KR102004843B1 - Organic light emitting display device and manufacturing method of the same - Google Patents

Abstract

An organic light emitting display according to an exemplary embodiment of the present invention includes a substrate, first electrodes disposed on the substrate, a first electrode disposed on the first electrodes and defining a plurality of pixels, And a second electrode disposed on the light-emitting layers, wherein the light-emitting layers are disposed on the first electrodes of the plurality of pixels, and the second electrode is disposed on the light-emitting layers. Wherein the bank layer positioned on one line includes a hydrophobic layer formed on the hydrophilic layer, and the bank layer located on a line connecting adjacent pixels emitting the same color among the plurality of pixels, .

Description

TECHNICAL FIELD [0001] The present invention relates to an organic electroluminescence display device and a method of manufacturing the same,

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

2. Description of the Related Art In recent years, the importance of flat panel displays (FPDs) has been increasing with the development of multimedia. For example, a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), an organic light emitting display Various flat-panel displays have been put into practical use. Among the organic electroluminescent display devices, organic electroluminescent display devices have attracted attention as natural color display devices because they emit light in all regions of visible light including blue, and have high luminance and low driving voltage. Also, since it has self-luminescence, it has a large contrast ratio, can realize an ultra-thin display, has a simple process, and has a relatively low environmental pollution. On the other hand, since the response time is as short as several microseconds (μs), the moving picture is easy to implement, the viewing angle is not limited, the liquid crystal display device is stable even at low temperature, and the driving circuit is driven with a low voltage of 5V to 15V.

1 is a view illustrating a conventional organic light emitting display device. Referring to FIG. 1, a first electrode 30 formed of a transparent conductive material is disposed on a substrate 20, and a bank layer 40 defining a plurality of pixels is exposed by partially exposing the first electrode 30. A light emitting layer 50 is formed on the first electrode 30 exposed by the bank layer 40 and a second electrode 60 is formed on the light emitting layer 50 to constitute a conventional organic light emitting display device 10. Here, the light emitting layer 50 may be formed of a polymer material. In this case, the polymer material is dissolved in a solvent, and then the polymer material is coated on the bank layer 40 by an ink jet method or the like, To the inside of the bank layer 40 while the solvent is removed.

However, the conventional bank layer 40 uses a polyimide-based organic material because the polymer material is located on the upper surface of the bank layer 40 because the interface property with the polymer material is good. Therefore, in addition to the region where the luminescent layer 50 and the first electrode 30 are in contact, light also spreads on the slope and the upper surface of the bank layer 40, causing deterioration in light emission characteristics such as white balance.

The present invention provides an organic light emitting display device and a method of manufacturing the same that can improve pixel uniformity and aperture ratio.

According to an aspect of the present invention, there is provided an organic light emitting display including a substrate, first electrodes disposed on the substrate, first electrodes disposed on the first electrodes, A bank layer including at least a hydrophilic layer, light emitting layers respectively disposed on the first electrodes of the plurality of pixels, and a second electrode disposed on the light emitting layers, Wherein the bank layer located on a line connecting adjacent pixels emitting a color comprises a hydrophobic layer formed on the hydrophilic layer and is disposed on a line connecting adjacent pixels emitting the same color among the plurality of pixels Wherein the bank layer is made of only the hydrophilic layer.

And a line connecting adjacent pixels emitting the same color among the plurality of pixels is parallel to the short side of the substrate.

And a line connecting adjacent pixels emitting different colors among the plurality of pixels is parallel to a long side of the substrate.

And the hydrophilic layer is wider than the hydrophobic layer.

And the hydrophilic layer is thinner than the hydrophobic layer.

The substrate may further include a thin film transistor including a gate electrode, a semiconductor layer, a source electrode, and a drain electrode.

According to another aspect of the present invention, there is provided a method of fabricating an organic light emitting display, the method including forming a substrate, first electrodes on the substrate, forming a hydrophilic material and a hydrophobic material on the first electrodes, A bank layer formed of a hydrophilic layer and a hydrophobic layer is formed on a line connecting adjacent pixels emitting light of different colors among the plurality of pixels, and among the plurality of pixels, Forming a bank layer made of a hydrophilic layer on a line connecting adjacent pixels, forming light emitting layers on the first electrodes of the plurality of pixels, and forming a second electrode on the light emitting layers The method comprising the steps of:

The light emitting layers are formed by an ink jet method.

An organic light emitting display device and a method of fabricating the same according to an embodiment of the present invention are characterized in that a bank layer formed only of a hydrophilic layer is formed between pixels emitting light of the same color and a hydrophilic layer is formed between pixels emitting light of different colors By forming the bank layer formed by stacking the hydrophobic layers, it is possible to prevent different light emitting materials from being mixed between pixels emitting different colors, and uniformly apply the light emitting material between pixels emitting the same color. Therefore, there is an advantage that the scan uniformity caused by the volume deviation of the light emitting material applied to the light emitting layer can be compensated and the pixel uniformity can be improved. Further, since the bank layer formed only of the hydrophilic layer is formed, the alignment margin of the hydrophilic layer and the hydrophobic layer is not ensured, which is an advantage that the aperture ratio of the pixel can be improved.

1 is a view showing a conventional organic light emitting display device.
2 is a plan view of an organic light emitting display according to an embodiment of the present invention.
3 is a cross-sectional view taken along line I-I 'of FIG. 2;
4 is a view showing a bank layer of an organic light emitting display device.
5A to 5G are views illustrating a method of manufacturing an organic light emitting display according to an exemplary embodiment of the present invention.
FIG. 6A is an image showing pixel emission of an organic light emitting display having a two-layer structure of a hydrophilic layer and a hydrophobic layer in all the bank layers, FIG. Is an image showing pixel emission of an organic light emitting display in which a bank layer composed of a hydrophilic layer and a hydrophobic layer is formed between pixels having only a hydrophilic layer and emitting light of different colors.

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

FIG. 2 is a plan view of an organic light emitting display according to an exemplary embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line I-I 'of FIG. 2, FIG.

Referring to FIG. 2, the organic light emitting display 100 of the present invention includes a plurality of pixels SP disposed on a substrate 110. The plurality of pixels SP are formed as a unit pixel by using a red pixel R for emitting red light, a green pixel G for emitting green light and a blue pixel B for emitting blue light as unit pixels, . The red, green, and blue pixels R, G, and B are arranged in a direction parallel to the long side LS of the substrate 110, and pixels of the same color are arranged in a direction parallel to the short side SS of the substrate 110 .

More specifically, referring to FIG. 3, a semiconductor layer 115 is located on a substrate 110. A first insulating layer 120 is disposed to cover the semiconductor layer 115 and a gate electrode 125 corresponding to the semiconductor layer 115 is disposed on the first insulating layer 120. A second insulating layer 130 which is an interlayer insulating layer is formed on the gate electrode 125 and contact holes CH for exposing a part of the semiconductor layer 115 are formed on the second insulating layer 130 and the first insulating layer 120, . A source electrode 135a and a drain electrode 135b which are electrically connected to the semiconductor layer 115 through the contact holes CH are formed on the second insulating layer 130 to constitute a thin film transistor TFT.

A third insulating film 140 is positioned on the thin film transistor TFT and a via hole 145 is formed in the third insulating film 140 to expose the drain electrode 135b of the thin film transistor TFT. The first electrode 150 connected to the drain electrode 135b of the thin film transistor TFT is positioned on the third insulating film 140 via the via hole 145. The bank layer 160 including the openings 166 for isolating the adjacent first electrodes 150 on the first electrode 150 and exposing a portion of the first electrode 150 is located. The bank layer 160 comprises at least one of a hydrophilic layer 162 and a hydrophobic layer 164. The light emitting layer 170 is located on the first electrode 150 exposed by the opening 166. The second electrode 180 is positioned on the substrate 100 including the light emitting layer 170 to constitute the organic light emitting display device 100 of the present invention.

Meanwhile, in the present invention, the bank layer 160 located between pixels emitting different colors comprises a laminated structure of a hydrophilic layer 162 and a hydrophobic layer 164. The hydrophilic layer 162 improves bonding strength with the polymer material of the light emitting layer 170 by using the material having the hydrophilic interface property and the hydrophobic layer 164 has a hydrophobic interfacial characteristic, It lowers the bonding force with the material. Accordingly, even if the polymer material of the light emitting layer 170 is formed on the inclined surface or the upper surface of the bank layer 160, the bonding force with the hydrophobic layer 164 is poor and flows into the bank layer 160. Accordingly, it is possible to prevent a problem that materials emitting light of different colors are mixed with adjacent pixels to mix color of light.

In addition, the bank layer 160 located between the pixels emitting the same color consists of the hydrophilic layer 162 only. Since the same material is used for the luminescent materials emitting the same color to each other, they may be mixed with pixels emitting the same color. In particular, since the bank layer 160 consists of only a single layer of the hydrophilic layer 162, the applied luminescent material has the advantage that it can be applied uniformly to each other across the pixels emitting the same color.

4, the width W1 of the hydrophilic layer 162 in the bank layer 160 of the present invention is wider than the width W2 of the hydrophobic layer 164. This is to facilitate formation of the hydrophobic layer 164 since the hydrophilic layer 164 is formed thereon after the hydrophilic layer 162 is formed. In addition, the light emitting material is formed so as to have a constant taper so that the light emitting material can flow well into the bank layer 160.

In addition, the thickness H1 of the hydrophilic layer 162 is formed to be thinner than the thickness H2 of the hydrophobic layer 164. Since the thickness H1 of the hydrophilic layer 162 acts as a barrier between the pixels emitting the same color, it must be able to be passed to pixels emitting the same adjacent color when applying the luminescent material. In addition, the hydrophobic layer 164 should act as a barrier between the pixels emitting different colors, so that different luminescent materials can not cross the hydrophobic layer 164. The thickness H1 of the hydrophilic layer 162 is formed to be equal to the thickness of the same light emitting material and the thickness H2 of the hydrophobic layer 164 is different from the thickness H1 of the hydrophilic layer 162 The luminescent material must be formed in a thickness that can not be exceeded.

Referring again to FIG. 3, the width W3 of the bank layer 160 located between the pixels emitting the same color has a width W1 of the bank layer 160 located between pixels emitting different colors, . Since there are a plurality of signal wirings between the pixels emitting light of different colors, the width W3 of the bank layer 160 is made wide so as to cover them. On the other hand, since there are a small number of signal wirings between pixels emitting the same color, the width W3 of the bank layer 160 is narrower than the width W3 of the bank layer 160 described above.

The organic light emitting display according to an embodiment of the present invention having the above structure may have a structure in which a bank layer 160 formed only of a hydrophilic layer 162 is formed between pixels emitting the same color, By forming the bank layer 160 formed by stacking the hydrophilic layer 162 and the hydrophobic layer 164 between the light emitting pixels, it is possible to prevent the different light emitting materials from being mixed in between the pixels emitting light of different colors, It is possible to uniformly apply the light emitting material between the pixels emitting light of colors. Accordingly, there is an advantage that a scan mura caused by a volume deviation of the light emitting material applied to the light emitting layer can be compensated. Since the bank layer 160 formed only of the hydrophilic layer 162 is formed, it is not necessary to secure the alignment margin of the hydrophilic layer 162 and the hydrophobic layer 164, so that the aperture ratio of the pixel can be improved There is an advantage.

Hereinafter, a method of manufacturing an organic light emitting display according to an embodiment of the present invention will be described.

5A to 5G are views illustrating a method of fabricating an organic light emitting display according to an exemplary embodiment of the present invention. Hereinafter, in order to facilitate the understanding of the present invention, the same reference numerals are given to the same components as those of the above-described configuration.

Referring to FIG. 5A, a substrate 110 is prepared. The substrate 110 is made of glass, plastic or metal, but may be flexible. A buffer layer may be further formed on the substrate 110 to protect a thin film transistor formed in a subsequent process from an impurity such as alkali ions or the like that flows out from the substrate 110.

A semiconductor layer 115 is formed on the substrate 110. The semiconductor layer 115 may include amorphous silicon or crystallized polycrystalline silicon. In addition, the semiconductor layer 115 may include a source region and a drain region including a p-type or an n-type impurity, and may include a channel region other than the source region and the drain region. A first insulating layer 120, which may be a gate insulating layer, is formed on the semiconductor layer 115. The first insulating layer 120 may be a silicon oxide (SiOx), a silicon nitride (SiNx), or a multilayer thereof.

A gate electrode 125 is formed on the first insulating layer 120 at a position corresponding to a predetermined region of the semiconductor layer 115, that is, a channel region when impurities are injected. The gate electrode 125 may be formed of one selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper Any one of them or an alloy thereof. The gate electrode 125 may be formed of one selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Ne, Or an alloy of any one selected from the above. For example, the gate electrode 125 may be a double layer of molybdenum / aluminum-neodymium or molybdenum / aluminum.

Next, a second insulating film 130, which may be an interlayer insulating film, is formed on the gate electrode 125. The second insulating layer 130 may be a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof. A part of the second insulating layer 130 and the first insulating layer 120 are etched to form contact holes CH exposing a part of the semiconductor layer 115. At this time, a part of the semiconductor layer 115 exposed by the contact holes CH may be a source region and a drain region.

5B, a source electrode 135a and a drain electrode 135b are electrically connected to the semiconductor layer 115 through the contact holes CH that penetrate the second insulating layer 130 and the first insulating layer 120, Thereby forming the electrode 135b. The source electrode 135a and the drain electrode 135b may be formed of a single layer or a multilayer and may be formed of a single layer of molybdenum (Mo), aluminum (Al) And may be made of any one selected from the group consisting of chrome (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) When the source electrode 135a and the drain electrode 135b are multilayered, a triple layer of molybdenum / aluminum-neodymium, titanium / aluminum / titanium, molybdenum / aluminum / molybdenum or molybdenum / aluminum- neodymium / ≪ / RTI > Thus, a thin film transistor including the semiconductor layer 115, the gate electrode 125, the source electrode 135a, and the drain electrode 135b is formed.

Next, a third insulating film 140 is formed on the source electrode 135a and the drain electrode 135b. The third insulating layer 140 may be a planarizing layer for alleviating the step difference of the lower structure. The third insulating layer 140 may be formed of an organic material such as polyimide, benzocyclobutene series resin, or acrylate, (Spin on glass), which is then cured and then cured. Alternatively, the third insulating layer 140 may be a passivation layer and may be formed of a silicon nitride layer (SiNx), a silicon oxide layer (SiOx), or a multilayer thereof. Then, the third insulating film 140 is etched to form a via hole 145 for exposing the drain electrode 135b of the thin film transistor.

The first electrode 150 is formed on the substrate 110 on which the via hole 145 is formed. The first electrode 150 may be an anode. Here, when the structure of the organic light emitting display device is a backlight or a double-sided light emission, the first electrode 150 is made of a transparent material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ZnO . The first electrode 150 may be formed of any one of aluminum (Al), silver (Ag), and nickel (Ni) under the layer of any one of ITO, IZO, and ZnO, And may have a multilayer structure including the reflective layer between two layers of any one of ITO, IZO, and ZnO. Accordingly, the first electrode 150 is very much the via hole 145 and can be connected to the drain electrode 135b of the thin film transistor.

Next, referring to FIG. 5C, a hydrophilic layer 162 is formed by applying a hydrophilic material on the substrate 110 on which the first electrode 150 is formed and patterning the hydrophilic material. The hydrophilic layer 162 is formed of a hydrophilic material and may be formed of an inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed of a material such as polyimide, photo acryl, And the like. The hydrophilic layer 162 is formed to have a thickness of at least 0.5 mu m. At this time, the hydrophilic layer 162 is located between the plurality of pixels to define a plurality of pixels. That is, both the pixels are formed between the pixels emitting the same color and the pixels emitting the different colors.

Referring to FIG. 5D, a hydrophobic layer 164 is formed on the hydrophilic layer 162 by applying a hydrophobic substance onto the substrate 110 having the hydrophilic layer 162 formed thereon and patterning the same. The hydrophobic layer 164 is formed of a material having a hydrophobic property, and any material having hydrophobicity may be used. At this time, the hydrophobic layer 164 is formed to be thicker than the hydrophilic layer 162. At this time, the hydrophobic layer 164 is formed only between pixels emitting different colors, and is not formed between pixels emitting the same color. Accordingly, a bank layer 160 formed between the pixels emitting light of different colors and composed of a lamination of the hydrophilic layer 162 and the hydrophobic layer 164, and the hydrophilic layer 162 formed between the pixels emitting the same color, The bank layer 160 is formed.

Next, referring to FIG. 5E, light emitting materials for forming a light emitting layer on the first electrode 150 exposed by the bank layer 160 are applied using an inkjet method. More specifically, an ink containing a light emitting material emitting red, green, and blue is applied onto the first electrode 150 through the inkjet apparatus. At this time, the red light emitting material 172R is applied to the red light emitting pixels and the green light emitting material 172G is applied to the green light emitting pixels. In the characteristics of the ink-jet method, light emitting materials are sequentially applied to a plurality of pixels, and the light emitting materials are uniformly distributed in a mutually intersecting manner over the bank layer 160 composed of only the hydrophilic layer 162 in the pixels emitting the same color . On the other hand, in the pixels emitting light of different colors, the bank layer 160 composed of the hydrophilic layer 162 and the hydrophobic layer 164 acts as a barrier so that different light emitting materials are not mixed.

Next, referring to FIGS. 5F and 5G, a heat treatment is performed on the substrate 110 coated with the light emitting materials to remove the solvent and the impurities of the light emitting material to form the light emitting layer 170. Next, a second electrode 180 is formed on the light emitting layer 170. The second electrode 180 may be a cathode electrode and may be made of magnesium (Mg), calcium (Ca), aluminum (Al), silver (Ag), or an alloy thereof having a low work function. Here, the second electrode 180 may be formed to have a thickness thin enough to transmit light when the organic light emitting display device has a front or both-side light emitting structure, and when the organic light emitting display device has a back light emitting structure, It can be formed thick enough to reflect light. 5G, an organic light emitting display device according to an embodiment of the present invention is manufactured.

6A is an image showing pixel emission of an organic light emitting display device having a two-layer structure of a hydrophilic layer and a hydrophobic layer, and FIG. 6B is a view showing a state in which all bank layers emit light of the same color according to the embodiment of the present invention And a bank layer made of a hydrophilic layer and a hydrophobic layer is formed between pixels having only a hydrophilic layer between pixels and emitting light of different colors.

Referring to FIG. 6A, the width of the bank layer is enlarged due to the bank layer having the two-layered structure of the hydrophilic layer and the hydrophobic layer, so that the light emitting region of the pixel is reduced and the aperture ratio is low. On the other hand, referring to FIG. 6B, since the bank layer made of a hydrophilic layer is formed between the pixels emitting the same color, the light emitting region of the pixel is not reduced, and the aperture ratio is higher than that of FIG. 6A.

As described above, the organic light emitting display according to an exemplary embodiment of the present invention and the method of fabricating the same include the steps of forming a bank layer formed only of a hydrophilic layer between pixels emitting the same color, By forming the bank layer formed by the lamination of the hydrophilic layer and the hydrophobic layer, it is possible to prevent the different luminescent materials from being mixed between the pixels emitting different colors and to uniformly apply the luminescent material between the pixels emitting the same color can do. Accordingly, there is an advantage that a scan mura caused by a volume deviation of the light emitting material applied to the light emitting layer can be compensated. In addition, since the bank layer formed only of the hydrophilic layer is formed, an alignment margin of the hydrophilic layer and the hydrophobic layer is not ensured, which is an advantage that the aperture ratio of the pixel can be improved.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: organic electroluminescent display device 110: substrate
115: semiconductor layer 120: first insulating film
125: gate electrode 130: second insulating film
135a and 135b: source and drain electrodes
140: third insulating film 150: first electrode
160: bank layer 162: hydrophilic layer
164: hydrophobic layer 170: light-emitting layer
180: second electrode

Claims (8)

Board;
First electrodes positioned on the substrate;
A bank layer located on the first electrodes and defining a plurality of pixels, the bank layer including at least a hydrophilic layer;
Emitting layers respectively disposed on the first electrodes of the plurality of pixels;
And a second electrode located on the light emitting layers,
The bank layer located on a line connecting adjacent pixels emitting different colors among the plurality of pixels includes a hydrophobic layer formed on the hydrophilic layer,
Wherein the bank layer located on a line connecting adjacent pixels emitting the same color among the plurality of pixels comprises only the hydrophilic layer.
The method according to claim 1,
Wherein a line connecting adjacent pixels emitting the same color among the plurality of pixels is parallel to a short side of the substrate.
3. The method of claim 2,
And a line connecting adjacent pixels emitting different colors among the plurality of pixels is parallel to a long side of the substrate.
The method according to claim 1,
Wherein the hydrophilic layer is wider than the hydrophobic layer.
The method according to claim 1,
Wherein the hydrophilic layer is thinner than the hydrophobic layer.
The method according to claim 1,
Wherein the substrate further comprises a thin film transistor including a gate electrode, a semiconductor layer, a source electrode, and a drain electrode.
Board;
Forming first electrodes on the substrate;
A plurality of pixels are defined by forming a hydrophilic material and a hydrophobic material on the first electrodes, respectively, and patterning the hydrophilic material and the hydrophobic material on the lines connecting adjacent pixels emitting different colors among the plurality of pixels, Forming a bank layer made of a hydrophilic layer on a line connecting adjacent pixels emitting the same color among the plurality of pixels;
Forming light emitting layers on the first electrodes of the plurality of pixels, respectively; And
And forming a second electrode on the light emitting layers. ≪ Desc / Clms Page number 20 >
8. The method of claim 7,
Wherein the light emitting layers are formed by an ink jet method.

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