KR20110138787A - Organic electro-luminescence device and method for fabricating of the same - Google Patents

Abstract

PURPOSE: An organic electro-luminescence device and a manufacturing method thereof are provided to form a sub electrode on the top of a bank or between adjacent banks, thereby preventing a voltage drop of a second electrode by the sub electrode. CONSTITUTION: A first substrate(101) and a second substrate(102) are bonded by a seal pattern(120). A thin film driving transistor(DTr) and an organic electro-luminescence diode(E) are formed on the first substrate. A semiconductor layer(201) is formed on a pixel area(P) of the first substrate. A gate insulating film(203) is formed on the semiconductor layer. Source and drain electrodes(211,213) are formed on the top of a first interlayer insulating film(207a).

Description

Organic electroluminescent device and method for manufacturing same {Organic electro-luminescence device and method for fabricating of the same}

The present invention relates to an organic light emitting display device and a method for manufacturing the same, and more particularly, to an organic light emitting display device and a method for manufacturing the same, which prevents the voltage drop of the second electrode and improves the efficiency of the process.

Until recently, cathode ray tubes (CRTs) were mainly used as display devices. Recently, however, flat panel displays such as plasma display panels (PDPs), liquid crystal display devices (LCDs), and organic luminescence emitting devices (OLEDs), which can replace CRTs, have recently been used. Devices are being widely researched and used.

Among the flat panel display devices as described above, the organic light emitting display device (hereinafter referred to as OLED) is a self-light emitting device, and since the backlight used in the liquid crystal display device which is a non-light emitting device is not necessary, a light weight can be achieved.

In addition, the viewing angle and contrast ratio are superior to the liquid crystal display device, and it is advantageous in terms of power consumption. It is also possible to drive DC low voltage, has a fast response speed, and the internal components are solid, so it is strong against external shock and has a wide temperature range. It has advantages

In particular, since the manufacturing process is simple, there is an advantage that can reduce the production cost more than the conventional liquid crystal display device.

1 is a view schematically showing a cross section of a general OLED, wherein the OLED is a top emission method.

As shown, the OLED 10 is composed of a first substrate 1 and a second substrate 2 facing the first substrate 1, and the first and second substrates 1, 2 are connected to each other. It is spaced apart and the edge thereof is encapsulated and sealed through a fail pattern 20.

In detail, the driving thin film transistor DTr is formed in each pixel region P on the first substrate 1, and the first electrode 11 connected to each driving thin film transistor DTr and An organic light emitting layer 13 emitting light of a specific color on the first electrode 11 and a second electrode 15 are 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 to serve as an anode, and the second electrode 15 has a smaller work function than the first electrode 11. It consists of and serves as a cathode (cathode) electrode.

At this time, according to the transmission direction of the light emitted through the organic light emitting diode (E) is divided into a top emission type (top emission type) and a bottom emission method (bottom emission type), the lower emission method has a problem that the aperture ratio is lowered In recent years, the top emission method has been mainly used.

Therefore, in the case of the top emission method, the light emitted from the organic light emitting layer 13 must pass through the second electrode 15, but the second electrode 15 has an opaque characteristic as it is made of a metal material having a low work function value. Will have

Accordingly, the second electrode 15 is used by thickly depositing a transparent conductive material on a semi-transparent metal film in which a thin metal material having a low work function is deposited. The second electrode 15 may damage the organic light emitting layer 13. It is formed by low temperature deposition to minimize the.

Thus, when the second electrode 15 is formed by low temperature deposition, the second electrode 15 is poor in film quality, and the same cathode voltage is not applied to each pixel region P, and the voltage drop IR drop is applied. ), A voltage difference occurs in a region near and far from a voltage input region.

In addition, the second electrode 15 has a higher resistivity, and when the resistivity becomes higher, the voltage drop is further increased, which in turn causes unevenness in brightness and image characteristics, and increases power consumption of the OLED 10. It causes a problem.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide an organic light emitting device capable of preventing a voltage drop.

Accordingly, the second object is to improve the luminance and image characteristics by providing a uniform signal.

In order to achieve the object as described above, the present invention includes a first substrate formed 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 an organic light emitting layer disposed between the first and second electrodes and the first and second electrodes; The organic light emitting diode is formed by patterning the organic light emitting layer for each pixel area, and includes an auxiliary electrode in electrical contact with the second electrode.

In this case, the auxiliary electrode overlaps an edge of the first electrode, and is located at an upper portion of a bank formed at a boundary of each pixel region or between adjacent banks, and the auxiliary electrode is formed of a conductor through which current can flow. .

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

The apparatus further includes a second substrate facing the first substrate.

In addition, the present invention includes forming a driving thin film transistor on a first substrate in which a pixel region is defined; Forming a first electrode in contact with the driving thin film transistor; Forming an auxiliary electrode on a boundary of the pixel area above the first electrode; Forming an organic light emitting material layer on an 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 on the auxiliary electrode by heating sublimation to form an organic light emitting layer for each pixel region; It is formed on the front surface of the first substrate including the organic light emitting layer, and provides a method of manufacturing an organic light emitting device comprising the step of forming a second electrode in contact with the auxiliary electrode.

In this case, after forming the first electrode, forming a bank at a boundary of the pixel region to overlap the edge of the first electrode, wherein the auxiliary electrode is formed on the bank.

After forming the auxiliary electrode, forming a bank to cover the edges of the pixel areas and to expose the auxiliary electrode, wherein the auxiliary electrode is heated to 100 to 1000 ° C. or more.

In addition, the auxiliary electrode is made of a conductor through which a current can flow, the auxiliary electrode is made of a double layer, the first layer in contact with the second electrode is silver (Ag), aluminum (Al), gold ( Au), indium tin oxide (ITO), or indium zinc oxide (IZO), and the second layer located below the first layer is molybdenum (Mo), tungsten (W), chromium ( Cr).

In this case, the auxiliary electrode may be formed in a matrix type having 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 made of the same material as the first electrode.

The auxiliary electrode may be made of one of indium tin oxide (ITO) or indium zinc oxide (IZO), and after forming the second electrode, a seal pattern may be formed between the first substrate and the edge portion. And bonding the second substrate.

As described above, according to the present invention, by further forming an auxiliary electrode between the upper banks or between adjacent banks, the voltage drop of the second electrode is prevented from occurring through the auxiliary electrodes.

As a result, a uniform signal can be applied to the organic light emitting display device, whereby luminance and image characteristics can be made uniform.

In addition, in the process of forming the organic light emitting layer, the organic light emitting layer is applied or deposited on the entire surface of the substrate, and the organic light emitting layer is separated by each pixel region through the auxiliary electrode, thereby improving the efficiency of the process There is.

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

As illustrated, 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 for encapsulation. It is composed of a substrate 102, the first and second substrates 101, 102 are spaced apart from each other, the edge portion thereof is sealed and bonded through a seal pattern (seal pattern 120).

Here, the semiconductor layer 201 is formed in the pixel region P on the first substrate 101. The semiconductor layer 201 is made of silicon, and a central portion thereof forms an active region 201a that forms a channel. Source and drain regions 201b and 201c doped with a high concentration of impurities on both sides of the region 201a.

The gate insulating film 203 is formed on the semiconductor layer 201.

A gate electrode 205 and a gate wiring extending in one direction are formed on the gate insulating film 203 to correspond to the active region 201a, although not shown in the drawing.

In addition, a first interlayer insulating film 207a is formed on the entire upper surface of the gate electrode 205 and the gate wiring (not shown), wherein the first interlayer insulating film 207a and the gate insulating film 203 thereunder are active regions. First and second semiconductor layer contact holes 209a and 209b exposing the source and drain regions 201b and 201c located on both sides thereof are provided.

Next, an upper portion of the first interlayer insulating layer 207a including the first and second semiconductor layer contact holes 209a and 209b is spaced apart from each other and exposed through the first and second semiconductor layer contact holes 209a and 209b. And source and drain electrodes 211 and 213 in contact with the drain regions 201b and 201c, respectively.

The 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 drain contact hole 215 exposes 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 layer formed on the semiconductor layer 201. The 203 and the gate electrode 205 form a driving thin film transistor DTr.

On the other hand, although not shown in the figure, data wirings (not shown) defining the pixel region P are formed to cross the gate wirings (not shown). 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 addition, the switching thin film transistor (not shown) and the driving thin film transistor DTr in the drawing show a top gate type in which the semiconductor layer 201 is made of a polysilicon semiconductor layer as an example. It may be formed of a bottom gate type made of amorphous silicon of impurities.

In addition, the first electrode 111 constituting the organic light emitting diode E, the organic light emitting layer 113, and the second electrode 115 are sequentially disposed in an area that substantially displays an image on the second interlayer insulating film 207b. It is formed.

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. It is.

A bank 119 is positioned 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. FIG.

That is, the bank 119 is formed in a matrix type having a lattice structure as a whole, and the first electrode 111 is the pixel region P with the bank 119 as a boundary for each pixel region P. Star is formed in a separate structure.

At this time, the OLED 100 according to the first embodiment of the present invention is characterized in that the auxiliary electrode 200 is further formed on the bank 119, the auxiliary electrode 200 of the second electrode 115 Prevents voltage drop.

In addition, the organic light emitting layer 113 is separated and formed for each pixel region P by the auxiliary electrode 200. Therefore, the OLED 100 according to the first embodiment of the present invention may improve the efficiency of the process in the process of forming the organic light emitting layer 113. We will discuss this in more detail 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 layer 207b.

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

In addition, the light emitted from the organic light emitting layer 113 is driven by the upper emission method emitted toward the second electrode 115.

Here, the organic light emitting layer 113 may be composed of a single layer made of a light emitting material, and in order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, and an emitting material layer ), And may be composed of multiple layers of 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 the selected color signal, the OLED 100 is injected from the hole provided from the first electrode 111 and the second electrode 115. The electrons are transported to the organic light emitting layer 113 to form an exciton, and when the exciton transitions from the excited state to the ground state, light is generated and emitted in the form of visible light.

At this time, since the emitted light passes through the transparent second electrode 115 to the outside, the OLED 100 implements an arbitrary image.

On the other hand, since the light emitted from the organic light emitting layer 113 must pass through the second electrode 115, the second electrode 115 should be made of a transparent conductive material, the transparent conductive material is indium-tin-oxide (ITO) or Although a material such as indium-zinc-oxide (IZO) is used, such a transparent conductive material has a high work function and is difficult to use as the second electrode 115.

Accordingly, the second electrode 115 is used by thickly depositing a transparent conductive material on a semi-transparent metal film in which a thin metal material having a low work function is deposited. The second electrode 115 may be formed of an organic light emitting layer formed by heat or plasma. It is formed by low temperature deposition in order to minimize the damage of 113, resulting in poor film quality and high resistivity.

In this way, as the film quality of the second electrode 115 is bad and the specific resistance is high, the same cathode voltage is not applied to each pixel region P, but is closer to the portion where the voltage is input by the IR drop. The voltage difference occurs in a region far from the region, which causes non-uniformity of brightness or image characteristics, and causes a problem of increasing power consumption of the OLED 100.

Accordingly, the OLED 100 according to the first embodiment of the present invention further forms an auxiliary electrode 200 on the bank 119 and prevents the voltage drop of the second electrode 115 through the auxiliary electrode 200. This is to prevent such a problem.

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

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

This will be described in more detail through the manufacturing method of the OLED (100 of FIG. 2) according to the first embodiment of the present invention. Here, since 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, only the manufacturing method of the first substrate 101 will be described. would.

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

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

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

Although not shown in the drawings, the method for forming the same is described in detail. After depositing amorphous silicon, coating of photoresist, exposure through a mask, development of exposed photoresist, and remaining amorphous photoresist exposed after development The semiconductor layer 201 is formed by performing a series of processes called patterning through a mask process such as etching the silicon layer and ashing or stripping the remaining photoresist.

In this case, the method may further include crystallizing polysilicon by heat treatment after dehydrogenation of the semiconductor layer 201.

Next, after the first insulating material is deposited on the substrate 101 on which the semiconductor layer 201 is formed to form the gate insulating film 203, the first metal layer is deposited on the gate insulating film 203, and as described above. As described above, the first metal layer is formed as the gate electrode 205 in the center of the semiconductor layer 201 through a mask process.

Here, the first insulating material is preferably any one of silicon nitride (SiNx) or silicon oxide (Si02) which is an inorganic insulating material.

The first metal layer is formed by depositing one or two or more materials selected from metal materials such as aluminum (Al) or aluminum alloy (AlNd), molybdenum (Mo), nickel (Ni), tungsten (W), and the like. It is preferable to set it as.

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

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

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

Next, an inorganic insulating material is deposited on the exposed source and drain regions 201b and 201c including the gate electrode 205 and patterned by performing a mask process, thereby forming source and drain regions 201b on both sides of the gate electrode 205. And a first interlayer insulating film 207a having first and second semiconductor layer contact holes 209a and 209b exposing a portion thereof, respectively.

Next, the first and second semiconductors are deposited by depositing a metal material 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 performing a mask process. Source and drain electrodes 211 and 213 in contact with the source and drain regions 201b and 201c are formed through the layer contact holes 209a and 209b, respectively.

In this case, 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 coated on the entire surface of the substrate 101 on which the source and drain electrodes 211 and 213 are formed, and the second interlayer is formed on the entire surface of the substrate 101. The insulating film 207b is formed.

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

Next, as shown in FIG. 3B, indium-tin-oxide (ITO) or indium-zinc- which is a transparent conductive material having a relatively high work function value over the second interlayer insulating film 207b having the drain contact hole 215. By depositing and patterning an oxide (IZO) to have a thickness of about several thousand micrometers, each pixel region (P of FIG. 2) contacts the drain electrode 213 of the driving thin film transistor DTr through the drain contact hole 215. One electrode 111 is formed.

Next, as shown in FIG. 3C, one of photosensitive organic insulating materials, for example, black resin, graphite powder, gravure ink, black spray, and black enamel is coated on the first electrode 111. By patterning this, the bank 119 is formed on the first electrode 111.

The bank 119 is formed in a matrix type having a lattice structure as a whole to distinguish between the pixel areas P of FIG. 2.

Next, as shown in FIG. 3D, a low-resistance metal material on the bank 119, for example, silver (Ag), aluminum (Al), gold (Au), indium tin oxide (ITO), or indium zinc The auxiliary electrode 200 is formed by depositing one material selected from a metal material such as an oxide (IZO) material.

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

When the auxiliary electrode 200 is formed of a double layer, the first layer (not shown) in contact with the bank 119 may include molybdenum (Mo), tungsten (W), and chromium (Cr), which are metal materials having excellent bonding strength with the bank 119. ), Made of titanium (Ti), and a second layer (not shown) formed covering the first layer (not shown) may be made of the above-described low resistance metal material.

In addition, the auxiliary electrode 200 may be formed of any material of which the current can flow.

Next, as illustrated in FIG. 3E, an organic light emitting material is coated or deposited on the entire surface of the substrate 101 including the auxiliary electrode 200 to form the organic light emitting material layer 113a.

The organic light emitting material layer 113a may be coated or sprayed using a nozzle coating device (not shown), a dispensing device (not shown), or an inkjet device (not shown) to form an organic light emitting material layer (on the front surface of the substrate 101). 113a) may be formed, or the organic light emitting material layer 113a may be formed through a vacuum thermal evaporation method.

At this time, 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 formed in a powder state in a vacuum chamber (not shown), thereby heating and subliming the organic light emitting material to be deposited. do.

Although not shown in the drawings, the organic light emitting material layer 113a may be composed of a single layer made of a light emitting material, and a hole injection layer, a hole transporting layer, a light emitting layer ( It may be composed of multiple layers of an emitting material layer, an electron transporting layer, and an electron injection layer.

Next, as illustrated in FIG. 3F, each pixel region is removed by removing the organic light emitting material layer (113a of FIG. 3E) positioned on the auxiliary electrode 200 by heat generated by applying current to the auxiliary electrode 200. Each of the organic light emitting layers 113 (p) of FIG. 2 is formed.

This is a joule's heating method. When a current is applied to the auxiliary electrode 200 made of a metal material, heat is generated. The generated heat heats the organic light emitting material layer (113a of FIG. 3E) positioned on the auxiliary electrode 200, wherein the heated organic light emitting material layer (113a of FIG. 3E) is in contact with the auxiliary electrode 200. Only the heated area is heated. Accordingly, the organic light emitting material layer (113a of FIG. 3E) in contact with the auxiliary electrode is heated and sublimed to be 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 separate structure for each pixel region (P of FIG. 2).

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

At this time, the auxiliary electrode 200 is preferably heated to 350 ~ 500 ℃ that the organic light emitting material can be heat sublimated.

Next, as shown in 3g, a metal material having a relatively small work function value, for example, aluminum (Al), on the organic light emitting layer 113 formed by separating the pixel region (P in FIG. 2) by the auxiliary electrode 200. The second electrode to have a relatively thin thickness on the front of the substrate 101 by thermal evaporation or ion beam deposition of one of aluminum alloy, silver (Ag), magnesium (Mg) and gold (Au). Form 115.

In this case, the second electrode 115 is preferably formed at a low temperature in order to minimize the damage of the organic light emitting layer 113.

Although not shown in the drawings, 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, for example, indium, is disposed on the second electrode 115. An auxiliary second electrode (not shown) having a thickness of about 500 kPa to 2000 kPa may be further formed of -tin-oxide (ITO) or indium-zinc-oxide (IZO).

In this case, the second electrode 115 comes into contact with the exposed auxiliary electrode 200, and thus, the second electrode 115 hardly experiences a voltage drop due to internal resistance. It is possible to prevent the luminance unevenness inside.

In addition, in the process of forming the organic light emitting layer 113, the OLED (100 of FIG. 2) according to the first exemplary embodiment of the present invention is not separately configured for each pixel region (P of FIG. 2), By coating or depositing on the entire surface, it is possible to improve the efficiency of the process.

That is, when the organic light emitting material is formed by coating or spraying each pixel region (P of FIG. 2) using a nozzle coating device (not shown), a dispensing device (not shown), or an inkjet device (not shown), Since the quantification of the organic light emitting material to be coated or sprayed on the pixel region (P of FIG. 2) and the location to be coated or sprayed should be considered, the process thereof may be very difficult.

In addition, when the organic light emitting material is deposited for each pixel region (P of FIG. 2) through a vacuum thermal deposition method, a shadow mask (not shown) having an opening for each pixel region (P of FIG. 2) is required. As the process cost is improved and additional processes such as the alignment process of the shadow mask (not shown) and the substrate 101 are required, the process time is also increased.

On the contrary, in the present invention, the organic light emitting material is not formed for each pixel region (P of FIG. 2), but is formed by coating or depositing the entire surface of the substrate 101 and then forming the organic light emitting layer 113 through the auxiliary electrode 200. ) Can be separated for each pixel region (P in FIG. 2), thereby preventing the above problems from occurring and improving the efficiency of the process.

4A to 4C are plan views schematically illustrating how auxiliary electrodes are formed.

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

 At this time, it is preferable that the auxiliary electrode wirings 200a and 200b are further provided on one side of the substrate 101 to apply voltage or current to the auxiliary electrode 200.

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

Second embodiment

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

Prior to the description, in order to avoid duplicate description with the above-described first embodiment, the same reference numerals are given to the same parts, which play the same role as the foregoing description, and only characteristic features will be described.

The OLED 100 according to the second embodiment of the present invention is characterized in that the bank 119 is formed to surround the edge of each pixel region P for each pixel region P. In this case, the auxiliary electrode 200 Is formed between neighboring banks 119.

Therefore, the second electrode 115 formed on the front surface of the substrate 101 comes into contact with the auxiliary electrode 200 formed between the banks 119 adjacent to each other, whereby the second electrode 115 may have an internal resistance. The voltage drop phenomenon due to the second generation is hardly generated, and therefore, the luminance unevenness in the display area can be prevented.

In addition, the OLED 100 according to the second embodiment of the present invention also after the organic light emitting layer 113 is applied or deposited on the entire surface of the substrate 101, the auxiliary electrode 200 formed between the adjacent banks 119 By separating the respective pixel areas (P) through the, it is possible to improve the efficiency of the process.

In particular, in the OLED 100 according to the second embodiment of the present invention, the auxiliary electrode 200 may be formed of the same material as the first electrode 111 of the organic light emitting diode E in the same process. Can improve the efficiency.

This will be described in more detail through the manufacturing method of the OLED 100 according to the second embodiment of the present invention. Here, 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 light emitting diode E is formed, only the manufacturing method of the first substrate 101 will be described. would.

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

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

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

Next, as shown in FIG. 6B, indium-tin-oxide (ITO) or indium-zinc- which is a transparent conductive material having a relatively high work function value over the second interlayer insulating film 207b having the drain contact hole 215. By depositing and patterning an oxide (IZO) to have a thickness of about several thousand micrometers, each pixel region (P of FIG. 2) contacts the drain electrode 229 of the driving thin film transistor DTr through the drain contact hole 215. The auxiliary electrode 200 is formed corresponding to the boundary between the first electrode 111 and each pixel region (P of FIG. 5).

The auxiliary electrode 200 is formed in a matrix type having a lattice structure as a whole to distinguish between the pixel areas P of FIG. 2.

Next, as shown in FIG. 6C, a photosensitive organic insulating material, for example, black resin, graphite powder, gravure ink, black spray, black, is disposed on the first electrode 111 and the auxiliary electrode 200. The bank 119 is formed by applying and patterning one of the enamels.

The bank 119 is formed to have edges for each pixel region (P of FIG. 5), and the auxiliary electrode 200 formed between the adjacent banks 119 corresponding to the boundary of each pixel region (P of FIG. 5). ) Will be exposed.

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

Although not shown in the drawings, the organic light emitting material layer 113a may be composed of a single layer made of a light emitting material, and a hole injection layer, a hole transporting layer, a light emitting layer ( It may be composed of multiple layers of an emitting material layer, an electron transporting layer, and an electron injection layer.

Next, as illustrated in FIG. 6E, an organic light emitting material layer positioned on the auxiliary electrode 200 by heat generated by applying current to the auxiliary electrodes 200 exposed between the adjacent banks 119 (FIG. By removing 113a of 6d, the organic light emitting layer 113 separated for each pixel region (P of FIG. 5) is formed.

This is a joule's heating method. When a current is applied to the auxiliary electrode 200 made of a metal material, heat is generated. The generated heat heats the organic light emitting material layer (113a of FIG. 6d) positioned on the auxiliary electrode 200, wherein the heated organic light emitting material layer (113a of FIG. 6d) is in contact with the auxiliary electrode 200. Only the heated area is heated. Accordingly, the organic light emitting material layer (113a of FIG. 6D) in contact with the auxiliary electrode 200 is heated and sublimed to be 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 of FIG. 5).

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

In this case, it is preferable that the auxiliary electrode 200 is heated to 350 ° C. or higher in which the organic light emitting material may be heated and sublimed.

Next, as shown in FIG. 6F, a metal material having a relatively small work function value, for example, aluminum (Al), is formed on the organic light emitting layer 113 formed by separating the pixel region (P) of the auxiliary electrode 200. The second electrode to have a relatively thin thickness on the front of the substrate 101 by thermal evaporation or ion beam deposition of one of aluminum alloy, silver (Ag), magnesium (Mg) and gold (Au). Form 115.

In this case, the second electrode 115 comes into contact with the exposed auxiliary electrode 200, and thus, the second electrode 115 hardly experiences a voltage drop due to internal resistance. It is possible to prevent the luminance unevenness inside.

In addition, in the process of forming the organic light emitting layer 113, the OLED (100 of FIG. 5) according to the second embodiment of the present invention is not separately configured for each pixel region (P of FIG. 5), After the coating or deposition is formed on the entire surface, the organic light emitting layer 113 is separated by each pixel region (P of FIG. 2) through the auxiliary electrode 200, thereby improving process efficiency.

In particular, the OLED (100 of FIG. 5) according to the second embodiment of the present invention may form the auxiliary electrode 200 in the same process with the same material as the first electrode 111 of the organic light emitting diode E. As a result, the efficiency of the process can be improved.

The present invention is not limited to the above embodiments, and various modifications can 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 film
209a and 209b: first and second semiconductor layers, 211 source electrodes and 213 drain electrodes
215: drain contact hole

Claims (17)

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 an organic light emitting layer disposed between the first and second electrodes and the first and second electrodes;
An auxiliary electrode in which the organic light emitting layer is patterned for each pixel region and in electrical contact with the second electrode
Organic electroluminescent device comprising a.
The method of claim 1,
And the auxiliary electrode overlaps an edge of the first electrode and is positioned at an upper portion of a bank formed at a boundary of each pixel region or between adjacent banks.
The method of claim 1,
The auxiliary electrode is an organic light emitting device consisting of a conductor through which current can flow.
The method of claim 1,
The auxiliary electrode is composed of a double layer, and the first layer in contact with the second electrode is silver (Ag), aluminum (Al), gold (Au), indium tin oxide (ITO), or indium zinc- An organic electroluminescent device comprising one of oxides (IZO), wherein the second layer located below the first layer is one of molybdenum (Mo), tungsten (W), and chromium (Cr).
The method of claim 1,
The auxiliary electrode may be formed in a matrix type having a lattice structure, or may have a linear structure in a row direction or a column direction of each pixel region.
The method of claim 1,
The organic light emitting device further comprises a second substrate facing the first substrate. Forming a driving thin film transistor on a first substrate having a pixel region defined therein;
Forming a first electrode in contact with the driving thin film transistor;
Forming an auxiliary electrode on a boundary of the pixel area above the first electrode;
Forming an organic light emitting material layer on an 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 on the auxiliary electrode by heating sublimation to form an organic light emitting layer for each pixel region;
Forming a second electrode on a front surface of the first substrate including the organic light emitting layer and making contact with the auxiliary electrode;
Organic electroluminescent device manufacturing method comprising a.
The method of claim 7, wherein
After forming the first electrode, forming a bank at a boundary of the pixel region so as to overlap an edge of the first electrode.
The method of claim 8,
The auxiliary electrode is an organic light emitting device manufacturing method formed on the bank.
The method of claim 7, wherein
And forming a bank covering edges of each of the pixel areas after forming the auxiliary electrode and exposing the auxiliary electrode.
The method of claim 7, wherein
The auxiliary electrode is heated to 100 ~ 1000 ℃ or more organic light emitting device manufacturing method.
The method of claim 7, wherein
The auxiliary electrode is a method of manufacturing an organic light emitting device consisting of a conductor through which current can flow.
The method of claim 7, wherein
The auxiliary electrode is composed of a double layer, and the first layer in contact with the second electrode is silver (Ag), aluminum (Al), gold (Au), indium tin oxide (ITO), or indium zinc- Made of one of oxides (IZO), the second layer positioned below the first layer is one of molybdenum (Mo), tungsten (W), chromium (Cr) organic light emitting device manufacturing method.
The method of claim 7, wherein
The auxiliary electrode may be formed in a matrix type having a lattice structure, or may have a linear structure in a row direction or a column direction of each pixel region.
The method of claim 7, wherein
And the auxiliary electrode is made of the same material as the first electrode.
The method of claim 15,
The auxiliary electrode is an organic electroluminescent device manufacturing method consisting of one of indium tin oxide (ITO) or indium zinc oxide (IZO).
The method of claim 7, wherein
After the formation of the second electrode, bonding the second substrate to each other with a seal pattern interposed between the first substrate and the edge portion.

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