JP2020114783A - Etching device - Google Patents

Abstract

To provide an etching device capable of suppressing the deposition of sludge to a tank, a piping or the like in the device.SOLUTION: An etching device 10 is composed in such a manner that an etching liquid is jetted to a glass substrate 24 carried in a prescribed direction, and comprises: an etching chamber 161; an etching liquid storage part 60; and a liquid feed part 70. The etching chamber 161 is composed so as to jet an etching liquid to the glass substrate 24. The etching liquid storage part 60 is composed so as to store the etching liquid jetted in the etching chamber 161. The liquid feed part 70 feeds the etching liquid in the etching liquid storage part 60 to the etching chamber 161. Further, in the etching device 10, the etching chamber 161, the etching liquid storage part 60 and the liquid feed part 70 are arranged in a vertical direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to a single-wafer etching apparatus that sprays an etching solution onto a thin substrate such as a glass substrate.

In recent years, flat panel displays such as liquid crystal displays have been increasingly required to be thin. In the manufacturing process of a flat panel display panel, it is manufactured by sealing a functional layer required for image display such as a liquid crystal layer with two glass substrates. In order to provide a thin display, it is effective to thin the glass substrate by an etching process.

As the etching process, a wet etching process of bringing a glass substrate into contact with an etching solution is generally adopted. Wet etching processing is roughly classified into single-wafer etching and immersion etching. Single-wafer etching is a method in which an etching solution is sprayed onto a glass substrate being conveyed using a spray nozzle or the like. The immersion etching is performed by immersing a jig holding a plurality of glass substrates in an etching bath containing an etching solution. In particular, single-wafer etching is considered to be advantageous for etching large-sized glass substrates as compared with immersion etching, and the demand for single-wafer etching has been increasing in recent years.

Normally, the single-wafer etching apparatus processes the substrate to be processed in the processing chamber, so that there is no possibility that the etching solution is scattered outside the apparatus or acid gas such as hydrofluoric acid leaks out of the apparatus (for example, , Patent Document 1). Therefore, the single-wafer etching apparatus is considered to be excellent in terms of worker safety and working environment.

JP 2012-051801 A

However, if the etching process is continued for a long time, an insoluble product (hereinafter referred to as sludge) is generated in the etching solution. Sludge is generated when a metal ion complex generated by a reaction between an etching solution and a glass substrate is saturated in the etching solution. When a large amount of sludge is generated, problems such as adhesion to piping and tanks (particularly, the bottom portion) of the etching apparatus occur, so measures such as stirring the etching solution in the tank of the etching apparatus have been taken. However, even if measures are taken to prevent sludge adhesion, it has been difficult to prevent sludge adhesion and accumulation as the amount of sludge increases. For this reason, the tank, the pipes, and the like have to be regularly cleaned, which sometimes reduces the work efficiency.

An object of the present invention is to provide an etching apparatus that can suppress the attachment of sludge to the inside of pipes and tanks.

An etching apparatus according to the present invention is an etching apparatus configured to spray an etching liquid onto a substrate to be processed which is conveyed in a predetermined direction, and includes an etching processing unit, an etching liquid storage unit, and a liquid sending unit. ing. The etching processing unit is configured to spray an etching liquid onto the substrate to be processed. The etching liquid storage unit is configured to store the etching liquid sprayed by the etching processing unit. The liquid feeding part feeds the etching liquid in the etching liquid containing part to the etching processing part. Further, in the etching apparatus, the etching processing unit, the etching liquid storage unit, and the liquid feeding unit are arranged in the vertical direction.

The etching liquid is sprayed in the etching processing unit, then stored in the etching liquid storage unit, and sent again to the etching processing unit by the liquid feeding unit. At this time, the etching solution can be discharged from the bottom of the etching solution processing section by disposing the etching solution storage section immediately below the etching processing section. For this reason, the risk of sludge being accumulated at the bottom of the etching liquid processing unit is reduced. In addition, since the etching liquid storage unit can also send the etching liquid from the bottom to the liquid supply unit, the risk of sludge accumulation in the etching liquid storage unit can be reduced.

In addition, it is preferable to further include a collection unit that collects solid matter in the etching liquid between the etching liquid storage unit and the liquid feeding unit. By disposing the collecting unit in front of the liquid sending unit, it is possible to prevent sludge from entering the liquid sending unit and causing a problem in the liquid sending unit. Further, by collecting the sludge outside the etching liquid accommodating portion, maintenance of the collecting portion becomes easy.

Further, it is preferable that the etching solution storage section has a stirring section for stirring the etching solution. By having the stirring unit, the etching liquid in the etching liquid storage unit is stirred and the sludge is prevented from remaining in one place. As a result, the sludge is prevented from sticking to the wall surface of the etching liquid storage portion.

According to the present invention, it is possible to provide an etching apparatus capable of suppressing the attachment of sludge to the inside of pipes and tanks.

It is a schematic diagram of an etching device concerning one embodiment of the present invention. It is a schematic side view of the etching apparatus which concerns on one Embodiment of this invention. It is a figure which shows the structure of an etching liquid accommodating part. It is a figure which shows the structure of an etching process part, an etching liquid accommodating part, and a liquid sending part. It is a figure which shows the structure of an etching process part. It is a figure showing the state where the door of the ceiling part was opened.

From here, an etching apparatus according to an embodiment of the present invention will be described with reference to the drawings. 1 and 2 are schematic views of a glass substrate etching apparatus 10. The etching apparatus 10 includes a carry-in unit 12, a front water washing chamber 14, a first etching chamber 161, a second etching chamber 162, a rear water washing chamber 18, a carry-out unit 20, and a transport roller 30.

As shown in FIG. 2, the transport roller 30 is arranged along the length direction of the etching apparatus 10 and configured to transport the glass substrate 24 in the horizontal direction. The carrying rollers 30 are arranged at regular intervals along the carrying direction of the glass substrate 24, and are configured to carry the glass substrate 24 by supporting it from below. The transport speed of the glass substrate 24 is preferably set appropriately in consideration of the size and plate thickness of the glass substrate 24, the spray pressure of the etching liquid, the composition of the etching liquid, and the like. The etching apparatus 10 is configured to perform an etching process such as thinning on the glass substrate 24 being transported by the transport roller 30 by spraying an etching solution.

The carry-in unit 12 is configured to introduce the glass substrate 24 into the etching apparatus 10 by placing the glass substrate 24 on the transport roller 30. The glass substrate 24 is etched by passing through each chamber while being transported in the horizontal direction by the transport roller 30, and is etched to a desired plate thickness. The glass substrates 24 are sequentially loaded into the etching apparatus 10 at a predetermined interval.

The pre-water washing chamber 14 is arranged at the rear stage of the carry-in section 12. The pre-water washing chamber 14 is configured to inject the cleaning liquid onto the glass substrate 24 being transported by the transport roller 30 from the spray units 32 arranged above and below the transport roller 30. If the etching solution is brought into contact with the dried glass substrate, the glass substrate may become cloudy. Therefore, the etching apparatus 10 is configured to inject the cleaning liquid in the preceding stage of the etching chamber. In this embodiment, city water is used as the cleaning liquid.

The first etching chamber 161 and the second etching chamber 162 have substantially the same configuration, and are configured to spray an etching solution onto the glass substrate 24 being transported. In each of the etching chambers 161, 162, a spray unit 32 is arranged above and below the transport roller 30, and the spray liquid is sprayed from the spray unit 32 onto the glass substrate 24 on the transport roller 30.

The spray unit 32 has a plurality of spray nozzles 36 arranged in the liquid supply pipe 34, and is configured to spray the etching liquid uniformly onto the glass substrate 24. The reciprocating movement of the spray unit 32 allows the etching solution to be uniformly sprayed onto the glass substrate 24 and to prevent the etching solution from staying on the upper surface of the glass substrate 24. The arrangement of the spray unit 32 and the number of the spray nozzles 36 can be appropriately changed according to the size of the substrate to be processed and the etching amount.

The etching solution in the present embodiment contains at least hydrofluoric acid, and may contain an inorganic acid such as hydrochloric acid or sulfuric acid, or a surfactant. The composition of the etching liquid and the liquid temperature can be appropriately changed according to the etching amount and the type of the substrate to be processed. Further, the etching apparatus 10 has two etching chambers, but the number of etching chambers can be changed in consideration of the substrate to be processed, the installation place, and the like.

The etching liquid sprayed in each etching chamber is discharged from a discharge port 38 arranged at the bottom of the etching chamber, as shown in FIG. Further, the bottom of the etching chamber is inclined downward toward the outlet 38. The etching liquid that has dropped from the top flows smoothly toward the discharge port 38, so that the accumulation of sludge in the etching chamber is prevented.

The etching chamber and the etching liquid storage unit 60 are connected by a pipe 381, and the etching liquid discharged from the discharge port 38 is collected in the etching liquid storage unit 60 arranged below the etching chamber. The etching liquid storage unit 60 is a tank for storing the etching liquid. The etching liquid sprayed in the etching chambers 161 and 162 is configured to flow into different tanks for each chamber. In addition, a chemical solution such as hydrofluoric acid is replenished into the etching solution container 60 from a chemical solution tank (not shown), if necessary.

As shown in FIG. 3, a stirring unit 62 is provided in the etching liquid storage unit 60. The stirring unit 62 has a suction unit 621 and a spraying unit 622, and is configured to stir the etching liquid in the etching liquid storage unit 60. The suction portion 621 has a hole formed at the tip thereof, and is configured to suck the etching liquid from a predetermined position in the etching liquid storage portion 60. The suction unit 621 is connected to the circulation pipe 64 (see FIG. 4). A motor 641 is provided in the circulation pipe 64, and is configured to suck the etching liquid from the suction unit 621 and send the etching liquid to the spray unit 622.

Further, in the circulation pipe 64, a collection unit 74 is provided on the front side of the motor 641. The collecting unit 74 is a filter having a mesh member for collecting sludge in the etching liquid. The collecting unit 74 is arranged in the circulation pipe 64 and prevents the sludge from flowing into the motor 641. The mesh diameter of the collecting section 74 is appropriately set according to the size of the sludge, but it is preferable to use a filter having a mesh diameter of about 0.8 to 2 mm. By providing the sludge recovery mechanism outside the etching liquid container 60, it is not necessary to arrange a structure that may cause retention of the etching liquid in the etching liquid container 60. Furthermore, since replacement and maintenance of the collection unit 74 are facilitated, a decrease in production efficiency is reduced.

The injection part 622 is a substantially U-shaped perforated pipe and has a plurality of injection holes formed therein. The ejection unit 622 circulates the etching liquid so that sludge does not accumulate in the etching liquid storage unit 60 by injecting the etching liquid sucked from the suction port 621 into the etching liquid storage unit 60. In addition, the shape of the spraying unit 622 is not particularly limited as long as the etching liquid in the etching liquid storage unit 60 can be circulated so that the sludge does not stick to the wall surface or the like.

A liquid feed unit 70 is provided below the etching liquid storage unit 60. The liquid sending unit 70 is configured to send the etching liquid collected in the etching liquid storage unit 60 to the spray unit 32. The etching liquid in the etching liquid storage unit 60 is sent to the liquid sending unit 70 through the pipe 72. The liquid feeding unit 70 is a pump unit, and a magnet pump is used in the present embodiment, but the type of pump is not particularly limited. Further, a control valve is appropriately provided in the pipe 72 to control the flow rate of the etching liquid and the like.

The spray unit 32 is arranged above and below the etching chamber, and is provided with a liquid delivery unit 70 and a pipe 72 corresponding to each spray unit. That is, two liquid feeding parts 70 and pipes 72 corresponding to the upper and lower spray units 32 are provided for one etching liquid storage part 60. Two outlets 80 to which the pipes 72 are connected are formed on the bottom surface of the etching liquid container 60, and the etching liquid is discharged from the outlets 80. In addition, also in the pipe 72, the collecting unit 74 is arranged in front of the liquid sending unit 70, and sludge is collected.

Since the discharge port 80 is provided on the bottom surface of the etching solution storage unit 60 and the pipe 72 extends in the vertical direction from the discharge port 80 to the solution sending unit 70, the etching solution is hardly accumulated and is sent. Since it is liquefied, the sticking of sludge is suppressed in the etching apparatus.

As shown in FIGS. 1 and 5, each etching chamber 161, 162 is covered with a ceiling portion 40 having an arcuate cross section. The ceiling portion 40 includes a transparent member 42, a frame body 44, and a protective film 46. The transparent member 42 is made of a resin member that is resistant to the etching liquid, and has a circular arc shape in cross section. Examples of the resin member used as the transparent member 42 include polyethylene resin, fluorine resin, polypropylene resin and the like. The transparent member 42 can be processed into a desired curved surface shape by thermal processing.

The frame body 44 is attached to the outer wall side of the transparent member 42 in order to maintain the strength of the processing chamber. The frame body 44 is made of a metal member such as iron, and is arranged in a grid pattern. Since the frame body 44 is attached to the outer wall side of the transparent member 42, it is not necessary to dispose an extra structure on the inner wall side of the transparent member 42. For this reason, the problem that the scattered etching solution is accumulated in the uneven portion on the inner wall side is solved, and the etching solution can be discharged along the wall surface of the ceiling portion 40. Further, since the ceiling portion 40 has few structures, it is possible to improve the visibility in the etching chamber.

The protective film 46 is a transparent film attached to the inner surface side of the transparent member 42. As the protective film 46, a polymethylpentene film can be used. Since the polymethylpentene film is a transparent film and has chemical resistance, it does not deteriorate even if it is attached to the inner wall of the etching chamber. Further, since polymethylpentene has a low surface tension, the etching solution scattered on the inner wall easily flows along the wall surface.

When a polymethylpentene film is used, the polymethylpentene resin is stretched and cut into a predetermined size suitable for a component to be applied, and then a surface modification treatment is performed by a corona surface treatment machine. The surface modification treatment can be performed using a known corona discharge treatment device such as a vacuum tube type or a thyristor type. In this embodiment, a distance of about 0.1 to 10 mm is provided between the discharge electrode and the polymethylpentene film, and an applied voltage of 0.1 to 50 kV is applied for processing. The surface of the polymethylpentene film that has been subjected to the surface modification treatment becomes the surface to be attached to another transparent resin, and the adhesive layer is formed on this surface to be attached.

As shown in FIG. 6A, the transparent member 42 is provided with a door body 50 that can be opened and closed. The door 50 selectively opens or closes the opening 52 formed in the ceiling 40. When closed, the door body 50 is fitted into the opening 52 to seal the etching chamber. A sealing material is arranged at the peripheral edge of the opening 52 to improve the airtightness of the etching chamber.

The door body 50 is formed of the transparent member 42 like the ceiling portion 40, and has a curved shape. Further, the protective film 46 is also attached to the inner surface side of the door body 50. As a result, the risk that the etching liquid will stay in the door body 50 is reduced, and the etching liquid drops along the ceiling portion 40.

The door body 50 is rotatably supported by a hinge portion 54 at the end of the opening 52. The hinge 54 is also made of the transparent member 42. As shown in FIG. 6(A), the door body 50 can be rotated upward to open. The door body 50 includes a grip portion 56, and a worker or the like lifts the grip portion 56 so that the door body 50 rotates about the hinge portion 54. The door body 50 is preferably fixed by a fixing mechanism that can be fixed in a state of being opened upward.

Due to the curved shape of the door body 50, the etching liquid attached to the inner wall side of the door body 50 does not attach to the periphery of the etching apparatus 10 even when the door body 50 is opened. Further, as shown in FIG. 6B, since the etching liquid flows along the curved shape of the door body 50, it finally drops into the etching chamber through the opening 52. As a result, it is possible to prevent the peripheral portion of the etching apparatus 10 from being soiled.

Two adjacent processing chambers such as the pre-water washing chamber 14 and the first etching chamber 161 are separated by a partition wall as shown in FIG. The housing of the etching chamber including the partition walls (excluding the ceiling portion 40) is formed of a resin having a hydrofluoric acid resistance such as polyvinyl chloride. In order to allow the glass substrate 24 to pass therethrough, a partition 28 is formed in the partition wall so as to connect the two processing chambers. The slit portion 28 is formed to have a height that allows the glass substrate 24 to pass therethrough, and is preferably formed to have a height of 4 to 10 mm.

The post-water washing chamber 18 is arranged at the subsequent stage of the second etching chamber 162. Similar to the front water washing chamber 14, the post water washing chamber 18 is configured to spray the cleaning liquid onto the glass substrate 24 from above and below to wash away the etching liquid. As the cleaning liquid, city water is used as in the case of the pre-water cleaning chamber 14.

A liquid cutter 26 is arranged at the most downstream portion of the post-cleaning chamber 18. The liquid cutter 26 is a cylindrical member disposed above the transport roller 30, and is configured to rotate along the upper surface of the glass substrate 24 and physically remove water on the glass substrate 24. The glass substrate 24 on which the liquid cutter 26 has been dried is unloaded from the etching apparatus 10 at the unloading unit 20. In the carry-out section 20, the glass substrate 24 on the carrying roller 30 is collected by a robot arm, a worker or the like.

Although the present embodiment has been described by taking the glass substrate as an example, the etching apparatus according to the present invention is not limited to the transportation of the glass substrate, and is applicable to a resin substrate or a laminated substrate as long as it is a thin substrate. It is possible.

The description of the above embodiments is to be considered as illustrative in all points and not restrictive. The scope of the invention is indicated by the claims rather than the embodiments described above. Further, the scope of the present invention is intended to include meanings equivalent to the claims and all modifications within the scope.

10-Etching Equipment 12-Inlet 14-Front Washing Chamber 161-First Etching Chamber 18-Post-Washing Chamber 24-Glass Substrate 30-Conveying Roller 60-Etching Liquid Storage 70-Liquid Transfer

Claims (3)

An etching apparatus configured to spray an etching liquid onto a substrate to be processed which is conveyed in a predetermined direction,
An etching processing unit for spraying an etching solution onto the substrate to be processed,
An etching liquid storage unit for storing the etching liquid sprayed in the etching processing unit,
A liquid feed unit that feeds the etching liquid in the liquid storage unit to the etching chamber,
At least
An etching apparatus, wherein the etching processing section, the etching solution storage section, and the liquid delivery section are arranged in a vertical direction. The etching apparatus according to claim 1, further comprising: a collection unit that collects solid matter in the etching liquid between the etching liquid storage unit and the liquid feeding unit. The etching apparatus according to claim 1 or 2, wherein the etching solution storage section includes a stirring section for stirring the etching solution.

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