KR100766944B1 - Method for manufacturing of passive matrix type organic light emitting display - Google Patents

Abstract

A method for manufacturing a passive matrix type organic light emitting display apparatus is provided to improve a color reappearance rate of a blue pixel by fractionizing the film thickness of an organic light emitting layer by each pixel. A method for manufacturing a passive matrix type organic light emitting display apparatus includes the steps of: preparing an exclusive mask by each pixel of red, green, and blue colors; forming a lower part common layer on each pixel using the exclusive mask by each pixel; forming a light emitting layer on the lower part common layer of each pixel using the exclusive mask by each pixel; and forming an upper part common layer on the light emitting layer of each pixel using the exclusive mask by each pixel.

Description

Manufacturing method of passive organic light emitting display device {METHOD FOR MANUFACTURING OF PASSIVE MATRIX TYPE ORGANIC LIGHT EMITTING DISPLAY}

1 is a process block diagram illustrating a method of manufacturing a passive organic light emitting display device according to an exemplary embodiment of the present invention.

2 is a plan view illustrating an example of a pixel-specific mask used to form an organic light emitting layer of a passive organic light emitting diode display according to an exemplary embodiment of the present invention.

3 is a schematic block diagram of a general passive organic light emitting display device.

4 is a cross-sectional view illustrating a detailed structure of the organic light emitting layer illustrated in FIG. 3.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a passive organic light emitting display device, and more particularly, to a method of manufacturing a passive organic light emitting display device having improved color reproducibility of a blue pixel.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such flat panel displays include Liquid Crystal Display (LCD), Field Emission Display (FED), Plasma Display Panel (PDP) and Organic Light Emitting Display (PDP). ).

The organic light emitting diode display is a self-luminous display device that electrically excites an organic compound to emit light. The organic light emitting diode display may display an image by voltage driving or current driving N × M organic light emitting devices.

The organic light emitting diode has a diode characteristic and is also called an organic light emitting diode, which is composed of an anode electrode as a hole injection electrode, an organic thin film as a light emitting layer, and a cathode electrode as an electron injection electrode. Holes and electrons are injected into the organic thin film to emit light when an exciton in which holes and electrons are combined falls from an excited state to a ground state.

The organic light emitting diode display having such a configuration may be classified into an active matrix type organic light emitting display and a passive matrix type organic light emitting display according to a driving method.

A general configuration of the passive organic light emitting display device will be briefly described with reference to FIGS. 3 and 4 as follows.

 The anode electrode 20 is formed in a stripe pattern in the display area of the substrate 10, and the pixel area of the anode electrode 20 is exposed by an inter insulator 30. Here, the insulating layer may be configured to expose the pixel region in a plurality of lattice patterns.

A separator 40 is stacked on the insulating layer 30 in a direction orthogonal to the anode electrode 20. It is formed into a structure.

The organic light emitting layer 50 and the cathode electrode 60 are sequentially stacked on the anode electrode 20 in the space between the separators 40.

Here, the anode electrode 20 serves as a first electrode for supplying holes to the organic light emitting layer 50, and the cathode electrode 60 serves as a second electrode for supplying electrons to the organic light emitting layer 50.

The organic light emitting layer 50 includes a common layer 52 that is commonly deposited regardless of the color of each pixel, and an emission layer 54 that is individually deposited according to the color of each pixel.

The common layer 52 includes a lower common layer 56 stacked between the anode electrode 20 and the light emitting layer 54, and an upper common layer 58 stacked between the light emitting layer 54 and the cathode electrode 60. Include.

The lower common layer 56 includes a hole injection layer 56a and a hole transport layer 56b, and the upper common layer 58 includes an electron transport layer 58a and an electron injection layer 58b. Of course, in some cases, the electron injection layer 58b may be omitted, and the detailed laminated structure of the common layer 52 may be modified in various forms.

The passive organic light emitting diode display having such a configuration emits light when an exciton in which holes and electrons injected from the anode electrode 20 and the cathode electrode 60 are injected into the organic light emitting layer 50 falls from the excited state to the ground state. This is done to display an image through the substrate 10.

Therefore, in forming the organic light emitting layer described above, when forming the common layer 52, a separator 40 formed on the same mask, for example, an insulating film, is not formed for each pixel of red, green, and blue. The deposition operation is performed at the same time, and the emission layer 54 is individually deposited using a dedicated mask provided for each pixel.

When the light emitting layer 54 is deposited, full color is realized by controlling the film thickness.

However, according to the above-described prior art, only adjusting the film thickness of the light emitting layer has a limitation in improving the color reproducibility of the blue pixel.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a method of manufacturing a passive organic light emitting display device which effectively improves the color reproducibility of each pixel.

The present invention to achieve the above object,

A method of manufacturing a passive organic light emitting display device in which an organic light emitting layer including a common layer and a light emitting layer is deposited on a substrate on which a lower structure is formed, and the organic light emitting layer for each pixel is formed using a dedicated mask for each pixel in red, green, and blue colors. Provided is a method of manufacturing a passive organic light emitting display device, which is deposited separately.

In practicing the present invention, the common layer may include a lower common layer stacked between the anode electrode and the light emitting layer, and an upper common layer stacked between the light emitting layer and the cathode electrode, and the lower common layer may include a hole injection layer and a hole. The transport layer may be included, and the upper common layer may include the electron transport layer. Of course, the upper common layer may further include an electron injection layer stacked between the electron transport layer and the cathode electrode.

More specifically, in the method of manufacturing a passive organic light emitting display device according to an embodiment of the present invention, a passive organic light emitting display in which an organic light emitting layer including a lower common layer, a light emitting layer and an upper common layer is deposited on a substrate on which a lower structure is formed. A method of manufacturing an apparatus, the method comprising: preparing a mask for each pixel of red, green, and blue, forming a lower common layer on each pixel using the mask for each pixel, and forming a mask for each pixel. Forming a light emitting layer on the lower common layer of each pixel by using a light emitting layer; and forming an upper common layer on the light emitting layer of each pixel by using a dedicated mask for each pixel; The thickness of at least one of the upper common layers is formed differently from the corresponding layers of the red and green pixels.

According to such a structure, by optimizing the film thickness of the common layer and the light emitting layer which comprise an organic light emitting layer for every pixel, the color reproducibility of a blue pixel can be improved compared with a red pixel and a green pixel.

Therefore, when the full color is implemented, an excellent display device may be manufactured.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a process block diagram illustrating a method of manufacturing a passive organic light emitting display device according to an exemplary embodiment of the present invention, and FIG. 2 is a diagram illustrating an example of a mask for each pixel used in the organic light emitting layer deposition process of FIG. 1.

The method of manufacturing the passive organic light emitting display device of the present invention is characterized in that the organic light emitting layer deposited on the pixel region of the anode electrode is optimized according to the color reproducibility of each pixel, and more specifically, to improve the color reproducibility of the blue pixel. It is characterized by.

Here, the organic light emitting layer includes a common layer including a lower common layer (hole injection layer and hole transport layer) and an upper common layer (electron transport layer), and a light emitting layer laminated between the hole transport layer and the electron transport layer, and in some cases May further include an electron injection layer between the electron transport layer and the cathode electrode.

Of course, the detailed laminated structure of the organic light emitting layer may be modified according to product specifications, but in the following embodiments, the lower common layer (hole injection layer and hole transport layer), the light emitting layer, and the upper common layer (electron transport layer and electron injection layer) ) Will be described in a stacked structure sequentially.

In order to optimize the color reproducibility for each pixel, the present invention optimizes the film thickness of the common layer for each pixel.

More specifically, it is known that among the red, green, and blue pixels, the blue pixel has a lower color reproducibility than the red and green pixels.

Accordingly, in the exemplary embodiment of the present invention, the color reproducibility of the blue pixel is improved by forming the film thickness of at least one of the common layers differently from the blue pixel and other pixels (red and / or green pixels).

To this end, in the present invention, a common layer is deposited using a pixel-specific mask used when the light emitting layer is deposited.

FIG. 2 shows a blue pixel dedicated mask used for depositing an organic light emitting layer of blue pixels.

In FIG. 2, reference numeral 100 denotes a mask body, and reference numeral 110 denotes an opening region corresponding to a blue pixel. Reference numerals 210 and 310 indicated by dotted lines indicate opening regions corresponding to red and green pixels, respectively.

Of course, only the opening region 110 corresponding to the blue pixel is formed in the blue pixel exclusive mask of FIG. 2.

In FIG. 2, red, green, and blue pixels are arranged in a horizontal direction to form one cell, but this is not essential and may be changed in various forms according to product specifications.

When forming the organic light emitting layer of each pixel using the pixel-specific mask having such a configuration, a lower structure is first formed on the substrate.

Here, the lower structure includes a first electrode serving as an anode electrode formed in a stripe pattern, an insulating film exposing a pixel region of the anode electrode, and a separator formed on the insulating film.

The separator is formed in a direction orthogonal to the anode electrode.

After forming the lower structure, a red pixel dedicated mask is disposed at a position adjacent to the lower structure, and then a hole injection layer is deposited on the red pixel using the mask.

Subsequently, after disposing a mask dedicated for green pixels, a hole injection layer is deposited on the green pixels using the mask. Similarly, after disposing a mask for blue pixels, a hole injection layer is deposited on the blue pixels.

Subsequently, by depositing a hole transporting layer on each pixel in the above-described order, a lower common layer consisting of a hole injection layer and a hole transporting layer is completed.

Thereafter, a light emitting layer is deposited on each pixel while the mask is sequentially changed, and an electron transporting layer and an electron injection layer are sequentially deposited according to the above-described method to deposit and form an upper common layer on each pixel.

In the above description, the lower common layer, the light emitting layer, and the upper common layer are sequentially formed according to pixels, but the description is not necessary.

For example, it is also possible to form all of the lower common layer, the light emitting layer and the upper common layer on the anode electrode of the red pixel with the red pixel exclusive mask disposed therein, and form the organic light emitting layer of the green pixel and the blue pixel in the same manner. .

In the above embodiment, the organic light emitting layer of the red pixel is first formed, but the organic light emitting layer of the green pixel or the blue pixel may be formed first.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

According to the manufacturing method of the passive organic light emitting display device according to the embodiment of the present invention described above, since the thickness of the organic light emitting layer can be further controlled for each pixel, the color reproducibility of the blue pixel is applied to the red pixel and the green pixel. It can be improved.

Therefore, when the full color is implemented, an excellent display device may be manufactured.

Claims (9)

A method of manufacturing a passive organic light emitting display device in which an organic light emitting layer including a common layer and a light emitting layer is deposited on a substrate on which a lower structure is formed. A method of manufacturing a passive organic light emitting display device, wherein the organic light emitting layer for each pixel is deposited separately using a mask for each pixel of red, green, and blue. The method of claim 1, The common layer includes a lower common layer stacked between an anode electrode and a light emitting layer, and an upper common layer stacked between the light emitting layer and a cathode electrode. The method of claim 2, The lower common layer includes a hole injection layer and a hole transport layer manufacturing method of a passive organic light emitting display device. The method of claim 2 or 3, The upper common layer includes an electron transport layer. The method of claim 2 or 3, The upper common layer further comprises an electron injection layer stacked between the electron transport layer and the cathode electrode. A method of manufacturing a passive organic light emitting display device in which an organic light emitting layer including a lower common layer, an emission layer, and an upper common layer is deposited on a substrate on which a lower structure is formed. Preparing a dedicated mask for each pixel of red, green, and blue; Forming a lower common layer on each pixel using the dedicated mask for each pixel; Forming a light emitting layer on a lower common layer of each pixel by using the dedicated mask for each pixel; And Forming an upper common layer on the light emitting layer of each pixel by using the dedicated mask for each pixel Including; And forming a thickness of at least one of the lower common layer and the upper common layer of the blue pixel differently from the corresponding layers of the red and green pixels. The method of claim 6, The lower common layer includes a hole injection layer and a hole transport layer manufacturing method of a passive organic light emitting display device. The method of claim 6, The upper common layer includes an electron transport layer. The method of claim 6, The upper common layer further comprises an electron injection layer stacked between the electron transport layer and the cathode electrode.

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