JP2016072440A - Etching system and etching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an etching system and an etching method which allow for long life of the devices and facility, and sustainability of etching quality, while suppressing consumption of the etchant.SOLUTION: An etching system 10 includes an etching section 142, an etchant supply section 144, a liquid mixing section 12, and a hydrofluoric acid regeneration device 18. The liquid mixing section 12 is connected with the etchant supply section 144, and is configured so that an etchant can be produced by mixing more than one kinds of liquid containing at least hydrofluoric acid. The hydrofluoric acid regeneration device 18 is configured to regenerate the hydrofluoric acid by using the reaction products of etching, and to supply the regenerated hydrofluoric acid to the liquid mixing section 12. The etchant of amount corresponding to the supply amount from the liquid mixing section 12 to the etchant supply section 144 is supplied from the etchant supply section 144 to the hydrofluoric acid regeneration device 18.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an etching system for performing an etching process on a glass substrate using an etching solution containing hydrofluoric acid, and in particular, while reducing consumption of the etching solution, extending the life of the apparatus / equipment and etching quality. The present invention relates to an etching system and an etching method capable of improving the quality.

  There are various methods for processing a glass substrate used for a flat panel display such as a liquid crystal display or a touch panel. Conventionally, an etching process using an etchant containing hydrofluoric acid has been widely performed. By such an etching process, a slimming process for reducing the weight of the glass substrate, a cutting process for dividing the sheet-like mother substrate into a plurality of panels, and the like have been performed. In addition, with the widespread use of etching treatments, a technique for removing impurities such as products generated during etching from an etching solution has been developed, and sedimentation and filtration have been performed for recycling the etching solution.

  However, in the recycling of the etchant, depending on the substance produced by the reaction with the etchant, impurities may not be removed by sedimentation or filtration. In order to solve such a problem, there has been conventionally employed a technique in which at least chemical treatment or reverse osmosis membrane treatment is performed on the etching waste liquid, and the obtained etching liquid is recycled (for example, patents). Reference 1).

  In an etching system employing such a recycling technology, among impurities generated in the etching process, substances dissolved in etching waste liquid that could not be removed by conventional methods, and particle sizes of 1 μm or less It was supposed that even the particulate matter dispersed in the etching effluent as colloidal particles could be removed.

JP 2006-326444 A

  However, the conventional etching solution recycling technology employs a configuration in which the etching solution is drained and impurities are removed after the etching process, so that the etching solution in the latter half of the etching process is compared with the etching solution in the first half of the etching process. Is likely to contain many impurities. For this reason, in the latter half of the etching process, there is a problem that sludge easily adheres to pipes, tanks, valves and the like. As a result, while it is possible to increase the number of times the etching solution is recycled, there is a high possibility that the lifetime of the etching apparatus and its associated equipment will be shortened. Furthermore, as a result of the quality of the etching solution changing between the first half and the second half of the etching process, there is also a risk that the etching quality is degraded.

  An object of the present invention is to provide an etching system and an etching method capable of extending the life of an apparatus / equipment while maintaining the etching quality while suppressing the consumption of the etching solution.

  The etching system according to the present invention includes an etching unit, an etching solution supply unit, a liquid mixing unit, and a first recycling unit. The etching means is configured to perform an etching process on the glass substrate with an etching solution containing hydrofluoric acid. The etching solution supply unit is configured to be able to store an etching solution to be supplied to the etching unit, and is configured to supply and collect the etching solution to the etching unit. The liquid mixing means is connected to the etching liquid supply means and is configured to be able to generate an etching liquid by mixing two or more liquids containing at least hydrofluoric acid. In this etching system, the first recycling means is connected to the etchant supply means, regenerates hydrofluoric acid using the reaction product of the etching process, and uses the regenerated hydrofluoric acid as the etchant mixing means. Configured to supply. Then, an amount of the etching liquid corresponding to the amount supplied from the liquid mixing means to the etching liquid supply means is configured to be supplied from the etching liquid supply means to the first recycling means.

  In this configuration, when the etching solution is supplied from the liquid mixing unit to the etching solution supply unit, an amount of the etching solution corresponding to the supply amount is supplied from the etching solution supply unit to the first recycling unit. Even if the etching solution is replenished at any time, the etching solution is not wasted. That is, the etching solution discharged from the etching solution supply means is not discarded, but the hydrofluoric acid regeneration process is executed in the first recycling means. Etching solution is not wasted even if supplied.

  As a result, it is not necessary to force the etching solution used for the etching process to last for a long time, so that the etching process can always be performed using a fresh etching solution. For this reason, it becomes difficult to generate | occur | produce the problem that the apparatus and equipment of an etching process deteriorate by sludge etc. in etching liquid. As a result, it is possible to extend the life of the etching processing apparatus / equipment. Further, by replacing the etching solution with a fresh one as needed, the quality of the etching solution is hardly different between the first half and the second half of the etching process, and the etching quality is improved. Further, the used etching solution replaced with the fresh solution is not wasted, but is regenerated with hydrofluoric acid in the first recycling means and supplied again to the liquid mixing means. Therefore, the consumption of the etching solution can be suppressed.

  In the above-described configuration, the second recycling is configured to receive the etching solution stored in the etching solution supply unit, and is configured to remove unnecessary substances from the received etching solution and return them to the etching solution supply unit. Preferably further means are provided. By providing such second recycling means, it is possible to further maintain the quality of the etching solution stored in the etching solution supply means, so that further improvement in etching quality can be expected.

  In the above configuration, it is preferable that the etching solution is supplied from the liquid mixing unit to the etching solution supply unit at a predetermined interval. By adopting such a configuration, the old etchant is less likely to stay in the etchant supply means, so that the quality of the etchant used for the etching process can be improved, resulting in improved etching quality. It becomes possible.

  According to the present invention, it is possible to extend the life of the apparatus / equipment and to maintain the etching quality while suppressing the consumption of the etching solution.

It is a figure showing the outline of the etching system concerning one embodiment of the present invention. 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 outline of the hydrofluoric-acid reproduction | regeneration part which concerns on one 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, an etching system 10 according to an embodiment of the present invention includes an etching apparatus 14 and a hydrofluoric acid regeneration apparatus 18. The etching apparatus 14 includes at least an etching processing unit 142 and an etching solution supply unit 144. The etching processing unit 142 corresponds to the etching means according to the present invention, and is configured to perform an etching process by bringing an etching solution containing hydrofluoric acid controlled to a predetermined concentration range into contact with the glass substrate. The etching solution supply unit 144 is configured to supply the etching solution to the etching processing unit 142 and to collect the etching solution used in the etching processing unit 142.

  The etching apparatus 14 is connected to the liquid mixing unit 12. The liquid mixing unit 12 mixes various chemicals (hydrofluoric acid, hydrochloric acid, sulfuric acid, etc.) and water supplied by the etching system 10 to prepare an etching solution or a cleaning solution for cleaning the inside of the etching apparatus 14. It is configured to blend. The liquid prepared in the liquid mixing unit 12 is supplied to the etching processing unit 142 via the etching solution supply unit 144.

  Further, the etching solution supply unit 144 is connected to the filtration processing unit 16. The filtration processing unit 16 collects unnecessary materials (products such as sludge generated during glass substrate etching) contained in the etching solution in the etching solution supply unit, and again supplies the etching solution from which the unnecessary materials have been removed to the etching solution supply unit 144. Configured to be returned to. A typical example of the filtration processing unit 16 is a filter press, but it is also possible to use a filtration device other than the filter press. In this embodiment, the filtration processing unit 16 corresponds to the second recycling means of the present invention.

  The hydrofluoric acid regeneration device 18 is configured to receive the etching solution discharged from the etching device 14 and supply the regenerated hydrofluoric acid to the liquid mixing unit 12 after performing the hydrofluoric acid regeneration process. This hydrofluoric acid regeneration device includes at least two buffer tanks 182 and 184 and a hydrofluoric acid regeneration unit 20. The buffer tank 182 is configured to store the etching solution discharged from the etching solution supply unit 144. The buffer tank 184 is configured to store the hydrofluoric acid regenerated by the hydrofluoric acid regenerating unit 20. The regenerated hydrofluoric acid stored in the buffer tank 184 is appropriately supplied to the liquid mixing unit 12 by liquid transport means such as a pump. In this embodiment, the hydrofluoric acid regeneration device 18 corresponds to the first recycling means of the present invention.

  Then, the etching apparatus 14 is demonstrated using FIG. 2 (A)-FIG.2 (C). In this embodiment, the glass substrate 100 is continuously conveyed to one or a plurality of etching processing units 142 one by one, and the etching processing unit 142 is configured to inject an etching solution onto the glass substrate. A single-wafer etching apparatus 14 is employed. In the etching apparatus 14, the etching solution is supplied from the etching solution supply unit 144 to the etching processing unit 142 by a known liquid feeding unit such as a pump. In the etching processing unit 142, an etching solution is sprayed on the upper surface, the lower surface, or the upper and lower surfaces of the glass substrate 100. The etchant sprayed onto the glass substrate 100 and coming into contact with the glass substrate flows down to the bottom of the etching processing unit 142 and is collected by the etching solution supply unit 144. Since the recovered etching solution contains silicon-based compounds and aluminum-based compounds dissolved from the glass substrate 100, the quality of the etching solution is sent by sending the etching solution from the etching solution supply unit 144 to the filtration processing unit 16 as needed. Is maintained.

  As shown in FIG. 2C, the etching solution supply unit 144 includes an etching solution tank 145 configured to be able to store an etching solution to be supplied to the etching processing unit 142. The etching solution tank 145 is configured such that when the amount of liquid exceeds a predetermined amount, the excess liquid overflows and flows out. Specifically, an amount of the etching solution corresponding to the amount supplied from the liquid mixing unit 12 to the etching solution supply unit 146 overflows and is supplied to the hydrofluoric acid regeneration device 18. For this reason, it is possible to replenish a new etching solution from the liquid mixing unit 12 to the etching solution supply unit 144 at a predetermined interval and discharge the existing etching solution to the hydrofluoric acid regeneration device 18 according to the replenishment amount. It has become.

  Next, an example of processing in the hydrofluoric acid regeneration unit 20 will be described with reference to FIG. The hydrofluoric acid regeneration unit 20 is configured to process the drainage generated in the etching apparatus 14. The hydrofluoric acid regeneration unit 20 includes a first filter press 22, a sludge container 24, a reaction unit 26, a second filter press 28, a distillation unit 30, and first to third reaction devices 32, 34, and 36. Prepare.

  The first filter press 22 is configured to filter the drainage (for example, mixed acid drainage) of the etching apparatus and collect acid sludge. The sludge storage tank 24 is configured to receive and store the acid sludge collected by the first filter press 22. The acid sludge stored in the sludge storage tank 12 is appropriately handled and processed by an industrial waste disposal contractor as necessary.

  The reaction unit 26 is configured to receive the filtrate of the first filter press 22. Further, chemicals (in this embodiment, sodium carbonate) that react efficiently with fluorine in the mixed acid drainage are added to the reaction unit 26. The second filter press 28 is configured to receive the slurry that has been reacted for a desired time in the reaction unit 26 and to separate the received slurry into solid and liquid.

  The distillation unit 30 is configured to receive the filtrate discharged from the second filter press 28. In this embodiment, the distillation unit 30 is supplied with a mixed acid drainage solution with a reduced fluorine concentration via the reaction unit 26 and the second filter press 28. The distillation unit 30 separates hydrofluoric acid from the mixed acid by performing a distillation process on the received mixed acid effluent, and collects the separated hydrofluoric acid. The hydrofluoric acid recovered by the distillation unit is supplied to the buffer tank 184.

  The first reactor 32 is configured to accommodate the cake dehydrated by the second filter press 28. In this embodiment, the first reactor 32 contains sodium silicofluoride. Sodium hydroxide is added to the first reactor 32, and sodium fluoride is obtained by reacting sodium silicofluoride and sodium hydroxide.

  The obtained sodium fluoride is accommodated in the second reactor 34. In the second reactor 34, calcium fluoride is obtained by the reaction between sodium fluoride and the added calcium hydroxide aqueous solution or calcium chloride aqueous solution. This calcium fluoride is accommodated in the third reactor 36. In the third reactor 36, calcium fluoride reacts with concentrated sulfuric acid to recover hydrofluoric acid, and the recovered hydrofluoric acid is supplied to the buffer tank 184.

  The regenerated hydrofluoric acid collected in the buffer tank 184 is appropriately sent to the liquid mixing unit 12 and used when the etching liquid is prepared in the liquid mixing unit 12. On the other hand, the remaining products generated in the first reactor 32, the second reactor 34, and the third reactor 36 are discharged in a detoxified state in a non-illustrated abatement facility. The

  In this configuration of the etching system 10, when an etching solution is supplied from the liquid mixing unit 12 to the etching solution supply unit 144, an amount of etching solution corresponding to the supply amount is supplied from the etching solution supply unit 144 to the hydrofluoric acid regeneration device 18. Therefore, even if the etching solution is replenished at any time during the etching process, the etching solution is not wasted but received by the hydrofluoric acid regeneration device 18. In the hydrofluoric acid regenerating apparatus, hydrofluoric acid is regenerated using the reaction product of the etching process, and the amount of unused hydrofluoric acid supplied to the liquid mixing unit 12 is reduced in order to return the regenerated hydrofluoric acid to the liquid mixing unit 12. It becomes possible to reduce.

  Therefore, since it is not necessary to force the etching solution to last for suppressing the consumption of hydrofluoric acid, it is possible to suppress the deterioration of the etching apparatus 14 due to the deterioration of the etching solution (including the generation of sludge). become. That is, it is possible to perform the etching process while always supplying a fresh etching solution from the liquid mixing unit 12 while suppressing the amount of hydrofluoric acid used. For this reason, it becomes possible to realize both the life extension of the etching apparatus 14 and the reduction of the amount of hydrofluoric acid used.

  Furthermore, by replacing the etching solution with what is supplied from the liquid mixing unit 12 as needed, the etching solution is unlikely to deteriorate during the etching process, and the quality of the etching solution is unlikely to differ between the first half and the second half of the etching process. . For this reason, the etching quality is improved.

  In addition, unnecessary quality of the etchant in the etchant supply unit 144 is sequentially removed in the filtration unit 16, so that the quality of the etchant can be more reliably maintained. In this way, an etching apparatus is used by extending the lifetime of the etching solution in the filtration processing unit 16 and replacing the etching solution with a new etching solution as needed instead of forcibly extending the lifetime of the etching solution. It is possible to reduce the amount of hydrofluoric acid used and maintain the etching quality without imposing a burden on 14.

  In the etching system 10, the control unit 50 may supply an etching solution from the liquid mixing unit 12 to the etching solution supply unit 144 at a predetermined interval by controlling an automatic valve, a pump driver, and the like. By appropriately controlling automatic valves, pump drivers, and the like according to a program (recipe) incorporated in the control unit 50, replenishment of the etchant and delivery of the used etchant to the hydrofluoric acid regenerator 18 at an optimal timing. Is possible. As a result, the old etching solution is less likely to stay in the etching solution supply means, so that the quality of the etching solution used for the etching process can be improved. And it becomes possible to improve the quality of etching.

  In the above-described embodiment, the example of the etching apparatus 14 that uses the single wafer conveyance method and sprays the etching solution onto the glass substrate has been described, but the example of the etching apparatus 14 is not limited thereto. For example, as shown in FIGS. 4 (A) and 4 (B), the present invention is also used in a dip type etching apparatus 15 that performs etching by immersing a plurality of glass substrates 100 at a time and immersing them in an etching solution. The invention can be applied.

  The etching apparatus 15 supplies gas from the gas supply unit 156, and generates bubbling from the diffuser tube in the etching solution tank. A rising flow is generated in the etching solution tank and overflows in the upper part of the etching solution tank. The overflowed etchant passes through a filter or the like as necessary, and then returns to the etchant tank again. In such an etching apparatus 15 as well, it is possible to obtain the same effects as those of the above-described embodiment by employing the etching solution supply unit 144 having the same configuration as that described above.

  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.

DESCRIPTION OF SYMBOLS 10-Etching system 12- Liquid mixing part 14- Etching apparatus 16- Filtration processing part 18- Hydrofluoric acid reproduction | regeneration apparatus 20- Hydrofluoric acid reproduction | regeneration part 50- Control part 142- Etching processing part 144- Etching liquid supply part 182, 184- Buffer tank

Claims (4)

Etching means configured to perform an etching process on the glass substrate with an etching solution containing hydrofluoric acid,
Etching solution supply means configured to be capable of containing an etching solution to be supplied to the etching means, and configured to supply and collect the etching solution to the etching means;
A liquid mixing means connected to the etching liquid supply means and configured to generate an etching liquid by mixing two or more liquids containing at least hydrofluoric acid;
A first recycle connected to the etching solution supply means and configured to regenerate hydrofluoric acid using a reaction product of the etching process and supply the regenerated hydrofluoric acid to the etching solution mixing means. Means,
An etching system configured to supply an amount of etching liquid corresponding to the amount supplied from the liquid mixing means to the etching liquid supply means from the etching liquid supply means to the first recycling means.   A second recycle unit configured to receive the etchant contained in the etchant supply unit, and configured to remove unnecessary substances from the received etchant and return the undesired product to the etchant supply unit; The etching system according to claim 1, further comprising:   3. The etching system according to claim 1, wherein an etching solution is supplied from the liquid mixing unit to the etching solution supply unit at a predetermined interval. Etching the glass substrate with an etchant containing hydrofluoric acid;
Removing unwanted materials from the etchant during the etching process;
Replenishing a predetermined amount of etchant during the etching process;
During the etching process, a step of sending an etching solution in an amount corresponding to the predetermined amount to a hydrofluoric acid regeneration unit that regenerates hydrofluoric acid using a reaction product of the etching process;
Etching method including:

Images