KR20130020614A - Polishing device for plate-shaped body and polishing system - Google Patents

Abstract

PURPOSE: A polishing device for a plate shape body capable of polishing a large substrate having a plate shape without the reduction of the flow of slurry and a polishing system thereof are provided to secure a polishing value by maintaining a constant polishing rate and restrain reattachment of a polished glass to the polished surface by increasing the circulation amount of the slurry. CONSTITUTION: A polishing device for a plate shape body(10) includes a plate shape body retaining means and grinding pads(58,60). The plate shape body retaining means retains a plate shape body of which one side is over 1000mm in length. The grinding pad is installed to face the plate shape body retained by the plate retaining means. The grinding pad is formed at the central part of the facing surface of the plate shape body with multiple slurry supply holes supplying slurry to the contact part of the plate shape body, and a slurry absorption hole is formed at the contact part to absorb the supplied slurry. The central part of the facing surface of the plate shape body of the grinding pad in which the slurry absorption hole is formed is within the range of 25% of a diameter from the center of the grinding pad. Multiple grooves are formed to an arbitrary direction on the facing surface of the plate shape body of the grinding pad, and the groove formed on the central part in line with a direction perpendicular to the arbitrary direction has a wider width than the width of a groove formed outside the central part in line with the direction perpendicular to the arbitrary direction.

Description

Plate Polishing Device and Polishing System {POLISHING DEVICE FOR PLATE-SHAPED BODY AND POLISHING SYSTEM}

The present invention relates to a plate-shaped polishing apparatus and a polishing system.

The glass substrate for FPD (Flat Panel Display) used for a liquid crystal display etc. shape | molds molten glass into plate shape by the glass manufacturing method called the float method, and this is made into the fine surface of it by the continuous polishing apparatus disclosed by patent document 1 etc. By grinding | polishing and removing unevenness | corrugation and a curvature, it is manufactured by the thin plate which satisfy | filled the flatness calculated | required as a glass substrate for FPD.

The polishing apparatus like patent document 1 is using the slurry which disperse | distributed the abrasive | polishing agent to a dispersing agent, and grinds the surface (henceforth a to-be-polished surface) of a glass substrate. A slurry is supplied between the polishing surface of a polishing pad and the to-be-polished surface of a glass substrate from the slurry supply hole provided in the center part of a polishing pad. If the amount of the slurry supplied between the polishing surface of the polishing pad and the surface to be polished of the glass substrate becomes uneven at the polishing surface, the flatness of the polished surface of the polished glass substrate is deteriorated. Therefore, the supplied slurry needs to spread uniformly on the polishing surface.

The present applicant has a slurry supply hole in the center of the polishing surface in order to spread the supplied slurry evenly on the surface to be polished of the glass substrate, and the polishing surface is radially formed by a plurality of grooves formed outward from the center. A divided polishing pad is proposed in Japanese Patent Application No. 2010-111116.

For example, in the polishing apparatus described in Patent Literature 2, the polishing pad has a polishing surface having a high plan view on a surface of the polishing pad facing the substrate, and a plurality of grooves are formed on the polishing surface at substantially equal intervals in the front-rear direction, and polishing During the processing, the diffusion of the abrasive is promoted, and a plurality of abrasive supply holes and abrasive discharge holes penetrating up and down and facing the substrate are alternately lined on substantially the entire surface of the polishing surface.

Japanese Patent Laid-Open No. 2004-122351 Japanese Patent Publication No. 2009-125873

However, there is a limit to increase the flow rate of the slurry as a method of flowing the slurry supplied to the center portion of the polishing pad to the outside of the polishing pad by the groove formed on the polishing surface of the polishing pad. It was difficult to secure the amount of polishing near the center by controlling the flow rate of the slurry.

For example, in the polishing apparatus like patent document 1, the to-be-polished surface of a glass substrate is polished using the slurry which disperse | distributed the abrasive | polishing agent as a dispersing agent as mentioned above. At this time, when polishing the glass substrate of 1000 mm or more on one side, it is necessary to increase the slurry supply amount in order to spread the slurry widely on the entire surface to be polished of the glass substrate. However, the amount of slurry supplied from the supply hole of a polishing pad increases more than the amount of slurry supplied from the center part of a glass substrate to the periphery part by the groove | channel formed in the polishing surface of a polishing pad. That is, as shown in FIG. 10, the slurry S of the to-be-polished surface of the glass substrate G adhere | attached to the film body 310 of a carrier from the slurry supply hole 330 provided in the center of the polishing pad 320 is carried out. When the polishing pad 320 is polished while supplying the slurry, the slurry S is stored in the center portion Z of the glass substrate G. As a result, the center part Z of the glass substrate G is spaced apart from the polishing pad 320, and the center part Z of the glass substrate G becomes difficult to grind | polish, and there exists a problem that a polishing shortage arises.

Further, as described in Patent Document 2, when polishing, the slurry is sucked from the entire surface of the polishing pad and discharged to the outside of the glass substrate. When the slurry suction hole is formed again, the slurry is supplied to the peripheral portion of the surface to be polished of the glass substrate. The amount of slurry decreases, and polishing scratches and the like easily occur. In addition, since the capacity of the suction pump for sucking the slurry is also limited, it is necessary to increase the suction pump. This leads to a complicated pipe route for supply and suction of slurry, which increases cost and maintenance. Further, there is a problem that control of slurry supply and suction becomes cumbersome, and in particular, the larger the glass substrate, which is the polishing object, becomes, the more complicated the adjustment becomes.

The present invention has been made in view of the above circumstances, and in particular, when polishing a large-size substrate, the slurry flow rate is reduced, the backside thickness is reduced, the polishing amount near the center of the substrate is secured, and the polishing is performed normally. It is an object of the present invention to provide a plate-like polishing apparatus and a polishing system which can suppress the reattachment of components of a polished substrate to a surface to be polished of a substrate by improving the circulation of.

In order to achieve the above object, the plate-like polishing apparatus of the present invention includes plate-shaped body holding means for holding a plate-shaped body whose length is 1000 mm or more, and a polishing pad provided to face the plate-shaped body held by the plate-shaped body holding means. And the polishing pad is formed on the plate facing surface, a plurality of slurry supply holes for supplying a slurry to a contact portion between the polishing pad and the plate, and is formed only at a central portion of the plate facing surface. A slurry suction hole for sucking the slurry supplied to the contact portion is formed.

Accordingly, even in the case of polishing a large plate-shaped substrate having a square of 1000 mm or more on one side, the slurry is sucked only from the center portion of the polishing pad, thereby ensuring a polishing value near the center without reducing the slurry flow rate. Normal polishing can be performed.

Moreover, as one embodiment, it is preferable that the center part of the said plate-shaped object facing surface of the said polishing pad in which the said slurry suction hole is formed is a range within 25% of the diameter from the center of the said polishing pad.

In this way, by sucking the slurry only from the center portion of the polishing pad, a polishing value near the center can be ensured and normal polishing can be performed without reducing the slurry flow rate.

Moreover, as one embodiment, the groove | channel of the groove | channel formed in the said center part along the direction orthogonal to the said arbitrary direction, in which the some groove | channel is formed linearly in the arbitrary direction in the said plate-shaped object opposing surface of the said polishing pad. It is preferable that it is formed wider than the width | variety of the groove | channel formed in the outer side of the said center part along the direction orthogonal to the said arbitrary direction.

In addition, as an embodiment, the apparatus further comprises means for oscillating the polishing pad in a horizontal direction relative to the plate-shaped member holding means, and means for rotating and revolving the polishing pad, wherein the plate-shaped body of the polishing pad is provided. On the opposite surface, a plurality of grooves are formed in a straight line in the swinging direction, and the width of the grooves formed in the center portion in a direction orthogonal to the swinging direction is outside the center portion in a direction orthogonal to the swinging direction. It is preferable that it is formed wider than the width of the formed groove.

Thereby, the slurry of the center part of a polishing pad can be discharged | emitted well, and the polishing value of the center vicinity can be ensured.

Moreover, as one embodiment, it is preferable that the said center part is a range within 25% of the diameter from the center of the said polishing pad.

Thereby, the slurry of the center part of a polishing pad can be discharged | emitted well, and the polishing value of the center vicinity can be ensured.

In addition, in order to achieve the above object, in the polishing system of the present invention, the plate-shaped body holding means for holding a plate-shaped body whose length is 1000 mm or more, and the polishing plate provided against the plate-shaped body held by the plate-shaped body holding means. It has a pad, The said polishing pad is formed in the said plate-shaped object opposing surface, It is formed in the center part of the said plate-shaped object opposing surface, The several slurry supply hole which supplies a slurry to the contact part of the said polishing pad and the said plate-shaped object, A slurry suction hole for sucking the slurry supplied to the contact portion is formed, and a slurry tank for storing a slurry containing abrasive grains as an abrasive, and the polishing pad and the plate from the slurry tank through the slurry supply hole. Through slurry supply means for supplying the slurry to the contact portion of the upper body, and through the slurry suction hole. And slurry recovery means for sucking the slurry supplied to the contact portion and returning the sucked slurry to the slurry tank, a concentration meter for detecting the concentration of the slurry provided in the slurry supply means, and a detection result of the concentration meter. On the basis of the above, when the concentration of the slurry is lower than a predetermined lower limit, the concentration meter is controlled to add an abrasive and a predetermined additive to the slurry tank, and when the concentration of the slurry exceeds a predetermined upper limit, the densitometer And a control unit for controlling the cleaning to be performed.

Accordingly, the slurry is circulated and the concentration of the slurry is detected by a densitometer. When the concentration value is lower than the predetermined lower limit value, cerium oxide or an additive is added to the slurry, or when the concentration value exceeds the predetermined upper limit value. In the case where the concentration meter is washed, the polishing rate is kept constant, the polishing value is secured, and the adhesion of the polished glass component to the polishing surface can be suppressed by increasing the slurry circulation amount.

Moreover, as one embodiment, it is preferable that the said predetermined additive is a dispersing agent which prevents aggregation of the said abrasive.

Thereby, aggregation of cerium oxide can be prevented and a polishing rate can be maintained.

Moreover, as one embodiment, it is preferable that the center part of the said plate-shaped object facing surface of the said polishing pad in which the said slurry suction hole is formed is a range within 25% of the diameter from the center of the said polishing pad.

Thereby, the slurry of the center part of a polishing pad can be discharged | emitted well, and the polishing value of the center vicinity can be ensured.

Moreover, as one embodiment, it is preferable to add the case where the said density meter wash | cleans the density | concentration of the said slurry exceeding a preset upper limit, or to perform it every 30 to 40 minutes instead.

Thereby, the density meter is clogged and abnormal value is not detected, and density value can always be detected correctly.

As described above, according to the present invention, even in the case of polishing a large plate-shaped substrate having a square of 1000 mm or more on one side, it is possible to perform normal polishing by securing the polishing value near the center without reducing the slurry flow rate. Can be. In addition, the slurry is circulated and the concentration of the slurry is detected by a concentration meter. When the concentration value is lower than the predetermined lower limit value, cerium oxide or an additive is added to the slurry, or when the concentration value exceeds the predetermined upper limit value. When cleaning is performed, the polishing rate is kept constant, the polishing value is secured, and the reattachment of the polished glass component to the polishing surface can be suppressed by increasing the slurry circulation amount.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows the whole structure of the grinding | polishing apparatus as one Embodiment of the plate-shaped grinding | polishing apparatus used for the grinding | polishing system of this invention.
2 is an assembled perspective view of a carrier for installing a membrane frame and a membrane frame.
3 is a side view illustrating an embodiment of a polishing stage and a polishing head.
4 is a plan view of the polishing pad of the polishing apparatus shown in FIG. 1.
5 is a plan view showing a range of formation of slurry suction holes on a polishing pad surface.
6A is a cross-sectional view of the polishing surface center portion groove of the polishing pad.
6B is a cross-sectional view of the outer groove of the polishing surface of the polishing pad.
7 is a schematic view showing a slurry circulation system.
8 is a graph showing a time change of the concentration detection value by the densitometer.
It is a top view which shows the polishing amount according to the position of the to-be-polished surface of a glass substrate at the time of attracting a slurry.
It is a top view which shows the polishing amount according to the position of the to-be-polished surface of a glass substrate, when a slurry is not aspirated.
10 is a cross-sectional view showing a slurry supply problem in a conventional polishing apparatus.

 EMBODIMENT OF THE INVENTION Hereinafter, with reference to an accompanying drawing, the plate-shaped object grinding apparatus and polishing system which concern on this invention are demonstrated in detail.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows the whole structure of the grinding | polishing apparatus as one Embodiment of the plate-shaped grinding | polishing apparatus used for the grinding | polishing system of this invention.

The polishing apparatus 10 shown in FIG. 1 has a thickness of 0.7 mm or less (for example, 0.2 mm to 0.7 mm) in a glass substrate G having a large size of 1000 mm long by 1000 mm wide or more. It is a grinding | polishing apparatus which grinds the to-be-polished surface of large glass substrate G to the flatness required for the glass substrate for liquid crystal displays.

The polishing apparatus 10 is a glass substrate adhesion stage which adheres the glass substrate import conveyor 12 which carries in the glass substrate G before grinding | polishing, and the glass substrate G to the film frame (plate-shaped adhesive member) 14. (16), the 1st polishing stage 18, the 2nd polishing stage 20, the glass substrate removal stage 22 which removes the polished glass substrate G from the film frame 14, and the conveyor for carrying out a glass substrate 24, the membrane frame cleaning stage 26, the membrane frame drying stage 28, and the membrane frame conveyance conveyor 30 are mainly provided.

Hereinafter, for the sake of simplicity, the glass substrate bonding stage 16, the first polishing stage 18, the second polishing stage 20, the glass substrate removing stage 22, the film frame cleaning stage 26, and the film The frame drying stage 28 is simply described as stages 16, 18, 20, 22, 26, 28.

The polishing apparatus 10 conveys the conveyance apparatus 150 which conveys the film frame 14 from the stage 16 to the stage 18, and the conveyance which conveys the film frame 14 from the stage 18 to the stage 20. The conveying apparatus 154 which conveys the membrane frame 14 from the apparatus 152 and the stage 20 to the stage 22 is provided. Such conveying apparatuses 150, 152 and 154 are controlled in the same configuration by the control unit 200 which collectively controls the polishing apparatus 10, and reciprocate in synchronism in the left and right directions on FIG.

The glass substrate G before the grinding | polishing carried in by the glass substrate loading conveyor 12 is adsorbed-held by the adsorption | suction bed 34 provided in the arm 33 of the robot 32. As shown in FIG. And it moves to the conveyor 36 from the glass substrate loading conveyor 12 by the rotation operation of the arm 33, and is conveyed to the stage 16 by the conveyor 36. As shown in FIG.

In the stage 16, the glass substrate G before polishing is adhered to the film frame 14.

2, the assembled perspective view of the carrier 52 which mounts the membrane frame 14 and the membrane frame 14 is shown.

As shown in FIG. 2, the film frame 14 uses a rectangular film body 38 to which the glass substrate G can be bonded between the rectangular upper frame 40 and the lower frame 42. After installing, it is comprised by fastening the upper frame 40 and the lower frame 42 with the bolt which is not shown in figure.

In addition, the membrane frame 14 and the membrane body 38 are not limited to the rectangular shape, but may be circular.

When the glass substrate G before grinding | polishing is demonstrated to the film frame 14, the film frame 14 is hold | maintained by the lifting device which is not shown in the stage 16, and the film frame 14 When the glass substrate G is located below, the film frame 14 is moved downward by the elevating device, and the flexible and self-adsorbing film body 38 installed in the film frame 14 shown in FIG. Is pressed to the to-be-polished surface of glass substrate G. By this pressing force, the to-be-polished surface of the glass substrate G adheres to the film | membrane 38. FIG. Thereafter, the film frame 14 is held by the conveying apparatus 150 of FIG. 1, conveyed to the stage 18, and the carrier (plate-shaped holding means) 52 of the polishing head (to be described later) in the stage 18. Is installed on. In addition, the membrane frame 14 described below points to the whole in which the membrane body 38 was mounted.

2, the ancestor frame 78 is being fixed to the upper outer peripheral part of the carrier 52 with the bolt which is not shown in figure. Through holes 80, 80, ... are opened at predetermined equal intervals in the flange portion of the ancestor frame 78, and slide-contact frames 82 are provided in the through holes 80, 80, ... A sliding frame bracket 84 protruding from the upper surface of the penetrating member penetrates from below. In addition, the sliding frame fixture 84 penetrates the ancestor spring 88 and is connected to a screw jack (not shown).

Then, the sliding frame 82 is pulled against the carrier 52 by operating the screw jack and pulling the sliding frame roughness 84 upward against the pressing force of the ancestor spring 88. Thereby, the membrane frame 14 detachably attached to the sliding frame 82 is pulled up, and predetermined tension is given to the membrane body 38.

In addition, a spindle 56 is connected to the carrier 52.

3 is a side view illustrating an embodiment of a polishing stage and a polishing head.

Next, the polishing head 50 shown in FIG. 3 is demonstrated. In addition, since the polishing head 50 of the stage 18 and the polishing head 50 of the stage 20 have the same structure, it demonstrates with the same code | symbol.

As shown in FIG. 3, the polishing head 50 is equipped with the main body casing 51, and the revolving drive mechanism part which is not shown in figure is built in the main body casing 51. As shown in FIG. The idle drive mechanism portion is constituted by the planetary gear mechanism portion and the motor, and the output shaft of the planetary gear mechanism portion driven by the motor is connected to the spindle 56 vertically lowered in the vertical direction. As described above, the carrier 52 is connected to the spindle 56. As a result, when the planetary gear mechanism portion is driven, the carrier 52 and the membrane frame 14 are revolved about a predetermined revolving center.

In addition, the main body casing 51 shown in FIG. 3 is connected to the lifting mechanism 156 via the slider 158. The lifting mechanism 156 lifts and lowers the main body casing 51 with respect to the slider 158 so that the carrier 52 is circular polishing pad 58 of the stage 18 and circular polishing pad 60 of the stage 20. In addition to being moved forward and backward, the polishing surface of the glass substrate G adhered to the film frame 14 is pressed against the polishing pads 58 and 60 at a predetermined polishing pressure.

In addition, the slider 158 may be removed from the polishing apparatus 10, and the main body casing 51 may be directly connected to the lifting mechanism 156.

The polishing pad 58 is attached to the upper surface of the polishing platen 62. The polishing plate 62 is rotatably supported by the polishing table 64 via a bearing (not shown), and the rotation center thereof is set coaxially with the central axis of the polishing pad 58. Then, by driving a motor (not shown), the polishing pad 58 is rotated (rotated) about its central axis. In addition, the polishing pad 58 side may not need to rotate, and does not necessarily require a motor. As described below, the polishing pad 58 side may be rocked.

The polishing table 64 is supported by the pair of guide rails 69 and 69 arranged in parallel so as to be slidable. By providing a driving unit (not shown) for reciprocating the polishing table 64 along the guide rails 69 and 69, the polishing pad 58 is swinged in the horizontal direction when necessary. The swinging direction of the polishing pad 58 may be a direction orthogonal to the conveying direction by the conveying apparatus 150 of FIG. 1, or may be a direction parallel to the conveying direction. In other words, the polishing pad 58 may be a direction that swings in the horizontal direction.

In addition, a plurality of hoses (not shown) for supplying a slurry to the back surface side of the polishing pad 58 are connected to the polishing plate 62. In order not to entangle these hoses, the rotation of the polishing pad 58 is restricted so as to pivot in a predetermined angle range from a predetermined reference position. The slurry supplied from the hose to the back surface side of the polishing pad 58 is supplied to the polishing surface of the polishing pad 58 through the slurry supply hole passing through the interior of the polishing pad 58.

In addition, the revolving operation such as the range of the revolving angle of the polishing pad 58, the revolving speed and the like, and the revolving rotation speed per unit time are independently controlled by the controller 200 of FIG.

In addition, since each part structure of the polishing pad 60 is the same as that of the above-mentioned polishing pad 58, the description is abbreviate | omitted here.

3, the linear guides 70 and 70 are provided in the slider 158 of the stage 18. As shown in FIG. The linear guides 70 and 70 are fitted to the guide rails 72 and 72. These guide rails 72 and 72 are arranged toward the maintenance stage 74 which maintains the spindle 56 and the carrier 52 of the stage 18 like the broken line of FIG.

In addition, similarly to the slider 158 of the stage 20, the linear guides 70 and 70 are provided like FIG. 3, and the linear guides 70 and 70 are inserted in the guide rails 160 and 160. As shown in FIG. These guide rails 160 and 160 are arranged toward the maintenance stage 76 which maintains the spindle 56 and the carrier 52 of the stage 20 like the broken line of FIG.

In addition, the slider 158 may be removed from the polishing apparatus 10, and the linear motion guides 70 and 70 may be provided directly on the elevating apparatus 156.

In addition, the carrier 52 is provided with the air chamber not shown in FIG. 3, and communicates with the air supply path 102 shown with the broken line in FIG. The air supply path 102 extends outside the polishing head 50 via a rotary joint (not shown) provided in the polishing head 50, and is connected to the air pump 106 via the valve 104. It is. Accordingly, when the valve 104 is opened, the compressed air from the air pump 106 is supplied to the air chamber provided in the carrier 52 via the air supply path 102. The pressure of the compressed air supplied to this air chamber is transmitted to the glass substrate G through the film body 38, and the pressure-polishing surface of the glass substrate G by this pressure causes the polishing pads 58 and 60 of FIG. Pressurized to polish.

Polishing of the glass substrate G conveys the film frame 14 with the glass substrate G from the stage 16 to the stage 18 by the conveying apparatus 150, as shown in FIG. After polishing the to-be-polished surface of the glass substrate G in 18, the film frame 14 with glass substrate G with the conveying apparatus 152 is conveyed sequentially from the stage 18 to the stage 20, and The polishing is performed in two steps by polishing the surface to be polished of the glass substrate G in the stage 20.

In this embodiment, a slurry suction hole for sucking a slurry is provided near the slurry supply hole in the center of the polishing surface of the polishing pad, and the slurry is circulated by sucking and returning the slurry from the slurry suction hole to the center of the polishing surface of the polishing pad. The back pressure generated is reduced, the desired polishing amount is secured, and normal polishing is performed.

FIG. 4 is a plan view of the polishing pad 58 of the polishing apparatus 10 shown in FIG. 1 (described as the polishing pad 58 as described above, since the polishing pad 60 also has the same configuration).

4, the slurry supply hole 122 and the slurry suction hole 124 formed in the polishing surface of the polishing pad 58, and the groove 126 for flowing the slurry are shown.

As shown in FIG. 4, the slurry supply hole 122 shown by the white circle and the slurry suction hole 124 shown by the black circle are provided in the polishing surface of the polishing pad 58. As shown in FIG. The number and arrangement of the slurry supply holes 122 and the slurry suction holes 124 and the number of the grooves 126 shown in FIG. 4 are merely examples, and are not limited thereto. ) Is formed.

Thus, the slurry supply hole 122 which supplies a slurry between the polishing pad 58 and the glass substrate G (not shown in FIG. 4) is large in the substantially whole surface of the polishing pad 58 (for example, For example, dozens) are installed.

On the other hand, the slurry suction hole 124 which suctions a slurry is formed only in the center part of the polishing pad 58, and especially sucks a slurry from a center part.

5 is a plan view showing a range of formation of slurry suction holes in the polishing surface of the polishing pad 58.

As indicated by broken lines in FIG. 5, the range in which the slurry suction holes 124 are formed on the polishing surface of the polishing pad 58 is the inside of the circle drawn at a radius C from the center of the polishing pad 58. The area F of is preferable. The radius C is here 25% or less of the diameter H of the polishing surface of the polishing pad 58. When radius C is less than 25% of diameter H, the grinding | polishing lack of the center part of the to-be-polished surface of glass substrate G can be eliminated, and when it exceeds 25% of diameter H, the grinding | polishing surface of glass substrate G The slurry becomes difficult to spread widely around the periphery.

As shown in FIG. 4, the slurry supplied to the polishing surface center portion of the polishing pad 58 from the slurry supply hole is attached to the polishing surface of the polishing pad 58 at the center portion of the polishing pad 58. A groove 126 is formed to flow outside the 58 and to spread the slurry widely throughout the polishing surface of the polishing pad 58 (so-called “sculpture”).

The groove 126 through which this slurry flows is one diameter H of the polishing pad 58 polishing surface substantially parallel to the rocking direction of the polishing head 50 (see FIG. 3) performing a linear rocking motion (FIG. 4). Along the dashed line), is formed in a straight line substantially perpendicular to the diameter H over the entire D of the diameter H. That is, the groove 126 is formed in the direction orthogonal to the swinging direction of the polishing head 50.

4, the width | variety of the groove | channel 126 differs in the center part E of diameter H, and its outer side according to diameter H. As shown in FIG. That is, in the center part E of diameter H, the width | variety is formed wider than the outer side of center part E, and it is formed narrower than the width in the center part E outside the center part E with respect to the whole D of diameter H according to the diameter H. In addition, the width | variety of the groove | channel 126 shall mean here the distance between the angle and the angle of the protrusion which forms the groove | channel 126 as shown by the symbol W1 in FIG. 6A, and the symbol W2 in FIG. 6B.

In this way, the width of the groove 126 is formed by passing the slurry stored in the center portion E of the polishing pad 58 through the groove 126 formed in the center portion E from both ends of the groove 126. It is for preventing a slurry from remaining in a center part by making it easy to discharge to an outside. In addition, the depth of each groove | channel 126 of the center part E and the outer side of the center part E may be the same, and may differ.

FIG. 6: A is sectional drawing of the groove of the center part E along the diameter H of the polishing surface of the polishing pad 58 shown in FIG. 4, and FIG. 6B is the outer side of the center part E along the diameter H of the polishing surface of the polishing pad 58. FIG. It is a cross section of the groove. In the center part E of the polishing pad 58, the lateral cross-sectional shape of the groove 126 is concave, and the width W1 is 3 mm. Moreover, in the outer side of the center part E along the diameter H of the polishing surface of the polishing pad 58, the side cross-sectional shape of the groove 126 is concave, and the width W2 is 1.5 mm. However, width W1, W2 is not limited to the said value, Preferably it is 1.5-3.0 mm. In addition, although the space | interval L1 and L2 of the groove | channel 126 are all 3 mm, it is not limited to this, Preferably it is 3.0-9.0 mm. Although the depths T1 and T2 of the grooves 126 are all 2.0 mm, the depths T1 and T2 need not be the same.

Therefore, as illustrated in FIG. 4, two polishing grooves 126 are provided on the polishing surface of the polishing pad 58, and the slurry supply hole 122, the slurry suction hole 124, and the groove 126 through which the slurry flows. .

In this embodiment, while supplying a slurry to the contact part of the polishing pad 58 and glass substrate G, a slurry is sucked in, a slurry is returned to a slurry tank (after-mentioned), and the returned slurry is returned to the polishing pad 58 again. It supplies to the contact part of glass substrate G, and circulates a slurry.

7 shows a schematic diagram of this slurry circulation system.

As shown in FIG. 7, the rotary joint 128 is provided in the opposing surface side of the polishing pad 58 polishing surface 58a, and is formed in the whole polishing surface 58a of the polishing pad 58 via this. While the slurry is supplied from the slurry supply hole 122, the slurry is sucked from the slurry suction hole 124 formed in the center portion of the polishing pad 58 and the polishing surface 58a.

In the case of supplying the slurry, the slurry is introduced into the slurry supply line 123 by the pump 132 from the slurry tank 130, and the polishing pad 58 from the slurry supply hole 122 via the rotary joint 128. Slurry is supplied to the contact part of the grinding | polishing surface 58a of () and glass substrate G (not shown in FIG. 7).

In the case of sucking the slurry, the slurry is sucked by the pump 134 from the slurry suction hole 124 formed only in the center portion of the polishing surface 58a of the polishing pad 58. The sucked slurry is introduced into the slurry recovery conduit 125 through the rotary joint 128 and returned to the slurry tank 130 via the punching metal filter 136. By the punching metal filter 136, the cullet of the glass substrate G contained in the attracted slurry is removed. The slurry returned to the slurry tank 130 is sucked by the pump 132 again and supplied to the polishing surface 58a of the polishing pad 58. In this way, the circulation of the slurry takes place.

Moreover, the flowmeter 138 is provided in the slurry supply line 123 between the rotary joint 128 and the pump 132, and the flow volume of the slurry supplied is always monitored.

In addition, a concentration meter 140 is installed in the pipe line 123a branched from the slurry supply pipe line 123. For example, the concentration of the slurry is monitored by flowing it to the pipe line 123a branched at a flow rate of about 10 liters per minute. have. The slurry passed through the densitometer 140 is returned to the slurry tank 130 again. In addition, a slurry concentration is a mass ratio (mass%) of the abrasive | polishing agent to a slurry.

The detection results of the flow meter 138 and the densitometer 140 are input to the control unit 142.

The control part 142 controls the pumps 132 and 134 according to the detection result of the flowmeter 138, and controls the supply amount of the slurry in grinding | polishing.

In addition, when the concentration of the slurry decreases according to the detection result of the densitometer 140, the control unit 142 opens the electromagnetic valve 144 to discharge the abrasive (abrasive) from the abrasive storage container 146 in the slurry tank ( While injecting into 130, the electromagnetic valve 148 is opened to inject the dispersant into the slurry tank 130 from the dispersant storage container 149.

This is because the abrasive tends to agglomerate, and if the polishing is continued for a long time, the abrasive is agglomerated and precipitated, the slurry concentration is lowered, and the polishing rate is gradually worsened. Therefore, a dispersant is added as an additive to the slurry, It is to prevent aggregation and maintain the polishing rate.

Examples of the abrasive include cerium oxide, zirconium oxide, iron oxide, and silicon dioxide. These abrasives may be used alone or in combination of two or more thereof.

As a dispersing agent, acrylic acid / maleic acid copolymer Na salt (polyti A-550, Lion Co., Ltd. product) can be considered, For example, methanol, Na citrate, etc. may be added.

In addition, in order to prevent aggregation of the abrasive, a small voltage of 1 to 2.5 V may be applied to the slurry.

By adding such a dispersing agent and applying a small voltage, it becomes possible to prevent agglomeration of an abrasive, to prevent a fall of a polishing rate, and to improve a polishing rate.

The concentration control of the slurry by the detection result of the densitometer 140 will be described with reference to FIG. 8.

8 is a graph showing a time change of the concentration detection value by the densitometer 140. The vertical axis represents slurry concentration, and the horizontal axis represents time. The upper limit and the lower limit of the vertical axis are the upper limit and the lower limit of the target slurry concentration range.

In the initial stage of polishing, the slurry concentration of the slurry changes within the desired range, but after a certain time, the slurry concentration decreases. Therefore, as described above, the control unit 142 opens the electromagnetic valves 144 and 148 at a time point t _L below the lower limit value of the slurry concentration set in advance by the control unit 142, and the predetermined amount of abrasives and dispersant may be applied. It is added to the slurry in the slurry tank 130.

In addition, when the slurry is blocked inside the densitometer 140, the slurry concentration rises. At this time, the control unit 142 determines that the concentration meter 140 is blocked at the time t _u when the control unit 142 exceeds the upper limit of the slurry concentration, and the concentration meter 140 is flushed (washed).

In addition to the conduit 123a, the concentration meter 140 is connected to a brushing conduit (not shown). However, during normal operation, the opening / closing valve of the flushing conduit is closed, and the opening / closing valve of the conduit 123a is opened. It is. When flushing, in order to switch the connection to the densitometer 140 from the pipe line 123a to the flush line, the open / close valve of the flush line is opened and the open / close valve of the pipe line 123a is closed. Thereafter, a mixture of water and compressed air sent from the flushing conduit is introduced at the inlet of the densitometer 140, and the mixture is removed from the slurry blocked in the densitometer 140. The removed slurry is discharged from the outlet of the densitometer 140. After completion of flushing, each of the pipeline opening and closing valves is returned to its original state in order to switch the connection from the flushing pipeline to the pipeline 123a.

Although flushing may be performed when the density | concentration value detected by the densitometer 140 exceeded the upper limit in this way, you may perform it regularly so that it may carry out once every 30 to 40 minutes. Thereby, the density meter is clogged and abnormal value is not detected, and density value can always be detected correctly.

9A and 9B show the effect of the present embodiment. FIG. 9: A and 9B are the figures which show the grinding | polishing amount according to the position of the to-be-polished surface of glass substrate G, and standardizes the polishing amount of the peripheral part of the to-be-polished surface of glass substrate G as 100. FIG. 9A is a case where slurry suction is carried out, and FIG. 9B shows a case where slurry suction is not performed.

As shown in FIG. 9B, when slurry suction is not performed, the polishing amount at the center of the surface to be polished of the glass substrate G is 80, which is significantly lower than the polishing amount at the peripheral edge of the surface to be polished. On the other hand, as shown in FIG. 9A, when slurry suction is carried out, it turns out that the polishing amount in the center part of glass substrate G is 90, and is improved compared with the case where slurry suction is not carried out.

As described above, in the present embodiment, when polishing a large-sized glass substrate having at least one side of a rectangle of 1000 mm or more, the slurry remaining in the center portion is reduced by forcibly sucking the slurry under polishing at the center portion of the polishing pad. Back pressure can be suppressed and the amount of polishing at the center can be ensured.

Further, the slurry is sucked from the hole formed in the polishing pad surface, and the sucked slurry is again supplied to the polishing surface of the polishing pad to circulate, thereby increasing the circulation amount of the slurry. In addition, by aspirating the slurry under polishing and increasing the circulation amount of the slurry, it is possible to reduce the retention of the polished glass component in the slurry. In addition, it can suppress that the polished glass component reattaches to a grinding | polishing surface.

In addition, by increasing the circulation amount of the slurry by suction, the temperature rise of the slurry can be suppressed, and contamination adhesion to the glass substrate can be suppressed. Moreover, deterioration of the selective abrasiveness by softening of a polishing pad can be suppressed by suppressing the temperature rise of a slurry.

As mentioned above, although the plate-shaped object grinding apparatus and the grinding | polishing system which concern on this invention were demonstrated in detail, this invention is not limited to the above example and may be various improvement and deformation in the range which does not deviate from the summary of this invention. Of course.

This application is based on the JP Patent application 2011-178443 of an application on August 17, 2011, The content is taken in here as a reference.

10: (plate) polishing apparatus
12: Conveyor for Carrying Glass Substrate
14: membrane frame (plate-like adhesive member)
16: glass substrate adhesion stage
18: first polishing stage
20: second polishing stage
22: glass substrate removal stage
24: conveyor for transporting glass substrates
26: membrane frame cleaning stage
28: membrane frame drying stage
30: membrane frame conveying conveyor
32: robot
33: arm
34: adsorption pad
36: conveyor
38: membrane
51: body casing
52: carrier (plate-like holding means)
56: spindle
58, 60: polishing pad
62: polishing table
64: polishing table
122: slurry feed hole
124: slurry suction hole
126: home
128: rotary joint
130: slurry tank
132, 134: pump
136: punching metal filter
138: flow meter
140: densitometer
142: control unit
144, 148: electromagnetic valve
146: abrasive storage container
149: dispersant storage container
150: conveying device
200:

Claims (9)

Plate-shaped body holding means for holding a plate-shaped body of which the length of one side is 1000 mm or more,
And a polishing pad provided to face the plate-like member held by the plate-body holding means,
The polishing pad is,
A plurality of slurry supply holes formed on the plate facing surface and supplying a slurry to a contact portion between the polishing pad and the plate;
Slurry suction hole which is formed only in the center part of the said plate-shaped object opposing surface, and sucks the said slurry supplied to the said contact part.
The plate-shaped grinding | polishing apparatus in which this is formed. The plate-shaped polishing apparatus according to claim 1, wherein a central portion of the plate-shaped opposing surface of the polishing pad in which the slurry suction hole is formed is within a range of 25% of its diameter from the center of the polishing pad. The method according to claim 1 or 2,
A plurality of grooves are formed in a straight line in an arbitrary direction on the plate facing surface of the polishing pad, and the width of the grooves formed in the center portion in a direction orthogonal to the arbitrary directions is orthogonal to the arbitrary directions. Plate-like polishing device formed in a direction wider than the width of the groove formed on the outside of the central portion. The apparatus according to any one of claims 1 to 3, further comprising: means for oscillating the polishing pad in a horizontal direction relative to the plate-shaped body holding means, and means for rotating and revolving the polishing pad,
A plurality of grooves are formed in a straight line in the swinging direction on the plate-like object facing surface of the polishing pad, and the width of the grooves formed in the center portion in a direction orthogonal to the swinging direction is perpendicular to the swinging direction. Plate-shaped polisher formed wider than the width of the groove formed on the outside of the central portion along. The plate-shaped polishing apparatus according to claim 3 or 4, wherein the center portion is within 25% of the diameter from the center of the polishing pad. Plate-shaped body holding means for holding a plate-shaped body of which the length of one side is 1000 mm or more,
And a polishing pad provided to face the plate-like member held by the plate-body holding means,
In the polishing pad,
A plurality of slurry supply holes formed on the plate facing surface and supplying a slurry to a contact portion between the polishing pad and the plate;
Slurry suction hole which is formed only in the center part of the said plate-shaped object opposing surface, and sucks the said slurry supplied to the said contact part.
Is formed,
A slurry tank for storing a slurry containing abrasive grains as an abrasive;
Slurry supply means for supplying the slurry from the slurry tank to a contact portion between the polishing pad and the plate-shaped object through the slurry supply hole;
Slurry recovery means for sucking the slurry supplied to the contact portion through the slurry suction hole and returning the sucked slurry to the slurry tank;
A densitometer for detecting the concentration of the slurry provided in the slurry supply means;
On the basis of the detection result of the densitometer, when the concentration of the slurry is lower than a predetermined lower limit, the slurry tank is controlled to add an abrasive and a predetermined additive, and the concentration of the slurry exceeds the predetermined upper limit. In one case, a control unit for controlling the cleaning of the densitometer
Polishing system having a. The polishing system of claim 6, wherein the predetermined additive is a dispersant that prevents agglomeration of the abrasive. The polishing system according to claim 6 or 7, wherein a central portion of the plate-like object facing surface of the polishing pad in which the slurry suction hole is formed is within a range of 25% of its diameter from the center of the polishing pad. The polishing system according to any one of claims 6 to 8, wherein the cleaning of the densitometer is performed every 30 to 40 minutes, or instead of the case where the concentration of the slurry exceeds a preset upper limit. .

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