KR20060001712A - An organic luminescence display and method for fabricating the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a method of manufacturing the same, which can be enlarged by forming a conductive layer on an encapsulation substrate and electrically connecting the upper electrode to prevent voltage drop of the upper electrode.

An organic electroluminescent display of the present invention comprises an insulating substrate; A lower electrode formed on the insulating substrate; An organic light emitting layer formed on the lower electrode; An upper electrode formed on the organic light emitting layer; Conductive spacers dispersed on the upper electrode; It characterized in that it comprises an encapsulation substrate including a conductive layer on one surface formed on the spacer.

OLED display, voltage drop, conductive layer, encapsulation

Description

An organic luminescence display and method for fabricating the same

1 is a plan view illustrating a completed panel of a conventional organic light emitting display device.

2 illustrates a plan view of a completed panel of an organic light emitting display device according to an exemplary embodiment of the present invention.

3A to 3C are cross-sectional views taken along the line II ′ of FIG. 2, and illustrate cross-sectional views for describing a manufacturing process of the organic light emitting display device according to the present invention.

-Brief description of drawing symbols-

200: organic light emitting display device 210: common power supply voltage line

220: cathode electrode 221: cathode power line

240: scan driver 250: data driver

270: outer portion 280, 360: conductive layer

320: organic electroluminescent element 330: conductive spacer

350: sealing board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to form a conductive layer on an encapsulation substrate, and to electrically connect the cathode to the cathode to prevent voltage drop of the cathode to increase the size of the top emission organic field. A light emitting display device and a method of manufacturing the same.

With the advent of the high information age, there is an increasing demand for fast and accurate information in the hand, and the development of a display device that is light and thin, easy to carry, and has high information processing speed is rapidly being made. Conventional CRTs have high weight, volume, and power consumption, and LCDs have technical limitations on process complexity, narrow viewing angles, contrast ratios, and large area.

In order to solve the above problems, the organic light emitting display device is a self-luminous type in which electrons and holes are recombined in the organic light emitting layer to generate light by applying a voltage to the organic layer including the organic light emitting layer. Not only can it be light and thin, but also the process can be simplified, and the response speed is the same as the CRT, and it is advantageous in terms of power consumption. Accordingly, organic electroluminescent devices are rapidly rising as next generation displays.

Such an organic light emitting display device is formed by bonding a lower substrate on which an organic light emitting element is formed and an upper substrate, which is an encapsulation substrate on which a moisture absorbent is formed, so as not to be exposed to moisture and oxygen to the organic light emitting element as much as possible. It is broken.

Hereinafter, a conventional organic light emitting display device will be described with reference to the accompanying drawings.

1 is a plan view illustrating a completed panel of a conventional organic light emitting display device.

Referring to FIG. 1, an organic light emitting display device includes a pixel unit 160 including a plurality of pixels, and a common power supply voltage line arranged at an upper side, a left side, and a right side of the pixel unit 160 to apply a power supply voltage. 110 and a scan driver 140 for outputting a selection signal and a common power line (not shown in the drawing; Vdd line) for supplying common power from the common power supply voltage line 110 to the pixel unit 160. And a data driver 150 for outputting a data signal, and are encapsulated with an encapsulant 170.

In addition, the organic light emitting display device 100 further includes a cathode electrode 122 arranged to correspond to the pixel unit 160, and a cathode power line 120 formed on one side of the pixel unit 160. Although not shown in the drawing, the cathode power line 120 has a contact hole for connection with the cathode electrode 122 to provide a cathode voltage from the cathode power line 120 to the cathode electrode.

In the conventional organic light emitting display device having the above configuration, the selection signal and the data signal are applied to the pixel unit 160 from the scan driver 140 and the data driver 150, and the common power voltage line 110 is removed from the common power voltage line 110. When the cathode voltage is applied from the power supply voltage and the cathode power supply line 120 to the cathode electrode 122, the switching transistor and the driving transistor (not shown) constituting each pixel arranged in the pixel unit 160 are driven to EL. The device (not shown in the figure) will emit light.

Here, the power supply voltage becomes lower as the distance from the external terminal to which the power supply voltage is supplied, that is, the power supply voltage, and the power supply voltage applied to the pixel region is lowered due to the voltage drop of the power supply voltage. Further, as the distance from the cathode power line increases and the distance from the external terminal to which the cathode voltage is applied, the power supply voltage decreases. In this voltage drop phenomenon, the resistance of the power supply line increases as the distance from the supply side of the power supply voltage increases, and the voltage drop (IR drop) increases as the resistance of the cathode power line increases as the distance from the supply side of the cathode voltage increases. ) Increases.

Accordingly, the same cathode voltage is not applied to the cathode electrodes formed for each pixel position, but a voltage difference is generated in a region near and far from a region where power is input due to voltage drop (IR drop), so that the amount of electron emission is changed. This can cause nonuniformity in brightness and image characteristics, and also increases the power consumption.

In addition, there is a problem in that it is difficult to apply to the medium-to-large organic light emitting display due to the voltage drop phenomenon.

In order to solve the above problem, Shoji Terada et al. Have an organic electroluminescent display device that forms an auxiliary electrode on a pixel defining layer to prevent voltage drop of the cathode at 54.5L of SID2003. Announced about.

However, the above method has a problem in that the organic layer is damaged when the metal film used as the auxiliary electrode is deposited and patterned on the pixel defining layer in the process of forming the auxiliary electrode, and also prevents the upper electrode voltage drop. The mask process is added to form an auxiliary electrode for the problem that the process is complicated.

An object of the present invention is to solve the above problems of the prior art, the present invention is to form a conductive layer on the sealing substrate to provide a uniform voltage to the upper electrode organic electroluminescence for preventing the voltage drop of the upper electrode The purpose is to provide a display device.

In addition, an object of the present invention is to provide a top-emitting organic electroluminescent display device capable of preventing the voltage drop of the upper electrode to improve the brightness and image characteristics, thereby increasing the size.

The present invention for achieving the above object is an insulating substrate; A lower electrode formed on the insulating substrate; An organic film including at least an organic light emitting layer formed on the lower electrode; An upper electrode formed on the organic layer; Conductive spacers dispersed on the upper electrode; An organic light emitting display device includes an encapsulation substrate including a conductive layer on one surface formed on an upper portion of the spacer.

In addition, the present invention comprises the steps of providing an insulating substrate; Forming a lower electrode on the insulating substrate; Forming an organic light emitting layer on the lower electrode; Forming an upper electrode on the organic light emitting layer; Forming a conductive spacer on the upper electrode; Forming an encapsulation substrate on the spacer and the upper electrode;

A conductive layer is formed on one surface of the encapsulation substrate.

The upper electrode may be an anode electrode or a cathode electrode, and the lower electrode may be formed of an electrode opposite to the upper electrode.

In addition, the conductive layer is formed to prevent a voltage drop of the upper electrode, and is electrically connected to the upper electrode through the conductive spacer.

As a result, the conductive layer may receive a power supply voltage from an external terminal to uniformly apply a voltage to the cathode electrode disposed below the conductive layer.

Hereinafter, an organic light emitting display device according to the present invention will be described with reference to the accompanying drawings.

2 illustrates a plan view of a completed panel of an organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 2, an organic light emitting display device according to an exemplary embodiment of the present invention is formed by dividing a pixel portion 260 in which a plurality of pixels are arranged and an outer portion 270 encapsulated with an encapsulant.

A common power supply voltage line 210 arranged at an upper side, left and right sides of the pixel portion in the outer portion 270 to provide a power supply voltage to the pixel portion, and a scan driver 240 for outputting a selection signal to the pixel portion; And a data driver 250 for outputting a data signal to the pixel unit.

Further, a cathode electrode 220 formed on the pixel portion, a conductive space (not shown) formed on the cathode electrode, and a conductive layer 280 electrically connected to the conductive space are provided. An encapsulation substrate 270 is included.

Here, the conductive layer receives a voltage from the cathode voltage line 221 to uniformly provide a voltage to the cathode electrode.

3A to 3C are cross-sectional views taken along the line II ′ of FIG. 2, and illustrate cross-sectional views for describing a manufacturing process of the organic light emitting display device according to the present invention.

3A is a cross-sectional view of a lower substrate 300 on which an organic light emitting element is formed.

Referring to FIG. 3A, the organic light emitting diode 320 is formed on the lower insulating substrate 310. The organic light emitting device 320 includes an anode electrode 321, an organic film 322 including at least an organic light emitting layer, and a cathode electrode 323.

In addition, the organic layer may be composed of several layers depending on its function, including at least an organic emission layer, a hole injection layer (HIL), a hole transport layer (HTL), a hole blocking layer (HBL), and an electron transport layer. (ETL) and the electron injection layer (EIL) has a multilayer structure further comprising at least one layer.

Subsequently, conductive spacers 330 are dispersed on the cathode electrode 323.

For example, the conductive spacer may be formed of one metal material selected from the group consisting of Au, Ag, In, Al, and Ni, or glass balls or synthetic resin coated with metal material.

Thus, by forming a conductive spacer on the organic light emitting device, it can be electrically connected to the cathode of the organic light emitting device and the conductive layer of the encapsulation substrate to be formed later.

3B is a cross-sectional view of the upper substrate 340 on which a conductive layer is formed as an encapsulation substrate.

Referring to FIG. 3B, an encapsulation substrate 350 is provided on the upper substrate, and a conductive layer 360 having conductivity is formed on one surface of the encapsulation substrate. Here, the encapsulation substrate may be made of a transparent glass substrate, a plastic and a metal material, and the conductive layer may include Mg, Ca, Al, Ag, Ba, Pt, Au, Ir, Cr, Mg, Ag, Ni, Al, and these. It may be a reflective material made of an alloy of or a transparent conductive film made of ITO or IZO.

3C is a cross-sectional view of an organic light emitting display device in which the upper substrate of FIG. 3A and the lower substrate of FIG. 3B are bonded.

As shown in FIG. 3C, the sealant 370 is used to seal the lower substrate including the organic light emitting diode and the upper substrate including the conductive layer under a reduced pressure atmosphere. As a result, an inner space of the lower substrate and the lower substrate is formed lower than atmospheric pressure in the air, thereby increasing adhesion of the two substrates.

Here, one surface of the conductive layer formed below the encapsulation substrate and one surface of the cathode electrode are formed to face each other, and are electrically connected to each other through a conductive spacer.

As a result, the conductive layer formed on one surface of the encapsulation substrate may receive a power voltage from an external terminal to uniformly provide a cathode voltage through the conductive spacer.

As described above, according to the present invention, an organic electroluminescent display device can be provided which prevents the voltage drop of the upper electrode by forming a conductive layer on the encapsulation substrate to provide a uniform voltage to the upper electrode.

In addition, it is possible to provide an organic light emitting display device in which a voltage drop of the upper electrode is prevented to prevent unevenness of brightness and image characteristics.

In addition, by preventing the voltage drop of the upper electrode, an organic light emitting display device having reduced power consumption can be provided.

In addition, by preventing the voltage drop of the upper electrode, a medium to large organic light emitting display device can be provided.

In addition, an organic light emitting display device having improved lifespan and reliability can be provided.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (18)

An insulating substrate; A lower electrode formed on the insulating substrate; An organic film including at least an organic light emitting layer formed on the lower electrode; An upper electrode formed on the organic layer; Conductive spacers dispersed on the upper electrode; And an encapsulation substrate including a conductive layer on one surface of the spacer. The method of claim 1, The upper electrode may be an anode electrode or a cathode electrode. The method of claim 1, And the conductive layer provides a voltage to an upper electrode. The method of claim 1, The upper electrode is electrically connected to the conductive layer by the conductive spacer. The method of claim 1, The organic electroluminescent display device of claim 1, wherein the upper electrode and the conductive layer formed on the encapsulation substrate face each other. The method of claim 1, And the conductive spacer is one metal material selected from the group consisting of Au, Ag, In, Al, and Ni, or a glass sphere or a synthetic resin coated with a metal material. The method of claim 1, And the conductive layer is a reflective material or a transparent material. The method of claim 7, wherein Wherein the reflective material is one selected from the group consisting of Mg, Ca, Al, Ag, Ba, Pt, Au, Ir, Cr, Mg, Ag, Ni, Al, and alloys thereof. The method of claim 7, wherein And the transparent material is made of ITO or IZO. Providing an insulating substrate; Forming a lower electrode on the insulating substrate; Forming an organic light emitting layer on the lower electrode; Forming an upper electrode on the organic light emitting layer; Forming a conductive spacer on the upper electrode; Forming an encapsulation substrate on the spacer and the upper electrode; A conductive layer is formed on one surface of the encapsulation substrate. The method of claim 10, And the upper electrode is an anode electrode or a cathode electrode. The method of claim 10, And wherein the conductive layer provides a voltage to an upper electrode. The method of claim 10, And the upper electrode is electrically connected to the conductive layer by the conductive spacer. The method of claim 10, The conductive spacer is one of a metal material selected from the group consisting of Au, Ag, In, Al and Ni, or a metal material coated glass sphere or synthetic resin manufacturing method of the organic light emitting display device, characterized in that formed. The method of claim 10, The conductive layer is a method of manufacturing an organic light emitting display device, characterized in that the reflective material or a transparent material. The method of claim 15, The reflective material is one selected from the group consisting of Mg, Ca, Al, Ag, Ba, Pt, Au, Ir, Cr, Mg, Ag, Ni, Al, and alloys thereof. Manufacturing method. The method of claim 15, The transparent material is ITO or IZO manufacturing method of the organic light emitting display device, characterized in that formed of a transparent material. The method of claim 12, The organic light emitting display device is a method of manufacturing an organic light emitting display device, characterized in that the sealing step is performed under a reduced pressure atmosphere.

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