KR102656234B1 - Organic light emitting display and method of fabricating the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device that can improve efficiency and a manufacturing method thereof. The organic light emitting display device and manufacturing method according to the present invention include at least two sub-pixels where each pixel displays a different color. In addition, the inorganic insulating film disposed between the substrate and the light emitting device has an embossed surface in the white sub-pixel among at least two sub-pixels, and has a flat surface in the white sub-pixel and the sub-pixels of a different color, thereby improving efficiency.

Description

Organic light emitting display device and method of manufacturing the same {ORGANIC LIGHT EMITTING DISPLAY AND METHOD OF FABRICATING THE SAME}

The present invention relates to an organic light emitting display device and a manufacturing method thereof, and particularly to an organic light emitting display device capable of improving efficiency and a manufacturing method thereof.

Video display devices, which display various information on a screen, are a core technology of the information and communication era and are developing into thinner, lighter, more portable, and higher performance. Accordingly, organic light emitting display devices, which display images by controlling the amount of light emitted from the organic light emitting layer, are receiving attention as flat panel displays that can reduce the weight and volume, which are disadvantages of cathode ray tubes (CRTs). This organic light emitting display (OLED) is a self-luminous device and has low power consumption, high-speed response speed, high luminous efficiency, high luminance, and wide viewing angle.

An organic light emitting display device displays an image by arranging multiple pixels in a matrix form. Each pixel has at least two sub-pixels that implement different colors. Among at least two sub-pixels, the lifespan of the white sub-pixel is shorter than that of the other color sub-pixels, so the aperture ratio of the white sub-pixel is set to be larger than that of the other color sub-pixels in consideration of the lifespan of the white sub-pixel. In this case, as the aperture ratio of the white sub-pixel increases, the aperture ratio of other color sub-pixels decreases, resulting in a problem that the overall efficiency of the organic light emitting display device is lowered.

The present invention aims to solve the above problems, and provides an organic light emitting display device capable of improving efficiency.

In order to achieve the above object, the organic light emitting display device and method of manufacturing the same according to the present invention include at least two sub-pixels where each pixel displays different colors, and the inorganic insulating film disposed between the substrate and the light emitting element has at least Among the two sub-pixels, the white sub-pixel has an embossed surface, and the white sub-pixel and the other color sub-pixels have a flat surface, thereby improving efficiency.

At least one inorganic insulating film having an embossed surface is disposed between the anode electrode of the white sub-pixel of the organic light emitting display device according to the present invention and the substrate. This embossed surface scatters the white light generated in the light-emitting stack of white sub-pixels, improving the light extraction efficiency of white sub-pixels compared to other color sub-pixels. As the light extraction efficiency of the white sub-pixel improves, the aperture ratio of the white sub-pixel can be reduced, and as the aperture ratio of the white sub-pixel decreases, the aperture ratio of the red, green, and blue sub-pixels increases. Accordingly, the present invention improves the overall efficiency of the organic light emitting display device.

1 is a plan view showing an organic light emitting display device according to the present invention.
FIG. 2 is a cross-sectional view showing in detail the pad area and circuit area of each sub-pixel shown in FIG. 1.
FIG. 3 is a cross-sectional view showing in detail the emission areas of each of the red, green, blue, and white sub-pixels shown in FIG. 1.
FIG. 4 is a cross-sectional view showing another example of the light emitting area of each of the red, green, blue, and white sub-pixels shown in FIG. 1.
Figure 5 is a diagram for explaining the efficiency of an organic light emitting display device according to a comparative example and an embodiment of the present invention.
FIGS. 6A to 6I are cross-sectional views for explaining the manufacturing method of the organic light emitting display device shown in FIGS. 2 and 3.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the attached drawings.

FIG. 1 is a plan view showing an organic light emitting display device according to the present invention, and FIG. 2 is a cross-sectional view showing the organic light emitting display device shown in FIG. 1 .

The organic light emitting display device according to the present invention shown in FIGS. 1 and 2 includes an active area (AA) and a pad area (PA).

The pad area (PA) includes a scan line (SL), a data line (DL), a low-voltage (VSS) supply line (not shown), and a high-voltage (VDD) supply line (not shown), respectively, located in the active area (AA). A plurality of pads 170 that supply a driving signal are formed.

Each of the plurality of pads 170 includes a first pad electrode 172, a second pad electrode 174, and a pad cover electrode 176.

The first pad electrode 172 is formed of the same material as the gate electrodes 106 and 156 on the gate insulating pattern 112 having the same shape as the first pad electrode 172.

The second pad electrode 174 is electrically connected to the exposed first pad electrode 172 through the first pad contact hole 178a penetrating the interlayer insulating film 116. The second pad electrode 174 is formed of the same material as the source and drain electrodes 108, 158, 110, and 160 on the interlayer insulating film 116 that is the same layer as the source and drain electrodes 108, 158, 110, and 160.

The pad cover electrode 176 is electrically connected to the exposed second pad electrode 174 through the second pad contact hole 178b penetrating the protective film 118. This pad cover electrode 176 is exposed to the outside and comes into contact with the circuit transfer film on which the driving integrated circuit is mounted or the circuit transfer film connected to the driving integrated circuit. At this time, the pad cover electrode 176 is made of a metal with strong corrosion resistance and acid resistance on the protective film 118, and can prevent corrosion by external moisture, etc. even when exposed to the outside. For example, the pad cover electrode 176 is made of the same material as the anode electrode 132 and is formed on the same plane. That is, the pad cover electrode 176 is made of a transparent conductive film such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), which has strong corrosion resistance and acid resistance.

The active area (AA) is an area where a plurality of sub-pixels (SP) are arranged in a matrix form and an image is displayed. A plurality of sub-pixels (SP) are composed of a red sub-pixel (SPR), a green sub-pixel (SPG), a blue sub-pixel (SPB), and a white sub-pixel (SPW) to form a unit pixel. The arrangement order of red, green, blue, and white sub-pixels (SPR, SPG, SPB, SPW) varies greatly within each unit pixel and may vary depending on color or structure. Each of these red, green, blue, and white sub-pixels (SPR, SPG, SPB, SPW) includes a light-emitting element 130 disposed in the light-emitting area EA, and a pixel driving circuit that independently drives the light-emitting element 130. is provided.

The pixel driving circuit includes a switching thin film transistor (TS), a driving thin film transistor (TD), and a storage capacitor (Cst). Here, the switching thin film transistor (TS) and the driving thin film transistor (TD) are disposed in the circuit area (CA) included in the non-emission area excluding the emission area (EA) of each sub-pixel (SP), and the storage capacitor (Cst) is disposed in the emission area (EA) of each sub-pixel.

The switching thin film transistor (TS) is turned on when a scan pulse is supplied to the scan line (SL) and transmits the data signal supplied to the data line (DL) to the storage capacitor (Cst) and the second gate electrode ( 156). As shown in FIG. 2, this switching thin film transistor (TS) has a first gate electrode 106 connected to the scan line SL, a first source electrode 108 connected to the data line DL, and a second gate. It includes a first drain electrode 110 connected to the electrode 156, and a first active layer 104.

The driving thin film transistor (TD) controls the current supplied from the high voltage (VDD) supply line according to the driving voltage charged in the storage capacitor (Cst) and supplies a current proportional to the driving voltage to the light emitting device 130, thereby producing a light emitting device ( 130) emits light. This driving thin film transistor (TD) has a second gate electrode 156 connected to the first drain electrode 110, a second source electrode 158 connected to a high voltage (VDD) supply line, and a light emitting element 130. and a second drain electrode 160 and a second active layer 154.

Each of the first and second gate electrodes 106 and 156 of the switching thin film transistor (TS) and the driving thin film transistor (TD) has a gate insulating pattern 112 of the same pattern as the first and second gate electrodes 106 and 156, respectively. In between, it overlaps with the first and second actives 104 and 154, respectively.

Each of the first and second active layers 104 and 154 is formed to overlap each of the first and second gate electrodes 106 and 156 with the gate insulating pattern 112 therebetween, and is formed between the first source and first drain electrodes 108 and 110. And, a channel region is formed between the second source and second drain electrodes 158 and 160. Each of the first and second active layers 104 and 154 is formed of an oxide semiconductor containing at least one metal selected from Zn, Cd, Ga, In, Sn, Hf, and Zr, or is formed of polycrystalline silicon or amorphous silicon.

Each of the first and second source electrodes 108 and 158 is insulated from each of the first and second gate electrodes 106 and 156 with an interlayer insulating film 116 therebetween. Each of the first and second source electrodes 108 and 158 is connected to each of the first and second active layers 104 and 154 through first and second source contact holes 124S and 164S, respectively, penetrating the interlayer insulating film 116. do. Each of the first and second drain electrodes 110 and 160 is insulated from each of the first and second gate electrodes 106 and 156 with an interlayer insulating film 116 therebetween. Each of the first and second drain electrodes 110 and 160 is connected to each of the first and second active layers 104 and 154 through first and second drain contact holes 124D and 164D, respectively, penetrating the interlayer insulating film 116. do.

The first drain electrode 110 is electrically connected to the second gate electrode 156 of the driving thin film transistor (TD). The second drain electrode 110 is exposed through the pixel contact hole 120 that penetrates the protective film 118 disposed between the second drain electrode 110 and the anode electrode 132 and is connected to the anode electrode 132. do.

A light blocking layer 102 and a buffer layer 114 are sequentially stacked between the first and second active layers 104 and 154 and the substrate 101. The buffer layer 114 is formed in a single-layer or multi-layer structure of silicon oxide or silicon nitride on the substrate 101 made of glass or a plastic resin such as polyimide (PI). This buffer layer 114 serves to ensure good crystallization of the first and second active layers 104 and 154 by preventing diffusion of moisture or impurities generated in the substrate 101 or controlling the heat transfer rate during crystallization. do. The light blocking layer 102 is formed on the substrate 101 to overlap the active layer 104. This light blocking layer 102 absorbs or reflects light incident from the outside, and thus can block external light incident on the active layer 104. The light blocking layer 102 is formed of an opaque metal such as Mo, Ti, Al, Cu, Cr, Co, W, Ta, and Ni. Since the buffer layer 114 and the light blocking layer 102 are formed through the same mask process as each of the first and second active layers 104 and 154, the buffer layer 114 and the light blocking layer 102 are formed by the first and second active layers (104, 154). 104,154) and are formed with the same shape and same line width, respectively.

The storage capacitor Cst includes a storage lower electrode 142 and a storage upper electrode 144 that overlap with the interlayer insulating film 116 therebetween.

The storage lower electrode 142 is exposed through the storage contact hole 146 penetrating the interlayer insulating film 116 and is connected to the second drain electrode 160 of the driving thin film transistor (TD). This storage lower electrode 142 is made of the same material as the second gate electrode and is disposed on the gate insulating pattern 112.

The storage upper electrode 144 is connected to the first drain electrode 110 of the switching thin film transistor (TS). This storage upper electrode 144 is made of the same material as the first drain electrode 110 and is disposed on the interlayer insulating film 116.

The light emitting device 130 includes an anode electrode 132 connected to the second drain electrode 160 of the driving transistor (TD), at least one light emitting stack 134 formed on the anode electrode 132, and a light emitting stack. (134) and has a cathode electrode 136 formed thereon.

The anode electrode 132 is disposed on the planarization layer 128 and is exposed by the bank 138. This anode electrode 132 is electrically connected to the second drain electrode 160 of the driving transistor (TD) exposed through the pixel contact hole 120. The anode electrode 132 is made of a transparent conductive film such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) and transmits the light generated in the light-emitting stack 134 toward the substrate 101.

The light-emitting stack 134 is formed by stacking a hole-related layer, an organic light-emitting layer, and an electron-related layer on the anode electrode 132 in that order or in reverse order. In addition, the light emitting stack 134 may include first and second light emitting stacks facing each other with a charge generation layer (CGL) in between. In this case, the organic light-emitting layer of one of the first and second light-emitting stacks generates blue light, and the other organic light-emitting layer of the first and second light-emitting stacks generates yellow-green light, thereby generating the first and second light-emitting stacks. White light is generated through

The bank 138 exposes the anode electrode 132 to provide an emission area EA. This bank 138 may be formed of an opaque material (eg, black) to prevent light interference between adjacent sub-pixels SP. In this case, the bank 138 includes a light-blocking material made of at least one of color pigment, organic black, and carbon.

The cathode electrode 136 is formed on the top and side surfaces of the light emitting stack 134 and the bank 138 to face the anode electrode 132 with the light emitting stack 134 interposed therebetween. This cathode electrode 136 is formed as a single-layer structure made of an opaque conductive film with high reflection efficiency, or as a multi-layer structure including a transparent conductive film and an opaque conductive film with high reflection efficiency. The transparent conductive film is made of a material with a relatively high work function value such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), and the opaque conductive film is made of Al, Ag, Cu, Pb, Mo, It has a single-layer or multi-layer structure containing Ti, APC(Ag;Pb;Cu), or alloys thereof. For example, the cathode electrode 136 is formed in a structure in which a transparent conductive film, an opaque conductive film, and a transparent conductive film are sequentially stacked, or in a structure in which a transparent conductive film and an opaque conductive film are sequentially stacked. In this way, the cathode electrode 136 including an opaque conductive film with high reflection efficiency reflects the light generated in the light emitting stack 134 toward the substrate 101.

The color filter 148 is disposed on the protective film 118 to overlap the light emitting area EA provided by the bank 138. One of red (R), green (G), and blue (B) color filters 148 is disposed in each sub-pixel (SP). That is, the red color filter 148 is in the red (R) sub-pixel (SP), the green color filter 148 is in the green (G) sub-pixel (SP), and the blue color filter is in the blue (B) sub-pixel (SP). A filter 148 is placed. Accordingly, the white light generated by the light emitting device 130 passes through the color filter 148, and the color filter 148 implements light of the color corresponding to the color filter 148. Meanwhile, the color filter 148 may be formed to extend to cover at least one of the switching and driving thin film transistors (TS and TD).

Meanwhile, color light corresponding to each sub-pixel (SP) may be generated in each light emitting stack 134 without the color filter 148. That is, the light emission stack 134 of the red sub-pixel (SP) generates red light, the light emission stack 134 of the green sub-pixel (SP) generates green light, and the light emission stack 134 of the blue sub-pixel (SP) generates blue light. You may.

At least one inorganic insulating film 116 or 118 having an embossed surface is disposed between the anode electrode 132 of the white sub-pixel (SPW) and the substrate 101 of the organic light emitting display device according to the present invention. The inorganic insulating films 116 and 118 having an embossed surface have more stable film characteristics than the organic insulating film, and thus can prevent the embossed surface from being damaged by external shock, etc. compared to the organic insulating film having an embossed surface. In the present invention, as shown in FIG. 3, the interlayer insulating film 116 and the protective film 118 of the white sub-pixel (SPW) have an embossed surface, or as shown in FIG. 4, the white sub-pixel (SPW) has a protective film ( 118) has an embossed surface as an example.

The interlayer insulating film 116 and the protective film 118 of the organic light emitting display device according to the present invention shown in FIGS. 3 and 4 are flat in the emission area EA of the red, green, and blue sub-pixels (SPR, SPG, and SPB). It has a surface. The protective film 118, anode electrode 132, light emitting stack 134, and cathode electrode of the light emitting area (EA) of the red, green, and blue sub-pixels (SPR, SPG, and SPB) are disposed on the interlayer insulating film 116. (136) has a flat surface along the surface of the interlayer insulating film 116.

In the emission area EA of the white sub-pixel SPW shown in FIG. 3, the interlayer insulating film 116 has an embossed surface having a plurality of concave or convex microlenses toward the substrate 101. At this time, the interlayer insulating film 116 disposed in the white sub-pixel (SPW) is formed in a concave or convex hemisphere or semi-ellipsoid shape. And, the maximum thickness (d1) of the interlayer insulating film 116 with an embossed surface in the white sub-pixel (SPW) is the maximum thickness (d1) of the interlayer insulating film 116 with a flat surface in the red, green, and blue sub-pixels (SPR, SPG, and SPB). It is formed thicker than the maximum thickness (d2). Accordingly, the interlayer insulating film 116 in the white sub-pixel (SPW) can stably form an embossed surface having a desired depth or thickness. An organic layer is not disposed between the interlayer insulating layer 116 and the anode electrode of the light emitting area (EA) of the white sub-pixel (SPW). That is, the planarization layer 128 disposed on the interlayer insulating film 116 is disposed in the red, green, and blue sub-pixels (SPR, SPG, and SPB) excluding the white sub-pixel (SPW). Accordingly, the protective film 118, anode electrode 132, light emitting stack 134, and cathode electrode 136 disposed on the interlayer insulating film 116 have an embossed surface along the surface of the interlayer insulating film 116.

In addition, the protective film 118 in the emission area EA of the white sub-pixel SPW shown in FIG. 4 has an embossed surface having a plurality of concave or convex micro lenses toward the substrate 101. At this time, the maximum thickness of the protective film 118 disposed in the white sub-pixel (SPW) is thicker than the maximum thickness of the protective film 118 in the red, green, and blue sub-pixels (SPR, SPG, and SPB). Accordingly, the protective film 118 in the white sub-pixel (SPW) can stably form an embossed surface having a desired depth or thickness. The anode electrode 132, the light emitting stack 134, and the cathode electrode 136 disposed on the protective film 118 of the light emitting area (EA) of the white sub-pixel (SPW) are embossed along the surface of the protective film 118. will have

Accordingly, any one of the interlayer insulating film 116 and the protective film 118 of the white sub-pixel (SPW) and the embossed surface of the anode electrode 132, the light emitting stack 134, and the cathode electrode 136 are formed into the light emitting stack 134. ) to improve the light extraction efficiency of the white sub-pixel (SPW) compared to other color sub-pixels (SPR, SPG, SPB) by scattering the white light generated. As the light extraction efficiency of the white sub-pixel (SPW) improves, the aperture ratio of the white sub-pixel (SPW) can be reduced, and as the aperture ratio of the white sub-pixel (SPW) decreases, the red, green and blue sub-pixels (SPR, The opening ratio of SPG, SPB) increases. Accordingly, the organic light emitting display device according to the present invention has a higher efficiency compared to the comparative example having a flat interlayer insulating film in the red, green, blue, and white sub-pixels (SPR, SPG, SPB, and SPW), as shown in FIG. 5. This improves.

FIGS. 6A to 6I are cross-sectional views for explaining the manufacturing method of the organic light emitting display device shown in FIGS. 2 and 3.

Referring to FIG. 6A, a light blocking layer 102, a buffer layer 114, and first and second active layers 104 and 154 are formed simultaneously on the substrate 101.

Specifically, a first conductive layer, a buffer layer 114, and a semiconductor layer are sequentially deposited on the substrate 101. An opaque metal such as Mo, Ti, Cu, AlNd, Al or Cr or an alloy thereof is used as the first conductive layer, and an inorganic insulating material such as SiOx or SiNx is used as the buffer layer 114, and is used as a semiconductor layer. Amorphous silicon, polycrystalline silicon, or oxide semiconductor is used. Then, the first conductive layer, buffer layer, and semiconductor layer are patterned simultaneously through a photolithography process and an etching process, so that the light blocking layer 102, the buffer layer 114, and the first and second active layers 104 and 154 have the same shape and same shape. It is formed by line width. Referring to FIG. 6B, a gate insulating pattern 112 is formed on a substrate 101 on which a light blocking layer 102, a buffer layer 114, and first and second active layers 104 and 154 are formed. First and second gate electrodes 106 and 156, storage lower electrode 142, and first pad electrode 172 are formed thereon.

Specifically, a gate insulating film is formed on the substrate 101 on which the active layers 104 and 154 are formed, and a second conductive layer is formed thereon by a deposition method such as sputtering. As the gate insulating film, an inorganic insulating material such as SiOx or SiNx is used. As the second conductive layer, a metal material such as Mo, Ti, Cu, AlNd, Al or Cr, or an alloy thereof is used as a single layer, or a multilayer structure using these materials is used. Then, the first and second gate electrodes 106 and 156, the storage electrode 142, and the first pad electrode 172 are formed by simultaneously patterning the second conductive layer and the gate insulating film through a photolithography process and an etching process, and Gate insulating patterns 112 are formed in the same pattern at the bottom of each.

Referring to FIG. 6C, source and drain contact holes 124S, 124D, and 164S are formed on the substrate 101 on which the first and second gate electrodes 106 and 156, the storage electrode 142, and the first pad electrode 172 are formed. , 164D), an interlayer insulating film 116 having a storage contact hole 146 and a first pad contact hole 178a is formed.

Specifically, the interlayer insulating film 116 is formed on the substrate 101 on which the first and second gate electrodes 106 and 156 and the first pad electrode 172 are formed by a deposition method such as PECVD. Then, the interlayer insulating film 116 is first patterned through a photolithography process and an etching process using a halftone mask, thereby forming the source and drain contact holes (124S, 124D, 164S, 164D), storage contact holes 146, and the first In addition to the pad contact hole 178a being formed, an interlayer insulating film 116 having a thicker thickness is formed in the white sub-pixel (SPW) than in the red, green, and blue sub-pixels (SPR, SPG, and SPB). Here, each of the source and drain contact holes 124S, 124D, 164S, and 164D, the storage contact hole 146, and the first pad contact hole 178a is formed to penetrate the interlayer insulating film 116, thereby forming the first and second active The layers 104 and 154, the storage lower electrode 142, and the first pad electrode 172 are exposed. Then, the interlayer insulating film 116 of the white sub-pixel (SPW) is secondary patterned through a photolithography process and an etching process, thereby forming the white sub-pixel (SPW) except for the red, green, and blue sub-pixels (SPR, SPG, and SPB). The interlayer insulating film 116 has an embossed surface.

Meanwhile, in FIG. 6C, the formation process of the source and drain contact holes 124S, 124D, 164S, and 164D, the storage contact hole 146, and the first pad contact hole 178a, and the interlayer insulating film ( 116) Although the example of the surface embossing process being performed separately was explained, the two processes can also be formed simultaneously through one mask process.

Referring to FIG. 6D, the first and second interlayer insulating films 116 having source and drain contact holes 124S, 124D, 164S, and 164D, storage contact holes 146, and first pad contact holes 178a. Two source electrodes 108 and 158, first and second drain electrodes 110 and 160, a storage upper electrode 144, and a second pad electrode 174 are formed.

Specifically, a third conductive layer is formed on the interlayer insulating film 116 by a deposition method such as sputtering. As the third conductive layer, a metal material such as Mo, Ti, Cu, AlNd, Al, Cr, or an alloy thereof is used as a single layer, or a multilayer structure using these materials is used. Then, the first and second source electrodes 108 and 158, the first and second drain electrodes 110 and 160, and the storage upper electrode are formed on the interlayer insulating film 116 by patterning the third conductive layer through a photolithography process and an etching process. 144 and a second pad electrode 174 are formed.

Referring to FIG. 6E, on the substrate 101 on which the first and second source electrodes 108 and 158, the first and second drain electrodes 110 and 160, the storage upper electrode 144 and the second pad electrode 174 are formed. A protective film 118 having a pixel contact hole 120 and a second pad contact hole 178b is formed.

Specifically, SiOx and SiNx on the substrate 101 on which the first and second source electrodes 108 and 158, first and second drain electrodes 110 and 160, storage upper electrode 144, and second pad electrode 174 are formed. The protective film 118 is formed by depositing an inorganic insulating material such as the entire surface. Then, the protective film 118 is patterned through photolithography and etching processes to form the pixel contact hole 120 and the second pad contact hole 178b.

Referring to FIG. 6F, a color filter 148 is formed on the substrate 101 on which the protective film 118 is formed.

Specifically, a red color resin is applied on the substrate 101 on which the protective film 118 is formed, and then the red color resin is patterned through a photolithography process to form a red color filter 148 in the red sub-pixel (SPR). do. Then, green color resin is applied on the substrate 101 on which the red color filter 148 is formed, and then the green color resin is patterned through a photolithography process to form a green color filter 148 in the green sub-pixel (SPG). is formed. Then, a blue color resin is applied on the substrate 101 on which the green color filter 148 is formed, and then the blue color resin is patterned through a photolithography process to form a blue color filter 148 in the blue sub-pixel (SPB). is formed.

Referring to FIG. 6G, a planarization layer 128 is formed on the substrate 101 on which the color filter 148 is formed.

Specifically, an organic film such as photo acrylic resin is applied to the entire surface of the substrate 101 on which the color filter 148 is formed and then patterned through a photolithography process to form the planarization layer 128. The planarization layer 128 is formed to cover the color filters 148 of the red, green, and blue sub-pixels (SPR, SPG, and SPB) and to expose the protective film 118 on the embossed surface of the white sub-pixel (SPW). is formed

Referring to FIG. 6H, an anode electrode 132 and a pad cover electrode 176 are formed on the substrate 101 on which the planarization layer 126 is formed.

Specifically, a fourth conductive layer is deposited on the entire surface of the substrate 101 on which the planarization layer 128 is formed. A transparent conductive film is used as the fourth conductive layer. Then, the fourth conductive layer is patterned through a photolithography process and an etching process to form the anode electrode 132 and the pad cover electrode 176. At this time, the anode electrodes 132 of the red, green, and blue sub-pixels (SPR, SPG, SPB) formed on the flattening layer 128 have a flat surface and are formed on the protective film 118 of the embossed surface. The anode electrode 132 of the white sub-pixel (SPW) to be formed has an embossed surface.

Referring to Figure 6i, the bank 138 is formed on the substrate 101 on which the anode electrode 132 and the pad cover electrode 176 are formed, and then the organic light emitting stack 134 and the cathode electrode 136 are sequentially formed. do.

Specifically, a photosensitive organic layer is applied to the entire surface of the substrate 101 on which the anode electrode 132 and the pad cover electrode 176 are formed, and then the photosensitive organic layer is patterned through a photolithography process to form the bank 138. A white emitting stack 134 and a cathode electrode 136 are sequentially formed on the substrate 101 on which the banks 138 are formed through a deposition process using a shadow mask.

Meanwhile, in the present invention, each pixel driving circuit is described as having a switching transistor (TS) and a driving transistor (TD), but in addition, it may further include a sensing transistor that detects the threshold voltage of the driving transistor (TD). .

In addition, in the present invention, each pixel has been described as an example of having a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel, but in addition, the present invention provides a unit having at least two sub-pixels including a white sub-pixel. Applicable to all pixels.

The above description is merely an exemplary description of the present invention, and various modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention do not limit the present invention. The scope of the present invention should be interpreted in accordance with the scope of the patent claims below, and all technologies within the equivalent scope thereof should be interpreted as being included in the scope of the present invention.

116: interlayer insulating film 118: protective film
130: light emitting element 132: anode electrode
134: light emitting layer 136: cathode electrode

Claims (15)

In the organic light emitting display device, each pixel has at least two sub-pixels that display different colors,
With a substrate;
a light emitting element disposed on the substrate to correspond to each of the at least two sub-pixels;
an inorganic insulating film disposed between the substrate and the light emitting element, having an embossed surface in a white sub-pixel among the at least two sub-pixels and a flat surface in a sub-pixel of a color different from the white sub-pixel;
a color filter disposed on the other color sub-pixels excluding the white sub-pixel;
An organic light emitting display device comprising a planarization layer disposed on the other color sub-pixels excluding the white sub-pixel. According to claim 1,
It is further provided with a pixel circuit that drives the light emitting element,
The pixel circuit is
a driving thin film transistor connected to the light emitting element;
It has a switching thin film transistor connected to the driving thin film transistor,
The light emitting device is
an anode electrode connected to the driving thin film transistor;
a cathode electrode facing the anode electrode;
An organic light emitting display device comprising at least one light emitting stack disposed between the anode electrode and the cathode electrode. According to claim 2,
an interlayer insulating film disposed between each of the source and drain electrodes of the driving thin film transistor and the gate electrode of the driving thin film transistor;
Further comprising a protective film disposed between the drain electrode of the driving thin film transistor and the anode electrode,
The organic light emitting display device wherein the inorganic insulating film is the interlayer insulating film and the protective film. According to claim 2,
Further comprising a protective film disposed between the drain electrode of the driving thin film transistor and the anode electrode,
The organic light emitting display device wherein the inorganic insulating film is the protective film. According to any one of claims 2 to 4,
The organic light emitting display device wherein the at least two sub-pixels displaying different colors include the white sub-pixel, the red sub-pixel, the green sub-pixel, and the blue sub-pixel. According to claim 5,
The anode electrode, light emitting stack, and cathode electrode of the white sub-pixel disposed on the inorganic insulating film have an embossed surface,
An organic light emitting display device wherein the anode electrode, light emitting stack, and cathode electrode of each of the red, green, and blue sub-pixels disposed on the inorganic insulating film have flat surfaces. According to claim 5,
The organic light emitting display device wherein the maximum thickness of the inorganic insulating film of the white sub-pixel is thicker than the maximum thickness of the inorganic insulating film of the red, green and blue sub-pixels. According to claim 5,
The color filter is,
a red color filter disposed in the red sub-pixel;
a green color filter disposed in the green sub-pixel;
A blue color filter disposed in the blue sub-pixel,
The planarization layer is disposed in the red, green, and blue sub-pixels. According to claim 1,
The embossed surface has a plurality of micro lenses that are concave or convex toward the substrate. According to claim 2,
The anode electrode includes a transparent conductive material,
An organic light emitting display device wherein the cathode electrode includes a reflective conductive material. According to claim 2,
a light blocking layer disposed on the substrate and overlapping an active layer of each of the driving and switching thin film transistors;
Further comprising a buffer layer disposed between the light blocking layer and the active layer,
Each of the light blocking layer and the buffer layer has the same line width and the same shape as each of the active layers of each of the driving and switching thin film transistors. A method of manufacturing an organic light emitting display device in which each pixel has at least two sub-pixels that display different colors, comprising:
forming an inorganic insulating film on a substrate having an embossed surface in a white sub-pixel among the at least two sub-pixels and a flat surface in a sub-pixel of a color different from the white sub-pixel;
forming a color filter disposed in the other color sub-pixels excluding the white sub-pixel;
forming a planarization layer disposed on the other color sub-pixels excluding the white sub-pixel;
A method of manufacturing an organic light emitting display device comprising forming a light emitting element disposed on the inorganic insulating film to correspond to each of the at least two sub-pixels. According to claim 12,
It further includes the step of sequentially forming an interlayer insulating film and a protective film between the substrate and the anode electrode of the light emitting device,
The method of manufacturing an organic light emitting display device, wherein the inorganic insulating layer is at least one of the interlayer insulating layer and the protective layer. According to claim 3 or 4,
The substrate is
a light emitting area where the light emitting element is disposed;
It is included in a non-emission area excluding the light-emitting area, and includes a circuit area where the pixel circuit is arranged,
The inorganic insulating film is disposed between the color filter and the substrate in the light emitting area. According to claim 14,
An anode electrode provided in a light emitting area corresponding to the other color sub-pixels excluding the white sub-pixel is in contact with the planarization layer,
An organic light emitting display device wherein an anode electrode provided in a light emitting area corresponding to the white sub-pixel is in contact with the inorganic insulating layer.

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