WO2020045850A1

WO2020045850A1 - Flexible display and method for manufacturing same

Info

Publication number: WO2020045850A1
Application number: PCT/KR2019/009946
Authority: WO
Inventors: 김상일; 홍문표; 윤정식
Original assignee: 고려대학교 세종산학협력단
Priority date: 2018-08-29
Filing date: 2019-08-08
Publication date: 2020-03-05
Also published as: KR102075841B1

Abstract

A flexible display according to one embodiment of the present invention may comprise: a substrate divided into M*N pixel regions and peripheral regions defined as regions between the pixel regions; a light emitting unit disposed in each of the M*N pixel regions and including a first electrode, a second electrode, and an organic light emitting layer disposed between the first and second electrodes; and an encapsulation layer which encapsulates the light emitting unit, and divides and independently encapsulates the M*N pixel regions.

Description

Flexible display and manufacturing method

The present invention relates to a flexible display and a method for manufacturing the same, and more particularly, to a flexible display and a method for manufacturing the same having high flexibility while ensuring performance of encapsulation.

Traditional displays simply meant devices that output electrical signals in visual form. Recently, however, a display is not only developed as a device for displaying information, but also has a form of flexibility.

Flexible displays are evolving into a bendable stage that can be bent and bent, a rollable stage that can be rolled like a roll, and a foldable stage that can be folded like a piece of paper. Recent displays continue to evolve into stretchable stages that can be scaled up and down while scaling up and down to one or two axes.

In this regard, an organic light emitting layer is used to emit light of the flexible display. Although the organic light emitting layer provides high display characteristics, it is sensitive to penetration of moisture and air in terms of using organic materials. Therefore, a high level of water vapor transmission rate (WVTR) is required. Accordingly, studies to achieve the required WVTR characteristics through thin film encapsulation (TFE) have been continued.

TFE technology consists of cross-lamination of inorganic and organic films. In addition, the inkjet coating process of the organic film during the TFE process includes defining a region in which the organic film is formed as a dam having a predetermined thickness and applying the organic film to the region defined by the dam. In particular, the dam is formed to be spaced a predetermined distance from the side of the OLED light emitting layer. This is to prevent moisture and / or air from penetrating in the lateral direction of the OLED light emitting layer. As a result, the encapsulation organic film may be formed within the side separation distance between the dam and the OLED light emitting layer.

Accordingly, although the TFE technology provides the WVTR characteristics, the OLED layer has a high thickness of the organic layer constituting the TFE, the thickness of the dam is high, and the dam is located at a predetermined distance away from the side of the OLED emitting layer. It is disadvantageous in terms of flexibility because a thick organic film is formed within the distance from the side surface of the dam to the dam. That is, since the display is thickened by the organic layer and / or the dam, a problem arises in that the flexibility characteristic is lowered.

Accordingly, the inventors have invented a flexible display and a method of manufacturing the same, which provide high encapsulation properties and further have high flexibility.

One technical problem to be solved by the present invention is to provide a flexible display having a high encapsulation property and a high flexibility characteristics and a method of manufacturing the same.

Another technical problem to be solved by the present invention is to provide a flexible display excellent in mass production suitability and its manufacturing method by utilizing the existing process.

The technical problem to be solved by the present invention is not limited to the above.

The flexible display according to an exemplary embodiment of the present invention may include a substrate partitioned into a peripheral area defined as a pixel area of M * N and an area between the pixel areas, the pixel electrodes of M * N, and a first electrode and a second electrode. It may include a light emitting part including an electrode and an organic light emitting layer disposed between the first and the second electrode and an encapsulation layer encapsulating the light emitting portion, and separately encapsulating the pixel region of the M * N. (M and N are positive integers)

In an embodiment, the encapsulation layer may include a first inorganic layer, a second inorganic layer, and an organic layer disposed between the first and second inorganic layers, wherein the encapsulation layer includes the second inorganic layer. May cover one side of the organic layer.

In one embodiment, one surface of the first inorganic layer and one surface of the second inorganic layer may directly contact each other on the peripheral region.

In one embodiment, the organic layer may not be formed on the peripheral region.

In an embodiment, a surface defined by the thickness of the second inorganic layer and one surface of the first inorganic layer may contact each other on the pixel area.

In an embodiment, the organic layer may be completely surrounded by the first and second inorganic layers.

In an embodiment, the width of the organic layer may be narrowed in the direction of the second inorganic layer from the first inorganic layer.

In one embodiment, it may further include a third inorganic layer formed on the second inorganic layer.

In one embodiment, the third inorganic layer may be covered to directly contact the other side of the organic layer.

In an embodiment, one side of the second inorganic layer may be recessed in a center direction of the pixel area on a plane.

According to one or more exemplary embodiments, a flexible display manufacturing method includes: a first electrode, a second electrode, and the first and the second electrodes, for each pixel area, among peripheral areas defined as M * N pixel areas and areas between the pixel areas. The method may include forming a light emitting part including an organic light emitting layer disposed between the second electrodes, and forming an encapsulation layer on the light emitting part to separately encapsulate the pixel area of M * N.

The forming of the encapsulation layer may include forming a first inorganic layer on the light emitting part, and forming a negative photoresist layer on the first inorganic layer. Patterning the negative photoresist layer into a plurality of sacrificial structures having an inverse taper shape, forming a net tapered organic layer between the sacrificial structures through an inkjet process, removing the sacrificial structures, and the organic layer. It may include the step of forming a second inorganic layer on the.

In example embodiments, after forming a negative photoresist layer on the first inorganic layer, a mask having an opening corresponding to the peripheral region and a blocking portion corresponding to the pixel region may be formed. The method may further include disposing on the negative photoresist layer.

In an embodiment, the patterning of the negative photoresist layer into a plurality of sacrificial structures having an inverse taper shape may include removing the negative photoresist region unexposed by the blocking portion of the mask. have.

In an embodiment, after the forming of the second inorganic layer, the method may further include removing at least one inorganic layer of the first and second inorganic layers on the peripheral area.

The forming of the encapsulation layer may include forming a first inorganic layer on the light emitting part, and forming a positive photoresist layer on the first inorganic layer. Patterning the positive photoresist layer into a plurality of sacrificial structures, forming a second inorganic layer on the plurality of sacrificial structures, and patterning the second inorganic layer to form one region of the plurality of sacrificial structures. Exposing to the outside, removing the plurality of sacrificial structures through the externally exposed region to form a tunnel, forming an organic layer inside the tunnel, and forming a third inorganic layer on the second inorganic layer. It may comprise the step of forming.

In an embodiment, in the forming of the tunnel, one layer of the tunnel may include the first inorganic layer, and the other layer of the tunnel may be a second inorganic layer spaced apart from the first inorganic layer. The tunnel may be formed on the pixel area.

In an embodiment, in the forming of the organic layer, the organic layer may be selectively formed in the pixel area among the pixel area and the peripheral area.

In example embodiments, the first inorganic layer, the organic layer, the second inorganic layer, and the third inorganic layer may be stacked on the pixel area.

In example embodiments, the patterning of the second inorganic layer to expose one region of the plurality of sacrificial structures to the outside may include a side surface of the second inorganic layer formed on a plane to a center direction of the pixel region. Patterning the second inorganic layer to be embedded.

In an embodiment, after the forming of the third inorganic layer, the method may further include removing at least one inorganic layer of the first to third inorganic layers on the peripheral area.

The flexible display according to an exemplary embodiment of the present invention may include a substrate partitioned into a peripheral area defined as a pixel area of M * N and an area between the pixel areas, the pixel electrodes of M * N, and a first electrode and a second electrode. It may include a light emitting part including an electrode and an organic light emitting layer disposed between the first and the second electrode and an encapsulation layer encapsulating the light emitting portion, and separately encapsulating the pixel region of the M * N. (M and N are positive integers).

As a result, since the organic layer for encapsulation on the peripheral region can be omitted, the thickness of the peripheral region can be reduced. As the thickness of the peripheral area becomes thinner, it can provide excellent flexibility properties.

In addition, since the organic layer for encapsulation can be formed without a separate dam, it is possible to additionally secure the flexible characteristics limited by the space of the conventional dam.

In this case, the forming of the encapsulation layer may include forming a first inorganic layer on the light emitting part, forming a negative photoresist layer on the first inorganic layer, and the negative Patterning a photoresist layer of a plurality of sacrificial structures having an inverse taper shape, forming an organic layer having a net tapered shape through an inkjet process between the sacrificial structures, removing the sacrificial structures, and forming a film on the organic layer. It may include the step of forming an inorganic layer.

By forming the inverse tapered sacrificial structure using the negative photoresist, a net tapered organic layer can be formed between the sacrificial structures. Accordingly, since the second inorganic layer may be deposited on the side of the organic layer, it may provide excellent sealing characteristics.

In another example, the forming of the encapsulation layer may include forming a first inorganic layer on the light emitting part, forming a positive photoresist layer on the first inorganic layer, Patterning the positive photoresist layer into a plurality of sacrificial structures, forming a second inorganic layer on the plurality of sacrificial structures, patterning the second inorganic layer to externally cover one region of the plurality of sacrificial structures Exposing to a structure, removing the plurality of sacrificial structures through the externally exposed region to form a tunnel, forming an organic layer inside the tunnel, and forming a third inorganic layer on the second inorganic layer. It may include the step.

A positive tapered tunnel can be formed using a positive photoresist, and an organic ink can be injected into the tunnel to form a pure tapered organic layer. In this step, by utilizing the phenomenon that the organic ink is automatically injected into the tunnel by capillary force, a high precision dispensing process is not required, and process convenience may be provided.

Furthermore, after the net tapered organic layer is formed, the inorganic layer on the peripheral region can be removed. This makes the thickness of the peripheral area thinner, so that a higher level of flexibility can be provided.

1 illustrates a plane of a flexible display according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a pixel of a flexible display according to a first exemplary embodiment of the present invention.

3 is a cross-sectional view (B-B ′ line of FIG. 1) of the flexible display according to the first embodiment of the present invention.

4 is a view for explaining a method of manufacturing a flexible display according to a first embodiment of the present invention.

5 is a view for explaining a method of manufacturing an encapsulation layer according to a first embodiment of the present invention.

6 to 14 are views for explaining in detail the manufacturing method of the encapsulation layer according to the first embodiment of the present invention.

15 is a cross-sectional view (B-B ′ line of FIG. 1) of the flexible display according to the second embodiment of the present invention.

16 is a view for explaining a method of manufacturing an encapsulation layer according to a second embodiment of the present invention.

17 to 22 are views for explaining in detail the manufacturing method of the encapsulation layer according to a second embodiment of the present invention.

23 to 26 are views for explaining a method of manufacturing an encapsulation layer according to a modification of the second embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical idea of the present invention is not limited to the exemplary embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed contents are thorough and complete, and that the spirit of the present invention to those skilled in the art can fully convey.

In the present specification, when a component is mentioned as being on another component, it means that it may be formed directly on the other component or a third component may be interposed therebetween. In addition, in the drawings, the thicknesses of films and regions are exaggerated for effective explanation of technical contents.

In addition, in various embodiments of the present specification, terms such as first, second, and third are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as the first component in one embodiment may be referred to as the second component in other embodiments. Each embodiment described and illustrated herein also includes its complementary embodiment. In addition, the term 'and / or' is used herein to include at least one of the components listed before and after.

In the specification, the singular encompasses the plural unless the context clearly indicates otherwise. In addition, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, element, or combination thereof described in the specification, and one or more other features, numbers, steps, configurations. It should not be understood to exclude the possibility of the presence or the addition of elements or combinations thereof. In addition, the term "connection" is used herein to mean both indirectly connecting a plurality of components, and directly connecting.

In the present specification, the inverse taper shape means the shape of the lower narrow light, and the forward taper shape may mean the lower light narrow shape.

In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a plan view of a flexible display according to an embodiment of the present invention, FIG. 2 is a diagram for circuitry illustrating a pixel of the flexible display according to an embodiment of the present invention, and FIG. 3 is a view of the present invention. The cross section (B-B 'line of FIG. 1) of the flexible display which concerns on 1st Example is shown.

Referring to FIG. 1, the flexible display according to the first embodiment of the present invention may include a flexible substrate 110.

The flexible substrate 110 may be divided into a peripheral area N defined as an area between the pixel area P of M (horizontal direction) * N (vertical direction) and the pixel area P. The pixel area P may be defined as an area emitting a specific color such as R, G, and B, and the peripheral area N may be defined as a spatial area between one pixel area and a pixel area adjacent thereto. . At this time, M and N may be a positive integer.

According to an example, the flexible substrate 110 may be a substrate having flexibility. For example, the flexible substrate 110 may be formed of at least one material of polyethylene terephthalate (PET), polyethylenaphthalate (PEN), and polyimide (PI). The material of the flexible substrate 110 is only one example, but is not limited thereto.

According to an example, a barrier may be formed on one surface of the flexible substrate 110 to prevent penetration of moisture and air.

Referring to FIG. 2, which schematically illustrates the pixel region P of FIG. 1, the pixel region P includes a light emitting part including an organic light emitting layer OL and a driving element for driving the organic light emitting layer OL. Can be. In this case, the driving device may include a switch transistor ST, a data transistor DT, a capacitor C, and an anode electrode and a cathode electrode for providing holes and electrons to the organic light emitting layer OL.

More specifically, the gate electrode of the switch transistor ST is electrically connected to the gate line GLine, the source electrode of the switch transistor ST is electrically connected to the data line DLine, and the switch transistor ST The drain electrode may be electrically connected to the gate electrode of the data transistor DT and one electrode of the capacitor C. In addition, the source electrode of the data transistor DT may be electrically connected to the EVDDLine, and the drain electrode of the data transistor DT may be electrically connected to the other electrode of the capacitor C and the anode electrode AE (see FIG. 3). have. In addition, the cathode electrode CE (see FIG. 3) may be electrically connected to the EVSSLine.

The pixel region P described with reference to FIG. 2 has been described assuming a 2T1C structure composed of two transistors and one capacitor, but the technical idea of the present invention is not limited to the 2T1C structure.

In addition, the flexible display according to an embodiment of the present invention may be applied to any type of top emission type and bottom emission type.

FIG. 3 shows a cross section of the line B-B 'of FIG. 1, ie the two pixel regions P and the peripheral region N therebetween.

Referring to FIG. 3, the flexible substrate 110 may be divided into a pixel region P and a peripheral region N. FIG.

In the pixel region P, a transistor (the data transistor DT of FIG. 2 in FIG. 3), an anode AE, an organic light emitting layer OL, and a cathode electrode CE may be formed.

The data transistor DT is provided on the flexible substrate 110, and is formed on the active layer ACT, the first insulating layer I1 and the first insulating layer I1 provided on the active layer ACT. The gate electrode GE is provided, the second insulating film I2 provided on the gate electrode GE, and the second insulating film I2 are provided on the gate electrode GE, and contact the active layer ACT through a contact hole. It may include a source electrode (SE) and a drain electrode (DE).

The data transistor DT may transfer a current of the EVDDLine connected to the source electrode SE to the anode AE through the drain electrode DE. That is, when an ON signal is applied to the gate electrode GE of the data transistor DT, the anode AE may receive a current.

The gate electrode GE is a metal or an alloy of at least one of Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, Cu, or a single layer or It can be formed in multiple layers.

The active layer ACT may include a semiconductor material, and the semiconductor material may be made of crystalline silicon. This is just an example and the active layer ACT may be made of another material.

The source electrode SE and the drain electrode DE are any of Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, Cu, for example. As one metal or alloy thereof, it may be formed in a single layer or in multiple layers.

An interlayer insulating layer ILD may be provided on the source electrode SE and the drain electrode DE. The interlayer insulating layer ILD may be formed of an organic material.

The anode electrode AE is formed on the interlayer insulating film ILD, and the anode electrode AE is connected to the drain electrode DE through a contact hole formed in the interlayer insulating film ILD. .

Meanwhile, the partition wall W may be formed to define a region in which the organic light emitting layer OL is formed. The partition wall W includes at least one of an inorganic insulating material such as silicon nitride (SiNx) and silicon oxide (SiOx) or an organic insulating material such as benzocyclobutene or acrylic resin. Can be done.

An organic light emitting layer OL may be formed on the anode AE. For example, the organic light emitting layer OL may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer. At this time, for each pixel, the organic light emitting layer OL may be provided to emit light of different colors.

The cathode electrode CE may be provided on the organic light emitting layer OL. For example, the cathode electrode CE may provide electrons to the organic light emitting layer OL.

An encapsulation layer may be provided on the cathode electrode CE. It may block moisture and / or oxygen that may penetrate into the encapsulation layer.

According to an embodiment, the encapsulation layer may encapsulate the light emitting part, in particular the organic light emitting layer OL, and may be encapsulated independently by partitioning the pixel area of the M * N. The encapsulation layer may include a first inorganic layer 120, an organic layer 130, and a second inorganic layer 140. In this case, the organic layer 130 of the encapsulation layer may be formed in the pixel region P, but may not be formed in the peripheral region N. That is, the encapsulation layer may thus independently seal the pixel region illustrated on the left side of FIG. 3 and the pixel region illustrated on the right side of FIG. 3.

More specifically, referring to the pixel region P of FIG. 3, the second inorganic layer 140 may completely cover one side of the organic layer 130. In addition, a surface defined by the thickness of the second inorganic layer 140 and one surface of the first inorganic layer 120 may contact each other (C1). That is, the organic layer 130 may be completely surrounded by the first and second

inorganic layers

120 and 140. In this case, the width of the organic layer 130 may be narrowed from the first inorganic layer 120 to the second inorganic layer 140.

Meanwhile, referring to the peripheral area N of FIG. 3, the organic layer 130 may not be formed on the peripheral area N. FIG. Accordingly, the first inorganic layer 120 and the second inorganic layer 140 may be in direct contact with each other (C2) on the peripheral region (N).

That is, the organic layer for encapsulation may be formed in the pixel region P of the flexible display according to the first exemplary embodiment of the present invention, but the organic layer for encapsulation may not be formed in the peripheral region N. FIG. Accordingly, the height of the pixel area P may be higher than the height of the peripheral area N. FIG. The low height of the peripheral area N means that the peripheral area N becomes thin. Therefore, when the display is folded or pulled in the surface direction, higher flexibility S can be provided.

On the contrary, when the organic layer 130 of the encapsulation layer is formed in the peripheral region N, the thickness of the peripheral region N becomes thick. When the thickness of the peripheral area N becomes thick, deformation of the display may be limited even when the display is folded or pulled in the plane direction. In particular, in the case of the organic layer, since the thickness is much thicker than the inorganic layer, it may be a factor that inhibits the flexibility characteristics.

However, according to the first embodiment of the present invention, the encapsulation organic layer 130 is selectively formed in the pixel region P among the pixel region P and the peripheral region N, so that the peripheral region N is more smoothly folded. Can be pulled out. That is, flexibility characteristics can be improved. In addition, since the organic layer 130 is formed in the pixel region P, excellent WVTR characteristics may be provided.

The flexible display according to the first embodiment of the present invention has been described above with reference to FIGS. 1 to 3. Hereinafter, a method of manufacturing a flexible display according to a first embodiment of the present invention will be described with reference to FIGS. 4 to 13.

Referring to FIG. 4, a method of manufacturing a flexible display according to a first exemplary embodiment of the present invention may include a first electrode and a first electrode for each pixel region, among peripheral regions defined as M * N pixel regions and regions between the pixel regions. Forming a light emitting part including a second electrode and an organic light emitting layer disposed between the first and second electrodes (S110) and encapsulating the pixel area of the M * N on the light emitting part and encapsulating independently. Forming a layer may be included (S120).

In step S110, the light emitting unit may be formed.

To this end, a sacrificial substrate may be prepared, and the flexible substrate 110 may be formed on the sacrificial substrate. Thereafter, the light emitting part including the driving device and the organic light emitting layer OL may be formed on the flexible substrate 110. In this case, the light emitting part may be formed in the pixel area P. FIG. Since the process of forming the light emitting unit is a known technique, a detailed description thereof will be omitted.

According to an example, the sacrificial substrate may be removed after the encapsulation layer forming step according to step S120.

After step S110, the encapsulation layer forming step according to step 120 may be performed. A detailed description of step S120 will be made with reference to FIG. 5.

Referring to FIG. 5, in the method of manufacturing an encapsulation layer according to the first embodiment of the present invention (step S120), forming a first inorganic layer on the light emitting part (S122) and a negative sound on the first inorganic layer Forming a negative photoresist layer (S124), and disposing a mask having an opening corresponding to the peripheral area and a blocking part corresponding to the pixel area on the negative photoresist (S126). ), Patterning the negative photoresist layer into a plurality of sacrificial structures having an inverse taper shape (S128), and forming a plurality of organic layers having a forward taper shape between the sacrificial structures through an inkjet process (S130). It may include at least one of removing the sacrificial structure (S132) and forming a second inorganic layer on the organic layer (S134). Hereinafter, each step will be described in detail with reference to FIGS. 6 to 14.

단계 S122Step S122

The first inorganic layer 120 may be formed on the light emitting part. Referring to FIG. 6, the first inorganic layer 120 may be formed over the pixel area P and the peripheral area N by step S122. For example, the first inorganic layer may be made of SiNx.

단계 S124Step S124

Referring to FIG. 7, a negative photoresist layer 150 may be formed on the first inorganic layer 120. In this case, the negative photoresist means a resist in which the exposed portion does not dissolve in the developer. On the contrary, positive photoresist means a resist in which an exposed part is soluble in development.

For reference, in FIG. 7 and subsequent drawings, components under the first inorganic layer 120 are omitted.

단계 S126Step S126

Referring to FIG. 8, a mask 160 having an opening corresponding to the peripheral region N and a blocking portion corresponding to the pixel region may be disposed on the negative photoresist layer 150.

단계 S128Step S128

Referring to FIG. 9, the negative photoresist layer 150 may be exposed. Light may be applied to the peripheral area N by the mask 160. Accordingly, as shown in FIG. 10, the lighted area may be patterned into the sacrificial structure 152. On the other hand, it can be removed without receiving light.

In this case, the sacrificial structure 152 may have an inverse taper shape. That is, it may have a shape in which the width in the height direction at the interface of the first inorganic layer 120 widens.

단계 S130Step S130

Referring to FIG. 11, a net tapered organic layer 130 may be formed between the sacrificial structures 152 through an inkjet process. In this case, the sacrificial structure 152 may function as a mold defining the shape of the organic layer 130. An organic ink, for example, a photocurable organic ink, may be applied into a mold provided by the sacrificial structure 152. After the organic ink is applied, light may be irradiated to cure the organic ink. The cured organic ink may be the organic layer 130 of the encapsulation layer.

According to an example, since the sacrificial structure 152 has an inverse taper shape, the organic layer 130 may have a forward taper formation on the contrary.

단계 S132Step S132

As shown in FIG. 12, the sacrificial structure 152 may be removed. The sacrificial structure 152 may be removed and the organic layer 130 may remain.

Accordingly, the organic layer 130 having a net tapered shape may be formed on the pixel region P.

단계 S134Step S134

As shown in FIG. 13, a second inorganic layer 140 may be formed on the organic layer 130. The second inorganic layer 140 may be made of SiNx.

The second inorganic layer 140 may be deposited by a CVD process. Since the organic layer 130 has a forward taper shape, the second inorganic layer 140 may have a side surface as well as an upper surface of the organic layer 130. Even can be deposited smoothly. Accordingly, the organic layer 130 is surrounded by the second inorganic layer 140.

In another aspect, an encapsulation layer in which the first inorganic layer 120, the organic layer 130, and the second inorganic layer 140 are sequentially formed is provided on the pixel region P by the deposition of the second inorganic layer 140. Can be. In this case, since the organic layer 130 is completely sealed by the first and second

inorganic layers

120 and 140, it may provide excellent encapsulation characteristics.

Meanwhile, since the organic layer 130 is not deposited on the peripheral region N, the first inorganic layer 120 and the second inorganic layer 140 may be sequentially formed. That is, since the formation of the organic layer 130 is omitted in consideration of the fact that the light emitting part is not formed on the peripheral area N, the height may be lower than that of the pixel area P. FIG. Accordingly, the peripheral region N may provide excellent flexibility characteristics.

Meanwhile, according to an embodiment, after step S134, a process of removing the inorganic layer of the peripheral region N may be performed. For example, the first inorganic layer 120 and the second inorganic layer 140 in the peripheral region N illustrated in FIG. 13 may be removed. More specifically, only the second inorganic layer 140 may be removed, and both the first and second

inorganic layers

120 and 140 may be removed.

After the process of removing the inorganic layer in the peripheral region N, the

inorganic layers

120 and 140 may have a larger area than the organic layer 130 so as to surround the side of the organic layer 130. have.

As the inorganic layer of the peripheral area N is removed, the thickness of the peripheral area N may be reduced. Accordingly, the flexibility of the peripheral area N may be further improved.

The flexible display according to the first embodiment of the present invention described with reference to FIGS. 1 to 3 may be manufactured by the flexible display manufacturing method according to the first embodiment of the present invention described with reference to FIGS. 4 to 13. have.

In the flexible display manufacturing method according to the first embodiment of the present invention described above, in order to form an organic layer for encapsulation in the pixel region P among the pixel region P and the peripheral region N, a negative photoresist layer (150) is used. At this time, the negative photoresist layer 150 is patterned into the sacrificial structure 152 on the peripheral region N, but has a reverse tapered shape. According to an example, when the light is applied to the negative photoresist layer 150 in the direction of the flexible substrate 110 through the mask 160, the light intensity decreases toward the flexible substrate 110 in the mask 160. As a result, it is naturally patterned into a sacrificial structure 152 having a reverse taper shape without a separate subsequent process. Accordingly, by applying an organic ink to a region defined as a space between the sacrificial structures 152 and curing the applied organic ink, a naturally tapered organic layer 130 may be formed. Thereafter, in the deposition of the second inorganic layer 140, since the organic layer 130 has a forward tapered shape, the second inorganic layer 140 may be smoothly formed on the side surface of the organic layer 130.

On the other hand, as shown in FIG. 14, when the positive photoresist PPR is formed on the first inorganic layer 120 (FIG. 14A), the positive photoresist is removed because the exposed region is removed. A sacrificial structure PPR 'of a pure tapered shape may be formed. As described above, since the exposure energy is applied in the direction of the first inorganic layer 120 in the mask 160, the exposure energy is weakened toward the first inorganic layer 120 in the mask 160. Accordingly, the region removed by the developer has an inverse taper shape, and the remaining sacrificial structure PPR 'has a forward taper shape. Accordingly, the reverse tapered organic layer 130 'is formed by the forward tapered sacrificial structure PPR' (FIG. 14B). After removing the sacrificial structure PPR ′ and depositing the second inorganic layer 140 ′ on the organic layer 130 ′, the second inorganic layer 140 ′ may be formed on the organic layer 130 ′. However, it cannot be formed on the side of the organic layer 130 '(see DIP, FIG. 14 (c)). Accordingly, since the organic layer cannot be completely surrounded by the first and second inorganic layers, encapsulation cannot be performed.

If it is desired to change the shape of the reverse tapered organic layer formed without the sacrificial structure to the net tapered shape, heat treatment may be performed (thermal reflow). However, since heat treatment requires high temperature heat of about 200 degrees or more, there is a concern that the light emitting part including the organic material may be damaged. Accordingly, there is a difficulty in applying additional heat treatment.

However, in the first embodiment of the present invention, the side of the organic layer is smoothly sealed by using a negative photoresist to form the organic layer in a simple tapered manner. Accordingly, it is possible to partition and encapsulate the pixel area of M * N independently.

1 to 14, the flexible display according to the first embodiment of the present invention and a manufacturing method thereof have been described. Hereinafter, a flexible display and a method of manufacturing the same according to the second embodiment of the present invention will be described with reference to FIGS. 15 to 22. In the description of the second embodiment of the present invention, a portion corresponding to the above-described first embodiment will be omitted.

Referring to FIG. 15, unlike the flexible display according to the second embodiment of the present disclosure, the third inorganic layer 170 may be further included on the second inorganic layer 140. That is, the third inorganic layer 170 may have a structure covering the entire second inorganic layer 140. In this case, on the pixel region P, the first inorganic layer 120, the organic layer 130, the second inorganic layer 140, and the third inorganic layer 170 may be stacked while sequentially directly contacting each other.

In addition, on the peripheral area N, the third inorganic layer 170 may directly contact the second inorganic layer 140 (C3). Accordingly, the first inorganic layer 120, the second inorganic layer 130, and the third inorganic layer 170 may be sequentially stacked while directly contacting the peripheral region N. FIG.

Although not shown, the third inorganic layer 170 may directly contact the first inorganic layer 120 according to the peripheral region N. FIG. In other words, there may be a region in which the second inorganic layer 140 is also omitted in the peripheral region N. In this case, the third inorganic layer 170 is in direct contact with the first inorganic layer 120. It can be stacked while.

Therefore, in the second embodiment, since the organic layer 130 for encapsulation is omitted on the peripheral region N, the thickness of the peripheral region N may be thinner than the thickness of the pixel region P. FIG. Accordingly, flexibility characteristics can be improved.

16 is a view for explaining the manufacturing method of the encapsulation layer according to the second embodiment of the present invention, Figures 17 to 22 are for explaining in detail the manufacturing method of the encapsulation layer according to the second embodiment of the present invention. Drawing.

The method of manufacturing the encapsulation layer according to the second embodiment of the present invention is the same as in step S110 (see FIG. 4) of the method of manufacturing the encapsulation layer according to the first embodiment of the present invention. Step S120 will be described.

Referring to FIG. 16, a method of manufacturing an encapsulation layer according to a second embodiment of the present invention (step S120) may include forming a first inorganic layer on the light emitting part (S150), and forming the encapsulation layer on the first inorganic layer. Forming a positive photoresist layer (S152), patterning the positive photoresist layer into a plurality of sacrificial structures (S154), and forming a second inorganic layer on the plurality of sacrificial structures. In operation S156, the second inorganic layer is patterned to expose one region of the plurality of sacrificial structures to the outside, and the tunnel is formed by removing the plurality of sacrificial structures through the externally exposed region. It may include at least one of the step (S160), the step of forming an organic layer in the tunnel (S162), the step of forming a third inorganic layer on the second inorganic layer (S164). Hereinafter, each step will be described in detail with reference to FIGS. 17 to 22.

단계 S150Step S150

The first inorganic layer 120 may be formed on the light emitting part. Since step S152 corresponds to step S122 (see FIG. 5) of the first embodiment, a detailed description thereof will be omitted.

단계 S152Step S152

A positive photoresist layer may be formed on the first inorganic layer 120. A negative photoresist is utilized in the first embodiment, but the difference is that a positive photoresist is utilized in step S152.

단계 S154Step S154

Referring to FIG. 17, the positive photoresist layer may be patterned into a plurality of sacrificial structures 153. Although not shown for this purpose, a mask may be utilized. In this case, the mask may have a light blocking portion corresponding to the pixel region P, and may have a light opening corresponding to the peripheral region N. FIG. Accordingly, as shown in FIG. 18, the sacrificial structure 153 may be patterned in a line shape. In this case, the sacrificial structure 153 may have a forward taper shape.

단계 S156Step S156

The second inorganic layer 140 may be formed on the plurality of sacrificial structures 153. Since the sacrificial structure 153 has a forward tapered shape, the second inorganic layer 140 may also be deposited in a forward tapered shape.

단계 S158Step S158

The formed second inorganic layer 140 may be patterned. In this case, as illustrated in FIG. 18, a portion of the sacrificial structures 152 may be patterned to expose the outside.

단계 S160Step S160

The plurality of sacrificial structures 153 may be removed through an area exposed to the outside by the second inorganic layer 140. Accordingly, as shown in FIG. 19, the tunnel 160 may be formed in the second inorganic layer 140. That is, as the sacrificial structure 153 is removed, the tunnel 160 may be formed by the space occupied by the sacrificial structure 153.

One layer of the tunnel 160 may include the first inorganic layer 120, and the other layer of the tunnel 160 may include the second inorganic layer 140.

Since the sacrificial structure 153 has a forward tapered shape, the tunnel 160 also has a forward tapered shape.

단계 S162Step S162

The organic layer 130 may be formed in the tunnel 160. To this end, when an organic ink, for example, a photocurable organic ink, is provided as shown in FIG. 20, the organic ink may be introduced into the tunnel 160 by capillary force. Thereafter, the organic ink outside the tunnel 160 may be removed through a cleaning process. In this case, the organic ink inside the tunnel 160 is not removed by the capillary force and may be held. Thereafter, the organic layer 130 may be formed on the pixel region P by photocuring the organic ink inside the tunnel 160 through a front surface photocuring process.

Alternatively, after the organic ink is injected into the tunnel 160, the organic layer 130 may be formed by curing light of the organic ink by selectively irradiating light only to the tunnel 160 using a mask. The uncured organic ink can then be removed through a cleaning process.

As a result, as shown in FIG. 21, the organic layer 130 may be formed in the tunnel 60. That is, the organic layer 130 may be formed between the first inorganic layer 120 and the second inorganic layer 130. In addition, one side of the organic layer 130 may be surrounded by the first inorganic layer 120 and the second inorganic layer 140.

단계 S164Step S164

The third inorganic layer 170 may be formed after step S162. The third inorganic layer 170 may be formed on the entire surface. As shown in FIG. 22, the third inorganic layer 170 may serve to cover the entrance of the tunnel 160. In addition, since the second inorganic layer 140 has a forward tapered shape, the third inorganic layer 170 may be easily deposited along the shape of the second inorganic layer 140. That is, the third inorganic layer 170 may effectively seal the side surface of the second inorganic layer 140.

For example, the third inorganic layer 170 may also be made of SiNx.

Accordingly, the first inorganic layer 120, the organic layer 130, the second inorganic layer 140, and the third inorganic layer 170 may be sequentially stacked on the DD ′ line of FIG. 22, that is, the pixel region P. FIG. have. A cross section taken along the line D-D 'of FIG. 22 may be shown as shown in FIG. 15.

In addition, the first inorganic layer 120 and the third inorganic layer 170 may be sequentially stacked on the line E-E 'of FIG. 22. In other words, the organic layer 130 and the second inorganic layer 140 may be omitted on the E-E 'line.

According to an embodiment of the present disclosure, after step S164, a process of removing the inorganic layer of the peripheral region N may be performed.

For example, the first inorganic layer 120, the second inorganic layer 140, and the third inorganic layer 170 of the peripheral area N positioned on the line D-D ′ illustrated in FIG. 22 may be removed. In this case, only the third inorganic layer 170 may be removed, the second and third

inorganic layers

140 and 170 may be removed, and the first to third

inorganic layers

120, 140, 170 can all be removed.

As another example, the first inorganic layer 120 and the third inorganic layer 170 of the peripheral area N positioned on the line E-E ′ shown in FIG. 22 may be removed. In this case, only the third inorganic layer 170 may be removed, and both the first and third

inorganic layers

120 and 170 may be removed.

The flexible display and the manufacturing method thereof according to the second exemplary embodiment of the present invention have been described above with reference to FIGS. 15 to 22. Hereinafter, a flexible display and a method of manufacturing the same according to a modified example of the second embodiment of the present invention will be described with reference to FIGS. 23 to 26. In describing the modified example of the second embodiment of the present invention, portions overlapping with the above-described second embodiment will be omitted.

The method of manufacturing the encapsulation layer according to the modification of the second embodiment of the present invention may be made of the method of manufacturing the encapsulation layer according to the second embodiment described above with reference to FIG. 16. However, there is a difference in each step, it will be described focusing on the difference.

Steps S150 to S154 are the same as the modified example of the second embodiment and the above-described second embodiment, and thus description thereof will be omitted.

According to a modification of the second exemplary embodiment of the present invention, in operation S158, the second inorganic layer 140 is patterned to expose one region of the plurality of sacrificial structures 152 to the outside. One side may be patterned to merge in the direction of the center of the pixel area on a plane.

That is, in step S158 of the second exemplary embodiment of the present invention, the second inorganic layer 140 is patterned as shown in FIG. 18, but in step S158 of the modified example of the second exemplary embodiment of the present invention, the BT line (the second inorganic layer 140 of FIG. The second inorganic layer 140 may be patterned so as to be embedded in the T direction.

Subsequently, even in step S160 of the modified example of the second embodiment of the present invention, the sacrificial structure 153 may be removed through an area exposed to the outside by the second inorganic layer 140. Accordingly, as shown in FIG. 24, the inlet and / or outlet of the tunnel 160 defined by the second inorganic layer 140 may also have a forward taper shape.

Thereafter, in step S162 of the modified example of the second embodiment of the present invention, the organic layer 130 may be formed in the tunnel 160. In this case, as shown in FIG. 25, the organic layer 130 may have a net taper shape on all four sides.

Subsequently, in step S164 of the modified example of the second embodiment of the present invention, the third inorganic layer 170 may be formed. In this case, as shown in FIG. 26, since all four side surfaces of the organic layer 130 have a forward tapered shape, the third inorganic layer 170 may be deposited to have a better film quality. In other words, since the inlet and / or outlet portions of the tunnel 160 also have a forward tapered shape, the third inorganic layer 170 may be more smoothly deposited.

As a result, the flexible display according to the modified example of the second embodiment of the present invention can be manufactured. According to the present modified example, since the second inorganic layer 140 is patterned into the structure embedded in the center direction of the pixel region, the organic layer 130 is formed in the forward taper shape at the tunnel entrance defined by the second inorganic layer 140. Can be. Accordingly, the third inorganic layer 170 may be smoothly deposited on the side of the second inorganic layer 140 having the forward tapered shape and the side of the organic layer 130 having the forward tapered shape.

According to the second embodiment of the present invention and its modified example, the organic ink for thin film encapsulation is filled in the tunnel 160 because the organic ink for thin film encapsulation is naturally sucked by capillary force to fill the tunnel. There is no need for a high difficulty process of dispensing to be internal, and the remaining liquid can be removed by cleaning, thus providing ease of processing.

According to the embodiments of the present invention described above, an independent encapsulation may be performed for each pixel without a separate dam structure for forming an organic layer for encapsulation.

On the contrary, in order to encapsulate the organic light emitting layer side surface, the side surface of the organic light emitting layer and the dam have to be separated by a predetermined distance. That is, only when the organic light emitting layer and the distance between the dam, the organic layer could be formed within the distance. Therefore, in the prior art, the distance between pixels was inevitably farther apart.

In the present invention, by omitting the dam structure, the maximum area of the peripheral area between the pixel area and the pixel area is secured, and the thickness of the peripheral area is minimized by omitting the organic layer for encapsulation in the peripheral area. In this way, improved flexibility characteristics can be provided.

As mentioned above, although this invention was demonstrated in detail using the preferable embodiment, the scope of the present invention is not limited to a specific embodiment and should be interpreted by the attached Claim. In addition, those of ordinary skill in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

Claims

A substrate partitioned into a peripheral region defined by a pixel region of M * N and an region between the pixel regions;

A light emitting unit disposed in each pixel area of the M * N and including a first electrode, a second electrode, and an organic light emitting layer disposed between the first and second electrodes; And

And a sealing layer encapsulating the light emitting part and separately encapsulating the pixel area of the M * N.

(M and N are positive integers)
According to claim 1,

On the pixel area, the encapsulation layer includes a first inorganic layer, a second inorganic layer, and an organic layer disposed between the first and second inorganic layers,

And the second inorganic layer covers one side of the organic layer.
The method of claim 2,

On the peripheral area, one side of the first inorganic layer and one side of the second inorganic layer are in direct contact with each other.
The method of claim 3, wherein

The flexible display, wherein the organic layer is not formed on the peripheral region.
The method of claim 2,

And a surface defined by the thickness of the second inorganic layer and one surface of the first inorganic layer are in contact with each other on the pixel area.
The method of claim 2,

And said organic layer is completely surrounded by said first and said second inorganic layers.
The method of claim 2,

The width | variety of the said organic layer becomes narrow in the direction from the said 1st inorganic layer to the said 2nd inorganic layer.
The method of claim 2,

And a third inorganic layer formed on the second inorganic layer.
The method of claim 8,

And the third inorganic layer covers the other side of the organic layer to make direct contact.
The method of claim 8,

One side surface of the second inorganic layer is embedded in the plane in the direction of the center of the pixel area, flexible display.
A light emitting part including a first electrode, a second electrode, and an organic light emitting layer disposed between the first and second electrodes, for each pixel area, among the peripheral areas defined as the pixel area of M * N and the area between the pixel areas. Forming; And

And forming an encapsulation layer on the light emitting part to separately encapsulate the pixel area of M * N.
The method of claim 11, wherein

Forming the encapsulation layer,

Forming a first inorganic layer on the light emitting part;

Forming a negative photoresist layer on the first inorganic layer;

Patterning the negative photoresist layer into a plurality of sacrificial structures of inverse taper shape;

Forming a net tapered organic layer between the sacrificial structures through an inkjet process;

Removing the sacrificial structure; And

Forming a second inorganic layer on the organic layer.
The method of claim 12,

After forming a negative photoresist layer on the first inorganic layer,

And disposing a mask having an opening corresponding to the peripheral area and a blocking part corresponding to the pixel area on the negative photoresist layer.
The method of claim 13,

Patterning the negative photoresist layer into a plurality of sacrificial structures of inverse taper shape,

Removing the negative photoresist area unexposed by the blocking portion of the mask.
The method of claim 12,

After forming the second inorganic layer,

Removing at least one inorganic layer of the first and second inorganic layers on the peripheral region.
The method of claim 11, wherein

Forming the encapsulation layer,

Forming a first inorganic layer on the light emitting part;

Forming a positive photoresist layer on the first inorganic layer;

Patterning the positive photoresist layer into a plurality of sacrificial structures;

Forming a second inorganic layer on the plurality of sacrificial structures;

Patterning the second inorganic layer to expose one region of the plurality of sacrificial structures to the outside;

Forming a tunnel by removing the plurality of sacrificial structures through the externally exposed region;

Forming an organic layer in the tunnel; And

Forming a third inorganic layer on the second inorganic layer.
The method of claim 16,

In the step of forming the tunnel,

One layer of the tunnel is made of the first inorganic layer, and the other layer of the tunnel is made of a second inorganic layer spaced apart from the first inorganic layer,

The tunnel is formed on the pixel region;

Flexible display manufacturing method.
The method of claim 17,

In the step of forming the organic layer,

And the organic layer is selectively formed in the pixel region of the pixel region and the peripheral region.
The method of claim 18,

And stacking the first inorganic layer, the organic layer, the second inorganic layer, and the third inorganic layer on the pixel region.
The method of claim 16,

Patterning the second inorganic layer to expose one region of the plurality of sacrificial structures to the outside;

And patterning the second inorganic layer such that one side of the second inorganic layer is embedded in a plane in the direction of the center of the pixel area.