KR101050344B1 - Organic EL display device and manufacturing method thereof - Google Patents

Abstract

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

Here, the present invention provides an organic light emitting layer comprising: an array unit for forming an organic light emitting unit including an anode electrode and a cathode electrode; a substrate including a non-array unit outside the array unit; And a ground pad part connected to the cathode electrode and separated into at least two parts from the vialay part and formed at each corner of the vialay part.

According to the present invention, by separating and forming ground pads in different places, the amount of current flowing from the common electrode to the ground pad can be dispersed to delay the temperature rise due to the concentration of current and thereby deterioration of the device. The lifespan of the EL display device is extended.

Ground pads, deterioration, gate pads

Description

Organic electroluminescent display device and method of manufacturing the same {Organic Electro-Luminescence Display device and the fabrication method

1 is a schematic plan view of a general organic electroluminescent display device.

FIG. 2 is a schematic plan view of an active matrix organic light emitting display device according to an exemplary embodiment of the present invention.

3 is a schematic plan view of an active matrix organic light emitting display device according to another exemplary embodiment of the present invention.

4 is a schematic plan view of an active matrix organic light emitting display device according to another embodiment of the present invention.

Description of the Related Art [0002]

208, 308, 408: cathode electrodes 209, 309, 409: array portion

211, 311, and 411: first data and current supply pad portion

212 and 412: second data and current supply pad portion

221, 321, and 421: first gate pad part

222, 322, 422: second gate pad portion

231, 331, and 431: first ground pad portion

232, 332, 432: second ground pad portion                 

333 and 433: third ground pad portion

434: fourth ground pad portion

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

At present, many display devices have been put to practical use in the high information society.

Like televisions, CRTs (cathode ray tubes) that emit electrons from an electron gun onto phosphors are demanding about 100 million units annually worldwide as displays for desktop computers. In addition, liquid crystal displays (LCDs), which have been frequently used for notebook computers, are expanding their use in monitors and digital cameras. Since the LCD is a non-light emitting element, the image is displayed by the light of the backlight, but the CRT and EL (Electro-Luminescence) elements are self-luminous type display elements. In particular, the EL element is divided into an inorganic EL element and an organic EL element by the fluorescent compound to be used.

Inorganic EL elements currently in practical use often operate by alternating current, and the luminance depends on the voltage and the frequency.

The organic EL device injects electrons and holes from the outside, and emits light by their recombination energy.

When applied as a display, the organic EL element has a self-luminous type, and thus has a wider viewing angle, higher contrast, and better visibility than a liquid crystal element.

In addition, since the backlight is unnecessary, it is possible to realize a thinner and lighter weight, and since the current only needs to be sent to a pixel that needs to emit light, it is also possible to reduce the power consumption in comparison with the LCD which needs to illuminate the backlight all over regardless of the display contents. It is advantageous.

In addition, it is attracting attention as a display for the IMT-2000 because direct current low voltage driving and fast response speed enable easy moving picture display.

Furthermore, since the organic ELs are all made of solid, they are resistant to vibrations and have a wide range of operating temperatures.

In general, an organic light emitting display device has a cathode electrode and an anode electrode disposed on a transparent substrate such as glass to face each other under an organic light emitting layer, and light is emitted from the organic light emitting layer by a voltage applied between the cathode electrode and the anode electrode. It emits light and transmits.

In this case, the anode electrode smoothly supplies holes and forms an indium-tin-oxide (ITO) thin film having excellent electrical conductivity and light transmittance so that light emitted from the organic light emitting layer can be transmitted through the sputtering method. Silver is formed of a metal having a low work function to supply electrons smoothly.

Therefore, when positive and negative voltages are applied to the anode electrode and the cathode electrode, holes injected from the anode electrode and electrons injected from the cathode electrode are recombined in the organic light emitting layer to emit light.

On the other hand, in the organic electroluminescent device, unit pixels are arranged in a matrix form, and an image is displayed by selectively driving the organic light emitting layer of the unit pixel through a thin film transistor provided in each unit pixel.

1 is a schematic plan view of a general organic light emitting display device.

As shown in FIG. 1, the active matrix type organic light emitting display device 101 includes a gate pad portion 102 for applying a scan signal to each pixel, and a data pad portion 103 for inputting a data signal. And a ground pad portion (ground pad) which is a ground line connected to the array portion 109 that actually emits light, the cathode electrode 108 of the organic light emitting element formed over the entire surface of the array portion 109, and the cathode electrode 108. ; 107).

In addition, a current supply pad 106 formed in a direction parallel to the data pad 103 is formed, and as many pixels as the number of gate lines are connected to each current supply line VDD.

In addition, although not shown in the drawing, a lower portion of the cathode electrode 108 is an insulating layer having the same pattern as the cathode electrode 108, and a fluoride (LiF) or an oxide (LiF) to facilitate the inflow of electrons from the cathode electrode 108. LiO2) layer.                         

In addition, an insulating film (not shown) is interposed between the cathode electrode 108 and the ground pad part 107.

Since the cathode electrode 108 and the ground pad part 107 cannot be formed at the same time, the cathode electrode 108 and the ground pad part 107 are connected through the ground contact hole formed in the insulating layer.

The organic light emitting display device configured as described above emits light by a current flowing from the anode to the cathode in the organic light emitting layer.

Then, the current is finally grounded to the ground pad portion to exit.

Therefore, the current flowing by the voltage difference of the first common electrode eventually flows all the way to the ground pad portion, whereby a phenomenon of concentration of current occurs.

As shown in FIG. 1, in the conventional organic light emitting display device, the ground pad portion is disposed to one side, so that currents coming from the current supply line VDD are concentrated at the ground pad portion, thereby causing a local temperature rise on the panel. Will cause.

As a result, the temperature of the organic light emitting display device is increased, thereby changing or decreasing the characteristics of the device.

The present invention provides an active matrix organic electroluminescent display in which an amount of current flowing from a common electrode to a ground pad is distributed by separating and forming ground pads, which are ground lines, in different places in an active matrix organic electroluminescent display device. It is an object to provide an element and a method of manufacturing the same.

In order to achieve the above object, an embodiment of an organic light emitting display device according to the present invention includes a display unit for forming an organic light emitting unit including an organic light emitting layer, an anode electrode, and a cathode electrode; An organic electroluminescent panel consisting of a non-display portion, characterized in that it comprises a ground pad portion which is connected to the cathode electrode and separated into at least two portions of the non-display portion, and formed at corners of the non-display portion, respectively.

The organic light emitting layer is formed of an electron transport layer, a light emitting layer, a µµ transport layer and a hole injection layer.

An active layer having a source and drain region heavily doped with impurities and having a channel region at an intermediate portion thereof, a gate electrode formed through a gate insulating layer on a channel region of the active layer, and the source / drain region And a plurality of thin film transistors including source / drain electrodes electrically connected to each other.

A gate pad unit applying a gate signal to the display unit; A data pad unit applying a data signal to the display unit; A current supply pad unit for supplying current to the display unit is further formed.                     

In addition, to achieve the above object, a method of manufacturing an organic light emitting display device according to an embodiment of the present invention, preparing a substrate; Forming an organic light emitting part including an organic light emitting layer, an anode electrode, and a cathode on a display portion of the substrate, and forming at least two ground pad portions formed in a non-display portion of the substrate to be connected to the cathode electrode and divided in different directions; Should be made, including.

Forming an organic light emitting part including an organic light emitting layer, an anode electrode and a cathode electrode in the display portion, the gate pad portion applying a gate signal to the display portion on the non-display portion, a data pad portion applying a data signal, and a current; Characterized in that each of the current supply pad portion for supplying the outer edge is formed.

In order to achieve the above object, another embodiment of the organic light emitting display device according to the present invention includes a first substrate for forming an array portion; A second substrate disposed to face the first substrate and forming an organic light emitting part including an organic light emitting layer, an anode electrode, and a cathode electrode; And at least two ground pad parts connected to the cathode electrode outside the array unit and divided in different directions.

An active layer having a source and drain region heavily doped with impurities and having a channel region at an intermediate portion thereof, a gate electrode formed through a gate insulating layer on a channel region of the active layer, and the source / drain region And a plurality of thin film transistors including source / drain electrodes electrically connected to the region.

In addition, in order to achieve the above object, a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present invention includes a first substrate forming an array portion, an organic light emitting layer, an anode electrode, and a cathode disposed opposite to the first substrate. And preparing a second substrate for forming an organic light emitting part including an electrode, and forming at least two ground pad parts connected to the cathode electrode and separated in different directions from the outside of the array part. .

A gate pad portion for applying a gate signal to the array portion, a data pad portion for applying a data signal, and a current supply pad portion for supplying current may be formed at outer edges of the array portion.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a schematic plan view of an active matrix organic light emitting display device according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the active matrix organic electroluminescent display device according to the present invention includes a display portion and a non-display portion that is not related to image display at the edge of the display portion.

Although not specifically illustrated, unit pixels are arranged in a matrix form in the array unit 209 formed in the display unit, and each pixel includes a driving thin film transistor, a switching thin film transistor, and an organic light emitting diode. Is formed.

The organic light emitting device is formed of an electron transport layer, a light emitting layer, a hole transport layer and a hole injection layer.

In addition, the driving thin film transistor includes an active layer having a source and a drain region heavily doped with impurities in an array portion and a channel region in an intermediate portion thereof, and a gate formed through a gate insulating layer on the channel region of the active layer. And a source / drain electrode electrically connected to the source / drain region.

As shown in FIG. 2, the active matrix type organic light emitting display device includes a gate pad part 221 or 222 for applying a scan signal to each pixel, a first input for inputting a data signal and supplying current. 2 the data and current supply pad portions 211 and 212, the array portion 209 that actually emits light, the �� electrode electrode 208 of the organic light emitting element formed over the entire array portion 209, and the cathode electrode ( A ground pad 7 which is a ground line connected to the 208 is included.

Although not shown in the drawings, a lower portion of the cathode electrode 208 is an insulating layer having the same pattern as the cathode electrode 208 and a fluoride (LiF) or an oxide (LiF) to facilitate the inflow of electrons from the cathode electrode 208. LiO2) layer.

In addition, an insulating film (not shown) is interposed between the cathode electrode 208 and the ground pad parts 231 and 232.                     

Since the cathode electrode 208 and the ground pad parts 231 and 232 are not formed at the same time, the cathode electrode 208 and the ground pad parts 231 and 232 are connected through the ground contact hole formed in the insulating layer.

In this case, the first and second data and current supply pad parts 211 and 212 form a current supply line at the time of forming the data line and are formed together at opposite edges of the array unit.

The gate pads 221 and 222 for applying a scan signal to each pixel of the array unit 209 and the ground pads 231 and 232 made of a ground line are divided into two and designed to be ground pad units 231. , 232), so that the concentration of current can be distributed, thereby preventing the temperature rise and the deterioration caused by the nearby temperature.

That is, the first ground pad part 231, the first gate pad part 221, the second ground pad part 232, and the second gate pad part 222 are formed at edges of the substrate outer surface to face each other.

In the organic electroluminescent display device configured as described above, light is emitted by a current flowing from the anode to the cathode in the actual organic EL layer. At this time, the current is finally grounded to the ground pad portion (231, 232) to exit.

Accordingly, the current generated from the first data and current supply pad unit 211 is discharged to the second ground pad units 231 and 232 formed nearby, and the second data and current supply pad unit 212 The current generated in the) exits to the first ground pad part 231 formed nearby.

That is, the current flowing due to the voltage difference of the first common electrode eventually flows toward the first and second ground pad portions 231 and 232 which are dispersed, so that the concentration of current in the ground pad portion can be prevented. do.

3 is a schematic plan view of an active matrix organic light emitting display device according to another exemplary embodiment of the present invention.

Here, the parts not described in detail are described with reference to the same parts in FIG.

As shown in FIG. 3, the active matrix organic light emitting display device according to the present invention includes an array portion 309 and a non-light emitting portion not related to image display at the edge of the array portion 309. There is a substrate formed outside the array.

In this case, the data and current supply pad part 311 forms a current supply line at the time of forming the data line, and is formed at one edge of the outside of the array part 309.

In addition, a third ground pad part 333 is formed at a corner facing the data and current supply pad part 311.

The gate pads 321 and 322 for applying a scan signal to each pixel of the array unit 309 and the ground pads 331 and 332 made of a ground line are divided into two parts to design the ground pad unit 331. , 332 and 333 can distribute the concentration of the current, thereby preventing the temperature rise and the deterioration caused therefrom.

That is, the first ground pad part 331, the first gate pad part 321, the second ground pad part 332, and the second gate pad part 322 are formed at edges of the substrate outside to face each other.

Therefore, the current flowing due to the voltage difference of the first common electrode eventually flows toward the first, second, and third ground pad portions 331, 332, and 333 which are dispersed, thereby preventing concentration of current in the ground pad portion. You can do it.

4 is a schematic plan view of an active matrix organic light emitting display device according to another embodiment of the present invention.

Here, the parts not described in detail are described with reference to the same parts in FIG.

As shown in FIG. 4, the active matrix type organic light emitting display device according to the present invention is designed by dividing the first and second data and current supply pad parts 411 and 412 into two sides, and is formed outside the array part 409. Each is formed to face the edge.

 In addition, the first and second gate pad parts 421 and 422 are divided into two sides, and the first and second gate pad parts 421 and 422 are designed at edges of the outer edge of the array part 409 where the first and second data and current supply pad parts 411 and 412 are not formed. It is formed to face each other.

The first to fourth ground pad parts 431, 432, 433, which are formed in parallel with the first and second data and current supply pad parts 411 and 412, and the first and second gate pad parts 421 and 422, respectively. 434).

That is, the substrate may face the first ground pad part 431, the first data and current supply pad part 411, the second ground pad part 432, and the second data and current supply pad part 412, respectively. It is formed at the edge of the outer edge, the outer edge of the substrate so that the third ground pad portion 433, the first gate pad portion 421, the fourth ground pad portion 434 and the second gate pad portion 422 face each other It is formed in the corner of the.

Thus, by forming the ground pad portions 431, 432, 433, and 434 at four corners of the substrate, the concentration of the current in the vicinity of the ground pad portions 431, 432, 433, and 434 can be dispersed to increase the temperature. This can prevent deterioration of the device.

According to the embodiments of the organic light emitting display device described above, the array portion and the organic light emitting portion are formed on a substrate, and the present invention may be applied to a dual panel type organic light emitting display device.

In the dual panel type organic light emitting display device, an array unit and an organic light emitting unit are formed on different substrates, and a pattern for electrically connecting the array unit and the organic light emitting unit is provided separately.

Accordingly, as another embodiment of the organic light emitting display device according to the present invention, a first substrate for forming an array portion, and an organic light emitting portion for forming an organic light emitting layer, an anode electrode and a cathode electrode disposed opposite to the first substrate; There are two substrates.

A ground pad portion for connecting with the cathode electrode formed on the second substrate is formed outside the first substrate on which the array portion is formed.

Here, as mentioned above, referring to FIGS. 2 to 4, the ground pad part includes at least two or more ground pad parts divided in different directions from the outside of the substrate.

In the above, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. will be. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, the active matrix type organic light emitting display device can distribute the amount of current flowing from the common electrode to the ground, thereby delaying the temperature rise due to the concentration of current and thereby degrading the device, thereby extending the life of the organic light emitting display device. It is effective to let.

Claims (10)

In an organic electroluminescent panel comprising a display unit for forming an organic light emitting unit including an organic light emitting layer, an anode electrode, and a cathode electrode, and a non-display unit outside the display unit, And a ground pad portion connected to the cathode electrode and separated from at least two portions of the non-display portion and formed at each corner of the non-display portion. The method of claim 1, The organic light emitting layer is formed of an electron transport layer, a light emitting layer, a hole transport layer and a hole injection layer. The method of claim 1, The display portion includes an active layer having a source and drain region heavily doped with impurities and a channel region in an intermediate portion thereof, a gate electrode formed through a gate insulating layer on a channel region of the active layer, and the source and drain regions. And a plurality of thin film transistors each comprising a source and a drain electrode electrically connected to each other. The method of claim 1, A gate pad unit applying a gate signal to the display unit; A data pad unit applying a data signal to the display unit; And a current supply pad part for supplying current to the display unit. Preparing a substrate; An organic light emitting part including an organic light emitting layer, an anode electrode, and a cathode electrode is formed on a display portion of the substrate; And forming at least two ground pad portions formed in the non-display portion of the substrate and connected to the cathode electrode and being divided in different directions. The method of claim 5, In the step of forming an organic light emitting portion consisting of an organic light emitting layer, an anode electrode and a cathode in the display portion, An organic electroluminescent display device having a gate pad portion for applying a gate signal to the display portion, a data pad portion for applying a data signal, and a current supply pad portion for supplying current to the non-display portion, respectively, at outer corners Method of preparation. A first substrate forming an array portion, Preparing a second substrate disposed to face the first substrate and forming an organic light emitting part including an organic light emitting layer, an anode electrode, and a cathode electrode; And forming at least two ground pad portions connected to the cathode electrode and separated in different directions outside the array portion. The method of claim 7, wherein An active layer having a source and drain region heavily doped with impurities and having a channel region at an intermediate portion thereof, a gate electrode formed through a gate insulating layer on a channel region of the active layer, and the source and drain regions An organic light emitting display device comprising: a plurality of thin film transistors each comprising a source and a drain electrode electrically connected to a region. Preparing a first substrate forming an array portion and a second substrate disposed opposite to the first substrate and forming an organic light emitting portion including an organic light emitting layer, an anode electrode, and a cathode electrode, And forming at least two ground pad portions which are connected to the cathode electrode and are divided in different directions outside the array portion. The method of claim 9, Fabrication of an organic light emitting display device, characterized in that the gate pad portion for applying a gate signal to the array portion, the data pad portion for applying a data signal, and the current supply pad portion for supplying current are formed at the outer edge of the array portion, respectively. Way.

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