WO2013118578A1

WO2013118578A1 - Polishing pad and polishing apparatus

Info

Publication number: WO2013118578A1
Application number: PCT/JP2013/051337
Authority: WO
Inventors: 一義山本
Original assignee: 旭硝子株式会社
Priority date: 2012-02-10
Filing date: 2013-01-23
Publication date: 2013-08-15
Also published as: TW201343331A; JPWO2013118578A1; CN104105573A; KR20140133497A

Abstract

The present invention relates to a polishing pad which comprises: a plurality of first grooves that are provided in parallel at a predetermined interval in a surface to be polished; a plurality of second grooves that are provided in the surface to be polished to intersect with the first grooves; and a plurality of holes comprising a polishing liquid supply hole and a polishing liquid suction hole that are provided in bottom surfaces of the first groove and the second groove.

Description

Polishing pad and polishing apparatus

The present invention relates to a polishing pad and a polishing apparatus using the polishing pad.

A glass plate for FPD (Flat Panel Display) used for liquid crystal displays and the like is formed of molten glass into a plate shape by a glass manufacturing method called a float method, and this is a continuous type disclosed in Patent Document 1 and the like. By polishing and removing fine irregularities and undulations on the surface with a polishing apparatus, a thin plate satisfying the flatness required as a glass plate for FPD is produced.

The polishing apparatus of Patent Document 1 uses a slurry in which an abrasive is dispersed with a dispersant to polish the surface of a glass plate (hereinafter referred to as a surface to be polished) with a polishing pad. Slurry is supplied between the polishing surface of the polishing pad and the surface to be polished of the glass plate from a slurry supply hole provided in the center of the polishing pad, but when the amount of slurry supplied becomes uneven on the polishing surface The flatness of the polished surface of the polished glass plate is deteriorated. Therefore, in the polishing apparatus, it is necessary to distribute the slurry uniformly over the entire polishing surface of the polishing pad.

In order to spread the slurry uniformly over the entire polishing surface of the polishing pad, the present applicant has a slurry supply hole in the center of the polishing surface, and the polishing surface is radially formed by a plurality of grooves formed outward from the center. A divided polishing pad is proposed in Patent Document 2.

Further, the polishing pad of the polishing apparatus described in Patent Document 3 is provided with a plurality of grooves at substantially equal intervals on the polishing surface, thereby promoting the diffusion of the abrasive during polishing. In addition, the polishing pad of Patent Document 3 is provided with a large number of abrasive supply holes and abrasive discharge holes that are alternately arranged over substantially the entire polishing surface.

Japanese Unexamined Patent Publication No. 2004-122351 Japanese Unexamined Patent Publication No. 2011-235425 Japanese Unexamined Patent Publication No. 2009-125873

However, even with the polishing pads of Patent Documents 2 and 3, there is a problem that a large glass plate having a side length exceeding 2000 mm cannot be polished with good quality and high productivity.

That is, the polishing pad of Patent Document 2 supplies slurry from a slurry supply hole provided at the center of the polishing surface of the polishing pad and spreads the slurry over the entire polishing surface via radial grooves. When this polishing pad is enlarged to polish the above-mentioned large glass plate, it is difficult to spread the slurry over the entire polishing surface.

Moreover, the polishing pad of Patent Document 3 supplies abrasive from a plurality of abrasive supply holes provided on the polishing surface, and spreads the polishing agent over the entire polishing surface through grooves provided at equal intervals on the polishing surface. However, when this polishing pad is enlarged to polish the above-mentioned large glass plate, it is difficult to spread the polishing agent over the entire polishing surface.

Therefore, in the polishing pads of Patent Documents 2 and 3, when attempting to solve the above problem by increasing the amount of slurry (abrasive) supplied from the slurry (abrasive) supply hole, Since the slurry is basically difficult to spread over the entire polishing surface, the amount of slurry supplied from the slurry supply hole is larger than the amount of slurry discharged outside from the groove on the polishing surface. In this case, slurry is retained between the polishing pad and the glass plate, and back pressure is generated. As a result, the glass plate is separated from the polishing pad, and the separated portion is difficult to be polished by the polishing pad, which causes a problem that the polishing quality and productivity of the glass plate are deteriorated. The back pressure can be measured by a pressure gauge provided in a pipe line connecting the slurry supply hole and the slurry supply source.

Also, the following problems occur due to the back pressure.

That is, the polishing pad is periodically pressed against the truing grindstone to perform truing. In this case, truing is performed while supplying the truing liquid from the polishing pad slurry supply hole between the polishing surface of the polishing pad and the polishing surface of the truing grindstone. Since the pressure acts on the polishing pad, there is a problem that the polishing surface where the back pressure is generated is not true. Abrasive material such as cerium oxide, which is a component in the slurry, is attached to the polished surface where truing is not performed. When the glass plate is polished in this state, the abrasive material adheres to the glass plate and the quality of the glass plate It was a cause of lowering. In addition, since the polishing surface on which truing is not performed has a low polishing ability, the polishing time becomes long, which causes a reduction in the productivity of the glass plate. Furthermore, the life of the polishing pad was shortened due to the fact that the polishing surface of the polishing pad was not uniformly polished during truing.

The present invention has been made in view of such circumstances, and particularly when polishing a large plate-like body having a side length exceeding 2000 mm, the back pressure is reduced without reducing the supply amount of the polishing liquid. An object of the present invention is to provide a polishing pad and a polishing apparatus capable of improving the polishing quality and improving the productivity by reducing the polishing time by spreading the polishing liquid over the entire polishing surface of the polishing pad.

In order to achieve the above object, a polishing pad of the present invention includes a plurality of first grooves provided in parallel to a polishing surface at a predetermined interval, and a polishing pad provided in the polishing surface and intersecting the first groove. A plurality of second grooves, and a plurality of holes including a polishing liquid supply hole and a polishing liquid suction hole provided on a bottom surface of the first groove and the second groove.

According to the present invention, since the polishing surface of the polishing pad is provided with the second groove intersecting the first groove in addition to the first groove, the polishing liquid supplied from the polishing liquid supply hole to the polishing surface is It efficiently diffuses on the polishing surface through the first groove and the second groove. Therefore, the back pressure generated between the plate and the polishing pad is reduced, so that the polishing quality of the plate can be improved and the supply amount of the polishing liquid can be increased, so that the polishing time can be shortened. Productivity is improved.

The second groove of the present invention communicates the hole and the hole. That is, since the holes are the polishing liquid supply hole and the polishing liquid suction hole, the second groove may communicate the polishing liquid supply holes with each other, and the polishing liquid supply hole and the polishing liquid suction hole communicate with each other. Alternatively, the polishing liquid suction holes may be communicated with each other. The polishing liquid supplied from the polishing liquid supply hole diffuses over the entire polishing surface of the polishing pad by passing through the first groove and the second groove. Further, the second groove only needs to be provided in a portion of the polishing surface where a high back pressure is generated with respect to the polishing pad provided with only the first groove. Furthermore, the crossing form of the second groove with respect to the first groove may be an orthogonal direction or a direction other than that direction. Further, the second groove may be linear or bent.

The plurality of first grooves of the present invention are penetrated by an outer peripheral surface in contact with the polishing surface, and the plurality of second grooves are a part of the plurality of second grooves. It is preferable that all the grooves of the plurality of second grooves are not penetrated with respect to the outer peripheral surface.

It is preferable to provide a plurality of grooves on the polishing surface of the polishing pad from the viewpoint of diffusion and discharge of the polishing liquid. However, as the number of grooves increases, “streaks” due to the edges of the grooves are generated on the surface to be polished of the plate-like body, which may deteriorate the polishing quality of the plate-like body. Therefore, the newly provided second groove is not provided with a plurality of pieces, and only a required length may be provided at a necessary portion for reducing the back pressure. That is, by passing a part of the plurality of second grooves with respect to the outer peripheral surface or making all the grooves of the plurality of second grooves non-penetrating with respect to the outer peripheral surface, The length of the groove can be made shorter than that of the first groove, and generation of “stripes” can be suppressed. Further, even if the length of the second groove is shortened, the polishing liquid that has flowed into the second groove flows into the first groove through the intersection with the first groove, and from the outer peripheral surface of the polishing surface. Since it is discharged, the polishing liquid does not stay between the plate-like body and the polishing pad, and no back pressure is generated. Since the polishing pad of the present invention capable of suppressing back pressure in this way is polished flat by a truing grindstone even during truing, the polishing quality of the plate-like body can be improved and the polishing time can be greatly shortened. Therefore, the productivity of the plate-like body is also improved. There is also an advantage that the life of the polishing pad is extended.

The polishing liquid supply hole of the present invention is arranged over the entire polishing surface, and the arrangement density of the central portion of the polishing surface is set higher than the arrangement density other than the central portion, and the second groove is It is preferable that the arrangement density of the central portion of the polishing surface is set to be higher than the arrangement density of the portion excluding the central portion.

According to the present invention, in order to spread the polishing liquid over the entire polishing surface of the polishing pad, it is preferable to provide a large number of polishing liquid supply holes in the central portion of the polishing surface, and the back pressure generated in the central portion is reduced. In order to suppress it, a large number of second grooves are provided in the center of the polishing surface. As a result, the polishing liquid can easily spread over the entire polishing surface, and the back pressure generated in the central portion can be reliably suppressed.

It is preferable that the second groove of the present invention is provided so as to be point symmetric about the center point of the polishing surface.

According to the present invention, the flatness of the surface to be polished of the plate-like body is further improved by providing the second groove so as to be point symmetric about the center point of the polishing surface.

In the present invention, the surface area of the polished surface is preferably larger than the surface area of the polished surface so as to polish the polished surface of a rectangular plate having a side length of more than 2000 mm.

As described above, the length of one side of the plate-like body to be polished by the polishing pad of the present invention is preferably more than 2000 mm, but the length of one side exceeds 2500 mm, in particular, the length of one side exceeds 2800 mm. It is particularly effective for polishing. Further, the polishing pad may be circular or rectangular.

The present invention also provides a polishing apparatus for polishing a surface to be polished of a plate-like body with the polishing pad of the present invention in order to achieve the above object.

The polishing apparatus of the present invention may be a polishing apparatus that revolves the plate-like body side about the revolution axis and rotates the polishing pad side, or may be a polishing apparatus that rotates and revolves the plate-like body side. In addition, the force for removing the micro unevenness | corrugation on the surface of a plate-shaped body can be obtained by revolving a plate-shaped body side.

According to the polishing pad and the polishing apparatus of the present invention, even when polishing a large plate-shaped body, the polishing liquid is supplied to the polishing surface of the polishing pad while reducing the back pressure without reducing the supply amount of the polishing liquid. Since it can be spread over the entire area, polishing quality and productivity are improved.

FIG. 1 is a plan view showing an overall structure of a polishing apparatus according to an embodiment. FIG. 2 is an assembled perspective view of the carrier and the membrane frame. FIG. 3 is a side view showing an embodiment of a polishing head and a polishing stage. FIG. 4 is a perspective view including a partially broken portion showing the configuration of the polishing surface plate. FIG. 5 is an enlarged cross-sectional view of a main part showing a structure for attaching the film frame to the carrier. FIG. 6A is a diagram illustrating an initial state in which the glass plate is removed from the film frame by expanding the film body. FIG. 6B is a diagram in which compressed air is injected from the compressed air injection nozzle onto the boundary between the edge of the glass plate and the film body. FIG.6 (c) is explanatory drawing which a glass plate peels from a film body. FIG. 6D is an explanatory diagram in which the glass plate is completely removed from the film body and placed on the table. FIG. 6E is an explanatory view in which the membrane frame is removed from the carrier by the removal device and the membrane frame is placed on the jack. FIG. 7 is a perspective view showing the configuration of the transport apparatus. FIG. 8 is an enlarged perspective view of a main part showing the configuration of the transport device. FIG. 9 is a plan view showing the configuration of the transport apparatus. FIG. 10 is an explanatory diagram showing the movement trajectory of the film frame revolved around the revolution center. FIG. 11 is a plan view of the polishing surface of the polishing pad. FIG. 12 is an enlarged perspective view of a main part of the polishing surface of the polishing pad.

Hereinafter, preferred embodiments of a polishing pad and a polishing apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a plan view showing an overall structure of a polishing apparatus 10 according to an embodiment. FIG. 2 is an assembled perspective view of the carrier 52 and the membrane frame 14. FIG. 3 is a side view showing an embodiment of the polishing head 50 and the polishing stage.

The polishing apparatus 10 polishes the surface to be polished of a large rectangular glass plate G having a side length of more than 2000 mm and a thickness of 0.2 mm to 0.7 mm, for example, to the flatness required for the glass plate for a liquid crystal display. Polishing apparatus.

As shown in FIG. 1, the polishing apparatus 10 includes a glass plate carry-in conveyor 12 for carrying a glass plate G before polishing, a glass plate attaching stage 16 for attaching the glass plate G to the film frame 14, and a first polishing stage 18. , Second polishing stage 20, glass plate removal stage 22 for removing polished glass plate G from film frame 14, glass plate carry-out conveyor 24, film frame cleaning stage 26, film frame drying stage 28, and film frame return conveyor 30 is mainly provided.

Hereinafter, in order to simplify the description, the glass plate attaching stage 16, the first polishing stage 18, the second polishing stage 20, the glass plate removing stage 22, the film frame cleaning stage 26, and the film frame drying stage 28 will be described. Are simply described as

stages

16, 18, 20, 22, 26, 28.

The polishing apparatus 10 includes a transport device 150 that transports the film frame 14 from the stage 16 to the stage 18, a transport device 152 that transports the film frame 14 from the stage 18 to the stage 20, and transports the film frame 14 from the stage 20 to the stage 22. A conveying device 154 is provided. These

transfer devices

150, 152, and 154 have the same configuration, and their operations are controlled by a control unit 200 that controls the polishing apparatus 10 in an integrated manner, and are reciprocated synchronously in the left-right direction in FIG.

The unpolished glass plate G carried in by the glass plate carrying-in conveyor 12 is sucked and held by a suction pad 34 provided on the arm 33 of the robot 32. Then, it is transferred from the glass plate carry-in conveyor 12 to the conveyor 36 by the rotation operation of the arm 33, and is conveyed to the stage 16 by the conveyor 36.

At the stage 16, the glass plate G before polishing is stuck to the film frame 14. The sticking method will be described. The film frame 14 is held by a lifting device (not shown) on the stage 16, and when the glass plate G is positioned below the film frame 14, the film frame 14 is moved downward by the lifting device. Then, the flexible and self-adsorbing film body 38 stretched on the film frame 14 shown in FIG. 2 is pressed against the non-polished surface of the glass plate G (the surface facing the polished surface of the glass plate G). With this pressing force, the non-polished surface of the glass plate G is adhered to the film body 38. Thereafter, the film frame 14 is held by the transfer device 150 of FIG. 1 and transferred to the stage 18 of FIG. 3 where it is attached to the carrier (plate-shaped body holding portion) 52 of the polishing head 50. The film frame 14 described below refers to the whole of the film body 38 stretched. The transport device 150 will be described later.

As shown in FIG. 2, the film frame 14 is formed by stretching a rectangular film body 38 to which the glass plate G can be attached between an upper frame 40 and a lower frame 42 that are also rectangular, and then the upper frame 40. And the lower frame 42 are fastened by bolts (not shown).

Next, the polishing head 50 shown in FIG. 3 will be described. Since the polishing head 50 of the stage 18 and the polishing head 50 of the stage 20 have the same structure, the same reference numerals are used for explanation.

The polishing head 50 includes a main body casing 51, and a revolving drive mechanism (not shown) is built in the main body casing 51. The revolution drive mechanism is composed of a planetary gear mechanism and a motor, and the output shaft of the planetary gear mechanism driven by the motor is connected to a spindle 56 that is suspended in the vertical direction. A carrier 52 is connected to the spindle 56. Therefore, when the planetary gear mechanism is driven, the carrier 52 and the film frame 14 are revolved around a predetermined revolution center P (see FIG. 10).

Furthermore, the main body casing 51 shown in FIG. 3 is connected to an elevating mechanism 156 via a slider 158. The main body casing 51 is moved up and down with respect to the slider 158 by the elevating mechanism 156, whereby the carrier 52 is moved back and forth with respect to the circular polishing pad 58 of the stage 18 and the circular polishing pad 60 of the stage 20. The surface to be polished of the glass plate G attached to the frame 14 is pressed against the polishing surfaces of the

polishing pads

58 and 60 with a predetermined polishing pressure.

It should be noted that 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.

FIG. 4 is a perspective view including a partially broken portion showing the configuration of the polishing surface plate 62.

4 is attached to the upper surface of the polishing surface plate 62. The polishing pad 58 shown in FIG. The polishing surface plate 62 is rotatably supported by a polishing table 64 via a bearing 65, and the center of rotation is set coaxially with the central axis of the polishing pad 58. A gear portion 66 is provided on the side surface of the polishing surface plate 62, and a gear 67 rotated by a motor 68 is engaged with the gear portion 66. Further, the gear portion 66 is formed in an arc shape centering on the central axis of the polishing pad 58. Accordingly, by rotating the motor 68 forward and backward, the polishing pad 58 rotates in the clockwise direction and the counterclockwise direction around the central axis.

The polishing table 64 is slidably supported by a pair of

guide rails

69 and 69 arranged in parallel. By providing a drive unit (not shown) for reciprocating the polishing table 64 along the guide rails 69, 69, the polishing pad 58 is swung in the horizontal direction indicated by the arrow A when necessary. The swinging direction of the polishing pad 58 may be a direction orthogonal to the transport direction by the transport device 150 of FIG. 1 or may be a direction parallel to the transport direction. That is, any direction that swings the polishing pad 58 in the horizontal direction may be used.

In the polishing surface plate 62 of FIG. 4, slurry (polishing liquid) is supplied to a plurality of slurry supply holes (polishing liquid supply holes) provided vertically through the polishing pad 58 (in the thickness direction of the polishing pad 58). A large number of pipes (not shown) for supplying the water are connected. In order to prevent the pipes from being entangled, the turning angle of the polishing pad 58 is set so as to turn in a predetermined angle range from a predetermined reference position. The slurry passes through the plurality of slurry supply holes, is supplied to the polishing surface 176 of the polishing pad 58, and passes through a plurality of grooves (first groove and second groove) provided on the polishing surface 176. It is diffused throughout the polishing surface 176. Then, the slurry is discharged to the outside of the polishing pad 58 from a plurality of slurry suction holes (polishing liquid suction holes) provided on the polishing surface 176 and an outer peripheral surface 177 in contact with the polishing surface 176. The slurry supply hole, the groove, and the slurry suction hole of the polishing pad 58 will be described later.

Further, the range of the swing angle of the polishing pad 58, the swing operation such as the swing speed, the revolution operation such as the revolution speed per unit time, and the swing range and swing speed indicated by the arrow A in FIG. The control unit 200 is independently controlled.

Note that the configuration of each part of the polishing pad 60 is the same as the configuration of the polishing pad 58 described above, and therefore the description thereof is omitted here.

On the other hand, as shown in FIG. 3,

linear guides

70 and 70 are attached to the slider 158 of the stage 18. The linear motion guides 70, 70 are fitted to the guide rails 72, 72. The guide rails 72 and 72 are disposed toward a maintenance stage 74 for maintaining the spindle 56 of the stage 18 and the carrier 52 as indicated by broken lines in FIG.

Further, as shown in FIG. 3, linear motion guides 70, 70 are similarly attached to the slider 158 of the stage 20, and the linear motion guides 70, 70 are fitted to the

guide rails

160, 160. The guide rails 160 and 160 are arranged toward a maintenance stage 76 for maintaining the spindle 56 and the carrier 52 of the stage 20 as indicated by broken lines in FIG.

The slider 158 may be removed from the polishing apparatus 10 and the linear motion guides 70 and 70 may be directly attached to the lifting mechanism 156.

Next, the carrier 52 shown in FIGS. 2 and 5 will be described. FIG. 5 is an enlarged cross-sectional view of a main part showing a structure for attaching the film frame 14 to the carrier 52.

A lifting frame 78 is fixed to the upper outer periphery of the carrier 52 by bolts (not shown). Through

holes

80, 80... Are opened at predetermined equal intervals in the flange portion of the lifting frame 78, and project through the through

holes

80, 80... On the upper surface of a slide frame 82 (slide-contact frame). The slidable frame suspension 84 is penetrated from below as shown in FIG. Further, as shown in FIG. 5, the sliding frame lifting tool 84 is penetrated by a lifting spring 88 disposed between the lifting frame 78 and the lifting disk spring 86, and the lifting disk spring 86. And is connected to a screw jack 92.

Therefore, the sliding frame 82 is lifted with respect to the carrier 52 by operating the screw jack 92 and pulling the sliding frame suspension 84 upward against the urging force of the lifting spring 88. Thereby, the membrane frame 14 detachably attached to the sliding frame 82 is pulled up, and a predetermined tension is applied to the membrane body 38.

In the carrier 52,

injection ports

98, 98... For discharging compressed air to the air chamber 54 are opened. These

injection ports

98, 98... Communicate with an air supply path 102 indicated by a broken line and a solid line in FIG. 3 via an air chamber 100 provided on the upper surface of the carrier 52. The air supply path 102 extends outside the polishing head 50 via a rotary joint (not shown) attached to the polishing head 50, and is connected to the air pump 106 via a valve 104. Therefore, when the valve 104 is opened, the compressed air from the air pump 106 is supplied to the air chamber 54 via the air supply path 102, the air chamber 100 of FIG. Thereby, the pressure of the compressed air is transmitted to the glass plate G through the film body 38, and the polished surface of the glass plate G is pressed against the polishing surface 176 of the polishing pad 58 (60) in FIG. Is done.

Next, the structure of the means for attaching / detaching the membrane frame 14 to / from the sliding frame 82 shown in FIGS. 2 and 5 will be described.

A plurality of

pins

108, 108... Are projected at equal intervals on the upper frame 40 of the membrane frame 14, and a large-diameter head portion 110 provided at the upper end of these pins 108 is provided at the bottom of the sliding frame 82. The membrane frame 14 is attached to the sliding frame 82 by being engaged with the hook 112 fixed to the sliding frame 82. The engaging force between the head portion 110 and the hook 112 is strengthened by the reaction force of the film body 38 when the film body 38 is lifted by the screw jack 92, and the polishing resistance received from the film body 38 during polishing causes the head portion from the hook 112. 110 does not come off.

The polishing of the glass plate G is performed by transferring the film frame 14 with the glass plate G attached thereto from the stage 16 to the stage 18 by the transfer device 150 as shown in FIG. The film frame 14 to which the glass plate G is attached by the transfer device 152 is sequentially transferred from the stage 18 to the stage 20, and the polished surface of the glass plate G is polished on the stage 20 in two stages. Further, when the polishing of the glass plate G is completed at the stage 20, the film frame 14 is removed from the carrier 52 and conveyed to the stage 22 by the conveying device 154. The polishing stage may be one or two or more depending on the application. In consideration of efficiency and cost, it is preferable to provide two stages of a rough polishing stage and a finish polishing stage, but a finish polishing stage may be added for high quality purposes in some cases.

In the method of removing the film frame 14 from the carrier 52, first, the screw jack 92 shown in FIG. Next, the film frame 14 is slid with respect to the carrier 52 to remove the head portion 110 from the hook 112. Thereby, the film frame 14 is removed from the carrier 52.

On the other hand, in the stage 22 shown in FIG. 1, the glass plate G that has been polished is removed from the film frame 14 that has been transported by the transport device 154. The removed glass plate G is conveyed by the conveyor 138, and is adsorbed by the adsorption head 144 attached to the arm 142 of the robot 140, and is transferred to the glass plate carry-out conveyor 24 by the operation of the robot 140. 10 to the outside.

6 (a) to 6 (d) show a process of removing the polished glass plate G from the film frame 14, which is performed in the stage 22. FIG. 6 (a) to 6 (d) illustrate an example in which the glass frame G is removed from the film frame 14 and then the film frame 14 is removed from the carrier 52. As described above, the film frame 14 is removed from the carrier 52. After removal, the glass plate G may be removed from the membrane frame 14.

As shown in FIG. 6A, when the carrier 52 is positioned above the table 204 installed on the stage 22, air is supplied to the air chamber 54 via the air supply path 102 to expand the film body 38. This state is the initial state of removal of the glass plate G. In this state, the glass plate G and the film body 38 are relatively displaced from each other, and the glass plate G is easily detached from the film body 38 due to the elastic force that causes the glass plate G to return flat. That is, conventionally, the detaching process that burdens the equipment by forcibly removing the glass plate G can be easily performed by expanding the film body 38.

Other embodiments may be mentioned to shorten the work time in the removal process. As shown in FIG. 6 (b), after the step of FIG. 6 (a), the compressed air is supplied to the edge of the glass plate G from a plurality of compressed

air injection nozzles

206, 206 disposed opposite to the edge of the glass plate G. It sprays on the boundary part of a part and the film body 38. FIG. Thereby, the glass plate G is peeled from the film body 38 as shown in FIG. Since the adsorption force of the film body 38 is reduced by the compressed air, the glass plate G is easily removed from the film body 38. In addition, it may replace with compressed air and may inject water, and the same effect can be acquired even if it injects water and compressed air together. In FIG. 6C, the compressed air injection nozzle 206 is omitted.

FIG. 6D shows a state in which the glass plate G is completely removed from the film body 38 and placed on the table 204. Thereafter, the glass plate G is conveyed by the conveyor 138 shown in FIG. 1, and then transferred to the glass plate carry-out conveyor 24 by the robot 140 and carried out of the polishing apparatus 10.

On the other hand, when the glass plate G is completely removed from the film body 38 as shown in FIG. 6D, the film frame 14 is then removed from the carrier 52 by the removal device as shown in FIG. 14 is placed on the

jacks

208 and 208. The film frame 14 is conveyed to the film frame cleaning stage 26 by the conveyor 146 shown in FIG.

The film frame 14 conveyed to the stage 26 is washed with water here. The film frame 14 that has been cleaned is conveyed to the stage 28 by the conveyor 148, where it is heated and dried. Then, the dried film frame 14 is transported to the stage 16 by the film frame return conveyor 30 and reused for attaching the glass plate G.

Next, the transport device 150 (152, 154) will be described with reference to FIGS. 7, 8, and 9 are a perspective view, a main part enlarged perspective view, and a plan view, respectively, showing the configuration of the transfer device 150 (152, 154).

The transfer device 150 includes four holding

portions

162, 162,... That hold the protrusions 43 provided at the four corners of the film frame 14 from below. These holding

portions

162, 162... Are arranged on both sides of the conveyance path of the film frame 14 formed between the stage 16 and the stage 18, and are connected to the shaft 166 of the robot 164. The shaft 166 is driven in the vertical direction and the horizontal direction by the robot 164, whereby the holding unit 162 is driven in the vertical direction and the horizontal direction.

Further, as shown in FIG. 8, a guide block 168 is fixed to the lower part of the robot 164, and the guide block 168 is fitted to guide

rails

170, 170 disposed on both sides of the conveyance path of the film frame 14. The guide block 168 is screwed into a feed screw 172 of a feed screw device disposed along the guide rail 170. Thereby, the film frame 14 to which the glass plate G is adhered is held by the holding

portions

162, 162... Of the transfer device 150 (152, 154) and transferred from the stage 16 to the stage 18. Further, the film frame 14 transported to the stage 18 can be placed on the polishing pad 58 of the stage 18 by the downward movement operation of the holding

parts

162, 162, and then the horizontal direction of the holding

parts

162, 162,. The holding

portions

162, 162... Can be retracted from the film frame 14 by the moving operation. Further, the holding

portions

162, 162... Evacuated from the film frame 14 are returned toward the stage 16 during the polishing of the glass plate G. Here, the film frame 14 to which the next glass plate G placed on the stage 16 is stuck is held by the holding

parts

162, 162, and waits until the next conveyance. The movement of the holding unit 162 between the stages, the vertical direction with respect to the film frame 14, and the horizontal operation are controlled by the control unit 200 shown in FIG.

In the embodiment, the guide rails 170 are disposed on both sides of the conveyance path of the film frame 14, but the number of the guide rails 170 is not limited to a pair (two). It may be disposed only on one side of the conveyance path of the film frame 14. However, when the guide rails 170 are disposed on both sides of the conveyance path, the glass plate G can be held from both sides facing the guide rail 170, so that the glass plate G can be stably held.

FIG. 10 is a plan view showing movement trajectories of the film frame 14 and the spindle 56 revolved around the revolution center P. FIG. As shown in FIG. 10, the membrane frame 14 is revolved without colliding with the cylindrical casing 174 that protects the guide rail 170 and the like.

FIG. 11 is a plan view of the polishing surface 176 schematically showing the configuration of the polishing surface 176 of the polishing pad 58 (60) in an easily understandable manner. FIG. 12 is an enlarged perspective view showing a main part of the polishing surface 176.

Further, an arrow A in FIG. 11 indicates the swinging direction of the polishing pad 58 (60) (see FIG. 4), and an arrow B indicates the turning direction of the polishing pad 58 (60). Further, the swinging direction is set to a direction orthogonal to the groove 178 described below.

Furthermore, the polishing surface 176 of the polishing pad 58 (60) of the embodiment has an elliptical shape having a major axis D ₁ and a minor axis D ₂ .

The shape of the polishing pad 58 (60) is not limited to an elliptical shape as shown in FIG. 11, and may be a perfect circle or a rectangular shape, for example.

As shown in FIG. 11, the polishing surface 176 of the polishing pad 58 has a plurality of grooves (first grooves: so-called “cutting”) provided in parallel in the left-right direction in the figure with a predetermined interval in the up-down direction in the figure. 178, 178 ... are provided. Further, the polishing surface 176 is provided with a plurality of grooves (second grooves: so-called “divisions”) 184, 184... Intersecting with the

grooves

178, 178. Further, a plurality of slurry supply holes (polishing liquid supply holes) 180, 180... And a plurality of slurry suction holes (polishing liquid suction holes) 182, 182 are formed on the bottom surfaces of the

grooves

178, 178. A plurality of holes are provided. In FIG. 11, the slurry supply hole 180 is indicated by “◯”, and the slurry suction hole 182 is indicated by “●”.

In FIG. 12, the dimensions of the groove 178 and the groove 184, and the dimensions of the slurry supply hole 180 and the slurry suction hole 182 are the size of the glass plate, the flatness of the polishing surface required for the product of the glass plate, and the size of the polishing pad 58. It is defined by the material. Therefore, although these dimensions are not limited, for example, the groove pitch P of the grooves 178 is preferably 4.5 to 9 mm, the groove width W ₁ is preferably 1.5 to 3 mm, and the groove depth T ₁ Is preferably 1 to 5 mm, more preferably 1 to 3 mm. The groove width W ₂ of the groove 184 is preferably 1.5 to 5 mm, more preferably 3 to 5 mm, and the groove depth T ₂ is preferably 1 to 5 mm, and more preferably 1 to 3 mm.

According to the polishing pad 58 of the embodiment, the polishing surface 176 is provided with the groove 184 intersecting with the groove 178 in addition to the normal cutting groove 178, and thus supplied to the polishing surface 176 from the slurry supply hole 180. The slurry efficiently diffuses on the polishing surface 176 through the

grooves

178 and 184. Therefore, since the back pressure generated between the glass plate G and the polishing pad 58 is reduced, the polishing quality of the glass plate G can be improved and the supply amount of slurry can be increased, so that the polishing time can be shortened and the productivity can be reduced. Will improve.

Further, the groove 184 communicates the hole and the hole. That is, since the holes are the slurry supply hole 180 and the slurry suction hole 182, the groove 184 may connect the

slurry supply holes

180 and 180, and the slurry supply hole 180 and the slurry suction hole 182 communicate with each other. Further, the slurry suction holes 182 and 182 may be communicated with each other.

The polishing liquid supplied from the slurry supply hole 180 diffuses over the entire polishing surface 176 of the polishing pad 58 by passing through the groove 178 and the groove 184. Further, the groove 184 may be provided at a location where the back pressure is generated higher in the polishing surface 176 than the conventional polishing pad having only the groove 178. Further, the crossing form of the groove 184 with respect to the groove 178 may be the orthogonal direction shown in FIG. 11 or a direction other than that direction. Further, the groove 184 may have a linear shape as shown in FIG. 11 from one end to the other end of the groove 184 or a bent line shape.

The groove 178 penetrates the outer peripheral surface 177 in contact with the polishing surface 176. On the other hand, all the

grooves

184, 184... Except for the groove 184 A (two

grooves

184 A, 184 A are shown in FIG. 11) are non-penetrating with respect to the outer peripheral surface 177 of the polishing surface 176. That is, one end and the other end of the groove 184 are located on the polishing surface 176. In addition, a part of the grooves 184 </ b> A of the

grooves

184, 184. That is, one end of some of the grooves 184A among the

grooves

184, 184... Is located on the polishing surface 176, and the other end is penetrated by the outer peripheral surface 177. In other words, at least one of the one end and the other end of all the grooves 184 including the groove 184A is preferably non-penetrating with respect to the outer peripheral surface 177 of the polishing surface 176. . Further, it is preferable that the groove 184 </ b> A is disposed at the center of the polishing surface 176 from the viewpoint of reducing back pressure. The central portion of the polishing surface 176 is the central portion in the left-right direction in FIG. The central portion in the left-right direction is a direction parallel to the groove 178 of the polishing surface 176 and is a range within 25% of the diameter of the polishing surface 176 from the center point O.

The

grooves

184 and 184A are provided with the hole (slurry supply hole 180 or slurry suction hole 182) at at least one end. By providing the hole at such a position, the circulation of the slurry flowing in the

grooves

178, 184, 184A is improved.

Although it is preferable to provide a plurality of

grooves

178 and 184 on the polishing surface 176 of the polishing pad 58 from the viewpoint of diffusion and discharge of slurry, the surface to be polished of the glass plate G is increased as the number of

grooves

178 and 184 increases. In some cases, “streaks” are generated due to the edge of the groove, and the polishing quality of the glass sheet G is deteriorated.

Therefore, the newly provided groove 184 is not provided with a plurality of grooves, and it is only necessary to provide a required length at a necessary place for reducing the back pressure. That is, by making the plurality of

grooves

184, 184... Non-penetrating with respect to the outer peripheral surface 177 of the polishing surface 176, the length of the groove 184 can be made shorter than the groove 178, and the occurrence of “streak” can be suppressed. it can. Even if the length of the groove 184 is shortened, the slurry that has flowed into the groove 184 flows into the groove 178 through the intersection with the groove 178 and is discharged from the outer peripheral surface 177 of the polishing surface 176. It does not stay between the glass plate G and the polishing pad 58, and no back pressure is generated. In addition, it is preferable that all the grooves 184 are not penetrated with respect to the outer peripheral surface 177.

Since the polishing pad 58 of the embodiment capable of suppressing the back pressure in this way is polished flat by the truing grindstone even during truing, the polishing quality of the glass plate G is improved and the polishing time is greatly increased. Since it can be shortened, the productivity of the glass plate G is improved. Further, there is an advantage that the life of the polishing pad 58 is extended.

The slurry supply holes 180 of the polishing pad 58 according to the embodiment are arranged dispersed throughout the polishing surface 176, and the arrangement density of the central portion of the polishing surface 176 is higher than the arrangement density other than the central portion. Is arranged. Further, the grooves 184 are arranged over the entire polishing surface 176, and are provided so that the arrangement density of the central portion of the polishing surface 176 is higher than the arrangement density of the portion excluding the central portion.

In order to spread the slurry over the entire polishing surface 176 of the polishing pad 58, it is preferable to provide a large number of slurry supply holes 180 in the central portion of the polishing surface 176, and in order to suppress back pressure generated in the central portion, polishing is performed. It is preferable to provide a number of second grooves 184 in the center of the surface 176. As a result, the slurry can easily spread over the entire area of the polishing surface 176, and the back pressure generated in the central portion can be reliably suppressed.

On the other hand, the groove 184 is preferably provided so as to be symmetric with respect to the center point O of the polishing surface 176. Thereby, the flatness of the to-be-polished surface of the glass plate G further improves.

Further, in the polishing pad 58 of the embodiment, the slurry suction hole 182 is arranged at the center of the polishing surface 176. As a result, the slurry can be sucked from the central portion of the polishing pad 58, so that the polishing margin near the center of the glass plate G can be secured and normal polishing can be performed without reducing the amount of slurry supplied from the slurry supply hole 180. . The central portion of the polishing surface 176 is preferably within a range within 25% of the diameter of the polishing surface 176 from the center point O of the polishing surface 176.

Note that the diameter of the polishing surface 176 means the diameter on the short diameter side when the polishing surface 176 is elliptical. The 25% means 25% of the length of the short side when the polished surface 176 is rectangular. In this case, the range of the central portion of the polishing surface 176 is a rectangular shape with one side having a length within 25%, and the center point of the range is the center point O of the polishing surface.

As described above, the length of one side of the glass plate G polished by the polishing pad 58 of the embodiment is preferably more than 2000 mm. However, the length of one side is more than 2500 mm, and in particular, the length of one side is more than 2800 mm. The polishing pad 58 of the embodiment is particularly effective for polishing the plate G.

Further, the polishing pad 58 preferably has a larger surface area of the polishing surface 176 than the surface area of the polished surface of the glass plate G in order to efficiently polish the glass plate G of the above size.

Next, the operation of the polishing apparatus 10 configured as described above will be described.

〔Example〕
The specifications of the

stages

18 and 20 are shown below.

Polishing pressure: 2 kPa to 25 kPa
Slurry: Slurry in which cerium oxide is dispersed in water is supplied from the slurry supply holes of the

polishing pads

58 and 60. Polishing pad 58: Groove 178 made of polyurethane foam and having slurry flow on the surface (groove pitch 4.5 mm, groove width 1 0.5 mm, groove depth 1-5 mm), size: circular with a major axis of 5040 mm, minor axis of 4800 mm Polishing pad 60: a soft urethane suede having a groove 178 for flowing slurry on the surface (groove pitch 4.5 mm, groove width 1 0.5 mm, groove depth 1 to 5 mm), size: circular glass plate G with major axis 5040 mm and minor axis 4800 mm: thickness 0.2 mm to 0.7 mm
The shape of the glass plate G: a rectangle with a long side of 3130 mm and a short side of 2880 mm The non-polished surface of the glass plate G: closely adhered to the polyurethane suction pad constituting the film body 38 As shown in FIG. A plurality of

grooves

184, 184... Intersecting with the grooves 178 are provided on the surface. 12 As, the groove width _{W 2} of the groove 184 is 4 mm, the groove depth _{T 2} are a 3 mm.

[First polishing step by stage 18]
Polishing time: determined by required flatness and necessary machining allowance (for example, 2 minutes)
Revolving diameter of carrier 52: 150 mm
Revolving speed of carrier 52: 110 rpm
Swing speed of the polishing table 64: 180 mm / min
The swing stroke of the polishing table 64: ± 100 mm
Turning range of polishing surface plate 62: ± 80 °
Swivel speed of polishing surface plate 62: 7.4 ° / sec
[Second polishing step by stage 20]
Polishing time: last 30 sec
Revolving diameter of carrier 52: 150 mm
Revolving speed of carrier 52: 110 rpm
Swing speed of the polishing table 64: 180 mm / min
The swing stroke of the polishing table 64: ± 100 mm
Turning range of polishing surface plate 62: ± 80 °
Swivel speed of polishing surface plate 62: 0.1 ° / sec
The above is the specification of each

stage

18, 20. By polishing the glass plate G with these

stages

18, 20, minute irregularities and undulations on the surface of the glass plate G can be removed. Further, since the polishing time was significantly shortened as compared with the conventional polishing pad having only the groove 178, the productivity was improved.

In addition, the revolution operation of the carrier 52 and the turning operation of the polishing surface plate 62 are controlled independently, and the turning speed (angular velocity) of the polishing surface plate 62 is changed to a low speed during the polishing time of the glass plate G, thereby polishing pad 58. , 60 unevenness due to the

grooves

178 and 184 can be suppressed. Here, the force by the revolution operation becomes a force for removing minute irregularities on the surface of the glass plate G, and the force by the turning operation becomes a force for controlling the quality of the surface to be polished.

In addition, although the glass plate was illustrated as a plate-shaped body in embodiment, it is not limited to a glass plate, Another plate-shaped body may be sufficient.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope and spirit of the invention.
This application is based on Japanese Patent Application No. 2012-027648 filed on Feb. 10, 2012, the contents of which are incorporated herein by reference.

G ... Glass plate, 10 ... Polishing device, 12 ... Conveyor for carrying glass plate, 14 ... Film frame, 16 ... Glass plate sticking stage, 18 ... First polishing stage, 20 ... Second polishing stage, 22 ... Glass Plate removal stage, 24 ... Glass plate carry-out conveyor, 26 ... Membrane frame cleaning stage, 28 ... Membrane frame drying stage, 30 ... Membrane frame return conveyor, 32 ... Robot, 33 ... Arm, 34 ... Suction pad, 36 ... Conveyor, 38 ... Film body, 40 ... Upper frame, 42 ... Lower frame, 43 ... Projection, 50 ... Polishing head, 51 ... Body casing, 52 ... Carrier, 54 ... Air chamber, 56 ... Spindle, 58 ... Polishing pad, 60 ... Polishing pad, 62 ... Polishing platen, 64 ... Polishing table, 65 ... Bearing, 66 ... Gear part, 67 ... Gear, 68 ... Motor, 69 ... Guide rail, 70 ... Linear guide, 72 ... Guide 74, maintenance stage, 76 ... maintenance stage, 78 ... lifting frame, 80 ... through hole, 82 ... sliding frame, 84 ... sliding frame lifting tool, 86 ... lifting spring, 88 ... lifting spring , 90 ... Through-hole, 92 ... Screw jack, 98 ... Injection port, 100 ... Air chamber, 102 ... Air supply path, 104 ... Valve, 106 ... Air pump, 108 ... Pin, 110 ... Head part, 112 ... Hook, 138 ... conveyor, 140 ... robot, 142 ... arm, 144 ... suction head, 146, 148 ... conveyor, 150, 152, 154 ... conveyor, 160 ... guide rail, 162 ... holding part, 164 ... robot, 166 ... axis, 168 ... guide block, 170 ... guide rail, 172 ... feed screw, 176 ... polishing surface, 177 ... outer peripheral surface, 178 ... groove, 180 ... Lari supply hole, 182 ... slurry suction hole, 184 ... groove, 184A ... groove, 200 ... controller, 204 ... table, 206 ... compressed air injection nozzle, 208 ... jack

Claims

A plurality of first grooves provided in parallel on the polishing surface at a predetermined interval;
A plurality of second grooves provided on the polishing surface and intersecting the first grooves;
A plurality of holes comprising a polishing liquid supply hole and a polishing liquid suction hole provided on the bottom surface of the first groove and the second groove;
A polishing pad having.
The plurality of first grooves are penetrated by an outer peripheral surface in contact with the polishing surface,
In the plurality of second grooves, some of the plurality of second grooves are penetrated with respect to the outer peripheral surface, or all the grooves of the plurality of second grooves are formed with respect to the outer peripheral surface. The polishing pad according to claim 1, which is non-penetrating.
The polishing liquid supply holes are arranged over the entire polishing surface, and the arrangement density of the central portion of the polishing surface is set higher than the arrangement density other than the central portion,
3. The second groove according to claim 1 or 2, wherein the second groove is arranged over the entire polishing surface, and the arrangement density of the central portion of the polishing surface is set higher than the arrangement density of the portion excluding the central portion. The polishing pad as described.
The polishing pad according to any one of claims 1 to 3, wherein the polishing liquid suction hole is disposed in a central portion of the polishing surface.
The polishing pad according to any one of claims 1 to 4, wherein the second groove is provided so as to be point-symmetric about a center point of the polishing surface.
The surface area of the polishing surface is larger than the surface area of the surface to be polished so as to polish the surface to be polished of a rectangular plate-like body having a length of one side exceeding 2000 mm. The polishing pad as described.
A polishing apparatus for polishing a surface to be polished of a plate-like body with the polishing pad according to any one of claims 1 to 6.