JPH07302124A - Drive - Google Patents

Abstract

PURPOSE:To prevent the adverse influence given to the positioning accuracy due to the heating of a driving device by measuring the temperature of a driving means or the temperature of a place near the driving means at least at a single point and controlling the temperature of a refrigerant that is circulated by a cooling device based on the measured temperature. CONSTITUTION:A controller 14 gives a command to a driver 15 so that a positioning subject 10 is set at a prescribed position based on the position data on a position measurement means 12. Thus the driver 15 drives the driving means 1a and 1b. Under such conditions, the temperature varies if the means 1a and 1b generate the heat. A temperature measurement means 2 measures the temperature by a temperature sensor 5 placed at the means 1b (1a), and a temperature control means 4 controls the temperature of a refrigerant 3a that is circulated by a cooling device 6. Thus the temperature changes of both means 1a and 1b can be eliminated. Then the thermal deformation never occurs since the temperature change of the means 1b is eliminated. Therefore the change of distance is eliminated between the subject 10 and a position standard 11 and no error is caused in measurement of positions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device mounted on a precision positioning device such as an XY table of a semiconductor exposure device or a shape measuring device, or a high precision processing machine.

[0002]

2. Description of the Related Art Today, for example, a positioning accuracy on the order of nanometers (nm) is required, for example, 100 m.
m low thermal expansion material (coefficient of thermal expansion 1 × 10 ^-6 ) deforms 100 nm with a temperature change of 1 ° C, and position measurement is possible even if the air temperature change in the optical path of the optical interferometer is 1 ° C. Since the value changes by 100 nm depending on the conditions, it is essential to cool the drive device that recovers the heat emitted from the drive device as a measure for preventing these temperature changes.

Conventionally, since the heat generated by the driving device causes thermal deformation of the structure and air fluctuation which causes an error in the optical interferometer, the precision positioning device is cooled by using a refrigerant, a heat pipe, a Peltier element or the like. The temperature and flow rate of the refrigerant, the heat radiating temperature of the heat pipe, the driving current of the Peltier element, etc. are set in advance so that the driving device and the device in which the driving device is mounted will reach the prescribed temperature when the driving device generates heat. is doing. Especially, when the heat is recovered by circulating the refrigerant, the temperature and flow rate of the refrigerant are set in advance so that the recovered amount is almost equal to the calorific value or the driving device or the positioning device reaches a predetermined temperature. It is carried out.

FIG. 5 is a block diagram showing an example of such a conventional driving device. As shown in the figure, in the drive device for precisely positioning the positioning target 10 by the position measuring means 12, the controller 14, and the driver 15, the cooling device 6 circulates the refrigerants 3a and 3b to drive the drive means 1a. , 1b to recover the heat. The temperature of the refrigerant 3a flowing at this time is a preset temperature, and the temperature control means 4 issues a command to the cooling device 6 based on the temperature.

[0005]

However, in the above-mentioned conventional example, since the refrigerant having a temperature preset based on the total heat generation amount is circulated at the time of driving, the heat generation amount of the driving device is not constant, and the driving device is not driven. Since the amount of heat generated varies depending on the drive pattern of the device, the temperature changes,
Even when the drive device is stopped and the heat generation is very small or zero, the temperature of the drive device is lowered because the coolant whose coolant temperature is assumed to be used is used and the heat recovery amount is always constant. There were drawbacks such as passing by. Due to this drawback, the temperature of the structure around the drive unit and the temperature of the atmosphere were fluctuated, and the positioning accuracy of the nanometer order was adversely affected by the thermal deformation of the structure, the measurement error of the position caused by the temperature change, and the like. .

An object of the present invention is to eliminate the adverse effects on the positioning accuracy due to the heat generated by the drive unit in view of the problems of the prior art.

[0007]

In order to achieve this object, the present invention provides a drive device including drive means for performing precise positioning, and a cooling device for recovering heat generated from the drive means by using a refrigerant. A temperature measuring means for measuring the temperature of the driving means or in the vicinity thereof at at least one location, and a control means for controlling the temperature of the refrigerant circulated by the cooling device based on the temperature obtained by the temperature measuring means. With this, the temperature change of the drive device, the structure around the drive device, the atmosphere, etc. is reduced, the thermal deformation of the structure, the measurement error due to the temperature change is reduced, and the positioning accuracy of the drive device is improved. It is a thing.

That is, when the driving means generates a lot of heat and the temperature rises, the temperature of the refrigerant is lowered to increase the cooling amount, and conversely, when the heat generation is little and the temperature decreases, the temperature of the refrigerant is raised to decrease the cooling amount. The temperature of the apparatus, the structure in the vicinity thereof, or the atmosphere is kept from fluctuating. When the temperature of the refrigerant decreases, the temperature difference between the cooling means and the driving means, which is an object to be cooled, increases, the amount of heat transferred increases, and the cooling capacity increases. Therefore, the temperature of the driving device or the like is controlled by the temperature of the refrigerant.

When the temperature measuring means measures the temperature of the refrigerant in the vicinity of the driving means, for example, when the temperature measuring point of the temperature measuring means is the temperature of the refrigerant passing through the driving device, the temperature of this refrigerant is Since it serves as an index of the amount of heat generated or the temperature of the driving means, the increase or decrease in the temperature of the refrigerant passing through the driving means is detected, and the temperature of the refrigerant sent out by the cooling device is adjusted.

Further, the driving means is a linear motor,
The temperature measuring means is a coil of a linear motor, a permanent magnet,
Or, in the case of measuring the temperature at at least one place in the vicinity of them, the temperature measurement point is in the vicinity of the coil which is the heat source and the temperature change can be measured immediately. Time delay of temperature control and cooling control is suppressed to a minimum. Further, since the heat source, the temperature measurement point, and the cooling part are close to each other, the calorific value can be accurately estimated and the cooling amount can be accurately predicted, and the heat recovery amount of the refrigerant by controlling the refrigerant temperature corresponds to the calorific value. Be adjusted accurately. Therefore, by optimizing the cooling amount and increasing the efficiency, the temperature of the device is kept constant, disturbance factors such as length measurement error due to thermal deformation and temperature change are reduced, and the positioning accuracy of the drive device is improved.

[0011]

【Example】

[Embodiment 1] FIG. 1 is a constitutional view showing a drive device according to a first embodiment of the present invention, and best shows the features of the present invention. In the figure, 1a and 1b are a pair of drive means, 1a is a fixed side drive means, and 1b is a movable side drive means movable in the left-right direction in the drawing. 5 is a temperature sensor arranged in the driving means 1a or 1b, 2 is a temperature measuring means for outputting the temperature data measured by the temperature sensor 5 to the outside, 3a is a supply-side refrigerant for cooling the driving means 1a, 1b, 3b is Refrigerant on the return side for cooling the driving means 1a, 1b, 4 is temperature control means for receiving temperature data from the temperature measuring means 2 and outputting a command signal for controlling the temperature of the refrigerant 3a, and 6 is for temperature control means 4. A cooling device 10 for flowing a refrigerant having a predetermined temperature based on a command signal is a movable side driving means 1
Positioning target placed on b, 11 is movable side drive means 1
Position reference of the positioning object 10 placed on b, 12 is position measuring means for measuring the position of the positioning object 10 with reference to the position reference 11, 13 is a length measured by the position measuring means 12, and 14 is position measurement. Positioning object 10 obtained from the means 12
A controller that outputs a command signal for controlling the drive amount of the driving device based on the position data of 15 and a driver 15 that drives the driving means 1a and 1b in accordance with the command signal from the controller 14.

Positioning target 1 is generated by moving driving means 1b in the left-right direction in the drawing with respect to fixed driving means 1a.
0 moves in the same direction, and the position of the positioning target 10 is measured by the position measuring means 12 with the position reference 11 as a reference. For example, when the position reference 11 is a reflecting mirror and the position measuring means 12 is a laser interferometer, the length 13 is the optical path length, and this is the position of the positioning target 10. In general, since the positioning object 10 and the position reference 11 are somewhat separated from each other, and the position of the position reference 11 is set as the position of the positioning object 12, the distance variation between them is an error in positioning. The controller 14 gives a command to the driver 15 so that the positioning object 10 is positioned at a predetermined position by using the position data of the position measuring means 12, and the driver 15
Drives the driving means 1a, 1b. At that time, if the driving means 1a, 1b generate heat, the temperature tends to change. The temperature measuring means 2 measures this temperature using the temperature sensor 5,
The temperature control means 4 controls the temperature of the refrigerant 3a circulated by the cooling device 6 so that the temperature changes of the driving means 1a and 1b are eliminated.

For example, when the driving means 1b generates a large amount of heat and the temperature rises, the temperature of the refrigerant 3a is lowered to increase the cooling amount.
By increasing the temperature of a and decreasing the cooling amount, the drive device,
Alternatively, the temperature of the structure or the atmosphere in the vicinity should not be changed. If the temperature of the refrigerant 3a decreases,
The temperature difference between the cooling means and the driving means 1a, 1b increases,
Therefore, since the amount of heat transfer increases and the cooling capacity increases,
The temperature of the drive device or the like can be controlled by the temperature of the refrigerant 3a.

When the temperature change of the driving means 1b disappears in this way, the thermal deformation of the driving means 1b disappears and the distance change between the positioning object 10 and the position reference 11 disappears. Therefore, since there is no change in the distance between the positioning target 10 and the position reference 11, the position of the position reference 11 measured by the position measuring means 12 can be regarded as the position of the positioning target 10, and an error in position measurement is eliminated. Further, by reducing the temperature change of the driving means 1a or 1b, it is possible to prevent the ambient temperature, in particular, the temperature change of the optical path 13 to be measured, and to prevent the measured value of the position measuring means 12 from fluctuating. Disappears.

As described above, when the driving device is driven to position the object to be positioned, the temperature of the driving means is measured, and the temperature of the refrigerant is adjusted so that the temperature does not change. Since the temperature change in the vicinity or in the atmosphere can be reduced and the thermal deformation of the structure and the fluctuation of the air can be suppressed, the positioning accuracy can be improved as compared with the conventional case.

FIG. 2 is a block diagram showing an arrangement example of the temperature sensor 5 by extracting the inside of the broken line in FIG. In the figure, 5 is a temperature sensor arranged in the driving means 1b, 5a, 5b, 5
c is a temperature sensor arranged in the driving means 1a, 5d is a temperature sensor for measuring the temperature of the atmosphere arranged in the atmosphere near the driving means 1a or 1b, and 5e is the refrigerant 3 on the return side.
It is a temperature sensor arranged in b. The temperature sensor is arranged at any one point of the driving means 1a, 1b, the atmosphere, the refrigerant 3b, or the like among these arrangement positions, or at two or more points thereof, and the temperature measuring means 2 measures 1
The temperature control means 4 controls the temperature of the refrigerant based on the temperature above the point. The temperature sensor 5d is effective for suppressing the temperature change of the air, and if the temperature sensor 5e is used, the increase or decrease of the heat generation amount can be inferred by the amount of the temperature increase of the refrigerant. For example, if the temperature of the refrigerant 3b increases, the temperature of the refrigerant 3a increases. It is possible to suppress the temperature change of the driving means and its vicinity, or the temperature of the atmosphere.

[Embodiment 2] FIG. 3 shows a second embodiment of the present invention and is a structural view (partially sectional view) showing another embodiment in which a linear motor is used as a driving means. 21a, 2
1b, 21c and 21d are permanent magnets, and 22 is a permanent magnet 21.
Reference numerals a to 21d are fixed to the yoke, 23 is a coil through which an electric current flows, and 24 is a coil support tool that supports the coil 23 and serves as a flow path for the refrigerants 3a and 3b. The position measuring means, controller, driver, etc. are not shown. Since the coil 23 is in the magnetic field generated by the permanent magnet 21, a Lorentz force is generated in the left-right direction in the drawing when a current flows through the coil 23, and the yoke 22 and the coil support 24 are relatively driven in the left-right direction. It When driving this linear motor, a current flows through the coil 23 and the coil 23 generates heat. The temperature sensor 5 is arranged in the coil 23 or in the vicinity thereof, the temperature measuring means 2 measures the temperature, the temperature control means 4 commands the refrigerant temperature so that the temperature change disappears, and the cooling device 6 commands the temperature. Refrigerant 3a is flowed. This refrigerant directly cools the coil 23 and the coil support 24, which are heat sources, and recovers the heat, and therefore has the effect of suppressing the temperature change of the structure of the drive unit and the atmosphere. The temperature sensor 5 includes a coil support 24, a yoke 22, and permanent magnets 21 a to 21.
The same effect can be obtained by arranging it in d, the refrigerant 3b, or the like.

[Embodiment 3] FIG. 4 is a structural view showing a third embodiment of the present invention in which a multipole linear motor is used as a driving means, and is a drawing in which a coil portion of the linear motor is extracted. 23a, 23b and 23c are coils, 5A, 5B and 5
C is a temperature sensor arranged in each of the coils 23a, 23b and 23c. In the case of a multi-pole linear motor, since there are a plurality of coils, it is possible to arrange the temperature sensor at an appropriate point as in the case of the single pole in FIG. 3, but as shown in FIG. It is also possible to arrange a temperature sensor and determine the temperature of the refrigerant based on the plurality of temperatures measured by the temperature measuring means 2. Since the current flowing through each coil is different and the temperature is also different, the temperature of the refrigerant can be controlled by weighting each temperature or selecting the maximum value of each temperature. Also in the case of a multi-pole linear motor, the same effect as in the above embodiment can be obtained.

[0019]

As described above, in the drive device including the drive means for performing the precise positioning and the cooling device for recovering the heat generated from the drive means by using the refrigerant, the temperature of the drive means or the vicinity thereof. Since the temperature of the refrigerant is measured at at least one location and the temperature of the coolant circulated by the cooling device is controlled based on the temperature, the temperature change of the driving means, the structure around the driving means, the atmosphere, etc. is reduced, This has the effect of reducing the length measurement error caused by the thermal deformation and temperature change of the structure, and further improving the positioning accuracy of the drive unit on the nanometer order.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a drive device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing an arrangement example of temperature sensors by extracting the inside of the broken line in FIG.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention in which a linear motor is used as a driving means.

FIG. 4 is a configuration diagram showing only a coil portion, showing a third embodiment of the present invention in which a multipole linear motor is used as a driving unit.

FIG. 5 is a configuration diagram showing a conventional example of a driving device.

[Explanation of symbols]

1a: fixed side driving means, 1b: movable side driving means,
2: Temperature measuring means, 3a: Supply side refrigerant, 3b: Return side refrigerant, 4: Temperature control means, 5, 5a, 5b, 5c, 5
d, 5e: Temperature sensor, 6: Cooling device, 10: Positioning object, 11: Position reference, 12: Position measuring means, 13: Length to be measured, 14: Controller, 15: Driver, 2
1a, 21b, 21c, 21d: Permanent magnet, 22: Yoke, 23: Coil, 24: Coil support, 23a, 23
b, 23c: coil, 5A, 5B, 5C: temperature sensor.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area H01L 21/027 21/68 K

Claims (3)

[Claims] 1. A drive device comprising a drive means for performing precise positioning and a cooling device for recovering heat generated from the drive means by using a refrigerant, wherein the temperature of the drive means or in the vicinity thereof is measured at at least one location. And a control unit that controls the temperature of the refrigerant circulated by the cooling device based on the temperature obtained by the temperature measurement unit. 2. The drive unit according to claim 1, wherein the temperature measuring unit measures the temperature of the refrigerant near the drive unit. 3. The drive device according to claim 1, wherein the drive means is a linear motor, and the temperature measuring means measures a temperature of at least one position of a coil of the linear motor, a permanent magnet, or their vicinity. A drive device characterized by being.