KR101370596B1 - Method for manufacturing a tempered glass - Google Patents

Abstract

The present invention relates to a method of manufacturing a tempered glass and, especially, to a method of manufacturing chemically reinforced glass using dry-etching comprising: a pre-treating process of processing a glass plate into a desired shape and removing organic materials on the surface of the processed glass plate; a dry etching step of installing the glass base materials in which the organic materials are removed in a vacuum chamber, injecting gas for etching the surface of the glass base materials and dry etching the surface of the glass base materials by applying pressure in order to excite gas to plasma; a chemical reinforcement step of putting the chemically reinforced glass base materials into a molten solution for ion exchange; and a post-treating step of washing the chemically reinforced glass base material. The present invention is harmless to a human since the method does not use chemicals such as a strong acid solution or a hydrofluoric acid-base compound, does not need an additional industrial waste disposal facility since industrial waste such as waste water is not generated, is environment-friendly and reduces manufacturing costs as compared to an existing wet etching method which uses chemicals and treats industrial waste since the method use power and gas. [Reference numerals] (AA) Start; (BB) End; (S10) Primary washing; (S20) Film (Ink) masking; (S30) Glass forming; (S40) Masking removing; (S50) Secondary washing; (S60) Dry etching; (S70) Chemical reinforcement; (S80) Cooling; (S90) Tertiary washing

Description

METHODS FOR MANUFACTURING A TEMPERED GLASS

The present invention relates to the production of tempered glass, and more particularly to a method for producing a chemical tempered glass using dry etching.

In general, chemical tempered glass made of soda-lime glass has a high surface hardness, is less scratched, and has excellent impact resistance, and is widely used for protecting electronic display devices such as LCDs and OLEDs. In particular, as the development of mobile electronic devices such as mobile phones and smart phones is rapidly developed, chemically strengthened glass having excellent mechanical properties such as surface hardness and impact resistance, and satisfying light weight and slimness, has been widely used in these products.

와 같은 칼륨 용융액에 소다라임 등의 유리(10)를 침지시켜 유리 내의 Na+ 이온과 Na+ 이온보다 이온 반경이 큰 칼륨 용융액 내의 K+ 이온을 치환시킴으로써, 유리 표면의 압축응력을 발생시킴으로서 이루어진다. 그러나 유리를 화학 강화할 때 유리 표면에 Na+ 이온과 K+ 이온의 치환을 제한하는 여러 요소, 예컨대 유기 오염, 불순물, 유리의 부식층 등이 존재하면 도 2에 도시된 바와 같이 유리 표면의 Na+ 이온과 K+ 이온이 균일하게 치환되지 못하여 화학 강화된 유리 표면의 압축 응력이 불균일하게 된다. 이렇게 불균일한 유리 표면의 압축 응력은 작은 외부 충격에도 국부적으로 파손되거나 크랙(crack)을 유발할 수 있다. 또한 유리 표면의 부분적인 압축응력의 차이에 의한 스트레스(stress)로 인해 화학 강화된 유리의 경도, 강도 및 내충격성을 저해하게 된다. 따라서 K+ 용융액에 유리를 침지하여 화학 강화를 하기 전에 유리 표면을 세정 및 식각하여 Na+ 이온과 K+ 이온의 치환을 제한하는 여러 요소를 제거해야 한다.A typical glass chemical strengthening process is shown in FIG.

The glass 10 such as soda lime is immersed in a potassium melt such as to replace the Na + ions in the glass and the K + ions in the potassium melt having a larger ionic radius than the Na + ions, thereby generating a compressive stress on the glass surface. However, when chemically strengthening the glass, if there are various factors that limit the substitution of Na + ions and K + ions on the glass surface, such as organic contamination, impurities, and a corrosion layer of the glass, Na + ions and K + ions on the glass surface as shown in FIG. This uniform substitution is not possible and the compressive stress of the chemically strengthened glass surface becomes nonuniform. This uneven compressive stress on the glass surface can cause local breakage or cracking even with small external impacts. In addition, stress due to the difference in partial compressive stress of the glass surface inhibits the hardness, strength and impact resistance of chemically strengthened glass. Therefore, before immersing the glass in K + melt and chemically strengthening, the glass surface must be cleaned and etched to remove various factors that limit the substitution of Na + and K + ions.

As a general washing method, a glass is immersed in an aqueous alkali solution such as KOH or NaOH, or an organic solvent such as toluene or IPA, or an ultrasonic wave or a brush has been used. The glass surface etching method is typically a wet etching method in which a glass is immersed in an acidic solution mainly composed of hydrofluoric acid or a mixed solution containing sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid together with hydrofluoric acid. Has been used.

However, the wet etching method is partially under-etched or over-etched, as shown in FIG. 3, depending on the cleaning state of the glass surface, and thus, the wet etching method does not guarantee a uniform etching state over the entire glass surface. Not only does it get a hardening quality, but it also causes haze defects due to differences in the degree of etching of the surface. More specifically, the general wet etching method is a selective etching method by a chemical reaction, and when it is used, the glass surface is partially etched because fine organic or inorganic contaminants that cannot be removed during the cleaning process as shown in FIG. 3 interfere with the etching. If not, or the difference in the etching rate, the glass surface becomes uneven as a whole. Therefore, when the glass surface is chemically strengthened, as shown in FIG. 4, non-uniform ion substitution results in uneven compressive stress of the chemically strengthened glass surface. The nonuniform compressive stress of the glass surface causes stress on the tempered glass surface, thereby lowering the hardness, strength and impact resistance of the chemically strengthened glass, as well as causing diffuse reflection and haze defects due to uneven surface roughness.

In addition, even if the contaminant is completely removed during the cleaning process, in general wet etching, additional etching occurs from the wet etching to the rinsing process, and the concentration, specific gravity, pH, etc. of the etching solution during the continuous use of the etching solution. Due to this change, constant quality control is difficult, and hydrofluoric acid-based compounds and strong acid solutions are not only very harmful to the human body, but also increase the environmental pollution and industrial waste disposal costs such as waste water generated by using them. Occurs.

Accordingly, the present invention has been made to solve the above problems, to provide a method for producing chemically strengthened glass using a dry etching method to produce a uniform chemically strengthened glass by generating a uniform compressive stress on the glass surface,

Furthermore, in the glass chemical strengthening process, a method of manufacturing chemically strengthened glass using dry etching, which not only significantly improves serious quality problems such as poor haze caused by general wet etching methods, but also significantly reduces environmental pollution and human hazards. In providing.

Chemical tempered glass manufacturing method according to an embodiment of the present invention for solving the above problems,

A pretreatment step for processing the glass sheet into a desired shape and removing organic matter present on the processed glass substrate surface,

A dry etching step of installing the glass substrate from which the organic material is removed in a vacuum chamber, and dry etching the glass substrate surface by applying a voltage so that the gas is plasma excited after gas injection for etching the glass substrate surface;

Chemically strengthening the dry-etched glass substrate in a melt for ion substitution;

And a post-treatment step of cleaning the chemically strengthened glass substrate.

Furthermore, the gas injected in the dry etching step may be argon gas. In this case, the pretreatment step may include at least a glass forming step for processing the glass plate into a desired shape, and removing masking of the glass-formed glass substrate. And cleaning said unmasked glass substrate surface,

Characterized in that the gas injected in the dry etching step is a mixture of argon and oxygen, in this case the pretreatment step is at least a glass forming step for processing the glass plate to the desired shape, and removing the masking of the glass molded glass substrate Characterized in that it comprises a step.

Further, the gas injected in the dry etching step may be a mixture of argon, oxygen, and fluorine-based gases, in which case the pretreatment step includes at least a glass forming step for processing the glass sheet into a desired shape, and a glass-formed glass substrate. And removing the masking of the

The gas injected in the dry etching step is characterized in that the argon, oxygen, nitrogen, hydrogen, helium and fluorine-based single gas or a mixture of these gases.

According to the embodiment of the present invention as described above, the present invention is a part of the chemical strengthening process of the glass, by immersing the glass in the K + melt to dry etching the glass surface prior to chemical strengthening, so that the glass substrate is uniform It is an invention having the effect of smoothly chemically strengthening. More specifically, it is possible to realize uniform chemical strengthening quality by uniformly generating compressive stress on the glass surface by minimizing undesirable effects such as unevenness and overetching on the glass surface in the wet etching process. It has an effect of minimizing serious quality defects such as haze generated in the conventional wet etching method.

In addition, since the present invention does not use strong acidic solutions or chemicals such as hydrofluoric acid compounds used in the conventional wet etching method, it is less harmful to the human body and does not generate industrial waste such as wastewater, and thus does not require a separate industrial waste treatment facility and is environmentally friendly. In addition, since only the power and gas are used, the manufacturing cost is lowered compared to the conventional wet etching method, which requires chemical treatment and industrial waste treatment.

In addition, if the dry ashing process using the oxygen plasma is used instead of the cleaning process performed before the conventional wet etching process, the process is simplified and the manufacturing cost is reduced compared to the wet etching which requires the two steps of wet cleaning and wet etching. It is a useful invention having a lowering effect.

1 is a schematic diagram for general glass chemical strengthening.
FIG. 2 is a schematic diagram of a heterogeneous ion substitution reaction due to organic to inorganic contamination and corrosion layer remaining on the glass surface in a general glass chemical strengthening process. FIG.
Figure 3 is a schematic diagram of the etching state of the non-uniform glass surface caused by the general wet etching method in the glass chemical strengthening process.
4 is a schematic view of a glass substrate surface chemically strengthened after wet etching the glass surface in a general manner.
5 is a process flow chart for explaining a method for producing chemically strengthened glass using a dry etching method according to an embodiment of the present invention.
6 is a schematic diagram illustrating a configuration of a dry etching apparatus including an external ion generator that may be used in manufacturing chemically strengthened glass according to an embodiment of the present invention.
FIG. 7 is a schematic diagram of plasma excitation of argon gas and acceleration of argon ions required to explain the dry etching process of FIG. 5. FIG.
8A to 8C and 9 are views illustrating a glass surface etching state when performing a dry etching process according to an embodiment of the present invention.
10 is a view for explaining a method of measuring the degree of strengthening of the chemical strengthened glass produced according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

First, Figure 5 illustrates a process flow diagram for explaining a method for producing chemically strengthened glass using a dry etching method according to an embodiment of the present invention. As shown in FIG. 5, in the method of manufacturing chemically strengthened glass using the dry etching method according to the exemplary embodiment of the present invention, the first step of cleaning the prepared glass sheet (S10), the both sides of the primary cleaned glass sheet are protected by a tape or Film masking step of coating the protective ink using screen printing (S20), glass forming step (S30) of processing the protective sheet or the glass plate coated with the protective ink into a desired shape, protective tape coated on both sides of the molded glass substrate B) Masking removal step of removing the protective ink (S40), secondary cleaning of the processed glass substrate (S50), dry etching the secondary cleaned glass substrate (S60), chemically strengthening the dry etched glass substrate To be completed through the step (S70) and the cooling and tertiary cleaning step (S80, S90), a more specific manufacturing method will be described in detail below.

First, a glass sheet is prepared to manufacture chemically strengthened glass using a dry etching method according to an embodiment of the present invention. The glass sheet should be one capable of chemical strengthening by ion substitution such as soda lime glass, aluminosilicate glass, borosilicate glass, and the like. Moreover, it is preferable that a glass plate material is manufactured from the raw material component which does not contain potassium oxide substantially.

When the glass sheet is prepared, as a first step for preparing a chemically strengthened glass using a dry etching method according to an embodiment of the present invention, a first cleaning step for removing organic or inorganic contamination remaining on the surface of the prepared glass sheet (S10). ). In order to remove organic contamination, the glass sheet is immersed in an aqueous alkali solution such as NaOH or KaOH aqueous solution, or the glass sheet is immersed in an organic solvent such as acetone, toluene, xylene or the like. In order to remove inorganic contamination, a method of dipping in an acidic solution such as sulfuric acid or nitric acid or hydrogen peroxide solution is used. In order to remove both organic and inorganic pollution at the same time, glass plates are immersed in a solution diluted in water at a ratio of 1% to 15% by weight of FPD-100, OP-151, etc., of Deconex. In the cleaning step, in order to more effectively remove organic or inorganic contamination of the glass surface, it is preferable to apply ultrasonic waves to the cleaning bath or to raise the temperature of the cleaning solution to about 40 to 80 degrees. In addition, the scrubbing method of rubbing the glass surface with a roll body such as a nylon brush or PVA sponge in the cleaning solution can more effectively remove organic or inorganic contamination.

After the first cleaning is completed, the film masking step S20 is performed as a preliminary step for processing the prepared glass sheet into a desired shape. Protective tape or protective ink is coated on both sides of the glass plate to prevent contamination of the glass surface and scratches by glass foreign materials generated during normal NC machining and to minimize chipping of the edges of the machined surface. In general, the protective tape is coated by laminating, and the protective ink is coated by silk printing. If protective ink is used, the protective ink must be readily soluble in organic solvents or water or physically removable. Thereafter, the glass forming step (S30) of processing the glass plate having both surfaces prepared in the film masking step with the protective film or the protective ink to a desired shape using an NC processing machine is performed.

When the glass molding is performed, a masking removing step (S40) of removing the protective tape or the protective ink coated on both surfaces of the molded glass substrate is performed. For reference, the protective ink is removed by dipping in an organic solvent capable of dissolving the protective ink or water at 60 to 100 ° C.

Thereafter, a second cleaning step (S50) of the surface of the unmasked glass substrate is performed. In the second cleaning step S50, the adhesive material or the organic residual film of the protective tape remaining on the glass surface is immersed in the organic cleaning liquid and removed. As the organic cleaning liquid, an alkaline aqueous solution or an organic solvent used for removing organic contamination in the first cleaning step is used, and it is more effective to use ultrasonic waves or to heat the cleaning liquid.

After the secondary cleaning, dry etching the surface of the secondary cleaned glass substrate is performed (step S60). Dry etching the surface of the glass substrate is intended to provide a more uniform chemical strengthening of the glass substrate by removing negative factors that limit the substitution of Na + ions on the glass surface and K + ions in the molten potassium nitrate solution, such as the corrosion layer on the glass surface. will be.

torr)에 도달하면 MFC를 통해 아르곤 가스(140)를 주입한다. 이때 베이스 진공도는 2 X 10^-5 torr 내지 5 X 10^-4 torr가 적당하며 아르곤 가스의 주입양은 50 sccm 내지 2,000 sccm 정도가 적당하다. 아르곤 가스를 주입한 상태의 공정 진공도는 2 X 10^-4 Torr 내지 5 X 10^-3 torr 정도가 적당하다. 아르곤 가스를 주입한 후 이온 소스(120)에 전압을 인가하면 아르곤 가스가 여기(excited)되어 아르곤 플라즈마가 형성된다. 이를 아르곤 가스의 플라즈마 여기(excitation)와 아르곤 이온의 가속에 대한 모식도를 나타낸 도 7을 참조하여 부연 설명하면,For reference, Figure 6 schematically shows an apparatus for dry etching the surface of the glass substrate according to an embodiment of the present invention. As shown in FIG. 6, the glass substrate 100 is placed on a susceptor positioned to face an ion source 120 (anode electrode) mounted in the process chamber 110, and then the exhaust pump 130 is operated to exhaust the glass substrate 100. . Start evacuation to the base vacuum

torr), argon gas 140 is injected through the MFC. At this time, the base vacuum degree is appropriately 2 X 10 ^-5 torr to 5 X 10 ^-4 torr, and the injection amount of argon gas is suitably about 50 sccm to 2,000 sccm. The process vacuum degree in which argon gas is injected is suitably about 2 X 10 ^-4 Torr to 5 X 10 ^-3 torr. When an argon gas is injected and a voltage is applied to the ion source 120, the argon gas is excited to form an argon plasma. This will be described in detail with reference to FIG. 7, which shows a schematic diagram of plasma excitation of argon gas and acceleration of argon ions.

First, the ion source 120, which is a positive electrode plate 120, is installed on the opposite side of the ground plate 150 in the vacuum chamber, and then argon gas is injected between the two plates, and then a voltage is applied. Is formed. Argon ions Ar + in the plasma thus formed are accelerated toward the ground plate 150 by the potential difference between the ion source 120 and the ground plate 150. Therefore, when arranging the glass substrate 100 on the ground plate 150 and then applying a voltage to the ion source 120 to accelerate the argon ions, the accelerated argon ions hit the surface of the glass surface is shown in Figure 8a It is finely physically etched as one. FIG. 8A illustrates a state in which the surface of the glass substrate 100 is etched by the above-described argon ion dry etching method, but some organic-inorganic contamination remains on the surface of the etched glass substrate 100, compared to the conventional wet etching method. It can be seen that the glass surface is remarkably uniform.

For reference, the voltage applied to the ion source 120 is appropriately 600 V to 5,000 V. When the permanent magnet is properly disposed on the ion source 120, argon ions are accelerated by helical motion, which is effective for increasing the density of plasma. . The ion etching time of the glass substrate 100 is suitable for approximately 10 seconds to 300 seconds, and it is effective to rotate the glass substrate for uniform ion etching. After etching one surface of the glass substrate 100, the other surface should be etched. This can be done by turning the glass substrate 100 upside down without breaking the vacuum by using a properly designed device in the process chamber 110, or by installing the ion source 120 on both sides of the glass substrate 100 to simultaneously It can also be etched. For reference, the direction of the plasma excited gas ions is preferably incident within the range of 0 to 60 degrees from the direction perpendicular to the glass substrate 100 plane.

As another method of dry etching the glass substrate 100, a dry etching method using argon and an oxygen mixed gas may be used. That is, when oxygen is injected together with the argon gas into the process chamber 110, the organic material may be burned away by the strong oxidation of the excited oxygen plasma. The organic material oxidized by the oxygen plasma is vaporized and discharged out of the vacuum chamber 110 by the exhaust pump 130. Therefore, when oxygen is injected together with argon gas in the dry etching step (S60) of the organic substrate 100, the organic residues remaining on the glass surface in the second cleaning step (S50), for example, the organic residual film or the adhesive material of the protective tape, etc. can be effectively Since it can be removed, a more uniform surface of the glass substrate 100 can be obtained as shown in FIG. 8B. In addition, if the surface of the glass substrate 100 is first treated with an oxygen plasma for 5 to 120 minutes before the physical etching by the argon plasma, the second cleaning step (S50) may be replaced as it may replace the cleaning of organic contamination. ) May be omitted. That is, by removing the organic contamination of the glass surface using oxygen or oxygen-argon mixed gas before etching the glass surface using argon ions, a more uniform glass etching surface can be obtained. When the glass surface is chemically strengthened, the compressive stress of the glass surface chemically strengthened by uniform ion substitution as shown in FIG. 9 is also uniform, resulting in not only improving the hardness, strength, and impact resistance of the glass. The occurrence of diffuse reflection and haze defects can be minimized.

As another dry etching method, a dry etching method using argon gas and a fluorine-based reactive gas may be used. That is, when a fluorine-based reactive gas such as CF 4 is injected into the process chamber 110 along with the argon gas, the fluorine-based reactive gas reacts with the surface of the glass substrate 100 to form reactive ion etching. Reactive ion etching has a significantly higher etching rate than physical etching, which not only shortens the etching time, but also fine scratches on the surface of the glass substrate 100 as shown in FIG. 8C, and edges during processing of the glass substrate. By eliminating or mitigating micro cracks and the like occurring nearby, the strength, impact resistance and optical properties of the chemically strengthened glass are improved.

Injecting a mixed gas of argon and oxygen or injecting an argon and fluorine-based reactive gas may be carried out before and after the step of injecting only argon gas to maximize the effect.

As described above, the dry etching step (S60) according to the embodiment of the present invention is any one of the dry etching step by argon gas, the dry etching step by argon-oxygen mixed gas, the dry etching step by argon-fluorine-based reactive gas. Can be processed by one. In order to evaluate these three dry etching steps, the following experimental data were mentioned below. First, 350 sccm of argon was injected into the process chamber for argon gas, and the process vacuum was 2.7 X 10 ^-4 torr. It was. In addition, a voltage of 3,000 V and a current of 156 mA were applied. In the case of the argon-oxygen mixed gas, argon was injected into the process chamber at a flow rate of 320 sccm and oxygen 50 sccm, and the process vacuum at this time was 2.8 × 10 ⁻⁴ torr. In addition, a voltage of 3,000 V and a current of 150 mA were applied. Finally, in the case of argon-oxygen-fluorine-based reactive gas, 270 sccm of argon, 50 sccm of oxygen, and 50 sccm of CF4 were injected into the process chamber, and the process vacuum was 2.9 X 10 ^-4 torr. In addition, a voltage of 3,000 V and a current of 159 mA were applied.

Dry etching the surface of the glass substrate 100 under the above three conditions was visually inspected in the dark room using a 50 W halogen lamp. As a result of visual inspection, when the surface of the glass substrate 100 was etched by using a conventional wet etching method, haze phenomenon appeared on the surface of the glass substrate when the glass surface was illuminated with a 50 W halogen lamp, whereas dry etching was performed using only argon gas. In one case, the haze phenomenon of the glass surface was drastically reduced, and in the case of dry etching with an argon-oxygen mixed gas and an argon-oxygen-fluorine-based reactive gas, the haze phenomenon could not be detected by visual inspection.

When the dry etching step S60 described above is completed, the step S70 of chemically strengthening the dry-etched glass substrate 100 is then performed. Chemical strengthening is carried out using molten salts such as potassium nitrate at molten salt temperatures of 300 ° C. to 450 ° C. for 1 to 30 hours. In particular, the chemical strengthening is preferably performed at a temperature below the glass transition temperature of the glass substrate using a molten salt of potassium nitrate or sodium nitrate. This low temperature chemical strengthening enables the exchange of alkali ions in the surface layer with ions of large ionic radius. In this case, the treatment time is preferably 16 hours or less.

After performing the chemical strengthening is performed a cooling step (S80). In chemical strengthening, it is necessary to gradually cool the glass substrate 100 that has been strengthened. This is to prevent the breakage of the glass through the slow cooling step to obtain the compressive strength of the surface while at the same time to obtain the dense and beautiful surface of the tissue. After the cooling step S80, a third step of washing the slow cooled glass substrate 100 is performed (S90). After chemical strengthening, the glass substrate 100 may have foreign substances such as molten salts remaining on its surface. For this purpose, the glass substrate 100 may be cleaned by immersing the glass substrate 100 in water or water diluted with a detergent. In the case of cleaning using an immersion method, more effective cleaning is possible by applying ultrasonic waves, and a scrubbing method of contacting a glass substrate with a roll body such as a nylon brush or a PVA sponge may be used.

Hereinafter, exemplary embodiments of manufacturing the chemically strengthened glass using the dry etching method as described above will be described, and the strength of the chemically strengthened glass manufactured according to the exemplary example and the haze defect inspection result of the glass substrate surface will be described in detail. .

Example 1

First, prepare soda-lime glass sheet of 370mm (short side) X 470mm (long side) X 1.7mm (thickness). The glass plate was immersed for 5 minutes at a temperature of 50 ° C. in a cleaning solution diluted with 3% by weight of FPD-100, manufactured by Deconex, in ultrapure water and subjected to primary cleaning. Both surfaces of the glass plate material after primary washing are laminated by laminating a low adhesion protective film. The glass plate with the protective film is processed using a NC router at a linear speed of 1.8 mm per second in a size of 50 mm x 110 mm. After removing the protective film attached to both sides of the finished glass substrate, the second cleaning under the same conditions as the first cleaning, and then dry etching in the dry etching apparatus shown in FIG. At this time, the base vacuum degree is 3.0 X 10 ^-5 torr, the injection amount of argon gas is 350sccm, the process vacuum is 2.7 X 10 ^-4 torr, the voltage applied to the ion source is 3,000 V, the current is 156 mA. The glass substrate dry-etched under the above conditions was immersed in a mixed salt treatment bath of 60 wt% KNO ₃ and 40 wt% NaNO ₃ for 6 hours at 360 ° C. for chemical strengthening. The glass substrate is then washed with water to remove foreign matter such as molten salts attached to the surface. In this way, the glass base material of Example 1 is produced. About the glass base material thus obtained, strength measurement is performed using the apparatus shown in FIG. Specifically, as shown in FIG. 10, a glass base material is placed on the support which has an opening part smaller than a glass base part in a center part. Then, the central portion of the glass substrate is pressed by the pressure port 300 that descends to the free fall at a certain height. The material of the pressure port 300 is SUS303 and the weight is 130g. As a result, the breaking load of the glass substrate is measured as the height of the pressing port 300 when the glass substrate is broken. The same strength measurement is performed about ten glass base materials, and the average value, maximum value, and standard deviation of intensity | strength are determined. In addition, in the dark room, a 50 W halogen lamp is illuminated on the surface of the glass substrate at an angle of 45 degrees to visually inspect the glass substrate surface to determine whether there is a haze defect. The intensity | strength of the said glass base material and the haze defect test result of the glass base material surface are shown in following Table 1.

[Example 2]

In the same manner as in Example 1, the glass substrate, which is formed in the same shape and has been subjected to the second cleaning, is subjected to dry etching in the dry etching equipment devised in the present invention. At this time, the base vacuum degree is 3.0 X 10 ^-5 torr, the injection amounts of argon gas and oxygen gas are 320sccm and 50sccm, respectively, and the process vacuum is 2.8 X 10 ^-4 torr, the voltage applied to the ion source is 3,000 V and the current is 150 mA. The glass substrate dry etched under the above conditions was chemically strengthened under the same conditions as in Example 1 and then washed with water to remove foreign substances such as molten salts attached to the surface of the glass substrate. In this way, the glass base material of Example 2 is produced. The glass substrate thus obtained was subjected to the strength measurement and the determination of the presence or absence of haze defects using the apparatus shown in FIG. 10 as in Example 1, and the strength of the glass substrate of Example 2 and the haze defect inspection results on the surface of the glass substrate. Is shown in Table 1 below.

[Example 3]

In the same manner as in Example 1, the glass substrate, which has been molded in the same shape and has undergone secondary cleaning, is subjected to dry etching in the dry etching apparatus shown in FIG. 6. At this time, the base vacuum degree is 3.0 X 10 ^-5 torr, the argon gas, oxygen gas, and CF4 injection amount is 270 sccm, 50 sccm, 50 sccm, respectively, and the process vacuum is 2.9 X 10 ^-4 torr, and the voltage applied to the ion source is 3,000 V, current Is 159mA. The glass substrate dry etched under the above conditions was chemically strengthened under the same conditions as in Example 1 and then washed with water to remove foreign substances such as molten salts attached to the surface of the glass substrate. In this way, the glass substrate of Example 3 is produced. The glass substrate thus obtained was subjected to the strength measurement and the determination of the presence or absence of a haze defect using the apparatus shown in FIG. 10 as in Example 1, and the strength of the glass substrate of Example 3 and a haze defect inspection result of the glass substrate surface. Is shown in Table 1 below.

Comparative Example 1

As in Example 1, the glass substrate, which was formed into the same shape and subjected to the second cleaning, was chemically strengthened under the same conditions as in Example 1, and then washed with water to remove foreign substances such as molten salt attached to the glass substrate surface. In this way, the glass base material of the comparative example 1 is produced. The glass substrate thus obtained was subjected to the strength measurement and the determination of the presence or absence of a haze defect using the apparatus shown in FIG. 10 as in Example 1, and the strength of the glass substrate of Comparative Example 1 and a haze defect inspection result of the glass substrate surface. Is shown in Table 1 below.

[Comparative Example 2]

The surface of the glass base material which was shape | molded in the same shape and the 2nd washing | cleaning similarly to Example 1 is wet-etched by the conventional wet etching method. In this case, a hydrofluoric acid and a fluorinated silicate mixture is used as an etchant for wet etching. The temperature of the etchant is 60 ° C. and the etching time is 10 minutes. The glass substrate wet etched under the above conditions was chemically strengthened under the same conditions as in Example 1 and then washed with water to remove foreign substances such as molten salts attached to the glass substrate surface. In this way, the glass substrate of Comparative Example 2 is produced. The glass substrate thus obtained was subjected to the strength measurement and the determination of the presence or absence of haze defects using the apparatus shown in FIG. 10 as in Example 1, and the strength of the glass substrate of Comparative Example 2 and the haze defect inspection result of the glass substrate surface. Is shown in Table 1 below.

division Breaking load (height, mm) Bad haze Average maximum Standard Deviation Example 1 537 570 15.7 minuteness Example 2 561 580 12.0 none Example 3 729 770 20.2 none Comparative Example 1 205 320 65.2 Very many Comparative Example 2 914 1,080 224.6 plenty

As can be seen from Table 1, the glass substrates of Examples 1 to 3 have a very high fracture strength and exhibit a small standard deviation in fracture strength compared to Comparative Example 1 in which the etching process is omitted. In addition, the glass substrates of Examples 1 to 3 significantly improved haze defects as compared with Comparative Example 1. This result is because the surface of the glass substrate is very uniform by dry etching.

Similarly, the glass substrates of Examples 1 to 3 have lower average breakdown loads than the comparative example 2 to which the conventional wet etching is applied, but show a small standard deviation, and the haze defects are greatly improved. This is because defects on the surface of the glass substrate, which cannot be solved by the conventional wet etching method, can be substantially removed by the dry etching method proposed in the present invention.

Therefore, the strength of the glass substrates prepared by chemically strengthening by the method of Examples 1 to 3, particularly Examples 2 to 3 of the present invention was greatly increased, and negative defects of the glass substrate such as poor haze were also minimized. It was found through experiments.

As described above, the present invention is a part of the chemical strengthening process of the glass, by immersing the glass in the K + melt and dry etching the glass surface before chemical strengthening, so that the glass substrate is chemically strengthened uniformly and smoothly. It is an invention having an effect. More specifically, it is possible to realize uniform chemical strengthening quality by uniformly generating compressive stress on the glass surface by minimizing undesirable effects such as unevenness and overetching on the glass surface in the wet etching process. It has an effect of minimizing serious quality defects such as haze generated in the conventional wet etching method.

In addition, since the present invention does not use strong acidic solutions or chemicals such as hydrofluoric acid compounds used in the conventional wet etching method, it is less harmful to the human body and does not generate industrial waste such as wastewater, and thus does not require a separate industrial waste treatment facility and is environmentally friendly. In addition, since only the power and gas are used, the manufacturing cost is lowered compared to the conventional wet etching method, which requires chemical treatment and industrial waste treatment.

In addition, if the dry ashing process using the oxygen plasma is used instead of the cleaning process performed before the conventional wet etching process, the process is simplified and the manufacturing cost is reduced compared to the wet etching which requires the two steps of wet cleaning and wet etching. It is a useful invention having a lowering effect.

On the other hand, the present invention has been described with reference to the embodiments shown in the drawings but this is only exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. For example, in the embodiment of the present invention, the gas injected in the dry etching step has been described using argon, oxygen, and fluorine-based gas as an example, in addition to this, a single gas such as nitrogen, hydrogen, helium or a mixture of these gases may be used. have. Accordingly, the true scope of the present invention should be determined only by the appended claims.

Claims (10)

A pretreatment step for processing the glass sheet into a desired shape and removing organic matter present on the processed glass substrate surface,
A dry etching step of installing the glass substrate from which the organic material is removed in a vacuum chamber, and dry etching the glass substrate surface by applying a voltage so that the gas is plasma excited after gas injection for etching the glass substrate surface;
Chemically strengthening the dry-etched glass substrate in a melt for ion substitution;
And a post-treatment step of cleaning the chemically strengthened glass substrate. The method of claim 1, wherein the gas injected in the dry etching step is characterized in that the argon gas, in this case, the pretreatment step is at least a glass forming step for processing the glass plate to a desired shape, and the masking of the glass-formed glass substrate And removing the masking and cleaning the surface of the masked glass substrate. The method of claim 1, wherein the gas injected in the dry etching step is a mixed gas of argon and oxygen, in this case, the pre-treatment step is a glass forming step for processing at least the glass plate into a desired shape, and glass molded glass Method for producing a chemically strengthened glass comprising the step of removing the masking of the substrate. The method of claim 1, wherein the gas injected in the dry etching step is a mixture of argon, oxygen and fluorine-based gas, in this case, the pretreatment step is a glass forming step for processing at least the glass plate to a desired shape, and glass forming Method for producing a chemically strengthened glass comprising the step of removing the masking of the glass substrate. The method of claim 1, wherein the gas injected in the dry etching step is argon, oxygen, nitrogen, hydrogen, helium and fluorine-based single gas, or a mixture of these gases. The process pressure according to any one of claims 1 to 5, wherein the process pressure in the vacuum chamber of the dry etching step is

A method for producing chemical tempered glass, characterized by having a torr range value. The method of any one of claims 1 to 5, wherein the dry etching step,
A method for producing chemical tempered glass, comprising an ion asher pretreatment process and using oxygen and ozone as process gases for this purpose. The method according to any one of claims 1 to 5, wherein the direction of the plasma-excited gas ions in the dry etching step is incident within a range of 0 to 60 degrees from the direction perpendicular to the glass substrate surface. . The method of claim 1, wherein the melt of the chemically strengthening step is a melt of potassium nitrate or sodium nitrate. The chemically strengthened glass according to any one of claims 1 to 5, wherein the melt of the chemical strengthening step is a melt of potassium nitrate or sodium nitrate, and the melt temperature has a value ranging from 300 ° C to 450 ° C. Manufacturing method.

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