JP2016056032A - Etching equipment and etchant for glass substrate therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide etching equipment and etchant for glass substrate which can prevent dispersion of the etchant, can prevent damage in the equipment, and can reduce generated waste fluid.SOLUTION: Etching equipment at least comprises a conveying route, etch means and wiping means. The conveying route can convey glass substrate continuously. The etch means spreads thicken etchant for the glass substrate transported along the conveying route. The wiping means is arranged for the down stream of the etch means in the conveying route, and wipes the thicken etchant put on the glass substrate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an etching apparatus that performs an etching process on a glass substrate, and more particularly, to an etching apparatus that hardly causes contamination inside the apparatus and that has a small amount of waste liquid, and an etching liquid for a glass substrate that is used in the etching apparatus.

  Conventionally, many techniques for etching a glass substrate used in a flat panel display such as a liquid crystal display have been developed. In the case of thinning a glass substrate or in the case of surface treatment, cutting, or film peeling on a glass substrate, an etching treatment is often performed using an etching solution containing hydrofluoric acid. Some of these technologies employ a continuous processing method that continuously etches glass substrates that are sequentially transported in an etching apparatus, and this continuous processing method improves productivity. Has been planned.

  However, when a glass substrate is continuously etched in an etching apparatus, a fluid etching solution is likely to scatter and an etching solution containing sludge on the walls and the upper and lower edges of the etching chamber. Often adhered. When the etching solution adheres to the inside of the apparatus, as a result, the etching solution or a solution thereof crystallizes and hangs down in an icicle shape downward or protrudes in a convex shape upward. was there.

  Therefore, some of the conventional techniques are configured to spray a processing solution for removing the adhering etching solution on the walls or openings in the etching chamber, that is, where the etching solution may adhere. There is an etching apparatus (see, for example, Patent Document 1). This conventional technique removes the etching solution adhering to the walls and openings in the etching chamber, so that it is difficult to produce a crystallized product of the etching solution in the etching chamber, and the crystallized product and the glass substrate come into contact with each other. Can be prevented.

JP 2007-217752 A

  However, in the prior art including the above-mentioned Patent Document 1, it is not possible to prevent the etching solution from being scattered in the etching process, and therefore, contamination inside the apparatus occurs at a portion that cannot be removed by the processing solution. Further, in addition to the normal waste liquid, the processing liquid for removing the etching liquid also becomes a waste liquid, which causes a new problem that the amount of the waste liquid generated from the apparatus increases.

  An object of the present invention is to provide an etching apparatus and an etching liquid for glass substrate that can prevent the scattering of the etching liquid and prevent the internal contamination of the apparatus and reduce the amount of the generated waste liquid.

  The etching apparatus according to the present invention includes at least a conveyance path, etching means, and wiping means. A conveyance path is comprised so that a glass substrate can be conveyed continuously. The conveyance path is generally configured by a plurality of conveyance rollers, a conveyor belt, and the like, and is configured to sequentially convey the glass substrates one by one with a predetermined interval. The etching means is configured to apply a thickened etching solution to the glass substrate transported along the transport path. Examples of the etching means include a configuration in which the thickened etching solution is spray-coated, a configuration in which the thickened etching solution is roll-coated, and a configuration in which the thickened etching solution is die-coated. The viscosity of the etching solution may be appropriately selected depending on the coating method. However, if the viscosity is approximately 10 to 1000 mPa · s, it is an experiment to satisfy both the prevention of scattering and the realization of a suitable coating treatment. Is known.

  The wiping means is disposed downstream of the etching means in the conveyance path, and is configured to wipe the thickened etching solution applied to the glass substrate. As an example of the wiping means, there is a configuration in which a wiping unit is provided that presses a wiping cloth against a glass substrate to absorb and wipe off the thickened etching solution applied to the glass substrate.

  In the above-described configuration, since the etching solution is thickened to an appropriate viscosity and the flowability of the etching solution is reduced, the scattering of the etching solution inside the apparatus is prevented. In addition, since the etching liquid is collected by the wiping means and a large amount of liquid for cleaning the glass substrate is not required, the amount of waste liquid generated in the etching apparatus is reduced.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent scattering of etching liquid, to prevent the inside of an apparatus from being polluted, and to reduce the amount of waste liquid generated.

It is a figure showing the outline of the etching device concerning one embodiment of the present invention. It is a figure which shows the example of the coating system of a thickening etching liquid. It is a figure which shows an example of the wiping process in a wiping chamber. It is a figure which shows the outline of the etching apparatus which concerns on other embodiment of this invention. It is a figure which shows the outline of the etching apparatus which concerns on other embodiment of this invention.

  As shown in FIG. 1, the etching apparatus 10 according to the first embodiment of the present invention includes an introduction unit 12, a pretreatment chamber 14, an etching chamber 16, a wiping chamber 18, a cleaning chamber 20, and a discharge unit 22. Yes. A partition wall having a slit-like opening through which the glass substrate 24 can pass is disposed between each of these parts, and the glass substrate 24 is discharged from the introduction part 12 via each part by a plurality of transport rollers 26. It is conveyed to the part 22. In this embodiment, the transport path is configured by the plurality of transport rollers 26, but a transport path that incorporates a belt conveyor may be configured.

  The introduction part 12 has an open top surface and is configured to receive a glass substrate 24 to be etched by the etching apparatus 10. Usually, the glass substrate 24 to be processed is placed on the transport roller 26 of the introduction unit 12 by an operator or a robot. The pretreatment chamber 14 is configured to perform a pretreatment for an etching process on the glass substrate 24. In this embodiment, the surface of the glass substrate 24 is washed with water in the pretreatment chamber 14. However, degreasing, alkali cleaning, and the like can be performed in the pretreatment chamber 14, and the pretreatment chamber 14 itself can be omitted from the etching apparatus 10 when the pretreatment is unnecessary. .

  The etching chamber 16 is configured to perform an etching process on the glass substrate 24. In this embodiment, the etching chamber 16 corresponds to the etching means of the present invention. As shown in FIGS. 1 and 2A, in the etching chamber 16, the thickened etching solution is sprayed from the spray nozzle 162 onto the glass substrate 24. Since the etching solution is sprayed only when a sensor (not shown) detects that the glass substrate 24 exists at the etching position, waste of the etching solution is prevented. The etching solution contains hydrofluoric acid at a concentration of at least 3% by weight and has a viscosity of about 10 to 1000 mPa · s (preferably about 700 mPa · s ± 10%) from the viewpoint of preventing scattering and the efficiency of the etching process. It is thickened.

  Here, instead of the spray coating method shown in FIG. 2A, a roll coating method using an application roll 164 as shown in FIG. 2B or a slot die 166 as shown in FIG. It is also possible to employ the die coating method used. In this embodiment, using a hydrofluoric acid as a polishing component, magnesium sulfate as a thickener, and water as a solvent, a thickened etching solution having a hydrofluoric acid concentration of 30% by weight and a magnesium sulfate concentration of 30% by weight was prepared. The viscosity of this thickening etchant was measured using a B-type viscometer with rotor No. 4. It was 690 Pa · s when measured under the conditions of a rotation speed of 0.3 rpm and a liquid temperature of 20 ° C.

  In order to adjust the viscosity of the etching solution, it is preferable to include a thickener that can make the etching solution viscous. As the thickener, one or more kinds may be selected from magnesium compounds, surfactants, flocculants, water-absorbing polymers, antifoaming agents, urea, natural sugars, adhesives, and the like. Examples of the magnesium compound include magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium carbonate, magnesium hydroxide, magnesium citrate, and magnesium acetate. Examples of the surfactant include ester, phenol, amide, fatty acid ester, phosphate ester, sulfonic acid, nonionic, amine, ether, and polymeric alcohols. Examples of the flocculant include anionic and cyanol, but are not particularly limited thereto. The water absorbing polymer may be a synthetic or natural water absorbing polymer. In the case of using a thickener having low solubility in water, an organic solvent such as glycerin, ethylene glycol, ethanol or the like can be added to water and used as a solvent. Among the above-mentioned elements, it is preferable to contain magnesium sulfate and an amine-based surfactant in the polishing liquid. In this embodiment, an etching liquid whose temperature is adjusted to about 20 ° C. to 40 ° C. by incorporating them is adopted. ing.

  In the etching chamber 16, the chemical polishing component having the function of etching the glass substrate 24 and the thickener having the function of increasing the solution viscosity are both contained at a constant concentration, and an etching solution in a desired viscosity range is added to the glass substrate 24. A predetermined amount is applied to the entire surface of the substrate, and a chemical reaction is allowed to proceed while the glass substrate 24 is being conveyed through the etching chamber 16. The time for this chemical reaction can be adjusted to a predetermined length by appropriately setting the length of the etching chamber 16 and the rotation speed (transport speed) of the transport roller 26. In this embodiment, the rotation speed of the transport roller 26 is set so that the chemical reaction is performed for about 30 seconds to 180 seconds, but the setting of the rotation speed is not limited to this range.

  The wiping chamber 18 is disposed downstream of the etching chamber 16 in the transfer path. The wiping chamber 18 includes a wiping unit 180 that wipes the etching solution applied to the glass substrate. As shown in FIG. 3A, the wiping unit 180 includes a wiping cloth 186, a supply roll 184, a winding roll 185, a pressure roll 182 and a tension roll 188. The wiping cloth 186 is used for wiping the thickened etching solution applied to the glass substrate 24. In the present embodiment, a highly absorbent nonwoven fabric is used. The structure of the wiping cloth 186 is not particularly limited as long as it has high absorbency and does not damage the glass substrate 24. The cloth is made of nylon or polyester fine fibers, paper waste or the like. It is possible to use the material of the following.

  The supply roll 184 is configured to wind and receive the wiping cloth 186 supplied to the wiping position. The winding roll 185 is configured to collect the used wiping cloth 186 that has been wiped at the wiping position. The pressure roll 182 is configured to press the wiping cloth 186 toward the glass substrate 24. The tension roll 188 is provided to hang the wiping cloth 186 in an effectively stretched state.

 As shown in FIG. 3B, the wiping cloth 186 pressed against the glass substrate 24 by the pressure roller 182 at the wiping position wipes off the thickened etching solution applied to the glass substrate 24. When the sensor (not shown) detects that the glass substrate 24 has reached the wiping position, the winding roll 185 starts to wind the wiping cloth 186, so that the glass substrate 24 is always supplied from the supply roll 184. Wipe off with a clean wiping cloth 186. As a result, it becomes possible to prevent the glass substrate 24 from being soiled by wiping. Here, the wiping efficiency is improved by the wiping cloth 186 by arranging the supply roll 184 and the winding roll 185 so that the wiping cloth 186 advances in the direction opposite to the conveyance direction of the glass substrate 24 at the wiping position. However, it is not limited to this configuration.

  In this embodiment, the etching process and the wiping process are performed in separate rooms, but it is also possible to execute these processes in the same room. In this case, it is preferable to arrange one or a plurality of etching units and wiping units at a desired interval in the same room. The etching unit may be the same as the configuration described in FIGS. 2A to 2C, and the wiping unit is the same as the configuration described in FIGS. 3A and 3B. Good ones.

  A cleaning chamber 20 is arranged downstream of the wiping chamber 18, and the wiped glass substrate 24 is guided to the cleaning chamber 20. The cleaning chamber 20 includes a washing shower nozzle 202 for rinsing the glass substrate 24 and an air knife 204 for draining the glass substrate 24, and the glass substrate 24 is washed in the cleaning chamber 20 as necessary. . In the cleaning chamber 20, when cleaning using a cleaning liquid instead of water is necessary, such cleaning may be performed as appropriate.

  The discharge part 22 is arrange | positioned in the most downstream of a conveyance path, and it is comprised so that upper part may open | release. The glass substrate 24 that has been subjected to the etching process and the wiping process in the etching apparatus 10 is transported to the discharge unit 22 and is collected from above the transport roller 26 by an operator or a robot.

  According to the above embodiment, it becomes possible to perform the etching process with respect to the surface of the glass substrate 24 continuously. For example, the etching apparatus 10 can be suitably used when irregularities are formed on the surface of the glass substrate 24 and antiglare (anti-glare [AG]) processing is performed. Furthermore, since the etching solution hardly flows or jumps on the glass substrate 24 by using the thickened etching solution, the inside of the etching apparatus 10 is contaminated by the etching solution or sludge. It becomes possible to prevent.

  Next, another example of the etching apparatus will be described with reference to FIG. In the etching apparatus 10 described above, only one side of the glass substrate 24 is processed in the pretreatment chamber 14 and the cleaning chamber 20 because etching is performed only on one side. However, as shown in FIG. You may make it process on both surfaces of the board | substrate 24. FIG. FIG. 4 shows an example in which the glass substrate 24 is etched by a roll coating method using an application roll 164, and both surfaces of the glass substrate 24 are pretreated and cleaned.

  Further, another example of the etching apparatus will be described with reference to FIGS. 5A and 5B. In the configuration shown in FIGS. 5A and 5B, a die coating method using a slot die 166 is employed. Here, an example in which an etching solution is applied to both surfaces of the glass substrate 24 and both surfaces of the glass substrate 24 are processed simultaneously is shown. In the case of etching processing on both surfaces, the glass substrate 24 can be made thinner in addition to the unevenness forming process of the glass substrate 24. However, if a thickened etching solution that does not flow on the glass substrate 24 is left in contact with the glass substrate 24 for a long time, not only the etching efficiency is deteriorated, but also the surface abnormality (protrusion etc.) of the glass substrate 24 may occur. It is preferable that the viscous etching solution is frequently wiped off by a wiping unit and a new thickening etching solution is applied.

  When the plate thickness to be etched increases, it may be necessary to repeatedly process the glass substrate 24 by the etching apparatus shown in FIG. For this reason, a configuration in which the glass substrate 24 automatically repeatedly passes through the etching chamber and the wiping chamber may be employed as in the configuration example shown in FIG. By adopting such a configuration, even when the glass substrate 24 is made thin, it is possible to prevent internal contamination of the apparatus and reduce the amount of waste liquid.

  In the above-described embodiment, in order to prevent the occurrence of protrusions or the like due to precipitates on the glass substrate coated with the thickening etchant, the thickening etchant is applied and removed immediately. However, this is not the case when it is desired to increase the surface area of the glass substrate. For example, if a thickened etching solution is applied to a glass substrate to generate precipitates and then only the thickened etching solution is absorbed by the wiping cloth, a glass substrate having a large porous glass surface area may be generated. It becomes possible. By generating such a porous glass-like glass substrate, it can be used as an electrostatic adsorption type filter member.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10-Etching apparatus 12-Introducing section 14-Pretreatment chamber 16-Etching chamber 18-Wiping chamber 20-Cleaning chamber 22-Discharging unit 24-Glass substrate 26-Conveying roller 180-Wiping unit

Claims (4)

A conveyance path capable of continuously conveying a glass substrate;
Etching means configured to apply a thickened etching solution to the glass substrate transported along the transport path;
A wiping means disposed downstream of the etching means in the transport path and wiping the thickened etching solution applied to the glass substrate;
An etching apparatus comprising at least   The etching apparatus according to claim 1, wherein the etching means and the wiping means are continuously arranged in this order.   The etching apparatus according to claim 1, wherein the thickening etchant has a viscosity of 10 to 1000 mPa · s.   An etching solution for a glass substrate that can be used in the etching apparatus according to claim 1, wherein the glass substrate includes at least hydrofluoric acid and is thickened with a magnesium salt. Etching solution.

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