KR19990084134A - The method of coating optical lens - Google Patents

Abstract

[purpose]

The present invention relates to a method of coating a spectacle lens to provide a spectacle lens to prevent scratches, ultraviolet rays, electromagnetic wave blocking, fog and the like.

[Configuration]

After injecting a gas or liquid containing carbon into a vacuum container, plasma discharge is induced at a low frequency of 60 에서 at room temperature to dissociate the gas, thereby degrading the radicals in which CH, CH ₂ and CH ₃ are decomposed. Generated and attached to the lens to coat the diamond-like carbon thin film (aC: H)

[effect]

Produces plasma at a commercial frequency of 60 kHz at room temperature and provides a method of coding diamond carbon thin films on spectacle lenses by chemical vapor deposition to prevent scratches, ultraviolet rays, electromagnetic interference, and blurring of the spectacle lenses, thus extending the life of the lens. In addition, there are characteristics that can improve eye health.

Description

The method of coating optical lens

The present invention relates to a method for coating a spectacle lens, and more particularly, to generate a plasma at a commercial frequency at room temperature and to provide a method of coding a diamond carbon thin film on a conventional spectacle lens by chemical vapor deposition. The present invention relates to a method of coating a spectacle lens to provide a spectacle lens that can improve the life of the lens, eye health by preventing scratches, ultraviolet rays, electromagnetic shielding, and fog on the spectacle lens.

Conventionally, the spectacle lens is processed by using transparent plastic or glass. In the process of using the spectacles, the surface of the lens may be inadvertently handled, and the transparency of the spectacle lens may not be maintained. There was a lot of economic loss to replace the whole, and there was frost on the surface of the lens due to steam (gas) generated in high humidity weather or eating hot foods, which lost transparency. there was.

Although a method of coating diamond on the optical lens is provided, at least a room temperature and a high frequency of at least 200 ° C are required, and thus, the equipment and the coating work are cumbersome.

The present invention is to provide a method for coating a diamond on the spectacle lens by a low-frequency plasma chemical vapor deposition method at room temperature to solve the above conventional problems.

It is possible to prolong the life of the product by coating it in the above way so that there is no risk of scratches on the lens by providing spectacle lenses with high chemical inertness, thermal conductivity, electrical resistance, light transmittance, hardness and lubricity. To achieve excellence and convenience.

Hereinafter, the configuration of the present invention will be described in detail by one embodiment as follows.

After injecting a gas or liquid containing carbon into a vacuum container, plasma discharge is induced at a low frequency to dissociate the gas to generate radicals in which CH, CH ₂ and CH ₃ are decomposed. A diamond-like carbon thin film (aC: H) is coated by spraying or applying to a lens.

In this way, materials containing carbon (C), such as methane (CH ₄ ), acetylene (C ₂ H ₂ ), butane (C ₃ H ₈ ), etc., which are in gaseous or liquid form, are injected into a vacuum container, When discharged at a low frequency of 60 kHz, dissociated gases produce decomposed active species such as CH, CH ₂ and CH ₃ . Therefore, diamond carbon thin film is formed while attaching the generated active species to the spectacle lens.

Referring to the process made through the experiment according to the present invention as described above are as follows.

A mixed plasma of methane (CH ₄ ) and hydrogen (H ₂ ) is placed in a cylindrical reaction chamber having a diameter of 20 cm and a height of 25 cm, and a reactive plasma is generated by using a glow discharge using a domestic commercial frequency of 60 Hz.

Each electrode in the reaction chamber was made of stainless steel discs of the same size with a diameter of 10 cm, the distance between the two electrodes is 3 cm, the heating of the substrate is a cartridge type to insert the heater from the outside of the reaction chamber. It was equipped to be able.

As the power supply, domestic electricity of 60 kW was used as it was, and the power density was 0.03 to 0.08 W / cm 2.

As the substrate, an alkali-free Corning7059 glass or a slide glass for microscope was used, and multi-stage ultrasonic cleaning was performed with distilled water, methanol, acetone, etc. to maintain maximum cleanliness. In addition, a silicon substrate may be used for FTIR measurement, but in this case, it may be used after removing the surface oxide film by treating with diluted hydrofluoric acid solution.

The sample used for the experiments in the present invention as described above, while maintaining the total pressure of 1.5torr while changing the pressure ratio of methane from 1% to 30% in the gas mixture of methane (CH ₄ ) and hydrogen (H ₂ ) Produced while shedding.

The temperature of the board | substrate was room temperature, and the voltage of the low frequency (60 kV) power supply applied to the electrode was set to 250-300V, and the current was 10-20 mA.

Sample produced by the above experiment

Sample no CH ₁ CH ₂ CH ₃ CH ₄ CH ₅ CH ₆ CH ₄ / (CH ₄ / H ₂ ) (%) One 2.5 5 10 20 30 Appl. (V) 248 280 289 285 272 298 Current (mA) 20 13 13 12 12 11 Thickness 1400 1700 2000 2700 2800 3140 Band gap (eV) - 1.3 1.2 1.9 2.0 - H-cont (at%) - 15 32 49 68 -

As shown in the above table, the results are mainly due to the change in the pressure ratio of methane.

According to the characteristics of the sample, the discharge voltage (280V) and the discharge current (13mA) of the low frequency power source for plasma generation were kept constant (power density: 0.05W / cm 2) and the pressure ratio of methane in the mixed gas of methane and hydrogen in the reaction chamber Is changed from 1% to 30%, and the deposition rate increases rapidly until the pressure ratio of methane is about 10% in the process of deposition at room temperature. It is generally considerably lower than 40 mW / min when deposited by RF plasma CVD. This is because LF plasma has a lower plasma density than RF plasma.

In addition, a-Si; H thin film deposited by methane (CH ₄ ) decomposition was lower than a-Si deposited by methylene (SiH ₄ ) decomposition by LF plasma. This is because of the greater energy.

In addition, the electron temperature and electron density were measured to investigate the characteristics of plasma according to the pressure ratio of methane during the manufacturing process of the thin film. The electron temperature was reduced to 4-7 eV with the increase of the methane content. This is because the amount of methane that is not decomposed increases with increasing content, and the electron density is about 10 ⁷ / cm 3, which is almost unchanged due to the increase in methane content. It is confirmed by the experiment.

And looking at the physical properties of the sample, first to determine the dark electrical conductivity of the sample according to the temperature in order to determine the basic electrical properties of the produced sample. After all cancer electrical conductivity of the sample at room temperature for ^{10 -11 [Ω · ㎝] -1} , from ^{100 ℃ 10 -9 [Ω · ㎝} -1] level, and the specific resistance is 10 ^11, and 10 ⁹ Ω · ㎝ the high It can be seen that the resistance value.

Also, the photoelectric conductivity according to the measured temperature was shown. The result was about 20, which is much lower than 10 ^{5, which} is photosensetivity ( ^σ p / ^σ a) at a-Si: H, and decreased with increasing temperature. This means that there is a density of states in the aC: H sample that trap carriers excited by light.

When the transmittance according to the wavelength of the manufactured a-C: H thin film is expressed in%, the transmittance is more than 90% from 400 nm to 900 nm, and particularly has a good transmittance of 95% between 600 nm and 900 nm. The measured transmittance is converted into an absorption coefficient

(αhν) ^1/2 = C (hν-E _opt )

From the optical energy gap (E _opt ) can be obtained. Where α is the light absorption coefficient, hν is the energy of photons, and C is a constant relating to the characteristics of the absorption edge, respectively.

The change in the methane gas content of this optical energy gap tends to increase from 1.2 eV to 2.0 eV as the methane content increases from 2% to 20% of the pressure ratio. This fact indicates that as the methane content increases, the hydrogen content in the sample increases, which means that the increase in the optical energy gap means that the optical energy gap increases with the increase in the methane content.

XRS measurements were performed to determine the elemental composition of the produced aC: H thin film. As a measuring device, a compound surface analyzer (made by ULVAC-PH1) capable of AES, XPS, SIMS, and RHEED was used. The device features a CMA (Cylindrical Mirror Analyzer) and an X-ray source of 1253.6 eV and 265 W M _g -K _α as an optoelectronic tube. AES measurement is possible with this device, but since the substrate of this sample is glass, which is an insulator, the spectrum could not be measured normally due to the charging effect of the sample.

The argon ion used in the XPS measurement was Ar ⁺ with an ion acceleration voltage of 2 kV and an emission current of 20 mA. The binding energy was scanned in the range of 0 to 1100 eV, and C _KLL and O _KLL are peaks of Auger electrons excited by X-rays. The main photoelectron peaks are C _1s and O _1s , and since O _1s is rarely observed after sputtering, it is assumed that the peaks were in the outermost adsorption gas layer. Therefore, it is assumed that the main component of this aC: H thin film is carbon. And since no significant peaks are observed, other impurities can be considered to be beyond the limits of this measuring device.

The carbon peak of C _1s is where the binding energy is 287.05 eV (as deposited) and 282.6 eV (after sputtering), and the half width (FWHM) of these peaks was 1.75 eV and 1.84 eV, respectively. This result is in good agreement with what other researchers have measured on DLC.

Spectrum was measured by FTIR spectrometer (MIDAC) to determine the composition of the sample. In this result, attention was paid to the stretching of the CH bond in the vicinity of 3000cm ^-1 , and the area of absorption peak was calculated from the equation developed by K.Mui et al., And the hydrogen content (C _H ) was determined from this value. The results are shown in Fig. 8. As the methane content increases from 2% to 20%, the hydrogen content (C _H ) changes with increasing 15-70 atm.%.

As a result, the sample with 10% methane content satisfies the optimum fabrication conditions with relatively high deposition rate and few defects, and the metastable states, which are mainly in a-Si: H, were also observed.

Therefore, as mentioned above, the deposition rate of the sample during manufacture is 2-7∀Å / min, which is lower than other methods, while the transparency (95%) and the resistance (specific resistance 10 ⁹ -10 ¹¹ Ω · cm) are very good and purity. A good quality aC: H thin film was obtained.

During the fabrication process, the electron temperature of plasma is about 4-7 eV and the electron density is about 10 ⁷ / cm ³ .

The optical energy gap of the fabricated sample is about 1.2 ~ 2.0 eV, and the hydrogen content is about 15-70 atm.%. It can be seen that there is a significant difference depending on the pressure ratio of methane gas. Manufacture of a-C: H thin film using LF is insufficient for commercialization, but good results can be expected if it fully utilizes its advantages. The challenge in the future is to find an improved method that can lead to improved deposition rates and increased photosensitivity.

Therefore, as described above, the spectacle lens was coated with hydrogenated diamond at room temperature by 60 ㎐ low-frequency plasma chemical vapor deposition.

Therefore, as above, plasma is generated at 60Hz, which is a commercial frequency at room temperature, and a method of coding a diamond carbon thin film on the spectacle lens by chemical vapor deposition is prevented, so that scratches, ultraviolet rays, electromagnetic wave blocking, and blurring of the spectacle lens are prevented. It has the characteristics of extending the life of the lens and improving the health of the eyes.

Claims (1)

After injecting a gas or liquid containing carbon into a vacuum container, plasma discharge is induced at a low frequency of 60 에서 at room temperature to dissociate the gas, thereby degrading the radicals in which CH, CH ₂ and CH ₃ are decomposed. The method of coating the spectacle lens, characterized in that the diamond carbon film (aC: H) is coated as they are attached to the lens.