TWI409140B - A method for manufacturing a glass substrate, and a manufacturing apparatus for a glass substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass substrate optimally carrying out grinding in response to a grinding position of the glass substrate. <P>SOLUTION: In the method for manufacturing a glass substrate including a grinding process of grinding both end faces of a conveyed glass substrate, a pair of grinding wheels grinding both end faces is turnably held and applied with first force in a glass substrate direction, and it is held so as to follow with respect to fluctuation in a width direction of the glass substrate. In the pair of grinding wheels, when carrying in or carrying out the glass substrate in the grinding process, second force is applied such that turning is regulated. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

Method for producing glass substrate and device for manufacturing glass substrate

The present invention relates to a method of manufacturing a glass substrate.

Since the prior art, glass substrates for electronic devices have been manufactured by cutting sheet-like glass into a desired size. The side surface (end surface) of the glass (glass substrate) cut into a desired size is formed with minute irregularities or cracks. Such irregularities or cracks may cause breakage and imperfection of the glass substrate. In order to prevent breakage and breakage of such a glass substrate, for example, the end surface of the glass substrate is polished by a polishing member as shown in Patent Document 1 (Japanese Laid-Open Patent Publication No. 2009-297865). Patent Document 1 proposes a method of detecting a load current value at the time of contact between a polishing wheel and a glass substrate, and appropriately polishing the end surface of the glass substrate using the load current value.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-297865

However, in the technique disclosed in Patent Document 1, the end surface of the glass substrate is polished during the conveyance of the glass substrate. When the end surface of the glass substrate is polished during the conveyance of the glass substrate, the end surface of the glass substrate may not be appropriately polished depending on the state of conveyance of the glass substrate.

An object of the present invention is to provide a method for producing a glass substrate which improves the precision of polishing when the end surface of the glass substrate is polished while being conveyed.

The method for producing a glass substrate of the present invention includes a polishing step of polishing both end faces of the glass substrate to be conveyed. Further, one of the both end faces is polished to the grinding stone to be held in a rotatable manner, and a first force is applied in the direction of the glass substrate. Further, the pair of grinding stones are kept to follow the fluctuation in the width direction of the glass substrate. Here, the glass substrate direction is a direction orthogonal to the conveyance direction of the glass substrate. In addition, the fluctuation of the width direction of the glass substrate means the change of the position of the glass substrate in the direction orthogonal to the conveyance direction of the glass substrate. Further, the pair of polishing stones are given a second force by the regulation of the rotation when the glass substrate is moved in and out during the polishing step. When the glass substrate is carried in and out, the glass substrate is in contact with the polishing stone and the glass substrate is separated from the grinding stone.

Moreover, it is preferable to absorb the impact by the contact of the glass substrate and the grindstone by the elastic member while the second force is applied so as to regulate the swirling of the pair of grindstones.

Further, it is preferable that a pair of polishing stones are placed in the polishing step of the glass substrate during the loading and the unloading, and are protruded to the inside of the glass substrate, and the peripheral edge portion is in contact with the front end of the glass substrate. The glass substrate is polished by retracting the peripheral portion as the glass substrate is transferred.

In the method for producing a glass substrate of the present invention, polishing can be performed optimally according to the polishing position of the glass substrate, and there is no unpolished region.

Hereinafter, a polishing apparatus 10a for a glass substrate GL used in a method for producing a glass substrate according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the "transport direction" refers to the transport direction of the glass substrate GL, and the "width direction" refers to the width direction of the glass substrate GL. In addition, the "inclination of the glass substrate GL" refers to the inclination of the glass substrate GL with respect to the conveying device 80, and the "position of the glass substrate GL in the width direction" means the width direction of the glass substrate GL with respect to the conveying device 80. The location. In addition, the "glass substrate direction" is a direction orthogonal to the direction in which the glass substrate is conveyed, and the "variation in the width direction of the glass substrate" means a glass substrate in a direction orthogonal to the direction in which the glass substrate is conveyed. Change in location.

(1) Overall composition

First, a plurality of steps S1 to S7 included in the method for producing a glass substrate of the present invention will be described with reference to Fig. 1 . The plurality of steps include a forming step S1, a cutting step S2, a grinding step S3, a polishing step S4, a washing step S5, an inspection step S6, and a shipping step S7.

In the forming step S1, first, the glass raw material is melted to form molten glass. Thereafter, removal of bubbles contained in the molten glass or the like is performed. Further, the molten glass which is homogenized by the removal of bubbles or the like is formed into a sheet-shaped glass by a melting method. Thereafter, the sheet glass is cut into a predetermined size to form a raw material sheet.

In the cutting step S2, the raw material sheet is cut to a desired size. Here, the raw material sheet is cut into a glass size used in an electronic device or a flat panel display. The raw material sheet (glass substrate GL) which has been cut by the cutting step S2 is transported downstream by the conveying device 80 as shown in FIG. 2 . The conveying device 80 used in the present embodiment includes conveying belts 81 and 82 extending in the conveying direction of the glass substrate GL. The conveyance belts 81 and 82 are arranged at a predetermined interval in a direction transverse to the conveyance direction of the glass substrate GL (the width direction of the glass substrate GL). The conveyor belts 81 and 82 are in contact with the lower surface of the glass substrate GL, and are transported downstream while adsorbing the glass substrate GL. Further, the transport device 80 used in the present embodiment transports the glass substrate GL downstream at a speed of 5 m/s to 15 m/s. More preferably, the glass substrate GL is transported downstream at a speed of 10 m/s to 15 m/s. Further, the glass substrate GL produced in the method for producing a glass substrate of the present embodiment has a thickness of 0.2 mm to 0.8 mm. The thickness of the glass substrate GL is preferably from 0.2 mm to 0.4 mm.

In the grinding step S3, the glass substrate GL conveyed downstream by the conveying device 80 is ground by the grinding wheels 9a and 9b. Specifically, the end surface of the glass substrate GL is ground. The end surface is a side surface (cut surface) of the glass substrate GL. As shown in FIG. 3, the end surface of the glass substrate GL includes a front end portion TP, a rear end portion EP, and a central portion CP. The distal end portion TP is an end surface on the downstream side with respect to the transport direction D1. The rear end portion EP of the glass substrate GL is an end surface on the upstream side with respect to the transport direction D1. The central portion CP of the glass substrate GL is sandwiched between the front end portion TP and the rear end portion EP of the glass substrate GL. The end surface of the glass substrate GL is processed into a slightly curved shape (R-face processing) by the grinding wheels 9a and 9b. The grinding wheels 9a and 9b are disposed on both sides of the conveying device 80 as shown in Fig. 2 . Further, the grinding wheels 9a and 9b are rotated in the direction of the arrow R3 of Fig. 2 .

In the polishing step S4, the end faces of the glass substrate GL which have been ground by the grinding step S3 are polished by the grinding wheels 11a and 11b. As shown in FIG. 2, the grinding wheels 11a and 11b are disposed downstream of the grinding wheels 9a and 9b and on both sides of the conveying device 80. Further, the grinding wheels 11a and 11b rotate in the direction of the arrow R3 of Fig. 2 .

In the cleaning step S5, the glass substrate GL is cleaned. Thereby, fine foreign matter or stain adhering to the surface of the glass substrate GL is removed. After the cleaning, the glass substrate GL is dried.

In the inspection step S6, it is determined whether or not the glass substrate GL is defective. Here, the defective glass substrate GL is removed as a defective product.

Thereafter, in the shipping step S7, the glass substrate GL is bundled and sent to the customer.

Hereinafter, the configuration of the polishing apparatus 10a used in the polishing step S4 will be described in detail. In the method of manufacturing a glass substrate of the present embodiment, the glass substrate GL is transported to the polishing step S4 in a predetermined state. The predetermined state refers to the position of the glass substrate GL estimated when the glass substrate GL is correctly conveyed, and the position of the glass substrate GL actually transferred is within a certain range (±0.1 mm). The offset of the position of the glass substrate GL includes the bias of the glass substrate GL on one side in the width direction of the transport device 80 and the inclination of the glass substrate GL with respect to the transport device 80. The bias of the glass substrate GL on one side in the width direction of the transport device 80 means that the center line C1 (see FIG. 2) of the glass substrate GL is offset in the width direction from the center line C2 (see FIG. 2) of the transport device 80. . The center line C1 of the glass substrate GL and the center line C2 of the transport device 80 are lines along the transport direction of the glass substrate GL. Therefore, the state in which the glass substrate GL is biased to the one side in the width direction of the transport device 80 is a state in which the center line C1 of the glass substrate GL is slightly shifted to the right in the width direction of the center line C2 of the transport device 80, or the glass substrate GL. The center line C1 is slightly shifted to the left side in the width direction of the center line C2 of the conveying device 80 (see FIGS. 13A to 13C). Further, the inclination of the glass substrate GL with respect to the conveying device 80 means that the distance from the front end portion TP of the glass substrate GL to the grinding wheels 11a and 11b is different from the distance from the rear end portion EP of the glass substrate GL to the grinding wheels 11a and 11b. State. Therefore, in a state where the glass substrate GL is inclined with respect to the transport apparatus 80, the right end portion of the glass substrate GL is located on the downstream side of the left end portion of the glass substrate GL, or the right end portion of the glass substrate GL is located. The left end portion of the glass substrate GL is in a state of being upstream of the transport direction (see FIGS. 16A to 16C).

(2) Composition of the grinding device

The polishing apparatuses 10a and 10b polish the end faces of the glass substrate GL which have been ground by the grinding wheels 9a and 9b to reduce irregularities or cracks in the end faces.

The schematic configuration of the polishing apparatus 10a of the present embodiment is shown in Figs. 4A and 4B. 4A is a plan view of the polishing apparatus 10a, and FIG. 4B is a side view of the polishing apparatus 10a. 4A and 4B show a polishing apparatus 10a including the grinding wheel 11a shown on the right side of Fig. 2. Hereinafter, the configuration of the polishing apparatus 10a will be described in detail, and the configuration of the polishing apparatus 10b including the other polishing wheel 11b shown in Fig. 2 is also the same as that of the polishing apparatus 10a. The configuration and operation of the polishing apparatus 10b are symmetrical with respect to the center line C2 of the conveying apparatus 80 and the configuration of the polishing apparatus 10a (see FIGS. 11A to 11C and the like).

The polishing apparatus 10a mainly includes a grinding wheel (corresponding to a grinding stone) 11a, a robot arm 12a, a substrate 13a, a brake mechanism 14a, and a control unit 15.

(2-1) Grinding wheel

The grinding wheel 11a is in contact with the end surface of the glass substrate GL which has been ground by the grinding wheel 9a, and the unevenness or crack of the end surface is reduced. A resin-filled fiber is used for the grinding wheel 11a. Hard particles such as diamond abrasive grains, cerium carbide abrasive grains, CBN (Cubic Boron Nitride) abrasive grains, or cerium oxide abrasive grains are dispersed in the resin. Thereby, the grinding wheel 11a includes a peripheral portion having elasticity.

A groove for cutting into the end face of the glass is formed in the grinding wheel 11a. The groove is in contact with the glass substrate GL so as to cover the end surface and the end surface of the glass substrate GL. The grinding wheel 11a is rotated about the wheel rotating shaft 110a by the motor 17a. Specifically, the polishing wheel 11a rotates so that the peripheral edge portion of the polishing surface of the polishing wheel 11a that is in contact with the end surface of the glass substrate GL travels in a direction opposite to the transport direction D1 of the glass substrate GL (arrow R3 in FIG. 2). .

(2-2) Robot arm

The arm 12a is configured to be rotated about the arm rotating shaft 120a. The robot arm 12a changes the inclination with respect to the conveyance direction D1 by the rotation. The polishing apparatus 10a maintains the pressure applied from the grinding wheel 11a to the glass substrate GL within a certain range by changing the inclination of the robot arm 12a, and causes the grinding wheel 11a to follow the end surface of the glass substrate.

As shown in FIG. 4B, the robot arm 12a includes a first end portion 121 and a second end portion 122. The first end portion 121 is an end portion located in the vicinity of the glass substrate GL, and the second end portion 122 is an end portion located at a position away from the glass substrate GL. A grinding wheel 11a is rotatably attached to the first end portion 121. A constant pressure cylinder 16a is attached to the second end portion 122. The constant pressure cylinder 16a applies a constant force (load) to the second end portion 122 in the direction of the arrow F1 (corresponding to the first force) (see FIG. 4A). When a force is applied to the second end portion 122 by the constant pressure cylinder 16a, the robot arm 12a is rotated in the direction of the arrow R1 around the arm rotating shaft 120a. A stopper portion 15a is disposed in the vicinity of the second end portion 122 of the robot arm 12a. The second end portion 122 of the robot arm is brought into contact with the stopper portion 15a by the rotation of the robot arm 12a. Thereby, the rotation of the robot arm 12a in the R1 direction is suppressed. Further, the rotation of the arm 12a in the R1 direction can be suppressed by the contact of the grinding wheel 11a with the end surface of the glass substrate GL.

Furthermore, the rotation of the robot arm 12a can also be restricted by the action of the brake mechanism 14a described below. The relationship between the braking mechanism 14a and the rotation of the robot arm 12a will be described together with the description of the brake mechanism 14a described below.

(2-3) Substrate

As shown in FIG. 4B, the substrate 13a is a plate that holds the constant pressure cylinder 16a and the arm rotation shaft 120a.

(2-4) Brake mechanism

The brake mechanism 14a limits the range of rotation (corresponding to the second force) of the arm 12a during loading and unloading of the glass substrate GL. As shown in FIG. 5, the brake mechanism 14a includes an upper mechanism 41 and a lower mechanism 42. The upper mechanism 41 is configured to move up and down. Specifically, the upper mechanism 41 moves up and down between a position (regular position) that comes into contact with the lower mechanism 42 and a position (released position) that is separated from the lower mechanism 42. The rotation of the robot arm 12a is restricted by the upper mechanism 41 being in contact with the lower mechanism 42 at the regulatory position. That is, the brake is applied to the rotation of the robot arm 12a. On the other hand, when the upper mechanism 41 is separated from the lower mechanism 42 and is at the release position, the arm 12a is freely rotatable. That is, the brake is released. Thereby, the robot arm 12a is freely rotated according to the inclination of the glass substrate GL. Hereinafter, the configuration of the upper mechanism 41 and the lower mechanism 42 will be described in detail.

(2-4-1) Upper mechanism

The upper mechanism 41 mainly includes a brake cylinder 411 and an upper contact unit 412.

The brake cylinder 411 is fixed to the plate 411a by a screw 411b. Further, the brake cylinder 411 is coupled to a push-and-pull rod 411c via a plate 411a. The push-pull rod 411c is connected to the upper contact unit 412 described below. The brake cylinder 411 moves the upper contact unit 412 up and down. The upper contact unit 412 is moved between the release position located above and the regulation position located below by the brake cylinder 411.

The upper contact unit 412 is a member that is in contact with the lower mechanism 42. Insertion portions 413a, 413b, and 413c are formed in the upper contact unit 412. A slide shaft 414 is inserted into the insertion portions 413a to 413c. The slide shaft 414 extends in a vertical direction between the lower surface of the plate 411a and the upper surface of the robot arm rotation shaft 120a. When the upper contact unit 412 is moved up and down by the brake cylinder 411, it moves along the slide shaft 414. Further, the insertion portions 413a to 413c are configured to accommodate the slider bearing 415 and the elastic member 416. The sliding bearing 415 has a function of smoothly moving the upper contact unit 412 along the sliding shaft 414. That is, the upper contact unit 412 moves up and down along the slide shaft 414 via the sliding bearing 415.

The elastic member 416 has a through hole h1. The through hole h1 is formed in a central portion of the elastic member 416. The slide shaft 414 and the slide bearing 415 are disposed inside the through hole h1. That is, the elastic member 416 is disposed around the sliding bearing 415. The elastic member 416 is a urethane-based material, a lanthanide-based material, or a rubber. Here, a urethane-based material is used as the elastic member 416. The resilient member 416 has a degree of elasticity that causes the robot arm 12a to move slightly relative to the sliding shaft 414 when the upper contact unit 412 is in the regulatory position. Specifically, as shown in FIGS. 7A and 7B, the elastic member 416 has elasticity that allows the mechanical arm 12a to be rotated by a certain amount in the R1 direction or the R2 direction. In the present embodiment, the slide shaft 414 and the slide bearing 415 are shifted by 0.1 mm to 0.3 mm from the center line C3 by a specific amount by the mechanical arm 12a. Here, the specific amount is an amount that allows the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL to be an appropriate distance. Further, the center line C3 is a straight line extending from the center of the upper contact unit 412 toward the center of the insertion portions 413a to 413c. Although the elasticity of the elastic member 416 is changed depending on the type of the glass substrate GL (the composition of the glass substrate GL), in the present embodiment, it is preferable to use the elastic member 416 having the following degree of elasticity: the upper contact unit When the 412 is in the regulation position, the rotation of the arm 12a is slightly allowed, and when the arm 12a is rotated within the allowable range, the slide shaft 414 and the slide bearing 415 are shifted by 0.2 mm from the center line C3 to the left and right.

As shown in FIG. 5, a fixed brake pad 417 is attached to the lower surface of the upper contact unit 412. For the fixed brake pad 417, a material having a specific rigidity and a specific friction coefficient is used. The specific rigidity refers to the rigidity which is the same as the rigidity of the elastic member 416, or the rigidity which is stronger than the rigidity of the elastic member 416. Further, the specific friction coefficient refers to a coefficient of friction in which the fixed brake pad 417 can be opposed to the external forces F1 and F2 when the upper mechanism 41 is at the regulation position. The fixed brake pad 417 is in contact with the rotating brake pad 422 of the lower mechanism 42 described below.

(2-4-2) Lower mechanism

The lower mechanism 42 is a mechanism that is in contact with the upper mechanism 41 at the regulatory position. The lower mechanism 42 mainly includes a lower contact unit 421. The lower contact unit 421 is disposed at the second end of the arm 12a. A rotating brake pad 422 is attached to the upper surface of the lower contact unit 421. Specifically, the rotary brake pad 422 is attached in contact with the fixed brake pad 417 of the upper mechanism 41 located at the regulation position. Similarly to the above-described fixed brake pad 417, a material having a specific rigidity and a specific friction coefficient is also used for the rotary brake pad 422.

(2-5) Control Department

As shown in FIG. 6, the control unit 15 is connected to the grinding wheel 11a, the arm rotating shaft 120a, the brake mechanism 14a, the motor 17a, and various sensors 16. The control unit 15 mainly includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a hard disk. The control unit 15 performs control of each configuration based on a program or various information stored in a ROM, a RAM, a hard disk, or the like. Further, the control unit 15 may generate and transmit a control command to both of the polishing apparatuses 10a and 10b.

(3) Position of the sliding shaft corresponding to the rotation of the robot arm

Next, a change in the position of the slide shaft 414 when the brake mechanism 14a is actuated will be described with reference to FIGS. 7A and 7B. As described above, the brake mechanism 14a includes the elastic member 416 in the insertion portions 413a to 413c. When the brake mechanism 14a is actuated, the rotation of the robot arm 12a is hindered by the slide shaft 414. However, the deformation is caused by the elastic member 416 around the sliding shaft 414, and the mechanical arm 12a is allowed to slightly rotate.

7A and 7B are views showing the positions of the rotation directions R1 and R2 of the arm 12a and the position of the slide shaft 414 which changes according to the rotation of the arm 12a when the brake mechanism 14a is actuated. Fig. 7A shows a case where the arm 12a is rotated in the direction R1 when the brake mechanism 14a is actuated, and the slide shaft 414 is moved in the direction M1. Fig. 7B shows a state in which the slide shaft 414 is moved in the direction M2 when the arm 12a is rotated in the direction R2 when the brake mechanism 14a is actuated.

As shown in FIGS. 7A and 7B, the amount of rotation (rotation range) of the arm 12a is determined in accordance with the degree of deformation of the elastic member 416.

(4) Relationship between the force applied to the arm and the position of the sliding shaft

Next, the relationship between the force applied to the arm 12a and the position of the slide shaft 414 in the insertion portion 413a will be described with reference to Figs. 8A to 8C. Here, the force applied to the arm 12a refers to a force applied by the constant pressure cylinder 16a (external force F1) and a force applied by the grinding wheel 11a in contact with the glass substrate GL (external force F2). 8A to 8C are enlarged views of the insertion portion 413a of Figs. 7A and 7B.

In Fig. 8A, the slide shaft 414 is located at the center (appropriate position) of the insertion portion 413a. When the sliding shaft 414 is in the proper position, the sliding shaft 414 is located at the center of the center line C3. When the slide shaft 414 is at the proper position, the force to rotate the arm 12a by the external force F2 is in a state of being balanced with the force by which the external arm F1 is required to rotate the arm 12a. It is considered that the distance from the glass substrate GL to the center of the grinding wheel 11a is a specific distance interval when the sliding shaft 414 is at the proper position. The elastic member 416 has a uniform thickness around the sliding shaft 414 and the sliding bearing 415. That is, the elastic member 416 is not deformed, and the prototype is maintained.

In Fig. 8B, the robot arm 12a is slightly rotated clockwise, with the result that the slide shaft 414 is located offset to the left from the center line C3. Here, the force at which the mechanical arm 12a is to be rotated by the external force F2 is greater than the force by which the external force F1 is to be rotated. It is considered that the distance from the glass substrate GL to the center of the grinding wheel 11a is closer than a specific distance. The left side of the center line C3 of the elastic member 416 is compressed and deformed. By compressing the elastic member 416, the grinding wheel 11a is protected from excessive rise of the external force F2 when the brake mechanism 14a is actuated.

In Fig. 8C, the robot arm 12a is slightly rotated counterclockwise, and as a result, the slide shaft 414 is located offset to the right from the center line C3. Here, the force at which the mechanical arm 12a is to be rotated by the external force F1 is greater than the force at which the mechanical arm 12a is to be rotated by the external force F2. It is considered that the distance from the glass substrate GL to the center of the grinding wheel 11a is farther apart than the specific distance. The right side of the center line C3 of the elastic member 416 is compressed and deformed. Although the compressed elastic member 416 is intended to be restored to the prototype, the external force F1 is larger than the force (recovery force) to be restored to the prototype. The grinding wheel 11a applies a certain range of pressure to the end surface of the glass substrate GL to be in contact therewith. Further, by the restoring force of the elastic member 416, the impact transmitted from the glass substrate GL to the grinding wheel 11a at the start of processing of the glass substrate GL is lowered. That is, the impact transmitted from the glass substrate GL to the grinding wheel 11a is absorbed by the elastic member 416.

(5) Outline description of the grinding step

Next, the outline of the polishing step will be described using FIG. Further, the polishing apparatus 10a operates the brake mechanism 14a in advance and waits for the glass substrate GL to be transported.

First, in step S101, it is judged by the sensor 16 whether or not the grinding wheel 11a has come into contact with the glass substrate GL. In the present embodiment, as shown in FIG. 10, the grinding wheel 11a is brought into contact with the end surface of the glass substrate GL such that the outer edge (peripheral portion) of the grinding wheel 11a is located inside the specific distance W from the end surface of the glass substrate GL. . That is, the grinding wheel 11a is disposed so as to protrude to the inner side of both end portions of the glass substrate. Here, the specific distance W is preferably a value in a range of more than 0 and less than 100 μmm. The specific distance W is preferably 50 μmm. By bringing the end surface of the glass substrate GL into contact with the rotating grinding wheel 11a, the front end portion TP of the glass substrate GL is polished while the brake mechanism 14a is actuated (first polishing step). The grinding wheel 11a is polished while following the end surface of the glass substrate within a range in which the elastic member 416 is deformable. In other words, the polishing wheel 11a is brought into contact with the front end portion TP (front end surface) of the glass substrate GL, and the peripheral portion is retracted from the glass substrate GL to the glass substrate GL as the glass substrate GL is transported in the downstream direction. Grinding.

If the sensor 16 detects the contact between the grinding wheel 11a and the glass substrate GL in step S101, the counting of the timer is started in step S102. Further, in step S103, the brake mechanism 14a is released. That is, the robot arm 12a is freely rotated in accordance with the inclination of the glass substrate GL with respect to the conveying device 80 (the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL). Then, the mechanical arm 12a is stabilized at a position where the external force F2 is intended to cause the mechanical arm 12a to rotate in the R2 direction and the force to be rotated by the external force F1 to rotate the mechanical arm 12a in the R1 direction. At the position, the grinding wheel 11a grinds the end surface of the glass substrate GL (second polishing step). The mechanical arm 12a is freely rotated by the inclination of the glass substrate GL, and the polishing wheel 11a is polished while following the end surface of the glass substrate.

Thereafter, in step S104, it is determined whether or not the time measured by the timer has reached a certain time. When the specific time is not reached, the standby time is reached until the specific time is reached, and if the specific time is reached, the process proceeds to step S105.

In step S105, the brake mechanism 14a is actuated. That is, the end surface of the glass substrate GL is polished in a state where the regulatory robot arm 12a is rotated (third polishing step). The grinding wheel 11a is polished while following the end surface of the glass substrate within a range in which the elastic member 416 is deformable.

(6) Detailed description of the grinding step

Next, the operation of the polishing apparatus 10a corresponding to the conveyance state of the glass substrate GL will be described with reference to FIGS. 11A to 16C. 11A to 11C, FIGS. 13A to 13C, and FIGS. 16A to 16C are views showing a plurality of examples of the conveyance state of the glass substrate GL. Specifically, the polishing apparatus 10a and 10b are configured such that the inclination of the glass substrate GL, the fluctuation of the width direction of the glass substrate GL, and the distance from the center of the polishing wheel 11a to the end surface of the glass substrate GL cause the robot arm The operation of 12a causes the grinding wheel 11a to follow the end surface of the glass substrate GL. Further, in the present embodiment, the polishing wheel 11a is configured to polish the end surface of the glass substrate GL with a certain range of pressure applied to the glass substrate GL.

In FIGS. 11A to 16C, an arrow D1 indicates a conveyance direction of the glass substrate GL. An arrow F1 indicates that an external force is applied from the constant pressure cylinder 16a, and an arrow F2 indicates an external force applied from the glass substrate GL. Further, the magnitudes of the arrow F1 and the arrow F2 indicate the magnitude of the external force. Further, in FIGS. 11A to 16D, FIGS. 11B, 12C, 13B, 14C, 15C, and 16B show a state in which the brake mechanism 14a is released, and the other figures show a state in which the brake mechanism 14a is being actuated.

(6-1) The distance from the center of the grinding wheel to the end face of the glass substrate is the proper distance

11A to 11C and Figs. 12A to 12D show the case where the distance from the center of the grinding wheel 11a to the glass substrate GL is an appropriate distance. The appropriate distance is the distance at which the sliding shaft 414 is at an appropriate position when the grinding wheel 11a comes into contact with the end surface of the glass substrate GL. In FIGS. 11A to 11C , a case where the glass substrate GL is disposed at the center of the transport device 80 will be described as an example. Here, the center line C1 of the glass substrate GL coincides with the center line C2 of the conveying device 80. That is, the distance L1 from the outer side of the conveyance belts 81 and 82 to the end surface of the glass substrate GL is the same on the downstream side, the upstream side, the left side, and the right side of the glass substrate GL.

Fig. 11A shows a state before the grinding wheel 11a comes into contact with the end surface of the glass substrate GL. Here, as shown in FIG. 12A, only the external force F1 is applied to the mechanical arm 12a. The robot arm 12a is intended to be rotated in the direction indicated by the arrow R1. Since the brake mechanism 14a is actuated, the mechanical arm 12a is not freely rotated, but the rotation of the elastic member 416 allows the rotation of the mechanical arm 12a (elastic member deformation step). Thereby, the robot arm 12a is slightly rotated in the direction of the arrow R1. At this time, the position of the slide shaft 414 is shifted from the appropriate position toward the M1 direction.

Thereafter, when the glass substrate GL is in contact with the grinding wheel 11a, an external force F2 is also applied to the arm 12a as shown in Fig. 12B. The robot arm 12a receives an external force F2 and is intended to rotate in a direction indicated by an arrow R2. Since the brake mechanism 14a is actuated, the mechanical arm 12a is not freely rotated, but the rotation of the elastic member 416 allows the rotation of the mechanical arm 12a (elastic member deformation step). Thereby, the robot arm 12a is slightly rotated in the direction of the arrow R2. At this time, the position of the slide shaft 414 is shifted in the M2 direction. Here, the mechanical arm 12a is slightly rotated in the direction of the arrow R2, and the sliding shaft 414 is returned to the proper position. When the grinding wheel 11a located at the position indicated by the solid line in FIG. 11A before the contact with the glass substrate GL is in contact with the front end portion TP of the glass substrate GL, it moves to the position indicated by the broken line. In this manner, the front end portion TP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (first polishing step).

Fig. 11B shows a state after the first polishing step and the front end portion TP of the glass substrate GL is located further downstream than the grinding wheels 11a and 11b. That is, FIG. 11B shows a state in which the central portion CP of the glass substrate GL is polished. When the polishing apparatuses 10a and 10b polish the central portion CP of the glass substrate GL, the brake mechanisms 14a and 14b are released. That is, the upper mechanism 41 is located away from the lower mechanism 42 and is located at the release position. In the release position, no external force F1, F2 is applied to the upper contact unit 412. As described above, since the distance from the center of the grinding wheel 11a to the glass substrate GL shown in Fig. 11B is an appropriate distance, the robot arm 12a is not rotated, and the mechanical arm 12a is intended to be oriented in the R1 direction by the external force F1. The force of the rotation is in a state of balancing the force by which the external force F2 is required to rotate the robot arm 12a in the R2 direction (refer to Fig. 12C). The grinding wheel 11a grinds the end surface of the glass substrate GL in a state in which the force to be rotated in the R1 direction is balanced with the force to be rotated in the R2 direction (second polishing step). That is, the polishing wheel 11a is polished while following the end surface of the glass substrate.

Fig. 11C shows the glass substrate GL before it leaves the grinding wheel 11a. In other words, the state in which the polishing of the central portion CP of the glass substrate GL is completed and the end portion EP of the glass substrate GL is polished is shown. As shown in Fig. 12D, an external force F1 and an external force F2 are applied to the mechanical arm 12a. This is a state in which the external force F1 is intended to cause the mechanical arm 12a to rotate in the R1 direction and the external force F2 to balance the force of the mechanical arm 12a in the R2 direction. That is, the sliding shaft 414 is in the proper position. Here, the brake mechanism 14a is actuated. The rear end portion EP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (third polishing step). Thereafter, when the glass substrate GL is separated from the grinding wheel 11a, only the external force F1 is applied to the arm 12a. Thereby, as shown in FIG. 12A, the mechanical arm 12a is intended to be rotated in the R1 direction by the external force F1, and the elastic member 416 is compressed (elastic member deformation step). Thereby, the slide shaft 414 is slightly offset from the proper position toward the M1 direction.

(6-2) The distance from the center of the grinding wheel to the end face of the glass substrate is not the proper distance

13A to 16C show the operation of the polishing apparatus 10a (and 10b) from the case where the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL is not an appropriate distance. 13A to 13C show a state in which the glass substrate GL is located on one side in the width direction of the deflection conveyance device 80, and FIGS. 16A to 16C show a state in which the glass substrate GL is inclined with respect to the conveyance device 80. In the following, the operation of the polishing apparatus 10a in the case where the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL is not an appropriate distance is divided into a position where the glass substrate GL is located on one side in the width direction of the deflection conveyance device 80, The case where the glass substrate GL is inclined with respect to the conveyance device 80 is demonstrated.

(6-2-1) The case where the glass substrate is biased to one side in the width direction of the conveying device

13A to 13C show that the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL is smaller than the proper distance (the grinding wheel 11a on the right side of the paper surface), and the distance from the center of the grinding wheel 11b to the end surface of the glass substrate GL is larger than The case of the proper distance (grinding wheel 11b on the left side of the paper). The distances L2 and L3 from the outer side of the conveyor belts 81 and 82 to the end faces of the glass substrate GL are the same on the upstream side and the downstream side of the glass substrate GL.

First, the case where the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL is smaller than the proper distance will be described using FIGS. 13A to 13C (the polishing apparatus 10a on the right side of the paper) and FIGS. 14A to 14D.

Fig. 13A shows a state before the grinding wheel 11a comes into contact with the end surface of the glass substrate GL. Here, as shown in Fig. 14A, only the force F1 from the constant pressure cylinder 16a is applied to the robot arm 12a. The robot arm 12a is intended to be rotated in the direction indicated by the arrow R1. Since the brake mechanism 14a is actuated, the mechanical arm 12a is not freely rotated, but the rotation of the elastic member 416 allows the rotation of the mechanical arm 12a (elastic member deformation step). Thereby, the robot arm 12a is slightly rotated in the direction of the arrow R1. At this time, the position of the slide shaft 414 is slightly shifted from the proper position toward the M1 direction.

Thereafter, when the glass substrate GL is in contact with the polishing wheel 11a, a force F2 from the glass substrate GL is also applied to the arm 12a (see FIG. 14B). Here, since the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL is smaller than the proper distance, the force F2 applied to the robot arm 12a becomes larger than the force F2 applied to the robot arm 12a in Fig. 12B. The robot arm 12a is subjected to an external force F2 and is to be largely rotated in a direction indicated by an arrow R2. Since the brake mechanism 14a is actuated, the mechanical arm 12a does not rotate freely, but the large deformation of the elastic member 416 allows the rotation of the mechanical arm 12a (elastic member deformation step). Thereby, the robot arm 12a is rotated in the direction of the arrow R2. At this time, the position of the slide shaft 414 is shifted from the appropriate position toward the M2 direction. Here, excessive deformation of the glass substrate GL is suppressed by the large deformation of the elastic member 416 (the excessive cut inhibiting step). When the grinding wheel 11a located at the position indicated by the solid line in FIG. 13A before the contact with the glass substrate GL is in contact with the front end portion TP of the glass substrate GL, it moves to the position indicated by the broken line. In this manner, the front end portion TP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (first polishing step).

Fig. 13B shows a state after the first polishing step and the front end portion TP of the glass substrate GL is located on the downstream side of the grinding wheel 11a. That is, FIG. 13B shows a state in which the central portion CP of the glass substrate GL is polished. When the polishing apparatus 10a polishes the central portion CP of the glass substrate GL, the brake mechanism 14a is released. That is, the upper mechanism 41 is located away from the lower mechanism 42 and is located at the release position. In the release position, no external force F1, F2 is applied to the upper contact unit 412. Thereby, the compressed elastic member 416 is restored to its original shape (recovery step). That is, as shown in FIG. 14C, the upper contact unit 412 is rotated such that the slide shaft 414 moves from the position of the solid line to the position of the broken line (appropriate position). On the other hand, the mechanical arm 12a directly receives the external force F1 and the external force F2 by releasing the brake mechanism 14a. Thereby, the robot arm 12a is rotated until the force to be rotated in the R1 direction is balanced with the force to be rotated in the R2 direction, and is from the center of the grinding wheel 11a to the glass substrate GL. The grinding wheel 11a is moved in such a manner that the distance of the end face becomes an appropriate distance. The grinding wheel 11a grinds the end surface of the glass substrate GL in a state where the force to be rotated in the R1 direction is balanced with the force to be rotated in the R2 direction (second polishing step).

Fig. 13C shows that the glass substrate GL is about to leave the grinding wheel 11a. In other words, the state in which the polishing of the central portion CP of the glass substrate GL is completed and the rear end portion of the glass substrate GL is polished is shown. As shown in Fig. 14D, an external force F1 and an external force F2 are applied to the mechanical arm 12a, and the force for which the force is to be swung in the R1 direction is balanced with the force for which the rotation is to be performed in the R2 direction. Here, the brake mechanism 14a is actuated. When the brake mechanism 14a is actuated, the force generated by the external force F1 and the external force F2 is balanced, so that the upper contact unit 412 is not affected by any external force F1, F2. Thus, the resilient member 416 remains prototyped such that the sliding shaft 414 stays in the center (appropriate position) of the resilient member 416. The rear end portion EP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (third polishing step). Thereafter, when the glass substrate GL is separated from the grinding wheel 11a, only the external force F1 is applied to the arm 12a. Therefore, as shown in Fig. 14A, the elastic member 416 is deformed, and the rotation of the arm 12a is allowed (the elastic member deforming step). Further, the slide shaft 414 is slightly shifted from the appropriate position toward the M1 direction as the robot arm 12a is rotated.

Next, the case where the distance from the center of the grinding wheels 11a and 11b to the end surface of the glass substrate GL is larger than the proper distance will be described using FIGS. 13A to 13C (the polishing apparatus 10b on the left side of the paper) and FIGS. 15A to 15D. Further, although the arrangement of the polishing apparatus 10a of FIGS. 15A to 15D is different from the arrangement of the polishing apparatus 10a of FIGS. 13A to 13C, the operation principle is the same.

As described above, FIG. 13A shows a state before the grinding wheel 11b is in contact with the end surface of the glass substrate GL. Here, as shown in Fig. 15A, only the force F1 from the constant pressure cylinder 16a is applied to the robot arm 12a. The robot arm 12a is intended to be rotated in the direction indicated by the arrow R1. Since the brake mechanism 14a is actuated, the mechanical arm 12a is not freely rotated, but the rotation of the elastic member 416 allows the rotation of the mechanical arm 12a (elastic member deformation step). Thereby, the robot arm 12a is slightly rotated in the direction of the arrow R1. At this time, the position of the slide shaft 414 is slightly shifted from the proper position toward the M1 direction.

Thereafter, when the glass substrate GL comes into contact with the grinding wheel 11a, an external force F2 is also applied to the arm 12a (see FIG. 15B). Here, since the distance from the center of the grinding wheel 11a to the end surface of the glass substrate GL is larger than the proper distance, the force F2 applied to the robot arm 12a becomes smaller than the force F2 applied to the robot arm 12a in Fig. 12B. The robot arm 12a is intended to be rotated slightly in the direction indicated by the arrow R2. Since the brake mechanism 14a is actuated, the robot arm 12a does not rotate freely, but the shape of the elastic member 416 is slightly restored, and the robot arm 12a is allowed to rotate at a level corresponding to the recovery (recovery step). Thereby, the robot arm 12a is rotated in the direction of the arrow R2. At this time, the position of the slide shaft 414 is shifted from the appropriate position toward the M2 direction. The grinding wheel 11a located at a position shown by the solid line in FIG. 13A before coming into contact with the end surface of the glass substrate GL is moved to a position indicated by a broken line after coming into contact with the glass substrate GL. In this manner, the front end portion TP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (first polishing step).

As described above, FIG. 13B shows a state in which the central portion CP of the glass substrate GL is polished. That is, FIG. 13B shows a state in which the front end portion TP of the glass substrate GL is located downstream of the grinding wheel 11b after the first polishing step. When the polishing apparatus 10b polishes the central portion CP of the glass substrate GL, the brake mechanism 14b is released. That is, the upper mechanism 41 is located away from the lower mechanism 42 and is located at the release position. In the release position, no external force F1, F2 is applied to the upper contact unit 412. Thereby, the compressed elastic member 416 is restored to its original shape (recovery step). That is, as shown in FIG. 15C, the upper contact unit 412 is rotated such that the slide shaft 414 is moved from the position of the solid line to the position of the broken line (appropriate position). On the other hand, by releasing the brake mechanism 14a, the robot arm 12a directly receives the force F1 from the constant pressure cylinder and the force F2 from the glass substrate GL. Thereby, the robot arm 12a is rotated until the force to be rotated in the R1 direction is balanced with the force to be rotated in the R2 direction, and is from the center of the grinding wheel 11a to the glass substrate GL. The grinding wheel 11a is moved in such a manner that the distance of the end face becomes an appropriate distance. The grinding wheel 11b grinds the end surface of the glass substrate GL in a state in which the force to be rotated in the R1 direction is balanced with the force to be rotated in the R2 direction (second polishing step).

As described above, Fig. 13C shows that the glass substrate GL is about to leave the grinding wheel 11b. In other words, the state in which the polishing of the central portion CP of the glass substrate GL is completed and the rear end portion of the glass substrate GL is polished is shown. As shown in Fig. 15D, an external force F1 and an external force F2 are applied to the mechanical arm 12a, and the force for which the force is to be swung in the R1 direction is balanced with the force for which the rotation is to be performed in the R2 direction. Here, the brake mechanism 14a is actuated. When the brake mechanism 14a is actuated, the force generated by the external force F1 and the external force F2 is balanced, so that the upper contact unit 412 is not affected by any external force F1, F2. Thus, the resilient member 416 remains prototyped such that the sliding shaft 414 stays in the center (appropriate position) of the resilient member 416. The rear end portion EP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (third polishing step). Thereafter, when the glass substrate GL is separated from the grinding wheel 11a, only the external force F1 is applied to the arm 12a. Therefore, as shown in Fig. 15A, the elastic member 416 is deformed, and the rotation of the arm 12a is allowed (the elastic member deforming step). Further, the slide shaft 414 is slightly shifted from the appropriate position toward the M1 direction as the arm is rotated.

(6-2-2) The case where the glass substrate is inclined with respect to the conveying device

16A to 16C show the distances L2, L3 from the outer side of the conveyor belts 81, 82 to the front end portion TP of the glass substrate GL, and the distances L3, L2 from the outer side of the self-propelled belts 81, 82 to the rear end portion EP of the glass substrate GL. Different situations. In other words, in terms of the relationship between the polishing apparatus 10a on the right side of the paper and the glass substrate GL, the distance from the center of the grinding wheel 11a to the front end portion TP of the glass substrate GL is smaller than the proper distance from the center of the grinding wheel 11a to the rear end of the glass substrate GL. The distance between some EPs is greater than the proper distance. Further, in terms of the relationship between the polishing apparatus 10b on the left side of the paper and the glass substrate GL, the distance from the center of the grinding wheel 11b to the front end portion TP of the glass substrate GL is larger than the proper distance from the center of the grinding wheel 11b to the rear end of the glass substrate GL. The distance of part EP is less than the proper distance.

In this case, as shown in FIGS. 14A to 14D, when the grinding wheel 11a comes into contact with the end surface of the glass substrate GL, the brake mechanism 14a is actuated, so that the arm 12a is not freely rotated. However, the rotation of the arm 12a is allowed by the deformation of the elastic member 416 (elastic member deformation step). When the robot arm 12a is rotated, the position of the slide shaft 414 in the insertion portion changes. Then, the front end portion TP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (first polishing step).

When the grinding wheel 11a comes into contact with the glass substrate GL, the brake mechanism 14a is immediately released. The robot arm 12a is rotated so that the force to be rotated in the R1 direction is balanced with the force to be rotated in the R2 direction, so that the grinding wheel 11a faces the glass substrate along the inclination of the glass substrate GL. The end face of GL is ground (second polishing step). At this time, in the release position, no external force F1, F2 is applied to the upper contact unit 412. Thereby, the elastic member 416 is restored to the original shape (recovery step).

When the polishing of the central portion CP of the glass substrate GL is completed, the brake mechanism 14a is actuated. The rear end portion EP of the glass substrate GL is ground by the grinding wheel 11a in a state where the brake mechanism 14a is actuated (third polishing step). In the third polishing step, the brake mechanism 14a is actuated without applying the external forces F1 and F2 to the elastic member 416. The elastic member 416 is deformed in accordance with the external force F1 or the external force F2 with respect to the inclination of the glass substrate GL after the brake mechanism 14a is actuated. Thereby, the grinding wheel 11a follows the end surface of the glass substrate GL within a range in which the elastic member 416 is deformable.

After the glass substrate GL is separated from the grinding wheel 11a, only the external force F1 from the constant pressure cylinder 16a is applied to the mechanical arm 12a, so that the elastic member 416 is deformed (elastic member deformation step), and the sliding shaft 414 is from the appropriate position to the M1 direction. Slightly offset.

(7) Features

(7-1)

In the method of manufacturing the glass substrate of the above embodiment, the end surface of the glass substrate GL can be preferably polished regardless of the state of the glass substrate GL to be conveyed.

In the polishing step of the glass substrate in the usual method for producing a glass substrate, the glass substrate continuously conveyed is polished by a transfer device. Here, as a polishing apparatus for polishing a glass substrate, a polishing apparatus of a load timing control type and a polishing apparatus of a standby control type are considered. In the load timing control type polishing apparatus, a load is applied to the polishing wheel in advance, and the polishing wheel is brought close to the glass substrate in accordance with the timing at which the glass substrate is conveyed to polish the end surface of the glass substrate. However, the load timing control type polishing apparatus is difficult to preferably polish the entire end surface of the glass substrate due to mechanical operation errors and response delays of electrical control (ie, the front end portion TP of the glass substrate, the central portion CP, and Backend section EP). In particular, in recent years, with the demand for mass production of glass substrates, the transport speed of the glass substrate by the transfer device has also been increasing. Due to the increase in the transport speed of the glass substrate, the front end portion TP of the glass substrate is particularly prone to omission polishing. Further, the standby control type polishing apparatus waits for the polishing wheel to stand by at a position in contact with the glass substrate to be conveyed, and polishes the end surface of the glass substrate that has been in contact with the polishing wheel. When the polishing apparatus of the standby control type is in a position where the grinding wheel is in a standby position (standby position), the polishing of the front end portion TP of the glass substrate can be prevented, but when the standby position of the grinding wheel is inappropriate, The corner portion of the glass substrate is in violent contact with the grinding wheel, and the glass substrate is broken and the grinding wheel is abnormally worn or an unpolished portion is generated. Further, in order to eliminate the above-described problem by the standby control type polishing apparatus, it is necessary to further improve the accuracy of the driving unit included in the polishing apparatus or the conveying accuracy of the conveying apparatus. Moreover, if a device with higher precision is to be used, the cost will become higher and it is not preferable.

However, in the method of manufacturing a glass substrate according to the above embodiment, the polishing apparatuses 10a and 10b used in the polishing step S4 include polishing wheels 11a and 11b that can follow the fluctuation in the width direction of the glass substrate GL. Here, the fluctuation of the width direction of the glass substrate GL is a change of the glass substrate GL in the direction which intersects the conveyance direction of the glass substrate GL. In other words, the glass substrate GL is transported in a state in which one side of the deflecting transport device 80 is transported, or the glass substrate GL is transported in a state of being inclined with respect to the transport device 80, and the self-polishing wheels 11a and 11b to the glass substrate GL are transported. When the distance between the end faces is changed, the entire end surface of the glass substrate GL including the tip end portion TP can be preferably polished.

(7-2)

In the polishing apparatuses 10a and 10b of the above-described embodiment, when the central portion CP of the glass substrate GL is polished, the brake mechanisms 14a and 14b are released, and the external force F1 from the constant pressure cylinder is applied to the grinding wheels 11a and 11b. The robot arms 12a, 12b are freely rotated, and the grinding wheels 11a, 11b follow the end faces of the glass substrate GL. When the polishing of the central portion is completed, the brake mechanisms 14a and 14b are actuated to wait for the glass substrate (subsequent glass substrate) GL to be conveyed next. Here, in the polishing apparatuses 10a and 10b in a state where the brake mechanisms 14a and 14b are actuated, the grinding wheels 11a and 11b are disposed at positions where the end faces of the subsequent glass substrates GL are suitable for polishing.

In general, as in the case of the transport device 80 used in the above-described embodiment, when the transport device 80 includes a transport belt, bending or the like caused by deterioration of the transport belt may occur. In this case, the position at which the glass substrate GL is transported may be shifted at a certain period. However, the polishing apparatuses 10a and 10b used in the above embodiment determine the position of the end surface of the glass substrate GL suitable for polishing based on the polishing state of the preceding glass substrate GL. That is, the preferred polishing position of the subsequent glass substrate GL is estimated based on the position where the polishing of the end face of the preceding glass substrate GL has been completed. Thereby, the end surface of the glass substrate GL can be appropriately polished regardless of the deterioration or abnormality of the conveyance.

(7-3)

Further, in the polishing apparatuses 10a and 10b of the above embodiment, the elastic members 416 are accommodated in the insertion portions 413a to 413c. In the upper contact unit 412, a slide shaft 414 is inserted inside the elastic member 416 accommodated in the insertion portions 413a to 413c. When the preferred polishing position of the subsequent glass substrate GL inferred by the polishing apparatus 10a, 10b is slightly offset, the polishing wheel 11a, 11b is appropriately combined with the glass substrate by deforming the elastic member 416. The end faces of the GL are in contact with each other to cause the robot arms 12a, 12b to rotate. Thereby, even when the position where the subsequent glass substrate GL is conveyed is different from the estimated polishing position, the positions of the grinding wheels 11a and 11b can be finely adjusted. Thereby, the polishing of the front end portion TP of the glass substrate GL can be surely performed.

Further, even when the position where the grinding wheels 11a and 11b are in standby is too close to the end surface of the glass substrate GL, the elastic member 416 absorbs the impact caused by the contact between the glass substrate GL and the grinding wheels 11a and 11b. The glass substrate GL is prevented from being damaged and the abrasive wheels 11a and 11b are abnormally worn.

(7-4)

In the above-described embodiment, during the operation of the brake mechanisms 14a and 14b, as described above, the elastic member 416 is deformed in accordance with the conveyance state of the glass substrate GL, and the rotation of the robot arms 12a and 12b is allowed. The elastic member 416 is deformed by being compressed by the sliding shaft 414. Further, in the above-described embodiment, the brake mechanisms 14a and 14b are released while the central portion CP of the glass substrate GL is being polished, and the shape of the elastic member 416 is restored while the brake mechanisms 14a and 14b are being released. Therefore, the brake mechanisms 14a and 14b are thereafter operated to polish the rear end portion EP of the preceding glass substrate GL, and further, the elastic member 416 can be largely deformed when the subsequent polishing of the glass substrate GL is started. In other words, when the grinding wheel 11a comes into contact with the subsequent glass substrate GL, the elastic member 416 is in a state of being most compressed by the external force F1. At this time, the elastic member 416 is in a state in which the external force F2 can be most flexibly handled (the state in which the range in which the mechanical arms 12a and 12b can be rotated is the largest). Therefore, it is possible to flexibly cope with the case where the subsequent glass substrate GL is transported at a position different from the inferred better polishing position.

(7-5)

In the polishing apparatuses 10a and 10b of the above embodiment, the robot arms 12a and 12b are rotated such that the distance from the center of the grinding wheels 11a and 11b to the end surface of the glass substrate GL is maintained at an appropriate distance. Thereby, not only when the glass substrate GL is inclined with respect to the conveying device 80 but also when the glass substrate GL is biased to one side in the width direction of the conveying device 80, and the grinding wheels 11a and 11b are worn by the grinding wheels 11a and 11b, the grinding wheels 11a and 11b are worn. When the diameter is changed, the end surface of the glass substrate GL can be preferably polished.

(7-6)

In the above embodiment, the glass substrate GL is mass-produced, and the glass substrate GL is conveyed at a relatively high speed. Specifically, the transport speed of the glass substrate GL is 5 m/s to 15 m/s (preferably 10 m/s to 15 m/s). When the glass substrate GL is in contact with the grinding wheels 11a and 11b at a speed of 5 m/s to 15 m/s (preferably 10 m/s to 15 m/s), the positions where the grinding wheels 11a and 11b stand by are not appropriate. In the case of the case, the glass substrate GL is liable to be damaged. Further, in the case of producing a glass substrate having a very small thickness as in the case of the glass substrate GL manufactured in the above embodiment, the glass substrate GL is more likely to be damaged.

However, in the above embodiment, while the glass substrate GL is being polished, the robot arms 12a and 12b are freely rotated, and the polishing wheels 11a and 11b are moved to a position suitable for the state of the subsequent glass substrate GL. Further, since the polishing apparatuses 10a and 10b include the elastic member 416, the elastic member 416 is compressed when the estimated conveyance state of the subsequent glass substrate GL is different from the conveyance state of the subsequent glass substrate GL which is actually conveyed. The rotation of the robot arms 12a, 12b is allowed.

As a result, in the method for producing a glass substrate of the above-described embodiment, even when a very thin glass substrate is produced in a large amount, the damage of the glass substrate to be polished can be reduced, and the productivity of the glass substrate GL can be improved.

(8) Modifications

(8-1) Modification A

In the above embodiment, the brake mechanisms 14a and 14b are actuated before the glass substrate GL is to be separated from the grinding wheels 11a and 11b. However, the brake mechanisms 14a and 14b may be moved in the middle of the central portion of the glass substrate GL.

(8-2) Modification B

In the above embodiment, the conveying device 80 including the suction type conveying belts 81 and 82 is used as the mechanism for conveying the glass substrate GL. However, the conveying device 80 may have another configuration. For example, the conveying device 80 may include a belt that sandwiches the front surface and the back surface of the glass substrate GL on both sides in the width direction of the glass substrate GL. Further, the conveying device 80 may be a table that transports the glass substrate GL and transports it.

(8-3) Modification C

In the above-described embodiment, the polishing wheel 11a is brought into contact with the end surface of the glass substrate GL such that the outer edge of the polishing wheel 11a is located inside the specific distance W from the end surface of the glass substrate GL. Here, the specific distance W is based on the degree of elasticity of the elastic member 416, the size of the diameter of the insertion portion, the ratio of the elastic member 416 in the insertion portion, the range of rotation of the arm, and the conveyance accuracy of the conveying device 80. The decision is not limited to the distance described in the above embodiment.

Further, in the above embodiment, it has been described that the elastic member 416 preferably has a certain amount of rotation allowing the arm 12a, and the sliding shaft 414 and the sliding bearing 415 are shifted by 0.2 mm from the center line C3 to the left and right. The elasticity is considered to be changed according to the type of the glass substrate GL (the composition of the glass substrate GL). However, the degree of elasticity of the elastic member may be considered in consideration of the conveyance precision or polishing of the glass substrate GL by the transfer device 80. The degree of wear of the wheel 11a is determined. Further, the degree of elasticity of the elastic member may be changed depending on the transport speed of the glass substrate GL or the thickness of the glass substrate GL.

In the above embodiment, the polishing wheel 11a can polish the end surface of the glass substrate GL with a certain range of pressure applied to the glass substrate GL regardless of the state of the glass substrate GL. Therefore, in the configuration of the above-described brake mechanisms 14a and 14b, the pressure is not limited to the value exemplified in the above embodiment as long as it is designed to apply a certain range of pressure when it comes into contact with the glass substrate GL.

(8-4) Modification D

In the above embodiment, the fixed brake pad 417 is partially attached to the lower surface of the upper contact unit 412, and the rotary brake pad 422 is partially attached to the upper surface of the lower contact unit 421, but the fixed brake pad 417 can also be mounted. On the entire lower surface of the upper contact unit 412, the rotary brake pad 422 may also be mounted on the entire upper surface of the lower contact unit 421.

10a. . . Grinding device

10b. . . Grinding device

11a. . . Grinding wheel

11b. . . Grinding wheel

12a. . . Robotic arm

12b. . . Robotic arm

13a. . . Substrate

13b. . . Substrate

14a. . . Brake mechanism

14b. . . Brake mechanism

15a. . . Stop

16a. . . Constant pressure cylinder

16b. . . Constant pressure cylinder

17a. . . motor

41. . . Upper mechanism

42. . . Lower mechanism

120a. . . Robot arm rotation axis

411. . . Brake cylinder

411a. . . board

411b. . . Screw

411c. . . Push rod

412. . . Upper contact unit

413a. . . Insertion

413b. . . Insertion

413c. . . Insertion

414. . . Sliding shaft

415. . . Sliding bearing

416. . . Elastic member

417. . . Fixed brake pad

421. . . Lower contact unit

422. . . Rotary brake pad

H1. . . Through hole

Fig. 1 is a schematic view showing a procedure included in a method of manufacturing a glass substrate.

Fig. 2 is a view showing the arrangement of the conveying device and the grinding wheel and the grinding wheel used in the embodiment with respect to the glass substrate.

Fig. 3 is a view showing an end surface (a front end portion, a central portion, and a rear end portion) of the glass substrate.

4A is a schematic plan view of a polishing apparatus.

Fig. 4B is a schematic side view of the polishing apparatus.

Fig. 5 is a view showing a grinding wheel and a brake mechanism attached to a robot arm.

Figure 6 is a diagram showing a control block.

Fig. 7A is a view showing a change in the position of the slide shaft corresponding to the rotation of the robot arm.

Fig. 7B is a view showing a change in the position of the slide shaft corresponding to the rotation of the robot arm.

Fig. 8A is a view showing the proper position of the slide shaft.

Fig. 8B is a view showing a state in which the slide shaft is displaced from the proper position.

Fig. 8C is a view showing a state in which the slide shaft is shifted from the proper position.

Fig. 9 is a flow chart showing the operation of the polishing apparatus in the polishing step.

Fig. 10 is a view showing the positional relationship between the grinding wheel and the glass substrate.

Fig. 11A is a view showing an example in which the grinding wheel and the glass substrate are at an appropriate distance (before the grinding wheel comes into contact with the glass substrate) when the grinding wheel is in contact with the glass substrate.

Fig. 11B is a view showing a state in which the grinding wheel rotates the central portion of the glass substrate after the state shown in Fig. 11A.

Fig. 11C is a view showing a state after the state shown in Fig. 11B and the grinding wheel grinds the rear end portion of the glass substrate.

Fig. 12A is a view showing the state of the external force and the sliding shaft in Fig. 11A.

Fig. 12B is a view showing the state of the external force and the sliding axis after the state shown in Fig. 12A and the grinding wheel is in contact with the glass substrate (when the front end portion of the glass substrate is polished).

Fig. 12C is a view showing the state of the external force and the sliding axis in Fig. 11B.

Fig. 12D is a view showing the state of the external force and the sliding axis in Fig. 11C.

Fig. 13A is a view showing an example in which the grinding wheel and the glass substrate are not at an appropriate distance (before the grinding wheel comes into contact with the glass substrate) when the grinding wheel is in contact with the glass substrate.

Fig. 13B is a view showing a state in which the grinding wheel rotates the central portion of the glass substrate after the state shown in Fig. 13A.

Fig. 13C is a view showing a state after the state shown in Fig. 13B and the grinding wheel grinds the rear end portion of the glass substrate.

Fig. 14A is a view showing the state of the external force and the sliding axis in Fig. 13A (when the distance between the grinding wheel and the glass substrate is relatively close).

Fig. 14B is a view showing the state of the external force and the sliding axis after the state shown in Fig. 14A and the grinding wheel is in contact with the glass substrate (when the front end portion of the glass substrate is polished).

Fig. 14C is a view showing the state of the external force and the sliding axis in Fig. 13B.

Fig. 14D is a view showing the state of the external force and the sliding axis in Fig. 13C.

Fig. 15A is a view showing the state of the external force and the sliding axis in Fig. 13A (when the distance between the grinding wheel and the glass substrate is far).

Fig. 15B is a view showing the state of the external force and the sliding axis after the state shown in Fig. 15A and the grinding wheel is in contact with the glass substrate (when the front end portion of the glass substrate is polished).

Fig. 15C is a view showing the state of the external force and the sliding axis in Fig. 13B.

Fig. 15D is a view showing the state of the external force and the sliding axis in Fig. 13C.

Fig. 16A is a view showing another example in which the grinding wheel and the glass substrate are not at an appropriate distance (before the grinding wheel comes into contact with the glass substrate) when the grinding wheel is in contact with the glass substrate.

Fig. 16B is a view showing a state in which the grinding wheel rotates the central portion of the glass substrate after the state shown in Fig. 16A.

Fig. 16C is a view showing a state after the state shown in Fig. 16B and the grinding wheel grinds the rear end portion of the glass substrate.

11a. . . Grinding wheel

12a. . . Robotic arm

14a. . . Brake mechanism

41. . . Upper mechanism

42. . . Lower mechanism

120a. . . Robot arm rotation axis

411. . . Brake cylinder

411a. . . board

411b. . . Screw

411c. . . Push rod

412. . . Upper contact unit

413a. . . Insertion

413b. . . Insertion

413c. . . Insertion

414. . . Sliding shaft

415. . . Sliding bearing

416. . . Elastic member

417. . . Fixed brake pad

421. . . Lower contact unit

422. . . Rotary brake pad

H1. . . Through hole

Claims (7)

A method for producing a glass substrate, comprising: a polishing step of polishing both end faces of the glass substrate to be conveyed, wherein the polishing of the both end faces is performed by grinding the grindstone by means of a spinning machine The arm is held, and the mechanical arm is rotated by applying a first force to the mechanical arm in the direction of the glass substrate, and is maintained to be in contact with the both end faces with respect to the width direction of the glass substrate; In the case where the polishing stone is carried in and out of the glass substrate in the polishing step, the brake mechanism is used to apply the second force to the arm by regulating the rotation of the arm. The front end portion and the rear end portion of the above glass substrate. The manufacturing method of claim 1, wherein the second arm is applied to the robot arm by the brake mechanism during the polishing step from the time when the glass substrate is unloaded to the subsequent movement of the glass substrate. The manufacturing method according to claim 1 or 2, wherein in the polishing step, during the loading and unloading of the glass substrate, the rotation of the elastic member allows the rotation of the robot arm regulated by the second force. The manufacturing method of claim 3, wherein the elastic member absorbs an impact caused by contact between the glass substrate and the polishing stone while the second arm is applied to the mechanical arm by the brake mechanism. The manufacturing method of claim 1 or 2, wherein the pair of abrasive grindstones are attached to In the polishing step of the glass substrate, during the loading and the unloading, the glass substrate is protruded further inside than the both ends of the glass substrate, and the peripheral edge portion of the polishing stone is brought into contact with the front end portion of the glass substrate. The glass substrate is conveyed so that the peripheral portion is retracted and the glass substrate is polished. The manufacturing method of claim 1 or 2, wherein the brake mechanism includes a vertical movement upper mechanism and a lower mechanical mechanism; and the mechanical mechanism is provided when the upper mechanism is in contact with the lower mechanism The second force does not apply the second force to the robot arm when the upper mechanism is located away from the lower mechanism. A glass substrate manufacturing apparatus for polishing both end faces of a glass substrate to be conveyed, comprising: a rotatable robot arm; and holding and polishing one of the both end faces to the grinding grindstone by the mechanical arm And a pair of grinding stones; the pair of grinding stones are rotated by a first force applied to the arm in the direction of the glass substrate, and the arm is rotated to maintain a change with respect to a width direction of the glass substrate And the pair of polishing stones are in a state in which the second force is applied to the robot arm by the brake mechanism during the loading and unloading of the glass substrate by the brake mechanism Next, the front end portion and the rear end portion of the glass substrate are ground.