KR20180106718A - Method of flexible substrate and method of organic electroluminescent device using the same - Google Patents

Abstract

The present invention provides a manufacturing method of a flexible substrate with excellent planarization property. The manufacturing method of a flexible substrate according to the present invention comprises a step (a) of providing a substrate having one surface on which a microstructure protrudes; and a step (b) of manufacturing a flexible substrate having a rear surface corresponding to the one surface of the substrate and covering the one surface of the substrate. The flexible substrate extracts light incident to the rear surface of the flexible substrate to the front surface of the flexible substrate.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a flexible substrate and a method of manufacturing an organic electroluminescent device using the same,

The present invention relates to a flexible substrate manufacturing method and a method of manufacturing an organic light emitting device using the same.

There are TFT-LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diode) that are currently being commercialized to develop into next generation displays (flexible display, transparent display). In order to go to the next-generation display, TFT-LCD has a problem that it needs a backlight unit to emit light. OLEDs do not require a backlight unit because of their self-emission, but they require shorter technological advancement and shortened device life. However, as a result of efforts to develop OLEDs by various organizations, large-area OLED TVs have been introduced and recently, curved TVs have been launched. In terms of price competition, it is ten times more expensive than TFT-LCD, but it boasts clear picture quality, wide viewing angle and fast response time. Generation OLED technology in the first-generation TFT-LCD technology. In the handset market, products based on OLEDs, which replace LCDs, are increasing in popularity, and are expected to increase their share in the TV market. OLEDs are also attracting a lot of attention outside the display field. Recently, the field of illumination applying OLED is emerging. It is more than twice as efficient as conventional light sources, is environmentally friendly, and consumes less power.

OLEDs are completed by stacking organic materials and electrodes. Because they are stacked with materials that have different refractive index values, significant losses occur when light exits to the outside. Since about 20% of the incident light is only emitted and the rest is lost, a lot of research is being carried out to extract 80% of the light. Optical extraction layer technology is being introduced as a technology to maximize light efficiency. This technology can be applied to both backlighting that emits light in the direction of the glass substrate and front emission that emits light in the opposite direction, and can improve the efficiency of light by 30% to 40%. The optical extraction layer technology is classified into an external light extraction technique for extracting the light confined in the glass substrate to the outside and an internal light extraction technology for extracting the trapped light of the organic material to the outside.

The external light extraction technique may be to form a microlens array, an external light scattering layer, a silica microsphere, etc. on the entire surface of the glass substrate (the interface between the air and the glass substrate) A microcavity, a photonic crystal, an internal light scattering layer, a nano-irregularity structure, or the like may be formed on the interface.

However, such an external light extraction technology and an internal light extraction technology have a problem in that the process is complicated and an expensive cost is required. In addition, the external light extraction technology and the internal light extraction technology have limitations in terms of light efficiency.

Korean Patent No. 10-1695525

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a method of manufacturing a flexible substrate excellent in planarization characteristics.

Another object of the present invention is to provide a method for producing a flexible substrate excellent in light extraction properties.

However, these problems are illustrative, and the technical idea of the present invention is not limited thereto.

According to an aspect of the present invention, there is provided a method of manufacturing a flexible substrate, comprising the steps of: a) providing a substrate on which a microstructure protrudes; And b) fabricating a flexible substrate having a back surface corresponding to one surface of the substrate and covering one surface of the substrate, wherein the flexible substrate is configured to direct light incident on the back surface of the flexible substrate to the front surface of the flexible substrate .

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, after the step b), c) separating the flexible substrate from the substrate.

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, the microstructure may be formed into a semi-spherical shape, a semi-elliptical shape, a bell shape, a disc shape, a cylindrical shape, a star column shape, a triangular column shape, a square column shape, And may be one or two or more three-dimensional structures selected from a tetragonal, pyramidal, or mixture thereof.

In the method for producing a flexible substrate according to an embodiment of the present invention, the step b) comprises: b1) subliming a dimer derived from a compound represented by the following formula (1); b2) separating the sublimed dimer into feruler precursor monomers; And b3) depositing the separated feruler precursor monomer to cover one side of the substrate:

[Chemical Formula 1]

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, the flexible substrate may be ferro-phosphorous.

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, the refractive index of the flexible substrate may be 1.5 to 1.7.

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, the flexible substrate may have a thickness of 1 to 100 탆, but the present invention is not necessarily limited thereto.

The present invention also includes a method of manufacturing an organic light emitting device using the above-described method for manufacturing a flexible substrate.

In the method for fabricating an organic light emitting diode according to an embodiment of the present invention, the step of laminating the first electrode, the organic light emitting layer, the second electrode, and the protective layer on the flexible substrate may be sequentially performed.

The flexible substrate manufacturing method according to the technical idea of the present invention can provide a flexible substrate for OLED excellent in light extraction efficiency.

Further, the flatness of the flexible substrate according to the present invention is excellent, and the uniformity of light emission is excellent. In addition, since it does not deviate largely from the conventional manufacturing process, the process and material costs are low, and mass production is easy.

On the other hand, even if the effects are not explicitly mentioned here, the effect described in the following specification, which is expected by the technical features of the present invention, and its potential effects are treated as described in the specification of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a process flow chart showing a method of manufacturing a flexible substrate according to an embodiment of the present invention. Fig.
2 is a schematic process diagram showing a method of manufacturing a flexible substrate according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail. The following embodiments and drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. In addition, unless otherwise defined in the technical and scientific terms used herein, unless otherwise defined, the meaning of what is commonly understood by one of ordinary skill in the art to which this invention belongs is as follows, A description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted.

In describing the present invention, the term "front surface of a flexible substrate" may mean a surface (boundary surface) where air and a flexible substrate come into contact with each other. For example, in the case of a tandem OLED device in which an organic layer, an electrode layer, and the like are sequentially stacked on the upper surface of the flexible substrate, the lower surface (bottom surface) of the flexible substrate may mean the front surface of the flexible substrate.

In describing the present invention, the term "rear surface of a flexible substrate" may mean a surface (boundary surface) where the organic material layer and the flexible substrate are in contact with each other. For example, in the case of a tandem OLED device in which an organic layer, an electrode layer, and the like are sequentially stacked on the upper surface of the flexible substrate, the upper surface of the flexible substrate may mean the rear surface of the flexible substrate.

Hereinafter, a method for manufacturing a flexible substrate according to the present invention will be described with reference to Figs. 1 and 2. Fig.

FIG. 1 is a process flow chart of a method of manufacturing a flexible substrate according to an embodiment of the present invention, and FIG. 2 is a process schematic diagram of a method of manufacturing a flexible substrate according to an embodiment of the present invention.

As shown in FIGS. 1 and 2, a method of manufacturing a flexible substrate according to an embodiment of the present invention may include a substrate manufacturing step (S100), a flexible substrate manufacturing step (S200), and a flexible substrate separating step (S300) have.

The substrate manufacturing step S100 may refer to a step of fabricating the substrate 101 such that the microstructures 110 protrude from the substrate 100.

Here, the substrate 100 may be a substrate. As a specific, non-limiting example, the substrate 100 may comprise a rigid substrate or a flexible substrate. Specifically, the rigid substrate may be a glass substrate including soda lime glass, or a ceramic substrate such as alumina. The flexible substrate may be a polymer substrate such as polyimide. However, the present invention is not limited thereto Of course not.

In the method of manufacturing a flexible substrate according to an exemplary embodiment of the present invention, the microstructure 110 may be formed into a semi-spherical shape, a semi-elliptical shape, a bell shape, a disc shape, a cylindrical shape, a star column shape, a triangular column shape, May be one or two or more three-dimensional structures selected from hexagonal, tetrahedral, pyramidal, or mixture thereof. The microstructure 110 having such a shape brings about the effect of introducing a nano embossing structure on the rear surface of the flexible substrate according to the present invention. Accordingly, the first electrode layer and the rear surface of the flexible substrate, And extracting light isolated from the front surface of the flexible substrate to the outside of the front surface of the flexible substrate.

In a specific and non-limiting example, the substrate manufacturing step S100 may include a1) forming a precursor layer on the substrate 100 so that the microstructures 110 protrude from the substrate 100 A2) forming a metal layer on the precursor layer, a3) forming an organic layer on the metal layer, a4) forming an organic mask from the organic layer by heat treatment of the organic layer, a5) And forming the light scattering layer formed by protruding the structure 110.

In the step a1), the precursor layer may be formed by vapor deposition. For example, the precursor layer may be formed by a sputtering method, a chemical vapor deposition (CVD) method, an E-beam evaporation method, a thermal evaporation method, and / or an atomic layer deposition ; ALD).

The precursor layer may also comprise at least one of the transparent materials. For example, the precursor layer may include an oxide (e.g., SiO ₂ , SnO ₂ , TiO ₂ , TiO ₂ -SiO ₂ , ZrO ₂ , Al ₂ O ₃ , HfO ₂ , In ₂ O ₃ , (For example, SiN _x ) and / or a resin (for example, a polyethylenic, a polyacrylic, a polyvinyl chloride (PVC) resin, a polyvinylpyrrolidone (PVP) resin, a polyimide, Epoxy-based resin).

Also, in step a2), the metal layer may include a material that is resistant to dry etching. For example, the metal layer may include a metal (e.g., platinum, gold, silver, copper, nickel, chromium, tungsten, zinc (PMMA), polydimethylglutarimide (PMGI), polymethylglutarimide (PMGI), tin oxide (PMGI), tin ), SU-8), a ceramic material (for example, Al ₂ O ₃ ), and / or an organic compound. If the thickness of the metal layer is thin, the metal layer can be deposited in island form without forming a layer.

Also, in step a3), the organic layer may be formed by vapor deposition and / or coating (e.g., spin coating). The organic layer may include a polymer material having a glass transition temperature (Tg) ranging from room temperature to 200 ° C. For example, the organic layer may comprise polymers and / or oligomers such as polystyrene, polyethylene, polyacrylate.

On the other hand, the organic layer may include a low melting point metal material having a melting point ranging from room temperature to 300 < 0 > C. For example, the organic layer may comprise lead, tin and / or an alloy thereof.

In addition, in step a4), the organic mask having the above-described microstructure may be formed by a non-wetting phenomenon from a flatly coated organic layer. The non-wetting phenomenon refers to the formation of a non-uniform pattern in which a material having wettability is partially depressed or protruded from a uniformly applied film state on the surface. A hole may be formed in the film due to the non-wetting phenomenon, so that the substrate under the film may be exposed.

Further, when the organic layer is heat-treated or the atmosphere is changed, a non-wetting phenomenon occurs between the metal layer and the organic layer. At this time, the organic mask can expose a part of the metal layer. The heat treatment process may be performed by using an oven and / or a hot plate, thermal annealing, and / or rapid thermal annealing (RTA).

On the other hand, in the step a4), the heat treatment process may be performed in a range below the softening point of the substrate. For example, the heat treatment may be carried out at a temperature of from room temperature to 250 ° C. The change of the atmosphere may be an organic solvent vapor or a vacuum atmosphere.

The organic mask may also have irregular patterns, sizes and / or arrangements. For example, the organic mask may include irregular patterns in the form of columnar, elliptical, capsule, or hole. The irregular pattern of the organic mask can also be controlled by controlling the heat treatment temperature and time, the atmosphere of the heat treatment process, the concentration of the organic solution, the thickness of the organic layer, the kind and / or the molecular weight of the polymer contained in the organic layer.

Also, in step a5), the etching may include a first etching and a second etching.

That is, in step a5), a metal mask may be formed by the first etching. At this time, the first etching may include wet etching. For example, the first etching may be performed by nitric acid, hydrofluoric acid, or buffered oxide etch (BOE).

The metal mask may be formed using the organic mask described above. In detail, the exposed metal layer can be etched by the organic mask having the microstructure described above. Thus, the metal mask may have the above-described microstructure. The metal mask may expose a portion of the precursor layer. The precursor layer may not be etched in the first etching process.

Next, by the second etching of the precursor layer, a light-scattering layer having a microstructure can be formed. At this time, the second etching may include dry etching. For example, the second etching may be performed by Reactive Ion Etching (RIE) and / or Inductively Coupled Plasma (ICP).

A metal mask may also be used in the second etch. Since the metal mask includes a material resistant to dry etching, the shape of the mask can be maintained in the second etching process. The etching rate can be controlled by adjusting the process time, the type and ratio of gas used for etching, and the like. By the second etching of the exposed precursor layer, a light-scattering layer having a microstructure can be formed.

After the step a5), the steps of removing the organic mask and the metal mask described above may be performed. In one example, the organic mask may be removed by an organic solvent (e.g., acetone, toluene, etc.). The metal mask may be removed by etchant.

Next, the flexible substrate manufacturing step (S200) will be described.

The step (S200) of manufacturing the flexible substrate may mean the step of manufacturing the flexible substrate 200 made of a polymer resin covering the substrate 101 described above.

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, the polymer resin is preferably a parylene.

Specifically, the flexible substrate manufacturing step (S200) comprises: b1) subliming a dimer derived from a compound represented by the following formula (1); b2) separating the sublimed dimer into feruler precursor monomers; And b3) depositing the separated ferulic precursor monomer to cover one side of the substrate 101:

[Chemical Formula 1]

In detail, in the step b1), the temperature at which the dimer is sublimated may be a temperature commonly used in the art. As a specific, non-limiting example, in step b), the dimer may be heated to about 100 캜 or higher.

In the method of manufacturing a flexible substrate according to an embodiment of the present invention, the dimer may be di-para-xylylene.

Thereafter, the step b2) may be performed to form a temperature of 600 to 800 in order to separate or pyrolysis the dimer into a ferrolein precursor in the form of a monomer.

The b3) step may then be performed to cool the separated feruler precursor monomer to deposit in the form of a polymeric resin. When the step b3) is carried out, the cooling temperature may be a temperature usually performed in this field. In a specific, non-limiting example, the cooling temperature may be from -50 to +50. For example, the temperature is preferably lowered to -20 or lower for fast film formation. In order to improve the film quality, the temperature is preferably higher than room temperature, but the present invention is not limited to the cooling temperature. On the other hand, the room temperature may mean 25 to 30.

When the step b3) is performed, the ferulic acid precursor monomer is prepared as a ferulic polymer, and the ferulic monolith covers one surface of the base material 101.

As described above, the ferrule film deposited by the ferrule precursor supplied on the substrate described above is formed by depositing ferrulein molecules on the microstructure 110 formed on the substrate 100 to change the shape of the microstructure as it is A ferromagnetic film can be formed while being imitated. That is, since the formation of the paraline film using the vapor deposition according to the present invention can prevent uneven film formation due to the bubbles generated during the application of the conventional solution, one surface of the ferrolein film can prevent the microstructure 110 And the like.

Finally, the flexible substrate separation step (S300) will be described.

The step of separating the flexible substrate (S300) may mean separating the flexible substrate 200 manufactured in the above-described flexible substrate manufacturing step (S200) from the substrate (101).

In detail, the separation of the flexible substrate may be carried out by a method commonly used in this field. For example, a specific and non-limiting example is to attach an adhesive tape to the back surface of the flexible substrate to separate the flexible substrate from the substrate have.

Taken together, the method of manufacturing a flexible substrate according to an embodiment of the present invention includes the steps of manufacturing the substrate (S100) and the step of manufacturing a flexible substrate (S200), so that the refractive index of the flexible substrate may be 1.5 to 1.7. Since the flexible substrate having such a refractive index has a higher refractive index than that of the conventional glass substrate, the light extraction effect is higher. Further, the flexible substrate can further improve the light extraction effect because it further includes the microstructure described above.

The thickness of the flexible substrate may be sufficient to serve as a support. As a specific example, the flexible substrate may have a thickness of 1 to 100 μm, but the present invention is not limited to the thickness of the flexible substrate.

The present invention also includes a method of manufacturing an organic light emitting device using the above-described method for manufacturing a flexible substrate.

The method of fabricating an organic light emitting diode according to an embodiment of the present invention may include sequentially stacking a first electrode, an organic light emitting layer, a second electrode, and a protective layer on the back surface of the flexible substrate. This is effective for extracting the light trapped in the organic light emitting device to the outside through the scattering effect. The laminating step may be a method commonly used in this field.

Here, the first electrode may be an anode electrode. The first electrode may receive a voltage from the outside and supply holes to the organic light emitting layer. The first electrode may transmit light. The first electrode may include a transparent conductive oxide (TCO). For example, the first electrode may be formed of at least one selected from the group consisting of zinc oxide (ZnO), tin oxide (SnO ₂ ), indium tin oxide (ITO), gallium-doped zinc oxide (ZnO) Zinc oxide (ZnO: B), and / or aluminum-doped zinc oxide (AZO). The refractive index of the first electrode may be greater than the refractive index of the flexible substrate. The first electrode may have a refractive index of approximately 1.8 to 2.0. For example, the first electrode comprising indium tin oxide may have a refractive index of 1.9.

The organic light emitting layer may generate light through recombination of holes supplied from the first electrode and electrons supplied from the second electrode. The organic light emitting layer may have a single-layer structure or a multi-layer structure including an auxiliary layer. And may further include an auxiliary layer for increasing the luminous efficiency of the organic luminescent layer. The auxiliary layer may include at least one of a hole injecting layer, a hole transfer layer, an electron transfer layer, and / or an electron injecting layer.

The organic light emitting layer may be an organic light emitting material commonly used in this field. As a specific and non-limiting example, the organic light emitting layer may include an aryl amine, a carbazole series, and a spiro series. In another specific, non-limiting example, the organic light-emitting layer comprises 4,4-N, N-dicarbazole-biphenyl (CBP), N, N-dicarbazolyl- (N, N-dicarbazoyl-3,5-benzene, mCP), poly (vinylcarbazole) PVK, polyfluorene, 4,4'- 6-biphenylcarbazolyl)] - 1-1, 1'-biphenyl 4,4'-bis [9- (3,6-biphenylcarbazolyl)] - , 10-bis [(2 ', 7'-t-butyl) -9', 9 "-spirobifluorenyl anthracene, tetrafluorene and the like.

Further, the organic light emitting layer may further include a dopant conventionally used in this field. The dopant may be selected from the group consisting of iridium (III) bis (4,6- di-fluorophenyl) -pyridinato-N, C ') picolinate, tris (phenylmethyl-benzimidazolyl) iridium (III) iridium III), Ir (dfppz) ₃ (tris (4,6-difluorophenylpyrazolyl) iridium (III)), Ir (dbfmi) (mertris (Ndibenzofuranyl-N'-methylimidazole) , Ir (dbi) ₃ [fac-tris [1- (2,4-diisopropyldibenzo [b, d] furan-3-yl) -2-phenyl-1H- imidazole] _{(mpim) 3 [fac-tris} (mesityl-2-phenyl-1H-imidazole) iridium (III)], Ir (dmp) 3 (iridium (III) tris [3- (2,6-dimethylphenyl) -7-methylimidazo [1,2-f] phenanthridine]), and the like.

Further, the organic light emitting layer may have a refractive index of about 1.6 to 1.9. For example, the organic light emitting layer may have a refractive index of 1.75.

The second electrode may be a cathode. The second electrode may receive electrons from the outside and supply electrons to the organic light emitting layer. The second electrode may comprise a conductive material. The second electrode may include a material having a lower work function than the first electrode. For example, the second electrode may include at least one of aluminum (Al), silver (Ag), magnesium (Mg), molybdenum (Mo), and / or their alloys. The second electrode may reflect light generated in the organic light emitting layer toward the first electrode.

The protective layer may be a sealing protective layer and / or a packaged flexible layer. The protective layer may be made of an air impermeable material. The protective layer may comprise a transparent material. The protective layer may protect the organic light emitting layer.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (8)

comprising the steps of: a) providing a substrate having a microstructure projected on one surface thereof; And
b) fabricating a flexible substrate having a back surface corresponding to one side of the substrate and covering one side of the substrate,
Wherein the flexible substrate extracts the light incident on the rear surface of the flexible substrate to the front surface of the flexible substrate.
The method according to claim 1,
After the step b)
c) separating the flexible substrate from the substrate.
The method according to claim 1,
The microstructure
One or more three-dimensional structures selected from the group consisting of hemispherical, semi-elliptical, bell, disc, cylinder, star, triangular, square, hexahedral, tetrahedral, pyramidal, In flexible substrate.
The method according to claim 1,
The step b)
b1) subliming a dimer derived from a compound represented by the following formula (1);
b2) separating the sublimed dimer into feruler precursor monomers; And
b3) depositing the separated ferulic precursor monomer to cover one side of the substrate;
[Chemical Formula 1]

The method of claim 1, wherein
Wherein the flexible substrate is a ferrolein.
The method of claim 1, wherein
Wherein the refractive index of the flexible substrate is 1.5 to 1.7.
The method of claim 1, wherein
Wherein the flexible substrate has a thickness of 1 to 100 mu m.
A method for manufacturing an organic light emitting device, comprising: sequentially laminating a first electrode, an organic light emitting layer, a second electrode, and a protective layer on a flexible substrate according to claim 1.

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