KR101149935B1 - Organic Light Emitting Diodes - Google Patents

Abstract

The present invention relates to an organic electroluminescent device having an encapsulation structure that can effectively protect the damage of the device from external impact and reduce the weight to be suitable for a large area display.

The present invention provides a non-light emitting region including a first electrode, a substrate including a patterned light emitting region other than the non-emitting region, an organic light emitting portion formed on the substrate and including a second electrode, and an organic light emitting portion on the substrate. Provided is an organic electroluminescent device having a spacer protruding higher and a shield cap coupled to a substrate to seal an organic light emitting portion.

Description

Organic Light Emitting Diodes

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

2 is a plan view of a conventional organic light emitting display device.

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

4 is an enlarged partial view of FIG.

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

6 is a 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 having an encapsulation structure that can effectively protect the damage of the device from external impact and reduce the weight to be suitable for a large area display.

The organic light emitting display device, which has recently attracted attention as a display device, uses a principle of emitting light when an electron and a hole are paired and extinguished when charge is injected into an organic light emitting portion formed between the electron injection electrode and the hole injection electrode. Many researches and developments are being made due to its excellent characteristics in driving voltage, wide viewing angle, low power consumption, light weight and color. However, there has been a problem in the commercialization of the organic light emitting device so far, the life is short.

Determining the lifespan of a device can be divided into two parts. One is the reduction in luminance during operation (operation-lifetime), which is due to impurities in the organic material, the interface between the organic material and the electrode, the low glass transition temperature (Tg) of the organic material, and the oxidation of the device by oxygen and moisture. The other is that the light emitting area gradually decreases due to moisture even if it is not driven, and does not emit light later (shelf-lifetime). Therefore, the lifetime of the organic light emitting display device is determined by the smaller of these two lifetimes.

There can be two types of moisture that already exist inside and penetrate from the outside during the process of making a device. The main problem is penetration from outside. Therefore, various methods have been proposed to solve this problem, and the representative one is so-called encapsulation, which surrounds the device with a shield cap made of metal or glass.

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

Referring to FIG. 1, in the conventional organic light emitting display device 10, an organic light emitting part 14 formed between a first electrode and a second electrode on a substrate 12 includes a shield cap 16 and a photocurable or thermosetting epoxy resin. It adhere | attached with the sealing agent 18, such as these. A thin film type moisture absorbent 22 was attached to the inner surface 20 of the shield cap 16.

At this time, the material of the shield cap 16 used was a metal type or glass such as stainless steel. At this time, the shield cap 16 is deformed when the entire element is pressed or impacted from the back side, so that the shield cap 16 is sufficiently thick so as not to be in contact with the electrode or the organic material layer of the organic light emitting unit 14 to maintain the strength. There was a need.

In the case of a 1 to 3 "class substrate for a mobile communication terminal, the thickness T of the metal shield cap 16 is 0.1 to 0.5t (0.1 to 0.5mm), and the thickness of the glass shield cap 16 is 0.3 to 1.0t. (0.3 ~ 1.0mm) is sufficient. However, in the case of 4-8 "or 10" or larger medium and large substrates, there is a problem that the thickness of the shield cap 16 becomes thicker to reduce the deformation caused by impact. There was also a problem in that the weight increased and the risk of breakage increased rapidly due to the potential stress due to the thickness. For example, the thickness of the shield cap 16 in the case of the glass shield cap 16 used at 20 "or more Is about 5mm and due to the weight of the shield cap 16, most of the weight of the organic light emitting device 10 was occupied by the weight of the glass shield cap (16).

When the metal shield cap 16 is used, the thickness required to secure the strength may be thinner than that of the glass shield cap, but the weight of the shield cap was much heavier since the metal density is larger than that of the glass. In addition, it was difficult to press-process using a mold to maintain flatness.

2 is a plan view of a conventional organic light emitting display device.

Referring to FIG. 2, the conventional organic light emitting diode 10 used in a large panel of 20 ″ or more uses a plurality of film-type absorbents 22 inside the shield cap 16 as the size of the panel increases. As a result, as the size of the panel increased, the amount and number of the moisture absorbents 50 to be used increased.

Referring to FIGS. 1 and 2, the conventional organic light emitting display device 10 has the shield cap 16 or the like due to the pressure (shock) applied from the outside as the total weight increases and the quantity and number of the absorbents 22 increase. The substrate 12 is deformed, and the film-type absorbent 22 attached to the inner surface 20 of the shield cap 16 hits the organic light emitting portion 14, so that the shock is transmitted, thereby causing serious damage to the device. . Meanwhile, since the thickness T of the shield cap 16 is increased and the film adhesive 22 deepens the depth of the recess D of the shield cap 16, damage due to external impact can be reduced, but the shield cap There was a problem that the weight and volume of (16) increases.

In order to solve the above problems, an object of the present invention is to provide an organic light emitting device having an encapsulation structure that can effectively protect the device from external impact.

It is another object of the present invention to provide an organic light emitting display device having a small weight and volume to be suitable for a large area display.

The present invention for achieving the above object is a substrate comprising a non-light emitting region including a first electrode, and a patterned light emitting region other than the non-emitting region; An organic light emitting part formed on the substrate and including a second electrode; A spacer protruding higher than the organic light emitting portion on the substrate; A shield cap coupled to the substrate to seal the organic light emitting unit; It is formed inside the shield cap and includes a plurality of moisture absorbing portion formed to absorb moisture therein, the spacer is located in the area corresponding to the moisture absorbing portion to contact the moisture absorbing portion when the deformation of the shield cap and the substrate by the external pressure to act as a buffer In addition, the present invention provides an organic light emitting display device which is spaced apart from the moisture absorption unit.

 The shield cap may be any one of a metal can or a glass cap, and a plurality of moisture absorbing parts may be formed inside the shield cap to absorb moisture therein.

In another aspect, a substrate including a non-light emitting area including a first electrode and a patterned light emitting area other than the non-light emitting area; An organic light emitting part formed on the substrate and including a second electrode; A shield cap coupled to the substrate to seal the organic light emitting unit; An inert medium filled in an inner space formed by the substrate and the shield cap; A spacer protruding higher than the organic light emitting portion on the substrate; It is formed inside the shield cap and includes a plurality of moisture absorbing portion formed to absorb moisture therein, the spacer is located in the area corresponding to the moisture absorbing portion to contact the moisture absorbing portion when the deformation of the shield cap and the substrate by the external pressure to act as a buffer In addition, the present invention provides an organic light emitting display device which is spaced apart from the moisture absorption unit.

In this case, the substrate may further include a spacer protruding higher than the organic light emitting unit. The spacer may be a photoresist, an organic layer of any one of polyimide and polyacryl, or an inorganic layer of any one of SiO _X and SiN _Y.

 The spacer may be formed in the non-light emitting region on the substrate to fix the moisture absorbing portion without reducing the light emitting area of the organic light emitting portion. The spacer may be formed in any one of the insulating film or the partition wall of the non-light emitting region in the case of the passive matrix type, and may be formed in either the thin film transistor or the storage capacitor forming region in the case of the active matrix type.

In addition, the spacer may be formed at a position opposite to the moisture absorbing portion formed inside the shield cap. The spacer may be formed in a predetermined region of the center portion of the substrate.

The inert medium may be a liquid, which may be a florin-based liquid. The moisture absorbent may be dispersed in the liquid. On the other hand, the inert medium may be a high pressure inert gas.

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

Example 1

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

Referring to FIG. 3, in the organic light emitting display device 30 according to the first embodiment of the present invention, an organic light emitting part 34 formed between a first electrode and a second electrode on a substrate 32 includes a metal or glass shield. The cap 36 is adhered with a sealing agent 38 such as a photocurable or thermosetting epoxy resin. In addition, a plurality of thin film type moisture absorbents 42 were attached to the inner surface 40 of the shield cap 36.

On the other hand, the plurality of spacers 44 protrude higher than the organic light emitting part 34 on the substrate 32. The spacer 44 is formed at a position facing the plurality of moisture absorbents 42 adhered to the shield cap 36. As the spacer 44 is formed at a position opposite to the absorbent 42, the absorbent 42 is in direct contact with the organic light emitting part 34 even when the shield cap 36 or the substrate 32 is deformed by external pressure. You can block.

That is, even if the spacer 44 is deformed by the external pressure of the shield cap 36 and the substrate 32, the moisture absorbent 42 first contacts the spacer 44 before being directly in contact with the organic light emitting part 34. The spacer 44 may act as a buffer to prevent deterioration and damage of the organic light emitting part 34. Accordingly, even if the thickness t of the shield cap 36 is thin and the depth d is low, problems caused by deformation of the shield cap 36 and the substrate 32 can be solved. Overall, the thickness, weight, and volume of the organic light emitting display device 30 can be reduced.

The spacer 44 may be a photoresist, an organic layer made of polyimide, polyacryl, or an inorganic layer made of SiO _X or SiN _Y. In addition, it is preferable that the spacer 44 has a large number and increases its height as the impact and deformation are large. The size of the spacer is 100 μm or less, it is safe to set the height of several hundred μm or less, but is not limited thereto.

4 is a partially enlarged view of FIG. 3.

Referring to FIG. 4, the organic light emitting display device 30 includes an insulating film 48, a partition wall 50, and a first electrode 46 on the substrate 32 in the same manner as a conventional passive matrix type organic light emitting display device. The organic light emitting film 52 and the second electrode 54 are formed to form the organic light emitting part 34. The spacer 44 is formed on the insulating film 48 corresponding to the non-light emitting region so as to face the moisture absorbent 42 of the shield cap 36 higher than the organic light emitting portion 34. The formation of the spacers 44 on the insulating film 48 corresponding to the non-emission area is not intended to reduce the light emitting area of the organic light emitting element 30.

Example 2

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

Referring to FIG. 5, the organic light emitting display device 60 according to the second exemplary embodiment of the present invention has a substrate 32, an organic light emitting part 34, a shield cap 36, and a sealing agent 38. Is the same as in Example 1. However, the organic electroluminescent device 60 of Example 2 differs from Example 1 in that the moisture absorbent 42 of Example 1 does not exist and the spacer 44 does not exist on the substrate 32.

On the other hand, in the organic light emitting display device 60 according to the second embodiment of the present invention, an inert liquid 62 is filled in an internal space (encapsulation space) between the substrate 32 and the shield cap 36. The inert liquid 62 is preferably a fluorine-based material that does not react with the organic light emitting part 34 and has a small amount of deformation with respect to pressure, but is not limited thereto. The inert liquid 62 buffers the substrate 32 and the shield cap 36 from being deformed when an external pressure is applied to the substrate 32 or the shield cap 36.

In addition, the powder type absorbent 64 is dispersed in the inert liquid 62 and may play the same role as the thin film type absorbent of Example 1.

Example 3

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

Referring to FIG. 6, the organic light emitting diode 70 according to the third embodiment of the present invention includes a substrate 32, an organic light emitting portion 34, a shield cap 36, a sealant 38, and a moisture absorbent ( 42) and the same as in the first embodiment in that the spacer 44 is provided. However, the organic light emitting diode 70 of Example 2 has a high-pressure inert or neutral gas 72 filled in an internal space (encapsulation space) between the substrate 32 and the shield cap 36. Embodiment 1 Is different.

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 first embodiment, the spacer is described as being formed on the front surface of the substrate, but the spacer may be formed in a predetermined region of the center portion of the substrate where the deformation of the substrate or the shield cap is high.

In the first embodiment, the spacer has been described as being an inorganic layer or an organic layer, but may be a multilayer consisting of an inorganic layer and an organic layer. When the spacer is a multilayer, it is preferable that the outermost layer is an inorganic layer in order to prevent the moisture or impurities of the moisture absorbent from being transferred to the organic light emitting part in contact with the moisture absorbent.

In the first embodiment, the organic electroluminescent device is described as being formed in a passive matrix type in an insulating film whose spacer is a non-light emitting area, but the spacer may be formed in other non-light emitting areas such as partition walls other than the insulating film. In addition, when the organic light emitting diode is an active matrix type that turns on / off a voltage to the first electrode by using a thin film transistor or a storage capacitor, a spacer may be formed in a non-light emitting region such as a thin film transistor or a storage capacitor.

In the first embodiment, the spacer has been described as being formed in the non-light emitting area in order not to reduce the light emitting area, but may be formed in the light emitting area such as the organic light emitting film in spite of the decrease in the light emitting area.

In the first embodiment, the material of the shield cap is made of glass or metal as an encapsulant, but an organic, organic and / or inorganic thin film may be formed on the organic light emitting part together with the shield cap.

In the third embodiment, it has been described that the absorbent is attached to the shield cap, but the absorbent may not be present. If the inert gas is sufficiently present inside or can remove moisture introduced from the outside, a moisture absorbent may not be necessary separately.

In the first embodiment, the moisture absorbent is described as a thin film type moisture absorbent, but any type of moisture absorbent or moisture absorbing means other than the thin film type moisture absorbent may be used. For example, the powdered moisture absorbent may be used in the grooves sealed with a transparent tape.

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, 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 structure, the present invention has the effect of efficiently protecting the device from external impact.

Another effect of the invention is that the weight and volume of the shield cap can be made small to be suitable for large area displays.

Claims (15)

A substrate including a non-light emitting area including a first electrode and a patterned light emitting area other than the non-light emitting area; An organic light emitting part formed on the substrate and including a second electrode; A spacer protruding higher than the organic light emitting part on the substrate; A shield cap coupled to the substrate to seal the organic light emitting part; Is formed on the inside of the shield cap includes a plurality of moisture absorbing portion formed to absorb moisture therein, The spacer is located in an area corresponding to the moisture absorbing portion and spaced apart from the moisture absorbing portion to contact with the moisture absorbing portion when the shield cap and the substrate are deformed by external pressure. The spacer is formed in the non-light emitting region on the substrate. delete delete A substrate including a non-light emitting area including a first electrode and a patterned light emitting area other than the non-light emitting area; An organic light emitting part formed on the substrate and including a second electrode; A shield cap coupled to the substrate to seal the organic light emitting part; An inert medium filled in an inner space formed by the substrate and the shield cap; A spacer protruding higher than the organic light emitting part on the substrate; Is formed on the inside of the shield cap includes a plurality of moisture absorbing portion formed to absorb moisture therein, The spacer is located in an area corresponding to the moisture absorbing portion and spaced apart from the moisture absorbing portion to contact with the moisture absorbing portion when the shield cap and the substrate are deformed by external pressure. The spacer is formed in the non-light emitting region on the substrate. delete delete The method according to claim 1 or 4, The spacer is an organic light emitting device, characterized in that the organic material layer of any one of a photoresist, polyimide, polyacryl. The method according to claim 1 or 4, The spacer is an organic light emitting display device, characterized in that the inorganic layer of any one of SiO _X , SiN _Y. The method according to claim 1 or 4, The spacer is formed in any one of the insulating film or the partition wall of the non-light emitting region in the case of the passive matrix type, and formed in any one of the thin film transistor or the storage capacitor forming region in the case of the active matrix type. delete delete delete delete delete The method according to claim 1 or 4, The spacer is formed in a predetermined region of the central portion of the substrate.

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