KR20160053043A - Organic Light Emitting Display Device and Manufacturing Method thereof - Google Patents

Abstract

The present invention relates to an organic light emitting display device including a first substrate, a transmission part, a light emitting part, an auxiliary electrode, and an N^th contact hole (N is an integer of one or more). The transmission part is located on the first substrate and transmits natural light. The light emitting part is located on the first substrate and is adjacent to the transmission part and emits light by itself. The auxiliary electrode is located between the transmission part and the light emitting part. The contact hole is located in a region corresponding to the auxiliary electrode and has an undercut shape. Part of the auxiliary electrode is electrically connected to part of a lower electrode and part of an upper electrode by the contact hole. So, display quality can be improved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting display,

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

As the information technology is developed, the market of display devices, which is a connection medium between users and information, is getting larger. Accordingly, a flat panel display (FPD) such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display and a plasma liquid crystal display (PDP) ) Have been increasing. Among them, liquid crystal display devices capable of realizing high resolution and capable of not only miniaturization but also enlargement are widely used.

Some organic light emitting display devices among the above-described display devices include a display panel including a plurality of sub-pixels arranged in a matrix form and a driver for driving the display panel. The driving unit includes a scan driver for supplying a scan signal (or a gate signal) to the display panel, and a data driver for supplying a data signal to the display panel.

In an organic light emitting display, when a scan signal, a data signal, or the like is supplied to sub-pixels arranged in a matrix form, the selected sub-pixel emits light, thereby displaying an image.

The organic electroluminescent display device may have a structure having a light emitting portion for emitting self-emitted light, as well as a structure including a transparent portion transmitting natural light and a light emitting portion emitting self-emitted light. However, in the organic light emitting display device having the transmissive part and the light emitting part proposed in the related art, there has been reported a problem that luminance irregularity occurs due to the resistance problem (high resistance, resistance difference problem, etc.) of electrodes formed on the display panel, do.

In order to solve the problems of the background art described above, the present invention improves the fairness by reducing the mask through elimination of the barrier ribs, implements the display panel having the low resistance electrode structure, improves the luminance unevenness problem, will be.

The present invention relates to an organic light emitting display device including a first substrate, a transmissive portion, a light emitting portion, an auxiliary electrode, and an Nth (N is an integer of 1 or more) contact holes. The transmissive portion is located on the first substrate and transmits natural light. The light emitting portion is located on the first substrate and is adjacent to the transmissive portion and emits self-emitted light. The auxiliary electrode is positioned between the transmissive portion and the light emitting portion. The contact hole is located in the region corresponding to the auxiliary electrode and has an undercut shape. A part of the auxiliary electrode is electrically connected to a part of the lower electrode and a part of the upper electrode by the contact hole.

The contact hole may include a recessed region for providing a space in which a portion of the lower electrode and a portion of the upper electrode are electrically connected and a non-recessed region for providing a space in which a portion of the auxiliary electrode and a portion of the lower electrode are electrically connected. have.

In the undercut, a part of the lower insulating film where the auxiliary electrode is located may be formed, and a part of the upper insulating film which is located on the lower insulating film and covers the auxiliary electrode may be formed to pass through.

The auxiliary electrode may be arranged in a line shape in parallel with a data line for transmitting a data signal to the light emitting portion.

The auxiliary electrode may be located on the same layer as the data line.

A part of the lower electrode is located in the same layer as the lower electrode included in the light emitting part, and can be electrically separated.

In another aspect, the present invention relates to a method of manufacturing an organic light emitting display. A method of manufacturing an organic electroluminescent display device includes defining a transmissive portion that transmits natural light on a first substrate and a light emitting portion that emits self-emitted light, and forming an auxiliary electrode on a lower insulating film positioned between the transmissive portion and the light emitting portion ; Forming an upper insulating film covering the auxiliary electrode located on the lower insulating film; Forming an Nth (N is an integer of 1 or more) contact holes having an undercut shape in a region corresponding to the auxiliary electrode; Forming a lower electrode on the upper insulating film; Forming a bank layer covering a part of the lower electrode on the upper insulating film; Forming an organic light emitting layer on the lower electrode; And forming an upper electrode on the organic light emitting layer, wherein a part of the auxiliary electrode is electrically connected to a part of the lower electrode and a part of the upper electrode by the contact hole.

The contact hole may include a recessed region for providing a space in which a portion of the lower electrode and a portion of the upper electrode are electrically connected and a non-recessed region for providing a space in which a portion of the auxiliary electrode and a portion of the lower electrode are electrically connected. have.

The undercut may be formed such that a part of the lower insulating film is recessed and a part of the upper insulating film is penetrated.

The auxiliary electrode is disposed in the same layer as the data line for transmitting the data signal to the light emitting portion and is arranged in a line shape in parallel with the data line and a part of the lower electrode is located on the same layer as the lower electrode included in the light emitting portion, And can be electrically separated.

The present invention can improve the processability by mask reduction (mask process is omitted) by removing the barrier for use (connection) of the auxiliary electrode, and uses part of the data metal layer (or source drain metal layer) as the auxiliary electrode, It is possible to lower the resistance (low resistance electrode structure). In addition, since the present invention can realize a display panel having a low resistance electrode structure, there is an effect of improving not only luminance non-uniformity but also display quality.

1 is a schematic block diagram of an organic light emitting display device.
Fig. 2 is an exemplary circuit configuration of a subpixel. Fig.
3 is a plan view showing subpixels according to an experimental example;
4 is a plan view showing subpixels according to a first embodiment of the present invention;
5 is an enlarged view showing an electrode and an auxiliary electrode.
FIG. 6 is a cross-sectional view showing regions A1-A2 of FIG. 5;
7 is a cross-sectional exemplary view of a subpixel according to a first embodiment of the present invention;
8 and 9 are plan views showing subpixels according to a second embodiment of the present invention.
10 is a cross-sectional exemplary view of a subpixel according to a second embodiment of the present invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

≪ Embodiment 1 >

FIG. 1 is a schematic block diagram of an organic light emitting display device, FIG. 2 is an exemplary circuit configuration of a subpixel, and FIG. 3 is a plan view showing subpixels according to an experimental example.

1, an organic light emitting display includes an image processor 110, a timing controller 120, a data driver 130, a gate driver 140, and a display panel 150.

The image processing unit 110 outputs a data enable signal DE together with a data signal DATA supplied from the outside. The image processing unit 110 may output at least one of a vertical synchronizing signal, a horizontal synchronizing signal, and a clock signal in addition to the data enable signal DE, but these signals are omitted for convenience of explanation.

The timing controller 120 receives a data signal DATA from a video processor 110 in addition to a data enable signal DE or a driving signal including a vertical synchronizing signal, a horizontal synchronizing signal, and a clock signal. The timing controller 120 includes a gate timing control signal GDC for controlling the operation timing of the gate driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 130, .

The data driver 130 samples and latches the data signal DATA supplied from the timing controller 120 in response to the data timing control signal DDC supplied from the timing controller 120 and converts the sampled data signal into a gamma reference voltage . The data driver 130 outputs the data signal DATA through the data lines DL1 to DLn. The data driver 130 is formed in the form of an IC (Integrated Circuit).

The gate driver 140 outputs the gate signal while shifting the level of the gate voltage in response to the gate timing control signal GDC supplied from the timing controller 120. The gate driver 140 outputs a gate signal through the gate lines GL1 to GLm. The gate driver 140 may be formed in the form of an IC (Integrated Circuit) or a gate in panel structure in the display panel 150.

The display panel 150 displays an image corresponding to the data signal DATA and the gate signal supplied from the data driver 130 and the gate driver 140. The display panel 150 includes subpixels SP positioned between the first substrate and the second substrate and displaying an image.

The subpixels are formed in a top emission mode, a bottom emission mode, or a dual emission mode depending on the structure. The subpixels SP include a red subpixel, a green subpixel, and a blue subpixel or a white subpixel, a red subpixel, a green subpixel, and a blue subpixel. The subpixels SP may have one or more different emission areas depending on the emission characteristics.

As shown in FIG. 2, one sub-pixel includes a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode OLED. The organic light emitting diode OLED operates to emit light in accordance with the driving current generated by the driving transistor DR.

The switching transistor SW operates in response to a gate signal supplied through the first gate line GL1 so that a data signal supplied through the first data line DL1 is stored as a data voltage in the capacitor Cst. The driving transistor DR operates so that a driving current flows between the first power supply line VDD and the second power supply line VSS in accordance with the data voltage stored in the capacitor Cst. The compensation circuit CC is a circuit for compensating the threshold voltage and the like of the driving transistor DR.

The compensation circuit CC consists of one or more thin film transistors and a capacitor. The configuration of the compensation circuit (CC) is very various according to the compensation method, and a detailed illustration and description thereof are omitted. The thin film transistor is implemented based on low temperature polysilicon (LTPS), amorphous silicon (a-Si), oxide or organic semiconductor layers.

In FIG. 2, one compensator CC is included in one subpixel. However, the compensation circuit CC may be omitted when the subject of compensation is located outside the sub-pixel such as the data driver 130 or the like. That is, one subpixel is basically composed of a 2T (Transistor) 1C (Capacitor) structure including a switching transistor SW, a driving transistor DR, a capacitor Cst and an organic light emitting diode (OLED) (CC) is added, it may be composed of 3T1C, 4T2C, 5T2C, and the like.

The organic light emitting display device described above may be implemented as a top emission type, a bottom emission type, or a dual emission type. In addition, the organic light emitting display device described above may be implemented in various forms, such as providing curved surfaces, artificially or mechanically bending.

In addition, the organic light emitting display device may have a structure including a light emitting portion that emits self-emitted light, and a structure including a transmissive portion that transmits natural light and a light emitting portion that emits self-emitted light.

As shown in Fig. 3, the display panel of the experimental example has a light emitting portion and a transparent portion having white, red, green and blue subpixels (W, R, G, B). The light emitting portion and the transmissive portion are located adjacent to each other. The white, red, green and blue subpixels W, R, G and B located in the light emitting portion are separately connected to the data lines DLw, DLr, DLg and DLb and the gate lines GL, respectively .

The white, red, green, and blue subpixels W, R, G, and B emit white, red, green, and blue light, respectively. The transmitting portion transmits natural light. The display panel of the experimental example can transmit a picture (picture), a letter, a number, etc. located on the back surface as it is when the picture is not displayed. On the other hand, when an image is displayed on the display panel of the experimental example, the transmitted picture or the like is not displayed (disappears) and an image corresponding to the data signal supplied to the display panel is displayed.

However, the organic light emitting display device implemented with the display panel of the experimental example has the problem that the luminance unevenness occurs due to the resistance problem (high resistance, resistance difference problem, etc.) of electrodes formed on the display panel, .

FIG. 4 is a plan view showing subpixels according to the first embodiment of the present invention, FIG. 5 is an enlarged view showing an electrode and an auxiliary electrode, and FIG. 6 is a cross-sectional view showing a region A1-A2 of FIG.

As shown in Fig. 4, the display panel of the first embodiment of the present invention has a light emitting portion and a transmissive portion having white, red, green and blue subpixels (W, R, G, B). The white, red, green and blue subpixels W, R, G and B located in the light emitting portion are separately connected to the data lines DLw, DLr, DLg and DLb and the gate lines GL, respectively .

The white, red, green, and blue subpixels W, R, G, and B emit white, red, green, and blue light, respectively. The transmitting portion transmits natural light. The display panel of the embodiment can transmit a picture (figure), a letter, a number, etc. located on the back surface when the image is not displayed. On the other hand, when an image is displayed on the display panel of the embodiment, the transmitted picture or the like is not displayed (disappears) and an image corresponding to the data signal supplied to the display panel is displayed.

The white, red, green, and blue subpixels (W, R, G, B) are defined as one pixel. The light emitting portion defined by one pixel may have a light emitting region that is equal to or smaller than the transmissive portion. The light emitting region may be divided into regions emitting white light, red light, green light, and blue light, but the present invention is not limited thereto.

The display panel of the first embodiment of the present invention includes an auxiliary electrode DLa positioned between the light emitting portion and the transmissive portion. The auxiliary electrode DLa is formed in a line shape in parallel with the data lines DLw, DLr, DLg, and DLb. The auxiliary electrode DLa is electrically connected to the adjacent electrodes exposed through at least one of the contact holes CH1 to CH3. The contact holes CH1 to CH3 are formed in a rectangular shape, a rectangular shape, a circular oval shape, or a polygonal shape.

As shown in FIG. 5, the first to third contact holes CH1 to CH3 are formed in an undercut shape, thereby including a recessed region (left side of the contact holes) and a non-recessed region (right side of the contact holes). The depression region is a region for providing a space for electrically connecting the cathode electrode and the dummy anode electrode independent of the anode electrode, and the non-depression region is a region for providing a space for electrically connecting the dummy anode electrode and the auxiliary electrode.

The cathode electrode is electrically connected to the dummy anode electrode in the recessed region by the undercut (UC) shape formed by the first to third contact holes CH1 to CH3. And the dummy anode electrode is electrically connected to the auxiliary electrode in the non-depressed region. The cathode electrode is electrically connected to the auxiliary electrode through the dummy anode electrode located in the recessed region and a peripheral region (see Anode and auxiliary electrode connection Pass) which is an outer region of the non-recessed region.

As shown in Fig. 6, the first contact hole CH1 is formed as follows. A data metal layer is formed on the lower insulating film 155 and patterned to form an auxiliary electrode 156d (AUX). An upper insulating film 157 is formed on the lower insulating film 155 to cover the auxiliary electrode 156d (AUX).

A photoresist layer PR is formed on the upper insulating film 157 and the periphery of the auxiliary electrode 156d (AUX) is etched by dry (DE) or wet (WE) A first contact hole CH1 having an undercut (UC) shape in a certain space is formed. An undercut UC is formed on the lower insulating film 157. The lower insulating film 157 is formed on the lower insulating film 157 and covers the auxiliary electrode 156d (AUX) Is formed so as to pass through.

When the periphery of the auxiliary electrode 156d (AUX) is etched, the first contact hole CH1 is formed with a recessed region located under the auxiliary electrode 156d (AUX) by the undercut (UC) (AUX). The UC-shaped portion of the first contact hole CH1 has a relatively gentle inclination and is not electrically disconnected (disconnected) even if a thin film is formed on the recessed region and its peripheral region.

Thereafter, when the photoresist layer PR is removed and an anode electrode, a dummy anode electrode, an organic light emitting layer, and a cathode electrode are formed on the upper insulating film 157, the cathode electrode is electrically connected to the dummy anode electrode and the auxiliary electrode, Resistance electrode structure connected to the lower electrode. The low-resistance electrode structure can improve the display quality as well as improve the problem of luminance unevenness due to the resistance problem (high resistance, resistance difference problem, etc.) of electrodes formed on the display panel.

Hereinafter, an example of the first embodiment of the present invention will be described using subpixels formed based on a coplanar thin film transistor. Hereinafter, a region located between the first contact hole and the light emitting portion will be described with reference to a cross-sectional view.

7 is a cross-sectional exemplary view of a subpixel according to the first embodiment of the present invention.

As shown in FIG. 7, a buffer layer 151 is formed on the first substrate 150a. The first substrate 150a may be formed of glass, polyimide (PI), polyethersulfone (PES), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate PEN), and acrylonitrile butadiene styrene (ABS).

The buffer layer 151 may block the harmful components flowing out from the first substrate 150a and improve the adhesive force with the film formed later, but may be omitted. The buffer layer 151 may be formed of a single layer or a multilayer of a silicon oxide film (SiOx) or a silicon nitride film (SiNx).

A semiconductor layer 152 is formed on the buffer layer 151. The semiconductor layer 152 has source and drain regions connected to the source and drain electrodes and a channel region located therebetween. The semiconductor layer 152 is implemented based on low temperature polysilicon (LTPS), amorphous silicon (a-Si), oxide, or organic. In one embodiment, the semiconductor layer 152 is made of an amorphous oxide semiconductor such as indium gallium zinc oxide (IGZO).

On the buffer layer 151, the first and the first insulating films 153a and 153b are formed apart from each other. The 1a and 1b insulating films 153a and 153b are formed in an island shape. The first insulating film 153a is located to cover the channel region of the semiconductor layer 152 and the first insulating film 153b is located corresponding to the region where the first electrode of the capacitor Cst is formed. The first and the first insulating films 153a and 153b may be formed of a single layer or multiple layers of a silicon oxide film (SiOx) or a silicon nitride film (SiNx).

First and first gate metal layers 154a and 154b are formed on the first and the first insulating films 153a and 153b. The first and the first gate metal layers 154a and 154b are formed in an island shape. The first 1a gate metal layer 154a becomes the gate electrode of the thin film transistor TFT and the first b gate metal layer 154b becomes the first electrode of the capacitor Cst. The first and the first b gate metal layers 154a and 154b may be formed of a material selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Or an alloy thereof, and may be composed of a single layer or multiple layers.

On the buffer layer 151, a second insulating layer 155 corresponding to a lower insulating layer is formed. The second insulating film 155 is formed to cover the first and the first gate metal layers 154a and 154b formed on the buffer layer 151. [ The second insulating film 155 has a contact hole exposing a part of the source and drain regions of the semiconductor layer 152. The second insulating film 155 may be formed of an organic material such as a silicon oxide film (SiOx), a silicon nitride film (SiNx), a polyimide, a benzocyclobutene series resin, an acrylate or a photoacrylate ≪ / RTI >

The first to the first d data metal layers 156a to 156d are formed on the second insulating film 155. [ The first data metal layer 156a is connected to the source region of the semiconductor layer 152. [ The first b data metal layer 156b is connected to the drain region of the semiconductor layer 152. [ The first c data metal layer 156c is formed in a region corresponding to the first b-gate metal layer 154b corresponding to the first electrode of the capacitor Cst. The first d data metal layer 156d is formed in the auxiliary electrode region spaced apart from the first c data metal layer 156c.

The 1a and 1b data metal layers 156a and 156b are the source and drain electrodes of the thin film transistor TFT. One of the 1a and 1b data metal layers 156a and 156b is connected (or becomes a data line) to the data line. The first c data metal layer 156c becomes the second electrode of the capacitor Cst. The first d data metal layer 156d becomes an auxiliary electrode. The 1a and 1b data metal layers 156a and 156b may be formed of a material selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Or an alloy thereof, and may be composed of a single layer or multiple layers. For example, the 1a and 1b data metal layers 156a and 156b may be selected from Cu / MoTi, MoTi / Cu / MoTi, Mo / Al, or Mo / AlNd.

On the second insulating film 155, a third insulating film 157 corresponding to the upper insulating film is formed. The third insulating film 157 is formed to cover the first and the first data metal layers 156a and 156b. The third insulating film 157 has a contact hole exposing a portion of the first data metal layer 156b and the first data metal layer 156d (AUX).

The first contact hole CH1 exposing a part of the first d data metal layer 156d (AUX) is formed in an undercut structure. The first contact hole CH1 is formed in the shape of an undercut so as to extend from the bottom of the first d data metal layer 156d (AUX), which is the auxiliary electrode, to the top of the auxiliary electrode 156d (AUX) (Right side of the first contact hole). The first contact hole CH1 of the undercut structure is formed over the third insulating film 157 and the second insulating film 155. [ The third insulating layer 157 may be a single layer or multiple layers of a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx).

On the third insulating film 157, first to lower first electrodes 158a to 158c are formed. The first lower electrode 158a is formed in a region corresponding to the first data metal layer 156b. The first lower electrode 158b is electrically separated from the first lower electrode 158a and is formed around the recessed region of the first contact hole CH1. The first c lower electrode 158c is formed in the periphery of the non-depressed region of the first contact hole CH1. The first to the first c lower electrodes 158b and 158c are defined as dummy anode electrodes.

The first lower electrode 158a is formed in a region corresponding to the first data metal layer 156b and thus is electrically connected to the first data metal layer 156b. Since the first lower electrode 158b is formed in the periphery of the depression region of the first contact hole CH1, a part of the first lower electrode 158b is formed in the peripheral region of the first contact hole CH1, Region. The first c lower electrode 158c is formed in the periphery of the non-depressed region of the first contact hole CH1 so that a part of the first lower electrode 158c is electrically connected to the first b lower electrode 158b in the peripheral region of the first contact hole CH1, A part of which is electrically connected to the first d data metal layer 156d (AUX) in the non-depressed region of the first contact hole CH1.

The first to c-th lower electrodes 158a to 158c are selected as an anode electrode or a cathode electrode of the organic light emitting diode OLED. The first to the first c lower electrodes 158a to 158c are selected from an opaque metal material, a transparent oxide material or an opaque metal material and a transparent oxide material. For example, the first to the first c lower electrodes 158a to 158c may be selected as an anode electrode, and this may also serve as a reflector.

On the other hand, the region corresponding to the first lower electrode 158a corresponds to the light emitting portion, and the region corresponding to the first b and the first c lower electrodes 158b and 158c corresponds to the non-light emitting portion (or the transmissive portion).

On the third insulating film 157, a bank layer 159 is formed. The bank layer 159 has a contact hole exposing a part of the first lower electrode 158a. The bank layer 159 has a recessed region and a non-recessed region by the first contact hole CH1. The bank layer 159 is formed of an organic material such as a silicon oxide film (SiOx), a silicon nitride film (SiNx), a polyimide, a benzocyclobutene series resin, an acrylate, or a photoacrylate Lt; / RTI >

On the bank layer 159, first and first organic light emitting layers 160a and 160b are formed. The first organic emission layer 160a is formed to cover the first lower electrode 158a and the first lower electrode 158b located in the recessed region of the first contact hole CH1. The first organic light emitting layer 160b is formed to cover the first c lower electrode 158c located in the non-concave region of the first contact hole CH1.

The 1a and 1b organic luminescent layers 160a and 160b are layers emitting red, green, blue, and white light. The first and the first organic luminescent layers 160a and 160b may include at least one of a hole injecting layer, a hole transporting layer, an electron transporting layer, and an electron injecting layer together with a light emitting layer. Further, the first and the first organic luminescent layers 160a and 160b may further include a functional layer (s) contributing to smooth and balanced movement of holes and electrons and efficient luminescence.

First and first b upper electrodes 161a and 161b are formed on the first and second organic light emitting layers 160a and 160b. The first upper electrode 161a is formed to cover a part of the first lower electrode 158c in addition to the first lower organic emission layer 160a and the first upper organic layer 161b covers the first organic emission layer 160b. .

The step coverage of the first and the first organic light emitting layers 160a and 160b is lower than that of the first to the first c lower electrodes 158a to 158c so that the first and second organic light emitting layers 160a and 160b are disconnected by the undercut shape of the first contact hole CH1. As a result, the first b lower electrode 158b located in the recessed region is exposed, which is electrically connected to the first upper electrode 161a.

The first upper electrode 161a is electrically connected to the first lower electrode 158b in the recessed region of the first contact hole CH1. The first lower electrode 158b is electrically connected to the first lower electrode 158c in the peripheral region of the first contact hole CH1. The first c lower electrode 158c is electrically connected to the first d data metal layer 156d (AUX) in the non-depressed region of the first contact hole CH1. As a result, the first upper electrode 161a is connected to the first lower electrode 158c and the first d data metal layer 156d (AUX) to have a low resistance electrode structure. It is preferable that the first c lower electrode 158c and the first d data metal layer 156d (AUX) are selected as materials with good step coverage so as to improve electrical connection characteristics.

The 1a and 1b upper electrodes 161a and 161b are selected as a cathode electrode or an anode electrode of the organic light emitting diode OLED. The 1a and 1b upper electrodes 161a and 161b are selected from a transparent oxide material, an opaque metal material or an opaque metal material and a transparent oxide material.

A total of seven masks are used in the process of fabricating the display panel made up of subpixels. Specifically, the semiconductor layer 152, the first and the first gate metal layers 154a and 154b, the second insulating film 155, the first to d data metal layers 156a to 156d, the third insulating film 157, Masks are used to form the first to e < th > c lower electrodes 158a to 158c and the bank layer 159, respectively.

≪ Embodiment 2 >

FIGS. 8 and 9 are plan views showing subpixels according to a second embodiment of the present invention, and FIG. 10 is a cross-sectional view of a subpixel according to a second embodiment of the present invention.

8, the display panel of the second embodiment of the present invention has a light emitting portion and a transmissive portion having white, red, green and blue subpixels (W, R, G, B) And has a light emitting portion and a transmissive portion having blue subpixels (W, R, G, B).

 The white, red, green and blue subpixels W, R, G and B located in the light emitting portion are separately connected to the data lines DLw, DLr, DLg and DLb and the gate lines GL, respectively . The white, red, green, and blue subpixels W, R, G, and B emit white, red, green, and blue light, respectively. The transmitting portion transmits natural light.

The display panel of the embodiment can transmit a picture (figure), a letter, a number, etc. located on the back surface when the image is not displayed. On the other hand, when an image is displayed on the display panel of the embodiment, the transmitted picture or the like is not displayed (disappears) and an image corresponding to the data signal supplied to the display panel is displayed.

The white, red, green, and blue subpixels (W, R, G, B) are defined as one pixel. The light emitting portion defined by one pixel may have a light emitting region that is equal to or smaller than the transmissive portion. The light emitting region may be divided into regions emitting white light, red light, green light, and blue light, but the present invention is not limited thereto.

The display panel of the second embodiment of the present invention includes an auxiliary electrode DLa positioned between the light emitting portion and the transmissive portion. The auxiliary electrode DLa is formed in a line shape in parallel with the data lines DLw, DLr, DLg, and DLb. The auxiliary electrode DLa is electrically connected to the adjacent electrodes exposed through the N (N is an integer of 3 or more) contact holes CH1 to CHn. The auxiliary electrodes DLa are spaced apart from one another along the transmissive portion. When the plurality of contact holes CH1 to CHn are formed in this manner, the contact resistance between the auxiliary electrode DLa and the electrodes can be reduced.

The display panel of the second embodiment of the present invention has a low resistance electrode structure in which the cathode electrode is electrically connected to the dummy anode electrode and the auxiliary electrode by the structure of the auxiliary electrode DLa and the contact holes CH1 to CHn.

Hereinafter, an example of a second embodiment of the present invention will be described using subpixels formed based on a coplanar thin film transistor. Hereinafter, a region located between the first contact hole and the light emitting portion will be described with reference to a cross-sectional view.

As shown in FIG. 10, a light blocking layer LS is formed on the first substrate 150a. The light blocking layer LS is located corresponding to the channel region of the semiconductor layer 152 formed below. The light blocking layer LS is selected as a material capable of efficiently blocking and reflecting external light.

A buffer layer 151 is formed. The first substrate 150a may be formed of glass, polyimide (PI), polyethersulfone (PES), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate PEN), and acrylonitrile butadiene styrene (ABS).

The buffer layer 151 may block the harmful components flowing out from the first substrate 150a and improve the adhesive force with the film formed later, but may be omitted. The buffer layer 151 may be formed of a single layer or a multilayer of a silicon oxide film (SiOx) or a silicon nitride film (SiNx).

A semiconductor layer 152 is formed on the buffer layer 151. The semiconductor layer 152 has source and drain regions connected to the source and drain electrodes and a channel region located therebetween. The semiconductor layer 152 is implemented based on low temperature polysilicon (LTPS), amorphous silicon (a-Si), oxide, or organic. In one embodiment, the semiconductor layer 152 is made of an amorphous oxide semiconductor such as indium gallium zinc oxide (IGZO).

On the buffer layer 151, the first and the first insulating films 153a and 153b are formed apart from each other. The 1a and 1b insulating films 153a and 153b are formed in an island shape. The first insulating film 153a is located to cover the channel region of the semiconductor layer 152 and the first insulating film 153b is located corresponding to the region where the first electrode of the capacitor Cst is formed. The first and the first insulating films 153a and 153b may be formed of a single layer or multiple layers of a silicon oxide film (SiOx) or a silicon nitride film (SiNx).

First and first gate metal layers 154a and 154b are formed on the first and the first insulating films 153a and 153b. The first and the first gate metal layers 154a and 154b are formed in an island shape. The first 1a gate metal layer 154a becomes the gate electrode of the thin film transistor TFT and the first b gate metal layer 154b becomes the first electrode of the capacitor Cst. The first and the first b gate metal layers 154a and 154b may be formed of a material selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Or an alloy thereof, and may be composed of a single layer or multiple layers.

On the buffer layer 151, a second insulating layer 155 corresponding to a lower insulating layer is formed. The second insulating film 155 is formed to cover the first and the first gate metal layers 154a and 154b formed on the buffer layer 151. [ The second insulating film 155 has a contact hole exposing a part of the source and drain regions of the semiconductor layer 152. The second insulating film 155 may be formed of an organic material such as a silicon oxide film (SiOx), a silicon nitride film (SiNx), a polyimide, a benzocyclobutene series resin, an acrylate or a photoacrylate ≪ / RTI >

The first to the first d data metal layers 156a to 156d are formed on the second insulating film 155. [ The first data metal layer 156a is connected to the source region of the semiconductor layer 152. [ The first b data metal layer 156b is connected to the drain region of the semiconductor layer 152. [ The first c data metal layer 156c is formed in a region corresponding to the first b-gate metal layer 154b corresponding to the first electrode of the capacitor Cst. The first d data metal layer 156d is formed in the auxiliary electrode region spaced apart from the first c data metal layer 156c.

The 1a and 1b data metal layers 156a and 156b are the source and drain electrodes of the thin film transistor TFT. One of the 1a and 1b data metal layers 156a and 156b is connected (or becomes a data line) to the data line. The first c data metal layer 156c becomes the second electrode of the capacitor Cst. The first d data metal layer 156d becomes an auxiliary electrode. The 1a and 1b data metal layers 156a and 156b may be formed of a material selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Or an alloy thereof, and may be composed of a single layer or multiple layers.

On the second insulating film 155, a third insulating film 157 corresponding to the upper insulating film is formed. The third insulating film 157 is formed to cover the first and the first data metal layers 156a and 156b. The third insulating film 157 has a contact hole exposing a portion of the first data metal layer 156b and the first data metal layer 156d (AUX).

The first contact hole CH1 exposing a part of the first d data metal layer 156d (AUX) is formed in an undercut structure. The first contact hole CH1 is formed by a shape of an undercut and located at a lower portion of the auxiliary electrode 156d (AUX) (the left side of the first contact hole) and an upper portion of the auxiliary electrode 156d (AUX) (Right side of the first contact hole). The first contact hole CH1 of the undercut structure is formed over the third insulating film 157 and the second insulating film 155. [ The third insulating layer 157 may be a single layer or multiple layers of a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx).

On the third insulating film 157, first to lower first electrodes 158a to 158c are formed. The first lower electrode 158a is formed in a region corresponding to the first data metal layer 156b. The first lower electrode 158b is electrically separated from the first lower electrode 158a and is formed around the recessed region of the first contact hole CH1. The first c lower electrode 158c is formed in the periphery of the non-depressed region of the first contact hole CH1. The first to the first c lower electrodes 158b and 158c are defined as dummy anode electrodes.

The first lower electrode 158a is formed in a region corresponding to the first data metal layer 156b and thus is electrically connected to the first data metal layer 156b. Since the first lower electrode 158b is formed in the periphery of the depression region of the first contact hole CH1, a part of the first lower electrode 158b is formed in the peripheral region of the first contact hole CH1, Region. The first c lower electrode 158c is formed in the periphery of the non-depressed region of the first contact hole CH1 so that a part of the first lower electrode 158c is electrically connected to the first b lower electrode 158b in the peripheral region of the first contact hole CH1, A part of which is electrically connected to the first d data metal layer 156d (AUX) in the non-depressed region of the first contact hole CH1.

The first to c-th lower electrodes 158a to 158c are selected as an anode electrode or a cathode electrode of the organic light emitting diode OLED. The first to the first c lower electrodes 158a to 158c are selected from an opaque metal material, a transparent oxide material or an opaque metal material and a transparent oxide material. On the other hand, the region corresponding to the first lower electrode 158a corresponds to the light emitting portion, and the region corresponding to the first b and the first c lower electrodes 158b and 158c corresponds to the non-light emitting portion (or the transmissive portion).

On the third insulating film 157, a bank layer 159 is formed. The bank layer 159 has a contact hole exposing a part of the first lower electrode 158a. The bank layer 159 has a recessed region and a non-recessed region by the first contact hole CH1. The bank layer 159 is formed of an organic material such as a silicon oxide film (SiOx), a silicon nitride film (SiNx), a polyimide, a benzocyclobutene series resin, an acrylate, or a photoacrylate Lt; / RTI >

On the bank layer 159, first and first organic light emitting layers 160a and 160b are formed. The first organic emission layer 160a is formed to cover the first lower electrode 158a and the first lower electrode 158b located in the recessed region of the first contact hole CH1. The first organic light emitting layer 160b is formed to cover the first c lower electrode 158c located in the non-concave region of the first contact hole CH1.

The 1a and 1b organic luminescent layers 160a and 160b are layers emitting red, green, blue, and white light. The first and the first organic luminescent layers 160a and 160b may include at least one of a hole injecting layer, a hole transporting layer, an electron transporting layer, and an electron injecting layer together with a light emitting layer. Further, the first and the first organic luminescent layers 160a and 160b may further include a functional layer (s) contributing to smooth and balanced movement of holes and electrons and efficient luminescence.

First and first b upper electrodes 161a and 161b are formed on the first and second organic light emitting layers 160a and 160b. The first upper electrode 161a is formed to cover a part of the first lower electrode 158c in addition to the first lower organic emission layer 160a and the first upper organic layer 161b covers the first organic emission layer 160b. .

The first upper electrode 161a is electrically connected to the first lower electrode 158b in the recessed region of the first contact hole CH1. The first lower electrode 158b is electrically connected to the first lower electrode 158c in the peripheral region of the first contact hole CH1. The first c lower electrode 158c is electrically connected to the first d data metal layer 156d (AUX) in the non-depressed region of the first contact hole CH1. As a result, the first upper electrode 161a is connected to the first lower electrode 158c and the first d data metal layer 156d (AUX) to have a low resistance electrode structure.

The 1a and 1b upper electrodes 161a and 161b are selected as a cathode electrode or an anode electrode of the organic light emitting diode OLED. The 1a and 1b upper electrodes 161a and 161b are selected from a transparent oxide material, an opaque metal material or an opaque metal material and a transparent oxide material. It is preferable that the first c lower electrode 158c and the first d data metal layer 156d (AUX) are selected as materials with good step coverage so as to improve electrical connection characteristics.

A total of eight masks are used in the process of fabricating the display panel made up of subpixels. Specifically, the light blocking layer LS, the semiconductor layer 152, the first and the first gate metal layers 154a and 154b, the second insulating layer 155, the first to the first d data metal layers 156a to 156d, A mask is used to form the insulating film 157, the first to the first c lower electrodes 158a to 158c, and the bank layer 159. [

As described above, according to the present invention, it is possible to improve the processability by reducing the number of masks (mask process is omitted) by removing the barrier ribs for using (connecting) the auxiliary electrode, and using a part of the data metal layer (or the source drain metal layer) (Low resistance electrode structure) can be lowered. In addition, since the present invention can realize a display panel having a low resistance electrode structure, there is an effect of improving not only luminance non-uniformity but also display quality.

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.

110: image processor 120: timing controller
130: Data driver 140: Gate driver
150: display panel DLa: auxiliary electrode
CH1 to CHn: first to Nth contact holes LS: light-blocking layer
152: semiconductor layer q 154a, 154bL first and first gate metal layers
155: second insulating film 156a to 156d: first to d data metal layers
157: third insulating films 158a to 158c: first to c < th >
159: bank layers 161a to 161b: first and second upper electrodes

Claims (10)

A first substrate;
A transmissive portion located on the first substrate and transmitting natural light;
A light emitting portion located on the first substrate and adjacent to the transmissive portion and emitting self-emitted light;
An auxiliary electrode positioned between the transmissive portion and the light emitting portion; And
(N is an integer equal to or greater than 1) contact holes located in a region corresponding to the auxiliary electrode and having an undercut shape,
A part of the auxiliary electrode
And a part of the lower electrode and a part of the upper electrode are electrically connected by the contact hole. The method according to claim 1,
The contact hole
A recessed region for providing a space in which a part of the lower electrode and a part of the upper electrode are electrically connected,
And a non-denting area for providing a space in which a part of the auxiliary electrode and a part of the lower electrode are electrically connected to each other. The method according to claim 1,
The undercut
A portion of the lower insulating film where the auxiliary electrode is located is recessed,
And a part of the upper insulating film which is located on the lower insulating film and covers the auxiliary electrode is formed to pass through. The method according to claim 1,
The auxiliary electrode
Wherein the light emitting unit is arranged in a line shape in parallel with a data line for transmitting a data signal to the light emitting unit. 5. The method of claim 4,
The auxiliary electrode
And the organic light emitting display device is located in the same layer as the data line. The method according to claim 1,
A part of the lower electrode
Wherein the organic light emitting diode is disposed on the same layer as the lower electrode included in the light emitting portion, and is electrically isolated. Defining a transmissive portion that transmits natural light on the first substrate and a light emitting portion that emits self-emitted light, and forming an auxiliary electrode on the lower insulating film located between the transmissive portion and the light emitting portion;
Forming an upper insulating film covering the auxiliary electrode on the lower insulating film;
Forming an Nth (N is an integer of 1 or more) contact holes having an undercut shape in a region corresponding to the auxiliary electrode;
Forming a lower electrode on the upper insulating film;
Forming a bank layer on the upper insulating film to cover a part of the lower electrode;
Forming an organic light emitting layer on the lower electrode; And
And forming an upper electrode on the organic light emitting layer,
Wherein a part of the auxiliary electrode is electrically connected to a part of the lower electrode and a part of the upper electrode by the contact hole. 8. The method of claim 7,
The contact hole
A recessed region for providing a space in which a part of the lower electrode and a part of the upper electrode are electrically connected,
And a non-denting area for providing a space in which a part of the auxiliary electrode and a part of the lower electrode are electrically connected to each other. 8. The method of claim 7,
The undercut
A part of the lower insulating film is recessed,
Wherein a portion of the upper insulating layer is formed to pass through the upper insulating layer. 8. The method of claim 7,
The auxiliary electrode
A plurality of data lines arranged in the same layer as the data lines for transmitting data signals to the light emitting units,
A part of the lower electrode
Wherein the light emitting unit is disposed on the same layer as the lower electrode included in the light emitting unit, and is electrically separated.

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