KR100692840B1 - Organic Electro Luminescence Display And Fabricating Method Thereof - Google Patents

Abstract

The present invention relates to an organic electroluminescent device and a method of manufacturing the same, which can prevent a failure of a voltage supply line and reduce power consumption.

The present invention provides an electroluminescent cell array; And a base voltage supply line for supplying a base voltage to the electroluminescent cell array and having only three opaque metal layers.

Description

Organic Electroluminescent Display and Manufacturing Method thereof {Organic Electro Luminescence Display And Fabricating Method Thereof}             

1 is a cross-sectional view showing the overall structure of a conventional active organic electroluminescent display.

FIG. 2 is a circuit diagram illustrating a subpixel of the active organic light emitting display device illustrated in FIG. 1.

3A and 3B are a plan view and a cross-sectional view showing a base voltage supply unit of a conventional active organic electroluminescent display.

4A to 4E are views showing a method of manufacturing the base voltage supply line shown in FIG. 3B.

5 is a cross-sectional view illustrating a base voltage supply line of an active organic light emitting display device according to an exemplary embodiment of the present invention.

6A and 6E are cross-sectional views illustrating a method of manufacturing a base voltage supply line of the active organic light emitting display device shown in FIG. 5.

<Explanation of symbols for the main parts of the drawings>

9: Data Driver 13: Base Voltage Supply Line

51,151: substrate 59, 159: first opaque metal layer

77,177: third opaque metal layer 52,152: buffer layer

58,158 source electrode 60,160 drain electrode

10,110: organic light emitting layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent display, and more particularly, to an organic electroluminescent display and a method of manufacturing the same, which can prevent power supply failure and reduce power consumption.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such flat panel displays include liquid crystal displays, field emission displays, plasma display panels, and electroluminescent displays (hereinafter referred to as "ELDs"). Etc. In particular, ELD is basically formed by attaching electrodes to both sides of an EL layer including a hole transport layer, a light emitting layer, and an electron transport layer, and is attracting attention as a next-generation flat panel display because of its wide viewing angle, high opening ratio, and high color.

Such ELDs are largely divided into inorganic ELDs and organic ELDs depending on the materials used. Among them, the organic ELD has the advantage of being able to be driven at a lower voltage than the inorganic ELD because when the charge is injected into the organic EL layer formed between the hole injection electrode and the electron injection electrode, electrons and holes are paired up and extinguished to emit light. . In addition, organic ELDs can form devices on flexible flexible substrates, such as plastics, and can be driven at lower voltages of 10V or less than PDPs or inorganic ELDs, and have a relatively low power consumption. This is excellent.

FIG. 1 is a plan view schematically showing the overall structure of an active organic ELD, and FIG. 2 is a circuit diagram showing a subpixel of the active organic ELD shown in FIG.

The substrate of the organic ELD shown in FIG. 1 is divided into a display area 50 having a pixel matrix and a non-display area 40 except for the display area 50.

As shown in FIG. 2, the display area 50 of the substrate of the organic ELD includes sub-pixels 150 arranged in regions defined by intersections of the gate line GL and the data line DL. Each of the subpixels 150 receives a data signal from the data line DL when the gate pulse is supplied to the gate line GL, and generates light corresponding to the data signal.

To this end, each of the subpixels 150 is connected to an EL cell 0EL having a cathode connected to a base voltage GND supply line 13, a gate line GL, and a data line DL, and a driving voltage. A cell driver 152 is provided between the (VDD) supply line 11 and the anode of the EL cell OEL. The cell driver 152 includes a switching thin film transistor T1, a driving thin film transistor T2, and a capacitor C.

The switching thin film transistor T1 is turned on when a scan pulse is supplied to the gate line GL, and supplies the data signal supplied to the data line DL to the first node N1. The data signal supplied to the first node N1 is charged to the capacitor C and supplied to the gate terminal of the driving thin film transistor T2. The driving thin film transistor T2 controls the amount of light emitted from the EL cell OEL by controlling the amount of current I supplied from the supply voltage source VDD to the EL cell OEL in response to the data signal supplied to the gate terminal. . In addition, since the data signal is discharged from the capacitor C even when the switching thin film transistor T1 is turned off, the driving thin film transistor T2 maintains the current from the driving voltage supply line until the data signal of the next frame is supplied. I) is supplied to the EL cell OEL so that the EL cell OEL maintains light emission.

In the non-display area 40 of the substrate of the organic ELD, the gate driver 9 connected to the gate line GL of the display area 50, the data driver 19 connected to the data line DL, and the driving voltage supply line (11), a base voltage supply line (13), a control signal supply pad (3) and an aging pad (5).

The gator driver 9 sequentially supplies scan signals to the gator line GL, and the data driver 19 causes the pixel signals supplied through the data line DL to be supplied to each subpixel 150.

The driving voltage supply line 11 is connected to the driving thin film transistor T2 to supply a common voltage.

The control signal supply pad 3 supplies a gate control signal and a data control signal generated from a timing controller (not shown) mounted on a printed circuit board (PCB) to the gate driver 9 and the data driver 19.

The aging pad 5 supplies an aging signal to the EL cell OEL of the display area 50 during the aging process of stabilizing the characteristics of the EL cell OEL.

The base voltage supply line 13 supplies a base voltage for driving an EL cell generated from a separate voltage source to the cathode of the EL cell.

3A is a plan view illustrating a base voltage supply line of a conventional active organic light emitting display device, and FIG. 3B is a cross-sectional view of the base voltage supply unit illustrated in FIG. 3A taken along line II ′.

The base voltage supply line 13 shown in FIGS. 3A and 3B includes a first metal layer 59 and a second metal layer 57 and a first metal layer 59 and a second metal layer sequentially formed on the substrate 51. A protective film 69 formed to cover the 57 and having a contact hole 85, and a transparent conductive layer 73 formed on the protective film 69 and in contact with the second metal layer 57 through the contact hole 85 thereof. And a third metal layer 77 formed on the transparent metal layer 73.

The base voltage supply line 13 supplies the base voltage generated by the power supply to a cathode electrode (not shown) connected to the EL cell.

4A to 4F are cross-sectional views illustrating a method of manufacturing the base voltage supply line illustrated in FIG. 3B in conjunction with a thin film transistor.

First, the buffer layer 52 is deposited on the substrate 51 and then patterned to form the buffer layer 52 on the display area 50 of the substrate 51. Thereafter, an amorphous silicon film is deposited and then patterned to form an active layer 64 of the thin film transistor. Thereafter, the gate insulating film 62 is entirely deposited and patterned on the substrate 51 on which the active layer 64 is formed, thereby forming the gate insulating film 62. As the gate metal layer is entirely deposited on the substrate 51 on which the gate insulating layer 62 is formed, and then patterned, the gate electrode 56 of the thin film transistor is formed as shown in FIG. 4A. At the same time, the first metal layer 59 of the base voltage supply line 13 is formed on the non-display area 40 of the substrate. Here, aluminum neodium (AlNd) or the like is used as the gate metal material.

An interlayer insulating film 66 is formed by depositing an insulating material on the substrate 51 on which the gate electrode 56 and the first metal layer 59 are formed. As the interlayer insulating film 66, an inorganic insulating material containing silicon nitride (SiNx) or an organic insulating material containing BCB or acrylic resin is used. Thereafter, the interlayer insulating layer 66 is patterned by a photolithography process and an etching process to form a source contact hole 44S and a drain contact hole 44D exposing the active layer 64, and the gate electrode 56 is exposed. do.

After the source / drain metal material is deposited on the substrate 51 on which the interlayer insulating layer 66 is formed, the source / drain electrodes 58, 60, and 61 are patterned by a photolithography process and an etching process. ) And the second metal layer 57 are formed at the same time. The source / drain electrodes 58, 60, 61 are in contact with the active layer 64, respectively, and the second metal layer 57 is in contact with the first metal layer 59. Here, molybdenum (Mo) or the like is used as the source / drain metal material.

The passivation layer is deposited on the substrate 51 on which the source / drain electrodes 58, 60, 61 and the second metal layer 57 are formed, respectively, thereby forming a passivation layer. As the protective film material, an inorganic insulating material containing silicon nitride (SiNx) or an organic insulating material containing BCB or acrylic resin is used. After that, by patterning by a photolithography process and an etching process, as shown in FIG. 4C, the second metal layer of the pixel contact hole 70 and the base voltage supply line 13 for exposing the drain electrode 60 of the thin film transistor are exposed. A protective film 69 having a through hole 53 for exposing the 57 is formed.

After the transparent conductive material is deposited on the substrate 51 on which the passivation layer 69 is formed and patterned by a photolithography process and a wet etching process, the anode is connected to the drain electrode 60 of the thin film transistor as shown in FIG. 4D. An electrode 72 is formed. At the same time, a transparent conductive layer 73 is formed on the passivation layer 69 of the base voltage supply line 13 and the second metal layer 57 on the non-display area 40 of the substrate. In this case, as the transparent conductive material, Indium-Tin-Oxide (ITO) Etc. are used.

 Thereafter, the insulating film 88 and the organic light emitting layer 74 are sequentially formed on the display area 50 of the substrate 51 on which the anode electrode 72 is formed.

A conductive metal material is deposited on the insulating film 88 of the thin film transistor, the organic light emitting layer 74, and the transparent conductive layer 73 of the base voltage supply line 13, and then patterned by a photolithography process and an etching process. As shown, the cathode electrode 76 and the third metal layer 177 of the ground voltage supply line 13 are simultaneously formed. Here, aluminum (Al) or the like is used as the conductive metal material.

As described above, the conventional base voltage supply line 13 is in contact with the transparent conductive layer 73 and the third metal layer 77. Accordingly, the oxide (Oxide) included in the transparent conductive layer 73 and aluminum (Al) of the third metal layer 7 react to form aluminum oxide having a high resistance between the transparent conductive layer 73 and the second metal layer 77 ( AlOx) layer is formed. Since the current injection is not easy by the aluminum oxide (AlOx) layer having high resistance, there is a problem that power consumption is increased.

In addition, when the third metal layer 77 and the transparent conductive layer 73 which have a large difference in electromotive force are in contact with each other, a relatively large potential difference is generated between the third metal layer 77 and the transparent conductive layer 73 to cause galvanic corrosion. This will happen. That is, the corrosion of the transparent conductive layer 73 having a relatively high corrosion resistance is suppressed and the third metal layer 77 having a relatively low corrosion resistance is corroded relatively quickly.

Accordingly, an object of the present invention relates to an organic light emitting display device and a method of manufacturing the same, which can prevent a failure of a voltage supply line and reduce power consumption.

In order to achieve the above object, the organic electroluminescent device according to the present invention comprises an electroluminescent cell array; And a base voltage supply line for supplying a base voltage to the electroluminescent cell array and having only three opaque metal layers.

The three opaque metal layers may include a first metal layer formed of the same material as the gate electrode of the thin film transistor included in the field emission cell array; A second metal layer formed on the first metal layer and formed of the same material as the source / drain electrodes of the thin film transistor; The thin film transistor may be formed on the second metal layer, and the thin film transistor may include a third metal layer formed of the same material as the cathode electrode.

The first metal layer comprises aluminum neodium; The second metal layer comprises molybdenum; The third metal layer is characterized in that it comprises aluminum.

And a protective film formed to cover the first and second metal layers and having a hole for contacting the second metal layer and the third metal layer.

A method of manufacturing an organic electroluminescent device according to the present invention is a field emission display device having a plurality of pixels including a field emission cell and a thin film transistor having a field emission cell, wherein the electric field is formed together with a gate electrode of the thin film transistor. Forming a first metal layer of a base voltage supply line for supplying a base voltage to the emission cell; Forming a second metal layer of the base voltage supply line together with a source / drain electrode of the thin film transistor; And forming a third metal layer of the base voltage supply line together with the anode of the field emission cell.

The first metal layer comprises aluminum neodium; The second metal layer comprises molybdenum; The third metal layer is characterized in that it comprises aluminum.

And forming a passivation layer covering the thin film transistor and the first and second metal layers and having a hole for contacting the second metal layer and the third metal layer.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 6E.

5 is a cross-sectional view illustrating a base voltage supply line of an active organic ELD according to an embodiment of the present invention.

The base voltage supply line illustrated in FIG. 5 includes first to third metal layers 159, 157, and 177 sequentially formed on the non-display area on the substrate 151. The third metal layer 177 is formed of the same material as the cathode electrode to supply the base voltage to the cathode electrode. The first metal layer 159 is formed of the same material as the gate electrode of the second driving thin film transistor, and the second metal layer 157 is formed of the same material as the source / drain electrode of the second driving thin film transistor. The first and second metal layers 159 and 157 increase the conductivity of the third metal layer 177. Here, the second metal layer 157 is stacked on the first metal layer 159, and the third metal layer 177 is stacked on the second metal layer 157. The third metal layer 177 is in contact with the second metal layer 157 by a through hole penetrating through the passivation layer 169.

The base voltage supply line supplies the base voltage generated by the power supply to the cathode electrode connected to the EL cell.

Accordingly, the base voltage supply line contacts the second metal layer 157 and the third metal layer 177 having a small electromotive force difference such as molybdenum (Mo) and aluminum (Al) to reduce contact resistance and to corrode aluminum (Al). Can be prevented.

6A through 6F are cross-sectional views illustrating a method of manufacturing the ground voltage supply line illustrated in FIG. 5 in conjunction with a thin film transistor.

First, the buffer layer 152 is deposited on the substrate 151 and then patterned to form the buffer layer 152 on the display area of the substrate 151. Thereafter, an amorphous silicon film is deposited and then patterned to form an active layer 164 of the thin film transistor. Thereafter, the gate insulating film 162 is entirely deposited and patterned on the substrate 151 on which the active layer 164 is formed, thereby forming the gate insulating film 162 of the thin film transistor. A gate metal layer is deposited on the substrate 151 on which the gate insulating layer 162 is formed, and then patterned, thereby forming the gate electrode 156 of the thin film transistor as shown in FIG. 6A. At the same time, the first metal layer 59 of the base voltage supply line is formed on the non-display area of the substrate 51. Here, aluminum neodium (AlNd) or the like is used as the gate metal material.

An interlayer insulating film 166 is formed by depositing an insulating material on the substrate 151 on which the gate electrode 156 and the first metal layer 159 are formed. The interlayer insulating layer 166 may be formed of an inorganic insulating material containing silicon nitride (SiNx) or an organic insulating material containing BCB or an acrylic resin. Afterwards, the interlayer insulating layer 166 is patterned by a photolithography process and an etching process to form a source contact hole 144S and a drain contact hole 144D that expose the active layer 164, and expose the gate electrode 156. do.

After the source / drain metal material is deposited on the substrate 151 on which the interlayer insulating film 166 is formed, the source / drain electrodes 158, 160, 161 and the second are patterned by a photolithography process and an etching process, as shown in FIG. 6B. The metal layer 157 is formed at the same time. The source / drain electrodes 158, 160, and 161 are in contact with the active layer 164, and the second metal layer 157 is in contact with the first metal layer 159. Here, molybdenum (Mo) or the like is used as the source / drain metal material.

A passivation layer is deposited on the substrate 151 on which the source / drain electrodes 158, 160, 161 and the second metal layer 157 are formed, respectively, thereby forming a passivation layer. As the protective film material, an inorganic insulating material containing silicon nitride (SiNx) or an organic insulating material containing BCB or acrylic resin is used. After that, by patterning by a photolithography process and an etching process, as illustrated in FIG. 6C, the pixel contact hole 170 and the second metal layer 157 of the base voltage supply unit for exposing the drain electrode 160 of the thin film transistor are exposed. The passivation layer 169 having the through hole 153 for exposure is formed.

After the transparent conductive material is deposited on the substrate 151 on which the passivation layer 169 is formed and patterned by a photolithography process and a wet etching process, the anode is connected to the drain electrode 160 of the thin film transistor as shown in FIG. 6D. The electrode 172 is formed. In this case, the transparent conductive material deposited on the base voltage supply line is selectively etched by a wet etching process to expose the first metal layer 159. In this case, as the transparent conductive material, Indium-Tin-Oxide (ITO) Etc. are used.

 Thereafter, the insulating film 188 and the organic light emitting layer 174 are sequentially formed on the display area of the substrate 151 on which the anode electrode 172 is formed.

The conductive metal material is deposited on the insulating film 188 and the organic light emitting layer 174 of the thin film transistor and the second metal layer 157 of the base voltage supply line, and then patterned by a photolithography process and an etching process, as shown in FIG. 6E. As described above, the cathode electrode 176 and the third metal layer 177 of the ground voltage supply line are simultaneously formed. The third metal layer 177 is in contact with the second metal layer 157 through the through hole 153. Here, aluminum (Al) or the like is used as the conductive metal material.

As such, in the base voltage supply line of the organic light emitting display device according to the exemplary embodiment, a third metal layer 177 including aluminum is formed on the second metal layer 157 including molybdenum (Mo). Molybdenum (Mo) included in the second metal layer 157 and aluminum included in the third metal layer 177 may prevent corrosion of aluminum when the base voltage supply line is exposed to a corrosive environment because the electromotive force difference is small.

In addition, the transparent conductive material deposited on the base voltage supply line is removed by wet etching, thereby preventing the formation of highly resistant aluminum oxide formed by the reaction of the oxide and aluminum included in the transparent conductive material. As a result, current injection is easy and power consumption is reduced.

As described above, the organic electroluminescent device and the method of manufacturing the same according to the present invention can reduce the contact resistance because the base voltage supply part is formed of only an opaque metal layer including a metal having a small electromotive force difference. As a result, current injection is easy and power consumption is reduced.

In addition, since only a metal layer including a metal having a small electromotive force difference is in contact, it is possible to prevent a failure of the ground voltage line due to corrosion of the metal.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (7)

An electroluminescent cell array; And a base voltage supply line for supplying a base voltage to the electroluminescent cell array and formed of only three opaque metal layers. The method of claim 1, The three opaque metal layers A first metal layer formed of the same material as the gate electrode of the thin film transistor included in the electroluminescent cell array; A second metal layer formed on the first metal layer and formed of the same material as the source / drain electrodes of the thin film transistor; And a third metal layer formed on the second metal layer and formed of the same material as the cathode electrode of the thin film transistor. The method of claim 2, The first metal layer comprises aluminum neodium; The second metal layer comprises molybdenum; And the third metal layer comprises aluminum. The method of claim 2, And a protective layer formed to cover the first and second metal layers and having a hole for contacting the second metal layer and the third metal layer. An organic electroluminescent display device having a plurality of pixels including an electroluminescent cell and a thin film transistor for providing an electroluminescent cell, Forming a first metal layer of a base voltage supply line for supplying a base voltage to the electroluminescent cell together with a gate electrode of the thin film transistor; Forming a second metal layer of the base voltage supply line together with a source / drain electrode of the thin film transistor; And forming a third metal layer of the base voltage supply line together with an anode of the electroluminescent cell. The method of claim 5, wherein The first metal layer comprises aluminum neodium; The second metal layer comprises molybdenum; And the third metal layer comprises aluminum. The method of claim 5, wherein And forming a passivation layer formed to cover the thin film transistor and the first and second metal layers, and having a hole for contacting the second metal layer and the third metal layer. Method for manufacturing a display device.

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