JP2007175817A - Planarization processing apparatus and supporting method of plane stage processed with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planarization processing apparatus for processing the surface of a large-sized workpiece to be flat with a less man-hour, and a method for supporting the workpiece so that the processed surface of the workpiece becomes flat. <P>SOLUTION: The workpiece W is fixedly held on a vacuum suction part of the fixed type support body 1 whose heights at three places are fixed. When air is supplied into an air cylinder of a displacement type support body 2 to lift it and it contacts to the back surface of the workpiece W, the position of the displacement type support body 2 in the height direction is fixed and the workpiece W is fixedly held. A processing head 10 is moved in this state, and the surface of the workpiece W is polished and ground to process it to be flat. When the workpiece processed like this is used as a work stage of an exposure device, for example, the support body is disposed so as to be the same positional relationship as the disposition of the fixed type support body 1 when it is processed, and the workpiece is installed so that the surface of the workpiece becomes flat by recreating the same support state when it is processed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a planar processing apparatus for processing a surface into a planar shape by polishing, grinding, etc., and a support method when using a flat plate processed in this way as a stage, in particular, a large printed circuit board or The present invention relates to a flat plate processing apparatus suitable for use in an exposure stage of an exposure apparatus on which a liquid crystal substrate is placed, and a method of supporting a flat plate processed in this way.

Conventionally, a surface grinding machine is known as an apparatus for processing the surface of a workpiece (workpiece) so as to be flat (see, for example, Patent Document 1, Patent Document 2, and the like).
The surface grinding machine is usually provided with a table, and a work is placed on the table to grind the surface, and the table surface must be formed in a flat surface.
However, if the workpiece to be processed is large, the table becomes large. It is difficult to produce a large table with a flat surface, and the weight of the table increases.
Therefore, when manufacturing a large flat plate used for the stage of an exposure apparatus, for example, the work is not placed on a flat table, but is supported on a flat surface by three or more points by a support. It is conceivable to process.

FIG. 13 shows a schematic configuration of a planar processing apparatus for processing a workpiece by supporting it with three or more supports. In addition, the figure (a) is the side view seen from the direction parallel to the workpiece | work surface.
In the figure, a blade for polishing and grinding a workpiece W to a flat surface is attached to the machining head 10. A processing stage 13 is provided on the base plate 12 of the processing apparatus, and fixing members 20 and 30 for holding and fixing the workpiece W to be processed are provided on the processing stage 13.
After the workpiece W is placed on the processing stage 13, it is fixed by the fixing members 20 and 30.

The fixing members 20 and 30 include three main fixing members 20 (indicated by triangles in FIG. 13) for determining the plane of the workpiece W, and one or a plurality of fixing members 20 when the main fixing member 20 alone cannot sufficiently fix the workpiece W. An auxiliary fixing member 30 (shown in a T shape in FIG. 13) is provided.
The main fixing member 20 is fixed in the height direction (the vertical direction in the drawing) with respect to the processing stage 13. The height of the auxiliary fixing member 30 can be adjusted. In FIG. 13A and FIG. 14 below, for convenience of explanation, the fixing members 20 and 30 are shown as being arranged in a straight line, but the main fixing member 20 is arranged at the apex position of the triangle. The auxiliary fixing member 30 is disposed, for example, between the main fixing members 20 and the periphery of the workpiece W.
At least one of the processing head 10 and the processing stage 13 is provided with a moving mechanism 11, and the processing head 10 and / or the processing stage 13 move in the XY directions (the left-right direction and the front-rear direction in the figure). The surface of the workpiece W is polished and ground by the cutting tool of the processing head 10. FIG. 13 shows a case where the machining head 10 moves.

FIG. 14 shows a specific configuration example of the fixing members 20 and 30. (A) is the auxiliary | assistant fixing member 30, (b) is the main fixing member 20, (c) is a top view of (a) and (b).
The fixing members 20 and 30 are workpiece supporting portions 21 and 31 for setting the height position of the workpiece W to be processed, workpiece fixing portions 22 and 32 for pressing and fixing the workpiece W on the workpiece supporting portions 21 and 31, and workpiece fixing. It comprises fulcrum parts 23 and 33 which are fulcrum points of the parts 22 and 32.
The workpiece fixing portions 22 and 32 are passed through screws 22b and 32b upright on the machining stage. By tightening the nuts 22a and 32a, the workpiece fixing portions 22 and 32 are supported on the workpiece support portions 21 and 31 with the fulcrum portions 23 and 33 as fulcrums. Press the work W.
In the main fixing member 20 shown in FIG. 14B, the height of the work support portion 21 is determined, and the plane of the work W to be placed is determined by this height.
The work support portion 31 of the auxiliary fixing member 30 shown in FIG. 5A is composed of a screw 31a and a nut 31b, and the height can be adjusted.

FIG. 15 shows a processing procedure using the planar processing apparatus as described above.
As shown in FIG. 15A, for example, when processing a workpiece W having a convex warp, the workpiece W is placed on the processing stage 13 as shown in FIG.
Of the fixing members 20 and 30 provided on the processing stage 13, the workpiece W is first placed on the workpiece supporting portion 21 of the three main fixing members 20, and the workpiece W is held by tightening the nut 22 a of the workpiece fixing portion 22. Fix it. The heights of the work support portions 21 of the three main fixing members 20 are adjusted in advance so as to form a plane parallel to the moving plane of the processing head 10 or the processing stage 13.

If the workpiece W is small, it may be fixed by the main fixing member 20 alone. However, if the workpiece W is large in size with one side exceeding 1 m, polishing and grinding will be performed only by holding the three positions with the main fixing member 20. In particular, vibration occurs in the peripheral portion of the workpiece W, and high-precision machining cannot be performed.
As an example of a large workpiece whose one side exceeds 1 m, an exposure stage of an exposure apparatus for a large printed circuit board or a liquid crystal substrate is raised.
Therefore, as shown in FIG. 15 (c), a portion other than the main fixing member 20 of the workpiece W is held by the auxiliary fixing member 30. At this time, the auxiliary support member 30 is measured while measuring the height from the processing stage 13 with the dial gauge 100 so that the workpiece W is free from waviness due to warpage or deflection due to its own weight, and the surface of the workpiece W is flat as a whole. The height of the workpiece support 31 is adjusted. Thereafter, the workpiece W is held and fixed by tightening the nut 32 a of the workpiece fixing portion 32.
When the workpiece W becomes flat, the surface of the workpiece W is ground and ground by the cutting tool of the machining head 10 shown in FIG.

When the planar processing is finished, the workpiece W is removed from the fixing means 20 and 30. However, at this time, the workpiece W is released from the force applied so as to eliminate warping and deflection. Therefore, the workpiece W removed from the fixing means 20 and 30 is warped again as shown in FIG.
Therefore, the workpiece W is turned upside down and placed on the processing stage 13 again, and the surface opposite to the previous one is processed by the same procedure as described above.
After processing, the fixing means 20, 30 are removed. If warping of the workpiece still occurs, turn the workpiece over again. Thereafter, this operation is repeated until a desired flatness is obtained.
JP-A-11-58227 JP-A-5-237765

The work stage of the exposure apparatus is processed by the method as described above, for example, but in order to obtain high exposure accuracy, the requirement for surface accuracy is strict, for example, a flatness of 10 μm for a size of 200 mm × 200 mm Required.
Recently, the object to be exposed is a large object such as a liquid crystal panel or a printed circuit board, and the work stage of the exposure apparatus is also enlarged. In such a work stage, a flatness of 20 to 50 μm is required for a size of 1000 mm × 1000 mm.
For this reason, the above procedure is repeated about 7 times, but the work reversing work is large and difficult, and it takes time for processing. Moreover, there is also a problem that it is not known whether or not a desired plane accuracy can be obtained even if the work is inverted.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a planar processing apparatus that accurately and flatly processes the surface of a large workpiece with relatively few man-hours without repeatedly reversing the workpiece. An object of the present invention is to provide a method for supporting a workpiece machined by the plane machining apparatus so that the surface thereof is flat.

As a result of investigating a technique for processing a surface of a large workpiece accurately and flatly with a relatively small number of man-hours without repeating the inversion of the workpiece, the inventors have found that the following may be performed.
That is, a processing head for polishing and grinding a plate-like workpiece to a flat surface, and a processing stage provided with a support on which a workpiece to be polished and ground to a flat surface is placed and held, and the processing head or the processing stage includes In a planar processing apparatus in which the surface of a workpiece that moves in a plane and is processed on a processing stage is processed into a plane by the processing head, the support is fixed to a fixed support having a constant height and a set position. 3 of the above-mentioned fixed support body or displacement support body with a total height of 4 or more. The workpiece is placed on the three supports, and the workpiece is held by the support.
In addition, the other support is a displacement support, and the push-up force of the work by the displacement support is adjusted so that the displacement support is in contact with the work without applying force, or the weight of the work In this state, the workpiece is pushed up with a force that cancels the bending caused by the above-mentioned condition. In this state, the height of the displacement support is held, and the workpiece is held by each displacement support.
In this state, the work surface is ground and ground to a flat surface by the machining head. Of the supports, the number of fixed supports may be three or less, or all of the supports may be displacement supports.
When the workpiece ground and ground in this way is removed from the processing apparatus, it is released from the force applied as described above, and its surface is not necessarily flat, but is supported during the processing. If the support method by the body can be reproduced, the surface should be kept flat.
Therefore, when using the workpiece machined as described above as a flat stage, arrange the support so that the arrangement of the support when the workpiece is machined is the same, and above the above The processed workpiece is placed so that the surface processed into a flat shape is on the upper side and the support point by the support is the same as that at the time of processing.
In addition, when the lifting force of the displacement type support is in contact with the workpiece without applying any force during processing, it is necessary to provide the support at the same position as the displacement type support when used as a flat stage. However, it may be supported at other support points.

That is, in the present invention, the above problem is solved as follows.
(1) A processing head for polishing and grinding a plate-like workpiece to a flat surface, and a processing stage provided with a support on which a workpiece to be ground and ground on a flat surface is placed and held, and the processing head or the processing stage Moves on the plane and the surface of the workpiece held on the machining stage is machined into a plane by the machining head, and the support is rotated on a pedestal mounted on the machining stage. Connected to the shaft by a fixed support body that has a vacuum suction part that is attached via a bearing and holds the workpiece from the back side, the height of the stationary support body, an air cylinder that moves the shaft up and down with arbitrary thrust, and the like A plate-like body, a holding means for holding the plate-like body in a fixed position by fixing and holding the plate-like body, and a tip end of the shaft via a rotary bearing. Vignetting, height composed of a vacuum suction unit for holding the workpiece from the back side is composed of a variable displacement type support.
Then, the total of the fixed-type support body and the displacement-type support body is four or more, and at least three of the support bodies are arranged so as to be at the apex position of the triangle.
(2) In the above (1), the number of the fixed supports is three or less among the supports.
(3) In the above (1), all of the supports are displacement-type supports.
(4) A plate-like workpiece is supported by at least three supports arranged so as to be at the apex position of the triangle, and the surface opposite to the surface supported by the support is planarized by a processing device. When processing and using the workpiece as a flat stage, the support is arranged so as to have the same arrangement as the support when the workpiece is processed, and the processed workpiece is The flat surface is placed on the upper side, and the support point by the support is the same as that at the time of processing.

In the present invention, the following effects can be obtained.
(1) A support on which a workpiece is placed and held is a fixed support whose height is not changed, and a height variable displacement support provided with means for holding the height at a set position. Since the workpiece is held by four or more supports and the surface of the workpiece is processed flat, the support is arranged so as to be the same as the arrangement of the support when the workpiece is processed. And the state at the time of a process can be reproduced by mounting the said processed workpiece | work on it, and it can install so that the workpiece | work surface may become flat. Therefore, it can be used in, for example, a work stage of an exposure apparatus in this state.
Therefore, it is possible to manufacture a flat plate that can be installed so that the surface becomes flat with a small number of man-hours without reversing the workpiece as in the conventional example.
(2) By using a displacement type support as a support and pushing up the work with a thrust that cancels the deflection of its own weight, it is possible to use three supports to support the work load at three points. The load applied to the support can be reduced.
For this reason, it becomes possible to apply to a heavy and heavy workpiece.
(3) By making all of the supports into displacement-type supports, there is no need to prepare two members, a displacement-type support and a fixed-type support.

FIG. 1 is a diagram showing a configuration of a planar processing apparatus according to an embodiment of the present invention, which is a diagram seen from the side.
In the figure, on a processing stage 13, three fixed support bodies 1 (illustrated by triangles) having a fixed height and a plurality of displacement support bodies 2 (illustrated by a T-shape) having variable heights are provided. Is provided.
In the figure, the supports 1 and 2 are shown as being arranged in a straight line. However, as will be described later, the fixed support 1 is arranged at the apex position of the triangle, and the displacement type The support 2 is arranged, for example, around the processing stage 13 or between the supports 1.
A cutting tool for polishing and grinding a workpiece to a flat surface is attached to the processing head 10, and a workpiece (not shown) is placed and held on the supports 1 and 2.
Either one of the processing head 10 and the processing stage 13 is provided with a moving mechanism 11, and the processing head 10 or the processing stage 13 or both move in the XY directions (the left-right direction and the front back direction in the figure), and the workpiece The surface is ground by the cutting tool of the processing head 10. FIG. 1 shows a case where the machining head 10 moves.

FIG. 2 shows the structure of the fixed support 1.
The fixed support 1 is fixed in the height direction with respect to the processing stage 13 in the same manner as the main fixing member 20 shown in the prior art.
A vacuum suction portion 1c having a vacuum suction groove 1d formed on the surface thereof is mounted on the pedestal 1a via a rotary bearing 1b. A vacuum pipe 1e is connected to the vacuum suction portion 1d.

FIG. 3 shows the structure of the displacement support 2. This figure is a cross-sectional view.
Although the height can be adjusted in the same manner as the auxiliary fixing member 30 of the prior art, an air cylinder is used instead of a screw type.
An air cylinder 2 a is provided on the processing stage 13. In the air cylinder 2a, the shaft 2b moves up and down with an arbitrary thrust by changing the pressure of the supplied air.
The shaft 2b of the air cylinder 2a is connected to the intermediate platform 2c. A spring 2g is provided between the air cylinder 2a and the intermediate stand 2c.
Fixed disks 2d (for example, leaf springs) are attached to both sides of the intermediate platform 2c so as to extend downward, and pads 2e of an air lock mechanism 2f are provided on both sides of the fixed disks 2d. When air is supplied to the air lock mechanism 2f, the pad 2e moves in the direction of the arrow in the figure, and the fixed disk 2d is sandwiched and fixed.
A vacuum suction part 2i is provided on the upper part of the intermediate stage 2c via a rotary bearing 2h. The structure of the vacuum suction portion 2i is the same as that of a fixed support, and a vacuum suction groove 2j is formed on the surface and a vacuum pipe 2k is connected.

Returning to FIG. 1, an air pipe 3 is connected to the air cylinder 2a of each of the displacement-type supports 2, and the air pipe 3 is connected to a pressure source via a gauge 3a and a regulator 3b. And by setting the pressure of the air supplied to the air cylinder 2a of each support body 2 by the regulator 3b, the vacuum suction part 2i of the displacement type support body 2 is pushed up with a force corresponding to the air pressure.
Further, a vacuum source is connected to the vacuum suction portions 1c and 2i of the supports 1 and 2 through vacuum pipes 1e and 2k, which are not shown in the drawing.

Next, referring to FIG. 4 and FIG. 5, the procedure of the first embodiment of the present invention for machining a workpiece will be described. FIG. 4 is a plan view showing an arrangement example of the supports 1 and 2 in this embodiment, and FIG. 5 is a side view. In FIG. 5, for the convenience of explanation, the supports 1 and 2 are shown as being arranged in a straight line, but the supports 1 and 2 are arranged as shown in FIG. 4, for example.
In this embodiment, as shown in FIG. 4, three fixed supports 1 having the same height are arranged so as to be at the apex position of the triangle, and the load of the work is set by three fixed supports. The displacement type support body 2 is disposed around the base plate 13 (work) to prevent the work from vibrating (called chatter) during processing.

(1) As shown in FIG. 5A, the workpiece W is placed on the processing stage 13. The workpiece W is placed on the vacuum suction portions 1c of the three fixed support members 1 provided on the processing stage 13, and is held and fixed. The height of the fixed support 1 is set in advance so that the plane formed by the three fixed supports is parallel to the plane on which the machining head 10 moves. At this time, the displacement support 2 is lowered and does not come into contact with the workpiece W. Up to this point, the process is basically the same as that in the prior art.
(2) As shown in FIG.5 (b), air is supplied to the air cylinder 2a of the displacement type support body 2, and the vacuum suction part 2i is raised. When the vacuum suction part 2i comes into contact with the back surface of the workpiece W and holds the workpiece, the air lock mechanism 2f is operated to sandwich the fixed disk 2d between the pads 2e, and the position of the displacement support 2 in the height direction And the work W is held by the vacuum suction part 2i.
(3) The displacement support 2 is in contact with the workpiece W, and no pushing force is applied to the workpiece W. That is, the displacement support 2 is only in contact with the workpiece, and no force acts on the workpiece W.
The force that pushes up the workpiece W works only in the fixed support 1 portion.
(4) In this state, as shown in FIG. 5C, the machining head 10 is moved to polish and grind the surface of the workpiece W into a flat surface. Although the displacement type support body 2 does not push up the workpiece W, the height direction is fixed because the workpiece W is held by the vacuum suction portion 2i and the pad 2e sandwiches the fixed disk 2d. Therefore, the workpiece W does not vibrate during machining.
This completes the planar processing of the workpiece.

Next, the case where the workpiece processed in this way is used as a work stage of a light irradiation apparatus, for example, an exposure apparatus will be described with reference to FIG. Here, a case will be described in which a support having an air pad is used as the support, and the processed workpiece (referred to as a flat plate 50) is supported by being floated by air.
As shown in FIG. 6A, the same positional relationship as the arrangement of the fixed support 1 when the surface of the work W (planar plate 50) is processed on the base plate 15 on which the work stage of the exposure apparatus is placed. The stage fixed support 5 is arranged so as to be.
That is, the stage-type fixed support 5 is arranged on the base plate 15 so as to be the same as the arrangement of the fixed support 1 at the time of processing, and the flat plate 50 whose surface is processed flat is flattened. The processed surface is placed on the upper side, and the support point by the support 5 is placed at substantially the same position as at the time of processing.

FIG. 6B shows a configuration example of the stationary support 5 for the stage that is levitated by the air.
As shown in the figure, an air pad 5c is mounted on a pedestal 5a via a rotary bearing 5b. By supplying air from an air supply pipe 5e, air is ejected from an air outlet 5d of the air pad 5c, The processed flat plate 50 is levitated.
A flat compensation plate 50a having a flat surface is attached to a portion facing the fixed support 5 on the back side of the flat plate 50 in order to prevent leakage of air ejected from the air pad 5c.
As described above, the flat plate 50 is placed on the fixed support 5 and air of a predetermined pressure is supplied to the air pads 5c of the three fixed supports 5, so that the flat plate 50 is brought into the air pad 5c. From about 10 μm to be supported.
Thereby, on the base plate 15 of the exposure apparatus, the same support state as when the flat plate 50 is processed into a flat surface by a processing machine is reproduced, and the surface of the flat plate 50, that is, the surface of the stage becomes flat. .
At the time of processing, the support is supported by the displacement support 2 in addition to the fixed support 1, but the displacement support 2 is only in contact with the workpiece W, and no force is applied to the workpiece W. When the face plate 50 is used as a stage, it is not necessary to support the displacement plate 2 above.
According to the present embodiment, it is not necessary to turn the workpiece upside down and repeat the plane machining many times as in the conventional case, and the plane stage can be manufactured by one plane machining, and the machining man-hour is greatly reduced. be able to.

Next, a second embodiment of the present invention will be described.
In the first embodiment described above, the load of the workpiece is supported by the three fixed supports 1, and the workpiece is not pushed up by the displacement support. However, in this embodiment, the three fixed supports 1 are supported. In addition to supporting the workpiece, the displacement support 2 pushes up the workpiece with a force that cancels the deflection of its own weight so that it can handle heavier workpieces.
FIG. 7 is a plan view showing an example of arrangement of supports in the present embodiment, and FIG. 8 is a side view.
In FIG. 8, the supports 1, 2, 2 ′ are shown as being arranged in a straight line, and the number of displacement type supports is also different from FIG. 7, but FIG. 8 is a conceptual diagram. Each support 1, 2, 2 ′ is arranged as shown in FIG. 7, for example.
In this embodiment, as shown in FIG. 7, three fixed supports 1 having the same height are arranged so as to be at the apex position of the triangle, and the displacement-type support 2 is bent by its own weight. In addition, a displaceable support 2 ′ is disposed around the base plate 13 (work) to prevent the work from vibrating (called chatter) during processing. Note that the installation positions of the fixed support 1 and the displacement support 2 are obtained by simulation as will be described later.

Next, the procedure of the second embodiment of the present invention for planarizing a workpiece will be described with reference to FIG. (1) As shown in FIG. 8A, the workpiece W is placed on the processing stage 13. The workpiece W is placed on the vacuum suction portion 1c of the three fixed supports 1 provided on the processing stage 13, and is held and fixed. At this time, the displacement-type supports 2 and 2 ′ are lowered and do not come into contact with the workpiece W. In addition, arrangement | positioning of the said fixed type support body 1 and the displacement type support body 2 is calculated | required by the simulation demonstrated below.
(2) As shown in FIG. 8B, air is supplied to the air cylinder 2a of the displacement support 2 to raise the vacuum suction part 2i. The vacuum suction unit 2i is in contact with the back surface of the workpiece W and holds the workpiece W by suction. In this state, a thrust force that cancels the deflection due to the weight of the workpiece W is applied to the displacement support 2 to push up the workpiece W.
Here, “thrust that only cancels deflection due to its own weight” actually requires strict calculation, but can be explained as follows.
For example, when a workpiece of 60 kg is supported at six locations including three fixed support bodies 1 and three displacement support bodies 2, ideally 10 kg of 60 kg ÷ 6 = 10 kg is “deflection due to its own weight. "Thrust that only cancels".

The method of actually giving the workpiece “thrust that only cancels the deflection due to its own weight” is shown below.
(A) For example, FIG. 9 is a diagram in which gravity is applied to each point when a workpiece of 2470 mm × 2170 mm × 10 mm and weighing about 140 kg is supported at six points.
This figure shows the position of the support point where the deflection is minimized, the load applied to each support point, and the amount of deflection of the plane plate by computer simulation when the plane plate is supported at 6 points. is there. In the figure, 24.7 kg, 21.6 kg,... Are loads applied to the respective support points, and lines shown so as to surround each of the support points are contour lines connecting points having the same amount of displacement.
In this manner, the gravity applied to each support is calculated based on the size and weight of the workpiece and the position of the support in advance by computer simulation. Here, in the above calculation, a support point that minimizes the amount of deflection of the work is searched, and the gravity applied to the support point is obtained.
(A) As shown in FIG. 9, the gravity concerning each support body obtained by calculation shall be 24.7 kg, 21.6 kg, 24.7 kg, 24.6 kg, 21.6 kg, 24.6 kg.

(C) The supports 1 and 2 are provided on the processing stage 13 so that the positional relationship of the support points obtained by the simulation is reproduced. Here, three places are supported by the fixed support 1 and the other three places are supported by the displacement support 2.
(D) Air is supplied to the air cylinder 2a of the displacement support 2 so that a thrust (holding force) corresponding to the gravity applied to the position where the displacement support 2 is provided.
Since the thrust (holding force) of the air cylinder is uniquely determined with respect to the air pressure to be supplied, if the gravity applied to the target displacement support 2 is 24.7 kg, a thrust of 24.7 kg ( If the gravity is 21.6 kg, a pressure at which 21.6 kg of thrust (holding force) is obtained is applied.
The air pressure is adjusted by a regulator 3b provided in an air pipe 3 connected to each displacement support 2 shown in FIG.
By applying the predetermined thrust obtained by the above calculation to the displacement support 2, gravity is applied to the fixed support 1 as calculated.

(3) Returning to FIG. 8 (b), with the thrust that cancels the deflection caused by the weight of the workpiece W applied to the displacement support 2, the air lock is operated and the fixed disk is sandwiched between the pads, Fix the position of the displacement support in the height direction. The fixed support member and the displacement support member are in a state where the weight of the work is evenly applied.
As shown in FIG. 7, in this embodiment, in addition to the displacement support 2, a displacement support 2 ′ for preventing chattering of the workpiece at the time of machining is provided on the periphery of the work W. It has been. As described above, the displacement support 2 ′ may be applied with a thrust force that cancels the deflection due to its own weight. However, as described in the first embodiment, the displacement-type support 2 ′ is not in contact with the work W. It is better not to apply force. That is, as described in the first embodiment, air is supplied to the air cylinder 2a of the displacement support 2 to raise the vacuum suction portion 2i, and the vacuum suction portion 2i comes into contact with the back surface of the workpiece W. When the work is held, the air lock mechanism 2f is operated, the fixed disk 2d is sandwiched between the pads 2e, the position in the height direction of the displacement support 2 is fixed, and the work W is held by the vacuum suction part 2i.

(4) As shown in FIG. 8C, in this state, the processing head 10 is moved, and the surface of the workpiece W is polished and ground to be processed into a flat surface. The displacement type supports 2 and 2 'hold the work W by the vacuum suction part 2i, and the pad 2e sandwiches the fixed disk 2d, so the height direction is fixed. Therefore, the workpiece does not vibrate during machining.
This completes the planar processing of the workpiece.
In the above description, the displacement support 2 is raised after the workpiece W is placed on the fixed support 1. However, before the workpiece W is placed, the displacement support 2 may be raised. That is, a pressure for obtaining a thrust obtained by simulation in advance is supplied to the displacement support 2 to raise the cylinder, and the workpiece W is placed thereon.

When the workpiece processed in this way is used as a work stage of a light irradiation apparatus, for example, an exposure apparatus, it is the same as described in the first embodiment, and here, as in the first embodiment, A case will be described in which a support having an air pad is used as a support and the work (referred to as a flat plate 50) is supported by being levitated by air.
As shown in FIG. 10 (a), the arrangement of the fixed support 1 and the displacement support 2 when the surface of the flat plate 50 is processed flat on the base plate 15 on which the work stage of the exposure apparatus is placed. The stage fixed support 5 and the stage displacement support 6 are arranged so as to have the same positional relationship, and the flat plate 50 whose surface is processed flat is the upper surface of the flat plate 50 and the support 5 The support point is placed so that it is at the same position as when processing. The stage fixed support 5 is the one shown in FIG. 6B.
Similar to the fixed support 5 shown in FIG. 6 (b), the displacement support 6 is obtained by replacing the vacuum suction portion 2i of the displacement support shown in FIG. 3 with an air pad. Is shown in FIG. As shown in the figure, the displacement support 6 includes an air cylinder 6a, a shaft 6b, an intermediate base 6c, a spring 6g, a fixed disk 6d, an air lock mechanism 6f, a pad 6e, and a rotary bearing 6h. An air pad 6i is provided.
Then, air is ejected from the air ejection holes 6j of the air pad 6i, and the processed flat plate 50 is levitated.
As in the case of the fixed support 5, a flat compensator having a flat surface is provided at a portion facing the displacement support 6 on the back side of the flat plate 50 in order to prevent leakage of air ejected from the air pad 5 c. 50a is attached.
The displacement support 2 ′ that is in contact with the workpiece and does not apply force to the workpiece W does not need to be provided on the base plate 15.

As described above, the flat plate 50 is placed on the stage fixed support body 5 and the stage displacement support body 6 and the air pad 6i of the displacement support body 6 is lifted and processed by the processing machine. The flat plate 50 is pushed up by pressure, and the height direction is fixed by the air lock mechanism 6f.
Prior to placing the workpiece, the pressure that obtains the same thrust as that during processing may be supplied to the displacement support 6 to raise the air cylinder, and the workpiece may be placed thereon.
Then, air of the same pressure is supplied to the air pads of the three fixed support members 5 and the three displacement support members 6, and the flat plate 50 is supported by being floated about 10 μm from the air pad 5c.
Thereby, on the base plate 15 of the exposure apparatus, the same support state as when the flat plate 50 is processed into a flat surface by a processing machine is reproduced, and the surface of the flat plate 50, that is, the surface of the stage becomes flat. .

As described above, according to this embodiment, similarly to the first embodiment, it is not necessary to turn the workpiece over and repeat the plane machining many times as in the prior art, and the plane stage is manufactured by one plane machining. This can greatly reduce the number of processing steps.
Further, since the work is supported by the fixed support and the work is pushed up by the thrust that cancels the weight of the work by the displacement support, the load applied to each support can be reduced. For this reason, it can also be applied to heavy and heavy workpieces.

In the first and second embodiments, the structure of FIG. 2 is exemplified as the fixed support. However, the displacement support shown in FIG. 3 is used as the fixed support, and all the supports are used. It can also be a displacement support.
In other words, the fixed support is fixed in the height direction and has a plane at three points. However, the displacement support shown in FIG. 3 can also be fixed in the height direction by the air lock mechanism 2f. Can work the same as a stationary support.
If the displacement support 2 is used as the fixed support 1, it is not necessary to prepare two members, the displacement support 2 and the fixed support 1.
Next, with reference to FIG. 11, a procedure for flattening a workpiece when all of the supports are displacement-type supports will be described. In FIG. 11, the displacement-type supports are shown to be arranged in a straight line, but as described above, the supports 2 are arranged as shown in FIG. 7, for example. In the following description, the displacement support 2 ′ is not provided, and the displacement support 2 is provided at the installation position of the fixed support 1 in place of the fixed support 1. To do.

(1) As shown in FIG. 11A, a workpiece W is placed on the processing stage 13. The workpiece W is placed on the vacuum suction portion 2i of the displacement support 2 with the air cylinder 2a lowered, and is held and fixed.
On the processing stage, three stoppers 16 (only two are shown in the figure) are provided on which a workpiece to be processed forms a plane parallel to the moving plane of the processing head.
(2) As shown in FIG. 11 (b), each air cylinder 2a of the displacement support body 2 is provided with a thrust force that cancels the self-weight deflection of the workpiece obtained by the simulation shown in the second embodiment. Supply air with pressure.
The workpiece W rises in a state where each support point is in a gravity balance, contacts the stopper 16 with a slight pushing pressure, and the workpiece W becomes parallel to the moving plane of the machining head 10.
In this state, the air lock mechanism 2f of the displacement support 2 is operated to sandwich the fixed disk 2d with the pad 2e, and the position of the displacement support 2 in the height direction is fixed. The weights of the workpieces W are equally applied to the displacement support members 2.
(3) As shown in FIG. 11C, the stopper 16 is retracted, and the processing head 10 is moved in this state to polish and grind the surface of the workpiece W into a flat surface. The displacement support 2 holds the workpiece W by the vacuum suction part 2i, and the pad 2e sandwiches the fixed disk 2d, so that the height direction is fixed. Therefore, the workpiece does not vibrate during machining.
This completes the planar processing of the workpiece.

When the workpiece processed in this way is used as a work stage of an exposure apparatus, for example, as shown in FIG. 12, the surface of the flat plate 50 is flattened on a base plate 15 on which the work stage of the exposure apparatus is placed. The stage displacement support 6 (see FIG. 10B) is arranged so as to have the same positional relationship as the arrangement of the displacement support 2 when processed. Here, as in the first and second embodiments, a case will be described in which a stage displacement support 6 having an air pad is used as a support and is supported by being levitated by air. In this case, the flat compensation plate 50a is attached to the back side of the flat plate 50 as described above.
In the state where the air cylinder 2a of the displacement type support body 6 is lowered, the flat plate 50 whose surface is processed to be flat is the upper surface, and the support point by the support body 6 is substantially the same position as at the time of processing. It is mounted on the vacuum suction part of the displacement type support 6 so as to hold and is fixed.
Next, the same pressure as when the air cylinder 6a of the displacement support 6 is processed by a processing machine is applied to raise the shaft 6b, push up the flat plate 50, and fix the height direction by the air lock mechanism 6f.
Before placing the flat plate 50, the pressure that obtains the same thrust as that during processing is supplied to the displacement support 6 in advance to raise the air pad, and the flat plate 50 is placed thereon. Also good.
Also in this embodiment, as in the first and second embodiments, it is not necessary to turn the workpiece over and repeat the plane machining many times as in the prior art, and the plane stage is manufactured by one plane machining. This can greatly reduce the number of processing steps. Moreover, it is not necessary to prepare two members, the displacement support body 2 and the fixed support body 1.

It is a figure which shows the structure of the plane processing apparatus of the Example of this invention. It is sectional drawing which shows the structure of a fixed type support body. It is sectional drawing which shows the structure of a displacement type support body. It is a top view which shows the example of arrangement | positioning of the support body in a 1st Example. It is a figure which shows the process sequence of the 1st Example of this invention. It is a figure which shows the support structure in the case of using the workpiece | work processed in the procedure of the 1st Example as a work stage. It is a top view which shows the example of arrangement | positioning of the support body in a 2nd Example. It is a figure which shows the process sequence of the 2nd Example of this invention. It is a figure which shows an example of the simulation result of the gravity concerning each point. It is a figure which shows the support structure in the case of using the workpiece | work processed in the procedure of the 2nd Example as a work stage. It is a figure explaining the procedure which carries out the plane processing of the workpiece | work when all the supports are displacement type supports. It is a figure which shows the support structure in the case of using the workpiece | work processed in the procedure of FIG. 11 as a work stage. It is a figure which shows schematic structure of the plane processing apparatus which supports and processes a workpiece | work with the support body of 3 or more points | pieces. It is a figure which shows the specific structural example of a main fixing member and an auxiliary fixing member. It is a figure explaining the process sequence by the apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed support body 2,2 'displacement type support body 3 Air piping 5 Stage fixed support body 6 Stage displacement support body 10 Processing head 11 Movement mechanism 12 Base plate (processing machine)
13 Processing stage 15 Base plate (work stage)
16 Stopper 50 Flat plate (Work processed flat)
50a Planar compensation plate

Claims (4)

A processing head for polishing and grinding a plate-like workpiece to a flat surface, and a processing stage provided with a support on which a workpiece to be ground and ground to a flat surface is placed and held,
In the planar machining apparatus in which the machining head or the machining stage moves in a plane and the surface of the workpiece held on the machining stage is machined into a plane by the machining head,
The support is
A fixed support that has a vacuum suction part that is mounted on a pedestal mounted on a processing stage via a rotary bearing and holds a workpiece from the back surface, and has a constant height.
A means for moving the shaft up and down with an arbitrary thrust; a holding means for holding the position of the shaft at a set position; and a vacuum suction part which is attached to the tip of the shaft via a rotary bearing and holds the workpiece from the back surface. It consists of a displacement-type support with a variable height,
The total of the fixed type support body and the displacement type support body is four or more, and at least three of them are arranged so as to be at the apex position of the triangle. . The flat processing apparatus according to claim 1, wherein among the supports, the number of fixed supports is three or less. 2. The planar machining apparatus according to claim 1, wherein all of the supports are displacement type supports. A plate-like workpiece is supported by at least three supports arranged so as to be at the apex position of the triangle, and the surface opposite to the surface supported by the support is processed into a planar shape by a processing device,
When using the above workpiece as a flat stage,
The support is arranged so as to have the same arrangement as that of the support when the workpiece is processed, and the processed workpiece is processed into a flat surface on the upper side, and the support. A support method for a planar stage, wherein the support point is placed so that the support point is the same as that during processing.

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