TW201901146A - Glass plate, method for inspecting end surface of glass plate, and method for manufacturing glass plate - Google Patents

Abstract

The present invention is provided with, in said order: a first observation step for enlarging and observing a specific region (R) of a polished surface (S1a) formed on an end surface (S1) of a glass plate (S) to be inspected, and acquiring a first enlarged image; a cleaning step for cleaning the specific region (R) while applying an external stimulus to the specific region (R); a second observation step for once again enlarging and observing the specific region (R), and acquiring a second enlarged image; and an evaluation step for comparing the first enlarged image and the second enlarged image and counting the number of fine recessed parts newly formed inside the specific region (R) after the first observation step.

Description

Glass plate, glass plate end face inspection method, and glass plate manufacturing method

The present invention relates to a method for inspecting an end face of a glass plate or a glass plate, and a method for producing the glass plate.

Flat panel displays (FPDs) such as liquid crystal displays, plasma displays, and electro-luminescence (EL) displays are advancing high definition. Along with this, in a glass plate used as a substrate for an FPD, a precise circuit is formed by the manufacturing process of the FPD.

In the end face of the glass plate for FPD, the grinding process (including the grinding process) is usually performed using a grindstone, but in many cases, micro cracks accompanying the grinding process (for example, micro crack) are generated in the polished surface of the end face. ). The microcracks grow with time and may be responsible for the production of glass frits (particles) from the abrasive surface. Such a glass frit has a particle diameter of, for example, about 0.1 μm to 10 μm. Further, in many cases, the glass frit is a hidden glass frit which does not exist at the end surface inspection after the polishing process, and is easily leaked in the end surface inspection for the glass frit adhered to the end surface. As a result, even when the FPD is manufactured using the glass plate which passed the end surface inspection, the manufacturing of the FPD may be inferior due to the glass frit generated from the micro crack. In particular, in the case of a high-definition FPD, since a precise circuit needs to be formed, even a small amount of minute glass frit can easily cause a circuit breakage or the like, resulting in defective manufacturing of the FPD.

Here, Patent Document 1 discloses a method of inspecting an end face of a glass plate, which takes into consideration glass frit which may be generated from microcracks. Specifically, it is disclosed in the same literature that the resin hose is slid while pressing the front end of the resin tube onto the end surface of the glass sheet, thereby rubbing the end surface of the glass sheet to rub the end surface The particles are sucked into the wiped particles from the front end of the hose of the resin, and the number of the rubbed particles is counted using a Particle Counter. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-230646

[Problems to be solved by the invention]

In the end face inspection method disclosed in Patent Document 1, since the small foreign matter in the air is also taken in from the tip end of the resin hose, the fine foreign matter is counted as the glass frit, and the accuracy of the end surface inspection of the glass plate becomes Very bad for this problem. As a result, even in the glass plate which is inspected by the end face disclosed in Patent Document 1, there is a possibility that the manufacturing of the FPD due to the glass frit generated from the microcracks is still defective. Therefore, it is desired to more reliably provide a glass plate having few glass frits generated from the end faces.

An object of the present invention is to provide a glass plate having few glass frits generated from an end surface by more accurately improving the accuracy of inspection of the end surface of the glass sheet. [Means for solving the problem]

The present invention, which was originally developed to solve the above problems, is a method for inspecting an end surface of a glass sheet having an abrasive surface on an end surface of a glass sheet, which is characterized by comprising: a first observation step for observing a specific region of the polished surface; external stimulation a step of giving an external stimulus to the polished surface of the glass plate; a washing step to clean the specific area; a second observation step to observe the specific area again; and an evaluation step, the observation result and the second observation of the first observation step The observation results of the steps are compared, and the number of minute recesses newly formed in a specific region after the first observation step is counted. According to this configuration, even when micro cracks are present in a specific region provided on the polishing surface of the glass sheet, the micro cracks are forcibly grown due to external stimuli given by the external stimuli giving step, and are easily used as glass. Powder appears. Further, the glass frit thus produced is removed from the specific region of the polishing surface by the cleaning in the cleaning step, and therefore, the portion corresponding to the glass frit generated from the microcrack in the specific region of the polishing surface forms minute recesses. Therefore, in the evaluation step, the observation result of the specific region of the polishing surface in the first observation step before the external stimulation administration step and the cleaning step and the specificity of the polishing surface in the second observation step after the external stimulation administration step and the cleaning step By comparing the observation results of the regions, the number of minute recesses newly formed in a specific region after the first observation step can be accurately counted. The number of the minute recesses correctly reflects the amount of the glass frit generated from the microcracks as described above, and therefore, even if the amount of the glass frit is not directly counted, it is possible to correctly consider the glass frit which may be generated from the microcracks. End face inspection of the glass plate.

In the above configuration, it is preferable that the washing step also serves as an external stimulus applying step, and the external region is cleaned while giving an external stimulus to the specific region. In this way, the external stimulation giving step is also performed simultaneously in the washing step, so that the inspection efficiency is improved as compared with the case where the two steps are performed separately.

In the above configuration, the washing step which also serves as the external stimulation applying step may be ultrasonic cleaning. In this manner, cleaning is performed while giving an external stimulus to a specific region of the polishing surface by the vibration accompanying the ultrasonic cleaning.

In the above configuration, the washing step which also serves as the external stimulation applying step may be chemical cleaning. In this manner, cleaning is performed while external stimulation is applied to a specific region of the polished surface by a chemical reaction accompanying chemical cleaning. Here, the chemical cleaning can be either acid cleaning or alkaline cleaning. Moreover, it is also possible to use ultrasonic cleaning liquid for ultrasonic cleaning, thereby using chemical cleaning and ultrasonic cleaning.

In the above configuration, preferably, in the first observation step, the specific area is magnified and the first enlarged image is acquired, and in the second observation step, the specific area is magnified and the second magnification is obtained. The image, in the evaluating step, compares the first magnified image with the second magnified image. In this way, the correct information of the specific region of the polished surface can be acquired using the image, so that the counting accuracy of the number of minute defects in the evaluation step can be improved.

In the above configuration, it is preferable that a marking portion as a setting reference of the specific region is formed on the polishing surface. In this way, the set deviation of a specific region between the first observation step and the second observation step can be reduced as much as possible. Therefore, the counting accuracy of the number of minute defects in the evaluation step is also improved.

The present invention, which is the first to solve the above problems, is a method for producing a glass sheet, comprising: a cutting step of separately cutting out a glass sheet from a plurality of original glass sheets to obtain a plurality of glass sheets; The end face of the sheet glass plate is subjected to grinding; and an extraction inspection step is performed, the inspection glass plate is taken out from the plurality of glass plates, and the inspection glass plate is inspected by the end face inspection method of the glass plate. Here, the glass plate for inspection includes a case where the glass plate obtained in the cutting step is directly used, and a case where a small piece obtained by cutting the glass plate is used. According to this configuration, the accuracy of the end surface inspection of the glass sheet can be improved by the above-described reason, and therefore, a glass sheet having few glass frits generated from the end surface can be provided.

The present invention, which was originally developed to solve the above problems, is a glass plate having a polishing surface on an end surface, and is characterized in that, when an abrasive cleaning surface is used for ultrasonic cleaning for 15 minutes at an operating temperature of 40 ° C, The polished surface is newly formed by ultrasonic cleaning and has a density of minute recesses having a size corresponding to the glass frit from 0/mm ² to 1000/mm ² . According to this configuration, it is a glass plate having few glass frits generated from the end surface regardless of the passage of time. In other words, for example, even if external stimulation is received in the cleaning step or the like included in the manufacturing process of the FPD, the glass frit generated from the end face can be reduced as much as possible in the subsequent FPD manufacturing step. [Effects of the Invention]

According to the invention as described above, the accuracy of the end surface inspection of the glass sheet can be improved. Therefore, it is possible to more reliably provide a glass plate having few glass frits generated from the end faces.

Hereinafter, an embodiment of a method for producing a glass sheet of the present invention will be described. In the following, the method of inspecting the end surface of the glass sheet will be described in the same manner as the method of manufacturing the glass sheet. However, the method of inspecting the end surface of the glass sheet may be carried out separately from the method of manufacturing the glass sheet.

The method for producing a glass sheet according to the present embodiment includes a cutting step, a polishing step, and an extraction inspection step.

In the cutting step, as shown in FIG. 1, the original glass sheet M is cut along the line to cut CL, and a plurality of sheets (four sheets in the illustrated example) are obtained from one sheet of the original glass sheet M. The so-called multi-chamfering of the plate G. Further, in the cutting step, the peripheral edge portion of the original glass sheet M may be trimmed to obtain one glass sheet G from one sheet of the original glass sheet M.

In the present embodiment, the original glass sheet M is formed by an overflow flow down draw method, but is not limited thereto. For example, it may be formed by another down-draw method or a float method such as a slot down draw or a redraw method.

As a method of cutting the original glass sheet M, a so-called bending stress cut is formed by forming a scribe line on the line to cut CL of the original glass sheet M and then dividing it along the scribe line. Further, as the cutting method of the original glass sheet M, thermal stress cutting (for example, laser cutting), melting (for example, laser melting), or the like may be used.

In the polishing step, as shown in FIG. 2, the end faces (cut faces) of the plurality of glass sheets G cut in the cutting step are polished. Further, in the present invention, grinding is included in the polishing. Specifically, first, the first polishing tool 2 (for example, a grindstone) is advanced on both sides of the glass sheet G on the upstream side stage 1, and the end faces G1 on the opposite sides are polished. Next, after the glass sheet G is rotated by 90 degrees on the rotary table 3, the second grinding tool 5 (for example, grindstone) is advanced on the remaining opposite sides of the rotating glass sheet G on the downstream side table 4. The end faces G2 on both sides of the remaining opposite sides are ground. Thereby, the end faces G1 and G2 of the four sides of the glass sheet G are polished. In addition, the polishing flow shown in FIG. 2 is only an example. When the end faces G1 and G2 of the four sides of the glass sheet G are polished, the order of movement of the glass sheet G or the polishing tool 2 and the polishing tool 5 or the polishing tool 2 is polished. The number of tools 5 and the like are not particularly limited. For example, the end surface of one side of the glass sheet G may be polished a plurality of times using a grinding tool having a different texture thickness or a different bonding material, and finely ground after the coarse grinding.

As shown in FIG. 3, the first polishing tool 2 includes a first processing surface 21 having a cylindrical surface extending in the thickness direction of the glass sheet G, and a second processing surface 22 having a conical surface. Both end portions of the processing surface 21 have inclinations opposite to each other with respect to the thickness direction of the glass sheet G. Therefore, the end surface G1 of the glass sheet G polished by the first polishing tool 2 is polished to conform to the shapes of the first processed surface 21 and the second processed surface 22 of the first polishing tool 2. That is, the end surface G1 of the glass sheet G polished by the first polishing tool 2 includes a first polishing surface G1a extending in the thickness direction, and a pair of second polishing surfaces G1b provided at both ends of the first polishing surface G1a. And having an inclination opposite to each other with respect to the plate thickness direction. Although the illustration is omitted, the second polishing tool 5 has the same configuration as the first polishing tool 2, and therefore the end surface G2 of the glass sheet G polished by the second polishing tool 5 is also polished by the first polishing tool 2. The end surface G1 of the glass plate G has the same shape. Here, in Fig. 3, a portion X with cross-hatching indicates a glass portion removed by grinding.

Further, the case where the first polishing surface G1a and the second polishing surface G1b of the glass sheet G are simultaneously formed by one first polishing tool 2 has been described. However, the polishing surfaces G1a and the polishing surfaces may be separately formed by using different polishing tools. Face G1b. The same applies to the second grinding tool 5. Further, the cross-sectional shape of the end surface G1 and the end surface G2 of the polished glass sheet G is not particularly limited, and may be a semicircular shape, an arc shape, a semi-elliptical shape, a shape composed of a plurality of straight lines, or the like. Alternatively, the cross-sectional shape of the end surface G1 and the end surface G2 of the glass sheet G may be a shape in which the cross-sectional shape of the second polishing surface G1b is changed to an arc shape in the cross-sectional shape shown in FIG. 3 .

The feed speed of the grinding tool 2 and the grinding tool 5 is preferably from 1 m/min to 15 m/min, more preferably from 1 m/min to 10 m/min. That is, since the feed rate of the polishing tool exceeds 15 m/min and is 60 m/min or less in the polishing of a general glass plate, the preferred range of the feed speed of the polishing tool 2 and the polishing tool 5 is The general feed rate is slower than that. Further, the feed speed of the polishing tool 2 and the polishing tool 5 refers to the relative speed of the polishing tool 2 and the polishing tool 5 with respect to the glass plate G when the glass plate G is moved while being moved.

In the extraction inspection step, one or more glass sheets G are extracted from the plurality of glass sheets G (in the same lot) polished in the grinding step as the inspection glass sheet S (refer to FIG. 4), The inspection glass plate S was subjected to end surface inspection. In addition, the extraction may be performed at regular intervals. Alternatively, it may be carried out every time the manufacturing conditions such as the polishing conditions are changed. Further, the end surface inspection of the inspection glass plate S corresponds to the end surface inspection method of the glass plate.

The end face inspection includes a first observation step, a washing step, a second observation step, and an evaluation step.

In the first observation step, as shown in FIG. 4, the polishing surface S1a formed on the end surface S1 of the inspection glass plate S by a scanning electron microscope (SEM) (corresponding to the glass plate G) A specific region R of the polishing surface S1b (corresponding to the second polishing surface of the glass sheet G) is enlarged and observed, and a first enlarged image of the specific region R is acquired.

In the inspection glass plate S, the extracted glass plate G can be used as it is, but in the present embodiment, a small piece in which the extracted glass plate G is further cut so as to include the polished surface is included.

In the present embodiment, the specific region R is provided on the first polishing surface S1a. The reason for this is that it is considered that the first polishing surface S1a has a possibility of coming into contact with other members than the first polishing surface S1b, and the risk of occurrence of the glass frit is higher. Further, the specific region R may be provided on the second polishing surface S1b instead of the first polishing surface S1a, or may be provided on both the first polishing surface S1a and the second polishing surface S1b.

It is preferable to form a marking portion (not shown) as a setting reference of the specific region R on the first polishing surface S1a in which the specific region R is provided. The marking portion is formed, for example, by forming a concave groove (scratch) or forming a film (sputtering film or the like) on the first polishing surface S1a. Further, the marking portion is not limited to being formed by these methods, but is preferably formed by a method that is difficult to remove by a washing step. The marking portion is formed, for example, along the outer edge of the rectangular shape of the specific region R.

In the cleaning step, as shown in FIG. 5, the polishing surface S1a of the inspection glass plate S and the specific region R provided on the polishing surface S1b are cleaned while giving external stimulation. The portion to be cleaned in the cleaning step may be only a specific region R or a portion containing a specific region R. The example of the drawing is only an example of the cleaning aspect. When the details are described, the inspection glass plate S is suspended by the support member 6 and includes a portion of the specific region R provided on the first polishing surface S1a (Fig. In the example, the substantially lower half of the inspection glass plate S is immersed in the cleaning liquid 8 in the container 7. At this time, it is preferable that the first polishing surface S1a of the specific region R is provided so as not to be in contact with the container 7 in order to improve the contact efficiency with the cleaning liquid 8. The container 7 is disposed in the ultrasonic cleaner 10 in which the water 9 as the ultrasonic wave transmitting medium is stored, and the specific region R of the glass plate for inspection S is transmitted by the ultrasonic vibration transmitted to the cleaning liquid 8 via the water 9. The part is ultrasonically cleaned.

The ultrasonic cleaning time is preferably from 1 minute to 60 minutes, more preferably from 3 minutes to 30 minutes. The temperature of the ultrasonic cleaning is preferably from 15 ° C to 80 ° C, more preferably from 25 ° C to 60 ° C. The frequency of ultrasonic cleaning is preferably from 10 kHz to 1000 kHz, more preferably from 20 kHz to 200 kHz.

Preferably, it is obtained by mixing an alkali detergent (for example, tetramethylammonium hydroxide ((CH ₃ ) ₄ NOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), etc.) into pure water. A cleaning agent (for example, hydrogen chloride (HCL), nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), or the like) is mixed into pure water to obtain a cleaning liquid 8 to chemically clean the glass plate for inspection S. In the case where the ultrasonic cleaning is used, external vibration is given to the polishing surface S1a and the polishing surface S1b of the inspection glass plate S by the vibration during ultrasonic cleaning, so that external stimulation due to the chemical reaction can no longer be given. . In other words, when the ultrasonic cleaning is used, the cleaning liquid 8 may be an external stimulus that does not cause a chemical reaction between the polishing surface S1a of the glass plate S for inspection and the polishing surface S1b, such as pure water.

Further, the cleaning step may be performed by high-pressure cleaning in which a specific region R of the inspection glass plate S or a portion containing the specific region R is sprayed with a high-pressure liquid such as high-pressure water. In this case, the polishing surface S1a and the polishing surface S1b of the inspection glass plate S are cleaned by external stimulation while the high-pressure liquid is applied.

In the second observation step, the specific region R of the inspection glass plate S observed in the first observation step is magnified by SEM, and a second enlarged image of the specific region R is acquired. Further, it is preferable that the magnification observation by the SEM in the second observation step is the same as the magnification observation by the SEM in the first observation step (acceleration voltage, observation magnification, etc.).

In the evaluation step, the observation result of the first observation step, that is, the first enlarged image is compared with the observation result of the second observation step, that is, the second enlarged image, and is counted and newly formed in the specific region R after the first observation step. The number of tiny recesses inside.

In the present embodiment, the concave portion having the size corresponding to the glass frit in a plan view (the visual field from the vertical direction of the specific region R) is determined as a minute concave portion, and is counted. The criterion for determining the minute recesses may be appropriately set according to the required quality. For example, a recess having a length of about 0.1 μm to 10 μm in plan view may be determined as a minute recess. Alternatively, the concave portion having a length of about 0.1 μm to 5 μm in plan view may be set as a minute concave portion. Regarding the number of minute recesses, the minute recesses may be automatically counted by image processing or the like, or may be manually counted by an operator.

Regarding the size of the specific region R, it is possible to predict the minuteness of the entire first polishing surface G1a (and/or the second polishing surface G1b) of the glass sheet G in accordance with the number of minute recesses counted in the evaluation step to some extent. The size of the number of recesses is sufficient. Therefore, the specific region R is preferably a rectangular region set to have a side of 10 μm to 500 μm.

The magnification of the magnification observation of the specific region R is related to the detection accuracy of the minute recesses. Therefore, the magnification of the magnification observation is preferably from 1,000 to 50,000 times, more preferably from 5,000 to 50,000 times.

Here, the first enlarged image and the second enlarged image are illustrated in FIGS. 6 to 13 . Fig. 6 and Fig. 7, Fig. 8 and Fig. 9, Fig. 10 and Fig. 11, Fig. 12 and Fig. 13 are observation results of the same specific regions, respectively. In FIG. 6 and FIG. 7, FIG. 10 and FIG. 11, the surface roughness of the first polishing surface S1a provided with the specific region R is thickened in order to simulate the possibility of increasing the glass frit from the microclip with time. degree.

When the polishing surface provided with the specific region R is a rough surface, if the magnification of the magnification observation (10000 times) is tried, the micro concave portion which is not confirmed in the first enlarged image shown in FIG. 6 is used. The second enlarged image shown in Fig. 7 is newly confirmed (the portion circled by the circle C1 in Fig. 7). On the other hand, in the case where the polishing surface provided with the specific region R is a smooth surface, the minute concave portion which is not confirmed in the first enlarged image shown in FIG. 8 is in the second enlarged image shown in FIG. Not confirmed yet.

In addition, when the magnification of the magnification observation (1000 times) is tried, when the polishing surface provided with the specific region R is a rough surface, the micro concave portion which is not confirmed in the first enlarged image shown in FIG. 10 A plurality of places (portions circled by a circle C2 in Fig. 11) are newly confirmed in the second enlarged image shown in Fig. 11. On the other hand, in the case where the polishing surface provided with the specific region R is a smooth surface, the minute concave portion which is not confirmed in the first enlarged image shown in FIG. 12 is in the second enlarged image shown in FIG. Not newly confirmed.

According to the results, it has been confirmed that the number of minute recesses tends to increase in the glass plate for inspection which is highly likely to generate glass frit from microcracks. Therefore, according to the end face inspection of the present embodiment, even if the number of the glass frit is not directly counted, it is possible to accurately determine whether or not the glass frit is likely to be generated in a large amount in the future by counting the minute recesses in the evaluation step. Moreover, the size of the glass frit can be predicted to some extent depending on the size of the minute recesses.

In the evaluation step, the number of minute recesses counted (preferably the density of the minute recesses indicated by (the number of minute recesses) / (the area of the specific area)) is a predetermined determination value (for example, 1000/ When mm ^{2 or less} , preferably 500 pieces/mm ² or less, the glass plate G included in the same batch as the glass plate for inspection S can be evaluated as being less likely to generate glass powder in the future. Therefore, in this case, the quality of the glass plate G contained in the same lot is judged as "qualified", and it is shipped as a product directly.

The glass plate G which was judged to be qualified as described above was formed by ultrasonic cleaning on the polishing surface when the polishing surface was subjected to ultrasonic cleaning for 15 minutes using an alkali cleaning solution having a temperature of 40 ° C. The density (the number of minute recesses/the area of the polished surface) of the minute recesses of the corresponding size of the powder is 0/mm ² to 1000/mm ² (preferably 0/mm ² to 500/mm ² ). In the case of such a glass sheet G, even if cleaning or etching is repeatedly performed in the production process of the FPD, it is not easy to cause electrode formation failure or the like due to the occurrence of glass frit in each film formation step. Therefore, it can be preferably used as a glass substrate for high-precision FPD such as indium gallium zinc oxide (IGZO).

Here, the evaluation of the characteristics of the glass sheet G judged to be acceptable was performed as follows. That is, the measurement of the density of the minute recesses is performed in the same manner as the end face inspection. At this time, a Quanta 250 field emission gun (FEG) manufactured by FEI Corporation was used for observation of minute recesses (SEM observation). Further, the magnification is 10000 times and the specific region R is a rectangular region having a side of 10 μm. VELVO-CLEAR's Ultrason VS-3 was used for ultrasonic cleaning and the frequency of the ultrasonic wave was 35 kHz. An aqueous solution containing 0.2% by mass of KOH was used for the alkali cleaning solution. In the determination of the minute concave portion, the concave portion having a length of about 0.1 μm to 5 μm in plan view is determined as a minute concave portion.

On the other hand, in the evaluation step, when the number of the minute recesses counted exceeds the determination value, the quality of the glass sheet G included in the same batch as the inspection glass sheet S is judged as "failed", and For example, the polishing conditions of the polishing step (the feed rate of the polishing tool or the type of the polishing tool) are changed. In the evaluation step, the end face inspection and the polishing condition are repeated until the number of the minute recesses counted is equal to or less than the determination value. When the feed rate of the polishing tool 2 and the polishing tool 5 is set to be in the range of 1 m/min to 15 m/min as described above, it is easy to manufacture the glass sheet G whose quality meets the qualification criteria.

If the eye point is changed, the end face inspection can also be used for the selection of the grinding tool. In other words, the polishing tool used when the number of minute recesses in the evaluation step is equal to or less than the determination value is "passed", and the grinding tool used when the number of minute recesses in the evaluation step exceeds the determination value is set to "No". The grinding tool is selected.

Further, the present invention is not limited to the configuration of the above embodiment, and is not limited to the above-described effects. The present invention can be variously modified without departing from the spirit and scope of the invention.

In the above embodiment, an external stimulus is applied to the polished surface of the glass sheet, and a cleaning step for cleaning the polished surface of the glass sheet, that is, a washing step which also serves as an external stimulation applying step, is described, but may be separated. An external stimulus giving step of externally stimulating the polished surface of the glass plate and a washing step of washing the polished surface of the glass plate are performed. In this case, in the external stimulation applying step, the contact member may be moved while pressing the contact member including the resin material or the like on the polishing surface of the glass plate, and the polished surface of the glass plate may be externally applied. stimulate. Further, external stimulation can be given to the polished surface of the glass plate by spraying high-pressure gas or fine particles on the polished surface of the glass plate.

In the above-described embodiment, the case where the specific region is observed using the SEM has been described. However, the specific region may be performed using an optical microscope, a laser microscope, or a computed tomography (CT). Observed.

1‧‧‧Upstream side workbench

2‧‧‧First grinding tool (abrasive tool)

3‧‧‧Rotating table

4‧‧‧Downside workbench

5‧‧‧Second grinding tool (grinding tool)

6‧‧‧Support members

7‧‧‧ Container

8‧‧‧ cleaning solution

9‧‧‧ water

10‧‧‧ Ultrasonic cleaning machine

21‧‧‧First processing surface

22‧‧‧Second processing surface

C1, C2‧‧‧ round

CL‧‧‧ cut-off line

G‧‧‧glass plate

G1, G2‧‧‧ end face

G1a‧‧‧ first ground surface

G1b‧‧‧second ground surface

M‧‧‧Original glass plate

R‧‧‧Specific area

S‧‧‧Inspection glass plate

S1‧‧‧ end face

S1a‧‧‧First ground surface (grinding surface)

S1b‧‧‧Second grinding surface (grinding surface)

X‧‧‧ Glass parts removed by grinding

Fig. 1 is a plan view for explaining a cutting step. Fig. 2 is a plan view for explaining a grinding step. Fig. 3 is a side view showing the polishing tool used in the polishing step. 4 is a perspective view showing a glass plate for inspection. Fig. 5 is a longitudinal sectional view for explaining a washing step. 6 is a view showing an example of a first enlarged image of a specific region acquired by the first observation step in a case where the polishing surface is a rough surface. FIG. 7 is a view showing an example of a second enlarged image of a specific region acquired by the second observation step in the case where the polishing surface is a rough surface. 8 is a view showing an example of a first enlarged image of a specific region acquired by the first observation step in a case where the polishing surface is a smooth surface. FIG. 9 is a view showing an example of a second enlarged image of a specific region acquired by the second observation step in the case where the polishing surface is a smooth surface. FIG. 10 is a view showing an example of a first enlarged image of a specific region acquired by the first observation step in a case where the polishing surface is a rough surface. FIG. 11 is a view showing an example of a second enlarged image of a specific region acquired by the second observation step in the case where the polishing surface is a rough surface. FIG. 12 is a view showing an example of a first enlarged image of a specific region acquired by the first observation step in a case where the polishing surface is a smooth surface. FIG. 13 is a view showing an example of a second enlarged image of a specific region acquired by the second observation step in the case where the polishing surface is a smooth surface.

Claims (8)

A method for inspecting an end surface of a glass sheet, which is an end surface inspection method of a glass sheet having an abrasive surface on an end surface, comprising: a first observation step of observing a specific region of the polishing surface; an external stimulation giving step, a specific area is given an external stimulus; a washing step is performed to wash the specific area; a second observation step is performed to observe the specific area again; and an evaluation step, an observation result of the first observation step and the second The observation results of the observation step are compared, and the number of minute recesses newly formed in the specific region after the first observation step is counted. The method for inspecting an end surface of a glass sheet according to the first aspect of the invention, wherein the cleaning step also serves as the external stimulation applying step, and the external region is cleaned while applying the external stimulus to the specific region. The method for inspecting an end face of a glass sheet according to claim 2, wherein the washing step which also serves as the external stimulus applying step is ultrasonic cleaning. The method for inspecting an end face of a glass sheet according to the second or third aspect of the invention, wherein the washing step which also serves as the external stimulus applying step is chemical cleaning. The method for inspecting an end face of a glass sheet according to any one of the preceding claims, wherein, in the first observation step, the specific region is enlarged and observed to obtain a first enlarged view. Image, and in the second observation step, magnifying the specific area and acquiring a second enlarged image, in the evaluating step, the first enlarged image and the second enlarged image Like to compare. The method for inspecting an end surface of a glass sheet according to any one of the first aspect, wherein the marking portion serving as a reference for setting the specific region is formed on the polishing surface. A method for manufacturing a glass plate, comprising: a cutting step of separately cutting a glass plate from a plurality of original glass plates to obtain a plurality of glass plates; and a grinding step of grinding the end faces of the plurality of glass plates; An inspection inspection step of extracting the inspection glass plate from the plurality of glass sheets and using the end surface inspection method of the glass sheet according to any one of claims 1 to 6 to the inspection glass sheet checking. A glass plate having an abrasive surface on an end surface, wherein the glass plate is characterized in that, in the case of ultrasonic cleaning using the alkali cleaning liquid at a temperature of 40 ° C for 15 minutes, on the polishing surface, The density of the minute recesses newly formed by the ultrasonic cleaning and having a size corresponding to the glass frit is 0/mm ² to 1000/mm ² .