JPH1066367A - Electrostatic levitation apparatus of levitator made of dielectric and insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time required to lift a levitation, improve the levitation rigidity and the stability of the levitation system and, further, improve a restoration force applied to the levitation in its horizontal direction and the rigidity of the restoration force. SOLUTION: In order to form the electrodes of a stator 10, a plurality of electrode groups, which are respectively composed of a plurality of electrodes arranged alternately are formed on an insulating substrate. A controller 40 which generates a control voltage by which a levitation 20 is lifted stably is provided. The gap between the stator and the levitation is detected by displacement sensors 31-34 and fed back to the controller. The control voltage generated by the controller and a constant DC voltage are alternately applied to the electrodes and many boundaries between the electrodes to which different voltages ate applied are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic levitation in which a levitation body, especially a levitation body made of a dielectric or an insulator such as glass or ceramics, is completely non-contacted from the surrounding environment by using electrostatic force. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
Document "Electrostatic Levitation of 8-inch Silicon Wafer", Proceedings of the Electrostatics Society of Japan, pp. 141-144, 1995. FIG. 7 is a plan view of an electrode surface of a stator of such a conventional electrostatic levitation device.

[0003] In this figure, reference numeral 910 denotes a stator;
Reference numerals 914 denote electrodes, 991 to 994 denote holes for displacement sensors. The stator 910 is made of an insulating substrate, on which four conductive electrodes 911 to 914 are uniformly formed to form one ring. The outer diameter of this ring is a floating body (silicon wafer) facing the stator 910.
Is equal to the outer diameter of In order to detect the position and orientation of the floating body, the electrodes 911 to 914 are provided with displacement sensor holes 991 to 994, and the displacement sensors are provided in the displacement sensor holes 991 to 994, respectively.

In such a conventional electrostatic levitation system,
Floating body (silicon wafer) detected using displacement sensor
By actively controlling the voltage applied to the electrodes 911 to 914 based on the position and posture of the floating body, the floating body is stably levitated. Conventionally, in order to keep the potential of the floating body at zero volt, the electrodes 911 and 913 are controlled by a positive voltage, and the electrodes 912 and 914 are controlled by a negative voltage.

Before describing the concept of the stator electrode structure according to the present invention, first, a case where a conductor or a semiconductor such as a silicon wafer is levitated by using an electrode structure in a conventional electrostatic levitation apparatus is described. The electric field formed when a dielectric or insulator such as glass or ceramics is levitated, the behavior of the charge on the surface of the levitating body, and the electrostatic levitation force generated by the charge are briefly described with reference to FIG. explain.

The restoring force acting in the horizontal direction when the floating body of the dielectric or insulator is displaced in the horizontal direction from the position immediately below the electrodes will be described with reference to FIG. Next, the concept of a stator electrode structure suitable for electrostatic levitation of a dielectric or insulator according to the present invention will be described with reference to FIG. 8 to 10, 911, 91
Reference numerals 2,915 to 918 indicate electrodes. Among them, the electrode 911
Reference numerals 912 and 912 denote the electrodes of the conventional electrostatic levitation device as described above. The electrostatic force acting between the electrode and the floating body in FIGS. 8 and 10 shows only the vertical component of the floating body.
In FIG. 9, the horizontal restoring force of the floating body is a horizontal component of the electrostatic force acting between the electrode and the floating body.

First, a case where a semiconductor such as a conductor or a silicon wafer is levitated by using a conventional electrostatic levitating apparatus will be described. When the control of the voltage applied to the electrodes is started when the floating gap is sufficiently smaller than the area of the overlapping portion between the electrode and the floating body, a voltage + V is applied to the electrode 911 and a voltage −V is applied to the electrode 912. An electric field and charge distribution as shown in FIG. That is, since charges can move freely in a conductor or a semiconductor, immediately after a voltage is applied to the electrodes 911 and 912, a positive charge is applied to the electrodes 911 and a floating body A surface facing the electrodes 911 is applied. A negative charge (a negative charge on the electrode 912 and a positive charge on the surface of the floating body A facing the electrode 912) appears instantaneously over the entire surface of the electrode and the floating body A.

As a result, a strong electric field is uniformly formed in the gap between the electrode and the floating body A, and the floating body receives a levitation force of approximately the same magnitude per unit area over the entire surface thereof, and a voltage is applied to the electrode. It will fly as soon as it is applied. Next, when a floating body B made of a dielectric or an insulator such as glass or ceramics is floated with a conventional electrode structure, when a voltage is applied to the electrode, the dielectric or the insulator is not a conductor. Polarization results in the formation of an electric field and charge distribution as shown in FIG. At this time, an upward force and a downward force act on the interface of the floating body B, and the force obtained by subtracting the downward force from the upward force becomes the floating force.

When the floating body B is a dielectric or an insulator, an electric field formed by applying a voltage to the electrode is:
It is strong near the boundary between the electrodes 911 and 912, but becomes weaker as the distance from the boundary increases. Therefore, many polarizations occur near the boundary and the levitation force increases. However, the polarization is reduced and the levitation force decreases at a location far from the boundary because the electric field is weak.

In the vicinity of the boundary, there are lines of electric force entering from the upper surface of the floating body B and exiting from the upper surface of the floating body B,
In this portion, only the upward force acts on the floating body B, and a strong floating force is obtained. Further, the dielectric and the insulator are polarized early because the electric field is strong near the boundary, but the polarization lag increases in a distant place. As a result, the levitation force gradually increases over a longer period of time at a location far from the boundary than at the vicinity of the boundary. Further, since a strong electric field is formed near the boundary, a dipole is induced in the flying body B, and a strong electrostatic attraction force is generated between the dipole and the dipole formed on the electrode.

The case of a high-resistance body having a weak conductivity such as a sheet glass will be described as follows. In the case of a high-resistance body, the electric field near the boundary between the electrodes is strong, so that the electric charges gather quickly at the part of the floating body B facing the vicinity of the boundary, but since the electric field strength is small at the part far from the boundary, It takes a considerable amount of time because charges are collected. That is, when a voltage is applied to the electrodes 911 and 912,
The levitation force increases quickly near the boundary, but gradually increases over a long period of time far from the boundary.

Next, the restoring force of the floating body in the horizontal direction will be described. When the floating body A is a conductor or a semiconductor, the principle of the restoring force acting on the floating body A is the edge effect. However, when the floating body B is a dielectric or an insulator, the restoring force due to its edge effect is very small, and can be explained as follows. As shown in FIG. 9, when the floating body C of the dielectric or the insulator is displaced in a horizontal direction from a position directly below the electrode, a dielectric relaxation phenomenon of the floating body C or a high resistivity of the floating body,
The state of charge distribution induced when the levitation body C floats right below the electrode does not change immediately even if the levitation body C shifts in the horizontal direction. As a result, a restoring force acts near the boundary as shown in FIG. The restoring force near the boundary is larger than the rest of the floating body C because the amount of electric charge induced near the boundary is much larger than the amount of electric charge induced near the edge of the floating body C. It is much larger.

As described above, in order to obtain a strong levitation force over the entire surface of the levitation body C and to quickly increase the levitation force,
It can be seen that many boundaries between electrodes to which different voltages are applied may be made. That is, as shown in FIG. 10, a large number of electrodes are formed on the stator, and the electrodes are positive and negative (or
By alternately applying voltages of (positive and zero, negative and zero), a strong electric field is generated over the entire surface of the floating body D, and the floating body D can be quickly levitated. In addition, it is needless to say that the restoring force and the rigidity of the floating body D in the horizontal direction can thereby be increased.

[0014]

As described above, the conventional electrostatic levitation device has an electrode structure composed of four electrodes as shown in FIG. 7, so that there are only four boundaries between the electrodes. When a dielectric or insulator such as glass or ceramics is levitated, there has been a problem that the levitating time (the time from the start of control until the levitating body floats) is increased.

According to experiments, the temperature was 20 ° C. and the humidity was 45% R.
Under an environment of H, a voltage of ± 1.5 kV is first applied to the electrode, and a glass plate having a diameter of 100 mm and a thickness of 0.7 mm is floated from an initial gap of 0.35 mm to a target gap of 0.3 mm for about 2 minutes. It took some time. In addition, there is a problem that the time appearing on the surface of the floating body with respect to the change in the voltage applied to the electrode has a large time delay, so that the floating system is likely to be unstable and the floating rigidity is low.

Further, when the floating body is displaced in a horizontal direction from a position directly below the electrode, the horizontal restoring force acting on the floating body is small. When the paper is transported in a floating state, the transport speed cannot be increased, and the transport efficiency and the reliability of the transport system cannot be increased. Therefore,
SUMMARY OF THE INVENTION The present invention eliminates the above-described problems, quickly raises a floating body, shortens the floating time, increases the floating rigidity and stability of the floating system, and furthermore, restores the floating body in the horizontal direction. An object of the present invention is to provide an electrostatic levitation device of a levitation body made of a dielectric or an insulator capable of improving a force and its rigidity.

[0017]

According to the present invention, there is provided an electrostatic levitation apparatus for floating a floating body made of a dielectric or an insulator using electrostatic force. A plurality of electrode groups are formed, each electrode group is a stator formed of a plurality of electrodes arranged alternately, a floating body facing the stator, the stator and the floating body A displacement sensor that detects the gap of the, and a controller that generates a control voltage for stably levitating the levitation body, from the controller based on the levitation position of the levitation body detected using the displacement sensor The created control voltage and constant DC voltage are alternately applied to the electrodes of each electrode group.

(2) In the electrostatic levitation device of a levitation body made of a dielectric or an insulator according to the above (1), the plurality of electrodes forming each electrode group have different areas from each other. . (3) In the electrostatic levitation device of a levitation body made of a dielectric or an insulator according to the above (1), the plurality of electrodes forming each electrode group have the same area.

(4) In the electrostatic levitation apparatus for a floating body made of a dielectric or an insulator according to the above (1), a plurality of electrodes forming each electrode group have a control created based on the position of the floating body. Voltage and zero volts are alternately applied. (5) In the electrostatic levitation apparatus for a floating body made of a dielectric or an insulator according to the above (1), the polarity of the control voltage generated based on the position of the floating body is selected so that the potential of the floating body becomes zero volt. It is like that.

(6) In the electrostatic levitation device for a floating body made of a dielectric or an insulator according to the above (3), a plurality of electrodes forming each electrode group having the same area are provided with the floating body. The control voltage generated based on the position and the voltage having the same absolute value of the opposite polarity to the control voltage are alternately applied so that the potential of the floating body becomes zero volt.

(7) In the electrostatic levitation device for a floating body made of a dielectric or an insulator according to the above (1), the floating body is a plate-like body. (8) In the electrostatic levitation apparatus for a floating body made of a dielectric or an insulator according to the above (7), the floating body is a glass plate. (9) In the electrostatic levitation device for a floating body made of a dielectric or an insulator according to the above (7), the floating body is a ceramic plate.

As described above, according to the present invention, a number of electrodes are formed on a stator, and a control voltage and a constant DC voltage (including zero volts) or a control voltage and a polarity opposite to the control voltage are applied to the electrodes. By alternately applying a voltage having the same absolute value as above, many boundaries between electrodes to which different voltage values are applied are created, and a strong electric field is generated over the entire surface of the floating body (dielectric or insulator) As a result, the levitation body can be swiftly levitated to shorten the levitation time, and at the same time, the levitation rigidity and the stability of the levitation system can be increased. Also, the restoring force acting on the floating body in the horizontal direction and its rigidity can be improved.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an electrostatic levitation device of a levitation body made of a dielectric or an insulator, showing a first embodiment of the present invention. FIG. 2 shows an electrode structure and wiring of a stator in the electrostatic levitation device. Show.

In FIG. 1, 10 is a stator, 20 is a floating body made of a dielectric or an insulator facing the stator 10,
31 to 34 are displacement sensors, and 40 is a controller.
As shown in FIGS. 1 and 2, the stator 10 is formed of an insulating substrate, and electrodes 11a to 11d and 12a to 12f for applying a floating force to a floating body 20 formed of a dielectric or an insulator.
d, 13a to 13d and 14a to 14d are formed.

These electrodes are divided into four groups having the same shape and are evenly arranged on the stator 10. That is, the electrodes 11a to 11d form one electrode group (this is referred to as electrode group 1), and the electrodes 12a to 12d form one electrode group (this is referred to as electrode group 2) and the electrodes 13a to 13d Represents one electrode group (hereinafter referred to as an electrode group 3) with the electrode 14a.
14d is one electrode group (this is electrode group 4
) Is formed.

Each electrode group is composed of four electrodes, of which the innermost electrode has a rectangular shape, and the remaining three electrodes have a rectangular shape having a rectangular hollow. The four electrodes have equal areas. The long sides and short sides of the rectangular electrodes formed by the outermost electrodes 11a, 12a, 13a, and 14a in each electrode group are shorter than the longer sides of the floating body 20. It is equal to the length of the side.

The electrodes forming each electrode group are 1
Are connected to each other (see the dotted line in FIG. 2).
To form one set of electrodes. That is, electrode group 1
Is taken as an example, the electrode 11a and the electrode 11c are connected to each other on the back surface to form one set of electrodes (this is referred to as one set of electrodes of the electrode group 1).
The electrode b and the electrode 11d are connected to each other on the back surface, and form one set of electrodes (this is referred to as two sets of electrodes of the electrode group 1). The same applies to the electrode groups 2, 3, and 4.

Of the two sets of electrodes forming each electrode group, one set of electrodes receives a control voltage from the controller 40 and the other set of electrodes always receives zero volts. That is, one set of electrodes (electrode 1
1a and 11c) have a control voltage V1, and one set of electrodes (electrodes 12a and 12c) of electrode group 2 has a control voltage V2.
A control voltage V3 is applied to one set of electrodes (electrodes 13a and 13c) of electrode group 3 and one set of electrodes (electrode 14) of electrode group 4.
Control voltage V4 is applied to a and 14c).

Then, two sets of electrodes (electrodes 11b and 11d) of electrode group 1 and two sets of electrodes (electrode 1
2b and 12d) and two pairs of electrodes (electrode 13)
b and 13d) and two sets of electrodes of electrode group 4 (electrode 14b
And 14d), a voltage of zero volts is always applied. It should be noted that the innermost 11d, 12d, 13d, and 14d of each electrode group has a displacement sensor hole 9 for detecting the floating position of the floating body 20.
1 to 94 are open.

The above-mentioned voltage to the electrodes is supplied from the back surface through through holes (not shown). In all of the following embodiments, the voltage to the electrodes is supplied from the back surface through the through holes, as in the first embodiment. Next, in order to stably float the floating body 20, the voltages V1 and V
2, V3 and V4 may be actively controlled. That is, the position and orientation of the levitation body 20 are detected using the displacement sensors 31 to 34, and the controller 40 is controlled based on the detected signals.
Control voltages V1 and V for stably floating the floating body 20
2, V3, and V4, and one set of electrodes (11a and 11c) of electrode group 1, one set of electrodes (electrodes 12a and 12c) of electrode group 2, and one set of electrodes (13
a and 13c) and one set of electrodes (electrode 14
a and 14c), the floating body 20 can be stably levitated.

As described above, in the first embodiment, the electrodes to which the control voltage is applied and the electrodes to which zero volt is applied are alternately arranged, and a large number of boundaries between the electrodes are formed. When floating the dielectric or insulator, the time from the start of control to the floating can be shortened. In addition, the stability and levitation rigidity of the levitation system,
The restoring force of the floating body in the horizontal direction and its rigidity can be improved.

According to experiments, using the above-described stator 10,
Under the boundary of a temperature of 20 ° C. and a humidity of 45% RH, a floating experiment of a glass plate of width × length × thickness (100 mm × 100 mm × 0.7 mm) was performed, and the initial gap was 0.35 mm in only about 1 second from the start of control. It was confirmed that the target surface floated to the target gap of 0.3 mm. In this experiment, the initial voltage applied to one set of electrodes in each electrode group was 3 kV, and zero volts was applied to two sets of electrodes in each electrode group.

Next, a second embodiment of the present invention will be described. FIG. 3 shows an electrode structure and wiring of a stator of an electrostatic levitation device of a floating body made of a dielectric or an insulator according to a second embodiment of the present invention. In this figure, 110 is a stator, 111a
~ 111j, 112a ~ 112f, 113a ~ 113
j, 114a to 114f indicate electrodes, and 191 to 194 indicate holes for displacement sensors.

The strip-shaped electrodes 111a to 111j,
112-112f, 113a-113j, 114a-1
14f are divided into four groups, as in the first embodiment, and are formed on the stator 110 made of an insulating substrate. That is, the electrodes 111a to 111j form an electrode group 1, the electrodes 112a to 112f form an electrode group 2, the electrodes 113a to 113j form an electrode group 3, and the electrodes 114a to 114f form an electrode group 4. Electrode group 1 has the same shape as electrode group 3, and electrode group 2 has the same shape as electrode group 4.

The lengths of the long side and the short side of the rectangular electrode formed by the four electrode groups are equal to the lengths of the long side and the short side of the floating body, respectively. A large number of electrodes forming the same electrode group have the same area and are connected to every other electrode (see the dotted line in FIG. 3), forming two sets of electrodes. ing.

That is, taking the electrode group 1 as an example, the electrodes 111a, 111c, 111e, 111g, 111i
Are connected to each other on the back surface to form one set of electrodes of electrode group 1, and electrodes 111b, 111d,
111f, 111h, and 111j are connected to each other on the back surface, and form two sets of electrodes of electrode group 1. The same applies to the electrode groups 2, 3, and 4.

As in the first embodiment, of the two sets of electrodes forming each electrode group, a control voltage from a controller is applied to one set of electrodes, and another set of electrodes is formed. Is always applied with zero volts. That is, one set of electrodes of electrode group 1 (electrodes 111a, 111c, 111e,
111g, 111i) is supplied with the control voltage V1 by one set of electrodes (electrodes 112b, 112d, 112f) of the electrode group 2.
Control voltage V2 is applied to one set of electrodes of electrode group 3 (electrodes 113b, 113d, 113f, 113h, 113j)
And the control voltage V4 is applied to one set of electrodes (electrodes 114a, 113c and 113e) of the electrode group 4.

Then, two sets of electrodes of the electrode group 1 (electrodes 111b, 111d, 111f, 111h, 111j)
And two pairs of electrodes (electrodes 112a, 112a
c, 112e) and two sets of electrodes of electrode group 3 (electrode 1
13a, 113c, 113e, 113g, 113i)
And two sets of electrodes of electrode group 4 (electrodes 114b, 114b
d, 114f), a voltage of zero volts is always applied.

As described above, in the second embodiment, strip electrodes having a simple shape are arranged in a line, and a control voltage and zero volts are alternately applied to the electrodes to form a large number of boundaries between the electrodes. A floating body made of a rectangular dielectric or insulator is floated with high stability in a short time. Also,
By arranging the electrodes forming the electrode groups 1 and 3 in the horizontal direction, the restoring force and its rigidity in the horizontal direction (the horizontal direction in FIG. 3) can be reduced, and the electrodes forming the electrode groups 2 and 4 can be arranged in the vertical direction. In order to improve the restoring force and its rigidity in the vertical direction (vertical direction in FIG. 3).

Next, a third embodiment of the present invention will be described. FIG. 4 is a view showing an electrode structure of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a third embodiment of the present invention. In FIG. 4, reference numeral 210 denotes a stator;
14, 211aa to 211ae, 211ba to 211b
e, 211ca to 211ce, 212aa to 212a
e, 212ba-212be, 212ca-212c
e, 213aa to 213ae, 213ba to 213b
e, 213ca-213ce, 214aa-214a
e, 214ba-214be, 214ca-214ce
Indicates electrodes, and 291 to 294 indicate holes for displacement sensors.

Electrodes 211aa to 211ae, 211ba
To 211be and 211ca to 211ce are connected to each other on the back surface, and are supplied with a control voltage V1 (not shown). Electrodes 212aa to 212ae, 212ba to 212
be, 212ca to 212ce are connected to each other on the back surface, and supplied with a control voltage V2 (not shown). Electrode 21
3aa to 213ae, 213ba to 213be, 213
ca to 213ce are connected to each other on the back surface, and the control voltage V
3 (not shown) are supplied. Electrodes 214aa to 214
ae, 214ba-214be, 214ca-214c
e are connected to each other on the back side, and are connected to a control voltage V4 (not shown).
Is supplied.

Further, the grid electrodes 211 to 214 have
Zero volts are always supplied. The total area of the electrodes to which the same control voltage is applied in each electrode group is equal to the area of the electrodes to which zero volt is applied. By actively controlling the control voltages V1, V2, V3, and V4 using the stator 210, a rectangular dielectric or insulator is floated in a short time with good stability.

Next, a fourth embodiment of the present invention will be described. FIG. 5 is a view showing an electrode structure and wiring of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a fourth embodiment of the present invention. In this figure, 310 is a stator,
311a to 311d, 312a to 312d, 313a to
313d, 314a to 314d are electrodes, 391 to 394
Indicates a displacement sensor hole.

In the fourth embodiment, a disk made of a dielectric or insulator such as circular glass or ceramic is used as a floating body. Therefore, except for the fact that the structure of the electrodes formed on the stator 310 is formed in a shape corresponding to the circular shape of the floating body, the basic concept of the structure is that of the stator 10 of the first embodiment. (See FIG. 2). That is, the electrodes are divided into four groups, and the electrodes forming each group are wired as shown in FIG. 5 to form two sets of electrodes.

Of the two sets of electrodes, zero volts is always applied to one set of electrodes, and a control voltage is applied to the other set of electrodes. The electrodes forming each group are fan-shaped and have the same area. The outer diameter of the circle formed by the outermost electrodes 311a, 312a, 313a, and 314a of each electrode group is equal to the outer diameter of the floating body.

In the first to fourth embodiments, the electrostatic force applied to the floating body is controlled at four points above the floating body in order to stably float the plate-like body in space.
This is a case where redundancy is provided, and it is sufficient to control the electrostatic force at at least three places in order to stably levitate the floating body. FIG. 6 is a view showing an electrode structure and wiring of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a fifth embodiment of the present invention.

In FIG. 6, reference numeral 410 denotes a stator, 411a.
~ 411d, 412a ~ 412d, 413a ~ 413d
Indicates an electrode, and 491 to 493 indicate holes for a displacement sensor. In the fifth embodiment, the levitation force may be controlled at a minimum of three places on the levitation body in order to stably levitate the levitation body. Therefore, the electrodes are formed from the four groups of the fourth embodiment (see FIG. 5). Except for the three groups, the basic concept of the structure and wiring is the same as that of the fourth embodiment.

By using this stator 410 and actively controlling the control voltage applied to the electrodes of the stator, a circular dielectric or insulating disk can be stably levitated in a short time. it can. In the fourth and fifth embodiments described above, the shape of the electrode formed on the stator can be changed to a shape based on the gist of the second and third embodiments. Needless to say.

In the first to fifth embodiments, a floating body made of a circular or rectangular dielectric or insulator is used as a floating body. However, a floating body having any other shape may be used. It is needless to say that, based on the gist of the present invention, the floating structure can be raised in a short time and the restoring force in the horizontal direction can be increased by devising the electrode structure.

Further, in the first to fifth embodiments described above, the case where the floating body is a dielectric or an insulator has been exemplified.
The present invention can be applied to a case where various types of floating bodies such as conductors and semiconductors are used. In the first to fifth embodiments, it is needless to say that a constant voltage other than zero volt can be applied to the electrode to which zero volt is always applied.

In the first to fourth embodiments, when it is desired to maintain the potential of the floating body (especially, a conductor or a semiconductor) at zero volt, the control voltage V
Of the 1, V2, V3, and V4, the polarity of the two control voltages may be opposite to the polarity of the remaining two control voltages having the same polarity. For example, the polarities of the control voltages V1 and V3 can be positive, and the polarities of the control voltages V2 and V4 can be negative. In this case, when the floating body floats with a certain gap just below the stator, the potential of the floating body can be maintained at zero volt.

Further, in the first to fifth embodiments, a voltage having a polarity opposite to the control voltage can be applied to the electrode to which zero volt is always applied. In other words, with reference to the first embodiment (FIG. 2) of the present invention, the control voltage -V1 is applied to the two sets of electrodes (electrodes 11b and 11d) of the electrode group 1, and the two sets of electrodes (electrodes of the electrode group 2). 12b
And 12d), the control voltage −V2 is applied to the electrode group 3 2
The control voltage -V3 is applied to the assembled electrodes (electrodes 13b and 13d).
The control voltage -V4 can be applied to two sets of electrodes (electrodes 14b and 14d) of the electrode group 4. This allows
The floating body potential will remain at zero volts. The same applies to the second to fifth embodiments of the present invention.

In the first to fifth embodiments, it goes without saying that the shape of the electrodes forming each group can be changed or the number of electrodes can be increased or decreased based on the spirit of the present invention. Further, in the first, second, fourth, and fifth embodiments, the case where the areas of the electrodes forming each group are equal to each other is exemplified, but the areas may be different.

Further, in the third embodiment, the case where the area of the electrode to which the control voltage is applied and the area of the electrode to which zero volt is always applied in each group is exemplified, but it is needless to say that the areas can be different. . The present invention is not limited to the above embodiments, and various modifications are possible based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

[0055]

As described above, according to the present invention, the following effects can be obtained. By forming a large number of electrodes on the stator and alternately applying a control voltage and zero volts to the electrodes, a large number of boundaries between the electrodes to which different voltages are applied are formed, and a floating body (particularly,
A strong electric field can be generated over the entire surface of a dielectric or insulator such as glass or ceramics).

As a result, the floating body can be floated in a short time, and at the same time, the floating rigidity and the stability of the floating system can be improved. Also, by forming a large number of boundaries between the electrodes as described above, it is possible to increase the restoring force acting on the floating body and its rigidity when the floating body is displaced in the horizontal direction.

Thus, the non-contact support of the floating body by electrostatic force can be performed more accurately and with good controllability. In addition, when a glass plate or the like is conveyed while levitating by electrostatic force using a conveyance device such as a robot, it is possible to levitate in a short time, and furthermore, the restoring force in the horizontal direction and its rigidity are improved. Therefore, the transfer speed can be increased, and the efficiency and reliability of the transfer system can be increased.

As described above, the present invention is applicable to the field of optical equipment, liquid crystal display manufacturing process, semiconductor manufacturing industry, precision machine industry, etc. It can be used for a transfer device and the like.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an electrode structure and wiring of a stator in the electrostatic levitation device of a levitation body made of a dielectric or an insulator according to the first embodiment of the present invention.

FIG. 3 is a view showing an electrode structure and wiring of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a second embodiment of the present invention.

FIG. 4 is a view showing an electrode structure and wiring of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a third embodiment of the present invention.

FIG. 5 is a view showing an electrode structure and wiring of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a fourth embodiment of the present invention.

FIG. 6 is a view showing an electrode structure and wiring of a stator of an electrostatic levitation device of a levitation body made of a dielectric or an insulator according to a fifth embodiment of the present invention.

FIG. 7 is a plan view of an electrode surface of a stator of a conventional electrostatic levitation device.

FIG. 8 shows a case where a conductor or a semiconductor such as a silicon wafer is levitated using an electrode structure in a conventional electrostatic levitation device;
The behavior of the electric field formed when a dielectric or insulator such as glass or ceramics is levitated, or the behavior of the charge on the levitating surface,
FIG. 4 is an explanatory diagram of an electrostatic levitation force generated by the charge.

FIG. 9 is an explanatory diagram of a restoring force acting in the horizontal direction when a floating body made of a dielectric or an insulator is horizontally displaced from a position directly below an electrode in a conventional electrostatic levitation device.

FIG. 10 is an explanatory diagram illustrating a concept of a stator electrode structure suitable for electrostatic levitation of a levitation body made of a dielectric or an insulator according to the present invention.

[Explanation of symbols]

10, 110, 210, 310, 410 Stator 20 Floating body 31, 32, 33, 34 Displacement sensor 40 Controller 11a to 11d, 12a to 12d, 13a to 13d, 1
4a to 14d, 111a to 111j, 112a to 112
f, 113a to 113j, 114a to 114f, 211
To 214, 211aa to 211ae, 211ba to 21
1be, 211ca to 211ce, 212aa to 212
ae, 212ba-212be, 212ca-212c
e, 213aa to 213ae, 213ba to 213b
e, 213ca-213ce, 214aa-214a
e, 214ba-214be, 214ca-214c
e, 311a to 311d, 312a to 312d, 313
a to 313d, 314a to 314d, 411a to 411
d, 412a to 412d, 413a to 413d Electrodes 91 to 94, 191 to 194, 291 to 294, 391
~ 394,491-493 Displacement sensor hole

Claims (9)

[Claims] 1. An electrostatic levitation device for floating a floating body made of a dielectric or an insulator using electrostatic force. (A) A plurality of electrode groups are formed on an insulating substrate, and the electrode groups are alternately formed. A stator formed from a plurality of electrodes arranged; (b) a floating body facing the stator;
(C) a displacement sensor for detecting a gap between the stator and the floating body, (d) a controller for generating a control voltage for stably floating the floating body, and (e) the displacement sensor A control voltage and a constant DC voltage generated from the controller based on the floating position of the floating body detected by using a dielectric or an insulator, which are alternately applied to the electrodes of the respective electrode groups. Electrostatic levitation device for levitation. 2. The dielectric levitation device according to claim 1, wherein said plurality of electrodes forming said electrode groups have different areas from each other. Electrostatic levitation device for levitation bodies made of materials and insulators. 3. The electrostatic levitation device of a levitation body made of a dielectric or an insulator according to claim 1, wherein the plurality of electrodes forming each of the electrode groups have the same area. An electrostatic levitation device for levitation bodies made of dielectrics and insulators. 4. The electrostatic levitation apparatus for a floating body made of a dielectric or an insulator according to claim 1, wherein the plurality of electrodes forming each of the electrode groups are controlled based on the floating position of the floating body. An electrostatic levitation device for a levitation body made of a dielectric or an insulator, wherein a voltage and zero volts are alternately applied. 5. The electrostatic levitation apparatus for a levitation body made of a dielectric or an insulator according to claim 1, wherein the polarity of the control voltage generated based on the levitation position of the levitation body is 0 volt. An electrostatic levitation device for a levitation body made of a dielectric or an insulator, characterized by being selected as follows. 6. The electrostatic levitation device of a levitation body made of a dielectric or an insulator according to claim 3, wherein the plurality of electrodes forming the respective electrode groups have the same area,
A control voltage generated based on the floating position of the floating body, and a voltage having the same absolute value of the opposite polarity to the control voltage are alternately applied, and the potential of the floating body becomes zero volts. Electrostatic levitation device for levitation bodies made of materials and insulators. 7. The electrostatic levitation device for a floating body made of a dielectric or an insulator according to claim 1, wherein the floating body is a plate of a dielectric or an insulator. An electrostatic levitation device for a floating body consisting of a body. 8. The electrostatic levitation apparatus for a floating body made of a dielectric or an insulator according to claim 7, wherein the floating body is a glass plate. Electro-levitation device. 9. The electrostatic levitation device for a floating body made of a dielectric or an insulator according to claim 7, wherein the floating body is a ceramic plate. Electro-levitation device.