Patent Application
20110223319
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2010-055102, filed on Mar. 11, 2010, the entire contents of which are incorporated herein by reference.
Exemplary embodiments described herein generally relate to a method of fabricating an organic electroluminescence display device used as a display.
Generally, an organic electroluminescence (called an organic EL hereinafter) display device used as a display includes a laminated layer with a light emission function layer, a second electrode (cathode) and the like on a substrate. The light emission function layer includes thin film transistors, first electrodes (pixel electrode or anode), hole injection layers, and organic EL elements. Further, the laminated layer is encapsulated by resin, for example.
First, as shown in
Next, pixel electrodes 102 are arranged with prescribed interval on the interlayer insulator of the substrate 101, and each of the pixel electrodes 102 is electrically connected to each of thin film transistors.
Next, as shown in
After that, as shown in
Therefore, a shape of the barrier layer 103 is deformed by heat which is generated in printing an image of the light emission function layer 105. Consequently, failure such as variability of a transfer width or a transfer defect is easily generated. In the printing process, the transfer defect is generated when a transfer material is printed from a portion above the barrier layers so as to trap air bubbles between the barrier layers. Accordingly, improvement of transfer accuracy is further desired.
An aspect of the present disclosure, there is provided a method of fabricating an organic electroluminescence display device, including forming a plurality of first electrodes with a prescribed interval on a substrate, forming a light emission function layer including a light emission layer on at least an upper surface of each of the first electrodes, forming a barrier layer on a upper surface of the light emission function layer between the first electrodes after forming the light emission function layer, forming a second electrode on the first electrode.
Embodiments of a method of fabricating an organic EL display device will be described below in detail with reference to
Throughout the attached drawings, similar or same reference numerals show similar, equivalent or same components.
A fabricating method according to the embodiments includes forming a substrate, forming an encapsulating substrate, and sticking both the substrate and the encapsulating substrate each other.
First, forming the substrate is described with reference to
Thin film transistors, each of which is called as TFT hereinafter, as a switching transistor, wirings and the like are formed on a substrate body of the substrate 1. An interlayer insulator is arranged on the substrate to cover the thin film transistors and the wirings. Further, a contact plug is formed in a surface of the planarized interlayer insulator in order to connect between the first electrode 2 and the TFT.
a substrate body is formed by a transparent material or an opaque material. A glass substrate, a transparent resin substrate or the like, for example, is used as the transparent substrate, and a metal substrate, an opaque resin substrate or the like, for example, is used as the opaque material.
In forming TFT or various kinds of wirings, after various kinds of films are formed by CVD, sputtering or the like, which are well-known methods, the films are patterned by photolithography and etching or the like, which are well-known methods. Further, a source area and a drain area of the TFT are formed by ion-doping or the like, which are well-known method.
As shown in
As shown in
Further, the laminated layer is formed as a continuous layer over the display region in this embodiment. However, the laminated layer may be patterned with respect to each pixel region, each row, or each column. The corresponding pixels are included in both the row and the column.
As shown in
In such a manner, the light emission function layer 3 constituted with the hole injection layer 3a, the hole transport layer 3b and the light emission layer 3c is formed.
The hole injection layer 3a acts as a layer in which holes are injected from the first electrode 2. Materials mentioned below can be used as the hole injection layer 3a, such as 3,4-polyethylenethiophene/polystyrenesulfonate (PEDOT/PSS), polystyrene, polypyrrole, polyaniline, polyacetylene, or derivatives of these materials or the like in polymer materials, for example, and copper phthalocyanine, m-MTDATA, TPD, α-NPD or the like in low molecular materials, for example.
The hole transport layer 3b acts as a layer in which holes are injected from a lower electrode 7 mentioned after. Materials mentioned below can be used as the hole transport layer 3b, such as PEDOT (poly(ethylenedioxy)thiophene), PSS (polystyrenesulfonate) or the like.
The light emission layer 3c includes an organic EL element emitting blue when emitted light is blue, for example, an organic EL element emitting green when emitted light is green, for example, and an organic EL element emitting red when emitted light is red, for example.
As specific materials, rubrene, platinum octaethylporphyrin, benzothienylpyridine-acetylacetone-iridium complex, polyethylene terephthalate, perinone, 9-(Diethylamino)-5H-benzo[α]phenoxazin-5-one, aluminoquinoline complex, bis(benzquinolinate) beryllium complex, quinacridone, coumalin, anthracene, diphenyltetrazene, 2-tert-butyl-9,10-di(naphthalen-2-yl), perylene, tetra-phenylanthracene, tetra-phenylbutadiene, 9,10-bis((phenylethynyl)anthracene, poly(para-phenylene vinylene),
Each of the first electrodes is patterned corresponding to the row including the pixel areas in this embodiment. However, patterning may be carried out corresponding to each of the pixel area or the column including the pixel areas.
Successively, as shown in
Further, a solution of a barrier layer material is formed on the prescribed area and dried in super inkjet coating.
The barrier layer 4 is formed to surround the first electrode 2, and is composed of photosensitive resin or non-photosensitive resin, for example, acrylic resin, polyimide resin or the like.
As shown in
The electron transport layer 5 in which electrons are transported is composed of quinolinol derivative, oxadiazole derivative, triazole derivative, fullerene derivative, phenanthroline derivative, quinoline derivative or the like, for example, can be used. Further, the electron transport layer 5 is formed to cover the barrier layer 4 in this embodiment. However, barrier layer 6 may be formed on the electron transport layer 5, and patterning may be carried out corresponding to each of the pixel area including the pixel areas or the column.
The electron injection layer 6, which is formed on the electron transport layer 5, is composed of a material including oxide, for example. Specifically, lithium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride, aluminum oxide or the like can be nominated.
As shown in
The second electrode 7 composed of a material with smaller work function, such as lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) or the like, or an electrode including such as aluminum (Al), silver (Ag), gallium (Ga), vanadium (V), titanium (Ti), bismuth (Bi), tin (Sn), chromium (Cr), antimony (Sb), copper (Cu), cobalt (Co), gold (Au) or the like.
Next, an encapsulation substrate with a cap shape, for example is formed, successively, the encapsulation substrate is arranged on the substrate 1 with the structure mentioned above. The substrate and the encapsulation substrate is attached each other using a encapsulation member composed of UV hardening resin so as to be airproofed. The organic EL display device is formed by the process mentioned above.
The barrier layer 4 is formed after the light emission function layer 3 is arranged, so that the barrier transfer layer can be directly transferred to be faithfully formed as the pattern in nearly flatten state in this embodiment. Therefore, failure such as variability of a transfer width or a transfer defect can be decreased in the barrier layer, so that transfer accuracy can be improved.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
For example, the electron transport layer 5 is formed to cover the barrier layer 4 and the exposed light emission function layer 3 after the barrier layer 4 is formed in the embodiment. However, an order between forming electron transport layer 5 and forming the barrier layer 4 can be exchanged. In other words, first, the electron transport layer 5 is formed on the light emission function layer 3 as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-055102 | Mar 2010 | JP | national |
