KR100659121B1 - Organic light emitting display device - Google Patents

Abstract

An organic light emitting display device is provided to guarantee a larger display area by extending a length of moisture permeation with changing a path thereof by enlarging an applying width of sealant without increase in a dead space. In an organic light emitting display device, a first substrate(10) has a concave portion(11). A second substrate(20) facing the first substrate(10) includes a convex portion(21), corresponding to the concave portion(11). A display unit(30) is placed between the first and second substrates(10,20) to embody an image. A sealant(50) connects the first substrate(10) with the second substrate(20) by being placed between the first substrate(10) and the second substrate(20).

Description

Organic light emitting display device

1 is a cross-sectional view of an organic light emitting diode display according to an exemplary embodiment of the present invention;

2 is a cross-sectional view illustrating an example of the display unit of FIG. 1;

3 is a cross-sectional view of an organic light emitting diode display according to another exemplary embodiment of the present invention;

4 is a cross-sectional view of an organic light emitting diode display according to another exemplary embodiment of the present invention;

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

<Brief description of the main parts of the drawing>

10: first substrate 11: recess

20: second substrate 21: convex portion

30: display unit 50: sealant

60: desiccant

The present invention relates to an organic light emitting display, and more particularly, to an organic light emitting display having an improved sealing structure.

In general, an organic light emitting diode display can be made ultra thin and flexible due to its driving characteristics.

However, such an organic light emitting diode display has a property that is degraded by the penetration of moisture. Therefore, a sealing structure is needed to prevent the penetration of moisture.

Conventionally, a metal can or a glass substrate is processed into a cap shape so as to have a groove to form a sealing member, and the sealing member is applied to a substrate on which a device is formed using a UV curing sealant or a thermosetting sealant. The method of joining was used.

On the other hand, in the organic light emitting display, it is important to reduce the non-emission area, that is, the dead space, other than the display unit where the image is implemented. As a result, the width of the sealant is reduced. When the sealant is reduced in width, the path of penetration of moisture and oxygen from the side surface of the sealant exposed to the outside air is short, resulting in a shortening of the life of the device. do.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an organic light emitting display device capable of increasing the lifetime of the device by increasing the penetration path of moisture and oxygen through the sealant.

In order to achieve the above object, the present invention provides a first substrate having a concave portion, a second substrate facing the first substrate and having a convex portion corresponding to the concave portion, the first substrate and Provided is an organic light emitting display device including a display unit interposed between a second substrate to implement an image, and a sealant interposed between the first and second substrates to bond the first and second substrates. .

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

1 illustrates an organic light emitting display device according to an exemplary embodiment of the present invention.

As shown in FIG. 1, an organic light emitting diode display according to an exemplary embodiment of the present invention includes a first substrate 10 and a second substrate bonded by a sealant 50 to face the first substrate 10. And 20. Glass material may be used for the first substrate 10 and the second substrate 20, but is not limited thereto, and a plastic material, a metal foil, and the like may also be applied. Hereinafter, the first substrate 10 and the second substrate 20 will be described based on the glass material.

According to a preferred embodiment of the present invention, the first substrate 10 includes a recess 11 inserted into the central portion at a predetermined depth, and the recessed portion (2) is opposed to the second substrate 20. The convex part 21 which protrudes corresponding to the recessed part 11 is provided in the position corresponding to 11). When the first substrate 10 and the second substrate 20 are made of glass, the concave portion 11 and the convex portion 21 can be obtained simply by etching.

As shown in FIG. 1, the concave portion 11 and the convex portion 21 are formed to be coupled to each other at a predetermined distance.

The display unit 30 is formed in the recess 11 of the first substrate 10.

The display unit 30 may be provided as an AM organic light emitting display device as shown in FIG. 2. An example thereof will be described below.

As shown in FIG. 2, an insulating layer, such as a barrier layer and / or a buffer layer, may be formed on the upper surface of the first substrate 10 to prevent diffusion of impurity ions, to prevent penetration of moisture or external air, and to planarize a surface thereof. 32) can be formed.

On this insulating layer 32, an active layer 33 of the TFT is formed of a semiconductor material, and a gate insulating film 34 is formed to cover it. The active layer 33 may be an inorganic semiconductor such as amorphous silicon or polysilicon or an organic semiconductor, and has a source region 33a, a drain region 33b, and a channel region 33c therebetween.

The gate electrode 35 is provided on the gate insulating layer 34, and the interlayer insulating layer 36 is formed to cover the gate insulating layer 34. The source electrode 37 and the drain electrode 38 are provided on the interlayer insulating layer 36, and the planarization layer 39 and the pixel defining layer 40 are sequentially provided to cover the interlayer insulating layer 36.

The gate insulating film 34, the interlayer insulating film 36, the planarization film 39, and the pixel defining layer 40 may be provided as an insulator, and may be formed in a single layer or a plurality of layers, and may be formed of an organic material, an inorganic material, Or organic / inorganic composites.

The stacked structure of the TFT as described above is not necessarily limited thereto, and all TFTs of various structures are applicable.

The pixel electrode 41, which is an electrode of the organic light emitting diode OLED, is formed on the planarization layer 39, and the pixel definition layer 40 is formed on the pixel definition layer 40. After openings are formed to expose the pixel electrode 41, the organic light emitting film 42 of the organic light emitting diode OLED is formed.

The organic light emitting diode OLED displays predetermined image information by emitting red, green, and blue light according to the flow of current, and the pixel electrode 41 contacted to the drain electrode 38 of the TFT through a contact hole. ) And a counter electrode 43 provided to cover all the pixels, and an organic light emitting film 42 disposed between the pixel electrodes 41 and the counter electrode 43 to emit light.

The pixel electrode 41 and the counter electrode 43 are insulated from each other by the organic light emitting layer 42, and light is emitted from the organic light emitting layer 42 by applying voltages having different polarities to the organic light emitting layer 42. To be done.

The organic light emitting film 42 may be a low molecular or high molecular organic film. When using a low molecular organic film, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL) : Electron Injection Layer can be formed by stacking single or complex structure, and usable organic materials are copper phthalocyanine (CuPc), N, N-di (naphthalen-1-yl) -N , N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: NPB), tris-8-hydroxyquinoline aluminum It can be applied in various ways including Alq3. These low molecular weight organic films are formed by the vacuum deposition method. In this case, the hole injection layer, the hole transport layer, the electron transport layer, the electron injection layer and the like can be commonly applied to red, green, and blue pixels as a common layer. Thus, unlike FIG. 2, these common layers may be formed to cover all pixels, such as the counter electrode 43.

In the case of the polymer organic film, the structure may include a hole transporting layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyfluorene are used as the light emitting layer. Polymer organic materials such as (Polyfluorene) are used and can be formed by screen printing or inkjet printing.

The organic layer as described above is not necessarily limited thereto, and various embodiments may be applied.

The pixel electrode 41 functions as an anode electrode, and the counter electrode 43 functions as a cathode electrode. Of course, the polarities of the pixel electrode 41 and the counter electrode 43 may be reversed. It's okay.

In the case of a bottom emission type in which an image is embodied in the direction of the first substrate 10, the pixel electrode 41 may be a transparent electrode, and the opposite electrode 43 may be a reflective electrode. In this case, the pixel electrode 41 is formed of ITO, IZO, ZnO, In2O3 or the like having a high work function, and the counter electrode 43 is formed of a metal having a small work function, that is, Ag, Mg, Al, Pt, Pd, Au, or the like. , Ni, Nd, Ir, Cr, Li, Ca and the like.

In the case of a top emission type for implementing an image in the direction of the counter electrode 43, the pixel electrode 41 may be provided as a reflective electrode, and the counter electrode 43 may be provided as a transparent electrode. have. At this time, the reflective electrode serving as the pixel electrode 41 is formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, a compound thereof, and the like, and then thereon It may be formed by forming a high work function ITO, IZO, ZnO, In2O3 or the like. The transparent electrode serving as the counter electrode 43 is formed by depositing a metal having a small work function, that is, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, and a compound thereof. After that, an auxiliary electrode layer or a bus electrode line may be formed thereon with a transparent conductive material such as ITO, IZO, ZnO, or In 2 O 3.

In the case of a double-sided light emission type, both the pixel electrode 41 and the counter electrode 43 may be provided as transparent electrodes.

The pixel electrode 41 and the counter electrode 43 are not limited to those formed of the above-described materials, and may be formed of a conductive organic material, a conductive paste containing conductive particles such as Ag, Mg, Cu, or the like. In the case of using such a conductive paste, it may be printed using an inkjet printing method, and after printing, may be baked to form an electrode.

The passivation film 44 made of an inorganic material, an organic material, or an organic / inorganic composite laminate may be further provided on the upper surface of the counter electrode 43 of the display unit 30 manufactured as described above. The passivation film 44 may use an inorganic scavenger film and / or an organic insulating film. In the case of a top-emitting display in which an image is realized in the direction of the sealing member 20, the passivation film 44 is formed of a transparent insulating film.

As the inorganic insulating film, SiO2, SiNx, SiON, Al2O3, TiO2, Ta2O5, HfO2, ZrO2, BST, PZT, etc. may be included, and as the organic insulating film, a general-purpose polymer (PMMA, PS), a polymer derivative having a phenol group , Acrylic polymers, imide polymers, arylether polymers, amide polymers, fluorine polymers, p-xylene polymers, vinyl alcohol polymers and blends thereof may be included. The passivation film 44 may also be formed as a composite laminate of an inorganic insulating film and an organic insulating film.

On the other hand, the sealant 50 is applied to the edges of the concave portion 11 and the convex portion 21 to bond the first substrate 10 and the second substrate 20 to each other. The sealant 50 uses a thermosetting or UV curing sealant.

In this way, the display portion 30 is seated in the recess 11, and the sealant 50 is bonded to the recess 11 and the convex portion 21 outside thereof, thereby increasing the moisture permeation distance through the sealant 50. .

In fact, as shown in Figure 1, the moisture permeable distance through the sealant 50 has a vertical distance (b) in addition to the horizontal distance (a), and became longer, and at the same time, because the path of the moisture permeation has a curvature rather than a straight line, This became more difficult.

As described above, the present invention increases the application width of the sealant and extends the moisture vapor transmission distance by changing the moisture vapor transmission path without increasing the dead space, thereby securing a wider display area and increasing the life of the device. I can improve it.

Although not shown in FIG. 1, the convex portion 21 may be coated with a desiccant to absorb the moisture therein.

The desiccant may be applied to any desiccant capable of absorbing moisture, and more preferably, may be maintained even after absorbing moisture.

As the desiccant, a transparent nanoporous oxide layer including nano-sized porous oxide particles and containing nano-sized pores may be used.

The porous oxide particles may be at least one selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, metal halides, metal sulfates and metal perchlorates having an average particle diameter of 100 nm or less.

In this case, the alkali metal oxide is lithium oxide (Li 2 O), sodium oxide (Na 2 O) or potassium oxide (K 2 O), and the alkaline earth metal oxide is barium oxide (BaO), calcium oxide (CaO), or magnesium oxide (MgO). And the metal sulfate is lithium sulfate (Li2SO4), sodium sulfate (Nai2SO4), calcium sulfate (CaSO4), magnesium sulfate (MgSO4), cobalt sulfate (CoSO4), gallium sulfate (Ga2 (SO4) 3), titanium sulfate (Ti) (SO4) 2), or nickel sulfate (NiSO4), and the metal halide is calcium chloride (CaCl2), magnesium chloride (MgCl2), strontium chloride (SrCl2), yttrium chloride (YCl2), copper chloride (CuCl2), Cesium fluoride (CsF), tantalum fluoride (TaF5), niobium fluoride (NbF5), lithium bromide (LiBr), calcium bromide (CaBr3), cerium bromide (CeBr4), selenium bromide (SeBr2), vanadium bromide (VBr2) (MgBr 2), barium iodide (BaI 2) or magnesium iodide (MgI 2), and the metal perchlorate is barium perchlorate (Ba (ClO 4) 2) or perchloric acid. May be a magnesium (Mg (ClO4) 2).

The average diameter of pores in the transparent nanoporous oxide film may be 100 nm or less.

In addition, the transparent nanoporous oxide film may be a transparent nanoporous calcium oxide (CaO) film.

The transparent nanoporous oxide film is a sol mixture obtained by dispersing nano-sized porous oxide particles in a solvent and an acid is applied to the convex portion 21 of the second substrate 20 by screen printing, and then dried and heat treated. You can get it.

It is preferable that the said heat processing temperature is 250 degrees C or less, especially 100-200 degreeC. If the heat treatment temperature exceeds 250 ℃, the moisture absorption characteristics due to the reduction of the specific surface area by pre-sintering between particles is deteriorated, which is undesirable.

In the process of mixing the nano-sized porous oxide particles with a solvent and an acid, it is preferable to proceed in the following order in terms of dispersibility.

Solvent and acid are added to adjust the pH to a range of 1-8, especially about 2, followed by addition of nano-sized porous oxide particles. At this time, the acid may be optionally added.

The acid is an optional component, with the added advantage of improving dispersibility. Examples of the acid include nitric acid, hydrochloric acid, sulfuric acid, acetic acid and the like. And the content of the acid is preferably 0.01 to 0.1 parts by weight based on 100 parts by weight of the porous oxide particles.

The solvent may be used as long as it can disperse the porous oxide particles. Specific examples thereof include ethanol, methanol, propanol, butanol, and isopropanol. At least one selected from the group consisting of methyl ethyl ketone, pure water, propylene glycol (mono) methyl ether (PGM), isopropyl cellulose (IPC), methylene chloride (MC), and ethylene carbonate (EC), the content of which is porous 60 to 99 parts by weight based on 100 parts by weight of the oxide particles.

The transparent nanoporous oxide film formed by the above-described manufacturing method is a thin film having a thickness of 0.1 µm to 12 µm, has sufficient moisture absorption and oxygen adsorption characteristics, and has an excellent function of sealing the display unit 30.

The transparent nanoporous oxide film formed by the above-described method has pores formed therein, and the film is kept transparent before or after absorbing the moisture. The pore should have an average diameter of 100 nm or less, preferably 70 nm or less, and more preferably 20 to 60 nm. If the average diameter of the pores exceeds 100nm it is not preferable because it does not have sufficient hygroscopic properties.

The transparent nanoporous oxide film formed by this method has the property of being kept transparent before or after absorbing moisture.

3 illustrates another exemplary embodiment of the present invention, in which the sealant 50 includes the entire display unit 30. In this case, the penetration of moisture by the sealant 50 can be further blocked, and as described above, the moisture penetration path can be complicated to further improve durability.

The concave portion 11 and the convex portion 21 as described above do not necessarily have a right angle structure, as shown in FIGS. 1 and 3, and as shown in FIG. 4, the outer side of the concave portion 11 and the convex portion 21. It may be inclined. In this case, there is an effect that the coating width of the sealant 50 is widened, and thus the penetration distance of moisture may be further increased.

On the other hand, the display unit 30 described above does not necessarily need to be formed in the recess 11 of the first substrate 10. 5 illustrates another preferred embodiment of the present invention, in which the display unit 30 is formed on the convex portion 21 of the second substrate 20. In this case, the above-described desiccant 60 may be applied to the recess 11 of the first substrate 10.

In the case of the embodiment of FIG. 5, the same effects as those of the embodiment of FIG. 1 may be obtained.

According to the present invention made as described above, the moisture permeable distance through the sealant becomes longer, and at the same time, because the path of the moisture permeation has a curve rather than a straight line, the moisture permeability becomes more difficult.

Accordingly, the present invention increases the coating width of the sealant and extends the moisture permeation distance by changing the moisture permeation path without increasing the dead space, thereby securing a wider display area and at the same time the life of the device. Also can be improved.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those skilled in the art that various modifications and embodiments may be made therefrom.

Claims (7)

A first substrate having a recess; A second substrate facing the first substrate and having a convex portion corresponding to the recessed portion; A display unit interposed between the first substrate and the second substrate to implement an image; And And a sealant interposed between the first substrate and the second substrate to bond the first substrate and the second substrate. The method of claim 1, At least one of the first substrate and the second substrate is formed of any one of glass, plastic, and metal. The method of claim 1, And the concave portion and the convex portion are positioned at the centers of the first and second substrates, respectively. The method of claim 1, The concave portion and the convex portion are each provided with an area including the display portion. The method of claim 1, And the sealant is disposed at edges of the concave portion and the convex portion. The method of claim 1, And the sealant is disposed to cover the display unit. The method of claim 1, An organic light emitting display device comprising a desiccant interposed between a first substrate and a second substrate.

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