KR20100000822A - Organic light emitting display and manufacturing method for the same - Google Patents

Abstract

PURPOSE: An organic electroluminescent display device and a manufacturing method thereof are provided to improve reliability and life of the device by absorbing the moisture or oxygen from the outside through a hygroscopic layer. CONSTITUTION: A transistor is formed on a first substrate(S101). A bottom electrode is formed on a second substrate(S102). A bank layer is formed on the bottom electrode(S103). A spacer is formed on a bank layer(S104). An organic light emitting layer is formed on the bottom electrode(S105). A top electrode is formed on the bank layer to cover the spacer and the organic light emitting layer(S106). A hygroscopic layer is formed on the top electrode except for the spacer region(S108). One of the top electrode and the hygroscopic layer is oxidized(S109). The first substrate and the second substrate are attached(S110).

Description

Organic Light Emitting Display and Manufacturing Method for the Same

The present invention relates to an organic light emitting display device and a manufacturing method thereof.

An organic light emitting display device used in an organic light emitting display device is a self-light emitting device in which a light emitting layer is formed between two electrodes positioned on a substrate.

In addition, the organic light emitting display device may include a top-emission method, a bottom-emission method, or a dual-emission method 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.

On the other hand, some of the conventional organic light emitting display device has a structure in which a transistor and an organic light emitting diode are formed on the first substrate and the second substrate, respectively, and the first substrate and the second substrate are bonded and sealed with an adhesive member.

In this structure, when moisture penetrates into the inside of the panel, unexpected oxidation proceeds in the thin film, thereby increasing resistance in an area electrically connecting the first substrate on which the transistor is formed and the second substrate on which the organic light emitting diode is formed. There is a problem that causes a display failure, or the reliability or life of the device is deteriorated, and the improvement thereof is required.

An object of the present invention for solving the above problems of the background art is to prevent the unexpected oxidation of the thin film to solve the problem of display defects, and through the moisture absorbing layer which can absorb moisture or oxygen, It is to provide an organic light emitting display device that can improve the life.

The present invention as a means for solving the above problems, forming a transistor on a first substrate; Forming a lower electrode on the second substrate; Forming a bank layer having an opening on the lower electrode, the opening exposing a portion of the lower electrode; Forming a spacer on the bank layer; Forming an organic emission layer on the lower electrode; Forming an upper electrode on the bank layer to cover the spacer and the organic light emitting layer; Forming a moisture absorbing layer on the upper electrode except for the region where the spacer is located; Oxidizing at least one of the upper electrode and the moisture absorption layer in a chamber atmosphere containing oxygen (O 2) or dry air (CDA); And it provides a method for manufacturing an organic light emitting display device comprising the step of bonding the first substrate and the second substrate.

In the upper electrode forming step, the upper electrode may be formed in a single layer or multiple layers.

When the upper electrode is formed of a plurality of layers, in the oxidizing step, only the base electrode layer of the upper electrode may be oxidized, or the base electrode layer and the moisture absorbing layer of the upper electrode may be oxidized, or only the moisture absorbing layer may be oxidized.

When the upper electrode is a multilayer, at least one of the electrode layers constituting the upper electrode may be formed of another material.

The oxidation step can be carried out before or during the bonding step.

The moisture absorption layer may include calcium (Ca), magnesium (Mg) or manganese (Mn).

On the other hand, in another aspect, the present invention, a transistor located on the first substrate; A second substrate spaced apart from the first substrate and bonded to the first substrate; A lower electrode on the second substrate; A bank layer disposed on the lower electrode and having an opening that exposes a portion of the lower electrode; A spacer located on the bank layer; An organic light emitting layer on the lower electrode; An upper electrode on the bank layer to cover the spacer and the organic light emitting layer; And a moisture absorbing layer disposed on the upper electrode except for a region in which the spacer is located, wherein at least one of the upper electrode and the moisture absorbing layer is oxidized.

The upper electrode may be formed in a single layer or a plurality of layers.

When the upper electrode is formed of a multilayer, only the base electrode layer of the upper electrode may be oxidized, the base electrode layer and the moisture absorbing layer of the upper electrode may be oxidized, or only the moisture absorbing layer may be oxidized.

The moisture absorption layer may include calcium oxide (CaO), magnesium oxide (MgO), or manganese oxide (MnO).

The present invention provides an organic light emitting display device that can prevent the unexpected oxidation of the thin film to solve the problem of display defects and improve the reliability and lifetime of the device through a moisture absorbing layer capable of absorbing moisture or oxygen. It is effective to provide.

In addition, the present invention has the effect of reducing the degree of foreign matter defects that may occur in the sub-pixel during the manufacturing process to minimize the defect occurrence rate and improve the production yield.

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

1 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention, and FIGS. 2 to 5 are schematic cross-sectional views of an organic light emitting display device for helping the description of FIG. 1.

1 to 5, a method of manufacturing an organic light emitting display device according to an embodiment of the present invention may be as follows.

First, as shown in FIGS. 1 and 2, a step S101 of forming a transistor on a first substrate is performed.

The first substrate 110 may be a glass plate, a metal plate, a ceramic plate, or a plastic plate (polycarbonate resin, acrylic resin, vinyl chloride resin, polyethylene terephthalate resin, polyimide resin, polyester resin, epoxy resin, silicone resin, fluorocarbon resin, etc.). ) Can be used.

The gate 111 may be located on the first substrate 110. The gate 111 may be a gate of the driving transistor formed on the first substrate 110. The gate 111 is any one selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu). It may be made of one or an alloy thereof. In addition, the gate 111 may include molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be a multilayer made of any one or alloys thereof. In addition, the gate 111 may be a double layer of molybdenum / aluminum-neodymium or molybdenum / aluminum.

The first insulating layer 112 may be positioned on the gate 111. The first insulating layer 112 may be a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof, but is not limited thereto.

The active layer 113 may be positioned on the first insulating layer 112. The active layer 113 may include amorphous silicon or polycrystalline silicon crystallized therefrom. Although not shown, the active layer 113 may include a channel region, a source region, and a drain region, and the source region and the drain region may be doped with P-type or N-type impurities. In addition, the active layer 113 may include an ohmic contact layer to lower the contact resistance.

The source 114 and the drain 115 may be positioned on the active layer 113. The source 114 and the drain 115 may be formed of a single layer or multiple layers. When the source 114 and the drain 115 are a single layer, molybdenum (Mo), aluminum (Al), chromium (Cr), Gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) may be made of any one or an alloy thereof. In addition, when the source 114 and the drain 115 are multiple layers, the double layer of molybdenum / aluminum-neodymium and the triple layer of molybdenum / aluminum / molybdenum or molybdenum / aluminum-neodymium / molybdenum may be used.

The second insulating layer 116 may be positioned on the source 114 and the drain 115. The second insulating layer 116 may be a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof, but is not limited thereto. The second insulating layer 116 may be a passivation layer or a planarization layer.

In the above, as an example, the transistor located on the first substrate 110 is a batam gate type. However, the transistor located on the first substrate 110 is not limited thereto and may also be formed as a top gate type. 2 schematically illustrates a scan wiring, a data wiring, a power wiring, a capacitor, and the like, on the first substrate 110.

Next, as shown in FIG. 3, a step (S102) of forming a lower electrode on the second substrate is performed.

The second substrate 120 may use the same material as or different from that of the first substrate 110. The lower electrode 121 formed on the second substrate 120 may be selected as an anode, and the lower electrode 121 selected as the anode may use a transparent material such as indium tin oxide (ITO) or indium zinc oxide (IZO). Can be.

Next, as shown in FIG. 3, a step S103 of forming a bank layer having an opening exposing a part of the lower electrode on the lower electrode is performed.

The bank layer 122 formed on the lower electrode 121 may include an organic material such as a benzocyclobutene (BCB) resin, an acrylic resin, or a polyimide resin. Here, the bank layer 122 may have an opening that exposes a portion of the lower electrode 121, and the opening may be defined as a substantially light emitting area of the subpixel.

Next, as shown in FIGS. 1 and 3, a step (S104) of forming a spacer on the bank layer is performed.

The spacer 123 formed on the bank layer 122 may be formed of an organic material or an inorganic material. The spacer 123 protrudes to contact the source 114 or the drain 115 positioned on the first substrate 110 when the first substrate 110 and the second substrate 120 are bonded to each other. The spacer 123 may be formed as an isosceles having a narrower area in contact with the source 114 or the drain 115 than the base area.

Next, as shown in FIGS. 1 and 3, forming an organic emission layer on the lower electrode is performed (S105).

The organic emission layer 124 formed on the lower electrode 121 may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Description of this will be described in more detail below.

Next, as shown in FIGS. 1 and 3, an upper electrode is formed on the bank layer to cover the spacer and the organic light emitting layer (S106).

The upper electrode 125 formed on the bank layer 122 to cover the spacer 123 and the organic light emitting layer 124 may be selected as a cathode, and the upper electrode 125 selected as the cathode may be opaque such as aluminum (Al) or the like. And materials with high reflectivity can be used. In addition, the upper electrode 125 may be formed in a single layer or a plurality of layers. Description of this will be described in more detail below.

Next, as shown in FIGS. 1 and 3, the step (S107) of oxidizing the upper electrode in a chamber atmosphere containing oxygen (O 2) or dry air (CDA) is performed. Since some oxygen (O2) is contained in the dry air (CDA), the oxidation step performed in the dry air (CDA) may be slower than the oxygen (O2) atmosphere.

Meanwhile, oxidizing the upper electrode 125 may be optional. Accordingly, when the upper electrode 125 is not oxidized, the oxidation step may be skipped and the next step may be performed.

Next, as shown in FIGS. 1 and 4, a step (S108) of forming a moisture absorbing layer on the upper electrode except for the region where the spacer is located is performed.

The moisture absorption layer 126 may be formed of an oxide such as calcium (Ca), magnesium (Mg), or manganese (Mn). The moisture absorption layer 126 is formed except for a region where the spacer 123 is located. The reason for this is that in the case of the moisture absorbing layer 126, the oxidation progress rate is faster than the material constituting the upper electrode 125. Accordingly, when the upper electrode 125 is oxidized, the contact resistance between the upper electrode 125 formed on the spacer 123 and the source 114 or the drain 115 increases. Therefore, the reason for forming the moisture absorbing layer 126 except for the region where the spacer 123 is located is to prevent the above-described problem from occurring.

On the other hand, when the upper electrode 125 is not oxidized, the moisture absorbing layer 126 is oxidized in a subsequent oxidation process.

Next, as shown in FIGS. 1 and 4, step S109 of oxidizing the moisture absorption layer in a chamber atmosphere including oxygen (O 2) or dry air (CDA) is performed.

When the oxide absorbent layer 126 is oxidized, such as calcium (Ca), magnesium (Mg), or manganese (Mn), the material forming the oxide absorbent layer 126 may be calcium oxide (CaO), magnesium oxide (MgO), or manganese oxide ( Oxidized to MnO).

On the other hand, when the oxide absorbent layer 126 such as calcium (Ca), magnesium (Mg) or manganese (Mn) is oxidized, the effect of the device is superior to that of the absorbent material through calcium (Ca) or the like. It can improve the service life and reliability. In addition, even when the moisture absorbing layer 126 is oxidized, as in the case where the upper electrode 125 is oxidized, the defective inducing region due to the foreign particles or the abnormal thin film state may be inactivated to lower the defective rate and improve the production yield.

In an embodiment of the present invention, at least one of the upper electrode 125 and the moisture absorption layer 126 may be selectively oxidized in a chamber atmosphere including oxygen (O 2) or dry air (CDA). In addition, the above-described oxidation step (S107, S109) may be carried out before or during the bonding step (S110) to be carried out later.

Here, when the upper electrode 125 is formed of a plurality of layers, only the bottom electrode layer of the upper electrode may be oxidized in the oxidation step S107. Alternatively, the base electrode layer of the upper electrode 125 may be oxidized in the oxidation step S107 and the moisture absorbing layer 126 may be oxidized in the next oxidation step S109. Alternatively, only the moisture absorbing layer 126 may be oxidized in the oxidation step S109. Here, when the upper electrode 125 is formed of a plurality of layers, at least one of the electrode layers constituting the upper electrode 125 may be formed of another material.

On the other hand, as in an embodiment of the present invention, the reason for selectively oxidizing at least one of the upper electrode 125 and the moisture absorbing layer 126 may be a defect-induced region due to foreign particles or abnormal thin film state in the device during the manufacturing process, etc. This is because the device can be fabricated in response to the same process defects as in this case.

FIG. 6 is a diagram illustrating the presence of foreign particles on a thin film.

The foreign particle 130 may occur when performing a deposition process or the like in a chamber or in an unspecified state. For example, the foreign particles may occur in a series of processes of forming the lower electrode 121, the organic emission layer 124, and the upper electrode 125. The foreign particles 130 may generate a leakage current between the electrode layers and further damage or destroy some regions of the subpixels, thereby causing problems such as display defects or dark spots. However, when the upper electrode 125 is formed and the oxidation process is performed as in the present invention, since the oxidation proceeds along the path formed around the foreign particle 130, the insulating layer 140 is formed. It is possible to cope with process defects such as leakage current (or short) generation problem caused by 130).

Next, as shown in FIGS. 1 and 5, the step S110 of bonding the first substrate and the second substrate is performed.

The first substrate 110 and the second substrate 120 may be bonded using an adhesive member. When the first and second substrates 110 and 120 are bonded by the bonding step, the upper electrode 125 and the transistor formed on the first substrate 110 positioned on the spacer 123 formed on the second substrate 120. The source 114 or drain 115 of is electrically connected. Here, when the first and second substrates 110 and 120 are bonded together, a power supply unit connecting the lower electrode 121 formed on the second substrate 120 and the power wiring formed on the first substrate 110 in addition to the spacer 123. Also connected (not shown).

Meanwhile, the organic light emitting display device formed as described above may be formed as shown in FIG. 7.

7 is a cross-sectional view of an organic light emitting display device according to another embodiment of the present invention.

An organic light emitting display device according to another embodiment of the present invention is similar to the organic light emitting display device described above with reference to FIG. 5. However, referring to FIG. 7, in the organic light emitting display device according to another exemplary embodiment, the auxiliary electrode 127 may be further formed on or under the lower electrode 121. In addition, the partition wall 128 may be further formed on the bank layer 122 to give an advantage in the manufacturing process.

Hereinafter, the structures of the organic light emitting layer and the upper electrode will be described.

8 and 9 are cross-sectional views of the organic light emitting layer and the upper electrode.

8 and 9, the organic light emitting layer 124 may include a hole injection layer 124a, a hole transport layer 124b, a light emitting layer 124c, an electron transport layer 124d, and an electron injection layer 124e. .

The hole injection layer 124a 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 124b 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 124c may include a material emitting red, green, blue, and white light and may be formed using phosphorescent or fluorescent materials.

When the light emitting layer 124c is 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 Phosphorescent light containing a dopant including any one or more selected from the group consisting of iridium), PQIr (acac) (bis (1-phenylquinoline) acetylacetonate iridium), PQIr (tris (1-phenylquinoline) iridium) and PtOEP (octaethylporphyrin platinum) It may be made of a material, alternatively 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 124c is green, the light emitting layer 124c may include a host material including CBP or mCP, and may be made of a phosphor including a dopant material including Ir (ppy) 3 (fac tris (2-phenylpyridine) iridium). Alternatively, the composition may be made of a fluorescent material including Alq3 (tris (8-hydroxyquinolino) aluminum), but is not limited thereto.

When the light emitting layer 124c is blue, the light emitting layer 124c may include a host material including CBP or mCP, and may be made of a phosphor including a dopant material including (4,6-F2ppy) 2Irpic. Alternatively, it may be made 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, but It is not limited.

The electron transport layer 124d serves to facilitate the transport of electrons, 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 124e 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.

However, the present invention is not limited thereto, and at least one of the hole injection layer 124a, the hole transport layer 124b, the electron transport layer 124d, and the electron injection layer 124e may be omitted.

Here, referring to FIG. 8, the upper electrode 125 may include a bottom electrode layer 125a made of a metal such as aluminum (Al), a middle electrode layer 125b made of a metal such as silver (Ag), and an aluminum (Al). It may be composed of a top electrode layer 125c made of metal.

In this case, the electrode layers which can be oxidized in the oxidation step S107 are the bottom electrode layers 125a to the top electrode layer 125c, but it is advantageous to oxidize the bottom electrode layer 125a. This is because it is easy to deactivate the defect-induced region due to the foreign particle or abnormal thin film state. However, whether or not the oxidation process of the upper electrode 125 may be considered together with whether or not the oxidation process of the moisture absorption layer 126.

Here, referring to FIG. 9, the upper electrode 125 may include a bottom electrode layer 125a made of a metal such as aluminum (Al), a first middle electrode layer 125b made of a metal such as aluminum (Al), and silver (Ag). The second middle electrode layer 125c made of a metal such as, and the top electrode layer 125d made of a metal such as aluminum (Al).

In this case, the electrode layers that can be oxidized in the oxidation step S107 are the bottom electrode layers 125a to 125d, but it is advantageous to oxidize the bottom electrode layers 125a. This is because it is easy to deactivate the defect-induced region due to the foreign particle or abnormal thin film state. However, whether or not the oxidation process of the upper electrode 125 may be considered together with whether or not the oxidation process of the moisture absorption layer 126.

One embodiment of the present invention is a pre-oxidation for oxidizing at least one of the upper electrode 125 and the moisture absorbing layer 126 before or during bonding the first substrate 110 and the second substrate 120 ( Pre-Oxidation process is used to prevent unexpected oxidation of the thin film. In addition, the device may be manufactured in response to a process defect such as when a defect causing area due to a foreign particle or an abnormal thin film state is located in the device during the manufacturing process. In addition, the problem of display defects caused by process defects can be solved, and the reliability and lifespan of the device can be improved through a moisture absorbing layer capable of absorbing moisture or oxygen. In addition, by reducing the degree of foreign material defects to minimize the occurrence rate of defects, it is possible to improve the production yield.

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 flowchart illustrating a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

2 to 5 are schematic cross-sectional views of an organic light emitting display device for helping the description of FIG. 1.

FIG. 6 is a diagram illustrating the presence of foreign particles on a thin film. FIG.

7 is a cross-sectional view of an organic light emitting display device according to another embodiment of the present invention.

8 and 9 are cross-sectional views of the organic light emitting layer and the upper electrode.

<Explanation of symbols on main parts of the drawings>

110: first substrate 111: gate

114: source 115: drain

120: second substrate 121: lower electrode

122: bank layer 123: spacer

124: organic light emitting layer 125: upper electrode

126: moisture absorption layer

Claims (10)

Forming a transistor on the first substrate; Forming a lower electrode on the second substrate; Forming a bank layer on the lower electrode, the bank layer having an opening that exposes a portion of the lower electrode; Forming a spacer on the bank layer; Forming an organic emission layer on the lower electrode; Forming an upper electrode on the bank layer to cover the spacer and the organic light emitting layer; Forming a moisture absorbing layer on the upper electrode except for a region where the spacer is located; Oxidizing at least one of the upper electrode and the moisture absorbing layer in a chamber atmosphere containing oxygen (O 2) or dry air (CDA); And A method of manufacturing an organic light emitting display device comprising the step of bonding the first substrate and the second substrate. The method of claim 1, In the upper electrode forming step, The upper electrode may be formed of a single layer or a plurality of layers of the organic light emitting display device. The method of claim 2, In the oxidation step when the upper electrode is formed in a multilayer, And oxidizing only the bottom electrode layer of the upper electrode, oxidizing the bottom electrode layer and the moisture absorbing layer, respectively, or only the moisture absorbing layer, of the upper electrode. The method of claim 2, When the upper electrode is a multilayer And at least one of the electrode layers constituting the upper electrode is formed of a different material. The method of claim 1, The oxidation step, A manufacturing method of an organic light emitting display device, characterized in that performed before or during the bonding step. The method of claim 1, The moisture absorption layer, A method of manufacturing an organic light emitting display device comprising calcium (Ca), magnesium (Mg) or manganese (Mn). A transistor positioned on the first substrate; A second substrate facing the first substrate and spaced apart from the first substrate; A lower electrode on the second substrate; A bank layer positioned on the lower electrode and having an opening exposing a portion of the lower electrode; A spacer located on the bank layer; An organic light emitting layer on the lower electrode; An upper electrode on the bank layer to cover the spacers and the organic light emitting layer; And It includes a moisture absorbing layer located on the upper electrode except for the region where the spacer is located, And at least one of the upper electrode and the moisture absorbing layer is oxidized. The method of claim 7, wherein The upper electrode, An organic light emitting display device, characterized in that formed in a single layer or multiple layers. The method of claim 8, When the upper electrode is formed of a multilayer And only a bottom electrode layer of the upper electrode is oxidized, a bottom electrode layer and the moisture absorbing layer of the upper electrode are oxidized, or only the moisture absorbing layer is oxidized. The method of claim 7, wherein The moisture absorption layer, An organic light emitting display device comprising calcium oxide (CaO), magnesium oxide (MgO), or manganese oxide (MnO).

Images