KR100813840B1 - Organic light emitting display apparatus - Google Patents

Abstract

In order to reduce the resistance of the wiring, the present invention provides a substrate, a power supply line formed on the substrate, an insulating film formed on the substrate and formed on the power supply line, and a pixel formed on the insulating film and including a plurality of pixels. A region, a plurality of first electrodes disposed in each pixel, a plurality of organic emission layers disposed in each pixel, a second electrode formed on each pixel region, and electrically connected to the power supply line, and formed in the insulating layer And a via hole electrically connecting the power supply line and the second electrode, wherein the via hole extends along the power supply line.

Description

Organic light emitting display apparatus

1 is a schematic plan view of an organic light emitting diode display according to an exemplary embodiment of the present invention.

2 is a circuit diagram schematically illustrating a pixel circuit of one unit pixel of an organic light emitting diode display of the present invention.

3 is a circuit diagram illustrating a more specific example of FIG. 2.

4 is a cross-sectional view taken along the line IV-IV of FIG. 1.

5 is a cross-sectional view taken along the line VV of FIG. 1.

<Brief description of symbols for the main parts of the drawings>

110: substrate 120: buffer layer

130: semiconductor layer 140: gate insulating film

150: gate electrodes 131, 151 and 171: first, second and third metal layers

160: interlayer insulating film 170: source electrode

175: drain electrode 180: passivation film

181: contact hole 182: via hole

200: pixel region 210: first electrode

220: pixel defining layer 230: organic light emitting layer

240: opening 300: drive power supply line

310: driving line 320: driving power supply terminal

400: second electrode 410: power supply line

420: power supply terminal 500: vertical drive circuit portion

520: vertical drive terminal 600: horizontal drive circuit portion

620: horizontal drive terminal 700: terminal portion

800: sealing unit 900: sealing substrate

 The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device capable of lowering resistance of a wiring.

Among the flat panel display devices, organic or inorganic light emitting display devices are attracting attention as next-generation display devices because they have self-emissive display devices that have a wide viewing angle, excellent contrast, and fast response speed. In addition, an organic light emitting display device in which a light emitting layer is formed of an organic material has excellent luminance, driving voltage, and response speed, and may be multicolored, compared to an inorganic light emitting display device.

The organic light emitting diode display is classified into a passive matrix (PM) type of a passive driving method and an active matrix (AM) type of an active driving method according to a driving method. In the PM type, the anode and the cathode are arranged in columns and rows so that the cathode is supplied with a scanning signal from a row driving circuit, and only one row of the plurality of rows is selected. In addition, a data signal is input to each pixel in the column driving circuit. On the other hand, the AM type controls a signal input for each pixel by using a thin film transistor (TFT), which is suitable for processing a large amount of signals, and has been in the spotlight as a display device for implementing a video.

In the organic light emitting diode display, a power supply line for supplying power to the electrode is formed. The electrode and the power supply line are electrically connected through the via hole.

On the other hand, screen quality problems such as power consumption reduction and luminance improvement are becoming more important as the resolution and size of display devices increase. And in this screen quality problem, the resistance of each wire is an important factor. However, when the via hole is formed in the related art, the portion where the electrode and the power supply line are connected may become small or partially etched. Therefore, the organic light emitting material does not emit light or the luminance increases due to the increase in resistance even when the electrode and the power supply line are not in contact or contact. There was a problem of deterioration.

The present invention provides an organic light emitting display device which can improve the structure of a via hole to lower resistance of vertical wiring between a power supply line part and an electrode.

The present invention relates to a substrate, a power supply line formed on the substrate, an insulating film formed on the substrate, an insulating film formed on the power supply line, a pixel region formed on the insulating film, the pixel region including a plurality of pixels, A plurality of first electrodes, a plurality of organic light emitting layers disposed on the respective pixels, a second electrode formed on each of the pixel areas and electrically connected to the power supply line, and formed on the insulating layer; A via hole electrically connecting two electrodes is disclosed, and the via hole extends along the power supply line.

In the present invention, the second electrode and the power supply line overlap each other with the insulating layer interposed therebetween, and most of the region of the power supply line overlapping the second electrode may be exposed by the via hole. Can be.

In the present invention, the insulating film may be made of a material containing acrylic.

In the present invention, the pixel region may include a plurality of thin film transistor layers, and the power supply line may be formed of the same material as the source electrode or the drain electrode of the thin film transistor.

Hereinafter, with reference to the embodiments of the present invention shown in the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 is a schematic plan view of an organic light emitting diode display according to an exemplary embodiment of the present invention. FIG. 2 is a circuit diagram schematically illustrating a pixel circuit of one unit pixel of the organic light emitting diode display of the present invention. FIG. A circuit diagram showing a more specific example.

4 is a cross-sectional view taken along line IV-IV of FIG. 1, and FIG. 5 is a cross-sectional view taken along line V-V of FIG. 1.

As shown in FIG. 1, in the organic light emitting diode display, a pixel region 200 is formed on a substrate 110, and an image is realized through the pixel region 200. The pixel region 200 is sealed from the outside by the sealing substrate 900. The substrate 110 and the sealing substrate 900 are bonded to each other at the sealing portion 800. However, the encapsulation layer may be formed without the encapsulation part 800 and the encapsulation substrate 900.

At one end of the substrate 110 on which the pixel region 200 is formed, a terminal part 700 having predetermined terminals is disposed. The terminal portion 700 is exposed to the outside of the sealing portion 800.

A driving power supply line 300 for supplying driving power to the driving line (Vdd line) 310 of the pixel area 200 and a power supply line 410 for supplying power to the electrode around the pixel area 200. And various circuit parts for controlling a signal applied to the pixel region 200.

The driving power supply line 300 is disposed so as to surround the entire pixel region 200 from the driving power supply terminal 320 of the terminal unit 700, and is connected to the driving line 310 crossing the pixel region 200. Is also placed.

On one side of the pixel region 200, a power supply line 410 electrically connected to one electrode of the organic light emitting diode of the pixel region 200 is disposed. One electrode of the organic light emitting diode may extend to cover the power supply line 410, and an insulating layer is interposed between the electrode and the power supply line 410, and they are connected by the via hole 182.

The vertical driving circuit 500 and the horizontal driving circuit 600 are respectively disposed between the driving power supply line 300 and the pixel region 200. The vertical driving circuit unit 500 may be a scan driving circuit unit applying a scan signal to the gate line of the pixel area 200 and is connected to the vertical driving terminal 520 of the terminal unit 700. The horizontal driving circuit unit 600 may be a data driving circuit unit for applying a data signal to a data line of the pixel region 200 and is electrically connected to the horizontal driving terminal 620 of the terminal unit 700. The vertical and horizontal driving circuit units 500 and 600 may be formed on the substrate 110 by a patterning method, or may be formed such that a chip such as an external IC or COG is mounted thereon.

The pixel region 200 may include a plurality of pixels, and each pixel may have a pixel circuit as shown in FIG. 2. Referring to FIG. 2, each pixel may have a pixel circuit.

As shown in FIG. 2, each pixel includes a driving line (Vdd line) 310 in which a data line and a scan line serve as a driving power source of an organic light emitting diode (OLED).

The pixel circuit of each pixel is electrically connected to the data line, the scan line, and the driving line 310 to control light emission of the organic light emitting diode.

FIG. 3 illustrates a specific example of FIG. 2. As can be seen here, each pixel of the organic light emitting diode display according to the exemplary embodiment of the present invention specifically includes at least one of a switching TFT M2 and a driving TFT M1. It may include two thin film transistors, a capacitor unit Cst, and an organic light emitting diode OLED.

The switching TFT M2 is turned on / off by a scan signal applied to the scan line Scan to transfer the data signal applied to the data line Data to the storage capacitor Cst and the driving TFT M1. The switching element is not necessarily limited to the switching TFT M2 as shown in FIG. 3, and may include a switching circuit including a plurality of thin film transistors and capacitors, and a circuit that compensates for the Vth value of the driving TFT M1. The circuit may further include a circuit for compensating for the voltage drop of the driving line (Vdd line) 310.

 The driving TFT M1 determines the amount of current flowing into the organic light emitting element OLED according to the data signal transmitted through the switching TFT M2.

The capacitor unit Cst stores the data signal transmitted through the switching TFT M2 for one frame.

In the circuit diagram shown in FIG. 3, the driving TFT M1 and the switching TFT M2 are illustrated as PMOS TFTs, but the present invention is not necessarily limited thereto, and at least one of the driving TFT M1 and the switching TFT M2 may be used. It goes without saying that one may be formed of an NMOS TFT. The number of thin film transistors and capacitors is not necessarily limited thereto, and may include a greater number of thin film transistors and capacitors.

 The organic light emitting diode display according to the exemplary embodiment may have a cross section as illustrated in FIG. 4.

Referring to FIG. 4, a TFT, a sealing part 800, a driving power supply line 300, an organic light emitting element, and the like are formed on the substrate 110.

The substrate 110 may be acrylic, polyimide, polycarbonate, polyester, mylar or other plastic materials, but is not limited thereto, and a metal foil such as SUS and tungsten may be used, and the glass may be used. Ash is also available.

 A buffer layer 120 may be formed on the upper surface of the substrate 110 to prevent diffusion of impurity ions, to prevent penetration of moisture or external air, and to planarize a surface thereof. The buffer layer 120 is formed of an insulating layer.

The semiconductor layer 130 of the TFT is formed on the buffer layer 120, and the gate insulating layer 140 is formed to cover it. The semiconductor layer 130 may be an inorganic semiconductor such as amorphous silicon or polysilicon, or an organic semiconductor. The semiconductor layer 130 includes a source region, a drain region, and a channel region formed therebetween.

The gate electrode 150 is formed on the gate insulating layer 140, and the interlayer insulating layer 160 is formed to cover the gate insulating layer 140. The source electrode 170 and the drain electrode 175 are formed on the interlayer insulating layer 160, and the passivation layer 180 and the pixel defining layer 220 are sequentially formed to cover the interlayer insulating layer 160.

The gate insulating layer 140, the interlayer insulating layer 160, the passivation layer 180, and the pixel defining layer 220 may be formed of an insulator. The gate insulating layer 140, the interlayer insulating layer 160, and the pixel defining layer 220 may be formed of a single layer or a plurality of layers. / Inorganic composites.

The stacked structure of the TFT 40 as described above is not necessarily limited thereto, and all TFTs of various structures are applicable.

The first electrode 210, which is one electrode of the OLED, is formed on the passivation layer 180, and the pixel definition layer 220, which is an insulating layer, is formed on the passivation layer 180. The pixel defining layer 220 may be formed of a material including acrylic. A predetermined opening 240 is formed in the pixel definition layer 220 to expose the first electrode 210, and then an organic emission layer 230 of the OLED is formed.

The organic light emitting diode OLED displays predetermined image information by emitting red, green, and blue light according to the flow of current, and is electrically connected to the drain electrode 175 of the TFT through the contact hole 181. The first electrode 210 and the second electrode 400 formed to cover the entire pixel, and the organic light emitting layer 230 disposed between the first electrode 210 and the second electrode 400 to emit light.

The first electrode 210 and the second electrode 400 are insulated from each other by the organic light emitting layer 230, and the organic light emitting layer 230 emits light by applying voltages of different polarities to the organic light emitting layer 230. .

The organic light emitting layer 230 may be a low molecular or high molecular organic film. When using a low molecular organic film, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL) : Electron Injection Layer) can be formed by stacking single or complex structure, and usable organic materials are copper phthalocyanine (CuPc), N, N-di (naphthalen-1-yl) -N, N '-Diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: NPB), tris-8-hydroxyquinoline aluminum ( Alq3) can be used in various ways. These low molecular weight organic films are formed by the vacuum deposition method. In this case, the hole injection layer, the hole transport layer, the electron transport layer, the electron injection layer, etc. may be commonly applied to red, green, and blue pixels as a common layer. Therefore, unlike FIG. 4, these common layers may be formed to cover all pixels, like the second electrode 400.

In the case of the polymer organic film, the structure may be generally formed of a hole transport layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transport layer, and a poly-phenylenevinylene (PPV) system and polyfluorene (Polyfluorene) are used as the light emitting layer. A polymer organic material such as) may be used, and it may be formed by screen printing or inkjet printing.

The organic layer is not necessarily limited thereto, and various embodiments may be applied.

The first electrode 210 functions as an anode electrode, and the second electrode 400 functions as a cathode electrode. Of course, the polarities of the first electrode 210 and the second electrode 400 are It may be reversed.

In the case of a bottom emission type in which an image is embodied in the direction of the substrate 110, the first electrode 210 may be formed as a transparent electrode, and the second electrode 400 may be formed as a reflective electrode. . In this case, the transparent electrode may be formed using ITO, IZO, In2O3, ZnO, or the like having a high work function, and the second electrode 400 may include Ag, Mg, Al, or Pt having a low work function. , Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, and compounds thereof.

In the case of the top emission type, the first electrode 210 may be formed as a reflective electrode, and the second electrode 400 may be formed as a transparent electrode. In this case, the reflective electrode to be the first electrode 210 is formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or a compound thereof, and the like. It can be formed by forming a high work function ITO, IZO, ZnO, In2O3 or the like on the above. The transparent electrode serving as the second electrode 400 is formed by depositing a metal having a small work function, that is, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or a compound thereof. After that, an auxiliary electrode layer or a bus electrode line may be formed thereon with a transparent conductive material such as ITO, IZO, ZnO, or In 2 O 3.

In the case of the double-sided light emission type, both the first electrode 210 and the second electrode 400 may be formed as transparent electrodes. The first electrode 210 and the second electrode 400 are not necessarily limited to those formed of the above-described materials, and may be formed of a conductive organic material, a conductive paste containing conductive particles such as Ag, Mg, Cu, or the like. In the case of using such a conductive paste, it may be printed using an inkjet printing method, and after printing, may be baked to form an electrode.

After the organic light emitting element OLED is formed, the upper portion thereof is sealed to block from the outside air. In order to seal, a sealing substrate 900 is used. The encapsulation substrate 900 may be formed of the same material as the substrate 110 described above. At the time of sealing, the sealing substrate 900 is adhered with an adhesive such as a sealant. Thus, the sealing part 800, which is an area to be bonded to the substrate 110, is formed.

The gate electrode 150, the source electrode 170, and the drain electrode 175 may be formed of a metal material such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, and a compound thereof. Or a transparent conductive material such as ITO, IZO, ZnO, or In 2 O 3. In addition, a conductive paste containing conductive organic materials or conductive particles such as Ag, Mg, and Cu may be used.

The driving power supply line 300 is formed outside the pixel area 200. The driving power supply line 300 is electrically connected to the driving power supply terminal 320 of the terminal unit 700, and the driving power supply line 300 supplies uniform driving power over the entire pixel area 200 to improve luminance. In order to make it uniform, the pixel region 200 may be formed to surround the whole. The driving power supply line 300 is connected to the driving line 310.

The driving line 310 is disposed across the pixel area 200 and electrically connected to the source electrode 170.

The power supply line 410 is formed at one side of the pixel region 200, and may be simultaneously formed of the same material on the same layer as the source electrode 170 and the drain electrode 175 of the TFT. An insulating layer is formed on the power supply line 410, and the passivation layer 180 and the pixel defining layer 220 may be formed as an insulating layer. The passivation layer 180 and the pixel defining layer 220 are opened to form the via hole 182 to electrically connect the power supply line 410 and the second electrode 400.

As can be seen in FIG. 4, the via hole 182 is formed in one structure that extends along the power supply line 410 to expose most of the width of the power supply line 410. According to the present invention, the exposed area of the power supply line 410 is larger than the existing one, and is open and wide without interruption in the middle.

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 1, and is a vertical cross-sectional view of the via hole 182. In other words, the power supply line 410 and the second electrode 400 vertically overlap each other. At this time, the passivation layer 180 and the pixel defining layer are exposed to maximize the exposure of the power supply line 410 overlapping the second electrode 400. An opening 220 is formed to form a via hole 182.

Conventionally, when the via hole 182 is formed, the passivation layer 180 and the pixel defining layer 220 are less open, so there is a problem of less contact. However, in the present invention, the via hole 182 is formed in one wide and open structure. By maximizing the exposed area of the power supply line 410, wiring resistance may be reduced.

When the via hole 182 is formed, the via hole 182 may be formed by patterning using a mask. The via hole 182 may have an ellipse or a strip shape, but in order to maximize the exposed area of the power supply line 410, the via hole 182 may have a rectangular shape having the same shape as the power supply line 410.

The capacitor may be formed at the time of TFT formation, and the first metal layer 131, the second metal layer 151, and the third metal layer 171 overlap each other vertically.

The first metal layer 131 may be formed at the same time when the semiconductor layer 130 is formed of the same material as the semiconductor layer 130. The second metal layer 151 may be simultaneously formed when the gate electrode 150 is formed of the same material as the gate electrode 150. The third metal layer 171 may be formed at the same time when the source electrode and the drain electrode 175 are formed of the same material as the source electrode and the drain electrode 175.

The organic light emitting diode display according to the present invention can lower the resistance of the vertical wiring between the power supply unit and the electrode.

Although described with reference to the embodiment shown in the drawings it is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this.

Claims (4)

Board; A semiconductor layer formed on the substrate; A gate insulating film covering the semiconductor layer; A gate electrode formed on the gate insulating film; An interlayer insulating layer covering the gate electrode; A source electrode and a drain electrode formed on the interlayer insulating film and electrically connected to the semiconductor layer; An electrode power supply line formed on said interlayer insulating film and formed simultaneously with said source electrode and drain electrode using the same material as said source electrode or drain electrode; An insulation layer formed on the electrode power supply line; A pixel region formed on the insulating layer and including a plurality of pixels; A plurality of first electrodes disposed in the pixels; A plurality of organic light emitting layers on each pixel; A second electrode formed on each pixel area and electrically connected to the electrode power supply line; A via hole formed in the insulating layer and electrically connecting the electrode power supply line and the second electrode; The via hole extends along the electrode power supply line. According to claim 1, The second electrode and the electrode power supply line overlap with the insulating layer interposed therebetween, The organic light emitting diode display of which a portion of the region of the electrode power supply line overlapping the second electrode is exposed by a via hole. According to claim 1, The insulating layer is an organic light emitting display device made of a material containing acrylic. delete

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