Patent Description:
The embodiments of the present disclosure relate to an organic light-emitting display (OLED) device, and more particularly to an OLED device capable of suppressing a particle cover layer from being excessively spread.

As the era of information technology has unfolded, the field of display devices has been growing rapidly, as information can be represented in electrical signals in the form of visual images. In accordance with this, research is ongoing for various flat panel display devices to make them thinner, lighter and capable of consuming less power. Flat panel display devices include a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device, an electro-wetting display (EWD) device, and an organic light emitting display (OLED) device, etc..

Among others, an OLED device is capable of producing light on its own, and thus, does not require an additional light source, unlike an LCD. Therefore, an OLED device can be made lighter and thinner. Further, an OLED device has advantages in that it is driven with low voltage to consume less power, and it has fast response time, wide viewing angle and infinite contrast ratio (CR). For these reasons, an OLED device is acknowledged as the next generation display device. However, an OLED device is especially vulnerable to moisture and oxygen permeation, making it is less reliable than other flat panel display devices.

An OLED device displays images using an organic light-emitting element which is self-luminous. An OLED device includes a plurality of pixels, each of which includes an organic light-emitting element. An organic light-emitting element includes a first electrode and second electrode facing each other. The organic light-emitting element further includes a light-emitting layer disposed between the first electrode and the second electrode, and is made of an organic substance and creates electroluminescence.

For a top emission OLED device, a first electrode is transparent or transflective (semi-transparent) while a second electrode is reflective, so that light generated from an organic light-emitting layer is emitted upwardly through the first electrode. Additionally, in order to ensure the reliability of an OLED device, a transparent, encapsulation unit is formed on the organic light-emitting element to protect the organic light-emitting element from oxygen and moisture. Previously in a top emission OLED device, a glass encapsulation unit was employed as the encapsulation unit.

<CIT> discloses an organic light emitting diode (OLED) display. In one aspect, the display includes a substrate having a light emission area and a non-emission area outside the light emission area, an organic light emitting unit formed on the light emission area and a blocking unit that is disposed on the non-emission area to surround the organic light emitting unit. The OLED display further includes a coating unit formed to coat an external surface of the blocking unit and an encapsulation unit formed by alternately stacking at least one first thin film and at least one second thin film on an area surrounded by the blocking unit so as to encapsulate the organic light emitting unit.

<CIT> discloses a flexible organic electroluminescent device including a switching thin film transistor and a drive thin film transistor formed at the each pixel region on a substrate; a first electrode connected to a drain electrode of the drive thin film transistor, and formed at the each pixel region; a bank formed on the display area and non-display area of the substrate; a spacer formed on a bank in the non-display area, and disposed in the vertical direction in parallel to a lateral surface of the display area; an organic light emitting layer separately formed for each pixel region; a second electrode formed on an entire surface of the organic light emitting layer; an organic layer formed on an entire surface of the substrate; a barrier film located to face the substrate.

<CIT> discloses that an organic light emitting diode (OLED) display comprises: a substrate; a display unit formed on the substrate and including an organic light emitting element; an interception layer positioned at the outside of the display unit on the substrate; and a thin film encapsulation layer which is formed with a stacked film of an inorganic film and an organic film, which has an end portion contacting the interception layer, and which covers the entire display unit and at least a part of the interception layer.

<CIT> discloses that a display device includes a substrate including a display region and a peripheral region, display structures at the display region of the substrate, a plurality of blocking structures at the peripheral region of the substrate wherein the blocking structures have heights different from each other, an organic layer on the display structures and the blocking structures, and an inorganic layer on the organic layer.

<CIT> discloses an organic electroluminescence display device capable of reducing the width of wiring without a voltage drop by contacting the lower lines and the upper lines with a contact member such as a solder ball, conductive paste or ACF in a sealing process, thereby forming a double structure of common power supply bus lines and/or cathode bus lines after, when forming source/drain electrodes of thin film transistors, forming lower lines of common power supply bus lines and/or cathode bus lines formed on a peripheral part of the organic electroluminescence display device and forming upper lines at positions on an encapsulating substrate corresponding to the lower lines, and a method for fabricating the organic electroluminescence display device.

Recently, as a replacement for inflexible flat panel display devices, a flexible organic light emitting display (FOLED) is under development. A FOLED employs a flexible substrate made of a flexible material such as plastic and can be bent like paper while still exhibiting its display functionality.

In view of the above, the inventors of the embodiments of the present disclosure have been studying to commercialize FOLED devices. Meanwhile, the inventors of the embodiments of the present disclosure have concluded that a glass substrate is not appropriate for an encapsulation unit since it is not flexible. Accordingly, the inventors of the application have studied on a novel, transparent and flexible encapsulation layer, which can be mass-produced and commercially available.

Specifically, there has been an attempt to implement an encapsulation unit of an FOLED device by using a single, flexible encapsulation layer made of an inorganic substance. However, such a flexible encapsulation layer has poor flowability and is too thin to fully cover the foreign matter, and thus, cracks are easily made by the foreign matter such as dust or particles. Therefore, moisture permeates through the cracks and causes defects in the FOLED. As defects occur, production yield becomes lower, leading to a serious problem for implementing mass production.

Under the circumstances, the inventors have devised a flexible encapsulation unit capable of improving the foreign matter-related issues, in such a manner that a particle cover layer made of an organic substance having good flowability is disposed on a flexible encapsulation layer in order to cover the foreign matter by making the top surface of the particle cover layer even, and then another single flexible encapsulation layer made of an inorganic substance is disposed on the even surface of the particle cover layer.

With high flowability, the particle cover layer effectively covers the foreign matter. However, it is difficult to control the region where the particle cover layer is applied to. That is, the organic substance of the particle cover layer easily flows in an unwanted direction. In addition, in order to make a narrow bezel, the area of the non-pixel becomes smaller. It makes the control over the particle cover layer more difficult. As a result, the particle cover layer is spread beyond the originally designed region. Hereinafter, this is referred to as an "excessive spread. " In case a particle cover layer is excessively spread, it can be perceived as a spot, spoiling the appearance of an FOLED. In addition, as the particle cover layer cannot effectively protect moisture permeation, moisture may permeate through the excessively spread area.

In conclusion, for a FOLED device including a flexible encapsulation unit in which a first encapsulation layer is disposed, a particle cover layer is applied onto a part of the first encapsulation layer, and a second encapsulation layer is disposed on the particle cover layer and the first encapsulation layer, yet an excessive spread of the particle cover layer is one of the biggest issues that have to be overcome.

The inventors of the embodiments of the present disclosure have reached the idea that the excessive spread can be effectively suppressed by forming a structure in the non-pixel area, which may suppress the particle cover layer from being excessively spread. The inventors have also found that an evenness of the particle cover layer can be improved as the excessive spread is suppressed.

In view of the above, an object of the present disclosure is to provide an OLED device capable of suppressing an organic substance of a particle cover layer from being excessively spread, by forming a structure in a non-pixel area with a variety of configurations and materials.

Another object of the present disclosure is to provide an OLED device in which a multilayer structure for suppressing an organic substance from being excessively spread is formed in a non-pixel area, where a top layer of the multilayer structure includes a plurality of subsidiary structures, and the organic substance is dispersed via a storage space defined inside the subsidiary structures.

Yet another object of the present disclosure is to provide an OLED device in which a plurality of stair-like dams for suppressing an organic substance from being excessively spread is formed in a non-pixel area, and the organic substance can be dispersed by the stair-like dams.

Yet another object of the present disclosure is to provide an OLED device in which a metal structure for suppressing an organic substance from being excessively spread is formed in a non-pixel area, where the metal structure includes a plurality of subsidiary metal structures, and the organic substance can be dispersed via a storage space defined between the plurality of subsidiary metal structures.

It should be noted that objects of the present disclosure are not limited to the above-described object, and other objects of the present disclosure will be apparent to those skilled in the art from the following descriptions.

The present invention provides an organic light-emitting display (OLED) device according to claim <NUM>. According to an aspect of the present invention, there is provided an organic light-emitting display (OLED) device including: a pixel area defined by the plurality of pixels on a flexible substrate; a non-pixel area around the pixel area; a gate driver in the non-pixel area; a common voltage line, which supplies a common voltage to the plurality of pixels, formed at the outer side of the pixel area and the gate driver to surround the pixel area and the gate driver; a flexible encapsulation unit configured to cover the pixel area and the non-pixel area and comprising a first encapsulation layer, a particle cover layer and a second encapsulation layer; a structure in the non-pixel area configured to surround the pixel area and the gate driver and to partially overlap the common voltage line, wherein the structure is disposed directly on the common voltage line so as to suppress the particle cover layer from being excessively spread.

In an embodiment, the structure may include a plurality of walls. Among the plurality of walls, a height of a wall disposed closer to the inside (e.g. closer to the pixel area) among the plurality of walls may be configured to be lower than a height of a wall disposed closer to the outside (e.g. further away from the pixel area) among the plurality of walls.

In an embodiment, the organic light-emitting display (OLED) device may include a barrier film including a pressure-sensitive adhesive layer and attached on the flexible encapsulation unit by the pressure-sensitive adhesive layer, wherein the barrier film is attached on the second encapsulation layer of the flexible encapsulation unit. The structure may have a particular height and may be configured to surround the particle cover layer in the non-pixel area, so that the pressure-sensitive adhesive layer is configured to be pressed by the structure in the non-pixel area.

In an embodiment, the structure may be a multilayer structure, and the multilayer structure may be made of the same materials as materials of at least two of a bank, a spacer, a planarizing layer and an interlayer film disposed in the plurality of pixels, and the structure may have such a height that suppresses the particle cover layer from being excessively spread and increases adhesion of the barrier film.

In an embodiment, a width in cross section of a top layer of the multilayer structure may be narrower than a width in cross section of a bottom layer thereof.

In an embodiment, the first encapsulation layer may cover the plurality of pixels, the gate driver, the structure and an outer periphery of the structure. The particle cover layer may cover the pixel area and is suppressed from being excessively spread by the structure. The second encapsulation layer may cover whole or a portion of the first encapsulation layer and the particle cover layer. The second encapsulation layer may be in contact with the first encapsulation layer at the outer side of the structure, and the area where the first encapsulation layer is in contact with the second encapsulation layer may be extended from the outer periphery of the structure by a distance away from the pixel area.

In an embodiment, the wall disposed closer to the pixel area may be a double layer and may be made of the same materials as materials of a bank and a spacer disposed in the plurality of pixels, and wherein the wall disposed further from the pixel area may be a triple layer and may be made of the same materials as materials of the bank, the spacer and a planarizing layer disposed in the plurality of pixels. In an embodiment, the particle cover layer may act as a compensation layer that planarizes the plurality of pixels and a height of the particle cover layer gradually decreases within the non-pixel area from the outer periphery of the plurality of pixels to the structure.

It should be noted that effects of the embodiments of the present disclosure are not limited to those described above and other effects of the embodiments of the present disclosure will be apparent to those skilled in the art from the following descriptions.

The above and other aspects, features and other advantages of the embodiments of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:.

Advantages and features of the embodiments of the present disclosure and methods to achieve them will become apparent from the descriptions of example embodiments herein below with reference to the accompanying drawings. However, the present disclosure is not limited to example embodiments disclosed herein but may be implemented in various different ways. The example embodiments are provided for making the disclosure of the present disclosure thorough and for fully conveying the scope of the embodiments of the present disclosure to those skilled in the art. It is to be noted that the scope of the embodiments of the present disclosure is defined only by the claims.

The figures, dimensions, ratios, angles, numbers of elements given in the drawings are merely illustrative and are not limiting. Further, in describing the present disclosure, descriptions on well-known technologies may be omitted in order not to obscure the gist of the present disclosure. It is to be noticed that the terms "comprising," "having," "including" and so on, used in the description and claims, should not be interpreted as being restricted to the means listed thereafter unless specifically stated otherwise. Where an indefinite or definite article is used when referring to a singular noun, e.g., "a," "an," "the," this includes a plural of that noun unless specifically stated otherwise.

In describing elements, they are interpreted as including error margins even without explicit statements.

In describing positional relationship, such as "an element A on an element B," "an element A above an element B," "an element A below an element B," and "an element A next to an element B," another element C may be disposed between the elements A and B unless the term "directly" or "immediately" is explicitly used.

As used herein, a phrase "an element A on an element B" refers to that the element A may be disposed directly on the element B and/or the element A may be disposed indirectly on the element B via another element C.

The terms first, second, third and the like in the descriptions and in the claims are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. These terms are used to merely distinguish one element from another. Accordingly, as used herein, a first element may be a second element within the technical idea of the embodiments of the present disclosure.

Like reference numerals denote like elements throughout the descriptions.

The width in the cross section of an element refers to the width in the middle of the height of the cross section throughout the descriptions.

The angle of an element refers to an angle made by a plane and a sloped surface in the middle of the height of the cross section throughout the descriptions.

The drawings are not to scale and the relative dimensions of various elements in the drawings are depicted schematically and not necessarily to scale.

Features of various example embodiments of the present disclosure may be combined partially or totally. As will be clearly appreciated by those skilled in the art, technically various interactions and operations are possible. Various example embodiments can be practiced individually or in combination.

<FIG> is a schematic plan view of an OLED device according to an example embodiment of the present invention. <FIG> is a schematic cross-sectional view of a sub-pixel of one of a plurality of pixels illustrated in <FIG>. <FIG> is a schematic cross-sectional view of the OLED device taken along line III - III' illustrated in <FIG>. <FIG> is a schematic enlarged view of area X illustrated in <FIG>.

An OLED device according to an example embodiment of the present invention includes a pixel area defined by a plurality of pixels on a flexible substrate, a non-pixel area around the pixel area, a gate driver in the non-pixel area, a common voltage line, which supplies a common voltage to the plurality of pixels, formed at the outer side of the pixel area and the gate driver to surround the pixel area and the gate driver a flexible encapsulation unit configured to cover the pixel area and the non-pixel area and comprising a first encapsulation layer a particle cover layer and a second encapsulation layer; a structure in the non-pixel area configured to surround the pixel area and the gate driver, and to partially overlap the common voltage line, wherein the structure is disposed directly on the common voltage line so as to suppress the particle cover layer from being excessively spread.

Hereinafter, a top emission OLED device capable of suppressing a particle cover layer from being excessively spread according to an example embodiment of the present invention will be described with reference to <FIG>.

Referring to <FIG>, an OLED device <NUM> includes: a plurality of pixels <NUM> disposed on a flexible substrate <NUM>; a gate driver <NUM> configured to drive a plurality of gate lines <NUM>; a data driver <NUM> configured to apply an image signal to a plurality of data lines <NUM>; a common voltage line <NUM> disposed at the outer periphery of the gate driver <NUM> to apply common voltage Vss to the plurality of pixels <NUM>, and a flexible encapsulation unit <NUM>.

Each of the plurality of pixels <NUM> includes sub-pixels emitting light of red, green and blue (RGB) colors. Each of the plurality of pixels <NUM> may further include a sub-pixel emitting light of white color. Each of the sub-pixels may further include a color filter. The plurality of pixels <NUM> is driven by thin-film transistors connected to the plurality of gate lines <NUM> and the plurality of data lines <NUM> intersecting each other. The area where the plurality of pixels <NUM> is disposed may be referred to as a pixel area <NUM>.

The data driver <NUM> generates a gate start pulse (GSP) for driving the gate driver <NUM> and a variety of clock signals. Further, the data driver <NUM> converts a digital image signal received from an external source into an analog image signal using a gamma voltage generated in a gamma voltage generator, and applies it to the plurality of pixels <NUM> via the plurality of data lines <NUM>. The data driver <NUM> may be mounted on the substrate <NUM> by an anisotropic conductive film (ACF) applied onto a plurality of pads formed on the substrates <NUM>. In addition, a flexible printed circuit (FPC), a cable, etc., may be mounted on another plurality of pads for receiving an image signal and a control signal from an external source by an ACF. The area where the pluralities of pads are formed, on which the data driver <NUM>, the FPC, etc., are mounted, may be referred to as a pad area <NUM>. The ACF can be replaced with a conductive adhesive or conductive paste and the embodiments of the present disclosure are not limited by the types of the conductive adhesive means.

The gate driver <NUM> includes a plurality of shift registers. Each of the shift registers is connected to the respective gate lines <NUM>. The gate driver <NUM> receives a gate start pulse (GSP) and a variety of clock signals from the data driver <NUM>. As the shift registers in the gate driver <NUM> shifts gate start pulses sequentially, each of the plurality of pixels <NUM> connected to the respective gate lines <NUM> is activated. The non-pixel area corresponds to the area around the pixel area <NUM> including the area where the gate driver <NUM> is formed, except the pad area <NUM>.

The common voltage line <NUM> may be made of the same material as that of the gate lines <NUM> and/or the data lines <NUM> as a single layer or a multilayer. An insulating layer may be formed on the common voltage line <NUM>. The common voltage line <NUM> may supply a common voltage to a second electrode of each of the plurality of pixels <NUM>. As illustrated in <FIG>, the common voltage line <NUM> is formed at the outer side of the pixel area <NUM> and the gate driver <NUM> to surround them. For a top emission OLED device, the second electrodes in the pixel area <NUM> have high electric resistance. Accordingly, there is a problem in that the resistance of the second electrode increases as it becomes more distant from the common voltage line <NUM>. In order to help relieve this problem, the common voltage line <NUM> is disposed to surround the pixel area <NUM>. To electrically connect the second electrodes of the plurality of pixels <NUM> to the common voltage line <NUM>, the second electrodes may be formed on the gate driver <NUM> to be extended to a part of the gate driver <NUM>. Further, the second electrodes may be connected to a connecting unit made of the same material as that of the first electrodes formed on the gate driver <NUM>. The connecting unit made of the same material as that of the first electrodes may be formed over the gate driver <NUM> and may be connected to the common voltage line <NUM> over the gate driver <NUM>. If there is an insulating layer between the connecting unit and the common voltage line <NUM>, the connecting unit and the common voltage line <NUM> may be connected to each other via a contact hole.

The flexible encapsulation unit <NUM> is formed to cover the pixel area <NUM> and non-pixel area. In addition, the flexible encapsulation unit <NUM> is formed not to cover the pad area <NUM>. Specifically, the flexible encapsulation unit <NUM> effectively protects the moisture permeation and also has good electrical insulating property. Accordingly, in case the flexible encapsulation unit <NUM> covers the pad area <NUM>, the plurality of pads formed on the pad area <NUM> may be insulated. For this reason, it is desired that the flexible encapsulation unit <NUM> is not formed on the pad area <NUM>.

The flexible encapsulation unit <NUM> includes a first encapsulation layer <NUM>, a second encapsulation layer <NUM>, and a particle cover layer <NUM>. In particular, in order to suppress the particle cover layer <NUM> from being excessively spread, the structure <NUM> is formed in the non-pixel area to surround the pixel area <NUM>. In embodiments of the present disclosure, references to excessive spread refers to avoiding or reducing overflow of the particle cover layer <NUM> over the structure <NUM>. In other words, the structure <NUM> is arranged to contain or limit the particle cover layer <NUM>. The structure <NUM> surrounds the pixel area <NUM> and the gate driver <NUM>. The structure <NUM> partially overlaps the common voltage line <NUM>. In the claimed invention the structure <NUM> is disposed directly on the common voltage line <NUM>. The flexible encapsulation unit <NUM> will be described in more detail with reference to <FIG>. In embodiments of the present disclosure, reference is made to the structure <NUM> containing or limiting the particle cover layer <NUM>.

Referring to <FIG>, the OLED device <NUM> includes a substrate <NUM> made of a flexible material, a thin-film transistor <NUM> disposed on the substrate <NUM>, an organic light-emitting element <NUM> driven by the thin-film transistor <NUM>, and a flexible encapsulation unit <NUM> sealing the organic light-emitting element <NUM>.

The substrate <NUM> may be a flexible film such as a polyimide-based material. In addition, a back plate for supporting the OLED device <NUM> may be provided on the rear surface of the substrate <NUM> to suppress the OLED device <NUM> from being too flappy. Further, multiple buffer layers made of silicon nitride SiNx and silicon oxide SiOx may be disposed between the substrate <NUM> and the thin-film transistor <NUM>, thereby protecting moisture and/or oxygen permeation into the substrate <NUM>.

The thin-film transistor <NUM> includes an active layer <NUM>, a gate electrode <NUM>, a source electrode <NUM> and a drain electrode <NUM>. The active layer <NUM> is covered by a gate insulating film <NUM> formed on the front surface of the substrate <NUM>. The gate electrode <NUM> is made of the same material as that of the gate line <NUM> and is formed on the gate insulating film <NUM> over at least a part of the active layer <NUM>. The gate electrode <NUM> is covered by an interlayer insulating film <NUM> formed on the front surface of the gate insulating film <NUM>. The interlayer insulating film <NUM> may be formed in a multilayer structure of silicon nitride and silicon oxide. The thickness of the silicon nitride is between <NUM> µm and <NUM> µm, and the thickness of silicon oxide is, preferably, between <NUM> µm and <NUM> µm. More preferably, the thickness of silicon nitride is <NUM> µm, and the thickness of silicon oxide is <NUM> µm, and thus, the thickness of the interlayer insulating film <NUM> is <NUM> µm. The source electrode <NUM> and the drain electrode <NUM> are made of the same material as that of the data line <NUM> and are formed on the interlayer insulating film <NUM> spaced apart from each other. The source electrode <NUM> is connected to one end of the active layer <NUM> via a first contact hole <NUM> passing through the gate insulating film <NUM> and the interlayer insulating film <NUM>. The drain electrode <NUM> is disposed over at least the other end of the active layer <NUM> and is connected to the active layer <NUM> via a first contact hole <NUM> passing through the gate insulating film <NUM> and the interlayer insulating film <NUM>. The thin-film transistor <NUM> including the active layer <NUM> is covered by a planarizing layer <NUM> formed on the front surface of the interlayer insulating film <NUM>. Additionally, an insulating layer made of silicon nitride for protecting the thin-film transistor <NUM> from contamination may be formed between the interlayer insulating film <NUM> and the planarizing layer <NUM>. The structure of the thin-film transistor <NUM> is not limited to that described above but various types of structure may be employed.

The organic light-emitting element <NUM> includes a first electrode <NUM>, a second electrode <NUM> facing the first electrode <NUM>, and an organic light-emitting layer <NUM> disposed between them. A light-emitting area of the organic light-emitting layer <NUM> may be defined by a bank <NUM>.

The first electrode <NUM> is disposed on the planarizing layer <NUM> in the light-emitting area of each of the pixels <NUM>, and is connected to the drain electrode <NUM> of the thin-film transistor <NUM> via a second contact hole <NUM> passing through the planarizing layer <NUM>. The planarizing layer <NUM> may be made of photo acryl having low dielectric permittivity. The thickness of the planarizing layer <NUM> is preferably between <NUM> µm and <NUM> µm, more preferably <NUM> µm. By the planarizing layer <NUM> made of the material at the thickness, the first electrode <NUM> is less affected by parasitic capacitance generated by the thin-film transistor <NUM>, the gate line <NUM> or the data line <NUM>. Further, the evenness of the first electrode can be improved.

The bank <NUM> is formed in a tapered shape on the planarizing layer <NUM> in the non-emitting area of each of the pixels <NUM>. The bank <NUM> is formed on the edge of the first electrode <NUM>, overlapping at least a part thereof. The height of the bank <NUM> is preferably between <NUM> µm and <NUM> µm, more preferably <NUM> µm. A spacer <NUM> is formed on the bank <NUM>. The spacer <NUM> may be made of the same material as that of the bank <NUM>. The bank <NUM> and the spacer <NUM> may be made of polyimide. The space <NUM> serves to protect the organic light-emitting element <NUM> from being damaged by a fine metal mask (FMM) used in patterning the organic light-emitting layer <NUM>. The height of the spacer <NUM> is preferably between <NUM> µm and <NUM> µm, more preferably <NUM> µm. With the spacer <NUM> having such height, the organic light-emitting element <NUM> can be protected from being damaged by the mask. The spacer <NUM> may be formed without using a fine metal mask patterning.

In addition, since the heights of the planarizing layer <NUM>, the bank <NUM> and the spacer <NUM> are also related to the height of the structure <NUM> described below, the height of the structure <NUM> may be determined by taking the thickness of the particle cover layer <NUM> into account.

The organic light-emitting layer <NUM> is formed on the first electrode <NUM>. The second electrode <NUM> is formed such that it faces the first electrode <NUM> with the organic light-emitting layer <NUM> therebetween. The organic light-emitting layer <NUM> may be made of phosphor or fluorescent material, and may further include an electron transport layer, a hole transport layer, a charge generation layer and etc..

The first electrode <NUM> may be made of a metal material having a high work function. The first electrode <NUM> may be made of a reflective material so that it has a reflective property or a reflective plate may be additionally disposed under the first electrode <NUM>. To the first electrode <NUM>, an analog image signal is applied to display an image.

The second electrode <NUM> is made of a very thin, metal material having a lower work function or a transparent conductive oxide (TCO). If the second electrode <NUM> is made of a metal material, it has a thickness equal to or less than <NUM>Å. With such a thickness, the second electrode <NUM> is a transflective (semitransparent) layer, and thus, the second electrode <NUM> is regarded as a substantially transparent layer. To the second electrode <NUM>, the common voltage Vss is applied.

On the second electrode <NUM>, a flexible encapsulation unit including a first encapsulation layer, a particle cover layer, and a second encapsulation layer <NUM> are formed. The flexible encapsulation unit <NUM> will be described in more detail with reference to <FIG>.

<FIG> illustrates a part of the OLED device <NUM>, from the pixel area <NUM> to an edge of the OLED device <NUM>. Specifically, a substrate <NUM>, a pixel area <NUM> formed on the substrate <NUM>, a gate driver <NUM> formed on a non-pixel area, a common voltage line <NUM> formed on the non-pixel area, a flexible encapsulation unit <NUM> covering the pixel area <NUM> and the non-pixel area, and a barrier film <NUM> are illustrated.

The gate driver <NUM> is composed of thin-film transistors which are formed with the thin-film transistors <NUM> which are included in the plurality of pixels <NUM> during the same manufacturing process. Therefore, the layered structure of the gate driver <NUM> will not be described to avoid redundancy.

A structure <NUM> is disposed directly on the common voltage line <NUM>. The height of the structure <NUM> is increased by the thickness of the common voltage line <NUM>. Detailed description of the elements described above with respect to <FIG> will be omitted to avoid redundancy.

The flexible encapsulation unit <NUM> includes a first encapsulation layer <NUM>, a particle cover layer <NUM>, and a second encapsulation layer <NUM>. The first encapsulation layer <NUM> is configured to cover the plurality of pixels <NUM>, the gate driver <NUM>, and the structure <NUM>. The particle cover layer <NUM> covers the pixel area <NUM>, while suppressed from being excessively spread by the structure <NUM>. Thus, the particle cover layer <NUM> comes to abut the structure <NUM>. The second encapsulation layer <NUM> is configured to cover the first encapsulation layer <NUM> and the particle cover layer <NUM>. The structure <NUM> has a particular height and surrounds the particle cover layer <NUM> in the non-pixel area. The structure <NUM> has such a height that it suppresses the particle cover layer <NUM> from being excessively spread, and increases the adhesion between the barrier film <NUM> and the flexible encapsulation unit <NUM>.

The first encapsulation layer <NUM> is made of an inorganic substance. The first encapsulation layer <NUM> may be formed with silicon nitride SiNx or aluminum oxide AlyOz by using, but is not limited to, vacuum film deposition techniques such as a chemical vapor deposition (CVD), an atomic layer deposition (ALD), etc..

In case the encapsulation layer <NUM> is made of silicon nitride, the thickness of the first encapsulation layer <NUM> is preferably between <NUM>,<NUM>Å and <NUM>,<NUM>Å, more preferably <NUM>,<NUM>Å. The water vapor transmission rate (WVTR) measurement was conducted on the first encapsulation layer <NUM> having the thickness of <NUM>,<NUM>Å, and as a result, the WVTR was measured to be <NUM> × <NUM>-<NUM> g/m<NUM>/day.

In case the encapsulation layer <NUM> is made of aluminum oxide, the thickness of the first encapsulation layer <NUM> is preferably between <NUM>Å and <NUM>, <NUM>Å, more preferably <NUM>Å. The WVTR measurement was conducted on the first encapsulation layer <NUM> having the thickness of <NUM>Å, and as a result, the WVTR was measured to be <NUM>×<NUM>-<NUM> g/m<NUM>/day.

The particle cover layer <NUM> is made of an organic substance. The particle cover layer <NUM> may be made of, but is not limited to, silicon oxycarbide (SiOCz) or an acryl-based or epoxy-based resin. A viscosity of the particle cover layer <NUM> for effectively covering foreign matter is preferably between <NUM> centipoises (cps) and <NUM>,<NUM> cps, and more preferably between <NUM>,<NUM> cps and <NUM>,<NUM> cps.

For example, in case the particle cover layer <NUM> is made of SiOCz, the particle cover layer <NUM> may be formed by a CVD process. SiOCz is normally an inorganic substance but can be regarded as an organic substance under a particular configuration. Specifically, the flowability of SiOCz differs depending on the ratio between carbon atoms and silicon atoms (C/Si). For example, SiOCz with lower flowability acts like an inorganic substance, so that it covers foreign matter less effectively. On the other hand, SiOCz with higher flowability acts like an organic substance, so that it covers foreign matter more effectively. The flowability was measured by varying the ratio between the atoms. The result indicates that the flowability decreases if the ratio between C/Si is equal to or higher than approximately <NUM>, and the flowability increases if the ratio between C/Si is equal to or less than <NUM>. Accordingly, foreign matter can be easily covered if the ratio between C/Si is equal to or less than <NUM>. Accordingly, the ratio between C/Si of SiOCz of the particle cover layer <NUM> is preferably <NUM> or less. In addition, by controlling the temperature of deposition process to be <NUM> or less, the flowability is increased, so that the evenness of the particle cover layer <NUM> improves, and thus, can cover foreign matter easily. Accordingly, the second encapsulation layer <NUM> can be formed on the even surface of the particle cover layer <NUM>.

The ratio between C/Si of SiOCz may be controlled by adjusting the ratio between oxygen O<NUM> and hexamethyldisiloxane (HMDSO) during a CVD process. The thickness of the particle cover layer <NUM> made of SiOCz is preferably between <NUM> and <NUM>, more preferably <NUM>. In particular, in case the particle cover layer <NUM> is made of SiOCz, the flexible encapsulation unit <NUM> can be very thin, thus the OLED device <NUM> can be thinner.

For example, in case the particle cover layer <NUM> is made of an acryl-based or an epoxy-based resin, the particle cover layer <NUM> may be formed by slit coating or screen printing process. In this case, as the epoxy-based resin, high-viscosity bisphenol-A based epoxy or low viscosity bisphenol-F based epoxy may be applicable. The particle cover layer <NUM> may further include additive agents. For example, a wetting agent for reducing the surface tension of the resin to improve uniformity of the resin, a leveling agent for improving the surface evenness of the resin, and a defoaming agent for removing foams in the resin may be added as the additive agents. The particle cover layer <NUM> may further include an initiator. For example, an antimony-based initiator or an anhydride-based initiator may be applicable that initiates a chain reaction by heat to cure a liquid resin.

In particular, when the resin is thermally cured, it is important to control the processing temperature to be below <NUM>. In case the resin is thermally cured above <NUM>, the already formed, organic light-emitting layer <NUM> may be damaged. Accordingly, a resin that is cured below <NUM> is used.

Additionally, as the temperature of the resin increases, the viscosity of the liquid resin rapidly becomes low, and after a while, the viscosity rapidly becomes high as the resin is cured. However, while the viscosity of the resin is low, the flowability is too high. Therefore, excessive spread is especially highly likely to occur during this time.

The thickness of the particle cover layer <NUM> made of a resin may be between <NUM> and <NUM>, preferably <NUM>.

As illustrated in <FIG>, the cross section of the particle cover layer <NUM> has an even upper surface in the pixel area <NUM> and the thickness of the particle cover layer <NUM> becomes gradually thinner in the non-pixel area. The portion of the particle cover layer <NUM> that becomes gradually thinner has a slope which may refract light, deteriorating the image quality. Accordingly, the portion of the particle cover layer <NUM> that becomes gradually thinner is preferably located in the non-pixel area.

The particle cover layer <NUM> serves to cover foreign matter or particles that may be occurred during manufacturing processes. For example, there may be a defect in the first encapsulation layer <NUM> due to a crack caused by foreign matter or particles. The particle cover layer <NUM> may cover such an irregular surface or foreign matter, so that the top surface of the particle cover layer <NUM> becomes even. That is, the particle cover layer <NUM> compensates the foreign matters and planarizes the pixel area <NUM> to the plurality of pixels <NUM>. Consequently, the particle cover layer <NUM> can be also referred as the compensation layer. Also, the height of the particle cover layer <NUM> is gradually decreased from the outer periphery of the plurality of pixel <NUM> toward the structure <NUM>.

However, the particle cover layer <NUM> is not suitable for protecting the organic light-emitting element <NUM> from moisture. Additionally, since the particle cover layer <NUM> has high flowability, it frequently deviates from the designed values.

The structure <NUM> according to an example embodiment of the present invention is formed in the non-pixel area of the OLED device <NUM>. The structure <NUM> is spaced apart from the pixel area <NUM> and is spaced apart from the outermost periphery of the substrate <NUM>. As illustrated in <FIG>, the flow of the particle cover layer <NUM> is suppressed by the structure <NUM>.

Referring to <FIG>, the structure <NUM> has a multilayer structure of a first layer <NUM> and a second layer <NUM>, for suppressing the particle cover layer <NUM> from being excessively spread. The first layer <NUM> and the second layer <NUM> are formed while the bank <NUM> and the spacer <NUM> are formed during the same process. That is, the structure <NUM> may be formed in a multilayer structure having a height between <NUM> and <NUM> by a design alteration of a mask without undergoing any additional process. In other words, the height of the structure <NUM> can be varied depending on design of the bank <NUM> and the spacer <NUM>. As described above, in case the heights of the bank <NUM> and the spacer <NUM> are <NUM> and <NUM>, respectively, the height of the multilayer structure <NUM> is <NUM>. In particular, such a height of the structure <NUM> is optimized for the plurality of pixels <NUM>. In embodiments of the present disclosure, the structure <NUM> may include at least one of an organic material and an inorganic material, and the first encapsulation layer <NUM> covering the structure <NUM> resists penetration of moisture through the structure <NUM>.

The first encapsulation layer <NUM> is formed on the structure <NUM> conforming to the shape of the structure <NUM>. The slope Θ of the wall of the first encapsulation layer <NUM> formed on the structure <NUM> is equal to the slope in the cross section of the first layer <NUM> and the second layer <NUM>. The gradient of the slope of the bank <NUM> and the spacer <NUM> in the cross section may range from <NUM>° to <NUM>° with respect to the substrate <NUM>. The slope of the bank <NUM> may be equal to or different from that of the spacer <NUM>.

In case the particle cover layer <NUM> is made of SiOCz, the height of the structure <NUM> is similar to the height of the particle cover layer <NUM>, so that it is possible to effectively suppress the particle cover layer <NUM> from being excessively spread. The particle cover layer <NUM> is formed such that conforming to the wall of the first encapsulation layer <NUM> formed on the structure <NUM>. That is, the particle cover layer <NUM> has a corresponding shape according to the shape of the wall of the first encapsulation layer <NUM>.

In addition, if the structure <NUM> is higher than the particle cover layer <NUM> adjacent thereto, the structure <NUM> is capable of suppressing overflow of the particle cover layer <NUM>. Accordingly, the structure <NUM> can be formed close to the pixel area <NUM> as much as possible. In this case, it is desirable to form the structure <NUM> spaced apart from the pixel area <NUM> by a distance L2 equal to or less than <NUM>,<NUM>.

In case the particle cover layer <NUM> is made of an acryl-based or epoxy-based resin, the height of the particle cover layer <NUM> may be between <NUM> and <NUM>. Accordingly, the height of the particle cover layer <NUM> is higher than the height of the structure <NUM>. As described above, the upper surface of the particle cover layer <NUM> is even within the pixel area <NUM> and the height of the particle cover layer <NUM> is gradually decreased within the non-pixel area. In this case, it is preferably to form the particle cover layer <NUM> at a position where the height of the particle cover layer <NUM> becomes lower to be equal to the height of the structure <NUM>, so that the structure <NUM> can effectively suppress the particle cover layer <NUM>.

For example, if an epoxy-based resin used in an example embodiment of the present disclosure has the thickness of <NUM> and the viscosity of <NUM>,<NUM> cps, it is desirable to form the structure <NUM> spaced apart from the pixel area <NUM> by <NUM>,<NUM> to <NUM>,<NUM>, which is regarded as an optimal distance for this example. That is, at the particular distance L2 which is regarded as the optimal distance, the structure <NUM> can effectively suppress the particle cover layer <NUM> from overflowing. Therefore, it is important to keep the distance L2 for this example. However, the distance is not limited to the above example since the configuration varies depending on the height of the structure <NUM>, the thickness and viscosity of the particle cover layer <NUM>, and the area where it is applied.

In addition, the particle cover layer <NUM> may not flow over the structure <NUM> even if the structure <NUM> is slightly lower than the particle cover layer <NUM>, as the particle cover layer <NUM> has a certain surface tension.

The second encapsulation layer <NUM> is formed on the particle cover layer <NUM> and the first encapsulation layer <NUM>. The first encapsulation layer <NUM> comes in contact with the second encapsulation layer <NUM> at the outer side of the structure <NUM>. The length L1 of the area where the first encapsulation layer <NUM> comes in contact with the second encapsulation layer <NUM> at the outer side of the structure <NUM> is preferably <NUM> or greater. That is, the area where the first encapsulation layer <NUM> comes in contact with the second encapsulation layer <NUM> for sealing the particle cover layer <NUM> is extended from the outer periphery of the structure by a distance. In particular, as the first encapsulation layer <NUM> is configured to be in contact with the second encapsulation layer <NUM> at least <NUM>, the particle cover layer <NUM> can be sealed by the first encapsulation layer <NUM> and the second encapsulation layer <NUM> even if the particle cover layer <NUM> flows over the structure <NUM>. With this configuration, the particle cover layer <NUM> is sealed by the first encapsulation layer <NUM> and the second encapsulation layer <NUM>, so that the direct path of moisture permeation via the particle cover layer <NUM> is suppressed. In this case, the first encapsulation layer <NUM> is larger than the second encapsulation layer <NUM>. Accordingly, the area of the second encapsulation layer <NUM> may be smaller than that of the first encapsulation layer <NUM>. However, the embodiments of the present disclosure are not limited to the length L1 or the area of the first encapsulation layer <NUM> and the area of the second encapsulation layer <NUM>.

Further, as the second encapsulation layer <NUM> is formed on the even surface, which is the upper surface of the particle cover layer <NUM>, it is possible to significantly reduce cracks or seams due to foreign matter and an irregular surface. Specifically, the second electrode <NUM> is formed conforming to the bank <NUM> and the spacer <NUM>. Accordingly, the second electrode <NUM> does not have an even surface. As the first encapsulation layer <NUM> is formed conforming to the irregular surface of the second electrode <NUM>, the first encapsulation layer <NUM> may have cracks due to the irregular surface. In contrast, the second encapsulation layer <NUM> has an even surface. Accordingly, the second encapsulation layer <NUM> may have fewer cracks than the first encapsulation layer <NUM>.

As illustrated in <FIG>, after the second encapsulation layer <NUM> is formed, the barrier film <NUM> is attached on the second encapsulation layer <NUM>. By the barrier film <NUM>, the OLED device <NUM> can further protect the oxygen and moisture permeation. In particular, the process of attaching the barrier film <NUM> need not be carried out under strict vacuum conditions like a CVD process or an ALD process, but the barrier film <NUM> can be attached via a simple roll-to-roll laminating process while effectively protecting oxygen and moisture permeation by the flexible encapsulation unit <NUM>. Accordingly, it is possible to avoid cumbersome repetitions of depositing organic insulating layers and inorganic insulating layers under vacuum conditions for suppressing damages on the organic light-emitting element <NUM> by oxygen and moisture, so that the process time can be significantly reduced and manufacturing cost can be drastically saved. In addition, without the barrier film adhered by a roll-to-roll process, more encapsulation layers made of an inorganic substance may be required. Therefore, cracks are made easier in the flexible encapsulation unit as inorganic substance tends to be brittle by bending. However, by using the barrier film <NUM>, the number of the layers of the inorganic substance deposited by a CVD can be reduced while effectively suppressing moisture permeation. As a result, the good flexible encapsulation unit <NUM> can be implemented. However, the embodiments of the present disclosure are not limited by the barrier film.

The barrier film <NUM> includes a barrier film body <NUM> and a pressure-sensitive adhesive layer <NUM>. The barrier film body <NUM> may be made of, but is not limited to, one of a copolyester thermoplastic elastomer (COP), a cycoolefin copolymer (COC) and a polycarbonate (PC). The barrier film <NUM> has to transmit image in the pixel area <NUM>, and thus, preferably has optically isotropic properties in order to maintain the quality of displayed images.

The thickness of the barrier film body <NUM> is preferably between <NUM> and <NUM>, more preferably <NUM>. With such a thickness, WVTR of the barrier film <NUM> was measured to be <NUM>×<NUM>-<NUM> g/m<NUM>/day.

The capability of protecting the moisture permeation of the OLED device <NUM> is determined based on the overall WVTR, taking into account WVTRs of the first encapsulation layer <NUM>, the second encapsulation layer <NUM> and the barrier film <NUM>. Accordingly, in order to improve the WVTR of the OLED device <NUM>, the relationship with the barrier film <NUM> is also important, as well as the first encapsulation layer <NUM> and the second encapsulation layer <NUM>.

Specifically, the thickness of the barrier film <NUM> may be determined taking into account the encapsulation performance of the first encapsulation layer <NUM> and the second encapsulation layer <NUM>. For example, in case the encapsulation performance of the first encapsulation layer <NUM> and the second encapsulation layer <NUM> are improved, the thinner the barrier film <NUM> can be applied.

The pressure-sensitive adhesive layer <NUM> is made of a transparent, two-sided adhesive film. In addition, the structure <NUM> is configured to provide additional pressure to a corresponding portion of the pressure-sensitive adhesive layer <NUM> while the barrier film is laminated by a roll-to-roll process. As the height of the structure increases, the additional pressure can be increased. The pressure-sensitive adhesive layer <NUM> may be made of an insulative material such as olefin-based, acryl-based, and silicon-based materials. The pressure-sensitive adhesive layer <NUM> may have a thickness between <NUM> and <NUM>. In particular, the pressure-sensitive adhesive layer <NUM> may be made of a hydrophobic, olefin-based material that protects the moisture permeation. The pressure-sensitive adhesive layer <NUM> has the nature that its adhesion is increased if pressed at a constant pressure. If the pressure-sensitive adhesive layer <NUM> is made of a hydrophobic, olefin-based insulative material, the pressure-sensitive adhesive layer <NUM> has a WVTR of <NUM>/m<NUM>/day or less. In this manner, in addition the first encapsulation layer <NUM>, the second encapsulation layer <NUM> and the barrier film body <NUM>, the oxygen and moisture permeation into the pixel area <NUM> can be further protected even by the pressure-sensitive adhesive layer <NUM>. As a result, the life span and reliability of the OLED device <NUM> can be improved.

An OLED device according to another example embodiment of the present invention includes a structure having a different configuration from that described above with respect to the above example embodiment.

Hereinafter, a top emission OLED device according to another example embodiment of the present disclosure will be described with reference to <FIG> and <FIG>, which is capable of suppressing the particle cover layer from being excessively spread.

<FIG> is a simplified enlarged view of an OLED device according to another example embodiment of the present disclosure. <FIG> is a schematic plan view for illustrating effects of a structure in an OLED device according to another example embodiment of the present disclosure.

Referring to <FIG>, a structure <NUM> in an OLED device <NUM> includes a first layer <NUM> and a second layer <NUM>. The first layer <NUM> is a single layer. The second layer <NUM> on the first layer <NUM> includes a plurality of subsidiary structures <NUM> and <NUM>. That is, the second layer <NUM> located on the top of the multilayer structure <NUM> includes the plurality of subsidiary structures <NUM> and <NUM>. A storage space <NUM> is defined between the subsidiary structures <NUM> and <NUM> spaced apart from each other. The storage space <NUM> surrounds the pixel area <NUM>. The storage space <NUM> may act as a channel or a canal, configured to disperse a particle cover layer <NUM> when the particle cover layer <NUM> overflows the subsidiary structure <NUM>. During the process of forming the channel, a part of the first layer <NUM> may be etched to further deepen the storage space <NUM>.

The width in the cross section of the first layer <NUM> is preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. The width in the cross section of the storage space <NUM> of the second layer <NUM> is preferably between <NUM> and <NUM>, more preferably <NUM>. The width in the cross section of the plurality of subsidiary structures <NUM> and <NUM> of the second layer is <NUM>. That is, the width in the cross section of the second layer <NUM> located on the top of the multilayer structure <NUM> is narrower than that of the first layer <NUM> located on the bottom thereof.

The widths in the cross sections of the plurality of subsidiary structures <NUM> and <NUM> of the second layer <NUM> may differ from each other. For example, the inner subsidiary structure <NUM> that is closer to the outer periphery of the pixel area <NUM> may have a wider cross section than the outer subsidiary structure <NUM> because the subsidiary structure <NUM> has to bear the weight of the particle cover layer <NUM>, like a dam for storing water.

By varying factors related to the storage space <NUM>, the particle cover layer <NUM> can be more effectively dispersed.

For example, by forming the plurality of subsidiary structures <NUM> and <NUM> defining the storage space <NUM> closely to each other, capillary action can be more easily induced, so that the particle cover layer <NUM> can be dispersed more quickly via the storage space <NUM>. Capillary action is the ability of a liquid to flow in a narrow pipe without the assistance of, and in opposition to gravity.

For example, the viscosity of the particle cover layer <NUM> may be lowered. As the viscosity of the particle cover layer <NUM> becomes low, the particle cover layer <NUM> can be dispersed more quickly via the storage space <NUM>.

For example, by adding a wetting agent to the particle cover layer <NUM> in order to change its surface tension and in turn its wettability, the particle cover layer <NUM> can be dispersed more quickly via the storage space <NUM>.

The plurality of subsidiary structures <NUM> and <NUM> is especially effective when it is required to reduce the distance between the structure <NUM> and the pixel area <NUM> in order to make a narrow bezel.

Referring to <FIG>, if the particle cover layer <NUM> flows over the inner subsidiary structure <NUM>, the particle cover layer <NUM> is dispersed into two ways along the storage space <NUM>. Accordingly, the particle cover layer <NUM> is stored in the storage space <NUM> inside the subsidiary structures <NUM> and <NUM>, and thus, it is possible to effectively suppress the particle cover layer <NUM> from flowing over the outer subsidiary structure <NUM> of the structure <NUM>.

Preferably, the storage space <NUM> surrounds all four sides of the pixel area of the OLED device <NUM>. With this configuration, even if the particle cover layer <NUM> flows over one of the four sides, the particle cover layer <NUM> can be effectively dispersed by the storage space <NUM> formed along the four sides.

With the exception of the portions explained above, the OLED device <NUM> according to another embodiment is identical to the OLED device <NUM> of a previous embodiment, and thus, redundant features will not be described for the sake of brevity.

An OLED device according to yet another example embodiment of the present invention includes a structure with a different configuration from that described above with respect to the above example embodiments.

Hereinafter, a top emission OLED device according to another example embodiment of the present invention will be described with reference to <FIG> and <FIG>, which is capable of suppressing the particle cover layer from being excessively spread.

<FIG> is a schematic enlarged view of an OLED device according to yet another example embodiment of the present invention. <FIG> is a schematic plan view for illustrating effects of a structure of an OLED device according to yet another example embodiment of the present invention.

Referring to <FIG>, a structure <NUM> includes a plurality of subsidiary walls <NUM>, <NUM> and <NUM>. The plurality of subsidiary walls <NUM>, <NUM> and <NUM> may act as dams. The first subsidiary wall <NUM> is a single layer structure and is made of the same material as that of the bank <NUM> as illustrated in <FIG>. The second subsidiary wall <NUM> is a double-layer structure and is made of the same materials as that of the bank <NUM> and the spacer <NUM> as illustrated in <FIG>. The first subsidiary wall <NUM> and the second subsidiary wall <NUM> are spaced apart from each other. The third subsidiary wall <NUM> is a triple-layer structure and is made of the same materials as that of the bank <NUM>, the spacer <NUM> and the planarizing layer <NUM> as illustrated in <FIG>. The second subsidiary wall <NUM> and the third subsidiary wall <NUM> are spaced apart from each other. The wall <NUM> includes a first storage space <NUM> and a second storage space <NUM>. The first subsidiary wall <NUM> is lower than the second subsidiary wall <NUM>, and the second subsidiary wall <NUM> is lower than the third subsidiary wall <NUM>. With this configuration, in case the particle cover layer <NUM> overflows, the particle cover layer <NUM> can be dispersed firstly via the first storage space <NUM> between the first subsidiary wall <NUM> and the second subsidiary wall <NUM>. Then, in case the particle cover layer <NUM> overflows secondly, the particle cover layer <NUM> can be dispersed via the second storage space <NUM> between the second subsidiary wall <NUM> and the third subsidiary wall <NUM>.

That is, as the subsidiary walls <NUM>, <NUM> and <NUM> become higher from the inside to the outside of the OLED device <NUM> with storage spaces <NUM> and <NUM> formed between the subsidiary walls <NUM>, <NUM> and <NUM>, the overflowing particle cover layer <NUM> can be dispersed more effectively.

The plurality of subsidiary walls <NUM>, <NUM> and <NUM> is especially effective when it is required to reduce the distance between the structure <NUM> and the pixel area <NUM> in order to make a narrow bezel.

The OLED device according to the example embodiment of the present invention may be modified in a variety of ways.

In some embodiments, the number of subsidiary walls and layers of the subsidiary walls may be designed in a variety of ways by selecting from among the bank <NUM>, the spacer <NUM>, the planarizing layer <NUM>, the interlayer insulating film <NUM> and/or the common voltage line <NUM> of the plurality of pixels <NUM>.

In some embodiments, for the pixel area <NUM> having four sides, a portion of a structure formed on the first side may have three subsidiary walls in parallel with the outer periphery of the pixel area <NUM> that are spaced apart from each other. The other portions of the structure formed on the second and third sides each may have two subsidiary walls that are in parallel with the outer periphery of the pixel area <NUM> and spaced apart from each other, and the remaining portion of the structure formed on the fourth side may have one subsidiary wall that is in parallel with the outer periphery of the pixel area <NUM>. That is, different numbers of subsidiary walls may be formed along the outer periphery of the pixel area <NUM>.

In some embodiments, the pixel area <NUM> may have walls spaced apart from four corners of the outer periphery, and shapes of the storage spaces at the corners defined inside the walls may be a rounded shape, a curved shape or diagonal shape, instead of storage spaces at a right angle shape. With such shapes, when the overflowing particle cover layer <NUM> is dispersed from one side to another via a storage space, the flow of the particle cover layer can be facilitated at the corners. As a result, overflow of the particle cover layer at the corners can be suppressed and dispersion of the particle cover layer at the corners can be improved.

In some embodiments, the pixel area <NUM> may have a circular or oval shape. The structure formed around the pixel area <NUM> may be formed in a circular or oval shape, conforming to the pixel area <NUM>.

<FIG> is a schematic enlarged view of a stair-like dam of an OLED device according to yet another example embodiment of the present invention. <FIG> is a schematic plan view for illustrating effects of the stair-like dam of an OLED device according to yet another example embodiment of the present disclosure. With the exception of the portions explained above, the OLED device <NUM>, according to the other embodiment as illustrated in <FIG> and <FIG>, is identical to the OLED device <NUM> of a previous embodiment as illustrated in <FIG>, and thus, redundant features will not be described for the sake of brevity.

Referring to <FIG> and <FIG>, the height of the stair-like dam <NUM> becomes higher toward the extended area where the first encapsulation layer <NUM> contacts the second encapsulation layer <NUM>. Specifically, the stair-like dam <NUM> has a multilayer structure including a first stair <NUM> and a second stair <NUM>. The first stair <NUM> and the second stair <NUM> are formed during the processes of forming the bank <NUM> and the spacer <NUM>, respectively. That is, the stair-like dam <NUM> may be formed in a multilayer structure having a height between <NUM> and <NUM> by a design alteration of a mask without undergoing any additional process. In other words, the height of the stair-like dam <NUM> can be varied depending on design of the bank <NUM> and the spacer <NUM>. As described above, in case the heights of the bank <NUM> and the spacer <NUM> are <NUM> and <NUM>, respectively, the height of the multi-layered, stair-like dam <NUM> is <NUM>. In particular, such a height of the stair-like dam <NUM> is optimized for the plurality of pixels <NUM>. In addition, the stair-like dam <NUM> may be configured as three stairs by using the planarizing layer <NUM>. In this case, the overall thickness may be further increased by <NUM> at most. That is, the maximum height of the stair-like dam <NUM> having three stairs may be up to <NUM>.

Referring to <FIG> and <FIG>, the first inner wall <NUM> of the first stair <NUM> of the stair-like dam <NUM> may disperse the particle cover layer <NUM> into two ways with respect to the first inner wall <NUM>. Specifically, as illustrated in <FIG>, by the first inner wall <NUM>, the particle cover layer <NUM> is dispersed into two ways indicated by arrows A1 with respect to the first inner wall <NUM>. Accordingly, the particle cover layer <NUM> is dispersed into the two ways with respect to the first inner wall <NUM> before the particle cover layer <NUM> flows over the first inner wall <NUM>. Then, in case the particle cover layer <NUM> flows over the first inner wall <NUM>, it reaches the second stair <NUM> and is dispersed into two ways indicated by arrows A2 with respect to the second inner wall <NUM>.

According to this configuration of the stair-like dam <NUM>, when the particle cover layer <NUM> overflows, it is effectively dispersed by the stairs sequentially.

The first encapsulation layer <NUM> is formed on the stair-like dam <NUM> conforming to the shape of it. The slope Θ of the wall of the first encapsulation layer <NUM> formed on the stair-like dam <NUM> is equal to the slope in the cross section of the first stair <NUM> and the second stair <NUM>. The slope of the bank <NUM> and the spacer <NUM> in the cross section may range from <NUM>° to <NUM>° with respect to the substrate <NUM>. The slope of the bank <NUM> may be equal to or different from that of the spacer <NUM>.

<FIG> is a schematic enlarged view of stair-like dams in an OLED device according to yet another example embodiment of the present invention. <FIG> is a schematic plan view for illustrating effects of the stair-like dams in an OLED device according to yet another example embodiment of the present invention. The OLED device <NUM> as illustrated in <FIG> and <FIG> includes stair-like dams different from the stair-like dam <NUM> as illustrated in <FIG> and <FIG>.

Referring to <FIG>, the OLED device <NUM> includes a first subsidiary stair-like dam 840a and a second subsidiary stair-like dam 840b. Each of the stair-like dams includes a first stair 841a and 841b and a second stair 842a and 842b, respectively. The second stairs 842a and 842b are formed on the first stair 841a and 841b, respectively. The second stairs 842a and 842b are disposed more to the outside of the pixel area <NUM> at least by <NUM> than the first stairs 841a and 841b, respectively, in order to form the first stairs 841a and 841b. A storage space <NUM> is defined between the first subsidiary stair-like dam 840a and the second subsidiary stair-like dam 840b. The storage space <NUM> may act as a channel configured to disperse the particle cover layer <NUM> when the particle cover layer <NUM> overflows.

The width in the cross section of the first stairs 841a and 841b is preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. The widths in the cross section of the second stairs 842a and 842b are preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. The width of the storage space <NUM> is determined by the distance between the first subsidiary stair-like dam 840a and the second subsidiary stair-like dam 840b. The distance is between <NUM> and <NUM>, more preferably <NUM>.

The width in cross section of the first stair 841a of the first subsidiary stair-like dam 840a may differ from that of the first stair 841b of the second subsidiary stair-like dam 840b. For example, the first stair 841a of the first subsidiary stair-like dam 840a that is closer to the pixel area <NUM> may have a wider cross section than the first stair 841b of the second subsidiary stair-like dam 840b because the first stair 841a has to bear the weight of the particle cover layer <NUM> more.

The width in cross section of the second stair 842a of the first subsidiary stair-like dam 840a may differ from that of the second stair 842b of the second subsidiary stair-like dam 840b. For example, the second stair 842a of the first subsidiary stair-like dam 840a that is closer to the pixel area <NUM> may have a wider cross section than the second stair 842b of the second subsidiary stair-like dam 840b because the second stair 842a has to bear the weight of the particle cover layer <NUM> more.

For example, in case the distance between the subsidiary stair-like dams is reduced, the storage space <NUM> formed therebetween may promote capillary action, so that the particle cover layer <NUM> can be dispersed more quickly via the storage space <NUM>.

The plurality of subsidiary stair-like dams 840a and 840b is especially effective when it is required to reduce the distance between the subsidiary stair-like dams 840a and 840b and the pixel area <NUM> in order to make a narrow bezel.

Referring to <FIG>, if the particle cover layer <NUM> flows over the first stair 841a and the second stair 842a of the first subsidiary stair-like dam 840a sequentially, the particle cover layer <NUM> flows into the storage space <NUM> to be dispersed into two ways along the storage space <NUM>. Accordingly, the particle cover layer <NUM> is stored in the storage space <NUM>, and it is possible to effectively suppress the particle cover layer <NUM> from flowing over the second subsidiary stair-like dam 840b.

With the exception of the portions explained above, the OLED device <NUM> according to the other embodiment is identical to the OLED device <NUM> of a previous embodiment, and thus, redundant features will not be described for the sake of brevity.

<FIG> is a schematic enlarged view of a metal structure in an OLED device according to yet another example embodiment of the present invention. The OLED device <NUM> illustrated in <FIG> is identical to the OLED device <NUM> illustrated in <FIG> except that the structure <NUM> in the OLED device <NUM> is replaced by a metal structure, and thus, redundant features will not be described for the sake of brevity).

The metal structure <NUM> is formed in the non-pixel area of the OLED device <NUM>. The metal structure <NUM> is spaced apart from the pixel area <NUM> and is spaced apart from the outermost periphery of the substrate <NUM>. As illustrated in <FIG>, the flow of the particle cover layer <NUM> is blocked by the metal structure <NUM>. Referring to <FIG>, the metal structure <NUM> may be formed via a screen printing process. Specifically, a metal paste is applied onto a mask of a metal mesh, and then a squeegee is moved. As a result, the metal structure <NUM> is applied around the particle cover layer <NUM>. In the metal paste, an initiator may be included that enables curing by heat or ultraviolet waves.

In particular, such a screen printing process has advantages in that it can be carried out at a lower temperature than sputtering, which is typically used for metal deposition, and that it does not involve a chemical process which may possibly damage the OLED device <NUM>. In addition, when the metal structure is formed via such as a screen printing process, it is possible to make the height of the metal structure similar to the height of the particle cover layer <NUM>. Specifically, the height of the metal structure <NUM> may be between <NUM> and <NUM>.

Further, the metal structure <NUM> may be produced via a dispensing nozzle process that is capable of applying a metal paste.

In addition, the metal structure <NUM> may be produced via an ink-jet coating process that is capable of applying an ink containing a metal.

Further, the metal structure <NUM> may be produced via a rolling-printing process that is capable of applying a metal paste.

The metal structure <NUM> may be made of silver (Ag), tin (Sn), aluminum (Al), an indium tin oxide (ITO), etc..

The metal structure <NUM> is disposed directly on the common voltage line <NUM>. Accordingly, the height of the metal structure <NUM> is increased as the thickness of the common voltage line <NUM> increases. Accordingly, the common voltage line <NUM> can be electrically connected to the metal structure <NUM>, and the same effect is obtained as if the thickness of the common voltage line <NUM> were increased. As a result, the capacity of the common voltage line <NUM> can be increased.

The first encapsulation layer <NUM> is formed on the metal structure <NUM> conforming to the shape of the metal structure <NUM>. The second encapsulation layer <NUM> is formed on the particle cover layer <NUM> and the first encapsulation layer <NUM>. The first encapsulation layer <NUM> comes in contact with the second encapsulation layer <NUM> at the outer side of the structure <NUM>. With this configuration, the particle cover layer <NUM> is sealed by the first encapsulation layer <NUM> and the second encapsulation layer <NUM>, so that the direct path of moisture permeation via the particle cover layer <NUM> is suppressed.

<FIG> is a schematic enlarged view of a metal structure in an OLED device according to yet another example embodiment of the present invention. <FIG> is a schematic plan view for illustrating effects of the metal structure in an OLED device according to another example embodiment of the present invention. The OLED device <NUM> illustrated in <FIG> and <FIG> includes a different metal structure <NUM> from the OLED device <NUM> illustrated in <FIG>.

Referring to <FIG>, the structure <NUM> in the OLED device <NUM> includes a first subsidiary metal structure <NUM> and a second subsidiary metal structure <NUM>. The first subsidiary metal structure <NUM> and the second subsidiary metal structure <NUM> are spaced apart from each other, and a storage space <NUM> is defined therebetween. The storage space <NUM> may act as a channel.

The width in the cross section of the first subsidiary metal structure <NUM> and the second subsidiary metal structure <NUM> is preferably between <NUM> and <NUM>, more preferably <NUM>. The width in the cross section of the storage space <NUM> is preferably between <NUM> and <NUM>, more preferably <NUM>.

The width in the cross section of the first subsidiary metal structure <NUM> may differ from that of the second subsidiary metal structure <NUM>. For example, the inner first subsidiary metal structure <NUM> that is closer to the outer periphery of the pixel area <NUM> may have a wider cross section than the outer second subsidiary metal structure <NUM> because the first subsidiary metal structure <NUM> has to bear the weight of the particle cover layer <NUM>, like a dam for storing water.

For example, by forming the first and second subsidiary metal structures <NUM> and <NUM> defining the storage space <NUM> closely to each other, capillary action can be more easily induced, so that the particle cover layer <NUM> can be dispersed more quickly via the storage space <NUM>. In addition, the viscosity of the particle cover layer <NUM> may be lowered, or a wetting agent may be added to the particle cover layer <NUM>.

Referring to <FIG>, in case the particle cover layer <NUM> flows over the inner first subsidiary metal structure <NUM>, the particle cover layer <NUM> is dispersed into two ways along the storage space <NUM>. Accordingly, the particle cover layer <NUM> is contained in the storage space <NUM> inside the subsidiary metal structures <NUM> and <NUM>, and thus, it is possible to effectively suppress the particle cover layer <NUM> from flowing over the outer second subsidiary metal structure <NUM> of the metal structure <NUM>.

Claim 1:
An organic light-emitting display (OLED) device (<NUM>) comprising:
a pixel area (<NUM>) defined by a plurality of pixels (<NUM>) on a flexible substrate (<NUM>);
a non-pixel area around the pixel area (<NUM>);
a gate driver (<NUM>) in the non-pixel area;
a common voltage line (<NUM>), which supplies a common voltage to the plurality of pixels (<NUM>), formed at the outer side of the pixel area (<NUM>) and the gate driver (<NUM>) to surround the pixel area (<NUM>) and the gate driver (<NUM>);
a flexible encapsulation unit (<NUM>) configured to cover the pixel area (<NUM>) and the non-pixel area and comprising a first encapsulation layer (<NUM>), a particle cover layer (<NUM>) and a second encapsulation layer (<NUM>);
a structure (<NUM>) in the non-pixel area configured to surround the pixel area (<NUM>) and the gate driver (<NUM>) and to partially overlap the common voltage line (<NUM>), wherein the structure (<NUM>) is disposed directly on the common voltage line (<NUM>) so as to suppress the particle cover layer (<NUM>) from being excessively spread.