KR20020090572A - Method for manufacturing an organic electroluminescent display - Google Patents

Abstract

PURPOSE: A method for manufacturing an organic electroluminescent display is provided to reduce the manufacturing process of an interlayer insulating film and a separator by forming positive or negative photo sensitive photoresist in a single layer or a multi layer. CONSTITUTION: A transparent electrode(102) is formed on a glass substrate(100). A photosensitive insulating films(104a) are formed on the glass substrate(100). Layer insulating films(104b) and composite insulating films(104') are formed on the front and rear of the glass substrate(100) by patterning the photosensitive insulating films using masks. The composite insulating films(104') have separators(104a). An organic luminescent film(130) and a counterpart electrode(140) are formed on an luminescent zone among the layer insulating films(104b).

Description

Manufacturing method of organic electroluminescent display {METHOD FOR MANUFACTURING AN ORGANIC ELECTROLUMINESCENT DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an organic electroluminescent display, and in particular, an insulating film which prevents leakage current of a transparent electrode and a barrier film which separates pixels between organic light emitting films and a counter electrode when forming an opposite electrode can be simultaneously formed. It relates to a manufacturing method.

Currently, many display devices have been proposed as flat panel display devices, which are widely used in electronic notebooks, notebook computers, monitors, etc. Among them, LCD (Liquid Crystal Display) devices are attracting the most attention. However, LCDs have disadvantages of complicated manufacturing methods and expensive production equipment.

In recent years, organic electroluminescent devices have emerged as devices that solve such LCD problems. An organic electroluminescent device is a display that displays desired characters, images, and the like using characteristics of an organic light emitting material that emits self by applying a voltage. In addition, organic electroluminescent devices, which are in the spotlight as the demand is concentrated in the small product market of less than 5 inches, have excellent luminance because they emit light without the response speed and the color filter. In addition, since a separate light source is not required, power consumption is low, making it suitable as a portable display device.

The basic structure of the organic electroluminescent device is a structure in which a pair of transparent electrodes (Indium-Tin-Oxide) and a counter electrode are stacked on a glass substrate, and an organic light emitting layer is inserted between the electrodes. Is made of. Here, the organic light emitting film may be manufactured in a structure in which a hole injection film, a hole transporting film, a light emitting film, an electron transporting film and the like are stacked so as to transport electrons and holes and emit light. When a predetermined voltage is applied to the transparent electrode and the counter electrode, excitons are generated by injecting and recombining holes and electrons into the organic light emitting film, and when the excitons are deactivated, Light of wavelength is emitted (fluorescence, phosphorescence).

1 is a layout diagram of an organic electroluminescent display according to the prior art, in which a transparent electrode 12 and a separator 16 cross each other to form pixels of a matrix, and light is emitted to a portion of the crossed pixels. There is a light emitting area a, and the interlayer insulating film 14 fills in between the barrier rib films 16 except for the light emitting area a.

FIG. 2 is a vertical sectional view of the display taken along the line AA ′ of FIG. 1. 1 and 2, the organic electroluminescent display vertical structure of the prior art is a transparent electrode 12, an organic light emitting film 18, and a counter electrode 20 stacked on a glass substrate 10 through which light is transmitted. Organic electroluminescent device is formed. Then, an interlayer insulating film 14 for interlayer insulating the device is formed, and the partition film 16 is formed on the interlayer insulating film 14 except for the light emitting region a. At this time, the organic light emitting film 18 and the counter electrode 20 are stacked on the partition film 16.

The organic electroluminescent display of the prior art configured as above is manufactured as follows. 3A to 3E are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to the prior art.

First, as shown in FIG. 3A, after the transparent anode 12 is patterned on the glass substrate 10, the interlayer insulating layer 14 is formed and the portion corresponding to the emission region is etched. At this time, the etching of the interlayer insulating layer 14 is performed by a photo process using a photosensitive photoresist so that the etched taper of the interlayer insulating layer 14 is wider than the upper side.

3B, after the interlayer insulating layer 14 is etched, the barrier insulating layer 16 is formed on the entire surface of the resultant. In this case, the insulating layer 16 uses a non-photosensitive insulator such as silicon oxide (SiO 2), polyimide, or the like. Or photosensitive insulators such as photoresist or polyimide photoresist.

3C and 3D, the photolithography process using the mask 15 is performed to expose and develop the barrier insulating film 16 to form a barrier film 16 ′ that separates the pixels. For this reason, the transparent substrate 12 corresponding to the light emitting area a is exposed by the partition film 16 'and the interlayer insulating film 14. The taper of the barrier film 16 ′ is a photosensitive insulator, and when a negative photoresist is used, a taper has a shape of a reverse taper that is narrower at a lower side than an upper side depending on photosensitive characteristics. On the contrary, the partition film 16 'becomes a forward taper having a lower portion than the upper portion when a positive photoresist is used.

Then, as shown in FIG. 3E, the organic light emitting layer 18 and the counter electrode 20 are sequentially stacked on the resulting light emitting region a to manufacture an organic light emitting diode. At this time, the organic light emitting film 18 and the counter electrode 20 formed on the light emitting region a and the interlayer insulating film 14 are separated from each other by a taper of the barrier film 16 ′.

On the other hand, the manufacturing method of the organic electroluminescent display according to the prior art has the following problems. Generally, in the photolithography process of an organic electroluminescent display, light wavelengths such as 365 (I-line), 405 (H-line), and 436 (G-line) are used during exposure. At such wavelengths, the thin film pattern is not sharply patterned, and a taper of the pattern is formed according to the bipolar or cathodic characteristics of the photosensitive material. If the barrier layer 16 'is a bipolar photosensitive material, the barrier layer 16' has a positive taper, and an organic light emitting layer formed on the open emission region of the interlayer insulating layer 14 and the barrier layer 16 '. It becomes difficult for the 18 and the counter electrode 20 to be separated from each other. This is because the step coverage characteristic is improved by the positive taper of the partition film 16 '. As such, when the organic light emitting region a, the organic light emitting layer 18 and the counter electrode 20 on the barrier layer 16 ′ are not separated from each other, a short circuit occurs to generate a leakage current.

Therefore, in order to adjust the shape of the taper of the barrier rib film 16 'and the interlayer insulating film 14', each of them must be manufactured in a separate process, thereby increasing production cost and defective rate due to an increase in the number of manufacturing processes.

In addition, when adopting the front exposure method using the same photosensitive material as the material of the interlayer insulating film 14 and the partition film 16 ', it is necessary to apply and expose two or more photosensitive materials. There was a limit to patterning the septum correctly.

In order to solve the problems of the prior art, an object of the present invention is to use an interlayer insulating film and a partition film as the same photosensitive material, but by adjusting the taper angles of the interlayer insulating film and the partition film at the same time using the photolithography process of the front exposure and the rear exposure, patterning is performed. An organic electroluminescent display can be provided.

In order to achieve the above object, the present invention provides a method of manufacturing an organic electroluminescent display in which an organic electroluminescent device having a transparent electrode / organic light emitting film / counter electrode on a glass substrate is formed of a matrix, the step of forming a transparent electrode on the glass substrate And forming a photosensitive insulating film on the glass substrate on which the transparent electrode is formed, and patterning the photosensitive insulating film by an exposure and development process using respective masks on the front and rear surfaces of the glass substrate on which the transparent electrode is formed to form an interlayer insulating film and a partition film thereon. And forming an organic light emitting film and a counter electrode in a light emitting region between the interlayer insulating films.

1 is a layout diagram of an organic electroluminescent display according to the prior art,

FIG. 2 is a vertical sectional view of the display by the line AA ′ of FIG. 1;

3A to 3E are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to the prior art;

4A to 4E are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to an exemplary embodiment of the present invention;

5A through 5D are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to another embodiment of the present invention;

6A through 6D are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to another embodiment of the present invention;

7A to 7D are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to another embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

100 glass substrate 102 transparent electrode

104, 106, 108, 109, 110, 111: photosensitive insulating film

104a, 106a, 108a, 111a: partition wall

104b, 106b, 109a, 110a: interlayer insulating film

104 ', 106', 108 ', 110': composite insulating film

105a: front mask 105b: rear mask

130: organic light emitting film 140: counter electrode

a: light emitting area

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

4A through 4E are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to an exemplary embodiment of the present invention. These cross-sectional views show the organic electroluminescent display of the present invention cut by line AA ′ of FIG. 1. Referring to this, the manufacturing process of an embodiment according to the present invention is as follows.

First, as shown in FIG. 4A, the transparent electrode 102 is formed on the glass substrate 100. As shown in FIG. 4B, the photosensitive insulating film 104 is formed on the glass substrate 100 on which the transparent electrode 102 is formed. At this time, the photosensitive insulating film 104 is made of a single layer of the negative electrode material.

4C, an exposure process is performed using the front and rear masks 105a and 105b at the front and rear surfaces of the glass substrate 100 on which the photosensitive insulating layer 104 is formed. In this case, the exposure process may sequentially perform the front and rear exposure processes, or may simultaneously perform the front and rear exposure processes. Accordingly, the upper part of the photosensitive insulating film 104 is exposed by the front mask 105a, while the lower part of the photosensitive insulating film 104 is exposed by the rear mask 105b.

Then, as shown in Fig. 4D, the development process is performed to pattern the photosensitive insulating film 104 to form a composite insulating film 104 'having an interlayer insulating film 104b and a partition film 104a thereon. At this time, the taper functioning as the interlayer insulating film 104b has a positive taper angle because it is negatively exposed from the rear surface of the substrate by the rear mask 105b. Accordingly, the interlayer insulating film 104b is formed in a trapezoidal shape on the substrate 100. On the other hand, the taper functioning as the partition film 104a has an inverse taper angle because it is negatively exposed from the front surface of the substrate by the front face mask 105a. Accordingly, the portion that functions as the partition film 104a is formed on the substrate 100 in an inverted trapezoidal shape.

Then, as shown in FIG. 4E, the organic light emitting film 130 and the counter electrode 140 are formed in the light emitting region a between the interlayer insulating films 104b. At this time, the organic light emitting film 130 and the counter electrode 140 are formed on the partition film 104a. The organic light emitting film 130 and the counter electrode 140 are separated from each other by a taper of the interlayer insulating film 104b and the partition film 104a.

One embodiment of the present invention implements a composite insulating film 104 ′ in which part of the insulating film serves as an interlayer insulating film and the other part serves as a partition film through a single patterning process. The taper of the bulkhead was made. However, the present invention can adjust the bipolar or cathodic material of the photosensitive insulating film and variously modify the taper shapes of the interlayer insulating film and the partition film of the organic electroluminescent display.

5A to 5D are cross-sectional views sequentially illustrating a manufacturing process of an organic light emitting display according to another embodiment of the present invention. Referring to this, other embodiments of the present invention are as follows. Another embodiment of the present invention is that the photosensitive insulating film is replaced with a bipolar material compared to the above-described embodiment.

First, as shown in FIG. 5A, the transparent electrode 102 is formed on the glass substrate 100. And the photosensitive insulating film 106 is formed in the glass substrate 100 in which the transparent electrode 102 was formed. At this time, the photosensitive insulating layer 106 is made of a single layer of a bipolar material.

5B, an exposure process is performed using the front and rear masks 105a and 105b at the front and rear surfaces of the glass substrate 100 on which the photosensitive insulating layer 106 is formed. At this time, the upper portion of the photosensitive insulating film 106 is exposed by the front mask 105a, while the lower portion of the photosensitive insulating film 106 is exposed by the rear mask 105b.

Subsequently, as shown in FIG. 5C, the development process is performed to pattern the photosensitive insulating film 106 to simultaneously form the interlayer insulating film 106b and the partition film 106a thereon. At this time, the taper of the interlayer insulating film 106b has an inverse taper angle because the taper is exposed to the bipolar surface from the rear surface of the substrate by the rear mask 105b. Accordingly, the interlayer insulating film 106b is formed on the substrate 100 in an inverted trapezoidal shape. On the other hand, the taper of the partition film 106a has a positive taper angle because the taper has been exposed bipolarly from the front surface of the substrate by the front mask 105a. Accordingly, the partition film 106a is formed in a trapezoidal shape on the substrate 100.

Then, as shown in FIG. 5D, the organic light emitting film 130 and the counter electrode 140 are formed on the light emitting region a between the interlayer insulating film 106b and the partition film 106a. In this case, the step coverage may be improved by the taper of the barrier layer 106a, so that the organic emission layer 130 and the counter electrode 140 formed on the emission region a and the barrier layer 106a may not be separated from each other. . In addition, by adjusting the type and thickness of the photosensitive insulating film 106 and the exposure amount and time irradiated on the entire surface of the substrate, the amount of exposure to the upper portion of the photosensitive insulating film 106 can be adjusted to change the taper angle of the partition film 106a. As a result, the emission region a and the organic emission layer 130 and the counter electrode 140 on the barrier layer 106a may be separated from each other.

Next, another embodiment of the present invention uses the material of the interlayer insulating film and the photosensitive insulating film which becomes the partition film by front and back exposure processes as a composite layer in which bipolar and negative materials are laminated.

6A to 6D are cross-sectional views sequentially illustrating a manufacturing process of an organic electroluminescent display according to another embodiment of the present invention. Referring to this, in another embodiment of the present invention, both the interlayer insulating film 109a and the partition film 108a are patterned in a trapezoidal shape.

As shown in FIG. 6A, the transparent electrode 102 is formed on the glass substrate 100, and the photosensitive insulating layers 108 and 109 are formed thereon. In this case, the photosensitive insulating layer includes a composite layer in which the negative electrode material 109 and the positive electrode material 108 are sequentially stacked.

6B, an exposure process is performed using the front and rear masks 105a and 105b at the front and rear surfaces of the glass substrate 100, respectively. At this time, the portion of the photosensitive insulating film 108 that is positive is exposed by the front mask 105a, while the portion of the photosensitive insulating film 109 that is negative is exposed by the rear mask 105b.

Subsequently, as shown in FIG. 6C, the development process is performed to pattern the negative and bipolar photosensitive insulating films 108 and 109 to have the interlayer insulating film 109a and the partition insulating film 108a thereon. To form. At this time, the taper of the interlayer insulating film 109a has a positive taper angle because the taper is exposed to the cathode on the rear surface of the substrate by the rear mask 105b. Accordingly, the interlayer insulating layer 109a is formed in a trapezoidal shape on the substrate 100. On the other hand, the taper of the partition film 108a has a positive taper angle because it is negatively exposed from the front surface of the substrate by the front face mask 105a. Accordingly, the partition film 108a is formed in a trapezoidal shape on the substrate 100. In addition, the taper of the partition film 108a can also change the taper angle of the partition film 108a by adjusting the type and thickness of the photosensitive insulating film and the exposure amount and time irradiated on the entire surface of the substrate.

6D, the organic light emitting film 130 and the counter electrode 140 are formed in the light emitting region a between the interlayer insulating film 109a, respectively.

7A to 7D are cross-sectional views sequentially illustrating a manufacturing process of an organic light emitting display according to another embodiment of the present invention. Referring to this, another embodiment of the present invention is an interlayer insulating film 110a and a partition film 111a. ) Is patterned in an inverted trapezoidal form.

First, as shown in FIG. 7A, the transparent electrode 102 is formed on the glass substrate 100, and the photosensitive insulating layers 110 and 111 are formed thereon. In this case, the photosensitive insulating layer includes a composite layer in which the negative electrode material 110 and the positive electrode material 111 are sequentially stacked.

Then, as shown in FIG. 7B, the exposure process is performed using the front and rear masks 105a and 105b at the front and rear surfaces of the glass substrate 100. At this time, the portion of the photosensitive insulating layer 111 that is positive is exposed by the front mask 105a, while the portion of the photosensitive insulating layer 110 that is negative is exposed by the rear mask 105b.

Subsequently, as shown in FIG. 7C, the development process is performed to pattern the positive and negative photosensitive insulating layers 111 and 110, thereby forming the composite insulating layer 110 ′ having the interlayer insulating layer 110a and the partition layer 111a thereon. Form. At this time, the taper of the interlayer insulating film 110a has a positive taper angle because the taper of the interlayer insulating film 110a is negatively exposed from the rear surface of the substrate. Accordingly, the interlayer insulating layer 110a is formed on the substrate 100 in an inverted trapezoidal shape. On the other hand, the taper of the partition film 111a has a positive taper angle because the taper has been exposed bipolarly from the front surface of the substrate by the front mask 105a. Accordingly, the barrier rib layer 111a is formed in an inverted trapezoidal shape on the substrate 100.

Then, as illustrated in FIG. 7D, the organic emission layer 130 and the counter electrode 140 are formed in the emission region a between the interlayer insulating layers 110a.

As described above, according to the manufacturing method of the organic electroluminescent display according to the present invention, the interlayer insulating film and the partition film are formed by using the interlayer insulating film and the partition film as the same photosensitive insulating material and patterning the photosensitive insulating material by the photolithography process of front and rear exposure. And a composite insulating film having the same. Thereby, the manufacturing process of an interlayer insulation film and a partition film can be simplified.

In the present invention, when the bipolar or negative photosensitive insulating material is formed as a single layer / composite layer, a desired taper shape of the interlayer insulating film and the partition film can be obtained. For this reason, the present invention adjusts the interlayer insulating film and the partition film taper shape so that the light emitting area and the film on the upper part of the partition film are not connected to each other, thereby preventing leakage current due to an electric field concentrated at the corners of the light emitting area.

Conventionally, when the same photosensitive material is used as the material of the interlayer insulating film and the partition film, it is difficult to accurately control the exposure thickness because two or more insulating film coating processes are required. However, in the present invention, the interlayer insulating film and the partition film can be accurately patterned by the photosensitive insulating material of the same material by the front and rear exposure processes.

Therefore, the present invention can shorten the manufacturing process of the organic electroluminescent display and increase its yield.

On the other hand, the present invention is not limited to the above-described embodiment, various modifications are possible by those skilled in the art within the spirit and scope of the present invention described in the claims to be described later.

Claims (3)

In the manufacturing method of the organic electroluminescent display in which the organic electroluminescent element which has a transparent electrode / organic light emitting film / counter electrode on a glass substrate consists of a matrix, Forming the transparent electrode on the glass substrate; Forming a photosensitive insulating film on the glass substrate on which the transparent electrode is formed; Forming a composite insulating film having an interlayer insulating film and a partition film thereon by patterning the photosensitive insulating film in an exposure and development process using respective masks on the front and rear surfaces of the glass substrate on which the photosensitive insulating film is formed; And And forming the organic light emitting layer and the counter electrode in a light emitting region between the interlayer insulating layers. The method of claim 1, wherein the photosensitive insulating layer is formed of a single layer of a positive electrode material or a negative electrode material. The method of claim 1, wherein the photosensitive insulating layer is formed of a composite layer in which an anode material and an anode material are laminated.