Refining method for microstructure

Provided is a manufacturing method for a substrate having a microstructure. The manufacturing method for a substrate having a microstructure comprises the steps of: forming a microstructure on the upper surface of an auxiliary substrate; coating a base solution on the microstructure; forming a base substrate covering the microstructure by heat treating the base solution; and removing the auxiliary substrate from the base substrate.

TECHNICAL FIELD

The present disclosure relates to a substrate including nano/micro structures, a method for manufacturing the same, a method for refining a nano/micro structure, a method for manufacturing a nano/micro structure network, and a manufacturing apparatus therefor.

BACKGROUND ART

A micro/nano structure having a size of several nm to several hundred nm is manipulated and controlled in nano scale. Thus, new physical/chemical properties different from those of existing materials can be expected. Therefore, the micro/nano structure has been attracting a lot of attention as a next-generation material which can overcome the limitations of the existing materials.

Such a micro/nano structure is one type of core new material that provides a foundation for use in technologies of various fields such as organic light emitting elements, liquid crystal displays, touch panels, or solar cells. Generally, a micro/nano structure is manufactured to various sizes by a chemical method, and micro/nano structures are coated on a substrate by bar coating, spray coating, spin coating, dip coating, brush coating, gravure coating, or the like. Various techniques for manufacturing a substrate including micro/nano structures with excellent properties have been developed.

For example, Korean Patent Laid-open Publication No. 10-2013-0037483 (Application No. 10-2011-0101907) discloses a method for manufacturing a conductive film by forming a one-dimensional conductive nanomaterial including any one selected from a carbon nanotube, a metal nano wire, and a metal nano rod and forming a two-dimensional nanomaterial including any one selected from graphene, boronitride, and tungsten oxide on an upper surface of the one-dimensional conductive nanomaterial.

Meanwhile, if micro/nano structures having different sizes are used in a transparent electrode or the like, conductivity and transmittance are decreased and haze is increased. Accordingly, various techniques for manufacturing uniform-sized micro nano structures have been developed.

For example, Korean Patent Laid-open Publication No. 10-2013-0072956 (Application No. 10-2011-0140589) discloses a method for forming a metal nano wire by allowing a reaction solution to pass through a filter having a pore size of 5 μm to 10 μm.

Further, various techniques for reducing a resistance of a micro/nano structure network have been developed. Particularly, as for a silver nano wire, there has been suggested a method of performing a heat treatment, an acid steam treatment, and a graphene oxide treatment after coating. However, such methods have a problem of damaging micro/nano structures or a substrate on which the micro/nano structure are disposed.

DETAILED DESCRIPTION OF THE INVENTION

Technical Problem

An object to be achieved by the present disclosure is to provide a substrate including nano/micro structures with a minimized surface roughness and a method for manufacturing the same.

Another object to be achieved by the present disclosure is to provide a substrate including nano/micro structures with high reliability and a method for manufacturing the same.

Yet another object to be achieved by the present disclosure is to provide a substrate including flexible nano/micro structures and a method for manufacturing the same.

Still another object to be achieved by the present disclosure is to provide a substrate including transparent and conductive nano/micro structures and a method for manufacturing the same.

Still another object to be achieved by the present disclosure is to provide a refining method and a refining apparatus for a nano/micro structure with high reliability.

Still another object to be achieved by the present disclosure is to provide a refining method and a refining apparatus for nano/micro structures having substantially the same size.

Still another object to be achieved by the present disclosure is to provide a refining method and a refining apparatus for a nano/micro structure which can be simply manufactured.

Still another object to be achieved by the present disclosure is to provide a refining method and a refining apparatus for a nano/micro structure which can be improved in production yield.

Still another object to be achieved by the present disclosure is to provide a refining method and a refining apparatus for a nano/micro structure applicable to a continuous process.

An object to be achieved by the present disclosure is to provide a manufacturing method and a manufacturing apparatus for a nano/micro structure network which can have a substantially uniform sheet resistance.

Another object to be achieved by the present disclosure is to provide a manufacturing method and a manufacturing apparatus for a nano/micro structure network with a minimized resistance.

Yet another object to be achieved by the present disclosure is to provide a manufacturing method and a manufacturing apparatus for a nano/micro structure with minimized damage to a substrate.

The objects to be achieved by the present disclosure are not limited to the above-described objects.

Technical Solution

In order to achieve the above-described aspects, the present disclosure provides a method for manufacturing a substrate including nano/micro structures.

According to an exemplary embodiment, the method for manufacturing a substrate including nano/micro structures includes: forming nano/micro structures on an upper surface of an auxiliary substrate; coating a base solution on the nano/micro structures; forming a base substrate configured to cover the nano/micro structures by performing a heat treatment to the base solution; and removing the auxiliary substrate from the base substrate.

According to an exemplary embodiment, during the heat treatment to the base solution, at least parts of the nano/micro structures may be fused and bonded to each other.

According to an exemplary embodiment, there is a gap between the nano/micro structures and the auxiliary substrate, and the base solution fills the gap.

According to an exemplary embodiment, the nano/micro structures are disposed within the base substrate.

According to an exemplary embodiment, the method for manufacturing a substrate including nano/micro structures may further include: performing a pretreatment process for reducing surface energy of the upper surface of the auxiliary substrate before forming the nano/micro structures on the auxiliary substrate.

According to an exemplary embodiment, the method for manufacturing a substrate including nano/micro structures may further include: at least one of performing a heat treatment to the auxiliary substrate on which the nano/micro structures are formed before coating the base solution and performing a heat treatment to the base substrate after separating the auxiliary substrate.

According to an exemplary embodiment, the method for manufacturing a substrate including nano/micro structures may further include: forming a releasing layer on the upper surface of the auxiliary substrate before forming the nano/micro structures. The nano/micro structures are formed on the releasing layer, and the separating of the auxiliary substrate from the base substrate may include removing the releasing layer.

According to an exemplary embodiment, the auxiliary substrate is removed from the base substrate to expose a main surface of the base substrate adjacent to the upper surface of the auxiliary substrate.

According to an exemplary embodiment, the main surface of the base substrate may include a portion including the nano/micro structures and a portion including the base substrate.

According to an exemplary embodiment, the method for manufacturing a substrate including nano/micro structures may further include: forming a conductive film on the main surface of the base substrate.

In order to achieve the above-described aspects, the present disclosure provides a method for manufacturing an electronic element.

According to an exemplary embodiment, the method for manufacturing an electronic element may further include: manufacturing the substrate including nano/micro structures according to the above-described exemplary embodiments; and forming a semiconductor element on the main surface of the base substrate.

In order to achieve the above-described aspects, the present disclosure provides a substrate including nano/micro structures.

According to an exemplary embodiment, the substrate including nano/micro structures includes a base substrate including a flat main surface and nano/micro structures disposed within the base substrate so as to be adjacent to the main surface. The main surface of the base substrate may include a first portion including the base substrate and a second portion including the nano/micro structures.

According to an exemplary embodiment, the base substrate includes a counter surface facing the main surface, and the nano/micro structures are disposed within the base substrate and located relatively closer to the main surface than to the counter surface.

According to an exemplary embodiment, the nano/micro structures include an exposed portion constituting the main surface and a dent portion located under the main surface. The dent portion is covered by the first portion of the main surface.

In order to achieve the above-described aspects, the present disclosure provides a method for refining a nano/micro structure.

According to an exemplary embodiment, the method for refining a nano/micro structure may include: preparing a mixed solution including structures different from each other in mass; spreading the mixed solution including the structures on a substrate by supplying the mixed solution onto the substrate; collecting a part of the mixed solution spread on the substrate; and recovering the structures included in the collected part of the mixed solution from the collected part of the mixed solution.

According to an exemplary embodiment, the structures may be silver nano structures.

According to an exemplary embodiment, the substrate is inclined to the ground.

According to an exemplary embodiment, the collected part of the mixed solution is located within a predetermined distance range from a location at which the mixed solution is supplied to the substrate.

According to an exemplary embodiment, the collecting of the part of the mixed solution may include: removing the mixed solution spread on the substrate except the part of the mixed solution; and collecting the remaining part of the mixed solution.

According to an exemplary embodiment, the spreading of the mixed solution may include: drying the mixed solution, and the collecting of the part of the mixed solution may include: collecting the part of the dried mixed solution.

According to an exemplary embodiment, the collecting of the part of the mixed solution may include: supplying a solution that dissolves the part of the dried mixed solution onto the substrate.

According to an exemplary embodiment, the recovering of the structures may include: recovering the structures from the solution in which the part of the mixed solution is dissolved, with a centrifuge.

According to an exemplary embodiment, the method for refining a nano/micro structure may further include: forming a peeling layer on the substrate before supplying the mixed solution onto the substrate.

According to an exemplary embodiment, the peeling layer is dissolved by the solution.

According to an exemplary embodiment, the method for refining a nano/micro structure may further include: performing a pretreatment process for reducing surface energy of a surface of the substrate before supplying the mixed solution onto the substrate.

In order to achieve the above-described aspects, the present disclosure provides a refining apparatus for a nano/micro structure.

According to an exemplary embodiment, the refining apparatus for a nano/micro structure may include: a substrate including an upper surface inclined to the ground; and a mixed solution supply unit configured to supply a mixed solution including structures different from each other in mass to the upper surface of the substrate. The structures having relatively small mass are spread farther from a location where the mixed solution is supplied to the upper surface of the substrate than the structures having relatively great mass.

According to an exemplary embodiment, the refining apparatus for a nano/micro structure may further include an inclination adjusting unit configured to adjust an inclination between the upper surface of the substrate and the ground.

According to an exemplary embodiment, the refining apparatus for a nano/micro structure may further include a substrate pretreatment supply unit configured to supply plasma to the upper surface of the substrate.

According to an exemplary embodiment, the mixed solution supply unit may supply the mixed solution including the structures to a part of the upper surface of the substrate placed at a relatively high location from the ground.

According to an exemplary embodiment, the substrate may be provided plural in number and upper surfaces of the plurality of substrates may be inclined to the ground. Parts of the upper surfaces of the plurality of substrates placed at a relatively high location from the ground may be disposed to be adjacent to each other.

According to an exemplary embodiment, the upper surfaces of the plurality of substrates may be increased in size as being closer to the ground.

In order to achieve the above-described aspects, the present disclosure provides a method for manufacturing a nano/micro structure network.

According to an exemplary embodiment, the method for manufacturing a nano/micro structure network may include: forming a base layer including conductive structures on a substrate; forming a first network in which a first point of the base layer and a second point separated from the first point are electrically connected by the structures by applying a current between the first point and the second point; and forming a second network in which a third point of the base layer and a fourth point separated from the third point are electrically connected by the structures by applying a current between the third point and the fourth point.

According to an exemplary embodiment, the structures may include silver nano structures.

According to an exemplary embodiment, at least parts of the structures are bonded to each other by the current applied between the first point and the second point and the current applied between the third point and the fourth point.

According to an exemplary embodiment, the first to fourth points are located at edges of the base layer.

According to an exemplary embodiment, the current applied between the first point and the second point and the current applied between the third point and the fourth point respectively have current paths different from each other.

According to an exemplary embodiment, the current applied between the first point and the second point corresponds to the first network and the current applied between the third point and the fourth point corresponds to the second network.

In order to achieve the above-described aspects, the present disclosure provides a manufacturing apparatus for a nano/micro structure network.

According to an exemplary embodiment, the manufacturing apparatus for a nano/micro structure network may include: a first electrode and a second electrode extended in a first direction and separated from each other; a support rod configured to connect one end of the first electrode to one end of the second electrode; a rotation rod configured to be rotated around the first direction as a rotation axis and connected to the support rod; and a control unit configured to rotate the rotation rod after applying a current between the first electrode and the second electrode, and apply a current between the first electrode and the second electrode after rotating the rotation rod.

According to an exemplary embodiment, even when the rotation rod is rotated, a distance between the first electrode and the second electrode is uniformly maintained.

According to an exemplary embodiment, in a state where the first electrode and the second electrode are in contact with a first point of a base layer including conductive structures and a second point separated from the first point, respectively, a current is applied between the first electrode and the second electrode and the first electrode and the second electrode are rotated by the rotation rod, and in a state where the first electrode and the second electrode are in contact with a third point of the base layer and a fourth point separated from the third point, respectively, a current is applied between the first electrode and the second electrode.

According to an exemplary embodiment, the manufacturing apparatus for a nano/micro structure network may include: a support structure; a plurality of electrodes disposed adjacent to edges of the support structure; and a control unit configured to apply a current between a first electrode and a second electrode selected from the plurality of electrodes, and apply a current between a third electrode and a fourth electrode selected from the electrodes other than the first electrode and the second electrode among the plurality of electrodes after applying the current between the first electrode and the second electrode.

According to an exemplary embodiment, in a state where the plurality of electrodes including the first to fourth electrodes is in contact with the base layer including the conductive structures, a current is applied between the first electrode and the second electrode and between the third electrode and the fourth electrode.

According to an exemplary embodiment, the support structure includes first to fourth sides, and the plurality of electrodes is disposed along the first to fourth sides, respectively. The electrodes disposed along the first to fourth sides constitute first to fourth groups, respectively.

According to an exemplary embodiment, the first electrode and the second electrode are respectively included in different groups, and the third electrode and the fourth electrode are respectively included in different groups.

Advantageous Effects

According to a substrate including nano/micro structures and a method for manufacturing the same in accordance with an exemplary embodiment of the present disclosure, a base solution is coated on nano/micro structures formed on an auxiliary substrate, and a base substrate is formed by performing a heat treatment to the base solution. The auxiliary substrate is removed from the base substrate, so that a main surface of the base substrate adjacent to the auxiliary substrate is exposed. The main surface of the base substrate includes a portion including the nano/micro structures and may be substantially flat. Accordingly, it is possible to provide a substrate including nano/micro structures with a minimized surface roughness.

Further, according to a refining method and a refining apparatus for a nano/micro structure in accordance with an exemplary embodiment of the present disclosure, a mixed solution including structures different from each other in mass and/or size is supplied and spread on a substrate and only a part of the mixed solution is collected within a predetermined distance range from a location at which the mixed solution is supplied to the substrate. Structures having substantially the same mass and/or size can be refined from the collected part of the mixed solution.

Furthermore, according to a manufacturing method and a manufacturing apparatus for a nano/micro structure network in accordance with an exemplary embodiment of the present disclosure, a plurality of current paths different from each other is provided to a base layer disposed on a substrate and including conductive structures, so that a plurality of networks in which the structures are electrically connected may be formed. Accordingly, it is possible to provide a manufacturing method and a manufacturing apparatus for a nano/micro structure network with minimize damage to the substrate, a minimized resistance of the base layer, and substantially uniform sheet resistance.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the technical concept of the present disclosure is not limited to the exemplary embodiments described herein, but can be embodied in various forms. The exemplary embodiments described herein are provided to complete disclosure of the present disclosure and convey the concept of the present disclosure to a person having ordinary skill in the art.

In the present specification, in case where it is described that one element is on the other element, the one element may be directly formed on the other element or a third element may be intervened between them. Further, in the drawings, thicknesses of layers and areas are exaggerated for effective explanation of technical matters.

Although the terms “first”, “second”, “third”, and the like are used for describing various components in various exemplary embodiments, these components are not confined by these terms. These terms are merely used for distinguishing one component from the other components. Therefore, a first component mentioned in any one exemplary embodiment may be mentioned as a second component in another exemplary embodiment. Each exemplary embodiment described and illustrated herein includes complementary exemplary embodiments thereof. Further, in the present specification, the term “and/or” is used to mean at least one of the associated listed components is included.

A singular expression used herein includes a plural expression unless it is clearly construed in a different way in the context. The terms used herein, such as “including” or “having”, are used only to designate the features, numbers, steps, operations, constituent elements, or combinations thereof described in the specification, but should not be construed to exclude existence or addition of one or more other features, numbers, steps, operations, constituent elements, or combinations thereof. Further, the term “connection” used herein includes indirect connection and direction connection of a plurality of components.

Further, in the following description, a detailed explanation of well-known related functions or configurations may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure.

Furthermore, the term “nano/micro structure” used herein includes a wire, a rod, fiber, a line, a flake, a particle, or the like, and a minute structure having a micro size or a nano size.

A substrate including nano/micro structures and a method for manufacturing the same according to an exemplary embodiment of the present disclosure will be described.

FIG. 1is a flowchart provided to explain a method for manufacturing a substrate including nano/micro structures according to an exemplary embodiment of the present disclosure, andFIG. 2AthroughFIG. 2Fare diagrams provided to explain a substrate including nano/micro structures and a method for manufacturing the same according to an exemplary embodiment of the present disclosure.

Referring toFIG. 2A, an auxiliary substrate100is prepared. The auxiliary substrate100may include a flat upper surface. The auxiliary substrate100may be a flexible substrate. The auxiliary substrate100may be any one of a glass substrate, a silicon semiconductor substrate, a compound semiconductor substrate, or a polymer substrate. For example, the auxiliary substrate100may be any one of a PET substrate, a PC substrate, a PEN substrate, a PMMA substrate, a PU substrate, or a PI substrate.

A releasing layer110may be formed on the auxiliary substrate100. The releasing layer110may be configured to easily remove the auxiliary substrate100from a base substrate to be described later. For example, the releasing layer110may be formed using a silicon-based release agent or a fluorine-based release agent.

Referring toFIG. 1andFIG. 2B, nano/micro structures120may be formed on the upper surface of the auxiliary substrate100(S110). According to an exemplary embodiment, the nano/micro structures120may be formed of a conductive material. For example, the nano/micro structures120may be silver (Ag) nano wires. The nano/micro structures120may be formed by various methods such as bar coating, spin coating, spray coating, dip coating, brush coating, or gravure coating.

Before the nano/micro structures120are formed, a pretreatment process for reducing surface energy of the upper surface of the auxiliary substrate100and/or an upper surface of the releasing layer110may be performed to easily disperse the nano/micro structures120on the upper surface of the auxiliary substrate100. For example, a plasma process using a gas such as oxygen, argon, nitrogen, or hydrogen may be performed, or a UV or ozone process may be performed.

After the nano/micro structures120are formed, the auxiliary substrate100on which the nano/micro structures120are formed may be dried to remove a solvent supplied onto the auxiliary substrate100while the nano/micro structures120are formed. For example, the auxiliary substrate100may be dried at a temperature of 60° C. to 80° C.

After the nano/micro structures120are formed, a heat treatment process may be performed. The conductivity of the nano/micro structures120may be improved by the heat treatment process. For example, the heat treatment process may be performed at 160° C. to 180° C.

A gap120amay be present between the nano/micro structures120and the releasing layer110or between the nano/micro structures120and the auxiliary substrate100if the formation process of the releasing layer110is omitted.

Referring toFIG. 1andFIG. 2C, a base solution130may be coated on the nano/micro structures120(S120). The base solution130may be in a solution state and may include a material of a flexible substrate. For example, the base solution130may include at least any one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyether sulfone (PES), polyimide (PI), poly(methylmethacrylate) (PMMA), or acrylite.

The base solution130may be formed by various methods such as bar coating, spin coating, spray coating, dip coating, brush coating, or gravure coating.

According to an exemplary embodiment, before the base solution130is coated on the nano/micro structures120, the nano/micro structures120may be patterned.

Referring toFIG. 1andFIG. 2D, a base substrate132covering the nano/micro structures120may be formed by curing the base solution130through a heat treatment to the base solution130(S130). For example, the base solution130may be heat-treated at 70° C. to 300° C. More specifically, for example, if the base solution130is a PMMA solution, the base solution130may be heat-treated at 80° C. to 100° C.

While the base solution130is heat-treated, at least parts of the nano/micro structures120may be fused. Thus, parts of the nano/micro structures120adjacent to each other may be bonded120band connected to each other. Accordingly, the resistance of the nano/micro structures120may be reduced.

Referring toFIG. 1andFIG. 2E, the auxiliary substrate100and the releasing layer110may be removed from the base substrate132(S140). The auxiliary substrate100and the releasing layer110are removed, so that a main surface MS of the base substrate132may be exposed to the outside.

The main surface MS of the base substrate132may be a surface adjacent to the upper surface of the auxiliary substrate100. In other words, the main surface MS may be a surface in contact with the releasing layer110or the auxiliary substrate100before the auxiliary substrate100and the releasing layer110are removed. The base substrate132may include a counter surface facing the main surface MS.

As described above with reference toFIG. 2C, the base solution130is supplied onto the nano/micro structures120as being in a liquid state. The base solution in a liquid state may readily fill the gaps120abetween the releasing layer110and the nano/micro structures120or between the auxiliary substrate100and the nano/micro structures120if the formation process of the releasing layer110is omitted. Thus, the main surface MS of the base substrate132formed by converting the base solution130into a solid state through a heat treatment may become flat.

The exposed main surface MS may include a first portion MS1including the base substrate132and a second portion MS2including the nano/micro structures120. The first portion MS1and the second portion MS2may constitute one flat surface. A part of the base substrate132constituting the first portion MS1may be formed by performing a heat treatment to the base solution130filling the gap120a.

At least parts of the nano/micro structures120may include an exposed portion EP and a dent portion DP. The exposed portion EP may constitute the second portion MS2of the main surface MS. The dent portion DP may be located under the first portion MS1of the main surface MS.

The nano/micro structures120may be located within the base substrate132so as to be relatively closer to the main surface MS than to the counter surface.

The removing of the auxiliary substrate100and the releasing layer110may include separating the auxiliary substrate100from the releasing layer110and the base substrate132, and removing the releasing layer110from the base substrate132by dissolving the releasing layer110with a solvent. Otherwise, the releasing layer110and the auxiliary layer100may be removed from the base substrate132at the same time.

After the main surface MS is exposed by removing the auxiliary substrate100and the releasing layer110, the base substrate132may be heat-treated. Thus, the nano/micro structures120weakly bonded to each other while the base substrate132is formed by performing a heat treatment to the base solution130may become strongly bonded to each other.

Referring toFIG. 2F, after the main surface MS is exposed by removing the auxiliary substrate100and the releasing layer110, a conductive thin film140may be formed on the main surface MS. The conductive thin film140may include a conductive polymer (for example, PEDOT:PSS).

According to an exemplary embodiment of the present disclosure, the base substrate132is formed by performing a heat treatment to the base solution130in a liquid state on the nano/micro structures120formed on the auxiliary substrate100. Thus, the main surface MS of the base substrate132in contact with the auxiliary substrate100or the releasing layer110may become flat although the main surface MS includes the portion including the nano/micro structures120. Accordingly, it is possible to suppress deterioration in property of semiconductor elements, such as a thin film transistor, and an organic light emitting element, and the like formed on the main surface MS of the base substrate132.

Generally, if metal nano wires are formed on a substrate, a surface of the substrate has a surface roughness of several hundred nm. Even if an organic/inorganic thin film is formed on the surface of the substrate on which the metal nano wires are formed, the surface has a surface roughness of about 100 nm or more. If a semiconductor element is formed on the surface of the substrate having a high surface roughness, properties of the semiconductor element may deteriorate. For example, if an organic light emitting element is formed on the surface of the substrate, there may occur non-uniformity in an internal electric field or a short circuit between an anode and a cathode. Accordingly, internal degradation of the organic light emitting element may occur, resulting in a decrease in lifetime of the organic light emitting element.

However, as described above, according to an exemplary embodiment of the present disclosure, the semiconductor elements can be formed on the substrate having the main surface MS which includes the nano/micro structures120and is flat, and, thus, deterioration in property of the semiconductor elements can be minimized.

In the above-described exemplary embodiment, other micro materials may be formed on the auxiliary substrate100in addition to the nano/micro structures120. Details thereof will be described with reference toFIG. 3AandFIG. 3B.

FIG. 3AandFIG. 3Bare diagrams provided to explain a modification example of a metal nano wire substrate and a method for manufacturing the same according to an exemplary embodiment of the present disclosure.

Referring toFIG. 3A, the auxiliary substrate100and the releasing layer110on the auxiliary substrate100are provided as described above with reference toFIG. 2A. The nano/micro structures120and a nano material122may be formed on the releasing layer110. The nano material122may strengthen the connection between the nano/micro structures120and improve the dispersity of the nano/micro structures120.

According to an exemplary embodiment, before the nano/micro structures120are formed on the auxiliary substrate as described above with reference toFIG. 2B, the nano material122is formed on the auxiliary substrate100. After the nano material122is formed, the nano/micro structures120may be formed.

According to another exemplary embodiment unlike the above description, after the nano/micro structures120are formed on the auxiliary substrate100and before the base solution130is coated on the auxiliary substrate100, the nano material122may be formed on the auxiliary substrate100.

The nano material122may include a material different from the nano/micro structures120. For example, the nano material122may include at least any one of graphene flake, single-walled CNT, double-walled CNT, multi-walled CNT, C60, C85, or C70.

The nano material122may be formed together with a conductive organic material on the auxiliary substrate100. For example, the conductive organic material may include at least any one of PEDOT:PSS or PVP.

After the nano/micro structures120and the nano material122are formed on the auxiliary substrate100, the base solution130may be coated on the auxiliary substrate100as described above with reference toFIG. 2C. After the base solution130is coated, the base solution130may be heat-treated to form the base substrate132as described above with reference toFIG. 2D. The base substrate132may cover the nano/micro structures120and the nano material122.

Referring toFIG. 3B, the auxiliary substrate100and the releasing layer110may be removed from the base substrate132as described above with reference toFIG. 2E. Thus, the main surface MS of the base substrate132in contact with the releasing layer110(the main surface in contact with the auxiliary substrate100if the releasing layer110is omitted) may be exposed.

The exposed main surface MS may include the first portion MS1including the base substrate132, the second portion MS2including the nano/micro structures120, and a third portion MS3including the nano material122. The first portion MS1, the second portion MS2, and the third portion MS3may constitute one flat surface.

As described with reference toFIG. 2F, a conductive thin film may be further formed on the main surface MS of the base substrate132.

According to a modification example of the substrate including nano/micro structures and the method for manufacturing the same according to an exemplary embodiment of the present disclosure, the nano material122is formed on the auxiliary substrate100before or after the nano/micro structures120are formed. Thus, the bonding and the dispersity of the nano/micro structures can be improved.

Hereinafter, the results of a property evaluation of the substrate including nano/micro structures according to the above-described exemplary embodiments of the present disclosure will be described.

FIG. 4is an SEM image of a substrate including nano/micro structures according to an exemplary embodiment of the present disclosure.

Referring toFIG. 4, a silver nano wire is formed on an auxiliary substrate by bar-coating, and PMMA is formed on the silver nano wire by drop-casting.FIG. 4Ais an image showing a flat surface of the PMMA substrate including the silver nano wire, andFIG. 4Bis an image showing an inclined surface of the PMMA including the silver nano wire.

As can be seen fromFIG. 4, it is observed that silver nano wires are distributed on the PMMA substrate at an adequate density. Further, it is observed fromFIG. 4Bthat the PMMA covers parts of silver nano wires. In other words, the PMMA covers a silver nano wires having a high surface roughness and fills a space between the silver nano wires to reduce a surface roughness.

FIG. 5is a graph provided to explain a transmittance of a substrate including nano/micro structures according to an exemplary embodiment of the present disclosure.

Referring toFIG. 5, the transmittance of PEDOT:PSS, which is a conductive polymer used as a hole injecting layer, a silver nano wire, and a laminated structure of a silver nano wire and PEDOT:PSS were measured. As can be seen fromFIG. 5, the PEDOT:PSS has the highest transmittance and the laminated structure of PEDOT:PSS on a silver nano wire has the lowest transmittance.

FIG. 6is an atomic force microscopic image provided to explain a surface roughness of a substrate including nano/micro structures according to an exemplary embodiment of the present disclosure.

Referring toFIG. 6, according to an exemplary embodiment of the present disclosure, a silver nano wire was formed on a glass substrate, and a PMMA solution was coated on the silver nano wire and then heat-treated to form a PMMA substrate. Then, PMMA substrate including the silver nano wire was separated from the glass substrate and PEDOT:PSS was coated. A surface thereof was measured with an atomic force microscope. Further, as a comparative example of the exemplary embodiment of the present disclosure, a silver nano wire was formed on a glass substrate and PEDOT:PSS was formed on the silver nano wire. Then, a surface thereof was measured with the atomic force microscope.

FIG. 6AandFIG. 6Bare atomic force microscopic images of a surface of the silver nano wire formed on the glass substrate and a surface of the laminated structure of the silver nano wire and PEDOT:PES formed on the glass substrate, respectively, according to the comparative example of the present disclosure.FIG. 6CandFIG. 6Dare atomic force microscopic images of a surface of the silver nano wire transferred to the PMMA substrate and a surface of the laminated structure of PEDOT:PSS on the PMMA substrate including the silver nano wire, respectively, according to the exemplary embodiment of the present disclosure.

As can be seen fromFIG. 6A, a peak-to-valley surface roughness of the silver nano wire formed on the glass substrate according to the comparative example of the present disclosure was about 210 nm. In other words, the surface roughness was about two to three times higher than 80 nm, which is the thickness of the silver nano wire, due to overlaps of silver nano wires. Further, as can be seen fromFIG. 6B, a peak-to-valley surface roughness was reduced to 50 nm, i.e. about ¼, through a process of coating PEDOT:PSS on the silver nano wire formed on the glass substrate, but still had a high value.

Meanwhile, as can be seen fromFIG. 6C, if the silver nano wire is transferred to the PMMA substrate according to the exemplary embodiment of the present disclosure, a peak-to-valley surface roughness was 62 nm which is considerably lower than that ofFIG. 6A. Further, as can be seen fromFIG. 6D, if PEDOT:PSS is coated on the PMMA substrate including the silver nano wire, a peak-to-valley surface roughness was 26 nm which is considerably lower than that ofFIG. 6B, and the surface roughness was reduced by about 74% on the basis of a root-mean-square (RMS) roughness.

It is confirmed that a method of supplying a PMMA solution onto a silver nano wire disposed on a glass substrate, performing a heat treatment to the PMMA solution to form a PMMA film, removing the glass substrate and coating the PMMA film including the silver nano wire with PEDOT:PSS according to an exemplary embodiment of the present disclosure is an effective method for minimizing a surface roughness of a substrate including a silver nano wire.

A refining method and a refining apparatus for a nano/micro structure according to an exemplary embodiment of the present disclosure will be described.

FIG. 7throughFIG. 11are diagrams provided to explain a method for refining a nano/micro structure according to an exemplary embodiment of the present disclosure, andFIG. 12is a flowchart provided to explain a method for refining a nano/micro structure according to an exemplary embodiment of the present disclosure.

Referring toFIG. 7, a substrate200is provided. The substrate200may be a semiconductor substrate, a plastic substrate, or a glass substrate. The substrate200may be flexible.

A pretreatment210may be performed to the substrate200. Due to the pretreatment210of the substrate200, surface energy of the substrate may be reduced. According to an exemplary embodiment, the pretreatment210of the substrate200may include supplying at least any one of plasma, UV (ultra violet), or ozone to an upper surface of the substrate200. For example, plasma using oxygen (O), argon (Ar), nitrogen (N), or hydrogen (H) gas may be supplied to the upper surface of the substrate200.

Referring toFIG. 8, a peeling layer220may be coated on the upper surface of the substrate200. As described below, the peeling layer220is configured to easily separate a mixed solution including structures to be formed on the peeling layer220from the substrate200.

The peeling layer220may be coated by any one method of bar coating, spray coating, brush coating, or gravure coating. The peeling layer220may include a polymer material. For example, the peeling layer220may be formed of at least any one of polymethylmethacrylate, polyvinylpyrrolidone, polyethylene terephthalate, polystyrene, polyvinylchloride, polycarbonate, or polyimide. Otherwise, the peeling layer220may include a complex of the above-described polymer material and an inorganic material. For example, the inorganic material may include at least any one of Au, Si, Ag, Cu, Ni, Al, Sn, C, SiO2, ZnO, Al2O3, In2O3, or SnO2.

After the peeling layer220is coated, a heat treatment or plasma treatment230may be performed to the peeling layer220. Thus, the mixed solution including the structures can be easily spread on the peeling layer220.

Referring toFIG. 9andFIG. 12, a mixed solution240including structures242different from each other in mass is prepared (S210). According to an exemplary embodiment, the structures242may be silver nano structures such as silver nano particles and silver nano wires.

The mixed solution240including the structures242is supplied onto the upper surface of the substrate200, so that the mixed solution240including the structures242may be spread on the peeling layer220(S220). According to an exemplary embodiment, the mixed solution240may be supplied onto the substrate200so as not to cover the entire upper surface of the peeling layer220. For example, if a mixed solution is supplied onto a substrate having a size of 25×25 mm2, the mixed solution of about 10 μl to 15 μl may be supplied.

Among the structures242included in the mixed solution240supplied onto the substrate200, the structures242having relatively small mass can be spread farther from a location240P where the mixed solution240is supplied to the substrate200than the structures242having relatively great mass. In other words, as the structure242is closer to the location240P where the mixed solution240is supplied to the substrate200, the structure242may have a greater mass and/or size. Further, as the structure240is farther from the location240P where the mixed solution240is supplied to the substrate200, the structure242may have a smaller mass and/or size. For example, if the structure242is a silver nano structure including a silver nano particle and a silver nano wire, a relatively long silver nano wire may be disposed in an area close to the location240P where the mixed solution240is supplied to the substrate200and a relatively short silver nano wire or a silver nano particle may be disposed in an area far from the location240P where the mixed solution240is supplied to the substrate200.

According to an exemplary embodiment, the process of supplying the mixed solution240onto the substrate200and spreading the mixed solution240may include a process of drying the mixed solution240. In other words, after the mixed solution240is completely spread on the substrate200and before the structures242are randomly disposed within the mixed solution240, the mixed solution240may be dried, so that random disposal of the structures242can be suppressed. For example, the mixed solution240may be dried by applying heat to the mixed solution240.

Referring toFIG. 10throughFIG. 12, a part of the mixed solution240spread on the substrate200may be collected (S230). The collected part of the mixed solution240may be located within a predetermined distance range D1to D2from the location240P where the mixed solution240is supplied to the substrate200. In a plain view, the part of the mixed solution240located within the predetermined distance range D1to D2from the location240P where the mixed solution240is supplied to the substrate200may have a doughnut shape. The structures242included in the remaining part of the mixed solution240may have substantially the same mass and/or size.

The process of collecting of the part of the mixed solution240may include removing the rest of the mixed solution240located out of the predetermined distance range D1to D2from the location240P where the mixed solution240is supplied to the substrate200and collecting the remaining part of the mixed solution240. According to an exemplary embodiment, the rest of the mixed solution240may be removed by a physical method.

The structures242included in the collected part of the mixed solution240may be recovered from the part of the mixed solution240(S240). The process of recovering the structures242from the part of the mixed solution240may include supplying a solution250that dissolves the remaining part of the mixed solution240and the peeling layer220on the substrate200and recovering the structures242from the solution250including the structures242included in the remaining part of the mixed solution240. According to an exemplary embodiment, the process of recovering the structures242may include recovering the structures242from the solution250in which the part of the mixed solution240is dissolved, with a centrifuge.

According to an exemplary embodiment of the present disclosure, a mixed solution including structures different from each other in mass is supplied onto a substrate and spread on the substrate, and only a part of the mixed solution located within a predetermined distance range from a location where the mixed solution is supplied is collected. Thus, structures having substantially the same mass and/or size can be refined from the collected part of the mixed solution through a simple process.

If structures having substantially the same mass and/or size are refined from structures different from each other in mass and/or size using a filter or a centrifuge without the spreading process according to an exemplary embodiment of the present disclosure, the structures may be deformed or cut during the refining process.

However, as described above, according to an exemplary embodiment of the present disclosure, if structures having substantially the same mass and/or size are refined using a difference in degree of spread depending on the mass, a refining method of a nano/micro structure with minimized deformation and cutting of the structures and an improved production yield can be provided.

FIG. 7throughFIG. 11illustrate that a mixed solution is supplied to a substrate including an upper surface in parallel to the ground. However, according to another exemplary embodiment of the present disclosure, the upper surface of the substrate to which the mixed solution is supplied may be inclined to the ground. Details thereof will be described with reference toFIG. 13throughFIG. 15.

FIG. 13throughFIG. 15are diagrams provided to explain a method for refining a nano/micro structure according to another exemplary embodiment of the present disclosure.

Referring toFIG. 13, a substrate205and a supporting table201that supports the substrate205are provided. The substrate205may be of the same kind as the substrate200described above with reference toFIG. 7. The substrate205may be extended in a direction to be adjacent to the ground.

An upper surface104of the substrate205may be not parallel but inclined to the ground due to the supporting table201.FIG. 13illustrates that the supporting table201and the substrate205are separate components. However, the supporting table201and the substrate205may be formed as one body.

As described above with reference toFIG. 7, a pretreatment may be performed to the upper surface104of the substrate205using at least any one of plasma, UV (ultra violet), or ozone.

Referring toFIG. 14, a peeling layer222may be formed on the substrate205. Since the peeling layer222is conformal in thickness, an upper surface of the peeling layer222may also be inclined to the ground in the same manner as the upper surface104of the substrate205. The peeling layer222may be extended in a direction to be adjacent to the ground. The peeling layer222may be formed by the method described above with reference toFIG. 8.

Referring toFIG. 15, the mixed solution240including structures may be prepared as described above with reference toFIG. 9. The mixed solution240may be supplied onto the upper surface of the peeling layer222inclined to the ground. A location240P where the mixed solution240is supplied to the substrate205may be higher than the ground. Thus, the mixed solution240may be spread on the peeling layer222toward the ground. Since the mixed solution240is supplied onto the upper surface of the peeling layer222/the upper surface of the substrate205inclined to the ground, the mixed solution240can be easily spread. The process of spreading the mixed solution240may include a process of drying the mixed solution as described above with reference toFIG. 9.

As described above with reference toFIG. 9, among the structures included in the mixed solution240, the structures having relatively small mass can be spread farther from the location240P where the mixed solution240is supplied onto the substrate205than the structures having relatively great mass. That is, the structures having relatively small mass and/or size may be disposed adjacent to the ground and the structures having relatively great mass and/or size may be disposed far from the ground.

Then, as described above with reference toFIG. 10throughFIG. 12, a part240A of the mixed solution240located within predetermined distance range from the location240P where the mixed solution240is supplied onto the substrate205is collected. Thus, the structures having substantially the same mass and/or size can be refined.

A refining apparatus for a nano/micro structure to which the method for refining a nano/micro structure according to the above-described exemplary embodiment of the present disclosure will be described with reference toFIG. 16throughFIG. 18.

FIG. 16is a diagram provided to explain a refining apparatus for a nano/micro structure according to an exemplary embodiment of the present disclosure.

Referring toFIG. 16, a refining apparatus for a nano/micro structure according to an exemplary embodiment of the present disclosure may include the substrate205, a mixed solution supply unit310, a substrate pretreatment supply unit320, and an inclination adjusting unit330.

The substrate205may include an upper surface inclined to the ground as described above with reference toFIG. 13. The substrate205may be supported on a supporting table202.FIG. 16illustrates that the supporting table202and the substrate205are separate components. However, the supporting table202and the substrate205may be formed as one body.

The mixed solution supply unit310may supply a mixed solution including structures different from each other in mass onto the upper surface of the substrate205, as described above with reference toFIG. 9. The mixed solution supply unit310may supply the mixed solution onto a part of the upper surface of the substrate205placed at a relatively high location from the ground.

According to an exemplary embodiment, the mixed solution supply unit310may drop the mixed solution to one point of the upper surface of the substrate205. According to another exemplary embodiment, the mixed solution supply unit310may supply the mixed solution to the upper surface of the substrate205in the form of a line extended in one direction. The one direction may intersect with an extension direction of the upper surface of the substrate205toward the ground.

The substrate pretreatment supply unit320may supply at least any one of plasma, UV (ultra violet), or ozone to the upper surface of the substrate205, as described above with reference toFIG. 1, in order to perform a pretreatment to the upper surface of the substrate205.

The inclination adjusting unit330may adjust an inclination between the upper surface of the substrate205and the ground. For example, the inclination adjusting unit330may be a lifting device provided between the supporting table202and the substrate205.FIG. 16illustrates that the inclination adjusting unit330adjusts a height of a part of the substrate205adjacent to the ground to adjust an inclination between the upper surface of the substrate205and the ground. However, the inclination adjusting unit330may adjust a height of a part of the substrate205placed at a relatively high location from the ground to adjust an inclination between the upper surface of the substrate205and the ground.

According to an exemplary embodiment, the inclination adjusting unit330may maintain an inclination between the upper surface of the substrate205and the ground at a predetermined angle while the mixed solution is supplied onto the upper surface of the substrate205. According to another exemplary embodiment, the inclination adjusting unit330may change an inclination between the upper surface of the substrate205and the ground while the mixed solution is supplied onto the upper surface of the substrate205.

Unlike the illustration inFIG. 16, a plurality of substrates each including an upper surface inclined to the ground may be provided. Details thereof will be described with reference toFIG. 17andFIG. 18.

FIG. 17is a diagram provided to explain a refining apparatus for a nano/micro structure according to another exemplary embodiment of the present disclosure.

Referring toFIG. 17, the substrate205including the upper surface inclined to the ground illustrated with reference toFIG. 16may be provided plural in number. Parts of the upper surfaces of the plurality of substrates205placed at a relatively high location from the ground may be disposed to be adjacent to each other. Therefore, the single mixed solution supply unit310can easily supply the mixed solution to the upper surfaces of the plurality of substrates205. Thus, nano/micro structures can be continuously refined.

FIG. 17illustrates that the single mixed solution supply unit310is provided. However, two or more mixed solution supply units may be provided.

Unlike the illustration inFIG. 16andFIG. 17, an upper surface of a substrate may be increased in size as being closer to the ground. Details thereof will be described with reference toFIG. 18.

FIG. 18is a diagram provided to explain a refining apparatus for a nano/micro structure according to yet another exemplary embodiment of the present disclosure.

Referring toFIG. 18, unlike the illustration with reference toFIG. 17, upper surfaces of the plurality of substrates205asupported on a plurality of supporting tables205amay be gradually increased in size as being closer to the ground. In other words, a part of the upper surface of the substrate205alocated relatively adjacent to the ground may be wider than a part of the upper surface of the substrate205alocated relatively far from the ground. Thus, a part of a mixed solution spread on the upper surface of the substrate205acan be easily collected.

Upper surfaces of the plurality of supporting tables205athat support the plurality of substrates205amay also be gradually increased in size as being closer to the ground, in the same manner as the upper surfaces of the plurality of substrates205a.

Hereinafter, the results of a spread experiment of structures according to a method for refining a nano/micro structure in accordance with an exemplary embodiment of the present disclosure will be described.

FIG. 19is a microscopic image of a spread experiment of structures according to a method for refining a nano/micro structure in accordance with an exemplary embodiment of the present disclosure.

Referring toFIG. 19, 10 μl to 15 μl of methanol including silver nano wires was supplied onto a glass substrate having a size of 25×25 mm2 by drop-casting. It can be seen that the silver nano wires are spread depending on the mass from a central portion of the glass substrate to which the methanol including the silver nano wires is supplied.

Specifically, it was observed that an area (a) adjacent to the central portion of the glass substrate to which the methanol is supplied includes a small number of silver nano wires of 30 μm or more, and silver nano wires and silver nano particles of 5 μm to 15 μm. It was observed that an area (b) includes silver nano wires of about 30 μm at a relatively high density and also includes a considerable number of silver nano particles. Further, it was observed that an area (c) includes silver nano wires of about 30 μm at the highest density. Furthermore, it was observed that areas (d) and (e) mostly include silver nano wires of 10 μm or less and silver nano particles.

That is, it was observed that the silver nano wires have various degrees of spread depending on the mass, and, thus, it can be seen that nano/micro structures having substantially the same size can be selected and refined using a difference in degree of spread depending on the mass of a nano/micro structure.

A manufacturing method and a manufacturing apparatus for a nano/micro structure network according to an exemplary embodiment of the present disclosure will be described.

FIG. 20is a flowchart provided to explain a method for manufacturing a nano/micro structure network according to an exemplary embodiment of the present disclosure,FIG. 21throughFIG. 23are perspective views provided to explain a method for manufacturing a nano/micro structure network according to an exemplary embodiment of the present disclosure, andFIG. 24is a diagram provided to explain a network formed between contact points of structures according to a method for manufacturing a nano/micro structure network in accordance with an exemplary embodiment of the present disclosure.

Referring toFIG. 20andFIG. 21, a base layer410may be formed on a substrate400(S410).

The substrate400may be a semiconductor substrate, a plastic substrate, and/or a glass substrate. The substrate400may be flexible. For example, the substrate400may include any one of a glass substrate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyether sulfone (PES), polyimide (PI), or acrylite.

The base layer410may include a plurality of conductive structures. According to an exemplary embodiment, the structures may be silver nano structures such as silver nano particles and silver nano wires.

According to another exemplary embodiment, the structures in the base layer410may include at least any one of inorganic materials (for example, graphene flake, single-walled CNT, double-walled CNT, multi-walled CNT, C60, C85, C70, and the like), metal nano particles (for example, Au, Ag, Cu, Ni, Al, and the like), semiconductor materials (for example, Si, C, GaAs, ZnSe, InP, CdS, and the like), conductive organic materials (for example, PEDOT:PSS, PVP, and the like), semiconductor oxide materials (SiO2, ZnO, Al2O3, In2O3, SnO2, and the like), semiconductor quantum dot materials (for example, CdSe/CdSe, CdSe/ZnTe, ZnSe/ZnS, PbS/CdS, ZnS/CdSe, CdS/ZnS, and the like) in the form of core/shell, or semiconductor nano wire materials (for example, ZnO/ZnS, AlP/AlN, AlN/AlAs, and the like) in the form of core/shell in addition to the silver nano structures.

The process of forming the base layer410including the structures on the substrate400may be performed by bar coating, spray coating, spin coating, brush coating, dip coating, gravure coating, or the like.

Before the base layer410is formed on the substrate400, a pretreatment may be performed to an upper surface of the substrate400. Due to the pretreatment of the substrate400, surface energy of the substrate400may be reduced. According to an exemplary embodiment, the pretreatment of the substrate400may include supplying at least any one of plasma, UV (ultra violet), or ozone to the upper surface of the substrate400. For example, plasma using oxygen (O), argon (Ar), nitrogen (N), or hydrogen (H) gas may be supplied to the upper surface of the substrate400.

A first point P1and a second point P2different from the first point P1of the base layer410may be selected. The first point P1and the second point P2may be any points on the base layer410. For example, the first point P1and the second point P2may be points adjacent to edges of the base layer410.

By applying a current between the first point P1and the second point P2, a first network421in which the first point P1and the second point P2are electrically connected by the structures may be formed (S420). The first network421in which the first point P1and the second point P2are electrically connected may substantially correspond to a current path flowing between the first point P1and the second point P2.

Joule heat is generated by the current flowing between the first point P1and the second point P2. As illustrated inFIG. 5, a current junction may be formed by the joule heat at a contact point415awhere the structures415within the base layer410intersect with each other. That is, the contact point415awhere the structures415disposed adjacent to the current path intersect with each other has a relatively high resistance. Accordingly, the joule heat may be generated at the contact point415aof the structures415by a current flowing between the first point P1and the second point P2. Due to the joule heat, atoms constituting the structures415are moved, so that the structures415separated from each other may be directly connected to each other or a distance between the structures415separated from each other may be reduced. Accordingly, the resistance at the contact point415aof the structures415may be reduced, and the first network421in which the first point P1and the second point P2are electrically connected may be formed.

For example, if the structures415are silver nano structures, joule heat may be generated at a contact point where the silver nano structures intersect with each other by the current flowing between the first point P1and the second point P2. Due to the joule heat, silver atoms constituting the silver nano structures are moved through a polymer material surrounding the silver nano structures, so that the silver nano structures separated from each other may be connected to each other.

Referring toFIG. 20andFIG. 21, after the first network421is formed, a third point P3and a fourth point P4of the base layer410may be selected. The third point P3and the fourth point P4may be any points different from the first point P1and the second point P2. For example, the third point P3and the fourth point P4may be points adjacent to edges of the base layer410.

By applying a current between the third point P3and the fourth point P4, a second network422in which the third point P3and the fourth point P4are electrically connected by the structures may be formed (S430). The second network422in which the third point P3and the fourth point P4are electrically connected may substantially correspond to a current path flowing between the third point P3and the fourth point P4. The current path flowing between the third point P3and the fourth point P4may be different from the current path flowing between the first point P1and the second point P2.

Joule heat is generated by the current flowing between the third point P3and the fourth point P4. As illustrated inFIG. 5, the structures415adjacent to the current path flowing between the third point P3and the fourth point P4may be electrically connected to each other by the joule heat.

Referring toFIG. 4, after the first and second networks421and422are formed, a current may be applied between points other than the first to fourth points P1to P4, so that a plurality networks420electrically connected by the structures may be further formed.

According to an exemplary embodiment of the present disclosure, the base layer410including conductive structures is formed on the substrate400, and then, a plurality of processes of applying a current between any two points of the base layer410may be performed. Accordingly, a plurality of current paths different from each other may be provided in the base layer410and a plurality of networks different from each other may be formed so as to correspond to the plurality of current paths different from each other. Since the network in which the structures of the base layer410are electrically connected is formed, a resistance of the base layer410can be reduced. Further, since the plurality of networks is provided, a sheet resistance of the base layer410may be substantially uniform.

If the formation process of the network is omitted unlike the above-described exemplary embodiment of the present disclosure, the resistance may be increased due to a polymer/insulation material present between the structures. Further, if a heat treatment is performed to the structures to reduce the resistance, the substrate may be damaged.

However, as described above, according to an exemplary embodiment of the present disclosure, a plurality of current paths different from each other may be provided, so that a plurality of networks in which the structures are electrically connected may be formed. Accordingly, it is possible to provide a method for manufacturing a nano/micro structure with minimized damage to a substrate and a minimized resistance and a substantially uniform sheet resistance of the base layer410.

Hereinafter, a manufacturing apparatus for manufacturing a nano/micro structure according to the above-described method for manufacturing a nano/micro structure will be described.

FIG. 25is a diagram provided to explain a manufacturing apparatus for a nano/micro structure network according to an exemplary embodiment of the present disclosure.

Referring toFIG. 25, a manufacturing apparatus for a nano/micro structure network according to an exemplary embodiment of the present disclosure includes a support structure510, a plurality of electrodes521,522,523, and524disposed adjacent to edges of the support structure510, and a control unit550that controls the plurality of electrodes521,522,523, and524.

The support structure510may be disposed on the substrate400described with reference toFIG. 21throughFIG. 23and the base layer410disposed on the substrate400and including the conductive structures. The support structures510may include first to fourth sides. According to an exemplary embodiment, a size of the support structure510may be similar to that of the base layer410. The support structure510may be formed of an insulation material.

The plurality of electrodes521,522,523, and524may include a first group521disposed along the first side of the support structure510, a second group522disposed along the second side of the support structure510, a third group523disposed along the third side of the support structure510, and a fourth group524disposed along the fourth side of the support structure510. According to an exemplary embodiment, the plurality of electrodes521,522,523, and524may be disposed adjacent to the edges of the support structure510and thus may correspond to the edges of the base layer410.

FIG. 6illustrates that four or five electrodes are disposed along each side of the support structure510. However, the number of the electrodes may be three or less, or six or more.

In a state where the plurality of electrodes521,522,523, and524is in contact with the base layer410, the control unit550may apply a current between first and second electrodes selected from the plurality of electrodes521,522,523, and524. According to an exemplary embodiment, the first and second electrodes may be included in different groups. For example, the first electrode may be included in the first group521and the second electrode may be included in the third group523. Due to the current applied between the first electrode and the second electrode, a current may flow between a first point of the base layer410in contact with the first electrode and a second point of the base layer410in contact with the second electrode. Due to the current flowing between the first point and the second point, a first network in which the first point and the second point are electrically connected by the structures may be formed, as described above with reference toFIG. 20throughFIG. 24.

After the first network is formed, in a state where the plurality of electrodes521,522,523, and524is in contact with the base layer410, the control unit550may apply a current between third and fourth electrodes from the electrodes other than the first electrode and the second electrode among the plurality of electrodes521,522,523, and524. According to an exemplary embodiment, the third and fourth electrodes may be included in different groups. For example, the third electrode may be included in the second group522and the fourth electrode may be included in the fourth group524. Due to the current applied between the third electrode and the fourth electrode, a current may flow between a third point of the base layer410in contact with the third electrode and a fourth point of the base layer410in contact with the fourth electrode. Due to the current flowing between the third point and the fourth point, a second network in which the third point and the fourth point are electrically connected by the structures may be formed, as described above with reference toFIG. 20throughFIG. 24.

According to an exemplary embodiment, a magnitude of the current and/or an application time of the current applied between the first electrode and the second electrode for forming the first network may be substantially the same as a magnitude of the current and/or an application time of the current applied between the third electrode and the fourth electrode for forming the second network.

By repeating the process of forming the first network and the process of forming the second network, the method for manufacturing a nano/micro structure network described with reference toFIG. 20throughFIG. 24can be performed by the manufacturing apparatus for a nano/micro structure network according to an exemplary embodiment of the present disclosure.

FIG. 26andFIG. 27are diagrams provided to explain a manufacturing apparatus for a nano/micro structure network according to another exemplary embodiment of the present disclosure.

Referring toFIG. 26, a manufacturing apparatus for a nano/micro structure network according to another exemplary embodiment of the present disclosure may include a first electrode610, a second electrode620separated from the first electrode610, a support rod630, a rotation rod640, and a control unit650that controls the first electrode610, the second electrode620, and the rotation rod640. The manufacturing apparatus for a nano/micro structure network according to another exemplary embodiment of the present disclosure may be disposed on the substrate400described above with reference toFIG. 21throughFIG. 23and the base layer410disposed on the substrate400and including the conductive structures.

The first electrode610and the second electrode620may be separated from each other and extended in a first direction. The first direction may be a direction perpendicular to the upper surface of the base layer410. According to an exemplary embodiment, a length of the first electrode610may be substantially the same as that of the second electrode620.

One end of the first electrode610and one end of the second electrode620may be respectively connected to both ends of the support rod630. According to an exemplary embodiment, the first electrode610and the second electrode620may be fixed to the support rod630.

The rotation rod640may be connected to a central portion of the support rod630and extended in the first direction. The rotation rod640may be rotated around the first direction as a rotation axis. Accordingly, the support rod630may be rotated around the rotation rod640as a rotation axis, and the first electrode610and the second electrode620connected to the both ends of the support rod630may be rotated. The first electrode610and the second electrode620may be fixed to the both ends of the support rod630. Thus, even if the rotation rod640is rotated, a distance between the first electrode610and the second electrode620may be uniformly maintained.

In a state where the other ends of the first electrode610and the second electrode620are in contact with the base layer410, the control unit650may apply a current between the first electrode610and the second electrode620. Due to the current applied between the first electrode610and the second electrode620, a current may flow between a first point of the base layer410in contact with the first electrode610and a second point of the base layer410in contact with the second electrode620. According to an exemplary embodiment, the first point and the second point may be adjacent to the edges of the base layer410. Due to the current flowing between the first point and the second point, a first network661in which the first point and the second point are electrically connected by the structures may be formed, as described above with reference toFIG. 20throughFIG. 24.

After the first network661is formed, the control unit650may rotate the rotation rod640. Accordingly, the first electrode610and the second electrode620may be respectively brought into contact with a third point and a fourth point of the base layer410. As described above, even if the rotation rod640is rotated, a distance between the first electrode610and the second electrode620is uniformly maintained. Thus, a distance between the first point and the second point may be substantially the same as a distance between the third point and the fourth point.

In a state where the other ends of the first electrode610and the second electrode620are in contact with the third point and the fourth point of the base layer410, the control unit650may apply a current between the first electrode610and the second electrode620. Due to the current applied between the first electrode610and the second electrode620, a current may flow between the third point and the fourth point. Due to the current flowing between the third point and the fourth point, a second network662in which the third point and the fourth point are electrically connected by the structures may be formed, as described above with reference toFIG. 20throughFIG. 24.

According to an exemplary embodiment, a magnitude of the current and/or an application time of the current applied between the first electrode610and the second electrode620for forming the first network661may be substantially the same as a magnitude of the current and/or an application time of the current applied between the first electrode610and the second electrode620for forming the second network662. Further, as described above, since the distances between the points between which a current is applied by the first electrode610and the second electrode620are the same, a difference in length between a plurality of networks formed by the current applied by the first electrode610and the second electrode620can be minimized. Therefore, the uniformity in sheet resistance of the base layer410can be improved.

By repeating the process of forming the first network661and the process of forming the second network662, the method for manufacturing a nano/micro structure described with reference toFIG. 20throughFIG. 24can be performed by the manufacturing apparatus for a nano/micro structure according to an exemplary embodiment of the present disclosure.

Although the present disclosure has been described in detail with reference to the exemplary embodiments, the scope of the present disclosure is not limited to specific exemplary embodiments but should be construed based on the following claims. Further, it would be understood by a person having ordinary skill in the art that various changes and modifications can be made without departing from the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure relates to a substrate, a method for manufacturing the same, a method for refining a nano/micro structure, a method for manufacturing a nano/micro structure network, and a manufacturing apparatus therefor and is applied to technologies of various fields such as organic light emitting elements, liquid crystal displays, touch panels, or solar cells, etc.