JP4427315B2 - Polishing equipment - Google Patents

Description

The present invention polishes a plate-like workpiece plane having a large size of 1000 to 3500 mm on one side, such as a glass plate for exposure apparatus, an iron plate, a ceramic plate, a KNbO ₃ optical crystal, a photomask substrate ( The present invention relates to a polishing apparatus including a polishing surface plate (lapping surface plate) having a diameter of 4 to 12 m to be processed.

As the dimensions of the plate-like workpieces that require high-precision planar polishing, the size of the plate-like workpiece has increased significantly. Conventionally, it has been a polishing apparatus capable of polishing a photomask substrate having a size of at most 1300 mm × 1100 mm (for example, non-patent literature). 1).
As such a polishing apparatus, a planar polishing apparatus has been proposed in which a workpiece held by a carrier is pressed against a polishing surface plate, the carrier and the surface plate are rotated, and the work surface is swept by a cycloid curve by the surface plate and polished. (For example, see Patent Document 1).
In addition, a work (LCD glass plate) held by a carrier is pressed against a polishing platen composed of a triple concentric platen that is divided into three concentric circles around the rotation axis of the polishing platen. In addition, there has been proposed a flat polishing apparatus that rotates a polishing platen to polish a work surface with the polishing platen (see, for example, Patent Document 2).
Further, the grindstone plate is bonded to a disc-shaped pedestal having a flat grindstone bonding surface with an adhesive, and a plurality of kerfs reaching the grindstone bonding surface of the pedestal are formed on the upper surface of the grindstone plate. Has also been proposed (see, for example, Patent Document 3), in which a segmented grindstone plate is divided and a lattice-like gap corresponding to the kerf is provided between the segmented grindstone plate and the grindstone plate. ).
Also, a polishing surface plate in which 2 to 4000 circular segments, circular rings having regular polygonal outlines or corner corner segments are arranged in an annular shape on a grindstone base to form a cast metal circular grindstone ( A lapping machine has also been proposed (see, for example, Patent Document 4).
“Weekly Diamond”, September 7, 2002, p.62-63 JP 2000-42911 A JP 2002-346917 A Japanese Patent Laid-Open No. 11-277445 JP 2001-88038 A

Recently, a plate-like body with a side length of 2000 to 3500 mm is required as an iron plate, glass plate, ELD or photomask substrate for a sputtering apparatus, and polishing is performed with a conventional large polishing apparatus (lapping apparatus). I can't respond.
Moreover, although the said patent document 1 and the patent document 2 do not disclose the raw material of a polishing surface plate, as a raw material of an polishing surface plate, the stone material which is lighter than a metal, and has a small thermal conductivity and a thermal expansion coefficient is good. Granite, marble, the stone such as black granite, the thermal conductivity is as small as 2.4~2.7Kcal / mh ℃, thermal expansion coefficient 7~7.5x10- ⁶ / ℃ is small, and a specific gravity of 2.4 -2.9 lighter, heat resistance as high as 455-570 [deg.] C., and compressive strength as high as 1400-1600 kg / cm < ² >, so processing with better precision dimensionality and flatness than using resin such as metal or ABS This is preferable because it gives a finished work.

  As long as the size of the workpiece to be polished is small, it is possible to cover the polishing platen with a single piece of stone. As the next-generation 2000 mm iron plate and the next-generation 2500 mm iron plate become large, the diameter of the polishing surface plate will be as large as 4 to 12 m. However, there is a width specified by the Road Traffic Act in the work of transporting and transporting stones for polishing surface plate materials, and the current situation in Japan is that it is possible to transport and transport stones with a maximum width of 4.5 m. . An object of the present invention is to provide a polishing apparatus having a polishing surface plate having a diameter of 4 to 12 m in a polishing apparatus using a stone material as a polishing tool.

  According to the first aspect of the present invention, a disc-shaped or annular stone material having a diameter of 4 to 12 m is latticed on a disc-shaped or annular metal turntable having a diameter of 4 to 12 m supported by a rotating shaft. A plate-like work piece held by a carrier is placed on the surface of a disc-like or annular stone formed by adhering 9 to 121 grindstone segments cut at regular intervals with an adhesive. A polishing apparatus for polishing a plate-like workpiece surface by rotating a board, wherein the metal turntable has a central segment of a substantially elongated column wider than the diameter of the bearing of the rotary shaft. The center segment is composed of three metal members of a right segment and a left segment of an arc column connected to the left and right of the central segment, each segment joint surface of the metal turntable and a lattice of the grindstone segments of the stone The plane formed by the adhesive surface is parallel Without and being provided so as to cross the plate-like body Wa - there is provided a polishing apparatus used for surface polishing of click.

  According to a second aspect of the present invention, in the polishing apparatus, the stone material is formed by bonding and curing each grindstone segment with an inorganic powder-containing curable resin adhesive to form a disc-shaped or annular stone material. The upper surface of the powder-containing curable resin adhesive is ground or polished so that the surface of the stone material is flush.

  The invention of claim 3 is the curable epoxy resin in which the stone material is selected from marble, granite, and black granite in the polishing apparatus, and the inorganic powder curable resin adhesive contains 5 to 65% by weight of iron powder. It is an adhesive.

  According to a fourth aspect of the present invention, in the polishing apparatus, a spacer having a hardness smaller than the hardness of the metal constituting the turntable is deformed between the metal turntable and the stone. A plurality of concentric circles are inserted.

A metal turntable for bonding a stone segment to the surface is divided into a central segment of a substantially long column that is wider than the diameter of the bearing of the rotating shaft, and a right side of an arc column bonded to the left and right of this central segment. By dividing the segment into three members, the segment and the left segment, each segment can be transported, the seam area of each segment can be reduced, and the turntable metal can be less bent. I was able to.
It is possible to reduce the joint area by dividing the disk-shaped stone into two at the center. However, the joint surface hangs on the rotating shaft of the polishing surface plate, and the vibration stress of the rotating shaft causes the joint of the columnar stone. Concentrate on the surface to shorten the life of the polishing surface plate. Connecting segments of a metal turntable divided into 4 to 8 in a fan shape increases the seam area, the seam surface hangs on the rotation axis of the polishing surface plate, and the vibration stress of the rotation axis is reduced. Concentrate on the seam surface of the metal turntable to shorten the life of the polishing surface plate.

  It is applied to the joint surface of the metal turntable by providing the joint surface of each segment of the metal turntable and the plane formed by the grid-like adhesive surface of the stone grindstone segment of the stone material so as not to be parallel to each other. The load of the stone material is dispersed, and the deflection of the metal turntable is reduced.

  By making the adhesive contain inorganic powders such as iron powder, copper powder and other metal powders, granite powder, lime powder, talc and other stone powders, the thermal conductivity and thermal expansion coefficient of the adhesive layer are made closer to those of stone materials. Therefore, the dimensional accuracy of the workpiece can be improved. Moreover, the external appearances of the stone and the inorganic powder-containing curable resin adhesive can be made similar. The thermal conductivity of the stone is 2.5 to 2.7 Kcal / mh ° C., the thermal conductivity of iron is 45 to 50 Kcal / mh ° C., and the thermal conductivity of the iron powder-containing curable resin adhesive is 40 to 44 Kcal / mh. ° C. Iron has a low thermal conductivity compared to other metals such as copper and aluminum alloys, and since deformation due to heat is small, it gives a work with good dimensional accuracy.

  Thickness distribution because when the metal turntable is bent due to the load of 4 to 12m in diameter, the trajectory of the upper surface of the rotating stone will be blurred from the same circumference around the axis of rotation. Cannot be obtained. As described in the present invention, the deflection of the metal turntable deflected by the load of the stone is corrected by the presence of the spacer of the bending improvement material between the stone back surface and the metal turntable surface. This prevents the trajectory of the upper surface of the stone that is rotating at the time of workpiece machining from blurring from the same circumference around the center of the rotation axis.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view of the polishing apparatus, FIG. 2 is a plan view of a lower surface plate of the polishing apparatus, FIG. 3 is a plan view of a turn table before placing a disk-like or annular stone, and FIG. FIG. 5 is a plan view of a stone material showing a positional relationship between a lattice-shaped adhesive surface (solid line) and a turntable joint surface (imaginary line), and FIG. 5 is a plan view of a polishing apparatus showing another embodiment.

In the polishing apparatus 1 shown in FIGS. 1 to 3, the polishing apparatus 1 mainly includes a polishing surface plate (lower surface plate) 2 and an upper surface plate 3 having a carrier 4 on the lower surface.
The polishing surface plate 2 is supported by a rotating shaft 8 that is driven to rotate by a driving motor (not shown), a bearing 6 that includes a bearing 5 provided above the rotating shaft, and the rotating shaft 8. An annular metal turntable 10 having a hollow central portion, a deflection improving material spacer 11 fixed with bolts and nuts on the turntable surface, and the turntable 10 surface. It is comprised from the processing tool 9 which consists of a disk shape with a diameter of 4-12 m mounted on the top, or an annular | circular shaped stone material. Reference numeral 12 is a base, 13 is an abrasive supply pipe, 14 is an adhesive, 15 is a plate-like work, and 18 is a correction ring (surfacer).

  Examples of the metal material of the turntable 10 include cast iron, stainless steel, brass, copper and the like, but inexpensive and highly rigid stainless steel is preferable. Since the specific gravity of the metal is larger than that of the stone (the specific gravity of iron is 7.9), it is preferable to form a □ -shaped frame body and hollow the central portion 10c to reduce the overall weight. Specifically, a metal turntable has a central segment 10a of a substantially elongated column wider than the diameter of the bearing of the rotary shaft, and a right segment 10b of an arcuate column connected to the left and right of the central segment, and The left segment 10b is divided into three members. A column-shaped turntable 10 in which the center portion of each segment 10a, 10b, 10b is utilized, the joint surface of the center segment 10a and the left and right segments 10b, 10b are connected with bolts and nuts, and the center portion 10c is hollow. To do. The upper surface of the □ -shaped segments 10a, 10b, and 10b has a disk shape or an annular shape due to the connection. The annular inner side of the turn table 10 is fixed to the bearing 6.

  The segment 10a, 10b, 10b has a metal plate thickness of 50 to 150 mm and a height of 300 to 1000 mm. The diameter of the cylindrical turntable 10 is approximately equal to the diameter of the cylindrical stone material 9 and is 4 to 12 m.

  Spacers 11 dispersed and interposed between the metal turntable 10 and the disc-shaped or annular stone material 9 are smaller than the hardness of the material metal of the cylindrical turntable 10 (softer). ) A hard aluminum plate, zinc plate, vulcanized rubber plate, elastomer plate, synthetic resin plate and the like are used. The thickness of the spacer 11 which is a deflection improving material is 25 to 100 mm, and the shape may be any of a sector, a rectangle, a triangle, a square, an ellipse, a disk, a ring, a donut ring, and the like. A plurality of spacers 11 are preliminarily dispersed and fixed concentrically on the surface of the metallic turntable 10 (see FIG. 2), and a stone material 9 is placed thereon. The spacer 11 interposed between the metal turntable 10 and the stone 9 has the same circular path around the rotation axis center of the stone upper surface rotating when the flat work 15 is polished. Decrease the blur from the lap or eliminate the blur. The number of concentric stripes formed by the spacer 11 is preferably 2-6.

  The diameter of the rotating shaft 8 is 1,000 to 2,800 mm, and the diameter of the bearing 6 is 1,020 to 2,840 mm.

  The stone is preferably selected from marble, granite, and black granite in terms of compressive strength and bending strength. The upper limit of the cut stone segment width is determined due to the restrictions on conveyance and carry-in. Currently, the width is 4.5 m or less. Therefore, at present, those having a diameter of more than 4.5 m are divided and conveyed, and the segments divided at the site where the polishing apparatus is installed are bonded with the adhesive 14 to form a disk shape or an annular shape.

  As shown in FIG. 4, the stone 9 which is a flat work polishing (lapping) processing tool is a disc-like or annular stone having a diameter of 4 to 12 m, and n pieces (n is 2) in the vertical and horizontal directions. To 10) parallel and equally-spaced linear cut surfaces, and the grindstone segments are bonded with an adhesive to form a single stone. Therefore, the total number of grindstone segments is 9 or more and 121 or less of the square number of (n + 1) when it is a disk-shaped stone. FIG. 4a shows a stone material 9 to which n = 2 grindstone segments are bonded, FIG. 4b shows a stone material 9 to which n = 3 grindstone segments are bonded, and FIG. The stone material 9 which adhere | attached the grindstone segment divided | segmented into 73 pieces of n = 8 is shown. The height of the stone material 9 is preferably 300 to 600 mm.

The adhesive 14 for adhering each stone segment of the stone is preferably a structural adhesive such as an epoxy resin, and more preferably a curable resin adhesive containing 5 to 65% by weight of inorganic powder. As inorganic powders, calcium carbonate, clay, marble powder, black granite powder, granite powder, silica powder, Otani stone powder, carbon powder and other inorganic fillers, cast iron powder passing through 100-400 mesh sieve, iron powder, Examples thereof include metal powders such as copper powder, zinc powder, brass powder and aluminum powder. Metal powder and inorganic filler may be used in combination. The blending of the metal powder and the inorganic filler is used to approximate the thermal conductivity of the metal powder-containing curable resin adhesive 14 to the thermal conductivity of cast iron or stone.
The thermal conductivity α of the inorganic powder-containing curable resin adhesive that is a mixed adhesive can be approximated by the sum of the products of the volume ratio V _{i of the} substance to be blended and its thermal conductivity α _i .
α = ΣV _i x α _i

  From the viewpoint of easy adjustment of the thermal conductivity of the inorganic powder-containing curable resin adhesive, it is preferable to use iron powder as the metal powder and marble powder, granite powder, or black granite powder as the inorganic filler. The curable resin adhesive, which is a structural adhesive, includes a curing agent, one-pack or two-pack epoxy resin, epoxy novolak / phenolic resin, polyimide, unsaturated polyester resin, aromatic A polybenzimidazole adhesive can be used. From the viewpoint of heat resistance and cost, a two-component curable epoxy resin is preferable.

  Examples of epoxy resins include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, biphenyl diglycidyl ether, hydrogenated biphenyl diglycidyl ether, and the like. Curing agents include dicyandiamide, Examples of accelerators include 2-methyl imidazole, 2-undecyl imidazole, and 2,4-dimethyl imidazole.

An iron powder-containing two-component curable epoxy resin adhesive is commercially available from Devcon under the trade name DEVCON A (registered trademark). DEVCON A has a linear thermal expansion coefficient of 11.5 to 13.5 × 10 ⁻⁶ / ° C., a thermal conductivity of 0.120 to 0.130 cal / cm · sec · degree, and a specific gravity of 7.2.

  The depth at which the abrasive flows on the surface of the stone material 9 by applying the adhesive to the side surface height of 1 to 15 mm lower than the surface of the grindstone segment without applying the adhesive for adhering the grindstone segment to the entire side surface of the grindstone segment. You may form a grid-like groove | channel of 1-15 mm.

  As shown in FIG. 1, the metal turntable 10 is supported on the rotating shaft 8 on the lower surface thereof. The rotating shaft 8 receives the driving force of a driving motor (not shown) by the gear 7 and rotates the metallic turntable 10 at a rotational speed of 0.01 to 10 rpm.

  As shown in FIG. 4, the stone material 9 having a diameter of 4 to 12 m placed on the metal turntable 10 of the lower surface plate 2 includes the grindstone segment joint surface of the metal turntable and the stone material. The planes formed by the grid-like adhesion surfaces of the grindstone segments are provided not to be parallel but to intersect. The crossing angle is preferably 30 to 60 degrees, and a more preferable crossing angle is 45 degrees.

  In order to polish the plate-like workpiece 15 using the polishing apparatus 1 shown in FIG. 1, the workpiece 15 is fixed to the lower surface of the carrier 4 of the upper surface plate 3, and the lower surface of the workpiece is polished to the lower surface plate 2. The metal turntable 10 is brought into contact with the surface of the stone 9 (5 to 100 kPa) while the abrasive is supplied from the abrasive supply pipe 13 onto the surface of the stone 9 at a rate of 10 to 100 liters / minute. The lower surface plate 2 is rotated in the horizontal direction by rotating at a rotation speed of 01 to 10 rpm. At this time, the spindle 19 of the upper surface plate 3 fixing the work 15 to the lower surface is rotated by a driving motor (not shown). As the abrasive, an aqueous dispersion containing abrasive grains such as ceria, silica, alumina, and boehmite is used.

  The lapping apparatus 1 shown in FIG. 5 is not attached to the upper surface plate 3 of the polishing apparatus shown in FIG. 2, but is attached to the lower surface of the ring-shaped carrier 4 or the ring that is rotationally driven by the drive roller 16a and the fixed roller 16b. A mechanism for fixing the shaft 15 and an adjustment ring (surfacing) 18 supported by a spindle 20 so as to be brought into contact with the surface of the stone 9 of the lower surface plate 2 using a lifting mechanism (not shown). The polishing apparatus 1 thus obtained. The work 15 is hung with a crane and moved into the ring-shaped carrier 4 on the lower surface plate 2, and the work is placed on the lower surface plate 2, or the work is fixed to the lower surface of the carrier 4, and the work is fixed. The carrier is suspended by a crane and placed on the lower surface plate 2.

Example 1
A black granite cylinder with a diameter of 10 m and a height of 450 mm is cut with two equally spaced grids in the vertical direction and two in the horizontal direction, for a total of nine grindstone segments (maximum one side length of the segment). Obtained approximately 3.333 m) and carried it to the work site. On the cut surfaces of these grindstone segments, an iron powder-containing two-component curable epoxy resin adhesive DEVCON A (registered trademark) is applied to a thickness of 40 μm, and each black granite segment is bonded to each other to have a diameter of about 10 m and a height of 450 mm. After 10 days of standing, the adhesive is completely cured, and then the black and white granite columnar stone is polished to be flush with each other, and the cylindrical black granite stone polishing tool Manufactured.

  A cross-sectional □ -shaped frame center segment made of stainless steel (SS400) having a radial upper surface width of 3760 mm, a height of 580 mm, a maximum length of 10,000 mm, and a thickness of 40 mm, and a central portion made of stainless steel (SS400), and a radial upper surface width of 2940 mm, a height A total of three frame segments, a right-segment and a left-segment pair of 800 mm and 40 mm-thick stainless steel (SS400) with a hollow central section, were carried into the work site. The joints of these frame segments were closed with bolts and nuts to produce cylindrical metal turntables having a diameter of about 10 m.

  On the upper surface of the stainless steel turntable, a spacer made of a fan-shaped aluminum plate having a thickness of 20 mm and a width of 150 mm is laid in a concentric circle shape as shown in FIG. The nut was fixed to the surface of the turntable.

  The cast iron turntable provided with the spacer is supported on a rotating shaft having a diameter of 2100 mm, and the columnar black granite stone material is provided on the upper surface of the cast iron turntable provided with the spacer. It was placed and a lower surface plate having a diameter of 10 m was prepared.

  A rectangular iron plate having a length of 2500 mm, a width of 3200 mm, and a thickness of 4 mm is conveyed into a ring-shaped carrier provided on the lower platen of the polishing apparatus shown in FIG. 5, fixed in the carrier, and the carrier is rotated at 0.4 rpm. While rotating, the metal turntable is rotated at a rotational speed of 0.2 rpm while supplying a ceria water dispersion (abrasive) at a rate of 20 liters / minute from the abrasive supply pipe onto the granite surface. Thus, the polishing lower platen was rotated in the horizontal direction, and the iron plate was polished for 48 hours. The surface of the obtained polished iron plate was excellent in flatness.

Since the polishing apparatus of the present invention includes a polishing tool made of a stone having a diameter of 4 m or more, a flat work having a long side length of 2 m or more can be polished.
Further, the stone is formed by adhering a grindstone segment having a width of 4 m or less that can be transported without permission for truck transportation, and the metal turntable on which the stone is placed is also permitted to be transported by truck. It is formed by connecting three formwork segments with a maximum width of 4 m or less. This formwork segment is composed of a central segment of a substantially long column that is wider than the diameter of the bearing of the rotating shaft of the polishing surface plate. The center segment is composed of three members, a right segment and a left segment of an arc-shaped column that is connected to the left and right of the central segment, and each segment joint surface of the metal turntable and the lattice-shaped adhesive surface of the stone grinding stone segment Since the planes formed by are not parallel but are provided so as to intersect, the load on the stone is distributed without concentrating on each segment seam of the metal turntable. Data - integrators - Bull deflection is small.

It is a front view of the polish device of the present invention. It is a top view of the lower surface plate used for implementation of this invention. It is a top view of the turntable before a stone is mounted. It is a top view of the stone which shows the positional relationship of the grid-like adhesion surface of a stone, and the joint surface of a turntable. It is a top view of the polish device showing another mode.

Explanation of symbols

1 Polishing device 2 Polishing surface plate (lower surface plate)
3 Upper surface plate 4 Carrier 5 Bearing 6 Bearing 8 Rotating shaft of lower surface plate 9 Polishing tool made of stone 10 Metal turntable 10a Center frame segment 10b Left frame segment, right frame segment 11 Deflection improver (space Sa)
14 Adhesive 15 Flat work 17 Frame segment joint 18 Correction ring 19 Rotating shaft of upper surface plate

Claims (4)

  9 to 121 discs or toroidal stones with a diameter of 4 to 12 m on a disc-shaped or toric metal turntable with a diameter of 4 to 12 m supported by a rotating shaft. A plate-like workpiece held by a carrier is placed on the surface of a disc-like or annular stone formed by fixing the cut grindstone segments with an adhesive, and the carrier and polishing platen are rotated to obtain a plate-like workpiece. A polishing apparatus for polishing the surface of the metal shaft, wherein the metal turntable is connected to a central segment of a substantially elongated column wider than the diameter of the bearing of the rotary shaft and to the left and right of the central segment. It consists of three metal members of the right segment and left segment of the arc column, and the plane formed by the grid joint surface of each segment of the metal turntable and the grindstone segment of the stone is not parallel , Provided to cross Is characterized in that is, the plate-like body Wa - polishing apparatus used in the surface polishing of the click.   The above stone materials are bonded and cured to each disc segment with a curable resin adhesive containing inorganic powder to form a disc-shaped or annular stone material, and then the upper surface of the cured curable resin adhesive containing inorganic powder is ground. Alternatively, the polishing apparatus according to claim 1, wherein the surface of the stone is formed to be flush with each other.   The stone material is selected from marble, granite, and black granite, and the inorganic powder curable resin adhesive is a curable epoxy resin adhesive containing 5 to 65% by weight of iron powder. 2. The polishing apparatus according to 2.   Between the metal turntable and the stone, a plurality of spacers having a hardness smaller than the hardness of the metal constituting the turntable are inserted concentrically as a bending improver. The polishing apparatus according to claim 1.

Images