JP3523239B2 - Glass substrate chemical processing method and glass substrate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass substrate for various FPDs (flat panel displays) such as LCD.
The present invention relates to a chemical processing method for processing one or a pair of bonded substrates such as a glass substrate for (liquid crystal display), a glass substrate for PDP (plasma display panel) and a glass substrate for organic EL (electroluminescence).

[0002]

2. Description of the Related Art Conventional methods for processing glass substrates include physical methods and chemical methods. Physical methods include processing using a machine and processing by blast, and chemical methods include processing by wet etching. Recently, there is a trend for quality improvement as described below. 1) Eliminate surface scratches originally present on the glass substrate. 2) Eliminate the pattern traces remaining on the substrate from which the patterned thin film has been peeled off. 3) The entire outer surface of the glass substrate is thinned on one side to improve its flatness. 4) The entire outer surface of the glass substrate is thinned on both sides to improve its flatness. 5) A recess is formed on a part of one side of the outer surface of the glass substrate to improve the dimensions of each part and the flatness of each surface. 6) Produce recesses on both sides of the outer surface of the glass substrate to improve the dimensions of each portion and the flatness of each surface. 7) The glass substrate of 3) to 6) is read as two bonded substrates, and the same purpose is performed.

Among the quality improvement items, for example, 1) to
On the other hand, in the processing using a conventional machine, for example, mechanical polishing, unavoidable problems such as lack of flatness, generation of cracks and surface scratches, residual polishing pattern, and limit of polishing ability remain. On the other hand, in conventional wet etching,
It is difficult to eliminate surface scratches and traces of patterns that exist on the glass substrate from the beginning, and various problems occur as shown in the example below even when the plate thickness is reduced, ensuring quality equal to or better than that of raw glass. It was difficult to do. Hereinafter, the description will proceed with a liquid crystal glass substrate as a typical example.

For example, Japanese Patent No. 2722798 discloses an element assembly in which a pair of glass substrates having an area for a plurality of liquid crystal display elements are adhered to each other through a sealing material surrounding each liquid crystal enclosing area of each element section to form an element assembly. Assembling, a method of etching the outer surface of the liquid crystal glass substrate by dipping this element assembly in an etching solution based on hydrofluoric acid is disclosed,
Although it is possible to reduce the plate thickness, there is a problem that defects described later occur.

Further, in Japanese Patent Laid-Open No. 2000-147474, a bubble generator is provided at the bottom of an etching solution tank for storing an etching solution containing hydrofluoric acid, and the etching solution is agitated by the bubbles generated from the bubble generator. Then, the invention of an automatic etching apparatus for etching the surface of glass placed in an etching solution tank is disclosed.
When the outer surface of the liquid crystal glass substrate is processed using 7% hydrofluoric acid, there is a problem that defects described later occur.

In the present invention, it is intended to realize uniform processing of the glass surface by stirring the working liquid by the rising bubbles of nitrogen gas, but the rising bubbles and the working liquid flow down after reaching the liquid surface. Hinders the uniformity of the ascending flow, resulting in a problem that the surface is not uniformly processed.

The problems in the case of processing 50 to 300 μm by the conventional wet etching shown in the above two examples will be shown below. 1) White turbidity that can be seen even under a fluorescent lamp occurs. 2) Pits with a maximum diameter of 0.2 mm are generated. FIG. 14 is a graph showing the results of measurement by a surface roughness meter after processing. 3) The diameter of the pit increases as the amount of processing increases.
FIG. 15 is a graph showing the relationship between the pit diameter and the processing amount. 4) Up to 50 pits / cm ² are generated. FIG. 16 is a graph showing the relationship between the number of pits per unit area and the processing amount. It can be seen from FIG. 16 that the number of pits per unit area increases as the processing amount increases. 5) A swell that can be seen under a fluorescent lamp is generated. FIG. 17 is a graph showing the state of swelling 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 nonuniform. 7) Due to the processing, surface scratches artificially added before processing become wider and deeper (see FIGS. 18 and 19). FIG. 18 is a graph showing a cross section of a surface that is intentionally scratched before processing, and FIG. 19 is a graph showing a cross section of the surface after processing.

In addition, for example, when a color filter pixel is patterned after sputtering a liquid crystal glass substrate with Cr and the substrate becomes defective, the patterned Cr is usually peeled off and mechanical polishing is performed to leave a pattern mark. However, when conventional wet etching is performed instead of mechanical polishing, the pattern marks do not disappear, and there is a problem that the glass cannot be reused.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a glass substrate chemical processing method capable of obtaining glass substrates for various FPDs having high flatness while reducing the plate thickness. The main purpose is to provide.

[0010]

The present invention uses a glass substrate in a chemical processing liquid and a holder for a glass substrate storage jig.
Immersed in a chemical processing liquid tank Te, a chemical polishing method of thinning a part or all or both sides of part or all of one side which constitutes the outer surface of the glass substrate, issued microbubbles
Bubble discharge part to be made to grow and chemical processing arranged under it
A liquid discharge part is provided, and the chemical processing liquid is stored in the chemical processing liquid tank.
And the holder for the glass substrate storage jig
The outer part of the chemical processing liquid tank toward the bottom of the chemical processing liquid tank.
In the structure for generating the descending liquid flow in the processing liquid tank, the passage cross-sectional area of the descending liquid flow corresponding to the outer part of the glass substrate storage jig holder is the inner part of the glass substrate storage jig holder. The chemical polishing method is 1 to 3 times the cross-sectional area of passage of the rising liquid flow corresponding to.

Further, the chemical processing liquid preferably contains hydrofluoric acid and at least one inorganic acid selected from hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid. Other preferable chemical processing liquids include those containing hydrofluoric acid, one or more inorganic acids selected from hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, and an anionic surfactant. The present invention also provides a chemical processing by the chemical processing method.
Is the glass substrate.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is intended for processing a glass substrate or a glass substrate once manufactured as a glass substrate for various FPDs (hereinafter collectively referred to as "glass substrate"). Then, the present invention dips such a glass substrate in a chemical processing liquid and processes at least a part of one side of the outer surface of the glass substrate under specific conditions to reduce the plate thickness and flatten the surface. It is intended to provide various FPD glass substrates having excellent properties.

The chemical processing liquid used in the present invention preferably has a glass substrate processing speed in the range of 0.5 to 10 μm / min, and more preferably in the range of 1.0 to 5.0 μm / min. . According to the study by the present inventor, the processing speed is 1
When it exceeds 0 μm / min, it becomes difficult to manufacture a glass substrate having excellent flatness. On the other hand, the processing speed is 0.5 μm /
If it is less than the minute, a glass substrate having excellent flatness can be produced, but the production rate becomes too slow, which is not preferable from the viewpoint of productivity.

Specifically, when the processing speed exceeds 10 μm / min, pits and swells are likely to occur on the surface of the glass substrate after processing, and variations in plate thickness increase, so that the flatness of the glass substrate is sufficient. Cannot be secured. further,
The scratches that originally existed on the substrate surface before processing also remain. On the other hand, when the processing speed is in the range of 0.5 to 10 μm / min, the above problems can be solved and a glass substrate having excellent flatness can be manufactured.

The components contained in the chemical processing liquid are not particularly limited as long as the above-mentioned processing speed can be obtained, but preferred components for the present invention include hydrofluoric acid, ammonium fluoride and potassium fluoride. , Fluoride selected from sodium fluoride, hydrochloric acid, sulfuric acid, phosphoric acid, inorganic acid selected from nitric acid, acetic acid, organic acid selected from succinic acid, anionic surfactants such as sulfonate surfactants, An amine amphoteric surfactant can be mentioned.

Among the above components, hydrofluoric acid, fluoride, inorganic acid and organic acid chemically process the glass substrate and prevent reaction products such as fluoride from re-adhering to the surface of the glass substrate. Anionic surfactants and amine amphoteric surfactants are added in order to prevent reaction products such as fluorides from reattaching to the surface of the glass substrate. is there.

The chemical processing liquid used in the present invention can be used in any combination except that hydrofluoric acid is an essential component. The composition of the glass substrate used, the required processing speed,
Each component can be appropriately combined depending on processing accuracy and the like. According to the study by the present inventor, among the above components,
A combination of hydrofluoric acid and an inorganic acid (especially hydrochloric acid and nitric acid), a combination of hydrofluoric acid and an anionic surfactant, a combination of hydrofluoric acid, an organic acid (especially hydrochloric acid and nitric acid) and an anionic surfactant are particularly preferable. It has been confirmed that it can be used.

Since the gist of the present invention is to immerse the glass substrate in the above-mentioned chemical processing liquid, the storage tank for storing the chemical processing liquid and its peripheral devices are particularly limited. is not. For example, it is possible to use a chemical processing apparatus which is composed only of a storage tank that stores the chemical processing liquid. In this case, when processing the glass substrate,
As the reaction products such as silicofluoride gradually increase in the chemical processing liquid, many reaction products adhere to the surface of the glass substrate. It is also assumed that variations are likely to occur in each part on the substrate and it becomes difficult to secure the flatness of the surface of the glass substrate. However, before the quality of the chemical processing liquid is deteriorated by a preliminary study, the chemical processing liquid is replaced with a new one to ensure sufficient flatness of the glass substrate surface, which is the main object of the present invention. be able to.

Further, as another preferable example of the chemical processing apparatus, the chemical processing solution containing the reaction product during the chemical processing is continuously removed from the chemical processing solution storage tank, and a new chemical processing solution is continuously supplied. Mention may be made of chemical processing equipment which can be supplied. When such a chemical processing device is adopted, the reaction products generated after processing are removed outside the storage tank (outside the reaction system), and at the same time, fresh chemical processing liquid containing only the active ingredient is stored inside the storage tank (reaction tank). Since it is supplied to the inside of the system), uniform chemical processing of the glass substrate surface becomes possible.

Further, in the present invention, it is preferable to perform chemical processing while the chemical processing liquid produces a liquid flow which is substantially parallel to the processing surface of the glass substrate in order to improve the flatness of the glass substrate. . This is particularly remarkable when a glass substrate having low flatness, in which a large number of fine irregularities are present on the surface of the substrate before processing, is processed.

The above-mentioned effects can be explained as follows. The chemical processing method in the present invention is a solid-liquid reaction between a glass substrate (solid) and a processing liquid (liquid), and diffusion of the processing liquid into a diffusion layer forming a portion in the vicinity of the surface of the glass substrate, and glass as a processing component. It consists of multi-step reactions such as adsorption on the substrate surface, chemical reaction between processing components and glass, desorption of reaction products from the glass substrate, and diffusion of reaction products outside the diffusion layer. In each of the above reactions, the reaction rate of ~ is higher than the reaction rate of, so the overall reaction rate of this multi-step reaction is determined by the reaction rate of, and is considered to be diffusion-controlled.

Here, a glass substrate having a low flatness in which fine irregularities are present on the surface of the substrate is used to generate a liquid flow of the chemical processing liquid which is substantially parallel to the processing surface of the glass substrate. In this case, the convex portion on the substrate surface is more affected by the liquid flow than the concave portion. That is, in the convex portion, as a result of being subjected to a kind of stirring action by the liquid flow, the thickness of the diffusion layer becomes thin, so that the diffusion speed of the working liquid becomes large, and the reaction speed (that is, the processing speed) as a whole becomes large. On the other hand, in the concave part, the liquid flow is almost unaffected, and the liquid flow near the concave part is stagnant, so the thickness of the diffusion layer near the concave part hardly changes, and the reaction rate as a whole is smaller than that in the convex part. Become.

Here, when the entire working liquid is stirred by, for example, a stirrer and the glass substrate is immersed in a nearly vertical state, an ascending liquid flow does not effectively occur. It becomes difficult to make the flow of the chemical processing liquid substantially parallel. In order to effectively generate an ascending liquid flow, a method in which fine bubbles such as nitrogen gas are continuously generated from the bottom of the machining liquid while the top of the chemical machining liquid storage tank is filled with the chemical machining liquid Can be mentioned. Then, by immersing the glass substrate in such a processing liquid in a nearly vertical state, the processing surface of the glass substrate can be made substantially parallel to the rising liquid flow of the chemical processing liquid.

In the present invention, the processed portion of the glass substrate is not limited to all of both sides of the outer surface constituting the glass substrate, but a form required for various FPD glass substrates, for example, patterning of the substrate surface. Depending on the shape and the like, only the required processed portion can be appropriately processed. Specifically, for example, by forming an acid-resistant protective film on a portion that is not processed, performing a masking treatment, and removing the protective film after processing, part or all of one side surface of the glass substrate or both sides of the glass substrate Some can be chemically processed.

An embodiment for processing a glass substrate using the latter chemical processing apparatus of the above-mentioned chemical processing apparatuses will be specifically described below with reference to the drawings. Figure 1
FIG. 3 is a cross-sectional view showing an example of the chemical processing apparatus of the present invention.
The chemical processing apparatus 1 includes a chemical processing liquid storage tank 11,
At the bottom of the chemical processing liquid storage tank 11, there is arranged a bubble generating device 12 for introducing a gas and discharging it from a bubble discharging part 12a made of a porous material.
On the upper side of 2, there is arranged a glass substrate storage jig 18 for vertically inserting and holding a glass substrate or a laminated glass substrate. The glass substrate storage jig 18 is arranged in the glass substrate storage jig holder 17. A chemical processing liquid containing hydrofluoric acid as a main component is charged into the chemical processing liquid storage tank 11.

At the periphery of the chemical processing liquid storage tank 11, an overflow liquid receiving tank 13 for receiving the chemical processing liquid overflowed from the chemical processing liquid storage tank 11 is provided.
A filter 14 for removing a reaction product generated by processing, 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 to 3. Then, the chemical machining liquid discharger 16a is provided below the bubble generator 12 and has a number of holes for discharging the chemical machining liquid sent out by the pump 15 toward the bottom of the chemical machining liquid storage tank. The chemical processing liquid discharge device 16 supplies the chemical processing liquid to the chemical processing liquid storage tank 11 again.

Further, the chemical processing apparatus 1 may be provided with an ultrasonic oscillator or a rocking stirring blade (not shown). this is,
It is used to diffuse bubbles throughout the chemical processing liquid storage tank 11.

FIG. 2 is a perspective view showing an example of the bubble generating device 12. The bubble generating device 12 includes a gas introducing pipe 12b for introducing a gas such as nitrogen gas, and a plurality of porous pipe-like bubble discharging units 12a, 12a, ... Which are vertically connected to the gas introducing pipe 12b. Is equipped with. Also, FIG.
FIG. 7 is a perspective view showing an example of a bubble discharger 12 a of another bubble generator 12. The bubble discharging portion 12a is made of porous material and has a plate shape. 2 and 3, it is preferable that the bubble discharge portion 12a has a hole diameter of 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, it is possible to always supply a fresh chemical processing liquid to the surface of the glass substrate, and it is possible to prevent a reaction product such as a fluoride from reattaching to the surface of the glass substrate.

After the rising liquid flow of fine bubbles reaches the surface of the chemical processing liquid, it overflows from the peripheral portion of the chemical processing liquid storage tank 11, is received by the overflow liquid receiving tank 13, and is passed through the filter 14, It is again supplied to the chemical processing 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 ascending liquid flow, and it becomes impossible to secure a uniform ascending liquid flow. FIG. 4 shows a chemical processing liquid storage tank 11 and a glass substrate storage jig holder 1.
It is a top view which shows an example of 7. As shown in FIG. 4, the passing cross-sectional area of the descending liquid flow corresponding to the outer portion of the glass substrate storage jig holder 17 is the glass substrate storage jig holder 1
1 to 3 of the passing cross-sectional area of the rising liquid flow corresponding to the inner part of 7
It has been confirmed that a uniform ascending liquid flow can be ensured when it is doubled.

The reaction product such as a fluoride of the glass substrate component and the chemical processing liquid rises due to the upward flow of the fine bubbles, which circulates in the chemical processing liquid storage tank 11 and is circulated in the chemical processing liquid storage tank 11. If it is deposited on the bottom of the, the discharge of fine bubbles will be adversely affected, so it is necessary to prevent the deposition of reaction products. FIG. 5 is a perspective view showing an example of the chemical processing liquid discharge device 16. The chemical processing liquid discharger 16 is provided with a plurality of chemical processing liquid discharge portions 16a having a large number of holes in parallel, and the chemical processing liquid discharged by the pump 15 is directed downward from the chemical processing liquid discharge portion 16a. Alternatively, it is preferable to design so as to prevent the deposition of the reaction product as well as the supply of the chemical processing liquid by discharging it obliquely downward.

In the present invention, as a method of controlling the processing speed of the glass substrate by using the above-described chemical processing apparatus 1, there are changes in the composition of the chemical processing liquid and changes in the temperature of the chemical processing liquid.
FIG. 6 is a graph showing the relationship between the addition ratio of the chemical processing liquid and the processing speed. This chemical processing liquid is an aqueous solution in which the addition ratio of the processing components consisting of 20 parts by weight of hydrofluoric acid, 20 parts by weight of hydrochloric acid and 20 parts by weight of nitric acid to water is appropriately changed.
From FIG. 6, it is 1.1 μm / min when the addition ratio is 10%, but the processing speed increases as the addition ratio increases, and shows the maximum value of 3.7 μm / min at 40%, and then decreases a little. As a result, it can be seen that the addition ratio is approximately 3 μm / min and is almost constant up to 90%. When the addition ratio is 30% or less, the processing speed is slow, and when the addition ratio is 70% or more, cloudiness occurs on the glass surface and sludge as a reaction product adheres to the glass surface. Ratio 30 to 6
It is preferably 0%. Further, it has been confirmed that such a relationship is the same even when a chemical processing liquid composed of a combination of other processing components described above is used.

FIG. 7 is a graph showing the relationship between the processing speed and the temperature of a chemical processing liquid composed of 5% hydrofluoric acid and 10% hydrochloric acid using the chemical processing apparatus 1. The horizontal axis of this graph is the amount of deviation from the reference temperature (30 ° C.), and the vertical axis is the processing speed. It can be seen from FIG. 7 that the processing speed as a whole tends to increase as the temperature rises, but only 0.5 μm / min occurs within ± 5 ° C. of the reference temperature (30 ° C.). As described above, in the present invention, there is a temperature range in which the processing speed hardly changes. Therefore, in chemical processing, the relationship between the processing speed and the temperature is investigated in advance, and the intermediate temperature in the temperature range where the processing speed hardly changes is used as the reference temperature. Is preferably controlled. Further, by preliminarily examining the temperature region where the machining speed hardly changes, the condition of the machining time can be set gently according to the required machining accuracy.
For example, when the graph of FIG. 7 is obtained, in order to keep the variation of the processing amount within the range of 20 μm, the variation of the processing time is allowed up to 40 minutes.

[0033]

EXAMPLES The present invention will be specifically described below based on examples. [Example 1] An example of chemically processing a raw glass using the above-described chemical processing apparatus 1 is shown below. The relationship between the processing speed and the surface condition of the glass substrate when the following raw glass was immersed in a chemical processing liquid having a predetermined processing speed and the same processing amount was polished was examined. The results are shown in Table 1. (1) Size of raw glass and the respective target chemical processing amount No. 1; length 320 mm × width 400 mm × thickness 1.1 mm. Target amount of chemical processing: 0.3 mm. No.2; length 400 mm x width 500 mm x thickness 0.7 mm. Target amount of chemical processing: 0.2 mm. (2) Composition of chemical processing liquid Water is used as a solvent, hydrofluoric acid, hydrochloric acid, and nitric acid are used as chemical processing components.
5, 1.0, 3.0, 5.0, 10.0, 13.0, 15.0 (Unit: μm /
Min) was prepared.

[0034]

[Table 1]

In Table 1, the presence or absence of pits, swells and original scratches is the result of visual observation under a fluorescent lamp in a dark clean room. Further, FIG. 8 shows the measurement positions of the plate thickness of the No. 2 glass substrate after the chemical processing. Table 1 shows the results of measuring the plate thickness with an ultrasonic plate thickness gauge at each position shown in FIG. 8 and determining the difference between the maximum value and the minimum value as the variation. Here, small means a variation of 50 μm or less, and medium means 100 μm.
˜200 μm, large means 200 μm or more. From the results of Table 1, from the viewpoint of quality and productivity, the processing speed is preferably 0.5 to 10 μm / min, and particularly 1.0 to
It was found to be optimum at 5.0 μm / min.

[Embodiment 2] An example in which the raw glass is chemically processed by using the above-described chemical processing apparatus 1 is shown below. (1) Size of raw glass and the respective target chemical processing amount No. 1; length 320 mm × width 400 mm × thickness 1.1 mm. Target amount of chemical processing: 0.3 mm. No.2; length 400 mm x width 500 mm x thickness 0.7 mm. Target amount of chemical processing: 0.2 mm. (2) Composition of chemical processing liquid Using water as a solvent, a chemical processing liquid containing 5% hydrofluoric acid, 10% hydrochloric acid, and 5% nitric acid was used. (3) Method of acceptance inspection of final glass and final inspection Plate thickness measurement The plate thickness at the measurement position shown in FIG. 8 was measured using an ultrasonic plate thickness meter. Appearance inspection Fluorescent lamp (1500Lx or more), condensing lamp (10,000Lx)
The distance from the light source of the inspection device to the glass substrate and the distance from the glass substrate to the measurer are both 300 m.
The reflected light and the transmitted light with respect to the glass substrate were visually confirmed at m. (4) Experimental result The processing speed was 2.5 μm / min for one side of the elementary glass. Plate thickness Table 2 shows the plate thickness of the raw glass measured by the ultrasonic plate thickness meter.

[0037]

[Table 2]

Existence of Scratches FIG. 9 shows the results of inspecting the presence or absence of scratches in the raw glass before and after chemical processing. From the results of FIG. 9, it can be seen that the scratches existing before the chemical processing disappeared due to the chemical processing. FIG. 10 shows the result of measuring the surface condition after chemically processing the elementary glass having the surface flatness No. 2. From Table 2 and FIG. 10, 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 3] Using the chemical processing apparatus 1, 2
An example of chemically processing a bonded liquid crystal glass substrate is shown. (1) Size of bonded liquid crystal glass substrate and each target chemical processing amount No.3: 400 mm × 500 mm × 1.4 mm. Target amount of chemical processing: 0.4 mm on both sides. (2) Composition of chemical processing liquid Same as in Example 2. (3) Method of acceptance inspection and final inspection [Plate thickness measurement] The measurement position on the front side of the two bonded liquid crystal glass substrates is shown in FIG. 12, and the measurement position on the back side is shown in FIG. [Appearance inspection] The appearance inspection was performed in the same manner as in Example 2. (4) Experimental result 2.5 μm / working speed on one side of the laminated liquid crystal glass substrate
It was a minute. Plate thickness Table 3 shows the results measured by an ultrasonic plate thickness meter.

[0040]

[Table 3]

Existence of Scratches The results of inspecting the presence or absence of flaws before and after chemical processing are shown in FIG.
Shown in 1. From FIG. 11, it can be seen that the scratches existing before the chemical processing disappeared due to the chemical processing. Surface Flatness From Table 3, it can be seen that the target amount can be uniformly processed at each position of the laminated glass substrate, and the surface is flattened.

[Embodiment 4] The pixel for the color filter is C
Since the liquid crystal glass substrate patterned by r became defective, after removing Cr, chemical processing was performed by the chemical processing apparatus 1 in order to eliminate the pattern mark. (1) Size of glass substrate after Cr peeling and respective target chemical processing amount No. 4; length 400 mm × width 500 mm × thickness 0.7 mm. Target chemical processing amount: 5 μm. (2) Composition of chemical processing liquid The same composition as in Example 2 was used. (3) Method of acceptance inspection and final inspection Plate thickness measurement: The plate thickness at the measurement position shown in FIG. 8 was measured using an ultrasonic plate thickness meter. Visual inspection; conducted in the same manner as in Example 2. (4) Experimental result The processing speed was 2.5 μm / min for one side of the glass substrate. Plate thickness Table 4 shows the results measured by the ultrasonic plate thickness meter.

[0043]

[Table 4]

Presence or absence of pattern traces It was confirmed that all pattern traces disappeared by chemical processing. Surface flatness From Table 4 and the result of disappearance of pattern traces, it can be seen that the target amount of the liquid crystal glass substrate could be uniformly processed and the surface was flattened.

By carrying out the chemical processing method of the present invention as described above, the thickness of the liquid crystal glass substrate can be reduced,
It was confirmed that the surface could be flattened. In addition, since scratches originally present on the surface of the liquid crystal glass substrate can be eliminated, the glass can be reused. Furthermore, 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 used in this example 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.

[0046]

As described above in detail, according to the chemical processing method of the present invention, various glass substrates for FPD having a high flatness can be manufactured by chemically processing the glass substrate. can do.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a chemical processing apparatus.

FIG. 2 is a perspective view showing a first embodiment of a bubble generating device.

FIG. 3 is a perspective view showing a second embodiment of the bubble generating device.

FIG. 4 is a plan view showing an example of a chemical processing liquid storage tank and a holder for a glass substrate storage jig.

FIG. 5 is a perspective view showing an example of a chemical processing liquid discharge device.

FIG. 6 is a graph showing the relationship between the addition ratio of the chemical processing liquid and the processing speed.

FIG. 7 is a graph showing the relationship between processing speed and temperature.

FIG. 8 is a plan view showing measurement positions of the plate thickness of the No. 2 glass substrate.

FIG. 9 is a plan view showing the results of examining the presence or absence of surface scratches before and after chemical processing.

FIG. 10 is a plan view showing the results of examining the surface condition of No. 2 glass substrate with a surface roughness meter.

FIG. 11 is a plan view showing the results of checking the presence of scratches before and after chemical processing.

FIG. 12 is a plan view showing the measurement positions of the plate thickness of the outer surface of two No. 2 glass substrates that are bonded together.

FIG. 13 is a plan view showing the measurement positions of the plate thickness of the outer back surface of two No. 2 glass substrates bonded together.

FIG. 14 is a graph showing the results of measuring the surface after polishing by a conventional chemical processing method.

FIG. 15 is a graph showing the relationship between the pit diameter and the processing amount.

FIG. 16 is a graph showing the relationship between the number of pits per unit area and the processing amount.

FIG. 17 is a graph showing the state of swelling on the surface after processing.

FIG. 18 is a graph showing a cross section of a surface that is intentionally scratched before processing.

FIG. 19 is a graph showing a cross section of the surface after processing.

[Explanation of symbols]

1 Chemical processing equipment 11 Chemical processing liquid storage tank 12 Bubble generator 12a Bubble discharge part 13 Overflow liquid receiving tank 14 filters 15 pumps 16 Chemical processing liquid discharge device 17 Glass substrate storage jig holder 18 Glass substrate storage jig

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Otani 1-11-1 Rikura, Toyonaka-shi, Osaka Nishiyama Stainless Chemical Co., Ltd. (72) Inventor Koichi Mizoguchi 1-1-1 Rikura, Toyonaka-shi, Osaka Nishiyama (56) References JP-A-9-295833 (JP, A) JP-A-11-322367 (JP, A) JP-A-2000-281383 (JP, A) JP-A-52-139121 (JP , A) JP 52-144020 (JP, A) JP 10-242105 (JP, A) JP 10-289893 (JP, A) JP 2002-87844 (JP, A) JP 2001- 100165 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C23C 15/00-23/00 C23F 1/00-4/04 H01L 21/00

Claims (5)

(57) [Claims] 1. A glass substrate and a glass substrate in a chemical processing liquid.
Using the holder for the plate storage jig, immerse it in the chemical processing liquid tank ,
A chemical polishing method for thinning a part or all of one side or a part or all of both sides forming the outer surface of the glass substrate, which comprises a bubble discharge part for generating fine bubbles and a lower part thereof. Arranged
The chemical processing liquid is discharged from the
The glass substrate is stored while overflowing from the processing fluid tank.
On the outside of the jig holder, on the bottom of the chemical processing liquid tank
For producing a descending liquid flow in the chemical processing liquid tank
In, the cross-sectional area of passage of the descending liquid flow corresponding to the outer portion of the holder for glass substrate storage jig is 1 to the cross-sectional area of the passage of upward liquid flow corresponding to the inner portion of the holder for glass substrate storage jig. A chemical polishing method characterized by being three times as large. 2. The processing rate of the chemical polishing is 0.5 to 10
The chemical polishing method according to claim 1, wherein the chemical polishing method is μm / min. 3. The glass substrate according to claim 1, wherein the chemical processing liquid contains hydrofluoric acid and at least one inorganic acid selected from hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid. Chemical polishing method. 4. The chemical processing liquid contains hydrofluoric acid, at least one inorganic acid selected from hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, and an anionic surfactant. 2. The chemical polishing method for a glass substrate according to 2. 5. The chemical laboratory according to any one of claims 1 to 4.
A glass substrate that has been chemically polished by a polishing method.