JPH05191961A - Linear motor and xy drive table employing linear motor - Google Patents

Abstract

PURPOSE:To cool heated parts of a linear motor efficiently while eliminating vibration source such as cooling jacket. CONSTITUTION:Stator of a DC linear motor holds electromagnetic coils 4A-4F arranged in series in the longitudinal direction wherein respective electromagnetic coils 4A-4F are heating ends of heat pipes and parts of lead wires 4AL-4FL of the electromagnetic coils 4A-4F penetrate through heat-exchangers 10A-10F, respectively, and serve as the cooling ends of heat pipe to liquefy refrigerant in the heat pipes which is gasified by the heat of the electromagnetic coils 4A-4F. Lead wires 4AL-4FL are connected, respectively, through power amplifiers 11A-11F with a control circuit 12 for controlling the currents flowing through the electromagnetic coils 4A-4F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor used for an XY drive table of a semiconductor exposure apparatus, an inspection apparatus used in a manufacturing process of an integrated circuit such as a pattern inspection, and an XY drive table using the same. In particular, the present invention relates to a linear motor capable of efficiently cooling a heat generating portion and an XY drive table using the linear motor.

[0002]

2. Description of the Related Art An XY drive table used in a semiconductor exposure apparatus or a pattern inspection apparatus for an integrated circuit has a movable base for holding a substrate such as a wafer on two axis (X axis) orthogonal to each other on a surface plate.
A drive motor for reciprocating movement in the directions of the axis and the Y-axis). In recent years, efforts have been made to reduce the size and increase the accuracy of a device by utilizing a linear motor as the drive motor. A conventional example of such a linear motor will be described with reference to FIGS. 9 and 10.

The linear motor stator 151 is composed of a pair of hollow groove-shaped coil holding members 152a and 152b, and a pair of connecting members 153 for integrally connecting both of them.
a, 153b, and the pair of coil holding members 152
It is arranged between a and 152b, and consists of a plurality of electromagnetic coils 154A to 154F whose both ends are held by the grooves of the coil holding members 152a and 152b, respectively. The linear motor mover 155 includes a top plate 156 and a bottom plate 157.
A pair of permanent magnets 158a, 158 respectively held by
b and a pair of side plates 159a and 159b integrally connected to the opposing surfaces of the top plate 156 and the bottom plate 157, respectively. The top plate 156, the bottom plate 157, and the both side plates 159a,
159b forms a tubular frame with a rectangular cross section. The tubular frame or mover 155 is slidably fitted to the linear motor stator 151, as shown in FIG. Current is from power cable 160 to electromagnetic coil 154A
When sequentially supplied to ~ 154F, the linear motor mover 155 moves along the linear motor stator 151. At this time, the coil generates heat due to Joule heat, so that the cooling pipe 1 is attached to the water cooling jackets 152c and 152d of the coil holding members 152a and 152b.
Cooling water is supplied from 61 to the coil holding members 152a,
The contact surface between 152b and the coils 154A to 154F is cooled.

[0004]

However, according to the above-mentioned conventional technique, since the cooling water is supplied to the water cooling jacket of the coil holding member to cool the coil, there are the following problems.

(1) Only the contact surface between the coil holding member and the coil is cooled, and the portion of the coil facing the permanent magnet is not sufficiently cooled.

(2) Since the connecting members for connecting the coil holding members on both sides do not generate heat and thus do not need cooling, they are cooled by contact with the coil holding members.
The stator, which serves as a guide for the mover, is thermally deformed and the accuracy of the XY drive table deteriorates.

(3) When the electromagnetic coil is held by the mover, it is necessary to connect a cooling pipe to the mover, which requires a large driving force.

(4) Pressure fluctuations are easily transmitted from the pump for supplying the cooling water to the coil holding member, and vibration shock is likely to occur.

The present invention has been made in view of the above-mentioned problems of the prior art. The linear motor efficiently cools the heat generating portion of the linear motor and does not require a cooling jacket or the like as a vibration source. It is an object of the present invention to provide an XY drive table using the.

[0010]

In order to achieve the above object, the linear motor of the present invention and an XY using the same.
In the drive table, at least the electromagnetic coil is a part of the heat pipe, and at least a part of the lead wire of the electromagnetic coil is the other part of the heat pipe, and is cooled by the cooling means. And

The linear motor may be a linear DC motor, a linear synchronous motor or a linear induction motor.

[0012]

According to the apparatus of the present invention, the portion where the current of the linear motor flows and Joule heat is generated is the heating end of the heat pipe, and the refrigerant filled in the internal space of the heat generating portion is directly vaporized. To be cooled. The vaporized refrigerant flows to the cooling end of the heat pipe, is cooled and liquefied by the cooling means, and then returns to the heat generating portion of the linear motor to cool it. When the heat generating portion of the linear motor is composed of a plurality of electromagnetic coils, the refrigerant vaporized by each electromagnetic coil is guided to the cooled leader line and liquefied.

If the heat generating portion is the guide plate, the vaporized refrigerant is liquefied at the cooling end of the guide plate.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a linear DC motor of the first embodiment, in which a long stator 1 has a plurality of annular grooves 3 arranged in series in the longitudinal direction thereof. Each groove 3 accommodates an electromagnetic coil 4A-4F, respectively. A mover 5 slidable along the stator 1 includes a top plate 6 and a bottom plate 7 facing each other, a permanent magnet 8 fixed to the top plate 6,
And a tubular frame composed of a pair of side plates 9a, 9b integrally connected between the top plate 6 and the bottom plate 7.

As shown in FIG. 2, each electromagnetic coil 4A-4
The respective lead lines 4AL to 4FL of F are heat exchangers 10A to 10F and an amplifier 11 which are cooling means.
It is connected to the control circuit 12 via A to 11F. The control circuit 12 selects one of the electromagnetic coils 4A to 4F according to the position of the mover 5 according to the output of a position measuring device (not shown) that detects the position of the mover 5, and sequentially outputs the current. Supply. The electromagnetic coils 4A to 4 which are sequentially excited in this manner
F generates a thrust force for moving the mover 5 by the interaction with the permanent magnet 8 of the mover 5.

The electromagnetic coils 4A to 4F and the lead wires 4A to 4F are made of continuous heat pipes. The heat pipe is designated by 13 in its entirety in FIG.
The hollow tube 14 is made of a good conductor of electricity, the outer surface of the hollow tube 14 is covered with an insulating film 15, and the inner space of the hollow tube 14 is filled with ultrapure water or the like. The wick 16 impregnated with the refrigerant is filled.

When electric current is sequentially supplied to the electromagnetic coils 4A to 4F and Joule heat is generated in the electromagnetic coils, the refrigerant in the electromagnetic coils evaporates, and the evaporated refrigerant heats in the lead wire of each electromagnetic coil. It moves at high speed toward the exchangers 10A to 10F. The liquefied refrigerant that has been cooled and liquefied in each of the heat exchangers 10A to 10F moves in the direction opposite to the above in each of the leader lines, returns to the heat generating portion of each of the electromagnetic coils 4A to 4F, and absorbs heat again. Evaporate and head for the heat exchanger. Therefore, a pump for circulating the refrigerant is not required, and in addition, since the heat generating portions of the electromagnetic coils 4A to 4F can be directly cooled, there is no need to cool unnecessary portions.
The cooling efficiency is also extremely high.

FIG. 4 is a perspective view showing the linear synchronous motor of the second embodiment, in which the stator 21 is a pair of elongated members 22.
a, 22b, and a plurality of magnetic rods 23a, 23b ... Arranged between the two, the mover 25 includes a top plate 2
6, bottom plate yoke 26, three electromagnetic coils 24A, 24
Tooth poles 28 for holding B and 24C, and a pair of side plates 29a and 29 for integrally connecting the top plate 26 and the bottom plate yoke 26.
It is a tubular frame made of b. As shown in FIG. 5, each of the electromagnetic coils 24A, 24B, and 24C has a lead wire 2 that individually passes through heat exchangers 30A, 30B, and 30C that are cooling means.
Amplifiers 31A, 3 by 4AL, 24BL, 24CL
It is connected to the control circuit 32 via 1B and 31C. Each electromagnetic coil 24A, 24B, 24C and each lead wire 24AL, 24BL, 24CL is a heat pipe made of a hollow tube as in the first embodiment.

From the control circuit 32 to each electromagnetic coil 24A, 2
When a three-phase alternating current with a phase difference of 120 degrees is supplied to 4B and 24C, a moving magnetic field is generated between the tooth pole 28 and the bottom plate yoke 27, and the interaction between the moving magnetic field and the magnetic rods 23a, 23b ... The mover 25 continuously moves along the stator 21. Each of the electromagnetic coils 24A, 2 by the above current
The heat generated in 4B and 24C evaporates the refrigerant in the electromagnetic coil, and the vaporized refrigerant is respectively in the heat exchangers 30A and 30A.
Leaders 24AL, 24B toward 30B, 30C
After moving in L and 24CL and being cooled and liquefied by the heat exchanger, it returns to the heat generating portion again. As in the first embodiment, a pump for circulating the refrigerant is not required, and the heat generating portion can be directly cooled. In addition, this embodiment uses the mover 2
Reference numeral 5 holds the electromagnetic coils 24A, 24B and 24C, but it is lightweight because it does not require a coolant supply means, and therefore does not require a large driving force.

FIG. 6 is a perspective view showing the linear induction motor of the third embodiment. The stator 41 comprises a long guide plate 42 and a pair of fixed legs 43a and 43b supporting the guide plate 42, and a mover 45. Is a tubular frame composed of a top plate yoke 46, a bottom plate yoke 47, tooth poles 48 holding a pair of electromagnetic coils 44A and 44B, and a side plate 49 integrally connecting the top plate yoke 46 and the bottom plate yoke 47.

As shown in FIG. 7, each electromagnetic coil 44A. Four
4B is a heat exchanger 50 which is a cooling means individually.
By leader lines 44AL and 44BL passing through A and 50B,
It is connected to the control circuit 52 via the amplifiers 51A and 51B.

Each electromagnetic coil 44A, 44B and each lead wire 44AL, 44BL is a heat pipe made of a hollow tube as in the first embodiment. The derivative 42 is also made of a hollow plate, the outer surface of which is covered with an insulating film, and the inner space thereof is filled with a wick impregnated with a refrigerant such as ultrapure water. One end of the guide plate 42 is inserted into the heat exchanger 53 for cooling. That is, the guide plate 42 is a heat pipe made of a hollow body, like the electromagnetic coils 44A and 44B.

From the control circuit 52 to the electromagnetic coils 44A, 4
When a two-phase alternating current with a phase difference of 90 degrees is supplied to 4B, a moving magnetic field is generated between the tooth pole 48 and the bottom plate yoke 47, an induced current flows through the guide plate 42, and a thrust force for moving the mover 45 is generated. To do. The heat generated in each of the electromagnetic coils 44A, 44B and the induction plate 42 is carried to each of the heat exchangers 50A, 50B, 53 by the function of the heat pipe described above and removed. As in the first and second embodiments, the heat generating portion can be directly cooled without the need for a pump for circulating the refrigerant. Further, similarly to the second embodiment, the mover having the electromagnetic coil is light in weight because it does not require the refrigerant supply means,
Therefore, a large driving force is not required.

Next, X using the linear motor of the present invention
The Y drive table will be described with reference to FIG.

Wafer chuck 1 which is an XY drive table
01 is placed on the y movable table 102, and the y movable table 102 is
It is reciprocally movable in the Y-axis direction along the y-guide 103. The y guide 103 is integrally connected to the x movable base 104, and the x movable base 104 can reciprocate in the X axis direction along the x guide 105. The y movable base 102 includes the y linear motor stator 106 a and the y linear motor movable element 1.
It is reciprocally moved by a y linear motor 107 composed of 06b.

The x movable table 104 is reciprocated by an x linear motor 109 composed of an x linear motor stator 108a and an x linear motor movable element 108b.
The x-guide 105 is fixed to the surface plate 110, and the x-sliding body 111 and y which are integrally connected to the x-movable base 104.
Known air slides are provided between the guide 103 and the surface plate 110. Similarly, between the x guide 105 and the x slide body 111, and between the y movable base 102 and the y guide 1.
A well-known air slide is also provided between each of them. y linear motor 107 and x linear motor 1
Reference numerals 09 are linear DC motors similar to those in the first embodiment, and include y linear motor stators 106a and x.
Each of the linear motor stators 108a has the same structure as the stator 1 of the first embodiment, and the y linear motor mover 106b and the x linear motor mover 108b are
Each has a structure similar to that of the mover 5 of the first embodiment.

When the y linear motor 107 is driven,
y A current sequentially flows through a plurality of electromagnetic coils (not shown) of the linear motor stator 106a to generate heat, but as described above, each electromagnetic coil and the lead wire of each electromagnetic coil is a heat pipe. Is cooled by the heat exchanger, the generated heat is quickly removed from the heat generating portion. The same applies to the x linear motor stator 108a.

Therefore, the cooling efficiency is high, and the unnecessary portion is excessively cooled without impairing the accuracy of the XY drive table, and in addition, a coolant supply means such as a pump is not required, which may cause vibration shock. Nor.

In addition, in place of the linear DC motor, the second
It goes without saying that the linear synchronous motor of the embodiment or the linear induction motor of the third embodiment can be used as the y linear motor 107 and the x linear motor 109.

[0031]

Since the present invention is configured as described above, it has the following effects.

The heat generating portion of the linear motor is efficiently cooled, and since it is not necessary to continuously supply the refrigerant, vibration is not generated, and the weight of the mover can be easily reduced.

Further, the XY drive table of the present invention can prevent the accuracy from being lowered due to the cooling of the linear motor.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment.

FIG. 2 is a block diagram of the first embodiment.

FIG. 3 is an enlarged sectional view of a heat pipe.

FIG. 4 is a partially cutaway perspective view of a second embodiment.

FIG. 5 is a block diagram of a second embodiment.

FIG. 6 is a partially cutaway perspective view of a third embodiment.

FIG. 7 is a block diagram of a third embodiment.

FIG. 8 is a perspective view of an XY drive table.

FIG. 9 is a partially cutaway perspective view of a conventional example.

10 is a cross-sectional view taken along the line AA ′ of FIG.

[Explanation of symbols]

1, 21, 41, 151 Stator 4A-4F, 24A-24C, 44A, 44B, 154
A to 154F electromagnetic coil 4AL to 4FL, 24AL to 24CL, 44AL, 44
BL Lead wire 5,25,45,155 Mover 8,158a, 158b Permanent magnet 10A-10F, 30A-30C, 50A, 50B
Heat exchanger 11A to 11F, 31A to 31C, 51A, 51B
Power amplifier 12, 32, 52 Control circuit 13 Heat pipe 14 Hollow tube 23a, 23b ... Magnetic rod 28, 48 Tooth pole 42 Guide plate 101 Wafer chuck 102 y Movable table 103 y Guide 104 x Movable table 105 x Guide 106a y Linear motor stator 106b y Linear motor mover 107 y Linear motor 108a x Linear motor stator 108b x Linear motor mover 109 x Linear motor 110 Surface plate

Claims (5)

[Claims] 1. At least an electromagnetic coil is a part of a heat pipe, and at least a part of a lead wire of the electromagnetic coil is another part of the heat pipe and is cooled by a cooling means. Characteristic linear motor. 2. The linear motor according to claim 1, wherein the linear motor is a linear DC motor. 3. The linear motor according to claim 1, wherein the linear motor is a linear synchronous motor. 4. The linear motor according to claim 1, wherein the linear motor is a linear induction motor, the guide plate is a heat pipe, and one end of the guide plate is cooled. 5. An x movable table which is reciprocally movable in a predetermined direction along a surface plate, and an x movable table for moving the x movable table.
A linear motor, a y movable table which is reciprocally movable along the x movable table in a direction perpendicular to the moving direction of the x movable table, and a y linear motor for moving the y movable table. The XY drive table, wherein at least one of the x linear motor and the y linear motor is the linear motor according to any one of claims 1 to 4.