KR100680805B1 - Organic Light Emitting Diodes - Google Patents

Abstract

According to the present invention, a substrate is patterned into a non-light emitting region including an insulating film and a partition wall and a light emitting region including a first electrode in addition to the non-light emitting region, an organic light emitting portion formed on the substrate, and a second electrode formed on the organic light emitting portion. And a thermally conductive film formed on the second electrode and including a thermally conductive insulating film, and a shield cap in surface contact with at least a portion of the upper portion of the thermally conductive film.

According to the present invention, by maintaining the temperature of the elements in the panel as a whole, the deterioration rate such as color temperature change or luminance decrease can be kept the same, thereby maintaining the reliability of the elements.

Organic light emitting diode, display panel, insulating film, metal film

Description

Organic Light Emitting Diodes

1 is a cross-sectional view of a conventional organic light emitting display device.

2 is a cross-sectional view of a conventional passive organic light emitting display device (PMOLED).

3A to 3C are cross-sectional views illustrating a manufacturing process of an organic light emitting display device according to a first embodiment of the present invention.

4 is a plan view showing the heat flow of the organic light emitting display device according to the first embodiment;

5A to 5B are cross-sectional views illustrating a manufacturing process of an organic light emitting display device according to a second exemplary embodiment of the present invention.

6 is a plan view showing the heat flow of the organic light emitting display device according to the second embodiment;

The present invention relates to a display panel having an organic light emitting device that emits light by recombination of electrons and holes.

Typically, organic light emitting diodes (OLEDs) are self-luminous displays that emit light by electrically exciting organic compounds. This organic light emitting diode can be driven at low voltage and has advantages such as thinness. In addition, the organic light emitting device is attracting attention as a next-generation display that can solve the disadvantages that are pointed out as a problem in the liquid crystal display, such as wide viewing angle, fast response speed.

However, the organic light emitting device has been a big problem in practical use because of its lifetime despite the advantages. The lifetime of this organic light emitting device is determined by operation-lifetime and shelf-lifetime.

Operation-lifetime is a decrease in luminance due to driving, which is caused by impurities in the organic material, an interface between the organic material and the electrode, low crystallization temperature (Tg) of the organic material, and oxidation of the device by oxygen and moisture. On the other hand, even if the shelf-lifetime is not driven, the light emitting area gradually decreases due to moisture, so that the light cannot be emitted later.

Specifically, the factors that reduce the luminance during driving include (1) damage to organic matter and charge mobility due to electric charges (electrons and electric fields) generated during driving, and (2) driving such as AM (Active Matrix) or PM (Passive Matrix). Difference in deterioration due to different methods, (3) In case of AMOLED, deterioration of TFT (Thin Film Transister) during driving, (4) TFT heat generated during driving or Joule heat generated during light emission (especially AMOLED is caused by TFT during driving Deterioration rate due to generation), (5) organic matter deteriorated more rapidly by external moisture or oxygen during operation.

As heat is generated, the rate of deterioration (color coordinate variation and lifetime change of each material) of R, G, and B colors is also changed. Also, the rate of deterioration of organic matter is changed by temperature deviation caused by heat generation and thermal accumulation depending on the position. As time passes, the color coordinates of each location are different.

 Recently, as driving brightness increases and product size increases, technology for maximizing the generation of heat is becoming very important.

Various methods of dissipating heat have been proposed. The most common method is to (1) connect the metal wiring to each pixel part and dissipate heat through the wiring. In PMOLED, the bus electrode of scan and data is connected. In AMOLED, the data line and gate electrode connected to the TFT source and Connected scan lines, VDD power lines and drain electrodes. In addition, (2) a method of connecting a separate heat sink by attaching a paste having excellent conductivity (eg, Ag paste) to the substrate on which the OLED element is formed or the back of the shield cap, to increase the cooling effect by connecting a cooling fin to the heat sink. .

However, in the first method, since various electrodes are metals having excellent thermal conductivity, they are thin films of about 1 μm in thickness, and thus the heat generated by the device cannot be sufficiently extracted to the outside, and the length of wiring to the periphery increases rapidly toward the center of the panel to release heat. There were more and more difficult problems.

In addition, the second method is to radiate heat through the shield cap applied to the bottom emission method, and heat generated from the device or its surroundings is transferred to the rear shield cap through the gas inside the bag (neutral or inert). The cooling fin is adopted to release and increase the heat radiation effect.

Referring to FIG. 1, a conventional bottom emission type organic light emitting diode 10 includes a first electrode 14, an organic layer 16, and a second electrode 18 on a device formation substrate or a lower substrate 12. It was formed sequentially, and these were sealed by the shield cap 20 and the sealing agent 22. The lower substrate 12 is separated from the sealant 22 and the organic layer 16 to form a moisture absorbent 24 to remove moisture or oxygen. On the other hand, a paste adhesive 26 having excellent thermal conductivity is formed on the outer surface of the shield cap 20, and a cooling heat sink or cooling fin 28 is attached to the outer surface of the paste adhesive 26.

On the other hand, the top emission type organic light emitting device employs a method of bonding a heat sink and a cooling fin to a device forming substrate (lower substrate).

However, in the second method, even when a conductive paste is applied to a shield cap made of metal or glass, such as bottom emission, and a heat sink and cooling fins are connected, a gas having a poor thermal conductivity between the heat generating pixel and the shield cap (neutral or Inert) is filled, the heat is difficult to transfer to the shield cap, heating plate, cooling fins, etc., there was a problem that can not obtain a sufficient cooling effect.

In addition, when the heat sink and the cooling fins are installed on the element formation substrate (lower substrate) like the top emission, since the element formation substrate is a glass with poor thermal conductivity, it is difficult to sufficiently transfer the element generation heat.

FIG. 2 is a cross-sectional view of a conventional passive organic light emitting diode (PMOLED), and the organic film 108 and the second electrode 110 are formed on the substrate 102 on which the partition 112 is formed in the PMOLED 100 as shown in FIG. After the deposition, the method of contacting the shield cap 114 with the partition wall allows heat generated in the organic film 108 of the PMOLED 100 element to some extent to be transferred to the shield cap 114, thereby forming the partition wall 112. ) And the shield cap 114 has a good heat dissipation effect compared to the prior art that is separated.

However, even in this case, since the organic film 108 on the light emitting area is still separated from the partition wall 112, heat generated in the organic film 108 on the light emitting area is transferred to the shield cap 114 along the partition wall 112. There was a limit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display panel having an organic light emitting device capable of sufficiently dissipating heat, which is a main cause of luminance reduction during driving, to prevent deterioration and to prolong life. .

It is still another object of the present invention to apply conduction by applying an insulating film having high thermal conductivity between the partition wall and the second electrode on the light emitting area in PMOLED so that heat generated from the second electrode is efficiently transferred to the shield cap through the partition wall. It is to provide a display panel having an organic light emitting device for improving the heat dissipation efficiency by using.

Another object of the present invention is to apply a thermal conductive film so as to completely cover the side surface or the upper surface of the partition wall, an organic electroluminescent device capable of maximizing the heat dissipation effect by applying a metal film with excellent thermal conductivity on contact with the shield cap It is to provide a display panel having a.

In order to solve the above-described problems, the present invention provides a substrate patterned into a light emitting region including a first electrode in addition to a non-emitting region and a non-emitting region including an insulating film and a partition wall, an organic light emitting unit formed on the substrate, A second electrode formed on the organic light emitting unit, a thermally conductive film formed on the second electrode and including a thermally conductive insulating film, and a shield cap in surface contact with at least a portion of the upper portion of the thermally conductive film.

The thermal conductive film may further include a metal film formed on the thermal conductive insulating film.

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The present invention is characterized in that the thermally conductive film formed on a region where the partition wall is located is in contact with the shield cap.

The thermally conductive film is applied on the light emitting area and the non-light emitting area continuously.

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

Example 1

3A to 3C are cross-sectional views illustrating a manufacturing process of the organic light emitting display device according to the first embodiment of the present invention, and FIG. 4 is a plan view showing the heat flow of the organic light emitting display device according to the first embodiment.

Referring to FIGS. 2 through 4, before the second electrode 110 is coated and sealed with the shield cap 114 in the manufacturing process of the PMOLED device 100 shown in FIG. 2 (see FIG. 3A). A thermally conductive insulating film 122 is applied to completely cover the side surfaces of the second electrode 110 and the partition wall 112 formed on the region and the non-light emitting region (see FIG. 3B).

The thermally conductive insulating layer 122 is excellent in thermal conductivity and should be able to easily transfer heat emitted from the second electrode 110 to the shield cap 114. In addition, the thermally conductive insulating film 122 may be sufficiently thickly coated so as not to cause breakage of the film due to the slope of the sidewall of the partition wall 112 completely covering the side surface and the upper surface of the partition wall 112.

In addition, even if the thermally conductive insulating film 122 is thinly applied to reduce the thickness of the PMOLED 100 device, a film forming method may be formed continuously along the side surface of the partition wall 112 without breaking the film, for example, chemical vapor deposition (CVD). It is preferable to use methods such as deposition), PVD (physical vapor deposition), and sputter.

The thermally conductive insulating layer 122 is formed into a structure in which the height of the portion where the partition 112 is present is higher than that of other portions due to the height difference of the structure of the partition wall 112 formed on the substrate 102.

After the film formation of the thermally conductive insulating film 122 is completed, the shield cap 114 is sealed while being in contact with the upper surface of the thermally conductive insulating film 122 as shown in FIG. 3C. The protrusion of the thermally conductive insulating film 122 is shielded. Will come in contact with the bottom of 114.

4 illustrates a process in which heat generated in the organic light emitting diode according to the first exemplary embodiment of the present invention is discharged to the outside through the second electrode 110, the thermal conductive insulating layer 122, and the shield cap 114. have. As described above, heat is radiated to the nitrogen gas charged inside the PMOLED 100, and heat is emitted in a conductive manner along a film having excellent thermal conductivity as compared to a structure in which heat is radiated to the outside.

Example 2

5A to 5B are cross-sectional views illustrating a manufacturing process of an organic light emitting display device according to a second embodiment of the present invention, and FIG. 6 is a plan view showing a heat flow of the organic light emitting display device according to the second embodiment.

In the organic electroluminescent device according to the second embodiment of the present invention, the thermal conductive insulating film 122 is applied in the same process as in the first embodiment, and then the metal film 124 is further formed on the organic electroluminescent device to heat dissipation efficiency. It is a further improvement.

Since the metal film 124 has much larger thermal conductivity than the conventional insulating film, heat can be transferred to the shield cap 114 much more easily than when only the thermal conductive insulating film 122 is present.

To this end, as shown in FIGS. 5A to 5B, after the thermal conductive insulating film 122 is formed, the metal film 124 is thinly formed once more, and the shield cap is in contact with the metal film 124 thereon. Cover (114).

In the case of the metal film 124, the thickness and the film formation method should be selected so that the film does not break due to the inclination of the side wall of the partition 112, similarly to the thermal conductive insulating film 122.

As mentioned above, although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited thereto.

The configurations of the organic light emitting diodes described in the first and second embodiments are merely exemplary, and any type of organic light emitting diodes to be developed now or in the future may form part of the present invention.

In the first and second embodiments, the materials, sizes, and shapes of the respective components have been described, but these are examples of the present invention and various modifications are possible.

That is, it will be understood by those skilled in the art that the technical configuration of the present invention may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, the embodiments described above are to be understood as illustrative in all respects and not as restrictive.

According to this configuration, the present invention has the effect of sufficiently dissipating heat, which is the main cause of luminance reduction during driving, to prevent deterioration and extend the life.

In addition, the present invention, by allowing the heat generated in the organic film to be discharged to the outside through the second electrode and the partition wall, it is possible to reduce the deterioration rate, such as color temperature change or decrease in brightness, thereby maintaining the reliability of the device for a long time have.

Claims (5)

A substrate patterned into a light emitting region including an insulating layer and a partition wall, and a light emitting region including a first electrode in addition to the non-light emitting region; An organic light emitting part formed on the substrate; A second electrode formed on the organic light emitting part; A thermal conductive film formed on the second electrode and including a thermal conductive insulating film; An organic light emitting device comprising a shield cap in surface contact with at least a portion of the upper portion of the thermal conductive film. The method of claim 1, The thermal conductive film further comprises a metal film formed on the thermal conductive insulating film. delete The method of claim 1, And the thermally conductive film formed on a region where the partition wall is in contact with the shield cap. The method of claim 1, The thermal conductive film is an organic light emitting display device, characterized in that the coating is continuously applied to the light emitting region and the non-light emitting region.

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