TWI637927B - Method for manufacturing glass substrate, and device for manufacturing glass substrate - Google Patents

Abstract

An object of the present invention is to provide a glass substrate manufacturing method and a glass substrate manufacturing device which can reduce the load applied to the environment and can suppress the surface contamination of the glass substrate.

The end surface grinding device 20 processes the end surface 11 a by bringing the chamfered grindstone 40 into contact with the end surface 11 a of the glass substrate 10 and moving the chamfered grindstone 40 relative to the glass substrate 10. The end surface grinding device 20 supplies the contact portion 13 of the chamfered grindstone 40 and the end surface 11 a with a cooling liquid containing an aqueous solution containing a nonionic surfactant, and cools the contact portion 13. The end surface grinding device 20 makes the internal space 81 of the housing 30 containing the chamfered grindstone 40 negative pressure with respect to the external space 82 and sucks the cooling liquid from the internal space 81, thereby suppressing the cooling liquid from flowing into the external space 82 and contaminating Glass substrate 10. In addition, the end surface grinding device 20 reduces the amount of coolant used and reduces the load applied to the environment.

Description

Method for manufacturing glass substrate, and device for manufacturing glass substrate

The present invention relates to a method for manufacturing a glass substrate and a device for manufacturing a glass substrate.

Glass substrates used in the manufacture of flat panel displays (FPDs) such as liquid crystal displays and plasma displays are manufactured by, for example, an overflow down-draw method. In the overflow down-draw method, molten glass that flows into a groove on the upper surface of the formed body and overflows flows down both sides of the formed body and merges at the lower end of the formed body, thereby continuously forming a glass ribbon. The formed glass ribbon is cooled while being stretched downward, and then cut to obtain a glass substrate of a specific size. The obtained glass substrates are packaged and shipped after being subjected to an end surface processing step, a surface cleaning step, and an inspection step.

In the step of cutting the glass ribbon into a glass substrate of a specific size, a cutting method using a cutter or a laser is generally used. In a cutting method using a cutter, a crack is mechanically formed in a glass ribbon to cut it. Therefore, a crack having a depth of several μm to 100 μm is formed on the cut surface of the glass substrate. This crack causes deterioration of the mechanical strength of the glass substrate. Moreover, in the cutting method using a laser, a crack is formed in a glass ribbon by thermal stress, and it is cut | disconnected. Therefore, the cut surface of the glass substrate becomes sharp and defects are easily formed. A layer having cracks and sharp portions formed on a cut surface of a glass substrate is called a brittle failure layer, and must be removed by grinding and polishing the cut surface. That is, in order to improve the mechanical strength of the glass substrate, suppress the occurrence of defects in the glass substrate, and facilitate the processing in the subsequent steps, the end surface processing step of the glass substrate is performed.

Previously, in the end surface processing step of a glass substrate, a chamfering step of chamfering a corner portion of an end surface (cut surface) of the glass substrate was performed. In the chamfering step, the rotating grinding wheel is brought into contact with the end surface of the glass substrate and the grinding wheel is relatively moved relative to the glass substrate, thereby grinding the end surface of the glass substrate. The grinding wheel is a metal bonding wheel such as a diamond wheel. The temperature at which the grinding wheel is in contact with the end surface of the glass substrate, that is, the contact portion, is increased by frictional heat. When the temperature of the end surface of the glass substrate rises due to the frictional heat, there is a concern that the quality of the glass near the end surface may deteriorate the quality of the glass substrate shipped as a product. Therefore, in the chamfering step, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 62-43834), a method has been adopted in which a cooling liquid is supplied to a contact portion between a grinding wheel and an end surface of a glass substrate. On the other hand, the temperature rise of the end surface of the glass substrate is suppressed.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 62-43834

The cooling liquid used in the chamfering step is, for example, pure water and an aqueous solution containing organic matter. The cooling performance of an aqueous solution containing a non-ionic surfactant as an organic substance is higher than that of pure water. However, in the case where an aqueous solution containing a nonionic surfactant is used as the cooling liquid, it is preferable to use a small amount of the cooling liquid for the purpose of reducing the load applied to the environment.

In addition, in the chamfering step, when a cooling liquid containing a nonionic surfactant is attached to the surface of the glass substrate, there is a concern that the quality of the glass substrate may be lowered for the following reasons. For example, glass substrates used in the manufacture of FPDs have a black matrix on the surface and red (R). Green (G). A color filter is formed by RGB pixels, which are wavelength-selective elements through which blue (B) light passes. The black matrix blocks the leakage of light from the backlight in the area where no RGB pixels are arranged and prevents the color mixing of adjacent RGB pixels, thereby improving the display contrast. However, when cold When the non-ionic surfactant contained in the cooling solution remains on the surface of the glass substrate, the black matrix may not be able to sufficiently adhere to the surface of the glass substrate. Therefore, it is required to suppress the surface contamination of the glass substrate caused by the cooling liquid used in the chamfering step.

An object of the present invention is to provide a glass substrate manufacturing method and a glass substrate manufacturing device which can reduce the load applied to the environment and can suppress the surface contamination of the glass substrate.

The manufacturing method of the glass substrate of this invention is a method of processing an end surface by making a grindstone contact the end surface of a glass substrate, and moving a grindstone relatively with respect to a glass substrate. The manufacturing method of the glass substrate includes a grinding step, a cooling step, and a suction step. The grinding step is a step of grinding the end surface by rotating the grindstone stored in the housing and bringing the rotating grindstone into contact with the end surface. The cooling step is a step of cooling the contact portion by supplying a cooling liquid, which is an aqueous solution containing a non-ionic surfactant, to the contact portion between the grindstone and the end surface. The suction step is a step of sucking the cooling liquid from the internal space by making the internal space of the housing a negative pressure with respect to the external space of the housing. The casing has a slit for inserting the glass substrate into the internal space.

In the manufacturing method of the glass substrate, when the rotating grindstone is brought into contact with the end surface of the glass substrate to grind the end surface, a cooling liquid is supplied to the contact portion where the grindstone and the end surface are in contact with each other to make the end surface of the contact portion The temperature decreases. Accordingly, the temperature of the end surface of the contact portion is prevented from increasing due to the frictional heat between the grindstone and the end surface, so that the glass near the end surface is deteriorated and the quality of the glass substrate is reduced. In addition, since the cooling liquid supplied to the contact portion is sucked from the internal space of the housing containing the grindstone, the amount of the cooling liquid scattered to the external space of the housing and adhering to the glass substrate can be reduced. Therefore, the surface contamination of the glass substrate caused by the cooling liquid is suppressed. In addition, the cooling liquid sucked from the inner space of the casing is recovered and appropriately processed, thereby reducing the load imposed on the environment. Therefore, the manufacturing method of the glass substrate can reduce the load on the environment, and can suppress the surface pollution of the glass substrate.

In addition, the method for manufacturing a glass substrate of the present invention preferably further includes a suction step. The recovery step of the pumped cooling liquid recovery. In the cooling step, at least a part of the cooling liquid recovered in the recovery step is used to cool the contact portion.

In the manufacturing method of the glass substrate, the cooling liquid sucked after being supplied to the contact portion is recovered, and then the recovered cooling liquid is reused, thereby reducing the amount of cooling liquid used. If a cooling liquid containing an organic substance such as a nonionic surfactant is discharged to the outside, there is a concern that it may adversely affect the environment. Therefore, it is preferable that the amount of the cooling liquid used is small. Therefore, the manufacturing method of the glass substrate can reduce the load imposed on the environment.

Moreover, in the manufacturing method of the glass substrate of this invention, it is preferable that a housing also includes the suction port which sucks the cooling liquid of an internal space. The suction port is formed on the opposite side of the slit from the grinding stone in the internal space.

In the manufacturing method of this glass substrate, the suction port which draws a cooling liquid from an internal space is provided in the position where the cooling liquid supplied to a contact part is most difficult to suck. Therefore, the cooling liquid is suppressed from being sucked before the end surface of the contact portion is sufficiently cooled by the cooling liquid supplied to the contact portion. Thus, the method for manufacturing a glass substrate can efficiently cool the end surface of the glass substrate.

Moreover, in the manufacturing method of the glass substrate of this invention, it is preferable in the cooling process that the contact part is provided on the upstream side of the grinding stone in the rotation direction with respect to the contact part, and the contact part is cooled by pressing the coolant on the grindstone. liquid.

In the method for manufacturing a glass substrate, a grinding stone pressed by a cooling liquid is in contact with an end surface, and a cooling liquid is supplied to the contact portion to cool the end surface. Accordingly, the cooling liquid can be efficiently supplied to the contact portion without directly discharging the cooling liquid to the contact portion. Therefore, the amount of the cooling liquid that is not supplied to the contact portion and does not contribute to the cooling of the end surface can be reduced, and thus the amount of the cooling liquid used can be reduced. Therefore, the manufacturing method of the glass substrate can reduce the load imposed on the environment.

Moreover, in the manufacturing method of the glass substrate of this invention, it is preferable to control the flow velocity of the gas which flows into an internal space from an external space via a slit by adjusting the width of a slit in a suction process.

In the manufacturing method of the glass substrate, for example, the flow velocity of the gas passing through the slit can be increased by narrowing the width of the slit of the casing. The greater the flow velocity of the gas passing through the slit, the lower the amount of cooling liquid flowing from the internal space of the housing to the external space through the slit, and therefore, the amount of the cooling liquid supplied to the contact portion can be increased. Therefore, the method for manufacturing the glass substrate can control the amount of the cooling liquid that can be supplied to the contact portion by adjusting the width of the slit.

In the method for manufacturing a glass substrate of the present invention, it is preferable that the slit includes a pair of brushes for holding the glass substrate. In the suction step, the flow rate of the gas flowing from the external space into the internal space through the slit is controlled by adjusting the interval between the pair of brushes.

In the method for manufacturing the glass substrate, for example, by narrowing the interval between a pair of brushes provided in one of the slits, the flow velocity of the gas passing through the slits can be increased. The greater the flow velocity of the gas passing through the slit, the lower the amount of cooling liquid flowing from the internal space of the housing to the external space through the slit. If the outflow of the cooling liquid to the external space is suppressed, the supply amount of the cooling liquid to the contact portion can be adjusted, so that the amount of the cooling liquid supplied to the contact portion can be increased. Therefore, the method for manufacturing the glass substrate can control the amount of the cooling liquid that can be supplied to the contact portion by adjusting the interval between the pair of brushes.

Moreover, in the manufacturing method of the glass substrate of this invention, it is preferable that a grindstone is a metal bond wheel.

The manufacturing apparatus of the glass substrate of this invention is an apparatus which processes an end surface by making a grindstone contact the end surface of a glass substrate, and moving a grindstone relatively with respect to a glass substrate. The manufacturing apparatus of this glass substrate includes a grindstone, a rotating part, a cooling part, and a suction part. The grindstone is stored in the case. The rotating part is a mechanism for rotating the grindstone. The cooling section is a mechanism for supplying a cooling liquid, which is an aqueous solution containing a nonionic surfactant, to the contact portion between the grindstone and the end surface, and cooling the contact portion. The suction unit is a mechanism that makes the internal space of the housing a negative pressure with respect to the external space of the housing, and sucks the cooling liquid from the internal space. The casing has a slit for inserting the glass substrate into the internal space.

The method for manufacturing a glass substrate and the device for manufacturing a glass substrate according to the present invention can reduce the load imposed on the environment and can suppress the surface contamination of the glass substrate.

10‧‧‧ glass substrate

11a‧‧‧1st end face (end face)

11b‧‧‧1st end face (end face)

12a‧‧‧ 2nd end face (end face)

12b‧‧‧ 2nd end face (end face)

13‧‧‧Contact

20‧‧‧face grinding device (manufacturing device for glass substrate)

30‧‧‧shell

31‧‧‧Slit

32‧‧‧ a pair of brushes

32a‧‧‧hair brush hole

33‧‧‧Slit upper surface

34‧‧‧Slit lower surface

35‧‧‧ Suction tube

36‧‧‧ Suction port

40‧‧‧Chamfered millstone (millstone)

41‧‧‧ side

42‧‧‧Processing trough

43‧‧‧axis

50‧‧‧motor (rotary part)

60‧‧‧Coolant supply device (cooling section)

61‧‧‧Coolant supply pipe

62‧‧‧Coolant supply member

63‧‧‧coolant storage member

64‧‧‧ Subject

65‧‧‧ entrance

66‧‧‧Storage space

67‧‧‧Pressing surface

68‧‧‧ supply port

69‧‧‧coolant flow path

70‧‧‧ Coolant recovery device (suction section)

71‧‧‧Coolant suction section

72‧‧‧ Coolant Recovery Department

73‧‧‧Coolant cleaning department

74‧‧‧ Coolant storage section

75‧‧‧coolant discharge pipe

76‧‧‧ coolant reuse pipe

81‧‧‧Internal space

82‧‧‧External space

101‧‧‧The first chamfering device

102‧‧‧rotating device

103‧‧‧The second chamfering device

104‧‧‧Chamfering device

111‧‧‧1st Diamond Wheel

112‧‧‧2nd Diamond Wheel

113‧‧‧3rd Diamond Wheel

121‧‧‧The first grinding wheel

122‧‧‧ 2nd grinding wheel

S1 ~ S8‧‧‧ steps

X, Y, Z‧‧‧ axis

FIG. 1 is a flowchart of manufacturing steps of a glass substrate.

FIG. 2 is a diagram for explaining the end surface processing steps performed by the end surface processing apparatus.

Fig. 3 is a plan view of a part of the end surface grinding device.

FIG. 4 is a side view of the end surface grinding device viewed from the arrow IV in FIG. 3.

Fig. 5 is a schematic view showing the overall configuration of an end surface grinding device.

Fig. 6 is an external view of a casing.

Fig. 7 is a cross-sectional view of a coolant supply device.

The manufacturing method of the glass substrate which is embodiment of this invention is demonstrated with reference to drawings. The manufacturing method of the glass substrate of this embodiment uses the end surface processing apparatus 100 which processes the end surface of the glass substrate 10.

(1) Outline of manufacturing steps of glass substrate

First, the manufacturing process of the glass substrate 10 processed by the end surface processing apparatus 100 is demonstrated. The glass substrate 10 is used for manufacturing a flat panel display (FPD) such as a liquid crystal display, a plasma display, and an organic EL (electroluminescence) display. The glass substrate 10 has a thickness of, for example, 0.2 mm to 0.8 mm, and has dimensions of 680 mm to 2200 mm in length and 880 mm to 2500 mm in width.

As an example of the glass substrate 10, the glass substrate which is an aluminoborosilicate glass which has the following (a)-(j) composition is mentioned.

(a) SiO ₂ : 50% to 70% by mass; (b) Al ₂ O ₃ : 10% to 25% by mass; (c) B ₂ O ₃ : 1% to 18% by mass; (d) MgO : 0% to 10% by mass; (e) CaO: 0% to 20% by mass; (f) SrO: 0% to 20% by mass; (g) BaO: 0% to 10% by mass; (h) ) RO: 5 mass% to 20 mass% (R is at least one selected from Mg, Ca, Sr, and Ba); (i) R ' ₂ O: 0 mass% to 2.0 mass% (R' is from Li (Na, K and at least one selected); (j) at least one metal oxide selected from SnO ₂ , Fe ₂ O ₃ and CeO ₂ .

Furthermore, the glass having the above composition allows the presence of other trace components in a range of less than 0.1% by mass.

FIG. 1 is an example of a flowchart showing the manufacturing steps of the glass substrate 10. The manufacturing steps of the glass substrate 10 mainly include a forming step (step S1), a plate-like cutting step (step S2), a cutting step (step S3), a roughening step (step S4), an end surface processing step (step S5), The washing step (step S6), the inspection step (step S7), and the packing step (step S8).

In the forming step S1, the molten glass obtained by heating the glass raw material is continuously formed into a glass ribbon by an overflow down-draw method or a float method. The shaped glass ribbon is cooled to below the slow cooling point of the glass while the temperature is controlled in a way that does not cause strain and warpage.

In the sheet-shaped cutting step S2, the glass ribbon formed in the forming step S1 is cut to obtain an original sheet glass having a specific size.

In the cutting step S3, the original glass obtained in the plate-shaped cutting step S2 is cut to obtain a glass substrate 10 having a product size.

In the roughening step S4, a roughening process is performed to increase the surface roughness of the glass substrate 10 obtained in the cutting step S3. The roughening treatment of the glass substrate 10 is a wet etching treatment using, for example, an etching solution containing hydrogen fluoride.

In the end surface processing step S5, the roughening processing which has been performed in the roughening step S4 is performed. The end surface of the glass substrate 10 is chamfered and polished. The end surface processing step S5 is performed by the end surface processing apparatus 100. The chamfering of the end surface is a process of grinding the corner between a pair of the main surface of the glass substrate 10 and the end surface into an R shape. The grinding process of the end surface is a process for reducing the surface roughness of the chamfered end surface.

In the cleaning step S6, the glass substrate 10 which has been subjected to the end surface processing in the end surface processing step S5 is cleaned. On the glass substrate 10, foreign substances such as minute glass pieces generated in the cutting step S3 and the end surface processing step S5, or organic substances existing in the environment, are attached. These foreign materials are removed by cleaning the glass substrate 10.

In the inspection step S7, the glass substrate 10 which has been cleaned in the cleaning step S6 is inspected. Specifically, the shape of the glass substrate 10 is measured, and a defect of the glass substrate 10 is optically detected. Defects of the glass substrate 10 are, for example, flaws and cracks existing on the surface of the glass substrate 10, foreign matter adhering to the surface of the glass substrate 10, and fine bubbles existing inside the glass substrate 10.

In the packing step S8, the glass substrate 10 that passed the inspection in the inspection step S7 and the spacer paper for protecting the glass substrate 10 are alternately laminated on the pallet and packed. The packaged glass substrate 10 is shipped to a manufacturer of FPD and the like.

(2) Overview of the end processing steps

Next, an end surface processing step S5 in which the end surface processing apparatus 100 performs chamfering processing and polishing processing on the end surface of the glass substrate 10 will be described. FIG. 2 is a diagram for explaining the end surface processing step S5 performed by the end surface processing apparatus 100. The glass substrate 10 is transported along the specific path inside the end surface processing apparatus 100 in a state where the main surface is parallel to the horizontal plane.

The glass substrate 10 processed by the end surface processing apparatus 100 has a rectangular shape. The glass substrate 10 includes a pair of first end surfaces 11 a and 11 b and a pair of second end surfaces 12 a and 12 b. The first end faces 11 a and 11 b are end faces parallel to the short sides of the glass substrate 10. The second end faces 12 a and 12 b are end faces parallel to the long sides of the glass substrate 10.

The end surface processing device 100 mainly includes a first chamfering processing device 101 and a rotating device. 102, a second chamfering device 103, and a chamfering device 104. The first chamfering device 101, the rotation device 102, the second chamfering device 103, and the chamfering device 104 are sequentially arranged from the upstream side to the downstream side of the conveyance path of the glass substrate 10. The glass substrate 10 conveyed inside the end surface processing device 100 passes through the first chamfering processing device 101, the rotation device 102, the second chamfering processing device 103, and the chamfering device 104 in this order.

First, the first chamfering apparatus 101 chamfers the corners of the first end faces 11 a and 11 b of the glass substrate 10 using one pair of first diamond wheels 111 provided on one side of the conveyance path of the glass substrate 10. Thereafter, the first chamfering apparatus 101 polishes the first end faces 11 a and 11 b of the glass substrate 10 using a pair of first grinding wheels 121 provided on one of both sides of the conveyance path of the glass substrate 10. Then, the glass substrate 10 is transferred to the rotation device 102.

Next, the rotating device 102 rotates the glass substrate 10 by 90 ° in the horizontal plane. Thereafter, the glass substrate 10 is transferred to the second chamfering apparatus 103.

Next, the second chamfering processing device 103 chamfers the corners of the second end faces 12a, 12b of the glass substrate 10 using a pair of second diamond wheels 112 provided on one side of the conveyance path of the glass substrate 10. Thereafter, the second chamfering apparatus 103 polishes the second end faces 12 a and 12 b of the glass substrate 10 using a pair of second grinding wheels 122 provided on one of both sides of the conveyance path of the glass substrate 10. Then, the glass substrate 10 is transferred to the chamfering device 104.

Next, the chamfering device 104 uses four third diamond wheels 113 to chamfer the four corners of the main surface of the glass substrate 10. Then, the glass substrate 10 is conveyed to the cleaning step S6.

The first diamond wheel 111, the second diamond wheel 112, and the third diamond wheel 113 are, for example, metal bond wheels in which diamond abrasive grains with a particle size of # 400 are fixed by a metal bond containing iron. The first diamond wheel 111, the second diamond wheel 112, and the third diamond wheel 113 may be wheels of the same type.

The first grinding wheel 121 and the second grinding wheel 122 are, for example, metal bonding wheels having silicon carbide abrasive grains having a particle size of # 400 fixed by a metal bonding agent containing iron. The first grinding wheel 121 and the second grinding wheel 122 may be wheels of the same type. The bonding agent may be a cobalt-based or copper-based bonding material, or a resin-based bonding material.

(3) Structure of the face grinding device

Next, an end surface grinding device 20 for chamfering the end surface of the glass substrate 10 will be described. The end surface grinding device 20 corresponds to a manufacturing device of a glass substrate as an embodiment of the present invention. The first chamfering device 101 includes a pair of end surface grinding devices 20 that chamfer each of one of the glass substrates 10 to the first end surfaces 11 a and 11 b. Similarly, the second chamfering device 103 includes a pair of end surface grinding devices 20 that chamfer each of one of the glass substrates 10 and the second end surfaces 12 a and 12 b.

FIG. 3 is a plan view of a part of the end surface grinding device 20. FIG. 3 shows an end surface grinding device 20 of a first chamfering device 101 that performs chamfering of a first end surface 11 a of a glass substrate 10. FIG. 4 is a side view of the end surface grinding device 20 viewed from the arrow IV direction shown in FIG. 3. 3 and 4 show a cross section of the case 30. FIG. 5 is a schematic view showing the overall configuration of the end surface grinding device 20.

Hereinafter, the X-axis, Y-axis, and Z-axis are defined as shown in FIGS. 3 and 4. On a horizontal plane parallel to the main surface of the glass substrate 10, a two-dimensional orthogonal coordinate system including an X axis and a Y axis is set. The X axis is an axis parallel to the direction in which the glass substrate 10 is transported. The Y axis is an axis orthogonal to the direction in which the glass substrate 10 is transported. The Z axis is an axis orthogonal to a plane including the X axis and the Y axis.

The end surface grinding device 20 mainly includes a housing 30, a chamfered grindstone 40, a motor 50, a coolant supply device 60, a coolant recovery device 70, and a control unit (not shown). Next, each component of the end surface grinding apparatus 20 is demonstrated. The following description is also applicable to the end surface grinding device 20 of the second chamfering processing device 103.

(3-1) Housing

The case 30 is a rectangular parallelepiped container assembled from a metal plate. The case 30 is fixed inside the first chamfering apparatus 101. The housing 30 houses a chamfered grindstone 40 and a coolant supply device 60. A motor 50 is attached to the casing 30. FIG. 6 is an external view of the casing 30. The pair of fur brushes 32 is omitted in FIG. 6, and only the fur hole 32 a which is a protruding hole of the pair of fur brushes 32 is shown.

The casing 30 has a slit 31. The slit 31 is formed on the outer surface of the case 30 and is parallel to the X axis. Gap between lines. The slit 31 communicates with the internal space 81 of the casing 30 and the external space 82 of the casing 30. The slit 31 is a gap for inserting the first end surface 11 a of the glass substrate 10 located in the external space 82 into the internal space 81. The slit 31 is a space between the slit upper surface 33 and the slit lower surface 34 facing each other.

The casing 30 includes a pair of fur brushes 32 provided in one of the slits 31. The pair of brushes 32 protrude from the brush hole 32a of each of the slit upper surface 33 and the slit lower surface 34 in the Z-axis direction. The brush holes 32a are formed along the X-axis and the Y-axis, respectively. The material of the pair of brushes 32 is, for example, nylon. A pair of brushes 32 are sandwiched between the ends of the glass substrate 10 inserted into the slit 31. In addition, the pair of bristles 32 suppress the cooling liquid described below from flowing from the internal space 81 to the external space 82.

A suction pipe 35 that is a metal pipe is connected to the outer surface of the casing 30. The casing 30 is connected to the coolant recovery device 70 via a suction pipe 35. The suction pipe 35 is a pipe attached to the suction port 36, which is a hole formed on the outer surface of the casing 30. The suction port 36 is opened in the inner space 81 of the casing 30 on the opposite side of the slit 31 through the chamfered grindstone 40. That is, in the internal space 81, the suction port 36 faces the slit 31.

(3-2) Chamfer millstone

The chamfering grindstone 40 is a grindstone for chamfering the end surface of the glass substrate 10. In the end face grinding device 20 of the first chamfering processing device 101, the chamfering grindstone 40 is a first diamond wheel 111. In the end face grinding device 20 of the second chamfering processing device 103, the chamfering grindstone 40 is a second diamond wheel 112.

The chamfered grindstone 40 is disposed in the inner space 81 of the casing 30. The chamfered grindstone 40 is fixed in position with respect to the casing 30. The chamfered grindstone 40 has a cylindrical shape. A processing groove 42 is formed on the side surface 41 of the chamfering grindstone 40 along the circumferential direction. The chamfered grindstone 40 is connected to the motor 50 via a shaft 43 extending in the Z-axis direction. The shaft 43 penetrates the upper surface of the casing 30.

The chamfered grindstone 40 rotates around the rotation axis parallel to the Z axis by the rotation of the axis 43. The first end surface 11a of the glass substrate 10 is brought into contact with the surface (part of the side surface 41) of the processing groove 42 of the rotating chamfering grindstone 40, so that the first end surface 11a is chamfered. Below, the glass A portion where the first end surface 11 a of the substrate 10 contacts the chamfered grindstone 40 is referred to as a contact portion 13. In FIG. 3, the glass substrate 10 is conveyed to the right, and the chamfered grindstone 40 rotates counterclockwise. In this way, the chamfered grindstone 40 is rotated at the contact portion 13 in a direction opposite to the conveyance direction of the glass substrate 10.

(3-3) Motor

The motor 50 is mounted on the upper surface of the casing 30. The motor 50 is connected to the chamfering grindstone 40 via a shaft 43. The motor 50 is a power source for rotating the shaft 43 and rotating the chamfered grindstone 40 around the rotation axis.

(3-4) Coolant supply device

The coolant supply device 60 mainly includes a coolant supply pipe 61, a coolant supply member 62, and a coolant storage member 63. The cooling liquid supply pipe 61 is a pipe that passes through the casing 30. The coolant supply pipe 61 connects a coolant supply member 62 arranged in the internal space 81, a coolant storage member 63 arranged in the outer space 82, and a coolant recovery device 70 described below.

The cooling liquid supply member 62 is a member for pressing the cooling liquid to the side surface 41 of the rotating chamfered grindstone 40. The cooling liquid is an aqueous solution containing a non-ionic surfactant. The non-ionic surfactant is, for example, a sulfosuccinate. Since the coolant containing the non-ionic surfactant has a small surface tension, the contact portion 13 easily enters the gap between the side surface 41 (the surface of the processing groove 42) of the chamfering grindstone 40 and the first end surface 11a of the glass substrate 10. . The cooling liquid has the effect of removing and removing foreign matter such as glass particles generated by grinding the first end surface 11 a by the chamfered grindstone 40. In addition, the cooling liquid has the effect of cooling the contact portion 13 which is liable to become high temperature due to friction. In addition, the cooling liquid may contain an ammonia-based component, glycerin, etc. in addition to the non-ionic surfactant. The ammonia-based components are, for example, diethanol ammonia, triethanol ammonia, and alkanol ammonia.

The coolant supply member 62 is disposed adjacent to the chamfered grindstone 40 on the upstream side in the rotation direction of the chamfered grindstone 40 with respect to the contact portion 13. The coolant supply member 62 is fixed in position with respect to the chamfered grindstone 40.

FIG. 7 is a cross-sectional view of the coolant supply member 62. The coolant supply member 62 mainly has The main body 64, the introduction port 65, the storage space 66, the pressing surface 67, and the supply port 68. The introduction port 65 is a hole formed on the outer surface of the main body 64 and connected to the cooling liquid supply pipe 61. The storage space 66 communicates with the introduction port 65 and the supply port 68 and is an internal space of the main body 64. The pressing surface 67 is a surface facing the side surface 41 of the chamfered grindstone 40. The supply port 68 is a hole formed in the pressing surface 67. A narrow gap called a coolant flow path 69 is formed between the pressing surface 67 and the side surface 41. The width of the coolant flow path 69, that is, the size of the coolant flow path 69 in the radial direction of the chamfered grindstone 40, decreases toward the downstream side of the chamfered grindstone 40 in the rotation direction.

The cooling liquid storage member 63 is a container for storing a cooling liquid. The cooling liquid stored in the cooling liquid storage member 63 flows in the cooling liquid supply pipe 61 and flows into the storage space 66 through the inlet 65 of the cooling liquid supply member 62. The cooling liquid flowing into the storage space 66 is supplied to the cooling liquid flow path 69 through the supply port 68. The cooling liquid supplied to the cooling liquid flow path 69 flows to the side surface 41 of the chamfered grindstone 40 and the downstream side in the rotation direction of the chamfered grindstone 40. As the cross-sectional area of the coolant flow path 69 decreases toward the downstream side of the chamfered grindstone 40 in the rotation direction, the pressure of the coolant flowing in the coolant flow path 69 gradually increases. As a result, the cooling liquid flowing in the cooling liquid flow path 69 is pressed from the pressing surface 67 of the cooling liquid supply member 62 to the side surface 41 of the chamfered grindstone 40. Thereby, the cooling liquid supplied to the cooling liquid flow path 69 reliably flows into the processing groove 42 formed in the side surface 41.

(3-5) Coolant recovery device

The cooling liquid recovery device 70 is connected to the casing 30 via a suction pipe 35. The coolant recovery device 70 mainly includes a coolant suction section 71, a coolant recovery section 72, a coolant cleaning section 73, and a coolant storage section 74.

The coolant suction portion 71 sucks the gas in the internal space 81 of the casing 30 so that the internal space 81 of the casing 30 becomes a negative pressure with respect to the external space 82 of the casing 30. The cooling liquid suction unit 71 is, for example, a pump capable of sucking liquid and gas. The internal pressure of the internal space 81 relative to the external space 82 is made negative by the coolant suction portion 71, and thereby a gas flow from the external space 82 toward the internal space 81 through the slit 31 is generated.

On the surface of the chamfering grindstone 40, a cooling liquid supplied from a cooling liquid supply member 62 is attached. A part of the cooling liquid adhering to the chamfered grindstone 40 is scattered from the surface of the chamfered grindstone 40 by utilizing the centrifugal force generated by the rotation of the chamfered grindstone 40. In addition, a large amount of the cooling liquid supplied from the cooling liquid supply member 62 is attached to the side surface 41 of the chamfered grindstone 40 located at a position facing the slit 31. Therefore, a large amount of cooling liquid is scattered from the side surface 41 facing the slit 31 and the contact portion 13 toward the slit 31. However, the cooling liquid scattered toward the slit 31 flows through the gas from the outer space 82 through the slit 31 toward the inner space 81 without flowing out to the outer space 82 through the slit 31. Therefore, the cooling liquid suction portion 71 does not allow the cooling liquid scattered from the surface of the chamfering grindstone 40 to flow to the external space 82 but retains it in the internal space 81 in advance, and can pass through the suction port 36 of the housing 30 The suction is performed to the suction pipe 35. That is, the suction pipe 35 is a pipe through which the gas and the cooling liquid in the internal space 81 sucked by the cooling liquid suction unit 71 flow.

The cooling liquid recovery unit 72 is a separator that separates the gas from the mixture of the gas and the cooling liquid sucked by the cooling liquid suction unit 71 to recover the cooling liquid.

The coolant cleaning unit 73 is a mechanism for removing foreign substances contained in the coolant recovered by the coolant recovery unit 72. Foreign matter such as glass flakes may be mixed in the recovered cooling liquid. The coolant cleaning unit 73 is, for example, a filter provided on a flow path through which the recovered coolant flows.

The cooling liquid storage section 74 is a container that stores a cooling liquid from which foreign matter has been removed by the cooling liquid cleaning section 73. The cooling liquid storage section 74 includes a cooling liquid discharge pipe 75 for discharging the stored cooling liquid. The coolant storage section 74 is connected to the coolant storage member 63 via a coolant reuse pipe 76. The cooling liquid stored in the cooling liquid storage section 74 flows through the cooling liquid reuse pipe 76 and is supplied to the cooling liquid storage member 63, and further flows through the cooling liquid supply pipe 61 and is supplied to the cooling liquid supply member 62 for re-recycling. use.

(3-6) Control section

The control unit is a computer that controls the end surface grinding device 20. For example, the control unit controls the motor 50 and the coolant recovery device 70. Next, a control example of the control unit will be described.

The control unit adjusts the output of the motor 50 to control the rotation speed of the chamfered grindstone 40. In addition, the control unit adjusts the output of the cooling liquid suction unit 71 of the cooling liquid recovery device 70, and controls the flow rate of the gas passing through the slit 31, or the gas stored in the cooling liquid storage unit 74 by the cooling liquid recovery unit 72 The amount of coolant.

(4) Operation of the end surface processing device

Next, a description will be given of a step of chamfering the first end faces 11 a and 11 b of the glass substrate 10 by the pair of end face grinding devices 20 using one of the first chamfering devices 101. The following description can also be applied to the step of chamfering the second end faces 12 a and 12 b of the glass substrate 10 by one of the second chamfering devices 103 and the end face grinding device 20.

The glass substrate 10 that has been surface-treated in the roughening step S4 is transported along the X axis inside the end surface processing apparatus 100. Before the transfer, the direction of the glass substrate 10 is adjusted in advance so that the first end faces 11 a and 11 b of the glass substrate 10 are parallel to the X axis. The positions of the pair of end surface grinding devices 20 are adjusted in advance according to the size of the glass substrate 10.

While the glass substrate 10 is being transported along the X axis, the first end surfaces 11 a and 11 b of the glass substrate 10 are inserted into the slits 31 of the end surface grinding device 20. An end portion of the glass substrate 10 including the first end surfaces 11 a and 11 b inserted into the slit 31 is held by a pair of brushes 32.

Thereafter, while the glass substrate 10 is being transported along the X axis, the first end surfaces 11 a and 11 b of the glass substrate 10 are brought into contact with the chamfering grindstone 40 of the end surface grinding device 20 at the contact portion 13 to perform chamfering. In the contact portion 13, the corner portion between the main surface of the glass substrate 10 and the first end faces 11 a and 11 b is ground by the surface of the processing groove 42 of the chamfering grindstone 40 to be chamfered into an R shape.

In the contact portion 13, the first end faces 11 a and 11 b of the glass substrate 10 are cooled by a cooling liquid supplied to the processing tank 42 by the cooling liquid supply device 60. Thereafter, the cooling liquid is recovered by the cooling liquid recovery device 70. At least a part of the recovered cooling liquid is reused to cool the first end faces 11 a and 11 b of the glass substrate 10.

(5) Features

(5-1)

The end surface processing device 100 according to this embodiment includes an end surface grinding device 20 for chamfering the first end surface 11 a of the glass substrate 10. The end surface grinding device 20 makes the side surface 41 (the surface of the processing groove 42) of the rotating chamfering grindstone 40 contact the first end surface 11 a of the glass substrate 10, and relatively moves the chamfering grindstone 40 relative to the glass substrate 10. Thus, the first end surface 11a is chamfered.

In the chamfering process using the metal bonding wheel, that is, the first end face 11 a of the chamfered grindstone 40, the temperature of the first end face 11 a rises due to the frictional heat between the chamfered grindstone 40 and the glass substrate 10. When the first end surface 11a becomes a high temperature, there is a concern that the glass near the first end surface 11a is deteriorated and the quality of the glass substrate 10 as a final product may be reduced.

However, the end surface grinding device 20 can supply coolant to the contact portion 13 which is a portion where the side surface 41 (the surface of the processing groove 42) of the chamfered grindstone 40 and the first end surface 11 a of the glass substrate 10 contact each other, thereby suppressing the first end surface. The temperature of 11a rises. The cooling liquid is an aqueous solution containing a non-ionic surfactant. This cooling liquid has a smaller surface tension than pure water, and therefore can easily enter a small gap of the contact portion 13. Therefore, this cooling liquid has higher cooling performance than pure water.

Moreover, the end surface grinding device 20 can make the internal space 81 of the case 30 into a negative pressure with respect to the external space 82 of the case 30 by the coolant suction portion 71 of the coolant recovery device 70. As a result, a gas flow from the outer space 82 to the inner space 81 via the slit 31 is generated. Therefore, the cooling liquid pressed to the side surface 41 of the chamfering grindstone 40 and scattered from the side surface 41 and the contact portion 13 to the slit 31 by the centrifugal force does not flow out to the external space 82 through the slit 31. If the cooling liquid flows out into the external space 82, there is a concern that the cooling liquid adheres to the main surface of the glass substrate 10 and the quality of the glass substrate 10 is reduced. For example, in the case where the glass substrate 10 is used in the production of FPD, if the non-ionic surfactant contained in the cooling liquid remains on the main surface of the glass substrate 10, a black matrix cannot sufficiently adhere to the glass substrate 10. Major concerns. However, the end surface grinding device 20 can prevent the cooling liquid from flowing out to the external space 82, and can therefore prevent the glass substrate 10 from being contaminated by the non-ionic surfactant contained in the cooling liquid. surface.

(5-2)

In the end surface grinding device 20, the cooling liquid supplied to the contact portion 13 does not flow out into the external space 82, but is recovered by sucking the cooling liquid recovery device 70 from the internal space 81. The recovered coolant is removed from the foreign matter and supplied to the contact portion 13 again. That is, the end surface grinding device 20 can recover the cooling liquid used for cooling the first end surface 11 a of the glass substrate 10, and can reuse a part of the recovered cooling liquid. Therefore, the end surface grinding device 20 can reduce the amount of coolant used. When a cooling liquid containing an organic substance such as a nonionic surfactant is discharged to the outside, there is a concern that it may adversely affect the environment. In addition, there is a problem of environmental pollution in a facility in which the end surface grinding device 20 is installed due to the scattering of a cooling liquid containing organic matter, or a problem that the maintenance management cost of the end surface grinding device 20 increases. Therefore, it is preferable that the amount of the cooling liquid is small. Thus, the end surface grinding device 20 recovers the cooling liquid for reuse by the cooling liquid recovery device 70, thereby reducing the amount of cooling liquid used and reducing the load imposed on the environment.

(5-3)

Moreover, in the end surface grinding device 20, the suction port 36 for sucking the cooling liquid in the internal space 81 of the casing 30 is opened on the opposite side of the slit 31 through the chamfering grindstone 40. That is, the suction port 36 is provided at a position farthest from the contact portion 13, in other words, at a position where the cooling liquid supplied to the contact portion 13 is most difficult to be sucked. Therefore, the cooling liquid supplied to the contact portion 13 is suppressed from being sucked from the internal space 81 to the suction port 36 before the first end surface 11 a of the glass substrate 10 on the contact portion 13 is sufficiently cooled. Accordingly, the end surface grinding device 20 can effectively cool the first end surface 11 a of the glass substrate 10 using a cooling liquid.

(5-4)

In the end surface grinding device 20, the cooling liquid supply device 60 presses the cooling liquid to the side surface 41 of the chamfered grindstone 40 by the cooling liquid supply member 62, thereby supplying the cooling liquid to the contact portion 13 to the glass substrate. The first end surface 11a of 10 is cooled. In this way, the coolant supply device The setting 60 can supply the cooling liquid to the contact portion 13 without directly discharging the cooling liquid to the contact portion 13. Therefore, the cooling liquid supply device 60 can reduce the amount of the cooling liquid that is not supplied to the contact portion 13 and does not contribute to the cooling of the first end surface 11a, so that the amount of the cooling liquid used can be reduced. Thereby, the end surface grinding apparatus 20 can reduce the load imposed on the environment.

(6) Variations

As mentioned above, although the manufacturing method of the glass substrate of this invention was demonstrated, this invention is not limited to the said embodiment, Various improvements and changes can be implemented in the range which does not deviate from the meaning of this invention.

(6-1) Modification A

In the embodiment, the casing 30 of the end surface grinding device 20 has a pair of brushes 32 disposed between the slits 31. A pair of brushes 32 are sandwiched between the ends of the glass substrate 10 inserted into the slit 31. The pair of brushes 32 protrude from each of the slit upper surface 33 and the slit lower surface 34 in the Z-axis direction.

However, the end surface grinding device 20 may have a mechanism for adjusting the length of one pair of the brushes 32 protruding from each of the upper slit surface 33 and the lower slit surface 34. In this case, the control section of the end surface grinding device 20 can adjust the length of the pair of brushes 32 and control the interval between the pair of brushes 32. A pair of fur brushes 32 are arranged in a space between the slit upper surface 33 and the slit lower surface 34. Therefore, by adjusting the length of the pair of brushes 32, the control unit can control the flow velocity of the gas flowing from the outer space 82 of the casing 30 into the inner space 81 of the casing 30 through the slit 31.

When the suction force of the cooling liquid suction unit 71 of the cooling liquid recovery device 70 is fixed, if the interval between the pair of brushes 32 is narrowed, the flow velocity of the gas passing through the slit 31 is increased. The greater the flow velocity of the gas passing through the slit 31, the smaller the amount of the cooling liquid flowing from the internal space 81 to the external space 82 through the slit 31, and therefore, the amount of the cooling liquid supplied to the contact portion 13 can be increased. In addition, if the distance between the pair of brushes 32 is narrowed, the amount of the cooling liquid that is scattered from the chamfered grindstone 40 toward the slit 31 and flows out to the external space 82 can be reduced, so that the cooling liquid supplied to the contact portion 13 can be made. The amount increases.

As a result, the end surface grinding device 20 of this modified example can adjust the interval between the pair of brushes 32 by appropriately adjusting the thickness of the glass substrate 10 or the suction force of the cooling liquid suction portion 71, so that it can be supplied to the contact portion 13. The amount of coolant is increased.

The end surface grinding device 20 of the present modification may have a mechanism for adjusting the interval between the slits 31 instead of a mechanism for adjusting the length of the pair of brushes 32. In this case, the end surface grinding device 20 can adjust the interval between the pair of brushes 32 by adjusting the interval between the slits 31.

(6-2) Modification B

The end surface grinding device 20 of the modification A can increase the amount of the cooling liquid that can be supplied to the contact portion 13 by appropriately adjusting the interval between the pair of bristles 32. However, the housing 30 of the end surface grinding device 20 may not have a pair of fur brushes 32 provided between the slits 31. In this case, the housing 30 may also have a mechanism for adjusting the interval of the slits 31.

In this modified example, similarly to the modified example A, the control section of the end surface grinding device 20 can control the flow from the external space 82 of the casing 30 into the casing through the slit 31 by adjusting the interval between the slits 31. The flow velocity of the gas in the internal space 81 of 30.

When the suction force of the cooling liquid suction unit 71 of the cooling liquid recovery device 70 is fixed, if the interval between the slits 31 is narrowed, the flow velocity of the gas passing through the slit 31 is increased. The greater the flow velocity of the gas passing through the slit 31, the smaller the amount of the cooling liquid flowing from the internal space 81 to the external space 82 through the slit 31, and therefore, the amount of the cooling liquid supplied to the contact portion 13 can be increased. In addition, if the interval between the slits 31 is narrowed, the amount of the cooling liquid that is scattered from the chamfered grindstone 40 toward the slit 31 and flows out to the external space 82 can be reduced, so that the amount of the cooling liquid supplied to the contact portion 13 can be made increase.

Therefore, the end surface grinding device 20 of this modification can appropriately adjust the interval of the slits 31 according to the thickness of the glass substrate 10 or the suction force of the cooling liquid suction portion 71, so that the cooling that can be supplied to the contact portion 13 can be performed. The amount of fluid increases.

(6-3) Modification C

The end surface grinding device 20 according to the embodiment uses a cooling liquid supply member 62 capable of pressing the cooling liquid against the side surface 41 of the chamfered grindstone 40 to supply the cooling liquid to the contact portion 13. However, the end surface grinding device 20 may directly spray the cooling liquid on the side surface 41 or the contact portion 13 of the chamfered grindstone 40 and supply the cooling liquid to the contact portion 13.

(6-4) Modification D

In the embodiment, the end surface processing apparatus 100 includes a chamfering grindstone 40 for grinding the end surfaces 11 a, 11 b, 12 a, and 12 b of the glass substrate 10. The chamfered grindstone 40 is a diamond wheel, but may be a resin-bonded wheel. The resin bonding wheel is, for example, a grinding wheel in which abrasive grains generally used are fixed with a resin-based bonding agent having flexibility and elasticity. The particle size of the abrasive grains is, for example, about # 300 to # 500 prescribed by JIS (Japanese Industrial Standards) R6001-1987. Even when it is convenient to use a resin-bonded wheel, the end surface processing apparatus 100 may grind the end surfaces 11 a, 11 b, 12 a, and 12 b of the glass substrate 10 to perform chamfering.

Claims (8)

A method for manufacturing a glass substrate is a method for processing the end surface by contacting a grindstone with the end surface of the glass substrate and moving the grindstone relative to the glass substrate, and includes a grinding step. Grinding the end surface by rotating the grindstone stored in the housing and contacting the rotating grindstone to the end surface; the cooling step is to supply non-ion to the contact portion between the grindstone and the end surface. The surfactant is an aqueous solution of a surfactant, which cools the contact portion; and a suction step is performed by making the internal space of the casing into a negative pressure relative to the external space of the casing, and pumping from the internal space. The cooling liquid is sucked; and the casing has a slit for inserting the glass substrate into the internal space. For example, the method for manufacturing a glass substrate according to claim 1, further comprising a recovery step of recovering the cooling liquid sucked in the suction step, and using the cooling liquid recovered in the recovery step in the cooling step. The contact portion is cooled by at least a part of the contact portion. The manufacturing method of the glass substrate according to claim 1 or 2, wherein the casing further has a suction port for sucking the cooling liquid in the internal space, and the suction port is formed in the internal space with respect to the grinding stone. Opposite side of the slit. The method for manufacturing a glass substrate according to claim 1 or 2, wherein in the cooling step, the contact with the contact portion is located upstream of the grinding stone in the direction of rotation, and the cooling liquid is pressed against the grinding stone to the above The contact portion supplies the cooling liquid. The method for manufacturing a glass substrate according to claim 1 or 2, wherein in the suction step, a flow rate of a gas flowing from the external space to the internal space through the slit is controlled by adjusting a width of the slit. For example, the method for manufacturing a glass substrate according to claim 1 or 2, wherein the slit has a pair of brushes holding one of the glass substrates, and in the suction step, the self-control is controlled by adjusting the interval between the pair of brushes. The flow velocity of the gas flowing into the internal space from the external space through the slit. The method for manufacturing a glass substrate according to claim 1 or 2, wherein the grinding stone is a metal bonding wheel. A manufacturing device for a glass substrate is a person who makes a grinding stone contact the end surface of the glass substrate and moves the grinding stone relatively to the glass substrate to process the end surface, and includes a grinding stone stored in a shell A rotating part that rotates the grindstone; a cooling part that supplies the contact portion between the grindstone and the end surface with a cooling solution containing an aqueous solution containing a non-ionic surfactant to cool the contact portion; and A suction unit that makes the internal space of the housing a negative pressure relative to the external space of the housing and sucks the cooling liquid from the internal space; and the housing has a mechanism for inserting the glass substrate into the internal space. Slit.