KR102323194B1 - Flexible organic light emitting display apparatus - Google Patents

Abstract

In order to solve the above problems, a flexible organic light emitting display device according to an exemplary embodiment is provided. The flexible organic light emitting diode display includes a first encapsulation layer disposed over the pixel area and the bezel area, the first encapsulation layer disposed on the first encapsulation layer, and disposed on a part of the bezel area and the buffer layer and the buffer layer disposed in the pixel area, so that the bezel area is formed. and a second encapsulation layer disposed on the portion and the foreign material compensation layer and disposed on the foreign material compensation layer, the second encapsulation layer disposed on the entire pixel area and the bezel area, and ends of the buffer layer and the foreign material compensation layer are ends of the first encapsulation layer located in the inner side, the end of the second encapsulation layer is located outside the ends of the buffer layer and the foreign material compensation layer, the first encapsulation layer and the second encapsulation layer are configured to seal the buffer layer and the foreign material compensation layer, the buffer layer is silicon oxycarbon It is composed of (SiOC), and the foreign material compensation layer is characterized in that it is composed of an epoxy resin.

Description

Flexible organic light emitting display device {FLEXIBLE ORGANIC LIGHT EMITTING DISPLAY APPARATUS}

The present invention relates to a flexible organic light emitting display device, and more particularly, to a flexible organic light emitting display device having a transparent flexible encapsulation unit having improved flexibility.

The organic light emitting display device is a self-emission type display device, and unlike a liquid crystal display device, it does not require a separate light source, so it can be manufactured in a lightweight and thin form. In addition, the organic light emitting diode display is being studied as a next-generation display because it is advantageous in terms of power consumption due to low voltage driving, and has excellent color realization, response speed, viewing angle, and contrast ratio (CR).

In the case of a top-emission type organic light emitting diode display, a transparent or translucent electrode is used as a cathode to emit light emitted from the organic light emitting layer upward. In addition, in order to secure reliability of the organic light emitting display device, an encapsulation unit is formed on the organic light emitting device including the organic light emitting layer to protect the organic light emitting layer from moisture, physical impact, or foreign substances that may be generated during the manufacturing process. In a top emission type organic light emitting display device, a glass encapsulation unit or an encapsulation unit having a thin film encapsulation structure in which an inorganic encapsulation layer and an organic encapsulation layer are alternately stacked to increase moisture permeability to delay moisture penetration are used.

An encapsulation unit having a thin film encapsulation structure in which an inorganic encapsulation layer and an organic encapsulation layer are alternately stacked has advantages of thin thickness and a flexible organic light emitting display device, and thus has been widely studied. However, the flexibility varies according to the thickness.

Since the encapsulation portion of the flexible organic light emitting diode display is formed after the formation of the organic light emitting layer is completed, there is a limitation in the process. For example, since the organic light emitting layer is vulnerable to heat, the encapsulation unit may not be formed by a process requiring a high temperature. Accordingly, the organic encapsulation layer is generally formed by a process that can be performed at a low temperature, such as a screen printing method or a slit coating method.

In the case of using the screen printing method, the organic encapsulation layer is formed by pushing the material for the organic encapsulation layer in a liquid state on the screen using a squeegee. In a conventional flexible organic light emitting diode display, an organic encapsulation layer is formed to have a thickness of about 15 μm to 20 μm.

[Related technical literature]

1. Organic light emitting display panel and manufacturing method thereof (Korean Patent Application No. 10-2012-0131157)

The inventors of the present invention have recognized that the flexibility of the flexible organic light emitting diode display is inversely proportional to the thickness. Accordingly, the inventors of the present invention attempted to form a transparent flexible encapsulation unit having a thinner thickness using a screen printing method. However, when the foreign material compensation layer is thinly formed by using the screen printing method, high pressure must be applied using an organic squeegee. As the pressure increases, the organic light emitting device under the foreign material compensation layer is damaged.

Accordingly, the inventors of the present invention have invented a flexible organic light emitting diode display including a buffer layer for realizing a thin film of the transparent flexible encapsulation unit as described above.

Accordingly, an object of the present invention is to provide a flexible organic light emitting display device in which flexibility can be improved by forming a thin transparent flexible encapsulation part.

Another object of the present invention is to provide a flexible organic light emitting diode display capable of reducing defects by minimizing damage that may occur to an organic light emitting diode.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, a flexible organic light emitting display device according to an exemplary embodiment is provided. The flexible organic light emitting diode display includes a first encapsulation layer disposed over the pixel area and the bezel area, the first encapsulation layer disposed on the first encapsulation layer, and disposed on a part of the bezel area and the buffer layer and the buffer layer disposed in the pixel area, so that the bezel area is formed. and a second encapsulation layer disposed on the portion and the foreign material compensation layer and disposed on the foreign material compensation layer, the second encapsulation layer disposed on the entire pixel area and the bezel area, and ends of the buffer layer and the foreign material compensation layer are ends of the first encapsulation layer located in the inner side, the end of the second encapsulation layer is located outside the ends of the buffer layer and the foreign material compensation layer, the first encapsulation layer and the second encapsulation layer are configured to seal the buffer layer and the foreign material compensation layer, the buffer layer is silicon oxycarbon It is composed of (SiOC), and the foreign material compensation layer is characterized in that it is composed of an epoxy resin.

According to another feature of the present invention, the second encapsulation layer is configured to seal the buffer layer and the foreign material compensation layer by contacting the first encapsulation layer in the bezel region.

According to another feature of the present invention, the width of the cross section for sealing the buffer layer and the foreign material compensation layer in contact with the first encapsulation layer and the second encapsulation layer is 50 μm to 500 μm.

According to another feature of the invention, the buffer layer comprises at least a first buffer layer and a second buffer layer on the first buffer layer.

According to another feature of the present invention, the carbon content of the first buffer layer is greater than the carbon content of the second buffer layer.

According to another feature of the present invention, the flowability of the second buffer layer is relatively lower than that of the first buffer layer.

According to another feature of the present invention, the hardness of the first buffer layer is characterized in that it is lower than the hardness of the second buffer layer.

According to another feature of the present invention, the ratio of the thickness of the first buffer layer and the second buffer layer is (1: 2) to (4: 1) characterized in that it is composed of.

According to another feature of the present invention, the first encapsulation layer and the second encapsulation layer are made of silicon nitride or aluminum oxide.

According to another feature of the present invention, the thickness of the foreign material compensation layer is 10 μm or less.

According to another feature of the present invention, the thickness of the buffer layer is characterized in that 0.5 μm to 2 μm.

The present invention has an effect of providing a flexible organic light emitting display device capable of preventing damage when a foreign material compensation layer of an epoxy-based thin film is formed by forming a buffer layer made of silicon oxycarbon (SiOC).

In addition, the present invention has an effect of maximizing the flexibility of the flexible organic light emitting display device by minimizing the thickness of the encapsulation part.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic plan view of a flexible organic light emitting diode display according to an exemplary embodiment.
FIG. 2 is a schematic cross-sectional view of an organic light emitting diode display taken along line II-II' of FIG. 1 .
3 is a schematic cross-sectional view of a flexible organic light emitting diode display according to another exemplary embodiment.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be placed between two parts, unless 'directly' is used.

Reference to a device or layer “on” another device or layer includes any intervening layer or other device directly on or in the middle of another device.

Although first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

Like reference numerals refer to like elements throughout.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated component.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each embodiment may be implemented independently of each other or may be implemented together in a related relationship. may be

Hereinafter, a top emission type flexible organic light emitting diode display according to an exemplary embodiment will be briefly described with reference to FIGS. 1 to 2 .

1 is a schematic plan view of a flexible organic light emitting diode display according to an exemplary embodiment.

The pixel area A/A of the present invention refers to an area in which a plurality of pixels 111 are disposed.

The pad area P/A of the present invention refers to an area in which a plurality of pads are disposed.

The bezel area B/A of the present invention refers to an area surrounding the pixel area A/A.

In the pixel area A/A of the flexible organic light emitting diode display 100 , a plurality of pixels 111 and a plurality of data lines for transmitting data signals generated by the data driver 115 to the plurality of pixels 111 are provided. A plurality of gate lines 112 for transferring the gate signals generated by the 114 and the gate driver 113 to the plurality of pixels 111 are disposed.

In the bezel region B/A of the flexible organic light emitting diode display 100 , a gate driver 113 configured to transmit gate signals to the plurality of gate lines 112 and a common voltage ( A common voltage line 116 configured to apply Vss) is disposed. Some components disposed in the bezel area B/A may extend to the pad area P/A.

In the pad area P/A of the flexible organic light emitting diode display 100 , a data driver 115 configured to transmit image signals to a plurality of data lines 114 and a plurality of data lines connected to the data driver 115 ( 114) is placed. A plurality of pads are disposed in the pad area P/A.

An anisotropic conductive film (ACF) is applied to the pad area P/A. Components such as the data driver 115 , a flexible printed circuit (FPC), or a cable are bonded to the pad by an anisotropic conductive film.

The transparent flexible encapsulation unit 130 according to an embodiment of the present invention is configured to cover the bezel area B/A and the pixel area A/A. The transparent flexible encapsulation unit 130 is configured not to cover the plurality of pads formed in the pad area P/A. Specifically, since the transparent flexible encapsulation unit 130 has excellent moisture permeation delay ability as well as excellent electrical insulation, when the transparent flexible encapsulation unit 130 covers the pad area P/A, the pad area A problem in that the plurality of pads formed on (P/A) are insulated may occur.

The plurality of pixels 111 are disposed on the lower substrate 101 . The plurality of pixels 111 include sub-pixels emitting at least red, green, and blue (Red, Green, Blue; RGB) light. The plurality of pixels 111 may further include sub-pixels emitting white light. Each sub-pixel may further include a color filter. Each of the plurality of pixels 111 is configured to be driven by a plurality of thin film transistors connected to a plurality of gate lines 112 and a plurality of data lines 114 formed to cross each other.

The data driver 115 generates a gate start pulse for driving the gate driver 113 and a plurality of clock signals. The data driver 115 converts a digital image signal input from the outside into an analog image signal using a gamma voltage generated by a gamma voltage generator (not shown). The converted image signal is transmitted to the plurality of pixels 111 through the plurality of data lines 114 . The data driver 115 may be bonded to a plurality of pads formed on the lower substrate 101 .

The gate driver 113 includes a plurality of shift registers, and each shift register is connected to a respective gate line 112 . The gate driver 113 receives a gate start pulse (GSP) and a plurality of clock signals from the data driver 115 , and a shift register of the gate driver 113 sequentially shifts the gate start pulses. while activating the plurality of pixels 111 connected to each gate line 112 .

The common voltage line 116 is disposed in the bezel area B/A to supply a common voltage to the cathode. The cathode of the top emission type flexible organic light emitting diode display 100 is formed as a thin film for transparency. Therefore, the cathode has a high electrical resistance value. Accordingly, a voltage drop phenomenon occurs and the quality of the displayed image is deteriorated. In order to alleviate this problem, the common voltage line 116 is disposed to surround the pixel area A/A. However, the present invention is not limited thereto, and the common voltage line 116 may be formed on at least one side of the pixel area A/A. In addition, when the flexible organic light emitting diode display 100 increases in size, it is also possible to additionally dispose an auxiliary electrode.

FIG. 2 is a schematic cross-sectional view of an organic light emitting diode display taken along line II-II' of FIG. 1 .

The flexible organic light emitting diode display 100 according to an embodiment of the present invention includes a flexible lower substrate 101 , a thin film transistor 220 disposed on the lower substrate 101 , and an organic light emitting diode driven by the thin film transistor 220 . The light emitting device 240 , the gate driver 113 formed in the bezel area B/A area, and the common voltage line 116 formed in the bezel area B/A and supplying the common voltage Vss to the cathode 243 . ), a connection part 260 connecting the cathode 243 and the common voltage line 116 , and a transparent flexible encapsulation part 130 protecting the pixel area A/A from moisture.

The lower substrate 101 may be formed of a flexible film made of a polyimide-based material.

A back-plate supporting the flexible organic light emitting diode display 100 may be additionally included on the lower surface of the lower substrate 101 to prevent the flexible organic light emitting display apparatus 100 from being too easily bent.

_{A multi-buffer layer formed of silicon nitride (SiN x} ) and silicon oxide (SiO _x ) is added between the lower substrate 101 and the thin film transistor 220 to delay penetration of moisture and/or oxygen through the lower substrate 101 . It is also possible to do

The thin film transistor 220 includes an active layer 221 , a gate electrode 222 , a source electrode 223 , and a drain electrode 224 . The active layer 221 is covered with a gate insulating layer 225 . The gate electrode 222 is made of the same material as the gate line 112 and is disposed on the gate insulating layer 225 to overlap at least a portion of the active layer 221 .

The gate electrode 222 is covered with an interlayer insulating layer 226 formed on the entire surface of the gate insulating layer 225 . The interlayer insulating layer 226 may have a multilayer structure formed of silicon nitride and silicon oxide.

For example, the thickness of silicon nitride of the interlayer insulating film 226 is preferably 0.2 µm to 0.4 µm, and the thickness of silicon oxide is preferably 0.15 µm to 0.3 µm. More preferably, the thickness of the silicon nitride is 0.3 μm and the thickness of the silicon oxide is 0.2 μm, so that the thickness of the interlayer insulating layer 226 may be 0.5 μm.

The source electrode 223 and the drain electrode 224 are made of the same material as the data line 114 and are formed on the interlayer insulating layer 226 to be spaced apart from each other. The source electrode 223 is connected to one end of the active layer 221 , and is connected to the active layer 221 through a first contact hole 229a penetrating the gate insulating layer 225 and the interlayer insulating layer 226 . Also, the drain electrode 224 overlaps at least the other end of the active layer 221 , and is connected to the active layer 221 through a contact hole penetrating the gate insulating layer 225 and the interlayer insulating layer 226 . Although the above-described thin film transistor 220 has a coplanar structure, a thin film transistor having an inverted staggered structure may also be used.

The thin film transistor insulating layer 227 is disposed on the thin film transistor 220 . However, the present invention is not limited thereto, and it is also possible that the thin film transistor insulating film 227 is not disposed. The thin film transistor insulating layer 227 may additionally block moisture penetrating from the lower substrate 101 .

The planarization layer 228 is disposed on the thin film transistor insulating layer 227 . The second contact hole 229b passes through the planarization layer 228 and the thin film transistor insulating layer 227 . The planarization layer 228 may be formed of photo acryl having a low dielectric constant. The thickness of the planarization layer 228 is preferably 2 μm to 3.5 μm, more preferably 2.3 μm. The planarization layer 228 reduces parasitic-capacitance generated between the anode 241 and the thin film transistor 220 , the gate line 112 and the data line 115 , and flattens the anode 241 . improve the figure.

A lens shape for improving light extraction efficiency may be added to the planarization layer 228 of the region where the anode 241 is disposed.

The organic light emitting diode 240 includes an anode 241 and a cathode 243 facing each other and an organic light emitting layer 242 interposed therebetween. An emission area of the organic emission layer 242 may be defined by a bank 244 .

The organic light emitting diode 240 may be configured to emit any one of red, green, and blue (RGB) light, or may be configured to emit white light. When the organic light emitting diode 240 emits white light, a color filter may be added.

The anode 241 is disposed on the planarization layer 228 to correspond to the emission region of each pixel 111 , and the drain of the thin film transistor 220 through the second contact hole 229b passing through the planarization layer 228 . It is connected to the electrode 224 . The anode 241 is made of a metallic material having a high work function. The anode 241 is made of a reflective material so that the anode 241 has reflective properties. Alternatively, a reflector is added to the lower portion of the anode 241 . An image signal for displaying an image signal is applied to the anode 241 through the drain electrode 224 .

The bank 244 is disposed on the planarization layer 228 in the non-emission area between the pixels 111 and has a tapered shape. The bank 244 is configured to overlap at least a portion of the rim of the anode 241 . The height of the bank 244 is preferably 1 μm to 2 μm, and more preferably 1.3 μm.

Spacers 245 are disposed on bank 244 . Spacer 245 may be the same material as bank 244 . For example, banks 244 and spacers 245 may be formed of polyimide. The spacer 245 may protect the organic light emitting diode 240 from damage that may be caused by a fine metal mask (FMM) used when the organic light emitting layer 242 is patterned. The height of the spacer 245 is preferably 1.5 μm to 2.5 μm, and more preferably 2 μm. According to this configuration, damage to the organic light emitting diode 240 may be reduced during the fine metal mask process.

The organic light emitting layer 242 is formed on the anode 241 . The cathode 243 is disposed to face the anode 241 with the organic light emitting layer 242 interposed therebetween. The organic emission layer 242 may be made of a phosphorescent or fluorescent material, and may further include an electron transport layer, a hole transport layer, a charge generation layer, and the like.

The cathode 243 is formed of a very thin metallic material having a low work function or a transparent conductive oxide (TCO). When the cathode 243 is formed of a metallic material, the cathode 243 is formed to a thickness of 1500 Å or less, preferably 400 Å or less. When the cathode 243 is formed to this thickness, the cathode 243 becomes a substantially translucent layer, resulting in a substantially transparent layer. A common voltage Vss is applied to the cathode 243 .

The gate driver 113 is formed of a plurality of thin film transistors. The plurality of thin film transistors constituting the gate driver 113 are formed in the same process as the thin film transistors 220 of the pixel area A/A. Accordingly, a redundant description of the thin film transistors constituting the gate driver 113 will be omitted.

The common voltage line 116 is formed of a single layer or multiple layers using the same material as the gate line 112 and/or the data line 114 .

The common voltage line 116 supplies a common voltage Vss to the cathode 243 . A thin film transistor insulating layer 227 may be disposed on the common voltage line 116 . The common voltage line 116 is disposed outside the gate driver 113 .

The connection part 260 may be disposed on the planarization layer 228 to overlap the gate driver 113 . The connection part 260 connects the common voltage line 116 and the cathode 243 . The connection part 260 may be made of the same material as the anode 241 .

The connection part 260 is connected to the common voltage line 116 along the inclined surface of one end of the planarization layer 228 . In addition, when an insulating layer exists between the connection part 260 and the common voltage line 116 , a contact hole is formed.

The cathode 243 is disposed on the bank 244 and/or the spacer 245 and extends to a portion of the bezel area B/A. The cathode 243 is connected to the connection part 260 in the bezel area B/A area where the bank 244 is not formed.

In summary, the gate electrode 222 of the thin film transistor 220 receives the driving signal generated by the gate driver 113 through the gate line 112 . In addition, the conductivity of the active layer 221 is changed by the signal applied to the gate electrode 222 . The image signal applied to the source electrode 223 through the active layer 221 is applied to the anode 241 . Then, the common voltage Vss is applied to the cathode 243 so that the organic emission layer 242 emits light to display an image.

The cross-sectional structures of the thin film transistor 220 and the organic light emitting device 240 disposed on the bezel area B/A and the pixel area A/A have been described above.

The transparent flexible encapsulation unit 130 according to an embodiment of the present invention includes a first encapsulation layer 131 , a buffer layer 132 , a foreign material compensation layer 133 , and a second encapsulation layer 134 . do.

The first encapsulation layer 131 is disposed to cover the pixel area A/A and the bezel area B/A.

The first encapsulation layer 131 is made of aluminum oxide (Al _y O _z ). The first encapsulation layer 131 is deposited by atomic layer deposition (ALD). The thickness of the first encapsulation layer 131 is preferably 200 Å to 1500 Å, more preferably 500 Å.

The first encapsulation layer 131 may also be formed of silicon nitride (SiNx). In this case, the thickness of the first encapsulation layer 131 is preferably formed to be 5000 Å to 15000 Å, more preferably 10000 Å.

According to this configuration, the first encapsulation layer 131 may encapsulate the thin film transistor 220 and the organic light emitting device 240 . The first encapsulation layer 131 is deposited at a low temperature, so that the organic light emitting diode 240 is not damaged. In addition, the first encapsulation layer 131 may secure excellent moisture permeability. In addition, the first encapsulation layer 131 may achieve a visible light transmittance of 90% or more. In particular, since the thickness of the first encapsulation layer 131 is formed to be 1500 Å or less, excellent bending performance may be achieved.

The buffer layer 132 and the foreign material compensation layer 133 are disposed to cover a portion of the pixel area A/A and the bezel area B/A. Ends of the buffer layer 132 and the foreign material compensation layer 133 are located inside the ends of the first encapsulation layer 131 .

Hereinafter, after the second encapsulation layer 134 is described, the buffer layer 132 and the foreign material compensation layer 133 will be described in detail later.

The second encapsulation layer 134 is disposed to cover the pixel area A/A and the bezel area B/A.

The second encapsulation layer 131 is made of aluminum oxide (Al _y O _z ). The second encapsulation layer 134 is deposited by atomic layer deposition (ALD). The thickness of the second encapsulation layer 134 is preferably 200 Å to 1500 Å, more preferably 500 Å.

The second encapsulation layer 134 may also be made of silicon nitride (SiNx). In this case, the thickness of the second encapsulation layer 134 is preferably formed to be 5000 angstroms to 15000 angstroms, and more preferably 10000 angstroms.

An end of the second encapsulation layer 134 is positioned outside the ends of the buffer layer 132 and the foreign material compensation layer 133 . Accordingly, the second encapsulation layer 134 seals the buffer layer 132 and the foreign material compensation layer 133 while making contact with the first encapsulation layer 131 in the bezel area B/A. The width of the cross section for sealing the buffer layer 132 and the foreign material compensation layer 133 by contacting the first encapsulation layer 131 and the second encapsulation layer 134 may be between 50 μm and 500 μm, more preferably 300 μm. is formed According to this configuration, the first encapsulation layer 131 and the second encapsulation layer 134 are configured to seal the buffer layer 132 and the foreign material compensation layer 133 , so that the buffer layer 132 and the foreign material compensation layer 133 are formed. The direct moisture permeation pathway is eliminated.

The second encapsulation layer 134 is deposited at a low temperature, so that the organic light emitting diode 240 is not damaged. In addition, the second encapsulation layer 134 may secure excellent moisture permeability. In addition, the second encapsulation layer 134 may achieve a visible light transmittance of 90% or more. In particular, since the thickness of the second encapsulation layer 134 is formed to be 1500 Å or less, excellent bending performance may be achieved.

Hereinafter, the buffer layer 132 and the foreign material compensation layer 133 will be described in detail. A foreign material compensation layer 133 is disposed on the buffer layer 132 .

The buffer layer 132 is made of silicon oxycarbon (SiOC). The thickness of the buffer layer 232 is not limited thereto, but is configured to be 0.5 μm to 2 μm. SiOC is deposited through a chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD) process.

The buffer layer 132 protects the cathode 243 and the bank 244 from being damaged when the foreign material compensation layer 133 is formed by a screen printing process.

The flexible organic light emitting diode display preferably has a low thickness in order to have a lower critical radius of curvature. In particular, since the foreign material compensation layer 133 is thick, a flexible organic light emitting diode display having a lower critical curvature counterattack may be realized by reducing the thickness of the foreign material compensation layer 133 . However, when the foreign material compensation layer 133 is formed using the screen printing process, when the foreign material compensation layer 133 is formed to be less than 10 μm, the organic light emitting device is damaged by the mask having a mesh pattern during the squeegee process.

Accordingly, in the flexible organic light emitting display device according to an embodiment of the present invention, the buffer layer 132 is disposed under the foreign material compensation layer 133 , so that the foreign material compensation layer 133 with a thin thickness can be implemented without damaging the organic light emitting device. . In addition, when the buffer layer 132 is disposed under the foreign material compensation layer 133, it is possible to form a thickness of 10 μm or less. Furthermore, since the thickness of the buffer layer 132 is 2 μm or less, even if both the buffer layer 132 and the foreign material compensation layer 133 are formed, the buffer layer 132 and the foreign material compensation layer are thinner than 20 μm, which is the thickness of the conventional foreign material compensation layer. (133) can be formed. Accordingly, since a thinner flexible organic light emitting diode display may be implemented, the critical radius of curvature of the flexible organic light emitting display may be reduced.

In particular, in order to perform this function, it is preferable to configure the buffer layer 132 to have a hardness of at least 3H. In order for the hardness to be 3H or more, the carbon content of the buffer layer 132 is set to 30% or less. However, the present invention is not limited thereto.

The foreign material compensation layer 133 is made of an acrylic or epoxy-based resin. The foreign material compensation layer 133 is formed through, for example, a screen printing process.

In particular, the foreign material compensation layer 133 is not limited thereto, but is formed to a thickness of 3 μm to 10 μm or less. Preferably it consists of 5 micrometers. If the foreign material compensation layer 133 is 3 μm or less, an uncoated area such as a pin hole may occur during the screen printing process. can

Epoxy-based resins can be high-viscosity bisphenol-A-epoxy or low-viscosity bisphenol-F-epoxy. The foreign material compensation layer 133 may further include an additive.

For example, a wetting agent for reducing the surface tension of the resin to improve the uniformity of the resin, a leveling agent for improving the surface flatness of the resin, an antifoaming agent for removing air bubbles contained in the resin ( Defoaming agent) may be further added as an additive. The foreign material compensation layer 133 may further include an initiator. For example, it is possible to use an antimony-based initiator or anhydride-based initiator that hardens a liquid resin by initiating a chain reaction by heat.

In particular, when thermosetting resins, it is important to control the process temperature below 110°C. If the resin is thermally cured at a process temperature of 120°C or higher, the already formed organic light emitting layer 242 may be damaged. Therefore, resins with curing properties at 110°C or lower are used.

The transparent flexible encapsulation unit 130 according to an embodiment of the present invention is thinner than the prior art without damaging the organic light emitting device 240 even when screen printing is used by the above-described buffer layer 132 and foreign material compensation layer 133 . The transparent flexible encapsulation unit 130 may be implemented. Therefore, excellent moisture vapor transmission delay performance and excellent flexibility can be achieved.

Referring to FIG. 3 , the buffer layer 232 of the transparent flexible encapsulation unit 230 of the flexible organic light emitting diode display 200 according to another exemplary embodiment includes a first buffer layer 232a and a second buffer layer 232b. include

The first buffer layer 232a is composed of _{flowable SiOC y .} The second buffer layer 232b is made of SiOC _z having low flowability (Dense). The flowability of SiOC is determined by the carbon content of SiOC.

When the flowability of SiOC deteriorates, SiOC has properties close to inorganic materials and hardness increases. Therefore, it has a protective film property and the moisture permeability is improved, but the performance of compensating for foreign substances is reduced.

When the flowability of SiOC is improved, SiOC has properties close to organic materials and its hardness is lowered. Therefore, the performance of compensating for foreign substances is improved and it can be easily deformed.

_{The carbon content of SiOC y} of the first buffer layer 232a is approximately 30-50%. SiOC _y is configured to have a hardness of about 1H to 2H.

_{The carbon content of SiOC z} of the second buffer layer 232b is approximately 0 to 30%. SiOC _z is configured to have a hardness of about 3H to 5H.

That is, the carbon content of the first buffer layer 232a is greater than the carbon content of the second buffer layer 232b , and the hardness of the second buffer layer 232b is greater than that of the first buffer layer 232a .

The deposition process temperature of the first buffer layer 232a is controlled to be lower than the deposition process temperature of the second buffer layer 232b. In particular, the lower the process temperature, the better the degree of compensating for foreign substances in SiOC.

The transparent flexible encapsulation unit 230 according to another embodiment of the present invention is thinner than the prior art without damaging the organic light emitting device 240 even when screen printing is used by the above-described buffer layer 232 and foreign material compensation layer 133 . The transparent flexible encapsulation unit 130 may be implemented. Therefore, excellent moisture permeation delay performance and excellent flexibility can be achieved.

Since the flexible organic light emitting diode display 200 according to another embodiment of the present invention is the same as the flexible organic light emitting display device 100 according to an embodiment of the present invention except for the above-described parts, the overlapping contents will be described. omit

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100, 200: flexible organic light emitting display device
101: substrate
A/A: pixel area
B/A: Bezel area
P/A: pad area
113: gate driver
116: common voltage line
130, 230: flexible encapsulation unit
131: first encapsulation layer
132, 232: buffer layer
232a: first buffer layer
232b: second buffer layer
133: foreign material compensation layer
134: second encapsulation layer
220: thin film transistor
221: active layer
222: gate electrode
223: source electrode
224: drain electrode
225: gate insulating film
226: interlayer insulating film
227: thin film transistor insulating film
228: planarization layer
229a: first contact hole
229b: second contact hole
240: organic light emitting device
241: anode
242: organic light emitting layer
243: cathode
244: bank
245: spacer
260: connection

Claims (11)

A flexible organic light emitting diode display including a pixel area and a bezel area, the flexible organic light emitting diode display comprising:
a first encapsulation layer disposed over the pixel area and the bezel area;
a buffer layer disposed on the first encapsulation layer and disposed on a portion of the bezel area and the pixel area;
a foreign material compensation layer disposed on the buffer layer and disposed on a portion of the bezel area and the pixel area; and
a second encapsulation layer disposed on the foreign material compensation layer and disposed over the pixel area and the bezel area;
Ends of the buffer layer and the foreign material compensation layer are located inside the end of the first encapsulation layer,
An end of the second encapsulation layer is located outside the ends of the buffer layer and the foreign material compensation layer,
The first encapsulation layer and the second encapsulation layer are configured to seal the buffer layer and the foreign material compensation layer,
The buffer layer is composed of silicon oxycarbon (SiOC), the foreign material compensation layer is composed of an epoxy resin,
The buffer layer includes a first buffer layer and a second buffer layer on the first buffer layer,
The carbon content of the first buffer layer is greater than the carbon content of the second buffer layer,
The hardness of the first buffer layer is 1H to 2H, and the hardness of the second buffer layer is 3H to 5H,
The thickness of the buffer layer is 0.5 μm to 2 μm,
The thickness of the foreign material compensation layer is 10 μm or less, the flexible organic light emitting display device. The method of claim 1,
and the second encapsulation layer is configured to seal the buffer layer and the foreign material compensation layer by contacting the first encapsulation layer in the bezel region. 3. The method of claim 2,
The flexible organic light emitting display device, characterized in that the width of a cross-section for sealing the buffer layer and the foreign material compensation layer in contact with the first encapsulation layer and the second encapsulation layer is 50 μm to 500 μm. delete delete The method of claim 1,
The flexible organic light emitting display device of claim 1 , wherein the flowability of the second buffer layer is relatively lower than that of the first buffer layer. delete The method of claim 1,
A thickness ratio of the first buffer layer and the second buffer layer is (1:2) to (4:1). The method of claim 1,
The flexible organic light emitting display device of claim 1, wherein the first encapsulation layer and the second encapsulation layer are made of silicon nitride or aluminum oxide. delete delete

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