KR101544067B1 - Method for fabricating of Organic Light Emitting Display Device - Google Patents

Abstract

The present invention relates to a method of manufacturing an organic light emitting display having improved reliability by preventing deterioration of an organic electroluminescent device and reducing contact defects, and a method of manufacturing an organic light emitting display includes preparing a bottom plate having a cell driver, , Directly forming a film base resin on the lower plate, removing the solvent in the film base resin to form an adhesive film, and forming an adhesive film on the lower plate on which the contact spacer and the organic electroluminescence device Aligning the upper plate and the lower plate, pressing the lower plate and the upper plate to attach the upper plate and the lower plate together with the adhesive film, and performing a hardening process on the upper plate and the lower plate.

OLED, moisture permeability, film, cementation, uniformity

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of fabricating an organic light-

The present invention relates to a method of manufacturing an organic light emitting display, and more particularly, to a method of manufacturing an organic light emitting display having improved reliability by preventing deterioration of an organic light emitting diode and reducing contact defects.

The image display device that realizes various information on the screen is a core technology of the information communication age and it is becoming thinner, lighter, more portable and higher performance. (PDP), Electro Luminescent Display (ELD), FED (Field Emission Display), OLED (Light Emitting Diode), and the like have been developed in recent years, Organic Light Emitting Display) are being actively studied.

Among them, organic light emitting display (OLED), which displays images by controlling the amount of light emitted from the organic light emitting layer by using a flat panel display capable of reducing weight and volume, which is a disadvantage of a cathode ray tube (CRT) The OLED display is a self-luminous device using a thin light emitting layer between electrodes, and has an advantage that it can be thinned like a paper.

In an active matrix organic light emitting display device (AMOLED), pixels composed of three color (R, G, B) sub-pixels are arranged in a matrix form to display an image. Each sub-pixel includes an organic electroluminescent element and a cell driver for independently driving the organic electroluminescent element. The cell driver includes at least two thin film transistors and a storage capacitor to control the amount of current supplied to the organic light emitting display according to the data signal to control the brightness of the organic light emitting display.

Such an organic light emitting display device is manufactured by forming cells 3 on a lower plate 1 and an upper plate 2 facing each other as shown in Fig. 1, and forming a living substance 7 on the edge of the substrate and bonding them together. However, as time goes by, moisture permeates between the lower plate 1 and the upper plate 2, or deteriorates the organic electroluminescent device due to outgasing from the inside, thereby lowering the lifetime. In addition, the substance 7 easily separates the lower plate 1 and the upper plate 2 due to internal cracks or cracks during external impact due to moisture and gases, thereby lowering the reliability of the OLED display.

To prevent this, a method of attaching the lower plate and the upper plate together with an adhesive film has been proposed. To describe this manufacturing method in detail, the adhesive film is cut to fit the substrate size as shown in the flowchart of FIG. 2 (P2). At this time, a cover film is attached to the upper surface and the lower surface of the adhesive film, respectively. Subsequently, the cover film attached to the lower surface of the adhesive film is removed, and the adhesive film is aligned on the lower plate (P4). Then, the lower plate and the adhesive film are attached (P6). At this time, the lower surface of the lower plate is brought into contact with the lower surface of the adhesive film from which the cover film is removed.

Subsequently, the remaining cover film attached to the upper surface of the adhesive film is removed (P8), and then the upper plate is aligned on the lower plate (P10). At this time, the upper surface of the adhesive film faces the upper plate. Next, the lower plate and the upper plate are bonded together with the adhesive film interposed therebetween (P12). Subsequently, a curing process is performed on the bonded lower plate and the upper plate to complete the OLED display (P14).

As shown in FIG. 3, the method of manufacturing an OLED display device according to the present invention includes the steps of: forming a thick adhesive film between a contact spacer and a lower substrate to cause an electrical contact failure between the upper substrate and the lower substrate, .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing an organic light emitting display in which deterioration of an organic electroluminescent device is prevented, contact defect is reduced, and reliability is improved.

A method of manufacturing an organic light emitting display according to the present invention includes the steps of preparing a lower plate having a cell driving unit, directly forming a film base resin on the lower plate, removing solvent in the film base resin to form an adhesive film Aligning an upper plate having contact spacers and an organic electroluminescence device on the lower plate on which the adhesive film is formed; pressing the upper plate and the lower plate to bond the upper plate and the lower plate to each other with the adhesive film; And performing a hardening process on the joined upper and lower plates.

The adhesive film includes a conductive filler and an adhesive material.

The film base resin is formed by directly applying the film base resin to the lower plate by a dropping method, a slit method, or an inkjet method.

The step of removing the solvent is performed by a drying process, and the drying process is performed by a heating method or a vacuum method.

The adhesive film is formed by a multi-coating method.

Here, the multi-coating method repeatedly performs one cycle, and one cycle includes a step of forming the film base resin and a step of removing the solvent.

The concentration of the conductive filler in the adhesive film formed by the multi-coating method is higher at the lower portion than the upper portion of the adhesive film.

Alternatively, the conductive filler in the adhesive film is higher in density than other portions between the electrode of the cell driving portion of the lower plate electrically contacted with the contact spacer of the upper plate by the multi-coating method.

The thickness of the adhesive film is designed so that the height between the contact spacer and the cell driving unit is 1 m or less.

On the other hand, the lower plate is a mother board, and the film base resin is formed on the mother board so as to correspond to the size of the magnetic board.

By directly forming an adhesive film on a lower plate, the present invention can simplify the process and improve the productivity.

Further, since the thickness of the adhesive film is uniform and its formation is easy, it is possible to prevent contact failure and improve the reliability of the organic light emitting display device.

In addition, by reducing the moisture permeability between the lower plate and the upper plate, deterioration of the organic electroluminescent device is prevented, and rigidity characteristics are improved, so that cracks are generated in the external impact or separation of the lower plate and the upper plate can be prevented.

Furthermore, the present invention can form the adhesive film by the multi-coating method, and it is easy to adjust the concentration and position of the conductive filler in the adhesive film.

Hereinafter, a method of manufacturing an OLED display according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a flowchart illustrating a method of manufacturing an OLED display according to an exemplary embodiment of the present invention.

First, a lower plate is prepared, and then a liquid film base resin is directly formed on the lower plate. (S2) At this time, a cell driver composed of electrodes and insulating film patterns is formed on the lower plate. The solvent in the liquid film base resin is removed. (S4) This completes the adhesive film. Next, the upper plate is aligned on the lower plate. (S6) At this time, an organic electroluminescent device composed of electrodes, contact spacers and organic layer patterns is formed on the upper plate. Subsequently, the lower plate and the upper plate are bonded together with an adhesive film. (S8) A curing process is performed on the lower plate and the upper plate,

The organic light emitting diode display is completed through steps S2 through S10, and more specifically, will be described with reference to FIGS. 5A through 5E.

Referring to FIG. 5A, a liquid film base resin 70 is coated on a lower plate 10 on which a cell driver 12 is formed.

The lower substrate 10 is a transparent insulating substrate made of glass, quartz, ceramics, plastic, or the like. The cell driving unit 12 includes a power supply unit and a plurality of sub-pixel driving units. One sub-pixel driver includes a plurality of signal lines, a transistor, a capacitor, and a plurality of insulating films, and the transistor includes a switching transistor and a driving transistor.

The switching transistor supplies a data signal from the data line in response to the scanning signal of the gate line, and the driving transistor controls the amount of current flowing to the organic electroluminescent element in response to the data signal from the switching transistor. The capacitor plays a role of allowing a constant current to flow through the driving transistor even if the switching transistor is turned off.

The film base resin 70 is formed on the lower plate 10 by a dropping method, a slit method, or an ink jet method so that the cell drive portion 12 on the lower plate 10 is sufficiently covered. The film base resin 70 comprises a conductive filler (not shown), an adhesive material, and a solvent.

As shown in Fig. 6A, the loading method is directly formed by dropping the film base resin 70 on the lower plate 10 using the rollers 82. Fig. 6B, the slit applicator 84 is moved to the slit applicator 84 while moving the slit applicator 84 in the direction of the arrow or perpendicular to the arrow so that the slit applicator 84 passes over the lower plate 10, The film base resin 70 is discharged through the slit 85 formed in the lower portion of the lower plate 10 to be directly formed on the lower plate 10. In the inkjet method, as shown in FIG. 6C, the film base resin 70 is directly sprayed onto the lower plate 10 by using a plurality of injection nozzles 86.

Referring to FIG. 5B, the solvent inside the liquid film base resin 70 is removed to complete the adhesive film 72. The process of removing the solvent is performed by moving the lower plate 10 on the heating stage 50 and performing the drying process. The drying process is carried out in a heating or vacuum mode.

On the other hand, the adhesive film 72 may be formed on the lower plate 10 by performing a single dropping method, a slit method, or an inkjet method as described above, but may be formed by performing a plurality of times. When the adhesive film 72 is formed by the multi-coating method which is performed a plurality of times, the drying process for removing the solvent in the film base resin 70 is also performed many times.

In the multi-coating method, after the film base resin 70 is formed on the lower plate 10, the drying process is performed, the film base resin 70 is formed on the film base resin 70, the drying process is performed, And the adhesive film 72 is completed several times. That is, if the process of forming the film base resin 70 and the drying process are defined as one cycle, the cycle is repeatedly performed to form the adhesive film 72.

When the adhesive film 72 is formed by such a multi-coating method, the concentration and position of the conductive filler (not shown) inside the adhesive film 72 can be easily adjusted. Particularly, the conductive filler (not shown) is concentrated between the electrodes (not shown) of the cell driver 12 of the lower plate 10 to be electrically contacted with a contact spacer (not shown) of a top plate It is possible to prevent contact failure and improve the reliability of the OLED display. Further, the concentration of the conductive filler in the adhesive film 72 can be made higher at the lower portion than the upper portion of the adhesive film 72. [

The thickness of the adhesive film 72 is set such that the height between the electrodes (not shown) of the cell driver 12 of the lower plate 10, which is to be electrically contacted with a contact spacer (not shown) Or less.

As described above, by directly forming the adhesive film 72 on the lower plate 10, the adhesive film 72 can be easily formed, the process can be simplified, and the productivity can be improved. In addition, since the thickness of the adhesive film 72 can be made uniform and the thickness of the adhesive film 72 can be easily adjusted, it is possible to prevent contact defects between the contact spacer and the cell driver 12 to be formed thereafter, thereby improving the reliability of the OLED display .

Referring to FIG. 5C, the upper plate 20 on which the contact spacer (not shown) and the organic electroluminescent device 22 are formed is aligned on the lower plate 10. At this time, the organic electroluminescent device 22 is directed to the lower plate 10.

The organic electroluminescent device 22 is divided into a plurality of sub-pixels and emits red, green, and blue light according to the current flow to display predetermined image information. The organic electroluminescent device 22 includes a cell driver (not shown) 12, respectively. The organic electroluminescent device 22 includes a first electrode (not shown), a second electrode (not shown) as a counter electrode, and an organic light emitting layer (not shown) disposed between the first electrode

The first electrode is used as an anode electrode, and is formed so as not to be connected to the first electrode of the adjacent sub-pixel by a predetermined distance from the boundary of the sub-pixel. The organic light emitting layer emits red, green, and blue light in units of subpixels as a layer in which an exciton formed by combining holes and electrons injected from the first electrode and the second electrode falls to a ground state and emits light. Such organic luminescence includes a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer.

The second electrode is used as a cathode electrode, and is formed over the entire surface of the top plate 20. The first electrode and the second electrode may be formed of a transparent conductive layer or a metallic material such as Cr, Al, AlNd, Mo, Cu, W, Au, Ni, Ag, . At least one of the first electrode and the second electrode is formed of a transparent conductive layer so that light emitted from the organic light emitting layer can emerge out of the device.

A contact spacer (not shown) is provided for maintaining the cell gap between the upper plate 20 and the lower plate 10 and for electrically connecting the upper plate 20 and the lower plate 10 to each other. (20). The contact spacer (not shown) is made of a conductive material so as to be electrically connected to the cell driver 12, or the contact spacer is formed to surround the conductive material.

5D, the upper plate 20 aligned on the lower plate 10 is pressed in the direction of the arrow to perform the process of attaching the lower plate 10 and the upper plate 20 together. In the laminating process, the other surface of the upper plate 20 on which the organic electroluminescent device 22 is formed is pressed by the plate 60 having the rubber bag 62 attached thereto to form an adhesive film (not shown) between the lower plate 10 and the upper plate 20 72 so that the lower plate 10 and the upper plate 20 are joined together. At this time, the rubber bag 62 is disposed between the other surface of the plate 60 and the upper plate 20.

The cell driver 12 of the lower plate 10 is electrically connected to the organic electroluminescent device 22 of the upper plate 20 by the conductive filler and the contact spacer in the adhesive film 72. [

Referring to FIG. 5E, a curing process is performed on the lower substrate 10 and the upper substrate 20 to complete the OLED display. The curing process is carried out in an oven (not shown) at 100 DEG C for 3 hours. However, the time and temperature of the curing process are not limited to this, but can be adjusted by the thickness of the adhesive film 72 or the like.

The adhesive film 72 is formed entirely between the lower plate 10 and the upper plate 20 by the curing process. As a result, the adhesive film 72 firmly seals the lower plate 10 and the upper plate 20 to prevent moisture and the like from penetrating from the outside, thereby preventing deterioration of the organic electroluminescent device 22, . In addition, the present invention can prevent a crack from occurring in the event of an external impact or to prevent the lower plate 10 and the upper plate 20 from being separated from each other.

If the lower substrate 10 is a mother substrate, the present invention may further include a step of cutting the mother substrate to a magnetic plate, and the film base resin 70 may be formed by a plurality of mosquitoes Can be formed directly on the plate.

The above-described techniques represent presently preferred embodiments, and the present invention is not limited to the above-described embodiments and the accompanying drawings. Modifications and other uses of the embodiments will be apparent to those skilled in the art, and such modifications and other uses are intended to be included within the spirit of the present invention or defined by the scope of the appended claims.

1 is a cross-sectional view illustrating a conventional method of manufacturing an organic light emitting display device.

2 is a flow chart showing a conventional laminating process.

FIG. 3 is a view for explaining a problem in a conventional laminating process.

4 is a flowchart illustrating a method of manufacturing an OLED display according to an exemplary embodiment of the present invention.

5A to 5E are cross-sectional views for explaining the manufacturing method of the OLED display of FIG. 4 in detail.

6A to 6C are views for explaining a coating method of the film base resin according to the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

10: lower plate 12: cell driver

20: upper plate 22: organic electroluminescent device

50: Heating stage 72: Adhesive film

Claims (10)

Preparing a lower plate having a cell driver; Directly forming a film base resin on the lower plate; Removing the solvent in the film base resin to form an adhesive film; Aligning a top plate having contact spacers and an organic electroluminescent device on the bottom plate on which the adhesive film is formed; Pressing the lower plate and the upper plate to bond the upper plate and the lower plate with the adhesive film; And And performing a curing process on the joined upper and lower substrates. The method of claim 1, wherein the adhesive film comprises a conductive filler and an adhesive material. The method according to claim 1, wherein the film base resin is formed by directly applying the film base resin to the lower plate by a dropping method, a slit method, or an inkjet method. The method of claim 1, wherein the solvent removal step is performed in a drying step, Wherein the drying step is performed by a heating method or a vacuum method. The method according to claim 2, wherein the adhesive film is formed by a multi-coating method. 6. The method of claim 5, wherein the multi-coating method repeatedly performs one cycle, Wherein one cycle comprises a step of forming the film base resin and a step of removing the solvent. 6. The method of claim 5, wherein the concentration of the conductive filler in the adhesive film formed by the multi-coating method is higher at the lower portion than the upper portion of the adhesive film. 6. The method of claim 5, wherein the conductive filler in the adhesive film is higher in concentration than other portions between the electrode of the cell driving portion of the lower plate in electrical contact with the contact spacer of the upper plate by the multi-coating method A method of manufacturing an organic light emitting display device.  The method according to claim 1, wherein the thickness of the adhesive film is designed so that a height between the contact spacer and the cell driving unit is 1 占 퐉 or less. The method of claim 1, wherein the lower substrate is a mother substrate, and the film base resin is formed on the mother substrate to correspond to the size of the substrate.

Images