WO2015182832A1

WO2015182832A1 - Microstructure manufacturing method and microstructure manufactured thereby

Info

Publication number: WO2015182832A1
Application number: PCT/KR2014/010381
Authority: WO
Inventors: 이동현
Original assignee: 단국대학교 산학협력단
Priority date: 2014-05-28
Filing date: 2014-10-31
Publication date: 2015-12-03
Also published as: KR101502278B1

Abstract

A method for manufacturing a microstructure of a nanomaterial by using paraffin wax is provided. An intaglio pattern is formed by pressing a master pattern on a paraffin wax layer and the inside of grooves of the intaglio pattern is filled with a nanomaterial suspension. The suspension contains a hydrophilic solvent so as to be naturally filled in only the grooves of the intaglio pattern. After the solvent evaporates, the nanomaterial is heat-treated and the paraffin wax layer is removed simultaneously, and thus the microstructure of the nanomaterial can be formed.

Description

Microstructure manufacturing method and microstructure manufactured thereby

TECHNICAL FIELD The present invention relates to microstructure fabrication techniques, and more particularly, to a method for preparing regular nanomaterial microstructures at low temperatures using paraffin wax and a printing process, and to microstructures produced thereby.

Indium tin oxide (ITO) is mainly used as a transparent electrode of an electronic device that requires light transmission such as a light emitting device or a solar cell. However, ITO has problems of rising raw material cost due to exhaustion of resources, environmental pollution, and difficulty in applying to flexible electronic devices.

Therefore, research to replace ITO is actively conducted. For example, research has been conducted on silver lattice patterning and graphene coating using silver nanomaterials or wire coating using printed electrons. However, such a microprocess using nanomaterials or printed electrons has a disadvantage in that the process of obtaining a microstructure of a desired pattern is very complicated.

The present invention provides a microstructure manufacturing method that can easily form a nanomaterial microstructure using paraffin wax in view of the above-described conventional problems.

The present invention provides nanomaterial microstructures made by the improved method described above.

The present invention provides a method for producing a microstructure, which comprises: forming a paraffin wax layer on a substrate; Forming an intaglio pattern on the paraffin wax layer; Filling the nanomaterial suspension into the groove of the intaglio pattern; Evaporating the solvent from the suspension; And removing the paraffin wax layer; a microstructure of the nanomaterial having the shape of an intaglio pattern is formed.

The intaglio pattern is formed by pressing a paraffin wax layer with a master mold having a master pattern.

The intaglio pattern may be striped or lattice.

The paraffin wax layer having the intaglio pattern may be substantially triangular in longitudinal section.

The suspension may be a silver nano suspension.

Removal of the paraffin wax layer utilizes pyrolysis, and pyrolysis of the paraffin wax layer may serve as heat treatment of the microstructure.

The solvent of the suspension can be hydrophilic.

The present invention also provides a microstructure produced by the above-described manufacturing method.

According to the present invention, there is provided a method for easily preparing nanomaterial microstructures using paraffin wax. By pressing a master pattern on the paraffin wax layer to form an intaglio pattern and filling a nanomaterial suspension into the groove of the intaglio pattern, a nanomaterial microstructure that can be applied to a transparent electrode or the like can be obtained. The suspension is naturally filled in the intaglio pattern of the paraffin wax layer by supplying a nanomaterial suspension containing a hydrophilic solvent onto the hydrophobic paraffin wax layer. In addition, in the manufacturing method of the present invention, since the removal of the paraffin wax layer after the microstructure is formed can be performed simultaneously with the heat treatment process of the nanomaterial microstructure, the process is very simple. Such nanomaterial microstructures may be preferably applied to electrodes of solar cells or displays that require both conductivity and light transmittance.

1 is a view for explaining a microstructure manufacturing method according to a first embodiment of the present invention.

2 is a view for explaining a microstructure manufacturing method according to a second embodiment of the present invention.

3 is a cross-sectional view illustrating a method according to a first embodiment of the present invention.

Figure 4 is a photograph showing a paraffin wax layer having an intaglio pattern formed in the course of the manufacturing method of the present invention, (a) shows a paraffin wax layer composed of a plurality of prismatic structures formed in the first embodiment, (b) is A paraffin wax layer composed of a plurality of pyramidal structures formed in Example 2 is shown.

FIG. 5 is a photograph showing nanomaterials arranged in a recessed pattern groove of a paraffin wax layer in the process of the manufacturing method of the present invention, (a) shows a nanomaterial array of a stripe pattern formed in the first embodiment, ( b) shows the lattice pattern of the nanomaterial array formed in the second embodiment.

6 is a photograph showing a nanomaterial microstructure formed by the method of manufacturing a microstructure of the present invention, (a) shows a nanomaterial microstructure of a stripe pattern formed according to the first embodiment, (b) is a second The nanomaterial microstructure of the lattice pattern formed according to the embodiment is shown.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiments of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Briefly, firstly, the present invention provides a method for preparing a microstructure using a hydrophobic paraffin wax. The paraffin wax layer is laminated on a surface desired to form a microstructure, and then pressed into a master pattern of a microstructure to form an intaglio pattern. The intaglio pattern may be a grooved prism or a lattice pattern. The nanomaterial suspension for forming the microstructure is then filled into the grooves of the intaglio pattern of the paraffin wax layer. If the solvent of the nanomaterial suspension is water or a hydrophilic material, the paraffin wax is hydrophobic, so the nanomaterial suspension can naturally fill the groove. After evaporating the solvent and pyrolyzing the paraffin wax layer, a microstructure of a prism pattern or a lattice pattern is formed. Preferably, when the microstructure is formed of a nanomaterial that can be formed as a transparent electrode, such as silver nano, heat treatment may be performed to reduce contact resistance.

The present invention can easily form a regular microstructure that can be applied to a transparent electrode such as a touch screen, a flexible display, a solar cell at a relatively low temperature.

Hereinafter, a manufacturing method according to a first embodiment of the present invention will be described in detail with reference to FIGS. 1, 3, 4 (a), 5 (a), and 6 (a).

1 and 3 illustrate a process of a method for manufacturing a microstructure according to a first embodiment of the present invention.

The microstructure manufactured by the manufacturing method according to the first embodiment of the present invention has a stripe pattern. First, a master mold having a stripe-shaped master pattern is prepared, and the master mold may be made of PDMS having elasticity.

After the master mold is prepared, the substrate 10 to form the microstructure is prepared as shown in FIGS. 1A and 3A. The substrate 10 applied herein is not particularly limited, but may be a substrate that provides a surface to form a microstructure. For example, the substrate 10 may be a glass substrate.

As another example, the substrate 10 may be a sacrificial substrate used only to form a microstructure, and the microstructure formed thereon may be transferred or moved to another structure.

Subsequently, as in FIGS. 1B and 3B, a paraffin wax layer 20 is formed on the substrate 10. The paraffin wax layer 20 may use spin coating, for example.

The paraffin wax used here is an alkane (C _n H _{2n + 2} ) series that can be easily deformed by pressure at low temperatures, and the deformed form is maintained after the pressure is removed. Therefore, as described in detail below, in the embodiments of the present invention by pressing the master pattern proceeds to the process of forming the intaglio pattern on the paraffin wax layer.

For example, as illustrated in FIGS. 1C and 3C, a master mold 30 having a master pattern prepared in advance is pressed onto the paraffin wax layer 20 to form an intaglio pattern. After removing the master mold 30, the paraffin wax layer 210 having the intaglio pattern is formed in FIGS. 1D and 3D.

The master pattern is a pattern identical or similar to the pattern of the microstructure to be obtained, which is embossed on the master mold. As described above, the master mold 30 may be made of PDMS or the like to have elasticity.

As shown in (c) and (c) of FIG. 1, when the master pattern of the master mold 30 is contacted with the paraffin wax layer 20 and pressure is applied below the melting temperature of the paraffin wax, the master pattern is transferred to the negative pattern. A paraffin wax layer 210 is formed. For reference, the paraffin wax layer 210 having the intaglio pattern may be referred to as a paraffin mold.

The paraffin wax layer 210 having the intaglio pattern, manufactured according to the first embodiment, includes a plurality of prismatic structures 212 as shown in FIGS. 1D and 3D. Such prismatic structure 212 may be substantially triangular in cross section.

Figure 4 (a) is an electron micrograph of the paraffin wax layer 210 consisting of a plurality of prismatic structures formed in the process of the microstructure manufacturing method according to the first embodiment of the present invention. 4 (a) is a plan view, and shows a state in which each of the plurality of prismatic structures 212 are spaced apart from each other.

As can be seen in FIGS. 1D and 3D, the paraffin wax of the prismatic structure 212 is substantially triangular in cross section, with groove grooves between the plurality of prismatic structures 212. 211 is formed.

Since the prismatic structures 212 are arranged to be spaced apart from each other, as shown in FIGS. 1D, 3D, and 4A, the prismatic structures 212 are disposed between the prismatic structures 212. The surface of the substrate 10 is exposed. In this case, the microstructure of the present invention is formed on the exposed surface of the substrate 10.

However, when the substrate 10 is used as a sacrificial substrate, that is, when the microstructure is moved or transferred to another structure, all the structures in which the prismatic structures 212 are spaced apart or not spaced from each other may be applied.

Next, as shown in FIGS. 1E and 3E, the nanomaterial suspension 41 is filled in the grooves 211 of the intaglio pattern, that is, between the prismatic structures 212. Preferably, the nanomaterial suspension 41 may comprise a hydrophilic solvent such as water, alcohol, and the like. In this case, when the nanomaterial suspension 41 is supplied to the upper surface of the prismatic structure 212 which is a hydrophobic paraffin wax, it is naturally filled only in the groove groove 211 of the intaglio pattern.

More preferably, since the prismatic structure 212 has such a triangular structure, the nanomaterial suspension 41 including the hydrophilic solvent can be more easily filled into the groove 211.

After the solvent evaporates from the nanomaterial suspension 41, the nanoparticles are aligned in the groove 211 between the paraffinic prismatic structures 212.

5 (a) is an electron micrograph showing the arrangement of silver nanomaterials in the grooves of the intaglio pattern of the paraffin wax layer in the process of the manufacturing method according to the first embodiment of the present invention. As shown in the photo, it can be seen that the silver nano bars are aligned inside the grooves 211 of the intaglio pattern.

1 (f) and 3 (f), the paraffin wax layer 210 having an intaglio pattern is removed. The paraffin wax may be removed using pyrolysis, and preferably, the paraffin wax layer 210 may be removed while simultaneously performing heat treatment of the nanomaterial microstructure. For example, in the production of electrodes using silver nano bars, heat treatment is performed at about 200 degrees to reduce contact resistance, and paraffin wax may be thermally decomposed during such heat treatment. In this heat treatment, the paraffin wax layer 210 is completely removed and only the arrangement of the silver nanorods is maintained.

6 (a) is an electron micrograph of the silver nano-fine structure manufactured by the manufacturing method according to the first embodiment of the present invention. In the picture, the linear arrangement of the silver nano bars can be confirmed, which can increase the light transmittance while having electrical conductivity, thereby providing a microstructure applicable to the transparent electrode.

Hereinafter, a method of manufacturing a microstructure according to a second embodiment will be described with reference to FIGS. 2A to 4F, 4B, 5B, and 6B. .

In the manufacturing method of the second embodiment of the present invention, the microstructure of the lattice pattern is manufactured. Formation of the microstructure of the lattice pattern is first pressed into a master mold having a lattice (grid) master pattern, or first pressed into a master mold 30 having a stripe master pattern used in the first embodiment. It can also be implemented by second-degree rotation by rotating 90 degrees.

In addition, the manufacturing method of the second embodiment is the same as or similar to the first embodiment, and will be described briefly below. For reference, the same reference numerals are given to the same or similar elements.

A substrate 10 is prepared as shown in FIG. 2A, and a paraffin wax layer 20 is formed on the substrate 10 as illustrated in FIG. 2B. The master mold 30 is pressed into the paraffin wax layer 20 to form a lattice engraving pattern (FIGS. 2C and 2D).

The intaglio pattern formed in the second embodiment has a lattice shape, and the paraffin wax layer 220 having the intaglio pattern includes a plurality of pyramid structures 222. These pyramid structures 222 are also substantially triangular in cross section, and as described above, when the microstructures are installed on the substrate 10, the pyramid structures may be spaced apart from each other.

The nanomaterial nanomaterial suspension 42 is supplied onto the paraffin wax layer 220 having the lattice-type intaglio pattern to fill the groove 221 of the intaglio pattern. Suspension 42 may include a hydrophilic solvent such as water or alcohol. After the solvent is evaporated, the paraffin wax layer 220 is removed using pyrolysis. In this case as well, the paraffin wax layer 20 may be removed at the same time when the heat treatment of the nanomaterial.

Figure 4 (b) is an electron micrograph showing a paraffin wax layer 220 having a lattice-shaped intaglio pattern formed in the process of the second embodiment. Here, the paraffin wax layer 220 having a plurality of pyramid structure arrangements can be confirmed. FIG. 5B is a photograph showing that the silver nano bars are arranged in a lattice shape in the groove 221 of the lattice-shaped intaglio pattern formed in FIG. 4B. 6 (b) is a photograph showing the arrangement of silver nano bars after removing the paraffin wax layer 20 through heat treatment.

As described above, according to the method for preparing a microstructure of the present invention, the stripe-like or lattice-shaped nanomaterial microstructure can be easily formed using paraffin wax. If such a microstructure is manufactured using a conductive material such as silver nano, the microstructure may be preferably applied to a transparent electrode of a solar cell, a touch panel of a display element, and the like, having conductivity and high light transmittance.

In the detailed description of the present invention has been described with respect to specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the scope of the invention.

(Explanation of the sign)

10:

substrate

20, 210, 220: paraffin wax layer

211, 221: groove groove 30: master mold

41, 42: Nanomaterial Suspension

Claims

Forming a paraffin wax layer on the substrate;

Forming an intaglio pattern on the paraffin wax layer;

Filling a nanomaterial suspension into the groove of the engraved pattern;

Evaporating the solvent from the suspension; And

Removing the paraffin wax layer,

The microstructure manufacturing method of forming a microstructure of the nanomaterial having the shape of the intaglio pattern.
The method according to claim 1,

The engraved pattern is a microstructure manufacturing method characterized in that formed by pressing the paraffin wax layer in a master mold having a master pattern.
The method according to claim 2,

The engraved pattern is a microstructure manufacturing method characterized in that the stripe or lattice.
The method according to claim 3,

The paraffin wax layer having the engraved pattern is a microstructure manufacturing method, characterized in that the longitudinal cross-section is substantially triangular.
The method according to claim 1,

The suspension is a microstructure manufacturing method characterized in that the silver nano suspension.
The method according to claim 1,

Removing the paraffin wax layer is a microstructure manufacturing method characterized in that using pyrolysis.
The method according to claim 6,

The pyrolysis of the paraffin wax layer is combined with the heat treatment of the microstructures.
The method according to claim 1,

And the solvent of the suspension is hydrophilic.
Forming an intaglio pattern in the form of a microstructure to be obtained in the paraffin wax layer;

Filling the silver nano suspension into the groove of the intaglio pattern; And

Performing heat treatment on the silver nano suspension,

The paraffin wax layer is a microstructure manufacturing method characterized in that the removal in the heat treatment process.
The method according to claim 9,

The engraved pattern is a microstructure manufacturing method characterized in that formed by pressing with a master mold having a master pattern.
The method according to claim 10,

The paraffin wax layer having the engraved pattern is a microstructure manufacturing method characterized in that consisting of a plurality of prismatic structures arranged spaced apart from each other.
The method according to claim 10,

The paraffin wax layer having the engraved pattern is a microstructure manufacturing method characterized in that consisting of a pyramidal structure arranged spaced apart from each other.
Microstructure produced by any one of the above claims 1 to 12.