KR100943321B1 - Devices for etching glass and Methods for removing sludge of glass panel - Google Patents

Abstract

The present invention relates to a sludge removal method of a glass etching apparatus and a glass substrate. In more detail, by recovering and condensing the gas generated through the etching reaction, the generation of sludge can be minimized and the life of the etching solution can be extended. A sludge removal method of a glass etching apparatus and a glass substrate is provided.

To this end, the present invention is an etching unit for etching the glass by the etching solution; And it provides a glass etching apparatus comprising a recovery unit for recovering and condensing the gas generated in the etching unit.

Sludge, silicon tetrafluoride, hydrofluoric acid, glass etching equipment, etching, condensation, concentration control

Description

Devices for etching glass and methods for removing sludge of glass panel

The present invention relates to a sludge removal method of a glass etching apparatus and a glass substrate. In more detail, by recovering and condensing the gas generated through the etching reaction, the generation of sludge can be minimized and the life of the etching solution can be extended. A sludge removal method of a glass etching apparatus and a glass substrate is provided.

Recently, research on flat panel displays has been actively conducted. Among them, a liquid crystal display ("LCD") device is widely used in portable televisions, notebook computers, and the like because of its excellent image quality and low power consumption. In the case of such a portable television or notebook computer, the user always carries it, so reducing the size and weight is a major challenge.

There are many ways to reduce the size and weight of the LCD, but reducing the weight of the glass substrate, which is the most basic component and the largest weight, is being studied.

In order to reduce the weight by reducing the thickness of the glass substrate, the most widely used method is to immerse the glass substrate in a container filled with etching liquid (deeping method) or spray the etching liquid onto the surface of the glass substrate (spray method). It is a method of etching the surface of a substrate.

In this case, a hydrofluoric acid (HF) solution is generally used as an etching solution, and the chemical reaction formula of the etching process is as follows.

SiO ₂ (s) + 4HF → SiF ₄ (g) + 2H ₂ O (l)

Glass and hydrofluoric acid react to generate silicon tetrafluoride (SiF ₄ ) gas.

Silicon tetrafluoride gas is contained in a hydrofluoric acid solution and reacts with hydrofluoric acid in a liquid state to generate solid silicon fluoride (H ₂ SiF ₆ ) as shown in the following chemical equation.

SiF ₄ (aq) + 2HF (aq) → H ₂ SiF ₆ (s)

Such silicon fluoride is sludge which is a by-product generated when etching a glass substrate. Sludge reduces the quality of the product and shortens the life of the etching solution.

According to the prior art, the sludge is removed by washing with a shower, but the sludge removal state shows a significant difference according to the strength of the distilled water, which is a cleaning liquid, and a significant difference of the sludge removal state depending on the state where the glass substrate is located. There is a problem that appears. Moreover, even by cleaning, the sludge stuck to the edge surface of the glass substrate is not completely removed, which causes a problem in that the glass substrate is defective. Sludge that is not completely removed has the problem of causing equipment corrosion in the subsequent scribe / break process.

In addition, according to the prior art, as the etching of the glass substrate proceeds, the concentration of hydrofluoric acid is lowered in the etching solution, thereby reducing the etching rate and the etching quality.

The present invention has been made to solve the above problems, in particular, it is possible to minimize the generation of sludge and to extend the life of the etching solution, while reducing the disposal cost and at the same time provides an environmentally friendly glass etching apparatus, high concentration of An object of the present invention is to provide a glass etching apparatus capable of regenerating hydrofluoric acid and a method for removing sludge from a glass substrate.

Glass etching apparatus according to the present invention devised to achieve the above object is an etching portion for etching the glass by the etching solution; And a recovery part for recovering and condensing the gas generated in the etching part.

The recovery unit may include an exhaust unit for exhausting the gas from the etching unit.

In addition, the recovery unit may include a condensation unit for condensing the gas.

The condenser may include a temperature controller and a liquid pipe provided inside the temperature controller to allow the liquid condensed by the temperature controller to pass therethrough.

In addition, a transfer unit may be provided between the temperature control unit and the liquid tube to collect and transfer the liquid to the liquid tube.

In addition, the transfer unit may be formed in a funnel shape.

In addition, the transfer unit may include a hole through which the gas passes.

In addition, the transfer unit may be provided with a guide groove for moving the liquid.

In addition, the transfer unit may be arranged in a plurality of repeatedly stacked.

The glass etching apparatus may further include a pump unit configured to circulate the etching liquid in the etching unit.

In addition, a heating unit may be further provided between the etching unit and the pump unit.

In addition, a transport pipe for supplying gas vaporized by the heating unit to the recovery unit may be provided.

In addition, a cooling unit may be further provided between the heating unit and the pump unit.

The etching unit may include a concentration measuring device for measuring the concentration of the etchant.

In addition, the glass etching apparatus may include a hydrofluoric acid supply pipe for supplying hydrofluoric acid from the recovery unit to the etching unit according to the measurement result of the concentration measuring device.

In addition, the glass etching apparatus may include a water supply pipe for supplying water from the recovery unit to the etching unit according to the measurement result of the concentration measuring device.

Sludge removal method of a glass substrate according to the present invention comprises the steps of: (a) recovering the mixed gas generated while etching the glass substrate using hydrofluoric acid as an etching solution; (b) condensing water vapor by lowering the temperature of the mixed gas recovered in step (a); (c) condensing hydrofluoric acid by lowering the temperature of the mixed gas passed through step (b); And (d) releasing the gas remaining after the step (c) to the outside.

In addition, the sludge removal method of the glass substrate may further comprise the step of adjusting the concentration of the etchant with water generated through the step (b) or hydrofluoric acid generated through the step (c).

In addition, the sludge removal method of the glass substrate may further include the step of heating the etchant to release silicon tetrafluoride (SiF ₄ ) gas dissolved in the etchant.

According to the present invention, by suppressing the generation of sludge which is a by-product generated during the etching of the glass substrate, it is possible to increase the quality and reliability of the product, and to extend the life of the etching solution to lower the manufacturing cost of the product.

In addition, according to the present invention, by minimizing the treatment of the waste hydrofluoric acid remaining after the etching operation of the glass substrate, there is an effect of reducing the disposal cost and at the same time provide an environmentally friendly glass etching apparatus.

Further, according to the present invention, silicon tetrafluoride is prevented by primarily evacuating silicon tetrafluoride generated in the etching reaction, and secondary silicon dioxide fluoride gas remaining in the etching solution is removed by heating the etching solution. There is an effect that can minimize the production of acid sludge.

In addition, according to the present invention, by condensing and recovering the water vapor and the hydrofluoric acid gas generated in the etching reaction separately, it is possible to regenerate and use a high concentration of hydrofluoric acid.

Further, according to the present invention, the concentration of the hydrofluoric acid in the etching solution can be kept constant by checking the concentration of the etching solution in real time and adding the recovered hydrofluoric acid to the etching solution if necessary.

In addition, according to the present invention, the separation path of the liquid condensed in the condensation unit and the non-condensed mixed gas has an effect of preventing the mixed gas from re-dissolving in the liquid.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the following will describe a preferred embodiment of the present invention, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

First, the principle of the glass etching apparatus according to the present invention will be briefly described.

When etching glass using an etching solution mainly containing hydrofluoric acid, the following chemical reactions occur.

SiO ₂ (s) + 4HF (aq) → SiF ₄ (g) + 2H ₂ O (l)

SiF ₄ (aq) + 2HF (aq) → H ₂ SiF ₆ (s)

At this time, the reaction 2 is a reaction occurring in the etching solution.

In order to prevent the generation of silicon fluoride by the reaction 2, in the present invention, silicon tetrafluoride gas, which is a reactant of the production of silicon fluoride, is prevented from being dissolved in the etching solution. To this end, in the present invention, the silicon tetrafluoride gas is not dissolved in the etching solution through forced exhaust. In addition, the hydrofluoric acid is recovered by condensing independently of each other using the point where the boiling points of the hydrofluoric acid gas and water vapor forced out of the silicon tetrafluoride gas are different from each other.

1 is a block diagram of a glass etching apparatus according to a preferred embodiment of the present invention.

In the glass etching apparatus according to the preferred embodiment of the present invention, referring to FIG. 1, the etching unit 10, the recovery unit 20, the pump unit 50, the heating unit 60, and the cooling unit 70 may be formed. It is formed to include. In addition, the glass etching apparatus is formed to include a transfer pipe 80, hydrofluoric acid supply pipe 90, water supply pipe (95).

The etching part 10 is a part for etching glass by the etching liquid. The etching unit 10 may be implemented in the form of an etching chamber, and the glass substrate may be etched in various ways including a dipping method and a spray method. For example, in the dipping method, a cassette (not shown) in which a plurality of glass substrates for LCD to be etched may be mounted in the etching unit. When hydrofluoric acid is used as an etchant, silicon tetrafluoride (SiF ₄ ) gas is produced as a reaction between glass and hydrofluoric acid. In order to prevent the silicon tetrafluoride gas from being dissolved in the etching solution again to generate silicon fluoride (H ₂ SiF ₆ ), the etching unit 10 is connected to the recovery unit 20. In addition, the etching unit 10 may be provided with a concentration measuring device (not shown) for measuring the concentration of the etching solution. For example, the concentration measuring device may be implemented with a pH meter.

The recovery unit 20 is a part for recovering and condensing the gas generated in the etching unit 10. To this end, the recovery unit 20 includes an exhaust unit 40 for exhausting the gas from the etching unit 10, and a condensation unit 40 for condensing the gas.

The exhaust unit 30 exhausts the silicon tetrafluoride gas to the outside of the etching unit 10 so that the silicon tetrafluoride gas generated in the etching unit 10 is not dissolved in the etching solution again. For example, the exhaust unit 30 may be implemented as a fan or the like. The exhaust unit 30 is forcibly discharged from the etching unit 10 together with the hydrofluoric acid gas and water vapor generated in the etching reaction in addition to the silicon tetrafluoride gas. The exhaust unit 30 may be located between the condensation unit 40 and the etching unit 10 as shown in FIG. 1, and the exhaust unit 30 may exhaust the exhaust gas exhausted from the etching unit 10 through a forced exhaust device. It is sent to the condensation unit 40. Although not shown, the exhaust may be located in the opposite direction of the etching portion relative to the condensation portion. In this case, the exhaust part is located at the end of the condensation part to allow the exhausted gas to pass smoothly through the condensation part.

The condensation unit 40 condenses and recovers the exhaust gas forcibly exhausted by the exhaust unit 30 for each component. Exhaust gases include silicon tetrafluoride gas and hydrofluoric acid gas and water vapor. The boiling point of silicon tetrafluoride is 86 degrees below zero, while the boiling point of Foshan is 19.54 degrees and the boiling point of water is 100 degrees (at 1 atm). As such, the condensation unit 40 recovers each component by adjusting the condensation temperature by utilizing different boiling points of the components constituting the exhaust gas. In addition, the condensation unit 40 may be provided with a concentration measuring device (not shown). The condensation unit 40 will be described in detail below with reference to FIGS. 2 to 5.

The pump unit 50 serves to circulate the etchant in the etching unit 10. That is, the pump unit 50 pumps the etching solution discharged after the etching and supplies it to the etching unit 10 again.

The heating unit 60 serves to separate and discharge the silicon tetrafluoride gas partially dissolved in the etching solution by heating the etching solution discharged after the etching. The exhaust 30 separates most of the silicon tetrafluoride gas from the etching solution, but very few silicon tetrafluoride gases may still be dissolved in the etching solution. In this manner, the silicon tetrafluoride gas remaining in the etching solution can be discharged by heating the etching solution. In general, the solubility of the gas decreases rapidly as the temperature of the solution increases. Thus, some dissolved silicon tetrafluoride gas is separated from the etching solution before the silicon fluoride is generated by heating through the heating unit 60 in the circulation of the etching solution.

The heating unit 60 is located between the etching unit 10 and the pump unit 50. The silicon tetrafluoride gas separated from the etching solution by the heating unit 60 is transferred to the exhaust unit 30 through the transfer pipe 80 and then discharged to the outside. Although not shown, the silicon tetrafluoride gas separated from the etching solution by the heating unit may be discharged to the outside through a separate outlet, or may be condensed by the condenser. In addition, although not shown, the heating unit may be further provided in the etching unit. At this time, it is preferable that the heating temperature of an etching solution is about 60-80 degreeC.

The cooling unit 70 is positioned between the heating unit 60 and the pump unit 50, and serves to restore the temporarily heated etching solution to the original temperature.

The hydrofluoric acid supply pipe 90 is a portion for supplying hydrofluoric acid from the recovery unit 20 to the etching unit 10 according to the measurement result of the concentration measuring apparatus provided in the etching unit 10.

Since hydrofluoric acid, the main component of the etching solution in the etching unit 10, is a reactant, its concentration gradually decreases as the etching reaction proceeds. Meanwhile, the etching solution recovered from the recovery unit 20 is a solution having a very high concentration of hydrofluoric acid. The hydrofluoric acid concentration is thus added to the etching solution in the etching unit 10 through the hydrofluoric acid supply pipe 90. The hydrofluoric acid concentration of the etched solution can be restored to the original state. In order to maintain a constant concentration of hydrofluoric acid in the etching solution in the etching unit 10, the concentration measuring apparatus provided in the etching unit 10 measures the concentration of the etching solution in real time. In this case, when the hydrofluoric acid concentration in the etching solution falls below a predetermined value, a suitable amount of high concentration of hydrofluoric acid is supplied through the hydrofluoric acid supply pipe 90.

The water supply pipe 95 is a portion for supplying water from the recovery unit 20 to the etching unit 10 according to the measurement result of the concentration measuring apparatus provided in the etching unit 10. When the hydrofluoric acid concentration in the etching solution in the etching unit 10 exceeds a predetermined value, the concentration of the etching solution is added to the etching solution in the etching unit 10 by adding water recovered from the recovery unit 20 through the water supply pipe 95. Keep it appropriate.

As described above, when the hydrofluoric acid supply pipe 90 and the water supply pipe 95 feed back the concentration from the concentration measuring device provided in the etching unit 10, the hydrofluoric acid supply pipe 90 and the water supply tube 95 are hydrofluoric acid or the hydrofluoric acid supply pipe 90 to the etching unit 10. By supplying water, the concentration of the etching solution is kept constant.

2 is a partial perspective view of a glass etching apparatus according to a preferred embodiment of the present invention. 3 is a vertical cross-sectional view of the condensation unit in the glass etching apparatus according to the preferred embodiment of the present invention. 4 is a cutaway perspective view of a condenser in a glass etching apparatus according to a preferred embodiment of the present invention. 5 is a plan view of a condenser in a glass etching apparatus according to a preferred embodiment of the present invention. In Figure 2 it is noted that the illustration of the remaining components except the etch and condensation is omitted for convenience.

The condensation part 40 includes a temperature control part 132, a liquid pipe 134, and a delivery part 136. The condensation part 40 may be formed in a substantially pipe shape, but may be formed in a shape in which the U-shaped pipe is repeatedly connected by bending the pipe shape several times. Thus, by lengthening the path | route of a condensation part, when exhaust gas passes once, it can condense most exhaust gas and can improve condensation efficiency.

The temperature controller 132 is provided to surround the outer circumferential surface of the condenser 40. The temperature controller 132 serves to adjust the condenser 40 to a desired temperature by providing a heating or cooling device. That is, the temperature control unit 132 appropriately adjusts the temperature of the condensation unit 40 to separate the exhaust gas delivered to the condensation unit 40 according to the boiling point.

The liquid pipe 134 is provided at the center of the condensation part 40. The liquid pipe 134 is provided inside the temperature controller 132 to serve to pass the liquid condensed by the temperature controller 132.

The delivery unit 136 collects the liquid condensed by the temperature control unit 132 and delivers the liquid to the liquid pipe 134. The transfer unit 136 is provided between the temperature control unit 132 and the liquid pipe 134. For example, the transfer unit 136 may be formed in a funnel shape as shown in FIG. 4, and a plurality of transfer units 136 may be repeatedly stacked in order to undergo a multi-step condensation process.

The transfer unit 136 includes a gas hole 138, a liquid collection hole 139, and a guide groove 140.

The gas hole 138 serves to transfer the non-condensed gas to the next delivery unit through the temperature control unit 132. In this case, the gas holes 138 may be formed at different positions for each unit delivery unit 136. Gas that has not condensed in the first unit delivery part of the exhaust gas is transferred to the next unit delivery part through the gas hole 138, and the amount of the transferred gas hits the surface of the delivery part to increase the amount of contact with the temperature control part 132. This is because it is preferable in terms of condensation efficiency.

The liquid collection hole 139 serves to transfer the liquid condensed in each unit delivery unit 136 into the liquid pipe 134. Accordingly, the exhaust gas is transferred to the next unit delivery unit 136 through the gas hole 138, and the exhaust gas is condensed and then transferred to the liquid pipe 134 through the liquid collection hole 139 of the unit delivery unit. Transferred.

In this way, the liquid pipe 134, which is the transfer passage of the condensed liquid, and the gas hole 138, which is the transfer passage of the exhaust gas, are physically separated to prevent the phenomenon of exhaust gas re-dissolving in the condensed liquid.

The guide groove 140 is formed on the surface of the delivery unit 136 so that the condensed liquid can smoothly move from the surface of the delivery unit 136 to the liquid collection hole 139. For example, the guide groove 140 may be formed in a trench shape, and the guide groove 140 may be formed to connect the inner circumferential surface of the temperature controller 132 and the liquid collection hole 139 to each other.

6 is a flowchart of a sludge removing method of a glass substrate according to a preferred embodiment of the present invention.

Sludge removal method of the glass substrate according to a preferred embodiment of the present invention, referring to Figure 6, mixed gas recovery step (S10), steam condensation step (S20), hydrofluoric acid condensation step (S30), remaining gas discharge step (S40) ) Although not shown, the sludge removal method of the glass substrate may further include a concentration adjusting step and an etching solution heating step.

The mixed gas recovery step S10 is a step of recovering the mixed gas generated while etching the glass substrate using hydrofluoric acid as an etching solution. Recover silicon tetrafluoride gas, hydrofluoric acid gas and water vapor generated during the etching process.

Steam condensation step (S20) is a step of condensing water vapor by lowering the temperature of the mixed gas recovered through the mixed gas recovery step (S10). When the temperature of the mixed gas is adjusted to about 25 to 85 degrees Celsius lower than the boiling point of water and higher than the boiling point of hydrofluoric acid and passed through the condensation unit 40, the vapor of the gaseous state is first recovered into a liquid state.

The hydrofluoric acid condensation step S30 is a step of condensing the hydrofluoric acid by lowering the temperature of the mixed gas that has undergone the steam condensation step S20. When the temperature of the mixed gas is adjusted to about 0 to 15 ° C. lower than the boiling point of hydrofluoric acid and higher than the boiling point of silicon tetrafluoride, and passed through the condensation unit 40, only the hydrofluoric acid is changed into a liquid state and recovered.

The remaining gas discharging step S40 is a step of discharging silicon tetrafluoride, which is the remaining gas after recovering water and hydrofluoric acid from the mixed gas while passing through the steam condensation step S20 and the hydrofluoric acid condensation step S30.

On the other hand, the concentration control step is a step of adjusting the concentration of the etchant with water generated through the steam condensation step (S20) or hydrofluoric acid generated through the hydrofluoric acid condensation step (S30). Etching unit 10 is provided with a concentration control device to measure the concentration in real time and feedback is maintained in the etching solution concentration in the etching unit 10 through the hydrofluoric acid supply pipe 90 and the water supply pipe (95).

The etchant heating step is a step of heating the etchant to release silicon tetrafluoride gas dissolved in the etchant. The heating unit 60 provided on the path through which the etchant circulates by the pump unit 50 heats the etchant to separate the silicon tetrafluoride gas from the etchant, and then the silicon tetrafluoride gas is externally supplied through the transfer pipe 80. To emit. This prevents silicon tetrafluoride gas from reacting in the hydrofluoric acid solution to generate silicon fluoride sludge.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention, but to describe the present invention, and the scope of the technical idea of the present invention is limited by the embodiments and the accompanying drawings. no. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

The present invention can be widely applied to the field of thin etching the glass substrate, including the glass substrate of the LCD panel.

1 is a block diagram of a glass etching apparatus according to a preferred embodiment of the present invention,

2 is a partial perspective view of a glass etching apparatus according to a preferred embodiment of the present invention,

3 is a vertical sectional view of the condensation unit in the glass etching apparatus according to the preferred embodiment of the present invention,

Figure 4 is a perspective view of the incision of the condensation portion of the glass etching apparatus according to an embodiment of the present invention,

5 is a plan view of a condenser in a glass etching apparatus according to a preferred embodiment of the present invention,

6 is a flowchart of a sludge removing method of a glass substrate according to a preferred embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10-etching part 20-recovery part

30-exhaust 40-condensation

50-Pump section 60-Heating section

70-Cooling Unit 80-Transfer Tube

90-Foshan Supply Line 95-Water Supply Line

132-Temperature Control Unit 134-Liquid Tubes

136-Delivery 138-Gas Hole

140-Guide Home

Claims (19)

In the apparatus for etching glass, Etching unit for etching the glass by the etching solution; And And a recovery part including an exhaust part for exhausting the gas generated in the etching part from the etching part and a condensation part for condensing the gas. The condensation unit is a glass etching apparatus, characterized in that it comprises a temperature control unit, and a liquid pipe provided in the inside of the temperature control unit through which the liquid condensed by the temperature control unit passes. delete delete delete The method of claim 1, And a transfer part configured to collect the liquid and deliver the liquid to the liquid pipe between the temperature control part and the liquid pipe. The method of claim 5, The glass etching apparatus, characterized in that the transfer portion is formed in a funnel shape. The method of claim 5, And the transfer part includes a gas hole through which the gas passes. The method of claim 5, And the transfer part includes a guide groove for moving the liquid. The method of claim 5, The transfer unit is a glass etching apparatus, characterized in that a plurality of repeatedly arranged arranged. The method of claim 1, The glass etching apparatus further comprises a pump unit for circulating the etching liquid in the etching portion. The method of claim 10, The glass etching apparatus further comprises a heating unit between the etching unit and the pump unit. The method of claim 11, And a transfer pipe for supplying gas vaporized by the heating unit to the recovery unit. The method of claim 11, The glass etching apparatus further comprises a cooling unit between the heating unit and the pump unit. The method of claim 1, The etching unit comprises a glass etching apparatus comprising a concentration measuring device for measuring the concentration of the etchant. The method of claim 14, And a hydrofluoric acid supply pipe for supplying hydrofluoric acid from the recovery unit to the etching unit according to the measurement result of the concentration measuring device. The method of claim 14, And a water supply pipe for supplying water from the recovery part to the etching part according to the measurement result of the concentration measuring device. In the method for removing the sludge generated during the etching of the glass substrate, (a) recovering the mixed gas generated while etching the glass substrate using hydrofluoric acid as an etching solution; (b) condensing water vapor by lowering the temperature of the mixed gas recovered in step (a); (c) condensing hydrofluoric acid by lowering the temperature of the mixed gas passed through step (b); (d) discharging the gas remaining after the step (c) to the outside; And (e) controlling the concentration of the etchant with water generated through the step (b) or with hydrofluoric acid generated through the step (c). delete The method of claim 17, And discharging the etching liquid discharged after etching the glass substrate to release silicon tetrafluoride (SiF ₄ ) gas dissolved in the etching liquid.

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