JP4384954B2 - Processing method, processing device, and rectangular flat plate processed product processed by this processing method - Google Patents

Description

  The present invention relates to a processing method and a processing apparatus for polishing a surface of a rectangular flat glass plate, which is a workpiece, to a predetermined shape over the entire surface, and a rectangular flat workpiece processed by the method.

  Image display devices such as liquid crystal displays or plasma displays have become larger, and now 5th generation (1100 × 1250mm) mother glass is used, and 7th generation (1870 × 2200mm) mother glass is provided. It is progressing to.

  As the size of these mother glasses increases, the size of the mask substrate that transfers the pattern onto the glass plate increases, for example, to 850 x 1200 mm, and the size of the display increases as the size of the display increases. Is required.

  A mask substrate for transferring a mask to a display glass plate constituting such a display is made of a glass plate made of rectangular flat glass, for example, quartz glass, and the surface thereof is required to have high flatness. .

  An example of a polishing technique that requires high flatness is a wafer processing technique that is one of the manufacturing processes of a semiconductor device.

  As one of polishing apparatuses for processing this wafer, an upper rotating body having a rotating shaft in the vertical direction and having a polishing tool on the lower surface, a rotating shaft in the vertical direction, and a workpiece on the upper surface. The working table holding the wafer is vertically opposed to each other, and the working table and the polishing tool are relatively reciprocated in the horizontal direction by a reciprocating mechanism. For example, the rotating body having the polishing tool is reciprocated in the horizontal direction. A polishing apparatus has been proposed in which a rotating polishing tool is brought into pressure contact with a rotating wafer for polishing. Such a processing method is also referred to as oscillating polishing, and the diameter of a polishing tool used for the oscillating polishing is smaller than the diameter of the wafer (Patent Document 1).

  The processing method disclosed in Patent Document 1 is also called chemical mechanical polishing (CMP) in which chemical action is used in combination with physical polishing, and the solubility of polishing objects such as acids, alkalis, and oxidizing agents is improved. An abrasive called a slurry in which abrasive grains (silica, alumina, cerium oxide, etc.) are dispersed in a solvent is used.

On the other hand, before starting the polishing of the wafer, the film thickness distribution on the polished surface side of the wafer is measured, the polishing amount is predicted based on the measurement result, the working table and the rotation speed of the polishing tool, the working table (wafer) and A program for controlling the relative movement speed of the polishing tool is created, and this program is transmitted to the polishing apparatus via a storage medium or communication means. The amount of polishing (h) at each position in the radial direction of the wafer is predicted based on the Preston equation, which is a basic equation for polishing, where the relative velocity between the wafer and the polishing tool is V, and the Preston constant is η. When the load, which is the pressure applied to the object to be polished, is P and the polishing time is t, it is expressed by h = η · P · V · t, and the polishing amount h increases as the relative speed V increases.
JP 2002-270558 A

  For example, the wafer polishing by the swing polishing method disclosed in the above cited reference 1 starts polishing from the outer peripheral side of the wafer toward the center of rotation, and increases the number of swings at a location where the polishing amount is large. The entire surface is made to be a uniform flat surface by reducing the number of oscillations at a location where the polishing amount is small.

  Here, since the diameter of the polishing tool is smaller than the diameter of the wafer, when polishing the outer peripheral portion of the wafer, if the outer peripheral portion of the polishing tool protrudes from the outer peripheral portion of the wafer, the entire surface of the polishing tool becomes the surface of the wafer. Therefore, the polishing tool is inclined with the protruding portion receiving the reaction force from the contact surface downward, and the contact pressure of the polishing tool on the contact surface increases. Therefore, if the amount of polishing is calculated by applying the above Preston equation as it is, the amount of polishing increases by an amount corresponding to the increase in pressure P. A predetermined amount of polishing can be obtained by correcting the time.

  By the way, when trying to polish the surface of the above-mentioned rectangular flat glass plate by the swing polishing method, the polishing amount at the corner of the rectangular flat glass plate to be polished is larger than the predicted polishing amount. There was a difficulty of becoming less.

  That is, the rectangular flat glass held on the working table naturally differs greatly in the pressure distribution generated between the wafer and the tool at the sides and corners, and the tool takes a rectangular locus similar to the rectangular flat plate. In this case, the eccentric load on the outer side of the corner portion with respect to the side portion becomes small, and the polishing amount becomes small.

  For this reason, it was proposed to place a dummy glass plate around the rectangular flat glass plate and apparently polish it as a disk shape similar to the above-mentioned wafer, but such a method uses a dummy glass plate. This is expensive, and is possible with a small glass plate. However, as described above, the mask substrate size is 850 × 1200 mm or larger, and the apparatus becomes expensive and practical. is not.

  The present invention has been made in view of such a conventional problem. A processing method, a processing apparatus, and a processing method capable of polishing the surface of a small-sized to large-sized rectangular flat glass plate to a predetermined shape over the entire surface. The object of the present invention is to provide a rectangular flat plate-like workpiece processed by the above method.

According to a first aspect of the present invention, as described in claim 1, a rotating rectangular flat plate-like workpiece and a processing tool that rotates and processes the surface of the workpiece are relatively swung. In the processing method for processing, when the processing tool processes the corners of the workpiece, the curved trajectory extending from the center in the length direction of each side of the workpiece to both corners of the side is connected. along the trajectories that will be formed Te, characterized in that the machining by the machining tool is performed.

A second invention is as described in claim 2, in the first invention described above, the innermost processing path relative to the workpiece this is along a rectangular trajectory similar to the rectangular shape of the workpiece Further, the machining is performed such that the curvature becomes larger as the outer machining locus is reached .

  According to a third aspect of the present invention, as described in the third aspect, in any one of the above-described inventions, the rotation of the workpiece and the swinging are synchronized.

  According to a fourth aspect of the present invention, in any one of the above aspects, the workpiece is a glass plate, and the processing tool is an abrasive tool.

  According to a fifth aspect of the present invention, in any one of the above-described aspects, the swing is performed in a straight line or an arc shape.

  According to a sixth aspect of the present invention, as in the sixth aspect of the present invention, in any one of the above inventions, this processing flattens the workpiece.

According to a seventh aspect of the present invention, the working table that holds the workpiece and is rotated and the machining tool for machining while rotating the surface of the workpiece on the working table are attached. The tool head to be rotationally driven, the swinging means for swinging the working table and the tool head relatively in the horizontal direction, and the rotation of the working table and the swinging by the swinging means are synchronously driven and controlled. A control device for controlling the swing of the swinging means based on data inputted to process the surface of the workpiece with a processing tool attached to the tool head. When the workpiece is a rectangular flat plate, when this processing tool processes the corner of the workpiece, it goes from the center in the length direction of each side of the workpiece to both corners of the side. Curved path extending in Te along the trajectories that will be formed by concatenating and controls the speed of the swing so that processing by the machining tool is performed.

An eighth invention is as claimed in claim 8, in the seventh invention described above, the control device similar to the innermost processing path relative to the workpiece in this rectangular shape of the workpiece along Align a rectangular locus, and controlling the speed of the swing, as processing to increase the bending is carried out according to fall outside of the machining path.

  According to a ninth aspect, in any one of the above aspects, the swinging means moves the working table in the horizontal direction.

  According to a tenth aspect of the present invention, as in the tenth aspect of the present invention, in any one of the above aspects, the rotation of the working table, the swinging by the swinging means, and the rotation of the tool head are controlled synchronously.

  According to an eleventh aspect, in any one of the above aspects, the swing is performed in a straight line or an arc shape.

  According to a twelfth aspect of the present invention, as described in the twelfth aspect of the present invention, in any one of the above inventions, this processing flattens the workpiece.

A thirteenth aspect of the invention is a rectangular flat plate-like workpiece characterized in that, as described in the thirteenth aspect , the rectangular flat plate-like workpiece processed by any one of the processing methods described above is a mask substrate.

According to the invention which concerns on Claims 1-6, when grind | polishing while rotating the rectangular plate-shaped to-be-processed object, for example, the corner | angular part of a glass plate, with the polishing tool as a processing tool, a polishing tool follows a pincushion-like locus. Since the polishing process is performed, the polishing tool can approach each corner of the glass plate for polishing, and the surface of the rectangular flat glass plate can be polished while maintaining a predetermined shape.

  Further, according to the inventions according to claims 7 to 12, it is possible to create a pincushion-like locus and a rectangular locus by appropriately controlling the swinging speed of the swinging means, and to create such a track. Therefore, there is no need for a mechanical mechanism, and the apparatus can be reduced in size.

According to the thirteenth aspect of the present invention, the size of the rectangular flat glass plate made of quartz glass forming a mask substrate for transferring a pattern onto a glass plate such as a liquid crystal display or a plasma display is 800 × 920 mm, 1300 × 1500. Even for such a large-sized object, it is possible to provide a surface whose surface is polished in a predetermined shape, particularly with high flatness.

  FIG. 1 is a diagram showing the relationship between a tool trajectory and a tool / workpiece in the machining method according to the present invention, FIG. 2 is a diagram showing an example of a tool trajectory, and FIG. 3 is a schematic view of a polishing apparatus that can effectively implement the present invention. Indicates.

  First, the configuration of the polishing apparatus shown in FIG. 3 will be described. This polishing apparatus 1 applies the above-described CMP, and is provided with a moving table 3 that can be reciprocated in the horizontal direction indicated by an arrow A on a machine base 2, and a working table 4 is rotatably mounted on the moving table 3. . A tool rotating head 6 is attached to the head support 5 so as to be positioned above the moving table 3. Here, the reciprocating direction of the moving table 3 is the X-axis direction, the horizontal axis orthogonal to the X-axis is the Y-axis, and the vertical axis is the Z-axis.

  The moving table 3 can arbitrarily set a moving position, a reciprocating amount, a reciprocating time, and the like by a reciprocating mechanism using a motor (not shown) as a driving source, and is controlled by a control device 7. The working table 4 can be arbitrarily set in the rotation direction and the rotation speed by a rotation drive mechanism using a motor (not shown) as a drive source, and the rotation is controlled by the control device 7. A rectangular flat glass plate made of, for example, quartz glass, which is a workpiece, is held and fixed to the working table 4 by, for example, a suction means.

  The head support 5 can be moved up and down by an elevating mechanism using a motor (not shown) as a drive source, and the tool rotary head 6 can be positioned at an arbitrary position in the y-axis direction by a manual or electric drive mechanism. I am doing so.

  The rotation head and rotation speed of the tool rotation head 6 can be arbitrarily set by a rotation drive mechanism 6a using a motor (not shown) as a drive source, and the rotation of the rotation head 6 is controlled by the control device 7. A polishing tool (not shown) as a tool is attached.

  The control device 7 is input with the polishing amount optimization data obtained by the polishing amount optimization calculation device 8 constituted by a personal computer or the like via a recording medium such as FD or CD or a communication means.

  The polishing amount optimization processing unit measures the surface shape of a rectangular flat glass plate, which is the object to be polished, with a shape measuring instrument, and optimizes the polishing amount with the measurement data input means 8a. The result is output to the calculation unit 8b, and the polishing apparatus 1 performs calculation so as to obtain an optimum polishing amount so that a predetermined shape can be obtained on the surface of the rectangular flat glass plate.

  In addition, since the rectangular flat glass plate to be polished is obtained by, for example, cutting while rotating the ingot, the surface shape of the glass plate is assumed to be formed on the rotation target with respect to the rotation center. Yes. For this reason, as shown in FIG. 1, when the surface shape in the first quadrant can be measured by looking at the coordinates of the X axis and the Y axis passing through the center as shown in FIG. The shape can be grasped. In other words, if only the optimum polishing amount in the first quadrant is obtained, it is possible to optimally polish the entire surface of the glass plate without obtaining the polishing amounts in the remaining three quadrants.

On the other hand, in the present invention, the trajectory of the polishing tool for polishing the surface of the rectangular flat glass plate is a box-shaped trajectory that matches the rectangular shape of the glass plate as a whole, as shown in FIG. The trajectory for polishing the corner of the plate is not a regular box-shaped trajectory (hereinafter referred to as a regular box trajectory) that is a rectangular trajectory similar to the rectangular shape of the glass plate , but curved toward each corner on each side. The trajectory is concatenated, and as a whole, a trajectory like a pincushion shape (hereinafter referred to as a pincushion trajectory) is formed such that the center in the length direction of each side is the bottom position.

A program for driving the moving table 3, the working table 4, and the tool rotary head 6 is installed in the control unit 7 b of the control device 7 so that the normal box locus and the spool locus shown in FIG. 1 are obtained. When the polishing amount optimization data from the polishing amount optimization data input unit 7a is input to this program, the moving amount of the moving table 3, the rotating speed of the working table 4, the rotating speed of the tool rotating head 6, etc. are set. The

Further, in the control unit 7b of the control device 7, in addition to the program for driving the moving table 3 and the working table 4, a program for driving the tool rotary head 6 may be installed. When the polishing amount optimization data from the polishing amount optimization data input unit 7a is input to this program, in addition to setting the movement amount of the moving table 3, the rotation speed of the working table 4, etc., The rotational speed can also be set.

  Such a normal box trajectory and a pincushion trajectory will be described by taking, for example, a case where the object to be polished shown in FIG. 2 is square.

  In the present embodiment, the reciprocating movement of the moving table 3 and the rotation of the working table 4 are driven synchronously, and the working table 4 is set to rotate once when the moving table 3 is reciprocated four times.

  A plurality of similar bobbin trajectories are actually prepared, and the number of times the same trajectory is repeated for each of the plurality of bobbin trajectories is set. Similarly, a plurality of similar normal box trajectories are prepared, and how many times the same trajectory is repeated for each of the plurality of box trajectories is set.

  The polishing amount optimizing calculation unit 8b uses, as a parameter, a distance (hereinafter referred to as a bobbin protrusion amount) M of a bobbin locus located closest to the rotation center and an outermost bobbin locus for a plurality of bobbin loci. The bobbin trajectory can be moved by an arbitrarily settable distance during M. By changing the arbitrary movement amount and the bobbin protrusion amount M, the optimization data such as the number of repetitions of the same trajectory changes.

  Here, when the relative movement of the tool rotary head 6 and the moving table 3 is simply swung linearly with respect to the rotating working table 4 without being synchronized with the rotation of the working table 4, the movement of the tool rotary head 6 is as follows. A circular locus (indicated by a one-dot chain line in FIG. 1) centering on the center of the rectangular flat glass plate on the working table 4 is formed, and the polishing amount of the corner portion of the rectangular flat glass plate is reduced.

In contrast, in the present embodiment, when the polishing tool and combined box-shaped trajectory in a rectangular shape of the glass sheet movement path of the polishing tool on the surface of the flat rectangular glass plate, to polish the corners yarn It passes through a position closer to the corner of the glass plate along the locus. At this time, the rotation center of the tool rotary head 6 indicated by a broken line in FIG. 1 exists in the glass plate, and the polishing tool attached to the tool rotary head 6 does not protrude much from the glass plate. For this reason, a decrease in contact pressure due to the polishing tool at the corner of the glass plate is not observed, and the corner of the glass plate can be polished with the predicted wear amount.

By synchronizing the rotation of the glass plate and the relative linear swing between the polishing tool and the working table 4 (in this embodiment, the movable table 3 is linearly swung in the X-axis direction), the above-described operation is performed. In order to form the rectangular trajectory, the linear rocking speed v from the rotation center of the polishing tool to the rotation center of the glass plate is v, and the rotation angle of the glass plate is θ. Must be controlled. In the XY coordinate system with the rotation center of the glass plate as the origin, the linear rocking velocity v at one point P (x, y) on the normal rectangular locus passing through the inside by a distance M from each edge of the glass plate is
v = d (√ (x ² + y ² )) / dt. Note that t is time.

  Moreover, when the length of the long side of a rectangular flat glass plate is W and the length of the short side is H, x and y are expressed by a few formulas.

Note that θ ₀ = tan ⁻¹ (H / W), W ′ = (W / 2) −M, and H ′ = (H / 2) −M.

x = W ′ y = W ′ tan θ (θ <θ ₀ ) 2 formula x = H ′ / tan θ y = H ′ (θ> θ ₀ or θ = θ ₀ ) 3 formula On the other hand, the bobbin trajectory indicated by the broken line in FIG. The x and y coordinates of one point on the bobbin locus where both ends of the bobbin locus protrude from the rectangular locus by a distance B are expressed by the following equations 4-6.

r = (H ′ ² + B ² ) / 2BR R = (W ′ ² + B ² ) / 2B 4 equation x = W ′ + r ± (√ {(W ′ + r) ² − (1 + tan ² θ) ( W ′ ² + 2rW ′)} / (1 + 1 / tan ² θ))
y = xtanθ (θ <θ ₀ ) Formula 5 x = ytanθ
y = H ′ + R ± (√ {(H ′ + R) ² − (1 + tan ² θ) (H ′ ² + 2RH ′)} / (1 + 1 / tan ² θ))
(Θ> θ ₀ or θ = θ ₀ ) Equation 6 Therefore, the linear rocking speed v in the bobbin trajectory is obtained from the values of x and y on the bobbin locus and Equation 1. The linear swing speed v on each of the plurality of regular box trajectories and each of the plurality of bobbin winding trajectories is calculated in advance by the control unit 7 with reference to the swing start position, and is stored in a memory (not shown) together with the number of repetitions of the same trajectory described above. Remembered.

  FIG. 4 shows the linear rocking speed of a rectangular trajectory passing through 30 (M) mm inside a rectangular glass plate with W = 300 mm and H = 240 mm and a bobbin trajectory having a protrusion amount (B). As shown in FIG. 4 (b), the rocking speed at the corner of the rectangular flat glass plate has a sharp change point, and particularly changes greatly from plus to minus in the case of a bobbin locus. Here, by synchronizing the rotational speed of the tool rotary head 6 with the amount of movement of the moving table 3 and the rotational speed of the working table 4, it is possible to mitigate the above-described rapid change in the rocking speed at the corners. is there.

  In the present embodiment, the regular box trajectory and the bobbin trajectory described above are executed, for example, with the position on the X axis passing through the rotation center of the glass plate as the starting point, and the glass plate has just rotated once to return to this starting point. When the moving amount of the moving table 3 is slightly larger than the previous swinging movement amount, the center of rotation of the polishing tool is shifted to the next starting position, and this time, a rectangular locus is newly drawn from that position, and the glass plate Polish the surface. Also, if the moving amount of the moving table 3 remains the same as the previous moving amount when the glass plate has just rotated once and returned to the starting point, the polishing tool will again polish the surface of the glass plate so as to draw the same locus. To do.

Thus, the surface of the glass plate was polished with a polishing tool so as to draw a pincushion locus at the corner of the glass plate with respect to the rectangular flat plate-like glass plate, and entered the distance M from the edge of each side of the glass plate. Since the surface of the glass plate is polished with a polishing tool so as to draw a regular rectangular locus from the position, the surface of each corner of the glass plate can be polished with a predetermined polishing amount. Can be polished in a predetermined shape over the entire surface.

  Here, whether or not the surface of the glass plate can be polished in a predetermined shape is achieved by predicting the polishing amount in the polishing amount optimization calculation unit 8b. Based on the prediction of the polishing amount, the predetermined shape is determined. The degree of processing (or flatness when the surface of the glass plate is processed flat over the entire surface) is simulated. In addition, as an example of a prediction method for optimization of the polishing amount, the first quadrant in the XY coordinate system described above is roughly divided into a plurality of sections, and the polishing amount (processing amount) in each divided section is changed variously. Divide the PV value (distance between peak and trough) in each divided section by the average processing amount to obtain the processing uniformity error, and the polishing amount with the smallest processing uniformity error is the optimum polishing amount. There is a way of thinking.

  Further, the control of the polishing device 1 by the control device 7 is simplified by replacing the polishing amount with the number of repetitions of the bobbin locus and the rectangular locus.

  The simulation results when the surface of the glass plate is flattened over the entire surface are shown in FIGS.

  The calculation conditions for this simulation are as follows.

Polishing tool: outer diameter 150mm, inner diameter 0mm
Flat glass size: 200 x 200 mm
Rotation speed: 100 rpm for both polishing tool and glass plate
Pressure: 49kPa
Relative elastic constant of polisher (IC1000): 4.4kPa / μm
Amount of wear: 0 μm (km · kPa)
Polishing amount: 0.204 μm (km · kPa)
Swing range: 5-90mm, 5-75mm
Constant speed rocking speed: 10mm / min
Polishing time: (at constant speed swing): 8.6min
For the pincushion trajectory and rectangular trajectory, calculate the processing amount when a square glass plate is polished with a circular polishing tool under the above-mentioned calculation conditions, and divide the PV value (distance between peak and valley) by the average processing amount. The processing uniformity error (%) was calculated. The polishing tool and the glass plate are rotated at a constant speed, and the polisher is assumed to be closed cell polyurethane (IC1000), and polishing is performed at a constant speed linear rocking speed of 10 mm / min. The polishing time was 8.6 minutes and the polisher was assumed not to wear out.

  FIG. 5 shows a case where a circular locus is drawn as a comparative example, where (a) shows the result when the rocking speed is constant, and (b) shows the result when the rocking speed is optimized. The results in four directions are shown by equally dividing the diagonal direction (45 ° direction) from the X-axis direction (0 ° direction) of the glass plate. Before the optimization shown in (a), the central portion of the glass plate is processed a lot, but after the optimization shown in (b), the difference in processing amount between the center and the periphery is reduced, and the error of ± 119% is ± Reduce to 50%.

  However, even after optimization, there is a large variation in the processing amount in the outer direction of the glass plate (especially in the direction of 45 degrees), and the uniformity cannot be improved unless this is improved.

  On the other hand, as shown in FIG. 6, in the case of the present invention in which the polishing tool is moved along the rectangular locus and the bobbin locus, the error before optimization shown in FIG. Compared to (a) of FIG. 5, ± 75%, which is a 40% reduction, reduces the decrease in the processing amount in the periphery, and the improvement in the 45 ° direction is particularly remarkable. The error after optimization shown in FIG. 6B is ± 15%, and the machining amounts at the center and the peripheral part are substantially equal, but variations due to the direction still remain. Further, as compared with the 0 ° direction, the machining amount decreases as the corner (45 °) is approached. For this reason, a pincushion trajectory that moves toward the outer peripheral side of the glass plate as the polishing tool approaches the corner is created so that the amount of processing increases toward the corner, and a simulation was performed. The result is shown in FIG.

  In this case, the swing range was 5 to 75 mm. Before the optimization shown in FIG. 7A, the error is worsened to ± 117% compared to the rectangular trajectory, but the variation in the processing amount in the peripheral portion becomes extremely small, and an error due to the direction is almost seen. Absent. Further, as shown in (b), the error after optimization was ± 9%, indicating that high flatness can be obtained.

FIG. 8 shows optimized swing speeds in a circular locus, a rectangular locus, and a bobbin locus. In either case, the rocking speed at the center is slower than the outer peripheral side of the rectangular flat glass plate. This velocity distribution serves to suppress a large amount of processing based on the eccentric load generated by the polishing tool protruding from the periphery, and to compensate for a relative velocity that decreases as it approaches the center.

  The results in FIGS. 5 to 8 described above are based on a simulation of a glass plate of 200 mm × 200 mm, but the same applies to a large glass plate of 800 × 900 × 10 mm or 1300 × 1500 × 15 mm. The effect of is obtained.

  In addition, although quartz glass was demonstrated as an example as a glass plate in above-described embodiment, this invention is not limited to this, A silicon wafer etc. can be grind | polished as a to-be-polished object.

  Further, in order to obtain the linear swing speed, the tool rotary head is not moved and the movable table is moved in the horizontal direction. However, the tool rotary head may be moved in the horizontal direction.

  Furthermore, when polishing the surface of the glass plate, a rectangular trajectory is drawn sequentially from the rotation center side of the glass plate toward the outer periphery, and then the movement trajectory of the polishing tool is set so that the pincushion trajectory is drawn sequentially. May be.

  In the above-described embodiment, the linear swing is described as an example, but the swing may be performed not only in a straight line but also in an arc shape.

  Further, in the above-described embodiment, any portion of the surface of the glass plate that is a workpiece is polished with a desired polishing amount, and flattening that can obtain high flatness over the entire surface of the glass plate. Although processing has been described as an example, it is needless to say that not only flattening processing but also an arbitrary portion can be processed with an arbitrary processing amount on the surface of a rectangular flat plate-like workpiece.

The figure which shows the movement locus | trajectory of the polishing tool with respect to the glass plate by this invention. The figure explaining the movement locus | trajectory of the grinding | polishing tool of FIG. Schematic of a polishing apparatus that can effectively implement the present invention Diagram showing linear rocking speed at the time of rectangular and bobbin winding trajectory The figure which shows the processing amount distribution at the time of circular regulation as a comparative example The figure which shows the processing amount distribution at the time of the rectangular locus by this invention The figure which shows the processing amount distribution at the time of the bobbin locus by this invention Diagram showing the optimal swing speed for each locus of circle, rectangle, and bobbin

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polishing apparatus 2 Machine stand 3 Moving table 4 Working table 5 Head support stand 6 Tool rotation head 6a Rotation drive mechanism 7 Controller 8 Polishing amount optimization arithmetic unit 8a Measurement data input means, 8b Polishing amount optimization arithmetic unit

Claims (13)

In a machining method of machining by relatively swinging a rotating rectangular flat plate-like workpiece and a machining tool for rotating and machining the surface of the workpiece, the machining tool is provided on the workpiece. when machining the corner portion, the along the trajectories of the lengthwise center of each side Ru is formed by concatenating a curved trajectory extending toward the both corner portions of the side of the workpiece machining by the machining tool A processing method characterized by being performed.   The innermost machining locus for the workpiece is along a rectangular locus similar to the rectangular shape of the workpiece, and the machining is performed such that the curvature increases as the outer machining locus is reached. The processing method according to claim 1.   The processing method according to claim 1 or 2, wherein the rotation of the workpiece and the oscillation are synchronized.   The processing method according to claim 1, wherein the workpiece is a glass plate, and the processing tool is an abrasive tool.   5. The processing method according to claim 1, wherein the rocking is performed in a straight line or an arc shape.   The processing method according to claim 1, 2, 3, 4, or 5, wherein the processing is to flatten the workpiece. A working table that is rotationally driven to hold a work piece, a tool head that is rotationally driven to attach a working tool for working while rotating the surface of the work piece on the working table, and the working table and the tool head A swinging means for relatively swinging the workpiece in the horizontal direction, and a working tool for controlling the rotation of the working table and the swinging by the swinging means synchronously and controlling the surface of the workpiece on the tool head. And a control device for controlling the swinging of the swinging unit based on the data input for processing at
When the workpiece is a rectangular flat plate, the control device is configured to process both corners of the side from the center in the length direction of each side of the workpiece when the machining tool processes the corner of the workpiece. processing apparatus, wherein a curved trajectory extending toward the section along the trajectories that will be formed by concatenating control the speed of the swing so that processing by the machining tool is performed.   The control device causes the innermost machining locus for the workpiece to follow a rectangular locus similar to the rectangular shape of the workpiece, and the machining is performed to increase the curvature as the outer machining locus is reached. The processing apparatus according to claim 7, wherein a speed of the swing is controlled.   9. The processing apparatus according to claim 7, wherein the swinging means moves the working table in a horizontal direction.   10. The processing apparatus according to claim 7, 8 or 9, wherein the rotation of the working table, the swinging by the swinging means, and the rotation of the tool head are controlled synchronously.   The processing apparatus according to claim 7, 8, 9, or 10, wherein the swinging is performed in a straight line or an arc shape.   The processing apparatus according to claim 7, 8, 9, 10 or 11, wherein the processing is for flattening a workpiece.   A rectangular flat plate-like workpiece processed by the processing method according to claim 1 is a mask substrate.