JP2003328940A - Vacuum exhaust device with usage of turbo molecular pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum exhaust device with the usage of a turbo molecular pump reducing influence of vibration of the turbo molecular pump to the outside. <P>SOLUTION: A friction damping mechanism 34 is arranged between the turbo molecular pump 30 and a vacuum chamber. As the friction damping mechanism 34, a vacuum casing 31 of the turbo molecular pump 30 and a vacuum flange 32 connected to the vacuum chamber are fastened by a bellows 33 having a small spring constant. Thus, damping with respect to relative movements between the vacuum flange 32 and the vacuum casing 32 is actuated. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum evacuation device using a turbo molecular pump, and more particularly to a vacuum evacuation device using a turbo molecular pump used in electron microscopes, semiconductor manufacturing equipment and the like.

[0002]

2. Description of the Related Art FIG. 19 is a vertical cross-sectional view of a conventional turbo molecular pump main body adopting a magnetic bearing, and FIG. 20 is a system conceptual diagram of the turbo molecular pump.

In FIG. 19, a turbo molecular pump 201 is shown.
Is the rotating shaft 203 to which the rotor blade 215 is attached and the stator 20.
2, and the sensor coils 208, 209, 2 for detecting the relative position between the rotary shaft 203 and the stator 202 by facing the lower end side of the rotary shaft 203 and the upper and lower parts of the rotary shaft 203.
10 are provided and these sensor coils 208, 20
The detection signal detected by 9, 210 is applied to the sensor circuit 255 in the controller 251 shown in FIG. 20 to generate the position detection signal (analog signal or digital signal) of the rotary shaft 203. An electromagnet 20 for supporting the rotating shaft 203 in a magnetic bearing is provided above and below the rotating shaft 203.
4, 205, 206 are provided. Further, a motor 207 for rotationally driving the rotary shaft 203 is provided so as to face the central portion of the rotary shaft 203.

As shown in FIG. 20, the motor 207 is rotationally controlled by a motor controller 258, the magnetic bearings by the electromagnets 204, 205, 206 are controlled by a magnetic bearing control circuit 256, and the magnetic bearing control circuit 256 and the motor are controlled. The controller 258 is arranged in the controller 251 provided outside the magnetic bearing spindle.

Further, as shown in FIG.
Emergency bearings 211 and 212 are provided at the upper and lower ends of the third bearing 3, respectively. The emergency bearings 211 and 212 support the rotary shaft 203 when the magnetic bearing device becomes uncontrollable. Although not shown in FIG. 19, a rotation detection sensor 262 that detects the rotation speed of the rotation shaft 203 is arranged inside the stator 202, and a rotation shaft rotation speed signal is generated via the rotation detection sensor amplifier 254. Be done.

As a sensor for detecting the relative position between the rotary shaft 203 and the stator 202, a magnetic sensor represented by a reluctance type or an eddy current type is generally used. Further, the vacuum casing 213 is provided with a vacuum exhaust port 214, and a stationary blade 216 is arranged so as to face the moving blade 215. By rotating the moving blade 215, the vacuum exhaust port 214 is removed. The air is evacuated and a vacuum is created.

[0007]

A turbo-molecular pump is a mechanical type that imparts kinetic energy to gas molecules by rotating a moving blade 215 attached to a rotary shaft 203 at high speed to dilute the gas above the spindle. It is a vacuum pump.
Therefore, there is a problem that the rotational vibration of the rotary shaft 203 is transmitted to the outside via the bearing. When a magnetic bearing as shown in Fig. 6 to be described later is used for this bearing, the vibration transmission ratio of the magnetic bearing, which is a non-contact bearing, is low, so comparison with the case where a contact type bearing such as a rolling bearing is used. Then, there is an advantage that the vibration transmission to the outside can be reduced. However, further reduction of vibration has been demanded for a turbo molecular pump used for observing an ultrafine structure such as a semiconductor exposure apparatus and nanoparticles.

Correspondingly, since the vibration component of the turbo molecular pump is mainly the rotation frequency component, the bearing support rigidity in this rotation frequency region is selectively reduced to reduce the vibration at this frequency. The way is done.

One method for selectively reducing the bearing rigidity in the rotation frequency range will be conceptually described with reference to FIG. The magnetic bearing detects the position of the rotating shaft 203 with a sensor, and a current based on a signal whose phase is compensated by the PID control circuit 271 is supplied to a coil of the electromagnet 277 to control the rotating shaft position. Up to now, in order to reduce the bearing rigidity in a specific frequency range, by inserting the band-elmination filter 275 in series with this PID control circuit, the center frequency of the filter is made to match the rotation frequency of the rotating shaft, and the Although a method for selectively reducing the vibration synchronized with the rotation frequency has been made, it is not yet sufficient.

Therefore, a main object of the present invention is to provide an evacuation device using a turbo molecular pump for further reducing vibration.

[0011]

SUMMARY OF THE INVENTION The present invention forms a vibration damping mechanism having a vibration transmission reduction mechanism between a turbo molecular pump and a vacuum chamber to reduce vibration transmission from the vacuum casing of the turbo molecular pump to the vacuum chamber. The vibration damping mechanism is provided between the vacuum cover and the vacuum flange, and the bellows with a low spring constant that fastens between the vacuum casing of the turbo molecular pump and the vacuum flange connected to the vacuum chamber. And a friction damping mechanism that is provided.

As a result, the relative movement between the vacuum flange and the vacuum casing is damped, so that even if vibration occurs in the turbo molecular pump, it can be damped by the friction damping mechanism.

Another aspect of the present invention is a vacuum exhaust system in which a vibration damping mechanism having a vibration transmission reducing mechanism is formed between the turbo molecular pump and the vacuum chamber in order to reduce the vibration transmission from the vacuum casing of the turbo molecular pump to the vacuum chamber. In the device, the vibration damping mechanism includes a bellows having a low spring constant for fastening between a vacuum casing of the turbo molecular pump and a vacuum flange connected to the vacuum chamber, and a piezoelectric provided between the vacuum casing and the vacuum flange. It is characterized by comprising an element and a discharge element for discharging a voltage generated in the piezoelectric element.

As a result, when there is relative movement between the vacuum flange and the vacuum casing, a voltage proportional to the relative displacement is generated in the piezoelectric element, and the voltage is discharged, whereby the relative movement between the vacuum flange and the vacuum casing. A damping force can be generated against.

Still another aspect of the present invention is a vacuum exhaust system in which a vibration damping mechanism having a vibration transmission reducing mechanism is formed between the turbo molecular pump and the vacuum chamber in order to reduce the vibration transmission from the vacuum casing of the turbo molecular pump to the vacuum chamber. An apparatus, comprising: a bellows having a low spring constant for fastening between a vacuum casing of a turbo molecular pump and a vacuum flange connected to the vacuum chamber; and a viscous damper provided between the vacuum casing and the vacuum flange. It is characterized by that.

Thus, the viscous damper can apply a damping force to the relative movement between the vacuum flange or the vacuum casing.

Further, another invention is a vacuum evacuation device which is used by attaching a vacuum flange of a vacuum chamber to a vacuum chamber from a turbo molecular pump, comprising a vibration detector attached to the vacuum chamber or the turbo molecular pump.
It is characterized in that a current corresponding to the output of the vibration detector is superimposed on a magnetic bearing electromagnet that supports a rotating shaft in the turbo molecular pump.

By controlling the current flowing through the electromagnet according to the output detected by the vibration detector in this way, the vibration of the mounting portion of the vibration detector can be reduced.

The output of the vibration detector is added to the preceding stage of the magnetic bearing control circuit.

Further, the current superimposed on the magnetic bearing electromagnet is characterized by being proportional to the vibration displacement component, the vibration velocity component, or the vibration acceleration component of the vacuum chamber obtained by the output of the vibration detector or the calculation.

Still another aspect of the present invention is the rotation in the turbo molecular pump based on the output of the vibration detector, the vibration displacement of the vacuum chamber, or the vibration displacement component, the vibration velocity component, or the vibration acceleration component of the vacuum chamber obtained by calculating these values. It is characterized in that the rotational speed component of the shaft is extracted and a current based on the extracted signal is superimposed on the magnetic bearing electromagnet.

Vibration is reduced by controlling the current flowing through the magnetic bearing electromagnet in this manner.

Further, the current to be superimposed on the magnetic bearing electromagnet is characterized in that it is obtained through a low-pass filter or a high-pass filter before being superimposed.

Still another aspect of the present invention is a vacuum evacuation device in which a vacuum flange of a turbo molecular pump is attached to a vacuum chamber for use, and an active damper comprising an electromagnetic actuator or a piezoelectric actuator attached to the turbo molecular pump is provided. It is controlled by a signal from a vibration detector attached to the vacuum chamber or the turbo molecular pump.

As described above, by controlling the active damper by the signal from the vibration detector, the vibration of the vacuum chamber or the turbo molecular pump can be reduced.

Further, the present invention is characterized in that the rotational speed component of the rotary shaft in the turbo molecular pump is extracted from the signal from the vibration detector attached to the turbo molecular pump, and the active damper is controlled by the extracted signal.

Further, the signal from the vibration detector attached to the turbo molecular pump is calculated by a low-pass filter or a high-pass filter, and the active damper is controlled by the signal obtained as a result.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
A detailed description will be given with reference to the drawings.

FIG. 1 is a sectional view of a turbo molecular pump according to the first embodiment of the present invention. In FIG. 1, the specific configuration of turbo molecular pump 30 is the same as that of the conventional example shown in FIG. 19, and therefore description thereof will not be repeated here.

Vacuum casing 3 of turbo molecular pump 30
1 and a vacuum flange 32 fixed to a vacuum chamber (not shown) are connected by a bellows 33 having a low spring constant, and a friction damping mechanism 34 is provided between the vacuum casing 31 and the vacuum flange 32.

FIG. 2 is an enlarged view of the friction damping mechanism 34 shown in FIG. The friction damping mechanism 34 is configured by laminating a plurality of ring-shaped thin plates 35. Turbo molecular pump 30
If vibration occurs inside the vacuum flange 3
The bellows 33 is deformed with respect to 2, and the vacuum casing 31
Vibrates relative to each other. As a result, relative friction is generated between the vacuum flange 32 and each thin plate 35 sandwiched between the vacuum casing 31, and the energy dissipation thereof causes a damping of relative movement between the vacuum flange 32 and the vacuum casing 31. Therefore, even if vibration occurs in the turbo molecular pump 30, the friction damping mechanism 34 can damp it, and the vibration transmission via the vacuum flange 32 can be suppressed.

In FIGS. 1 and 2, the friction damping mechanism 34 has a laminated structure of simple ring-shaped thin plates 35. However, the thin plates 35 may be formed of a circular plate or a thin plate having unevenness in the radial direction. Good. Further, these thin plates 35 do not have to be completely connected in a circumferential shape.

FIG. 3 is an enlarged view of another example of the friction damping mechanism 34 shown in FIG. In FIG. 3, even if the thin plates 35 are stacked in the radial direction of the rotation axis (the horizontal direction in FIG. 1), the bellows 33 may be wound from the outer diameter in multiple layers. The friction damping mechanism 34 shown here is sandwiched between the vacuum flange 32 and the vacuum casing 31 so that substances are mutually present, or between the vacuum flange 32, the vacuum casing 31, and the bellows 33. Any structure may be used in which a damping force is generated with respect to relative movement between the vacuum flange 32 and the vacuum casing 31 by generating friction.

Further, the thin plates 35 need only be in mechanical contact with each other and are capable of relative movement, and a rubber material having a partially elastic property or a resin having a high damping capacity may be interposed. Further, the friction damping mechanism 34 including the thin plate 35 is fixed to the vacuum flange 33 and the vacuum casing 31.
There is no limitation as long as the thin plates 35 are in mechanical contact with each other and are capable of relative movement.

FIG. 4 is a sectional view of a turbo molecular pump according to a second embodiment of the present invention, and FIG. 5 is an enlarged view of a main part of the friction damping mechanism 36 of FIG.

In FIG. 4, the friction damping mechanism 34 shown in FIG. 1 is replaced with a piezoelectric damping mechanism 36, and the other structures are the same. The piezoelectric damping mechanism 36 shown enlarged in FIG. 5 mainly includes a piezoelectric element 42 and a resistor 43.
The piezoelectric element 4 is deformed by the external force.
A voltage is generated in the thickness direction of 2. By discharging this voltage by the external resistor 43 and consuming it as heat energy, the acting force from the outside can be attenuated.

More specifically, referring to FIG. 5,
The vacuum flange 32 and the vacuum casing 31 are connected by a bellows 33, and the piezoelectric element 42, the spacer 41, and the spring 40 are further interposed between the vacuum flange 32 and the vacuum casing 31.
To form a piezoelectric damping mechanism. That is, when there is relative motion between the vacuum flange 32 and the vacuum casing 31, a force proportional to the relative displacement acts on the piezoelectric element 42 via the spring 40 and the spacer 41, and the elastic deformation of the piezoelectric element 42 due to this force. The voltage proportional to the amount is the piezoelectric element 4
Occurs in 2. By discharging this voltage by the resistor 43, a damping force for relative movement is generated between the vacuum flange 32 and the vacuum casing 31.

The piezoelectric element 42 is generally inferior in durability against tensile stress. Therefore, in FIG. 5, the spring 40 applies a preload to the piezoelectric element 42 in the compression direction, and the spacer 41 is provided to evenly apply a force acting on the piezoelectric element 42 via the spring 40. Depending on the adjustment of the bellows 33,
It is also possible to apply a preload to the piezoelectric element 42 without using the spring 40.

FIG. 6 is an enlarged view of the essential parts of another example of the friction damping mechanism of FIG. Although the piezoelectric element 42 is arranged vertically in FIG. 5, it can be arranged horizontally as shown in FIG. In this case, a protrusion 36 extending downward is formed at the bottom of the vacuum flange 32, and the vacuum casing 31
The protrusion 37 may be formed to extend upward from the outer end of the piezoelectric element 42, and the piezoelectric element 42 may be disposed between the protrusions 36 and 37.

FIG. 7 is a sectional view showing a turbo-molecular pump according to the third embodiment of the present invention. In the embodiment shown in FIG. 7, instead of the friction damping mechanism 34 shown in FIG.
The viscous damper 50 is provided.

FIG. 8 is a sectional view showing a concrete example of the viscous damper shown in FIG. In FIG. 8, the cylindrical cylinder 5
By injecting the viscous fluid 54 into 1 and having a gap of several tens of microns between the outer diameter of the piston 52 and the inner diameter of the cylinder 51, the viscous fluid 54 is generated by the relative motion between the piston 52 and the cylinder 51. Move through the gap, piston 52
Also, the viscous frictional force generated between the cylinder 51 and the viscous fluid 54 acts as a damping force for the relative movement between the cylinder 51 and the piston 52. That is, by connecting the piston 52 to one of the vacuum flange 32 or the vacuum casing 31 and the cylinder 51 to the other,
A damping force can be applied to the relative movement between the vacuum flange 32 and the vacuum casing 31.

In FIG. 8, a seal 53 is provided to prevent the viscous fluid 54 from leaking from the cylinder 51 to the outside.

FIG. 9 is a sectional view of a turbo molecular pump according to the fourth embodiment of the present invention. In FIG. 9, one end of a cylindrical bellows 64 is fixed to the vacuum casing 31, and the other end of the bellows 64 is fixed to the vacuum chamber 62. Then, the vibration detector 60 is attached to the vacuum chamber 62, and the detection signal from the vibration detector 60 is input to the controller 61 that controls the electromagnet current in the turbo molecular pump,
By controlling the electromagnet current, the output of the vibration detector 60 (the output proportional to the vibration displacement component or the vibration velocity component or the vibration acceleration component), that is, the vibration of the mounting portion of the vibration detector 60 can be reduced. It should be noted that the vibration detection direction of the vibration detector 60 and the rotor attraction direction by the magnetic bearing electromagnet need to be substantially matched.

When the vibration detector 60 measures vibrations in the X direction in FIG. 9 and in the Y direction which is perpendicular to the paper surface, each of the output signals of the vibration detector 60 coincides with that direction. Try to affect the electromagnet current. Further, when a vibration detector for measuring the vibration only in the X direction is attached, it is assumed that the vibration of the vacuum chamber 62 is mainly caused by the rotational vibration of the rotary shaft of the turbo molecular pump 65, and the vibration is detected. Estimate the vibration in the Y direction from the output of the detector,
The current of the electromagnet that acts in the Y direction may be affected.

Further, the radial direction control of the rotary shaft of the turbo molecular pump 65 is performed by the attraction force of the electromagnets arranged at the two upper and lower positions, and the output of this vibration detector is also controlled by controlling the upper and lower electromagnets. Alternatively, only one of them may be controlled. Further, the vibration detector 60 may be attached to the turbo molecular pump 65 itself. FIG. 10 is a diagram for explaining the concept of the vibration reduction method when the vibration detector measures two directions of X and Y.
Although FIG. 10 shows the signal flow only in the X direction,
The Y direction is set similarly.

As shown in FIG. 10A, the output of the vibration detector 60 described with reference to FIG. 9 is supplied to the rotary shaft 2 of the turbo molecular pump.
03 is a detection force of the relative position between the stator 202 and the position sensor output, and as shown in FIG. 10B, a magnetic bearing for controlling the electric current of the electromagnet based on this position sensor output. Control circuit (PID control circuit 7 in FIG. 10)
2, 75) and the output signal of the vibration detector 60 is reduced.

Further, the filter circuits 70 and 71 shown in FIGS. 10A and 10B are composed of a low pass filter, a high pass filter, a band pass filter or a band erasing filter, and are selected according to the frequency range in which vibration is desired to be reduced. .

FIG. 11 is a diagram showing frequency characteristics (Bode diagram) of each filter circuit. When it is desired to reduce only low-frequency vibration, the low-pass filter shown in FIG. 11A is used, and when only high-frequency vibration is desired to be reduced, the high-pass filter shown in FIG. 11B is used. 11 (c), a bandpass filter having a filter center frequency at a specific frequency shown in FIG. 11 (c) is used to reduce only the frequency of FIG. A band erminating filter having the center frequency of the filter at a specific frequency indicated by is used.

FIG. 12 is a diagram for explaining the concept of the vibration reducing method when the vibration detector measures the vibration only in the X direction. As shown in FIG. 12, the X-direction position sensor output is given to the PID control circuit 80, the electromagnet 84 is controlled via the power amplifier 83, and the Y-direction position sensor output is given to the PID control circuit 85 to change the X-direction position. The feature is that the output of the vibration detector for detecting the vibration is added not only to the X direction but also to the Y direction control for controlling the rotation axis of the turbo molecular pump. Here, the phase shift circuit 82
Is a circuit for estimating the vibration in the Y-axis direction from the X-direction.
Assuming that the vibration of the vacuum chamber is mainly caused by the rotational vibration of the rotary shaft of the turbo molecular pump, this vibration is defined as the rotational vibration of the XY coordinate system having a certain amplitude, and the vibration in the Y direction is the turbo molecular. X is synchronized with the rotational speed of the pump rotation axis, and X
The vibration in the Y direction is estimated under the assumption that the vibration in the direction is 90 degrees out of phase with the vibration in the direction, and this is added to the control in the Y direction.

FIG. 13 is a sectional view of a turbo molecular pump according to the fifth embodiment of the present invention. In the embodiment shown in FIG. 9, the vibration is reduced by controlling the electromagnet current of the turbo molecular pump based on the output of the vibration detector 60. On the other hand, in this embodiment, a dedicated actuator is fixed to the turbo molecular pump, and the actuator is moved according to the output of the vibration detector, so that the active damper damps the vibration.

In FIG. 13, the turbo molecular pump 65 is attached to the vacuum chamber 62 by the vacuum flange 63 via the cylindrical bellows 64, the vibration detector 60 is attached to the vacuum chamber 62, and the detection signal from the vibration detector 60 is detected. By controlling the actuator 67 mounted on the lower surface of the turbo molecular pump 65 via the dedicated controller 68,
The output of the vibration detector 60, that is, the vibration of the vibration detector mounting portion is reduced.

FIG. 14, FIG. 16 and FIG. 17 are diagrams showing an example of the structure of the actuator section explained in FIG. Figure 1
4 is an example in which a bimorph type piezoelectric actuator is used as an actuator, in which a piezoelectric element 92 is attached to both surfaces of a leaf spring 91 attached to an actuator case 90, and a weight 93 is attached to the tip of the leaf spring 91. is there. By controlling the voltage 94 applied to the piezoelectric element 92, the leaf spring 91 can be vibrated at a desired frequency with the actuator case 90 as a fulcrum. By making this vibration the opposite phase to the vibration of the vibration detector mounting portion, the vibration of the vibration detector mounting portion can be suppressed. Here, the controller 104 is shown in FIG.
As shown in FIG. 5, a PID control circuit 10 for performing proportional calculation, differential calculation, or integral calculation of the output of the vibration detector (output proportional to the vibration displacement component, the vibration velocity component, or the vibration acceleration component), or adding these calculation outputs.
It has a function of applying a voltage proportional to the output of 0 to the actuator.

FIG. 16 shows an example in which a laminated piezoelectric actuator is used instead of the bimorph type piezoelectric actuator shown in FIG. As shown in FIG. 16, the laminated piezoelectric element 102 is fixed to the actuator case 101, and the weight 103 is attached to the end portion thereof, and the controller 104 is configured in the same manner as in FIG.

FIG. 17 shows an example in which an electromagnetic actuator is used instead of the piezoelectric actuator shown in FIGS. The weight 107 is fixed to the end of the leaf spring 106 attached to the actuator case 105, and both sides of the weight 107 are attracted by the electromagnets 108, whereby desired vibration can be given. By making this vibration the opposite phase to the vibration of the vibration detector mounting portion, the vibration of the vibration detector mounting portion can be suppressed. The controller has the same configuration as in FIG.

Further, in the controller shown in FIG.
The filter circuit 110 shown in FIG. 18 may be inserted. This filter circuit is composed of a low-pass filter, a high-pass filter, a band-pass filter or a band-elimated filter, and is selected according to the frequency range in which vibration is desired to be reduced. The characteristics of each filter circuit are shown in FIG. 11 described above. When it is desired to reduce only low frequency vibration, the low pass filter shown in FIG. 11 (a) is used, and when only high frequency vibration is desired to be reduced, FIG. 11 (b) is used. When it is desired to reduce only a specific frequency such as a rotation frequency by using the high pass filter shown in FIG. 11, a band pass filter having a center frequency of the filter at the specific frequency shown in FIG. 11C is used. When it is desired to reduce the vibration other than the frequency of (1), the band-elimated filter having the center frequency of the filter at the specific frequency shown in FIG. 11 (d) is used.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the scope of the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0057]

As described above, according to the present invention, the influence of external vibration of the turbo molecular pump can be significantly reduced, and it is used in the exposure apparatus of semiconductor devices and the observation of ultrafine structures such as nanoparticles. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a sectional view of a turbo molecular pump according to a first embodiment of the present invention.

2 is an enlarged view of the friction damping mechanism shown in FIG.

FIG. 3 is an enlarged view of another example of the friction damping mechanism shown in FIG.

FIG. 4 is a sectional view of a turbo molecular pump according to a second embodiment of the present invention.

5 is an enlarged view of a main part of the friction damping mechanism of FIG.

FIG. 6 is an enlarged view of a main part of another example of the friction damping mechanism of FIG.

FIG. 7 is a sectional view showing a turbo molecular pump according to a third embodiment of the present invention.

8 is a cross-sectional view showing a specific example of the viscous damper shown in FIG.

FIG. 9 is a sectional view of a turbo molecular pump according to a fourth embodiment of the present invention.

FIG. 10 is a diagram for explaining the concept of a vibration reduction method when the vibration detector measures two directions of X and Y.

FIG. 11 is a diagram showing frequency characteristics (Bode diagram) of each filter circuit.

FIG. 12 is a diagram for explaining the concept of a vibration reduction method when the vibration detector measures vibration in only the X direction.

FIG. 13 is a sectional view of a turbo molecular pump according to a fifth embodiment of the present invention.

FIG. 14 is a diagram showing an example in which a bimorph-type piezoelectric actuator is used as an actuator.

FIG. 15 is a diagram showing an example in which an output of a vibration detector drives an actuator via a PID control circuit.

16 is a diagram showing an example in which a laminated piezoelectric actuator is used instead of the bimorph type piezoelectric actuator shown in FIG.

FIG. 17 is a diagram showing an example in which an electromagnetic actuator is used instead of the piezoelectric actuator of FIGS. 14 and 16.

FIG. 18 shows a filter circuit and a PID for the output of the vibration detector.
It is a figure which shows the example which drives an actuator via a control circuit.

FIG. 19 is a sectional view of a pump body of a conventional turbo molecular pump.

FIG. 20 is a diagram showing a system configuration of a conventional turbo molecular pump.

FIG. 21 is an explanatory diagram of a pump body of a conventional turbo molecular pump.

[Explanation of symbols]

30,65 Turbo molecular pump, 31 Vacuum casing, 32 Vacuum flange, 33, 64, Bellows, 34
Friction damping mechanism, 35 thin plate, 36 Piezoelectric damping mechanism, 3
6,37 Projection, 40 Spring, 41 Spacer, 42, 9
2 piezoelectric element, 43 resistance, 50 viscous damper, 51
Cylinder, 52 piston, 53 seal, 54 viscous fluid, 60 vibration detector, 61, 68, 104 controller, 62 vacuum chamber, 67 actuator,
70, 71, 81, 110 Filter circuit, 80, 8
5,100 PID control circuit, 82 phase shift circuit,
83,86 power amplifier, 84,87,108 electromagnet, 90,101,105 actuator case, 9
1, 106 leaf spring, 102 laminated piezoelectric element.

Claims (11)

[Claims] 1. A vacuum evacuation device in which a vibration damping mechanism having a vibration transmission reducing mechanism is formed between the turbo molecular pump and the vacuum chamber in order to reduce the vibration transmission from the vacuum casing of the turbo molecular pump to the vacuum chamber. The vibration damping mechanism is provided between the vacuum cover of the turbo molecular pump and a bellows having a low spring constant for connecting the vacuum casing and a vacuum flange connected to the vacuum chamber, and between the vacuum cover and the vacuum flange. A vacuum evacuation device using a turbo molecular pump, comprising a friction damping mechanism. 2. A vacuum evacuation device in which a vibration damping mechanism having a vibration transmission reducing mechanism is formed between the turbo molecular pump and the vacuum chamber to reduce the vibration transmission from the vacuum casing of the turbo molecular pump to the vacuum chamber. The vibration damping mechanism is a bellows having a low spring constant for fastening between a vacuum casing of the turbo molecular pump and a vacuum flange connected to the vacuum chamber, and between the vacuum casing and the vacuum flange. A vacuum evacuation device using a turbo molecular pump, comprising: a piezoelectric element provided; and a discharge element that discharges a voltage generated in the piezoelectric element. 3. A vacuum evacuation device in which a vibration damping mechanism having a vibration transmission reducing mechanism is formed between the turbo molecular pump and the vacuum chamber to reduce vibration transmission from the vacuum casing of the turbo molecular pump to the vacuum chamber. A bellows having a low spring constant for fastening between a vacuum casing of the turbo molecular pump and a vacuum flange connected to the vacuum chamber, and a viscous damper provided between the vacuum casing and the vacuum flange. A vacuum evacuation device using a turbo molecular pump. 4. A vacuum evacuation device which is used by attaching a vacuum flange of a vacuum chamber to a vacuum chamber from a turbo molecular pump, comprising a vibration detector attached to the vacuum chamber or the turbo molecular pump, and an output of the vibration detector. A vacuum evacuation device using a turbo molecular pump, wherein a current corresponding to the above is superimposed on a magnetic bearing electromagnet that supports a rotating shaft in the turbo molecular pump. 5. The vacuum evacuation device using the turbo molecular pump according to claim 4, wherein the output of the vibration detector is added to the preceding stage of the magnetic bearing control circuit. 6. The current superimposed on the magnetic bearing electromagnet is proportional to the vibration displacement component, the vibration velocity component, or the vibration acceleration component of the vacuum chamber obtained by the output of the vibration detector or the calculation. An evacuation device using the turbo-molecular pump according to claim 4. 7. The rotation of the rotary shaft in the turbo molecular pump from the vibration displacement output, the vibration displacement component of the vacuum chamber, or the vibration displacement component, the vibration velocity component, or the vibration acceleration component of the vacuum chamber obtained by the calculation of these values. The vacuum evacuation device using a turbo molecular pump according to claim 5 or 6, wherein several components are extracted and a current based on the extracted signal is superimposed on the magnetic bearing electromagnet. 8. The current to be superimposed on the magnetic bearing electromagnet is obtained through a low-pass filter or a high-pass filter before being superimposed.
8. A vacuum exhaust device using the turbo molecular pump according to any one of items 1 to 7. 9. A vacuum evacuation device in which a vacuum flange of a turbo molecular pump is attached to a vacuum chamber for use, and an active damper including an electromagnetic actuator or a piezoelectric actuator attached to the turbo molecular pump is provided, wherein the active damper is the vacuum chamber. A vacuum evacuation apparatus using a turbo molecular pump, which is controlled by a signal from a chamber or a vibration detector attached to the turbo molecular pump. 10. The rotational speed component of the rotating shaft in the turbo molecular pump is extracted from a signal from a vibration detector attached to the turbo molecular pump, and the active damper is controlled by the extracted signal. The vacuum evacuation device using the turbo molecular pump according to claim 9. 11. A signal from a vibration detector attached to the turbo molecular pump is calculated by a low-pass filter or a high-pass filter, and the active damper is controlled by a signal obtained as a result. A vacuum evacuation device using the turbo molecular pump according to Item 8 or 9.