JP3625341B2 - Table device - Google Patents

Description

また、対称軸３２４に直角な方向について次式が得られる。
【０１０３】

さらに、回転中心３０４回りのモーメントの釣合より次式がえられる。
【０１０４】
Ｆ２ ・Ｌ２＝ｆ３ ・Ｌ１ …（６）
ここで、まずｆ３ は式（６） より、
ｆ３＝Ｆ２ ・Ｌ２／Ｌ１ …（７）
で与えられ、また式（５） により、
ｆ１ ＝ｆ２ …（８）
であるから、これらを式（４） に代入して、

となる。
【０１０５】
ここで、φ＞θであり、さらにＬ１ ＞Ｌ２ であるから、式（９） の第２項は正の値となり、また第１項は式（３） で示したものと同じであるため、結局、図１４に示したテーブル装置で得られた接触力の増加分に、さらにバイアス力付与機構３２３の発生力の分を加えることができ、固定状態にある回転ガイド体３０９，３１０の接触力をより一層増加させたり、あるいは押付け力付与機構３１３，３１４の発生力を減少させたりすることが可能となる。
【０１０６】
なお、この例に係るテーブル装置３００ｂでは、式（９） から明らかなように、図１８中に示したφとθとが等しい場合でも、固定状態にある回転ガイド体３０９，３１０のテーブル本体３０２への接触力を効果的に増加させることが可能である。
【０１０７】
図１９には本発明の第６の実施形態に係るテーブル装置３００ｃの平面図が示されている。この図では図１８に示されるテーブル装置３００ｂと同一機能部分が同一符号で示されている。したがって、重複する部分の詳しい説明は省略する。
【０１０８】
この例に係るテーブル装置３００ｃでは、図１７に示されるテーブル装置、つまりテーブル本体３０２の回転中心３０４をテーブル本体３０２の中心からずらした装置に、テーブル本体３０２に回転角を生じさせる変位付与機構３２２，バイアス力付与機構３２３を付加したもとなっている。
【０１０９】
この例の場合も、変位付与機構３２２およびバイアス力付与機構３２３が、図１８に示したテーブル装置と同様な関係に設置されており、図１８に示したテーブル装置と同様に固定状態にある回転ガイド体３０９、３１０のテーブル本体３０２への接触力を増加させることができる。
【０１１０】
【発明の効果】
以上説明したように、本発明によれば、耐久性の向上、高精度な運動のいずれかが得られるテーブル装置を提供できる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係るテーブル装置の側面図
【図２】同装置の要部を取出して示す分解斜視図
【図３】同装置のロッドに生ずる損傷の様子を説明するための斜視図
【図４】同装置の機能を説明するための模式図
【図５】同装置の機能を説明するための模式図
【図６】同装置の変形例を説明するための要部分解斜視図
【図７】同装置の別の変形例を説明するための要部分解斜視図
【図８】同変形例の機能を説明するための模式図
【図９】同変形例の機能を説明するための模式図
【図１０】本発明の第２の実施形態に係るテーブル装置の側面図
【図１１】同装置を運用するためのシステム構成図の一例を示す図
【図１２】同装置に類似した装置の問題点を説明するための図
【図１３】同装置の作用を説明するための図
【図１４】本発明の第３の実施形態に係るテーブル装置の平面図
【図１５】図１４におけるＸ−Ｘ線に沿って矢印方向に見た側面図
【図１６】同装置の作用を説明するための図
【図１７】本発明の第４の実施形態に係るテーブル装置の平面図
【図１８】本発明の第５の実施形態に係るテーブル装置の平面図
【図１９】本発明の第６の実施形態に係るテーブル装置の平面図
【図２０】図１８に示した装置の作用を説明するための図
【図２１】従来のテーブル装置の平面図
【図２２】従来の別のテーブル装置の平面図
【符号の説明】
１００，２００，３００，３００ａ，３００ｂ，３００ｃ…テーブル装置
１０１，２０１，３０１…基台
１０２，２０２…テーブルガイド
１０４，２０４，３０２…テーブル本体
１０５，１０５ａ…移動力伝達体としてのロッド
１０７，１０７ａ，２０７…第１のローラ
１０８，１０８ａ，２０８…第２のローラ
１０９，２０９…回転駆動手段
１１０，１１０ａ…連結角度可変機構
１１５…角度基準指針
１１６…連結角度目盛り
２１１…水平面
３０４…回転中心
３０５〜３０８…転動面
３０９〜３１２…回転ガイド体
３１３，３１４…押付け力付与機構
３２２…変位付与機構
３２３…バイアス力付与機構[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device manufacturing apparatus or inspection apparatus, or a table apparatus used in a microscope or various machine tools that require minute positioning.
[0002]
[Prior art]
In recent years, the degree of integration of semiconductor devices such as LSIs has been increasing, and the pattern line width has become very fine as 1 μm or less. Accordingly, very high accuracy is required for a table device used for manufacturing or testing such a highly integrated semiconductor device.
[0003]
In the table apparatus, importance is attached to straightness, posture change amount, positioning accuracy, etc. during travel of the table body, and various table structures, position detection methods, drive methods, and the like have been developed.
[0004]
As a means for driving the table body, a drive device using a ball screw / nut is generally used. The features of this device are that the rigidity in the feed direction is high and it is easy to reduce vibration during positioning, and that it is relatively easy to improve the dimensional accuracy of the ball screw, so that it is easy to improve the positional accuracy, and in principle a reduction mechanism Therefore, a large load can be driven with a small motor, and at the same time, a high resolution can be obtained relatively easily. For this reason, it has become possible to position the nanometer region by adopting position detection means with very high resolution or by devising a control method.
[0005]
On the other hand, as a problem, it is impossible to completely eliminate the bending of the screw shaft of the ball screw, the ball screw swings every rotation of the screw shaft, and adversely affects the table accuracy. In addition, when high-speed rotation occurs, vibration due to the swinging of the ball occurs, and noise vibration due to collision between the balls, the ball and the return tube or the top occurs during the circulation of the balls.
[0006]
This problem is not so serious in a table apparatus incorporated in an exposure machine such as a stepper that performs step-and-repeat. However, a device that moves the table body at a constant speed and continuously collects data for inspection or a device that collects data for inspection will cause an increase in table speed fluctuation and table vibration during movement, which is a very big problem. .
[0007]
In recent years, therefore, the friction drive system has been increasingly used for table drive in apparatuses that continuously perform exposure or inspection at a constant speed. The friction drive system is a table in which a rod is moved linearly by sandwiching a round or square rod (moving force transmission body) connected to the table body with multiple rollers and rotating one roller with a motor or the like. This is a method of moving the main body linearly.
[0008]
This method is characterized by the fact that no balls are used, so there is no vibration or noise caused by the circulation of the ball, and the amount of displacement of the rod due to roller rotation is greatly reduced by improving roller manufacturing accuracy. In addition, the rotational speed of the roller can be lowered even when the table speed is high, so that even if the roller is eccentric, the speed fluctuation cycle becomes long and it is difficult to cause vibration.
[0009]
Because of these characteristics, the friction drive method is a driving method suitable for table driving that requires very high speed stability.
However, as a problem, since the driving force is obtained by using frictional force, the wear of the roller and the rod is inevitable, and in order to obtain a large driving force, it is necessary to press the roller and the rod with a very large force. For this reason, the contact stress between the roller and the rod is increased, the life of the surfaces of the roller and the rod is likely to be reduced, and slipping may occur.
[0010]
As for wear of the roller and the rod, measures are taken such as improving the hardness of the contact portion or applying traction oil or the like to the contact portion so that the roller and the rod do not directly contact each other. Further, the slip can be dealt with by directly measuring the displacement of the table and correcting the slip of the roller and the rod for positioning.
[0011]
Currently, the biggest challenge is to improve the durability and life of the rollers and rods.
A table apparatus used in the manufacture and inspection of a semiconductor device is often operated overnight in order to improve the productivity. For this reason, the mechanical system of the table is required to have such durability that maintenance is not required except for periodic inspection. In particular, the drive device is not easy to disassemble and replace, and is also expensive in cost, so that it is desired that the drive device can be used for as long as possible.
[0012]
Therefore, the present inventors have previously proposed a method for improving the durability of the friction drive device by reducing the contact stress between the roller and the rod and improving the method of supporting the roller. Thereby, the durability of the roller and the rod itself could be improved.
[0013]
However, as described above, the friction drive cannot avoid wear at the contact portion, and after use for a certain period (for example, two years), it is necessary to replace rollers, rods, and the like. It takes a considerable amount of time and money to replace the rollers and rods. Therefore, it is desired to replace the drive unit at least once every 4 to 5 years.
[0014]
On the other hand, when manufacturing or inspecting a photomask or a wafer used for manufacturing a semiconductor device, the sample is generally mounted on an XY table and the XY table is moved to process or inspect the sample. At this time, it is difficult to mount the sample on the XY table in a fixed posture, and there is a variation in the size of the sample. Therefore, after the sample is mounted on the XY table, it is necessary to slightly rotate the sample by the rotary table device. There is.
[0015]
Such a rotary table device is required to have the following performance.
(1) The posture variation of the sample on the rotary table is slight due to the rotation.
(2) The reproducibility of the rotation angle is good.
[0016]
(3) The mounted sample should not be deformed by the deformation of the rotary table.
(4) The resolution of the rotation angle is sufficiently small.
(5) It is less likely to deteriorate the environment such as dust generation.
[0017]
In order to satisfy such performance, a rotary table device considering the following matters is necessary.
(1) The accuracy of the guide surface of the rotary table is very high.
[0018]
(2) The friction on the guide surface of the rotary table is very small.
(3) The force acting on the guide surface of the rotary table is small.
(4) Displacement resolution and friction of the driving means of the rotary table are small.
[0019]
(5) Slip etc. should be minimized as much as possible on the guide surface of the rotary table.
Accordingly, in order to satisfy the above matters, a rotary table device as shown in FIGS. 21 and 22 may be used.
[0020]
In the turntable device shown in FIG. 21, a turntable 2 is mounted on a base 1 serving as a base. Here, the base 2 is generally an upper table of an XY table.
[0021]
The turntable 2 rotates by receiving a force from a non-contact electromagnetic drive mechanism (not shown) using the upper surface of the base 1 as a guide surface. In order to make this rotation center 3 constant, rolling surfaces 4, 5, 6, and 7 centering on the rotation center 3 are formed in the vicinity of the four corners of the rotary table 2, and the guide body and the rolling surfaces are formed on these rolling surfaces. The rollers 8, 9, 10, and 11 are in contact. Here, spring mechanisms 12 and 13 for applying a pressing force for securing a constant contact force are connected to the rollers 10 and 11, and the shafts of the remaining rollers 8 and 9 are fixed to the base 1. .
[0022]
When the turntable 2 rotates, air is blown to the base 1 to float, thereby reducing friction against rotation as much as possible. Further, after rotation, the rotary table 2 is fixed with a vacuum chuck or the like to reduce deformation and displacement of the rotary table 2.
[0023]
In such a rotary table device, the rotation guide is performed by the four rollers 8, 9, 10, and 11. Therefore, even a large rotary table can be rotated by a simple mechanism, and the rotation is guided by the rollers. There are features such as low resistance and the ability to rotate a relatively large rotation stroke with high accuracy.
[0024]
However, in such a rotary table device, the force generated by the pressing force applying means, that is, the spring mechanisms 12 and 13 is important. The rotation center 3 of the rotary table device is mainly defined by rollers 8 and 9 having fixed shafts. If the contact force between these rollers and the rotary table 2 is not large, the rotary table device floats after rotation. When it is stopped, the contact is cut off and the center of rotation is shifted, or the reproducibility of the rotation angle is deteriorated.
[0025]
However, if the generated force of the spring mechanisms 12 and 13 is increased in order to increase the contact force, the rotating table 2 is slightly deformed due to the generated force, or the rotation resistance of the rollers 10 and 11 is increased to reproduce the rotation angle. However, even after the turntable 2 is fixed, the generated force may cause the turntable 2 to be displaced by some kind of trigger, which may adversely affect the performance of the turntable device.
[0026]
In the rotary table device shown in FIG. 22, a displacement imparting mechanism 14 that selectively applies a rotational force to the rotary table 2 is installed on the side opposite to the rollers 8 and 9 to which the shaft is fixed. A bias force application mechanism 15 such as a tension spring is provided to ensure contact between the displacement application mechanism 14 and the rotary table 2.
[0027]
However, in such a configuration, the contact force at one of the rollers 8 to which the shaft is fixed is lowered due to the influence of the generated force of the bias force applying mechanism 15, and the performance is the same as described above. Deterioration may occur.
[0028]
[Problems to be solved by the invention]
As described above, one end of the moving force transmitting body is connected to a table body that is linearly movable, this moving force transmitting body is held by a roller, and the moving force transmitting body is moved by rotating the roller. In the table device in which the table main body is moved linearly by this, there is an advantage that it is easy to improve the moving speed stability of the table main body, but the durability of the roller and the moving force transmitting body is not sufficient, For example, when applied to a semiconductor device manufacturing / inspection apparatus that requires high-frequency operation over a long period of time, there has been a problem that the maintenance cost of the apparatus becomes high.
[0029]
Further, in the table apparatus having a structure in which the table body is rotated by guiding the vicinity of the four corners of the table body, the large table body can be rotated by a simple mechanism, and the table is guided by the roller. Therefore, it has advantages such as low rotation resistance and the ability to rotate a large rotation stroke with a certain degree of accuracy, but on the other hand, pressing force is required to achieve extremely high rotation accuracy and rotation angle reproducibility. When the pressing force of the application side roller is increased, there are problems such as deformation of the table body, increased rotational resistance, and displacement even after the table body is fixed.
[0031]
The present invention has been made in view of the above-described circumstances, and an object thereof is to sufficiently increase the contact force between the fixed roller and the table body without increasing the pressing force of the pressing force application side roller. Therefore, it is possible to provide a table device capable of highly accurate rotational movement.
[0036]
[Means for Solving the Problems]
According to this invention,
A table body provided rotatably,
Four rotating guide bodies that contact the peripheral surface of the table body and guide the table body rotatably;
A fixing means for fixing the positions of two rotation guide bodies adjacent in the circumferential direction of the rotation guide bodies;
In a table device comprising pressing force application means for applying a pressing force in the direction of the table body to the remaining two rotation guide bodies adjacent in the circumferential direction,
The angle between two lines connecting the two contact points where the two rotation guide bodies fixed by the fixing means contact the peripheral surface of the table body and the rotation center of the table body is the pressing force application. The two rotation guide bodies that receive the pressing force by the means are set to be larger than an angle between two lines connecting two contact points that contact the peripheral surface of the table body and the rotation center of the table body. A table device is provided.
[0037]
Moreover, according to this invention,
A table body provided rotatably,
Four rotating guide bodies that contact the peripheral surface of the table body and guide the table body rotatably;
A fixing means for fixing the positions of two rotation guide bodies adjacent in the circumferential direction of the rotation guide bodies;
A pressing force applying means for applying a pressing force in the direction of the table body to the remaining two rotation guide bodies adjacent in the circumferential direction;
A displacement applying means for applying a displacement in a circumferential direction around the rotation center of the table body to the table body;
In the table apparatus comprising the bias applying means for applying a contact force between the displacement applying means and the table body,
The bias force applying means is installed closer to the table body than the displacement applying means, and is fixed by the fixing means from the two rotation guide bodies that receive the pressing force by the pressing force applying means. There is provided a table device characterized by generating a force in the direction of two rotating guide bodies.
[0042]
In the table apparatus of the present invention, the angle between the two lines connecting the two contact points where the two rotation guide bodies fixed by the fixing means contact the peripheral surface of the table main body and the rotation center of the table main body is the pressing force. Since the two rotation guide bodies that receive the pressing force by the force applying means are set larger than the angle between the two lines connecting the two contact points that contact the peripheral surface of the table body and the rotation center of the table body. The two rotation guides receiving the pressing force are amplified by the wedge effect and the contact force between the two rotation guide bodies fixed by the fixing means and the table body is the pressing force from the two rotation guide bodies receiving the pressing force. The pressing force of the body against the table body can be made larger.
[0043]
In the table apparatus of the present invention, the direction of the force generated by the biasing force applying means for maintaining the contact force between the displacement applying means for causing rotational displacement in the table main body and the table main body is the force generated by the pressing force applying means. Since the direction is the same, the contact force between the two fixed rotation guide bodies and the table body is a combination of the pressing force generated by the pressing force applying means and the force generated by the bias force applying means. . Therefore, the contact force between the two fixed rotation guide bodies and the table body can be increased without increasing the pressing force of the pressing force applying means.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the invention will be described with reference to the drawings.
FIG. 1 is a side view of a table device 100 according to the first embodiment of the present invention.
[0045]
The table apparatus 100 is roughly divided into a base 101 as a base, a table guide 102 fixed on the base 101 with the guide surface horizontal, and a solid line arrow guided by the guide surface of the table guide 102. A table main body 104 that is movably arranged in a direction indicated by 103, and a columnar shape as a moving force transmission body that is connected to the table main body 104 at one end and transmits a moving force in the direction indicated by a solid arrow 103 to the table main body 104. A rod 105, a housing 106 fixed to the base 101 along the rod 105, and a housing 106 that is rotatably supported by a bearing or the like and that holds the rod 105 with a certain force with each other. The first roller 107, the second roller 108, and the first roller 107 are selectively rotated. A rotation driving means 109 composed of an electric motor or the like, a connection angle variable mechanism 110 provided between the table main body 104 and the rod 105, which changes the connection angle about the central axis of the rod 105 with respect to the table main body 104, and the connection The connecting portion 111 is provided between the angle variable mechanism 110 and the table main body 104 and has a pivot shape that absorbs the relative displacement between the rod 105 and the table main body 104.
[0046]
As shown in FIG. 2, the coupling angle variable mechanism 110 has a hole portion 112 that is substantially equal to the diameter of the rod 105 at the center and a part of the peripheral edge is cut out. The clamp mechanism 114 mainly connects the one end side of the rod 105 to the table body 104, specifically, the connecting portion 111 by inserting one end side of the rod 105 and tightening with the screw 113. An angle reference indicator 115 is engraved on the peripheral portion of the hole 112 on the end surface of the clamp mechanism 114 on the side where the rod 105 is inserted. Further, a connecting angle scale 116 is engraved at a position indicated by the angle reference pointer 115 when the rod 105 is inserted into the hole portion 112 and clamped on the circumferential surface of the one end side of the rod 105.
[0047]
In the table apparatus 100 configured as described above, when the first roller 107 is rotated by the rotation driving means 109, the rod 105 is moved to the solid arrow 103 by the action of the frictional force at the contact portion between the rod 105 and the first roller 107. Displaces in the direction indicated by. The rod 105 is connected to the table main body 104 via a connecting angle variable mechanism 110 and a connecting portion 111. Accordingly, the table main body 104 is displaced in the direction indicated by the solid line arrow 103 by the same amount as the displacement of the rod 105.
[0048]
By the way, in the table apparatus 100 adopting such a friction drive system, since wear at the contact portion between the rod 105 and the first roller 107 and the second roller 108 cannot be avoided, As shown in FIG. 3, traces 120, 121, 122 of damage due to wear are generated in the portion of the rod 105 that contacts the first roller 107. As shown in FIG. 4, the rod 105 is in contact with the first roller 107 and the second roller 108 at the contact portions 123 and 124, but the second roller 108 does not generate a driving force. Therefore, damage mainly occurs in the contact portion 123 with the first roller 107. In particular, at the portion corresponding to the turning point of the reciprocating motion, the driving force due to acceleration / deceleration is large, so that wear increases. In such a state, the wear powder rapidly wears and deteriorates the table performance such as speed fluctuation, so the rod 105 needs to be replaced.
[0049]
However, in this example, since the coupling angle variable mechanism 110 is provided, the coupling angle of the rod 105 can be changed, and the same state as when the rod 105 is replaced can be obtained by this change. Specifically, the pressure contact force between the first roller 107 and the rod 105 is reduced, and in this state, the screw 113 of the clamp mechanism 114 is loosened, and the angle reference pointer 115 and the connection angle scale 116 are viewed as shown in FIG. Thus, after rotating the rod 105 around the central axis of the rod by a certain angle 125, the screw 113 is fastened and fixed again, and then the pressure contact force between the first roller 107 and the rod 105 is returned to the original value. .
[0050]
By doing so, the contact position 126 that contacts the first roller 107 on the surface of the rod 105 and the contact position 127 that contacts the second roller 108 on the surface of the rod 105 are changed to the surface positions where there has been no contact so far. Thus, the same effect as when the rod 105 is replaced can be obtained. Therefore, by appropriately selecting the constant angle 125, the number of times of exchanging the rod 105 can be reduced by the amount of change of the connecting angle of the rod 105, and as a result, the life of the drive system in the table device can be greatly improved. Can do. Further, if the angle reference pointer 115 and the connection angle scale 116 are provided in the connection angle variable mechanism 110 as in this example, the connection angle changing operation and the connection angle management are facilitated.
[0051]
At the same time, the life of the first roller 107 which is a driving roller can be extended as follows.
That is, when the material of the rod 105 and the first roller 107 is the same and the surface hardness is substantially the same, the possibility of damage at the contact portion is substantially the same for both the rod 105 and the first roller 107. However, when the table main body 104 is reciprocated at a constant stroke, a driving force (frictional force) for acceleration / deceleration is always applied to the rod 105 at the same position, but in the case of the first roller 107, it is slippery. Since the position where the driving force works always changes, the damage is less likely to occur at a specific place than the rod 105. Basically, the first roller 107 is longer in life than the rod 105. However, even if the life of the rod 105 can be greatly extended by providing the variable coupling angle mechanism 110, the effect of extending the life of the drive system is reduced unless the life of the first roller 107 is extended.
[0052]
As a means for extending the life of the first roller 107, the first roller 107 and the rod 105 are manufactured by a combination of materials in which the surface hardness of the rolling surface of the first roller 107 is larger than the surface hardness of the rod 105. It is preferable.
[0053]
In general, the higher the hardness, the higher the wear resistance, and when a material with a different hardness comes into contact, the lower the hardness, the easier it is to wear. Therefore, the life can be further extended by selecting the material so that the hardness of the rolling surface of the first roller 107 is higher than the surface hardness of the rod 105.
[0054]
Specific examples of the material for forming the roller include cemented carbide (tungsten carbide) and ceramics (alumina, silicon nitride, etc.). Examples of the material for forming the rod include tool steel and stainless steel (such as those that can be quenched such as martensite).
[0055]
In the example illustrated in FIG. 1, the coupling angle variable mechanism 110 is configured by the clamp mechanism 114, but a coupling angle variable mechanism 110 a configured as illustrated in FIG. 6 may be used. This variable connecting angle mechanism 110a includes a hole 130 for fitting one end of the rod 105 into the element 129 on the connecting portion 111 side, an annular groove 131 on one end side peripheral surface of the rod 105, and the rod 129 on the element 129 side. A set screw 132 is provided so that when one end side of 105 is inserted into the hole 130, the tip portion can be fitted into the annular groove 131. Similarly to the previous example, the angle reference pointer 115 is engraved on the peripheral surface of the hole 130 on the end surface of the element 129, and the rod 105 is inserted into the hole 130 on the peripheral surface on one end side of the rod 105. Then, a connecting angle scale 116 is engraved at a position pointed by the angle reference pointer 115 when fixed with the screw 132.
[0056]
Moreover, in the example shown in FIGS. 1 and 6, a cylindrical rod is used as the moving force transmission body, but as shown in FIG. 7, a rod 105a having a square cross-sectional shape can also be used. In this example, since the clamp mechanism 114 similar to that shown in FIG. 1 is used as the coupling angle variable mechanism 110, a circle coaxial with the central axis of the rod 105a is formed on one end side of the rod 105a in order to adapt to this. A columnar connection portion 133 is formed.
[0057]
Since such a rod 105a is used, in this example, as shown in FIG. 8, the first roller 107a and the second roller 108a having a cylindrical rolling surface are used. Yes. The first roller 107a and the second roller 108a are in line contact with the rod 105a at the contact surfaces 134 and 135.
[0058]
Also in this example, when damage appears on the rolling surface of the rod 105a, the screw 113 of the clamp mechanism 114 is loosened, the rod 105a is once removed, and then, as shown in FIG. Rotate around 90 ° and reassemble, and tighten the screw 113.
[0059]
In this case, the connecting angle of the rod 105a can be changed only once. However, since the contact portion between the first roller 107a and the rod 105a is a line contact, the contact surface pressure is low, and in the case of the table apparatus shown in FIG. Compared with, the durability of the rolling surface itself is high, and there is not much influence due to the small number of changes in the coupling angle.
[0060]
FIG. 10 is a side view of a table device 200 according to the second embodiment of the present invention.
The table device 200 is substantially the same as the table device shown in FIG. 1, and is roughly divided into a base 201 as a base, a table guide 202 fixed on the base 201, and a guide for the table guide 202. A table body 204 that is guided by the surface and arranged to be movable in the direction indicated by the solid line arrow 203, and a moving force that is connected to the table body 204 at one end side and transmits the movement force in the direction indicated by the solid line arrow 203 to the table body 204. A cylindrical rod 205 as a transmission body, a housing 206 fixed to the base 201 along the rod 205, and supported by the housing 206 by a bearing or the like so as to be rotatable. The first roller 207 and the second roller 208 which are arranged in a holding relationship with force, and the first roller 2 7 is provided between the rod 205 and the table main body 204, and a pivot-like portion that absorbs the relative displacement between the rod 205 and the table main body 204. And the connecting mechanism 210.
[0061]
The table device 200 is installed such that the base 201 has an inclination θ with respect to the horizontal plane 211. This inclination θ is the inclination when the table main body 204 is stopped at the stroke center position or the average inclination of the base 201 during the reciprocating motion. In the example shown in FIG. 10, the base 201 is inclined so as to be lowered to the right. However, even if this is lowered to the left, the effect described below is not affected.
[0062]
When installing the table apparatus 200 as shown in FIG. 10, it is common to install so that the base 201 becomes substantially horizontal. However, in the example shown in FIG. 10, the base 201 is installed so that the moving direction of the table main body 204 has an inclination of θ with respect to the horizontal plane 211.
[0063]
12 and 13 are directed to a table device of a device such as a drawing / inspection device used in the semiconductor manufacturing field that reciprocates a fixed stroke many times with a trapezoidal speed pattern. 2 conceptually shows the relationship between the thrust required to drive the first roller 207 and the sliding angle of the first roller 207 with respect to the rod 205. Here, FIG. 12 shows a case where θ is zero degrees, and FIG. 13 shows a case where the inclination θ is in the downward direction as shown in FIG. Note that the slip angle graphs shown in FIGS. 12 and 13 conceptually show the qualitative slip amount and are slightly different from the actual slip amount, but this difference has no influence on the effect of this example. Not give.
[0064]
As shown in FIG. 12, when the moving direction of the table main body 204 is substantially horizontal, the acceleration sections C and F, the deceleration sections E and H, and the constant speed sections D and G are performed when the table main body 204 moves forward and backward B. Therefore, the slip angle in each section is almost the same between forward A and reverse B, and the cumulative slip angle is almost zero. Therefore, the position of the contact portion between the first roller 207 and the rod 205 when returning to the movement start point does not change, and the contact portion during acceleration / deceleration of the first roller 207 does not change even if the reciprocating motion is performed many times. Almost no change.
[0065]
As can be seen from FIG. 12, slip occurs particularly rapidly at the beginning of acceleration, and a large slip speed is generated. Since the wear of the contact surface is determined by the PV value that is the product of the contact force P and the sliding speed V, the portion of the rolling surface of the first roller 207 that becomes the contact portion during acceleration / deceleration is heavily worn, and the other portions Damage will appear sooner than. This is the same even when lubricating oil is applied to the contact portion, and the oil film becomes thinner only partly due to repeated acceleration and deceleration.
[0066]
However, as shown in FIG. 10, when the base 201 is tilted and the moving direction 203 of the table body 204 is tilted by a certain angle θ with respect to the horizontal plane 211, the torque of the rotation driving means 209 is reduced. FIG. 13 shows the relationship between the thrust required to drive the first roller 207 and the sliding angle of the first roller 207 with respect to the rod 205.
[0067]
In this case, if the mass of the table main body 204 is M, the moving direction 203 of the table main body 204 is inclined by θ with respect to the horizontal surface 211. Therefore, the gravity force component Mgsin θ of the table 204 is applied to the table main body 204. It always works in the right direction in FIG. Therefore, the thrust required for return B is larger than that of forward A due to the action of this component force. As a result, the slip amount of the first roller 207 with respect to the rod 205 is larger in the return time B than in the forward time A, and when it finally returns to the movement start point, the contact portion is the amount indicated by φ in FIG. Will shift. That is, the position of the contact portion of the first roller 207 is shifted by φ for each reciprocation.
[0068]
Therefore, by tilting the moving direction 203 of the table main body 204 with respect to the horizontal plane 211 by a certain angle θ, it is possible to prevent only a specific portion of the first roller 207 from becoming a contact portion during acceleration / deceleration. It is possible to avoid a situation in which a part of the wear of the first roller 207 progresses and the life of the first roller 207 is shortened.
[0069]
FIG. 11 is a schematic configuration diagram of a table system having a function capable of tilting the moving direction 203 of the table main body 204 with respect to the horizontal plane 211 by a certain angle θ.
[0070]
In this table system, a base 201 as a surface plate is installed on a foundation 215 via a gantry 216 and vibration isolation means 217. The posture change of the base 201 is corrected by the leveling means 218.
[0071]
The position control of the table main body 204 is performed by the length measuring unit processing unit 221 processing position information measured by the reflector 219 installed on the table main body 204 and the length measuring device 220 such as an interferometer installed on the base 201. The table current position information is sent to the table drive control unit 222, and the position of the table body 204 is feedback-controlled. By doing so, even if a slip occurs between the first roller 207 and the rod 205, the table body 204 can be accurately positioned by correcting the slip amount.
[0072]
There are the following three methods for giving the base 201 an inclination with respect to the horizontal plane.
The first method is a method of adjusting the distance between the base 201 and the vibration isolation means 217. Although this method is simple, there is a problem that it is difficult to adjust the tilt angle θ.
[0073]
The second method is a method of tilting the pedestal 216, but it is also difficult to adjust the delicate tilt angle θ as in the first method.
The third method is a method of adjusting the inclination of the base 201 using the leveling means 218 attached to the vibration isolation means 217. The leveling means 218 is a mechanism that corrects the posture change of the base 201 caused by the movement of the center of gravity when the table main body 204 moves, but the base 201 has a certain inclination in a steady state using the leveling means 219. By setting as described above, the inclination angle θ of the base 201 can be easily set. In addition, this makes it possible to easily perform fine angle adjustment and change of the tilt angle.
[0074]
Next, a method for determining the tilt angle θ of the base 201 will be described.
The appropriate inclination angle θ varies depending on the weight of the table main body 204 and the friction coefficient between the first roller 207 and the rod 205, so the relationship between the inclination setting value of the base 201 and the slip amount is basically determined through experiments or the like. Determine by measuring. The amount of slip between the first roller 207 and the rod 205 is measured by connecting a rotation angle detecting means (not shown) such as a rotary encoder to the rotation shaft of the first roller 207 and performing reciprocating motion. Obtained from the difference in angle at the starting point. Since the position of the table body 204, that is, the position of the rod 205 is precisely measured by the external measuring means 219 and 220, if the change in the detected angle of the rotation angle detecting means at the reference position such as the operation start point is measured, the slip The amount can be measured.
[0075]
However, if the inclination angle θ is too large, the PV value at the slip generation portion during acceleration / deceleration of the table main body 204 may increase, or the table main body 204 may start to slide during non-control. Therefore, it is desirable that the gravitational force applied to the table body 204 is not larger than the static friction force, that is, not more than the friction angle, even if it is large.
[0076]
1 and 10, each of the table devices has a base as a fixed portion. However, in the configuration in which the base is further a moving table, the guide table is also connected to the base. However, the effects described so far will not change.
[0077]
FIG. 14 shows a plan view of a table device 300 according to the third embodiment of the present invention, and FIG. 15 shows a side view seen in the direction of the arrow along the line XX in FIG. ing.
[0078]
In the table apparatus 300 according to this example, a table main body 302 is rotatably mounted on a base 301 serving as a base. Here, the base 301 is generally an upper table of an XY table, but is not limited to the shape of the base 301 and the presence or absence of motion.
[0079]
As shown in FIG. 15, the table main body 302 rotates using the upper surface 303 of the base 301 as a guide surface. As this guide surface, a static pressure air bearing or a sliding bearing having a small friction coefficient that does not restrain the displacement in the horizontal direction is used.
[0080]
In order to make the rotation center 304 of the table main body 302 constant, arc-shaped rolling surfaces 305 to 308 centering on the rotation center 304 are formed near the four corners of the table main body 302. The rolling surfaces 305 to 308 are cylindrical surfaces or conical surfaces having a slight inclination.
[0081]
Rotating guide bodies 309 to 312 formed of rollers or the like are in contact with the respective rolling surfaces 305 to 308. Two rotation guide bodies 309 and 310 adjacent in the circumferential direction are rotatably supported by a shaft fixed to the base 301. The remaining two rotation guide bodies 311 and 312 adjacent in the circumferential direction are formed by a shaft provided at the tip of the pressing force applying mechanisms 313 and 314 formed by a spring mechanism or the like for applying a constant pressing force. It is supported rotatably. The pressing force applying mechanisms 313 and 314 generate a pressing force in the direction toward the rotation center 304 with respect to the table main body 302. As the pressing force applying mechanisms 313 and 314, a mechanism using air pressure such as an air cylinder can be used in addition to the spring mechanism.
[0082]
When the table main body 302 is rotated, air is blown to the base 301 to lift the table main body 302 so that friction against rotation is minimized. Then, after rotation, the table body 302 is fixed with a vacuum chuck or the like to reduce deformation and displacement of the table main body 302 during processing or inspection of the sample.
[0083]
In such a table apparatus 300, since rotation guides 309 to 312 such as rollers are used as guides for rotation, the apparatus can be configured with a simple mechanism even when the table main body 302 is large. Since the rotation of the table main body 302 is guided by the bodies 309 to 312, there are advantages such as low rotational resistance and that it is possible to rotate a large rotation stroke with high accuracy. Further, the rotational movement guide of the table body 302 is performed by the four rotation guide bodies 309 to 312, and two of these are movable, and the table body 302 is pressed against the two rotation guide bodies 309 and 310 in a fixed state. Therefore, compared with a table device or the like which is composed of three conventional rotating guide bodies, and one of the rotating guide bodies is movable, the pressing force required for the rotating guide body in a movable state is small. There is also an advantage that distortion or deformation generated in the table main body 302 can be reduced.
[0084]
The table apparatus 300 according to this example is characterized by the installation positions of the rotation guide bodies 309 to 312. That is, in the table apparatus 300 according to this example, the angle φ between two lines connecting the centers of the adjacent rotation guide bodies 309 and 310 in the fixed state and the rotation center 304 of the table body 302 is in a movable state. The rotation guide bodies 309 to 312 are installed so as to be larger than an angle θ between two lines connecting the centers of certain adjacent rotation guide bodies 311 and 312 and the rotation center 304 of the table main body 302.
[0085]
Hereinafter, this operation will be described in detail.
FIG. 16 is a schematic diagram for explaining various forces acting on the table main body 302 of the table apparatus 300 shown in FIG.
[0086]
First, the force generated at the contact portion between the rotation guide bodies 309 and 310 in the fixed state and the rotation guide bodies 311 and 312 in the movable state and the table main body 302 will be described.
[0087]
The rotating guide bodies 311 and 312 in the movable state are pressed against the rolling surfaces 307 and 308 of the table main body 302 by the force F by the pressing force applying mechanisms 313 and 314, respectively. At this time, since the rolling surfaces 307 and 308 are circular arcs centered on the rotation center 304 of the table body 302, the direction of the force F generated at the contact point between the rotation guide bodies 311 and 312 and the table body 302 is the same. The force is directed toward the rotation center 304 of the table main body 302. At this time, a contact force having a magnitude of f1 is generated at the contact portion between the rotation guide bodies 309 and 310 and the table main body 302 in a fixed state, and the rolling surfaces 305 and 306 cause the force f1 to be generated on the table main body 302. Since the arc is centered on the rotation center 304, the force is directed toward the rotation center 304.
[0088]
Here, in order to consider the balance of forces in each direction, when a bisector 315 of the angle φ is introduced, the force balance equation in this direction becomes the following equation.
2Fcos (θ / 2) = 2f1 cos (φ / 2) (1)
From this formula (1), the contact force fl is expressed by the following formula.
[0089]
f1 = Fcos (θ / 2) / cos (φ / 2) (2)
Here, since φ> θ,
fl> F (3)
As f becomes larger, f1 becomes larger. Alternatively, F required to obtain a constant f1 is reduced.
[0090]
In this example, the forces generated by the pressing force applying mechanisms 313 and 314 are both the same F. However, even when the forces generated by the two pressing force applying mechanisms 313 and 314 are different, the description will be given first. The same effect as that obtained can be obtained, and the contact force of the rotation guide bodies 309 and 310 in the fixed state to the table main body 302 can be effectively increased.
[0091]
FIG. 17 shows a plan view of a table device 300a according to the fourth embodiment of the present invention. In this figure, the same functional parts as those of the table device 300 shown in FIG. 14 are denoted by the same reference numerals. Therefore, detailed description of overlapping parts is omitted.
[0092]
In the table apparatus 300 a according to this example, the rotation center 304 of the table body 302 is at a position shifted from the center of the table body 302. Therefore, the radius about the rotation center 304 of the rolling surfaces 305 and 306 of the table main body 302 in contact with the rotation guide bodies 309 and 310 in the fixed state is the rolling surface 307 in contact with the rotation guide bodies 311 and 312 in the movable state. , 308 is different from the radius of the rotation center 304.
[0093]
By doing so, it is possible to easily configure a table device in which the rotation center 304 is shifted from the center of the table body 302 with the same configuration as the table device 300 shown in FIG. This can contribute to facilitating the positioning of the sample using the positioning marks.
[0094]
Also in this table apparatus 300a, the angle φ between two lines connecting the centers of the rotation guide bodies 309 and 310 in the fixed state and the rotation center 304 is the center and the rotation center of the rotation guide bodies 311 and 312 in the movable state. The rotation guide bodies 309 to 312 are arranged so as to be larger than the angle θ between the two lines connecting 304.
[0095]
Therefore, even in the table apparatus 300a according to this example. Just like the table apparatus 300 shown in FIG. 14, the formulas (1) to (3) can be applied, and the contact force of the rotation guides 309 and 310 in the fixed state with respect to the table body 302 can be effectively increased. it can.
[0096]
In the table apparatus 300a according to this example, the same effect can be obtained even when there is a difference in the generated force of the pressing force applying mechanisms 313 and 314.
FIG. 18 is a plan view of a table device 300b according to the fifth embodiment of the present invention. In this figure, the same functional parts as those of the table device 300 shown in FIG. 14 are denoted by the same reference numerals. Therefore, detailed description of overlapping parts is omitted.
[0097]
In the table apparatus 300b according to this example, a displacement applying mechanism 322 for generating a rotation angle in the table main body 302 is added to the table apparatus 300 shown in FIG.
[0098]
That is. In the table apparatus 300b, a driven member 321 is fixed to the table main body 302, and a displacement applying mechanism 322 that generates a linear displacement is connected to the driven member 321. As this displacement imparting mechanism 322, a mechanism that generates linear displacement, such as a mechanism using a feed screw and a motor, a mechanism using a voice coil motor, or the like is used. In general, in this type of table apparatus, the displacement applying mechanism 322 and the driven member 321 are not fixed, and the displacement applying mechanism 322 and the driven member 321 are separately provided by a bias force applying mechanism 323 such as a tension spring. Are always in contact with each other.
[0099]
The table apparatus 300b according to this example is characterized in the installation locations of the bias force applying mechanism 323 and the displacement applying mechanism 322.
In other words, the displacement imparting mechanism 322 is in a movable state with the straight line 325 passing through the rotation center 304 perpendicular to the symmetry axis 324 of the table main body 302, that is, the line connecting the rotation guide bodies 309 and 310 in a fixed state. , 312 is parallel to the line connecting the rotation guides 304, contacts the driven member 321 in the vicinity of the straight line 325 passing through the rotation center 304, and connects the rotation guide bodies 311, 312 parallel to the symmetry axis 324 and movable. It is installed to generate displacement in the direction of the elliptical line. On the other hand, the bias force applying mechanism 323 is installed at a position closer to the rotation center 304 than the displacement applying mechanism 322, and is a line connecting the rotation guide bodies 309 and 310 that are parallel to the symmetry axis 324 and fixed by a tension spring or the like. It is installed so that the bias force acts in the direction.
[0100]
With such a configuration, the following force can be applied to the table body 302.
FIG. 20 is a schematic diagram for explaining the force acting on the table main body 302 of the table apparatus 300b shown in FIG. In this figure, the pressing force of the rotating guide bodies 311 and 312 in the movable state is both F1, and the magnitude of the force generated by the bias force applying mechanism 323 is F2.
[0101]
The magnitude of the contact force generated at the contact point between the rotation guide body 309 and the table main body 302 in the fixed state is f1, and the contact generated at the contact point between the rotation guide body 310 and the table main body 302 in the fixed state. The magnitude of the force is f2, the contact force at the contact portion of the displacement applying mechanism 322 is f3, the distance from the force application point of the displacement applying mechanism 322 to the rotation center 304 is L1, and the force action of the bias force applying mechanism 323 is The distance from the point to the center of rotation 304 is L2, and the balance of force in each direction and the balance equation of moment are established.
[0102]
First, the following equation is obtained from the balance of forces in the direction of the symmetry axis 324.

Further, the following equation is obtained in the direction perpendicular to the symmetry axis 324.
[0103]

Further, the following equation is obtained from the balance of moments about the rotation center 304.
[0104]
F2 · L2 = f3 · L1 (6)
Here, f3 is first calculated from equation (6):
f3 = F2 · L2 / L1 (7)
And by equation (5)
f1 = f2 (8)
Therefore, substituting these into equation (4),

It becomes.
[0105]
Here, since φ> θ and L1> L2, since the second term of the formula (9) is a positive value and the first term is the same as that shown in the formula (3), Eventually, the increase in contact force obtained by the table device shown in FIG. 14 can be further increased by the amount of force generated by the bias force applying mechanism 323, and the contact force of the rotation guide bodies 309 and 310 in the fixed state. Can be further increased, or the generated force of the pressing force applying mechanisms 313 and 314 can be reduced.
[0106]
In the table apparatus 300b according to this example, as is clear from the equation (9), even when φ and θ shown in FIG. 18 are equal, the table main bodies 302 of the rotation guide bodies 309 and 310 in the fixed state are used. It is possible to effectively increase the contact force to.
[0107]
FIG. 19 is a plan view of a table device 300c according to the sixth embodiment of the present invention. In this figure, the same functional parts as those of the table device 300b shown in FIG. 18 are denoted by the same reference numerals. Therefore, detailed description of overlapping parts is omitted.
[0108]
In the table apparatus 300c according to this example, a displacement applying mechanism 322 that generates a rotation angle in the table main body 302 in the table apparatus shown in FIG. 17, that is, an apparatus in which the rotation center 304 of the table main body 302 is shifted from the center of the table main body 302. , A bias force applying mechanism 323 is added.
[0109]
Also in this example, the displacement applying mechanism 322 and the bias force applying mechanism 323 are installed in the same relationship as the table device shown in FIG. 18, and the rotation in a fixed state is the same as the table device shown in FIG. The contact force of the guide bodies 309 and 310 to the table main body 302 can be increased.
[0110]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a table device that can achieve either improved durability or high-precision movement.
[Brief description of the drawings]
FIG. 1 is a side view of a table device according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a main part of the apparatus taken out.
FIG. 3 is a perspective view for explaining a state of damage occurring in the rod of the apparatus.
FIG. 4 is a schematic diagram for explaining the function of the apparatus.
FIG. 5 is a schematic diagram for explaining the function of the apparatus;
FIG. 6 is an exploded perspective view of an essential part for explaining a modification of the apparatus.
FIG. 7 is an exploded perspective view of a main part for explaining another modification of the apparatus.
FIG. 8 is a schematic diagram for explaining the function of the modification.
FIG. 9 is a schematic diagram for explaining the function of the modification.
FIG. 10 is a side view of a table device according to a second embodiment of the present invention.
FIG. 11 is a diagram showing an example of a system configuration diagram for operating the apparatus
FIG. 12 is a diagram for explaining problems of a device similar to the device
FIG. 13 is a diagram for explaining the operation of the apparatus;
FIG. 14 is a plan view of a table device according to a third embodiment of the present invention.
15 is a side view seen in the direction of the arrow along the line XX in FIG.
FIG. 16 is a diagram for explaining the operation of the apparatus;
FIG. 17 is a plan view of a table device according to a fourth embodiment of the present invention.
FIG. 18 is a plan view of a table device according to a fifth embodiment of the present invention.
FIG. 19 is a plan view of a table device according to a sixth embodiment of the present invention.
20 is a diagram for explaining the operation of the apparatus shown in FIG. 18;
FIG. 21 is a plan view of a conventional table device.
FIG. 22 is a plan view of another conventional table apparatus.
[Explanation of symbols]
100, 200, 300, 300a, 300b, 300c ... Table device
101, 201, 301 ... base
102, 202 ... Table guide
104, 204, 302 ... table body
105, 105a ... Rod as a moving force transmission body
107, 107a, 207 ... first roller
108, 108a, 208 ... second roller
109, 209 ... Rotation drive means
110, 110a ... Connection angle variable mechanism
115: Angle reference pointer
116 ... Connection angle scale
211 ... Horizontal plane
304 ... Center of rotation
305-308 ... Rolling surface
309-312 ... Rotating guide body
313,314 ... Pressing force application mechanism
322 ... Displacement applying mechanism
323 ... Bias force applying mechanism

Claims (2)

A table body provided rotatably,
Four rotating guide bodies that contact the peripheral surface of the table body and guide the table body rotatably;
A fixing means for fixing the positions of two rotation guide bodies adjacent in the circumferential direction of the rotation guide bodies;
In a table device comprising pressing force application means for applying a pressing force in the direction of the table body to the remaining two rotation guide bodies adjacent in the circumferential direction,
The angle between two lines connecting the two contact points where the two rotation guide bodies fixed by the fixing means contact the peripheral surface of the table body and the rotation center of the table body is the pressing force application. The two rotation guide bodies that receive the pressing force by the means are set to be larger than an angle between two lines connecting two contact points that contact the peripheral surface of the table body and the rotation center of the table body. The table apparatus characterized by the above-mentioned. A table body provided rotatably,
Four rotating guide bodies that contact the peripheral surface of the table body and guide the table body rotatably;
A fixing means for fixing the positions of two rotation guide bodies adjacent in the circumferential direction of the rotation guide bodies;
A pressing force applying means for applying a pressing force in the direction of the table body to the remaining two rotation guide bodies adjacent in the circumferential direction;
A displacement applying means for applying a displacement in a circumferential direction around the rotation center of the table body to the table body;
In the table apparatus comprising the bias applying means for applying a contact force between the displacement applying means and the table body,
The bias force applying means is installed closer to the table body than the displacement applying means, and is fixed by the fixing means from the two rotation guide bodies that receive the pressing force by the pressing force applying means. A table device characterized by generating a force in the direction of two rotating guide bodies.

Images