KR101568838B1 - Method for producing a glass with low reflection, anti-fingerprint properties - Google Patents

Abstract

The present invention relates to a method of forming a monomolecular film by immersing a glass substrate in a colloidal solution in which nanoparticles are dispersed and forming a monomolecular film by a Langmuir-Blodgett method, irradiating a laser beam onto the substrate to be processed, And forming a nano pattern in the form of a moth eye through etching. BACKGROUND OF THE INVENTION

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a glass having low reflection and fingerprint prevention properties,

More particularly, the present invention relates to a method of manufacturing glass, in which a glass substrate is immersed in a colloidal solution in which nanoparticles are dispersed, a monomolecular film is formed through a Langmuir-Blodgett method, To a method of manufacturing a glass having low reflection and fingerprint-preventing properties by forming a nanopattern in the form of a moth eye through etching by irradiating a laser with changing the micro density of the surface.

Recently, there is an increasing demand for thinning and high performance of products in the mining industry, display industry, semiconductor industry, and bio industry. In particular, a transparent touch panel as a user interface of an electronic device for this purpose is recognized as a very important component of electronic products in view of its usefulness, expandability and accessibility.

However, the cover glass, which is mainly used as a substrate of such a transparent touch panel, has a light reflectance level that can not be ignored by itself. Therefore, when the surroundings are bright as in an outdoor environment, . The brightness of the display must be increased to compensate for the reflection of light, and the power consumption for driving the display is increased.

In addition, fingerprints left on the screen as a foreign substance transferred to the cover glass when touching the screen with a finger are pointed as a factor that hinds visibility, and a film has been developed to be attached to the front of the touch panel , The visibility becomes worse depending on the reflectance and transmittance of the film itself.

In order to solve these problems, it is necessary to develop anti-reflection (AR) and anti-fingerprint (AF) technologies. Recently, when the surface of a nano structure in the form of a moth eye is used, It has been proved that the same problem can be solved. 1 is an exemplary view showing an example of the surface of a nanostructure on the surface of a moth eye.

There are three main methods of processing the surface of a conventional moth eye-type structure.

1. Lithography based: We use e-beam lithography because conventional UV photolithography can not achieve 100nm class nano patterns. However, this is a series process in which each pattern must be written in a high vacuum, and since the processing time is very long, it is practically impossible to mass-produce it.

In addition, a high-vacuum process is required, direct processing of the cover glass is not possible, and the process according to the indirect patterning method is very complicated. In addition, since the imprinting lithography method requires a metal template (manufactured by e-beam lithography) processed with a 100 nm class, the manufacturing process is complicated, and there is a problem in that it is difficult to initialize the investment cost, large size, and design change at high cost.

 2. Roll hot forming base: It is a technique to imprint the pattern pattern of the roll on the polymer film by heating / pressing the polymer film which is easy to heat deformation to the 100nm class roll, and is suitable for mass production . However, there is a problem in that it can not be directly applied to a glass having a very high thermoforming temperature, and since such a polymer AF / AR film is usually required to be attached on a cover glass, the total transmittance is lowered due to the limitation of the polymer self- There is a problem.

 3. Colloidal self-assembled photonic crystal (colloidal self-assembly): Nanoparticles are coated on a substrate as a single layer and used as a dry etching mask to form nanopatterns directly on the glass substrate. There is a problem that it is difficult to make an area and the process is complicated.

In addition, the technique of coating the nanoparticles with a single layer on the substrate is relatively unstable. Therefore, when such an operation is performed on each substrate, there is a high possibility that the yield is lowered due to frequent defects, There is a problem that the material cost is increased because it is required to be discarded after use.

As a result, in the end, industry today needs a technology to mass-produce nano patterns at low cost in cover glasses.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a method of fabricating a nanoparticle monolayer by depositing a processing substrate on a glass substrate on which a nanoparticle monomolecular film is formed, The present invention also provides a method of manufacturing a glass having low reflection and fingerprint prevention characteristics that can be mass-produced at low cost by a simple process.

According to another aspect of the present invention, there is provided a method of manufacturing a glass having low reflection and fingerprint prevention characteristics, comprising: a first step of depositing a transparent substrate provided on a motorized table in a solution that does not react with the transparent substrate and nanoparticles; A second step of forming a monolayer film of colloidal nanoparticles in the solution and producing an optical template having a single layer of nanoparticles attached to the entire surface of the transparent substrate through a Langmuir-Blodgett method; A third step of bonding the processed substrate to be processed to the entire surface of the optical template; A fourth step of irradiating the laser to the side of the processed substrate while transmitting the optical template to change the microstructure of the surface of the processed substrate; Separating the processed substrate from the optical template, immersing the processed substrate in an etching solution to form a nanopattern on the surface, and washing the processed substrate; .

At this time, in the fourth step, a plasma is generated on the surface of the processed substrate by using a pulsed laser with the laser to cut the surface, or the surface of the processed substrate is cut by using the laser with a CW laser (Continuous Wave Laser) Can be instantaneously dissolved and then solidified.

The second step may further include coating a functional layer for improving heat resistance or light transmittance on the nanoparticle side attached to the optical template.

The present invention does not require a vacuum process as in the prior art, and since the entire process of irradiating a laser and forming a nano pattern is performed by a parallel process, it is possible to obtain a large-sized nanopattern formation and an improvement in productivity.

In addition, since the manufacture of the optical template is very simple and easy, it is easy to change the design and it is possible to change the design specifications of the midge eye structure by pre-etching the nanoparticles.

In addition, the processed substrate can be applied not only to glass but also to substrates made of various materials such as silicon (Si), and it is not necessary to attach additional AF / AR layers to the completed substrate. Thus, high transmittance and AR / And an effect of improving the visibility can be obtained.

1 is an illustration showing an example of a surface of a nanostructure on the surface of a moth eye,
FIG. 2 is a flowchart showing a process procedure according to a preferred embodiment of the present invention,
FIG. 3 is a schematic view showing a state in which nanoparticles are attached to a glass substrate according to the present invention,
4 is a micrograph showing a nanoparticle layer coated on a transparent substrate according to the present invention,
5 is a cross-sectional view showing a state where a processing substrate is attached to a front surface of an optical template according to the present invention,
6 is a schematic view showing a state in which a cover glass is coated on a glass substrate coated with nanoparticles and a laser is irradiated,
FIG. 7 is a cross-sectional view showing a state in which the present invention is implemented in a positive and negative manner,
8 is a cross-sectional view illustrating a processed substrate on which a nanopattern is formed according to the present invention.

Hereinafter, a method of manufacturing a glass having low reflection and fingerprint prevention characteristics according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a flow chart illustrating a process procedure according to a preferred embodiment of the present invention. In the present invention, a line beam laser is used as a method for forming a large number of moth eye patterns on a surface of a glass substrate. And the optical template (optical template) are used to change the density of local microstructures in parallel.

First, in a first step S 110, the transparent substrate 110 provided on the electric table 170 is settled in the solution 150 that does not react with the transparent substrate 110 and the nanoparticles 130.

3 is a schematic view showing a state in which the nanoparticles 130 are attached on the transparent substrate 110 according to the present invention. As shown in FIG. 3 (a), the Langmuir- -Blodgett) The transparent substrate 110 is mounted on an electric table 170 capable of moving in the X-axis and Y-axis directions in order to form a film, and is set in an oblique manner in a solution contained in the water reservoir.

The transparent substrate 110 is preferably made of a tempered glass substrate having excellent heat resistance and laser penetration performance. The transparent substrate 110 may be used as a display screen having relatively low transparency or transparency such as SiO ₂ or polymer, Are also available.

DI water which is deionized water is used as the solution 150 in the embodiment of the present invention and all the solution 150 which does not chemically react with the transparent substrate 110 and the nanoparticle 130 described later But a material having a low affinity can be selected in consideration of affinity with the colloidal liquid in which the nanoparticle 130 described later is dispersed.

Next, in a second step (S 120), a colloidal nanoparticle 130 monolayer film is formed on the solution 150, and the surface of the transparent substrate 110 is exposed through a Langmuir-Blodgett A single-layer film of the nanoparticle 130 is adhered to an optical template.

The colloidal liquid mixed with the nanoparticles 130 is injected into the water storage tank 140 containing the solution 150. As mentioned above, the solution 150 and the liquid are not mixed with each other Material.

In the present invention, the nanoparticles 130 may be made of silica nanospheres, and the nanoparticles 130 may be made of a material selected from the group consisting of IPA (iso-propanol) and 1-buthanol are mixed at an appropriate ratio so that a monolayer interface of the nanoparticle 130 is formed on the surface of the solution 150.

At this time, the observation of the monolayer interface of the nanoparticle 130 can be confirmed by a diffraction phenomenon by light. In other words, the amount of the nanoparticles 130 increases, and a color change due to the instantaneous diffraction in which a multilayer is formed is observed.

After the single-layer interface of the nanoparticle 130 is formed, the transparent substrate 110 is moved in the X-axis direction through the transmission table 170 to remove the fine holes formed between the interfaces.

In this case, as shown in FIG. 3 (b), the nanorods are also formed between the transparent substrate 110 and the solution 150, and the nanoparticles 130 adhere to the back surface of the transparent substrate 110, It can be easily removed with ethanol after the process is finished.

In summary, nanoparticles 130 are formed on the surface of the transparent substrate 110 by a Langmuir-Blodgett method using the characteristic that the nanoparticles 130 are formed as a single layer on the liquid film with surface tension. Coating with a single layer creates a tightly coupled microlens array without difficulty.

FIG. 4 is a microscope photograph showing a nanoparticle layer coated on a transparent substrate according to the present invention as a single layer. When the transparent substrate 110 is pulled out of the solution 150 using the Langmuir-Blodgett method, Since the moving speed of the electric table 170 is maintained at a rate similar to the evaporation rate of the colloidal liquid used in the interface formation, an optical template having nanoparticles attached thereto as shown in FIG. 4 is obtained.

The Langmuir-Blodgett method is a method in which a monomolecular film (also referred to as Langmuir film) having a thickness of one layer of molecules, which is generated when an amphipathic molecule is developed on the surface of a living body, . The substrate is smoothly and vertically moved up and down across the monomolecular film held at a constant surface pressure, and the substrate can be stuck horizontally on the monomolecular film to repeat the accumulation.

In addition, a functional layer for improving heat resistance or light transmittance may be coated on the nanoparticle 130 attached to the optical template.

FIG. 5 is a cross-sectional view illustrating a process substrate mounted on a front surface of an optical template according to the present invention. In a third step (S 130), a processed substrate 120 to be processed is coupled to the entire surface of the optical template, do.

In the present invention, the processed substrate 120 is a glass plate, but various materials such as a polymer, a metal, and a ceramic can be used.

6 is a schematic view showing a state where a cover glass is coated on a glass substrate coated with nanoparticles and a laser is irradiated. In a fourth step (S 140), a laser 180 is irradiated onto the processed substrate 120, And the microstructure of the surface of the processed substrate 120 is changed.

6, a line beam laser 180 is scanned in the form of a scan, and the line beam laser 180 is individually focused by the spherical nanoparticles 130 as shown in FIG. 6, and the focused energy Heat is generated on the surface of the processed substrate 120, thereby changing the microstructure, specifically, the density.

The spacing and density of the regions where the microdensity changes occur can be controlled by adjusting the size of the nanoparticles 130 before forming the optical template. Specifically, silica nanospheres (silica nanoparticles) as in the examples can be immersed in a hydrofluoric acid solution (HF solution) for a certain period of time and uniformly reduced in size.

The area where the surface structure of the processed substrate 120 is changed by the laser 180 can be controlled by adjusting the output of the laser. For example, when the laser output is increased, the area is widened.

That is, when the laser beam 180 is irradiated onto the optical template, the coated nanoparticles function as respective microlenses, and thus laser light having a relatively large size is bundled into a nano- Laser. In general, when light enters a spherical lens, the focus of the spherical focal point is focused by the self-focusing effect, and the near-field focal point is focused to a size smaller than the used wavelength. .

This nanofocus laser 180 bundle has a very high energy intensity (W / cm < ² >) and therefore has a thermal effect on the material placed in the focus area. Such a thermal effect causes a heat treatment effect on the surface of the processed substrate 120, thereby changing the microstructure of the surface.

FIG. 7 is a cross-sectional view illustrating the embodiment of the present invention implemented in a positive and negative manner. The fourth step (S 140) of the present invention is applicable to both positive and negative types. Do.

This means that in the etching process of the fifth step described later, the embossing means that the etching rate of the laser-irradiated portion is fast, and the laser-irradiated portion finally forms the corrugation. In contrast, intaglio angles are the way in which the acid is formed because the etching rate of the laser irradiated part is slow.

In the embossing, a plasma is generated on the surface of the processed substrate with a high peak output by using a pulsed laser, and the surface area is increased by the rough surface of the irradiated area, thereby increasing the etching rate. A pulsed laser is a laser with oscillation and stoppage in time, which can greatly enhance the temporal coherence of energy.

On the other hand, the intaglio is heated to near the melting point of the surface of the processed substrate using a CW laser (Continuous Wave Laser), and is instantaneously melted and solidified. As a result, the heat treatment effect is generated and the density is increased. . A continuous wave laser (CW laser) is a concept in contrast to the above-mentioned pulse laser, which means that the laser can continue oscillating in a time constant output from the laser.

In the fifth step S 150, the processed substrate 120 is separated from the optical template, immersed in the etching solution to form a nano pattern 121 on the surface, and then washed to complete a glass having low reflection and fingerprint-preventing properties .

That is, if the processed substrate 120 separated for several to several thousand seconds is immersed in a solution capable of etching SiO ² such as hydrofluoric acid (HF), the surface of the processed substrate 120 corresponding to the period of the nanoparticles 130 A nano pattern 121 is formed. At this time, the etching rate and selectivity can be controlled by adjusting the concentration of hydrofluoric acid and mixing the additive solution.

8 is a cross-sectional view of a processed substrate on which a nanopattern according to the present invention is formed. In summary, a change in the microstructure of the surface of the processed substrate 120 through the fourth step (S 140) An etching rate difference is generated between the peripheral portion and the laser irradiating portion at the time of etching, and a nanostructure having a period of converging to the size of the initial nanoparticle 130 is formed. This allows nanotube texturing to the glass surface in large quantities without any vacuum process.

Since the optical template having the nanoparticles 130 attached thereto can be used semi-permanently once it is fabricated, it is possible to perform mass processing of the nanoparticles 121 without difficulty by repeating only the third and fourth steps for the same pattern specification .

It is to be understood that the invention is not limited to the disclosed embodiment, but is capable of many modifications and variations within the scope of the appended claims. It is self-evident.

110: transparent substrate 120: processed substrate
121: Nano pattern 130: Nano particle
140: Water tank 150: Solution
160: Injector 170: Electric table
180: laser

Claims (3)

A method of manufacturing a glass having low reflection and fingerprint-preventing properties,
A first step (S 110) of precipitating a transparent substrate provided on the electric table to a solution which does not react with the transparent substrate and the nanoparticles;
Forming a monolayer film of colloidal nanoparticles in the solution and fabricating an optical template having a mono-layer film of nanoparticles on the entire surface of the transparent substrate through a Langmuir-Blodgett method (S 120 );
A third step (S 130) of coupling the processed substrate to be processed to the entire surface of the optical template;
A fourth step (S 140) of irradiating the laser onto the side of the processed substrate while transmitting the optical template to change the microstructure of the surface of the processed substrate;
A fifth step (S 150) of separating the processed substrate from the optical template, immersing the processed substrate in an etching solution to form a nanopattern on the surface, and then washing the processed substrate; Wherein the glass has a low reflection and fingerprint-preventing properties.
The method according to claim 1,
In the fourth step (S 140)
A plasma is generated on the surface of the processed substrate using a pulsed laser, and the surface of the processed substrate is instantaneously melted and solidified using a CW laser (Continuous Wave Laser) with the laser Wherein the glass has a low reflection and fingerprint-preventing properties.
The method according to claim 1,
Wherein the second step (S 120) further comprises coating a functional layer for improving heat resistance or light transmittance on the nanoparticle side attached to the optical template. Gt;

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