KR20030024996A - Organic electroluminedcence device and method of fabricating the same - Google Patents

Abstract

PURPOSE: An organic electro-luminescence device and a fabricating method thereof are provided to lengthen a lifetime of the organic electro-luminescence device by injecting silicon oil into a space between a packaging plate and a substrate. CONSTITUTION: An anode electrode(34) is formed on a substrate(32). The anode electrode(34) is used as a data electrode. An organic compound layer(48) is formed on the anode electrode(34). A cathode electrode(46) is formed on the organic compound layer(48). A packaging plate(54) is used for protecting the organic compound layer(48) from oxygen and moisture. A sealant(52) is used for sealing the substrate(32) and the packaging plate(54). The organic compound layer(48) is formed by stacking sequentially a hole injection layer(36), a hole transfer layer(38), an emitting layer(40), an electron transfer layer(42), and an electron injection layer(44). The cathode electrode(46) is used as a scan electrode. A getter(57) is formed on a back face of the packaging plate(54). A semipermeable layer(51) is adhered on the back face of the packaging plate(54). An oil injection hole(60) is formed at an edge of the packaging plate(54). The oil injection hole(60) is used for injecting silicon oil.

Description

Organic electroluminescent device and its manufacturing method {ORGANIC ELECTROLUMINEDCENCE DEVICE AND METHOD OF FABRICATING THE SAME}

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device and a method of manufacturing the organic light emitting display device to improve the life of the organic light emitting device.

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 displays (hereinafter referred to as "LCDs"), field emission displays (FEDs) and plasma display panels (hereinafter referred to as "PDPs") and electroluminescence. (Electro-luminescence: "EL") There is a display device, etc. Researches are being actively conducted to increase the display quality of such a flat panel display device and to make a large screen.

Among them, PDP is attracting attention as a display device which is light and small and is most advantageous for large screen because of its simple structure and manufacturing process. On the other hand, active matrix LCDs with thin film transistors ("TFTs") as switching elements are difficult to screen due to the use of semiconductor processes, but demand is increasing as they are mainly used as display elements in notebook computers. have. However, LCDs are difficult to make large areas and consume large power consumption due to the backlight unit. In addition, the LCD has a large optical loss and a narrow viewing angle by optical elements such as a polarizing filter, a prism sheet, and a diffusion plate.

In contrast, EL display elements are classified into inorganic ELs and organic ELs depending on the material of the light emitting layer. The EL display elements are self-luminous elements that emit light by themselves and have advantages such as fast response speed and high luminous efficiency, luminance, and viewing angle.

Referring to Fig. 1, an organic EL element of the EL display element forms an anode electrode 4 on a substrate 2 with a transparent electrode pattern, and forms an organic compound layer 18 for light emission thereon. The cathode electrode 16 is formed on the organic compound layer 18 as a metal electrode.

The anode electrode 4 is made of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide (zinc) on the substrate 2. It is formed by photolithgraphy using any one of materials such as oxide (Indium-Tin-Zinc-Oxide; ITZO). This anode electrode 4 is used as a data electrode.

In the organic compound layer 18, a hole injection layer 6 and a hole transfer layer 8 are sequentially formed on the anode electrode 4. On the hole transport layer 8, an organic light emitting layer (Emitting Layer) 10 having a function of emitting light is formed. In addition, an electron transport layer 12 and an electron injection layer 14 are sequentially formed on the organic light emitting layer 10.

On the organic compound layer 18, a cathode electrode 16 such as aluminum (Al) having a high reflectance is formed. The cathode electrode 16 is used as a scan electrode.

In the organic EL device, when driving voltage and current are applied to the anode electrode 4 and the cathode electrode 16, holes in the hole injection layer 6 and electrons in the electron injection layer 14 proceed toward the organic light emitting layer 10, respectively. The fluorescent material in the organic light emitting layer 10 is excited. In this way, the visible light generated from the organic light emitting layer 10 displays an image or an image on the principle of exiting through the transparent anode electrode 4.

As described above, the organic light emitting layer 10 of the organic EL device is damaged by the moisture and oxygen in the air, and thus the cathode electrode 16 and the organic compound layer 18 are damaged and have a fatal effect on life. In order to solve this problem, an encapsulation process using a packaging plate formed of a material such as metal or glass is added.

Referring to Fig. 2, the conventional packaging plate 24 is formed of glass, plastic, canister, or the like as a material.

A central portion of the rear surface of the packaging plate 24 is recessed to fill a getter 27 for absorbing moisture and oxygen, and the concave space includes materials such as barium oxide (BaO) and calcium oxide (CaO). This is filled. In addition, in order to prevent the getter 27, which is a moisture absorbent, from falling on the organic compound layer 18, a semi-permeable membrane (not shown) is attached to the back surface of the packaging plate 24 so that moisture, oxygen, and the like flow in and out. As the semipermeable membrane, materials such as Teflon, polyester, and paper are used.

The packaging plate 24 faces the organic compound layer 18 formed on the substrate 2 with the sealant 22 applied to the edge of the substrate 2 interposed therebetween.

The sealant 22 is an ultraviolet curing epoxy or the like. The ultraviolet curable epoxy is pressurized between the substrate 2 and the packaging plate 24 by using a technique such as dispensing or printing to be bonded, and then irradiated with ultraviolet rays to cure.

Thus, in sealing using the sealing agent 22, after sealing, the organic EL element is filled with an inert gas without moisture or oxygen. For this purpose, a glove box or a vacuum chamber is used.

In the case of sealing using the packaging plate 24 as described above, when the size of the organic EL element is increased to 5 inches or more, the packaging plate 24 may be applied to the packaging plate 24 even if some force is applied to the packaging plate 24 and the substrate 2. This causes a problem that the organic compound layer 18 is damaged.

In addition, even if the sealing plate 24 is sealed, since the sealing material is an organic material, external impurity gas penetrates, and the organic compound layer 18 and the cathode electrode are damaged, which has a fatal effect on life.

Accordingly, an object of the present invention is to provide an organic electroluminescent device and a method of manufacturing the same, which can improve the life of the organic electroluminescent device.

1 is a perspective view showing an organic light emitting display device of passive type.

2 is a cross-sectional view showing a conventional organic electroluminescent device packaged.

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

4 is a perspective view showing the packaging plate shown in FIG.

5 is a cross-sectional view illustrating a sealing of an organic light emitting display device according to a first embodiment of the present invention in stages.

FIG. 6 is a cross-sectional view illustrating injecting the silicone oil shown in FIG. 5 using a syringe; FIG.

7 is a cross-sectional view showing the injection of the silicone oil shown in Figure 5 using a vacuum chamber.

8 is a cross-sectional view illustrating a sealing of an organic light emitting display device according to a second exemplary embodiment of the present invention in stages.

<Description of Symbols for Main Parts of Drawings>

2, 32, 72: substrate 4, 34, 54: anode electrode

6, 36: hole injection layer 8, 38: hole transport layer

10, 40: organic light emitting layer 12, 42: electron transport layer

14, 44: electron injection layer 16, 46: cathode electrode

18, 48: organic compound layer 22, 52, 82: sealant

24, 54, 74: package plate 27, 57, 77: getter

51: semipermeable membrane 56: syringe

59: vacuum chamber 60, 80: oil inlet

61, 81: sealing plate 63, 83: ultraviolet epoxy

In order to achieve the above object, an organic light emitting display device according to the present invention is formed on a substrate to generate light and to cover the organic light emitting layer to protect the organic light emitting layer from an impurity gas containing oxygen and moisture A packaging plate, a sealing member applied to an edge of the substrate to seal the packaging plate and the substrate, a liquid filler injected into an interior space between the packaging plate and the substrate, any of the packaging plate and the substrate It is formed on one and at least one injection hole for injecting the liquid filler in the inner space of the packaging plate and the substrate and a sealing member for sealing the injection hole.

The injection hole is characterized in that for discharging the gas present in the interior space between the packaging plate and the substrate.

The liquid filler is characterized in that the silicone oil.

The inner space between the packaging plate and the substrate is characterized in that the vacuum state.

And a chamber containing the liquid filler, wherein the injection hole is contacted with the liquid filler to inject the liquid filler into an internal space between the packaging plate and the substrate in a vacuum state.

The liquid filler is characterized in that it comprises particles of any one of barium oxide, calcium oxide and silica gel that can adsorb oxygen and moisture.

A method of manufacturing an organic light emitting display device according to the present invention includes the steps of forming an organic light emitting layer for generating light on a substrate, applying a sealing agent to an edge of the substrate, and a packaging plate and the substrate covering the organic light emitting layer. Forming at least one injection hole in any one of the at least one injection hole; discharging the gas in the inner space between the packaging plate and the substrate through the injection hole; curing the sealing agent; And injecting and filling a liquid filler for protecting the organic light emitting layer into the inner space between the packaging plate and the substrate through the injection hole, and sealing the injection hole.

The injecting of the liquid filler may include maintaining an internal space between the packaging plate and the substrate in a vacuum state, and contacting the injection hole with the liquid filler in a chamber in which the liquid filler is filled, so that the liquid filler is in the vacuum state. It characterized in that it comprises the step of being injected into the interior space between the packaging plate and the substrate.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

With reference to Figures 3 to 7 will be described a preferred embodiment of the present invention.

Referring to FIG. 3, the organic light emitting display device according to the first embodiment of the present invention includes an anode electrode 34 formed on the substrate 32, an organic compound layer 48 formed on the anode electrode 34, The cathode electrode 46 formed on the organic compound layer 48 and the packaging plate 54 for protecting the organic compound layer 48 from oxygen and moisture, and the substrate 32 and the packaging plate 54 to be applied. The seal member 52 which seals the 32 and the packaging plate 54 is provided.

The anode electrode 34 is formed on indium-tin-oxide (ITO), indium-zinc-oxide (IZO), indium-tin-zinc- on the substrate 32. It is formed by photolithography using any one of materials such as oxide (Indium-Tin-Zinc-Oxide; ITZO). The anode electrode 34 is used as a data electrode.

In the organic compound layer 48, a hole injection layer 36 and a hole transfer layer 38 are sequentially formed on the anode electrode 34. An organic emission layer 40 is formed on the hole transport layer 38 to emit light. In addition, an electron transfer layer 42 and an electron injection layer 44 are sequentially formed on the organic light emitting layer 40.

On the organic compound layer 48, a cathode electrode 46 such as aluminum (Al) having a high reflectance is formed. The cathode electrode 46 is used as a scan electrode.

In the organic EL device, when a driving voltage and a current are applied to the anode electrode 34 and the cathode electrode 46, holes in the hole injection layer 36 and electrons in the electron injection layer 34 proceed toward the organic light emitting layer 40, respectively. The fluorescent material in the organic light emitting layer 40 is excited. In this way, the visible light generated from the organic light emitting layer 40 displays an image or an image on the principle of exiting out through the transparent anode electrode 34.

The packaging plate 54 is formed of glass, plastic, canister, or the like to prevent the organic light emitting layer 40 from being easily degraded by moisture and oxygen in the atmosphere.

The central portion of the back of the packaging plate 54 is recessed to fill a getter 57 for absorbing moisture and oxygen, and the concave space includes a material such as barium oxide (BaO) or calcium oxide (CaO). This is filled.

In addition, in order to prevent the getter 57, which is a moisture absorbent, from falling on the organic compound layer 48, a semipermeable membrane 51 is attached to the back surface of the packaging plate 54 so that moisture, oxygen, and the like flow in and out. The semi-permeable membrane 51 is made of a material such as Teflon, polyester, and paper.

An oil inlet 60 penetrating the packaging plate 54 is formed at the edge of the packaging plate 54 as shown in FIG. 4. The oil inlet 60 serves as a passage through which the gas inside the panel is discharged to the outside when the packaging plate 54 presses the substrate 32 close during sealing between the packaging plate 54 and the substrate 32.

In addition, the oil inlet 60 has a passage in which the silicon oil, which will be described later, is injected to insulate the organic compound layer 48 or the cathode electrodes 46 inside the panel after the packaging plate 54 and the substrate 32 are sealed. do. This silicone oil is excellent in insulation and chemically stable, and is a material which does not affect the organic compound layer 48 and the cathode electrode 46 formed on the substrate 32.

The oil injection hole 60 has a diameter of about 0.01 mm to 10 mm so that the gas inside the organic EL element can be discharged. The size of the oil inlet 60 is not limited to the size described above because the size of the oil inlet 60 may vary depending on the speed at which the packaging plate 54 is pressed and the size of the substrate 32. As such, the oil inlet 60 may be one and may be a plurality.

Referring to FIG. 5, the packaging plate 54 faces the organic compound layer 48 formed on the substrate 32 with the sealant 52 applied to the edge of the substrate 32 interposed therebetween.

The packaging plate 54 and the substrate 32 are sealed by the sealant 52 while being pressed in a glove box or vacuum chamber filled with an inert gas free of moisture or oxygen.

To this end, the sealant 52 is used, such as ultraviolet curing epoxy. The ultraviolet curable epoxy is pressurized between the substrate 32 and the packaging plate 54 by using a technique such as dispensing, printing, or the like.

When the packaging plate 54 and the substrate 32 are pressurized close to each other, the gas inside the organic EL element is discharged to the outside through the oil injection hole 60 formed in the packaging plate 54. In other words, the packaging plate 54 and the substrate 32 are slowly pressurized so that the gas inside the organic EL element can sufficiently escape. For this reason, the pressure inside the organic EL element does not increase due to the gas exiting to the outside. Then, the sealing agent 52 is irradiated with ultraviolet rays to cure.

After a predetermined time, the silicone oil 58 is injected into the space between the packaging plate 54 and the substrate 32 through the oil inlet 60 of the sealed packaging plate 54.

The injection of the silicone oil 58 may be performed using a syringe 56 or a vacuum chamber 59 containing the silicone oil 58.

Referring to FIG. 6, in the method of injecting the silicone oil 58 using the syringe 56, the syringe 56 is inserted into one of the two oil inlets 60 at the furthest distance of the packaging plate 54. Inject the oil (58). Then, the silicon oil 58 is drawn out from the other oil inlet 60, thereby filling the silicone oil 58 in the space between the packaging plate 54 and the substrate 32.

Referring to FIG. 7, in the method of injecting the silicon oil 58 using the vacuum chamber 59, the organic EL element is placed in the vacuum chamber 59 containing the silicon oil 58, and then the inside of the vacuum chamber 59 is vacuumed. Pump into the state. Then, when the oil inlet 60 is immersed in the silicon oil 58 contained in the vacuum chamber 59 in a vacuum state, the silicon oil 58 naturally forms in the space between the packaging plate 54 and the substrate 32. Is injected. At this time, a getter material such as barium oxide, calcium oxide, silica gel, or the like may be introduced into the silicone oil 58. Such particles of getter material may have a size from 1 μm to 5 mm.

As such, after injecting the silicone oil 58 into the space between the sealed packaging plate 54 and the substrate 32, the oil inlet 60 is sealed using the sealing plate 61.

To this end, the sealing plate 61 may be an ultraviolet epoxy or a thermosetting epoxy or the like, but a low temperature process using an ultraviolet epoxy is used to prevent damage to the organic compound layer 48. Ultraviolet epoxy 63 is applied to the sealing plate 61 by a dispensing method. Then, the sealing plate 61 is attached to the oil inlet 60 of the packaging plate 54 and then cured by irradiating ultraviolet (UV) light to seal the oil inlet 60.

Referring to FIG. 8, an organic light emitting display device according to a second exemplary embodiment of the present invention includes an EL layer 78 formed on a substrate 72 and a packaging plate for protecting the EL layer 78 from oxygen and moisture. 74 and a sealing material 82 applied between the substrate 72 and the packaging plate 74 to seal the substrate 72 and the packaging plate 74.

An oil injection hole 80 for discharging the gas inside the organic EL element to the outside is formed in the substrate 72. The oil inlet 80 discharges gas when it is sealed between the packaging plate 74 and the substrate 72 by pressurization, and a passage for injecting silicon oil 76 to insulate the EL layer 78 is provided. do.

The oil injection hole 80 has a diameter of about 0.01 mm to 10 mm so that the gas inside the organic EL element can be discharged and the silicon oil 76 can be injected. The size of the oil inlet 80 is not limited to the size described above because the size of the oil inlet 80 may vary depending on the speed at which the packaging plate 74 is pressed and the size of the substrate 82. As such, the oil inlet 60 may be one and may be a plurality.

In the EL layer 78, an anode electrode (not shown), an organic compound layer formed on the anode electrode, and a cathode electrode formed on the organic compound layer are formed. In addition, in the organic compound layer, a hole injection layer and a hole transport layer are sequentially formed on the anode electrode. An organic light emitting layer having a function of emitting light is formed on the hole transport layer. The electron transport layer and the electron injection layer are sequentially formed on the organic light emitting layer.

In the EL layer 78, when a driving voltage and a current are applied to the anode electrode and the cathode electrode, the holes in the hole injection layer and the electrons in the electron injection layer proceed toward the organic light emitting layer, respectively, to excite the fluorescent material in the organic light emitting layer. In this way, the visible light generated from the organic light emitting layer displays an image or an image on the principle that the light exits through the transparent anode electrode.

The packaging plate 74 is formed of glass, plastic, canister, or the like as a material in order to prevent the EL layer 78 from being easily degraded by moisture and oxygen in the atmosphere.

A central portion of the rear surface of the packaging plate 74 is recessed to fill a getter 77 for absorbing moisture and oxygen, and the recessed space is filled with materials such as BaO and CaO. In addition, in order to prevent the getter 77, which is a moisture absorbent, from falling on the EL layer 78, a semipermeable film (not shown) is attached to the back surface of the packaging plate 74 so that moisture, oxygen, and the like enter and exit. As the semipermeable membrane, materials such as Teflon, polyester, and paper are used.

This packaging plate 74 faces the EL layer 78 formed on the substrate 72 with the sealing agent 82 applied to the edge of the substrate 72 interposed therebetween.

The packaging plate 74 and the substrate 72 are sealed by the sealing agent 82 while being pressed in a glove box or vacuum chamber filled with an inert gas without moisture or oxygen.

To this end, the sealant 82 is used, such as ultraviolet curing epoxy. The ultraviolet curable epoxy is pressurized between the substrate 82 and the packaging plate 74 by using a technique such as dispensing or printing to bond.

When the packaging plate 74 and the substrate 72 are pressed close together, the gas inside the organic EL element is forced out through the oil injection hole 80 formed in the substrate 72. In other words, the packaging plate 74 and the substrate 72 are slowly pressed so that the gas inside the organic EL element can sufficiently escape. For this reason, the pressure inside the organic EL element does not increase due to the gas exiting to the outside. Then, the sealant 82 is cured by irradiating ultraviolet rays.

After a predetermined time, the silicone oil 76 is injected into the space between the packaging plate 74 and the substrate 72 through the oil inlet 80 of the substrate 72. This injection of the silicone oil 76 uses the syringe 56 and the vacuum chamber 59 as shown in FIGS. 6 and 7. At this time, a getter material such as barium oxide, calcium oxide, silica gel, or the like may be introduced into the silicone oil 76. Such particles of getter material may have a size from 1 μm to 5 mm.

When the injection is completed in the space between the sealed packaging plate 74 and the substrate 72, the oil inlet 80 is sealed using the sealing plate 81.

To this end, the sealing plate 81 may be an ultraviolet epoxy or a thermosetting epoxy or the like, but it is preferable to use a low temperature process using the ultraviolet epoxy 83 to prevent damage to the EL layer 78. The ultraviolet-epoxy 83 is apply | coated to this sealing plate 81 by the dispensing method. Then, the sealing plate 81 is attached to the oil inlet 80 of the packaging plate 74 and irradiated with ultraviolet (UV) to harden to seal the oil inlet 80.

As described above, the organic light emitting display device according to the first and second embodiments of the present invention forms a gas outlet in one of the packaging plate and the substrate, and discharges the internal gas to the outside during pressurization, thereby increasing the pressure inside the panel during sealing. It does not increase significantly and can prevent the sealant from being damaged.

As described above, the organic light emitting display device and the manufacturing method thereof according to the present invention have excellent insulation property in the space between the packaging plate and the substrate of the organic EL device, and do not cause chemical reaction with the organic material or the cathode of the EL device. Filling silicone oil can increase the life of the device. In addition, a getter material such as barium oxide, calcium oxide and silica gel is added to the silicone oil to remove moisture and oxygen, which are impurity gases inside the EL device, thereby preventing the EL device from deteriorating, thereby increasing the life of the EL device. have.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

An organic light emitting layer formed on the substrate to generate light, A packaging plate covering the organic light emitting layer to protect the organic light emitting layer from an impurity gas containing oxygen and moisture; A sealing member applied to an edge of the substrate to seal the packaging plate and the substrate; A liquid filler injected into an inner space between the packaging plate and the substrate; At least one injection hole formed in any one of the packaging plate and the substrate to inject the liquid filler into the packaging plate and the inner space of the substrate; An organic light emitting display device comprising: a sealing member for sealing the injection hole. The method of claim 1, The injection hole is an organic light emitting device, characterized in that for discharging the gas existing in the interior space between the packaging plate and the substrate. The method of claim 1, The liquid filler is an organic light emitting device, characterized in that the silicone oil. The method of claim 1, And an inner space between the packaging plate and the substrate is in a vacuum state. The method of claim 4, wherein And a chamber containing the liquid filler, and injecting the injection hole into the liquid filler to inject the liquid filler into an interior space between the packaging plate and the substrate in a vacuum state. The method of claim 3, wherein The liquid filler is an organic electroluminescent device, characterized in that the particles of any one of barium oxide, calcium oxide and silica gel that can adsorb oxygen and moisture. Forming an organic light emitting layer for generating light on the substrate; Applying a sealing agent to an edge of the substrate; Forming at least one injection hole in any one of a packaging plate and the substrate covering the organic light emitting layer; Discharging a gas in an internal space between the packaging plate and the substrate through the injection hole; Curing the sealing agent; Injecting and filling a liquid filler for protecting the organic light emitting layer from the impurity gas into an inner space between the packaging plate and the substrate through the injection hole; The method of manufacturing an organic light emitting device comprising the step of sealing the injection hole. The method of claim 7, wherein Injecting the liquid filler, Maintaining an internal space between the packaging plate and the substrate in a vacuum state; Contacting the injection hole with the liquid filler in the chamber containing the liquid filler to inject the liquid filler into an interior space between the packaging plate and the substrate in a vacuum state. Manufacturing method.