KR20010088741A - Organic el display apparatus - Google Patents

Abstract

PURPOSE: An organic EL display device is provided to improve a life span of an organic EL display device and maintain a white balance by presenting a packet metal can or a packet glass for absorbing a heat emitted from an organic EL and for lowering a temperature inside a panel. CONSTITUTION: An ITO(indium tin oxide) layer is deposited on a glass plate. A hall carrier layer is deposited on the ITO layer. A cathode layer(216) is isolated for a distance from the ITO layer. An electron carrier layer and a hall carrier layer are placed on lower part of the ITO layer. An organic EL emitting layer(212) is placed between the electron carrier layer and the hall carrier layer, and is excited by an energy generated in combination of a hall with an electron. A packet member of metal can(220a) or glass is isolated for a distance from upper face of the cathode layer(216) and protects a panel from an outer force and moisture.

Description

Organic EL Display {ORGANIC EL DISPLAY APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL display device, and more particularly, to an organic EL display device in which an EL display device is formed in a structure that facilitates heat absorption and emission, thereby increasing the life of various internal elements.

As is well known, the organic EL display device does not require a back light when compared to a TFT liquid crystal display (LCD), which is widely used in flat panel displays, and there is no deterioration in luminance due to color filters, especially a black screen. The viewing angle is very good because no electricity is supplied at the time of driving, power consumption is low, and light refraction is not used.

And since there is no back light, color filter, etc., it is possible to reduce the weight, and as the response speed is less than 1/1000 of the liquid crystal when driving a video, it is possible to replace the LCD in the future as a natural image reproduction. It is a very likely display device.

Hereinafter, a conventional organic EL display device will be described in detail with reference to FIGS. 1A and 1B. 1A and 1B are side cross-sectional views showing a conventional full color organic EL (passive type) display device.

Referring to this, the conventional organic EL display devices 2 and 2 'are coated with a transparent indium tin oxide (ITO) 6 to form an anode on the glass substrate 4 at regular intervals to be applied to the anode. use.

In addition, a hole transport layer 8 is applied to the upper surface of the ITO 6 to allow movement of holes, and a cathode layer made of a metal film such as an Al film as a cathode of the ITO 6 as a counter electrode. 16 is configured.

Meanwhile, an electron transport layer 14 and a hole transport layer 8 are provided between the ITO 6 and the cathode layer 16, that is, the upper portion of the ITO 6, so that holes (+) and electrons (−) are provided. And a structure in which the organic EL light emitting layer 12 is excited between the holes and the electron transport layers 8 and 14 by energy generated when the electrons and holes are combined.

That is, by the electricity supplied to the flexible circuit board 18, the organic EL light emitting layer 12 of DCM 2, Kinacrid, or DPVBi emits its own light by the energy generated when electrons and holes are combined, and thus the three primary colors of RGB. Is a flat color display that is colorized using it.

Such organic EL is likely to generate a short circuit due to moisture and the like, and since the moisture adversely affects the organic light emitting layer, the chemically absorbent drying material 22 is provided inside the organic EL display devices 2 and 2 '. As a typical drying material, a chemical absorbent containing BaO as a main component is frequently used, and there is a problem in that a physically absorbent drying material such as silica gel cannot be used since the temperature rises to 100 ° C. or more during organic EL emission.

In order to protect the inner surfaces of the organic EL display devices 2 and 2 'by ultrasonic fusion and to prevent penetration of moisture, the upper surface of the cathode layer 16 may be encapsulated metal can 20 or encapsulated glass. 20 ') is configured. (Inner state is filled with nitrogen gas) At this time, SUS430 BA material and glass for sealing are used as a material of the sealing metal can used.

By the way, materials such as DCM2, kinaclean, DPVBi and the like used as the organic EL light emitting layer are easily deteriorated by the heat generated during self-emission. That is, since deterioration proceeds at a temperature of 80 to 100 ° C., as shown in FIG. 7, the luminance decreases by about one third when (1, 2) 10000 hours of driving is shown.

7 shows the life of the organic EL using the encapsulation glass 20 ', and 2 shows the life of the 1.8 inch organic EL using the encapsulating metal can 20. In particular, the encapsulated glass 20 'is weak in external shock and has low thermal conductivity, and thus has a low heat release rate than the encapsulated metal can 20 using SUS430 BA, which exhibits very poor characteristics in terms of lifespan due to rapid temperature rise and high saturation temperature. .

Another problem of the organic light emitting body is that the degree of deterioration of the organic EL light emitting layer 12 forming the RGB is different, respectively, there is a problem caused by the luminance difference of the RGB organic EL light emitting layer 12 increases with time. . That is, since the luminance difference of the organic EL light emitting layer 12 increases with time, the white balance is changed with time as compared with the initial setting value, so that a color coordinate transition occurs, so that a desired color cannot be reproduced. There is.

The problem is that the conventional organic EL encapsulation bodies 20 and 20 'shown in Figs. 1A and 1B absorb heat quickly and do not release the heat to the outside to generate heat due to light emission of the organic light emitting body. Due to accumulation. In addition, in the case of the drying material 22 installed inside the panel, the physical absorber such as silica gel, which is inexpensive, releases moisture again as the temperature rises, thereby having a problem of increasing the price by incorporating expensive drying material such as BaO, which is a chemical absorber. have.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described state of the art, and it is possible to rapidly absorb and release heat absorbed from an organic light emitting body to lower the internal temperature of the panel to improve the life of the display device and maintain the white balance. An object of the present invention is to provide an organic EL display device characterized by enabling the use of a low-cost drying material.

1A and 1B are side cross-sectional views showing an organic EL display device according to a conventional embodiment,

2 is a side sectional view showing an organic EL display device according to a first embodiment of the present invention;

3 is a side sectional view showing an organic EL display device according to a second embodiment of the present invention;

4 is a side sectional view showing an organic EL display device according to a third embodiment of the present invention;

5 is a side sectional view showing an organic EL display device according to a fourth embodiment of the present invention;

6 is a view showing a heat transfer state of an organic EL display device according to an embodiment of the present invention;

7 is a graph showing an hourly temperature increase rate of an organic EL display device according to an embodiment of the present invention;

8 is a graph showing a state of change in luminance per hour of the organic EL display device according to the embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

200a, 200b, 200c, 200d: organic EL display,

220a: blackened encapsulated metal cans, 220b: blackened encapsulated glass,

220c: encapsulated metal cans, 220d: encapsulated metal cans with heat dissipation fins,

222: drying material, 224: heat radiation fins.

In order to achieve the above object, according to a preferred embodiment of the present invention, an ITO layer of an anode deposited on a glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or glass to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer by a predetermined distance, the EL layer being generated from the cathode layer, the organic layer, and the electron and hole transport layer. In order to absorb heat thereon, the encapsulation member is provided with an organic EL display device characterized in that the encapsulation metal can has a heat radiation rate of at least 0.2 or more.

Preferably, the encapsulation member is provided with an organic EL display device characterized in that the surface is made black using either chemical blackening or wet high temperature blackening to increase the emissivity.

According to a second embodiment of the present invention, there is provided an ITO layer of an anode deposited on a glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or glass to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer by a predetermined distance, the EL layer being generated from the cathode layer, the organic layer, and the electron and hole transport layer. In order to absorb heat thereon, the sealing member is provided with an organic EL display device characterized in that the sealing glass has a heat radiation rate of at least 0.3 or more.

Preferably, the encapsulation member is provided with an organic EL display device characterized in that the emissivity is increased by surface treatment using either dark tint glass or surface pigment treatment.

According to a third embodiment of the present invention, there is provided an ITO layer of an anode deposited on a glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or glass to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer by a predetermined distance, the EL layer being generated from the cathode layer, the organic layer, and the electron and hole transport layer. An organic EL display device is provided, wherein the encapsulation member is an encapsulation metal can whose surface roughness is at least 4.0 um or more for dissipating heat through the upper surface.

Preferably, the sealing member is provided with an organic EL display device characterized in that the heat dissipation area of the surface is increased by either sand blasting or etching treatment.

According to a fourth embodiment of the present invention, there is provided an ITO layer of an anode deposited on a glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or glass to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer by a predetermined distance, the EL layer being generated from the cathode layer, the organic layer, and the electron and hole transport layer. An organic EL display device is provided in which the encapsulation member has a heat dissipation fin having a height of 0.1 mm or more attached to an upper surface thereof to release heat through the upper surface thereof.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail with reference to drawings.

The present invention absorbs the heat from the heat generating source of the encapsulated metal can or the encapsulation glass quickly and quickly releases the absorbed heat, thereby quickly encapsulating the heat generated from the heat generating source and encapsulating in a structure that lowers the saturation temperature.

That is, the heat radiation rate of the encapsulating metal can and the encapsulating glass is increased to increase the heat absorption and release rate, or the heat dissipation area is increased to improve the heat removal rate, thereby suppressing the temperature rise of the organic light emitting body which is a heat generating source.

First, before describing an embodiment of the present invention, heat transfer is first described. There are three major categories of heat transfer: radiant heat transfer, convective heat transfer, and conduction heat transfer. Here, radiant heat transfer means that heat is transmitted by radiating heat from the surface as radiation, a kind of electromagnetic wave, and is generally expressed by the following formula.

[Equation 1]

Qb = σT ⁴ , Q = ε * Qb

Where Qb is the blackbody heat radiation energy, σ is the Stefan-Boltzmann constant, and T is the absolute temperature. Q is the actual heat radiation energy of the solid surface, ε is the emissivity, ε is a value of 0 = ε = 1.

As shown in Equation 1, it can be seen that the larger the value of ε, the larger the thermal radiation energy. Convective heat transfer is a phenomenon in which heat is transferred in an environment in which a fluid is present, and is expressed by the following equation.

[Equation 2]

Q = h (Tw-T∞)

Where Q is the convective heat transfer energy, h is the constant, Tw is the temperature of the solid surface, and T∞ is the temperature of the fluid.

Finally, conduction heat transfer means that heat is transferred and transferred inside the material. The higher the heat conductivity, the faster the heat transfer rate. The thermal conductivity has a value of SUS of 15 to 20, (W / m * K) and copper of about 400. (At 300 ⁰ K)

2 is a side sectional view showing an organic EL display device according to a first embodiment of the present invention, and FIG. 3 is a side sectional view showing an organic EL display device according to a second embodiment of the present invention.

Referring to this, in the related art, encapsulated metal cans or glass are used as in FIGS. 1A and 1B, but the encapsulated metal is a BA (bright annealing) treated material, which has a low emissivity of 0.1 or less, which makes it difficult to absorb heat by radiant heat transfer (thermal reflectance). 0.9 or more). In addition, when glass is used as the encapsulating material, the glass itself acts as a cause of difficulty in heat dissipation due to poor thermal conductivity.

On the contrary, in the present invention shown in FIGS. 2 and 3, the blackening treatment is performed on the encapsulating metal can 220a to increase the emissivity. More specifically, the blackening treated in the encapsulating metal can 220a is DX gas and Using a moisture to oxidize Fe metal to Fe203 at a high temperature of more than 400 ℃ to give a black light, was produced by adjusting the temperature and humidity conditions to the emissivity to more than 0.3 to improve the radiant heat transfer rate.

3 is another embodiment of the present invention, while the conventional glass reflects most of the heat, in the present invention, in order to increase the emissivity of the encapsulation glass 220b, clear glass having a light transmittance of 87% or more is used. Instead, semi-tint glass with a transmittance of 60 or less is used to improve the heat absorption and release rate by increasing the emissivity.

4 is a side sectional view showing an organic EL display device according to a third embodiment of the present invention, and FIG. 5 is a side sectional view showing an organic EL display device according to a fourth embodiment of the present invention.

4, in order to increase the specific surface area of the material, the upper surface of the encapsulating metal can 220c may have a roughness of 4 μm or more by sand blasting, etching, or the like. The heat dissipation rate is increased by increasing the surface area of the upper surface in the heat dissipation direction of the encapsulating metal can 220c.

Referring to FIG. 5, an encapsulation metal can 220d is formed at a predetermined distance from the upper portion of the cathode layer 216, and a plurality of heat dissipation fins 224 are attached to an upper surface of the encapsulation metal can 220d. To increase the rate of heat release. As such, when the plurality of heat dissipation fins 224 constitute the encapsulated metal can 220d attached to the upper surface thereof, the specific surface area of the encapsulated metal can 220d becomes larger, so that the heat dissipation rate is increased in the embodiment shown in FIG. 4. It is further increased compared to.

In addition, in the case of the encapsulated metal cans 220a, 220c, and 220d or the encapsulated glass 220b according to the first, second, third, and fourth embodiments of the present invention, the heat dissipation rate is increased as compared with the conventional encapsulated metal cans or the encapsulated glass. Therefore, even when a physical moisture absorbent such as silica gel is used as the desiccant 222, the physical moisture absorbent can be continuously removed without deterioration of the physical moisture absorbent.

8 is a graph showing the saturation temperature and the temperature rise curve of the bag surface according to an embodiment of the present invention.

Referring to this, reference numeral 1 denotes a temperature rise curve of the encapsulation glass, reference numeral 2 denotes a temperature rise curve of a sealed metal can having an emissivity of 0.1, and reference numeral 3 denotes a temperature of a blackened encapsulated metal can having an emissivity of 0.9. Ascending curve is shown.

In addition, reference numeral 4 denotes a temperature rise curve of the encapsulation metal can 220c subjected to sand blast treatment, and reference numeral 5 denotes a temperature rise curve of the encapsulation metal can 220d with a heat radiation fin.

As shown in the graph, it can be seen that in the case of the reference numerals 3, 4, and 5, the heat release rate is fast and the saturation temperature is about 75 ° C., which is remarkably improved compared to the conventional 100 ° C. or more.

Due to this principle, as shown in FIG. 9, the organic EL display devices 200a, 200b, 200c, and 200d have a longer lifespan, thereby improving white balance, enabling the use of a physical absorbent, and the like. Can be effective.

The function and operation of the organic EL display device according to the embodiment of the present invention having the above-described configuration will be described in more detail with reference to the accompanying drawings.

In the case of the organic EL display devices 200a, 200b, 200c, and 200d according to the present invention, heat is transferred by the method as shown in FIG. When light and holes combine, light and heat are generated in the organic light emitting layer 212. In addition, encapsulated metal cans 220a, 220c, and 220d or encapsulated glass 220b are provided to quickly remove heat generated at this time to prevent deterioration of the organic light emitting layer 212.

Therefore, it is important that heat release induces an increase in the heat transfer rate as shown in FIG. 6 shows an example of heat transfer when a metal can is used as the sealing material. When heat is first released from the organic heat generating layer 212, the heat is convection and conduction heat transfer by nitrogen gas inside the organic EL, and at the same time, heat is transferred to the encapsulated metal can by radiant heat transfer.

In order to increase the heat transfer rate at this time, it is important to increase the concentration of nitrogen gas, that is, the pressure, or to absorb radiant heat from the encapsulated metal can. However, since the increase in the pressure of nitrogen gas present inside causes a decrease in the adhesion-tightness between the encapsulated metal can and the glass substrate, it is most effective to increase the heat absorption rate by increasing the heat absorption capacity by increasing the emissivity of the encapsulated metal can. . Thereafter, conduction heat transfer is made from the metal surface to the inside of the metal. In this case, the higher the heat conductivity coefficient of the metal, the faster the heat transfer and the faster the heat dissipation.

Therefore, it is preferable to use a metal material having a higher thermal conductivity than glass as the encapsulating material. Finally, the process of dissipating heat to the outside remains. At this time, since the air exists outside, heat dissipation is generated by convection, conduction heat transfer, and radiant heat transfer. At this time, it is good to induce the flow of air in order to help the heat release is to increase the convection heat transfer rate by inducing the flow of air by a cooling fan or the like. In addition, radiant heat, which is a kind of electromagnetic waves, is emitted from a place where the temperature is high to a low temperature. In this case, the higher the radiation rate of the metal can, the faster the radiant heat transfer rate is. The process may be performed. Finally, the higher the metal can surface area during heat absorption and release, the higher the heat transfer rate, ie convection, conduction, and radiant heat transfer rates.

On the other hand, the organic EL display device according to the embodiment of the present invention is not limited to the above embodiment but various modifications can be made without departing from the technical gist of the present invention.

As described above, the organic EL display device according to the present invention provides an encapsulated metal can or an encapsulated glass structure for quickly absorbing heat emitted from the organic light emitting layer and lowering the temperature inside the panel. Its lifespan can be improved, white balance can be maintained, stable color output is possible, and low-cost drying material can be used to reduce cost.

Claims (7)

An ITO layer of the anode deposited on the glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or a glass material in order to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer. And the encapsulation member is an encapsulation metal can having a heat radiation rate of at least 0.2 or more so as to absorb heat generated from the cathode layer, the organic layer, and the electron and hole transport layer thereon. The organic EL display device according to claim 1, wherein the encapsulation member is made of either chemical blackening or wet high temperature blackening to increase the emissivity by making the surface black. An ITO layer of the anode deposited on the glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transport layer provided between the ITO layer and the cathode layer, and having an electron transport layer for transporting electrons and a hole beneath the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or a glass material in order to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer. And the encapsulation member is an encapsulation glass having a heat radiation rate of at least 0.3 so as to absorb heat generated from the cathode layer, the organic layer, and the electron and hole transport layer thereon. 4. The organic EL display device according to claim 3, wherein the encapsulation member has a high emissivity by surface treatment using either dark tint glass or surface pigment treatment. An ITO layer of the anode deposited on the glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or a glass material in order to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer. And the encapsulation member is an encapsulation metal can having a surface roughness of at least 4.0 μm so as to release heat generated from the cathode layer, the organic layer, and the electron and hole transport layer through the upper surface. 6. The organic EL display device according to claim 5, wherein the encapsulation member increases the heat dissipation area of the surface by either sand blasting or etching treatment. An ITO layer of the anode deposited on the glass substrate; A hole transport layer deposited on the upper surface of the ITO layer; A cathode layer configured to be spaced apart from the ITO layer by a predetermined distance; A hole transporting layer provided between the ITO layer and the cathode layer, and having an electron transporting layer for transporting electrons and a hole in the lower portion of the ITO layer; An organic EL light emitting layer provided between the hole and the electron transport layer and excited by energy generated when the electrons and holes are combined; An EL display device comprising an encapsulation member made of a metal can or a glass material in order to protect a panel from external force and moisture by being spaced apart from an upper surface of the cathode layer. And a heat dissipation fin having a height of at least 0.1 mm on the upper surface of the encapsulation member so as to discharge heat generated from the cathode layer, the organic layer, and the electron and hole transport layer through the upper surface.