KR100637194B1 - Organic electro-luminescence display device and method for manufacturing the same - Google Patents

Abstract

The present invention provides a display device comprising: a display area having one or more pixels formed on one surface of a substrate;

A sealing substrate sealing the display area at least through a sealing material with the substrate,

An area sealed by the substrate and the sealing substrate, and a moisture absorption layer is provided on one surface of the sealing substrate,

An organic electroluminescent display device and a method of manufacturing the same are characterized in that an intersection area between the moisture absorbing layer and the display area is the same as that of the display area.

Description

Organic electroluminescent display device and method for manufacturing same {Organic electro-luminescence display device and method for manufacturing the same}

1A is a schematic perspective view of an organic electroluminescent display device according to an embodiment of the present invention;

FIG. 1B is a schematic cross sectional view taken along the line “A” of FIG. 1A;

1C is a schematic cross sectional view taken along the line II-II of FIG. 1B;

FIG. 1D is a schematic cross sectional view taken along the line I-I of FIG. 1A;

FIG. 1E is a schematic enlarged view of detail “C” of FIG. 1D;

2A to 2C are schematic cross-sectional views illustrating a manufacturing process of an organic electroluminescent display device according to another embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

110 substrate 120 buffer layer

130 ... semiconductor active layer 140 ... gate insulation layer

150 ... gate electrode 160 ... intermediate layer

170a, b ... source / drain electrode 180 ... protective layer

190 first electrode layer 191 pixel defining layer

192 Organic electroluminescent 200 Display area

210 ... second electrode layer 310 ... sealing material

400, 400 '... sealed board 400'a ... recess

400'b ... protrusion 410 ... hygroscopic layer

500 ... horizontal drive circuit

600 ... terminal part

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent display device, and more particularly, to an electroluminescent display device having a structure in which the sealing area is more effectively sealed to increase durability.

A flat panel display device such as a liquid crystal display device, an organic electroluminescent display device, or an inorganic electroluminescent display device has a passive matrix passive matrix type (PM) type and an active drive active matrix type depending on the driving method thereof. : AM) type. In the passive matrix type, the anode and the cathode are simply arranged in columns and rows, respectively, so that the cathode is supplied with a scanning signal from a row driving circuit. At this time, only one row of the plurality of rows is selected. In addition, a data signal is input to each pixel in the column driving circuit. On the other hand, the active matrix type is a thin film transistor (TFT) to control the input signal for each pixel is suitable for processing a large amount of signals are used as a display device for implementing a video.

On the other hand, the organic electroluminescent display device of the flat panel display device has an organic light emitting layer made of an organic material between the anode electrode and the cathode electrode. In the organic electroluminescent display device, as the anode and cathode voltages are applied to these electrodes, holes injected from the anode are moved to the organic light emitting layer via the hole transport layer, and electrons are transferred from the cathode electrode to the electron transport layer. Is injected into the organic light emitting layer via electrons and holes in the organic light emitting layer to recombine to generate excitons, and as the excitons change from the excited state to the ground state, the fluorescent molecules of the organic light emitting layer emit light to form an image. Form. In the full-color organic electroluminescent display device, full color is realized by including pixels emitting three colors of red (R), green (G), and blue (B) as the organic electroluminescent element.

Meanwhile, as disclosed in Korean Patent Laid-Open Publication No. 2004-0017703, in the case of an organic electroluminescent display device, the organic electroluminescent display device is formed in a sealed space formed by a substrate and a sealing substrate in order to prevent or reduce deterioration due to moisture and oxygen of the organic electroluminescent unit. Place the absorbent.

However, in the case of the organic electroluminescent display device having such a structure, a front emission type structure is adopted to improve brightness and performance, and if the absorbent according to the prior art is provided, the image is caused by light emitted from the organic electroluminescent unit. As a portion penetrating the moisture absorbent and a portion not penetrating the moisture absorbent are generated, screen distortion due to the optical path difference is generated.

The present invention is to solve the above problems, to provide an organic electroluminescent display device having a structure for maintaining a more improved screen quality.

In order to achieve the above object, according to one aspect of the invention,

A display area having one or more pixels formed on one surface of the substrate;

A sealing substrate sealing the display area at least through a sealing material with the substrate,

An area sealed by the substrate and the sealing substrate, and a moisture absorption layer is provided on one surface of the sealing substrate,

An organic electroluminescent display device is provided, wherein an intersection area between the moisture absorbing layer and the display area is the same as that of the display area.

According to the organic electroluminescent display device of the present invention, at least one end of the display area is disposed in an area in which the effective thickness of the moisture absorption layer is within 10% of the difference from the effective thickness of the moisture absorption layer at a position corresponding to the center of the display area. May be

According to the organic electroluminescent display device of the present invention, the encapsulation substrate has a groove portion on one surface facing the display area and a protrusion protruding along the outer end of the encapsulation substrate,

The outer end of the moisture absorbing layer may be in contact with the inner surface of the protrusion.

According to the organic electroluminescent display device of the present invention, the moisture absorbing layer may include an alkaline earth oxide .

According to the organic electroluminescent display device of the present invention, the moisture absorbing layer may include at least one of activated alumina, calcium, calcium oxide, barium, barium oxide, magnesium oxide, zeolite and silica gel.

According to the organic electroluminescent display device of the present invention, the light extracted from the display area may be emitted through the sealing substrate.

According to the organic electroluminescent display device of the present invention, light extracted from the display area may be emitted through the substrate and the sealing substrate.

According to another aspect of the present invention,

Forming a display area on one surface of the substrate;

Forming a moisture absorption layer on a sealing substrate corresponding to the substrate;

Applying a sealant to a seal corresponding position outside the moisture absorbing layer;

Sealing the substrate and the sealing substrate,

In the step of forming the moisture absorbing layer, the moisture absorbing layer provides a method of manufacturing an organic electroluminescent display device, characterized in that the cross-sectional area of the moisture absorbing layer and the display area is the same as the area of the display area.

According to the organic electroluminescent display device manufacturing method of the present invention, in the moisture absorption layer forming step, the moisture absorption layer, at least one end of the display area, the effective thickness of the moisture absorption layer is the moisture absorption layer at a position corresponding to the center of the display area The difference from the effective thickness may be formed to be disposed within an area within 10%.

According to the organic electroluminescent display device manufacturing method of the present invention, the sealing substrate has a groove portion on one surface facing the display area, and a protrusion projecting along the outer end of the sealing substrate,

At the time of forming the moisture absorbing layer, an outer end portion of the moisture absorbing layer may contact one inner surface of the protrusion.

According to the organic electroluminescent display device manufacturing method of the present invention, the moisture absorption layer may include an alkaline earth oxide.

According to the organic electroluminescent display device manufacturing method of the present invention, the moisture absorbing layer may include at least one of activated alumina, calcium, calcium oxide, barium, barium oxide, magnesium oxide, zeolite, silica gel.

According to the organic electroluminescent display device manufacturing method of the present invention, the moisture absorption layer may be formed by a coating method.

According to the organic electroluminescent display device manufacturing method of the present invention, the moisture absorption layer may be formed by a vapor deposition method.

According to another aspect of the invention,

A display area having one or more pixels formed on one surface of the substrate;

A sealing substrate sealing the display area at least through a sealing material with the substrate,

An area sealed by the substrate and the encapsulation substrate, wherein a moisture absorbing layer is provided on one surface of the encapsulation substrate, and an intersection area between the moisture absorbing layer and the display area is the same as that of the display area.

The sealing substrate has a groove portion on one surface facing the display area and a protrusion projecting along the outer end of the sealing substrate, wherein the outer end of the moisture absorption layer is in contact with the inner surface of the protrusion. Provided is a light emitting display device.

According to the organic electroluminescent display device of the present invention, at least one end of the display area is in an area in which the effective thickness of the moisture absorption layer is within 10% of the difference from the moisture absorption layer effective thickness at a position corresponding to the center of the display area. It may be arranged.

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

1A is a schematic perspective view of an electroluminescent display device according to an embodiment of the present invention. The display area 200 including one or more pixels is formed on one surface of the substrate 110, and the pad part 600 including one or more terminals is disposed on at least one side of the display area 200. A seal is disposed between the display area 200 and the pad part 600 to seal the display area 200 at least through the sealing material 310 together with the substrate 110. The encapsulation space formed by the substrate 110 and the encapsulation substrate 400 through the encapsulant 310 is provided with a moisture absorbing layer 410 (refer to FIG. 1D), which indicates that the display area 200 penetrates into the encapsulation space. It is possible to reduce or prevent deterioration due to the like.

Hygroscopic layer 410 is transparent As a hygroscopic layer , Barium, active Alumina Alkali, such as potassium oxide or barium oxide earth  May comprise an oxide, Magnesium oxide , Zeolite It may also include one or more of silica gel.

The moisture absorbing layer 410 may be formed by a coating method such as screen printing or spray coating, or may be formed through a method such as a vapor deposition method. In some cases, after the moisture absorption layer 410 is formed, it may be subjected to a curing process by energy irradiation such as UV irradiation or heat irradiation.

Meanwhile, a scan driver / data that transmits a scan signal and / or a data signal to an electric element that provides an electrical signal to the organic electroluminescent display area 200 according to the present invention, for example, a pixel constituting the display area 200. Vertical / horizontal drive circuitry, such as a driver, may be disposed in the sealed area between the display area 200 and the seal, or may be disposed outside the sealed area, such as the horizontal drive circuit 500 shown in FIG. The vertical / horizontal drive circuitry may take on a variety of configurations, such as in the form of COG, or may be comprised of external electrical elements via FPC or the like.

1B schematically shows an enlarged view of one pixel for the portion “A” of FIG. 1A. Here, one pixel of the structure including two top gate type thin film transistors and one capacitor is illustrated, which is merely an example for describing the present invention and the present invention is not limited thereto.

The gate electrode 55 of the first thin film transistor TFT1 that determines whether to select the pixel extends from the scan line to which the scan signal is applied. When an electrical signal such as a scan signal is applied to the scan line, the data signal input through the data line is transferred from the source electrode 57a of the first thin film transistor TFT1 to the semiconductor active layer 53 of the first thin film transistor TFT1. ) Is transferred to the drain electrode 57b of the first thin film transistor TFT1.

The extension 57c of the first thin film transistor TFT1 drain electrode 57b is connected to the first electrode 58a of the capacitor, and the other end of the first thin film transistor TFT2 is a driving thin film transistor TFT2. The gate electrode 150 is formed, and the second electrode of the capacitor is electrically connected to the driving line 31 in communication with the driving power supply line (not shown).

1C is a partial cross-sectional view taken along the line II-II of FIG. 1A. A portion indicated by (a)-(e) of the line II-II shows a cross section of the portion where the second thin film transistor TFT2 as the driving thin film transistor is disposed, and the portions (e)-(f) are the pixel openings 194. ), And parts (g)-(h) show the cross section of the drive line. In the case of the second thin film transistor TFT2, the semiconductor active layer 130 of the second thin film transistor TFT2 is formed on the buffer layer 120 formed on one surface of the substrate 110. The semiconductor active layer 130 may be composed of an amorphous silicon layer or may be composed of a polycrystalline silicon layer. Although not shown in detail in the drawing, the semiconductor active layer 130 is composed of a source and drain region doped with N + or P + type dopants, a channel region, and the semiconductor active layer 130 may be formed of an organic semiconductor. Various configurations are possible.

The gate electrode 150 of the second thin film transistor is disposed on the semiconductor active layer 130. The gate electrode 150 may be formed in consideration of adhesion to an adjacent layer, surface planarity and processability of the stacked layer, and the like. It is preferably formed of a material such as MoW, Al / Cu, but is not limited thereto.

A gate insulating layer 140 is disposed between the gate electrode 150 and the semiconductor active layer 130 to insulate them. An interlayer 160 as an insulating layer is formed on the gate electrode 150 and the gate insulating layer 140 as a single layer and / or a plurality of layers, and the source / drain of the second thin film transistor TFT2 is formed thereon. The electrodes 170a and b are formed, and the source / drain electrodes 170a and b may be formed of a metal such as MoW and the like, and may be formed later to achieve smoother ohmic contact with the semiconductor active layer 130. It may be heat treated.

A protective layer 180 may be formed on the source / drain electrodes 170a and b, which may be a passivation layer and / or a planarization layer for protecting and / or planarization, and a first electrode layer 190 thereon. The first electrode layer 190 is in electrical communication with the source / drain electrodes 170a and b through the via hole 181 formed in the protective layer 180. In the case of the bottom emission type, the first electrode layer 190 may be formed of a transparent electrode such as indium tin oxide (ITO). In the case of the top emission type, the first electrode layer 190 may be formed of a reflective electrode of Al / Ca and a transparent electrode such as ITO. Various modifications may be provided, for example. Here, in order to clarify the description of the present invention, the case where the first electrode layer 190 functions as an anode electrode is described, but the present invention is not limited thereto, and the first electrode layer may be configured as a cathode electrode, and the like. Various configurations are possible.

On the other hand, the protective layer 180 according to an embodiment of the present invention may be formed in a variety of forms, it may be formed of an inorganic material or an organic material, formed as a single layer or provided with a SiNx layer on the bottom, for example Various configurations are possible, such as being composed of a bilayer having an organic layer such as BCB (benzocyclobutene) or acryl.

A pixel defining layer 191 for defining pixels is formed on the passivation layer 180 except for the pixel opening 194, which is a region corresponding to the first electrode layer 190. An organic electroluminescence unit 192 including an emission layer is disposed on one surface of the first electrode layer 190 through the pixel opening 194.

The organic electroluminescent unit 192 may be formed of a low molecular or polymer organic film. When the low molecular organic film is used, a hole injection layer (HIL), a hole transport layer (HTL), and an organic light emitting layer (EML) An emission layer, an electron transport layer (ETL), and an electron injection layer (EIL) may be formed by stacking a single or a complex structure, and the usable organic material may be copper phthalocyanine (CuPc: copper). phthalocyanine), N, N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: NPB A variety of materials can be applied, including tris-8-hydroxyquinoline aluminum (Alq3). These low molecular weight organic films are formed by the vacuum deposition method.

In the case of the polymer organic film, the structure may include a hole transporting layer (HTL) and an organic light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyflu as the light emitting layer. Polymeric organic materials such as orene (Polyfluorene) are used, and various configurations are possible, such as being formed by screen printing or inkjet printing.

The second electrode layer 400 as the cathode is deposited on the entire surface of one surface of the organic electroluminescent unit 192, and the second electrode layer 210 is not limited to this type of front deposition. , May be formed of a material such as ITO, Mg-Ag, etc., may be formed of a plurality of layers instead of a single layer, and may be further provided with an alkali or alkaline earth metal fluoride layer such as LiF, etc. Can be.

Meanwhile, FIG. 1D shows a schematic cross sectional view taken along the line I-I of FIG. 1A. The display area 200 is formed on one surface of the substrate 110, and the display area 200 is disposed in a sealing space sealed by the substrate 110 and the sealing substrate 400 through the sealing material 310, and the sealing space. The moisture absorption layer 410 is interposed on one surface of the sealing substrate 400 therein. An intersection area of the moisture absorbing layer 410 and the display area 200 according to the present invention is the same as that of the display area 200. That is, since the moisture absorbing layer 410 according to the present invention occupies an arrangement area over the display area, light generated from the display area is not extracted through the end of the moisture absorbing layer 410.

In order to more completely prevent distortion of light extracted from the pixel at the end of the display area, the moisture absorbing layer has a larger area than the display area, but a constant relationship is maintained between the moisture absorbing layer and the display area ends, that is, the display area. At least one end of the 200 is preferably disposed in an area where the effective thickness of the moisture absorbing layer is 10% that is different from the effective thickness of the moisture absorbing layer at the position corresponding to the center of the display area. That is, the moisture absorption layer 410 formed on one surface of the encapsulation substrate 400, as shown in FIG. 1E, which is a schematic partial enlarged view of reference “C” of FIG. 1C, is particularly effective for spray coating and screen printing. As in the case of the same coating method, the end portion may be formed of a curved portion 410a and a flat portion 410b, and the light generated from the pixels of the display area 200 may be absorbed by the moisture absorbing layer ( In order to prevent image deformation due to penetration of the bent portion 410a of the 410, the position P2 of the end of the display area 200 is located at the point P1 where the effective thickness t of the moisture absorption layer 410 is te. It is preferably disposed inside, where te is 90% of tc, which is the effective thickness of the moisture absorbing layer at the position corresponding to the center of the display area. When the light generated from the pixel is emitted through a region where the effective thickness of the moisture absorption layer is smaller than te, the optical path through which the light generated from the pixel at the end of the display region 200 passes through the curved portion 410a of the moisture absorption layer 410 is provided. Since the light generated from the other pixels of the display area 200 penetrates the moisture absorbing layer 410 and the image path is severe due to a large difference in the optical path, the position P2 at the end of the display area 200 is absorbed. It is preferable to arrange | position inside the point P1 whose effective thickness is te.

As another embodiment of the present invention, a process of manufacturing an organic light emitting display device is illustrated in FIGS. 2A to 2C. Here, only one organic electroluminescent display device manufacturing process is illustrated for ease of description. First, as shown in FIG. 2A, the display area 200 is formed on one surface of the substrate 110. Thereafter, as shown in FIG. 2B, the moisture absorbing layer 410 is formed on the sealing substrate 400, and the groove 400a is formed on one surface of the sealing substrate 400, and the sealing substrate 400 is formed. A protrusion 400b is provided along the outer end portion, and the moisture absorbing layer 410 is disposed in the recess 410 of the sealing substrate 400. The recessed portion 400a formed on one surface of the sealing substrate 400 has a proper amount of material irrespective of the position where the moisture absorbing layer 410 material is placed, particularly when a moisture absorbing layer having a uniform thickness is to be formed using a coating method. Is spread out and is applied in the recess 400a, and the flow to the outside is blocked by the protrusion 400b disposed at the outer portion of the sealing substrate 400, so that the moisture absorbing layer 410 may be more easily formed. Then, as shown in FIG. 2B, a sealing material 310 is disposed on the outer end of the sealing substrate 400, that is, one surface of the protrusion 400b, and as shown in FIG. 2C, the substrate 110 and The encapsulation substrate 400 may be sealed through the encapsulant 310 to manufacture the organic light emitting display device according to the present invention. In some cases, the sealing material 310 may undergo a curing process through energy irradiation such as UV irradiation or heat irradiation.

Here, the overlapping area of the display area 200 and the moisture absorption layer 410 is the same as the area of the display area 200, and as shown in FIG. 2C, the position P1 of one end of the display area 200 is absorbed by moisture. Preferably, the thickness of the layer 410 is disposed inward toward the center of the display area 200 rather than at a point P2 which is 90% of the thickness at the center.

The above embodiments are examples for describing the present invention, but the present invention is not limited thereto. Although the above embodiments have been described with respect to an AM driven organic electroluminescent display device, various modifications may be applied to an inorganic electroluminescent display device and a PM driven type, and may be applied to both a top emission type and a double side emission type. Can be derived.

According to the present invention as described above, the following effects can be obtained.

First, the overlapping area of the moisture absorption layer disposed on the encapsulation substrate and the display area formed on one surface of the substrate is formed to be the same as the display area, so that the light generated from the display area passes through the area without the moisture absorption layer interposed therebetween. Image distortion due to emission can be reduced.

Second, one end of the display area is disposed inward from a point where the thickness of the moisture absorbing layer is 90% of the thickness at the center, so that light generated from pixels at the end of the display area passes through the bent portion at the end of the moisture absorbing layer. Can be further reduced or prevented.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (16)

delete Board; A display area formed on one surface of the substrate and including one or more pixels; A sealing substrate disposed corresponding to the substrate, the sealing substrate sealing the display area together with the substrate and the sealing material; And A moisture absorption layer formed on one surface of the sealing substrate between the substrate and the sealing substrate, And an effective thickness of the moisture absorbing layer at a position corresponding to one end of the display area is within 10% of the effective thickness of the moisture absorbing layer at a position corresponding to the center of the display area. The method of claim 2, The sealing substrate has a recessed portion on one surface facing the display area and a protrusion projecting along an outer end of the sealing substrate, And an outer end portion of the moisture absorbing layer is in contact with an inner surface of the protrusion. The method of claim 2, The moisture absorbing layer is an organic electroluminescent display device, characterized in that containing alkaline earth oxide. The method of claim 2, The moisture absorbing layer is an organic electroluminescent display device comprising at least one of activated alumina, calcium, calcium oxide, barium, barium oxide, magnesium oxide, zeolite, silica gel. The method of claim 2, And light emitted from the display area is emitted through the encapsulation substrate. The method of claim 2, And light emitted from the display area is emitted through the substrate and the encapsulation substrate. delete Forming a display area on one surface of the substrate; Forming a moisture absorption layer on a sealing substrate corresponding to the substrate; Applying a sealant to a seal corresponding position outside the moisture absorbing layer; Sealing the substrate and the sealing substrate, In the step of forming the moisture absorbing layer, the effective thickness of the moisture absorbing layer at a position corresponding to one end of the display area is within 10% of the effective thickness of the moisture absorbing layer at a position corresponding to the center of the display area. An organic electroluminescent display device manufacturing method characterized by forming a moisture absorption layer. The method of claim 9, The sealing substrate has a recessed portion on one surface facing the display area and a protrusion projecting along an outer end of the sealing substrate, In the step of forming the moisture absorption layer, the outer end of the moisture absorption layer manufacturing method of the organic electroluminescent display device, characterized in that in contact with the inner surface of the protrusion. The method of claim 9, The hygroscopic layer comprises an alkaline earth oxide. The method of claim 9, The hygroscopic layer comprises at least one of activated alumina, calcium, calcium oxide, barium, barium oxide, magnesium oxide, zeolite and silica gel. The method of claim 9, The moisture absorption layer is formed by a coating method. The method of claim 9, The moisture absorption layer is formed by an evaporation method of the organic electroluminescent display device manufacturing method. delete Board; A display area formed on one surface of the substrate and including one or more pixels; A sealing substrate sealing the display area with a sealing material together with the substrate; And A moisture absorption layer formed on one surface of the sealing substrate between the substrate and the sealing substrate, The intersection area of the moisture absorbing layer and the display area is the same as that of the display area, The sealing substrate has a recessed portion on one surface facing the display area and a protrusion projecting along the outer end of the sealing substrate, and the outer end of the moisture absorbing layer is in contact with the inner surface of the protrusion, And an effective thickness of the moisture absorbing layer at a position corresponding to one end of the display area is within 10% of the effective thickness of the moisture absorbing layer at a position corresponding to the center of the display area.

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