KR101950830B1 - Organic light emitting display device and method for fabricating the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a method of manufacturing the same, which can form a color filter even in a non-light emitting region and prevent light pumping from occurring in a non-light emitting region, The light emitting display includes a thin film transistor formed on a substrate; A protection layer formed on the entire surface of the substrate to cover the thin film transistor; A color filter formed on the protective film; A planarization layer formed on the entire surface of the protective film to cover the color filter; An organic light emitting cell formed on the planarization layer and electrically connected to the thin film transistor, the organic light emitting cell including a first electrode, an organic light emitting layer, and a second electrode; And a bank insulating film formed on the first electrode, the bank insulating film defining a light emitting region and a non-light emitting region, wherein the color filter includes: the subpixels embodying the same color; As shown in FIG.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to an organic light emitting diode (OLED) display and a method of manufacturing the same.

The image display device that implements various information on the screen is a key technology in the era of information and communication, and it is progressing in the direction of being thinner, lighter, more portable, but higher performance. An organic light emitting display device which controls the amount of light emitted from the organic light emitting layer by using a flat panel display device has recently been spotlighted as a flexible display capable of bending due to space and convenience.

The organic light emitting display includes a thin film transistor array part formed on a substrate, an organic light emitting cell located on the thin film transistor array part, and a glass cap for isolating the organic light emitting cell from the outside. The organic light emitting display utilizes an electroluminescent phenomenon in which an electric field is applied to the cathode and the anode formed at both ends of the organic light emitting layer to emit light by the binding energy when electrons and holes are injected into and transported from the organic light emitting layer, Electrons and holes emitted from the excited state fall from the excited state to the ground state.

Specifically, the organic light emitting display device has a plurality of subpixels, each of which is arranged in an area defined by the intersection of the gate wiring and the data wiring. Each of the subpixels receives a data signal from the data line when a gate pulse is supplied to the gate line, and generates light corresponding to the data signal. At this time, each sub-pixel includes a thin film transistor formed on a substrate and an organic light emitting cell connected to the thin film transistor.

FIG. 1 is a cross-sectional view of a general organic light emitting display, in which two adjacent sub-pixels are shown. FIG. 2 is a photograph of light leakage occurring in the non-emission region.

1, a general organic light emitting display includes a thin film transistor (TFT) 11 formed on a substrate 10, a first electrode 14, a first electrode 14 connected to the thin film transistor 11, And an organic light emitting cell including an organic light emitting layer 16 formed on the organic light emitting layer 16 and a second electrode 17 formed on the organic light emitting layer 16. At this time, each sub-pixel is divided through the bank insulating film 15, and light generated in the organic light emitting layer 16 emits light corresponding to the color filter 12.

In this case, most of the light generated in the organic light emitting layer 16 is emitted to the outside through the color filter 12 formed in the light emitting region defined by the bank insulating film 15, and is also emitted in the non-light emitting region as shown in FIG. 2 . Specifically, the light emitted from the organic light emitting layer 16 is emitted through the planarization layer 13 formed on the entire surface of the substrate 10 so as to cover the thin film transistor 11 and the color filter 12, do. In particular, the light emitted from the organic light emitting layer 16 is transmitted to the adjacent subpixels through the bank insulating film 15, and is emitted to the outside through the non-light emitting region of the adjacent subpixel.

At this time, although the light emitted from the non-light emitting region does not have a higher transmittance than the light emitted from the light emitting region, the color purity is lowered because the light is emitted finely, and as a result, the display quality of the display device is deteriorated. Therefore, although various methods have been devised to prevent light leakage in the non-luminescent region as described above, there is a limit in completely blocking light leakage.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a color filter which prevents color purity from being degraded even when light leakage occurs in a non- Emitting display device and a method of manufacturing the same.

According to an aspect of the present invention, there is provided an OLED display comprising: a thin film transistor formed on a substrate; A protection layer formed on the entire surface of the substrate to cover the thin film transistor; A color filter formed on the protective film; A planarization layer formed on the entire surface of the protective film to cover the color filter; An organic light emitting cell formed on the planarization layer and electrically connected to the thin film transistor, the organic light emitting cell including a first electrode, an organic light emitting layer, and a second electrode; And a bank insulating film formed on the first electrode, the bank insulating film defining a light emitting region and a non-light emitting region, wherein the color filter includes: the subpixels embodying the same color; As shown in FIG.

The subpixels implementing the same color are arranged side by side along the data line connected to the source electrode of the thin film transistor.

The width of the color filter formed in the non-emission region is equal to the width of the subpixel corresponding to the emission region.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting device including: forming a thin film transistor formed on a substrate; Forming a protective film on the entire surface of the substrate so as to cover the thin film transistor; Forming a color filter on the protective film; Forming a planarization layer on the entire surface of the protective film to cover the color filter; Forming an organic light emitting cell including a first electrode, an organic light emitting layer, and a second electrode, the organic light emitting cell being formed for each sub-pixel, the organic light emitting cell being electrically connected to the thin film transistor on the planarization layer; And forming a bank insulating layer on the first electrode, the bank insulating layer defining a light emitting region and a non-light emitting region, wherein the forming of the color filter comprises: Emitting region of the non-emitting region.

The subpixels implementing the same color are arranged side by side along the data line connected to the source electrode of the thin film transistor.

The width of the color filter formed in the non-emission region is equal to the width of the subpixel corresponding to the emission region.

The organic light emitting display of the present invention and the method of manufacturing the same have the following effects.

First, by forming a color filter in the non-emission region, light emitted to the outside through the planarization layer in the non-emission region is emitted to the outside after passing through the color filter. Therefore, even if light leakage occurs in the non-light emitting region, the color purity and display quality of the display device can be prevented from deteriorating.

Second, the color filter passes only the light of a specific wavelength among the white light emitted from the organic light emitting layer and absorbs the remaining light. Accordingly, since the transmittance of the light emitted to the outside after passing through the color filter in the non-emitting region is lowered, the intensity of the light leakage can be lowered.

1 is a sectional view of a general organic light emitting display device.
FIG. 2 is a photograph showing light leakage occurring in the non-emission region. FIG.
3A is a plan view of the organic light emitting display according to the present invention.
FIG. 3B is a cross-sectional view taken along line I-I 'of FIG. 3A. FIG.
4 is a plan view showing a color filter of the organic light emitting diode display of the present invention.
5A to 5F are process cross-sectional views of an organic light emitting display device according to the present invention.

Hereinafter, an organic light emitting display device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

3A is a plan view of the organic light emitting diode display of the present invention, and FIG. 3B is a cross-sectional view taken along line I-I 'of FIG. 3A. 4 is a plan view showing a color filter of the organic light emitting diode display of the present invention, and shows a red color filter.

As shown in FIG. 3A, on the substrate 100, a plurality of sub-pixels 100a are arranged in a matrix form. Particularly, when the organic light emitting layer is a white organic light emitting display device emitting white light, white light emitted from the organic light emitting layer is emitted to red (R), green (G), and blue Passes through the color filter and is emitted as light of various colors.

In particular, in order to improve brightness, white subpixels are additionally formed so that red, green, blue, and white (W) subpixels form one unit pixel. Further, red, green, blue, and white subpixels are arranged in a stripe structure. At this time, the white subpixel does not form a color filter, and white light emitted from the organic emission layer is directly emitted to the outside.

3B, each sub-pixel is connected to a thin-film transistor and a thin-film transistor formed on a substrate 100 and includes a first electrode 170a, an organic light-emitting layer 190, and a second electrode 170b. .

Specifically, a plurality of subpixels are defined on the substrate 100 by vertically crossing gate wirings (not shown) and data wirings (not shown). A thin film transistor is formed in a crossing region where a gate wiring (not shown) and a data wiring (not shown) cross each other.

The thin film transistor includes a gate electrode 110a, a source electrode 140a and a drain electrode 140b and a semiconductor layer 130 including an active layer 130a and an ohmic contact layer 130b sequentially stacked. At this time, the gate electrode 110a may be protruded from a gate wiring (not shown) to supply a scan signal from a gate wiring (not shown), or may be defined as a partial region of a gate wiring (not shown).

The active layer 130a overlaps the gate electrode 110a with the gate insulating film 120 formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx) or the like interposed therebetween. The ohmic contact layer 130b formed on the active layer 130a serves to reduce electrical contact resistance between the source and drain electrodes 140a and 140b and the active layer 130a. The ohmic contact layer 130b corresponding to the separated region of the source and drain electrodes 140a and 140b formed on the semiconductor layer 130 is removed to form a channel.

Specifically, the source electrode 140a is connected to a data line (not shown) to receive a pixel signal of a data line (not shown), and the drain electrode 140b faces the source electrode 140a with a channel therebetween . A protective film 150a is formed on the entire surface of the gate insulating film 120 with an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx) or the like, so as to cover the thin film transistor and the data line (not shown).

A color filter 160R is formed on the protective film 150a so that light generated in the organic light emitting layer 190 can pass through the color filter 160R and emit various colors. In the drawing, a red color filter 160R corresponding to a red subpixel is shown. The planarizing layer 160R is formed of an organic material such as acrylic resin, benzocyclobutene (BCB), polyimide (PI), polyamide (PA) (150b) is formed.

As described above, the light emitted from the organic light emitting layer 190 passes through the planarization layer 150b formed on the entire surface of the substrate 100 so as to cover the thin film transistor and the color filter 160R, Lt; / RTI > At this time, the light emitted from the non-luminescent region does not have a higher transmittance than the light emitted from the luminescent region, but the luminescent light is slightly emitted to lower the color purity, and as a result, the display quality is deteriorated.

Accordingly, the organic light emitting display of the present invention extends the color filter 160R formed in each sub pixel to the non-emission region. 4, a plurality of subpixels 100a are arranged in a matrix on a substrate 100, and a color filter is formed in a non-emission region between the subpixels 100a implementing the same color, The filter is formed in a stripe shape. That is, the color filter is formed along the non-emission region between the subpixels that implement the same color and the subpixels that implement the same color, and the subpixels that implement the same color correspond to the data connected to the source electrode of the thin film transistor And are arranged side by side along the wiring.

In the drawing, a red color filter 160R is formed in the non-emission region between the red subpixel 100a and the red subpixel 100a. At this time, the width of the color filter 160R is preferably equal to the width of the sub-pixel 100a. The plurality of subpixels 100a arranged in a matrix form preferably have subpixels 100a of the same color arranged in the same column.

Therefore, even if a light leakage occurs in the non-emission region between the subpixels, the emitted light passes through the color filter 160R in the non-emission region and is emitted to the outside, so that the emitted light has the same color as the subpixel, The color purity and the display quality can be prevented from deteriorating. Particularly, since the color filter 160R passes only the light of a specific wavelength among the white light emitted from the organic light emitting layer 190 and absorbs the remaining light, the color filter 160R reflects the light emitted from the non- The transmittance is lowered.

An organic light emitting cell including a first electrode 170a, an organic light emitting layer 190, and a second electrode 170b is formed on the planarization layer 150b. In this case, the first electrode 170a may be formed using an anode, such as tin oxide (TO), indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc (Indium Tin Zinc Oxide: ITZO), and the light emitted from the organic light emitting layer 190 is emitted to the outside through the substrate 100.

A bank insulating layer 180 having a bank hole for defining a light emitting region is formed on the first electrode 170a and an organic light emitting layer 190 is formed on the entire surface of the first electrode 170a including the bank insulating layer 180. [ Although the organic light emitting layer 190 is illustrated as a single layer in the drawing, the organic light emitting layer 190 may be formed of a plurality of organic layers as the case may be.

The second electrode 170b formed on the organic light emitting layer 190 is a cathode formed of a reflective metal such as aluminum (Al), magnesium (Mg), silver (Ag) And reflects the generated light in the direction of the first electrode 170a.

Although not shown, a hole injecting layer and a hole transporting layer may be further formed between the first electrode 170a and the organic light emitting layer 190. The hole injecting layer and the hole transporting layer may be formed by the organic light emitting layer 190, . An electron injecting layer and an electron transporting layer may be further formed between the organic light emitting layer 190 and the second electrode 170b and the electron injecting layer and the electron transporting layer may be used to inject electrons into the organic light emitting layer 190 well .

When a voltage is applied between the first electrode 170a and the second electrode 170b, a hole from the first electrode 170a is electron-emitted from the second electrode 170b, And then recombined in the organic light emitting layer 190 to form excitons. Then, the excitons emit light as they fall to the ground state, and emit light corresponding to the color filter 150.

Particularly, the light emitted from the organic light emitting layer 190 is transmitted to the adjacent sub-pixels through the bank insulating layer 180 and is emitted to the outside through the non-light emitting region of the adjacent sub-pixel. As described above, the color filter 160R is also formed in the non-emission region, so that color purity and display quality can be prevented from being degraded even if light leakage occurs.

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

5A to 5F are process sectional views of the organic light emitting diode display of the present invention.

As shown in FIG. 5A, a thin film transistor is formed on a substrate 100. Specifically, a gate metal layer is deposited on the substrate 100 and then patterned to form a gate wiring (not shown) and a gate electrode 110a. After the gate insulating film 120 is formed on the entire surface of the substrate 100 including the gate electrode 110a and the active layer 130a and the ohmic contact layer 130b are sequentially stacked on the gate insulating film 120, (130), source and drain electrodes (140a, 140b), and data lines (not shown). At this time, the data wiring (not shown) is perpendicular to the gate wiring (not shown), and subpixels are defined.

5B, a protective film 150a is formed on the entire surface of the gate insulating film 120 including the source and drain electrodes 140a and 140b with an inorganic insulating material such as SiOx and SiNx. Then, as shown in FIG. 5C, a protective film 150a The color filter 160R corresponding to each subpixel is formed. The red color filter 160R is shown in the drawing.

At this time, the color filter 160R is formed by depositing red, green, and blue pigments on each sub-pixel and patterning the red, green, and blue pigments. Particularly, a separate color filter is not formed in the white subpixel.

As described above, the light emitted from the organic emission layer 190 to be described later is transmitted through the planarization layer 150b formed on the entire surface of the substrate 100 so as to cover the thin film transistor and the color filter 160R, The light is also emitted from the light emitting region to generate light leakage, thereby deteriorating color purity and display quality.

Accordingly, the organic light emitting display of the present invention extends the color filter 160R formed in each sub pixel to the non-emission region. Specifically, the color filter is formed in a stripe shape so that a plurality of subpixels are arranged in a matrix on the substrate 100, and a color filter is formed in a non-emission region between subpixels implementing the same color. do. That is, the color filter is formed along the non-emission region between the subpixels that implement the same color and the subpixels that implement the same color, and the subpixels that implement the same color correspond to the data connected to the source electrode of the thin film transistor And are arranged side by side along the wiring. At this time, it is preferable that the width of the color filter 160R is equal to the width of the subpixel, and that a plurality of subpixels arranged in a matrix form have subpixels of the same color arranged in the same column.

When the color filter 160R is formed in the non-emission region as described above, even if a light leakage occurs in the non-emission region between the subpixels, the light passes through the color filter 160R in the non-emission region and is emitted to the outside. Therefore, the emitted light has the same color as that of the subpixel, and even if light leakage occurs in the non-emission area, the color purity and the display quality can be prevented from deteriorating. Furthermore, since the color filter 160R passes only the light of a specific wavelength among the white light emitted from the organic light emitting layer 190 and absorbs the remaining light, the color filter 160R reflects the light emitted from the non- The transmittance is lowered.

As shown in FIG. 5D, on the entire surface of the protective film 150a including the color filter 160R, there is formed an ink jet recording head such as ink jet, nozzle coating, spray coating, roll printing, A planarization layer 150b is formed of an organic material such as an acrylic resin, a polyimide resin or the like by a solution process. Then, the planarization layer 150b and the protective film 150a are selectively removed to expose the drain electrode 140b.

On the entire surface of the planarization layer 150b including the exposed drain electrode 140b is formed a tin oxide (TO), indium tin oxide (ITO), indium zinc oxide (IZO) ), Indium Tin Zinc Oxide (ITZO), or the like is deposited, and the first electrode 170a is formed by a photolithography process.

5E, a bank insulating layer 180 including a bank hole for exposing the first electrode 170a on the first electrode 170a and defining a light emitting region is formed. 5F, a solution process such as an ink jet, a nozzle coating, a spray coating, a roll printing, or the like is performed on the entire surface of the bank insulating film 180 including the bank holes, An organic light emitting layer 190 is formed by a solvolume process. Although not shown, a hole transporting layer and a hole injecting layer may be further formed between the organic light emitting layer 190 and the first electrode 170a so that holes are well injected from the first electrode 170a.

A second electrode 170b is formed on the organic light emitting layer 190 and a hole is formed between the organic light emitting layer 190 and the second electrode 170b so that electrons are well injected from the second electrode 170b An electron transport layer and an electron injection layer can be further formed.

As described above, the organic light emitting cells including the first electrode 170a, the organic light emitting layer 190, and the second electrode 170b are formed by recombining holes and electrons injected into the organic light emitting layer 190 to form an exciton The excitons emit light when the excitons fall to the ground state, and emit light corresponding to the color filters 160R formed in the respective sub pixels while passing through the color filters 160R under the organic light emitting cells. Also, although not shown, a process of forming a capping layer for capping the organic light emitting cells on the second electrode 170b may be performed.

The organic light emitting display of the present invention can prevent the color purity from being lowered due to the light leakage only by a conventional process of forming a color filter without any additional process.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

100: substrate 110a: gate electrode
120: gate insulating film 130: semiconductor layer
130a: active layer 130b: ohmic contact layer
140a: source electrode 140b: drain electrode
150a: protective film 150b: planarization layer
160R: color filter 170a: first electrode
170b: second electrode 180: bank insulating film
190: organic light emitting layer

Claims (6)

Thin film transistors positioned on each subpixel of the substrate arranged in a matrix form;
A protective film on the substrate and covering the thin film transistors;
A planarization layer disposed on the protective film;
First electrodes located on the planarization layer and overlapping each subpixel and electrically connected to the thin film transistor of the corresponding subpixel through one of the through holes passing through the protective film and the planarization layer;
A bank insulating film including bank holes exposing a portion of each first electrode to define a light emitting region and a non-light emitting region;
An organic light emitting layer disposed on the first electrodes exposed by the bank holes;
A second electrode located on the organic light emitting layer; And
A color filter disposed between the passivation layer and the planarization layer and overlapping the emission region of each subpixel,
The subpixels implementing the same color are arranged side by side along the first direction,
Each color filter extending in the first direction to overlap a non-emission region between sub-pixels implementing the same color,
And each color filter is spaced apart from the contact holes of the subpixels. The method according to claim 1,
Wherein the subpixels implementing the same color are arranged in parallel along a data line connected to a source electrode of the thin film transistor of each subpixel. The method according to claim 1,
And the width of each color filter in the second direction perpendicular to the first direction on the non-emission region is equal to the width of the emission region of the corresponding sub pixel in the second direction. Forming a thin film transistor on each subpixel of the substrate arranged in a matrix form;
Forming a protective film covering the thin film transistors on the substrate;
Forming color filters on the passivation layer of each subpixel;
Forming a planarization layer covering the color filters on the protective film;
Selectively etching the passivation layer and the planarization layer to form contact holes exposing drain electrodes of the thin film transistors of each sub pixel;
Forming first electrodes on the planarization layer of each subpixel through one of the contact holes, the first electrodes being electrically connected to the thin film transistor of the subpixel;
Forming a bank insulating film including bank holes exposing a partial area of a first electrode of each sub pixel in order to define a light emitting region and a non-light emitting region;
Forming an organic light emitting layer on the first electrodes exposed by the bank holes; And
And forming a second electrode on the organic light emitting layer,
The subpixels implementing the same color are arranged side by side along the first direction,
Each color filter extends in the first direction and is formed to overlap with a light emitting region of subpixels implementing the same color and a non-emitting region between the corresponding subpixels,
Wherein each color filter is spaced apart from the contact holes of the corresponding subpixels. 5. The method of claim 4,
Wherein the subpixels implementing the same color are arranged in parallel along a data line connected to a source electrode of the thin film transistor of each subpixel. 5. The method of claim 4,
And the width of each color filter in the second direction perpendicular to the first direction on the non-emission region is equal to the width of the emission region of the corresponding subpixel in the second direction.

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