KR20230035915A - Method for changing color of dlc thin film - Google Patents

Abstract

Disclosed is a process capable of changing an interference color of a DLC thin film. A color changing method of the DLC thin film according to one embodiment of the present invention comprises the following steps of: preparing a structure in which the DLC thin film is deposited on at least one surface; and surface treating the DLC thin film. The surface treatment is heat treatment or UV-O₃ treatment. Provided is the color changing method of the DLC thin film, capable of uniformly expressing a desired interference color.

Description

Method for changing color of DLC thin film {METHOD FOR CHANGING COLOR OF DLC THIN FILM}

The present invention relates to a process capable of changing the interference color of a DLC thin film.

In addition to enhancing surface hardness by uniformly depositing nano- and micro-scale thin films on structures, it is necessary to develop sensitive materials with beautiful surfaces using interference colors. Conventionally used anodizing, wet plating, and AIP vacuum deposition have environmental restrictions due to wet processes, and there is a limitation that deposition is impossible on non-conductive substrates.

DLC (Diamond Like Carbon) thin film is an amorphous carbon film with high hardness, wear resistance, high lubrication, corrosion resistance and chemical resistance. Considering high hardness and excellent wear resistance, DLC thin film is used for materials or friction parts in various industrial fields, and considering high insulation and excellent corrosion resistance, it is used for overseas/ship/plant parts, electrical/electronic devices, and bio parts. DLC thin films are used.

Attempts have been made to express color using DLC thin films, but DLC thin films have a problem in that it is difficult to secure uniform color as the color expressed changes dramatically even with slight fluctuations in nanoscale thickness, and if the desired color is not expressed There is a problem in that the DLC thin film must be re-coated from the beginning or etching must be performed for an excessive thickness. In addition, in order to locally express different colors, there is a cumbersome problem that a plurality of coating processes must be performed using a mask.

Korean Patent Publication No. 10-2010-0045877 (2010.05.04.)

The present invention is designed to solve the above problems, and to provide a method for changing the color of a DLC thin film that can uniformly express a desired interference color through surface treatment including subsequent heat treatment or UV-O ₃ treatment on the prepared DLC thin film. do.

A method for changing the color of a DLC thin film according to an embodiment of the present invention includes preparing a structure in which a DLC thin film is deposited on at least one surface; and surface treatment of the DLC thin film, wherein the surface treatment is heat treatment or UV-O ₃ treatment.

In addition, according to an embodiment of the present invention, the peak value of the Raman spectroscopy spectrum measured on the surface of the surface-treated DLC thin film may satisfy Equation (1) below.

(1) I(D)/I(G) ≥ 0.5

In Equation (1), I(D) is a peak value at 1350 cm ^-1 , and I(G) is a peak value at 1580 cm ^-1 .

In addition, according to an embodiment of the present invention, the surface treatment may further include O ₂ plasma treatment capable of changing the I(D)/I(G) fraction of Equation (1).

Also, according to an embodiment of the present invention, the DLC thin film of the structure may be deposited by a PECVD method or an LPCVD method.

Also, according to an embodiment of the present invention, the surface treatment of the DLC thin film may be performed under a vacuum atmosphere or an inert atmosphere.

Further, according to an embodiment of the present invention, the heat treatment may be performed in an electric furnace, a rapid heat treatment machine, or a laser heat treatment machine in a temperature range of 200 to 1000 °C.

In addition, according to one embodiment of the present invention, the heat treatment may be performed in a temperature range of 200 to 600 ℃.

Also, according to an embodiment of the present invention, the UV light source may be a mercury lamp having a wavelength of 150 to 300 nm.

Further, according to one embodiment of the present invention, the thickness of the DLC thin film may be 10 to 10,000 nm.

According to the present invention, it is possible to provide a method for changing the color of a DLC thin film that can simply implement a changed uniform interference color through surface treatment including subsequent heat treatment or UV-O ₃ - treatment.

1A is a Raman spectroscopy spectrum before subsequent heat treatment in Example 1, and FIG. 1B is a Raman spectral spectrum after subsequent heat treatment in Example 1.
FIG. 2a is a Raman spectroscopy spectrum before performing subsequent heat treatment in Example 2, and FIG. 2b is a Raman spectroscopy spectrum after performing subsequent heat treatment in Example 2.
FIG. 3a is a Raman spectroscopy spectrum before performing the subsequent heat treatment of Example 3, and FIG. 3b is a Raman spectral spectrum after performing the subsequent heat treatment of Example 3.
FIG. 4a is a Raman spectroscopy spectrum before UV-O ₃ treatment in Example 5, and FIG. 4b is a Raman spectroscopy spectrum after UV-O ₃ treatment in Example 5. FIG.

Although the preferred embodiment of the present invention will be described in more detail, the already well-known technical parts will be omitted or compressed for conciseness of description.

A method for changing the color of a DLC thin film according to an embodiment of the present invention includes preparing a structure in which a DLC thin film is deposited on at least one surface; and surface treatment of the DLC thin film, wherein the surface treatment may include heat treatment or UV-O ₃ treatment.

In the present invention, the structure is not particularly limited in terms of shape and material, and includes single-crystal, poly-crystal metal and non-metal materials, and includes all materials of various shapes.

Hereinafter, each step of the manufacturing method will be described in detail.

According to an embodiment, the DLC thin film may be prepared by depositing the DLC thin film on the structure using a PECVD method or an LPCVD method. According to a preferred embodiment, when the PECVD method is applied, it is possible to deposit a thin film having a uniform thickness even on a structure having a large area or a complex shape. The deposition process may be performed for 3 minutes or more, and may be appropriately controlled according to the desired thickness.

In the present invention, at least one surface of the deposited DLC thin film can be subjected to surface treatment including subsequent heat treatment or UV-O ₃ etching to secure a DLC thin film in which a desired interference color change is uniformly expressed. Interference color change can also be obtained through O ₂ plasma treatment that can change the I(D)/I(G) fraction.

Heat treatment according to an embodiment may be performed through laser irradiation of a rapid heat treatment machine or a laser heat treatment machine in addition to a conventional electric furnace, and may be performed on the entire or local area of the DLC thin film.

Heat treatment according to an embodiment may be performed at 200 to 1000 ° C, and heat treatment according to a preferred embodiment may be performed at a low temperature range of 200 to 600 ° C. The heat treatment time according to an embodiment may be 1 minute or more.

The surface treatment may be performed in an atmosphere in which the DLC thin film and the structure do not chemically react, and the heat treatment according to an embodiment may be performed in a vacuum atmosphere or an inert atmosphere.

The present invention can secure a color DLC thin film in which a desired interference color change is uniformly expressed through heat treatment. can be satisfied.

(1) I(D)/I(G) ≥ 0.5

In Equation (1), I(D) is a peak value at 1350 cm ^-1 , and I(G) is a peak value at 1580 cm ^-1 .

When the heat treatment according to the embodiment is performed, the I(D) value increases and the I(D)/I(G) value is controlled to be 0.5 or more, so that a uniform interference color change can be secured.

UV-O ₃ treatment according to an embodiment may utilize a mercury lamp having a wavelength of 150 to 300 nm as a UV light source. The energy of the irradiated UV light source is preferably 100 kcal/mol or more.

The present invention can secure a color DLC thin film in which a desired interference color change is uniformly expressed through UV-O ₃ treatment or O ₂ plasma treatment. According to an embodiment, measurement is performed on the surface of the UV-O ₃ treated DLC thin film. A peak value of one Raman spectroscopy spectrum may satisfy Equation (1) below.

(1) I(D)/I(G) ≥ 0.5

In Equation (1), I(D) is a peak value at 1350 cm ^-1 , and I(G) is a peak value at 1580 cm ^-1 .

During UV-O ₃ etching treatment, the energy of sp3 bond (CH 98kcal/mol, CC 88kcal/mol) and sp2 bond (CH 104kcal/mol, C=C 152kcal/mol) in the DLC thin film is lower than that of irradiated UV-ozone. As the bond having the binding energy is broken, the Raman peak value decreases.

When the UV-O ₃ treatment according to an embodiment is performed, the peak value is reduced and the I(D)/I(G) value is controlled to be 0.5 or more, so that a uniform color can be secured.

In the above, the description of performing the heat treatment and the UV-ozone etching treatment alone has been described, but the point that the I(D) value increases when the heat treatment is performed and the Raman peak value decreases when the UV-O ₃ treatment is performed Considering the heat treatment and UV-O ₃ treatment, a uniform interference color change may be obtained. According to an embodiment, the peak value of the Raman spectroscopy spectrum measured on the surface of the DLC thin film surface treated by low-temperature heat treatment, UV-O ₃ treatment, or O ₂ plasma treatment may satisfy Equation (1).

According to one example, the thickness of the DLC thin film subjected to surface treatment including subsequent heat treatment or UV-O ₃ treatment may be 10 to 10,000 nm.

Hereinafter, a preferred embodiment of the present invention will be described in more detail.

Example

A DLC thin film was deposited on a silicon substrate using PECVD equipment (Korea Vacuum Co., Ltd., Ka-DLC 800). The initial vacuum degree was 5 × 10 ^-6 Torr, and CH ₄ gas and Ar gas were injected at a ratio of 3: 1, respectively, and the DLC deposition process was performed at a vacuum degree of 2 to 2.5 × 10 ^-2 Torr and a temperature of 130 ° C. Specimens A, B, C, and D of 1 were prepared.

The thickness of the DLC thin film of the prepared specimen was measured using FE-SEM equipment (Hitachi, S-8000).

Psalter deposition time
(min) DLC thin film thickness
(nm) color index L* a* b* A 3 53.6 72.39 -0.63 23.35 B 5 59.5 39.97 9.89 3.02 C 10 123.0 80.65 -4.91 17.47 D 30 385.0 72.46 2.27 10.81

Examples 1 to 3 in Table 2 were prepared by heat-treating the prepared specimens A to C of Table 1. For the heat treatment, a tube furnace was used, and a nitrogen atmosphere having a N ₂ fraction of 99.9% or more was formed, and the heat treatment was performed by raising the temperature at a heating rate of 5° C./min while injecting N ₂ at a flow rate of 400 cc/min.

For the color index of Table 2, the spectrum of the visible light band was confirmed using UV-VIS-NIR (Shimadzu, UV-3105PC), and the Lab color index was measured with the Color Analyzer program.

The I(D)/I(G) values in Table 2 were calculated using a micro-Raman spectrometer (Unithink, UniRaman). The measurement range was 800 to 2400 cm ⁻¹ , and Examples 1 to 3 were exposed to a light source having a wavelength of 532 nm for 1 minute.

I(D) and I(G) in Table 2 are the peak values of the Raman spectroscopy spectrum measured on the surface of the DLC thin films of Examples 1 to 3, respectively, and I(D) is the peak value at 1350 cm ^-1 , and I (G) is the peak value at 1580 cm ^-1 .

Raman spectroscopy spectra before and after subsequent heat treatment of Examples 1 to 3 are shown in FIGS. 1 to 3, and I(D)/I(G) values are shown in Table 2. 1a, 2a, and 3a are Raman spectroscopy spectra before performing the subsequent heat treatment of Examples 1 to 3, respectively, and FIGS. 1B, 2B, and 3B are Raman spectra after performing the subsequent heat treatment of Examples 1 to 3, respectively. it's a spectrum

division used
Psalter heat treatment condition color index magnitude
(CD) I(D)/I(G) temperature
(℃) hour
(hour) L* a* b* before heat treatment after heat treatment Example 1 A 300 2 75.36 -0.19 24.00 3.07 0.407 0.525 Example 2 B 400 2 45.88 8.87 0.58 6.47 0.416 0.618 Example 3 C 500 2 85.05 -3.94 21.65 6.15 0.403 0.752

Referring to Table 2, as a result of color analysis of the specimens of Examples 1 to 3, there was no significant difference with the naked eye, but a clear change in interference color was confirmed as shown in the Lab color index shown in Table 2. In addition, referring to FIGS. 1 to 3, the I (D) value increased according to the heat treatment, and the I (D) / I (G) value of Examples 1 to 3 was controlled to 0.5 or more to ensure a uniform color. Able to know.

Meanwhile, samples A and D of Table 1 were subjected to UV-O ₃ treatment to prepare Examples 4 and 5 of Table 3 below. UV-O ₃ treatment was performed twice for 30 minutes using a UV0 ₃ cleaner (AHTECH, AC-6) to compare clear differences. At this time, a mercury lamp with a wavelength of 254 nm was used as the UV light source, and the irradiated energy was 113 kcal/mol.

For the color index of Table 3, the spectrum of the visible light band was confirmed using UV-VIS-NIR (Shimadzu, UV-3105PC), and the Lab color index was measured with the Color Analyzer program.

The I(D)/I(G) values in Table 3 were calculated using a micro-Raman spectrometer (Unithink, UniRaman). Example 4 was exposed to a light source having a measurement range of 800 to 2400 cm ⁻¹ and a wavelength of 532 nm for 1 minute.

I(D) and I(G) in Table 3 are the peak values of the Raman spectroscopy spectrum measured on the surface of the DLC thin film of Example 4, I(D) is the peak value at 1350 cm ^-1 , and I(G) is the peak value at 1580 cm ^-1 .

Raman spectroscopy spectra before and after UV-O ₃ treatment of Example 4 are shown in FIG. 4, and I(D)/I(G) values are shown in Table 3. FIG. 4a is a Raman spectroscopy spectrum before UV-O ₃ treatment in Example 4, and FIG. 4b is a Raman spectroscopy spectrum after UV-O ₃ treatment in Example 4. FIG.

division used
Psalter color index magnitude
(CD) I(D)/I(G) L* a* b* UV-O ₃
before etching UV-O ₃
after etching Example 4 A 69.07 -1.11 20.06 4.70 0.354 0.572 Example 5 D 70.16 -0.29 10.10 3.51 0.354 0.572

Referring to Table 3, the results of color analysis of the specimens of Examples 4 and 5 were similar to the naked eye without a significant difference, but a clear change in interference color was confirmed as shown in the Lab color index of Table 3 compared to the Lab color index of Table 1. In addition, referring to FIG. 4, it was found that the peak value decreased due to UV-O ₃ treatment, and the I(D)/I(G) value of Example 5 increased to 0.5 or more to secure a uniform color. .

In the foregoing, exemplary embodiments of the present invention have been described, but the present invention is not limited thereto, and those skilled in the art within the scope that does not deviate from the concept and scope of the claims described below. It will be appreciated that many changes and modifications are possible.

Claims (9)

Preparing a structure in which a DLC thin film is deposited on at least one surface; and
Including; surface treatment of the DLC thin film,
The surface treatment is a method for changing the color of a DLC thin film, characterized in that heat treatment or UV-O ₃ treatment. According to claim 1,
A method for changing the color of a DLC thin film in which the peak value of the Raman spectroscopy spectrum measured on the surface of the surface-treated DLC thin film satisfies the following formula (1).
(1) I(D)/I(G) ≥ 0.5
(In the above formula (1), I(D) is the peak value at 1350 cm ^-1 , and I(G) is the peak value at 1580 cm ^-1 ) According to claim 2,
The surface treatment,
A method for changing the color of a DLC thin film further comprising an O ₂ plasma treatment capable of changing the I(D)/I(G) fraction of Equation (1). According to claim 1,
The DLC thin film of the structure,
A method for changing the color of a DLC thin film comprising depositing by a PECVD method or an LPCVD method. According to claim 1,
The step of surface treating the DLC thin film,
A method for changing the color of a DLC thin film, characterized in that it is carried out under a vacuum atmosphere or an inert atmosphere. According to claim 1,
The heat treatment is a method of changing the color of a DLC thin film performed in an electric furnace, a rapid heat treatment machine, or a laser heat treatment machine in the temperature range of 200 to 1000 ° C. According to claim 6,
The heat treatment is a method for changing the color of a DLC thin film performed in a temperature range of 200 to 600 ° C. According to claim 1,
The UV light source is a mercury lamp having a wavelength of 150 to 300 nm. Method for changing the color of a DLC thin film. According to claim 1,
A method for changing the color of a DLC thin film in which the thickness of the DLC thin film is 10 to 10,000 nm.

Images