring and improve the efficiency of the process.

4A to 4C are plan views schematically showing a state in which auxiliary electrodes are formed.

As shown in FIG. 4A, the auxiliary electrode 200 may be formed in a matrix type of a lattice structure above the banks 119 covering the edge of each pixel region P, and may be formed as shown in FIGS. 4B and 4C Likewise, they may be formed in a linear structure along the row direction or the column direction of each pixel region P.

 At this time, auxiliary electrode wirings 200a and 200b for applying a voltage or a current to the auxiliary electrode 200 may be further provided on one side of the substrate 101. [

As described above, the OLED according to the first embodiment of the present invention (100 in FIG. 2) further includes the auxiliary electrode 200 on the bank 119, thereby forming the second electrode 115 The organic luminescent layer 113 is coated or deposited on the entire surface of the substrate 101 and then the organic luminescent layer 113 is formed on the entire surface of the substrate 101 through the auxiliary electrode 200 By separating the organic light emitting layer 113 for each pixel region P, the efficiency of the process can be improved.

- Embodiment 2

5 is a cross-sectional view schematically showing an OLED according to a second embodiment of the present invention.

Prior to the description, the same reference numerals are assigned to the same parts as those in the previous description in order to avoid redundant description with the first embodiment described above, and only the characteristic contents will be described.

The OLED 100 according to the second embodiment of the present invention is characterized in that the bank 119 is formed with the edge of each pixel region P for each pixel region P, Are formed between adjacent banks (119).

The second electrode 115 formed on the front surface of the substrate 101 is brought into contact with the auxiliary electrode 200 formed between the neighboring banks 119 through which the second electrode 115 is connected to the internal resistance So that it is possible to prevent the luminance non-uniformity in the display region.

The OLED 100 according to the second embodiment of the present invention may further include an auxiliary electrode 200 formed between neighboring banks 119 after the organic light emitting layer 113 is coated or deposited on the entire surface of the substrate 101, So that the efficiency of the process can be improved.

In particular, the OLED 100 according to the second embodiment of the present invention can form the auxiliary electrode 200 with the same material as the first electrode 111 of the organic electroluminescent diode E in the same process, Can be improved.

Hereinafter, a manufacturing method of the OLED 100 according to the second embodiment of the present invention will be described in more detail. Since the OLED 100 according to the second embodiment of the present invention has a structural feature in the first substrate 101 on which the organic electroluminescent diode E is formed, only the method of manufacturing the first substrate 101 will be described would.

6A to 6F are cross-sectional views illustrating steps of manufacturing a first substrate of an OLED according to a second embodiment of the present invention.

6A, a driving thin film transistor DTr is formed on a substrate 101. The driving thin film transistor DTr includes a semiconductor layer 201 and a gate insulating film 203 formed on the semiconductor layer 201, And a gate electrode 205, a first interlayer insulating film 207a formed on the gate electrode 205, and source and drain electrodes 211 and 213.

A second interlayer insulating film 207b is formed on the source and drain electrodes 211 and 213. [

Next, as shown in FIG. 6B, an indium-tin-oxide (ITO) or indium-zinc-oxide (ITO) film, which is a transparent conductive material having a relatively high work function value, is formed on the second interlayer insulating film 207b having the drain contact hole 215, (IZO) is deposited to have a thickness of several thousand angstroms and is patterned to form a thin film transistor (TFT) in contact with the drain electrode 229 of the driving thin film transistor DTr through the drain contact hole 215 for each pixel region The auxiliary electrode 200 is formed corresponding to the boundary between the one electrode 111 and each pixel region (P in FIG. 5).

The auxiliary electrode 200 is formed in a matrix type of a grid structure as a whole over the substrate 101 to distinguish between the pixel regions (P in FIG. 2).

Next, as shown in FIG. 6C, a photosensitive organic insulating material such as black resin, graphite powder, gravure ink, black spray, black (black), or the like is coated on top of the first electrode 111 and the auxiliary electrode 200. [ One of the enamel is applied and patterned to form the bank 119.

5) formed between the neighboring banks 119. The auxiliary electrodes 200 are formed to correspond to the boundaries of the pixel regions (P in FIG. 5) ).

6D, an organic light emitting material layer 113a is formed by applying or depositing an organic light emitting material on the entire surface of the substrate 101 including the bank 119 and the auxiliary electrode 200. Next, as shown in FIG.

Although not shown in the figure, the organic light emitting material layer 113a may be a single layer made of a light emitting material. In order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, emitting material layer, an electron transporting layer, and an electron injection layer.

Next, as shown in FIG. 6E, by the heat generated by applying a current to the auxiliary electrode 200 exposed between the neighboring banks 119, the organic light emitting material layer The organic emission layer 113 separated from each pixel region (P in FIG. 5) is formed.

This is a joule heating method in which heat is generated when an electric current is applied to the auxiliary electrode 200 made of a metal material. 6D) of the organic light emitting material layer (113a in FIG. 6D) is heated by the heat generated in the auxiliary electrode 200, Only the area that has been heated is heated. Accordingly, the organic light emitting material layer (113a in FIG. 6D) which is in contact with the auxiliary electrode 200 is heated and sublimated and removed on the auxiliary electrode 200. [

As a result, the auxiliary electrode 200 is exposed and the organic light emitting material layer (113a of FIG. 6D) has a separate structure for each pixel region (P in FIG. 5).

Such a row heating method is caused by the Joule's law, and the amount of heat generated in the auxiliary electrode 200 is proportional to the square of the applied current or voltage and the resistance of the auxiliary electrode 200.

At this time, it is preferable that the auxiliary electrode 200 is heated to 350 ° C or higher, at which the organic light emitting material can be sublimated by heating.

Next, as shown in FIG. 6F, a metal material having a relatively low work function value, for example, aluminum (Al) is deposited on the organic light emitting layer 113 formed separately for each pixel region (P in FIG. 2) by the auxiliary electrode 200, (Al), aluminum (Ag), magnesium (Mg), and gold (Au) is deposited on the entire surface of the substrate 101 by thermal deposition or ion beam deposition, (115).

At this time, the second electrode 115 is brought into contact with the exposed auxiliary electrode 200, so that the voltage drop due to the internal resistance of the second electrode 115 hardly occurs, It is possible to prevent a luminance non-uniformity phenomenon within the display panel.

The OLED 100 according to the second embodiment of the present invention is not separately formed for each pixel region (P in FIG. 5) in the process of forming the organic light emitting layer 113, And the organic light emitting layer 113 is separated for each pixel region (P in FIG. 2) through the auxiliary electrode 200, so that the efficiency of the process can be improved.

In particular, the OLED according to the second embodiment of the present invention (100 in FIG. 5) can form the auxiliary electrode 200 in the same process as the first electrode 111 of the organic electroluminescent diode E in the same process , The efficiency of the process can be further improved.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

100: OLED, 101: first substrate, 102: second substrate
111: first electrode, 113: organic light emitting layer, 115: second electrode
119: bank, 120: seal pattern, 200: auxiliary electrode
201: semiconductor layer (201a: active region, 201b, 201c: source and drain regions)
203: gate insulating film, 205: gate electrode, 207a, 207b: first and second interlayer insulating films
209a, 209b: first and second semiconductor layers, 211: source electrode, 213: drain electrode
215: drain contact hole

Claims (17)

A first substrate provided with a driving thin film transistor for each pixel region;
An organic light emitting diode electrically connected to each of the driving thin film transistors, the organic light emitting diode comprising first and second electrodes and an organic light emitting layer provided between the first and second electrodes;
An auxiliary electrode disposed on a boundary of the pixel region and in electrical contact with the second electrode;
A plurality of pixel electrodes arranged on the substrate,
Lt; / RTI >
Wherein the auxiliary electrode is a matrix type having a lattice structure made of the same layer and the same material as the first electrode or a linear structure along a row direction or a column direction of each pixel region.

delete The method according to claim 1,
Wherein the auxiliary electrode comprises a conductor through which a current can flow.
The method according to claim 1,
The auxiliary electrode is made of a double layer and the first layer in contact with the second electrode is made of Ag, Al, Au, Indium-Tin-Oxide (ITO) Oxide (IZO), and the second layer located under the first layer is one of molybdenum (Mo), tungsten (W), and chromium (Cr).
delete The method according to claim 1,
And a second substrate facing the first substrate. Forming a driving thin film transistor on a first substrate on which a pixel region is defined;
Forming a first electrode in the pixel region in contact with the driving thin film transistor;
Forming auxiliary electrodes at the boundaries of the pixel regions;
Forming an organic light emitting material layer on the entire surface of the first substrate including the auxiliary electrode;
Applying an electric current to the auxiliary electrode to form an organic light emitting layer by removing the organic light emitting material layer located above the auxiliary electrode by heating;
Forming a second electrode in contact with the auxiliary electrode on the entire surface of the first substrate including the organic light emitting layer
/ RTI >
Wherein the auxiliary electrode is formed in a matrix structure of a lattice structure or in a linear structure along a row direction or a column direction of each pixel region.

8. The method of claim 7,
And forming a bank at a boundary of the pixel region so as to overlap the edge of the first electrode after the first electrode is formed.
9. The method of claim 8,
Wherein the auxiliary electrode is formed on the bank.
8. The method of claim 7,
And forming a bank so that the auxiliary electrode is exposed after the auxiliary electrode is formed, the edge of each of the pixel regions being formed, and the bank being formed to expose the auxiliary electrode.
8. The method of claim 7,
Wherein the auxiliary electrode is heated to 100 to 1000 캜.
8. The method of claim 7,
Wherein the auxiliary electrode comprises a conductor through which a current can flow.
8. The method of claim 7,
The auxiliary electrode is made of a double layer and the first layer in contact with the second electrode is made of Ag, Al, Au, Indium-Tin-Oxide (ITO) Wherein the second layer is one of molybdenum (Mo), tungsten (W), and chromium (Cr).


delete 8. The method of claim 7,
Wherein the auxiliary electrode is formed of the same material as the first electrode.
16. The method of claim 15,
Wherein the auxiliary electrode comprises one of indium-tin-oxide (ITO) and indium-zinc-oxide (IZO).
8. The method of claim 7,
And bonding the second substrate to the first substrate and the edge portion with the seal pattern interposed therebetween after the second electrode is formed.

Images