KR102286365B1 - Adhesive film, organic light emitting display device using the same and method of manufacturing the same - Google Patents

Abstract

An adhesive film, an organic light emitting display device using the same, and a method of manufacturing the adhesive film are provided. The organic light emitting diode display includes a lower substrate and an upper substrate facing the lower substrate. An organic light emitting device is formed on a lower substrate. The adhesive film has an adhesive layer comprising a resin and a moisture absorbent dispersed in the resin, and a plurality of buffer spaces formed in the adhesive layer. Further, the adhesive film is disposed between the lower substrate and the upper substrate. In the organic light emitting display device according to an embodiment of the present invention, even if the moisture absorbent absorbs moisture and expands, an adhesive film having a plurality of buffer spaces for alleviating stress caused by the moisture absorbent absorbs and expands is used. Degradation of flatness of the upper and lower surfaces of the adhesive film may be minimized.

Description

Adhesive film, organic light emitting display device using same, and method of manufacturing adhesive film {ADHESIVE FILM, ORGANIC LIGHT EMITTING DISPLAY DEVICE USING THE SAME AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to an adhesive film, an organic light emitting display device using the same, and a method for manufacturing the adhesive film, and more particularly, to an organic light emitting display capable of improving the reliability of an organic light emitting display device by minimizing the lifting phenomenon of the adhesive film. The present invention relates to an adhesive film for encapsulating a device, an organic light emitting display device using the adhesive film, and a method of manufacturing the adhesive film.

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).

Organic materials and metal materials included in the organic light emitting diode display are easily oxidized or deteriorated by moisture (H2O) or oxygen (O2). That is, the organic light emitting diode display is very sensitive to environmental factors, and when moisture or oxygen penetrates into the organic light emitting display, dark spots and pixel shrinkage may occur due to deterioration of the organic light emitting layer or oxidation of metal electrodes. Various defects such as shrinkage) and problems such as reduced lifespan may occur. The pixel shrinkage defect refers to a defect in which the interface between the metal electrode and the organic light emitting layer is oxidized or deteriorated by moisture penetration, and thus the pixel turns black from the edge. If the pixel shrinkage defect continues for a long time, a dark spot defect in which the entire area of the pixel is discolored may occur, which may seriously affect the reliability of the organic light emitting diode display.

In order to solve this problem, various encapsulation methods have been applied to effectively block the penetration of moisture or oxygen. Among them, the front sealing method uses an adhesive film for bonding a lower substrate on which a thin film transistor, an organic light emitting device, etc. are formed and an upper substrate opposite to the lower substrate by face sealing the upper substrate and the lower substrate, thereby performing organic light emission. This is a method of protecting the organic light emitting device from penetration of moisture or oxygen from the outside by sealing the device. Accordingly, the adhesive film for encapsulating the organic light emitting diode display is also referred to as a face seal adhesive (FSA) film.

In the front encapsulation method as described above, in order to minimize penetration of moisture or oxygen from the side surface of the organic light emitting diode display, the adhesive film is disposed not only in the display area in which the organic light emitting diode is formed but also in the bezel area outside the display area. However, as the demand for an organic light emitting diode display having a narrow bezel and a zero bezel increases in recent years, the width of the bezel area is reduced, thereby reducing the width of the adhesive film disposed in the bezel area. . Accordingly, the moisture permeation distance or oxygen permeation distance from the side surface of the organic light emitting diode display is also reduced, and thus the organic light emitting diode display may be vulnerable to permeation of moisture or oxygen.

Accordingly, in order to improve the function of the adhesive film, a method of increasing the density of the moisture absorbent included in the adhesive film was considered. However, when moisture is absorbed by the moisture absorbent, the moisture absorbent expands and the size of the moisture absorbent positioned adjacent to the upper or lower surface of the adhesive film increases, so that the flatness of the upper or lower surface of the adhesive film is lowered, causing the adhesive film to float. This can happen. In addition, due to the lifting phenomenon of the adhesive film, a path through which moisture or oxygen can permeate is generated in the upper or lower portion of the adhesive film, so that moisture or oxygen can easily penetrate, thereby causing various defects in the organic light emitting device. this rises

[Related technical literature]

1. Adhesive film and sealing method of organic electronic device using same (International Application No. PCT/KR2012/009619)

2. Adhesive film and sealing method of organic electronic device using same (Korean Patent Application No. 10-2011-0113121)

The inventors of the present invention have invented an adhesive film having a new structure and a method for manufacturing the same in order to solve the problems caused by using the conventional adhesive film as described above. In addition, the inventors of the present invention have invented an organic light emitting diode display using an adhesive film having a new structure.

Accordingly, an object of the present invention is to provide an adhesive film and a method of manufacturing an adhesive film for encapsulating an organic light emitting diode display having a buffer space capable of alleviating stress caused by expansion of a moisture absorbent according to moisture penetration. will provide

Another object of the present invention is to provide an adhesive film and a method of manufacturing an adhesive film for encapsulating an organic light emitting diode display having a structure capable of minimizing the lifting phenomenon of the adhesive film.

Another problem to be solved by the present invention is to provide an organic light emitting diode display bonded using an adhesive film having improved encapsulation properties.

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.

An organic light emitting display device according to an embodiment of the present invention is provided. The organic light emitting diode display includes a lower substrate and an upper substrate facing the lower substrate. An organic light emitting device is formed on a lower substrate. The adhesive film has an adhesive layer comprising a resin and a moisture absorbent dispersed in the resin, and a plurality of buffer spaces formed in the adhesive layer. Further, the adhesive film is disposed between the lower substrate and the upper substrate. In the organic light emitting display device according to an embodiment of the present invention, even if the moisture absorbent absorbs moisture and expands, an adhesive film having a plurality of buffer spaces for alleviating stress caused by the moisture absorbent absorbs and expands is used. Degradation of flatness of the upper and lower surfaces of the adhesive film may be minimized.

According to another feature of the present invention, each of the plurality of buffer spaces is one of a hole passing through the adhesive layer, a recess in the upper or lower surface of the adhesive layer, and an air gap positioned in the adhesive layer.

According to another feature of the present invention, the lower substrate includes a display area in which the organic light emitting diode is formed and a bezel area surrounding the display area, and the density of the buffer space in the adhesive layer corresponding to the bezel area is determined by the adhesive layer corresponding to the display area. It is characterized in that it is larger than the density of the buffer space in

According to another feature of the present invention, it is characterized in that the plurality of buffer spaces exist only in the bezel area.

According to another feature of the present invention, the density of the plurality of buffer spaces in the adhesive layer is gradually increased from the central portion to the edge portion of the organic light emitting diode display.

According to another feature of the present invention, the plurality of buffer spaces are spaces for buffering stress caused by the moisture adsorbent absorbing moisture and expanding.

An adhesive film for encapsulating an organic light emitting diode display according to an exemplary embodiment is provided. The adhesive layer of the adhesive film includes a curable resin and a moisture absorbent dispersed in the curable resin. In addition, the adhesive film includes a plurality of buffer spaces formed in the adhesive layer. When the adhesive film for encapsulating the organic light emitting display device according to an embodiment of the present invention is used, a plurality of buffer spaces are formed in the adhesive film to relieve stress caused by the moisture absorbent absorbing moisture and expanding. It can be minimized that the moisture absorbent expands and the adhesive film is separated from the components on the upper or lower part of the adhesive film, and the occurrence of a lifting phenomenon of the adhesive film can be minimized.

According to another feature of the present invention, each of the plurality of buffer spaces is characterized in that it is one of a hole passing through the adhesive layer and a groove formed on the upper or lower surface of the adhesive layer.

According to another feature of the present invention, it is characterized in that the size of the hole and the size of the groove are larger than the size of the moisture adsorbent.

According to another feature of the present invention, the size of the hole and the size of the groove is characterized in that 10㎛ to 50㎛.

According to another feature of the present invention, the adhesive film further comprises an additional adhesive layer disposed on at least one of the upper surface and the lower surface of the adhesive layer, wherein wt% of the moisture absorbent in the additional adhesive layer is wt% of the moisture absorbent in the adhesive layer It is characterized by being smaller.

According to another feature of the present invention, the adhesive film further includes an upper protective film disposed on the adhesive layer, wherein the upper protective film has a plurality of through-holes respectively corresponding to the holes or grooves.

According to another feature of the present invention, the through hole is characterized in that it is concentric with a corresponding one of the hole and the groove.

According to another feature of the present invention, the plurality of buffer spaces are spaces for buffering stress caused by the moisture adsorbent absorbing moisture and expanding.

A method of manufacturing an adhesive film for encapsulating an organic light emitting display device according to an embodiment of the present invention is provided. The adhesive film manufacturing method includes the steps of applying a coating solution containing a curable resin and a moisture absorbent on the lower ledger protective film, drying the coating solution to form an adhesive layer, disposing an upper ledger protective film on the adhesive layer, protecting the lower ledger Cutting the film, the adhesive layer, and the upper ledger protective film in units of cells, and forming at least one of a hole penetrating the adhesive layer and a groove in which an upper surface or a lower surface of the adhesive layer is recessed in the adhesive layer. In the method of manufacturing an adhesive film for encapsulating an organic light emitting display device according to an embodiment of the present invention, a plurality of buffer spaces for alleviating stress caused by expansion as the moisture absorbent absorbs moisture can be formed without adding a separate process. Therefore, a plurality of buffer spaces can be easily formed without process difficulties.

According to another feature of the present invention, the step of forming at least one of the hole and the groove comprises forming a plurality of through-holes corresponding to each of the holes or grooves in the upper mother protective film or the lower mother protective film. do.

According to another feature of the present invention, the step of cutting and the step of forming at least one of the hole and the groove are characterized in that it is performed by irradiating a laser.

According to another feature of the present invention, the step of cutting and forming at least one of a hole and a groove may be performed in the direction from the upper part of the upper ledger protective film to the lower ledger protective film or from the lower part of the lower ledger protective film to the upper ledger protective film direction. It is characterized in that it is performed by imprinting (imprint).

The details of other embodiments are included in the detailed description and drawings.

The present invention can minimize the occurrence of a lifting phenomenon of the adhesive film even if the moisture absorbent dispersed in the adhesive film expands as it absorbs moisture.

In addition, the present invention may minimize the formation of a penetration path of moisture or oxygen between the adhesive film and components above or below the adhesive film, thereby improving the reliability of the organic light emitting diode display.

In addition, since the present invention does not necessarily require the use of a separate buffer layer for alleviating the stress caused by the expansion of the adhesive film, it is possible to reduce the cost for manufacturing the adhesive film.

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.

1A is a schematic plan view illustrating an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment.
1B is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment.
2 is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting display device according to another exemplary embodiment.
3 is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting diode display to which an additional adhesive layer is added according to another exemplary embodiment of the present invention.
4 is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting diode display to which a lower protective film and an upper protective film are added, according to another exemplary embodiment.
5 is a flowchart illustrating a method of manufacturing an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment of the present invention.
6A to 6D are schematic cross-sectional views illustrating a method of manufacturing an adhesive film for encapsulating an organic light emitting diode display according to an exemplary embodiment.
7 is a schematic cross-sectional view illustrating an organic light emitting diode display according to an exemplary embodiment.
8A and 8B are schematic plan views illustrating an adhesive film included in an organic light emitting diode display according to various embodiments of the present disclosure;

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 a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of 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. Like reference numerals refer to like elements throughout. 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 positioned between the 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, and technically various interlocking and driving are possible, as will be fully understood by those skilled in the art, and each embodiment may be independently implemented with respect to each other, It may be possible to implement together in a related relationship.

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

1A is a schematic plan view illustrating an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment. 1B is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment. 1A and 1B , the adhesive film 100 includes an adhesive layer 110 and a plurality of buffer spaces 120 . In FIG. 1A , the planar shape of the adhesive film 100 is illustrated as a rectangle for convenience of explanation, but the present invention is not limited thereto.

Referring to FIG. 1B , the adhesive layer 110 includes a curable resin 111 and a moisture absorbent 112 dispersed in the curable resin 111 . The curable resin 111 of the adhesive layer 110 is a base material of the adhesive layer 110 and may be made of a thermosetting resin or a photocurable resin. The curable resin 111 may be made of, for example, a polymer material such as an epoxy-based material or an olefin-based material, but is not necessarily limited thereto.

The moisture adsorbent 112 of the adhesive layer 110 may chemically react with moisture or oxygen flowing into the adhesive layer 110 to adsorb moisture or oxygen. The moisture adsorbent 112 may be made of, for example, one or a mixture of two or more of a metal powder such as alumina, a metal oxide, a metal salt, or phosphorus pentoxide (P ₂ O _{5 ).} The metal oxide may be, for example, lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), barium oxide (BaO), calcium oxide (CaO), or magnesium oxide (MgO). In addition, the metal salt is, for example, lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), cobalt sulfate (CoSO ₄ ), gallium sulfate ( Ga ₂ (SO ₄ ) ₃ ), titanium sulfate (Ti(SO ₄ ) ₂ ), or a sulfate such as _{nickel sulfate (NiSO 4 ).} In addition, metal salts are calcium chloride (CaCl ₂ ), magnesium chloride (MgCl ₂ ), strontium chloride (SrCl ₂ ), yttrium chloride (YCl ₃ ), copper chloride (CuCl ₂ ), cesium fluoride (CsF), tantalum fluoride (TaF) ₅ ), niobium fluoride _{(NbF 5} ), lithium bromide (LiBr), calcium bromide (CaBr ₂ ), cesium bromide (CeBr ₃ ), selenium bromide (SeBr ₄ ), vanadium bromide (VBr ₃ ), magnesium bromide (MgBr ₂ ) , a metal halide such as barium iodide (BaI ₂ ) or magnesium iodide (MgI ₂ ), or a metal chlorate such as barium perchlorate (Ba(ClO ₄ ) ₂ ), magnesium perchlorate (Mg(ClO ₄ ) ₂ ), and the like. However, the moisture adsorbent 112 is not limited to the above-described exemplary material.

A plurality of buffer spaces 120 are formed in the adhesive layer 110 to relieve stress caused by the moisture absorbent 112 absorbing moisture and expanding. 1A and 1B , each of the plurality of buffer spaces 120 is a hole penetrating the adhesive layer 110 . 1A and 1B, the buffer space 120 is illustrated as a cylindrical hole, but is not limited thereto, and the buffer space 120 may be a hole of various shapes, such as a polygonal pole, a conical pole, and the like. In FIGS. 1A and 1B , the plurality of buffer spaces 120 are shown to be regularly arranged in the adhesive layer 110 , but the present invention is not limited thereto, and the plurality of buffer spaces 120 are randomly arranged on the adhesive layer 110 . may be arranged.

A typical size of a moisture absorbent used in an adhesive film for encapsulating an organic light emitting diode display is 1 μm to 3 μm, and when the moisture absorbent absorbs moisture, the size of the moisture absorbent may theoretically expand by about two times. In addition, since a plurality of moisture absorbents are dispersed in the adhesive film, when all of the plurality of moisture absorbents are expanded, the thickness of the adhesive film is significantly increased, and accordingly, a lifting phenomenon of the adhesive film may occur. Accordingly, the size D1 of the buffer space 120 of the adhesive film 100 for encapsulating the organic light emitting diode display according to an embodiment of the present invention is larger than the size D2 of the moisture absorbent 112 . That is, the size D1 of the hole formed in the adhesive layer 110 is larger than the size D2 of the moisture adsorbent 112 . Here, the size of the hole (D1) means the minimum width of the hole on the plane. As shown in FIGS. 1A and 1B, when the upper surface of the hole is the cause, the size (D1) of the hole means the diameter of the circle, and the upper surface of the hole is In the case of an ellipse, the size (D1) of the hole means the length of the long axis of the ellipse, and when the upper surface of the hole is a polygon, the size (D1) of the hole means the maximum width inside the polygon. If the upper surface of the hole is a circle and the diameter of the circle is changed according to the depth of the hole, the size D1 of the hole means the minimum diameter of the circle. Here, the size D2 of the moisture adsorbent 112 means the maximum diameter of the moisture adsorbent 112 .

The size D1 of the buffer space 120 may be determined in consideration of a process for bonding the organic light emitting display device using the adhesive film 100 and whether moisture or oxygen permeates through the process. That is, when the size D1 of the buffer space 120 is smaller than 10 μm, the buffer space 120 is likely to be filled in the bonding process of the organic light emitting display device, and the size D1 of the buffer space 120 is 50 μm. When it is larger than ㎛, the buffer space 120 becomes a penetration path for moisture or oxygen, and thus reliability of the organic light emitting diode display may be deteriorated. Accordingly, the size D1 of the buffer space 120 of the organic light emitting diode display according to an exemplary embodiment may be 10 μm to 50 μm.

In the adhesive film 100 for encapsulating the organic light emitting diode display according to an embodiment of the present invention, stress caused by the moisture absorbent 112 absorbing moisture and expanding may be relieved by the plurality of buffer spaces 120 . there is. Therefore, even if the moisture absorbent 112 absorbs moisture and expands, the thickening of the adhesive layer 110 can be minimized, and in particular, as the moisture absorbent 112 dispersed at a specific point of the adhesive layer 110 expands, the adhesive layer ( 110) can be minimized locally. In addition, it may be suppressed from the occurrence of a lifting phenomenon of the adhesive film 100 in which the moisture absorbent 112 expands and the adhesive film 100 is spaced apart from the components on the upper or lower portions of the adhesive film 100 .

In addition, in the adhesive film 100 for encapsulating the organic light emitting display device according to an embodiment of the present invention, a plurality of buffer spaces 120 for alleviating stress caused by the moisture absorbent 112 absorbs moisture and expands. Since this is formed, since the use of a separate buffer layer is not necessarily required, the manufacturing cost of the adhesive film 100 can be reduced.

2 is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting display device according to another exemplary embodiment. The adhesive film 200 shown in FIG. 2 is substantially the same as that of the adhesive film 100 shown in FIGS. 1A and 1B except that the shapes of the plurality of buffer spaces 220 are different.

Referring to FIG. 2 , each of the plurality of buffer spaces 220 is a groove in which the upper surface of the adhesive layer 210 has a recessed shape. That is, the plurality of buffer spaces 220 may be formed in the adhesive layer 210 so that the height D3 of each of the plurality of buffer spaces 220 is smaller than the thickness of the adhesive layer 210 . The shape of the groove may be a pillar shape as shown in FIG. 2 , but is not limited thereto, and may have various shapes such as a hemispherical shape and a polygonal pyramid shape.

The height D3 of the buffer space 220 is greater than the size of the moisture adsorbent 112 . That is, the height D3 of the groove formed in the adhesive layer 210 is greater than the size of the moisture absorbent 112 . Here, the height D3 of the groove means the maximum length from the top to the bottom of the groove. In addition, the size of the buffer space 220 is larger than the size of the moisture adsorbent 112 .

In the adhesive film 200 for encapsulating an organic light emitting display device according to another embodiment of the present invention, the moisture absorbent 112 absorbs moisture in the adhesive layer 210 in which the moisture absorbent 112 is dispersed and expands. A groove is formed as a plurality of buffer spaces 220 to relieve the. Accordingly, when the moisture absorbent 112 absorbs moisture and expands, the stress generated by the expansion of the moisture absorbent 112 may be relieved by the plurality of buffer spaces 220 , and the adhesive layer 210 is localized. thickening can be minimized. Therefore, when the adhesive film 200 for encapsulating the organic light emitting display device according to another embodiment of the present invention is used, the moisture adsorbent 112 expands to prevent the adhesive film 200 from floating. can In addition, since the groove is formed only on the upper surface of the adhesive film 200 and the groove is not formed on the other surface of the adhesive film 200 , the adhesive force on the lower surface of the adhesive film 200 may be improved.

In FIG. 2 , all of the plurality of buffer spaces 220 are shown to be grooves, but each of the plurality of buffer spaces 220 may be one of a hole as shown in FIG. 1B and a groove as shown in FIG. 2 . That is, the adhesive layer 210 may be formed by mixing a hole penetrating the adhesive layer 210 and a groove in which the upper surface of the adhesive layer 210 is recessed. In FIG. 2 , the groove, which is the buffer space 220 , is shown in a shape in which the upper surface of the adhesive layer 210 is recessed.

3 is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting diode display to which an additional adhesive layer is added according to another exemplary embodiment of the present invention. The adhesive film 300 shown in FIG. 3 is substantially the same as the adhesive film 100 shown in FIGS. 1A and 1B except that an additional adhesive layer 315 is further included.

Referring to FIG. 3 , an additional adhesive layer 315 is disposed on the lower surface of the adhesive layer 110 . The additional adhesive layer 315 is disposed on the lower surface of the adhesive layer 110 to improve the adhesiveness of the adhesive film 300 . In addition, the additional adhesive layer 315 together with the plurality of buffer spaces 120 formed in the adhesive layer 110 may relieve stress caused by the moisture absorbent 112 absorbs moisture and expands.

The additional adhesive layer 315 includes a curable resin 111 . The curable resin 111 of the additional adhesive layer 315 may be made of the same material as the thermosetting resin or photocurable resin constituting the curable resin 111 of the adhesive layer 110 .

The additional adhesive layer 315 may further include a moisture absorbent 112 dispersed in the curable resin 111 . The moisture absorbent 112 of the additional adhesive layer 315 may be made of the same material as the moisture absorbent 112 of the adhesive layer 110 . When the additional adhesive layer 315 includes the moisture absorbent 112 , the wt% (weight%) of the moisture absorbent 112 in the additional adhesive layer 315 is the wt% of the moisture absorbent 112 in the adhesive layer 110 . It may be smaller, and the adhesive film 300 may be disposed such that the additional adhesive layer 315 is closer to the organic light emitting diode than the adhesive layer 110 in the bonding process of the organic light emitting display device.

In the adhesive film 300 for encapsulating an organic light emitting display device according to another embodiment of the present invention, an additional adhesive layer 315 is disposed on the lower surface of the adhesive layer 110 to improve the adhesiveness of the adhesive film 300 and at the same time The stress caused by the moisture adsorbent 112 expanding by absorbing moisture can be further alleviated, and the occurrence of the lifting phenomenon of the adhesive film 300 by the stress generated by the moisture adsorbent 112 expanding can be suppressed. there is. In addition, the weight % of the moisture absorbent 112 in the additional adhesive layer 315 is set to be smaller than the wt% of the moisture absorbent 112 in the adhesive layer 110 , and the additional adhesive layer 315 is formed in the bonding process of the organic light emitting display device. By disposing it closer to the organic light emitting device than the adhesive layer 110 , damage to the organic light emitting device can be minimized even when the moisture absorbent 112 of the adhesive layer 110 absorbs a lot of moisture.

In FIG. 3, it is shown that the additional adhesive layer 315 is disposed on the lower surface of the adhesive layer 110 shown in FIG. 1B, but as shown in FIG. may be placed. In addition, although it is illustrated that the additional adhesive layer 315 is disposed on the lower surface of the adhesive layer 110 in FIG. 3 , the additional adhesive layer 315 may be disposed on the upper surface of the adhesive layer 110 .

4 is a schematic cross-sectional view illustrating an adhesive film for encapsulating an organic light emitting diode display to which a lower protective film and an upper protective film are added, according to another exemplary embodiment. The adhesive film 400 shown in FIG. 4 is substantially the same as that of the adhesive film 100 shown in FIGS. 1A and 1B except that an upper protective film 430 and a lower protective film 440 are further included. do.

The upper protective film 430 and the lower protective film 440 are films for supporting and protecting the adhesive layer 110 until the adhesive film 400 is attached to the organic light emitting diode display. The upper protective film 430 is disposed on the adhesive layer 110 , and the lower protective film 440 is disposed under the adhesive layer 110 . Each of the upper protective film 430 and the lower protective film 440 may be formed of a general polymer material, for example, a polyethyleneterephthalate film, a polytetrafluoroethylene film, a polyethylene film. , polypropylene film, polybutene film, polybutadiene film, vinyl chloride copolymer film, polyurethane film, ethylene-vinyl acetate film, ethylene-propylene It may be an (ethylene-propylene) copolymer film, an ethylene-acrylic acid ethyl copolymer film, an ethylene-methyl acrylic acid methyl copolymer film, or a polyimide film.

The upper protective film 430 has a plurality of through holes 431 corresponding to each of the plurality of buffer spaces 120 of the adhesive layer 110 . That is, the plurality of through holes 431 of the upper protective film 430 are formed to correspond to the plurality of holes of the adhesive layer 110 . The correspondence between the plurality of buffer spaces 120 of the adhesive layer 110 and the plurality of through-holes 431 of the upper protective film 430 means that the buffer space 120 and the through-hole 431 are concentric. This means that the buffer space 120 and the groove may be formed to have the same shape and the same size. In FIG. 4 , the buffer space 120 is illustrated as a hole, but is not limited thereto, and the buffer space 120 is a groove as shown in FIG. 2 , and the groove and the buffer space 120 may be concentric. For a more detailed description of the plurality of through-holes 431 of the upper protective film 430 and the plurality of buffer spaces 120 of the adhesive layer 110 , refer to FIGS. 5 and 6A to 6D .

5 is a flowchart illustrating a method of manufacturing an adhesive film for encapsulating an organic light emitting diode display according to an exemplary embodiment. 6A to 6D are schematic cross-sectional views illustrating a method of manufacturing an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment. 6A to 6D are process cross-sectional views illustrating a method of manufacturing the organic light emitting diode display illustrated in FIG. 4 , and redundant descriptions of components described with reference to FIG. 4 will be omitted.

First, a coating solution 119 including a curable resin 111 and a moisture absorbent 112 is applied on the lower ledger protective film 449 (S50), and the coating solution 119 is dried to form an adhesive layer 110 (S51).

Referring to FIG. 6A , a coating solution 119 including a curable resin 111 and a moisture absorbent 112 is applied on the lower ledger protective film 449 to form a plurality of adhesive films 400 . The lower ledger protective film 449 is a ledger unit protective film having a size corresponding to the plurality of adhesive films 400 , and may be made of the same material as the lower protective film 440 as described above. In order to apply the coating solution 119, various coating methods such as roll coating, spray coating, etc. may be used.

Then, the coating solution 119 applied on the lower ledger protective film 449 is heated to dry the solvent of the coating solution 119 . As the coating solution 119 dries, an adhesive layer 110 is formed on the lower ledger protective film 449 as shown in FIG. 6B .

Next, an upper mother protective film 439 is disposed on the adhesive layer 110 ( S52 ).

In order to dispose the upper mother protective film 439 on the adhesive layer 110 , a lamination process using a roller or a press process may be used. The upper ledger protective film 439 is a ledger unit protective film having a size corresponding to the plurality of adhesive films 400 , and may be made of the same material as the upper protective film 430 as described above.

Then, the lower ledger protective film 449, the adhesive layer 110 and the upper ledger protective film 439 are cut in cell units (S53), and the adhesive layer 110 as a buffer space 120 in the adhesive layer 110 penetrates the adhesive layer 110. A hole is formed (S54).

The process of cutting the lower ledger protective film 449, the adhesive layer 110, and the upper ledger protective film 439 in cell units and the process of forming a hole penetrating the adhesive layer 110 in the adhesive layer 110 can be performed simultaneously. there is. For example, a process of cutting the lower ledger protective film 449, the adhesive layer 110, and the upper ledger protective film 439 in cell units and a process of forming a hole penetrating the adhesive layer 110 in the adhesive layer 110 As shown in FIG. 6C , imprinting may be performed in the direction of the lower ledger protective film 449 from the upper part of the upper ledger protective film 439 . Specifically, a hole is formed as a buffer space 120 in the cutter 691 and the adhesive layer 110 for cutting the lower ledger protective film 449, the adhesive layer 110, and the upper ledger protective film 439 in cell units. After placing a plurality of pins 692 on the upper ledger protection film 439 for 449) direction may be used. At this time, as shown in FIG. 6c, by adjusting the length of the cutter 691 and the pin 692, the lower ledger protective film 449 of the portion corresponding to the cutter 691 as shown in FIG. 6d, While the adhesive layer 110 and the upper ledger protective film 439 are cut in units of cells, a plurality of holes are formed as a plurality of buffer spaces 120 in the region of the adhesive layer 110 corresponding to the plurality of pins 692 . . At this time, since the pin 692 for forming the plurality of buffer spaces 120 penetrates the upper ledger protective film 439 on the adhesive layer 110 , the adhesive layer 110 includes a plurality of buffer spaces 120 as a plurality of buffer spaces. A plurality of through-holes 431 may be formed in the upper ledger protection film 439 to correspond to the holes at the same time that the holes are formed. Accordingly, as shown in FIG. 6D , the through hole 431 of the upper protective film 430 and the buffer space 120 of the adhesive layer 110 may be formed to be concentric. In FIG. 6C , it is shown that the imprint process is performed from the upper part of the upper ledger protective film 439 to the lower ledger protective film 449 , but the imprint process is performed from the lower part of the lower ledger protective film 449 to the upper ledger protective film 439 . ) direction can also be performed.

In the method for manufacturing an adhesive film for encapsulating an organic light emitting display device according to an exemplary embodiment of the present invention, a plurality of buffer spaces 120 for relieving stress caused by expansion as the moisture absorbent 112 adsorbs moisture is separately provided. It can be formed without additional processes. That is, as shown in FIG. 6c, the process of cutting the lower ledger protective film 449, the adhesive layer 110, and the upper ledger protective film 439 in units of cells and at the same time to form a plurality of buffer spaces 120 A plurality of buffer spaces 120 may be formed by imprinting a plurality of pins 692 on the upper ledger protective film 439 . That is, the cell unit cutting process and the plurality of buffer spaces 120 forming process may be simultaneously performed by adding only the plurality of pins 692 in the cell unit cutting process that has been conventionally performed. Accordingly, in the method for manufacturing an adhesive film for encapsulating an organic light emitting display device according to an embodiment of the present invention, a plurality of buffer spaces 120 may be easily formed without process difficulties.

6A to 6D, the lower ledger protective film 449, the adhesive layer 110, and the upper ledger protective film 439 are cut in cell units using the imprint method, and the adhesive layer 110 is provided as a buffer space 120 as a buffer space 120. Although described as forming a hole, the lower ledger protective film 449, the adhesive layer 110, and the upper ledger protective film 439 are cut in cell units using a laser irradiation method, and the adhesive layer 110 is buffered A hole may be formed as the space 120 . That is, by differently setting the irradiation time, the wavelength of the laser, the output of the laser, etc. of the laser respectively irradiated to the position where the cutting process should be performed and the position where the buffer space 120 should be formed, the cell unit cutting process and the plurality of buffer spaces The (120) forming process may be performed simultaneously.

Although it has been described that the plurality of buffer spaces 120 are holes in FIGS. 6A to 6D , the plurality of buffer spaces 120 may be grooves as shown in FIG. 2 . In this case, the grooves may be formed as the plurality of buffer spaces 120 by shortening the length of the plurality of fins 692 or changing the laser irradiation condition as compared with the case of forming the holes.

7 is a schematic cross-sectional view illustrating an organic light emitting diode display according to an exemplary embodiment. Referring to FIG. 7 , the organic light emitting diode display 70 includes a lower substrate 750 , an organic light emitting device 770 , an upper substrate 760 , and an adhesive film 700 , and may further include a protective layer 780 . may be

Referring to FIG. 7 , the lower substrate 750 is defined to have a display area DA that is an area where an actual image is displayed, and a bezel area BA that surrounds the display area DA and is an area where an image is not displayed. An organic light emitting device 770 is formed on a lower substrate 750 made of an insulating material. The organic light emitting device 770 includes an anode, an organic light emitting layer formed on the anode, and a cathode formed on the organic light emitting layer. The organic light emitting diode 770 is formed in a central portion of the lower substrate 750 corresponding to the display area DA of the lower substrate 750 . Although not shown in FIG. 7 , various circuits such as a thin film transistor and a capacitor for driving the organic light emitting diode 770 as well as various wirings may be formed on the lower substrate 750 .

A protective layer 780 is formed to protect the organic light emitting diode 770 from moisture or oxygen from outside the organic light emitting diode display 70 . An organic film or an inorganic film may be used as the protective film 780 , and the protective film 780 having various structures such as an organic film alone deposition structure, an inorganic film alone deposition structure, or an organic/inorganic film alternate deposition structure may be used. As the passivation layer 780 , for example, a layer on which silicon nitride (SiNx) is deposited may be used. Although it is illustrated in FIG. 7 that the passivation layer 780 is included in the organic light emitting diode display 70 , the passivation layer 780 may not be used depending on the implementation method of the organic light emitting display device 70 .

The upper substrate 760 is disposed to face the lower substrate 750 . The upper substrate 760 may be formed of, for example, a material such as glass, plastic, or metal, and a constituent material of the upper substrate 760 may be determined according to the emission direction of the organic light emitting diode display 70 .

An adhesive film 700 is disposed between the upper substrate 760 and the lower substrate 750 . The adhesive film 700 is a film for bonding the upper substrate 760 and the lower substrate 750 , and surface-bonds the upper substrate 760 and the lower substrate 750 . The adhesive film 700 is formed in the display area DA and the bezel area BA of the lower substrate 750 to seal the organic light emitting device 770 formed on the lower substrate 750 , and the organic light emitting diode display device ( 70) It is possible to protect the organic light emitting device 770 from penetration of moisture or oxygen from the outside.

The adhesive layer 710 of the adhesive film 700 may be in a cured state of the adhesive layer 710 described with reference to FIGS. 1B and 2 . That is, the adhesive layer 710 may be formed of a cured resin and a moisture absorbent dispersed in the resin. Also, as described with reference to FIG. 3 , the additional adhesive layer 315 may be further included in the adhesive film 700 , and the additional adhesive layer 315 may be disposed to cover the organic light emitting device 770 .

A plurality of buffer spaces 720 are formed in the adhesive layer 710 of the adhesive film 700 , which is a space for alleviating stress caused by the moisture absorbent of the adhesive layer 710 absorbing moisture and expanding. Each of the plurality of buffer spaces 720 includes a hole 721 passing through the adhesive layer 710 , a recess 722 in the upper surface of the adhesive layer 710 , and an air gap 723 positioned in the adhesive layer 710 . can be one of For example, when the adhesive layer 710 of the adhesive film 700 is in a cured state of the adhesive layer 110 shown in FIG. 1B , each of the plurality of buffer spaces 720 includes a hole 721 , a groove 722 , and It may be one of the air gaps 723 . As shown in FIG. 1B , only a hole penetrating the adhesive layer 110 may be formed in the adhesive layer 710 before the bonding process of the organic light emitting diode display 70 . However, when heat or pressure is applied to the upper substrate 760 and the lower substrate 750 for the bonding process, the shape of the top or bottom of the hole may be deformed. Accordingly, each of the plurality of buffer spaces 720 may be one of a hole 721 , a groove 722 , and an air gap 723 . In addition, when the adhesive layer 710 of the adhesive film 700 is in a cured state of the adhesive layer 710 shown in FIG. 2 , the shape of the top or bottom of the groove 722 may be deformed in the bonding process, and accordingly Each of the plurality of buffer spaces 720 may be one of a groove 722 and an air gap 723 . Here, the air gap 723 means a space surrounded by the adhesive layer 710 . In FIG. 7 , the groove 722 is illustrated as being formed on the upper surface of the adhesive layer 710 , but the groove 722 may have a shape in which the lower surface of the adhesive layer 710 is recessed.

In the organic light emitting diode display 70 manufactured by bonding the upper substrate 760 and the lower substrate 750 using an adhesive layer 710 including a moisture absorbent, when the moisture absorbent absorbs moisture, the moisture absorbent is It expands, whereby flatness of the upper and lower surfaces of the adhesive film 700 may be greatly reduced. When the flatness of the upper and lower surfaces of the adhesive film 700 is lowered, a predetermined space is generated between the adhesive film 700 and the upper or lower components of the adhesive film 700 of the adhesive film 700 . A lifting phenomenon may occur, and a moisture permeation path may be formed in the organic light emitting diode display 70 due to the lifting phenomenon of the adhesive film 700 , and thus the reliability of the organic light emitting diode display 70 may be deteriorated. Accordingly, in the organic light emitting diode display 70 according to an embodiment of the present invention, the adhesive film 700 in which the plurality of buffer spaces 720 are formed is used, and adhesion that may occur when the moisture absorbent absorbs moisture and expands. Stress in the film 700 may be relieved. In addition, since the stress in the adhesive film 700 is relieved, a decrease in flatness of the upper and lower surfaces of the adhesive film 700 may be minimized. Accordingly, in the organic light emitting diode display 70 according to an exemplary embodiment, the occurrence of a lifting phenomenon of the adhesive film 700 may be suppressed, and the reliability of the organic light emitting display device 70 may be improved.

8A and 8B are schematic plan views illustrating an adhesive film included in an organic light emitting diode display according to various embodiments of the present disclosure; In FIGS. 8A and 8B , only the adhesive films 810A and 810B and the plurality of buffer spaces 820A and 820B formed in the adhesive films 810A and 810B are illustrated for convenience of explanation, and the display area DA of the lower substrate and An area corresponding to the bezel area BA is separated by a dotted line. In addition, although it is illustrated in FIGS. 8A and 8B that all of the plurality of buffer spaces 820A and 820B are holes for convenience of explanation, the plurality of buffer spaces 820A and 820B may be grooves or air gaps.

First, referring to FIG. 8A , the density of the buffer space 820A corresponding to the bezel area BA is greater than the density of the buffer space 820A corresponding to the display area DA. That is, the density of the buffer space 820A in the adhesive layer 810A positioned in the bezel area BA is greater than the density of the buffer space 820A in the adhesive layer 810A positioned in the display area DA. The organic light emitting diode display is relatively vulnerable to moisture permeation from a side surface. That is, since interfaces between various components exist on the side surface of the organic light emitting diode display, and moisture or oxygen may penetrate through the interfaces, it is required to efficiently block moisture or oxygen from the side surface of the organic light emitting display device. Accordingly, a portion of the adhesive film corresponding to the bezel area BA may include a relatively larger amount of moisture absorbent than a portion corresponding to the display area DA. Accordingly, most of the moisture or oxygen penetrating through the side surface of the organic light emitting display device is absorbed by the moisture absorbent positioned to correspond to the bezel area BA. It can swell more than the moisture absorbent it is placed on. Accordingly, in the organic light emitting diode display according to another embodiment of the present invention, the density of the buffer space 820A corresponding to the bezel area BA is greater than the density of the buffer space 820A corresponding to the display area DA. , it is possible to more easily buffer the stress caused by the moisture absorbent in the bezel area BA absorbing moisture and expanding.

Next, referring to FIG. 8B , the plurality of buffer spaces 820B exist only in the bezel area BA. That is, all of the plurality of buffer spaces 820B of the adhesive film are formed only in the bezel area BA and are not formed in the display area DA. As described above, a relatively large amount of moisture absorbent may be included in the adhesive film portion corresponding to the bezel area BA in order to block moisture or oxygen penetrating through the side surface of the organic light emitting diode display. Accordingly, most of the moisture or oxygen penetrating through the side surface of the organic light emitting display device may be absorbed by the moisture absorbent dispersed in the adhesive film corresponding to the bezel area BA, and thus the adhesive film corresponding to the display area DA. The moisture adsorbent dispersed in it may not substantially swell. Accordingly, in the organic light emitting diode display according to another embodiment of the present invention, the plurality of buffer spaces 820B are formed only in the bezel area BA, so that the moisture absorbent in the bezel area BA absorbs moisture and expands. You can relieve stress more easily.

Although not shown in FIGS. 8A and 8B , the density of the plurality of buffer spaces in the adhesive layer may gradually increase from the central portion of the organic light emitting diode display toward the edge portion. That is, since the possibility of penetration of moisture or oxygen increases as the distance from the side surface of the organic light emitting diode display increases, a relatively large number of buffer spaces are formed in the edge portion of the organic light emitting diode display, and relatively large in the central portion of the organic light emitting diode display. Thus, a small number of filling spaces can be formed.

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. 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.

110, 210, 710, 810A, 810B, 810C: adhesive layer
111: curable resin
112: moisture absorbent
119: coating solution
315: additional adhesive layer
120, 220, 720, 820A, 820B, 820C: buffer space
721: Hall
722: home
723: air gap
430: upper protective film
431: through hole
439: upper ledger protection film
440: lower protective film
449: lower ledger protection film
750: lower substrate
760: upper substrate
770: organic light emitting device
780: shield
691: cutter
692: pin
100, 200, 300, 400, 700: adhesive film
70: organic light emitting display device
BA: Bezel Area
DA: display area

Claims (19)

lower substrate;
an organic light emitting device disposed on the lower substrate;
an adhesive film sealing the organic light emitting device; and
Including an upper substrate disposed on the adhesive film,
The adhesive film is
an adhesive layer comprising a resin and a moisture absorbent dispersed in the resin; and
It has a plurality of buffer spaces formed in the adhesive layer,
the lower substrate includes a display area in which the organic light emitting diode is formed and a bezel area surrounding the display area;
and a density of the buffer space in the adhesive layer corresponding to the bezel area is greater than a density of the buffer space in the adhesive layer corresponding to the display area. According to claim 1,
Each of the plurality of buffer spaces is one of a hole penetrating the adhesive layer, a recess in an upper or lower surface of the adhesive layer, and an air gap positioned in the adhesive layer. . delete According to claim 1,
and the plurality of buffer spaces exist only in the bezel area. According to claim 1,
and a density of the plurality of buffer spaces in the adhesive layer gradually increases from a central portion to an edge portion of the organic light emitting diode display. According to claim 1,
and the plurality of buffer spaces are spaces for buffering stress caused by the moisture absorbent absorbing moisture and expanding. an adhesive layer comprising a curable resin and a moisture absorbent dispersed in the curable resin; and
A plurality of buffer spaces formed in the adhesive layer,
The adhesive layer includes a first region corresponding to the center of the adhesive layer and a second region surrounding the first region,
The adhesive film for encapsulating an organic light emitting display device, wherein a density of the buffer space in the second region is greater than a density of the buffer space in the first region. an adhesive layer comprising a curable resin and a moisture absorbent dispersed in the curable resin;
a plurality of buffer spaces formed in the adhesive layer; and
An additional adhesive layer disposed on at least one of the upper and lower surfaces of the adhesive layer,
Each of the plurality of buffer spaces is one of a hole penetrating through the adhesive layer and a groove in the upper or lower surface of the adhesive layer,
The adhesive film for encapsulating an organic light emitting display device, characterized in that wt% of the moisture absorbent in the additional adhesive layer is smaller than the wt% of the moisture absorbent in the adhesive layer. 9. The method of claim 8,
The size of the hole and the size of the groove are larger than the size of the moisture absorbent, the adhesive film for encapsulating an organic light emitting display device. 9. The method of claim 8,
The adhesive film for encapsulating an organic light emitting display device, characterized in that the size of the hole and the size of the groove are 10 μm to 50 μm. 8. The method of claim 7,
the first area corresponds to a display area of the organic light emitting diode display;
and the second region corresponds to a bezel region of the organic light emitting diode display. an adhesive layer comprising a curable resin and a moisture absorbent dispersed in the curable resin;
a plurality of buffer spaces formed in the adhesive layer; and
an upper protective film disposed on the adhesive layer;
The plurality of buffer spaces is one of a hole penetrating the adhesive layer and a groove dug in the upper or lower surface of the adhesive layer,
The adhesive film for encapsulating an organic light emitting display device, wherein the upper protective film has a plurality of through holes corresponding to each of the holes or the grooves. 13. The method of claim 12,
The adhesive film for encapsulating an organic light emitting display device, wherein the through hole is concentric with a corresponding one of the hole and the groove. 8. The method of claim 7,
The adhesive film for encapsulating an organic light emitting display device, wherein the plurality of buffer spaces are spaces for buffering stress caused by the expansion of the moisture absorbent by absorbing moisture. applying a coating solution containing a curable resin and a moisture absorbent on the lower ledger protective film;
drying the coating solution to form an adhesive layer;
disposing an upper ledger protective film on the adhesive layer;
cutting the lower ledger protective film, the adhesive layer, and the upper ledger protective film in units of cells; and
and forming in the adhesive layer at least one of a hole penetrating through the adhesive layer and a groove in which an upper surface or a lower surface of the adhesive layer is recessed. 16. The method of claim 15,
The method of claim 1 , wherein the cutting and the forming of at least one of the hole and the groove are simultaneously performed. 16. The method of claim 15,
Forming at least one of the hole and the groove comprises forming a plurality of through-holes corresponding to each of the holes or the grooves in the upper mother protective film or the lower mother protective film, A method of manufacturing an adhesive film for encapsulating an organic light emitting display device. 18. The method of claim 17,
The method of claim 1 , wherein the cutting and the forming of at least one of the hole and the groove are performed by irradiating a laser beam. 18. The method of claim 17,
The cutting and forming at least one of the hole and the groove may include imprinting from the upper part of the upper ledger protective film to the lower ledger protective film or from the lower part of the lower ledger protective film to the upper ledger protective film. A method of manufacturing an adhesive film for encapsulating an organic light emitting display device, characterized in that it is performed by (imprinting).

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