KR20180061777A - Organic Light Emitting Diode Display Device - Google Patents

Abstract

The present invention relates to an organic light emitting diode display device. The organic light emitting diode display device of the present invention includes a substrate, a first electrode positioned in a pixel region on the substrate, a bank covering the edge of the first electrode and exposing the first electrode, a light emitting layer on the upper part of the first electrode in the pixel region, and a second electrode over the light emitting layer. The bank includes a first bank and a second bank in the upper part of the first bank. The first bank includes a protrusion part protruding into the pixel region from the side surface of the second bank. The protrusion part of the first bank has a groove surrounding the exposed part of the first electrode. The light emitting layer is formed in the groove. Accordingly, image quality can be improved by forming a light emitting layer having a uniform thickness through a solution process.

Description

[0001] The present invention relates to an organic light emitting diode (OLED) display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to a large-area, high-resolution organic light emitting diode display device capable of providing uniform luminance.

2. Description of the Related Art Flat panel displays having excellent characteristics such as thinning, lightening, and low power consumption have been widely developed and applied to various fields.

Among the flat panel display devices, an organic light emitting diode (OLED) display device, also referred to as an organic electroluminescent display device or organic electroluminescent display device, An exciton is formed by injecting an electric charge into the light emitting layer formed between the anode which is an injection electrode and electrons and holes, and then this exciton is irradiated by radiative recombination. Such an organic light emitting diode display device can be formed not only on a flexible substrate such as a plastic but also because it has a large contrast ratio and response time of several microseconds since it is a self- It is easy to manufacture and design a driving circuit because it is easy to operate, is not limited in viewing angle, is stable even at low temperature, and can be driven with a relatively low voltage of 5 V to 15 V of direct current.

The light emitting layer of the organic light emitting diode display is formed by a vacuum thermal evaporation method in which an organic light emitting material is selectively deposited using a fine metal mask.

However, such a deposition process increases the manufacturing cost by using a mask or the like, and is difficult to apply to a large-area and high-resolution display device due to fabrication variations, deflection, and shadow effects of the mask.

To solve this problem, a method of forming a light emitting layer by a soluble process has been proposed. A conventional organic light emitting diode display device including a light emitting layer formed by such a solution process will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing a conventional organic light emitting diode display, and shows one pixel region.

As shown in Fig. 1, the first electrode 20 is formed in the pixel region on the substrate 10. [ A bank 30 covering the edge of the first electrode 20 is formed on the first electrode 20. The bank 30 includes a lower bank 32 and an upper bank 34 above the lower bank 32.

A light emitting layer 40 is formed on the first electrode 20 surrounded by the bank 30 and a second electrode 50 is formed on the entire surface of the substrate 10 over the light emitting layer 40 and the bank 30 . The first electrode 20, the light emitting layer 40, and the second electrode 50 constitute an organic light emitting diode (D).

Here, the light emitting layer 40 is formed through a solution process. More specifically, a solution containing an organic luminescent material is dropped on the exposed first electrode 20 surrounded by the bank 30 and then dried to form a luminescent layer 40. At this time, the bank 30 defines a region where the light emitting layer 40 is to be formed, and prevents the solution dropped in one pixel region from penetrating into the adjacent pixel region.

However, when the light emitting layer 40 is formed by such a solution process, the evaporation of the solvent is not uniformly performed during the drying process of the solution, and the light emitting layer 40 formed in the pixel region is reduced in flatness. That is, when the solution is dried, the drying rate of the solvent at the center and the edge of the pixel region is different, and the height of the light emitting layer 40 increases from the center to the edge of the pixel region. Accordingly, the thickness of the light emitting layer 40 becomes thicker from the center to the edge of the pixel region, and the light emitting layer 40 is formed into a U-shape.

On the other hand, the light emitting layer 40 has a multi-layer structure in order to increase the light emitting efficiency.

2 is a view schematically showing a profile of a light emitting layer in a conventional organic light emitting diode display.

2, the light emitting layer 40 includes a hole injecting layer (HIL), a hole transporting layer (HTL), and an emitting material layer (EML) Each of the hole injecting layer (HIL), the hole transporting layer (HTL) and the light emitting material layer (EML) is formed through a solution process. Here, BK1 denotes the first bank.

At this time, the height of the hole injection layer (HIL) is higher at the edge than the center of the pixel region, and as the hole transport layer (HTL) and the light emitting material layer (EML) do. As a result, the thickness of the film becomes uneven, and the point where the flatness deteriorates tends to move toward the center of the pixel region.

The organic light emitting diode having such a non-uniform thickness light emitting layer is not uniform in light emission, and thus the brightness of the display device of the organic light emitting diode becomes uneven and the image quality is deteriorated.

In order to solve the above-described problems, the present invention aims to solve the problem of increased manufacturing cost and area and resolution limitation of an organic light emitting diode display device by a deposition process.

In addition, the present invention aims to solve the luminance uniformity problem of an organic light emitting diode display.

According to an aspect of the present invention, there is provided an organic light emitting diode display device including a substrate, a first electrode located in a pixel region on the substrate, a bank covering an edge of the first electrode and exposing the first electrode, A light emitting layer above the first electrode in the pixel region, and a second electrode above the light emitting layer, the bank including a first bank and a second bank above the first bank, wherein the first bank comprises: The protrusion of the first bank has a groove surrounding the exposed portion of the first electrode, and the light emitting layer is formed in the groove.

At this time, the groove surrounds the side surface of the first electrode and can expose the upper surface of the protective film under the first electrode.

Alternatively, the groove may be located above the first electrode.

One side of the groove can coincide with the side surface of the second bank.

Here, the first bank may have hydrophilicity and the second bank may have hydrophobicity.

In the present invention, by forming a light emitting layer of an organic light emitting diode by a solution process, it is possible to provide an organic light emitting diode display device with a reduced manufacturing cost and a large area and a high resolution.

In addition, by forming grooves in the first bank of the bank including the first bank and the second bank so that the light emitting layer is formed in the groove of the first bank, the flatness of the light emitting layer can be improved to form a thin film of uniform thickness have. Thus, the image quality can be improved.

Further, it is possible to prevent an increase in power consumption and a reduction in lifetime caused by the light emitting layer having an uneven thickness.

FIG. 1 is a cross-sectional view schematically showing a conventional organic light emitting diode display, and shows one pixel region.
2 is a view schematically showing a profile of a light emitting layer in a conventional organic light emitting diode display.
3 is a circuit diagram showing one pixel region of an organic light emitting diode display device according to an embodiment of the present invention.
4 is a schematic cross-sectional view of an organic light emitting diode display device according to a first embodiment of the present invention.
5 is a schematic plan view of an organic light emitting diode display device according to a first embodiment of the present invention.
6 is a view schematically showing a profile of a light emitting layer in an organic light emitting diode display device according to a first embodiment of the present invention.
7 is a schematic cross-sectional view of an organic light emitting diode display device according to a second embodiment of the present invention.

An organic light emitting diode display device according to the present invention includes a substrate, a protective film on the substrate, a first electrode located in a pixel region on the protective film, a bank covering the edge of the first electrode, A light emitting layer above the first electrode in the pixel region, and a second electrode above the light emitting layer, the bank including a first bank and a second bank above the first bank, Includes protrusions protruding into the pixel region from the side of the second bank, and protrusions of the first bank have grooves surrounding the exposed portions of the first electrode.

And the groove is spaced apart from the first electrode.

The groove surrounds the side surface of the first electrode.

The groove exposes an upper surface of the protective film.

The groove is located above the first electrode.

One side of the groove coincides with a side surface of the second bank.

The light emitting layer is also formed in the groove.

And the light emitting layer in the groove is in contact with the protective film.

The first bank has hydrophilicity, and the second bank has hydrophobicity.

Hereinafter, an organic light emitting diode display according to an embodiment of the present invention will be described in detail with reference to the drawings.

3 is a circuit diagram showing one pixel region of an organic light emitting diode display device according to an embodiment of the present invention.

3, an organic light emitting diode display device according to an embodiment of the present invention includes a gate line GL and a data line DL that define a pixel region P and intersect with each other, A switching thin film transistor Ts, a driving thin film transistor Td, a storage capacitor Cst, and an organic light emitting diode D are formed in the region P.

More specifically, the gate electrode of the switching thin film transistor Ts is connected to the gate wiring GL and the source electrode thereof is connected to the data wiring DL. The gate electrode of the driving thin film transistor Td is connected to the drain electrode of the switching thin film transistor Ts, and the source electrode thereof is connected to the high potential voltage VDD. The anode of the organic light emitting diode D is connected to the drain electrode of the driving thin film transistor Td and the cathode thereof is connected to the low potential voltage VSS. The storage capacitor Cst is connected to the gate electrode and the drain electrode of the driving thin film transistor Td.

The switching TFTs turn on according to the gate signal applied through the gate line GL and the data line DL is turned on at this time. Is applied to the gate electrode of the driving thin film transistor Td and the one electrode of the storage capacitor Cst through the switching thin film transistor Ts.

The driving thin film transistor Td is turned on according to a data signal to control a current flowing through the organic light emitting diode D to display an image. The organic light emitting diode D emits light by the current of the high potential voltage VDD transmitted through the driving thin film transistor Td.

That is, the amount of current flowing through the organic light emitting diode D is proportional to the size of the data signal, and the intensity of light emitted by the organic light emitting diode D is proportional to the amount of current flowing through the organic light emitting diode D, The region P displays different gradations according to the size of the data signal, and as a result, the organic light emitting diode display displays an image.

The storage capacitor Cst maintains the charge corresponding to the data signal for one frame so that the amount of current flowing through the organic light emitting diode D is kept constant and the gradation displayed by the organic light emitting diode D is maintained constant .

- First Embodiment -

FIG. 4 is a schematic cross-sectional view of an organic light emitting diode display according to a first embodiment of the present invention, FIG. 5 is a schematic plan view of an organic light emitting diode display according to a first embodiment of the present invention, Lt; / RTI > For convenience, only the bank and the first electrode are shown in Fig.

As shown in FIGS. 4 and 5, a semiconductor layer 122 patterned on the insulating substrate 110 is formed. The substrate 110 may be a glass substrate or a flexible substrate made of a polymer such as polyimide.

In this case, a light shielding pattern (not shown) and a buffer layer (not shown) may be formed under the semiconductor layer 122, and the light shielding pattern may be formed on the semiconductor layer 122 And prevents the semiconductor layer 122 from being deteriorated by light. The buffer layer may be made of an inorganic insulating material such as silicon oxide or silicon nitride. Alternatively, the semiconductor layer 122 may be formed of polycrystalline silicon. In this case, a buffer layer (not shown) may be formed between the substrate 110 and the semiconductor layer 122. In addition, impurities may be doped on both edges of the semiconductor layer 122 made of polycrystalline silicon.

A gate insulating layer 130 made of an insulating material is formed on the entire surface of the substrate 110 on the semiconductor layer 122. The gate insulating layer 130 may be formed of an inorganic insulating material such as silicon oxide (SiO2). When the semiconductor layer 122 is made of polycrystalline silicon, the gate insulating layer 130 may be formed of silicon oxide (SiO2) or silicon nitride (SiNx).

A gate electrode 132 made of a conductive material such as metal is formed on the gate insulating layer 130 to correspond to the center of the semiconductor layer 122. A gate line (not shown) and a first capacitor electrode (not shown) may be formed on the gate insulating layer 130. The gate wiring extends along one direction, and the first capacitor electrode is connected to the gate electrode 132. [

In the embodiment of the present invention, the gate insulating layer 130 is formed on the entire surface of the substrate 110, but the gate insulating layer 130 may be patterned to have the same shape as the gate electrode 132.

An interlayer insulating layer 140 made of an insulating material is formed on the entire surface of the substrate 110 on the gate electrode 132. The interlayer insulating layer 140 may be formed of an inorganic insulating material such as silicon oxide (SiO2) or silicon nitride (SiNx), or may be formed of an organic insulating material such as photo acryl or benzocyclobutene.

The interlayer insulating film 140 has first and second contact holes 140a and 140b that expose both upper surfaces of the semiconductor layer 122. [ The first and second contact holes 140a and 140b are spaced apart from the gate electrode 132 on both sides of the gate electrode 132. Here, the first and second contact holes 140a and 140b are also formed in the gate insulating film 130. Alternatively, when the gate insulating film 130 is patterned to have the same shape as the gate electrode 132, the first and second contact holes 140a and 140b are formed only in the interlayer insulating film 140. [

Source and drain electrodes 152 and 154 are formed on the interlayer insulating layer 140 with a conductive material such as a metal. A data line (not shown), a power line (not shown), and a second capacitor electrode (not shown) may be formed on the interlayer insulating layer 140.

The source and drain electrodes 152 and 154 are spaced around the gate electrode 132 and contact both sides of the semiconductor layer 122 through the first and second contact holes 140a and 140b, respectively. Although not shown, the data wiring extends in the direction perpendicular to the gate wiring and crosses the gate wiring to define the pixel region, and the power wiring for supplying the high potential voltage is located apart from the data wiring. The second capacitor electrode is connected to the drain electrode 154, and overlaps the first capacitor electrode to form a storage capacitor between the two interlayer insulating films 140 as a dielectric.

On the other hand, the semiconductor layer 122, the gate electrode 132, and the source and drain electrodes 152 and 154 constitute a thin film transistor. Here, the thin film transistor has a coplanar structure in which the gate electrode 132 and the source and drain electrodes 152 and 154 are located on one side of the semiconductor layer 122, that is, above the semiconductor layer 122.

Alternatively, the thin film transistor may have an inverted staggered structure in which a gate electrode is positioned below the semiconductor layer and source and drain electrodes are located above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

Here, the thin film transistor corresponds to a driving thin film transistor of an organic light emitting diode display, and a switching thin film transistor (not shown) having the same structure as the driving thin film transistor is further formed on the substrate 110. The gate electrode 132 of the driving thin film transistor is connected to the drain electrode (not shown) of the switching thin film transistor and the source electrode 152 of the driving thin film transistor is connected to the power supply wiring (not shown). In addition, a gate electrode (not shown) and a source electrode (not shown) of the switching thin film transistor are connected to the gate wiring and the data wiring, respectively.

A protective layer 160 is formed on the entire surface of the substrate 110 as an insulating material over the source and drain electrodes 152 and 154. The protective film 160 may be formed of an organic insulating material such as benzocyclobutene or photoacryl. An inorganic insulating layer formed of an inorganic insulating material such as silicon oxide (SiO2) or silicon nitride (SiNx) may be further formed under the passivation layer 160. [

The protective film 160 has a drain contact hole 160a for exposing the drain electrode 154. [ Although the drain contact hole 160a is illustrated as being spaced apart from the second contact hole 140b, the drain contact hole 160a may be formed directly on the second contact hole 140b.

A first electrode 162 is formed of a conductive material having a relatively high work function in a pixel region above the passivation layer 160. The first electrode 162 contacts the drain electrode 154 through the drain contact hole 160a. For example, the first electrode 162 may be formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

A bank 170 is formed of an insulating material on the first electrode 162. The bank 170 is located between adjacent pixel regions and has a through hole 170a for exposing the first electrode 162 and covers the edge of the first electrode 162. [

The bank 170 includes a first bank 172 and a second bank 174 above the first bank 172. Here, the width of the second bank 174 is narrower than the width of the first bank 172, and the first bank 172 includes protrusions protruding into the pixel region from the side surfaces of the second bank 174. In addition, the protrusion of the first bank 172 has a groove 172a surrounding the exposed portion of the first electrode 162.

More specifically, the groove 172a is spaced apart from the first electrode 162 and surrounds the side surface of the first electrode 162. [ When the groove 172a surrounds the side surface of the electrode of the first electrode 162 without being separated from the first electrode 162, the groove 172a exposes the first electrode 162, There is a problem that light emission occurs.

The depth of the groove 172a is equal to the thickness of the first bank 172 so that the groove 172a can expose the upper surface of the protective film 160 located under the first bank 172. [ Alternatively, the depth of the groove 172a may be smaller than the thickness of the first bank 172. [ Alternatively, the depth of the groove 172a may be greater than the thickness of the first bank 172, so that the groove 172a may extend to the inside of the protective film 160. [

Further, one side of the groove 172a may coincide with the side surface of the second bank 174. Alternatively, one side of the groove 172a may be spaced apart from the side of the second bank 174.

It is preferable that the transmission hole 170a exposing the first electrode 160 and the groove 172a surrounding the exposed portion of the first electrode 160 have the same shape. Although the transmission holes 170a and the grooves 172a are shown as being rectangular in FIG. 5, the shape of the transmission holes 170a and the grooves 172a may be changed. For example, the corners of the transmission hole 170a and the groove 172a may be curved. Alternatively, the transmission hole 170a and the groove 172a may have a substantially long circular shape having a major axis and a minor axis, or a polygonal shape, but are not limited thereto.

Meanwhile, although the groove 172a has a rectangular cross-section, the cross-sectional shape of the groove 172a is not limited thereto and can be changed. For example, the cross-sectional shape of the groove 172a may be triangular or semicircular.

The first bank 172 is made of a material having a relatively high surface energy to lower the contact angle with the later-formed light-emitting layer material. The second bank 174 is made of a material having a relatively low surface energy, By increasing the contact angle, it is possible to prevent the light emitting layer material from overflowing into adjacent pixel regions. Thus, the surface energy of the first bank 172 is higher than the surface energy of the second bank 174. For example, the first bank 172 may be formed of an inorganic insulating material or an organic insulating material having a hydrophilic property, and the second bank 174 may be formed of an organic insulating material having a hydrophobic property.

Alternatively, the first bank 172 and the second bank 174 may be an integral structure made of the same material. In this case, the first bank 172 and the second bank 174 may be formed of an organic insulating material having a hydrophobic property ≪ / RTI >

A light emitting layer 180 is formed on the first electrode 162 exposed through the transmission hole 170a of the bank 170. [ The light emitting layer 180 may be formed through a soluble process. As the solution process, a printing method or a coating method using an injection device including a plurality of nozzles may be used, but the present invention is not limited thereto. As an example, an inkjet printing method may be used in a solution process.

Here, the light emitting layer 180 is also formed in the groove 172a of the first bank 172, and the height of the light emitting layer 180 at the edge of the pixel region is lowered, thereby improving the flatness of the film. This will be described in detail later.

Although not shown, the light emitting layer 180 includes a hole auxiliary layer, an emitting material layer (EML), and an electron auxiliary layer sequentially stacked from the top of the first electrode 162, . ≪ / RTI > The hole-assist layer may include at least one of a hole injecting layer (HIL) and a hole transporting layer (HTL). The electron-assisted layer may include an electron transporting layer (ETL) and an electron injecting layer (EIL).

Here, the hole-assist layer and the light-emitting material layer are formed only in the transmission hole 170a, and the electron-assist layer may be formed substantially on the entire surface of the substrate 110. [ In this case, the hole-assist layer and the light-emitting material layer may be formed through a solution process, and the electron-assist layer may be formed through a vacuum deposition process.

A second electrode 192 is formed on the entire surface of the substrate 110 with a conductive material having a relatively low work function above the light emitting layer 180. Here, the second electrode 192 may be formed of aluminum, magnesium, silver, or an alloy thereof.

The first electrode 162 and the light emitting layer 180 and the second electrode 192 form an organic light emitting diode D. The first electrode 162 serves as an anode and the second electrode 192 serves as an anode. Serves as a cathode.

Although not shown, an encapsulation film (not shown) may be formed on the second electrode 192 to prevent external moisture from penetrating into the organic light emitting diode D. For example, the encapsulation film may have a laminated structure of the first inorganic insulating layer, the organic insulating layer and the second inorganic insulating layer, but is not limited thereto.

Here, the organic light emitting diode display according to an embodiment of the present invention may be a top emission type in which light emitted from the light emitting layer 180 is output to the outside through the second electrode 192. At this time, the first electrode 162 further includes a reflective layer (not shown) made of an opaque conductive material. For example, the reflective layer may be formed of an aluminum-palladium-copper (APC) alloy, and the first electrode 162 may have a triple-layer structure of ITO / APC / ITO. In addition, the second electrode 192 may have a relatively thin thickness through which light is transmitted, and the light transmittance of the second electrode 192 may be about 45-50%.

Alternatively, the organic light emitting diode display according to the exemplary embodiment of the present invention may be a bottom emission type in which light emitted from the light emitting layer 180 is output to the outside through the first electrode 162.

6 is a view schematically showing a profile of a light emitting layer in an organic light emitting diode display device according to a first embodiment of the present invention.

6, the light emitting layer 180 includes a hole injection layer HIL, a hole transport layer HTL, and a light emitting material layer EML sequentially stacked. The hole injection layer HIL, Each of the hole transporting layer (HTL) and the light emitting material layer (EML) is formed through a solution process.

Since the first bank BK1 at the edge of the pixel region has a groove 172a in FIG. 4 and the hole injection layer HIL is also formed in the groove 172a of the first bank BK1, The height of the hole injection layer (HIL) at the edge of the pixel region becomes lower than that of the conventional art. Accordingly, the flatness of the hole injection layer (HIL) is improved, and the flatness of the hole transport layer (HTL) and the light emitting material layer (EML) stacked on the hole injection layer (HIL) is also improved.

Therefore, a light emitting layer (180 in Fig. 4) having a uniform thickness can be formed.

- Second Embodiment -

7 is a schematic cross-sectional view of an organic light emitting diode display device according to a second embodiment of the present invention.

As shown in FIG. 7, the first electrode 262 is formed of a conductive material having a relatively high work function in a pixel region on the substrate 210. For example, the first electrode 262 may be formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

Although not shown, a plurality of insulating films, for example, a gate insulating film, an interlayer insulating film, and a protective film may be formed between the substrate 210 and the first electrode 262.

In addition, a switching thin film transistor, a driving thin film transistor, a storage capacitor, a gate wiring, a data line, and a power line may be formed between the substrate 210 and the first electrode 262, The thin film transistor may have the same structure as the thin film transistor shown in FIG.

A bank 270 is formed on the first electrode 262 as an insulating material and the bank 270 is located between adjacent pixel regions and has a through hole 270a for exposing the first electrode 262, Thereby covering the edge of the electrode 262.

The bank 270 includes a first bank 272 and a second bank 274 above the first bank 272. Here, the width of the second bank 274 is narrower than the width of the first bank 272, and the first bank 272 includes protrusions protruding into the pixel region from the side surfaces of the second bank 274. In addition, the protrusion of the first bank 272 has a groove 272a surrounding the exposed portion of the first electrode 262.

More specifically, the groove 272a is spaced apart from the first electrode 262 and is located at the top of the first electrode 262. [ At this time, the depth of the groove 272a is preferably smaller than the thickness of the protrusion of the first bank 272 so that the first electrode 262 is not exposed by the groove 272a. When the groove 272a exposes the first electrode 262, there is a problem that light emission occurs in an undesired region.

In addition, one side of the groove 272a may coincide with the side surface of the second bank 274. Alternatively, one side of the groove 272a may be spaced apart from the side of the second bank 274.

Here, it is preferable that the through hole 270a exposing the first electrode 260 and the groove 272a surrounding the exposed portion of the first electrode 260 have the same shape. For example, the transmission hole 270a and the groove 272a may be rectangular, or the edge of the transmission hole 270a and the groove 272a may be curved. Alternatively, the transmission hole 270a and the groove 272a may be substantially long circular shapes having a long axis and a short axis, or may have a polygonal shape, but are not limited thereto.

Meanwhile, although the groove 272a has a rectangular cross section, the cross-sectional shape of the groove 272a is not limited thereto and can be changed. For example, the cross-sectional shape of the groove 272a may be triangular or semicircular.

The first bank 272 is made of a material having a relatively high surface energy to lower the contact angle with respect to the later-formed light-emitting layer material. The second bank 274 is made of a material having a relatively low surface energy, By increasing the contact angle, it is possible to prevent the light emitting layer material from overflowing into adjacent pixel regions. Thus, the surface energy of the first bank 272 is higher than the surface energy of the second bank 274. For example, the first bank 272 may be formed of an inorganic insulating material or an organic insulating material having a hydrophilic property, and the second bank 274 may be formed of an organic insulating material having a hydrophobic property.

Alternatively, the first bank 272 and the second bank 274 may be an integral structure made of the same material. In this case, the first bank 272 and the second bank 274 may be formed of an organic insulating material having a hydrophobic property ≪ / RTI >

The light emitting layer 280 is formed on the first electrode 262 exposed through the transmission hole 270a of the bank 270. The light emitting layer 280 may be formed through a solution process. As the solution process, a printing method or a coating method using an injection device including a plurality of nozzles may be used, but the present invention is not limited thereto. For example, inkjet printing may be used in a solution process.

Here, the light emitting layer 280 is also formed in the groove 272a of the first bank 272, thereby lowering the height of the light emitting layer 280 at the edge of the pixel region, thereby improving the flatness of the film.

Although not shown, the light emitting layer 280 may include a hole assist layer, a light emitting material layer (EML), and an electron assist layer sequentially stacked from the top of the first electrode 262. The hole assist layer may include at least one of a hole injection layer (HIL) and a hole transport layer (HTL), and the electron assist layer may include at least one of an electron transport layer (ETL) and an electron injection layer (EIL).

Here, the hole-assist layer and the light-emitting material layer are formed only in the transmission hole 270a, and the electron-assist layer may be formed substantially on the entire surface of the substrate 210. [ In this case, the hole-assist layer and the light-emitting material layer may be formed through a solution process, and the electron-assist layer may be formed through a vacuum deposition process.

A second electrode 292 is formed on the entire surface of the substrate 210 as a conductive material having a relatively low work function on the light emitting layer 280. Here, the second electrode 292 may be formed of aluminum, magnesium, silver, or an alloy thereof.

As described above, in the organic light emitting diode display device according to the present invention, since a part or the whole of the light emitting layer is formed through a solution process that can be applied to a relatively small area, the manufacturing cost can be reduced by reducing the deposition process, Device.

Further, by forming the grooves in the first bank to form the light-emitting layers in the grooves of the first bank, it is possible to improve the flatness of the light-emitting layer to form a thin film of uniform thickness. Thus, the brightness can be made uniform and the image quality can be improved.

In addition, the efficiency, lifetime, driving voltage, color characteristics, and the like of the organic light emitting diode can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims. And changes may be made without departing from the spirit and scope of the invention.

110: substrate 122: semiconductor layer
130: gate insulating film 132: gate electrode
140: interlayer insulating film 140a, 140b: first and second contact holes
152: source electrode 154: drain electrode
160: Protective film 160a: Drain contact hole
162: first electrode 170: bank
170a: Through hole 172, 174: First and second banks
172a: groove 180: light emitting layer
192: second electrode D: organic light emitting diode

Claims (9)

Claims [1]
A protective film on the substrate;
A first electrode located in a pixel region on the protective film;
A bank covering an edge of the first electrode and exposing the first electrode;
An emission layer on the first electrode in the pixel region;
The second electrode
/ RTI >
Wherein the bank comprises a first bank and a second bank above the first bank,
Wherein the first bank includes protrusions protruding into the pixel region from the side surfaces of the second bank,
Wherein protrusions of the first bank have grooves surrounding the exposed portions of the first electrodes.
The method according to claim 1,
And the groove is spaced apart from the first electrode.
3. The method of claim 2,
And the groove surrounds a side surface of the first electrode.
The method of claim 3,
And the groove exposes an upper surface of the passivation layer.
3. The method of claim 2,
And the groove is located above the first electrode.
The method according to claim 1,
And one side of the groove coincides with a side surface of the second bank.
The method according to claim 1,
Wherein the light emitting layer is also formed in the groove.
8. The method of claim 7,
And the light emitting layer in the groove is in contact with the protective film.
9. The method according to any one of claims 1 to 8,
Wherein the first bank has hydrophilicity and the second bank has hydrophobicity.

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