JP5370913B2 - Glass substrate end surface polishing apparatus and end surface polishing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve productivity by largely shortening the time required for chamfering treatment of the end edge while simplifying a device required for polishing, reducing its cost, and improving quality of the periphery of a chamfering surface applied to the end edge of a glass substrate. <P>SOLUTION: A chamfering treatment is applied to the end edges 7x, 7y of the glass substrate 7 by rotating a polishing tool 1 around a rotating axis 8 while relatively moving rectilinearly with respect to the end edges 7x, 7y where front and back surfaces 7a, 7b and the end surface 7c of the glass substrate 7 intersect with each other. In the polishing surface of the polishing tool 1, a roughness degree of the polishing surface 3a of an outer peripheral side is smaller than the roughness degree of the polishing surface 4a of an inner peripheral side, and when the polishing tool 1 relatively moves rectilinearly with respect to the end edges 7x, 7y of the glass substrate 7, the chamfering surfaces are respectively formed on the end edges 7x, 7y of the glass substrate 7 by the both polishing surfaces 3a, 4a on an outer peripheral side and an inner peripheral side. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a glass substrate end surface polishing apparatus and an end surface polishing method thereof, and more specifically, a chamfering treatment is performed on an edge where the front and back surfaces of the glass substrate intersect with an end surface by a polishing tool having a polishing surface orthogonal to a rotation axis. It relates to technology.

  As is well known, various glass substrates represented by flat panel displays (FPD) such as liquid crystal displays (LCDs) are divided into predetermined dimensions after the glass original plate is produced by the overflow down draw method or the float method. It is manufactured by doing. This glass original is divided by using a diamond cutter, etc., after scribing on the surface of the glass original, folding the glass original so that the tensile stress is concentrated starting from the scribe marks. Is adopted.

  As shown in FIG. 5, the glass substrate manufactured by such a method has minute cracks at the edges 17x and 17y where the front and back surfaces 17a and 17b and the end surface (divided surface) 17c of the glass substrate 17 intersect. And glass powder are inevitably generated. Specifically, when a scribe is put on the surface of the glass original plate with a diamond cutter or the like, a minute region on the surface of the glass original plate is destroyed, and a minute crack called a median crack is generated in the thickness direction from the surface of the glass original plate.

  Furthermore, in the method of scribing the surface of the glass original plate with a diamond cutter or the like, not only the plate thickness direction but also the surface breaking force acts on the surface of the glass original plate, and a lateral crack of about 100 to 150 μm A minute crack called as a result is generated. This lateral crack causes a minute glass piece to be peeled off from the surface of the glass original plate, thereby causing minute glass powder to adhere to the front and back surfaces of the glass substrate. If such a small amount of glass powder adheres to the front and back surfaces of the glass substrate, for example, in the FPD manufacturing process, the electrode and wiring are disconnected, and as a result, the FPD manufacturing efficiency and product characteristics are impaired. It becomes difficult to remove the adhered fine glass powder by washing or the like.

  On the other hand, in recent years, as a method for avoiding such a problem, when a scribe is inserted, a method called laser scribe is employed to divide the glass original plate. This method irradiates the surface of the glass original plate with laser light, heats and expands the micro area of the glass original board, cools and shrinks the micro area, and utilizes the stress generated by the thermal expansion of the glass, A scribe is put in and the glass original plate is divided.

  This laser scribe is less likely to generate minute cracks (particularly lateral cracks) in the vicinity of the end face 17c and the end edges 17x and 17y of the glass substrate 17 than the technique of scribing with a diamond cutter or the like, and the obtained end face. Is also smooth. However, the glass substrate divided by the laser scribe has a substantially perpendicular crossing angle between the front and back surfaces and the end surface, and the edge of the glass substrate becomes extremely brittle. Then, when it comes into contact with a pin or the like of the positioning device, a defect or a minute crack is likely to occur at the contact portion.

  Under the circumstances as described above, since it is necessary to remove minute cracks (particularly lateral cracks), the front and back surfaces 17a and 17b and the end surface 17c of the glass substrate 17, particularly the edge 17x, are required to meet the demand. , 17y is polished.

  As a specific example, in paragraphs [0008] and [0009] of the specification in Patent Document 1, first, a first grindstone having a polished surface with a large roughness on an outer surface parallel to the rotation axis is used. The entire end face of the substrate is roughly polished in an R shape to be chamfered in a circular shape, and thereafter, the chamfered portion is finish-polished using a second grindstone having a polishing surface having a low roughness perpendicular to the rotation axis. It is described.

  Further, in paragraphs [0029] and [0033] of the specification in Patent Document 2, first, an end surface of a glass substrate is obtained by using an auxiliary polishing grindstone having a polishing surface having a large roughness on an outer surface parallel to the rotation axis. And a preliminary rough polishing of the edge, and then performing a main polishing of the rough polishing processing portion using a concave grindstone having a polishing surface with a low roughness on the outer surface parallel to the rotation axis. ing.

  Furthermore, in paragraph [0016] of the specification in Patent Document 3, etc., the abrasive grains on the bottom of the blade (concave bottom) are roughened and the blade is roughened on the concave polishing surface formed on the outer surface parallel to the rotation axis. It describes that chamfering of a glass substrate is performed using a chamfering total-type grindstone in which abrasive grains are gradually made finer as the distance from the bottom portion increases.

  Note that paragraphs [0060], [0061], etc. of the specification in Patent Document 4 have a circular polished surface disposed on the pedestal and perpendicular to the rotation axis, and the roughness of the inner peripheral portion of the polished surface. In addition to increasing the roughness and decreasing the roughness of the outer peripheral portion, the object to be polished such as a wafer is first subjected to rough cutting at the inner peripheral portion of the polishing surface and then finish-cutting at the outer peripheral portion of the polishing surface. Has been.

JP 2002-59346 A JP-A-10-277899 JP-A-11-267975 JP 2000-176829 A

  Incidentally, the polishing means described in Patent Document 1 and Patent Document 2 described above require two types of polishing tools (polishing grindstones) and two types of driving devices that rotationally drive them. The apparatus required for this is complicated and large in size, and the manufacturing cost of the apparatus increases.

  Moreover, both of the polishing means described in these two documents are configured to first perform rough polishing using a polishing grindstone having a high roughness and then perform final polishing using a polishing grindstone having a low roughness. Therefore, it is difficult or impossible to increase the processing speed, and the productivity is lowered. That is, if a grinding wheel having a large roughness is linearly moved at a high speed with respect to the edge of the glass substrate to form a desired chamfered surface on the edge, the front and back surfaces of the glass substrate and the chamfered surface There is a possibility that chipping, cracking, or the like may occur in the intersecting region or the region where the end surface of the glass substrate and the chamfered surface intersect. Even if this kind of chipping, cracking, or the like is minute, it not only causes a decrease in the end face strength of the glass substrate, but also causes a breakage of the glass substrate during subsequent transport or heat treatment. For this reason, it is necessary to move the polishing grindstone having a large roughness at a low speed and, after that, it is necessary to separately perform the final polishing, so that the processing speed is greatly reduced, and the productivity is inevitably lowered.

  Moreover, according to the grinding | polishing means described in said patent document 3, the plate thickness direction center part of the end surface of a glass substrate is only rough-cut by a rough abrasive grain, and the edge where the front and back surfaces and end surface of a glass substrate cross | intersect The edges are only finished with fine abrasive grains. Therefore, no rough cutting is performed on the edge of the glass substrate, and as a result, the time required to form a desired chamfered surface on the edge is unreasonably long. This causes a problem that the performance is greatly reduced.

  Note that the polishing means described in Patent Document 4 has a technical idea that the object to be polished, such as a wafer, is transferred from the inner peripheral portion for rough cutting of the polishing surface to the outer peripheral portion for finishing. In this way, the method of merely transferring the object to be polished from the inner peripheral portion of the polishing surface to the outer peripheral portion moves the edge of the glass substrate linearly from the inner peripheral portion of the polishing surface to the outer peripheral portion. Thus, it is substantially impossible to chamfer the edge. Moreover, since the roughing is first performed and then the finishing is performed, even if this polishing tool is applied to the chamfering processing of the edge of the glass substrate, it is difficult to increase the processing speed as already described or It is inevitable that it will become impossible and cause a decline in productivity.

  In view of the above circumstances, the present invention simplifies and reduces the cost of an apparatus required for polishing, and improves the quality of the periphery of the chamfered surface applied to the edge of the glass substrate, and the time required for the chamfering process of the edge. It is a technical problem to improve productivity by significantly shortening the above.

The apparatus according to the present invention, which has been created to solve the above technical problem, is such that a polishing tool having a polishing surface orthogonal to the rotation axis is relative to the edge where the front and back surfaces and the end surface of the glass substrate intersect. In the glass substrate end surface polishing apparatus configured to be chamfered on the edge of the glass substrate by rotating around the rotation axis while linearly moving, the rotation axis of the polishing tool is one. , the polishing surface of the polishing tool is constituted by the inner peripheral side a plurality of partial polishing surface for forming a且one face-up surfaces are arranged in compartments over the outer circumferential side from the plurality of partial polishing surface, The roughness of the partially polished surface on the outer peripheral side is relatively smaller than the roughness of the partially polished surface on the inner peripheral side, and these partially polished surfaces interpose gaps obtained by forming peripheral grooves between them. The slurry generated during polishing passes through the gap, The partially polished surface is configured to be discharged to the outside from a portion that is not in contact with the glass substrate, and the edge on the front side and the end on the back side among the edges where the front and back surfaces and the end surface of the glass substrate intersect The polishing tool disposed on the front surface side and the back surface side of the glass substrate so as to perform the chamfering treatment on both of the edges is simultaneously relative to the both edges at the same speed in the same direction. It is characterized in that a series of polishing processes including fine polishing, rough polishing, and final polishing are performed on both the edges by linear movement .

According to such a configuration, the polishing surface (a plurality of partially polished surfaces) of the polishing tool is orthogonal to one rotating shaft, and the roughness of the partially polished surface on the outer peripheral side of the partially polished surface is the inner peripheral side. Since the roughness of the partially polished surface is smaller than this, when this polishing tool is rotated around the rotation axis while moving linearly relative to the edge of the glass substrate, the edge is polished. First, the sharpened edge is finely ground (finely ground) by the partially polished surface on the outer peripheral side having a small roughness on the polished surface , and a so-called “running” effect is obtained. Thereby, in the initial stage of the chamfering process for the edge of the glass substrate, unreasonable stress concentration is suppressed, and occurrence of chipping (initial chipping), cracks, and the like due to flapping of the glass substrate is suppressed. A chamfered surface corresponding to the initial stage is formed on the edge. After this, as the next step, the polishing tool moves relatively linearly, so that the partially polished surface on the inner peripheral side having a large roughness on the polished surface comes into contact with the chamfered surface corresponding to the above-mentioned initial step, thereby roughing the surface. (Rough polishing) is performed. Since this advancing speed of polishing is increased by this rough polishing, the chamfering processing time is shortened, and at the start of the rough polishing, the edge is finely polished, and the above-described "running" is performed. The rough polishing is smoothly started and progressed without causing the occurrence of cracks, cracks, or the like or the extension thereof. After this, as a final stage, the polishing tool is further moved relatively linearly, and the above-mentioned partially polished outer peripheral surface of the polishing surface is in contact with the chamfered surface subjected to the rough polishing, Finishing (finish polishing) is performed. As a result, the occurrence of chipping or cracking at the rear end of the chamfered surface due to the vibration of the polishing tool acting on the chamfered surface from the rear end in the moving direction of the polishing surface is suppressed, and chamfering is caused due to rough polishing. Fine grinding powder or glass powder remaining on the surface is removed. In this way, with the relative linear movement of a single polishing tool, a series of polishing processes including fine polishing (roughening), rough polishing, and final polishing are performed on the edge of the glass substrate. Since the chamfering process can be performed in a short time while suppressing the occurrence of chipping and cracking by applying them sequentially, the equipment is greatly simplified while ensuring good quality around the chamfered surface. Productivity can be improved. Furthermore, the slurry (mixture of grinding fluid and polishing powder, glass powder, etc.) generated during polishing is obtained by forming gaps (circumferential grooves) formed between the polishing surfaces as the polishing tool rotates. Since this gap is a gap, this gap has a bottom) and is discharged to the outside from a portion where both polished surfaces are not in contact with the glass substrate. Thereby, since the slurry generated at the time of polishing can be prevented from scattering on the front and back surfaces of the glass substrate, contamination of the glass substrate is efficiently avoided. Either one or both of the polishing tool and the glass substrate may be linearly moved, but when the dimension along the edge of the glass substrate is longer than the maximum width dimension of the polishing surface of the polishing tool. It is advantageous to move the polishing tool in the direction along its edge while the glass substrate is fixed on the work table or the like. It is advantageous to make a linear movement across the line. Further, the polishing tool has a polished surface such that the crossing angle between the front and back surfaces of the glass substrate and the chamfered surface is 120 to 150 ° and / or the crossing angle between the end surface of the glass substrate and the chamfered surface is 120 to 150 °. Is preferably inclined.

In this case, the polishing surface of the polishing tool is divided and arranged from the inner peripheral side to the outer peripheral side, and is composed of a plurality of partial polishing surfaces for forming the chamfered surface. The roughness of the partially polished surface on the outer peripheral side is relatively smaller than the roughness of the partially polished surface on the inner peripheral side .

  In this way, since the polishing surface of the polishing tool is partitioned into a plurality of partially polished surfaces having different roughnesses, for example, the roughness gradually decreases as it moves from the inner peripheral side to the outer peripheral side. Thus, the polished surface can be produced easily and easily as compared with the case where the polished surface is formed. Thereby, the manufacture of the polishing tool can be facilitated and the manufacturing cost can be reduced. Note that the present invention does not exclude the case where the polishing surface is formed so that the roughness gradually decreases as the shift from the inner peripheral side to the outer peripheral side.

  Furthermore, it is preferable that each of the plurality of partially polished surfaces is a polished surface having a belt-like circular shape (circular ring shape) and arranged concentrically.

  This simplifies the shape and arrangement of the plurality of partially polished surfaces, thereby further facilitating the manufacture of the polishing tool and reducing the manufacturing cost.

In this configuration, each of the plurality of partially polished surfaces is formed on the surface of a partially polished plate having a belt-like circular shape and a predetermined thickness, and the partially polished plates have the above-described gaps interposed therebetween. It is preferable that they are arranged.

  In this way, the slurry generated during polishing (a mixture of grinding liquid and polishing powder or glass powder) passes through the gaps (grooves) between the partial polishing plates as the polishing tool rotates, The polished surface can be discharged to the outside from a portion that is not in contact with the glass substrate. Thereby, since slurry can be prevented from scattering on the front and back surfaces of the glass substrate, contamination of the glass substrate is efficiently avoided.

  In the above configuration, it is preferable that the polishing surface of the polishing tool does not have a partial polishing surface at the center, and the center is a recess.

  In this way, the slurry generated by polishing at the inner peripheral portion where the roughness of the polished surface is large is efficiently discharged to the outside through the concave portion in the central portion of the polished surface, so that the contamination of the glass substrate is further ensured. To be blocked.

  Furthermore, in the above configuration, when the glass substrate is produced by dividing the glass original plate after laser scribing, the plate thickness is preferably 200 μm or more.

  That is, since the glass substrate cut after forming the scribe on the glass original plate using laser scribe has a uniform and high dimensional accuracy, the chamfered surface formed on the edge of the glass substrate also has Uniform and high dimensional accuracy can be achieved. In this case, if the thickness of the glass original plate (glass substrate) is less than 200 μm, it is difficult to appropriately cut the glass original plate due to the specificity of the laser scribe, but the thickness is 200 μm or more. If it exists, after securing the advantage by said laser scribe effectively, a glass original plate can be cut | disconnected stably and a quality glass substrate can be obtained. Therefore, if a chamfering process is performed on the edge of such a glass substrate with a polishing tool having the above-described configuration, a high-quality chamfered surface can be formed in a short time.

  On the other hand, in the above configuration, when the glass substrate is prepared by putting a scribe on the surface of the glass original plate and bending and dividing the glass original plate starting from the scribe mark, the plate thickness is less than 200 μm. It is preferable.

  That is, the method using laser scribing as described above cannot properly cut a glass original plate having a thickness of less than 200 μm due to its specificity, but it is formed on the surface of the glass original plate using a diamond cutter or the like. According to the method of bending and dividing with a scribe mark as a starting point, since it does not have such a specificity, even if the thickness of the glass original plate is less than 200 μm, the glass original plate can be favorably cut to be a suitable glass substrate Can be obtained. In addition, the method of folding and dividing the scribe mark as a starting point is difficult to fold when the glass plate thickness is large and the cut surface is also malicious. Is advantageously less than 200 μm. Then, if the edge of the glass substrate is chamfered with a polishing tool having the above-described configuration, a high-quality chamfered surface can be formed in a short time.

  The apparatus having the above-described configuration is suitable for end face polishing of a glass substrate for flat panel display, and more preferably for end face polishing of a glass substrate for liquid crystal display.

  That is, this type of glass substrate is subjected to heat treatment during the manufacturing process of these displays, but in this heat treatment step, the glass substrate is not heated uniformly, and the temperature gradient from the surface of the glass substrate toward the inside is increased. It is customary to have it. When a temperature gradient occurs in the glass substrate, tensile stress acts on the front and back surfaces, the end face, and the chamfered surface of the glass substrate. In this case, if a minute crack or the like exists in the glass substrate, The probability of breakage increases. On the other hand, the end surface polishing apparatus having the above-described configuration is subjected to heat treatment because the probability of occurrence of microcracks on the chamfered surface of the glass substrate can be reduced as much as possible even when the moving speed of the polishing tool is increased. Even so, the probability that the glass substrate is broken is extremely low. In addition, it is preferable from a viewpoint of damage prevention that the chamfering surface of this glass substrate and the micro crack, a chip | tip, etc. which remain | survive around it are 10 micrometers or less.

On the other hand, the method according to the present invention, which was created to solve the above technical problem, is based on the polishing tool having a polishing surface orthogonal to the rotation axis, against the edge where the front and back surfaces and the end surface of the glass substrate intersect. In the method of polishing an end surface of a glass substrate, in which the edge of the glass substrate is chamfered by rotating around a rotation axis while relatively linearly moving, the polishing surface of the polishing tool having one rotation axis is: is composed of the inner peripheral side a plurality of partial polishing surface for being arranged in compartments over the outer circumferential side to form a且one face-up plane from roughness of the plurality of partial polishing surface, the outer peripheral side of the partial polishing surface Is relatively smaller than the roughness of the partially polished surface on the inner peripheral side, and these partially polished surfaces are arranged with a gap obtained by forming a circumferential groove between them, and are generated during polishing. Slurry passes through the gap and the partially polished surface is glass-based. While being discharged to the outside from a portion not in contact, the chamfering process on both the edge of the surface side of the edge and the back side of the end edge of the front and back surfaces and the end surface of the glass substrate crosses performed with The polishing tool disposed on the front surface side and the back surface side of the glass substrate is simultaneously moved linearly relative to both edges at the same speed in the same direction, It is characterized by performing a series of polishing treatments consisting of fine polishing, rough polishing, and finish polishing on the edge of each .

  Since the configuration of this method is the same as the basic configuration of the above-described apparatus, the explanation items including the operational effects of this method are substantially the same as the explanation items including the operational effects of the basic configuration of the above-described apparatus. Therefore, the description thereof is omitted here.

As described above, according to the present invention, a series of polishing processes including fine polishing (roughening), rough polishing, and finish polishing on both edges of the front and back sides of the glass substrate are performed on both edges. Since it is performed by rotation of a single polishing tool and relative linear movement, it is possible to simplify the device and ensure good quality around the chamfered surface, and to prevent the occurrence of chips and cracks. Therefore, the chamfering process can be performed in a short time, and the productivity is greatly improved. In addition, contamination of the glass substrate due to the slurry generated during polishing can be efficiently avoided.

  Hereinafter, an end surface polishing apparatus for a glass substrate according to an embodiment of the present invention will be described with reference to the accompanying drawings. The polishing target of the end surface polishing apparatus according to this embodiment is a glass substrate for FPD (particularly for PDP).

  FIG. 1 is a perspective view showing a polishing tool 1 which is a main component of a glass substrate end surface polishing apparatus according to the present embodiment. As shown in the figure, the polishing tool 1 includes an outer peripheral side polishing plate (hereinafter referred to as an outer peripheral side polishing plate) 3 fixed on a circular base 2, and an inner peripheral side partial polishing plate (hereinafter referred to as an outer peripheral side polishing plate). 4) (referred to as an inner peripheral polishing plate). Each of the outer peripheral side polishing plate 3 and the inner peripheral side polishing plate 4 is a plate-like body having a belt-like circular shape, and the surfaces formed by the planes of both the three and four are the outer polishing surface 3a and the inner polishing surface 4a. Has been. The two polishing surfaces 3a and 4a are arranged on the same plane and concentrically.

In this case, a gap 5 is formed between the outer peripheral surface of the inner peripheral side polishing plate 4 and the inner peripheral surface of the outer peripheral side polishing plate 3, and this gap 5 has the thickness of both polishing plates 3, 4. A circumferential groove with a corresponding depth and a constant width ( 0.5 to 4.0 mm ) is formed over the entire circumference. Further, the central portion of the base 2 in the polishing tool 1, that is, the inner portion of the inner peripheral polishing plate 4 is a recess 6 without having a polishing plate. The radius of the recess 6 is set to be longer than the radial dimension from the inner peripheral surface of the inner peripheral polishing plate 4 to the outer peripheral surface of the outer peripheral polishing plate 3. The abrasive grains of the outer peripheral polishing plate 3 are finer than the abrasive grains of the inner peripheral polishing plate 4, and therefore the roughness of the outer polishing surface 3a is made smaller than the roughness of the inner polishing surface 4a. Yes.

  As shown in FIG. 2, the polishing tool 1 has an edge 7x on the surface side where the surface 7a and the end surface 7c of the glass substrate 7 intersect, and a back surface side where the back surface 7b and the end surface 7c of the glass substrate 7 intersect. A chamfering process is performed on the edge 7y. More specifically, the glass substrate 7 is obtained by dividing the glass original plate after laser scribing when the plate thickness is 200 μm or more, and the divided surface corresponds to the end surface 7c. . On the other hand, when the plate thickness is less than 200 μm, the glass substrate 7 is obtained by putting a scribe on the surface of the glass original plate using a diamond cutter or the like and bending and dividing the glass original plate from the scribe mark as a starting point. The divided surface corresponds to the end surface 7c. When the edge 7x on the surface side of the glass substrate 7 is chamfered, the angle α between the both polishing surfaces 3a and 4a of the polishing tool 1 and the surface 7a of the glass substrate 7 is 30 to 60 ° (see FIG. It is arranged so as to be 45 ° in the illustrated example. When the edge 7y on the back surface side of the glass substrate 7 is chamfered, the angle β formed between the polishing surfaces 3a and 4a of the polishing tool 1 and the back surface 7b of the glass substrate 7 is 30 to 60 ° (see FIG. It is arranged so as to be 45 ° in the illustrated example.

Under such an arrangement, the polishing tool 1 is configured to linearly move along the edges 7x and 7y of the glass substrate 7 fixed on the work table 9 while rotating around the rotation shaft 8. ing. In this embodiment, as shown in FIG. 3, the polishing tool 1 disposed on the front surface side of the glass substrate 7 and the polishing tool 1 disposed on the back surface side of the glass substrate 7 are brought close to each other within a range that does not interfere. Under these conditions, both polishing tools 1 are linearly moved at the same speed in the same direction (arrow A direction) at the same time.

  In this case, as shown in FIG. 4, in the polishing tool 1, the edge 7x (7y) of the glass substrate 7 is in contact with both the inner polishing surface 4a and the outer polishing surface 3a and crosses the recess 6 at the center. However, the edge 7x (7y) does not have to be located on the center of the recess 6 and may be deviated from the center as in the illustrated example. Under this state, when the polishing tool 1 rotates in the direction indicated by the arrow B in the figure, the polishing tool 1 is configured to linearly move in the direction indicated by the arrow C. And although not shown in figure, from the center of the base | substrate 2 in this grinding | polishing tool 1, it is comprised so that grinding liquids, such as a high voltage | pressure water flow, may be injected toward the periphery of the edge 7x (7y) of the glass substrate 7. FIG. Yes. Furthermore, in this embodiment, when both polishing surfaces 3a and 4a of the polishing tool 1 move linearly while contacting the edge 7x (7y) of the glass substrate 7, the center side of the surface 7a of the glass substrate 7 and A grinding fluid such as a high-pressure water stream is jetted from the center side of the back surface 7b toward the corresponding edge 7x (7y).

  According to such a configuration, both the polishing surfaces 3a and 4a of the polishing tool 1 are rotated around the rotation shaft 8 and are in contact with the edge 7x (7y) of the glass substrate 7 while being in contact with the edge 7x (7y). When moving along a straight line, the edge 7x (7y) is first finely ground (finely polished) by the outer polished surface 3a having a low roughness, thereby obtaining a so-called “running” effect. As a result, unreasonable stress concentration in the initial stage of the chamfering process on the edge 7x (7y) of the glass substrate 7 is suppressed, and occurrence of chipping (initial chipping), cracks, and the like due to flapping of the glass substrate 7 is suppressed. In addition, a chamfered surface corresponding to the initial stage is formed on the edge 7x (7y).

  Thereafter, as the next step, the inner polished surface 4a having a large roughness comes into contact with the chamfered surface corresponding to the initial step, and rough cutting (rough polishing) is performed. This rough polishing increases the speed of polishing, thereby shortening the chamfering process time, and at the start of rough polishing, the edge 7x (7y) is finely polished to perform the above-described "running". Therefore, the rough polishing is smoothly started and progressed without causing the occurrence of cracks, cracks, or the like or extending them.

After this, as a final step, the outer polished surface 3a having a low roughness is again brought into contact with the chamfered surface that has been subjected to the rough polishing, and finishing (finish polishing) is performed. As a result, the occurrence of chipping or cracking on the chamfered surface due to improper propagation of the vibration of the polishing tool 1 to the chamfered surface is suppressed, and minute grinding remaining on the chamfered surface due to rough polishing. Powder or glass powder will be removed.

  In this case, since a grinding liquid such as a high-pressure water stream is sprayed and supplied from the center side of the front and back surfaces 7a and 7b of the glass substrate 7 toward the chamfered surface, minute glass powder generated due to the chamfering process is generated. Can be prevented from adhering to the front and back surfaces 7a and 7b of the glass substrate 7, and the problem that the periphery of the chamfered surface of the glass substrate 7 is burnt and damaged by frictional heat during polishing does not occur.

  In addition, during this chamfering process, a slurry made of a mixture of a grinding liquid and polishing powder, glass powder or the like is generated, and this slurry is mixed with the outer peripheral polishing plate 3 and the inner peripheral polishing plate as the polishing tool 1 rotates. 4 passes through the gap 5 (circumferential groove) between the two polishing surfaces 3a and 4a and is discharged to the outside from the portion where the polished surfaces 3a and 4a are not in contact with the glass substrate 7. Thereby, it is possible to prevent the slurry from being scattered on the front and back surfaces 7a and 7b of the glass substrate 7 as much as possible, and to effectively avoid contamination of the glass substrate 7.

  Further, since the polishing plate is not disposed in the central portion of the polishing tool 1 and the central portion is the concave portion 6, the malicious sludge generated by the polishing on the inner polishing surface 4a having a large roughness can be prevented. The slurry it has is efficiently discharged to the outside through the recess 6 inside. Thereby, contamination of the glass substrate 7 is prevented more reliably.

  In the above-described embodiment, the polishing plate is composed of two pieces of the inner peripheral polishing plate 4 and the outer peripheral polishing plate 3, but the present invention is not limited to this, and three or more polishing plates are used. In this case, the roughness of the polishing plate (polishing surface) on the outer peripheral side is relatively smaller than the roughness of the polishing plate (polishing surface) on the inner peripheral side. There is a need to.

  In order to confirm the effect of the polishing tool 1 illustrated in FIG. 1 described above, the present inventors compared Examples 1 to 3 with Comparative Examples 1 to 6 and compared with Examples 4 and 5. A comparison with Examples 7-10 was made as follows. In each of these Examples and Comparative Examples, OA-10 manufactured by Nippon Electric Glass Co., Ltd., which was molded by the overflow downdraw method, was used as the glass original plate. The front and back surfaces and end surfaces of the glass substrate were not polished. Moreover, as a glass original plate, two types with a plate thickness of 0.7 mm and a 0.1 mm thickness were prepared, and the surface of these glass original plates was scribed using a diamond chip or a laser scribe.

  First, for Examples 1 to 3 and Comparative Examples 1 to 6 of the present invention shown in Table 1 below, as a sample to be used, by dividing a glass original plate having a plate thickness of 0.7 mm along the scribe marks, A glass substrate having a side dimension of 730 mm and a long side dimension of 920 mm was obtained. The polishing tool for forming the chamfered surface on the edge of the glass substrate is that the outer peripheral side polishing plate (outer polishing surface) has a radius of 50 to 60 mm (10 mm width) in the first to third embodiments, and the inner peripheral side is polished. The plate (inner polishing surface) has a radius of 38 to 48 mm (10 mm width), and the gap between both polishing plates (the width of the circumferential groove) is 2 mm. In Example 1, the abrasive grains (diamond abrasive grains) on the outer peripheral side polishing plate are # 3000 and the abrasive grains on the inner peripheral side polishing plate are # 1500. In Example 2, the abrasive grains on the outer peripheral side polishing plate are # 3000 and the abrasive grain of the inner peripheral side polishing plate is # 2000, and in Example 3, the abrasive grain of the outer peripheral side polishing plate is # 3000 and the abrasive grain of the inner peripheral side polishing plate is # 2500. The plate was also a diamond polishing plate, that is, a resin material in which diamond abrasive grains are dispersed (the above-mentioned size of diamond abrasive grains conforms to JIS R6001: 1998 (the same applies to the following polishing plates)). On the other hand, in Comparative Examples 1 to 6, a single polishing plate is used, the polishing plate has a radius of 40 to 60 mm (20 mm width), and abrasive grains (diamond abrasive grains) are # 1500, # 2000, and # 2500, respectively. , # 2500, # 3000, and # 3000 were used.

  In each example and each comparative example (excluding comparative example 6), the moving speed of the polishing tool is selected so that the chamfer dimension (chamfer width) is in the range of 15 to 75 μm, and the glass substrate as the sample is measured. A substantially flat chamfered surface was formed on all edges. When performing this chamfering process, with the glass substrate placed on a surface plate and fixed, the intersection angle between the front and back surfaces of the glass substrate and the chamfered surface is 135 °, and the end surface of the glass substrate and the chamfered surface are After adjusting the contact angle of the polishing surface of the polishing tool so that the crossing angle is 135 °, polishing water is supplied from the center of the polishing tool (polishing plate) so that the desired chamfer dimension can be obtained. Polishing was performed by linearly moving the plate at two speeds of 250 mm / sec and 1000 mm / sec while rotating the plate at a peripheral speed of 2000 m / min. And about each of Examples 1-3 and Comparative Examples 1-6, the chamfering dimension, the crack which remain | survives in the edge (around chamfering surface periphery) of a glass substrate after grinding | polishing, and the adhesion characteristic of glass powder were evaluated. In this case, the chamfer dimension and the size of the crack around the chamfered surface were evaluated by performing chamfering treatment on 10 glass substrates under the same conditions, measuring 10 times for each, and calculating an average value thereof. . The results are shown in Table 1 below. In Table 1 below, the symbol “◎” means very good, the symbol “◯” means good, and the symbol “x” means bad.

  According to Table 1 above, the chamfering dimensions and the chamfered surface of each of the first to third embodiments of the present invention can be obtained even when the moving speed (polishing speed) of the polishing tool is as high as 1000 mm / sec. It was confirmed that good or extremely good results were exhibited in all of the peripheral cracks and adhesion of glass powder. On the other hand, as for Comparative Examples 1-4, not only when the moving speed of the polishing tool is 1000 mm / sec, but also at a low speed of 250 mm / sec, good results cannot be obtained. It was confirmed that the moving speed of the tool is low and the chamfer dimension is short, and Comparative Example 6 has the disadvantage that the chamfer dimension is extremely short.

  Next, for Examples 4 and 5 and Comparative Examples 7 to 11 of the present invention shown in Table 2 below, as a sample to be used, by dividing a glass original plate having a plate thickness of 0.1 mm along the scribe marks, A glass substrate having a short side dimension of 370 mm and a long side dimension of 470 mm was obtained. The polishing tool for forming a chamfered surface on the edge of the glass substrate is that the outer side polishing plate (outer polishing surface) has a radius of 23 to 30 mm (7 mm width) in Examples 4 and 5, and inner side polishing. The plate (inner polishing surface) has a radius of 15 to 22 mm (7 mm width), and the gap between both polishing plates (width of the circumferential groove) is 1 mm. In Example 4, the abrasive grains (diamond abrasive grains) on the outer peripheral side polishing plate are # 5000 and the abrasive grains on the inner peripheral side polishing plate are # 2500. In Example 5, the abrasive grains on the outer peripheral side polishing plate are # What was 5000 and the abrasive grain of the inner peripheral side polishing plate was # 3000 was used. On the other hand, in Comparative Examples 7 to 11, a single polishing plate was used, the polishing plate had a radius of 45 to 60 mm (15 mm width), and the abrasive grains (diamond abrasive grains) were # 2500, # 3000, and # 3000, respectively. , # 5000, # 5000 were used.

  In each example and each comparative example, when the chamfering process is performed, the crossing angle between the front and back surfaces of the glass substrate and the chamfered surface is 135 ° and the glass substrate is placed on a surface plate and fixed. Adjust the contact angle of the polishing surface of the polishing tool so that the crossing angle between the end surface of the substrate and the chamfered surface is 135 °, and then supply grinding water from the center of the polishing tool (polishing plate) to obtain the desired chamfering Polishing was performed by linearly moving the polishing plate at two speeds of 50 mm / sec and 300 mm / sec while rotating the polishing plate at a peripheral speed of 1500 m / min so as to obtain the dimensions. And about each of Example 4, 5 and Comparative Examples 7-11, the chamfering dimension, the crack which remain | survives in the edge (around chamfering surface periphery) of a glass substrate after grinding | polishing, and the adhesion characteristic of glass powder were evaluated. In this case, the chamfer dimension and the size of the crack around the chamfered surface were evaluated by performing chamfering treatment on 10 glass substrates under the same conditions, measuring 10 times for each, and calculating an average value thereof. . The results are shown in Table 2 below. In Table 2 below, the symbol “◯” means good and the symbol “x” means bad.

  According to Table 2 above, the glass substrate was damaged during polishing even when the moving speed of the polishing tool (polishing speed) was increased to 300 mm / sec in any of Examples 4 and 5 of the present invention. It was confirmed that good results were exhibited in all of the chamfered dimensions, cracks around the chamfered surface, and adhesion of glass powder. On the other hand, for Comparative Examples 7 to 11, only when the abrasive grains of the polishing plate were set to # 5000, chamfering treatment was possible without causing damage to the glass substrate, but there was a drawback that the chamfering dimension was short, In other comparative examples, it was confirmed that the glass substrate was broken and could not be used even when the moving speed of the polishing tool was lowered.

It is a perspective view which shows the polishing tool which is a component of the end surface polishing apparatus of the glass substrate which concerns on embodiment of this invention. It is a schematic front view which shows the state which is grinding | polishing the end surface of a glass substrate with the end surface polishing apparatus of the glass substrate which concerns on embodiment of this invention. It is a schematic plan view which shows the state which is grinding | polishing the end surface of a glass substrate with the end surface grinding | polishing apparatus of the glass substrate which concerns on embodiment of this invention. It is the schematic which shows the positional relationship of the polishing tool which is a component of the end surface grinding | polishing apparatus of the glass substrate which concerns on embodiment of this invention, and the edge of a glass substrate. It is a longitudinal cross-sectional view which shows the end surface periphery of a common glass substrate.

Explanation of symbols

1 Polishing tool 2 Base 3 Outer peripheral side polishing plate (partial polishing plate)
3a Outer polished surface (partially polished surface)
4 Inner peripheral side polishing plate (partial polishing plate)
4a Inner polished surface (partially polished surface)
5 Clearance (circumferential groove)
6 Recess 7 Glass substrate 7a Glass substrate surface 7b Glass substrate back surface 7c Glass substrate end face 7x, 7y Glass substrate edge 8 Rotating shaft

Claims (9)

A polishing tool having a polishing surface orthogonal to the rotation axis rotates around the rotation axis while linearly moving relative to the edge where the front and back surfaces and the end surface of the glass substrate intersect, whereby the edge of the glass substrate In the glass substrate end surface polishing apparatus configured to chamfer the edge,
The rotation axis of the polishing tool is a one, the polishing surface of the polishing tool has a plurality of partial polishing to be arranged in compartments over the outer circumferential side to form a且one face-up plane from the inner periphery A plurality of these partially polished surfaces, the roughness of the outer peripheral side partially polished surface is relatively smaller than the roughness of the inner peripheral side partially polished surface,
These partially polished surfaces are arranged with a gap obtained by forming a circumferential groove between them, slurry generated during polishing passes through the gap, and the partially polished surface is a glass substrate. configured to be discharged to the outside from a portion not in contact with,
Out of the edges where the front and back surfaces of the glass substrate and the end surfaces intersect, both the front edge and the back edge of the glass substrate are subjected to the chamfering treatment on both the front edge and the back edge. The disposed polishing tool is moved linearly relative to both edges at the same speed in the same direction at the same time, and fine polishing, rough polishing, and finish polishing are performed on both edges. An apparatus for polishing an end face of a glass substrate, characterized in that a series of polishing treatments comprising:   2. The glass substrate end surface polishing apparatus according to claim 1, wherein each of the plurality of partial polishing surfaces is a polishing surface having a belt-like circular shape and is arranged concentrically.   3. The glass substrate end surface polishing apparatus according to claim 1, wherein each of the plurality of partial polishing surfaces is formed on a surface of a partial polishing plate having a belt-like circular shape and a predetermined thickness.   The glass substrate end surface polishing apparatus according to any one of claims 1 to 3, wherein the polishing surface of the polishing tool does not have a partial polishing surface at a central portion, and the central portion is a concave portion.   The glass substrate end face polishing apparatus according to any one of claims 1 to 4, wherein the glass substrate is prepared by dividing a glass original plate after laser scribing, and has a thickness of 200 µm or more.   The glass substrate is produced by scribing the surface of the glass original plate and bending and dividing the glass original plate with the scribe mark as a starting point, and the thickness of the glass substrate is less than 200 μm. An end surface polishing apparatus for a glass substrate according to any one of the above.   The said glass substrate is a glass substrate for flat panel displays, The end surface grinding | polishing apparatus of the glass substrate in any one of Claims 1-6 characterized by the above-mentioned.   The said glass substrate is a glass substrate for liquid crystal displays, The end surface grinding | polishing apparatus of the glass substrate of Claim 7 characterized by the above-mentioned. A polishing tool having a polishing surface orthogonal to the rotation axis rotates around the rotation axis while linearly moving relative to the edge where the front and back surfaces and the end surface of the glass substrate intersect, whereby the edge of the glass substrate In the edge polishing method of the glass substrate for chamfering the edge,
Polishing surface of the polishing tool rotation axis is one is constituted of a plurality of partial polishing surface for forming the inner peripheral且are arranged in compartments over the outer circumferential side one from side faces up surface, the plurality The roughness of the partially polished surface of the outer peripheral side is relatively smaller than the roughness of the inner peripheral side partially polished surface,
These partially polished surfaces are arranged with a gap obtained by forming a circumferential groove between them, slurry generated during polishing passes through the gap, and the partially polished surface is a glass substrate. Discharged from the part that is not in contact with the outside ,
Out of the edges where the front and back surfaces of the glass substrate and the end surfaces intersect, both the front edge and the back edge of the glass substrate are subjected to the chamfering treatment on both the front edge and the back edge. The disposed polishing tool is moved linearly relative to both edges simultaneously at the same speed in the same direction, and fine polishing, rough polishing, and finish polishing are performed on both edges. A method for polishing an end face of a glass substrate, comprising performing a series of polishing treatments comprising :

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