KR102385486B1 - Organic light emitting display device - Google Patents

Abstract

According to an embodiment of the present invention, in the organic light emitting display device including an encapsulation part implemented to be suitable for a flexible structure, the encapsulation part is a low-viscosity material to have a lower inorganic layer covering the organic light emitting device and a thin thickness suitable for the flexible structure. and an organic layer having an outer edge defined by a low-surface energy region of the lower inorganic layer and an upper inorganic layer covering the organic layer.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY DEVICE}

The present invention relates to an organic light emitting display device including an encapsulation unit embodied to be suitable for a flexible structure, and more particularly, to an organic light emitting diode display including an encapsulation unit, and more particularly, by effectively controlling the flowability of the low-viscosity organic layer included in the encapsulation unit, thereby The present invention relates to an organic light emitting diode display capable of reducing a bubble phenomenon.

An organic light-emitting display device (OLED device) is a next-generation display device having self-luminance characteristics. An organic light-emitting display device includes an organic light-emitting element including two electrodes and an organic light-emitting layer disposed therebetween. The organic light emitting device uses the principle of injecting electrons and holes from two electrodes into the organic light emitting layer, respectively, and generating light by combining the injected electrons and holes.

Unlike a liquid crystal display device, the organic light emitting display device does not require a separate light source, and thus can be manufactured to be lightweight and thin. In addition, the organic light emitting diode display has advantages over the liquid crystal display in terms of viewing angle, contrast, response speed, power consumption, and the like. In addition, the organic light emitting diode display uses an organic light emitting device having a surface light emitting structure in which light is emitted by an organic light emitting layer interposed between two electrodes as a light source, thereby being more flexible than a liquid crystal display device. It has the advantage of being easy to implement, and has been spotlighted as a next-generation display device.

However, despite these advantages, the organic light emitting diode display is very vulnerable to moisture (H ₂ O) or oxygen (O ₂ ). Specifically, when moisture or oxygen penetrates into the organic light emitting device including the anode, the organic light emitting layer, and the cathode, dark spots or pixel shrinkage due to oxidation of the metal electrode or deterioration of the organic light emitting layer, etc. Various defects and life-shortage problems such as these may occur.

To solve this problem, a side encapsulation unit using a shield cap made of metal or glass or a front encapsulation unit encapsulating the entire organic light emitting device may be used in the organic light emitting diode display.

Meanwhile, in recent years, the thickness of the organic light emitting diode display is gradually becoming thinner to facilitate implementation of the flexible display. In order to reduce the thickness of the organic light emitting diode display, the thickness of the encapsulation unit for sealing the organic light emitting diode must also be reduced.

As mentioned above, the encapsulation unit is an important component for improving the reliability of the organic light emitting diode display, and a side encapsulation unit or a front encapsulation unit may be used to protect the organic light emitting device from infiltration of external moisture or oxygen. Among them, in particular, in the case of the front encapsulation unit, the entire organic light emitting device has a structure in which at least one inorganic layer and at least one organic layer are alternately stacked and sealed. There are advantages.

However, since the organic layer included in the front encapsulation unit is formed by a vacuum screen printing (VSP) process, it is difficult to reduce the thickness to a thickness suitable for flexibility. More specifically, the VSP process is a printing method in which an organic material is applied to a screen mask in a vacuum state, and then the organic material is applied to the substrate by pressing with a roller or the like. Therefore, the material of the organic layer included in the conventional front encapsulation unit has low flowability, which is advantageous for screen mask application, and has a certain thickness or more so as to minimize damage to the organic light emitting device located under the encapsulation unit due to pressurization of a roller or the like. A high-viscosity polymer having a high-viscosity polymer has been used. That is, in the case of forming the organic layer of the encapsulation unit using the VSP process, if the thickness of the organic layer is lowered, damage due to pressure may occur to the organic light emitting device.

The inventors of the present invention have recognized that when a low-viscosity polymer is applied as the organic layer of the encapsulation unit, the thickness of the encapsulation unit can be reduced to a level suitable for flexibility. More specifically, the inventors of the present invention, the organic layer of the encapsulation part using an inkjet process method in which a thin film is formed by spraying a liquid organic material with low viscosity to surround the organic light emitting device through fine nozzles. When formed, it was recognized that the encapsulation part may be very thin by a thickness suitable for flexibility.

However, in this case, a problem in that the liquid organic material easily flows in an unintended direction after being sprayed onto the organic light emitting device may be additionally generated. That is, the liquid organic material is not applied only in a designed area or a designated area, but is applied more widely in the outer direction of the organic light emitting display device due to the flowability of the organic material made of a low-viscosity material. This phenomenon is called "overspray".

Oversaturation of the organic layer may make it difficult to implement a narrow bezel of the organic light emitting diode display. More specifically, since the design must be designed to secure sufficient space in the non-display area of the organic light emitting diode display in consideration of the flowability of the organic material, an unnecessary outer portion of the organic light emitting diode display increases, and the bezel of the organic light emitting diode display increases. This can lead to increased problems. In addition, the over-saturated organic material may be visually recognized as a stain and may cause an appearance defect of the organic light emitting diode display. In addition, in the case of organic materials, since moisture penetration retardation performance is poor compared to inorganic materials, external moisture or oxygen may permeate through the over-saturated organic material, which may deteriorate the reliability of the organic light emitting diode display.

Accordingly, the inventor of the present invention recognizes these problems and applies a low-viscosity polymer as the organic layer of the encapsulation part so that the organic light emitting display device has a thickness suitable for flexible implementation, while also effectively controlling the flowability of the organic layer. An organic light emitting display device composed of parts was invented.

The problem to be solved according to an embodiment of the present invention is to apply a low-viscosity material to the organic layer of the encapsulation unit so that the encapsulation unit has a thin thickness suitable for implementing flexible, and at the same time, over-application of the organic layer on a part of the inorganic layer disposed under the organic layer An object of the present invention is to provide a flexible organic light emitting diode display capable of more easily controlling the flowability of a low-viscosity organic layer by configuring a low surface energy area that minimizes the phenomenon.

The problems to be solved according to an embodiment 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.

According to an embodiment of the present invention, in the organic light emitting display device including an encapsulation part implemented to be suitable for a flexible structure, the encapsulation part is a low-viscosity material to have a lower inorganic layer covering the organic light emitting device and a thin thickness suitable for the flexible structure. and an organic layer having an outer edge defined by a low-surface energy region of the lower inorganic layer and an upper inorganic layer covering the organic layer.

An organic light emitting diode display according to another embodiment of the present invention includes a substrate including a display area and a non-display area, an organic light emitting diode on the display area, and an encapsulation unit for sealing the organic light emitting diode. The encapsulation unit includes a lower inorganic layer disposed from the display area to at least a partial area of the non-display area to cover the organic light emitting device, a low-viscosity organic layer and a low-viscosity organic layer disposed from the display area to a specific area of the lower inorganic layer on the lower inorganic layer. and an upper inorganic layer covering the In another embodiment of the present invention, a specific region of the lower inorganic layer is configured to have a lower surface energy than other regions so that the over-saturation of the low-viscosity organic layer is minimized.

According to another embodiment of the present invention, in the organic light emitting display device having a structure in which an encapsulation unit having two inorganic layers and an organic layer disposed therebetween encapsulates an organic light emitting diode, the organic light emitting diode display is disposed below the organic layer among the two inorganic layers A low surface energy area that minimizes the flow of the organic layer in an outward direction of the organic light emitting display device in excess of a specified target value is configured in the inorganic layer.

According to an embodiment of the present invention, by configuring a low surface energy area in a part of the inorganic layer of the encapsulation unit, the flowability of the organic layer is improved in using a low-viscosity material as the organic layer of the encapsulation unit. Since it can be effectively controlled, there is an effect of minimizing the over-saturation of the organic layer.

Since there is no need to secure an unnecessary space due to over-saturation of the organic layer in the non-display area of the organic light emitting diode display, there is an advantageous effect on a narrow bezel.

Appearance defects of the organic light emitting display device due to overcoating of the organic layer and reliability defects caused by penetration of moisture or oxygen may be improved.

By using the low-viscosity material as the organic layer of the encapsulation part, the organic light emitting diode display may be implemented with a thin thickness suitable for flexibility.

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

Since the content of the invention described in the problem to be solved above, the means for solving the problem, and the effect do not specify the essential characteristics of the claim, the scope of the claim is not limited by the matters described in the content of the invention.

1A is a plan view of an organic light emitting diode display according to an exemplary embodiment.
FIG. 1B is a cross-sectional view taken along line I-I' of FIG. 1A.
2A to 2C are cross-sectional views for explaining the flowability of an organic layer in a low-surface energy region.
3 is a cross-sectional view of an organic light emitting diode display according to another exemplary embodiment.
4 is a cross-sectional view of an organic light emitting diode display according to another exemplary embodiment.
5 is a table showing an alignment defect rate according to whether or not a surface energy modifying layer is applied according to an embodiment of the present invention.

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 illustrative and 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 gist 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, cases including the plural are included unless otherwise explicitly stated.

In interpreting the components, it is construed 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 two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, when the temporal precedence is described with ‘after’, ‘after’, ‘after’, ‘before’, ‘immediately’ or ‘directly’ is not used. It may include cases that are not continuous unless otherwise specified.

Although the 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.

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 can be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or implemented together in a related relationship. may be

Hereinafter, an organic light emitting diode display according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1A is a plan view of an organic light emitting diode display 100 according to an exemplary embodiment, and FIG. 1B is a cross-sectional view taken along line I-I′ of FIG. 1A .

1A and 1B , the organic light emitting diode display 100 includes a substrate 110 , an organic light emitting device 120 , a bank 130 , an encapsulation unit 140 , an adhesive layer 150 , and a barrier film 160 . is composed of

The substrate 110 may be made of an insulating material, for example, a flexible film made of glass or a polyimide-based material. Although not shown in the drawings, a thin-film transistor or a capacitor for driving the organic light-emitting device 120 may be further disposed on the substrate 110 .

As shown in FIGS. 1A and 1B , the substrate 110 includes a display area (DA) and a non-display area (NDA).

The display area DA refers to an area in which an actual image is displayed, and may be located in the center of the substrate 110 . Also, the display area DA may be defined as an end of the cathode 123 of the organic light emitting diode 120 . That is, the display area DA may correspond to the area in which the cathode 123 is disposed on the substrate 110 .

The non-display area NDA refers to an outer area in which an image is not displayed, and may be disposed to surround the display area DA as shown in FIG. 1A . The bezel corresponds to an area in which an image is not displayed when the organic light emitting diode display 100 is viewed from the front, and may correspond to the non-display area NDA.

The organic light emitting diode 120 includes an anode 121 , an organic light emitting layer 122 , and a cathode 123 , and is disposed on the display area DA of the substrate 110 .

The anode 121 is an anode that supplies holes to the organic light emitting layer 122 , and is spaced apart from each other for each pixel, and is connected to a thin film transistor to receive a driving signal. The anode 121 may be formed of a transparent conductive oxide (TCO), such as indium tin oxide (ITO) or indium zinc oxide (IZO). When the organic light emitting diode display 100 is a top-emission type, the anode 121 may further include a reflective layer made of a metal material.

The bank 130 is disposed to cover both ends of the anode 121 , and pixels may be divided by the bank 130 . The bank 130 may be made of an organic material, for example, any one of polyimide and photoacryl.

The organic light emitting layer 122 is disposed on the anode 121 , and may be made of a phosphorescent or fluorescent material, and receives holes and electrons from the anode 121 and the cathode 123 , respectively, and emits light. According to the design of the organic light emitting device 120 , the organic light emitting layer 122 may be configured to emit a single color light such as red, green, or blue light for each pixel or to emit white light through a combination of a plurality of light emitting layers.

In a structure that emits monochromatic light, the organic emission layer 122 may be deposited through a fine metal mask (FMM). In this case, the organic light emitting layer 122 may be deposited only on the anode 121 in the area partitioned by the bank 130 as shown in the figure.

Although not shown in the drawing, in the structure emitting white light, the organic light emitting layer 122 can be deposited on the display area DA at once through a front deposition process. In this case, the organic light emitting layer 122 is formed by the anode 121 and the bank. It may be disposed on 130 . However, the present invention is not necessarily limited thereto, and the organic light emitting layer 122 may have various structures according to the design of the organic light emitting device 120 .

The cathode 123 is a cathode that supplies electrons to the organic light emitting layer 122 , and may be deposited over the entire display area DA at once through a front deposition process. The cathode 123 may be formed of a metal material or a transparent conductive oxide (TCO) material such as indium tin oxide (ITO) or indium zinc oxide (IZO). When the organic light emitting diode display 100 is a top emission type, the cathode 123 may be made of a very thin metal material, for example, about 400 Å or less, and in this case, the light from the organic light emitting layer 122 is emitted from the cathode ( 123) and may be emitted in an upward direction.

The encapsulation unit 140 encapsulates the organic light emitting device 120 , and includes a lower inorganic layer 141 , an organic layer 142 , and an upper inorganic layer 143 .

The lower inorganic layer 141 and the upper inorganic layer 143 are disposed to cover the organic light emitting diode 120 from the display area DA to at least a partial area of the non-display area NDA, and external moisture or oxygen It serves to reduce penetration into the organic light emitting device 120 .

The lower inorganic layer 141 and the upper inorganic layer 143 are made of an inorganic material, for example, silicon nitride (SiN _x ), aluminum oxide (Al _y O _z ) one of a chemical vapor deposition method (chemical vapor deposition, It can be formed through a vacuum deposition method such as CVD) or atomic layer deposition (ALD), but is not necessarily limited thereto.

The upper inorganic layer 143 is configured to cover the organic layer 142 , and as shown in FIG. 1B , like the lower inorganic layer 141 , at least a partial area from the display area DA to the non-display area NDA. placed up to In FIG. 1B , the structure in which the end of the upper inorganic layer 143 and the end of the lower inorganic layer 141 are on the same plane is illustrated, but the present invention is not limited thereto, and the upper inorganic layer 143 is the lower inorganic layer ( 141) may be configured to cover the ends.

The organic layer 142 is disposed between the lower inorganic layer 141 and the upper inorganic layer 143 . The organic layer 142 serves to compensate for a step difference caused by foreign substances mixed into the encapsulation unit 140 and to increase the path of penetration of moisture and oxygen.

Referring to FIG. 1B , an adhesive layer 150 may be disposed on the encapsulation unit 140 . The adhesive layer 150 serves to delay penetration of external moisture or oxygen and to fix the barrier film 160 to the substrate 110 . The adhesive layer 150 is made of a resin, and may be made of one of insulating materials such as epoxy, phenol, amino, olefin, acryl, and vinyl. there is. In addition, the adhesive layer 150 may be made of a curable resin or a pressure sensitive adhesive (PSA). In addition, the adhesive layer 150 may be composed of a plurality of layers.

A barrier film 160 may be disposed on the adhesive layer 150 . Like the adhesive layer 150 , the barrier film 160 serves to reduce the penetration of external moisture or oxygen, and serves to protect the adhesive layer 150 and the encapsulation unit 140 from external impact. The barrier film 160 may be made of any one of cyclo olefin polymer (COP), cyclo olefin copolymer (COC), and polycarbonate (PC), but is not limited thereto. When the organic light emitting diode display 100 is a top emission type, since light from the organic light emitting diode 120 passes through the barrier film 160 and emits light, the barrier film 160 is optically isotropic to maintain image quality. It may have characteristics.

The organic layer 142 according to an exemplary embodiment is made of an organic material having a low-viscosity characteristic, and thus the organic light emitting diode display 100 has a thickness suitable for a flexible display device. The organic layer 142 can be formed through an inkjet process method of forming a thin film by spraying a liquid organic material with low viscosity on the organic light emitting device through fine nozzles, and is about 1 μm to 10 μm or less. may have a thickness of

As mentioned above, conventionally, the organic layer is a high-viscosity material, for example, a material having a viscosity of about 500 cP (centipoise, centipoise) or more at 25 ° C. Through the VSP process method using pressure such as a roller Therefore, it was formed to have a thickness of at least a certain thickness, for example, about 20 μm or more so as to minimize damage to the organic light emitting device located under the encapsulation part. Therefore, there was a limit to lowering the thickness of the encapsulation part to a level suitable for flexibility. However, since the organic layer 142 according to an embodiment of the present invention is formed of an organic material having a low-viscosity characteristic through an inkjet process method, the thickness of the organic layer 142 can be made thin to a level suitable for flexibility.

The low-viscosity organic layer 142 may be made of a material having a viscosity of about 5 cP or more and 30 cP or less at 25° C., and may be made of, for example, one of epoxy or acrylic.

As shown in FIG. 1B , the organic layer 142 is disposed between the lower inorganic layer 141 and the upper inorganic layer 143 to cover the organic light emitting device 120 from the display area DA to the non-display area NDA. placed up to a specific area of More specifically, the organic layer 142 is disposed on the lower inorganic layer 141 from the display area DA to at least a portion of a low surface energy area (LSA) of the lower inorganic layer 141 .

The low-surface energy area LSA of the lower inorganic layer 141 corresponds to a portion of the non-display area NDA of the organic light emitting diode display 100 , and as shown in FIG. 1A , the display area DA placed to surround The low-surface energy region LSA serves to minimize the flow of the low-viscosity organic layer 142 in an outer direction of the organic light emitting diode display 100 beyond a specified target value. More specifically, the surface energy in the low-surface energy region LSA is configured to be lower than the surface energy in other regions of the lower inorganic layer 141 so that the oversaturation of the low-viscosity organic layer 142 is minimized. do.

For example, the low-surface energy region LSA may be formed using a plasma process. Specifically, after forming the lower inorganic layer 141 , if the remaining portion except for the low-surface energy region LSA is plasma-treated, the surface energy of the remaining portion becomes higher than that of the low-surface energy region LSA. can In this state, when the organic layer 142 is formed, the oversaturation of the organic layer 142 may be reduced due to a difference in surface energy of the lower inorganic layer 141 .

Alternatively, by forming a layer of a material having a lower surface energy than that of the lower inorganic layer 141 to correspond to the low-surface energy region LSA of the lower inorganic layer 141 , the surface energy of the lower inorganic layer 141 is formed. You can also implement the difference. This will be described later in more detail with reference to FIG. 3 .

The organic layer 142 is formed by an inkjet process in which a liquid organic material having a low viscosity is sprayed on the inside surrounded by the low-surface energy region LSA. In this case, the organic layer 142 flows in the outer direction of the organic light emitting diode display 100 due to flowability, but is not formed to exceed the low-surface energy region LSA of the lower inorganic layer 141 .

Referring to FIG. 1B , the liquid organic material is injected into a jetting area JA corresponding to a portion of the display area DA and the non-display area NDA surrounded by the low-surface energy area LSA. The injection area JA may be set from the display area DA to a part of the non-display area NDA so that the organic layer 142 seals the organic light emitting device 120 and delays penetration of external moisture or oxygen. there is.

The low-surface energy region LSA prevents the liquid organic material from flowing beyond a specified target value when the liquid organic material flows in the outer direction of the organic light emitting diode display 100 due to the flow property of the organic material after being injected into the injection region JA. plays a controlling role.

In order to describe this in more detail, it will be described with reference to FIGS. 2A to 2C as follows.

2A is a cross-sectional view for explaining a difference in contact angle according to surface energy. Referring to FIG. 2A , when the liquid material 180 is applied on the first layer 170 having the low-surface energy region (LSA), the liquid material is caused by the difference in surface energy of the first layer 170 . The contact angle of (180) is changed. As the surface energy of the first layer 170 increases, the surface area of the liquid material 180 in contact with the first layer 170 expands and the contact angle decreases.

As shown in FIG. 2A , when the liquid material 180 is dropped on a partial surface of the first layer 170 , the liquid material 180 has a first contact angle θ ₁ . In comparison, when the same liquid material 180 is dropped on the low-surface energy region LSA of the first layer 170 , the liquid material 180 has a value greater than the first contact angle θ ₁ . It has a second contact angle θ ₂ . A large contact angle means that the surface area of the liquid material 180 in contact with the first layer 180 is small, and a small surface area of the liquid material 180 means that the liquid material 180 does not flow widely. It means that it is controlled from a certain distance.

Referring to FIG. 2B with reference to FIG. 2A , when the organic layer 142 made of a liquid organic material is sprayed on the lower inorganic layer 141 through the nozzle 190 , the lower inorganic layer 141 is formed in a portion having a large surface energy. ), the surface area of the organic layer 142 in contact with the lower inorganic layer 141 tends to decrease in a portion having a low surface energy.

Accordingly, the organic layer 142 in contact with the low-surface energy region LSA of the lower inorganic layer 141 may be more moved from a portion having a small surface energy to a portion having a large surface energy. That is, it can be said that the organic layer 142 flows with a direction due to the difference in surface energy of the lower inorganic layer 141 , in other words, the portion having a small surface energy controls the flowability of the organic layer 142 . there is.

As shown in FIG. 2C , even when the organic layer 142 made of a liquid organic material is sprayed from a portion spaced apart from the low-surface energy region LSA by a predetermined distance and flows along the surface of the lower inorganic layer 141 , the organic layer 142 ) reaches the low-surface-energy region LSA, so that the surface area of the organic layer 142 in contact with the lower inorganic layer 141 tends to decrease, so that the organic layer 142 is no longer able to flow. That is, the flowability of the organic layer 142 may be controlled by the low-surface energy region LSA.

Again, referring to FIG. 1B , the low-viscosity organic layer 142 according to an embodiment of the present invention has flowability controlled by the low-surface energy region LSA of the lower inorganic layer 141, and Exceeding the target value, the flow in the outward direction of the organic light emitting diode display 100 may be minimized. That is, the outer end of the organic layer 142 is defined by the low-surface energy region LSA of the lower inorganic layer 141 .

The width of the low-surface energy region LSA of the lower inorganic layer 141 may be a minimum value determined in consideration of the viscosity of the organic layer 142 . Specifically, by configuring the width of the low-surface energy region LSA to be larger as the viscosity of the organic layer 142 is lower, the organic layer 142 does not exceed a specified target value and does not flow outward of the organic light emitting diode display 100 . can be controlled more effectively. However, when the width of the low-surface energy area LSA is excessively large, the width of the non-display area NDA is also increased, which may lead to an increase in the bezel. For example, when the organic layer 142 is made of a material having a viscosity of 5 cP or more and 30 cP or less at 25°C, the width of the low-surface energy region (LSA) may have a value of 50 µm or more and 300 µm or less, but must be However, the present invention is not limited thereto.

Therefore, according to an embodiment of the present invention, in using an organic material having a low-viscosity characteristic as the organic layer 142 of the encapsulation unit 140 , the flowability of the organic layer 142 can be more effectively controlled, so that the organic layer (142) has the effect of minimizing the oversaturation phenomenon. In addition, since there is no need to secure an unnecessary space due to overcoating of the organic layer 142 in the non-display area NDA of the organic light emitting diode display 100 , it may be advantageous for a narrow bezel. In addition, an appearance defect of the organic light emitting display device 100 due to oversaturation of the organic layer and a reliability defect caused by penetration of moisture or oxygen may be improved.

3 is a cross-sectional view of an organic light emitting diode display 200 according to another exemplary embodiment. The organic light emitting diode display 200 shown in FIG. 3 is different from the embodiment shown in FIGS. 1A and 1B only in the structure of the encapsulation unit 240 , so for convenience of explanation, the configuration is the same as or corresponding to that of the previous embodiment. A detailed description of the elements will be omitted.

The encapsulation part 240 of the organic light emitting diode display 200 according to another embodiment of the present invention includes a lower inorganic layer 241 , an organic layer 242 having a low-viscosity characteristic, an upper inorganic layer 243 , and a change in surface energy. It consists of layers 244 .

The surface energy changing layer 244 may be disposed in contact between the lower inorganic layer 241 and the organic layer 242 to correspond to the low-surface energy region LSA of the lower inorganic layer 141 . Also, the surface energy modifying layer 244 may be formed of an organic or inorganic material having a lower surface energy than that of the lower inorganic layer 241 . For example, when the lower inorganic layer 241 is made of silicon nitride (SiN _x ) having a surface energy of about 58 mN/m, the surface energy modifying layer 244 has a surface energy of about 25 mN/m of silicon oxycarbon (SiOC). _z ) may be formed.

Since the surface energy changing layer 244 is disposed to correspond to the low-surface energy region LSA of the lower inorganic layer 141 , although not shown in the drawings, it may be configured to surround the display area DA.

The width or thickness of the surface energy modifying layer 244 may be a minimum value determined in consideration of the viscosity of the organic layer 242 . Specifically, as the viscosity of the organic layer 242 is lower, the width of the surface energy modifying layer 244 may be configured to have a larger value so that the organic layer 242 does not flow beyond a specified target value. However, when the width of the surface energy modifying layer 244 is excessively large, the width of the non-display area NDA may also be increased to increase the bezel. For example, when the organic layer 242 is made of a material having a viscosity of 5 cP or more and 30 cP or less, the width of the surface energy modifying layer 244 may be 50 μm or more and 300 μm or less, but is not limited thereto.

By forming the thickness of the surface energy modifying layer 244 to be thicker as the viscosity of the organic layer 242 is lower, it may be effective to control the flowability of the organic layer 242 , but at least increase the thickness of the encapsulation part 240 . It is preferable to have a value that does not In addition, when the surface energy modifying layer 244 is formed through a deposition process, it is preferable that the thickness of the surface energy change layer 244 be the minimum that can generate a difference in surface energy while minimizing the process time and process. For example, the thickness of the surface energy modifying layer 244 may be about 0.1 μm or more and 1 μm or less.

The surface energy modifying layer 244 may be a material in consideration of adhesion between the lower inorganic layer 241 and the upper inorganic layer 242 . When the adhesive force between the lower inorganic layer 241 and the upper inorganic layer 242 is reduced by the surface energy changing layer 244 to form an interface, it becomes a penetration path for external moisture or oxygen to form the organic light emitting device 120 . reliability may be reduced. Therefore, it may be preferable that the surface energy modifying layer 244 be made of a material having a lower surface energy than the lower inorganic layer 241 and excellent adhesion to the lower inorganic layer 241 and the upper inorganic layer 242 . . For example, when the lower inorganic layer 241 and the upper inorganic layer 242 are silicon nitride (SiNx) and the surface energy modifying layer 244 is made of silicon oxycarbon (SiOC _z ), the surface energy modifying layer 244 ) may have a lower surface energy than that of the lower inorganic layer 241 , and may also have excellent adhesion to the lower inorganic layer 241 and the upper inorganic layer 242 .

Accordingly, according to another embodiment of the present invention, a surface energy modifying layer 244 made of a material having a lower surface energy than that of the lower inorganic layer 241 is disposed in a specific region of the lower inorganic layer 241 to form the lower inorganic layer ( When the low-surface energy region LSA of the 241 is configured, the flowability of the low-viscosity organic layer 242 is more effectively controlled, so that the over-saturation of the organic layer 242 is reduced. That is, since the over-saturation phenomenon due to the flowability of the organic layer 242 is minimized, it is possible to use an organic material having a low-viscosity characteristic as the organic layer 242 of the encapsulation unit 240 , and accordingly, the organic light emitting diode display 200 . ) can contribute to being composed of a thin thickness suitable for flexibility.

Although not shown in the drawings, the surface energy modifying layer may be removed after the organic layer is cured. When the liquid organic material is applied in the injection region surrounded by the surface energy change layer and then undergoes a curing process, it no longer flows outward of the organic light emitting diode display. Accordingly, if necessary, the surface energy modifying layer may be removed, and the upper inorganic layer may be deposited after the surface energy modifying layer is removed. In this case, it is not necessary to select a material for the surface energy changing layer in consideration of the adhesive force between the lower inorganic layer and the upper inorganic layer, so the degree of freedom in design can be increased.

4 is a cross-sectional view of an organic light emitting diode display 300 according to another exemplary embodiment. Since the organic light emitting diode display 300 shown in FIG. 4 differs only in the structure of the encapsulation unit 340 from the embodiment described in FIG. 3 , detailed descriptions of the same or corresponding components as in the previous embodiment are for convenience of explanation. A description will be omitted.

The encapsulation unit 340 of the organic light emitting diode display 300 according to another embodiment of the present invention includes a lower inorganic layer 341 , an organic layer 342 having low-viscosity characteristics, an upper inorganic layer 343 , and surface energy. Consists of a modified layer 344 and a dam 345 .

The dam 345 may be disposed in a portion of the non-display area NDA of the organic light emitting diode display 300 . The dam 345 can be formed through the same process as the bank 130 of the display area DA, and has a height greater than the thickness of the lower inorganic layer 341 . That is, the dam 345 can be formed by changing the design of the mask without an additional process, and the height thereof may be, for example, about 2.5 μm or more and 4.5 μm or less.

The dam 345 may contribute to further reducing the oversaturation of the low-viscosity organic layer 342 . In other words, the dam 345 may serve to control the flowability of the organic layer 342 together with the surface energy modifying layer 344 . As mentioned above, if the thickness of the surface energy modifying layer 344 increases as the viscosity of the organic layer 342 decreases, it may be advantageous to control the flowability of the organic layer 342, but the process conditions of the surface energy modifying layer 344, etc. Considering that, there may be a limit to increasing the thickness as much as desired. However, the dam 345 having a predetermined height can be formed at the same time when the bank 130 of the display area DA is formed without an additional process. The viscous organic layer 342 may partially block the flow in the outer direction of the organic light emitting diode display 300 .

In particular, as shown in FIG. 4 , when the dam 345 is disposed to correspond to the low-surface energy region LSA, more specifically, when the dam 345 is disposed to overlap the surface energy altering layer 344 , the surface energy Since there is an effect of increasing the thickness of the modifying layer 344 , the flowability of the low-viscosity organic layer 342 can be more effectively controlled.

The width of the surface energy modifying layer 344 may be greater than the width of the dam 345 disposed on the lower surface of the lower inorganic layer 341 . That is, as shown in FIG. 4 , the surface energy changing layer 344 disposed on the upper surface of the lower inorganic layer 341 covers the dam 345 disposed on the lower surface of the lower inorganic layer 341 . can In this case, there is an effect of increasing the thickness of the surface energy modifying layer 344 by the dam 345 as well as increasing the length of the surface energy modifying layer 344 within the same width. Accordingly, an area of the surface energy changing layer 344 that can come into contact with the organic layer 342 flowing outward of the organic light emitting diode display 300 is increased, and thus the oversaturation of the organic layer 342 can be further reduced. .

Although the dam 345 is illustrated as a single layer having a tapered shape in the drawing, various designs may be possible depending on the shape and height of the bank 130 formed in the display area DA. Also, in the case of a structure in which a spacer is additionally formed on the bank 130 in the display area DA according to the design of the organic light emitting diode display 300 , the dam overlaps the surface energy changing layer 344 . A structure having the same height as the spacer may be additionally disposed on the upper portion of the 345 . In this case, since the thickness of the surface energy modifying layer 344 is further increased by the dam 340 and the structure, the flow of the organic layer 342 can be more effectively controlled.

Accordingly, the encapsulation part 300 of the organic light emitting diode display 300 according to another embodiment of the present invention is configured to include the dam 345 disposed to overlap the surface energy changing layer 344 , and thus has a low-viscosity The flow property of the organic layer 342 of the characteristic is more effectively controlled, and the phenomenon of oversaturation of the organic layer 342 can be reduced. Accordingly, since it is not necessary to secure an unnecessary space in the non-display area NDA of the organic light emitting diode display 300 , it may be more advantageous for a narrow bezel. In addition, there is an effect that the poor appearance of the organic light emitting diode display 300 and the reliability of the organic light emitting diode display 300 are further improved due to penetration of external moisture or oxygen.

5 is a table showing an alignment defect rate according to whether or not a surface energy modifying layer is applied according to an embodiment of the present invention. More specifically, in the structure of the organic light emitting diode display 300 described with reference to FIG. 4 , a table showing the alignment defect rate according to whether the surface energy changing layer 344 is applied or not.

Referring to FIG. 5 , the structure of the embodiment corresponds to the structure of the organic light emitting diode display 300 described with reference to FIG. 4 . More specifically, the lower inorganic layer 341 was formed of silicon nitride (SiN _x ) having a surface energy of about 58 mN/m and a thickness of about 1 μm. The low-viscosity organic layer was formed of an epoxy-based polymer material having a viscosity of about 12 cP at 25°C. In order to reduce the flowability of the organic layer, the surface energy modifying layer disposed in the low-surface energy region (LSA) of the lower inorganic layer was formed of silicon oxycarbon (SiOC _z ) having a surface energy of about 25 mN/m, and about 0.1 It was formed to a thickness of ㎛. In addition, the surface energy changing layer was formed to cover the dam disposed on the lower surface of the lower inorganic layer, and more specifically, it was designed to have a width of about ±50 μm than the width of the dam. On the other hand, in the structure of the comparative example, the other structures were the same, but the low-surface energy region, specifically, the surface energy modifying layer was not applied on the lower inorganic layer.

In this experiment, 30 samples corresponding to Examples and Comparative Examples were prepared, respectively, and alignment defects were evaluated. The alignment defect refers to a defect in which the low-viscosity organic layer exceeds a specified target value and flows outward of the organic light emitting diode display. In the example structure, it was evaluated whether the organic layer had flowed past the low-surface energy region, that is, the surface energy modifying layer, and in the comparative example structure, more than that relative to the same location as the surface energy modifying layer of the example structure. It was evaluated whether or not it flowed.

Referring to FIG. 5 , in the structure of the embodiment, there was no sample in which alignment defects occurred among the 30 evaluation samples, and it was confirmed that the alignment defect rate was 0%. That is, it was confirmed that, despite the structure in which the low-viscosity organic layer was applied as the encapsulation part, the organic layer did not flow in the outer direction of the organic light emitting diode display in excess of the target value specified by the surface energy changing layer.

On the other hand, in the structure of the comparative example to which the surface energy changing layer was not applied, 12 samples in which alignment defects occurred among the 30 evaluation samples were found to have an alignment defect rate of 40%. That is, it was confirmed that the flowability of the low-viscosity organic layer was not properly controlled and flowed outward from the design value of the organic light emitting diode display.

Therefore, as shown in FIG. 5, by configuring a surface energy changing layer made of a material having a surface energy of 50% or less compared to the surface energy of the lower inorganic layer between the lower inorganic layer and the organic layer, the flow of the low-viscosity organic layer It was confirmed that the sex was controlled and the oversaturation phenomenon was reduced. Accordingly, by using the low-viscosity material as the organic layer of the encapsulation part, it may be advantageous for the organic light emitting diode display to have a thin thickness suitable for flexibility.

In the organic light emitting diode display according to an embodiment of the present invention, the organic light emitting diode may be disposed in the display area, and the low-surface energy area may correspond to a portion of the non-display area.

In the organic light emitting diode display according to an embodiment of the present invention, the organic layer may be formed of a material having a viscosity of 5 cP or more and 30 cP or less at 25°C.

In the organic light emitting diode display according to an embodiment of the present invention, the organic layer may be formed using an inkjet process.

In the organic light emitting diode display according to an embodiment of the present invention, the encapsulation unit may further include a surface energy changing layer disposed between the lower inorganic layer and the organic layer to correspond to the low-surface energy region.

In the organic light emitting diode display according to an embodiment of the present invention, the surface energy of the surface energy modifying layer may have a value of 50% or less of the surface energy of the lower inorganic layer.

In the organic light emitting diode display according to an embodiment of the present invention, the encapsulation unit may further include a dam member disposed on the lower surface of the lower inorganic layer to correspond to the surface energy changing layer.

In the organic light emitting diode display according to an embodiment of the present invention, the width of the surface energy changing layer may be greater than the width of the dam member.

In the organic light emitting diode display according to an embodiment of the present invention, the surface energy changing layer may be removed after the organic layer is cured.

In the organic light emitting diode display according to an embodiment of the present invention, the specific area of the lower inorganic layer corresponds to a part of the non-display area, and the low-viscosity organic layer is not disposed in excess of the specific area of the lower inorganic layer; From the display area to at least a portion of a specific area of the lower inorganic layer may be disposed.

In the organic light emitting diode display according to an embodiment of the present invention, a specific region of the lower inorganic layer may be disposed to surround the display region.

In the organic light emitting diode display according to an embodiment of the present invention, the encapsulation unit further includes a surface energy modifying layer disposed in contact with the lower inorganic layer and the low-viscosity organic layer to correspond to a specific region of the lower inorganic layer, and the surface The surface energy of the energy-altering layer may have a lower value than the surface energy of the lower inorganic layer.

In the organic light emitting diode display according to an embodiment of the present invention, the encapsulation unit may further include a dam member disposed on a lower surface of the lower inorganic layer to correspond to a specific region of the lower inorganic layer.

In the organic light emitting diode display according to an embodiment of the present invention, the low-surface energy region corresponds to a portion of the non-display region of the organic light emitting diode display, and the organic layer includes a low-surface energy region from the display region of the organic light emitting diode display. may be disposed up to at least a portion of

In the organic light emitting diode display according to an embodiment of the present invention, the organic layer may be made of a material having a viscosity of 5 cP or more and 30 cP or less at 25° C. so that the encapsulation part has a thin thickness suitable for flexibility.

In the organic light emitting diode display according to an embodiment of the present invention, the encapsulation unit further includes a surface energy modifying layer disposed to correspond to a low-surface energy region between the organic layer and the inorganic layer in contact with the lower portion of the organic layer, wherein the surface energy The surface energy of the modification layer may have a lower value than the surface energy of the inorganic layer in contact with the lower portion of the organic layer.

In the organic light emitting display device according to an embodiment of the present invention, the encapsulation unit may further include a dam member disposed on a lower surface of the inorganic layer in contact with the lower portion of the organic layer, and the dam member may be disposed to overlap the surface energy changing layer. .

Although 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. . Accordingly, 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 claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200, 300: organic light emitting display device
110: substrate
120: organic light emitting device
130: bank
140, 240, 340: encapsulation unit
141, 241, 341: lower inorganic layer
142, 242, 342: organic layer
143, 243, 343: upper inorganic layer
244, 344: surface energy modifying layer
345: dam
150: adhesive layer
160: film

Claims (19)

In the organic light emitting display device including an encapsulation part implemented to be suitable for a flexible structure,
The encapsulation unit,
a lower inorganic layer covering the organic light emitting device and including a low-surface energy region and a remaining region having a higher surface energy than the low-surface energy region;
an organic layer made of a low-viscosity material to have a thin thickness suitable for the flexible structure and having an outer end defined by a low-surface energy region of the lower inorganic layer; and
and an upper inorganic layer covering the organic layer. According to claim 1,
The organic light emitting device is disposed in the display area,
The low-surface energy region corresponds to a portion of the non-display region.
3. The method of claim 2,
The organic layer is made of a material having a viscosity of 5 cP or more and 30 cP or less at 25°C.
4. The method of claim 3,
The organic layer is formed by an inkjet process.
4. The method of claim 3,
The encapsulation unit may further include a surface energy changing layer disposed between the lower inorganic layer and the organic layer to correspond to the low-surface energy region.
6. The method of claim 5,
The surface energy of the surface energy changing layer has a value of 50% or less of the surface energy of the lower inorganic layer.
7. The method of claim 6,
The organic light emitting display device of claim 1, wherein the encapsulation unit further includes a dam member disposed on a lower surface of the lower inorganic layer to correspond to the surface energy changing layer.
8. The method of claim 7,
A width of the surface energy changing layer is greater than a width of the dam member.
7. The method of claim 6,
The surface energy changing layer is removed after the organic layer is cured.
a substrate including a display area and a non-display area;
an organic light emitting device on the display area; and
and an encapsulation unit for sealing the organic light emitting device,
The encapsulation unit,
a lower inorganic layer disposed from the display area to at least a partial area of the non-display area to cover the organic light emitting diode;
a low-viscosity organic layer disposed on the lower inorganic layer from the display area to a specific area of the lower inorganic layer;
An upper inorganic layer covering the low-viscosity organic layer,
The specific region of the lower inorganic layer has a lower surface energy than other regions so as to minimize the over-saturation of the low-viscosity organic layer.
11. The method of claim 10,
The specific area of the lower inorganic layer corresponds to a part of the non-display area,
The low-viscosity organic layer is disposed only from the display area to at least a portion of the specific area of the lower inorganic layer so as not to exceed the specific area of the lower inorganic layer.
12. The method of claim 11,
The specific area of the lower inorganic layer is disposed to surround the display area.
13. The method of claim 12,
The encapsulation unit further includes a surface energy changing layer disposed to be in contact with the lower inorganic layer and the low-viscosity organic layer corresponding to a specific region of the lower inorganic layer,
An organic light emitting diode display having a surface energy of the surface energy changing layer lower than a surface energy of the lower inorganic layer.
14. The method of claim 13,
The encapsulation unit may further include a dam member disposed on a lower surface of the lower inorganic layer to correspond to a specific region of the lower inorganic layer.
An organic light emitting diode display having a structure in which an encapsulation unit having two inorganic layers and an organic layer disposed between the two inorganic layers encapsulates an organic light emitting diode, the organic light emitting diode display comprising:
In the inorganic layer disposed under the organic layer among the two inorganic layers, a low surface energy area for minimizing the flow of the organic layer in an outward direction of the organic light emitting display device exceeding a specified target value; An organic light emitting diode display including a remaining region having a higher surface energy than the low-surface energy region.
16. The method of claim 15,
the low-surface energy region corresponds to a portion of the non-display region of the organic light emitting diode display;
The organic layer is disposed from the display area of the organic light emitting diode display to at least a portion of the low-surface energy area and does not exceed the low-surface energy area.
17. The method of claim 16,
The organic light emitting display device is formed of a material having a viscosity of 5 cP or more and 30 cP or less at 25° C. so that the encapsulation part has a thin thickness suitable for flexibility.
18. The method of claim 17,
The encapsulation unit further includes a surface energy modifying layer disposed to correspond to the low-surface energy region between the organic layer and the inorganic layer in contact with the lower portion of the organic layer,
The surface energy of the surface energy changing layer is lower than the surface energy of the inorganic layer in contact with the lower portion of the organic layer.
19. The method of claim 18,
The encapsulation unit further includes a dam member disposed on a lower surface of the inorganic layer in contact with the lower portion of the organic layer,
The dam member is disposed to overlap the surface energy changing layer.

Images