Light emitting display and method of manufacturing the same

A light emitting display and a method of manufacturing the same. The light emitting display includes a substrate, a plurality of first and second signal lines that cross each other on the substrate, a plurality of organic light emitting diodes (OLEDs) coupled between the first signal lines and the second signal lines, a power source supply line for supplying a power source voltage to the OLEDs, and a plurality of inspection signal lines coupled to at least one of the first signal lines or the second signal lines. At least one of the inspection signal lines is discontinuous at a region overlapping the power source supply line and ends of the discontinuous inspection signal line at the region overlapping the power source supply line are coupled to each other through a conductive region under the inspection signal line.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2007-0076945, filed on Jul. 31, 2007, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a light emitting display and a method of manufacturing the same.

2. Description of the Related Art

An organic light emitting display is a next generation display having a self-emission characteristic and has better characteristics in terms of a viewing angle, contrast, response speed, and consumption power than those of a liquid crystal display (LCD). A backlight is not required so that the organic light emitting display can be made light and thin.

Since the substrate of the organic light emitting display is formed of glass, a large amount of electrostatic discharge (ESD) is generated during manufacturing of the organic light emitting display. When the ESD is received to organic light emitting diodes (OLEDs) or a driving circuit that operates at high speed at a low voltage, erroneous operations may be generated or the OLEDs or the driving circuit may be damaged due to the ESD. When the externally generated ESD is received by the driving circuit through internal signal lines, the operations may be instantaneously stopped or the signal lines that constitute the circuit may be shorted. In particular, when an excessively large voltage is concentrated by the ESD, insulation may be damaged in the parts where the signal lines cross, thereby generating short.

SUMMARY OF THE INVENTION

Accordingly, it is a feature of the present invention to provide a light emitting display capable of preventing signal lines from being damaged by electrostatic discharge (ESD) and a method of manufacturing the same.

It is another feature of the present invention to provide a light emitting display capable of preventing short between signal lines that intersect each other and a method of manufacturing the same.

In order to achieve the foregoing and/or other features of the present invention, according to one aspect of the present invention, there is provided a light emitting display including a substrate, a plurality of first and second signal lines that cross each other on the substrate, a plurality of organic light emitting diodes (OLEDs) coupled between the first signal lines and the second signal lines, a power source supply line for supplying a power source voltage to the OLEDs, and a plurality of inspection signal lines, each of the inspection signal lines coupled to at least one of a corresponding one of the first signal lines or a corresponding one of the second signal lines. At least one of the inspection signal lines is discontinuous at a region overlapping the power source supply line and ends of the discontinuous inspection line at the region overlapping the power source supply line are coupled to each other through a conductive region under the inspection signal line.

According to another aspect of the present invention, there is provided a method of manufacturing a light emitting display. The method includes forming an active region of a TFT and a conductive region of an inspection signal line on a substrate, forming a gate insulation layer on the substrate, the gate insulation layer substantially covering the active region and the conductive region, forming contact holes in the gate insulation layer on the conductive region so that the conductive region is partially exposed at at least two locations, forming a gate electrode, a first signal line, and the inspection signal line coupled to the first signal line and coupled to the conductive region at said at least two locations through the contact holes in the gate insulation layer on the conductive region, forming an insulation layer on the substrate, the insulation layer substantially covering the gate electrode, the first signal line, and the inspection signal line, forming contact holes in the insulation layer on the active region so that the active region is partially exposed at at least two locations, forming source and drain electrodes coupled to respective said at least two locations of the active region through the contact holes, a second signal line that crosses the first signal line, and a power source supply line that crosses the conductive region, and forming an OLED to be coupled to the source electrode or the drain electrode.

According to still another aspect of the present invention, there is provided a substrate on which a plurality of light emitting displays are locate, the light emitting displays separable from each other by scribe lines that cross each other. The substrate includes: a plurality of first common signal lines on the substrate between the light emitting displays, and a plurality of second common signal lines on the substrate between the light emitting displays and crossing the first common signal lines. Each of the light emitting displays includes a plurality of first and second signal lines that cross each other on the substrate, a plurality of organic light emitting diodes (OLEDs) coupled between the first signal lines and the second signal lines, a power source supply line coupled to at least one of the plurality of first common signal lines to supply a power source voltage to the OLEDs, and a plurality of inspection signal lines coupled to the plurality of second common signal lines, each of the plurality of inspection signal lines coupled to at least one of a corresponding one of the first signal lines or a corresponding one of the second signal lines. At least one of the inspection signal lines is discontinuous at a region overlapping the power source supply line, and ends of the discontinuous inspection signal line at the region overlapping the power source supply line are coupled to each other through a conductive region under the inspection signal line.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1is a plan view illustrating a light emitting display according to an embodiment of the present invention.

The light emitting display according to an embodiment the present invention includes a plurality of scan lines118cand a plurality of data lines114bformed on a substrate100to cross each other, a plurality of pixels150coupled to the plurality of scan lines118cand the plurality of data lines114b, a power source supply line118dfor supplying a power source voltage to the pixels150, and a plurality of inspection signal lines114ccoupled to at least one of the scan lines118cand the data lines114b. Each of the plurality of pixels150includes an organic light emitting diode (OLED).

The substrate100is divided into a display region102and a non-display region104. The pixels150provided between the scan lines118cand the data lines114bare formed on the substrate in the display region102. In a passive matrix type, the pixels150are OLEDs that are coupled between the respective scan lines118cand the data lines114bin a matrix. In an active matrix type, each of the pixels150further includes thin film transistors (TFTs) for controlling the operations of the OLED and a capacitor for storing data voltage.

The non-display region104is a peripheral region of the display region102. A scan driver210and a data driver220for processing signals supplied from the outside through an input pad120to supply the signals to the scan lines118cand the data lines114b, the power source supply line118dfor supplying a power source voltage to the pixels150, and inspection signal lines114cfor supplying inspection signals to the scan lines118cand/or the data lines114bare formed on the substrate100in the non-display region104.

The scan driver210and the data driver220can be formed on the substrate100in the non-display region104in the manufacturing process of the pixels150or are manufactured as an additional integrated circuit semiconductor chip to be attached to the substrate100by a chip on glass (COG) method or a wire bonding method to be coupled to the scan lines118cand the data lines114b.

The power source supply line118dis formed so that the power source voltage is distributed from the power source bus lines formed in the non-display region104to the pixels150of the display region102. The inspection signal lines114care formed so that the inspection signals are distributed and provided from the signal bus lines formed in the non-display region104to the scan lines118cor the data lines114bof the display region102.

The light emitting display according to an embodiment of the present invention includes the inspection signal lines114cfor providing inspection signals to the scan lines118cand the data lines114bof the display region102. The inspection signal lines114care provided for effectively inspecting a plurality of display panels in the manufacturing processes in units of a mother substrate. During the manufacturing process, a plurality of display panels are manufactured on a substrate and the inspection signal lines114care provided to supply signals to the red (R), green (G), or blue (B) OLEDs (in the pixels150) of the display panels and to inspect the emission state and the brightness. In the drawings, only a few inspection signal lines114care illustrated. However, the inspection signal lines114care coupled to the plurality of data lines114bso that the R, G, or B OLEDs of the same column or all the columns is concurrently driven.

In the above structure, since the inspection signal lines114cformed in the non-display region104of the substrate100are coupled to the scan lines118cor the data lines114bof the display region102, the inspection signal lines114ccan cross the power source supply line118din the non-display region104. Therefore, when the thickness of the insulation layer between the power source supply line118dand the inspection signal lines114cis small or an excessive voltage is concentrated due to electrostatic discharge (ESD), shorts may be generated in the parts where the power source supply line118dcrosses the inspection signal lines114cdue to the damage of insulation.

Therefore, according to an embodiment of the present invention, the inspection signal line114cis partially opened (i.e., is discontinuous) in the part where the inspection signal line114ccrosses the power source supply line118dand the both opened ends (i.e., ends formed at the discontinuous portion of the inspection signal line114c) are coupled to each other through a conductive region under the inspection signal line114c.

FIGS. 2A and 2Bare a plan view and a sectional view illustrating an enlargement of the part (e.g., A ofFIG. 1) where the power source supply line118dand the inspection signal line114ccross each other. The power source supply line118dto which a power source voltage ELVDD is supplied and the inspection signal line114cto which an inspection data signal VDATA is supplied are illustrated.

Referring toFIGS. 2A and 2B, the inspection signal line114cis formed under the power source supply line118dand is electrically isolated from the power source supply line118dby insulation layers112,115, and116.

The inspection signal lines114care partially opened (i.e., is discontinuous) at the part (B ofFIG. 2B) where the inspection signal line114ccrosses the power source supply line118dand the both opened ends are coupled to each other through a conductive region110bunder the inspection signal line114c. Here, the both opened ends of the inspection signal line114care coupled to the conductive region110bthrough contact holes113formed in the insulation layer112between the inspection signal line114cand the power source supply line118d.

The distance between the opened ends of the inspection signal line114cis larger than the width of the power source supply line118dand the conductive region110bsufficiently overlap the both ends of the inspection signal line114c.

Then, the method of manufacturing the light emitting display according to an embodiment of the present invention having the above structure will be described with reference toFIGS. 3A to 3D.

FIGS. 3A to 3Dare sectional views illustrating a method of manufacturing the light emitting display according to an embodiment of the present invention. The display region in which the pixels150are formed and the non-display region104in which the power source supply line118dand the inspection signal line114ccross each other will be schematically described.

Referring toFIG. 3A, the substrate100divided into the display region102and the non-display region104is illustrated. An active region110aof the TFT is formed in the display region102of the substrate and the conductive region110bof the inspection signal line114cis formed in the non-display region104. The active region110aand the conductive region110bare formed of a semiconductor layer such as polysilicon. The active region110ais used as the source and drain regions and the channel region of the TFT and the conductive region110bis doped with P type or N type impurity ions to have conductivity. In addition, before forming the active region110aand the conductive region110b, a buffer layer (not shown) can be formed on the substrate100using a silicon oxide layer or a silicon nitride layer.

After forming the gate insulation layer112on the entire top surface including the active region110aand the conductive region110b, the contact holes113are formed so that both sides of the conductive region110bare partially exposed.

Referring toFIG. 3B, the gate electrode114a and the data line114b(shown inFIG. 1) coupled to the gate electrode114aare formed on the gate insulation layer112on the active region110aand the inspection signal line114ccoupled to both sides of the conductive region110bthrough the contact holes113is formed on the gate insulation layer112on both sides of the conductive layer110b. The gate electrode114aand the inspection signal line114ccan be formed of polysilicon or metal.

Referring toFIG. 3C, the interlayer insulation layers115and116are formed on the entire top surface including the gate electrode114aand the inspection signal line114c. Then, the interlayer insulation layers115and116and the gate insulation layer112are patterned to form contact holes117so that the source and drain regions of the active region110aare exposed. The interlayer insulation layers115and116for insulation and planarization have a double layer structure in the described embodiment, however, can have a single layer structure or a multiple layer structure in other embodiments.

Referring toFIG. 3D, source and drain electrodes118aand118bcoupled to the source and drain regions of the active region110athrough the contact holes117and a scan line118ccoupled to the source drain electrode118aand118bare formed in the display region and the power source supply line118dis formed in the non-display region104. Here, a part of the power source supply line118dcrosses the conductive region110bof the inspection signal line114c.

Then, the OLED of the pixel150is formed to be coupled to the source or drain electrode118aor118b. The OLED includes an anode electrode, an organic thin layer, and a cathode electrode and the organic thin layer has a structure in which a hole transport layer, an organic light emitting layer, and an electron transport layer are laminated to each other or can further include a hole injection layer and an electron injection layer. Processes of manufacturing the OLED are illustrated in Korean Patent Publication No. 2003-0092873 (published on Dec. 6, 2003), the entire content of which is incorporated by reference.

FIG. 4is a plan view illustrating the light emitting display according to an embodiment of the present invention that is manufactured in units of a mother substrate and illustrates a part of a mother substrate1000.

The mother substrate1000is divided into a plurality of display panels by scribe lines1100that cross each other. The light emitting display is formed in each display panel as illustrated inFIG. 1. At this time, the inspection signal lines114cand the power source supply lines118dof the display panels arranged in the same direction are commonly coupled to a common power supply line1210and a common signal line1220among the plurality of common signal lines arranged to cross each other on the mother substrate1000. Therefore, a power source voltage and inspection signals are supplied to the common power source supply line1210and the common signal line1220through a pad (not shown) formed at the edge of the mother substrate1000to inspect the OLEDs of the pixels150of the display panels. At this time, when the common power source supply line1210and the common signal line1220are properly arranged, the display panels can be selectively inspected.

After the light emitting displays are inspected, the mother substrate1000is cut off along the scribe lines1100to separate the plurality of display panels from each other. At this time, the mother substrate1000is cut off along the scribe lines1100so that the common power source supply line1210and the power source supply line118dare electrically separated from each and the common signal line1220and the inspection signal lines114care electrically separated from each other. The sections of the power source supply line118dand the inspection signal lines114ccan be exposed at the edge of the substrate100of the separated display panel.

In the separated display panel, the inspection signal lines114care electrically floated. However, in order to have the light emitting display stably operate, the scan lines118cor the data lines114bare coupled to the inspection signal lines114cthrough switches (not shown) formed of the TFTs so that the scan lines118cor the data lines114band the inspection signal lines114care electrically separated from each other.

As described above, there is provided a light emitting display including the inspection signal lines. The inspection signal line is partially opened in the part where the inspection signal line crosses the power source supply line and the both opened ends are coupled to each other through the conductive region formed under the inspection signal line. The distance between the power source supply line and the inspection signal line increases in the part where the power source supply line and the inspection signal line cross each other so that the thickness of the insulation layer increases. Therefore, since insulation is prevented from being damaged even when an excessive voltage is concentrated by the ESD, the electrical characteristic and reliability of the light emitting display are improved.