JP6288184B2 - Glass substrate and method for manufacturing glass substrate - Google Patents

Description

  The present invention relates to a glass substrate and a method for producing the glass substrate.

  When processing the glass substrate, such as when processing the glass substrate, it may be necessary to fix the glass substrate in a predetermined position and / or orientation. When such a glass substrate is positioned, a positioning jig such as a bar-shaped metal member is used. For example, when a plurality of positioning jigs configured to be slidable are used, the glass substrate can be sandwiched by such positioning jigs to determine the position of the glass substrate.

  During the positioning operation of the glass substrate by the positioning jig, the end surface of the glass substrate is brought into contact with the positioning jig. For this reason, the case where a crack arises in the end surface of a glass substrate often or a cullet (glass waste) arises from an end surface, and a cullet adheres to a glass substrate is recognized. A glass substrate having such a crack has a problem in quality. Further, when the cullet is attached to the glass substrate, the glass substrate is more likely to be damaged when the glass substrate is transported.

  For this reason, there is a demand for a glass substrate that is less prone to cracks and carets during positioning operations.

  The present invention has been made in view of such a background, and in the present invention, a glass substrate in which cracks are generated on the end surface or cullet is generated from the end surface is significantly suppressed during the positioning operation. The purpose is to provide. Another object of the present invention is to provide a method for producing a glass substrate in which cracks on the end face and cullet from the end face are significantly suppressed during the positioning operation.

In the present invention, a glass substrate having an end face connecting two surfaces,
A smooth region is disposed on at least a part of the end surface, and the smooth region has a smooth surface compared to other regions of the end surface,
The other region of the end face is referred to as a general region,
When the arithmetic average roughness of the general region is Ra (1) and the arithmetic average roughness of the smooth region is Ra (2), the ratio Ra (2) / Ra (1) is 0.8 or less. A glass substrate is provided.

Further, in the present invention, a method for producing a glass substrate,
(1) preparing a glass material having first and second surfaces and end faces connecting both surfaces;
(2) A step of grinding and polishing the end face of the glass material using a processing apparatus;
Have
The end surface is viewed as a surface to be processed from a top view of the glass material, a start point S to an end point E,
The processing apparatus includes a first grinding wheel and a first polishing wheel, a second grinding wheel and a second polishing wheel,
The first and second grinding wheels move along the work surface in a direction from the start point S toward the end point E, which is referred to as a moving direction, thereby grinding the end face of the glass material. Can
The first grinding wheel can polish the region of the end face of the glass material ground by the first grinding wheel by moving along the work surface in the movement direction, The second polishing wheel can polish the region of the end face of the glass material ground by the second grinding wheel by moving along the workpiece surface in the moving direction,
In the step (2),
(2-1) said first grinding wheel, from said position except the start point S and end point E of the workpiece surface, the surface of the workpiece along the moving direction, called the first grinding start point M ₁ Move and
Thereby, a region called a first grinding region is formed on the end face,
(2-2) said first grinding wheel, first polishing start point called P _1, from any position other than the first grinding start point M ₁ of the first ground area, along the movement direction To move the workpiece surface,
Thereby, a region called a first polishing region is formed on the end face,
(2-3) the second grinding wheel from a position called the second grinding start point M _2, along the moving direction, the moving the workpiece surface to a position called the first movement completion point N ₁ ,
Thus, the end surface is ground in a region called a second grinding region from the second grinding start point M ₂ to the first movement completion point N ₁ ,
It said second grinding start point M ₂ is present between the starting point S~ the first grinding start point M _1,
The first movement completion point N ₁ is
(I) exists between the first grinding start point M ₁ and the first polishing start point P ₁ excluding the first polishing start point P ₁ , or (ii) the first polishing start point P _1- Exists between end points E,
(2-4) the second grinding wheel from the position called the second polishing start point P _2, along the moving direction, the moving the workpiece surface to a position called the first polishing end point Q ₁ ,
Thus, the end surface is polished in a region called a second polishing region from the second polishing start point P ₂ to the first polishing completion point Q ₁ .
The second polishing start point P ₂ is present between the second grinding start point M _{2 ~} the first grinding start point M _1,
The first polishing end point Q ₁ is the case of the (i), except for the first polishing start point P _1, present in the first polishing region, the case of the (ii), the first polishing start Existing in the first polishing region excluding the point P ₁ to the first movement completion point N ₁ ,
In the case of (i), polishing is performed by the first and second polishing wheels between the first polishing start point P _{1 on} the end surface and the first polishing completion point Q ₁ (first). An overlapping polishing region is formed,
In the case of (ii), polishing is performed by the first and second polishing wheels between the first movement completion point N ₁ to the first polishing completion point Q ₁ of the end face (first). A method of manufacturing a glass substrate is provided in which an overlapping polishing region is formed.

  In the present invention, it is possible to provide a glass substrate that is significantly suppressed from causing cracks at the end face and cullet from the end face during the positioning operation. Moreover, in this invention, in the case of positioning operation, the manufacturing method of the glass substrate which can suppress significantly that a crack arises in an end surface or a cullet arises from an end surface can be provided.

It is the perspective view which showed schematically the glass substrate by one Embodiment of this invention. It is the figure which showed typically one end surface of the glass substrate shown in FIG. It is the figure which showed typically the flow of the manufacturing method of the glass substrate by one Embodiment of this invention. It is the perspective view which showed the form of the glass raw material typically. It is the figure which showed typically an example of the structure of the processing apparatus which can be used for the manufacturing method of the glass substrate by one Embodiment of this invention. It is the figure which showed typically an example of operation | movement of the processing apparatus shown in FIG. It is the figure which showed typically each movement locus of the 1st grinding wheel of the processing device shown in Drawing 5, the 1st grinding wheel, the 2nd grinding wheel, and the 2nd grinding wheel. It is the figure which showed typically the flow of another manufacturing method of the glass substrate by one Embodiment of this invention. It is the figure which showed typically an example of the structure of another processing apparatus which can be used for the manufacturing method of the glass substrate by one Embodiment of this invention. It is the figure which showed typically an example of operation | movement of the processing apparatus shown in FIG. The movement trajectories of the first grinding wheel, the first grinding wheel, the second grinding wheel, the second grinding wheel, the third grinding wheel, and the third grinding wheel of the processing apparatus shown in FIG. It is the figure shown typically.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Glass substrate according to an embodiment of the present invention)
With reference to FIG. 1 and FIG. 2, the structure of the glass substrate by one Embodiment of this invention is demonstrated. FIG. 1 is a schematic perspective view of a glass substrate (hereinafter simply referred to as “first glass substrate”) according to an embodiment of the present invention.

  As shown in FIG. 1, the 1st glass substrate 110 has the 1st surface 112 and the 2nd surface 114 which mutually oppose, and four end surface 116A-116D which connects both surfaces.

  In the example of FIG. 1, the first glass substrate 110 has a substantially rectangular shape, and thus has four end surfaces 116 </ b> A to 116 </ b> D. However, this is merely an example, and the first glass substrate 110 may have any shape, and as a result, the number of end faces may be any value. For example, when the first glass substrate 110 is substantially disk-shaped, the number of end faces is one. In addition, when the first glass substrate 110 has a substantially triangular shape, the number of end faces is three. The same applies when the first glass substrate 110 has a pentagonal shape or a polygonal shape.

  Here, the first glass substrate 110 has a feature of having a “smooth region” on at least one end face. Here, the “smooth area” means an area where the arithmetic average roughness Ra is smaller than the other areas on the target end face. Note that, on the target end face, a region other than the “smooth region” is also referred to as a “general region”.

  Hereinafter, the effect of the present invention will be described by taking as an example the case where the first end surface 116A of the first glass substrate 110 has such a “smooth region”.

  In FIG. 2, the form of 116 A of 1st end surfaces which have a "smooth area | region" is shown typically.

  As shown in FIG. 2, the surface of the first end surface 116 </ b> A is divided into a general region 120 and a smooth region 122. The smooth region 122 is sandwiched between the general regions 120 at the approximate center of the first end surface 116A.

  However, this is merely an example, and the position where the smooth region 122 exists is not particularly limited. Further, the number of smooth regions 122 is not particularly limited. For example, two or more smooth regions 122 may exist on the first end surface 116A. The installation position and the number of the smooth regions 122 are determined by the relationship with the positioning jig that comes into contact with the positioning of the first glass substrate 110.

  In FIG. 2, the boundary between the general area 120 and the smooth area 122 is exaggerated by a broken line. However, it should be noted that in the normal case, it is difficult to determine the general region 120 and the smooth region 122 and the boundary between them from the appearance.

Here, as described above, the smooth region 122 has a smaller arithmetic average roughness Ra than the general region 120. In particular, in the first glass substrate 110, when the arithmetic average roughness in the general region 120 is Ra (1) and the arithmetic average roughness in the smooth region 122 is Ra (2),

Ra (2) / Ra (1) ≦ 0.8 (1) Formula

It has the characteristic of satisfying.

  As described above, when the glass substrate is positioned by the positioning jig, the end surface of the glass substrate is brought into contact with the positioning jig. At this time, cracks may occur on the end face of the glass substrate, or cullet (glass waste) may be generated from the end face.

  On the other hand, in the 1st glass substrate 110, the smooth area | region 122 is arrange | positioned in the position which can contact | abut at least with a positioning jig of an end surface. Further, the arithmetic mean roughness in the smooth region 122 and the general region 120 has the relationship of the above-described formula (1). Such a smooth region 122 with few irregularities shows better strength than the general region 120 against contact of a member such as a positioning jig.

  Therefore, in the first glass substrate 110, even if the positioning jig abuts on the smooth region 122 of the first end surface 116A, the first end surface 116A cracks more than the positioning jig abuts on the general region 120. The occurrence of cullet can be significantly suppressed. Further, since the positioning jig comes into contact with the smooth region 122 with less unevenness, the wear and dust generation of the positioning member are significantly suppressed.

(General area 120 and smooth area 122)
Next, the general area 120 and the smooth area 122 on the end face will be described in more detail.

  As described above, the ratio Ra (2) / Ra (1) between the arithmetic average roughness Ra (2) in the smooth region 122 and the arithmetic average roughness Ra (1) in the general region 120 is 0.8 or less. The The ratio Ra (2) / Ra (1) is preferably 0.7 or less.

  Further, the arithmetic average roughness Ra (2) of the smooth region 122 is preferably 0.12 μm or less, and more preferably 0.08 μm or less.

  On the other hand, the arithmetic average roughness Ra (1) of the general region 120, that is, the region excluding the smooth region 122 of the first end face 116A, is preferably 0.2 μm or less, for example.

The total length L _s of the smooth region 122 of the first end surface 116A is preferably 1 mm or more and 30 mm or less. When the total length L _s of the smooth region 122 is 1 mm or more, it becomes easy to accurately bring the positioning jig into contact with the smooth region 122. In addition, the total length L _s of the smooth region 122 is preferably 30 mm or less from the viewpoint of the productivity of the first glass substrate 110. The total length L _s of the smooth region 122 is more preferably 3 mm or more and 10 mm or less.

Here, the “full length (L _s )” of the smooth region 122 is determined as follows.

A first length of the end surface of interest and L _1, the second length and L _2. Here, L ₁ ≧ L ₂ . For example, if the first end face 116A of FIG. 2, the dimension length L ₁ next to the X-direction, the dimension in the Z direction (thickness direction) the length L _2. In this case, as shown in FIG. 2, the total length L _s of the smooth region 122 is defined by the width of the smooth region 122 in the direction along the _first length L ₁ .

When the glass substrate is substantially disk-shaped and there is only one curved end surface, the first length L ₁ of such an end surface is the circumference length and the second length L _2. Corresponds to the thickness of the glass substrate. Therefore, the total length L _s of the smooth region is the length of the smooth region along the circumference.

  As described above, the installation position and the number of installation of the smooth region 122 on the first end surface 116A are not particularly limited. For example, two or more smooth regions 122 may be arranged at equal intervals or at non-equal intervals on the first end surface 116A.

  In the above example, the smooth region 122 is disposed on the first end surface 116 </ b> A of the first glass substrate 110. However, the smooth region 122 may be disposed on any end surface of the first glass substrate 110.

  For example, the smooth region 122 may be disposed on any one of the second end surface 116B to the fourth end surface 116D, and is disposed on two end surfaces such as the first end surface 116A and the second end surface 116B. Alternatively, it may be disposed on three end surfaces such as the first end surface 116A to the third end surface 116C, or may be disposed on all end surfaces of the first end surface 116A to the fourth end surface 116D. At this time, the installation position and the number of installation of the smooth regions 122 may be different from each other on the end faces 116A to 116D.

(Method of manufacturing a glass substrate according to an embodiment of the present invention)
Next, with reference to FIGS. 3-7, an example of the manufacturing method of the glass substrate by one Embodiment of this invention is demonstrated.

  FIG. 3 schematically shows a flow of a glass substrate manufacturing method (hereinafter simply referred to as “first manufacturing method”) according to an embodiment of the present invention. 4 to 7 schematically show the state of one step in the first manufacturing method.

As shown in FIG. 3, the first manufacturing method is:
(1) a step of preparing a glass material having first and second surfaces and an end face connecting both surfaces (step S110);
(2) Using a processing device, grinding and polishing the end face of the glass material (step S120);
Have

  Hereinafter, each step will be described in detail with reference to FIGS.

(Process S110)
First, a glass material is prepared. As illustrated in FIG. 4, the glass material 250 includes a first surface 252 and a second surface 254, and four end surfaces 256 </ b> A to 256 </ b> D that connect both surfaces.

  Hereinafter, for simplification of description, the top view of the glass material 250 and the sides corresponding to the four end faces 256A to 256D of the first surface 252 are defined as the first side 260A, the second side 260B, and the third side, respectively. The sides 260C and the fourth side 260D are referred to.

  The dimension of the glass material 250 is not particularly limited. For example, when a glass substrate for a liquid crystal display is manufactured, the glass material 250 is, for example, vertical (the length of the first side 260A and the third side 260C) 1800 mm to 3200 mm × horizontal (the second side 260B and the second side 4 side 260D length) 1500 mm to 2900 mm × thickness of 0.10 mm to 0.70 mm.

(Process S120)
Next, the end surface of the glass material 250 is ground and polished (hereinafter, collectively referred to as “processing”) using a processing apparatus.

  In addition, the end surface where the glass material 250 is processed is not particularly limited. For example, only one end face among the four end faces 256A to 256D may be processed. Alternatively, two or more end surfaces of the four end surfaces 256A to 256D, for example, all end surfaces may be processed.

  Here, as an example, a case where the first end surface 256A of the glass material 250 is processed will be described.

(Processing equipment)
FIG. 5 schematically shows a configuration of a processing apparatus that can be used in the first manufacturing method.

  As shown in FIG. 5, the processing apparatus 300 includes a table 302, first and second grinding wheels 380A and 382A, and first and second polishing wheels 385B and 387B.

  The table 302 is used for installing the glass material 250 on the top. The first and second grinding wheels 380A and 382A and the first and second grinding wheels 385B and 387B are both used for processing the first end face 256A of the glass material 250.

  The first grinding wheel 380A can grind the first end surface 256A of the glass material 250, and the first polishing wheel 385B can grind the first end surface 256A of the glass material 250. Similarly, the second grinding wheel 382A can grind the first end surface 256A of the glass material 250, and the second grinding wheel 387B can grind the first end surface 256A of the glass material 250. .

  The first grinding wheel 380A and the first grinding wheel 385B form a pair, and the first grinding wheel 385B can follow the grinding process of the first grinding wheel 380A later. Similarly, the second grinding wheel 382A and the second grinding wheel 387B are paired, and the second grinding wheel 387B can follow the grinding process of the second grinding wheel 382A later. .

  The first grinding wheel 380A is made of a grindstone that hardly undergoes elastic deformation and has a high grinding force. As such a grindstone, for example, a metal bond grindstone in which diamond or CBN abrasive grains are fixed by a metal bond that hardly undergoes elastic deformation can be exemplified. Similarly, the electrodeposition grindstone which has a diamond abrasive grain can also be illustrated.

  The same applies to the second grinding wheel 382A.

On the other hand, the first polishing wheel 385B is made of a grindstone having elasticity and suitable for polishing. As such a grindstone, for example, diamond, CBN, green silicon carbide (GC), alumina (Al ₂ O ₃ ), pumice, or garnet or other abrasive grains that easily undergo elastic deformation, butyl rubber, natural rubber, etc. A grindstone fixed with a bond can be exemplified.

  The same applies to the second grinding wheel 387B.

  In the present application, “grinding” means that the purpose is to cut the substrate so as to have a predetermined dimension and a predetermined cross-sectional shape, and “polishing” means that the purpose is chipping, cracks, etc. caused by grinding. It is to remove and reduce the roughness of the grinding surface.

(Specific processing steps)
In process S120, glass material 250 is installed in processing device 300, and glass material 250 is processed.

  First, as shown in FIG. 6, the glass material 250 is placed on the table 302 of the processing apparatus 300 such that the first side 260A faces the first and second grinding wheels 380A and 382A. . The glass material 250 may be fixed to the table 302 by suction.

  Next, the first grinding wheel 380A and the first grinding wheel 385B of the processing apparatus 300 are rotated at a predetermined rotational speed. Further, the second grinding wheel 382A and the second grinding wheel 387B of the processing apparatus 300 are rotated at a predetermined number of rotations.

Next, as shown in FIG. 6, the first grinding wheel 380 </ b> A is in contact with the first end surface 256 </ b> A of the glass material 250, along the first side (surface to be processed) 260 </ b> A, as indicated by the arrow A <b> ₁ . Move in the direction. Hereinafter, the direction of the arrow A _1, referred to as "moving direction". The first end face 256A of the glass material 250 is ground by the movement of the first grinding wheel 380A.

Further, after the first grinding wheel 380A starts grinding the first end surface 256A, the first polishing wheel 385B comes into contact with the first end surface 256A of the glass material 250 while the first grinding wheel 380A starts grinding. along the sides 260A, moves in the direction of arrow _{a 2.} The arrow A ₂ is the same direction as the arrow A ₁ (the X direction in FIG. 6), that is, the “movement direction”.

  By the movement of the first polishing wheel 385B, the region of the first end surface 256A of the glass material 250 that has been ground by the first grinding wheel 380A is polished.

The first grinding wheel 380A is substantially simultaneously with the grinding of the first end face 256A, or after a while, the second grinding wheel 382A is in contact with the first end face 256A of the glass material 250 while the first end face 256A is in contact with the first end face 256A. along the sides 260A, moves in the direction of arrow _{a 3.} The arrow A ₃ is the same direction as the arrow A ₁ (the X direction in FIG. 6), that is, the “movement direction”. The first end face 256A of the glass material 250 is ground by the movement of the second grinding wheel 382A.

Further, after a while after the grinding of the first end surface 256A by the second grinding wheel 382A is started, the second polishing wheel 387B makes contact with the first end surface 256A of the glass material 250 while the first end surface 256A is in contact with the first end surface 256A. along the sides 260A, moves in the direction of arrow _{a 4.} Arrow _{A 4} is, (X direction in FIG. 6) the same direction as the arrow _{A 1,} that is, "moving direction".

  By the movement of the second polishing wheel 387B, the region of the first end surface 256A of the glass material 250 that has been ground by the second grinding wheel 382A is polished.

  Here, the first grinding wheel 380 </ b> A is operated so as to start grinding from an intermediate portion of the first side 260 </ b> A of the glass material 250, for example, a substantially central portion. Then, the grinding is continued until the end point E of the first side 260A.

  Further, the first polishing wheel 385B is operated so as to start polishing from any position where the grinding by the first grinding wheel 380A on the first side 260A has already been completed. Then, the polishing is continued until the end point E of the first side 260A.

  On the other hand, the second grinding wheel 382A is operated to start grinding from the starting point S of the first side 260A of the glass material 250. Then, the grinding is stopped at the point of progressing to the middle of the first side 260A along the moving direction.

  The position where the grinding by the second grinding wheel 382A is stopped may be any position in the region already ground by the first grinding wheel 380A on the first side 260A. However, the position where the grinding by the second grinding wheel 382A is stopped is any one of the regions that are not ground by the first grinding wheel 385B among the regions already ground by the first grinding wheel 380A. Preferably it is a position. In this case, it can be avoided that the region polished by the first polishing wheel 385B is ground by the second grinding wheel 382A.

  Further, the second polishing wheel 387B is operated so as to start polishing from the start point S of the first side 260A of the glass material 250. Then, the polishing is continued to any position where the polishing by the first polishing wheel 385B is completed.

  However, when the grinding stop position by the above-mentioned second grinding wheel 382A exceeds the grinding start position by the first grinding wheel 385B, the second grinding wheel 387B is caused by this second grinding wheel 382A. Polishing is continued to a position exceeding the grinding stop position.

  Thereby, the grinding and polishing of the entire first side 260A of the glass material 250 is completed, and the glass substrate on which the first end surface 256A of the glass material 250 is processed is manufactured.

  In such a first manufacturing method, a region polished by both the first polishing wheel 385B and the second polishing wheel 387B in the first end surface 256A of the glass material 250 (hereinafter referred to as “overlapping polishing region”). ) Occurs. In such an overlapping polishing region, a smoother surface can be obtained by polishing twice as compared with other regions of the first end face 256A. In addition, when the first polishing wheel 385B and the second polishing wheel 387B polish the overlapping polishing region, the moving speed of the polishing wheel or the number of rotations is decreased compared to when polishing the other region. By doing so, a smooth surface is easily obtained, which is preferable.

  As described above, a smooth surface with few irregularities has a relatively good strength against contact with a member such as a positioning jig. Therefore, in the glass substrate manufactured by the first manufacturing method, such an overlapping polished region on the end surface is used as a contact place with a member such as a positioning jig, and the end surface is cracked, or there is It is possible to significantly suppress the occurrence of cullet.

(Duplicate polishing area formation process)
Here, with reference to FIG. 7, the process of forming the said overlapping grinding | polishing area | region is demonstrated in detail.

FIG. 7 schematically shows movement trajectories of the first grinding wheel 380A, the first grinding wheel 385B, the second grinding wheel 382A, and the second grinding wheel 387B. Figure 7 is (a), and schematic movement locus _{F 1} of the first grinding wheel 380A, and FIG. 7 (b) are schematic movement locus _{F 2} of the first grinding wheel 385B It is shown. FIG. 7 (c), schematic movement locus _{F 3} of the second grinding wheel 382A is shown. Further, in FIG. 7 (d), schematic movement locus _{F 4} of the second grinding wheel 387B is shown.

  In FIG. 7, the first grinding wheel 380A, the first grinding wheel 385B, the second grinding wheel 382A, and the second grinding wheel 387B move along the X direction (moving direction), thereby The first end surface 256A of the glass material 250 is ground and polished (that is, thinned) in the Y direction.

  Therefore, in FIG. 7, when two positions are compared relatively, the one in the direction (right side) in which the value of X becomes larger is referred to as “front (in)”, and the direction in which the value of X becomes smaller. Those with (on the left) are referred to as “behind”. Further, to stop the movement means to stop the movement in a state where it is in contact with the glass material 250, and the movement in the direction away from the glass material 250 is allowed.

  As shown in FIG. 7, the first side 260 </ b> A of the glass material 250 extends from the start point S to the end point E.

As shown in FIG. 7 (a), the first grinding wheel 380A is the middle of the first side 260A, i.e. in contact with the first end surface 256A in the first grinding start point _{M 1,} the first end face from here 256A grinding starts. Then, the first grinding wheel 380A continues grinding to the end point E of the first side 260A along the moving direction.

As a result, the first end surface 256A corresponding to the first side 260A of the glass material 250, the area to the end point E from the first grinding start point _{M 1} is ground. Hereinafter, this region is referred to as “first grinding region (491)”.

  In the first grinding region 491, the grinding amount (thickness reduction in the Y direction) of the first end surface 256A by the first grinding wheel 380A is, for example, in the range of 0.05 mm to 0.50 mm.

On the other hand, as shown in FIG. 7 (b), the first grinding wheel 385B is the middle of the first side 260A, i.e. in contact with the first end surface 256A in the first polishing start point _{P 1,} first from here The polishing of the end surface 256A of the first is started. Then, the first polishing wheel 385B continues polishing to the end point E of the first side 260A along the moving direction.

As a result, the first end surface 256A of the glass material 250, the area to the end point E from the first polishing start point P ₁ is polished. Hereinafter, this region is referred to as “first polishing region (492)”.

Here, the first polishing start point P ₁ may be any position within the range of the first grinding region 491 excluding the first grinding start point M ₁ and the end point E.

  In the first polishing region 492, the polishing amount of the first end surface 256A by the first polishing wheel 385B is, for example, in the range of 1 μm to 30 μm.

Further, as shown in FIG. 7C, the second grinding wheel 382A comes into contact with the first end face 256A at the start point S of the first side 260A, and from here along the moving direction, the first grinding wheel 382A It moved to the first movement completion point _{N 1} side 260A. Then, the second grinding wheel 382A is when it reaches the first movement completion point N _1, stops moving.

The first movement completion point N ₁ is the first grinding start point M ₁ and than in front, may be any position. It is especially preferred forwardly of the first grinding start point M _1. However, as shown in FIG. 7 (c), the first movement completion point N ₁ is preferably set in a region between the first grinding start point M _{1 ~} first polishing start point P _1.

Thus, the first side 260A of the glass material 250, the second grinding wheel 382A, a region from the start point S moves to the completion point _{N 1} first be ground. Hereinafter, this region is referred to as “second grinding region (493)”.

  In the second grinding region 493, the grinding amount (thickness reduction amount in the Y direction) of the first end surface 256A by the second grinding wheel 382A is substantially equal to the grinding amount in the first grinding region 491 by the first grinding wheel 380A. Equal to

However, normally, the grinding amount in the region from the first grinding start point M ₁ to the first movement completion point N ₁ is not twice the grinding amount in the other regions. This is because the second grinding wheel 382A is composed of a grindstone that hardly deforms as described above. That is, in the region from the first grinding start point M ₁ to the first movement completion point N ₁ , the first end face 256A has already been somewhat thinned in the Y direction by the first grinding wheel 380A. For this reason, even if the second grinding wheel 382 made of a member that is hardly deformed passes through this region, it is difficult to perform the same amount of grinding as the first grinding wheel 380A again. Normally, the grinding amount in the region from the first grinding start point M ₁ to the first movement completion point N ₁ after passing through the second grinding wheel 382 slightly increases as compared with the grinding amount in the other regions. It is.

Further, as shown in FIG. 7 (d), the second polishing wheel 387B contacts the first end surface 256A at the start point S of the first side 260A, and from here the first polishing wheel along the moving direction. move to the completion point _{Q 1.} Then, the second grinding wheel 387B is when it reaches the first polishing end point Q _1, stops moving.

As a result, the first side 260A of the glass material 250, the second grinding wheel 387B, a region from the start point S to the first polishing end point _{Q 1} is polished. Hereinafter, this region is referred to as a “second polishing region (494)”.

Here, as shown in FIG. 7 (c), when the first movement completion point N ₁ is set in a region between the first grinding start point M _{1 ~} first polishing start point P _1, the first polishing end The point Q ₁ may be at any position as long as it is within the range of the first polishing region 492 excluding the first polishing start point P ₁ .

On the other hand, the first movement completion point N ₁ may in front than the first polishing start point P _1, the first polishing end point Q ₁ is, is set to a position ahead of the first movement completion point N _1.

  In the second polishing region 494, the polishing amount of the first end surface 256A by the second polishing wheel 387B is made substantially equal to the polishing amount in the first polishing region 492 by the first polishing wheel 385B.

As a result of the above steps, when the first movement completion point N ₁ is set in the region between the first grinding start point M ₁ and the first polishing start point P ₁ , as shown in FIG. of the two polishing region 494, a region overlapping the first polishing region 492, i.e., in the first region of the polishing start point _{P 1} ~ first polishing end point _{Q 1,} the first grinding wheel 385B and the second grinding wheel Two polishing processes by 387B will be implemented. Accordingly, an overlapping polishing region 495 is formed here.

On the other hand, the first movement completion point N ₁ may in front than the first polishing start point P ₁ is the first region of the movement completion point N _{1 ~} first polishing end point Q _1, overlap polishing region 495 formed Is done.

  As described above, in the overlapping polishing region 495, a smoother surface can be obtained as compared with other regions of the first end surface 256A.

For example, when the arithmetic average roughness in the other region of the first end face 256A is Ra (3) and the arithmetic average roughness in the overlapping polishing region 495 is Ra (4),

Ra (4) / Ra (3) ≦ 0.8 (2) Formula

May be obtained.

(Additional process)
Through the above steps S110 to S120, a glass substrate having the overlapping polished region 495 on the first end face 256A can be manufactured from the glass material 250.

However, the first manufacturing method may additionally perform at least one of the following steps as necessary:
(A) Processing step of second end surface 256B of glass material 250,
(B) Processing step for third end surface 256C of glass material 250, and (c) Processing step for fourth end surface 256D of glass material 250.

  Among these, when the processing step (a) is performed, the glass material 250 may be rotated 90 ° counterclockwise in the processing apparatus 300 shown in FIGS. 5 and 6 described above. In such a state, an overlapping polishing region can be formed on the second end face 256B by performing the above-described steps.

  Further, when the processing step (b) is performed, the glass material 250 may be rotated (counterclockwise) 180 ° in the processing apparatus 300 shown in FIGS. 5 and 6 described above. In such a state, an overlapping polishing region can be formed on the third end face 256C by performing the above-described steps.

  Alternatively, the processing apparatus 300 may include processing means similar to the first grinding wheel 380A and the first grinding wheel 385B, and the second grinding wheel 382A and the second grinding wheel 387B (for example, the third grinding wheel and the first grinding wheel). 3 sets of grinding wheels and a set of 4th grinding wheel and 4th grinding wheel) may be provided. These are arranged so as to face the third side 260 </ b> C of the glass material 250.

  When the processing apparatus 300 has such a configuration, the first end surface 256A and the third end surface 256C of the glass material 250 can be processed at a time. For this reason, a processing speed improves.

  Further, when performing the processing step (c), the glass material 250 may be rotated 90 ° clockwise in the processing apparatus 300 shown in FIGS. 6 and 7 described above. In such a state, an overlapping polishing region can be formed on the fourth end face 256D by performing the above-described steps.

  Further, in the processing steps (a) and (c), when the processing apparatus 300 includes the third grinding wheel and the third grinding wheel, and the fourth grinding wheel and the fourth grinding wheel, glass is used. The material 250 may be rotated 90 ° clockwise or counterclockwise.

  In this case, the second end surface 256B and the fourth end surface 256D of the glass material 250 can be processed at a time. For this reason, a processing speed improves.

  The first manufacturing method using the processing apparatus 300 has been described above. However, the above description is merely an example, and various modifications can be made in the first manufacturing method.

For example, in the step shown in FIG. 7 of the above (a), the first grinding wheel 380A along the sides 260A, the first grinding start point _{M 1,} is moved to the end point E of the sides 260A. As a result, a first grinding region 491 is formed in the region from the first grinding start point M ₁ to the end point E.

However, the first grinding wheel 380A may stop grinding the first end face 256A at any position between the first grinding start point M ₁ and the end point E.

Further, in the step shown in FIG. 7 (c), the second grinding wheel 382A along the sides 260A, from the starting point S, is moved to the first movement completion point _{N 1.} As a result, between the start point S~ first movement completion point _{N 1,} second ground region 493 are formed.

However, the second grinding wheel 382A from any position between the start point S~ first grinding start point _{M 1} (excluding the first grinding start point _{M 1} is), begin grinding the first end face 256A May be.

Similarly, in the step shown in FIG. 7 of the above (b), the first grinding wheel 385B along the edges 260A, the first polishing start point _{P 1,} is moved to the end point E of the sides 260A. As a result, a first polishing region 492 is formed in the region from the first polishing start point P ₁ to the end point E.

However, the first polishing wheel 385B may stop polishing the first end face 256A at any position between the first polishing start point P ₁ and the end point E.

Similarly, in the step shown in FIG. 7 of the aforementioned (d), the second grinding wheel 387B along the edges 260A, from the starting point S, is moved to the first polishing end point _{Q 1.} As a result, the starting point S~ first region of the polishing end point _{Q 1,} the second polishing region 494 is formed.

However, the second grinding wheel 387B from any position in the range of the start point S~ first polishing start point _{P 1} (excluding the first polishing start point _{P 1} is), begins polishing the first end face 256A May be. The second grinding wheel 387B is a front than the first movement completion point N _1, and may be moved to any position as long as it is within range of the first polishing region 492.

  Further, the grinding by the second grinding wheel 382A (second grinding) may be started at any timing as long as the second grinding wheel does not pass the first grinding wheel. Similarly, the polishing by the second polishing wheel 387B (second polishing) may be started at any timing as long as the second polishing wheel does not pass the first polishing wheel. For example, the start of the second grinding is preferably performed at the same time as the grinding by the first grinding wheel 380A (first grinding) or before completion such as during execution. Similarly, the second polishing is preferably started at the same time as the polishing by the first polishing wheel 385B (first polishing) or before completion, such as during execution. Furthermore, it is preferable that the second grinding by the second grinding wheel 382A is before completion, such as before the start of the first grinding by the first grinding wheel 385B, at the same time, or during execution.

  That is, after the steps shown in FIGS. 7A and 7C are completed, the steps shown in FIGS. 7B and 7D may be performed. From the viewpoint of productivity, FIG. ) And (c) start at the same time or close timing, and before the steps of FIGS. 7A and 7C are completed, the steps of FIGS. 7B and 7D are started. Is preferred.

  In addition, one grinding wheel and two grinding wheels are paired, and a region ground with the grinding wheel is ground with the first grinding wheel, and at least a part of the region ground with the first grinding wheel overlaps. As described above, polishing may be performed with the second polishing wheel.

Further, the second polishing step may be performed between the first polishing start point P ₁ and the first polishing completion point Q ₁ .

  It will be readily apparent to those skilled in the art that other various modifications are possible.

(Method of manufacturing a glass substrate according to another embodiment of the present invention)
Next, a glass substrate manufacturing method (hereinafter referred to as “second manufacturing method”) according to another embodiment of the present invention will be described.

  In the first manufacturing method described above, one overlapping polishing region 495 is formed on at least one end surface of the glass material 250 (for example, the first end surface 256A). In contrast, in the second manufacturing method, a plurality of overlapping polishing regions are formed on one end surface of the glass material.

  Hereinafter, the second manufacturing method will be described with reference to FIGS.

  FIG. 8 schematically shows a flow of the second manufacturing method. 9 to 11 schematically show the state of one step in the second manufacturing method.

As shown in FIG. 8, the second manufacturing method is:
(1) a step of preparing a glass material having first and second surfaces and an end face connecting both surfaces (step S210);
(2) A step of grinding and polishing the end face of the glass material using a second processing apparatus (step S220);
Have

  Hereinafter, each step will be described in detail with reference to FIGS. 9 to 11.

(Step S210)
This step S210 is the same as step S110 in the first manufacturing method described above. Therefore, details of this step are omitted. In the following description, the reference numerals shown in FIG. 4 are used for representing each part of the glass material for the sake of clarity.

(Step S220)
Next, the end surface of the glass material 250 is processed using the second processing apparatus. Here, as an example, a case where the first end surface 256A of the glass material 250 is processed will be described.

(Second processing equipment)
In FIG. 9, the structure of the 2nd processing apparatus which can be used for a 2nd manufacturing method is shown typically.

  As shown in FIG. 9, the second processing apparatus 500 includes a table 502, first to third grinding wheels 580A to 584A, and first to third polishing wheels 585B to 589B.

  Among these, the configuration and functions of the table 502, the first and second grinding wheels 580A and 582A, and the first and second grinding wheels 585B and 587B are the same as those of the processing apparatus 300 described above. Therefore, details are omitted here.

  The third grinding wheel 584A can grind the first end face 256A of the glass material 250. The third polishing wheel 589B can polish the first end face 256A of the glass material 250.

  The first grinding wheel 580A and the first grinding wheel 585B form a pair, and the first grinding wheel 585B can follow the grinding process of the first grinding wheel 580A later. Similarly, the second grinding wheel 582A and the second grinding wheel 587B are paired, and the second grinding wheel 587B can follow the grinding process of the second grinding wheel 582A later. . Further, the third grinding wheel 584A and the third grinding wheel 589B are in a set, and the third grinding wheel 589B can follow the grinding process of the third grinding wheel 584A later.

  The third grinding wheel 584A is made of a grindstone that hardly undergoes elastic deformation and has a high grinding force. On the other hand, the third polishing wheel 589B is made of a grindstone having elasticity and suitable for polishing.

  When the first end surface 256A of the glass material 250 is processed by the second processing device 500, the glass material 250 is placed on the table 502 of the second processing device 500, as shown in FIG. . At this time, the glass material 250 is placed on the table 302 so that the first side 260A faces the first to third grinding wheels 580A to 584A.

  Next, the first grinding wheel 580A and the first polishing wheel 585B of the second processing apparatus 500 are rotated at a predetermined number of rotations. Further, the second grinding wheel 582A and the second polishing wheel 587B are rotated at a predetermined rotational speed. Further, the third grinding wheel 584A and the third polishing wheel 589B are rotated at a predetermined rotational speed.

Next, as shown in FIG. 10, the first grinding wheel 580A is, while in contact with the first end surface 256A of the glass material 250, along the first side (the surface to be processed) 260A, the arrow _{A 1} Move in the direction. Hereinafter, the direction of the arrow A _1, referred to as "moving direction". The first end face 256A of the glass material 250 is ground by the movement of the first grinding wheel 580A.

Further, after the first grinding wheel 580A starts grinding the first end surface 256A, the first polishing wheel 585B is in contact with the first end surface 256A of the glass material 250 while the first grinding wheel 580A is ground. along the sides 260A, moves in the direction of arrow _{a 2.} Here, the arrow A ₂ is the same direction as the arrow A ₁ , that is, the “movement direction”.

  By the movement of the first polishing wheel 585B, the region of the first end face 256A of the glass material 250 that has been ground by the first grinding wheel 580A is polished.

The first grinding wheel 580A is substantially simultaneously with the grinding of the first end face 256A, or after a while, the second grinding wheel 582A is in contact with the first end face 256A of the glass material 250 while the first end face 256A is in contact with the first end face 256A. along the sides 260A, moves in the direction of arrow _{a 3.} The arrow A ₃ is the same direction as the arrow A ₁ (the X direction in FIG. 6), that is, the “movement direction”. The first end face 256A of the glass material 250 is ground by the movement of the second grinding wheel 382A.

Further, after a while after the grinding of the first end surface 256A by the second grinding wheel 582A is started, the second polishing wheel 587B is in contact with the first end surface 256A of the glass material 250 while the first end surface 256A is in contact with the first end surface 256A. along the sides 260A, moves in the direction of arrow _{a 4.} Arrow _{A 4} is, (X direction in FIG. 6) the same direction as the arrow _{A 1,} that is, "moving direction".

  By the movement of the second polishing wheel 587B, the region of the first end surface 256A of the glass material 250 that has been ground by the second grinding wheel 582A is polished.

In addition, the third grinding wheel 584A is in contact with the first end surface 256A of the glass material 250 while the first grinding is performed almost simultaneously with or after the first grinding of the first end surface 256A by the second grinding wheel 582A. along the sides 260A, moves in the direction of arrow _{a 5.} Arrow _{A 5} represents, (X direction in FIG. 6) the same direction as the arrow _{A 1,} that is, "moving direction". By the movement of the third grinding wheel 584A, the first end face 256A of the glass material 250 is ground.

Further, after a while after the grinding of the first end face 256A by the third grinding wheel 584A is started, the third polishing wheel 589B is in contact with the first end face 256A of the glass material 250 while the first end face 256A is in contact with the first end face 256A. along the sides 260A, moves in the direction of arrow _{a 6.} The arrow A ₆ is the same direction as the arrow A ₁ (the X direction in FIG. 6), that is, the “movement direction”.

  By the movement of the third polishing wheel 589B, the region of the first end surface 256A of the glass material 250 ground by the third grinding wheel 584A is polished.

  Thereby, the grinding and polishing of the entire first side 260A of the glass material 250 is completed, and the glass substrate on which the first end surface 256A of the glass material 250 is processed is manufactured.

  FIG. 11 includes a first grinding wheel 580A, a first grinding wheel 585B, a second grinding wheel 582A, a second grinding wheel 587B, a third grinding wheel 584A, and a third grinding wheel 589B. A movement locus is shown typically.

Figure 11 is (a), and schematic movement locus _{F 1} of the first grinding wheel 580A, and FIG. 11 (b) are schematic movement locus _{F 2} of the first grinding wheel 585B has been shown, in FIG. 11 (c), are schematic movement locus _{F 3} of the second grinding wheel 582A is shown in FIG. 11 (d) schematically the second grinding wheel 587B specific are moving locus _{F 4} is shown, in FIG. 11 (e), the third and schematic movement locus _{F 5} of the grinding wheel 584A is shown in FIG. 11 (f), the third schematic movement locus F ₆ abrasive wheel 589B is shown.

  In FIG. 11, the first grinding wheel 580A and the first grinding wheel 585B, the second grinding wheel 582A and the second grinding wheel 587B, and the third grinding wheel 584A and the third grinding wheel 589B are all. It moves along the X direction (moving direction), and thereby the first end surface 260A of the glass material 250 is ground and polished (that is, thinned) in the Y direction.

As shown in FIG. 11 (a), the first grinding wheel 580A is the middle of the first side 260A, i.e. in contact with the first end surface 256A in the first grinding start point _{M 1,} the first end face from here 256A grinding starts. Then, the first grinding wheel 380A continues grinding to the end point E of the first side 260A along the moving direction.

As a result, the first end surface 256A corresponding to the first side 260A of the glass material 250, the area to the end point E from the first grinding start point _{M 1} is ground. Hereinafter, this region is referred to as “first grinding region (691)”.

On the other hand, as shown in FIG. 11 (b), the first grinding wheel 585B is the middle of the first side 260A, i.e. in contact with the first end surface 256A in the first polishing start point _{P 1,} first from here The polishing of the end surface 256A of the first is started. Then, the first polishing wheel 585B continues polishing to the end point E of the first side 260A along the moving direction.

As a result, the first end surface 256A of the glass material 250, the area to the end point E from the first polishing start point P ₁ is polished. Hereinafter, this region is referred to as a “first polishing region (692)”.

Here, the first polishing start point P ₁ may be any position within the range of the first grinding region 691 excluding the first grinding start point M ₁ and the end point E.

Further, as shown in FIG. 11 (c), the second grinding wheel 582A is the middle of the first side 260A, i.e. in contact with the first end face 256A in the second grinding start point _{M 2,} moving direction from here along the middle of the first side 260A, it is moved or move to completion point _{N 1} first. Then, the second grinding wheel 582A is when it reaches the first movement completion point N _1, stops moving.

Here, the second grinding start point M ₂ except the starting point S and the first grinding start point M ₁ side 260A, as long as it is within the range of the start point S~ first grinding start point M _1, any position It may be. The first movement completion point N ₁ may be any position of the forward first grinding start point M ₁ and than that. It is especially preferred forwardly of the first grinding start point M _1. However, as shown in FIG. 11 (c), the first movement completion point N ₁ it is preferably set in a region between the first grinding start point M _{1 ~} first polishing start point P _1.

Thus, the first side 260A of the glass material 250, the second grinding wheel 582A, the region of the second grinding start point _{M 2} moves to completion point _{N 1} first is ground. Hereinafter, this region is referred to as a “second grinding region (693)”.

Further, as shown in FIG. 11 (d), the second grinding wheel 587B is the middle of the first side 260A, i.e. in contact with the first end face 256A in the second polishing start point _{P 2,} the movement direction from here along the middle of the first side 260A, it is moved that is, until the first polishing end point _{Q 1.} Then, the second grinding wheel 587B is when it reaches the first polishing end point Q _1, stops moving.

As a result, the first side 260A of the glass material 250, the second grinding wheel 587B, a region from the second polishing start point _{P 2} to the first polishing end point _{Q 1} is being polished. Hereinafter, this region is referred to as a “second polishing region (694)”.

Second polishing start point P ₂ except the second grinding start point M ₂ and the first grinding start point M _1, if the second range of grinding start point M _{2 ~} first grinding start point M _1, any It may be the position.

Here, as shown in FIG. 11 (c), when the first movement completion point N ₁ is set in a region between the first grinding start point M _{1 ~} first polishing start point P _1, the first polishing end The point Q ₁ may be at any position as long as it is within the range of the first polishing region 692 excluding the first polishing start point P ₁ .

On the other hand, the first movement completion point N ₁ may in front than the first polishing start point P _1, the first polishing end point Q ₁ is, is set to a position ahead of the first movement completion point N _1.

When the first movement completion point N ₁ is set in the region between the first grinding start point M ₁ and the first polishing start point P ₁ , as shown in FIG. In the region overlapping with the first polishing region 692, that is, in the region from the first polishing start point P ₁ to the first polishing completion point Q ₁ , the first polishing wheel 385B and the second polishing wheel 387B perform two times. A polishing process will be performed. Accordingly, a first overlapping polishing region 695 is formed here.

On the other hand, when the first movement completion point N ₁ is at the front than the first polishing start point P ₁ is the first region of the movement completion point N _{1 ~} first polishing end point Q _1, the first overlap polishing region Is formed.

Further, as shown in FIG. 11 (e), the third grinding wheel 584A comes into contact with the first end surface 256A at the start point S of the first side 260A, and from here along the moving direction, the first grinding wheel 584A moving the second to the movement completion point _{N 2} sides 260A. The third grinding wheel 584A is when it reaches the second movement completion point N _2, it stops moving.

The second movement completion point N _2, the second grinding start point M ₂ and than in front, may be any position. It is especially preferred forward than the second grinding start point M _2. However, as shown in FIG. 11 (e), the second movement completion point N ₂ is preferably set in a region between the second grinding start point M _{2 ~} second polishing start point P _2.

Thus, the first side 260A of the glass material 250, by a third grinding wheel 584A, a region from the start point S to the second movement completion point _{N 2} are ground. Hereinafter, this region is referred to as “third grinding region (696)”.

Further, as shown in FIG. 11 (f), the third polishing wheel 589B contacts the first end face 256A at the starting point S of the first side 260A, and the second polishing wheel extends from here along the moving direction. move to the completion point _{Q 2.} The third grinding wheel 589B is when it reaches the second polishing end point Q _2, stops moving.

As a result, the first side 260A of the glass material 250, by a third grinding wheel 589B, a region from the start point S to the second polishing end point _{Q 2} are polished. Hereinafter, this region is referred to as “third polishing region (697)”.

Here, as shown in FIG. 11 (e), when the second movement completion point N ₂ is set in a region between the second grinding start point M _{2 ~} second polishing start point P _2, the second polishing end point Q ₂ are excluding second polishing start point P _2, as long as it is within range of the second polishing region 694, may be any position.

The second movement completion point N ₂ cases in the front than the second polishing start point P _2, the second polishing end point Q ₂ are set to a position ahead of the second movement completion point N _2.

When the second movement completion point N ₂ is set in a region between the second grinding start point M ₂ and the second polishing start point P ₂ , as shown in FIG. In the region overlapping with the second polishing region 694, that is, in the region from the second polishing start point P ₂ to the second polishing completion point Q ₂ , the second polishing wheel 587B and the third polishing wheel 589B are operated twice. A polishing process will be performed. Accordingly, a second overlapping polishing region 697 is formed here.

On the other hand, when the first movement completion point N ₂ is ahead of the second polishing start point P ₂ , the second overlapping polishing region is in the region of the second movement completion point N ₂ to the second polishing completion point Q _2. Is formed.

  As a result of the above steps, two overlapping polishing regions 695 and 698 can be formed on the first end surface 256A.

  The second manufacturing method using the second processing apparatus 500 has been described above. However, the above description is merely an example, and various changes can be made in the second manufacturing method.

For example, in the step shown in FIG. 11 of the aforementioned (a), the first grinding wheel 580A along the sides 260A, the first grinding start point _{M 1,} is moved to the end point E of the sides 260A. As a result, a first grinding region 691 is formed in the region from the first grinding start point M ₁ to the end point E.

However, the first grinding wheel 580A may stop grinding the first end face 256A at any position between the first grinding start point M ₁ and the end point E.

Further, in the step shown in FIG. 11 (b) described above, the first grinding wheel 585B along the edges 260A, the first polishing start point _{P 1,} is moved to the end point E of the sides 260A. As a result, a first polishing region 692 is formed in the region from the first polishing start point P ₁ to the end point E.

However, the first polishing wheel 585B may stop polishing the first end face 256A at any position between the first polishing start point P ₁ and the end point E.

Further, in the step shown in FIG. 11 (e), the third grinding wheel 584A along the sides 260A, from the starting point S, is moved to the second movement completion point _{N 2.} As a result, between the start point S~ second grinding start point _{M 2,} third ground region 696 are formed.

However, the third grinding wheel 584A from any position of the start point S~ second range of grinding start point M _2, may start the grinding of the first end surface 256A.

Further, in the step shown in FIG. 11 of the aforementioned (f), the third grinding wheel 589B along the edges 260A, from the starting point S, is moved to the second polishing end point _{Q 2.} As a result, the area of the start point S~ second polishing end point _{Q 2,} the third polishing region 697 is formed.

However, the third grinding wheel 589B from any position in the range of the start point S~ second polishing start point _{P 2} (excluding the second polishing start point _{P 2} are), begins polishing the first end face 256A May be.

  In the second manufacturing method described above, the grinding by the second grinding wheel 582A (second grinding) is started at any timing as long as the second grinding wheel 582A does not pass the first grinding wheel 580A. May be. Further, the grinding by the third grinding wheel 584A (third grinding) may be started at any timing as long as the third grinding wheel 584A does not pass the second grinding wheel 582A.

  Similarly, the polishing by the second polishing wheel 587B (second polishing) may be started at any timing as long as the second polishing wheel 587B does not pass the first polishing wheel 585B. Further, the polishing by the third polishing wheel 589B (third polishing) may be started at any timing as long as the third polishing wheel 589B does not pass the second polishing wheel 587B.

  In particular, the start of the second grinding is preferably performed at the same time as the first grinding or before completion such as during execution. Moreover, it is preferable that the start of the third grinding is simultaneously with the second grinding or before completion such as during execution.

  Similarly, the second polishing is preferably started at the same time as the first polishing or before completion, such as during the execution. The start of the third polishing is preferably at the same time as the second polishing or before completion such as during execution.

  Furthermore, it is preferable that the second grinding by the second grinding wheel 582A is before completion, such as before the start of the first grinding by the first grinding wheel 585B, at the same time, or during execution. Further, the third grinding by the third grinding wheel 584A is preferably performed before the completion of the second polishing by the second polishing wheel 587B, at the same time, or before completion.

  That is, after the steps shown in FIGS. 11A, 11C, and 11E are completed, the steps shown in FIGS. 11B, 11D, and 11F may be performed. 11 (a), (c) and (e) start at the same time or close to the timing, and before the steps of FIGS. 11 (a), (c) and (e) are completed. 11 (b), (d) and (f) are preferably started.

  Various other changes are possible.

  The method for forming two overlapping polishing regions on one end surface 256 </ b> A of the glass material 250 using the second processing apparatus 500 has been described above.

  From the above description, those skilled in the art can easily grasp a method of forming three or more overlapping polishing regions on one end face. For example, three or more overlapping polishing regions may be formed on one end face by providing additional grinding wheels and polishing wheels in the processing apparatus.

  The embodiment of the present invention has been described above. However, the aspect of the present invention is not limited to the above form.

  For example, in the above description, the method for manufacturing a glass substrate has been described by taking as an example the case where the glass material has a substantially rectangular shape. However, the glass material may have other shapes, for example, a disk shape.

  When the glass material is disk-shaped, the term “circumference” is used instead of “side” in the description of the first manufacturing method and the second manufacturing method. Further, by grasping that the end point E coincides with the start point S among the start point S and the end point E in the above-described side, even when the end surface is “circumferential”, the end surface is “side” -shaped. As with any case, it can be handled.

  For example, the processing apparatus 300 used for the first manufacturing method includes a plurality of grinding wheels and a plurality of polishing wheels arranged along the circumference of the glass material. Each grinding wheel and each polishing wheel are moved along a “movement direction” corresponding to the circumferential direction of the glass material.

  It will be readily appreciated by those skilled in the art that other various modifications are possible.

DESCRIPTION OF SYMBOLS 110 1st glass substrate 112 1st surface 114 2nd surface 116A 1st end surface 116B 2nd end surface 116C 3rd end surface 116D 4th end surface 120 General area | region 122 Smooth area | region 250 Glass material 252 1st surface 254 Second surface 256A to 256D End face 260A to 260D Side (surface to be processed)
DESCRIPTION OF SYMBOLS 300 Processing apparatus 302 Table 380A 1st grinding wheel 382A 2nd grinding wheel 385B 1st grinding wheel 387B 2nd grinding wheel 491 1st grinding area 492 1st grinding area 493 2nd grinding area 494 2nd grinding area 495 Overlapping polishing region 500 Second processing device 502 Table 570 First processing means 572 Second processing means 574 Third processing means 580A First grinding wheel 580B First polishing wheel 582A Second grinding wheel 582B Second Polishing wheel 584A Third grinding wheel 584B Third grinding wheel 691 First grinding region 692 First grinding region 693 Second grinding region 694 Second grinding region 695 First overlapping grinding region 696 Third grinding region 697 Third Polishing area 698 Second overlapping polishing area E end point M ₁ first grinding start point M ₂ second grinding start point N ₁ first movement completion point N ₂ second movement completion point P ₁ first polishing start point P ₂ second polishing start point Q ₁ first polishing Completion point Q ₂ Second polishing completion point S Start point

Claims (14)

A glass substrate having an end face connecting two surfaces,
A smooth region is disposed on at least a part of the end surface, and the smooth region has a smooth surface compared to other regions of the end surface,
The other region of the end face is referred to as a general region,
When the arithmetic average roughness of the general region is Ra (1) and the arithmetic average roughness of the smooth region is Ra (2), the ratio Ra (2) / Ra (1) is 0.8 or less. The
Said end face have a first length _{L 1} and a second length _{L 2,} where a _{L 1} ≧ _{L 2,}
The smooth region, the in the first direction of a length L _1, the glass substrate characterized by having a 10mm or less of the total length than 1 mm. The glass substrate according to claim 1, wherein a plurality of the smooth regions exist on the end surface. The glass substrate is rectangular and has first to fourth end faces,
Said end face, the first, at least one of the fourth end surface of the glass substrate of claim 1 or 2. Said Ra (1) is a glass substrate as described in any one of Claims 1 thru | or 3 which is 0.2 micrometer or less.   Said Ra (2) is a glass substrate as described in any one of Claims 1 thru | or 4 which is 0.12 micrometer or less. A method of manufacturing a glass substrate,
(1) preparing a glass material having first and second surfaces and end faces connecting both surfaces;
(2) A step of grinding and polishing the end face of the glass material using a processing apparatus;
Have
The end surface is viewed as a surface to be processed from a top view of the glass material, a start point S to an end point E,
The processing apparatus includes a first grinding wheel and a first polishing wheel, a second grinding wheel and a second polishing wheel,
The first and second grinding wheels move along the work surface in a direction from the start point S toward the end point E, which is referred to as a moving direction, thereby grinding the end face of the glass material. Can
The first grinding wheel can polish the region of the end face of the glass material ground by the first grinding wheel by moving along the work surface in the movement direction, The second polishing wheel can polish the region of the end face of the glass material ground by the second grinding wheel by moving along the workpiece surface in the moving direction,
In the step (2),
(2-1) said first grinding wheel, from said position except the start point S and end point E of the workpiece surface, the surface of the workpiece along the moving direction, called the first grinding start point M ₁ Move and
Thereby, a region called a first grinding region is formed on the end face,
(2-2) said first grinding wheel, first polishing start point called P _1, from any position other than the first grinding start point M ₁ of the first ground area, along the movement direction To move the workpiece surface,
Thereby, a region called a first polishing region is formed on the end face,
(2-3) the second grinding wheel from a position called the second grinding start point M _2, along the moving direction, the moving the workpiece surface to a position called the first movement completion point N ₁ ,
Thus, the end surface is ground in a region called a second grinding region from the second grinding start point M ₂ to the first movement completion point N ₁ ,
It said second grinding start point M ₂ is present between the starting point S~ the first grinding start point M _1,
The first movement completion point N ₁ is
(I) exists between the first grinding start point M ₁ and the first polishing start point P ₁ excluding the first polishing start point P ₁ , or (ii) the first polishing start point P _1- Exists between end points E,
(2-4) the second grinding wheel from the position called the second polishing start point P _2, along the moving direction, the moving the workpiece surface to a position called the first polishing end point Q ₁ ,
Thus, the end surface is polished in a region called a second polishing region from the second polishing start point P ₂ to the first polishing completion point Q ₁ .
The second polishing start point P ₂ is present between the second grinding start point M _{2 ~} the first grinding start point M _1,
The first polishing end point Q ₁ is the case of the (i), except for the first polishing start point P _1, present in the first polishing region, the case of the (ii), the first polishing start Existing in the first polishing region excluding the point P ₁ to the first movement completion point N ₁ ,
In the case of (i), polishing is performed by the first and second polishing wheels between the first polishing start point P _{1 on} the end surface and the first polishing completion point Q ₁ (first). An overlapping polishing region is formed,
In the case of (ii), polishing is performed by the first and second polishing wheels between the first movement completion point N ₁ to the first polishing completion point Q ₁ of the end face (first). A method for producing a glass substrate, wherein an overlapping polishing region is formed. The method of manufacturing a glass substrate according to claim 6 , wherein the step (2-3) is started before the completion of the step (2-1). The method of manufacturing a glass substrate according to claim 6 or 7 , wherein the step (2-3) is started before the completion of the step (2-2). In the (2-1), the first grinding wheel moves from the first grinding start point M ₁ to the end point E,
In the (2-2), the first grinding wheel moves from the first polishing start point P ₁ to the end point E, the production of a glass substrate according to any one of claims 6 to 8 Method. Wherein said second grinding start point M ₂ in (2-3) is the starting point S of the surface to be processed,
The second polishing start point P _2, said a starting point S of the surface to be processed, method of manufacturing a glass substrate according to any one of claims 6 to 9 in the (2-4). The said 1st grinding wheel and / or 2nd grinding wheel are the manufacturing methods of the glass substrate as described in any one of Claims 6 thru | or 10 which have a metal bond grindstone or an electrodeposition grindstone which has a diamond abrasive grain. The method for producing a glass substrate according to any one of claims 6 to 11 , wherein the first polishing wheel and / or the second polishing wheel has a rubber, nonwoven fabric, or resin grindstone. The processing apparatus further includes a third grinding wheel and a third polishing wheel,
The third grinding wheel can grind the end face of the glass material by moving along the work surface in the moving direction,
The third polishing wheel can polish the region of the end face of the glass material ground by the third grinding wheel by moving along the work surface in the moving direction,
In the step (2),
(2-5) the third grinding wheel, from a position called the third grinding start point M _3, along the moving direction, moving the workpiece surface to a position called second movement completion point N ₂ ,
Thus, the end surface is ground in a region called a third grinding region from the third grinding start point M ₃ to the second movement completion point N ₂ ,
The third grinding start point M ₃ are present between the starting point S~ the second grinding start point M _2,
The second movement completion point N ₂ is
(Iii) Present between the second grinding start point M ₂ and the second polishing start point P ₂ excluding the second polishing start point P ₂ , or (iv) the second polishing start point P ₂ ˜ Exists between end points E,
(2-6) the third polishing wheel from the position called third polishing start point P _3, along the moving direction, the moving the workpiece surface to a position called the second polishing end point Q ₂ ,
Thereby, the end face is polished in a region called a third polishing region from the third polishing start point P ₃ to the second polishing completion point Q ₂ ,
The third polishing start point P ₃ is present between the third grinding start point M _{3 ~} the second grinding start point M _2,
The second polishing end point Q ₂ are the case of the (iii), except for the second polishing start point P _2, present in the second polishing region, the case of the (iv), the second polishing start Existing in the second polishing region excluding the point P ₂ to the second movement completion point N ₂ ,
In the case of (iii), the second overlapping polishing polished by the second and third polishing wheels between the second polishing start point P ₂ and the second polishing completion point Q ₂ of the end face. A region is formed,
In the case of (iv), the second overlapping polishing polished by the second and third polishing wheels between the second movement completion point N ₂ to the second polishing completion point Q ₂ of the end face. region is formed, Ru, method of manufacturing a glass substrate according to any one of claims 6 to 12. Wherein (2-5) the third grinding start point M ₃ in is the starting point S of the surface to be processed,
The third polishing start point P _3, the a start point S of the surface to be processed, method of manufacturing a glass substrate according to claim 13 in the (2-6).

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