KR20090068505A - Organic light emitting diode display device and method of manufacturing the same - Google Patents

Abstract

An organic light emitting diode display device and a manufacturing method thereof are provided to prevent the deterioration of an aperture ratio due to a driving device by irradiating the light to the direction opposite to the substrate with the driving device. An organic light emitting diode display device includes a driving device, a protective film(120), a planarized film(130), an anode electrode(140), a bank pattern(150), an organic layer(160), and a cathode electrode(170). The driving device is arranged on each pixel of the substrate. The protective film is arranged on the substrate including the driving device. The planarized film is arranged on the protective film and has a trench arranged around the pixel. The anode electrode is arranged on the planarized film while being separated according to each pixel and reflects the light to the direction opposite to the substrate. The bank pattern covers the edge of the anode electrode and has a larger opening than the trench to form an undercut. The organic layer is arranged on the anode electrode exposed by the bank pattern and includes at least organic light emitting pattern. The cathode electrode is arranged on the organic layer, is electrically connected to the driving device, and is separated according to each pixel the undercut part.

Description

Organic light emitting diode display and manufacturing method thereof {ORGANIC LIGHT EMITTING DIODE DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to an organic light emitting diode display, and more particularly, to a top emission type organic light emitting diode display and a method of manufacturing the same.

Recently, the organic light emitting diode display is self-luminous and does not require a backlight, such as a liquid crystal display, so that it is not only light and thin, but also can be manufactured through a simple process, thereby increasing price competitiveness. In addition, organic light emitting diode display devices are rapidly rising as next generation displays due to low voltage driving, high luminous efficiency, and wide viewing angle.

The organic light emitting diode display device includes an organic light emitting diode device for generating light and a driving device for controlling driving of the organic light emitting diode, for example, a thin film transistor. Here, since the driving device individually drives the organic light emitting diode device, the organic light emitting diode device may display the same luminance even when a low current is applied to the organic light emitting diode device.

As a result, the organic light emitting diode display device includes a driving element, which is advantageous for low power consumption, high definition, and large size, and can improve the life of the organic light emitting diode display device.

However, the organic light emitting diode display has a problem in that the aperture ratio decreases as the image provided to the user through the substrate on which the driving device is formed is provided from the organic light emitting layer.

In order to increase the aperture ratio, the organic light emitting diode display device has a problem in that electrical characteristics of the driving device are deteriorated when the size of the driving device is reduced, thereby limiting the size of the driving device. For example, the electrical characteristics of the driving device are proportional to the width of the channel relative to the length of the channel.

Accordingly, the conventional organic light emitting diode display device may include a driving device to improve image quality and electrical characteristics of the organic light emitting diode display device, but the aperture ratio of the organic light emitting diode display device is lowered by the driving device.

One object of the present invention is to provide a top emission organic light emitting diode display that emits light in a direction opposite to the substrate on which the drive element is formed in order to prevent the aperture ratio from being lowered by the drive element.

Another object of the present invention is to provide an organic light emitting diode display device which can use a manufacturing apparatus of a general liquid crystal display device.

Another object of the present invention is to provide an organic light emitting diode display device which can improve the lifespan by preventing degradation of the organic layer.

Another object of the present invention is to provide a method of manufacturing the organic light emitting diode display.

In order to achieve the above technical problem, an aspect of the present invention provides a driving device disposed on each pixel of the substrate, and a protective film disposed on the substrate including the driving device. A planarization film disposed on the passivation layer, the planarization film having a trench disposed along the periphery of the pixel; A bank pattern having an opening wider than the trench to cover an edge of the bank pattern, an organic layer disposed on the anode electrode exposed by the bank pattern, the organic layer including at least an organic light emitting pattern, and The display device includes a cathode electrode disposed on the organic layer and electrically connected to the driving element portion, and separated by each pixel by the undercut portion.

In order to achieve the above technical problem, another aspect of the present invention provides a method of manufacturing an organic light emitting diode display. The manufacturing method includes forming a driving element portion on a pixel of a substrate, forming a protective film on a substrate including the driving element portion, a protective film disposed on a substrate including the driving element portion, and planarizing on the protective layer. Forming a film, forming an anode electrode disposed on the planarization film and reflecting light in a direction opposite to the substrate, covering an edge of the anode electrode and having an opening along the periphery of the pixel Forming a trench by etching the planarization layer corresponding to the opening to form an undercut portion, the organic layer disposed on the anode electrode exposed by the bank pattern and including at least an organic light emitting pattern And forming an organic layer on the organic layer and electrically connected to the driving element unit. And forming a cathode electrode separated for each pixel by the keotbu.

The organic light emitting diode display device of the present invention is designed to emit light in a direction opposite to the substrate on which the driving element is formed, thereby not only preventing the opening ratio from being lowered by the driving element but also controlling the driving element without regard to the opening ratio. You can design freely.

In addition, the organic light emitting diode display device of the present invention may include an anode electrode, an organic light emitting layer, and a cathode electrode which are sequentially arranged to prevent damage to the organic light emitting layer. In addition, since the cathode electrode is electrically connected to the driving element, an N-type thin film transistor of a conventional liquid crystal display device can be applied, and thus, no additional facility for manufacturing an organic light emitting diode display device is required.

In addition, the organic light emitting diode display of the present invention includes an undercut portion for separating the cathode electrode for each pixel, thereby preventing the occurrence of corrosion of the cathode electrode.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of the organic light emitting diode display. The following embodiments are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the invention is not limited to the embodiments described below and may be embodied in other forms. In the drawings, the size and thickness of the device may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 and 2 illustrate an organic light emitting diode display according to a first embodiment of the present invention.

1 is a plan view of an organic light emitting diode display according to a first exemplary embodiment of the present invention. 1 is an enlarged view of only one pixel of the plurality of pixels in the drawing for convenience of description.

Referring to FIG. 1, an organic light emitting diode display includes a plurality of pixels defined for displaying an image, driving element units S-Tr, D-Tr, and Cp electrically connected to each pixel, and an organic light emitting diode. An element portion (140, 160, 170 of FIG. 2).

A plurality of wirings 101, 102, 103, and 104 are provided to provide electrical signals to the driving element units S-Tr, D-Tr, and Cp and the organic light emitting diode element units 140, 160, and 170. have. For example, the plurality of wirings 101, 102, 103, and 104 may include a gate wiring 101, a data wiring 102, a ground wiring 103 that is parallel to the data wiring 102, and may define the pixels crossing each other. The common wiring 104 may be parallel to the gate wiring 101.

The driving element units S-Tr, D-Tr, and Cp are disposed in an intersection region of the gate line 101 and the data line 102, that is, a pixel. The driving element units S-Tr, D-Tr, and Cp may include a switching thin film transistor S-Tr, a driving thin film transistor D-Tr, and a capacitor Cp.

The switching thin film transistor S-Tr is electrically connected to the gate line 101 and the data line 102.

The driving thin film transistor D-Tr is electrically connected to the switching thin film transistor S-Tr and the ground line 103.

The capacitor Cp is electrically connected to the switching thin film transistor S-Tr and the driving thin film transistor D-Tr. In addition, the capacitor Cp is electrically connected to the ground line 103.

The organic light emitting diode element parts 140, 160, and 170 include an anode electrode 140, an organic layer 160 including at least an organic light emitting pattern, and a cathode electrode 170. The anode electrode 140 is electrically connected to the power line 104. The cathode electrode 170 is electrically connected to the driving thin film transistor D-Tr.

The driving principle of the organic light emitting diode display is as follows. The switching thin film transistor S-Tr is turned on / off according to a selection signal provided from the gate line 101. The electrical signal adjusted by the on / off of the switching thin film transistor S-Tr, for example, the data signal provided from the data line 102, may be transferred to the organic light emitting diode element unit 140, 160, 170. Is applied to the organic light emitting diode element parts 140, 160 and 170 to adjust the amount of current flowing through the organic light emitting diode element parts 140, 160 and 170 to adjust the luminance of the organic light emitting diode element parts 140, 160 and 170 to display an image. The capacitor Cp maintains the already applied electrical signal for a predetermined time until the next electrical signal is applied from the switching thin film transistor S-Tr to the driving thin film transistor D-Tr for uniformity of image quality. Keep it.

FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

1 and 2, the substrate 100 defines a plurality of pixels for displaying an image.

Driving element units S-Tr, D-Tr, and Cp are disposed in the pixels of the substrate 100. In the driving element units S-Tr, D-Tr, and Cp, a switching thin film transistor S-Tr, a driving thin film transistor D-Tr, and a capacitor Cp are disposed.

The driving thin film transistor D-Tr includes a gate electrode 111, a gate insulating layer 110, a semiconductor pattern 112, and source and drain electrodes 113 and 114. The gate electrode 111 is electrically connected to the drain electrode 114 of the switching thin film transistor S-Tr. The semiconductor pattern 112 includes an active pattern 112a formed of an amorphous silicon pattern and an ohmic contact pattern 112b formed of amorphous silicon that exposes a channel of the active pattern 112a and includes impurities, for example, N ⁺ . can do. In addition, the switching thin film transistor S-Tr includes a switching gate electrode 211 protruding from the gate wiring 101, a gate insulating layer 110 covering the switching gate electrode 211, and the switching gate electrode 211. A switching source pattern / drain disposed on both ends of the switching semiconductor pattern 212 with the switching semiconductor pattern 212 disposed on the gate insulating 110 layer corresponding to the channel of the switching semiconductor pattern 212 interposed therebetween. Electrodes 213 and 214. The capacitor Cp is a first storage electrode 131 connected to the gate electrode 111 overlapping the gate insulating layer 110 therebetween, and a second storage electrode 132 electrically connected to the ground wiring 103. ) May be included.

A common line 104 is disposed to be spaced apart from the driving element units S-Tr, D-Tr, and Cp and to cross the pixel. The common wiring 104 may be made of the same conductive material as the gate wiring 101. The common wiring 104 applies a common voltage to the anode electrode 140.

The passivation layer 120 is disposed on the substrate 100 including the driving element units S-Tr, D-Tr, and Cp and the common wiring 104. The passivation layer 120 may be formed of an inorganic insulating layer. For example, the passivation layer 120 may be a silicon oxide film or a silicon nitride film.

A planarization layer 130 having a flat upper surface may be further disposed on the passivation layer 120. The planarization layer 130 may be formed of an organic insulating layer. For example, the planarization layer 130 may be an acrylic resin, a urethane resin, a polyimide-based resin, a benzocyclobutene resin (BCB), or a silicone-based resin. ) And polyphenol resins.

The planarization layer 130 serves to planarize the step difference caused by the driving element units S-Tr, D-Tr, and Cp and the plurality of wirings 101, 102, 103, and 104. In addition, the planarization layer 130 may include the driving element units S-Tr, D-Tr, and Cp and the plurality of wirings 101, 102, 103, and 104 and the first electrode 140 disposed thereon. It serves to prevent the occurrence of parasitic caps of the liver.

Trenchs are formed along the periphery of the pixels of the planarization layer 130.

The passivation layer 120 and the planarization layer 130 may include first and second contact holes C1 and C2 exposing portions of the drain electrode 114 and portions of the common wiring 104, respectively. .

An anode electrode 140 separated for each pixel is disposed on the planarization layer 130. The anode electrode 140 may reflect light. The anode electrode 140 may be formed of a conductive material having a larger work function than the cathode electrode 170 to be described later. For example, the anode electrode 140 may include stacked first and second anode electrodes 140a and 140b. The first anode electrode 140a may be made of a conductive material that reflects light. For example, the first anode electrode 140a may be formed of any one of Al, AlNd, Ag, and Mo. The second anode electrode 140b may have a greater corrosion resistance than the first anode electrode 140a and may be made of a conductive material having a larger work function than the cathode electrode 170. For example, the second anode electrode 140b may be made of ITO or IZO.

The anode electrode 140 is electrically connected to the common wiring 104 through the second contact hole C2.

The anode electrode 140 may have an opening corresponding to a portion of the drain electrode 114. A connection pattern 145 electrically connected to the drain electrode 114 through the first contact hole C1 may be disposed in the opening. The connection pattern 145 may be made of the same material as the anode electrode 140.

The connection pattern 145 electrically connects the drain electrode 114 and the cathode electrode 170 to be described later. The connection pattern 145 prevents a short circuit in electrically connecting the drain electrode 114 and the cathode electrode 170 to each other by a large step between the drain electrode 114 and the cathode electrode 170. . In other words, the connection pattern 145 enables stable electrical contact between the drain electrode 114 and the cathode electrode 170, and thus the connection pattern 145 prevents dark spot defects of the organic light emitting diode display. And reliability can be improved.

The bank pattern 150 is disposed on the substrate 100 including the anode electrode 140 and the connection pattern 145. The bank pattern 150 covers an edge portion of the anode electrode 140. As a result, due to the charge concentration occurring at the edge of the anode electrode 140, the organic layer 160 between the edge of the anode electrode 140 and the cathode electrode 170 to be described later is deteriorated and thus the anode electrode ( 140 to prevent short defects between the cathode electrode 170 and the cathode.

The bank pattern 150 may be formed of an inorganic insulating layer, for example, silicon oxide or silicon nitride.

The bank pattern 150 has an opening corresponding to the trench of the planarization layer 130. That is, the bank pattern 150 has an opening along the periphery of the pixel. In this case, the opening has an opening having a smaller width than the trench. As such, the etching surface of the trench is disposed within the etching surface of the opening. That is, the opening of the bank pattern 150 and the trench of the planarization layer 130 may form an undercut portion.

An organic layer 160 including at least an organic light emitting pattern is disposed on the anode electrode 140 exposed from the bank pattern 150.

The organic layer 160 may further include a first charge injection layer and a first charge transport layer interposed between the anode electrode 140 and the organic light emitting pattern. In addition, a second charge transport layer and a second charge injection layer interposed between the organic light emitting pattern and the cathode electrode 170 may be further included.

The organic layer 160 and the bank pattern 150 expose a portion of the connection pattern 145.

The cathode electrode 170 electrically connected to the exposed connection pattern 145 is disposed in each pixel. Accordingly, the cathode electrode 170 is electrically connected to the drain electrode 114.

The cathode electrode 170 is separated for each pixel by the undercut portion 130a. As a result, the cathode electrode 170 may be separated for each pixel without damaging the organic layer 160.

The cathode electrode 170 may be formed of a transparent conductive film having a work function smaller than that of the anode electrode 140. In other words, the cathode electrode 170 may be a cathode electrode. For example, the cathode electrode 170 may be formed of a single layer or a double layer of ITO, IZO, Ag, Mg, Ca, Al, and Ba.

In the exemplary embodiment of the present invention, since the organic light emitting diode display includes the undercut portion 130a, the cathode electrode may be formed for each pixel without a separate mask process.

In addition, although the cathode electrode 170 is connected to the driving element portion, the organic light emitting element portion is arranged in the order of the anode electrode 140, the organic layer 160 and the cathode electrode 170 as in the prior art, the first The charge injection layer, the first charge transport layer, the second charge transport layer, and the second charge injection layer may use a conventional material as it is. In addition, since the anode 140 formed by the sputtering method is formed under the organic layer 160, damage to the organic layer 160 can be minimized.

In addition, as the cathode electrode 170 is designed to be electrically connected to the driving element, the organic light emitting diode display may use an N-type thin film transistor that is used in a conventional liquid crystal display. As a result, in order to form the organic light emitting diode display device, a facility of a conventional liquid crystal display device can be used without constructing a new facility.

Therefore, the organic light emitting diode display according to the embodiment of the present invention can improve the lifespan and driving voltage, and can reduce the process cost.

3 is a cross-sectional view illustrating an organic light emitting diode display according to a second exemplary embodiment of the present invention. The second embodiment of the present invention has the same configuration as the first embodiment described above except for the buffer pattern. Therefore, the second embodiment of the present invention will not be repeated description of the first embodiment, the same configuration will be given the same reference numerals.

Referring to FIG. 3, the organic light emitting diode display device includes a driving element unit (S-Tr, D-Tr, and Cp in FIG. 1), a planarization layer 130 including trenches along the periphery of the pixel, and the planarization layer 130. A buffer pattern 135 disposed on the buffer pattern, an anode electrode 140 disposed on the buffer pattern 135, a bank pattern 150 having an opening having a larger width than the trench to form an undercut portion, and the anode An organic layer 160 disposed on the electrode 140 and including at least an organic light emitting pattern, and a cathode electrode 170 separated for each pixel by the undercut portion.

The buffer pattern 135 may serve to prevent the outgas from being discharged from the planarization layer 130. Accordingly, the buffer pattern 135 may cover the etching surfaces of the first and second contact holes C1 and C2 to significantly reduce the emission of the outgas.

The buffer pattern 135 may serve to improve adhesion between the planarization layer 130 and the anode electrode 150 to be described later. This is because the adhesion between the planarization layer 130 made of an organic material and the anode electrode 150 made of an inorganic material is weak, so that the anode electrode 150 may be filled from the planarization film 130. Thus, the buffer pattern 135 may include an inorganic insulating material, for example, silicon oxide or silicon nitride.

Accordingly, as the buffer pattern 135 is further provided in the exemplary embodiment of the present invention, deterioration of the organic layer 160 due to the outgas can be prevented, thereby improving lifespan and reliability of the organic light emitting diode display.

In addition, the anode electrode 150 may be prevented from being peeled off, thereby preventing driving of the organic light emitting diode display device.

4 to 9 are cross-sectional views illustrating a method of manufacturing an organic light emitting diode display according to a third exemplary embodiment of the present invention.

Referring to FIG. 4, a substrate 100 in which a plurality of pixels are defined is provided. A driving thin film transistor D-Tr is formed in each pixel of the substrate 100. In order to form the driving thin film transistor D-Tr, a gate electrode 111 is first formed on the substrate 100. The gate electrode 111 may be formed by performing a deposition process to form a conductive film and then etching the conductive film. A gate insulating layer 110 is formed on the substrate including the gate electrode 111. The gate insulating layer 110 may be formed using chemical vapor deposition. The gate insulating layer 110 may be formed of silicon oxide or silicon nitride. A semiconductor pattern 112 including an active pattern 112a and an ohmic contact pattern 112b is formed on the gate insulating layer 110 corresponding to the gate electrode 111. Thereafter, source and drain electrodes 113 and 114 spaced apart from each other are formed on the ohmic contact pattern 112b, and the source and drain electrodes 113 are formed using the source and drain electrodes 113 and 114 as etch masks. And etching the ohmic contact pattern 112b between the portions 114 to expose the channel of the active pattern 112a. As a result, the driving thin film transistor D-Tr may be formed on the substrate.

In the process of forming the gate electrode 111, a common wiring 104 may be further formed.

In addition, in the process of forming the gate insulating layer 110, the gate insulating layer 110 may include a common contact hole exposing a part of the common wiring 104.

Although not shown in the drawing, in the process of forming the driving thin film transistor D-Tr, the switching thin film transistor S-Tr and the capacitor Cp may be simultaneously formed.

In addition, in the process of forming the source and drain electrodes 113 and 114, a data line 102 in FIG. 1 and a ground line 103 in FIG. 1 may be further formed.

Accordingly, the driving element portions S-Tr, D-Tr, and Cp, for example, the driving thin film transistor D-Tr, the switching thin film transistor S-Tr, the capacitor Cp, and a plurality of wirings on the substrate. For example, the gate wiring 101, the data wiring 102, the power wiring 104, and the ground wiring 103 can be formed.

Thereafter, the passivation layer 120 is formed on the substrate including the driving element units S-Tr, D-Tr, and Cp. The passivation layer 120 may be formed of an inorganic insulating layer. For example, the inorganic insulating film may be any one of a silicon oxide film, a silicon nitride film, and a laminated film thereof. The passivation layer 120 may be formed through chemical vapor deposition.

Referring to FIG. 5, a planarization layer 130 having a flat upper surface is formed on the passivation layer 120. The planarization layer 130 may be formed of an organic insulating layer. The planarization layer 130 may be formed through a wet process, for example, a spin coating method, a slit coating method, a printing method, a spray coating method, or the like.

First and second contacts penetrating the planarization layer 130 and the passivation layer 120 to expose a portion of the drain electrode 114 and a portion of the common wiring 104 exposed by the common contact hole, respectively. The holes C1 and C2 are formed.

When the planarization layer 130 is formed of a photosensitive material, the first and second contact holes C1 and C2 may be formed by performing an exposure and development process of the planarization layer 130 using a mask.

Although not shown, a buffer pattern may be further formed to cover the planarization layer 130 on which the first and second contact holes C1 and C2 are formed. The buffer pattern is formed by depositing an inorganic insulating material to form a buffer layer, and then etching the buffer layer to expose a part of the drain electrode 114 exposed through the first and second contact holes C1 and C2 and the common wiring. Expose 104.

Referring to FIG. 6, the common wiring is formed on the planarization layer 130 through a connection pattern 145 electrically connected to the drain electrode through the first contact hole C1 and the second contact hole C2. An anode electrode 140 is electrically connected to the 104.

In order to form the connection pattern 145 and the anode electrode 140, first and second conductive layers are sequentially formed on the planarization layer 130. The first conductive layer may be formed by depositing any one of a conductive material that reflects light, such as Al, AlNd, Ag, and Mo. The second conductive layer may be formed by depositing a conductive material having greater corrosion resistance than that of the first conductive layer, for example, ITO or IZO.

After forming a photoresist pattern having a predetermined pattern on the first and second conductive layers. The first and second conductive layers may be etched using the photoresist pattern as an etch mask to form an anode electrode 140 including the first and second anode electrodes 140a and 140b and a connection pattern 145. Can be. That is, the connection pattern 145 may be formed of a stacked structure of a material for forming the first anode electrode 140a and a material for forming the second anode electrode 140b.

Referring to FIG. 7, a bank pattern 150 covering an edge portion of the anode electrode 140 is formed. In other words, the bank pattern 150 has an opening 150a that exposes a pixel. In addition, the bank pattern 150 has an opening 150b formed along the periphery of the pixel.

In order to form the bank pattern 150, a bank layer is formed on a substrate including the anode electrode. The bank layer may be formed of an inorganic insulating material such as silicon oxide or silicon nitride. A photoresist pattern having a predetermined pattern is formed on the bank layer. The bank pattern 150 is formed by etching the bank layer using the photoresist pattern as an etching mask.

Referring to FIG. 8, a trench is formed in the planarization layer 130 using the bank pattern 150 as an etching mask. The planarization layer 130 is overetched compared to the bank pattern 150 to form a trench having a larger width than the opening. Thus, the trench etching surface of the planarization layer 130 is disposed inside the opening etching surface of the bank pattern 150, so that the planarization layer 130 and the bank pattern 150 are undercut portions 130a. Has That is, the undercut portion 130a is formed along the periphery of the pixel. Here, the etching of the planarization layer 130 may use an ashing process.

Referring to FIG. 9, an organic layer 160 including at least an organic light emitting pattern is formed on the anode electrode 140 exposed to the opening of the bank pattern 150.

The organic light emitting pattern may be separated for each pixel to implement different colors. The organic light emitting pattern may be formed by a wet process or a vacuum deposition method. In particular, the organic light emitting pattern may be formed through a vacuum deposition method using a shadow mask. In addition, the organic layer 160 may further form at least one of a first charge injection layer, a first charge transport layer, a second charge transport layer, and a second charge injection layer. The first charge injection layer, the first charge transport layer, the second charge transport layer, and the second charge injection layer may be formed as a common layer in all pixels, or may be formed to be separated for each pixel. The organic layer 160 is formed to expose the third contact hole C3.

The cathode electrode 170 is formed on the organic layer 160. The cathode electrode 170 is electrically connected to the drain electrode 114 through the third contact hole C3. In addition, the cathode electrode 170 is naturally separated by each pixel by the undercut portion 130a.

In order to form the cathode electrode 170, a conductive material may be deposited on a substrate including the bank pattern 150. In this case, the conductive material is separated and formed for each pixel by the undercut portion 130a. Since it is not necessary to provide a separate mask to separate the cathode electrode 170 for each pixel, it is possible to reduce the mask manufacturing cost and to be advantageously applied to a large area substrate.

Accordingly, the organic light emitting diode element, for example, the anode electrode 140, the organic layer 160, and the cathode electrode, which are electrically connected to the driving element units S-Tr, D-Tr, and Cp and are separated for each pixel. 170).

Therefore, in the embodiment of the present invention, by forming the anode electrode 140 under the organic layer by the sputtering method, deterioration of the organic layer can be reduced. This is because sputtering can cause deterioration of the organic layer as compared with thermal evaporation.

In addition, the cathode electrode 170 may be formed to be separated by each pixel through the undercut portion without adding a separate mask, thereby reducing the number of processes and preventing oxidation of the cathode electrode 170.

In addition, since the anode electrode is formed to be separated for each pixel, and a common voltage is applied to the anode electrode disposed in each pixel, the problem of luminance unevenness due to the resistance difference in the panel in the large-area substrate can be improved.

In addition, as the cathode electrode is designed to be electrically connected to the driving element portion, the organic light emitting diode display device may use an N-type thin film transistor that has been used in a conventional liquid crystal display device. As a result, in order to form the organic light emitting diode display device, a facility of a conventional liquid crystal display device can be used without constructing a new facility.

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

FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

3 is a cross-sectional view illustrating an organic light emitting diode display according to a second exemplary embodiment of the present invention.

4 to 9 are cross-sectional views illustrating a method of manufacturing an organic light emitting diode display according to a third exemplary embodiment of the present invention.

 (Explanation of reference numerals for the main parts of the drawings)

100: substrate 101: gate wiring

102: data wiring 103: ground wiring

104: common wiring 130: planarization film

130a: undercut portion 140: anode electrode

150: bank pattern 160: organic layer

170: cathode electrode S-Tr: switching thin film transistor

D-Tr: driving thin film transistor Cp: capacitor

Claims (10)

A driving element portion disposed on each pixel of the substrate; A protective film disposed on a substrate including the driving element portion; A planarization layer disposed on the passivation layer, the planarization layer having a trench disposed along the periphery of the pixel; An anode electrode which is separated for each pixel and disposed on the planarization layer and reflects light in a direction opposite to the substrate; A bank pattern covering an edge of the anode electrode and having an opening having a larger width than the trench to form an undercut portion; An organic layer disposed on the anode electrode exposed by the bank pattern, the organic layer including at least an organic light emitting pattern; And An organic light emitting diode display disposed on the organic layer and electrically connected to the driving element unit, and including a cathode electrode separated for each pixel by the undercut unit; The method of claim 1, And a buffer pattern disposed on the planarization layer. The method of claim 1, And a common wiring electrically connected to the anode electrode. The method of claim 1, And a connection pattern electrically connecting the driving element unit and the cathode electrode to each other. The method of claim 4, wherein And the connection pattern is made of the same conductive material as the anode electrode. The method of claim 1, And the anode electrode includes a first anode electrode that reflects light and a second anode electrode disposed on the first anode electrode and having greater corrosion resistance than the first anode electrode. Forming a driving element portion on a pixel of the substrate; Forming a protective film on a substrate including the driving element; A protective film disposed on a substrate including the driving element portion; Forming a planarization layer on the passivation layer; Forming an anode electrode disposed on the planarization layer and reflecting light in a direction opposite to the substrate; Forming a bank pattern covering an edge of the anode electrode and having an opening along the periphery of the pixel; Forming a trench by etching the planarization layer corresponding to the opening to form an undercut portion; Forming an organic layer disposed on the anode electrode exposed by the bank pattern, the organic layer including at least an organic light emitting pattern; And And forming a cathode electrode disposed on the organic layer and electrically connected to the driving element unit and separated by each pixel by the undercut unit. The method of claim 7, wherein And forming a buffer pattern on the planarization layer. The method of claim 7, wherein The anode electrode is formed of a laminated structure of a first anode electrode that reflects light and a second anode electrode disposed on the first anode electrode and having greater corrosion resistance than the first anode electrode. Method for manufacturing a display device. The method of claim 7, wherein And a connection pattern which is formed of the same conductive material as the anode electrode and electrically connects the driving element portion and the cathode electrode to each other.

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