KR100625460B1 - Oled - Google Patents

Abstract

The present invention relates to an organic electroluminescent device which emits light by recombination of electrons and holes, and a method of manufacturing the same.

According to the present invention, a non-light emitting region including an insulating film and a substrate patterned into a light emitting region other than the non-emitting region, an organic light emitting portion formed on the substrate, a second electrode formed on the organic light emitting portion, a substrate and a second electrode Provided is an organic electroluminescent device comprising a spacer protruding higher than an organic light emitting part therebetween, a moisture absorbing part formed on a second electrode, and a shield cap sealing the organic light emitting part.

Accordingly, it is possible to prevent deterioration by sufficiently dissipating heat, which is a major cause of luminance reduction during driving, and to arrange dehumidifying agents for absorbing oxygen and moisture, which cause deterioration of other devices, to prevent deterioration and extend life.

Description

Organic electroluminescent device and manufacturing method thereof

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

2 is a cross-sectional view of an organic light emitting display device according to a first embodiment of the present invention.

3 is a manufacturing process diagram of the moisture absorption unit of FIG. 2.

4 is a partial cross-sectional view of an organic light emitting display device according to a second exemplary embodiment of the present invention.

5 is a partial cross-sectional view of an organic light emitting display device according to a third exemplary embodiment of the present invention.

The present invention relates to an organic electroluminescent device which emits light by recombination of electrons and holes, and a method of manufacturing the same.

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 electroluminescent device is determined by operation lifetime and shelf lifetime.

Operation lifetime is a decrease in luminance during operation due to 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 emission area is gradually reduced by moisture, so that the shelf lifetime is not 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 (5) Accelerating deterioration due to external moisture or oxygen during driving.

The factor of heat generation among driving factors that reduce luminance during driving was a serious problem as the display size of AMOLED became larger, that is, the larger the active area of the display, the larger the size of the display, the larger the size of the display. There was a lot of heat in the center. For example, when 20 ”class AMOLED is used for TV, the center temperature rises to 70 ~ 80 ℃, and the lifespan falls to one tenth of normal temperature. Typically, when the temperature rises by 10 ° C., the lifetime drops to 1/2 or less.

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. As shown in FIG. 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.

In addition, the two conventional heat dissipation methods described above, in a situation where a dual-type organic light emitting device capable of displaying two screens simultaneously in a folder type electric field device is required by users, a dual type organic field There was a problem that can not be used in the light emitting device.

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

Another object of the present invention is to provide an organic light emitting display device and a method for manufacturing the same, which can be applied to a bidirectional organic light emitting display device without using a cooling fin or a heat sink.

In addition, another object of the present invention is to improve the reliability of the device by arranging the absorbent by using a shadow mask to improve the fact that it is difficult to form the absorbent in the actual active area in the heat radiation structure using the spacer. It is to provide a light emitting device and a method of manufacturing the same.

According to the present invention for achieving the above object, a non-light emitting region including an insulating film and a substrate patterned into a light emitting region other than the non-emitting region, an organic light emitting portion formed on the substrate, and a second electrode formed on the organic light emitting portion And an organic light emitting device including a spacer protruding higher than the organic light emitting part between the substrate and the second electrode, a moisture absorption part formed on the second electrode, and a shield cap sealing the organic light emitting part.

In this case, an upper portion of the second electrode on which the spacer is formed and a lower portion of the sheath cap may be in surface contact.

The spacer may be formed in the non-light emitting area. That is, in the case of the passive matrix, the spacer may be formed in any one of the insulating layer or the barrier rib region of the non-light emitting region, and in the case of the active matrix, the spacer may be formed in the region where the thin film transistor and the storage capacitor are disposed.

Meanwhile, a metal film is formed on the second electrode on which the spacer is formed so that the metal film can be in surface contact with the lower portion of the shield cap. In addition, although the moisture absorbing part is formed on the second electrode on which the spacer is formed, a metal film may be formed in an area in surface contact with the lower portion of the shield cap so that the metal film may be in surface contact with the lower part of the shield cap.

Meanwhile, the moisture absorbing unit may be formed in a region where the spacer is not formed. In this case, the moisture absorption unit may be a thin film.

In another aspect, the present invention provides a basic structure forming step of sequentially forming an organic light emitting portion and a second electrode on a substrate patterned as a light emitting region in addition to the non-light emitting region and the non-light emitting region including an insulating film; A spacer forming step of protruding spacers higher than the organic light emitting part between the two electrodes, a moisture absorbing part forming step of forming a moisture absorbing part on the second electrode, and an organic light emitting part sealed with a shield cap, wherein a lower portion of the shield cap is formed with a spacer. A method of manufacturing an organic light emitting display device having a shield cap forming step of making surface contact with an upper portion of a second electrode is provided.

At this time, in the moisture absorption unit forming step, the moisture absorption unit may be formed on the second electrode by thermal deposition or vacuum deposition using a patterned shadow mask.

On the other hand, the shadow mask is patterned to open the portion where the spacer is not formed, so that the moisture absorbing portion may be formed in the portion where the spacer is not formed.

In addition, the shadow mask is patterned to be open except for a portion in surface contact with the shield cap, so that the moisture absorption part may be formed on the second electrode on which the spacer is formed except for the portion in contact with the shield cap.

The method may further include forming a metal film on the second electrode that is in surface contact with the shield cap to form a metal film in surface contact with the lower portion of the shield cap.

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

Example 1

2 is a cross-sectional view of an organic light emitting display device according to a first embodiment of the present invention.

Referring to FIG. 2, in the organic light emitting diode 30 according to the first exemplary embodiment of the present invention, in addition to the non-light emitting region including the insulating layer 32 and the light emitting region including the organic light emitting portion 34, the light emitting region is patterned. The first substrate 36, the spacer 38 protruding higher than the organic light emitting part 34, the second electrode 39 formed on the organic light emitting part 34 and the spacer 38, and the second electrode. The moisture absorbent 40 formed on the 39 is provided. In addition, the organic electroluminescent device 30 is kept airtight by the shield cap 42 and the sealant 44.

In addition, in the case of AMOLED or PMOLED, an insulating film, a partition, a driving transistor, a storage capacitor, a switching transistor, and the like may exist, but are omitted from the drawings and detailed description thereof will be omitted. It is understood that these are all formed in the non-light emitting region in which the insulating film 32 is formed.

In the organic light emitting diode, the first electrode 31 is generally a transparent electrode and supplies holes to the organic light emitting part 34.

The organic light emitting part 34 includes an organic material layer that emits light using energy emitted when the holes and the electrons are supplied from the first electrode 31 and the second electrode 39 to be recombined, and then separated. In addition, the organic light emitting part 34 may include a charge injection transfer layer by participating in the injection and transfer of holes and electrons.

The spacer 38 is formed on the substrate 36 on which the non-light emitting region made of the insulating film 32 is patterned. Since the spacer 38 is formed in the non-emission region, the spacer 38 may be formed without reducing the emission region.

The size of the spacer 38 is several to 100 μm, and the overall height may be 1 to several hundred μm, but is not limited thereto. In addition, the spacer 38 may be a non-conductive metal having a high heat transfer coefficient, for example, Al, Cu, Ag, or the like. The number of spacers 38 may be appropriately selected in consideration of the amount of heat generated in the entire panel, the size of the spacers 38, and the like. That is, rather than forming the spacers 38 for every organic light emitting device of the panel, it is preferable to form an appropriate number in consideration of the above situation.

The second electrode 39 is a metal that supplies electrons to the organic light emitting part 34. The second electrode 39a in the portion where the spacer 38 is formed is formed higher than the second electrode 39b in the other portion. In addition, the upper surface 46 of the second electrode 39a in the portion where the spacer 38 is formed is in surface contact with the lower surface 48 of the shield cap 42. Since the upper surface 46 of the second electrode 39a in the portion where the spacer 38 is formed is in surface contact with the lower surface 48 of the shield cap 42, the first electrode 31 or the organic light emitting part 34. Heat generated from the back is transferred to the shield cap 42 through the spacer 38 and the second electrode 39 and is released to the outside.

The moisture absorption part 40 is formed on the 2nd electrode 39b of the part in which the spacer 38 is not formed. At this time, the moisture absorption unit 40 is a thin film that is thin and easy to form a film. As such, since the moisture absorbing part 40 is formed on the second electrode 39b in the portion where the spacer 38 is not formed, the moisture absorbing part 40 does not interfere with the heat radiating action by the spacer 38 and the second electrode 39. The entire area of the panel can be minimized.

3 is a manufacturing process diagram of the moisture absorption unit of FIG. 2.

Referring to FIG. 3, the moisture absorbing part 40 includes a substrate 36 on which the first electrode 31, the insulating film 32, the organic light emitting part 34, the spacer 38, and the second electrode 39 are formed. In the inverted state, the shadow mask 50 is only heated on the substrate 36 after only the portion where the spacer 38 is not formed is opened, thereby heating the deposition source 52 of the absorbent material. ) Is thermally deposited on the second electrode 39b of the portion where the spacer 38 is not formed.

At this time, the second electrode 39a of the portion where the spacer 38 is formed is blocked by the shadow mask 50 such that the moisture absorbent 40 is not formed.

After the moisture absorbent 40 is formed on the substrate 36, the shield cap 42 is attached to the substrate 36 and the shield cap 42 using the sealant 44. The manufacturing of the electroluminescent element 30 is completed. Since other manufacturing processes are the same as the conventional processes, detailed descriptions are omitted.

Example 2

4 is a partial cross-sectional view of an organic light emitting display device according to a second exemplary embodiment of the present invention.

The organic light emitting display device 54 according to the second exemplary embodiment of the present invention is generally the same as the first exemplary embodiment described above, but the metal film 56 is further formed on the second electrode 39a of the portion where the spacer 38 is formed. Is formed, and there is a difference in the surface where the upper surface of the metal film 56 is in surface contact with the lower surface of the shield cap 42.

The metal film 56 need not be conductive, but is preferably a metal having high thermal conductivity. Since the shield cap 42 is in contact with the metal film 56 having high thermal conductivity, heat generated in the organic light emitting diode 54 may be more efficiently discharged.

Since the metal film 56 is vacuum-deposited in the vacuum chamber by using a shadow mask in which only the portion where the moisture absorbing portion 40 is not formed is removed after the moisture absorbing portion forming step of forming the moisture absorbing portion 40 described with reference to FIG. Can be formed.

Example 3

5 is a partial cross-sectional view of an organic light emitting display device according to a third exemplary embodiment of the present invention.

The organic light emitting display device 58 according to the third exemplary embodiment of the present invention is the first electrode 31, the organic light emitting part 34, and the spacer 38 on the substrate 36 in the same manner as in the first and second embodiments. ), A second electrode 39 is formed.

On the other hand, the moisture absorbent 40 is formed on the second electrode 39 as a whole except for the portion in contact with the shield cap 42. The metal film 60 is additionally formed only at the portion in contact with the shield cap 42.

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.

In the above embodiments, the moisture absorption unit has been described as a thin film, but any moisture absorption unit is possible.

The configurations of the organic light emitting diodes described in the first to third 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 embodiment, the moisture absorbing portion has been described as being formed by thermal evaporation, but may be formed by any vapor deposition method such as CVD (Chemical Vapor Deposition). Moreover, you may use methods, such as photolithography and a print screen.

In the first embodiment, the spacer has been described as being a non-conductive metal having a large heat transfer coefficient, for example, Al, Cu, Ag, or the like, but may be an organic material such as a photoresist or an inorganic material such as SiO _x , SiN _x .

Although the first to third embodiments and modified embodiments have been described above, it can be understood that the present invention includes any combination thereof.

That is, the technical configuration of the present invention can be understood by those skilled in the art that the present invention can 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 extending the life by arranging a moisture absorbent for absorbing oxygen and moisture, which is sufficient to release heat, which is a major cause of luminance reduction during driving, to prevent deterioration, and to cause other element deterioration. There is.

In addition, the present invention has an effect that can be applied to the bidirectional organic electroluminescent device without using a cooling fin or a heat sink.

In addition, the present invention has an effect that can minimize the size of the panel by optimizing the space for forming the absorbent.

Claims (13)

A substrate patterned into a non-emission area including an insulating film and a light emitting area including a first electrode in addition to the non-emission area; An organic light emitting part formed on the substrate; A second electrode formed on the organic light emitting part; A spacer protruding higher than the organic light emitting part between the substrate and the second electrode; A moisture absorption unit formed on the second electrode; An organic light emitting display device comprising a shield cap for sealing the organic light emitting unit. The method of claim 1, And an upper portion of the second electrode on which the spacer is formed and a lower portion of the sheath cap are in surface contact. The method of claim 1, And the spacer is formed in the non-light emitting region. The method of claim 3, wherein The spacer is formed in any one or more of the insulating film or barrier rib forming portion of the non-light emitting region in the case of the passive matrix, the region formed with the thin film transistor and the storage capacitor in the case of the active matrix. The method of claim 1, The moisture absorbing unit is an organic light emitting display device, characterized in that formed in the region where the spacer is not formed. The method of claim 2, And a metal film is formed on the second electrode on which the spacer is formed so that the metal film is in surface contact with the lower portion of the shield cap. The method of claim 2, A moisture absorbing part is formed on the second electrode on which the spacer is formed, and a metal film is formed in an area in surface contact with the lower portion of the shield cap, so that the metal film is in surface contact with the lower part of the shield cap. . The method of claim 1, The moisture absorbing unit is an organic light emitting diode characterized in that the thin film (thin film). A basic structure forming step of sequentially forming an organic light emitting part and a second electrode on a patterned non-light emitting area including an insulating layer and a light emitting area including a first electrode in addition to the non-light emitting area; Forming a spacer between the substrate and the second electrode to protrude a spacer higher than the organic light emitting part; A moisture absorption unit forming step of forming a moisture absorption unit on the second electrode; And a shield cap forming step of sealing the organic light emitting part with a shield cap so that a lower portion of the shield cap is in surface contact with an upper portion of the second electrode on which the spacer is formed. The method of claim 9, In the moisture absorbing portion forming step, the moisture absorbing portion is formed on the second electrode by thermal evaporation or vacuum deposition using a patterned shadow mask. The method of claim 9, And the shadow mask is patterned to open the portion where the spacer is not formed, thereby forming the moisture absorbing portion in the portion where the spacer is not formed. The method of claim 9, The shadow mask is patterned to be open except for a portion in contact with the shield cap, so that the moisture absorbing part is formed on the second electrode except for the portion in contact with the shield cap. Method of manufacturing the device. The method of claim 12, And forming a metal film on the second electrode in surface contact with the shield cap, wherein the metal film is in surface contact with the lower portion of the shield cap.

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