KR101439261B1 - Flexible display device and manufacturing method of the same - Google Patents

Abstract

The present invention provides a display device comprising a flexible substrate, a first barrier layer formed on the first surface of the flexible substrate, a display element formed on the first surface of the first barrier layer, a sealing film covering the display element, And a protective film including a second barrier layer and a lower film disposed on a second surface opposite to the first surface, and a method of manufacturing the same.

Description

Technical Field [0001] The present invention relates to a flexible display device and a manufacturing method thereof,

The present invention relates to a flexible display device and a manufacturing method thereof.

The organic light emitting display includes a hole injecting electrode, an electron injecting electrode, and an organic light emitting element including an organic light emitting layer formed therebetween, wherein holes injected from the hole injecting electrode and electrons injected from the electron injecting electrode are injected into the organic light emitting layer Emitting type display device in which excitons generated in association with each other drop from an excited state to a ground state to generate light.

Since an organic light emitting display device which is a self-emission type display device does not require a separate light source, it can be driven at a low voltage and can be configured as a light and thin type. Due to its high quality characteristics such as wide viewing angle, high contrast, It is attracting attention as a next generation display device.

However, since the organic light emitting display has a characteristic of being deteriorated by external moisture or oxygen, the organic light emitting element must be protected from external moisture or oxygen.

One embodiment of the present invention relates to a flexible display device and a method of manufacturing the same, and more particularly, to a flexible display device that blocks water and oxygen penetrating not only an upper portion but also a lower portion thereof, and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a flexible substrate comprising: a flexible substrate; A first barrier layer formed on a first side of the flexible substrate; A display element formed on a first surface of the first barrier layer; A sealing film covering the display element; And a protective film disposed on a second surface opposite to the first surface of the flexible substrate, the protective film including a second barrier layer and a lower film.

According to an aspect of the present invention, the protective film is formed on the flexible substrate so that the second barrier layer is positioned relatively close to the second surface of the flexible substrate, and the lower film is located relatively far from the protective film. And may be located on the second side.

According to another embodiment of the present invention, the protective film and the second surface of the flexible substrate may be bonded by an adhesive layer.

According to another embodiment of the present invention, the adhesive layer may further include a getter.

According to another embodiment of the present invention, the second barrier layer may include an inorganic layer.

According to another embodiment of the present invention, the second barrier layer includes a cross-laminated structure of an inorganic layer and an organic layer.

According to another embodiment of the present invention, the flexible substrate may be a single layer of polyimide (PI).

According to another embodiment of the present invention, the lower film includes at least one of polyethylene terephthalate (PET), polystyrene (PS), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyethylene can do.

According to another aspect of the present invention, there is provided a flexible substrate comprising: a flexible substrate; A first barrier layer formed on a first side of the flexible substrate; A display element formed on a first surface of the first barrier layer; A sealing film covering the display element; And a protective film provided on the opposite side of the first side of the flexible substrate, wherein the protective film comprises: a second barrier layer positioned on the second side of the flexible substrate; And a lower film disposed on the barrier layer.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: sequentially forming a plastic substrate and a first barrier layer on a supporting substrate; Forming a thin film transistor on the first barrier layer; Forming a display element electrically connected to the thin film transistor on the thin film transistor; Forming an encapsulating film on the display element; Separating the support substrate from the plastic substrate; Forming a second barrier layer on the lower film; And attaching a film having the second barrier layer formed on one surface of the plastic substrate exposed while the supporting substrate is separated.

According to an aspect of the invention, separating the support substrate may include separating the support substrate from the plastic substrate using a laser beam.

According to still another aspect of the present invention, the step of forming the second barrier layer on the lower film includes: forming an inorganic layer on the lower film; Forming an organic layer on the inorganic layer; And forming an inorganic layer on the organic layer.

According to another aspect of the present invention, the step of attaching the film on which the second barrier layer is formed may include attaching using an adhesive including a getter.

According to another aspect of the present invention, the step of attaching the film having the second barrier layer includes attaching the second barrier layer so as to face the one side of the plastic substrate exposed while the support substrate is separated can do.

According to another aspect of the present invention, the forming of the display device may include forming the organic light emitting device.

According to another aspect of the present invention, the step of forming the plastic substrate on the supporting substrate includes: coating a polyimide (PI) resin on the supporting substrate; And

And curing the coated polyimide resin to form a single layer of plastic substrate.

According to another aspect of the present invention, the lower film includes at least one of polyethylene terephthalate (PET), polystyrene (PS), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyethylene .

According to an embodiment of the present invention as described above, it is possible to increase the rate of blocking water and oxygen penetrating through not only the upper portion but also the lower portion through a simple method.

FIG. 1 is a cross-sectional view schematically showing a flexible display device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically showing the structure of FIG.
3 is a cross-sectional view schematically showing a flexible display device according to another embodiment of the present invention.
4 is a cross-sectional view schematically showing one pixel region of the flexible display device of FIG.
5A to 5C are cross-sectional views schematically illustrating a method of manufacturing a flexible display device according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and particular embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another. The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, Should not be construed to preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof. In the following description, "/" may be interpreted as "and "

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. When a portion of a layer, film, region, plate, or the like is referred to as being "on" or "on" another portion, it includes not only the case directly above another portion but also the case where there is another portion in between.

FIG. 1 is a cross-sectional view schematically showing a flexible display device according to an embodiment of the present invention. FIG. 2 is a sectional view schematically showing the structure of FIG. 1, and FIG. 3 is a cross- Sectional view schematically showing the device.

1 and 2, the flexible display device includes a flexible substrate 110, a display element 130 formed on a first surface of the flexible substrate 110, a sealing film 160 covering the display element 130 , And a protective film (200) located on the second side of the flexible substrate (110).

The flexible substrate 110 may be a plastic substrate. For example, the substrate 110 may be formed of one or more materials selected from the group consisting of polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelenen naphthalate (PEN), polyethylene terephthalate polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC), poly (arylene ether sulfone), and polyether sulfone Or a combination thereof. Since polyimide has excellent mechanical strength and excellent heat resistance compared with other polymer materials having a maximum processable temperature of about 450 ° C., a certain heating process is performed in a process of forming a thin film transistor and an organic light emitting device on a polyimide substrate It is possible to stably perform the role of the flexible display substrate without being sagged by the loads of the elements and layers.

The first barrier layer 120 may be formed on the first side of the flexible substrate 110. The first barrier layer 120 may be made of an inorganic material such as SiOx, SiNx, or an organic material such as acrylic or polyimide. The first barrier layer 120 functions to block oxygen and moisture, while preventing the diffusion of moisture or impurities generated in the flexible substrate 110 or preventing the diffusion of moisture or impurities in the semiconductor layer (see FIG. 4) of a thin film transistor The crystallization of the semiconductor can be performed well by controlling the heat transfer rate at the time of crystallization.

The display element 130 is formed on the first surface of the flexible substrate 110 and forms a display portion of the flexible display device. The display device 130 may include an organic light emitting device 150 that emits red, green, blue, or red, green, blue, or white light according to the current flow to display predetermined image information And a device / wiring layer 140 for transferring a current to the organic light emitting device 150 according to a signal. Although the display device 130 includes the organic light emitting device 150 in the present embodiment, the specific configuration of the display device 130 will be described later with reference to FIG.

The sealing film 160 is located on the upper side of the display element 130 and can protect the display element 130 by sealing it from the outside. For this purpose, the sealing film 160 may be formed larger than the display element 130 to cover the front surface of the display element 130.

The sealing film 160 may be formed of a plurality of layers. For example, the sealing film 160 is a structure in which an inorganic film and an organic film are alternately laminated, and flexibility and thinness of the flexible display device can be easily realized. The inorganic film may be composed of a metal oxide, a metal nitride, a metal carbide, and a compound thereof. For example, it may comprise an inorganic film _x AlO, TiO _2, ZrO, SiO _x, AlON, AlN, SiN _x, SiO _x N _y, and InO _x, YbO _x of the inorganic material or the like. The organic film may include a polymer-based material. Examples of the polymer-based material may include an acrylic resin, an epoxy resin, a silicone resin, an allyl resin, polyimide, and polyethylene. The organic film can function to mitigate the internal stress of the inorganic film, or to complement and planarize the defect of the inorganic film.

The protective film 200 is located on the second side of the flexible substrate 110. The protective layer 200 may function to block oxygen and moisture flowing from the lower portion of the flexible substrate 110. For this, the protective film 200 includes a lower film 210 and a second barrier layer 220 formed on the lower film 210. For example, the second barrier layer 220 may be disposed on the second side of the flexible substrate 110, and the lower film 210 may be disposed on the second barrier layer 220. By disposing the second barrier layer 220 adjacent to the flexible substrate 110, it is possible to block the oxygen and moisture permeated from the lower portion and improve the blocking rate of oxygen and water permeated in the lateral direction.

The lower film 210 includes at least one of polyethylene terephthalate (PET), polystyrene (PS), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyethylene (PE).

The second barrier layer 220 may be formed as a single layer of an inorganic layer (see FIGS. 1 and 2). For example, the second barrier layer 220 may be formed as an inorganic layer comprising at least any one of SiNx, SiO _2, SiON, AlOx, ITO, ZnO, ZrO. The inorganic layer may be formed by a method such as CVD, ALD, sputtering or the like.

As another example, the second barrier layer 220 may include a structure in which the inorganic layers 221 and 223 and the organic layer 222 are alternately stacked (see FIG. 3). The second barrier layer 220 May be formed to include at least one inorganic layer (221, 223) and at least one organic layer (222). For example, the inorganic film 221, the organic layer 222, and the inorganic layer 223 may be stacked on the lower film 210 in this order. Inorganic layers 221 and 223 is an organic material having SiNx, SiO _2, SiON, AlOx, may include at least one of ITO, ZnO, ZrO, the organic layer 222 is an acrylic, epoxy, silicone (silicone), an allyl group Or the like. The inorganic layers 221 and 223 may be formed by a method such as CVD, ALD, or sputtering,

flash evaporation, inkjet printing, screen printing, and slit coating.

Although not shown in the drawing, the second barrier layer 220 may have the same number of inorganic layers and organic layers. For example, it may include a structure in which an inorganic layer, an organic layer, an inorganic layer, and an organic layer are stacked in this order on the lower film 210.

The adhesive layer 300 is interposed between the flexible substrate 110 and the protective film 200 and functions to integrate them. The adhesive layer 300 may be a commonly used adhesive material. Alternatively, the adhesive layer 300 may be a state in which the getter is dispersed in the adhesive material. By including the getter in the adhesive layer 300, the permeability of the adhesive layer 300 itself to moisture can be greatly reduced.

4 is a cross-sectional view schematically showing one pixel region of the flexible display device of FIG.

4, the display device 130 includes a pixel electrode 151 disposed on the flexible substrate 110, a counter electrode 153 disposed on the pixel electrode 151, a pixel electrode 151, And an organic light emitting element 150 having an organic light emitting layer 152 sandwiched between the electrodes 153. The organic light emitting diode 150 emits red, green, blue light or red, green, blue, and white light according to the current flow to display predetermined image information. The organic light emitting diode 150 is disposed on the device / .

The device / wiring layer 140 is disposed on the first side of the flexible substrate 110, for example, on the first side of the first barrier layer 120. The device / wiring layer 140 includes a driving thin film transistor (TFT), a switching thin film transistor (not shown), a capacitor, a thin film transistor, and wirings (not shown) connected to the capacitor for driving the organic light emitting element 150 . The driving thin film transistor (TFT) includes an active layer, a gate electrode, and a source electrode and a drain electrode.

The thin film transistor is formed on the first barrier layer 120, and may be a top gate thin film transistor as shown in FIG. As another embodiment, the thin film transistor may be a thin film transistor having another structure such as a bottom gate method.

When the top gate type thin film transistor is provided, the semiconductor layer 141, the gate insulating film 142, the gate electrode 143, the source electrode 144a and the drain electrode 144b are formed on the first barrier layer 120, An interlayer insulating film 145, and an insulating film 146 may be formed in this order

The semiconductor layer may be formed of polysilicon, in which case a predetermined region may be doped with an impurity. Alternatively, the semiconductor layer may be formed of amorphous silicon rather than polysilicon, or may be formed of various organic semiconductor materials such as pentacene.

When the semiconductor layer is formed of polysilicon, amorphous silicon is formed and crystallized to be converted into polysilicon. Examples of the crystallization method include a RAP (Lapid Thermal Annealing) process, an SPC (Solid Phase Crystallization) process, an ELA Various methods such as Laser Annealing, Metal Induced Crystallization (MIC), Metal Induced Lateral Crystallization (MILC) or Sequential Lateral Solidification (SLS) may be used. However, in order to use the flexible substrate 110 according to the present invention, It is preferable to use a method which does not require a heating step of heating. Conventionally, there has been a problem that the temperature of the substrate rises to 400 to 500 DEG C due to the high temperature process being continued in the process of activating the semiconductor, so that the plastic substrate can not be used. However, in the recent low temperature poly-silicon (LTPS) The activation of the semiconductor layer may be performed by irradiating the laser beam for a short period of time to remove the time for the substrate to be exposed to a high temperature of 300 DEG C or more so that the entire process can be performed at 300 DEG C or less. Therefore, a thin film transistor can be formed using a plastic film, preferably a polyimide substrate, as in this embodiment.

The sealing film 160 may be formed in a structure in which the inorganic film 161 and the organic film 162 are alternately stacked, and the specific material thereof is as described above.

5A to 5C are cross-sectional views schematically illustrating a method of manufacturing a flexible display device according to an embodiment of the present invention.

Referring to FIG. 5A, a display panel 100 is formed.

First, a flexible substrate 110 and a first barrier layer 120 are sequentially formed on a supporting substrate 10.

In one embodiment, the flexible substrate 110 can be formed by coating polyimide on a support substrate to a predetermined thickness and curing the polyimide. The first barrier layer 120 can be formed by forming an inorganic layer on the first surface of the flexible substrate 110. [ Alternatively, a method of attaching the flexible substrate 110 to the support substrate 10 using an intermediate adhesive layer may also be used .

The first barrier layer 120 may be made of an inorganic material such as SiOx, SiNx, or an organic material such as acrylic or polyimide. The first barrier layer 120 may be formed by CVD, ALD, sputtering, or the like.

A sealing film 160 covering the display element 130 to seal the display element 130 from the outside is formed by forming the display element 130 including the element / wiring layer 140 and the organic light emitting element 150, .

Next, the supporting substrate is separated from the flexible substrate 110. When the display panel 100 is completed through the above-described process, the supporting substrate bonded to the second surface of the flexible substrate 110 is separated from the flexible substrate 110. The support substrate and the flexible substrate 110 can be separated by irradiating the laser beam L from the lower portion of the support substrate. As the laser beam L, XeCl, KrF, ArF or the like combining AF, Kr, Xe, etc. with halogen gas F ₂ , HCl or the like can be used as light having a wavelength of 100 nm to 350 nm which is coherent have. At this time, it is preferable that the supporting substrate has a light transmitting property such that the transmission laser beam L can pass therethrough so that the laser beam L irradiated from the lower portion of the supporting plate can easily be transmitted.

Referring to FIG. 5B, a protective film 200 is formed.

First, a second barrier layer 220 is formed on the first side of the lower film 210. In one embodiment, the second barrier layer 220 may be formed of a single inorganic layer comprising at least any one of SiNx, SiO _2, SiON, AlOx, ITO, ZnO, ZrO. The lower film 210 includes at least one of polyethylene terephthalate (PET), polystyrene (PS), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyethylene (PE).

In yet another embodiment, the second barrier layer 220 may comprise a structure in which an inorganic layer and an organic layer are alternately laminated. The second barrier layer 220 comprises at least two inorganic layers, Layer < / RTI > For example, the organic EL device may include a structure in which an inorganic layer, an organic layer, and an inorganic layer are sequentially stacked on a lower film 210, or a structure in which an inorganic layer, an organic layer, an inorganic layer, and an organic layer are laminated. Inorganic layer SiNx, SiO _2, SiON, AlOx, ITO, ZnO, and may include at least one of ZrO, the organic layer was an acrylic resin, epoxy resin, silicone (silicone) resin, at least any one of an allyl-based resin . ≪ / RTI > The inorganic layer may be formed by a method such as CVD, ALD, or sputtering, and the organic layer may be formed by a printing method such as flash evaporation, inkjet printing, screen printing, or slit coating.

Referring to FIG. 5C, the display panel 100 and the protective film 200 are bonded together. The protective film 200 is attached to the second surface of the exposed flexible substrate 110 while the supporting substrate is separated. For example, the protective layer 200 is attached so that the second barrier layer 220 of the protective layer 200 faces the second surface of the flexible substrate 110. Since the adhesion is performed through the adhesive layer 300, the adhesive layer 300 is positioned between the flexible substrate 110 and the second barrier layer 220.

The adhesive layer 300 may include an adhesive material and a getter. The getter may be dispersed in the adhesive material. By including the getter in the adhesive layer 300, the permeability of the adhesive layer 300 itself to moisture can be greatly reduced.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications and variations without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover all such modifications and variations as fall within the true spirit of the invention.

100: display panel 110: flexible substrate
120: first barrier layer 130: display element
140: element / wiring layer 150: organic light emitting element
160: sealing film 200: protective film
210: lower film 220, 220 ': second barrier layer
221: inorganic layer 222: organic layer
223: inorganic layer 300: adhesive layer

Claims (17)

A flexible substrate;
A first barrier layer formed on a first side of the flexible substrate;
A display element formed on a first surface of the first barrier layer;
A sealing film covering the display element; And
And a protective film disposed on a second surface opposite to the first surface of the flexible substrate and including a second barrier layer and a lower film. The method according to claim 1,
The protective film may be a flexible substrate positioned on the second side of the flexible substrate such that the second barrier layer is located relatively close to the second side of the flexible substrate and the lower film is relatively far from the protective film. Display device. The method according to claim 1,
Wherein the protective film and the second surface of the flexible substrate are bonded by an adhesive layer. The method of claim 3,
Wherein the adhesive layer further comprises a getter. The method according to claim 1,
Wherein the second barrier layer comprises an inorganic layer. The method according to claim 1,
Wherein the second barrier layer comprises a cross-laminated structure of an inorganic layer and an organic layer. The method according to claim 1,
Wherein the flexible substrate is a single layer of polyimide (PI). The method according to claim 1,
Wherein the lower film comprises at least one of polyethylene terephthalate (PET), polystyrene (PS), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyethylene (PE). A flexible substrate;
A first barrier layer formed on a first side of the flexible substrate;
A display element formed on a first surface of the first barrier layer;
A sealing film covering the display element; And
And a protective film provided on the opposite side of the first surface of the flexible substrate,
The protective film may be formed,
A second barrier layer positioned on a second side of the flexible substrate; And
And a lower film positioned on the barrier layer. Forming a plastic substrate and a first barrier layer on the support substrate in order;
Forming a thin film transistor on the first barrier layer;
Forming a display element electrically connected to the thin film transistor on the thin film transistor;
Forming an encapsulating film on the display element;
Separating the support substrate from the plastic substrate;
Forming a second barrier layer on the lower film; And
And attaching a film having the second barrier layer formed on one side of the exposed plastic substrate while the supporting substrate is separated. 11. The method of claim 10,
Wherein the step of separating the support substrate comprises:
And separating the support substrate from the plastic substrate using a laser beam. 11. The method of claim 10,
The step of forming the second barrier layer on the lower film comprises:
Forming an inorganic layer on the lower film;
Forming an organic layer on the inorganic layer; And
And forming an inorganic layer on the organic layer. 11. The method of claim 10,
Wherein the step of attaching the film on which the second barrier layer is formed comprises attaching using an adhesive including a getter. 11. The method of claim 10,
The step of attaching the film, on which the second barrier layer is formed,
And attaching the second barrier layer so as to face one surface of the exposed plastic substrate while the supporting substrate is separated. 11. The method of claim 10,
Wherein the forming the display device comprises forming an organic light emitting device. 11. The method of claim 10,
Wherein forming the plastic substrate on the support substrate comprises:
Coating a polyimide (PI) resin on the support substrate; And
And curing the coated polyimide resin to form a single layer of plastic substrate. 11. The method of claim 10,
Wherein the lower film comprises at least one of polyethylene terephthalate (PET), polystyrene (PS), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyethylene (PE).

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