KR20070109226A - Organic light emitting device and fabrication method of the same - Google Patents

Abstract

An organic light emitting device and a manufacturing method thereof are provided to improve an image quality by preventing second electrodes adjacent to pixels from being short-circuited to each other. An organic light emitting device includes a substrate(400), a first electrode(410), an insulation film(420), a partition(425), a light emitting layer, and a second electrode. The first electrode is arranged on the substrate. The insulation film is arranged on the first electrode and includes an aperture for exposing a portion of the first electrode. The partition is arranged on the insulation film and formed by using a gravure offset printing scheme. The light emitting layer is patterned by the partition in the aperture. The second electrode is patterned by the partition on the light emitting layer.

Description

Organic Light Emitting Device and Fabrication Method of the same

1 is a cross-sectional view showing a conventional organic light emitting display device.

2 is a photograph showing a partition of a conventional organic light emitting display device.

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

4A to 4F are cross-sectional views of processes for describing a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

5 is a photograph showing a partition manufactured according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

400: substrate 410: first electrode

415: opening 420: insulating film

425: partition 430: light emitting layer

440: second electrode 450: gravure substrate

455: groove 465: blade

470: feed roller

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

Among flat panel display devices, an organic light emitting device is a self-luminous display device that electrically excites an organic compound to emit light. The organic light emitting diode does not need a backlight, so it can be light and thin and can simplify the process. In addition, low-temperature fabrication is possible, response speed is 1ms or less, high speed response speed, low power consumption, wide viewing angle, high contrast and the like.

The organic light emitting device includes an organic light emitting layer between the anode and the cathode, so that holes supplied from the anode and electrons received from the cathode combine in the organic light emitting layer to form an exciton, which is a hole-electron pair, and then the exciton is in the bottom state. It is emitted by the energy generated by the return.

1 is a cross-sectional view showing an organic light emitting display device according to the prior art.

Referring to FIG. 1, an organic light emitting display device includes an insulating layer 120 including a substrate 100, a first electrode 110 positioned on the substrate, and an opening 115 exposing a portion of the first electrode 110. In addition, the barrier rib 125 disposed on the insulating layer 120 and the light emitting layer 130 positioned in the opening 115 and patterned by the barrier rib 125 and the light emitting layer 130 are patterned by the barrier rib 125. The second electrode 140 is included.

Here, the partition wall 125 is formed by applying a negative photoresist on the insulating film 120 and then exposing and developing the negative photoresist. The partition wall 125 is used to pattern the light emitting layer 130 and the second electrode 140 for each pixel without using a separate metal mask. Therefore, the partition wall 125 must be formed in the shape of an inverse taper to prevent the light emitting layer or the metal layer from being sequentially stacked.

Figure 2 is a photograph showing a partition of the organic light emitting device according to the prior art.

As described above, the partition wall 125 should be formed to have a reverse taper shape. As shown in FIG. 2, the partition wall 125 formed by the prior art has a taper angle of 90 degrees or more, and has a reverse taper shape. It can be seen that it does not have. This is caused by a failure of the exposure and development process for forming the partition wall (125). This results in poor patterning of the second electrode 140, as shown at A in FIG. Therefore, a short is generated between the second electrodes of adjacent pixels, so that a desired video image cannot be obtained.

Accordingly, an object of the present invention is to provide an organic light emitting display device and a method of manufacturing the same, which can improve the reliability and manufacturing yield of the organic light emitting display device.

In order to achieve the above object, the present invention, an insulating film including a substrate, a first electrode located on the substrate, an opening positioned on the first electrode and exposing a portion of the first electrode, the insulating film is located on the insulating film and gravure An organic electroluminescent device comprising a partition formed by an offset printing method, an opening located in an opening, and a patterned light emitting layer formed by the partition and a second electrode patterned by the partition.

In addition, the present invention, the step of forming a reverse tapered groove in the gravure substrate, the step of filling the partition paste in the groove, transferring the partition paste filled in the groove to the transfer roller, transferred to the transfer roller Transferring the partition paste onto a substrate on which an insulating film including an opening for exposing the first electrode and the first electrode is formed to form a partition wall; forming a light emitting layer on the substrate including the partition and the opening; It provides a method of manufacturing an organic light emitting display device comprising the step of forming a second electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

Referring to FIG. 3, the first electrode 310 is positioned on the substrate 300, and the insulating layer 320 is positioned on the first electrode 310. The insulating layer 320 may include openings 315 exposing a portion of the first electrode 310.

The partition wall 325 is disposed on the insulating layer 320. The partition wall 325 is formed by gravure offset printing, and may have a reverse taper shape and a taper angle of 45 degrees or more and less than 90 degrees. In addition, the partition wall 325 may be made of an acrylic resin, a benzocyclobutene resin, a polyimide resin, or a novolac resin.

The emission layer 330 is disposed on the partition 325 and the opening 315, and the second electrode 340 is disposed on the partition 325 and the emission layer 330.

Hereinafter, a method of manufacturing an organic light emitting display device having the structure as described above will be described.

4A to 4F are cross-sectional views of processes for describing a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 4A, a first electrode 410 is formed on a substrate 400 made of glass, plastic, or metal. The first electrode 410 may be an anode, and may be formed of a transparent conductive film such as indium tin oxide (ITO), indium zinc oxide (IZO), indium cerium oxide (ICO), or zinc oxide (ZnO).

An insulating film 420 is stacked on the first electrode 410. Then, this is etched to form an opening 415 exposing a portion of the first electrode 410.

Referring to FIG. 4B, grooves 455 are formed on the gravure substrate 450. The groove 455 may have a reverse taper shape, and the taper angle θ of the groove 455 may be 45 degrees or more and less than 90 degrees.

Here, the taper angle (θ) of the groove 455 should be 45 degrees or more to secure the lower area of the partition wall to be formed by the groove 455, and less than 90 degrees to obtain a stable reverse tapered partition wall effectively. The light emitting layer and the second electrode can be patterned.

Referring to FIG. 4C, the partition paste is coated on the gravure substrate 450 including the recesses 455 to fill the recesses 455. Here, the partition paste may be made of an acrylic resin, a benzocyclobutyne resin, a polyimide resin, or a novolac resin.

Then, the blade 465 is used to remove the remaining paste 425a except for the partition paste 425 filled in the recess 455.

Referring to FIG. 4D, the partition roller paste 425 filled in the groove 455 is transferred to the transfer roller 470 while rotating and moving the transfer roller 470.

Referring to FIG. 4E, the transfer roller 470 to which the barrier paste 425 is transferred is aligned on the substrate 400 on which the first electrode 410 and the insulating film 420 are formed. Then, the barrier paste 425 attached to the transfer roller 470 is transferred onto the insulating film 420 while rotating the transfer roller 470 and moving the substrate in one direction. As a result, the partition wall 425 having the reverse taper shape can be formed on the insulating film 420.

Referring to FIG. 4F, an emission layer 430 is formed on the substrate 400 including the partition wall 425. Here, since the partition wall 425 having an inverse taper shape exists on the insulating layer 420, the light emitting layer 430 may be separately formed in the opening 415 of each pixel without a separate mask.

Next, a second electrode 440 is formed on the light emitting layer 430. The second electrode 440 may be a cathode, and may be made of magnesium (Mg), silver (Ag), aluminum (Al), calcium (Ca), or an alloy thereof. The second electrode 440 may also be patterned by the partition wall 425 to be formed separately in each pixel.

As described above, the organic light emitting display device according to the embodiment of the present invention includes a partition wall formed by a gravure offset printing method. Since the partition wall is manufactured in an inverse taper shape having a predetermined taper angle, the second electrode formed subsequently can be effectively patterned. Therefore, the phenomenon in which the second electrodes of the adjacent pixels are prevented from being shorted can be prevented, thereby improving the quality of the screen and increasing the reliability of the device.

In addition, since the inverted tapered partitions are conventionally formed by a photolithography process, a negative photoresist must be used as the material of the partitions. However, since the barrier rib of the organic light emitting device according to the embodiment of the present invention is formed by a gravure offset printing method, it is not necessary to be limited to a material that is reactive with light.

While the invention has been shown and described with reference to certain preferred embodiments, the invention is not so limited, and the invention is not limited to the scope and spirit of the invention as defined by the following claims. It will be readily apparent to one of ordinary skill in the art that various modifications and variations can be made.

The present invention can improve the quality of the screen of the organic light emitting device, it is possible to increase the reliability and manufacturing yield of the device.

Claims (8)

Board; A first electrode on the substrate; An insulating layer on the first electrode and including an opening exposing a portion of the first electrode; A partition wall disposed on the insulating layer and formed by gravure offset printing; An emission layer positioned in the opening and patterned by the partition wall; And And a second electrode on the emission layer and patterned by the barrier rib. The method of claim 1, The partition wall has an inverse taper shape, and the size of the taper angle θ of the partition wall is 45 degrees or more and less than 90 degrees. The method of claim 1, The partition wall is any one selected from the group consisting of acrylic resin, benzocyclobutene resin, polyimide resin and novolak resin organic light emitting device.  The method of claim 1, The first electrode is an anode, and the second electrode is a cathode. Forming an inverse tapered groove in the gravure substrate; Filling partition paste into the recess; Transferring the partition paste filled in the groove to a transfer roller; Transferring the barrier paste transferred to the transfer roller onto a substrate having an insulating film including a first electrode and an opening exposing the first electrode to form a barrier rib; Forming a light emitting layer on the substrate including the barrier rib and the opening; And A method of manufacturing an organic light emitting display device comprising the step of forming a second electrode on the light emitting layer. The method of claim 5, Filling the partition paste is. Applying a partition paste on a gravure substrate including the recesses; And A method of manufacturing an organic light emitting display device, the method comprising: removing the remaining paste for the partition wall except for the partition paste filled in the recess using a blade. The method of claim 5, The partition paste is a method of manufacturing an organic light emitting device comprising any one selected from the group consisting of acrylic resins, benzocyclobutene resins, polyimide resins and photoresists. The method of claim 5, The groove is a method of manufacturing an organic light emitting display device to have a tapered angle of 45 degrees or less than 90 degrees.

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