KR20110011078A - Organic light emitting display device and method of manufacturing thereof - Google Patents

Abstract

PURPOSE: An organic electroluminescent display device and a method thereof are provided to improve the color reproduction rate and luminous efficiency of a panel by a micro cavity effect. CONSTITUTION: A transistor is formed on a first substrate. Sub pixels are formed on a second substrate. A spacer(125) is projected so that upper electrodes are electrically connected to the source electrode or the drain electrode of the transistors. A lower electrode(121) comprises a semitransparent metal which is located between two transparent metals. A bank layer has opening regions which exposes a part of the lower electrode according to the region of the sub pixels. The upper electrodes(128) are formed on an organic light emitting layers according to the region of the sub pixels.

Description

Organic Light Emitting Display Device and Method of Manufacturing

Embodiments of the present invention relate to an organic light emitting display device and a method of manufacturing the same.

The organic light emitting display device used in the organic light emitting display device is a self-light emitting device having a light emitting layer formed between two electrodes positioned on a substrate. The organic light emitting display includes a top emission type, a bottom emission type, or a dual emission type according to a direction in which light is emitted. According to the driving method, it is divided into a passive matrix type and an active matrix type.

In the organic light emitting display device, when a scan signal, a data signal, and a power are supplied to a plurality of subpixels arranged in a matrix form, the selected subpixels emit light to display an image.

Some conventional organic light emitting display devices form transistors and organic light emitting diodes on a first substrate and a second substrate, and seal the first substrate and the second substrate with an adhesive member. Such a structure uses spacers for electrical connection between a transistor formed on the first substrate and an organic light emitting diode positioned on the second substrate.

On the other hand, the organic light emitting display device formed by separating the device into the first substrate and the second substrate as described above is formed in a top emission method for emitting light through the anode formed on the second substrate. However, this has a problem in that it is difficult to improve color reproduction and luminous efficiency than the normal type top emission method in which the transistor and the organic light emitting diode are positioned on the first substrate due to their structural characteristics.

The present invention for solving the above problems of the background art is to provide an organic light emitting display device and a method of manufacturing the same that can increase the color reproduction rate and luminous efficiency of the panel.

The present invention as a means for solving the above problems, the first substrate formed transistors; A second substrate on which sub pixels are formed; And spacers formed in the subpixels and protruding so that the upper electrodes included in the subpixels are electrically connected to the source electrode or the drain electrode of the transistors, wherein the subpixels are formed on the front surface of the display area defined in the second substrate. A bank layer having a lower electrode including a translucent metal formed between two transparent metals, an opening region exposing a part of the lower electrode for each region of the subpixels, and opening regions exposing the subpixels, respectively. Provided is an organic light emitting display device including organic light emitting layers formed on the substrate and upper electrodes formed on the organic light emitting layers for respective subpixel regions.

The lower electrode may be made of a transparent metal selected from any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO), and a translucent metal including silver (Ag) or a silver alloy.

The lower electrode may be formed to have a thickness different from at least one of the red subpixels, the green subpixels, and the blue subpixels.

The subpixels include partitions formed on the bank layer, and the upper electrodes may be formed by being divided into regions of the subpixels by the partitions.

The sub pixels may include bus electrodes positioned between the bank layer and the lower electrode.

The area of the opening regions may be different from at least one of the red subpixels, the green subpixels, and the blue subpixels.

At least one spacer may be formed on each of the subpixels on the bank layer.

In another aspect, the present invention provides a method for forming a semiconductor device, the method comprising: forming transistors on a first substrate; Defining a display area on the second substrate and forming a lower electrode including a translucent metal positioned between two transparent metals on the entire surface of the defined display area; Forming a bank layer having opening regions such that a part of the lower electrode is exposed for each sub pixel region; Forming protruding spacers on at least one region of each subpixel on the bank layer; Forming partitions on the bank layer such that the subpixels are divided into regions; Forming organic emission layers on the opening regions exposing the subpixels in each region; Forming upper electrodes to be divided into regions of subpixels and to cover spacers by using barrier ribs; And sealingly sealing the first substrate and the second substrate such that the upper electrodes formed to cover the spacers are electrically connected to the source electrode or the drain electrode of the transistors.

The lower electrode may be made of a transparent metal selected from any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO), and a translucent metal including silver (Ag) or a silver alloy.

The lower electrode may be formed to have a thickness different from at least one of the red subpixels, the green subpixels, and the blue subpixels.

The present invention has an effect of providing an organic light emitting display device and a method of manufacturing the same, which can increase the color reproducibility and luminous efficiency of the panel by the microcavity effect of the structure of the lower electrode formed in the form of the front electrode.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

FIG. 1 is a schematic block diagram of an organic light emitting display device according to an embodiment of the present invention, and FIG. 2 is an exemplary circuit diagram of a subpixel shown in FIG.

1 and 2, an organic light emitting display device according to an embodiment of the present invention includes a panel PNL including sub pixels SP arranged in a matrix form, and scan wirings of the sub pixels SP. A scan driver SDRV for supplying a scan signal to SL1..SLm and a data driver DVR for supplying a data signal to the data wiring DL1..DLn of the subpixel SP.

The subpixel SP has a 2T (Capacitor) structure including a switching transistor S1, a driving transistor T1, a capacitor Cst, and an organic light emitting diode D, or further includes a transistor and a capacitor. It may be configured as a structure.

In the case of the 2T1C structure, elements included in the subpixel SP may be connected as follows. The switching transistor S1 has a gate connected to the scan line SL1 supplied with the scan signal, one end connected to the data line DL1 supplied with the data signal, and the other end connected to the first node A. The driving transistor T1 has a gate connected to the first node A, one end connected to the second node B, and a third node C connected to the second power supply line VSS supplied with a low-voltage power supply. The other end is connected. One end of the capacitor Cst is connected to the first node A, and the other end thereof is connected to the third node C. In the organic light emitting diode D, an anode is connected to the first power line VDD to which power of a high potential is supplied, and a cathode is connected to one end of the second node B and the driving transistor T1.

In the above description, the transistors S1 and T1 included in the sub-pixel SP have been configured as N-types as an example. However, embodiments of the present invention are not limited thereto. The high potential power supplied through the first power line VDD may be higher than the low potential power supplied through the second power line VSS, and the first power line VDD and the second power line ( The level of power supplied through VSS) can be switched according to the driving method.

The subpixel SP described above may operate as follows. When the scan signal is supplied through the scan line SL1, the switching transistor S1 is turned on. Next, when the data signal supplied through the data line DL1 is supplied to the first node A through the switching transistor S1 turned on, the data signal is stored as a data voltage in the capacitor Cst. Next, when the scan signal is blocked and the switching transistor S1 is turned off, the driving transistor T1 is driven in response to the data voltage stored in the capacitor Cst. Next, when the high potential power supplied through the first power line VDD flows through the second power line VSS, the organic light emitting diode D emits light. However, this is only an example of the driving method, the embodiment of the present invention is not limited thereto.

Hereinafter, the structure of the organic light emitting display device described above will be described.

3 is a plan view of an organic light emitting display device according to an embodiment of the present invention, FIG. 4 is a plan view of a subpixel according to an embodiment of the present invention, and FIG. 5 is a plan view of an I-II region shown in FIG. 6 is a hierarchical structure diagram of an organic light emitting diode, and FIGS. 7 and 8 are enlarged views of the ZM region shown in FIG. 5.

Referring to FIG. 3, an organic light emitting display device according to an embodiment of the present invention includes a second substrate in which a display area AA is defined by a first substrate 110 on which transistors are formed and sub pixels arranged in a matrix form. And a substrate 140. The first substrate 110 and the second substrate 140 are bonded and sealed by an adhesive member formed in the non-display area NA positioned outside the display area AA. In the illustrated organic light emitting display device, the pad unit 170 is provided on the outer side of the first substrate 110 to receive various signals or power from the outside, and the first display device is driven by the driving device 160 formed of one chip. For example, the devices formed on the substrate 110 and the second substrate 140 are driven. Here, the driving device 160 includes a data driver, a scan driver, and the like described with reference to FIG. 1.

Referring to FIG. 4, subpixels SP1.. SP3 positioned corresponding to the two scan lines SL1 and SL2 are illustrated. The subpixels SP1.. SP3 may be defined as blue subpixels SP1, green subpixels SP2, and red subpixels SP3, respectively. The area of the opening areas OPN of each of the subpixels SP1..SP3 is formed under a condition such as SP1> SP2 ≥ SP3, but the present invention is not limited thereto. SP2 = SP3 or SP1 ≠ SP2 ≠ SP3 and the like. In other words, the areas of the opening areas OPN of the subpixels SP1.. SP3 are red subpixels SP3, green subpixels SP2, and blue subpixels SP1 depending on the light emitting material or the light emission characteristic. At least one of

Hereinafter, an organic light emitting display device according to an embodiment of the present invention will be described in more detail with reference to FIGS. 3 to 8.

3 to 8, gate electrodes 102 are formed on the first substrate 110. The gate electrodes 102 are gate electrode metals of the transistors formed on the first substrate 110. The gate electrodes 102 are formed of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be made of any one or an alloy thereof. In addition, the gate electrodes 102 include molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be a multi-layer consisting of any one or an alloy thereof selected from the group consisting of. In addition, the gate electrodes 102 may be a double layer of molybdenum / aluminum-neodymium or molybdenum / aluminum.

The first insulating layer 103 is positioned on the gate electrodes 102. The first insulating layer 103 may be, but is not limited to, a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof.

Active layers 104 are positioned on the first insulating layer 103. The active layers 104 may include amorphous silicon or polycrystalline silicon crystallized therefrom. Although not shown here, the active layers 104 may include a channel region, a source region, and a drain region, respectively, and the source region and the drain region may be doped with P-type or N-type impurities. In addition, the active layers 104 may include ohmic contact layers to lower contact resistance.

Source electrodes 105 and drain electrodes 106 are positioned on the active layers 104. The source electrodes 105 and the drain electrodes 106 may be formed of a single layer or multiple layers. Molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) when the source electrodes 105 and the drain electrodes 106 are a single layer ) And copper (Cu) may be made of any one or an alloy thereof. Alternatively, when the source electrodes 105 and the drain electrodes 106 are multiple layers, they may be formed of a double layer of molybdenum / aluminum-neodymium, a triple layer of molybdenum / aluminum / molybdenum or molybdenum / aluminum-neodymium / molybdenum. .

The second insulating layer 107 is positioned on the source electrodes 105 and the drain electrodes 106. The second insulating layer 107 may be a silicon oxide film (SiOx), a silicon nitride film (SiNx), or a multilayer thereof, but is not limited thereto. The second insulating film 107 may be a passivation film or a planarization film.

Contact electrodes 109 connected to the source electrodes 105 or the drain electrodes 106 of the transistors may be disposed on the second insulating layer 107.

The structure of the transistors formed by forming the transistors on the first substrate 110 has been described above. In the embodiment, the transistors are of the form of a batam gate electrode, and the driving transistor, which is one of the transistors, is described. However, the transistors disposed on the first substrate 110 are not limited thereto and may be formed in a top gate type.

The lower electrode 121 selected as the anode is positioned on the second substrate 140. The lower electrode 121 receives power from the first power line VDD. The lower electrode 121 selected as the anode includes a translucent metal 121b formed on the front surface of the display area AA defined on the second substrate 140 and positioned between two transparent metals 121a and 121c. Alternatively, the buffer layer 120 may be further disposed between the second substrate 140 and the lower electrode 121. (See FIG. 8) The buffer layer 120 may be formed of a silicon oxide film (SiOx) or silicon. It may be a nitride film (SiNx) or a multilayer thereof, in the case of the embodiment, the buffer layer 120 can be formed on the entire surface of the second substrate 140, as well as the front emission method having a different degree of freedom of thickness control to improve the optical characteristics Higher than Here, the thickness of the translucent metal 121b is formed thinner than the thickness of one of the transparent metals 121a and 121c. When the structure of the lower electrode 121 is formed in this way, a micro-cavity effect occurs in the direction of the lower electrode 121, which is a light emitting direction of the organic light emitting layers 127. Here, any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO) may be selected as the transparent metals 121a and 121c, and silver may be selected as the semi-transparent metal 121b. Ag) or silver alloys may be selected. When forming the lower electrode 121, the display area AA is defined on the second substrate 140, and the first transparent metal 121a, the semi-transparent metal 121b, and the first transparent metal are formed on the entire surface of the defined display area AA. It can be formed by depositing in order of two transparent metals 121c. In an embodiment, a lower portion formed in at least one of the red subpixels SP3, the green subpixels SP2, and the blue subpixels SP1 in order to increase the microcavity effect using the structure of the lower electrode 121. The thickness of the electrode 121 may be varied.

Bus electrodes 122 are positioned on the lower electrode 121. As illustrated in FIG. 4, the bus electrodes 122 may be formed to occupy a large area in the areas of the subpixels SP1.. SP3. The bus electrodes 122 may be formed of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). Can be. The bus electrodes 122 serve as an auxiliary electrode of the lower electrode 121.

Bank layers 123a and 123b are disposed on the lower electrode 121 and the bus electrodes 122. The bank layers 123a and 123b may have opening regions OPN exposing a portion of the lower electrode 121 for each region of the subpixels SP1... SP3. The bank layers 123a and 123b may include organic materials such as benzocyclobutene (BCB) resin, acrylic resin, or polyimide resin.

Partition walls 124 may be disposed on the bank layers 123a and 123b to divide the subpixels SP1... SP3 into regions. The partitions 124 may then be formed to provide process convenience when forming the organic light emitting layer and the upper electrode, which may be formed in an inverted taper shape with a narrower base area than the upper area.

Spacers 125 protruding to be adjacent to the partition walls 124 are disposed on the bank layer 123b. At least one spacer 125 may be formed for each region of the subpixels SP1... SP3. The spacers 125 may be formed to have a smaller top area than the bottom area. The spacers 125 may be formed of an organic material, an inorganic material, or an organic / inorganic composite, but are not limited thereto.

The organic emission layers 127 are positioned on the lower electrode 121 exposed through the opening regions OPN of the bank layers 123a and 123b. The organic light emitting layers 127 are formed by partitions 124 for each region of the subpixels SP1.. SP3. Meanwhile, referring to FIG. 6, the organic light emitting layers 127 may include a hole injection layer 127a, a hole transport layer 127b, a light emitting layer 127c, an electron transport layer 127d, and an electron injection layer 127e, respectively. have.

The hole injection layer 127a may play a role of smoothly injecting holes. CuPc (cupper phthalocyanine), PEDOT (poly (3,4) -ethylenedioxythiophene), PANI (polyaniline), and NPD (N, N-dinaphthyl) -N, N'-diphenyl benzidine) may be composed of any one or more selected from the group consisting of, but is not limited thereto.

The hole transport layer 127b serves to facilitate the transport of holes, NPD (N, N-dinaphthyl-N, N'-diphenyl benzidine), TPD (N, N'-bis- (3-methylphenyl) -N , N'-bis- (phenyl) -benzidine), s-TAD and MTDATA (4,4 ', 4 "-Tris (N-3-methylphenyl-N-phenyl-amino) -triphenylamine) It may be made of one or more, but is not limited thereto.

The emission layer 127c may include materials emitting red, green, blue, and white light and may be formed using phosphorescent or fluorescent materials. When the light emitting layer 127c emits red, it includes a host material including CBP (carbazole biphenyl) or mCP (1,3-bis (carbazol-9-yl), and PIQIr (acac) (bis (1-phenylisoquinoline) acetylacetonate iridium), PQIr (acac) (bis (1-phenylquinoline) acetylacetonate iridium), PQIr (tris (1-phenylquinoline) iridium) and PtOEP (octaethylporphyrin platinum) It may be made of a phosphor material, otherwise it may be made of a fluorescent material including PBD: Eu (DBM) 3 (Phen) or Perylene, but is not limited thereto.When the light emitting layer 127c emits green, CBP or mCP It includes a host material comprising a, and may be made of a phosphor containing a dopant material including Ir (ppy) 3 (fac tris (2-phenylpyridine) iridium), alternatively, Alq3 (tris (8-hydroxyquinolino) aluminum) fluorescent material When the light emitting layer 127c emits blue, the light emitting layer 127c may include a host material including CBP or mCP and may be formed of a phosphor including a dopant material including (4,6-F2ppy) 2Irpic. Alternatively, it may be composed of a fluorescent material including any one selected from the group consisting of spiro-DPVBi, spiro-6P, distilbenzene (DSB), distriarylene (DSA), PFO-based polymer and PPV-based polymer, It is not limited to this.

The electron transport layer 127d serves to facilitate electron transport, and may be made of any one or more selected from the group consisting of Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq, and SAlq. However, the present invention is not limited thereto.

The electron injection layer 127e serves to facilitate the injection of electrons, and may be Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq or SAlq, but is not limited thereto.

Herein, the present invention is not limited to FIG. 6, and at least one of the hole injection layer 127a, the hole transport layer 127b, the electron transport layer 127d, and the electron injection layer 127e may be omitted.

Upper electrodes 128 selected as cathodes are disposed on the organic emission layers 127. The upper electrodes 128 selected as the cathode may use an opaque and highly reflective material such as aluminum (Al). The upper electrodes 128 are formed to be divided by the partitions 124 according to the regions of the subpixels SP1 .. SP3 and cover the top of the organic emission layers 127 and the surface of the spacers 125. do.

According to the above structure, when the first substrate 110 and the second substrate 140 are vacuum-bonded, a contact connected to the source electrodes 105 or the drain electrodes 106 of the transistors formed on the first substrate 110. The electrodes 109 and the upper electrodes 128 of the subpixels SP1.. SP3 formed on the second substrate 140 are electrically connected to each other.

Meanwhile, in the organic light emitting display device according to the embodiment, two transparent metals 121a having a semi-transparent metal 121b having the structure of the lower electrode 121 in the light emitting direction of the organic light emitting layers 127 in order to obtain a micro cavity effect. , 121c). In the case of the metals 121a, 121b and 121c constituting the lower electrode 121, the etching of the semi-transparent metal 121b proceeds faster than the transparent metals 121a and 121c when etching is performed. Difficult to catch is common. Therefore, in the embodiment, when the lower electrode 121 is formed, a structure in which the semi-transparent metal 121b is included between the two transparent metals 121a and 121c in order to obtain a micro cavity effect is used. The lower electrode 121 is formed in a tube over the entire surface of the display area AA defined on the second substrate 140 so as not to perform pixelation for each region of the SP3.

The present invention has an effect of providing an organic light emitting display device and a method of manufacturing the same which can increase the color reproducibility and luminous efficiency of the panel by the microcavity effect of the structure of the lower electrode formed in the form of the front electrode.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

1 is a schematic block diagram of an organic light emitting display device according to an embodiment of the present invention;

FIG. 2 is an exemplary circuit diagram of a subpixel illustrated in FIG. 1. FIG.

3 is a plan view of an organic light emitting display device according to an embodiment of the present invention;

4 is a plan view of a subpixel according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view of the region I-II shown in FIG. 4. FIG.

6 is a hierarchical structure diagram of an organic light emitting diode.

7 and 8 are enlarged views of the ZM region shown in FIG.

<Explanation of symbols on main parts of the drawings>

110: first substrate 102: gate electrodes

105: source electrodes 106: drain electrodes

121: lower electrode 122: bus electrodes

124: partitions 127: organic light emitting layers

128: upper electrodes 140: second substrate

Claims (10)

A first substrate on which transistors are formed; A second substrate on which sub pixels are formed; And And spacers formed in the subpixels and protruding so that upper electrodes included in the subpixels are electrically connected to a source electrode or a drain electrode of the transistors, The subpixels, A lower electrode formed on the front surface of the display area defined in the second substrate and including a translucent metal positioned between two transparent metals; A bank layer having opening regions exposing a part of the lower electrode for each of the sub-pixels; Organic light emitting layers formed on the openings exposing the subpixels in each region; And an upper electrode formed on the organic light emitting layers for each of the subpixels. The method of claim 1, The lower electrode, A transparent metal selected from any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO), An organic light emitting display device comprising a translucent metal including silver (Ag) or a silver alloy. The method of claim 1, The lower electrode, And at least one of the red subpixels, the green subpixels, and the blue subpixels has a different thickness. The method of claim 1, The subpixels, Partition walls formed on the bank layer; And the upper electrodes are divided by regions of the subpixels by the partitions. The method of claim 1, The subpixels, And an bus electrode disposed between the bank layer and the lower electrode. The method of claim 1, The area of the opening areas is And at least one of the red subpixels, the green subpixels, and the blue subpixels are different. The method of claim 1, The spacers, And at least one formed on each of the sub-pixels on the bank layer. Forming transistors on the first substrate; Defining a display area on a second substrate and forming a lower electrode including a translucent metal positioned between two transparent metals on the entire surface of the defined display area; Forming a bank layer having opening regions such that a portion of the lower electrode is exposed for each of the sub-pixels; Forming protruding spacers on the bank layer to be positioned at least one by area of the subpixels; Forming barrier ribs on the bank layer such that the subpixels are divided into regions; Forming organic emission layers on the opening regions exposing the subpixels in each region; Forming upper electrodes to separate the sub-pixels and to cover the spacers by using the barrier ribs; And And sealingly sealing the first substrate and the second substrate such that upper electrodes formed to cover the spacers are electrically connected to source or drain electrodes of the transistors. The method of claim 8, The lower electrode, A transparent metal selected from any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO), A method of manufacturing an organic light emitting display device, comprising a translucent metal containing silver (Ag) or a silver alloy. The method of claim 8, The lower electrode, A method of manufacturing an organic light emitting display device, characterized in that the thickness of at least one of the red subpixels, the green subpixels, and the blue subpixels is different.

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