JP2004099437A - Glass substrate chemical processing method and chemical processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for chemically processing a glass substrate for various flat panel displays which realize uniform flattening of the surface of the glass substrate while realizing thinning of the glass substrate regardless of the size of the glass substrate and enable the glass to be recycled. <P>SOLUTION: A part or the whole of one side of the outer surface of the glass substrate or a part or the whole of both sides of the outer surface of the glass substrate is processed by producing the ascending liquid flow of a chemical processing liquid mainly made up of hydrofluoric acid and accompanied by bubbles from the bottom part of a chemical processing liquid storage tank 11 storing the chemical processing liquid and dipping the glass substrate in the processing liquid. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention provides one or a pair of glass substrates for various FPDs (flat panel displays), such as glass substrates for LCDs (liquid crystal displays), glass substrates for PDPs (plasma display panels), and glass substrates for organic EL (electroluminescence). The present invention relates to a chemical processing method for a glass substrate characterized by processing a part or the whole of one side of the outer surface of the bonded substrate, or both sides of the outer surface, and a chemical processing apparatus used for carrying out the method.

Conventional glass substrate processing methods include a physical method and a chemical method. Physical methods include processing using a machine and processing by blast, and chemical methods include processing by wet etching. Recently, there has been a trend to require the following quality improvements.
1) Eliminate surface scratches originally present on the glass substrate.
2) Eliminate pattern traces remaining on the substrate from which the patterned thin film has been peeled off.
3) Thin the entire outer surface of the glass substrate on one side to enhance its flatness.
4) The entire outer surface of the glass substrate is thinned on both sides to enhance its flatness.
5) A recess is formed on one side of the outer surface of the glass substrate to enhance the dimensions of each part and the flatness of each surface.
6) Depressed portions are formed on both sides of the outer surface of the glass substrate to enhance the dimensions of each portion and the flatness of each surface.
7) The same purpose is performed by replacing the glass substrates 3) to 6) with two bonded substrates.

Of the above-mentioned quality improvement items, for example, 1) to 4), processing using a conventional machine, for example, mechanical polishing, lacks flatness, generates cracks and surface scratches, leaves a polished pattern, and reduces polishing ability. Inevitable issues remain, such as limitations. On the other hand, in conventional processing by wet etching, it is difficult to eliminate surface scratches and pattern traces originally present on the glass substrate, and various problems occur even when the plate thickness is reduced as shown in the following example. However, it was difficult to secure the quality equal to or higher than that of elementary glass. Hereinafter, description will be made for a liquid crystal glass substrate as a representative example.

For example, Japanese Patent No. 2722798 discloses that an element assembly is assembled by bonding a pair of glass substrates each having an area corresponding to a plurality of liquid crystal display elements via a sealing material surrounding a liquid crystal sealing area of each element section. A method is disclosed in which the element assembly is immersed in a hydrofluoric acid-based etchant to etch the outer surface of the liquid crystal glass substrate. However, even though the thickness can be reduced, the problem that defects described later occur will occur. is there.

Also, Japanese Patent Application Laid-Open No. 2000-147474 has a bubble generator at the bottom of an etching solution tank for storing an etching solution containing hydrofluoric acid, and the etching solution is stirred by bubbles generated from the bubble generator. An invention of an automatic etching apparatus for etching the surface of glass placed in an etching solution tank is disclosed. However, when the outer surface of a liquid crystal glass substrate is processed using hydrofluoric acid of 15 to 17%, defects described later occur. There's a problem.

In the present invention, an attempt is made to achieve uniform processing of the glass surface by agitating the processing liquid with nitrogen gas rising bubbles, but the flow of the rising bubbles and the processing liquid falling after reaching the liquid surface is an upward flow. There is a problem that the surface is not processed uniformly since the uniformity of the surface is hindered.

The problems when processing by 50 to 300 μm by the conventional wet etching shown in the above two examples will be described below.
1) White turbidity that can be confirmed even under a fluorescent lamp is generated.
2) A pit having a maximum diameter of 0.2 mm is generated. FIG. 12 is a graph showing the results measured by a surface roughness meter after processing.
3) The diameter of the pit increases as the amount of processing increases. FIG. 13 is a graph showing the relationship between the pit diameter and the processing amount.
4) A maximum of 50 pits / cm 2 are generated. FIG. 14 is a graph showing the relationship between the number of pits per unit area and the processing amount. FIG. 14 shows that the number of pits per unit area increases as the processing amount increases.
5) Undulation visible under fluorescent light is generated. FIG. 15 is a graph showing the state of undulation on the surface after processing.
6) The difference between the maximum value and the minimum value of the plate thickness is 20 to 100 μm, which is non-uniform.
7) The width and depth of the surface flaws artificially formed before the processing are increased by the processing (see FIGS. 16 and 17). FIG. 16 is a graph showing a cross section of the surface intentionally scratched before processing, and FIG. 17 is a graph showing a cross section of the surface after processing.

Further, for example, when patterning pixels for a color filter after sputtering Cr on a liquid crystal glass substrate, when the substrate becomes defective, usually, the patterned Cr is peeled off and mechanical polishing is performed to eliminate pattern traces. However, when conventional wet etching is performed instead of mechanical polishing, there is a problem that pattern traces do not disappear and cannot be reused as raw glass.

The present invention has been made in view of such circumstances, and a glass substrate is immersed in a chemical processing solution containing hydrofluoric acid as a main component, and part or all of one side of the outer surface of the glass substrate, or both sides of the outer surface. Of various types of glass substrates for FPDs by which a high flatness glass substrate surface can be obtained without processing the various fluoride reaction products on the surface of the glass substrate by processing into a predetermined shape. The purpose is to provide.

Further, the present invention provides a chemical processing apparatus provided with a chemical processing liquid storage tank for storing a chemical processing liquid, a bubble generator, and an overflow liquid receiving tank for receiving the chemical processing liquid overflowed from the chemical processing liquid storage tank. It is another object of the present invention to provide a chemical processing apparatus having a pump for sending the chemical processing liquid received in the overflow liquid receiving tank to the chemical processing liquid storage tank again.

The present invention includes a glass substrate storage jig for disposing one or a plurality of glass substrates or a pair of glass substrates, so that the glass substrates or the pair of glass substrates can be simultaneously bonded. It is an object to provide a chemical processing apparatus capable of processing a plurality of sheets uniformly.

Further, another object of the present invention is to provide a chemical processing apparatus that can stir a chemical processing liquid more uniformly by providing an ultrasonic vibrator or a swinging stirring blade.

In the chemical processing method for a glass substrate of the first invention, an ascending liquid flow of the chemical processing liquid with bubbles is generated from the bottom of a chemical processing liquid storage tank storing a chemical processing liquid containing hydrofluoric acid as a main component. The method is characterized in that a glass substrate is immersed in a processing liquid to process part or all of one side of the outer surface of the glass substrate, or part or all of both sides of the outer surface.

The chemical processing method for a glass substrate according to the second invention is characterized in that, in the first invention, the rising liquid flow overflows from a peripheral portion of the chemical processing liquid storage tank. A chemical processing method for a glass substrate according to a third invention is characterized in that, in the second invention, the chemical processing liquid overflowed from the peripheral portion of the chemical processing liquid storage tank is supplied again to the chemical processing liquid storage tank. . A chemical processing method for a glass substrate according to a fourth aspect of the present invention is the method according to the third aspect, wherein the chemical processing liquid overflowed from the peripheral portion of the chemical processing liquid storage tank is passed through a filter to remove a reaction product generated by the chemical processing. And supplying it to the chemical processing liquid storage tank.

In the first to fourth inventions, since the chemical processing liquid is uniformly raised, fresh processing liquid is always supplied to the surface of the glass substrate, and the reaction product physically adheres to the surface of the glass substrate. Is prevented. The processing speed is determined by the diffusion speed and the reaction speed, but at the convex part of the surface of the glass substrate, the rising flow of fine bubbles constantly supplies an active chemical processing liquid, so the reaction is rate-determined, and the processing speed is sufficiently fast. Become. On the other hand, in the concave portion on the surface of the glass substrate, since the processing liquid is in a stagnant state, the diffusion rate is controlled and the processing speed is reduced. Therefore, the processing speed can be controlled by the upward flow of the fine bubbles, and the surface can be flattened while reducing the thickness of the glass substrate. Further, the scratches existing on the surface of the glass substrate from the beginning can be eliminated, and the glass can be reused.

In the second invention, since the rising liquid flow of the chemical processing liquid falls after reaching the surface of the chemical processing liquid storage tank and does not hinder the chemical processing liquid from rising uniformly thereafter, the glass substrate Can be more uniformly polished. In the third aspect, the chemical processing liquid can be smoothly circulated. In the fourth invention, it is possible to prevent the reaction product in the chemical processing liquid from adhering to the surface of the glass substrate.

A chemical processing apparatus according to a fifth aspect of the present invention is a chemical processing apparatus provided with a chemical processing liquid storage tank for storing a chemical processing liquid, wherein a bubble generating device and an overflow liquid for receiving the chemical processing liquid overflowing from the chemical processing liquid storage tank. A receiving tank and a pump for sending the chemical processing liquid received by the overflow liquid receiving tank to the chemical processing liquid storage tank again are provided. The bubble generator preferably receives gas and discharges the gas from a porous bubble discharge unit. In the circulation channel by the pump, a filter for removing a reaction product generated by polishing, and / or a chemical processing liquid that is disposed below the bubble generating device and is sent out by the pump is used. It is preferable to provide a chemical processing liquid discharge device having a large number of holes for discharging into the chemical processing liquid storage tank.

In the fifth invention, the chemical processing liquid can be uniformly raised, overflowed and supplied again to the chemical processing liquid storage tank. Further, if a filter is provided, the processing liquid after removing the reaction product can be provided. Can be circulated. Therefore, a uniform chemical processing liquid can be obtained, and fresh processing liquid is always supplied to the surface of the glass substrate only by using a filter. Further, it is possible to prevent the reaction product from physically re-adhering to the surface of the glass substrate. Since the active chemical processing liquid is always supplied by the rising flow of the fine bubbles at the convex portion of the surface of the glass substrate, the reaction is rate-determined, and the processing speed is sufficiently high. In the stagnation state, the diffusion rate is controlled and the processing speed is reduced. As a result, the surface can be flattened while the thickness of the glass substrate is reduced.

The chemical processing apparatus according to a sixth aspect is characterized in that, in the fifth aspect, a glass substrate storage jig for disposing one or more of a glass substrate or a pair of glass substrates bonded to each other is provided. In the sixth invention, a plurality of glass substrates or a pair of glass substrates bonded together can be simultaneously and uniformly processed.

化学 A chemical processing apparatus according to a seventh aspect is the chemical processing apparatus according to the fifth or sixth aspect, further comprising an ultrasonic vibrator or an oscillating stirring blade. In the seventh invention, the chemical processing liquid can be stirred more uniformly.

As described in detail above, in the case of the first invention, an ascending liquid flow with fine bubbles is generated from the bottom of the chemical processing liquid storage tank for storing the chemical processing liquid containing hydrofluoric acid as a main component, and the processing is performed. A glass substrate is immersed in a liquid, a part or all of one side of the outer surface of the glass substrate, or both sides of the outer surface are processed, and various fluorides are prevented from re-adhering to the surface of the glass substrate. Thereby, the thickness of the glass substrate can be reduced and the surface can be flattened.

In the case of the first to fourth inventions, since the chemical processing liquid is uniformly raised, fresh processing liquid is always supplied to the surface of the glass substrate, and the reaction product physically re-adheres to the surface of the glass substrate. Is prevented. Therefore, the processing speed can be controlled by the upward flow of bubbles, and the surface can be made more flat while reducing the thickness of the glass substrate. The chemical processing method of the present invention enables uniform processing with high productivity regardless of the size of the glass substrate. Further, the scratches existing on the surface of the glass substrate from the beginning can be eliminated, and the glass can be reused.

In the case of the fifth invention, the chemical processing liquid is uniformly raised and overflowed to remove the reaction product, and then supplied again to the chemical processing liquid storage tank to circulate the chemical processing liquid. , A fresh chemical processing liquid is always supplied, and the reaction products are prevented from physically re-adhering to the surface of the glass substrate. In the convex portion of the surface of the glass substrate, the active chemical processing liquid is always supplied by the rising flow of bubbles, so that the reaction rate is controlled and the processing speed is sufficiently high. In this state, the diffusion rate is controlled, and the processing speed is reduced. As a result, the surface can be flattened while the thickness of the glass substrate is reduced.

According to the sixth aspect, a plurality of glass substrates or a pair of glass substrates bonded together can be simultaneously and uniformly processed. In the case of the seventh invention, since the ultrasonic vibrator or the oscillating stirring blade is provided, the chemical processing liquid can be stirred more uniformly.

Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. FIG. 1 is a sectional view showing an example of the chemical processing apparatus of the present invention. The chemical processing apparatus 1 is provided with a chemical processing liquid storage tank 11, and a gas is introduced into the bottom of the chemical processing liquid storage tank 11 so as to discharge the gas from a porous bubble discharge unit 12 a. A device 12 is disposed, and a glass substrate storage jig 18 for vertically inserting and holding a glass substrate or a pair of glass substrates is disposed above the bubble generating device 12. I have. The glass substrate storage jig 18 is disposed in the glass substrate storage jig holder 17. A chemical processing liquid containing hydrofluoric acid as a main component is introduced into the chemical processing liquid storage tank 11.

An overflow liquid receiving tank 13 for receiving the chemical processing liquid overflowing from the chemical processing liquid storage tank 11 is provided at a peripheral portion of the chemical processing liquid storage tank 11, and the overflow liquid receiving tank 13 is formed by processing. A filter 14 for removing the reaction products and a pump 15 for sending the chemical processing liquid filtered by the filter 14 to the chemical processing liquid storage tank 11 again are connected. A chemical processing liquid discharge section 16a is provided below the bubble generating device 12 and has a number of holes for discharging the chemical processing liquid sent out by the pump 15 toward the bottom of the chemical processing liquid storage tank. The chemical processing liquid is again supplied to the chemical processing liquid storage tank 11 by the chemical processing liquid discharge device 16.

化学 Further, the chemical processing apparatus 1 may include an ultrasonic vibrator or an oscillating stirring blade (not shown). In this case, the chemical processing liquid can be stirred more uniformly.

FIG. 2 is a perspective view showing an example of the bubble generator 12. The bubble generator 12 includes a gas introduction pipe 12b for introducing a gas such as a nitrogen gas, and a plurality of porous pipe-shaped bubble discharge sections 12a, 12a,... Vertically connected to the gas introduction pipe 12b. It has. FIG. 3 is a perspective view showing an example of a bubble discharge unit 12a of another bubble generation device 12. The bubble discharging portion 12a is made of a porous material and has a plate shape. In both FIGS. 2 and 3, it is preferable that the hole diameter of the bubble discharge section 12a is 10 to 500 μm. Then, these bubble generators 12 are arranged below the holder 17 for the liquid crystal glass substrate storage jig, and the fine bubbles are discharged upward to uniformly raise the chemical processing liquid. By this rising liquid flow, a fresh chemical processing liquid can always be supplied to the surface of the glass substrate, and reaction products such as fluoride can be prevented from re-adhering to the surface of the glass substrate.

After the rising flow of the fine bubbles reaches the surface of the chemical processing liquid, it overflows from the periphery of the chemical processing liquid storage tank 11, is received by the overflow liquid receiving tank 13, passes through the filter 14, and then is subjected to the chemical processing again. The liquid is supplied to the liquid storage tank 11. When the chemical processing liquid is not allowed to overflow, if the cross-sectional area of the portion where the rising liquid flow turns into the descending liquid flow is small, the descending liquid flow intersects with the rising liquid flow, and a uniform rising liquid flow cannot be secured. FIG. 4 is a plan view showing an example of the chemical processing liquid storage tank 11 and the holder 17 for a glass substrate storage jig. As shown in FIG. 4, the passing cross-sectional area of the descending liquid flow corresponding to the outer portion of the glass substrate holding jig holder 17 corresponds to the rising liquid flow corresponding to the inner portion of the glass substrate holding jig 17. Is 1 to 3 times the passing cross-sectional area, it is ensured that a uniform ascending liquid flow can be ensured.

Reaction products such as fluorides between the components of the glass substrate and the chemical processing liquid rise due to the upward flow of fine bubbles, which circulate in the chemical processing liquid storage tank 11 and reach the bottom of the chemical processing liquid storage tank 11. The accumulation adversely affects the ejection of the fine bubbles, so that it is necessary to prevent the accumulation of the reaction products. FIG. 5 is a perspective view showing an example of the chemical processing liquid ejection device 16. The chemical processing liquid discharge device 16 is provided with a plurality of chemical processing liquid discharge sections 16a having a large number of holes, and the chemical processing liquid sent out by the pump 15 is directed downward from the chemical processing liquid discharge section 16a. Alternatively, it is preferable to design so as to supply the chemical processing liquid and prevent the accumulation of the reaction product by discharging the liquid obliquely downward.

Hereinafter, the present invention will be specifically described based on examples.
[Example 1] An example in which elementary glass was chemically processed using the chemical processing apparatus 1 of the present invention will be described below.
(1) Size of raw glass and chemical processing amount of each target No. 1; length 320 mm x width 400 mm x thickness 1.1 mm. Target chemical processing amount: 0.3 mm.
No.2; length 400mm x width 500mm x thickness 0.7mm. Target chemical processing amount: 0.2mm.
(2) Composition of chemical processing liquid A chemical processing liquid containing 5% of hydrofluoric acid, 10% of hydrochloric acid and 5% of nitric acid using water as a solvent was used.
(3) Method of Acceptance Inspection and Final Inspection of Elementary Glass <Sheet Thickness Measurement> The thickness at the measurement position shown in FIG. 6 was measured using an ultrasonic thickness gauge.
<Appearance inspection> Fluorescent lamp (1500Lx or more) and condensing lamp (10,000Lx or more) are used as inspection equipment, and the distance from the light source of the inspection equipment to the glass substrate and the distance from the glass substrate to the operator are both 300mm. Then, the reflected light and transmitted light with respect to the glass substrate were visually confirmed.
(4) Experimental result <Processing speed> It was 2.5 μm / min for one side of the elementary glass.
<Sheet thickness> Table 1 shows the thickness of the elementary glass measured by an ultrasonic thickness gauge.

＜キズの有無＞図７に化学加工前後における素ガラスのキズの有無を検査した結果を示した。図７より、化学加工前に存在したキズが化学加工により消失したことが判る。
＜表面の平坦性＞No.2の素ガラスを化学加工した後の表面状態を測定した結果を図８に示した。表１及び図８より、素ガラスの各位置において、均一に目標量を加工することができ、素ガラスの表面が平坦化されたことが判る。

<Presence or Absence of Flaw> FIG. 7 shows the result of inspection for the presence or absence of flaw in the elementary glass before and after the chemical processing. FIG. 7 shows that the scratches existing before the chemical processing disappeared due to the chemical processing.
<Surface Flatness> FIG. 8 shows the result of measuring the surface condition after chemically processing No. 2 elementary glass. From Table 1 and FIG. 8, it can be seen that the target amount can be uniformly processed at each position of the raw glass, and the surface of the raw glass is flattened.

[Example 2]
An example in which two bonded liquid crystal glass substrates are chemically processed using the chemical polishing apparatus 1 will be described.
(1) The size of the bonded liquid crystal glass substrate and the target amount of chemical processing No. 3; 400 mm x 500 mm x 1.4 mm. Target chemical processing amount: 0.4 mm for both sides.
(2) Composition of chemical processing liquid Same as Example 1.
(3) Method of Acceptance Inspection and Final Inspection Plate Thickness Measurement: FIG. 10 shows the measurement positions on the front side of the two bonded liquid crystal glass substrates, and FIG. 11 shows the measurement positions on the back side.
Appearance inspection: performed in the same manner as in Example 1.
(4) Experimental results <Processing speed> It was 2.5 μm / min for one side of the bonded liquid crystal glass substrate.
<Sheet thickness> Table 2 shows the results measured by an ultrasonic thickness gauge.

＜キズの有無＞化学加工前後におけるキズの有無を検査した結果を図９に示した。図９より、化学加工前に存在したキズが化学加工により消失したことが判る。
＜表面の平坦性＞表２から、貼り合わせガラス基板の各位置において、均一に目標量を加工することができ、表面が平坦化されていることが判る。

<Presence / absence of flaw> FIG. 9 shows the result of inspection for the presence / absence of flaw before and after chemical processing. FIG. 9 shows that the scratches existing before the chemical processing disappeared by the chemical processing.
<Surface Flatness> From Table 2, it can be seen that the target amount can be uniformly processed at each position of the bonded glass substrate, and the surface is flattened.

[Example 3]
Since the liquid crystal glass substrate in which the color filter pixels were patterned with Cr became defective, after the Cr was peeled off, chemical processing was performed by the chemical processing apparatus 1 in order to eliminate the trace of the pattern.
(1) Size of glass substrate after Cr peeling and each target chemical processing amount No. 4; length 400 mm x width 500 mm x thickness 0.7 mm. Target chemical processing amount: 5 μm.
(2) Composition of chemical processing liquid The same composition as in Example 1 was used.
(3) Method of Acceptance Inspection and Final Inspection Thickness measurement: The thickness at the measurement position shown in FIG. 6 was measured using an ultrasonic thickness gauge.
Appearance inspection: performed in the same manner as in Example 1.
(4) Experimental results <Processing speed> It was 2.5 μm / min for one side of the glass substrate.
<Plate Thickness> Table 3 shows the results measured by an ultrasonic plate thickness gauge.

＜パターン跡の有無＞パターン跡は化学加工により全て消失していることが確認された。
＜表面の平坦性＞表３とパターン跡の消失結果から、液晶ガラス基板を均一に目標量加工することができ、表面が平坦化されたことが判る。

<Presence / absence of pattern trace> It was confirmed that all the pattern traces disappeared due to the chemical processing.
<Surface Flatness> From Table 3 and the disappearance of the pattern trace, it can be seen that the target amount of the liquid crystal glass substrate could be uniformly processed and the surface was flattened.

As described above, it was confirmed that by performing the chemical processing method of the present invention, the surface of the liquid crystal glass substrate could be flattened while reducing the thickness thereof. In addition, since the scratches originally present on the surface of the liquid crystal glass substrate can be eliminated, the glass can be reused. Further, in the chemical processing method of the present invention, it is possible to process a glass substrate with high productivity regardless of the size of the glass substrate. The chemical processing apparatus 1 of the present invention is not limited to the one described in the above embodiment, and various design changes can be made without impairing the object of the present invention.

It is sectional drawing which shows an example of the chemical processing apparatus which concerns on this invention. 1 is a perspective view showing a first embodiment of a bubble generator. It is a perspective view showing a 2nd example of a bubble generator. It is a top view which shows an example of the holding | maintenance tool for a chemical processing liquid storage tank and a glass substrate storage jig. It is a perspective view showing an example of a chemical processing liquid discharge device. FIG. 3 is a plan view showing a measurement position of a thickness of the glass substrate of Example 1. It is a top view showing the result of having checked the presence or absence of a surface flaw before and after chemical processing. It is a top view which shows the result of having investigated the surface state of the glass substrate of Example 1 with the surface roughness meter. It is a top view which shows the result of having investigated the presence or absence of a flaw before and after chemical processing. FIG. 9 is a plan view showing the measurement position of the thickness of the outer surface of the two glass substrates of Example 2 bonded together. FIG. 9 is a plan view showing a measurement position of a thickness of an outer back surface of a substrate obtained by bonding two glass substrates of Example 2. It is a graph which shows the result of having measured the surface after processing by the conventional chemical processing method. 4 is a graph showing a relationship between a pit diameter and a processing amount. 5 is a graph showing the relationship between the number of pits per unit area and the processing amount. It is the graph which showed the state of the undulation of the surface after processing. It is a graph which shows the cross section of the surface which was intentionally scratched before processing. It is a graph which shows the cross section of the surface after processing.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Chemical processing apparatus 11 Chemical processing liquid storage tank 12 Bubble generator 12a Bubble discharge part 13 Overflow liquid receiving tank 14 Filter 15 Pump 16 Chemical processing liquid discharge apparatus 17 Holder for glass substrate storage jig 18 Glass substrate storage jig

Claims (7)

A rising liquid flow of the chemical processing liquid with bubbles is generated from the bottom of the chemical processing liquid storage tank storing the chemical processing liquid containing hydrofluoric acid as a main component, and the glass substrate is immersed in the processing liquid to form a glass. A chemical processing method for a glass substrate, wherein a part or all of one side of an outer surface of the substrate or a part or all of both sides of the outer surface is processed. The chemical processing method for a glass substrate according to claim 1, wherein the rising liquid flow is caused to overflow from a peripheral portion of the chemical processing liquid storage tank. The chemical processing method for a glass substrate according to claim 2, wherein the chemical processing liquid overflowing from the peripheral portion of the chemical processing liquid storage tank is supplied again to the chemical processing liquid storage tank. 4. The glass substrate according to claim 3, wherein the chemical processing liquid overflowed from a peripheral portion of the chemical processing liquid storage tank is passed through a filter to remove a reaction product generated by the chemical processing, and then supplied to the chemical processing liquid storage tank. 5. Chemical processing method. In a chemical processing apparatus provided with a chemical processing liquid storage tank for storing a chemical processing liquid, an air bubble generator, an overflow liquid receiving tank for receiving a chemical processing liquid overflowing from the chemical processing liquid storage tank, and the overflow liquid receiving tank And a pump for sending the chemical processing liquid received to the tank again to the chemical processing liquid storage tank. 6. The chemical processing apparatus according to claim 5, further comprising a glass substrate storage jig for arranging one or more of a glass substrate or a pair of glass substrates bonded together. The chemical processing apparatus according to claim 5, further comprising an ultrasonic vibrator or an oscillating stirring blade.

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