KR101039029B1 - Organic Light Emitting Display - Google Patents

Abstract

The present invention discloses a method of manufacturing an organic light emitting display. The disclosed invention includes forming a stripe-type lower electrode using a mask pattern on a substrate, and then forming an insulating layer array pattern in a matrix shape on the lower electrode; Forming a lower electrode hole exposing the lower electrode by etching the insulating layer into a plurality of holes per unit pixel of the array pattern; Forming an upper electrode on the insulating layer on which the lower electrode hole is formed; The first upper electrode and the second upper electrode are arranged in the shape of comb-shaped fine lines intersecting for each unit pixel, and the first upper electrode is formed by forming a mask pattern so as to be disposed in contact with the lower electrode hole. Etching the upper electrode layer using the mask pattern as a mask to form an upper electrode fine line pattern; And forming an organic compound on the upper electrode layer including the insulating layer.

Description

Organic Light Emitting Display

1 is a cross-sectional view illustrating a process of forming a general organic EL device.

2 is a view showing a light emitting mechanism of an organic El element.

3A and 3B are a perspective view and a cross-sectional view illustrating a process of forming a cathode electrode using a shadow mask.

4A to 4D are plan views illustrating a process of forming an organic El device according to the present invention.

Figure 5 is a cross-sectional view for explaining the deposition process of the organic EL device according to the present invention.

Explanation of symbols on the main parts of the drawing

500: light emitting substrate 510: lower electrode

520: insulating film 530: upper electrode

540: organic compound 550: luminescence

The present invention relates to a method of forming an organic light emitting display, and more particularly, by forming an anode and a cathode electrode layer in which an electric field is formed on the same plane, an existing polymer organic EL process can be improved. An organic light emitting display method.

In general, a flat panel display such as a notebook monitor is classified into an organic device and an inorganic device according to the type of material used. Inorganic devices include a plasma display and a field emission display, and an organic material using device is a liquid crystal display and an organic light emitting diode (OLED) which is a device used in the present invention. Emitting Display).

The inorganic devices can be used in a robust or wide temperature range, and have the advantage of functioning as a large flat plate, but are not commercialized as display devices due to high driving voltage or low efficiency in blue light emission. .

In particular, the organic EL device has a response speed of about 30,000 times faster than the liquid crystal display currently used, and thus, a video can be realized, and the liquid crystal display cannot emit light by itself. Since it is a light emitting device, it can contribute to wide viewing angle and high brightness.

Hereinafter, a method of forming an existing organic EL device will be briefly described with reference to the accompanying drawings.

1 is a process cross-sectional view for explaining an organic EL forming process according to the prior art.

As shown in FIG. 1, an ITO electrode used as the anode electrode layer 110 is formed on a glass substrate 100, and then an organic compound 120 is formed on the anode electrode layer 110. .

Subsequently, when the cathode electrode 130 is formed on the organic compound 120 to flow a current through the anode, the current flows through the organic compound 120 to emit light.

2 is a view for explaining the light emitting mechanism of the organic compound 120.

As shown in FIG. 2, when the potential difference occurs due to the difference in the work function of each electrode (Φ ₍₊₎ −Φ ₍₋₎ ), the organic compound 120 has electrons (−) supplied from the anode electrode and the cathode electrode. And by emitting light by transmitting holes (+) or by recombining them, we can observe them with our eyes. At this time, as the organic compound used, materials such as EIL (Electron Injection Layer), EML (Emitting Material Layer) and HTL (Hole Injection layer) are used.

In addition, the organic compound layer 120 is largely divided into an organic EL using a polymer and an organic EL using a low molecule. In particular, the organic EL using a polymer mainly uses a vacuum deposition method when forming an organic layer.

Figure 3a is a perspective view showing a process for explaining a conventional method for forming a polymer organic EL device, Figure 3b is a cross-sectional view of the process from the side.

As shown in FIG. 3A, after the transparent anode electrode 310 is formed on the glass substrate 300 in a stripe shape, the organic compound layer 320 is formed on the anode electrode layer 310 by a single layer or two to two. Deposit with three multilayer compounds.

Next, a stripe shadow mask pattern 330 orthogonal to the anode electrode is formed on the organic compound layer, and the cathode electrode 340 is deposited using the mask pattern 330 as a mask. The above-described method is mainly used in manufacturing a polymer organic EL device, and the low molecular organic EL device mainly forms a separator partition for forming a cathode in order to implement a high definition pixel, and then vacuum deposits the cathode electrode.

In this case, the reason why the shadow mask is not used when forming the low-molecular organic EL device is that the fine pattern of the shadow mask itself is limited in the prior art, causing problems such as disconnection of the metal line and sagging of the mask.

Nevertheless, the reason why the polymer organic EL uses the shadow mask is that it is not possible to form the separation partition for forming the cathode on the substrate because the organic layer is formed using the organic solvent in addition to the low molecular organic EL. However, since polymer organic EL has many advantages such as low voltage driving, high efficiency light emission, and use of a single organic layer, it is possible to improve manufacturing and production yields if the problem of high resolution image due to shadow mask is difficult to be solved.

In addition, in the case of the small and medium organic EL panel, the resistance of the anode line becomes high, and an auxiliary electrode is used to reduce it. In this case, additional process and cost increase problem for forming the auxiliary electrode occurs.

In addition, when displaying in both directions, the transparent ITO cathode electrode should be formed on the organic compound layer. In this case, the method for forming the ITO electrode has a problem of causing a lot of damage to the surface of the organic layer by using the Sputter method.

Accordingly, the present invention has been made to solve the above problems of the prior art, unlike the conventional upper and lower electrode structure parallel electrode array structure for arranging the anode and cathode electrodes on the same plane horizontally cross each other (In Plane Electrode (hereinafter referred to as IPE) is used to form a panel and apply an organic compound thereon to form a cathode electrode without using a shadow mask, and to emit light up and down without using a transparent electrode. It is an object of the present invention to provide a method of manufacturing an organic light emitting display.

According to an aspect of the present invention, there is provided a method of manufacturing an organic light emitting display, comprising: forming a stripe-type lower electrode using a mask pattern on a substrate, and then forming an insulating layer array pattern in a matrix shape on the lower electrode; Forming a lower electrode hole exposing the lower electrode by etching the insulating layer into a plurality of holes per unit pixel of the array pattern; Forming an upper electrode on the insulating layer on which the lower electrode hole is formed; The first upper electrode and the second upper electrode are arranged in the shape of comb-shaped fine lines intersecting for each unit pixel, and the first upper electrode is formed by forming a mask pattern so as to be disposed in contact with the lower electrode hole. Etching the upper electrode layer using the mask pattern as a mask to form an upper electrode fine line pattern; And forming an organic compound on the upper electrode layer including the insulating film.

(Example)
Hereinafter, a method of manufacturing an organic light emitting display according to the present invention will be described in detail with reference to the accompanying drawings.
4A to 4D are plan views illustrating a method of manufacturing an organic EL device having an IPE structure according to the present invention.
As shown in FIG. 4A, the lower electrode layer is deposited on the substrate 400, and then the lower electrode layer is etched using a mask pattern (not shown) as a mask to form a striped lower electrode 410. In this case, the lower electrode 410 may be formed of a transparent metal, and an opaque metal may be used. In addition, the thickness of the lower electrode 410 is hundreds of angstroms to thousands of angstroms, and varies depending on physical properties and process characteristics.
Next, as shown in FIG. 4B, after forming the array pattern 420 on the lower electrode 410, the insulating layer 430 is deposited, and the insulating layer 430 is etched to expose the lower electrode 410. Thus, a plurality of electrode holes 440 are formed. In this case, the plurality of electrode holes 440 are regularly arranged at inner edges of the unit pixel 450 of the array pattern 420.
In addition, the insulating layer 430 serves to insulate the lower electrode 410, which will be described later, from the upper electrode 460 having a different potential, and is connected to the first upper electrode 462 and the lower electrode through the electrode hole 440. It serves to make contact with 410.
Subsequently, as illustrated in FIG. 4C, an upper electrode layer is deposited on the insulating layer 430 on which the electrode holes 440 are formed, and then patterned to form a first upper electrode 462 and a second upper electrode 464 for each unit pixel. To form. Each of the first electrode 462 and the second upper electrode 464 has fine lines, and the fine lines have a comb shape to cross each other. The upper electrode layer 460 is dry etched using the anisotropic etching technique. The reason for using the anisotropic dry etching technique is to uniformly form the fine line widths of the first upper electrode 462 and the second upper electrode 464. This is to lower the resistance generated when applying current and to prevent the driving voltage from rising. However, the taper may be formed up to 10 ° 90 ° by wet etching for even application of the organic layer.
As shown in the enlarged view of the cell, the first upper electrode 462 is electrically connected to the lower electrode 410 through the electrode hole 440. Accordingly, the current applied to the lower electrode 410 is transferred to the first upper electrode 462 through the electrode hole 440. Fine lines of the first upper electrode 462 and the second upper electrode 464 are arranged in a form orthogonal to the lower electrode 410, and the second upper electrode 464 has a potential different from that of the first upper electrode 462. Has
In addition, the second upper electrode 464 and the first upper electrode 462 may be used as any electrode without being fixed to the cathode electrode and the anode electrode.
Subsequently, as illustrated in FIG. 4D, the organic compound 470 is coated on the insulating layer 430 on which the first and second upper electrodes 462 and 464 are formed.
In the structure of the organic EL device manufactured by the process of FIGS. 4A to 4D, as shown in FIG. 5, the lower electrode 410 and the insulating layer 430 are sequentially formed on the substrate 400. Upper electrodes 460 having different electric potentials are formed on the insulating layer 430.
In addition, when the organic compound 470 is coated on the upper electrode 460 and a current flows therethrough, light is emitted 550 while current flows between the fine lines of the upper electrode 460. Here, the organic compound 470 is a polymer and a single molecule having high efficiency, and the polymer material is PPV, MEH-PPV, Polythiophene, PolyPyrrole, OC1C10, etc. The material of is used. That is, when the organic compound is deposited on both electrodes arranged in parallel as described above, it is not necessary to use the shadow mask used in the conventional cathode formation process technology, and it is possible to use a high efficiency without the limitation of using the conventional transparent electrode. Various metal electrodes can be used. Since light is emitted between the fine electrodes of the first upper electrode and the second upper electrode, when the lower electrode and the substrate are used as transparent materials, the display can be bidirectionally displayed.

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As described above, according to the method of manufacturing an organic light emitting display according to the present invention, unlike the method of observing light emission using a conventional ITO transparent electrode by forming an electric field in a parallel electrode array structure (IPE), on the cathode electrode By depositing an organic compound, it is not necessary to use a transparent electrode, and light emission can be observed in both directions.                     

In addition, since the lower electrode and the upper electrode can be used by switching each potential without being fixed to the cathode and the anode electrode, there is no need to consider which electrode should be formed first.

In addition, a highly efficient organic EL panel can be manufactured using various metal electrodes and opaque electrodes having a high work function without using a high resistance ITO material when forming the anode electrode, and without forming a conventional shadow mask, a cathode electrode As a result, the reduction in device yield caused by using the shadow mask is solved.

Moreover, the light emission can be observed in both directions, which can be used for mobile phones and other small PDA panels.

Claims (7)

A lower electrode on the substrate, An array pattern positioned on the lower electrode, An insulating layer on the array pattern, A first upper electrode and a second upper electrode on the insulating layer, and An organic compound positioned on the insulating layer between the first upper electrode and the second electrode Including, And the first upper electrode and the second upper electrode each include a plurality of linear branches, and the branches are alternately arranged at regular intervals. The method of claim 1, And the first upper electrode and the second upper electrode are formed on the same plane. The method of claim 1, The insulating film includes a plurality of electrode holes exposing the lower electrode, The first upper electrode is connected to the lower electrode through the electrode hole. Organic light emitting display. The method of claim 3, The first upper electrode has a potential different from that of the second upper electrode, And a current flows between the first upper electrode and the second upper electrode to allow light to flow out between the branches of the first upper electrode and the second upper electrode. The method of claim 3, The substrate includes a plurality of unit pixels, And the electrode holes are arranged in a row at edges of the unit pixels. The method of claim 1, And sidewalls of the first upper electrode and the second upper electrode are inclined at an angle of 10 ° to 90 ° with respect to the substrate surface. The method of claim 1, And the first upper electrode and the second upper electrode are transparent electrodes or opaque electrodes.

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