KR100911183B1 - Method for manufacturing flexible substrate on which patterned CNT thin film is formed - Google Patents

Abstract

The present invention relates to a method of manufacturing a flexible substrate on which a patterned CNT thin film is formed, and more particularly, S1) forming a photoresist pattern on a porous nano template filter; S2) forming a silicon dioxide thin film pattern by depositing silicon dioxide on a region where the photoresist pattern does not exist on the porous nano template filter; S3) removing the photoresist pattern to obtain a filter mold having a silicon dioxide thin film pattern formed on a porous nano template filter; S4) mounting the filter mold on a vacuum filtration apparatus, injecting a CNT dispersion solution thereon, and vacuum filtration to form a CNT thin film pattern between the silicon dioxide thin film patterns; S5) applying a composition for forming a flexible substrate over the entire filter mold and curing it to form a flexible substrate; And S6) separating the filter mold from the flexible substrate, and a method of manufacturing the flexible substrate on which the patterned CNT thin film is formed.

The prepared CNT thin film is used as a transparent electrode and can be preferably applied to various flexible displays.

Description

A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed {FABRICATION OF FLEXIBLE SUBSTRATE EMPLOYED A THIN FILM OF PATTERNED CARBON NANO TUBE}

The present invention relates to a method for manufacturing a flexible substrate having a patterned CNT thin film which is used as a transparent electrode and is preferably applicable to various flexible displays.

The development of flexible display, transparent electrode, and touch sensor for touch panel technology has enormous market potential and huge market potential worldwide. The flexible display is thinner and lighter than the existing glass-based display, which is strong in impact and easy to carry, and is relatively free from space and shape constraints to secure various applications. have. Accordingly, research on the technology of the transparent electrode as well as the material of the substrate of the flexible display is being actively conducted.

Indium Tin Oxide (ITO) is most widely used as a transparent electrode of the flexible display. In order to make the ITO transparent electrode, expensive equipment such as vacuum deposition, etching, and corrosive chemicals have to be used, which has low economical efficiency and environmental pollution.

In the case of the ITO transparent electrode, when the circuit is formed on the flexible substrate and the substrate is bent, the ITO transparent electrode has excellent strength for small bending, but has a disadvantage of breaking for excessive bending. In addition, in the case of a touch sensor for a touch panel, in particular, in the case of a touch touch sensor, a decrease in detection accuracy due to electrode wear at a contact portion due to a plurality of contacts is a disadvantage to be solved.

In order to overcome the high price of ITO, development of alternative materials and process methods that are above or equal to those of ITO have enormous marketability.

Carbon nano tube (CNT) has been proposed as a material to replace ITO, transparent electrode to replace ITO by using CNT, transistor for transparent and flexible display, high sensitivity for touch panel. Development of touch sensor and high sensitivity gas sensor technology is underway.

Methods for forming CNT transparent electrodes include drop-casting, solution casting, dip-coating, Langmuir-Blodgett deposition, and electrophoresis. (electrophoresis), direct on-chip growth, spin-coating, spray method and the like are used. These methods do not facilitate the uniformity of the CNT thin film and the uniformity of the networking of the CNT forming the thin film. In addition, the shape of the CNT thin film is not uniform, and to solve this problem, additional chemical treatment must be applied to the surface.

In the conventional methods described above, such as chemical vapor deposition, it is difficult to control the thickness and mass of the CNT thin film, which makes it difficult to produce a uniform CNT thin film. In addition, in most cases, a binder is used to manufacture the CNT thin film, and the binder lowers the inherent properties of the CNT, thereby limiting its performance as a device, and making it difficult to apply due to complicated manufacturing process and increased production cost.

In addition, a second process must be performed in order to form the CNT thin film thus formed in a desired two-dimensional structure, that is, an electrode pattern. As a result, there are more steps in the process that require chemical pretreatment on the substrate in advance, which can lead to a change in the concentration of CNTs due to the loss of CNTs, thereby lowering the reliability of device characteristics.

Therefore, the present invention aims at minimizing the loss of CNTs and at the same time controlling the density of thin film applications using CNTs, and improving the uniformity of the thin films.

In order to solve the above problem, an object of the present invention is to provide a flexible display having a CNT thin film patterned as a transparent electrode, and to provide a flexible substrate having a patterned CNT thin film which can simplify and repeat the manufacturing process. It is to provide a manufacturing method.

In order to achieve the above object, the present invention

S1) forming a photoresist pattern on the porous nano template filter;

S2) forming a silicon dioxide thin film pattern by depositing silicon dioxide on a region where the photoresist pattern does not exist on the porous nano template filter;

S3) removing the photoresist pattern to obtain a filter mold having a silicon dioxide thin film pattern formed on a porous nano template filter;

S4) mounting the filter mold on a vacuum filtration apparatus, injecting a CNT dispersion solution thereon, and vacuum filtration to form a CNT thin film pattern between the silicon dioxide thin film patterns;

S5) applying a composition for forming a flexible substrate over the entire filter mold and curing it to form a flexible substrate; And

S6) separating the filter mold and the flexible substrate

It provides a method of manufacturing a flexible substrate formed with a patterned CNT thin film comprising a.

According to the method of the present invention, a flexible substrate on which a CNT thin film patterned is formed through a simple method is produced in-situ , minimizes the loss of CNT in the manufacturing process, and the film density of the prepared CNT thin film Since it is uniform and excellent, there is an effect of improving the reliability of the device.

Hereinafter, the present invention will be described in more detail.

The inventors of the present invention used a flexible substrate as a substrate, and in order to manufacture a flexible device in which a CNT thin film was formed as a transparent electrode, the concentration of the CNTs could be easily adjusted to control the uniformity of the thin film, so that the fabrication of the device was possible. The present invention has been completed in consideration of several solutions:

(1) applying existing optical lithography methods to the surface of the filter to allow repeated filtration on large area porous nano template filters;

(2) controlling the uniformity of the CNT thin film by adjusting the speed during filtration;

(3) transferring the CNT thin film pattern prepared by selective vacuum filtration to the flexible substrate;

(4) Application of various materials in thin film form.

1 is a flowchart showing a method according to the present invention, Figures 2 to 14 are schematic diagrams for explaining this.

Referring to FIG. 1, the flexible substrate on which the patterned CNT thin film is formed

S1) forming a photoresist pattern on the porous nano template filter;

S2) forming a silicon dioxide thin film pattern by depositing silicon dioxide on a region where the photoresist pattern does not exist on the porous nano template filter;

S3) removing the photoresist pattern to obtain a filter mold having a silicon dioxide thin film pattern formed on a porous nano template filter;

S4) mounting the filter mold on a vacuum filtration apparatus, injecting a CNT dispersion solution thereon, and vacuum filtration to form a CNT thin film pattern between the silicon dioxide thin film patterns;

S5) applying a composition for forming a flexible substrate over the entire filter mold and curing it to form a flexible substrate; And

S6) is manufactured through a step of separating the filter mold and the flexible substrate.

Each step will be described in more detail below.

S1) photoresist pattern forming step

First, in step S1) to form a photoresist pattern on the porous nano template filter.

Referring to FIG. 2, a photoresist 2 is applied onto the porous nano template filter 1.

The porous nano template filter (1) is a filter having a large number of pores of a nano size, it is preferable to use an AAO (anodic aluminum oxide) template, or a polycarbonate filter, AAO in terms of providing a uniform diameter and arrangement of pores The template can be used more preferably.

In this case, the porous nano template filter 1 uses a pore having a diameter of 20 to 100 nm, a pore depth of 60 to 100 μm, and a pore density of 100 pieces / μm ² to 500 pieces / μm ² . If the diameter of the pore is less than the above range, even if the CNT traps the pores of the filter to form the CNT network, the uniformity of the network is not constant. On the contrary, if the diameter exceeds the above range, the CNT formed is transmitted as it is. do.

In addition, if the depth of the pore is less than the range of the nano-template filter is thinner, the problem that the mold is broken when the mold and the substrate is separated in the subsequent process, if the above range exceeds the probability that the CNT trapped in the pores This lowers the problem of not evenly forming the CNT network.

When the density of the pores is less than the range, there is a low probability that CNTs are trapped in the pores, thereby preventing the formation of a uniform CNT thin film. On the contrary, when the pore density exceeds the range, low density CNT thin films are difficult to obtain.

The photoresist 2 is classified into a positive photoresist (positive PR) in which a largely exposed area reacts with a developer and is dissolved, and a negative photoresist (negative PR) in which the exposed area does not react with a developer. Negative photoresist is preferably used.

The photoresist pattern is formed by using an optical lithography method, for example, is performed through a coating-> exposure-> development process.

At this time, the application of the photoresist 2 can be a conventional wet coating method, typically a dip coating, doctor blade method, spin coating, spray coating, slit coating, casting method, or lamination method Etc. The photoresist 2 has a thickness of 1 μm or less.

Referring to FIG. 3, the mask 3 is positioned on the coated photoresist 2 and then exposed.

As the mask 3, a Cr mask, an emulsion mask, a film mask, or the like may be used, and a suitable one may be selected according to the minimum line width and lifetime to be processed.

This exposure process is performed using KrF (248 nm), ArF (193 nm), VUV (157 nm), EUV (13 nm), E-beam, X-ray or ion beam as the exposure source, 0.1 to 50 mJ / cm It is preferably carried out with an exposure energy of ^two .

At this time, the mask is appropriately selected so that the pattern of the photoresist 2 is 15 µm or less.

Referring to FIG. 4, the photoresist 2 film is treated with the post-exposure developer to remove other photoresist except the exposed portion to form a photoresist pattern 4.

The developing process refers to a process of melting a photoresist 4 of a portion, which is relatively weakly bonded, through a exposure process with a developing solution. Through this process, a photoresist pattern 4 is formed on the porous nano template filter 1. do.

At this time, the developer used may be carried out using an alkaline developer that is commonly used, it is preferable that the alkaline developer is an aqueous solution of tetramethylammonium hydroxide (TMAH) of 0.01 to 5% by weight.

S2) step of forming silicon dioxide pattern

Next, in step S2), silicon dioxide is deposited on the entire surface of the porous nano template filter 1 to form the silicon dioxide thin film pattern 5 in a region where the photoresist pattern 4 is not formed.

Referring to FIG. 5, the silicon dioxide thin film pattern 5 is deposited on the porous nano template filter 1 over the entire surface through a conventional deposition method.

The silicon dioxide thin film pattern 5 has the following advantages.

First, due to the high strength of the thin film of silicon dioxide, it exhibits better physical properties than the film formed by using a photoresist material, and cracks are generated by heat during the curing process performed to form a flexible substrate (eg, PDMS) in a subsequent process. Block the problem. In addition, as the silicon dioxide thin film is hydrophilic and the flexible substrate is hydrophobic, it is easy to separate the filter mold from the flexible substrate in a subsequent separation process due to the interfacial properties therebetween. have. In addition, the present inventors experimented by depositing a metal other than silicon dioxide, but it was confirmed that silicon dioxide exhibited the most excellent properties in terms of adhesion with the porous nano-template filter (1).

The deposition is not particularly limited in the present invention, and is generally performed by sputtering or ion beam deposition.

The photoresist pattern 4 is then removed by a subsequent strip process. In FIG. 5, for the sake of understanding, the photoresist pattern 4 and the silicon dioxide thin film pattern 5 are formed on the same layer, but in some cases, the silicon dioxide thin film is formed on the photoresist pattern 4. This can be appropriately controlled according to the deposition technique, in which case the silicon dioxide thin film formed on the photoresist pattern 4 can be removed in a subsequent development process. Details are described in more detail in the following text.

The height (thickness) of the silicon dioxide thin film pattern 5 is formed in the same manner as that of the photoresist pattern 4, and is 1 μm or less.

S3) filter mold forming step

Next, in step S3), the photoresist pattern 4 is removed to obtain a filter mold in which the silicon dioxide thin film pattern 5 is formed on the porous nano template filter 1.

Referring to FIG. 5, the photoresist pattern 4 and the silicon dioxide thin film pattern 5 are selectively positioned on the porous nano template filter 1, and the photoresist pattern 4 is removed by treating the photoresist pattern 4 with a stripping liquid. .

As a result, as shown in FIG. 6, the silicon dioxide thin film pattern 5 is formed on the porous nano template filter 1, which is used as a filter mold in a subsequent process and has the advantage of being repeatedly used.

The strip liquid may be an organic solvent or a dedicated remover capable of dissolving the photoresist, and may be a material commonly used in the art. Typically, isopropyl alcohol; Acetone; Organic amine compounds of monoethanol amine (MEA), 2- (2-aminoethoxy) -1-ethanol (AEE); Polar solvents of dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), carbitol acetate, propylene glycol monomethyl ether acetate (PGMEA); N-methylacetamide, dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-N'-ethylpropionamide, diethylacetamide (DEAc), dipropylacetamide (DPAc), N, N Single or mixed solvents selected from the group consisting of amide solvents of '-dimethylpropionamide and N, N'-dimethylbutylamide are used.

S4) CNT thin film pattern forming step

Next, in step S4), the filter mold is mounted on the vacuum filtration apparatus, the CNT dispersion solution is injected thereon, and then vacuum filtered to arrange the CNTs between the silicon dioxide thin film patterns 5.

Referring to FIG. 7, the CNT dispersion solution is brought into contact with the filter 5 on which the silicon dioxide thin film pattern 5 is formed.

Specifically, the CNT dispersion solution in which the CNT 7 powder is uniformly dispersed in the filter 1 on which the silicon dioxide thin film pattern 5 is formed is subjected to selective vacuum filtration.

The CNT dispersion solution is a mixture of CNT (7) powder, a surfactant and a solvent.

The surfactant is used to increase the dispersion stability of the dispersion solution, serves to lower the free energy of the CNT powder interface as well as to convert the surface charge. These surfactants are not particularly limited in the present invention, and may be one selected from the group consisting of nonionic surfactants, cationic surfactants, anionic surfactants, and mixtures thereof. Typically, the surfactant is sodium dodecyl sulfate (SDS), sodium octylbenzene sulfonate (NaOBS), sodium dodecyl benzene sulfate (SDBS), triton X-100 (TRITON X-100), sodium dodecyl sulfonate (SDSA), sodium butylbenzoate (NaBBS), dodecyltrimethylammonium bromide (DTAB), dextrin, polystyrene-polyethylene oxide (PS-PEO), and mixtures thereof, 9.5 to 10.5 mg per 1 mg of CNT powder is used to ensure sufficient dispersion stability.

In addition, it is possible to easily control the film density of the CNT thin film by adjusting the content of the CNT powder.

The solvent may be used as long as it can uniformly disperse the CNT powder. Typically water; Alcohols of methanol, ethanol, propanol or isopropanol; One kind selected from the group consisting of an organic solvent of methyl methacrylate, ethylene glycol, or dimethylformamide, and a mixed solvent thereof is possible.

The CNT dispersion solution is prepared by dispersing a surfactant in a solvent to form micelles, and adding CNT powder thereto to stirring. At this time, in order to more uniformly disperse the CNT powder and to improve the physical properties of the final CNT thin film, ultrasonic waves are applied before and after the agitation or simultaneously with the agitation.

Specifically, an ultrasonic wave having an output of 20 to 60 W and a frequency of 10 to 30 kHz is applied for 5 to 7 hours to separate a large bundle, and then an ultrasonic wave having a lower power and a higher frequency, that is, an output of 10 to 50 W and a frequency of 40 to 60 Ultrasound at kHz is applied for 6-7 hours to separate the fine bundles so that each single CNT in the CNT dispersion is easily separated. As a result, the CNT dispersion solution is removed in such a way that the large bundles and fine bundles of the CNTs are removed so that a single single CNT is uniformly floating in the dispersion solution.

In the present invention, a single CNT 7 is shown in FIG. 9 through selective vacuum filtration (SVF) (see FIG. 8) using the porous nano-template filter 1 on which the silicon dioxide thin film pattern 5 is formed. As such, it is positioned between the silicon dioxide thin film pattern 5.

Such selective vacuum filtration is mentioned in various documents [L. Hu et al , Nano Lett . 4, 2513 (2004); Z. Wu et al , Science 305, 1273 (2004), C.-S. Woo et al , Microelectron. Eng . 84, 1610 (2007).

The vacuum filtration device used at this time is not limited in the present invention, a general device as known in the art can be used. However, by controlling the suction rate to 0.3 ml / min to 1 ml / min during vacuum filtration, CNT is selectively positioned between the silicon dioxide thin film pattern.

If the suction rate is more than 1 ml / min, the CNT suspended in the CNT dispersion solution does not have a sufficient time to be uniformly placed into the pores and is filtered, resulting in a failure to form a uniform CNT thin film. The case occurs. Therefore, it is necessary to adjust the suction speed, which is to produce a uniform thin film through uniform CNT networking.

Subsequently, filtering is performed using deionized water to sufficiently remove the solvent present in the CNT bundle formed in the porous nano template filter. It is then dried at 80 ° C. for 10 to 30 minutes.

S5) flexible substrate forming step

Next, in step S5) after applying the composition for forming a flexible substrate over the entire filter mold on which the CNT thin film pattern is formed, it is cured to obtain a flexible substrate.

Referring to FIG. 10, a silicon dioxide thin film pattern 5 and a CNT thin film pattern 7 are selectively formed on the porous nano template filter 1 through the previous steps, and the silicon oxide thin film pattern 5 and The composition 8 for forming a flexible substrate is coated on the entire surface of the porous nano template filter 1 to include the CNT thin film pattern 7.

The composition 8 for forming a flexible substrate may be any polymer as long as it is capable of forming a known flexible substrate. Representatively, the polymer may be one selected from the group consisting of silicone-based polymers, acrylic polymers, and copolymers thereof. Specifically, the silicone-based polymer may be one selected from the group consisting of polysilane, polysiloxane, polysilazane, polycarbosilane, and combinations thereof, preferably poly Dimethylsiloxane (poly (dimethylsiloxane), PDMS) is possible. The acrylic polymer may be polyacrylate, polymethacrylate, polymethylacrylate, polymethylmethacrylate, polyethylacrylate, polyethylacrylate, or polyethylmethacrylate. (polyethylmetacrylate) and one selected from the group consisting of copolymers thereof are possible.

Referring to FIG. 11, after coating the composition 8 for forming a flexible substrate to a thickness of 1 to 2 mm, a curing process is performed at 70 to 80 ° C. for 60 to 180 minutes to form the flexible substrate 9.

The coating is then carried out with conventional wet coating. Typically, the coating composition obtained by dissolving the polymer in a solvent is coated on a substrate by conventional coating methods such as spin coating, dip coating, spray coating, gravure coating, and printing.

The composition 8 for forming the flexible substrate preferably has a suitable viscosity so that the polymer as described above can be coated, and at this time, a curing agent and / or a curing accelerator is used to promote curing as necessary.

In addition, if the curing temperature is less than the above range, there is a problem that the surface of the substrate is hardly cured. On the contrary, if the curing temperature is exceeded above, the surface of the substrate is completely cured, thereby making it difficult to transfer the CNT thin film pattern to the substrate. And if hardening time is less than 60 minutes, there exists a problem that hardening of the board | substrate surface is insignificant. On the contrary, when the curing time exceeds 180 minutes, the surface of the substrate is hardly cured, and it is difficult to transfer the CNT thin film pattern to the substrate. As a result, a CNT thin film pattern is present on and in the surface of the flexible substrate during curing.

S6) Separation step of filter mold and substrate

Next, in step S6), the filter mold and the substrate are separated to form a flexible substrate on which a patterned CNT thin film is formed.

12 and 13, the flexible substrate 9 and the filter mold are separated, and as a result, as shown in FIG. 14, the CNT thin film pattern 7 is formed on the flexible substrate 9.

The CNT thin film pattern 7 has a single-wall structure, where the single-wall structure refers to a long CNT strand consisting of one cylindrical wall.

Through the above-described steps, in the present invention, the patterned CNT thin film pattern could be formed on the flexible substrate, and the CNT thin film pattern may be used as a transparent electrode of the flexible device.

The process according to the invention has the advantage of being very simple and inexpensive compared to the production of conventional ITO transparent electrodes. In addition, there is no loss of CNTs, and the uniformity of the CNT thin film is excellent compared to the method of forming a CNT transparent electrode by a conventional casting method. In particular, the filter mold used in the present invention is excellent in physical properties such as durability as the pattern is formed of a silicon dioxide thin film can be used as a filter mold for a long time, repeatedly.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

(Example 1, Example 2)

(1) filter Of mold  Produce

After the (negative) photoresist was applied onto the porous nano template filter (pore size: 20 nm), a photoresist pattern was formed by exposure and development. Subsequently, the porous nano filter was mounted on a sputter, a vacuum deposition apparatus, and deposited under argon plasma using a SiO ₂ target as a source to form a silicon dioxide thin film (thickness: 5 μm).

Subsequently, the photoresist pattern was removed by treatment with a stripping solution (acetone) to obtain a porous nano template filter (filter mold) in which a silicon dioxide thin film pattern was formed.

(2) Preparation of CNT Dispersion Solution

Single-month CNTs (SWCNTs) synthesized by arc discharge in 100 mL of ionized water 6 mg / L, 32 mg / L, and sodium dodecylbenzene sulfanate surfactant 0.06 mg / L, 0.32 mg / L After adding 1% of the amount of CNTs, 100 mL (Example 1, 6 mg / L) and (Example 2, 32 mg / L) of CNT dispersions were uniformly mixed, respectively, by applying ultrasonic waves.

(3) manufacturing a substrate on which a CNT thin film is formed

The filter mold obtained in the above (1) was attached to the vacuum filtration apparatus shown in Fig. 15, and the CNT dispersion solution was poured thereon. Subsequently, the pressure was reduced under vacuum at a suction rate of 1 mL / min or less, followed by filtering with ionized water to remove the solvent in the dispersion solution. Thereafter, drying was performed in an oven at 80 ° C.

PDMS (polydimethylsilane) was then applied to the device and cured at 80 ° C. for about 1 hour.

Next, the cured PDMS membrane was separated from the filter mold to obtain a flexible PDMS membrane in which a CNT thin film was formed.

Experimental Example 2

In the same manner as in Example 1, a photoresist pattern was formed in various device patterns to obtain a flexible PDMS film having a CNT thin film.

FIG. 16A is a photograph showing a PDMS substrate on which various types of CNT thin film patterns are formed. Referring to FIG. 16A, it can be seen that the CNT thin film pattern forms a desired pattern according to the method of the present invention.

FIG. 16B is a scanning electron micrograph showing a cross section of a PDMS substrate on which a CNT thin film pattern is formed. As shown in (b) above, it can be seen that the CNTs are partially embedded in the PDMS substrate and are derived and formed on some surfaces.

Experimental Example 3

The CNT thin film and the Cr / Au (5 nm / 45 nm) electrode were electrically contacted using the stencil mask of the flexible PDMS substrate formed in Examples 1 and 2, and then IV characteristics were measured. It is shown in FIG.

Figure 17 (a) is an I-V graph according to the length of the CNT thin film pattern at 6 mg / L concentration, (b) is an I-V graph according to the length of the CNT thin film pattern at 32 mg / L concentration.

Referring to FIG. 17, the amount of current varies according to the concentration of CNT as a whole, and it can be seen that the conductivity of the thin film remains different according to the concentration of CNT. In addition, as shown in each graph, it can be seen that there is a change in conductivity depending on the length of the CNT thin film pattern.

These results show that the CNT thin film manufactured by the present invention can be applied as a transparent electrode or a transistor device that can be used in a transparent display.

1 is a flowchart illustrating a method of manufacturing a flexible substrate on which a patterned CNT thin film is formed according to the present invention.

2 to 14 are schematic views for explaining a method of manufacturing a flexible substrate on which the patterned CNT thin film according to the present invention is formed.

It is a schematic diagram of the vacuum filtration apparatus used in the Example.

FIG. 16A illustrates a PDMS substrate on which CNT thin film patterns of various shapes are formed, and FIG. 16B illustrates a scanning electron micrograph showing a cross section of a PDMS substrate on which a CNT thin film pattern is formed.

Figure 17 (a) is an I-V graph according to the length of the CNT thin film pattern at a concentration of 6 mg / l, (b) is an I-V graph according to the length of the CNT thin film pattern at a concentration of 32 mg / l.

Claims (14)

S1) forming a photoresist pattern on the porous nano template filter; S2) forming a silicon dioxide thin film pattern by depositing silicon dioxide on a region where the photoresist pattern does not exist on the porous nano template filter; S3) removing the photoresist pattern to obtain a filter mold having a silicon dioxide thin film pattern formed on a porous nano template filter; S4) mounting the filter mold on a vacuum filtration apparatus, injecting a CNT dispersion solution thereon, and vacuum filtration to form a CNT thin film pattern between the silicon dioxide thin film patterns; S5) applying a composition for forming a flexible substrate over the entire filter mold and curing it to form a flexible substrate; And S6) separating the filter mold and the flexible substrate Method of manufacturing a flexible substrate on which the patterned CNT thin film comprising a. The method of claim 1, The porous nano template filter (1) is to use a pore diameter of 20 to 100 nm, a pore depth of 60 to 100 ㎛, the pore density of 100 / ㎛ ² to 500 / ㎛ ² A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, The photoresist pattern is to be formed using an optical lithography method A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, The photoresist pattern is to be formed using a negative photoresist A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, The silicon dioxide thin film is formed by sputtering or ion beam deposition A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, Wherein the CNT dispersion is to include a CNT powder, a surfactant and a solvent A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 6, The surfactant is sodium dodecyl sulfate (SDS), sodium octylbenzene sulfonate (NaOBS), sodium dodecyl benzene sulfate (SDBS), triton X-100 (TRITON X-100), sodium dodecyl sulfonate (SDSA) , Sodium butylbenzoate (NaBBS), dodecyltrimethylammonium bromide (DTAB), dextrin, dextrin, polystyrene-polyethylene oxide (PS-PEO), and a mixture thereof. A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 6, The solvent is water; Alcohols of methanol, ethanol, propanol or isopropanol; To use one selected from the group consisting of methyl methacrylate, ethylene glycol, or an organic solvent of dimethylformamide, and a mixed solvent thereof A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, Wherein the CNT dispersion solution is prepared by stirring before or after, or at the same time to apply the ultrasonic wave A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 9, The ultrasonic application is to perform the ultrasonic wave of the output 20 to 60W, frequency 10 to 30 kHz for 5 to 7 hours A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, The vacuum filtration is carried out at a suction rate of 0.3 ml / min to 1 ml / min A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, The composition for forming the flexible substrate may be polysilane, polysiloxane, polysiloxane, polysilazane, polycarbosilane, polyacrylate, polymethacrylate, polymethylacrylate It includes one type of polymer selected from the group consisting of polymethylacrylate, polymethylmethacrylate, polyethylacrylate, polyethylmethacrylate and copolymers thereof A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. The method of claim 1, The curing is carried out at 70 to 80 ℃ for 60 to 180 minutes A method of manufacturing a flexible substrate on which a patterned CNT thin film is formed. A flexible display comprising a flexible substrate made according to any one of claims 1 to 13.

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