KR20090068504A - Organic light emitting diode display device and method of manufacturing the same - Google Patents

Abstract

An organic light emitting diode display and a manufacturing method thereof are provided to prevent a cathode electrode from corroding. An organic light emitting diode display device includes a substrate(100) in which a pixel is defined, a thin film transistor, a protective film(120), a planarized film(130), a reflective electrode(140), an anti-corrosion electrode(150), a bank pattern(160), a first electrode(170), an organic layer(180), and a second electrode(190). The protective film is arranged on the substrate including the thin film transistor. The planarized film is arranged on the protective film and includes a trench arranged around the pixel. A reflective electrode is arranged on the planarized film and is connected to the thin film transistor. The anti-corrosion electrode is arranged on the reflective electrode and is made of the conductive material with large corrosion resistance. The bank pattern is arranged on the planarized film while covering the edge part of the anti-corrosion electrode and the reflective electrode. The bank pattern comprises an undercut part with the planarized film by having the opening smaller than the trench. The first electrode is arranged on the substrate including the bank pattern and the reflective electrode and is separated by the undercut. The organic layer is arranged on the first electrode and includes at least organic light emitting pattern. The second electrode is arranged on the organic layer.

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 organic light emitting display device and a method of manufacturing the same.

The display device provides the image information to the user. Such display devices include liquid crystal display devices, field emission display devices, organic light emitting diodes display devices, plasma display devices, and the like. do.

In particular, the organic light emitting diode display device is a self-luminous type and does not require a backlight light source such as an LCD, so that the organic light emitting diode display can be made thin and light, and can be manufactured through a simple process. In addition, organic light emitting diode display devices have many advantages such as low voltage driving, high luminous efficiency, and wide viewing angle, and are rapidly rising as next generation displays.

The organic light emitting diode display includes a thin film transistor disposed on a substrate, an organic light emitting diode device electrically connected to the thin film transistor to generate light, and an encapsulation substrate covering the organic light emitting diode device.

The organic light emitting diode display may be classified into a bottom emission type and a top emission type according to a direction in which the light is emitted.

Among the top emission type organic light emitting diode display devices, since light is emitted through the sealing substrate, the top emission type has a larger aperture ratio than the bottom emission type. In addition, in the top emission type, the aperture ratio is not influenced by the driving device, and therefore, the driving device can be variously designed.

In the top emission type organic light emitting diode display device, after forming a thin film transistor, forming a cathode electrode electrically connected to the thin film transistor and reflecting light, and then forming an organic light emitting layer and an anode electrode on the cathode electrode As a result, the cathode is likely to corrode. In this case, the cathode electrode is made of a conductive material having corrosiveness. In particular, the corrosion problem may occur more seriously by the photo process for forming the cathode electrode. As a result, the cathode may supply electrons to the organic light emitting layer, which may cause problems such as an increase in driving voltage, a decrease in lifespan, and dark pixels.

Therefore, the organic light emitting diode display device has developed a top emission type organic light emitting diode display device to increase the aperture ratio, but the top emission type organic light emitting diode display device causes corrosion of the cathode electrode during the process, thereby deteriorating reliability. Has

One object of the present invention is to provide a top emission type organic light emitting diode display and a method of manufacturing the same that can prevent corrosion of a cathode electrode.

In addition, another object of the present invention is to provide a top emission type organic light emitting diode display device and a method of manufacturing the same that can reduce the number of processes by reducing the number of processes.

In order to achieve the above technical problem, an aspect of the present invention provides an organic light emitting diode display. The organic light emitting diode display device includes a substrate on which pixels are defined, a thin film transistor disposed on the pixel, a passivation layer disposed on the substrate including the thin film transistor, a passivation layer disposed on the passivation layer, and disposed along a periphery of the pixel. A planarization film having a trench, a reflection electrode disposed on the planarization film, electrically connected to the thin film transistor, disposed on the reflection electrode, and an anticorrosion electrode made of a conductive material having greater corrosion resistance than the reflection electrode, A bank pattern covering the edges of the reflective electrode and the anti-corrosion electrode and disposed on the planarization layer and having an opening having a width smaller than that of the trench to form the planarization layer and the undercut portion, the bank pattern and the reflective electrode; A first electrode disposed on the second electrode and separated by each pixel by the undercut; An organic layer disposed on the electrode, the organic layer including at least an organic light emitting pattern, and a second electrode disposed on the organic layer.

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 the steps of: providing a substrate on which pixels are defined, forming a thin film transistor on the pixel, a protective film disposed on the substrate including the thin film transistor, and forming a flattening film on the protective film; Forming a reflective electrode and an anticorrosion electrode electrically connected to the thin film transistor on the film, the bank pattern covering the edges of the reflective electrode and the anticorrosion electrode and disposed on the planarization layer and having an opening along the periphery of the pixel; Forming a trench having a width greater than that of the opening by etching the planarization layer using the bank pattern as an etching mask to form an undercut portion, the at least one electrode being disposed on the corrosion preventing electrode, the undercut Forming a first electrode separated for each pixel by a negative portion; The highest at least a step, and forming a second electrode on the organic layer to form an organic layer including an organic light-emitting pattern.

In the organic light emitting diode display according to the present invention, the cathode may be formed by vacuum deposition without a separate mask process, thereby preventing corrosion of the cathode and improving reliability.

In addition, the organic light emitting diode display device of the present invention can reduce the number of steps by forming the reflective electrode with a conductive material having high corrosion resistance and simultaneously forming the pad electrode in the process of forming the reflective 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 (170. 180. 190 in FIG. 2).

A plurality of wirings 101, 104, and 107 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 170, 180, 190. For example, the plurality of interconnections 101, 104, and 107 may include a gate interconnection 101, a data interconnection 104, and a power supply interconnection 107 parallel to the data interconnection 104. Can be.

In addition, pads may be disposed at ends of the plurality of wirings 101, 104, and 107 to receive electrical signals from an external driving circuit unit. The pads may include first and second gate pads 102 and 103 disposed at one end of the gate line 101, and first and second data pads 105 disposed at one end of the data line 104. 106 and first and second power pads 108 and 109 disposed at one end of the power line 107.

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 104, 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 104.

The driving thin film transistor D-Tr is electrically connected to the switching thin film transistor S-Tr and the power line 107.

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 power line 107.

The organic light emitting diode element parts 170, 180, and 190 include a first electrode 170, an organic layer 180 including at least an organic light emitting pattern, and a second electrode 190. The first 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 104, may be transferred to the organic light emitting diode element unit 170, 180, 190. Is applied to the organic light emitting diode element unit 170, 180, 190 by controlling the amount of current flowing through the organic light emitting diode element unit 170, 180, 190 to adjust the luminance is displayed 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 lines II ′ and II ′ of FIG. 1.

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

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 may include an active pattern 112a formed of an amorphous silicon pattern and an ohmic contact pattern 112b formed of amorphous silicon including impurities and exposing channels of the active pattern 112a. 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 connected to the first storage electrode 131 connected to the gate electrode 111 and the second storage electrode 132 electrically connected to the power line 107 with the gate insulating layer 110 interposed therebetween. ) May be included.

A plurality of wires electrically connected to the driving element units S-Tr, D-Tr, and Cp, for example, the gate wires 101, the data wires 104, and the power wires 107 are disposed around the pixels. have. In addition, first pad electrodes disposed at one end of the plurality of wires, for example, the first gate pad electrode 102 disposed at each end of the gate wire 101, the data wire 104, and the power wire 107. ), A first data pad electrode 105 and a first power pad electrode 108.

The passivation layer 120 is disposed on a substrate including the driving element units S-Tr, D-Tr, and Cp, a plurality of wires, and a plurality of first pad electrodes.

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, 104, and 107. In addition, the planarization layer 130 may include parasitics between the driving element units S-Tr, D-Tr, and Cp and the plurality of wirings 101, 104, and 107 and the first electrode 170 to be disposed thereon. It serves to prevent the occurrence of caps.

The planarization layer 130 may be disposed on the substrate to expose an edge portion, in particular, a failure turn formation region. This is because the flattening film 130 has a weak adhesive force with the failed turn. In this case, second pad electrodes electrically connected to the first pad electrode are disposed on the passivation layer 120. The second pad electrode may be made of a conductive material having greater corrosion resistance than the first pad electrode, for example, ITO or IZO. As a result, the first pad electrode may be corroded, thereby preventing the reliability of the organic light emitting diode display from deteriorating. However, the present invention is not limited thereto, and the planarization layer 130 may cover an edge portion of the substrate.

Trenchs are formed along the periphery of the pixels of the planarization layer 130. The trench has a bank pattern 160 and an undercut portion 130a to be described later. Thus, the first electrode 170 to be described later serves to separate each pixel.

Contact holes exposing a portion of the drain electrode and a portion of the first pad electrode may be disposed in the passivation layer 120 and the planarization layer 130, respectively.

In addition, a buffer pattern 135 may be further disposed on the planarization layer 130. The buffer pattern 135 may serve to prevent the outgas from being discharged from the planarization layer 130. In addition, the buffer pattern 135 may serve to improve adhesion between the planarization layer 130 and the reflective electrode 140 to be described later.

The buffer pattern 135 may include an inorganic insulating material such as silicon oxide or silicon nitride.

The reflective electrode 140 and the corrosion preventing electrode 150 may be disposed on the buffer pattern 135. The reflective electrode 140 and the corrosion preventing electrode 150 may be separated for each pixel. The reflective electrode 140 and the corrosion preventing electrode 150 may have the same etching surface. The reflective electrode 140 may be electrically connected to the drain electrode 114 of the driving thin film transistor through the contact holes of the planarization layer 130 and the passivation layer 120.

The reflective electrode 140 may be made of a conductive material having excellent light reflectance. For example, the reflective electrode 140 may include any one of AlNd, Al, Mo, and Ag.

The anti-corrosion electrode 150 may be formed of a conductive material having greater corrosion resistance than the reflective electrode 140. The anti-corrosion electrode 150 prevents corrosion of the drain electrode 114 exposed by the reflective electrode 140 or the contact hole, thereby making electrical contact between the reflective electrode 140 and the drain electrode 114. It is possible to prevent deterioration in stability. For example, the corrosion preventing electrode 150 may include any one of ITO and IZO.

A bank pattern 160 is disposed on the substrate to cover the edges of the reflective electrode 140 and the corrosion preventing electrode 150. That is, the bank pattern 160 has an opening corresponding to the pixel. As a result, due to the charge concentration occurring at the edges of the reflective electrode 140 and the corrosion preventing electrode 150, the edges of the reflective electrode 140 and the corrosion preventing electrode 150 and the second portion to be described later will be described. The organic layer 180 between the electrodes 190 serves to prevent deterioration.

The bank pattern 160 may be formed of an inorganic insulating layer, for example, silicon oxide or silicon nitride.

The bank pattern 160 has an opening corresponding to the trench of the planarization layer 130. That is, the bank pattern 160 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 160 and the trench of the planarization layer 130 may have an undercut structure.

The first electrode 170 is disposed on the corrosion preventing electrode 150 exposed from the bank pattern 150. The first electrode 170 may be formed of a conductive material that can reflect light. In addition, when the thin film transistor is N-type, the first electrode 170 may be formed of a conductive material having a lower work function than the second electrode 190 to be described later. For example, the first electrode 170 may include any one of Al, AlNd, and Ag.

In this case, when the first electrode 170 is formed to a thickness sufficient to reflect light, the reflective electrode 140 may not be separately provided in the embodiment of the present invention.

3 is an enlarged view illustrating an area A illustrated in FIG. 1.

Referring to FIG. 3, the opening of the bank pattern 160 and the trench of the planarization layer 130 may have an undercut portion 130a. The first electrode 170 is separated for each pixel by the undercut structure.

Accordingly, in order to form the first electrode 170, it may be formed through a deposition process without performing a separate photo process. As a result, the first electrode 170 may be prevented from being corroded through the photo process. In addition, since the first electrode 170 may be exposed by an external environment, the first electrode 170 may be prevented from being corroded.

Referring to FIGS. 1 and 2 again, an organic layer 180 including at least an organic light emitting pattern is disposed on the first electrode 170.

The organic layer 180 may further include a first charge injection layer and a first charge transport layer interposed between the first electrode 170 and the organic light emitting pattern. The display device may further include a second charge transport layer and a second charge injection layer interposed between the organic light emitting pattern and the second electrode 190.

The second electrode 190, which is a common electrode, is disposed on the organic layer 180. The second electrode 190 may be made of a transparent conductive material that can transmit light. In addition, the second electrode 190 may have a higher work function than the first electrode 170. For example, the second electrode 190 may be made of ITO or IZO.

Although not shown in the drawings, the substrate may further include an encapsulation member bonded to the substrate and the sealant pattern to seal the organic light emitting diode element from the outside.

Therefore, according to the embodiment of the present invention, the planarization film and the bank pattern are designed to have an undercut structure along the periphery of the pixel, so that a second electrode made of a highly corrosive conductive material may be formed through a deposition process rather than a photo process. The reliability of the organic light emitting diode display device can be prevented from being deteriorated by corrosion of the second electrode.

4 is a cross-sectional view illustrating an organic light emitting diode display according to a second exemplary embodiment of the present invention. Except for the buffer pattern and the second pad electrode, the second embodiment of the present invention has the same configuration as the first embodiment described above. 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. 4, an organic light emitting diode display includes a substrate, a thin film transistor, a passivation layer, a planarization layer having trenches disposed along the periphery of the pixel, a reflective electrode disposed on the planarization layer and electrically connected to the thin film transistor, and corrosion. An prevention layer, a bank pattern having an opening having a width smaller than that of the trench to form an undercut, a first electrode separated for each pixel by the undercut, an organic layer disposed on the first electrode and including at least an organic light emitting layer And a second electrode disposed on the organic layer.

A plurality of wires electrically connected to the driving element units S-Tr, D-Tr, and Cp, for example, the gate wires 101, the data wires 104, and the power wires 107 are disposed around the pixels. have. In addition, first pad electrodes disposed at one end of the plurality of wires, for example, the first gate pad electrode 102 disposed at each end of the gate wire 101, the data wire 104, and the power wire 107. ), A first data pad electrode 105 and a first power pad electrode 108.

The passivation layer 120, the planarization layer 130, and the buffer pattern 135 are formed on a substrate including the driving element units S-Tr, D-Tr, and Cp, a plurality of wires, and a plurality of first pad electrodes. It is arranged. Here, the planarization layer 130 may not be disposed on the plurality of first pad electrodes.

The passivation layer 120, the planarization layer 130, and the buffer pattern 235 may include a drain electrode 114, the first pad electrode, for example, a first gate pad electrode (102 of FIG. 1), and a first data pad electrode (FIG. Contact holes exposing 105 of the first electrode and the first power pad electrode 108 of FIG. 1 and the like. That is, the through hole may be formed through the passivation layer 120, the planarization layer 130, and the buffer pattern 235.

On the buffer pattern 235, a second pad electrode electrically connected to the first pad electrode, for example, a second gate pad electrode 203, a second data pad electrode (not shown), and a second power pad electrode ( Not shown). The second pad electrode may have a stacked structure of a material forming the reflective electrode 140 and a material forming the corrosion preventing electrode 150. As a result, the second pad electrode can prevent the first pad electrode from being corroded, thereby preventing the reliability of the organic light emitting diode display from deteriorating.

In addition, the second pad electrode may be formed in a process of forming the reflective electrode 140 and the corrosion preventing electrode 150, thereby reducing the number of mask processes.

5 through 11 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. For convenience of description, in the third embodiment of the present invention, a gate pad of one of the driving thin film transistor D-Tr and the plurality of pad electrodes of the driving device portion is defined and described.

Referring to FIG. 5, a substrate 100 in which a plurality of pixels are defined is provided. A driving thin film transistor D-Tr disposed in each pixel of the substrate 100 is formed. 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 first gate pad electrode 102 may be further formed.

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.

Further, in the process of forming the driving thin film transistor (D-Tr), a plurality of wires, for example, gate wires and data wires intersecting with each other, power wires intersecting the data wires, and disposed at each end of the plurality of wires The first pad electrode, for example, the first gate pad electrode 102, the first data pad electrode 105, and the first power pad electrode 108, may be formed.

Therefore, a plurality of wirings with driving element portions S-Tr, D-Tr, and Cp, for example, driving thin film transistors D-Tr, switching thin film transistors S-Tr, capacitors Cp, and the like on the substrate. And first pad electrodes may be formed.

Thereafter, a passivation layer 120 is formed on a substrate including the driving element units S-Tr, D-Tr, and Cp, a plurality of wires, and first pad electrodes. 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. 6, first and second contact holes C1 and C2 exposing the drain electrode 114 and the first gate pad electrode 102 are formed in the passivation layer 120, respectively. The second contact hole C may expose the first data pad electrode 105 and the first power pad electrode 108, respectively.

The first and second contact holes C1 and C2 form a photoresist pattern having a predetermined pattern on the passivation layer 120, and then etch the passivation layer 120 using the photoresist pattern as an etching mask. Can be formed.

Thereafter, a second gate pad electrode 103 covering the first gate pad electrode 102 exposed by the second contact hole C2 is formed. The second gate pad electrode 103 may be formed through an etching process using a photoresist pattern after depositing a conductive material such as ITO or IZO having greater corrosion resistance than the first gate pad electrode 102. . As a result, the first gate pad electrode 102 may be prevented from being corroded by being exposed to the external environment.

In addition, in the process of forming the second gate pad electrode 102, another second pad electrode, for example, a second data pad electrode and a second power pad electrode, may be further formed.

Referring to FIG. 7, 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.

A third contact hole C3 is formed through the planarization layer 130 and the passivation layer 120 to expose a portion of the drain electrode 114. Here, the planarization layer 130 may expose an edge portion of the substrate 100.

A buffer pattern 135 is formed on the planarization layer 130. In order to form the buffer pattern 135, a buffer layer is formed on the planarization layer 130. The buffer layer may be formed by depositing an inorganic insulating material such as silicon nitride or silicon oxide. Thereafter, after forming a photoresist pattern having a predetermined pattern on the buffer layer, the photoresist pattern is etched to form the buffer pattern 135 exposing the third contact hole C.

It is formed to cover the side surface of the third contact hole (C) of the buffer pattern 135. As a result, the buffer pattern 135 may prevent outgassing from the planarization layer 130.

Unlike the drawing, the buffer pattern 135 may be further disposed on an edge portion of the substrate 100.

Referring to FIG. 8, the reflective electrode 140 and the corrosion preventing electrode 150 are electrically formed on the buffer pattern 135.

In order to form the reflective electrode 140 and the anti-corrosion electrode 150, a reflective layer and an anti-corrosion layer are formed. The reflective layer may be formed by depositing a conductive reflective material. For example, the reflective layer may be formed of any one of Al, AlNd, Mo, and Ag. The anti-corrosion layer may be formed by depositing a conductive material having greater corrosion resistance than the conductive reflective material. The conductive material may be formed of ITO or IZO.

After forming a photoresist pattern having a predetermined pattern on the reflective layer and the anti-corrosion layer, the reflective layer and the anti-corrosion layer is etched using the photoresist pattern as an etching mask, the reflective electrode 140 and the anti-corrosion electrode 150 Can be formed.

The bank pattern 160 is formed on the substrate to cover the edges of the reflective electrode 140 and the corrosion preventing electrode 150. In other words, the bank pattern 160 has an opening to expose the pixel.

In addition, an opening is formed in the bank pattern 160 along the periphery of the pixel.

In order to form the bank pattern 160, a bank layer is formed on a substrate including the reflective electrode 140 and the corrosion preventing electrode 150. 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. Using the photoresist pattern as an etching mask, the bank layer is etched to form the bank pattern 160.

Referring to FIG. 9, a trench is formed in the planarization layer 130 using the bank pattern 160 as an etching mask. The planarization layer 130 is overetched compared to the bank pattern 160 to form a trench having a larger width than the opening. As a result, the trench etching surface of the planarization layer 130 is disposed inside the opening etching surface of the bank pattern 160, so that the planarization layer 130 and the bank pattern 160 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. 10, a reflective conductive material is vacuum deposited on the entire surface of the substrate including the bank pattern 160 to form a first electrode 170 separated for each pixel by the undercut portion 130a. Can be. The reflective conductive material may be any one of Al, AlNd, and Ag. As a result, the first electrode 170 may be formed by only the vacuum deposition without the photo process by the undercut portion 130a, thereby preventing the first electrode 170 from being corroded.

In order to prevent the short circuit of the first electrode 170, the depth of the undercut portion 130a must be greater than the thickness of the first electrode 170. The first electrode 170 does not need to be formed thick as the separate reflective electrode 140 is provided. For example, the first electrode 170 may be formed in a thickness range of 50 kPa to 500 kPa. In this case, the depth range of the undercut portion 130a may have a width of 500 μs to 1500 μs to prevent a short of the first electrode 170 and a short circuit of the second electrode 180.

In addition, unlike the embodiment of the present invention, the first electrode 170 may be thickly formed to reflect light without forming a separate reflective electrode. For example, the first electrode 170 may be formed to about 750 kV or more. At this time, the depth range of the undercut portion 130a may have a 1500Å to 2000Å.

Referring to FIG. 11, an organic layer 180 including at least an organic light emitting pattern is formed on the first electrode 170.

The organic light emitting pattern may be separated for each pixel to implement different colors. The organic light emitting pattern may be formed through 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 180 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 second electrode 190 is formed on the organic layer 180. The second electrode 190 may be formed of a material that can transmit light. For example, the second electrode 190 may be formed by vacuum depositing any one of ITO and IZO.

Therefore, as the undercut portion is formed along the periphery of the pixel by using the planarization film and the bank pattern, the first electrode may be formed by vacuum deposition. As a result, corrosion of the first electrode can be prevented, and deterioration in reliability of the organic light emitting diode display can be prevented.

12 to 15 are cross-sectional views illustrating a method of manufacturing an organic light emitting diode display according to a fourth exemplary embodiment of the present invention. The fourth embodiment of the present invention includes the same manufacturing method as the third embodiment described above, except that the buffer pattern and the second pad electrode are formed. Therefore, the fourth embodiment of the present invention will be omitted without repeating the description of the third embodiment, the same components are given the same reference numerals.

Referring to FIG. 12, in order to manufacture an organic light emitting diode display, first, driving element units S-Tr, D-Tr, and Cp, a plurality of wirings, and first pad electrodes are formed on a substrate.

In this case, the gate insulating layer disposed on the driving device may include a contact hole exposing the first gate pad electrode 102.

The drain electrode 114 and the first pad electrode, for example, the first gate pad electrode, on the substrate including the driving element units S-Tr, D-Tr, and Cp, a plurality of wires, and first pad electrodes. A passivation layer 120, a planarization layer 130, and a buffer pattern 235 having first and second contact holes C1 and C2 exposing 102 are formed.

Unlike the drawing, the planarization layer 130 may be further formed at an edge portion of the substrate.

Referring to FIG. 13, a reflective electrode 140 and an anti-corrosion electrode 150 that are electrically connected to the drain electrode 114 are formed on the buffer pattern 235.

In the process of forming the reflective electrode 140 and the corrosion preventing electrode 150, a second gate pad electrode 203 covering the first gate pad electrode 102 exposed through the second contact hole may be formed. Can be. That is, the second gate pad electrode 203 may have a structure in which a material for forming the reflective electrode 140 and a material for forming the corrosion preventing electrode 150 are stacked. As a result, the second gate pad electrode 203 may prevent the first gate pad electrode 102 from corroding.

Referring to FIG. 14, a bank pattern 160 is formed on the substrate to cover the edges of the reflective electrode 140 and the corrosion preventing electrode 150. In other words, the bank pattern 160 has an opening to expose the pixel. In addition, an opening is formed in the bank pattern 160 along the periphery of the pixel.

A trench having a larger width than that of the opening is formed in the planarization layer 130 corresponding to the opening of the bank pattern 160. As a result, an undercut portion formed by the bank pattern 160 and the planarization layer 130 is disposed along the periphery of the pixel.

Referring to FIG. 15, a reflective conductive material is vacuum deposited on the entire surface of the substrate including the bank pattern 160 to form a first electrode 170 separated for each pixel by the undercut portion.

Thereafter, the organic light emitting diode display device may be manufactured by forming the organic layer 180 and the second electrode including at least an organic light emitting pattern on the first electrode 170.

Therefore, in the present invention, as the second pad electrode is formed in the process of forming the anti-corrosion reflective electrode and the anti-corrosion electrode, the number of processes can be further reduced.

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 lines II ′ and II ′ of FIG. 1.

3 is an enlarged view illustrating an area A illustrated in FIG. 1.

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

5 through 11 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.

12 to 15 are cross-sectional views illustrating a method of manufacturing an organic light emitting diode display according to a fourth exemplary embodiment of the present invention.

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

100: substrate 101: gate wiring

102: first gate pad electrode 103, 203: second gate pad electrode

104: data wiring 105: first data pad electrode

106: second data pad electrode 107: power supply wiring

108: first power pad electrode 109: second power pad electrode

130: planarization film 135, 235: buffer pattern

140: reflective electrode 150: corrosion preventing electrode

160: bank pattern 170: first electrode

180: organic layer 190: second electrode

Claims (10)

A substrate on which pixels are defined; A thin film transistor disposed on the pixel; A protective film disposed on the substrate including the thin film transistor; A planarization layer disposed on the passivation layer and having a trench disposed along a periphery of the pixel; A reflection electrode disposed on the planarization layer and electrically connected to the thin film transistor; An anti-corrosion electrode disposed on the reflective electrode and made of a conductive material having greater corrosion resistance than the reflective electrode; A bank pattern covering the edges of the reflective electrode and the corrosion preventing electrode and disposed on the planarization film, the bank pattern having an opening having a width smaller than that of the trench to form the planarization film and the undercut part; A first electrode disposed on a substrate including the bank pattern and the reflective electrode and separated for each pixel by the undercut; An organic layer disposed on the first electrode and including at least an organic light emitting pattern; And An organic light emitting diode display device including a second electrode on the organic layer. The method of claim 1, And a buffer pattern interposed between the planarization layer and the bank pattern. The method of claim 1, Wires electrically connected to the thin film transistor; A first pad electrode disposed at an end of each of the wires; And And a second pad electrode electrically connected to the first pad electrode with the passivation layer interposed therebetween and made of a conductive material having a corrosion resistance compared to the first pad electrode. The method of claim 1, Wires electrically connected to the thin film transistor; A first pad electrode disposed at an end of each of the wires; And And a second pad electrode electrically connected to the first pad electrode with the passivation layer and the planarization layer interposed therebetween and made of a conductive material having corrosion resistance compared to the first pad electrode. . The method of claim 1, And the second pad electrode is formed of a stacked structure of a material forming the reflective electrode and a material forming the corrosion preventing electrode. Providing a substrate on which pixels are defined; Forming a thin film transistor on the pixel; A protective film disposed on the substrate including the thin film transistor; Forming a planarization layer on the passivation layer; Forming a reflection electrode and a corrosion prevention electrode electrically connected to the thin film transistor on the planarization layer; Forming a bank pattern covering the edges of the reflective electrode and the corrosion preventing electrode and disposed on the planarization layer, the bank pattern having an opening along the periphery of the pixel; Etching the planarization layer using the bank pattern as an etch mask to form an undercut portion to form a trench having a larger width than the opening; Forming a first electrode disposed on at least the corrosion preventing electrode and separated by each pixel by the undercut portion; Forming an organic layer including at least an organic light emitting pattern on the first electrode; And A method of manufacturing an organic light emitting diode display device, the method comprising forming a second electrode on the organic layer. The method of claim 6, And a buffer pattern interposed between the planarization layer and the bank pattern. The method of claim 6, Wires electrically connected to the thin film transistor; A first pad electrode disposed at an end of each of the wires; And Fabrication of an organic light emitting diode display device further comprising a second pad electrode electrically connected to the first pad electrode with the passivation layer interposed therebetween, the second pad electrode being made of a conductive material having a corrosion resistance compared to the first pad electrode. Way. The method of claim 6, Wires electrically connected to the thin film transistor; A first pad electrode disposed at an end of each of the wires; And An organic light emitting diode display further comprising a second pad electrode electrically connected to the first pad electrode with the passivation layer and the planarization layer interposed therebetween, the second pad electrode being made of a conductive material having a corrosion resistance compared to the first pad electrode. Method of manufacturing the device. The method of claim 9, And the second pad electrode is formed in the process of forming the reflective electrode and the anti-corrosion electrode.

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