KR100747429B1 - Organic light emitting diode display device - Google Patents

Abstract

An OLED(Organic Light Emitting Diode) display device is provided to perform an encapsulation process without a UV mask by forming an upper electrode layer to have a wider area than an organic light emitting layer. An OLED display device includes a substrate(110), a lower electrode layer(120), an insulating film(130), a separator(140), an organic light emitting layer(150), an upper electrode layer(160), and an encapsulation cap(170). The lower electrode layer(120) is formed on the substrate(110) in a stripe pattern extended in one direction. The insulating film(130) is formed on the lower electrode layer(120) to define a pixel area by exposing a part of the lower electrode layer(120). The separator(140) is formed on the insulating film(130), and crosses vertically the lower electrode layer(120). The organic light emitting layer(150) is formed on the exposed lower electrode layer(120) of the pixel area. The upper electrode layer(160) is formed on the organic light emitting layer(150), has a wider area than the organic light emitting layer(150), and has a thickness through which ultraviolet rays do not pass. The encapsulation cap(170) is formed on the substrate(110), and encapsulates the substrate(110).

Description

OLED display device {Organic light emitting diode display device}

1 is a cross-sectional view illustrating an LED display device according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view of a portion “A” of FIG. 1.

<Explanation of symbols for main parts of the drawings>

110: substrate 120: lower electrode layer

130: insulating film 140: partition wall

150: light emitting organic layer 160: upper electrode layer

170: sealing cap 180: sealant

The present invention relates to an OLED display device, and more particularly, by allowing the encapsulation process to be performed without using an ultraviolet (UV) mask, not only can a cost saving of mask manufacturing cost but also an OLED display device It is related to an LED display device that does not need to replace the mask every time the model of the device changes.

In general, organic light emitting diodes (OLEDs) can be driven at low voltages and can solve the drawbacks of LCDs such as thinning, wide viewing angles, and fast response speeds. In the following, it is attracting attention as a next-generation display having the advantages of having an image quality equal to or higher than that of a TFT-LCD and having a simple manufacturing process to be advantageous in future price competition.

The OLED is formed of an organic light emitting material in a space between a lower plate having a form in which an ITO transparent electrode pattern is formed as a positive electrode on a transparent glass substrate and an upper plate in which a metal electrode is formed as a negative electrode on a substrate, thereby forming a transparent electrode and a transparent electrode. A display device using a property that emits light while a current flows through an organic light emitting material when a predetermined voltage is applied between metal electrodes.

The OLED is required to cap the entire device using a metal or glass cap after the fabrication of the device is completed because the organic material used for light emission is vulnerable to temperature and humidity. Encapsulation It is called fair. Therefore, an encapsulation process is essential for manufacturing a reliable OLED device.

By the way, the conventional LED display device used a UV mask to perform this encapsulation process. However, since UV masks are made of quartz, which has good transmittance, they are expensive and costly to manufacture. Also, there is an inconvenience to open the chamber and replace the mask with the model every time the model of ODL element is changed.

Therefore, there is a need for an OLED display device capable of performing the encapsulation process without using such an expensive UV mask.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an OLED display device capable of performing an encapsulation process without using a UV mask.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above technical problem, the LED display device according to an embodiment of the present invention, the substrate; A lower electrode layer formed on the substrate in a stripe pattern extending in one direction; An insulating layer formed on the lower electrode layer to expose a portion of the lower electrode layer to define a pixel region; An inverse tapered partition formed on the insulating layer in a direction perpendicular to the lower electrode layer; A light emitting organic layer formed on the exposed lower electrode layer of the pixel region; An upper electrode layer formed on the light emitting organic material layer in an area larger than that of the light emitting organic material layer and having a thickness such that ultraviolet rays do not penetrate; And an encapsulation cap formed on the substrate to seal the substrate.

In an embodiment of the present invention, the upper electrode layer is preferably a metal material containing aluminum.

It is preferable that the aluminum has a thickness of 700 GPa or more.

The encapsulation cap is preferably a transparent insulating substrate containing glass.

Specific details of other embodiments are included in the detailed description and the accompanying drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

In addition, in the drawings, the size and thickness of layers and films or regions are exaggerated for clarity of description, and when any film or layer is described as being formed "on" of another film or layer, It may be directly on top of the other film or layer, and a third other film or layer may be interposed therebetween.

1 is a cross-sectional view illustrating an LED display device according to an exemplary embodiment of the present invention, and FIG. 2 is an enlarged plan view of part “A” of FIG. 1.

1 and 2, an OLED display device according to an exemplary embodiment of the present invention may include a substrate 110, a lower electrode layer 120, an insulating layer 130, a partition wall 140, a light emitting organic layer 150, and an upper electrode layer. 160 and an encapsulation cap 170.

The substrate 110 is a base layer for forming an LED display device according to an embodiment of the present invention, and is mainly formed using a transparent insulating substrate such as a glass substrate. However, it can also be formed using a plastic substrate having excellent transparency.

The lower electrode layer 120 is formed in a stripe pattern extending in one direction on the substrate 110. The lower electrode layer 120 is an anode electrode for hole injection, and has a high work function and indium tin oxide (ITO) or indium zinc oxide to transmit the emitted light. Oxide: Formed using a transparent metal oxide such as IZO).

Thus, by using the transparent metal oxide as the anode electrode for hole injection, it is possible to prevent the reduction of the luminous efficiency due to the non-emitting recombination of the anode electrode.

The insulating layer 130 is formed on the lower electrode layer 120 to expose a portion of the lower electrode layer 120 to define the pixel region Pixel. The insulating layer 130 may be formed using a polymer material having photosensitive characteristics while having an electrically sufficient insulating effect such as photoresist or polyimide.

The partition wall 140 is formed on the insulating layer 130 in a direction perpendicular to the lower electrode layer 120. The partition wall 140 is to prevent electrical short of each pixel region by the upper electrode layer 160 when the upper electrode layer 160 is formed, and has an electrical insulation effect to block the upper electrode layer 160 between adjacent pixel regions. It can be formed using a negative photoresist (Negative Photo Resist) capable of forming a reverse taper shape.

The light emitting organic layer 150 is formed on the exposed lower electrode layer 120 in the pixel region defined by the insulating layer 130 and includes a light emitting layer or the like to form a single layer or a multilayer structure. The light emitting organic layer 150 is electrically excited when subjected to an electric field, and thus generates light. For reference, as a material of the light emitting layer, aluminum complexes (Alq3) are generally used the most.

The upper electrode layer 160 is formed in a stripe pattern extending on the light emitting organic layer 150 in the same direction as the partition wall 140, that is, in a direction perpendicular to the lower electrode layer 120. The upper electrode layer 160 is a cathode electrode for injecting electrons, and is formed using a metal material having a low work function such as aluminum, which is a barrier formed between the upper electrode layer 160 and the light emitting organic layer 150. By lowering the barrier, a high current density is obtained in the electron injection to increase the luminous efficiency of the device.

When the upper electrode layer 160 is formed of aluminum, the upper electrode layer 160 is formed to have a larger area than the area of the light emitting organic layer 150, and should be formed to have a thickness of 700 Å or more, referring to Table 1 below. The explanation is as follows.

TABLE 1

Al thickness UV transmittance (mJ / ㎠) UV transmittance (%) 50 7366 92.075 100 3209 40.113 150 1365.3 17.066 200 552.4 6.905 250 226.5 2.831 300 99.34 1.242 350 35.62 0.445 400 31.24 0.391 450 28.14 0.352 500 2.82 0.035 550 0.93 0.012 600 0.54 0.007 650 0.125 0.002 700 0 0.000 750 0 0.000

Table 1 is an experimental chart measuring the amount of UV transmission according to the thickness of aluminum (Al) when the UV (ultraviolet) irradiation amount is 8000mJ / ㎠.

Referring to Table 1, when the upper electrode layer 160 made of aluminum is formed to be wider than the area of the light emitting organic layer 150, when the thickness of aluminum is 700 Å or more, the amount of UV transmission through aluminum is 0 mJ / cm 2. Therefore, when the upper electrode layer 160 made of aluminum is formed to be wider than the area of the light emitting organic layer 150 and the thickness thereof is 700 Å or more, the encapsulation process can be performed without using a UV mask. This not only saves expensive mask manufacturing costs, but also eliminates the need to replace the mask every time the model of the ODL element changes.

Meanwhile, when the upper electrode layer 160 is formed of a material other than aluminum, that is, a material such as calcium (Ca) or magnesium (Mg) having a low work function, the upper electrode layer 160 is formed as described above. It is formed wider than the area of), and is formed to a thickness such that the UV beam (Beam) is not transmitted. Here, the thickness such that the UV beam is not transmitted can be determined by experiment as shown in Table 1.

The encapsulation cap 170 is formed on the substrate 110 on which the lower electrode layer 120, the insulating layer 130, the partition wall, the light emitting organic layer 150, and the upper electrode layer 160 are formed to seal the substrate 110. That is, the encapsulation cap 170 encapsulates the substrate 110 to prevent oxidation of the light emitting material and the electrode from moisture introduced into the ODL element from the outside and protects the device from external shock. In this case, the encapsulation cap 170 is bonded to the substrate 110 by a sealant 180 and is preferably formed by using a transparent insulating substrate including glass.

As described above, the OLED display device according to the embodiment of the present invention forms the upper electrode layer 160 to have a larger area than the light emitting organic layer 150, and the UV beam does not transmit the thickness of the upper electrode layer 160. By forming, the encapsulation process can be performed without using a UV mask. As a result, not only the cost of manufacturing expensive masks can be saved, but also the masks need not be replaced every time the model of the ODL element is changed.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings and tables, the present invention is not limited to the above embodiments, but may be manufactured in various forms, and common knowledge in the art to which the present invention pertains. Those skilled in the art can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the LED display device according to an embodiment of the present invention, by performing the encapsulation process without using a UV mask, not only can the cost of mask manufacturing cost is expensive, but also the model of the LED display device is changed. There is no need to replace the mask every time.

Claims (4)

Board; A lower electrode layer formed on the substrate in a stripe pattern extending in one direction; An insulating layer formed on the lower electrode layer to expose a portion of the lower electrode layer to define a pixel region; An inverse tapered partition formed on the insulating layer in a direction perpendicular to the lower electrode layer; A light emitting organic layer formed on the exposed lower electrode layer of the pixel region; An upper electrode layer formed on the light emitting organic material layer in an area larger than that of the light emitting organic material layer and having a thickness such that ultraviolet rays do not penetrate; And And an encapsulation cap formed on the substrate to seal the substrate. The method of claim 1, The upper electrode layer is an LED display device, characterized in that the metal material containing aluminum. The method of claim 2, The aluminum LED display device, characterized in that having a thickness of 700Å or more. The method of claim 1, The encapsulation cap is an LED display device, characterized in that the transparent insulating substrate containing a glass.

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