Organic light emitting display and method for manufacturing the same

An organic light emitting display includes a first substrate including a plurality of anode electrodes on an insulating layer and a plurality of pixel definition layers around the plurality of anode electrodes. An impact absorbing layer is spaced from the plurality of pixel definition layers, and a spacer is on an upper surface of the impact absorbing layer. A second substrate faces the first substrate and is spaced from the first substrate by the spacer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean Patent Application No. 10-2008-0009614, filed on Jan. 30, 2008, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an organic light emitting display and a method for manufacturing the same.

2. Description of Related Art

Recently, various flat panel display devices having reduced weight and volume compared to cathode ray tube device have been developed. Exemplary flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an organic light emitting display (OLED), among others.

An organic light emitting display displays an image using an organic light emitting diode (OLED) generating light by recombination of electrons and holes.

An organic light emitting diode includes an anode electrode, a cathode electrode and an emission layer positioned between the anode electrode and the cathode electrode. When a current flows in a direction from the anode electrode to the cathode electrode, a color is expressed through light emission.

The market for such organic light emitting displays having excellent color reproducibility, a relatively thin configuration, etc. has been largely expanded into various applications such as personal digital assistants (PDAs), MP3 players, etc. in addition to cellular phones.

A conventional organic light emitting display may include a transparent substrate on which a thin film transistor and an organic light emitting diode etc. are formed, and a seal substrate sealing the transparent substrate. A spacer is included between the transparent substrate and the seal substrate in order to constantly maintain a distance therebetween.

In the organic light emitting display constituted as above, when impact is applied to the seal substrate or the transparent substrate from the outside, the impact may be transferred to the spacer.

The impact transferred to the spacer can also be transferred to the organic light emitting diode, thereby damaging the organic light emitting diode. In particular, the greater the impact strength transmitted, the greater the degree of damage to the organic light emitting diode becomes. A damaged organic light emitting diode does not emit light, potentially causing blurs to appear on the organic light emitting display.

The occurrence of a defect to an internal device is checked by a bending test and a ball drop test to evaluate the device's strength. If the device does not endure a threshold strength, the device is judged as insufficient to be launched in the market.

Accordingly, the strength of a device's organic light emitting display is important, and increasing the device's strength is also important.

SUMMARY OF THE INVENTION

According to aspects of the present invention, an organic light emitting display is provided with improved durability by including an impact absorbing layer and a method for manufacturing the same.

In one embodiment of the present invention, an organic light emitting display is provided including a first substrate having a plurality of anode electrodes on an insulating layer and a plurality of pixel definition layers around the plurality of anode electrodes. An impact absorbing layer is spaced from the plurality of pixel definition layers, and a spacer is on the impact absorbing layer. A second substrate faces the first substrate and is spaced from the first substrate by the spacer.

In one embodiment, an inert gas or an organic material is in a space between the first substrate and the second substrate. Further, the pixel definition layer and the impact absorbing layer may comprise the same material and may be formed by the same process.

In another embodiment, a method for manufacturing an organic light emitting display is provided including forming a thin film transistor on glass, forming an insulating layer on an upper surface of the thin film transistor, forming a plurality of anode electrodes electrically coupled to the thin film transistor on the insulating layer, forming a plurality of pixel definition layers positioned around the plurality of anode electrodes and impact absorbing layers spaced from the plurality of pixel definition layers by forming and patterning the insulating layer on the plurality of anode electrodes, and forming a spacer on the impact absorbing layer.

DETAILED DESCRIPTION

FIG. 1is a plan view showing an organic light emitting display.

Referring toFIG. 1, an organic light emitting display includes a transparent substrate and a seal substrate. Herein, the transparent substrate includes a thin film transistor, an insulating layer and an anode electrode10of the organic light emitting diode, etc. formed on an upper surface thereof. Also, a pixel definition layer (PDL) layer11is formed on the upper surface of the anode electrode10. The anode electrode is exposed in a specific region, for example, an emission region12that emits light. The emission region12is formed with an emission layer to form an organic light emitting diode. The organic light emitting diode is electrically coupled to the thin film transistor to emit light corresponding to a signal transmitted from thin film transistor. A plurality of spacers13are formed on one region of the PDL layer11. The spacers13function to constantly maintain a distance between the transparent substrate and the seal substrate.

When impact from the outside is applied to the seal substrate or the transparent substrate of the organic light emitting display constituted as above, the impact is transferred to the spacer13.

When the impact is transferred to the spacer13, the impact may be further transferred to the PDL layer11on the lower surface of the spacer. The impact transferred to the PDL layer11can also be transferred to the emission layer and the anode electrode10. Therefore, if the transferred impact strength is large, the organic light emitting diode may be damaged, preventing the organic light emitting diode from emitting light. As such, blurs may appear on the organic light emitting display.

Accordingly, embodiments of the present invention include an organic light emitting display having an impact absorbing layer to prevent or significantly reduce damage to the organic light emitting display. Hereinafter, the detailed description thereof will be provided with reference toFIG. 2.

FIG. 2is a cross-sectional view of a light emitting region of an organic light emitting display according to an embodiment of the present invention. With reference toFIG. 2, the light emitting region of the organic light emitting display includes a transparent substrate150and a seal substrate200sealing the transparent substrate150. Accordingly, the light emitting region can display images to be viewed by a viewer.

A buffer layer101is formed on the glass100of the transparent substrate150and a semiconductor layer102is formed on the upper surface of the buffer layer101. An insulation layer103is formed on the upper surface of the semiconductor layer102, and a gate electrode104is formed by forming and patterning a metal layer on the upper surface of the insulation layer103. An ion doping process is performed on the semiconductor layer102.

An insulation layer105is formed on the upper surface of gate electrode104and then a contact hole115is formed in the insulation layer. A source drain metal106is formed by forming and patterning the metal layer on the upper surface of the semiconductor layer102. The source drain metal106may contact both ends of the semiconductor layer102through the contact hole115.

The insulation layer107is formed to have a flattened upper surface. A contact hole117is then formed in the insulation layer107, and the anode electrode111is formed on the insulation layer107. The anode electrode111contacts the source drain metal106through the contact hole117.

The insulation layer is formed on the anode electrode111. The insulation layer becomes PDL layer108and an impact absorbing layer by means of an etching of the insulation layer. The PDL layer108is a film defining region in which an organic light emitting diode is formed. The anode electrode111is exposed to the inside of the PDL layer108. The emission layer (not shown) is formed on the upper surface of anode electrode111and a cathode electrode is formed on the upper of thereof to form the organic light emitting diode.

The impact absorbing layer109and the PDL layer108are formed to be spaced from each other. Therefore, although an impact may be applied to the impact absorbing layer109, it is not transferred to the PDL layer108. In other words, although force generated by the impact from the outside is applied to the impact absorbing layer109, the force is not transferred to the emission layer formed on the PDL layer108.

The spacer110is formed on the upper of the impact absorbing layer to maintain the distance between the transparent substrate150and the seal substrate200. At this time, the spacer110can be formed to contact the seal substrate200and can be formed to be spaced at a distance therefrom. If the impact is applied from the outside, the impact is applied to the spacer110. As such, the impact applied to the spacer110is transferred to only the impact absorbing layer109, thereby protecting the emission layer.

The transparent substrate150and seal substrate200of the organic light emitting display may be adhered to each other by means of epoxy or frit, among other fasteners or adherents. An inert gas such as N2 is injected to a space between the transparent substrate150and the seal substrate200.

Also, in order to further increase the device strength, various reinforcing materials such organic materials, etc. are formed between the transparent substrate150and the seal substrate200.

As mentioned above, with the organic light emitting display and the method for making the same according to embodiments of present invention, the impact absorbing layer109is formed so as to be spaced from the PDL layer108, and the spacer110is formed on the impact absorbing layer109, making it possible to prevent damage to the organic light emitting diode due to the impact applied from the outside.