KR100926025B1 - Double face plane polishing machine and method for polishing rectangular workpiece - Google Patents

Abstract

A carrier having a substrate storage pocket portion in a central portion thereof, a pair of eccentric rectangular polishing pads in which the carrier's left and right linear movement mechanisms and a rotation axis are deviated from the center point of the polishing pad, wherein the polishing surfaces of the pair of rectangular polishing pads are parallel to each other. A pair of eccentric rectangular polishing pads arranged to rotate at different axial centers, a lifting mechanism and a rotation driving mechanism of the eccentric rectangular polishing pads, and a polishing liquid on a surface of the substrate and the eccentric rectangular polishing pads in contact with the substrate storage pocket are in contact with each other. Provided is a double-side polishing apparatus for a rectangular substrate having polishing liquid supply means for supplying.

A rectangular substrate polishing method of holding a rectangular substrate in a substrate storage pocket of a carrier and passing the pair of eccentric rectangular polishing pads rotating in a reverse direction to simultaneously polish both surfaces of the rectangular substrate.

The pair of eccentric rectangular polishing pads are arranged so that their polishing surfaces are parallel and rotated at different axial centers, and the rectangular substrate is stopped for a predetermined time between the eccentric rectangular polishing pads and the straight line is polished during polishing of the rectangular substrate. Provided is a method of polishing a rectangular substrate for polishing both surfaces of the rectangular substrate by intermittently reciprocating the moving carrier from side to side.

 Polishing apparatus, polishing method

Description

DOUBLE FACE PLANE POLISHING MACHINE AND METHOD FOR POLISHING RECTANGULAR WORKPIECE

1 is a perspective view schematically showing a part of a double-side polishing apparatus of a rectangular substrate.

2 is a cross-sectional view schematically showing a part of the polishing head portion of the double-side polishing apparatus.

3 is a plan view illustrating the movement of the substrate and the eccentric rectangular polishing pad when the substrate is subjected to double-side polishing.

4 is a plan view of the carrier.

5 is a sectional view of a carrier having a rectangular substrate.

Description of the main symbols in the drawings

1, 2 eccentric rectangular polishing pads

Rotating axis of 1c, 2c eccentric rectangular polishing pad

3 rectangular glass substrates

4 carrier

5 polishing heads

6a, 6b hollow spindle

100 double side polishing device

Positioning device of 200 boards

300 pcs transfer robot

[Patent Document 1] Japanese Unexamined Patent Publication No. 2003-255291

[Patent Document 2] Japanese Unexamined Patent Publication No. 2004-21016

[Patent Document 3] Japanese Unexamined Patent Publication No. 2005-3845

[Patent Document 4] Japanese Unexamined Patent Publication No. Hei 6-218667

[Patent Document 5] Japanese Unexamined Patent Publication No. 2003-255291

[Patent Document 6] Japanese Unexamined Patent Publication No. 2004-122351

The present invention relates to a double-side polishing apparatus and a double-sided flattening method of a rectangular substrate that simultaneously polishes both sides of a rectangular substrate such as a glass substrate, a quartz substrate, a sapphire substrate, a GaAs substrate, and a silicon substrate to planarize the substrate and reduce its thickness. will be. In particular, the double-side polishing apparatus of this rectangular substrate is for a display device in which a liquid crystal is injected between the glass plates, a glass plate for a liquid crystal display device, a glass laminated plate for flat panel display, or an inner surface of the glass plate, and the liquid crystal is injected between the glass plates. It is used when polishing both surfaces of a glass substrate.

BACKGROUND ART An electrode is formed on a glass plate for a liquid crystal display device or a glass plate inner surface in which a liquid crystal is injected between glass plates, and a glass substrate for a display device in which liquid crystal is injected between the glass plates is known and used for a liquid crystal display panel. (See, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

Usually, the rectangular glass plate used for this liquid crystal display plate is made to reduce the thickness by grinding or lapping the surface, and to planarize the grinding or lapping surface by etching or by simultaneously polishing one or both surfaces.

As a grinding | polishing method of such a thin rectangular glass plate, the method (a) of grind | polishing both surfaces of a rectangular glass plate simultaneously with a polishing pad, and the method (b) of grinding | polishing by one surface are performed. As the double-side polishing method of the former (a), for example, a carrier body portion formed by forming a gear portion on an outer circumference and having a hole (pocket portion) having a size corresponding to the size of a rectangular glass plate formed in a rectangular shape, and The carrier body having a rectangular glass plate support member disposed between an end portion excluding the corner portion of the rectangular glass plate and a circumference portion excluding a portion corresponding to the corner portion of the rectangular glass plate formed in the carrier body portion. A carrier formed of a flexible material which is formed of a material having high strength and which is hard to cause breakage of the rectangular glass plate even when the contact portion of the rectangular glass plate support member with the rectangular glass plate is brought into contact with the rectangular glass plate is used. After supporting the rectangular glass plate on the carrier, The carrier of the polishing apparatus rotates the carrier through the gear part of the carrier body, and simultaneously, a pair of circular polishing pads formed by coaxially axially polishing the polishing pads on the front and back surfaces of the rectangular glass plate to make a rectangular glass plate. Polishing on both sides of the substrate (see Patent Document 4, for example).

In addition, after processing the longitudinal and horizontal dimensions of the liquid crystal cell provided with the pair of rectangular glass substrates to the product size, a pair of circular polishing pads formed by making the axial center of the polishing head coaxial is placed on the table of the liquid crystal cell (rectangular glass plate). In a polishing method of a liquid crystal display device in which a liquid crystal cell is polished thinly by sliding friction on a back surface, a liquid crystal cell is polished by forming a spacer member on one glass substrate on which a liquid crystal driving driver is mounted. The manufacturing method of a display apparatus is also proposed (for example, refer patent document 5).

A method of polishing a large rectangular glass plate of the latter (b) with a polishing pad on one side, for example, attaching a rectangular glass plate to a membrane frame provided with a membrane body capable of adhering the rectangular glass plate, and attaching the membrane frame to a carrier. Or attaching a membrane frame provided with a film body capable of adhering a rectangular glass plate to a carrier, adhering a rectangular glass plate to the membrane frame, and relatively close to the carrier and the polishing pad (table plate) to which the film frame is attached. And pressing the polishing surface of the rectangular glass plate adhered to the film body to the polishing pad, and after the polishing of the rectangular glass plate is finished, removing the film frame from the carrier and removing the rectangular glass plate from the film frame. Or after completion of polishing the rectangular glass plate, the rectangular glass from the film frame Remove the can, is the abrasive of the rectangular glass plate characterized in that with the film off the intra-frame processing is proposed from the carrier (for example, see Patent Document 6).

The method of grinding the front and back surfaces of the rectangular glass plate one by one has the advantage that it rarely occurs to protrude out of the polishing apparatus of the rectangular glass plate during polishing, but since one surface is polished one by one, it is possible to form many polishing processing steps. Since it is necessary and the process of reversing the front and back of a rectangular glass plate during grinding | polishing is needed, compared with the double-side polishing apparatus which grinds the front and back surfaces of a rectangular glass plate simultaneously, there exists a drawback that a polishing apparatus installation becomes large and footprint is large. The double-side polishing apparatus has the advantage that the polishing time is short compared with the polishing method one by one, but if the rectangular glass plate having a thickness of 1 mm or less is thin, the rectangular glass plate may be thrown out of the polishing apparatus in the carrier during polishing.

MEANS TO SOLVE THE PROBLEM This inventor pays attention to the principle of the movement which becomes a rice ball shape when a rice grain is squeezed by the palm of both hands, and the spin direction of a palm is up-down and reverse, the rotation axis of an up-and-down palm is shifted, and a palm is left and right slightly. It is understood that the rocking of the rice paddle has a great influence on being held in the shape of a rice ball without scattering the rice grain from the inside of the palm of both hands to the outside, and the movement of the palm is used for the polishing pad of the double-side polishing apparatus of the rectangular glass plate. The present invention has been achieved by applying motion to a carrier.

The invention of claim 1,

A carrier having a substrate storage pocket in a central portion thereof,

The left and right linear movement mechanism of the carrier,

A pair of eccentric rectangular polishing pads having a rotational axis deviated from the center point of the polishing pad, the pair of eccentric rectangular polishing pads arranged to rotate in parallel with the polishing surfaces of the pair of rectangular polishing pads,

A lifting mechanism and a rotation driving mechanism of the eccentric rectangular polishing pad, and

Polishing liquid supply means for supplying a polishing liquid to a surface where the substrate accommodated in the substrate storage pocket portion is in contact with an eccentric rectangular polishing pad;

It provides a double-side polishing device of a rectangular substrate having a.

The invention of claim 2,

A rectangular substrate polishing method of holding a rectangular substrate in a substrate storage pocket of a carrier and passing the substrate between a pair of eccentric rectangular polishing pads rotating in a reverse direction to simultaneously polish both surfaces of the rectangular substrate. A pair of eccentric rectangular polishing pads are arranged so that their polishing surfaces are parallel and rotated at different axial centers, while the rectangular substrate is stopped between the eccentric rectangular polishing pads for a predetermined time, and the carrier is removed during polishing of the rectangular substrate. Provided is a method for polishing a rectangular substrate, wherein both surfaces of the rectangular substrate are polished by intermittently reciprocating from side to side.

Effects of the Invention

Both surfaces of the rectangular substrate are polished by eccentric rectangular polishing pads which rotate in the opposite directions while swinging the rectangular substrate in the left and right directions, so that the thickness difference between the four corners of the polished rectangular substrate and other places is small and the thickness distribution is good. A rectangular substrate is obtained. Further, since the rotation directions of the pair of eccentric rectangular polishing pads in which the axial centers of the eccentric rectangular polishing pads are spaced apart from each other are opposite to each other, a thin rectangular substrate does not protrude from the pocket portion of the carrier during polishing.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in more detail with reference to the drawings.

1 is a perspective view showing a portion of a double-side polishing apparatus of a rectangular substrate, FIG. 2 is a cross-sectional view showing a portion of a polishing head portion of a double-side polishing apparatus, and FIG. 3 is a rectangular substrate and an eccentric rectangular polishing when the double-side polishing process is performed on the rectangular substrate. 4 is a plan view showing the movement of the pad, FIG. 4 is a plan view of the carrier, and FIG. 5 is a sectional view of the carrier sandwiching the glass plate.

In Fig. 1, reference numeral 100 denotes a double-side polishing apparatus for a rectangular substrate, 1 denotes an eccentric rectangular polishing pad on the upper side, 2 denotes an eccentric rectangular polishing pad on the lower side, and 3 denotes a rectangular substrate (work piece). 4 is the carrier, 5 is the polishing head, 6 is the spindle, 7 is the air cylinder, 8 is the carrier movement mechanism, 9 is the support, 10 is the guide rail, 11 is The small sub-motor 12 is a base and 13 is a wall material. Reference numeral 200 is a positioning device of a rectangular substrate, 201 is a roll conveyor, 202 is a roll-shaped brush, 203 is a positioning mechanism, 203a is a push bar, and 203b and 203c are positioning. It's a dam. 300 is a transfer robot of a rectangular substrate, 301 is an arm, and 302 is a vacuum suction hand.

The rectangular substrate 3 polished on both sides slides on the roll conveyor 201 of the positioning device 200, passes between the roll-shaped brushes 202, and weirs 203b and 203c of the positioning mechanism 203. ), The right end portion abuts and contacts, and then the push bar 203a is advanced to press the rear end portion of the rectangular substrate 3 so that the right end corner portion abuts against the weir 203b, thereby allowing the rectangular substrate 3 to the transfer robot 300. Coordinate position is determined. The push bar 203a is retracted before the rectangular substrate 3 is adsorbed by the vacuum suction hand 302 of the transfer robot 300.

In the polishing heads 5a and 5b of the double-side polishing apparatus 100 shown in FIG. 2, the eccentric rectangular polishing pads (plates) 1 and 2, which have a polishing cloth attached to the surface of the disc shaped support, have their polishing surfaces 1b and 2b. ) Are arranged up and down so as to deviate from the rotation centers 1c and 2c of each eccentric rectangular polishing pad with the rectangular substrate 3 held by the carrier 4 sandwiched in parallel with each other. The eccentric rectangular polishing pads 1 and 2 are axially supported by the hollow spindles (rotating shafts) 6a and 6b. The abrasive is supplied to the pipe 64 formed in the hollow rotary shafts 6a and 6b via the pipe 62 and the rotary joint 63 by the pump P, and the abrasive cloth 1a of the polishing pads 1 and 2 is provided. Wet 1b). The polishing pad is supported by the attachment frame 70, and the slider 71 formed at the lower portion of the attachment frame is movable on the guide rail 72 formed in the column 80 in the front-rear direction, and the polishing pad 1 ) Can be moved forward and backward in a direction orthogonal to the left and right transport direction of the carrier 4.

The hollow spindles 6a and 6b are connected to each other at a predetermined rotational speed, for example, 10 to 180 cm ^-1 by a rotation drive device having the prime mover M ₁ , the pulley 82, the gears 81, 83, and the like. It can be rotated in the opposite direction.

Pressurized air is supplied to the space 65 between the inner chamber of the hollow spindles 6a and 6b and the tube 64 from a compressor (not shown) via the tube 66 connected to the rotary joint 63. In addition, the gas in the space 65 is exhausted by the vacuum pump which is not shown in figure.

The spacing (home position) of the eccentric rectangular polishing pads 1 and 2 before processing is adjusted by the thickness of the rectangular substrate 3 to be processed. The size of the eccentric rectangular polishing pads 1 and 2 is preferably 1.3 to 2.0 times the size similar to that of the rectangular substrate to be polished.

As the material of the polishing cloths 1a and 2a, a diamond powder-containing polyurethane foam sheet, a diamond powder-containing polyamide fiber are processed into a nonwoven fabric shape, and a sheet-like material obtained by urethane prepolymer is used.

As the abrasive, slurry of water, ceria, alumina, diamond, and silica-based abrasive may be used. Although an abrasive | polishing agent changes with the kind of board | substrate of a to-be-polished object, a ceria-type abrasive slurry for a glass substrate, a colloidal silica slurry for a silicon substrate, and an alumina slurry and a diamond slurry for a sapphire substrate are preferable.

The eccentric rectangular polishing pads 1 and 2 are axially supported by the hollow spindles 6a and 6b so that the positions deviating from the diagonal intersections (center points) by 10 to 80 mm become the rotation axis centers 1c and 2c. These pairs of eccentric rectangular polishing pads 1 and 2 are provided so that their polishing surfaces 1a and 2a are parallel and point symmetrical with respect to the carrier 4. As for the distance between the rotating shaft centers 1c and 2c of these pair of eccentric rectangular polishing pads 1 and 2, 20-160 mm is preferable. The rotational directions of the spindle shafts 6a and 6b of the pair of eccentric rectangular polishing pads 1 and 2 are opposite directions, and the rotation speed of the eccentric rectangular polishing pads 1 and 2 is 10 to 200 min ⁻¹ and an eccentric rectangle. As for the pressing force with respect to the rectangular substrate 3 of a polishing pad, 20-100 g / cm <2> is preferable. In polishing the rectangular substrate, the carrier 4 is intermittently rocked from side to side. The rocking speed of the carrier 4 is preferably 80 to 200 cm / min, the amplitude of 25 to 100 mm, and the rocking cycle of 2 to 20 times / minute. Although the grinding | polishing process powder of the rectangular board | substrate 3 depends on the raw material of a board | substrate and a use, 2-100 micrometers is preferable.

As shown in FIGS. 4 and 5, the carrier 4 is a plastic plastic holding material in which a rectangular substrate storage pocket portion 4b is formed in a central portion inside a metal carrier frame 4a having a shape of cut out rectangle. 4c) is arrange | positioned, and relief space 4d, 4e, 4f, 4g is formed in the four corners of the rectangular substrate storage pocket part which contact | connects the rectangular substrate 3 of this plastic plastic holding material so that it may not reach the corner part of a rectangular substrate, The relief spaces 4h and 4i are formed also in the vicinity of the liquid crystal injection hole sealing material 4j and the liquid crystal suction port sealing material 4k of the rectangular substrate. When the rectangular substrate has dimensions of 193.4 mm long and 256.6 mm wide, the corner relief spaces 4d, 4e, 4f, and 4g have a 3.5 mm radius relief hole around the rectangular substrate corner, and are located near the liquid crystal inlet sealant. The relief spaces 4h and 4i have a dimension of 3 mm over a width of 30 mm.

The metal carrier frame 4a is made of stainless steel, aluminum, cast iron, brass, or the like. The plastic plastic holding material 4c made of resin is made of glass fiber reinforced epoxy resin, glass fiber reinforced aramid resin, glass fiber reinforced polyimide resin, or the like.

The front and rear ends of the carrier 4 are sandwiched by the carrier movement mechanism 8, and a ball screw (not shown) driven by the small sub-motor 11 drives the carrier movement mechanism 8 to rotate, thereby guiding the carrier movement mechanism 8. The carrier movement mechanism 8 slides on the rail 10. The carrier 4 is provided with a plurality of pocket portions 4a which are slightly larger than the outline of the rectangular substrate 3 while maintaining a predetermined distance of 0.5 to 1 mm in the center in the width direction and in the longitudinal direction. It is good to form the plastic rubber plate 4b inside the pocket part 4a. When the rectangular substrate 3 is engaged with the pocket portion 4a, the thickness of the carrier 4 is rectangular so that both surfaces of the substrate 3 can protrude beyond the polishing treatment from both sides of the carrier belt 4. It is thinner than the thickness of (3).

As shown in FIG. 3, the eccentric rectangular polishing pads 1 and 2 rotating at the rotational centers 1c and 2c while rotating the carrier 4 intermittently in the left and right direction are rotated in the opposite direction to both sides of the rectangular substrate 3. At the same time, the abrasive cloths 1a and 2a of the eccentric rectangular polishing pad are suppressed from being worn locally, so that the life of the rectangular rectangular polishing pad can be improved, and the surface flatness of the eccentric rectangular polishing pad is worn. Can be prevented, and the flatness of the rectangular substrate 3 can be improved and the uniformity of the thickness can be improved.

The polishing start point is preferably set to be about 0.05 mm to 0.1 mm larger than the thickness of the rectangular substrate 3 on which the space between the eccentric rectangular polishing pad 1 and the eccentric rectangular polishing pad 2 is held by the carrier 4. Polishing lancing amount adjustment to the rectangular substrate 3 is performed by raising and lowering the air cylinder 7. When the rectangular substrate 3 is polished by a predetermined amount, the eccentric rectangular polishing pads 1 and 2 are kept away from the carrier 4.

In order to perform the grinding | polishing process of a rectangular substrate efficiently, it is good to provide several double-sided polishing apparatus 100 as shown in FIG. 1 in parallel. The double-side polishing apparatus 100 is performed by changing polishing pads and polishing conditions, respectively, for example, preliminary polishing, finish polishing or preliminary polishing, intermediate finish polishing, and precision finish polishing. The polishing cloth elastic modulus, diamond powder abrasive grain count and content rate of the eccentric rectangular polishing pad used in each polishing process are naturally different, and the polishing time and rotation speed of the eccentric rectangular polishing pad also vary. For example, in the three-step polishing process, diamond abrasive grains of # 100 to # 325 are used for diamond abrasive grains of an eccentric rectangular preliminary polishing pad, and diamond abrasive grains of # 600 to # 2000 are used for diamond abrasive grains of an intermediate finishing polishing pad. The diamond abrasive grains of # 3000- # 8000 are used for the diamond and abrasive grain of a finishing polishing pad.

In the two-stage polishing step, the polishing treatment amount in the preliminary polishing is 60 to 95% of the total treatment amount to ensure the balance of the polishing rate and as a whole without generating surface defects such as cracks on the glass surface. In completing a grinding | polishing process in a short time, it is preferable and it is more preferable to set it as 75 to 85%. In the three-stage polishing step, it is preferable that the distribution of the total polishing thickness is set to 60 to 85% preliminary polishing, 13 to 35% intermediate polishing, and 2 to 5% precision finishing polishing. For example, when 50 micrometers is removed from both surfaces of the 0.60 mm-thick rectangular liquid crystal display glass plate, and it is set as the 0.5 mm-thick rectangular liquid crystal display glass substrate, in the case of a two-step grinding process, it is made into 0.52 mm thickness by the preliminary grinding process. . In the case of a three-stage polishing process, the thickness is 0.53 mm by preliminary polishing, 0.502 mm by intermediate finishing polishing, and 0.500 mm by precision finishing polishing.

As the rectangular substrate 3, in addition to glass substrates such as soda-lime silica glass, borosilicate glass, amino silicate glass, amino boric acid glass, alkali free low expansion glass, high strain point high expansion silicate glass, crystallized glass, Rectangular substrates, such as a quartz substrate, a sapphire substrate, a GaAs substrate, and a silicon substrate, are to be polished.

Using the pair of eccentric rectangular polishing pads of the present invention, the method of double-side polishing while shaking the glass laminate for a liquid crystal display panel in the left and right direction can obtain a glass laminate for a liquid crystal display panel with a uniform thickness distribution.

Claims (2)

A carrier having a substrate storage pocket in a central portion thereof, Left and right linear movement mechanism of the carrier, A pair of eccentric rectangular polishing pads having the axis of rotation deviated from the center point of the polishing pad, wherein the polishing surfaces of the pair of rectangular polishing pads are arranged in parallel with each other with the substrate therebetween, and the pair of polishing pads A pair of eccentric rectangular polishing pads arranged to rotate at a rotation axis, A lifting mechanism and a rotation driving mechanism of the eccentric rectangular polishing pad, and And a polishing liquid supply means for supplying a polishing liquid to a surface where the substrate accommodated in the substrate storage pocket portion and the eccentric rectangular polishing pad are in contact with each other. In the method of polishing a rectangular substrate, a rectangular substrate is held in a substrate storage pocket of a carrier and the substrate is passed between a pair of eccentric rectangular polishing pads which rotate in opposite directions, thereby simultaneously polishing both surfaces of the rectangular substrate. The polishing surfaces of the pair of eccentric rectangular polishing pads are arranged in parallel with each other with the substrate interposed therebetween, and the pair of polishing pads are arranged to rotate at different rotational centers, so that the rectangular substrate is placed in the eccentric rectangular polishing pad. A method of polishing a rectangular substrate, wherein both sides of the rectangular substrate are polished by intermittently reciprocating the carrier intermittently from side to side during the polishing of the rectangular substrate while stopping for a predetermined time between.

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