JP2016182647A - Manufacturing method of glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a glass substrate which can process an end surface of the glass substrate uniformly even when rigidity of the glass substrate is low.SOLUTION: A manufacturing method of a glass substrate includes a grinding process. In the grinding process, the glass substrate and grinding means are relatively moved along a longitudinal direction of an end surface while contacting the end surface of the glass substrate and the grinding means with each other to grind the end surface. The grinding process includes a floating process and a conveying process. In the floating process, a fluid is sprayed on a main surface of the glass substrate to float the glass substrate. In the conveying process, the glass substrate is conveyed by providing propulsion force parallel to the main surface to the glass substrate while grinding the end surface in a state that the end surface of the glass substrate floated by the floating process is in contact with the grinding means. In the conveying process, the propulsion force is adjusted so that grinding resistance, as force which the grinding means receives from the end surface, becomes constant.SELECTED DRAWING: Figure 2

Description

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

  In the manufacturing process of glass substrates used in flat panel displays (FPD) such as liquid crystal displays and plasma displays, the glass substrate is cut to a predetermined size, and then the cut surface of the glass substrate is ground to chamfer the corners of the cut surface. Grinding is performed. On the cut surface of the glass substrate, minute irregularities and cracks that can cause defects in the glass substrate are easily formed. By chamfering the corners of the end surface, which is the cut surface of the glass substrate, and then polishing the chamfered end surface, the occurrence of minute irregularities and cracks is suppressed.

  Conventionally, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2002-160147), a grinding wheel, which is a disc-shaped grindstone having grooves formed on the side peripheral surface, is used for grinding a glass substrate. Yes. In this method, the corner of the end surface of the glass substrate is chamfered by pressing the surface of the groove of the rotating grinding wheel against the end surface of the glass substrate conveyed in a predetermined direction.

  However, in this grinding process, since the grinding wheel is pressed against the end surface of the glass substrate being conveyed, the glass substrate receives force from the grinding wheel. Therefore, the glass substrate is required to have such a rigidity that it can sufficiently counter the processing resistance that is a force received from the grinding wheel. In recent years, the glass substrate has been made thinner, and it has become necessary to grind a glass substrate having a rigidity lower than that of a conventional glass substrate. Since the glass substrate is thinner as the glass substrate is thinner, the glass substrate may be damaged during processing due to processing resistance received from the grinding wheel.

  Further, in the grinding process using the grinding wheel, the processing resistance is reduced by moving the glass substrate in the pressing direction of the grinding wheel, and the end surface of the glass substrate may not be ground uniformly. Therefore, a method of grinding the end face so that the processing amount and quality of the end face of the glass substrate is uniform by controlling the processing resistance electrically and mechanically and adjusting the force with which the grinding wheel presses the glass substrate is used. It has been. However, this method can adjust the pressing force of the grinding wheel to be constant, but the force acting on the glass substrate cannot be made constant, and a glass substrate with low rigidity is being processed by processing resistance. It cannot be prevented from being damaged. In this method, high accuracy is required for position control and processing resistance control of the glass substrate and the grinding wheel, which may increase the processing cost.

  The objective of this invention is providing the manufacturing method of the glass substrate which can process the end surface of a glass substrate uniformly even when the rigidity of a glass substrate is low.

  The manufacturing method of the glass substrate which concerns on this invention includes a grinding process. In the grinding step, the end surface of the glass substrate and the grinding means are brought into contact with each other and the end surface is ground by relatively moving the glass substrate and the grinding means along the longitudinal direction of the end surface. The grinding process includes a levitation process and a transport process. In the levitation step, the glass substrate is levitated by spraying a fluid onto the main surface of the glass substrate. In the conveying process, the glass substrate that has been lifted by the floating process is applied with a propulsive force in a first direction parallel to the main surface while the end surface is being ground while the end surface is in contact with the grinding means. Transport the substrate. In the conveying step, the propulsive force is adjusted so that the grinding resistance, which is the force received by the grinding means from the end face, is constant.

  Moreover, it is preferable that a conveyance process gives a thrust to a glass substrate non-contactingly.

  Moreover, it is preferable that a grinding process grinds one of a pair of end surfaces which a glass substrate opposes first, and then grinds the other of a pair of end surface.

  Moreover, it is preferable that a grinding process grinds a pair of end surface which a glass substrate opposes simultaneously.

  Moreover, it is preferable that a grinding means rotates centering around a rotating shaft with an electric motor. In this case, it is preferable that the conveying step acquires the grinding resistance based on the load current value of the electric motor due to the contact between the rotating grinding means and the end surface.

  Moreover, it is preferable that the grinding means has a cylindrical shape and is installed so that an angle between the rotation axis connecting the centers of the pair of cylindrical bottom surfaces and the first direction is an acute angle.

  Moreover, it is preferable that the manufacturing method of a glass substrate is further equipped with the test | inspection process which optically test | inspects the glass substrate by which the end surface was ground by the conveyance process. In this case, the transporting process adjusts the driving force based on the result of the inspection of the glass substrate in the inspection process.

  The glass substrate preferably has a thickness of 0.3 mm or less.

  The method for manufacturing a substrate made of a brittle material according to the present invention includes a processing step. In the processing step, the end face is processed by relatively moving the substrate and the processing means along the longitudinal direction of the end face while contacting the end face of the substrate made of a brittle material and the processing means. The processing step includes a transporting step of transporting the substrate by applying a driving force parallel to the main surface of the substrate to the substrate while processing the end face. In the conveying process, the propulsive force is adjusted so that the machining resistance, which is the force received by the machining means from the end face, is constant.

  The method for producing a glass substrate according to the present invention can uniformly process the end surface of the glass substrate even when the rigidity of the glass substrate is low.

It is the schematic of the glass substrate end surface processing apparatus which concerns on embodiment. It is a top view of a glass substrate end surface processing apparatus. It is a side view of a glass substrate end surface processing apparatus. It is a top view of a float bearing. It is a top view of a slide bearing. It is a top view of the 1st grinding wheel which grinds the 1st end face. It is a side view of the 1st grinding wheel which grinds the 1st end face. It is a top view of the glass substrate end surface processing apparatus in the modification A. It is a side view of the glass substrate end surface processing apparatus in the modification A. It is a top view of the float bearing in the modification C.

(1) Configuration of Glass Substrate End Surface Processing Apparatus An embodiment of a glass substrate manufacturing method according to the present invention will be described with reference to the drawings. The glass substrate manufacturing method according to the present embodiment uses a glass substrate end face processing apparatus that processes the end face of the glass substrate. FIG. 1 is a schematic view of a glass substrate end face processing apparatus 1. The glass substrate end surface processing apparatus 1 grinds the end surfaces 3a and 3d of the glass substrate 3 while transporting the glass substrate 3 in a floated state. The end faces 3a and 3d are a pair of end faces facing each other. Hereinafter, if necessary, one end surface 3a is referred to as a first end surface 3a, and the other end surface 3d is referred to as a second end surface 3d.

  The glass substrate 3 processed by the glass substrate end surface processing apparatus 1 is obtained by cutting a glass ribbon formed from molten glass into a predetermined dimension by a float method, a down draw method, or the like. The glass substrate end surface processing apparatus 1 is particularly suitable for processing the end surfaces 3a and 3d of the thin glass substrate 3 having a thickness of 0.3 mm or less. The glass substrate 3 processed by the glass substrate end surface processing apparatus 1 is further subjected to end surface processing by polishing or the like as necessary, and is shipped as a product through a cleaning process and an inspection process.

  As FIG. 1 shows, the glass substrate end surface processing apparatus 1 is mainly provided with the conveyance mechanism 10, the grinding mechanism 20, and the control part (not shown). The transport mechanism 10 transports the glass substrate in a predetermined transport direction with the glass substrate 3 floating. The transport direction is the longitudinal direction of the end faces 3a and 3d. The glass substrates 3 are supplied one by one to the transport mechanism 10 by a belt conveyor or the like.

  The grinding mechanism 20 first grinds the first end surface 3a and then grinds the second end surface 3d. The corners of the end surfaces 3 a and 3 d of the glass substrate 3 are chamfered by the grinding mechanism 20. The grinding mechanism 20 has a pair of grinding wheels 21a and 21d installed so as to face the end faces 3a and 3d, respectively. Hereinafter, if necessary, one grinding wheel 21a is referred to as a first grinding wheel 21a, and the other grinding wheel 21d is referred to as a second grinding wheel 21d. The first grinding wheel 21 a grinds the first end surface 3 a of the glass substrate 3 being conveyed by the conveyance mechanism 10. The second grinding wheel 21d grinds the second end surface 3d of the glass substrate 3 being conveyed by the conveyance mechanism 10. In a state where the grinding wheels 21a and 21d are in contact with the end surfaces 3a and 3d, the end surfaces 3a and 3d are ground by transporting the glass substrate 3 along the transport direction. In FIG. 1, the direction in which the grinding wheels 21a and 21d rotate and the direction in which the glass substrate 3 moves are indicated by arrows.

  In the following description, the glass substrate end surface processing apparatus 1 uses the grinding wheels 21a and 21d to process and chamfer the corners below the end surfaces 3a and 3d into an R shape. However, the glass substrate end surface processing apparatus 1 can chamfer by further processing the corners above the end surfaces 3a and 3d into an R shape or a C shape using the grinding wheels 21a and 21d in the same manner. Next, the configuration and operation details of the transport mechanism 10 and the grinding mechanism 20 will be described.

(1-1) Transport Mechanism The transport mechanism 10 mainly includes a plurality of float bearings 22 and a plurality of slide bearings 24. FIG. 2 is a top view of the glass substrate end surface processing apparatus 1. FIG. 3 is a side view of the glass substrate end surface processing apparatus 1. In FIG. 2, the conveyance direction of the glass substrate 3 is indicated by an arrow. FIG. 3 is a diagram viewed along the conveyance direction of the glass substrate 3.

  As shown in FIGS. 2 and 3, the float bearing 22 and the slide bearing 24 are installed below the glass substrate 3. The glass substrate 3 has an upper surface 3b that is a main surface on the upper side in the vertical direction and a lower surface 3c that is a main surface on the lower side in the vertical direction. The upper surface 3b and the lower surface 3c are surfaces parallel to the horizontal plane. The end surfaces 3a and 3d are surfaces that connect the upper surface 3b and the lower surface 3c. In the following description, the “width direction” means a direction parallel to the upper surface 3b and the lower surface 3c of the glass substrate 3 and orthogonal to the transport direction. In the drawing, the conveyance direction is indicated by “y-axis”, the width direction is indicated by “x-axis”, and the vertical direction is indicated by “z-axis”. The first end surface 3a is an end surface on the left side in the transport direction.

  The float bearing 22 sprays a fluid onto the lower surface 3 c of the glass substrate 3 to float the glass substrate 3. The glass substrate 3 processed by the glass substrate end surface processing apparatus 1 is not in contact with anything other than the grinding wheels 21a and 21d by the float bearing 22. The vertical position of the float bearing 22 can be adjusted by a float bearing position adjusting mechanism (not shown). The position of the float bearing 22 in the vertical direction is adjusted in advance before using the glass substrate end surface processing apparatus 1.

  The float bearing 22 has a panel surface 22a facing the lower surface 3c of the glass substrate 3, a plurality of fluid ejection holes 22b formed in the panel surface 22a, and a plurality of fluid suction holes 22c formed in the panel surface 22a. . The fluid ejection hole 22b ejects air toward the lower surface 3c facing the panel surface 22a. The fluid suction hole 22c sucks air from the space between the panel surface 22a and the lower surface 3c.

  The fluid ejection hole 22b has a function of applying an upward force to the glass substrate 3 in the vertical direction. The fluid suction hole 22c has a function of applying a downward force in the vertical direction to the glass substrate 3. The fluid ejection holes 22b and the fluid suction holes 22c act on the glass substrate 3 in the vertical direction to stabilize the vertical position of the glass substrate 3 and the shape of the glass substrate 3. Further, the float bearing 22 can adjust the vertical position of the glass substrate 3 by controlling the flow rate of the air ejected from the fluid ejection hole 22b and the air sucked into the fluid suction hole 22c. . The adjustable range of the position of the end surface 3a in the vertical direction is a maximum of 30 μm. The smaller the distance between the lower surface 3c of the glass substrate 3 and the panel surface 22a, the stronger the force that supports the glass substrate 3. When the glass substrate 3 is levitated by the float bearing 22, the distance between the lower surface 3c and the panel surface 22a is, for example, 5 μm to 40 μm, preferably 10 μm to 30 μm, more preferably 15 μm to 30 μm. is there.

  FIG. 4 is a top view of the float bearing 22. The float bearing 22 is formed from a porous body. The material of the porous body is a material having high durability against high-temperature and high-pressure liquids and gases such as ceramics, carbon and aluminum. The fluid ejection holes 22b are pores of a porous body formed on the panel surface 22a, and are indicated by dots in FIG. The fluid suction hole 22c is a hole formed in the panel surface 22a using a drill or the like, and is indicated by a white circle in FIG. The diameter of the fluid suction hole 22c is larger than the diameter of the pore of the porous body, and is 0.3 mm to 1.0 mm. The fluid ejection hole 22b is formed on the entire panel surface 22a. The fluid suction holes 22c are formed at a plurality of positions in the width direction and the transport direction. In other words, the fluid ejection holes 22b and the fluid suction holes 22c are arranged so as to expand in both the width direction and the transport direction.

  In FIG. 4, the fluid suction holes 22c are formed at lattice point positions on the panel surface 22a. The distance d1 between the fluid suction holes 22c in the width direction and the distance d2 between the fluid suction holes 22c in the transport direction are appropriately set according to the thickness of the glass substrate 3 and the like. For example, when the thickness of the glass substrate 3 is 0.5 mm, the intervals d1 and d2 may be set to 18 mm, and when the thickness of the glass substrate 3 is 0.25 mm, the intervals d1 and d2 may be set to 4 mm. .

  The slide bearing 24 conveys the glass substrate by applying a propulsive force in a predetermined direction to the glass substrate 3 levitated by the float bearing 22 in a non-contact manner. The vertical position of the slide bearing 24 can be adjusted by a slide bearing position adjusting mechanism (not shown). The vertical position of the slide bearing 24 is adjusted in advance before using the glass substrate end surface processing apparatus 1.

  FIG. 5 is a top view of the slide bearing 24. The slide bearing 24 has a panel surface 24a facing the lower surface 3c of the glass substrate 3, a plurality of fluid ejection holes 24b, a plurality of fluid suction holes 24c, and a plurality of fluid grooves 24d. The fluid ejection holes 24b, the fluid suction holes 24c, and the fluid grooves 24d are formed on the panel surface 24a. The number of fluid ejection holes 24b is the same as the number of fluid suction holes 24c and the number of fluid grooves 24d. The fluid ejection holes 24b and the fluid suction holes 24c are holes formed in the panel surface 24a using a drill or the like. In FIG. 5, the fluid ejection holes 24b are indicated by white circles, and the fluid suction holes 24c are indicated by black circles. The diameters of the fluid ejection holes 24b and the fluid suction holes 24c are 0.3 mm to 1.0 mm. The fluid groove 24d is a groove that connects the fluid ejection hole 24b and the fluid suction hole 24c. The depth of the fluid groove 24d is 1.0 mm to 2.0 mm.

  The fluid ejection hole 24b of the slide bearing 24 ejects air. The air ejected from the fluid ejection hole 24b flows through the fluid groove 24d and is sucked into the fluid suction hole 24c. The slide bearing 24 applies a propulsive force in a predetermined direction to the floating glass substrate 3 in a non-contact manner by the air flowing through the fluid groove 24d. In FIG. 5, the direction of the propulsive force that the slide bearing 24 applies to the glass substrate 3 is indicated by a white arrow. For example, when the fluid groove 24d is formed along the transport direction, the floating glass substrate 3 receives a propulsive force in the transport direction. In addition, when the fluid groove 24d is formed along the width direction, the floating glass substrate 3 receives a propulsive force in the width direction. As shown in FIG. 3, in the glass substrate end surface processing apparatus 1, the transport mechanism 10 includes a slide bearing 24 that applies a driving force in the transport direction (y-axis direction) to the glass substrate 3, and a width direction (x-axis direction). The slide bearing 24 is provided to apply the propulsive force to the glass substrate 3. 2 and 3, the direction of the propulsive force that each slide bearing 24 applies to the glass substrate 3 is indicated by a white arrow. The slide bearing 24 conveys the glass substrate 3 along the conveyance direction by giving the glass substrate 3 a propulsive force in the conveyance direction, and gives the glass substrate 3 a propulsive force in the width direction, as will be described later. The force that the grinding wheels 21a and 21d receive from the glass substrate 3 is adjusted.

  As shown in FIG. 2, the float bearing 22 and the slide bearing 24 are each installed along the transport direction. The slide bearing 24 is adjacent to the float bearing 22 in the width direction. The slide bearings 24 that apply a propulsive force in the transport direction to the glass substrate 3 and the slide bearings 24 that apply a propulsive force in the width direction to the glass substrate 3 are alternately arranged in the transport direction. A float bearing 22 is installed on the side where the end faces 3a and 3d to be ground by the grinding wheels 21a and 21d are located in the width direction.

(1-2) Grinding mechanism The grinding mechanism 20 mainly includes a first grinding wheel 21a and a second grinding wheel 21d. FIG. 6 is a top view of the first grinding wheel 21 a that grinds the first end surface 3 a of the glass substrate 3. FIG. 7 is a side view of the first grinding wheel 21a for grinding the first end surface 3a of the glass substrate 3. As shown in FIG. FIG. 7 is a view seen along the width direction (x-axis direction) of the glass substrate 3. 6 and 7 show a portion in the vicinity of the first end face 3a of the glass substrate 3, and the moving direction of the glass substrate 3 is indicated by an arrow. In addition, the 2nd grinding wheel 21d which grinds the 2nd end surface 3d of the glass substrate 3 has the same structure and operation | movement as the 1st grinding wheel 21a demonstrated below.

  The first grinding wheel 21a is a cylindrical grindstone. The first grinding wheel 21a has a circular upper surface 31a, a circular lower surface 31b, and a side peripheral surface 31c that connects the upper surface 31a and the lower surface 31b. The first grinding wheel 21a rotates around a rotation shaft 31e that connects the center of the upper surface 31a and the center of the lower surface 31b.

  The first grinding wheel 21a is formed of a metal bond grindstone. The metal bond grindstone is a grindstone manufactured by fixing a plurality of kinds of metal powders or alloy powders with an iron-based binder and sintering them, and fixing abrasive grains on the surface of the sintered body. The abrasive grains are fine grains such as diamond, aluminum oxide and silicon carbide. The metal bond grindstone is a grindstone having a high shape retention force. The metal bond grindstone is, for example, a diamond wheel. When the first grinding wheel 21a is a diamond wheel, the grain size of the diamond abrasive grains is preferably # 400 to # 3000. The first grinding wheel 21a is rotated around the rotation shaft 31e by an electric motor (not shown).

  As shown in FIG. 6, when viewed along the vertical direction (z-axis direction), the first grinding wheel 21 a is between the rotation shaft 31 e and the conveyance direction (y-axis direction) of the glass substrate 3. The first installation angle θ1, which is an angle, is installed so as to be an acute angle. As shown in FIG. 7, when viewed along the width direction (x-axis direction), the first grinding wheel 21 a is between the rotation shaft 31 e and the conveyance direction (y-axis direction) of the glass substrate 3. The first installation angle θ2, which is an angle, is installed so as to be an acute angle. The first installation angle θ1 is less than 2 °, preferably less than 1 °. The second installation angle θ2 is less than 2 °, preferably less than 1 °. The length of the processing region of the first grinding wheel 21a, the grain size of the abrasive grains, and the density of the abrasive grains are appropriately set according to the processing conditions. The 1st end surface 3a is ground by contacting with the side peripheral surface 31c of the 1st grinding wheel 21a rotated around the rotating shaft 31e. As shown in FIGS. 6 and 7, the rotation direction of the first grinding wheel 21a is a direction in which the side peripheral surface 31c of the first grinding wheel 21a collides with the first end surface 3a from below.

  The position of the first grinding wheel 21a and the angle of the rotating shaft 31e can be adjusted by a grinding wheel position adjusting mechanism (not shown). The position of the first grinding wheel 21a and the angle of the rotation shaft 31e are adjusted in advance before using the glass substrate end surface processing apparatus 1. In the present embodiment, when the end surface 3a of the glass substrate 3 is processed, the position of the first grinding wheel 21a and the angle of the rotation shaft 31e are fixed.

(1-3) Control Unit The control unit is a computer mainly composed of a CPU, ROM, RAM, hard disk, and the like. The control unit is connected to the transport mechanism 10 and the grinding mechanism 20. The control unit controls the transport mechanism 10 and the grinding mechanism 20 based on programs and data stored in a ROM, RAM, hard disk, or the like.

  Specifically, the control unit controls the position of the float bearing 22 in the vertical direction, the flow rate of air ejected from the fluid ejection hole 22b, and the flow rate of air sucked into the fluid suction hole 22c. Accordingly, the control unit adjusts the distance between the lower surface 3 c of the glass substrate 3 and the panel surface 22 a of the float bearing 22.

  The control unit also controls the vertical position of the slide bearing 24, the flow rate of air ejected from the fluid ejection hole 24b, and the flow rate of air sucked into the fluid suction hole 24c. Thereby, the control unit adjusts the magnitude of the driving force acting on the glass substrate 3.

  Further, the control unit controls the positions of the grinding wheels 21a and 21d, the angle of the rotation shaft 31e of the grinding wheels 21a and 21d, and the rotation speed of the grinding wheels 21a and 21d. Thereby, the control unit adjusts the grinding amount of the glass substrate 3.

  Moreover, a control part acquires grinding resistance based on the load electric current value of the electric motor by contact with the rotating grinding wheels 21a and 21d and end surface 3a, 3d. The grinding resistance is a force in the width direction that the grinding wheels 21a and 21d receive from the glass substrate 3 being conveyed. The greater the load current value, the greater the grinding resistance. The control unit controls the slide bearing 24 so that the grinding resistance is constant, and the magnitude of the propulsive force in the width direction acting on the glass substrate 3 and the propulsive force in the transport direction acting on the glass substrate 3 are controlled. adjust.

(2) Operation of Glass Substrate End Surface Processing Apparatus The glass substrate 3 is ground by the grinding mechanism 20 while being transported by the transport mechanism 10. The glass substrate end surface processing apparatus 1 first grinds the first end surface 3a of the glass substrate 3, and then grinds the second end surface 3d of the glass substrate 3. The process by which the glass substrate end surface processing apparatus 1 grinds the first end surface 3a and chamfers the lower corner of the first end surface 3a will be described. The glass substrate 3 is transported along the transport direction while floating by the transport mechanism 10. The glass substrate 3 is subjected to a propulsive force in the transport direction and the width direction by the slide bearing 24. The glass substrate end surface processing apparatus 1 adjusts the driving force in the width direction acting on the glass substrate 3 so that the grinding resistance is constant. Moreover, the glass substrate end surface processing apparatus 1 adjusts the propulsive force in the transport direction acting on the glass substrate 3 so that the grinding resistance becomes constant. Thereby, the glass substrate end surface processing apparatus 1 conveys the first end surface 3a of the glass substrate 3 by the amount ground by the first grinding wheel 21a of the grinding mechanism 20. That is, unless the first end surface 3a of the glass substrate 3 is ground by the first grinding wheel 21a, the glass substrate 3 is not transported in the transport direction. While the glass substrate 3 is being ground, the grinding resistance that the first grinding wheel 21a receives from the first end surface 3a is kept constant.

(3) Features In conventional end face processing of a glass substrate, the end face is chamfered by pressing a rotating grinding wheel with a groove on the end face of the glass substrate. However, in this method, the processing resistance (grinding resistance) is reduced by moving the glass substrate in the pressing direction of the grinding wheel, and the end surface of the glass substrate may not be uniformly ground. Moreover, when processing a glass substrate with low rigidity, such as a thin glass substrate, the glass substrate may be damaged during processing due to processing resistance.

  However, in the glass substrate end surface processing apparatus 1 of the present embodiment, the grinding resistance applied to the glass substrate 3 that is ground while being conveyed in the conveying direction is kept constant. Therefore, the glass substrate end surface processing apparatus 1 can uniformly grind the end surfaces 3 a and 3 d of the glass substrate 3. Moreover, the glass substrate end surface processing apparatus 1 can control the grinding resistance by adjusting the propulsive force in the transport direction and the width direction acting on the glass substrate 3 to be transported. Therefore, the glass substrate end surface processing apparatus 1 can prevent the glass substrate 3 from being damaged during processing due to the grinding resistance by suppressing the grinding resistance low when performing end surface processing of the glass substrate having low rigidity. . In particular, the glass substrate end surface processing apparatus 1 can uniformly process the end surfaces 3a and 3d of the thin glass substrate 3 having a thickness of 0.3 mm or less. Therefore, the glass substrate end surface processing apparatus 1 can uniformly chamfer the end surfaces 3a and 3d of the glass substrate 3 having low rigidity.

  Moreover, in the glass substrate end surface processing apparatus 1, since the rotating shaft 31e of the grinding wheels 21a and 21d is inclined with respect to the vertical direction (z-axis direction), it exists on the side peripheral surface 31c of the grinding wheels 21a and 21d. The number of abrasive grains in contact with the end faces 3a, 3d of the glass substrate 3 being conveyed can be increased. If the rotating shafts 31e of the grinding wheels 21a and 21d are parallel to the vertical direction, the end surfaces 3a and 3d of the glass substrate 3 are in contact with only the abrasive grains present in a partial region of the side peripheral surface 31c. . However, by inclining the rotation shaft 31e of the grinding wheels 21a and 21d with respect to the vertical direction, the end surfaces 3a and 3d of the glass substrate 3 are brought into contact with abrasive grains existing in a large area of the side peripheral surface 31c. Can do. 6 and 7, the region of the side peripheral surface 31 c where the abrasive grains that can come into contact with the end surface 3 a of the glass substrate 3 are hatched is shown. Therefore, the glass substrate end surface processing apparatus 1 can reduce the processing load per abrasive grain of the grinding wheels 21a and 21d. Therefore, the glass substrate end surface processing apparatus 1 can extend the lifespan of the grinding wheels 21a and 21d, thereby extending the life of the glass substrate end surface processing apparatus 1 itself.

  Further, the glass substrate end surface processing apparatus 1 uses the float bearing 22 to convey the glass substrate 3 without bringing other members into contact with the upper surface 3b and the lower surface 3c of the glass substrate 3, and the end surface 3a of the glass substrate 3 , 3d can be ground. Therefore, the glass substrate end surface processing apparatus 1 can keep the state of the upper surface 3b and the lower surface 3c of the glass substrate 3 processed by the grinding mechanism 20 in a good state. When the glass substrate 3 is used for FPD, scratches and cracks formed on the main surface (the upper surface 3 b and the lower surface 3 c) of the glass substrate 3 are the main causes for reducing the quality of the glass substrate 3. Since the glass substrate end surface processing apparatus 1 can prevent the generation of scratches and cracks on the upper surface 3b and the lower surface 3c of the glass substrate 3, the quality of the glass substrate 3 can be improved.

  Moreover, in this embodiment, the driving force of a conveyance direction acts only on the glass substrate 3, and only the glass substrate 3 is conveyed. Therefore, the inertial mass of the object to be transported is small compared to the conventional configuration in which the glass substrate is transported together with the stage while the glass substrate is attracted and fixed to the surface of the stage, so that the force acting on the glass substrate 3 is increased. It can be adjusted with accuracy and the conveyance amount of the glass substrate 3 can be controlled with high accuracy.

  Moreover, in this embodiment, it is the range which is the range which contacts the end surfaces 3a and 3d at the time of the process of the end surfaces 3a and 3d of the glass substrate 3 by inclining the rotating shaft 31e of the grinding wheels 21a and 21d with respect to a perpendicular direction. The processing range of the wheels 21a and 21d can be increased, and the number of abrasive grains of the grinding wheels 21a and 21d in contact with the end faces 3a and 3d can be increased. As a result, it is possible to reduce the processing time required to obtain the same quality of the end faces 3a, 3d as before, and by processing the end faces 3a, 3d using the same processing time as before. The quality of the end faces 3a and 3d can be improved.

(4) Modification (4-1) Modification A
The glass substrate end surface processing apparatus 1 according to the embodiment first grinds the first end surface 3a of the glass substrate 3, and then grinds the second end surface 3d of the glass substrate 3. However, the glass substrate end surface processing apparatus 1 may grind the first end surface 3a and the second end surface 3d of the glass substrate 3 simultaneously. FIG. 8 is a top view of the glass substrate end surface processing apparatus 1 of the present modification. FIG. 9 is a side view of the glass substrate end surface processing apparatus 1 of the present modification. In FIG. 8, the conveyance direction of the glass substrate 3 is indicated by an arrow. FIG. 9 is a diagram viewed along the conveyance direction of the glass substrate 3. The glass substrate end surface processing apparatus 1 of the present modification chamfers the corners below the first end surface 3a and the second end surface 3d of the glass substrate 3 as in the embodiment.

  The glass substrate end surface processing apparatus 1 according to this modification includes a transport mechanism 10. The transport mechanism 10 includes a plurality of float bearings 22 and a plurality of slide bearings 24. The float bearing 22 and the slide bearing 24 are installed as shown in FIGS. 8 and 9, the driving force applied to the glass substrate 3 by the slide bearing 24 is indicated by a white arrow. The slide bearings 24 are installed on both sides of the float bearing 22 in the width direction. The float bearing 22 applies a vertical force to the glass substrate 3 at the center in the width direction of the glass substrate 3 to float the glass substrate 3. The slide bearing 24 is installed so as to apply to the glass substrate 3 a resultant force of the propulsive force in the width direction from the end faces 3a and 3d toward the center and the propulsive force in the transport direction. As shown in FIG. 8, the fluid groove 24 d of the slide bearing 24 is formed along a direction that forms a predetermined angle with respect to the width direction and the conveyance direction in the horizontal plane. Further, the same number of slide bearings 24 are installed on both sides in the width direction of the float bearing 22. The direction of the propulsive force applied to the glass substrate 3 by the slide bearings 24 on both sides in the width direction of the float bearing 22 is symmetric with respect to a straight line extending along the transport direction in the center of the glass substrate 3 in the width direction. As a result, the glass substrate 3 receives a propulsive force from the first end surface 3a toward the second end surface 3d and a propulsive force toward the first end surface 3a from the second end surface 3d in the width direction, and is thus conveyed in the conveyance direction. The glass substrate 3 is suppressed from moving in the width direction. Similar to the embodiment, the first end surface 3a and the second end surface 3d of the glass substrate 3 are ground by the first grinding wheel 21a and the second grinding wheel 21d, respectively.

  Also in this modification, the glass substrate end surface processing apparatus 1 can keep the grinding resistance applied to the glass substrate 3 to be ground while being transported in the transport direction, so that the end surfaces 3a and 3d of the glass substrate 3 are made uniform. Can be ground.

(4-2) Modification B
In the glass substrate end surface processing apparatus 1 according to the embodiment, the glass substrate 3 is supported above the float bearing 22 and the slide bearing 24 without contacting the float bearing 22 and the slide bearing 24.

  However, the glass substrate 3 may be supported below the float bearing 22 and the slide bearing 24 without contacting the float bearing 22 and the slide bearing 24. The float bearing 22 can support the upper surface 3b of the glass substrate 3 positioned below the panel surface 22a in a non-contact manner. The slide bearing 24 can apply a driving force to the glass substrate 3 located below the panel surface 24a. Therefore, also in this modified example, the glass substrate end surface processing apparatus 1 can keep the grinding resistance applied to the glass substrate 3 to be ground while being transported in the transport direction, so that the end surfaces 3a and 3d of the glass substrate 3 are fixed. Uniform grinding is possible.

(4-3) Modification C
The glass substrate end surface processing apparatus 1 according to the embodiment has a float bearing 22 formed from a porous body, and the fluid ejection holes 22b that apply an upward force to the glass substrate 3 are pores of the porous body. . However, the fluid ejection hole 22b may be a hole formed in the panel surface 22a using a drill or the like, like the fluid suction hole 22c.

  FIG. 10 is a view of the float bearing 322 of this modification as viewed from the top to the bottom along the vertical direction. A plurality of fluid ejection holes 322b and a plurality of fluid suction holes 322c are formed on the panel surface 322a of the float bearing 322. In FIG. 10, the fluid ejection holes 322b are indicated by black circles, and the fluid suction holes 322c are indicated by white circles. In FIG. 10, the fluid ejection holes 322b and the fluid suction holes 322c are formed at lattice point positions on the panel surface 322a. The diameter of the fluid ejection holes 322b is larger than the diameter of the pores of the porous body. The fluid ejection holes 322b are formed at a plurality of positions in the width direction and the transport direction. That is, the fluid ejection holes 322b are arranged so as to expand in both the width direction and the transport direction. The fluid suction hole 322c is the same as the fluid suction hole 22c of the embodiment. The fluid ejection holes 322b and the fluid suction holes 322c are alternately arranged in the width direction.

(4-4) Modification D
The glass substrate end surface processing apparatus 1 adjusts the propulsive force in the transport direction and the width direction acting on the glass substrate 3 so that the grinding resistance is constant. However, the glass substrate end surface processing apparatus 1 may adjust the propulsive force in the conveyance direction and the width direction acting on the glass substrate 3 so that the grinding resistance is within a predetermined range.

(4-5) Modification E
The glass substrate end surface processing apparatus 1 according to the embodiment includes grinding wheels 21a and 21d formed of a metal bond grindstone. However, the grinding wheels 21a and 21d may be formed of an elastic grindstone. The elastic grindstone is a grindstone formed by binding abrasive grains, which are hard grains, with a soft binding material having elasticity. The abrasive grains are fine grains such as diamond, aluminum oxide and silicon carbide. The binder is a soft resin such as polyvinyl alcohol and polyurethane. The elastic grindstone has a structure in which an infinite number of abrasive grains are held inside a sponge structure composed of a binder.

(4-6) Modification F
The glass substrate end surface processing apparatus 1 according to the embodiment may further include a polishing mechanism that polishes the end surfaces 3a and 3d of the glass substrate 3 ground by the grinding wheels 21a and 21d. The polishing mechanism polishes the end faces 3a and 3d using a polishing wheel formed of an elastic grindstone. The abrasive grains of the polishing wheel are preferably silicon carbide, and the grain size of the silicon carbide abrasive grains is preferably # 400 to # 1200. The binder that binds the abrasive grains of the polishing wheel is preferably a polyurethane-based resin binder having flexibility and elasticity.

  Further, the polishing mechanism of the glass substrate end surface processing apparatus 1 uses the same mechanism as the transport mechanism 10 and the grinding mechanism 20 of the embodiment so that the polishing resistance, which is the force that the polishing wheel receives from the end surfaces 3a and 3d, is constant. The glass substrate 3 may be transported by adjusting the propulsive force in the transport direction and the width direction of the glass substrate 3. Thereby, the polishing mechanism can uniformly polish the ground end surface 3a. As a result, since the end surface 3a of the glass substrate 3 processed by the glass substrate end surface processing apparatus 1 has almost no unpolished portion, minute glass particles are hardly generated from the processed glass substrate 3. Therefore, the glass substrate end surface processing apparatus 1 can improve the quality of the glass substrate 3 as a product.

(4-7) Modification G
The glass substrate end surface processing apparatus 1 according to the embodiment includes a cleaning mechanism for cleaning the glass substrate 3 whose end surfaces 3a and 3d are ground by the grinding mechanism 20, and an inspection for optically inspecting the glass substrate 3 cleaned by the cleaning mechanism. A mechanism may be further provided. The cleaning mechanism sprays a fluid onto the end surfaces 3a and 3d of the glass substrate 3 to remove foreign matters such as glass fine pieces adhering to the end surfaces 3a and 3d. The inspection mechanism acquires end surface quality data relating to the quality of the end surfaces 3 a and 3 d of the glass substrate 3. The end face quality data relates to, for example, the shape of the end faces 3a and 3d, the surface roughness (such as Ra and Rz) of the end faces 3a and 3d, and the number of defects such as scratches formed on the end faces 3a and 3d.

  The glass substrate end surface processing apparatus 1 according to the present modification includes the end surface quality data acquired by the inspection mechanism and the transport direction and the driving force in the width direction given by the transport mechanism 20 with respect to the glass substrate 3 to be processed. Acquire and store correlation data about relevance. The glass substrate end surface processing apparatus 1 adjusts the driving force applied to the glass substrate 3 so that the quality of the end surfaces 3a and 3d of the glass substrate 3 satisfies a predetermined condition based on the correlation data. Thus, the glass substrate end surface processing apparatus 1 performs feedback control for adjusting the propulsive force applied to the glass substrate 3 by the transport mechanism based on the result of the inspection of the glass substrate 3 by the inspection mechanism.

(4-8) Modification H
Embodiment and each modification are related with the method of processing the end surfaces 3a and 3d of the glass substrate 3. FIG. The glass substrate 3 is a glass substrate used for a flat panel display, for example. However, the embodiment and each modification can be applied to a method of processing an end face of a substrate made of a brittle material other than the glass substrate 3. Substrates made of a brittle material are, for example, semiconductor substrates and ceramic substrates. Further, the shape of the substrate is not limited to a rectangular shape. For example, the substrate may be a disk-shaped wafer. In this case, the driving force acting on the substrate is a force acting in the circumferential direction of the substrate.

3 Glass substrate 3a First end face (end face)
3b Top surface (main surface)
3c Bottom surface (main surface)
3d second end face (end face)
DESCRIPTION OF SYMBOLS 10 Conveyance mechanism 20 Grinding mechanism 21a 1st grinding wheel (grinding means)
21d Second grinding wheel (grinding means)
22 Float bearing 24 Slide bearing

JP 2002-160147 A

Claims (9)

A method of manufacturing a glass substrate, comprising: a grinding step of grinding the end face by moving the glass substrate and the grinding means relatively along the longitudinal direction of the end face while bringing the end face of the glass substrate into contact with the grinding means. Because
The grinding step includes
A levitation step of levitation of the glass substrate by spraying a fluid onto the main surface of the glass substrate;
In the state where the end face of the glass substrate that has been levitated by the levitation step is in contact with the grinding means, a propulsive force in a first direction parallel to the main surface is applied to the glass substrate while grinding the end face. A transporting process for feeding and transporting the glass substrate;
Have
The conveying step adjusts the propulsive force so that a grinding resistance, which is a force received by the grinding means from the end face, is constant.
A method for producing a glass substrate. The conveyance step provides the propulsive force to the glass substrate in a non-contact manner.
The manufacturing method of the glass substrate of Claim 1. In the grinding step, first, one of the pair of opposed end faces of the glass substrate is ground, and then the other of the pair of end faces is ground.
The manufacturing method of the glass substrate of Claim 1 or 2. The grinding step simultaneously grinds a pair of opposed end faces of the glass substrate.
The manufacturing method of the glass substrate of Claim 1 or 2. The grinding means is rotated around an axis of rotation by an electric motor,
The conveying step acquires the grinding resistance based on a load current value of the electric motor due to contact between the rotating grinding means and the end surface.
The manufacturing method of the glass substrate of any one of Claim 1 to 4. The grinding means has a cylindrical shape, and is installed such that an angle between the rotation axis connecting the centers of the pair of bottom surfaces of the cylindrical shape and the first direction is an acute angle.
The manufacturing method of the glass substrate of Claim 5. An inspection step of optically inspecting the glass substrate whose end face has been ground by the transporting step;
The transporting step adjusts the driving force based on the inspection result of the glass substrate in the inspection step.
The manufacturing method of the glass substrate of any one of Claim 1 to 6. The glass substrate has a thickness of 0.3 mm or less,
The manufacturing method of the glass substrate of any one of Claim 1 to 7. From a brittle material including a processing step of processing the end face by moving the substrate and the processing means relatively along the longitudinal direction of the end face while bringing the end face of the board made of a brittle material into contact with the processing means. A method for manufacturing a substrate comprising:
The processing step includes a transporting step of transporting the substrate by applying a driving force parallel to the main surface of the substrate to the substrate while processing the end surface.
The transporting step adjusts the propulsive force so that a machining resistance, which is a force received from the end face by the machining means, is constant.
A method for manufacturing a substrate made of a brittle material.