JP6662288B2 - Glass substrate, glass substrate manufacturing method, and black matrix substrate - Google Patents

Description

  The present invention relates to a glass substrate, a method for manufacturing a glass substrate, and a black matrix substrate.

A glass substrate used for an FPD (Flat Panel Display) such as a liquid crystal display device (LCD) is manufactured by, for example, forming a glass ribbon from molten glass by a float method or a fusion method, and cutting out the glass ribbon. On the surface of such a glass substrate, a layer having a high hydrophilicity containing an excess of OH groups (hereinafter referred to as an OH-rich hydrophilic layer) may be formed.
This is particularly remarkable when the glass formed into a plate shape from molten glass is polished with a polishing tool that rotates and revolves. In the polishing step, by removing fine irregularities and undulations on the surface, a thin plate having a predetermined thickness (for example, 0.1 to 1.1 mm) satisfying the flatness required for the FPD glass substrate is formed. ing.

  For polishing such a glass substrate, for example, an abrasive (slurry) containing cerium oxide particles as abrasive grains is used. Further, after polishing, residues such as abrasive grains adhering to the surface of the glass substrate are removed by cleaning with a cleaning liquid (for example, see Patent Document 1).

  An acidic cleaning solution containing an organic acid such as organic phosphonic acid is effective for removing residues such as abrasives containing abrasive grains of such cerium oxide particles.

  However, when a glass substrate made of aluminoborosilicate glass for an LCD or the like is washed with an acidic cleaning solution, a glass component such as aluminum ions may escape from the surface (surface layer) of the glass substrate due to a leaching action. is there. As a result, an OH-rich hydrophilic layer is easily formed on the surface of the glass substrate.

  In the glass substrate having the OH-rich hydrophilic layer formed on the surface as described above, a black matrix film (hereinafter, referred to as BM) for a color filter is formed on the surface by using a resin composition containing a black pigment such as carbon black. In the process of forming a BM film, there is a problem that the developer penetrates into the interface between the OH-rich hydrophilic layer and the resin-based BM film, and the BM film is easily peeled off from the OH-rich hydrophilic layer.

JP 2009-215093 A

The present invention has been made in order to solve the above-mentioned problem, and has high adhesion of a resin-based BM film (hereinafter, also referred to as a resin BM film) formed on the surface, and the resin BM film may be peeled off. The purpose is to provide a difficult glass substrate.
Further, in cleaning the surface of the polished glass substrate, the present invention suppresses a decrease in adhesion of the resin BM film formed on the surface of the polished glass substrate, thereby preventing the resin BM film from peeling. It is an object of the present invention to provide a method for manufacturing a glass substrate that can perform the method.

  The glass substrate of the present invention is a glass substrate made of silicate glass containing aluminum, and has an atomic concentration of aluminum (hereinafter, referred to as an Al concentration) inside the glass substrate and silicon measured by X-ray photoelectron spectroscopy. Of the glass substrate surface (hereinafter referred to as ΔAl / Si value) from the value of the ratio (hereinafter referred to as Al / Si value) to the atomic concentration (hereinafter referred to as Si concentration). ) Is 0.25 or less.

In the glass substrate of the present invention, the ΔAl / Si value is preferably 0.19 or less. The arithmetic average surface roughness of the surface of the glass substrate is preferably 0.2 nm or less.
Preferably, the silicate glass containing aluminum is an aluminoborosilicate glass having a composition containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , and an oxide of an alkaline earth metal. The silicate glass containing is preferably an aluminoborosilicate glass substantially containing no alkali metal component.

  The method for producing a glass substrate of the present invention is a method for producing the glass substrate of the present invention, wherein a glass substrate polished with an abrasive containing abrasive grains is washed with an aqueous cleaning liquid having a pH of more than 2.7. It is characterized by the following. In the method for producing a glass substrate of the present invention, the abrasive grains are preferably cerium oxide particles.

  The black matrix substrate of the present invention is characterized in that a BM film is formed on the glass substrate of the present invention.

According to the glass substrate and the black matrix substrate of the present invention, the adhesion of the resin BM film formed on the surface is good, and peeling of the resin BM film is prevented.
Further, according to the method for manufacturing a glass substrate of the present invention, it is possible to obtain a glass substrate in which the adhesion of the resin BM film formed on the surface is good and the resin BM film does not easily peel off.

It is a figure showing one embodiment of a cleaning method for obtaining a glass substrate of the present invention. 5 is a graph showing the relationship between the Al concentration and the Si concentration in the glass substrate obtained in Example 1 and the sputtering time at the time of measurement. 5 is a graph showing the relationship between the pH value of the cleaning solution in Examples 1 to 3 and Comparative Example 1 and the ΔAl / Si value of the glass substrate after cleaning. 4 is a graph showing the relationship between the ΔAl / Si values of the glass substrates obtained in Examples 1 to 3 and Comparative Example 1 and the remaining resolution of the resin BM film.

  Hereinafter, embodiments of the present invention will be described. The present invention is not limited to this embodiment, and other embodiments can be included in the scope of the present invention as long as the spirit of the present invention is met.

<Glass substrate>
The glass substrate according to the embodiment of the present invention is a glass substrate made of silicate glass containing aluminum, and is also X-ray photoelectron spectroscopic based on the Al / Si value inside the glass substrate measured by X-ray photoelectron spectroscopy. The ΔAl / Si value, which is a value obtained by subtracting the Al / Si value on the surface of the glass substrate measured by the method, is 0.25 or less. The ΔAl / Si value is preferably closer to 0 (zero). Specifically, the ΔAl / Si value is preferably 0.19 or less, more preferably 0.15 or less.

The glass substrate of the embodiment is, for example, a glass substrate for an FPD such as an LCD. The composition of the glass constituting the glass substrate is not limited as long as the glass is composed of silicate glass containing an aluminum component. However, oxides of SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , and alkaline earth metals are used. Aluminoborosilicate glass having a composition containing is preferred, and a so-called alkali-free aluminoborosilicate glass containing substantially no alkali metal component in the glass composition is more preferred. Here, the phrase "contains substantially no alkali metal component" means that the total content of alkali metal oxides in the glass composition is 1% by mass or less, preferably 0.1% by mass or less.
For example, the glass substrate according to the embodiment of the present invention has a strain point of 630 ° C. or higher, preferably 650 ° C. or higher, and has a composition expressed in terms of mass percentage based on oxide.
SiO ₂ : 54 to 73
Al ₂ O ₃ : 10 to 23
B ₂ O _3: 0 ~12
MgO: 0 to 12
CaO: 0 to 15
SrO: 0 to 16
BaO: 0 to 15
MgO + CaO + SrO + BaO: 8 to 26
Is preferable.

The Al concentration and the Si concentration inside and on the surface of the glass substrate are values measured by X-ray photoelectron spectroscopy. Here, the depth from the surface at the point where the Al concentration and the Si concentration are measured inside the glass substrate is preferably the depth determined as described below.
That is, while forming a recess hole (crater) on a glass substrate by using a C ₆₀ ion sputtering to measure the Al concentration and Si concentration at the bottom of the concave hole of varying depth, the distribution in the depth direction of each atom concentration Ask for. Then, a depth at which the distribution of the Al concentration and the Si concentration in the depth direction becomes constant is determined, and the value of the ratio between the Al concentration and the Si concentration measured at that depth is defined as the Al / Si value inside the glass substrate. Then, a ΔAl / Si value, which is a value obtained by subtracting the Al / Si value of the surface of the glass substrate from this value, is obtained.

  As described above, in the glass substrate according to the embodiment of the present invention, the degree of decrease in the Al / Si value on the surface of the glass substrate with respect to the Al / Si value inside the glass substrate is equal to or less than the predetermined value (0.25). Since the resin BM film is suppressed, the adhesion of the resin BM film formed on the surface of the glass substrate is good, and the resin BM film hardly peels off.

  As described above, in the cleaning after polishing of the glass substrate, an OH-rich hydrophilic layer is formed on the surface of the glass substrate as the escape amount of the Al component from the surface (surface layer) of the glass substrate increases. The ΔAl / Si value indicating how much the Al / Si value on the surface of the glass substrate is lower than the Al / Si value inside the glass substrate from which the Al component does not escape is the OH-rich hydrophilic layer. Shows the degree of formation. That is, the lower the ΔAl / Si value, the lower the deficiency of the Al component on the surface of the glass substrate, and the lower the hydrophilicity due to the OH groups on the surface of the glass substrate.

  Specifically, when the ΔAl / Si value, which is a value obtained by subtracting the Al / Si value on the surface of the glass substrate from the Al / Si value inside the glass substrate, is 0.25 or less, the OH on the surface of the glass substrate is Low hydrophilicity due to groups. Therefore, when the resin BM film is formed on the glass substrate, the intrusion of the developer into the interface between the glass substrate and the resin composition film for forming the BM is suppressed, and the adhesion of the resin BM film is improved and the film is peeled. Is prevented.

  Thus, the glass substrate of the present invention having a ΔAl / Si value of 0.25 or less can be obtained by the following method.

<Glass substrate manufacturing method>
The glass substrate according to the embodiment of the present invention is manufactured by forming a plate-shaped glass ribbon from molten glass by a float method or a fusion method, and cutting out the glass ribbon into a predetermined size. Further, if necessary, the glass formed into a plate shape is polished.
A method for manufacturing a glass substrate according to an embodiment of the present invention will be described below assuming that the method includes a polishing step. The method for manufacturing a glass substrate according to the embodiment includes a polishing step of polishing the glass substrate with an abrasive containing abrasive grains, and a cleaning step of cleaning the polished glass substrate. Then, the glass substrate polished with the abrasive containing abrasive grains is washed with an aqueous cleaning solution having a pH of more than 2.7, whereby the above-described glass substrate of the present invention can be obtained. The pH of the aqueous cleaning solution is preferably 3.0 or more, more preferably 3.5 or more.

The glass substrate to be cleaned is a glass substrate for an FPD such as an LCD, and is polished with an abrasive containing abrasive grains.
As described above, the glass constituting the glass substrate is preferably an aluminoborosilicate glass having a composition containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , and an oxide of an alkaline earth metal. Aluminoborosilicate glass substantially free of metal components is more preferred.

  In polishing before cleaning, the surface of such a glass substrate is polished with a polishing agent (slurry) containing abrasive grains using, for example, a polishing pad. The abrasive particles contained in the abrasive are not particularly limited, and include particles such as silica particles, alumina particles, cerium oxide particles, titania particles, zirconia particles, and manganese oxide particles. Cerium particles are preferred. The average grain size of the abrasive grains is preferably, for example, in the range of 0.8 to 1.0 μm. Through such a polishing step, the arithmetic average surface roughness Ra (JIS B0601-2013) of the surface of the glass substrate is preferably 0.2 nm or less.

  Examples of the aqueous cleaning liquid having a pH of more than 2.7 used in the embodiment of the present invention include an acidic cleaning liquid containing an organic acid and an alkaline cleaning liquid shown below. In order to ensure the flatness of the surface of the glass substrate, the pH of the aqueous cleaning solution is preferably less than 11, more preferably less than 9. From the above, the pH of the aqueous cleaning solution is more preferably in the range of 3.5 or more and less than 9.

(Acid cleaning solution)
Examples of the organic acid contained in the acidic cleaning solution include, but are not limited to, organic carboxylic acids such as ascorbic acid and citric acid, and organic phosphonic acids. An inorganic acid (for example, sulfuric acid, phosphoric acid, nitric acid, hydrofluoric acid, hydrochloric acid, etc.) can be added to the cleaning liquid together with these organic acids, and the inorganic acid can be used alone. When the inorganic acids are used, salts of these acids can be added together with the inorganic acids in order to suppress fluctuations in pH.

  Compounds having a chelating effect, such as organic carboxylic acids and organic phosphonic acids, may be contained in the cleaning solution from the viewpoint of detergency. On the other hand, since there is a possibility that the escape of the Al component from the glass may be promoted, it is better not to include these compounds in the cleaning solution from the viewpoint of the adhesion of the resin BM film.

  Here, examples of the organic carboxylic acid having a chelating effect include a dicarboxylic acid-based chelating agent, a tricarboxylic acid-based chelating agent, a gluconic acid-based chelating agent, a nitrilotriacetic acid-based chelating agent, and an iminosuccinic acid-based chelating agent.

The organic phosphonic acid refers to an organic compound having a structure in which a phosphonic acid group represented by the formula: -P (= O) (OH) ₂ is bonded to a carbon atom. The number of phosphonic acid groups represented by the above formula per organic phosphonic acid molecule is preferably 2 or more, more preferably 2 to 8, and particularly preferably 2 to 4.

As the organic phosphonic acid, a compound having a structure in which a hydrogen atom bonded to a carbon atom of a hydrocarbon which may have a substituent is substituted with a phosphonic acid group, and a compound bonded to a nitrogen atom of ammonia or an amine a hydrogen _{atom, -CH 2 -P (= O)} (OH) a compound having a structure resulting from substitution of the methylene phosphonic acid group represented by ₂ is preferred.
Specifically, organic phosphonic acids include methyldiphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), and hexamethylenediaminetetra (methylenephosphonic acid). ), Propylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetraminehexa (methylenephosphonic acid), tris (2-aminoethyl) aminehexa (methylenephosphonic acid), trans-1,2-cyclohexane Examples thereof include diamine tetra (methylene phosphonic acid), glycol ether diamine tetra (methylene phosphonic acid), and tetraethylene pentamine hepta (methylene phosphonic acid).

(Alkaline cleaning solution)
The alkaline cleaning solution contains a base, and may contain a chelating agent or a surfactant in addition to the base. The chelating agent may be contained in the cleaning liquid from the viewpoint of detergency. On the other hand, since there is a possibility that the escape of the Al component from the glass may be promoted, it is better not to include the chelating agent in the cleaning liquid from the viewpoint of the adhesion of the resin BM film.

  Examples of the base contained in the alkaline washing solution include alkali metal compounds such as alkali metal hydroxides and alkali metal carbonates, amines, and quaternary ammonium hydroxide. As the base, an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide is preferable.

Examples of the chelating agent include an ethylenediaminetetraacetic acid-based chelating agent, a gluconic acid-based chelating agent, a nitrilotriacetic acid-based chelating agent, and an iminosuccinic acid-based chelating agent. Particularly, an ethylenediaminetetraacetic acid-based chelating agent is preferable.
As the surfactant, a nonionic surfactant is preferable.

(Washing process)
In the washing step, an acidic detergent stock solution is diluted with water to make the pH greater than 2.7 (acidic wash solution), or an alkaline detergent stock solution diluted with water (alkaline solution). Is used to clean the surface of the polished glass substrate. It is preferable to perform the single-wafer cleaning. The cleaning method is not particularly limited as long as the cleaning liquid is brought into direct contact with the surface of the glass substrate for cleaning. As a cleaning method, for example, scrub cleaning, shower cleaning (spray cleaning), dip (immersion) cleaning, or the like can be used. The temperature of the cleaning solution is not particularly limited, and is used at room temperature (15 ° C) to 95 ° C. If the temperature exceeds 95 ° C., water in the cleaning solution may boil, which is inconvenient for the cleaning operation and is not preferred. After washing, drying may be performed. Examples of the drying method include a method of blowing hot air and a method of blowing compressed air.

  In the cleaning step, for example, as shown in FIG. A method of scrubbing (rubbing) the upper and lower surfaces of the glass substrate 3 with the rotating brushes 6 arranged on the upper and lower surfaces of the glass substrate 3 while spraying the cleaning liquid 5 can be adopted. The cleaning unit including the cleaning nozzle 4 for spraying the aqueous cleaning liquid 5 and the rotating brush 6 may be provided in only one stage, or may be provided in a plurality of stages. In the cleaning method shown in FIG. 1, the number of cleaning units is two. When washing is performed in a plurality of stages, that is, when a plurality of washing units are provided, the aqueous cleaning solution 5 sprayed in each stage has the same composition as one of an acidic washing solution and an alkaline washing solution from the viewpoint of workability. However, if the pH of the cleaning solution is within the above range, it is also possible to perform cleaning using a different aqueous cleaning solution 5 in each stage.

  Here, as the cleaning rotary brush 6, a plurality of cylindrical brushes made of PVA (polyvinyl alcohol) foam and having an outer diameter of 70 to 100 mm are used. Then, the rotating brush 6 is set so that the rotating axis of the rotating brush 6 is perpendicular to the surface to be cleaned of the glass substrate 3, here, both upper and lower surfaces, and the tip of the rotating brush 6 is coated on the glass substrate 3. It is arranged so as to be in contact with the surface to be cleaned or at a distance of less than 2 mm from the surface to be cleaned. The rotation speed of the rotating brush 6 is preferably set to 100 to 500 rpm.

  As the aqueous cleaning solution 5, a solution obtained by diluting the above-described acidic cleaning solution or alkaline cleaning solution with water so as to have a desired pH is used, and the diluted cleaning solution, that is, the flow rate (injection amount) of the water-based cleaning solution 5 is used. ) Is preferably 15 to 40 L / min. Further, the scrub time is preferably set to 1.5 seconds or more.

  In the method for manufacturing a glass substrate of the embodiment, the glass substrate polished with the abrasive containing cerium oxide particles is washed with an aqueous cleaning solution having a pH of more than 2.7 in the washing step, so that the glass substrate is polished. The ΔAl / Si value obtained by subtracting the Al / Si value of the surface of the glass substrate from the internal Al / Si value is adjusted to 0.25 or less. As a result, the formation of the OH-rich hydrophilic layer on the surface of the glass substrate is suppressed. As a result, in the process of forming the resin BM film, the intrusion of the developer into the interface between the surface of the glass substrate and the resin composition film for BM formation is prevented. As a result, the adhesion of the resin BM film is improved. Therefore, a glass substrate having good adhesion of the resin BM film and preventing film peeling can be obtained.

  Hereinafter, examples of the present invention will be specifically described, but the present invention is not limited to these examples. In the following examples, “%” means “% by mass” and “part” means “part by mass” unless otherwise specified.

(Examples 1 to 3, Comparative Example 1)
The surface of the glass substrate was polished as described below. As the glass substrate, a glass substrate for LCD made of aluminoborosilicate glass (trade name: AN100, manufactured by Asahi Glass Co., Ltd.) was used. Then, using a polishing pad, the surface of the glass substrate is coated with a slurry-like abrasive (SHOROX A10, manufactured by Showa Denko KK) containing cerium oxide particles having an average particle size of 0.8 to 1.0 μm. Polished using.
Then, the glass substrate whose surface was polished was cleaned using the cleaning method shown in FIG.

In Example 1, an alkaline detergent solution (trade name: PK-LCG28, manufactured by Parker Corporation) diluted with water so as to have a pH of 8.9 was used as an aqueous detergent solution.
In Examples 2 and 3, the acidic cleaning agent stock solution was diluted with water so that the pH became 5.3 (Example 2) and 3.9 (Example 3), respectively, and the aqueous cleaning solution was used. Used as The acidic detergent stock solution is PK-LCG492A (trade name of the acidic detergent stock solution manufactured by Parker Corporation) in which the concentration of organic phosphonic acid in the solution is reduced to 1/4.
Furthermore, in Comparative Example 1, an acidic cleaning agent stock solution (manufactured by Parker Corporation, trade name: PK-LCG492A) diluted with water so as to have a pH of 2.7 was used as an aqueous cleaning solution.

  In each of Examples 1 to 3 and Comparative Example 1, a rotating PVA product was sprayed onto the polished surface of the glass substrate at a flow rate of 25 L per minute (hereinafter also referred to as a cleaning liquid flow rate). The glass substrate was scrubbed with a rotating brush. The temperature of the aqueous cleaning liquid was 25 ° C. The scrub time in the cleaning step was 3 to 5 seconds.

  With respect to the surface of the glass substrate thus washed, the adhesion of the resin BM film was measured and evaluated by the following method. Further, the Al / Si value on the surface of the glass substrate (also referred to as surface Al / Si value), the Al / Si value inside the glass substrate (also referred to as internal Al / Si value), and the ΔAl / Si value were determined.

<Evaluation of adhesion of resin BM film>
First, the following components were blended in the following composition and mixed uniformly to prepare a photosensitive BM-forming resin composition having a solid content of 15%.
[Composition of BM-forming resin composition]
-Binder resin (manufactured by Nippon Kayaku Co., Ltd., trade name: ZCR1569H): 28.4 parts-Photoactivator (photopolymerization initiator)
(Ciba Specialty Chemical Company, trade name: Irgacure OXE02): 6.1 parts ・ Colloidal silica fine particles (Nissan Chemical Co., trade name: PAST): 20.3 parts ・ Carbon black: 32.5 parts ・ Interface Activator (manufactured by BYK Japan KK, trade name: BYK306): 0.3 part Crosslinking agent (manufactured by Nippon Kayaku, trade name: UX5002D): 6.1 parts
(Manufactured by Nippon Kayaku Co., Ltd., trade name: NC3000H): 3.0 parts ・ Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM403): 3.0 parts ・ Phosphate compound (phosphoric acid and monomethacryloyloxyethyl) Phosphate, 2: 1 (mass ratio) mixture of dimethacryloyloxyethyl phosphate): 0.3 part

Next, the BM-forming resin composition was applied (spin-coated) at 200 rpm for 10 seconds using a spin coater (MS-A100, manufactured by Mikasa Co., Ltd.) on the surface of the glass substrate after washing. Using a hot plate (manufactured by AS ONE Corporation, device name: HI-1000), the coating was heated and dried at 90 ° C. for 60 seconds to form a coating film. After that, using an exposure apparatus (manufactured by Dainippon Kaken, apparatus name: MA-1200), exposure (illuminance: 30 mW / cm ² , exposure amount: 30 mJ / cm ² , exposure GAP: 50 μm) was performed through a photomask. Using a developing device (manufactured by Actes, device name: ADE-3000S), development was performed for 15 seconds using a 0.045% KOH aqueous solution. Subsequently, a pattern of a resin BM film was formed on the surface of the glass substrate by washing with pure water.

The photomask had four types of pattern shapes L1 to L4 shown below, and had a total of 110 types of patterns in which the line width was changed by 1 μm for each type.
L1 25 linear patterns in one block (2835 μm × 2000 μm) with a pattern interval of 100 μm (line width is variable in the range of 1 to 25 μm)
L2: 30 linear patterns in one block (2952.6 μm × 2000 μm) with a pattern interval of 50 μm (line width is variable in the range of 1 to 30 μm)
L3: 25 linear patterns in one block (2682.5 μm × 2000 μm) with a pattern interval of 200 μm (line width is variable in the range of 1 to 25 μm)
L4: 25 short linear patterns in one block (2682.5 μm × 2000 μm) with a pattern interval of 200 μm (line width is variable in the range of 1 to 25 μm)

  The glass substrate after the pure water washing was observed with a laser microscope (manufactured by KEYENCE CORPORATION, device name: VK-9510), and the line width of a mask on which the pattern of the resin BM film remained on the glass substrate (hereinafter referred to as residual resolution). , L1 to L4 were examined. Then, the average of the remaining resolution for each of the four types of pattern shapes was obtained. Table 1 shows the results. The smaller the value of the remaining resolution, the higher the adhesion of the resin BM film formed on the glass substrate after cleaning.

<Measurement of surface Al / Si value>
The Al concentration and the Si concentration on the surface of the glass substrate after cleaning were measured using X-ray photoelectron spectroscopy (hereinafter referred to as XPS), and the Al / Si value (atomic concentration ratio) was determined.
For measurement, a PHI5500 manufactured by ULVAC-PHI was used, and peaks of Si (2p) and Al (2p) were used. The measurement was performed under the condition of an angle of 15 °. For analysis of the spectrum, analysis software MultiPak was used. The Shirley method was applied to subtract the background of the spectrum. Table 1 shows the obtained results.

<Measurement of internal Al / Si value>
For glass substrates used for measurement of surface Al / Si values, the depth profile of the Al concentration and Si concentration _was determined by XPS using _{C 60} ion sputtering. The same XPS measuring apparatus and analysis software as used for measuring the surface Al / Si value were used. The measurement conditions were a pass energy of 117.4 eV, an energy step of 0.5 eV / step, a monitor peak of Si (2p) and Al (2p), and a detection angle of 75 °. Then, the sputtering interval was set to 5 minutes, and every time the sputtering was performed for 5 minutes, the Al concentration and the Si concentration at the bottom of the formed crater were measured. Such a measurement was performed until the Al concentration and the Si concentration became constant. FIG. 2 shows the distribution of the Al concentration and the Si concentration in the depth direction in the glass substrate of Example 1 thus obtained. From this graph, it was determined that the Al concentration and the Si concentration were constant when the sputtering time was 40 minutes.

Incidentally, the measured sputter rate of _{C 60} ion sputtering in a thermal oxide film on the Si wafer (SiO ₂ film), since there was a 1.4 nm / min, the with respect to the glass substrate is similar sputtering rate Guessed. Therefore, it is considered that the Al concentration and the Si concentration inside the glass substrate become constant at 56 nm or more, which is the depth corresponding to the sputtering time of 40 minutes.
Further, since Examples 1 to 3 and Comparative Example 1 are glass substrates having the same composition, the internal Al / Si values of Examples 2, 3 and Comparative Example 1 can be regarded as the same as Example 1.

  Table 1 shows the residual resolution, surface Al / Si value, internal Al / Si value, and ΔAl / Si value thus measured for the glass substrates obtained in Examples 1 to 3 and Comparative Example 1.

  Next, based on the measurement results in Table 1, the relationship between the pH of the aqueous cleaning solution and the ΔAl / Si value and the relationship between the ΔAl / Si value and the remaining resolution were examined. FIG. 3 shows the relationship between the pH of the aqueous cleaning solution and the ΔAl / Si value, and FIG. 4 shows the relationship between the ΔAl / Si value and the remaining resolution.

FIG. 3 shows that there is a negative correlation between the pH of the aqueous cleaning solution and the ΔAl / Si value, and the ΔAl / Si value tends to decrease as the pH of the aqueous cleaning solution increases.
Further, from FIG. 4, there is a positive correlation between the ΔAl / Si value and the residual resolution, and it is recognized that the residual resolution tends to decrease as the ΔAl / Si value decreases. As described above, the smaller the residual resolution, the higher the adhesion of the resin BM film formed on the glass substrate after cleaning. Therefore, the smaller the ΔAl / Si value, the higher the adhesion of the resin BM film. I understand.

  As described above, in Examples 1 to 3 using an aqueous cleaning solution having a higher pH than that of Comparative Example 1, the ΔAl / Si value can be reduced to 0.25 or less, thereby improving the adhesion of the resin BM film. It turns out that it can be done.

ADVANTAGE OF THE INVENTION According to the glass substrate of this invention, the adhesiveness of the resin BM film formed in the surface is favorable, and peeling of the resin BM film is prevented. Therefore, the glass substrate of the present invention can be effectively applied to a glass substrate used for an FPD such as an LCD.
Further, according to the method for manufacturing a glass substrate of the present invention, a glass substrate suitable as a glass substrate for an FPD can be efficiently obtained.

  DESCRIPTION OF SYMBOLS 1 ... Conveyance roll, 2 ... Cleaning room, 3 ... Glass substrate, 4 ... Cleaning nozzle, 5 ... Water-based cleaning liquid, 6 ... Rotary brush.

Claims (5)

A glass substrate made of silicate glass containing aluminum obtained by a float method,
The silicate glass containing aluminum is an aluminoborosilicate glass having a composition containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , and an oxide of an alkaline earth metal, and substantially contains an alkali metal component. Without
From the value of the ratio of the atomic concentration of aluminum to the atomic concentration of silicon inside the glass substrate measured by X-ray photoelectron spectroscopy, the ratio of the atomic concentration of aluminum to the atomic concentration of silicon on the surface of the glass substrate minus the value (ΔAl / Si value) state, and are 0.25 or less, a glass substrate used to form the black matrix film.   The glass substrate according to claim 1, wherein the ΔAl / Si value is 0.19 or less.   The glass substrate according to claim 1, wherein the arithmetic average surface roughness of the surface of the glass substrate is 0.2 nm or less. A method for producing the glass substrate according to any one of claims 1 to 3,
A method for producing a glass substrate, comprising washing a glass substrate polished with an abrasive containing abrasive grains with an aqueous cleaning liquid having a pH of more than 2.7. The method for manufacturing a glass substrate according to claim 4, wherein the abrasive grains are cerium oxide particles.

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