JP4837993B2 - LINEAR MOTOR, MANUFACTURING METHOD THEREOF, AND STAGE DEVICE USING THE LINEAR MOTOR - Google Patents

Description

  The present invention relates to a linear motor configured to supply cooling water around a coil to suppress heat generation of the linear motor, a manufacturing method thereof, and a stage apparatus using the linear motor.

  For example, in a precision positioning apparatus used in a semiconductor manufacturing apparatus, a liquid crystal manufacturing apparatus, or the like, a linear motor is used as a driving means for driving a stage on which a workpiece such as a substrate is placed, and both ends of the stage are connected to a pair of linear motors. The translation drive is controlled by a motor.

  This type of linear motor includes a coil portion in which a plurality of coils are arranged in a row, and a magnet yoke portion in which a plurality of permanent magnets arranged to face the coil rows are arranged in a row. Yes. And a thrust (driving force) generate | occur | produces with respect to a permanent magnet by supplying with electricity to a coil part and generating electromagnetic force.

  In addition, as a configuration of the linear motor, there are a moving coil method in which the magnet yoke portion is a fixed side and the coil portion is a movable side, and a moving magnet method in which the coil portion is a fixed side and the magnet yoke portion is a movable side.

  In any of the above two methods, when a temperature increase due to heat generation from the coil occurs, the resistance value of the coil itself increases, and the drive current decreases. In a linear motor, the thrust is proportional to the drive current, and therefore the thrust decreases when the drive current decreases.

  In addition, the heat generated from the coil affects the outside environment. Therefore, the linear motor is provided with a cooling means for cooling the coil portion in order to reduce the influence of heat generated from the coil. As this cooling means, for example, a cooling pipe is attached to the coil part, and a refrigerant or pure water is supplied to the cooling pipe to cool the heat of the coil (for example, see Patent Document 1).

Further, in the linear motor, it is desired to increase the cooling efficiency of the coil. For example, a plurality of coils are covered with a resin material called a holder and a mold, and the periphery thereof is reinforced with a metal such as stainless steel or carbon fiber. Some of them are covered with a cover member made of a resin material such as CFRP (Carbon Fiber Reinforced Plastics) or ceramics, and a cooling channel is formed between the resin material and the cover member. In this cooling structure, an inert refrigerant (fluorine-based inert liquid) is allowed to flow through the cooling flow path, and the heat of the coil is recovered by heat exchange with the inert refrigerant. This inert refrigerant has the property of not impairing the function of the linear motor itself and does not affect the insulation of the coil. However, since the specific heat is relatively low, it is difficult to increase the cooling efficiency.
Japanese Patent Laying-Open No. 2003-224961

  However, since the linear motor is configured to generate a thrust (driving force) by passing a current through the coil array, when obtaining a larger thrust or when moving the moving part at a high speed, As the amount of heat generated by the coil increases, not only the performance of the linear motor itself is degraded, but also in precision positioning devices such as semiconductor manufacturing equipment, measuring instruments such as laser interferometers are affected, or moving parts are moved. A phenomenon that the supporting structural member is deformed due to a temperature change is an obstacle to precise positioning.

  While the amount of heat generated by the coil increases, there is a demand for higher cooling efficiency. For example, in the cooling structure for the coil, water having a specific heat higher than that of the inert refrigerant is used as the coolant. Is being considered.

  However, when water is supplied to the cooling flow path formed between the resin material and the cover member to increase the cooling efficiency, water penetrates into the resin material covering the coil, causing dielectric breakdown, Moisture that has entered between the coils vaporizes and expands due to heat generation, and the stress concentrated on the end faces exceeds the resin strength and causes cracks in the resin.

The present invention aims to provide a stage device using the production method and the linear motor manufacturing of the linear motor and a linear motor which solves the above problems.

  In order to solve the above problems, the present invention has the following features.

The invention according to claim 1 is a coil portion in which a plurality of coils are held by a resin material;
A magnet yoke portion arranged in parallel so that a plurality of permanent magnets face the coil portion;
A cover member covering the coil portion;
In the linear motor that is formed inside the cover member and has a cooling water flow path that cools the coil portion by supplying cooling water,
Provided inside the cover member is a metal case formed by welding a metal plate to a shape corresponding to the surface shape of the coil so as to cover the plurality of coils with a predetermined gap around the plurality of coils. ,
Filling the resin material in the gap formed between the metal case and the plurality of coils,
Both ends of the cover member are joined to the block by welding, and the cooling water flow path is formed between the metal case and the cover member.

The invention according to claim 2 is characterized in that the metal plate is a non-magnetic material.

The invention described in claim 3 is characterized in that an insulating material is interposed between the inside of the metal case and the resin material.

The invention according to claim 4 includes a first step of arranging a plurality of coils in parallel,
A second step of covering the periphery of the plurality of coils with a metal case formed by welding a metal plate to a shape corresponding to the surface shape of the coil via a predetermined gap;
A third step of filling a resin material into the gap formed between the metal case and the plurality of coils;
A fourth step of attaching a lead wire passage for drawing out the lead wire drawn out from the coil to the metal case;
A fifth step of covering the periphery of the metal case with a cover member forming a coil cooling water flow path to which cooling water is supplied and joining both ends of the cover member to the block by welding ;
A sixth step of attaching the Ma Gunetto yoke portion so that the plurality of permanent magnets is opposed to the coil,
It is characterized by having.

The invention according to claim 5 is characterized in that the linear motor according to any one of claims 1 to 3 is used as a drive means for a stage.

According to the present invention, the metal case that covers the surface of the resin material is provided inside the cover member , the resin material is filled in the gap formed between the metal case and the plurality of coils, and the metal case and the cover member Since the cooling flow path is formed between them, it is possible to efficiently cool the heat of the coil by supplying the cooling water, and the metal case can prevent the cooling water from penetrating the coil and the resin material. In addition to preventing dielectric breakdown and occurrence of cracks, the mechanical strength for holding a plurality of coils can also be increased.

  Further, according to the present invention, since the metal case is formed by joining the metal plates by welding to have a shape corresponding to the surface shape of the coil, it is possible to ensure airtightness at the joined portion, and the inner resin And can protect the coil.

  In addition, according to the present invention, since the insulating material is interposed between the inside of the metal case and the resin material, it is possible to further improve the insulation between the metal case and the coil.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view of a stage apparatus to which an embodiment of a linear motor according to the present invention is applied. As shown in FIG. 1, the stage apparatus 10 is an XY stage, and a base 14 fixed on a concrete base, a movable part 16 that moves on the base 14, and both ends of the movable part 16 are set to Y. And a pair of linear motors 20 driven in the direction.

  The movable part 16 is moved by the slider 18 driven by the linear motor 20, a Y slider 24 horizontally mounted in the X direction orthogonal to the moving direction so as to connect the sliders 18, and the Y slider 24 moves in the X direction. And an X slider 26.

  The slider 18 is guided by a guide portion 30 extending in the Y direction and supported so as to be slidable in the Y direction, and moves in the Y direction by a thrust (driving force) from the linear motor 20 as a driving means. Be controlled.

  The movable portion 16 is driven in the Y direction by the driving force of the linear motor 20 while the sliders 18 provided at both left and right ends are guided by the guide portion 30. Each linear motor 20 is controlled to simultaneously generate the same driving force so as to translate a pair of sliders 18 disposed at both ends of the movable portion 16.

  Here, the configuration of the linear motor 20 will be described with reference to FIG. As shown in FIG. 2, the linear motor 20 is a moving magnet type (MM type), a coil portion 60 fixed on the base 14, and a magnet yoke portion 62 that moves in the extending direction of the coil portion 60. It is composed of The coil unit 60 includes a plurality of coils 66 (see FIG. 4) which will be described later, and the magnet yoke unit 62 includes a permanent magnet 68 disposed to face the side surface of the coil unit 60.

  Further, the coil unit 60 generates a thrust (driving force) in the Y direction with respect to the permanent magnet 68 by applying a driving voltage. Therefore, the linear motor 20 is configured to apply a driving force in the Y direction to the slider 18 by generating a Lorentz force with respect to the permanent magnet 68 from the coil unit 60, and controls a voltage applied to the coil unit 60. As a result, the driving force can be generated so that the slider 18 travels at a constant speed in the Y direction.

  Here, the internal configuration of the coil unit 60 will be described in detail. 3A is a longitudinal sectional view showing the internal structure of the coil portion 60, and FIG. 3B is an enlarged sectional view showing the A portion in an enlarged manner. As shown in FIGS. 3A and 3B, the coil unit 60 is held in a state where a plurality of coils 66 are integrated by a mold (resin material) 76, and the surface of the mold 76 is inside the cover member 78. It is set as the structure which provided the metal case 80 which covers. A cooling water channel 74 through which cooling water flows is formed in the gap between the inner wall of the cover member 78 and the surface of the metal case 80.

  The metal case 80 of the present embodiment is formed of, for example, a non-magnetic and corrosion-resistant stainless steel plate (SUS304 or SUS316), and heat conduction to the cooling water is favorably performed, so that the cooling efficiency can be increased. The cover member 78 is made of stainless steel, resin material, or ceramic.

  The metal case 80 is a combination of the constituent members 80a to 80f, the constituent members 80a and 80b are side plates that cover the side surfaces of the coil 66 and the mold 76, the constituent member 80c is a lid that covers the upper portions of the coil 66 and the mold 76, The constituent member 80d is a bottom portion that covers the lower portions of the coil 66 and the mold 76, and the constituent members 80e and 80f are front and rear plates that cover the front and rear of the coil 66 and the mold 76 shown in FIG. Further, the butted portions of the constituent members 80a to 80f of the metal case 80 are melt-bonded by laser welding or the like. Therefore, the metal case 80 increases the mechanical strength of the coil part 60 and has an airtight structure inside.

  Furthermore, an insulating layer 81 (see FIG. 3B) is formed on the inner surface of the metal case 80. The insulating layer 81 is formed of an electrically insulating material or insulating paper, and is attached to the entire inner surface of the metal case 80. Thereby, the insulation of the metal case 80 and the coil 66 is ensured.

  Since the entire surface of the mold 76 is covered with the metal case 80, the cooling water flowing through the cooling water flow path 74 can be prevented from penetrating into the mold 76. Therefore, it is possible to prevent the dielectric breakdown caused by the cooling water in the coil 66. Further, in the metal case 80, the thickness of the constituent members 80a and 80b covering the side surfaces of the coil 66 and the mold 76 is formed to be thinner than the other, thereby efficiently transferring the heat of the coil 66 to the cooling water. Is possible. The thicknesses of the constituent members 80a and 80b are set so as to satisfy the conditions of heat conduction (cooling efficiency) and corrosion resistance (life).

  Further, the coil portion 60 has a cooling water channel 74 formed between the inner wall of the cover member 78 and the outer wall of the metal case 80, and the surface of the metal case 80 is cooled by the cooling water supplied to the cooling water channel 74. Is done. The upstream side of the cooling water channel 74 is in communication with the cooling water supply port 70, and the downstream side of the cooling water channel 74 is in communication with the cooling water discharge port 72.

  That is, the cooling water supplied from the cooling water supply port 70 pushes the cooling water filled in the entire area of the cooling water flow path 74 backward (Y direction), and performs heat exchange in the flow process to perform the exchange of each coil 66. Recover heat. The cooling water that has passed through the cooling water flow path 74 is collected from the cooling water discharge port 72, recooled by a cooling unit (not shown), and supplied to the cooling water supply port 70. Thereby, the whole coil part 60 is cooled by the cooling water which flows through the cooling water flow path 74.

  In the present embodiment, since the surface of the mold 76 is covered with the metal case 80, tap water containing chlorine can be used as the cooling water supplied to the cooling water channel 74. Further, since the cooling water has a specific heat higher than that of the inert refrigerant, the cooling water has good cooling efficiency and can sufficiently cool the heat generated from the coil 66. For this reason, when the thrust (driving force) of the linear motor 20 is increased or when the slider 18 is moved at a high speed, the amount of heat generated from the coil 66 may increase. However, the cooling water is supplied to the cooling water channel 74. This makes it possible to cool more efficiently than the conventionally used inert refrigerant.

  FIG. 4 is a perspective view showing a state in which two rows of coils 66 are arranged side by side. As shown in FIG. 4, the coil portion 60 is different in two coil arrays 60 </ b> A and 60 </ b> B in which U-shaped coils 66 whose both sides are bent by 90 degrees are arranged in parallel in the traveling direction (X direction). The coils 66 of the first coil row 60A and the coils 66 of the second coil row 60B are combined so as to be alternately fitted.

  Accordingly, the straight portion 66A of the coil 66 of the first coil row 60A is fitted into the recess 66C of the coil 66 of the second coil row 60B, and the straight portion 66A of the coil 66 of the second coil row 60B is fitted to the first coil row 60A. The concave portions 66C of the coils 66 are fitted, and the straight portions 66A of the coils 66 of the first coil row 60A and the straight portions 66A of the coils 66 of the second coil row 60B are alternately combined so as to overlap. Since the plurality of coils 66 are controlled by being divided into three phases of U phase, V phase, and W phase, two lead wires are drawn from each phase.

  FIG. 5 is a right side view of the coil unit 60. FIG. 6 is a longitudinal sectional view taken along line VV in FIG. As shown in FIGS. 5 and 6, rectangular blocks 82 and 84 are fitted and fixed to both ends of a cover member 78 in which a plurality of coils 66 are accommodated. When the cover member 78 and the blocks 82 and 84 are formed of a metal material such as stainless steel, the fitting portions are joined by welding to form an airtight structure.

  The cooling water supply port 70 passes through one block 82, and the cooling water discharge port 72 passes through the other block 84. And the cooling water supply port 70 and the cooling water discharge port 72 consist of metal pipes, and the outer periphery is joined to the blocks 82 and 84 by welding, and has an airtight structure.

  In addition, the lead wires 86 (six wires) of each coil 66 are inserted into the lead wire guide member 88 and drawn to the outside. The lead wire guide member 88 is made of a metal pipe such as stainless steel, and has one end inserted into the coil 66 side and the other end penetrating the block 84.

  The coil part 60 is provided with a cooling water supply port 70 through which cooling water is supplied at the upper front end, and a cooling water discharge port 72 through which the cooling water is discharged at the lower rear end. Therefore, the cooling water supplied from the cooling water supply port 70 flows downward while flowing backward (Y direction), and is discharged from the cooling water discharge port 72. Thereby, the heat by the coil 66 is recovered and cooled by the cooling water flowing through the cooling water channel 74.

  The cooling water supply port 70 and the cooling water discharge port 72 are not limited to the above metal pipe, but a female screw is provided in a through hole that penetrates the blocks 82 and 84, and a joint is screwed into the female screw, thereby supplying water and draining water. It is also possible to use a joint structure configured to be able to detachably connect a pipe or a flexible hose for performing the above.

Here, the procedure (process) of the manufacturing method of the linear motor 20 is demonstrated with reference to FIG. 7 thru | or FIG.
(Procedure 1) A plurality of coils 66 are arranged in parallel (see FIGS. 4 and 7). In this state, the relative position of each coil 66 is positioned using the positioning jig (first step).
(Procedure 2) A metal case 80 having an insulating layer 81 formed on the inner surface is prepared. And each structural member 80a-80f of the metal case 80 is arrange | positioned so that the circumference | surroundings of each coil 66 may be covered (refer FIG. 8). Further, the butted portions of the constituent members 80 a to 80 f are welded to accommodate the plurality of coils 66 inside the metal case 80. At that time, a gap 83 is interposed between the coil 66 and the inner surface of the metal case 80. The gap 83 is formed between the entire surface of the coil 66 and the entire inner surface of the metal case 80 by setting the positions of the constituent members 80a to 80f and the relative position of the coil 66 with a jig or the like ( Second step).
(Procedure 3) The molten resin material is filled from the filling port 90 provided in the upper part of the metal case 80 (see FIGS. 9A and 9B, the third step).

When the molten resin material is a thermosetting resin, the mold 76 that covers the entire surface of each coil 66 is completed by heating to a predetermined temperature and solidifying after completion of filling. As described above, according to the method of filling the gap 83 between the metal case 80 and the coil 66 with the resin material, the thickness of the mold 76 can be managed by the gap 83. The thickness can be further reduced, which can contribute to the miniaturization of the linear motor 20. In addition, this method eliminates the need for a mold for molding, so that the manufacturing cost can be reduced.
(Procedure 4) The lead wire guide member 88 into which the lead wire 86 is inserted is attached to the metal case 80 (see FIG. 6, fourth step).
(Procedure 5) The metal case 80 is covered with a cover member 78 (see FIG. 10). The cover member 78 is combined from both sides of the metal case 80 and joined to the upper end of the filling port 90 protruding upward and the lower end of the protrusion 92 protruding downward. And the metal cap 94 is welded to the filling port 90, and the filling port 90 is sealed (5th process).

Thereby, a cooling water flow path 74 is formed between the inner surface of the cover member 78 and the surface of the metal case 80.
(Procedure 6) The blocks 82 and 84 are joined to both ends of the cover member 78 by welding (see FIG. 6).
(Procedure 7) The magnet yoke part 62 is assembled to the coil part 60 (see FIG. 2). Thereby, the permanent magnet 68 of the magnet yoke part 62 opposes the coil part 60 (6th process). Thus, the linear motor 20 is completed.

  In the above embodiment, the linear motor used in the stage apparatus is taken as an example. However, the present invention is not limited to this, and the present invention can of course be applied to a linear motor used as driving means for other apparatuses.

  In the above embodiment, a moving magnet type (MM type) linear motor has been described. However, it goes without saying that the present invention can also be applied to a moving coil type (MC type) linear motor.

  Moreover, in the said Example, although the case where the metal case 80 was formed with a stainless steel material was mentioned as an example, not only this but other metal materials (for example, titanium etc.), if it is a metal which is nonmagnetic and has corrosion resistance Of course, may be used.

1 is a plan view of a stage apparatus to which an embodiment of a linear motor according to the present invention is applied. 2 is a perspective view showing a configuration of a linear motor 20. FIG. It is a figure which shows the internal structure of the coil part 60, (A) is a longitudinal cross-sectional view of the coil part 60, (B) is an expanded sectional view which expands and shows A part. It is a perspective view which shows the state which arranged the coil 66 of 2 rows in parallel. 4 is a right side view of a coil unit 60. FIG. 3 is a longitudinal sectional view showing the inside of a coil unit 60. FIG. It is a figure for demonstrating the procedure 1 of the manufacturing method of a linear motor. It is a figure for demonstrating the procedure 2 of the manufacturing method of a linear motor. It is a figure for demonstrating the procedure 3 of the manufacturing method of a linear motor. It is a figure for demonstrating the procedure 5 of the manufacturing method of a linear motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stage apparatus 14 Base 18 Slider 20 Linear motor 24 Y slider 60 Coil part 62 Magnet yoke part 66 Coil 68 Permanent magnet 70 Cooling water supply port 72 Cooling water discharge port 74 Cooling water flow path 76 Mold 78 Cover member 80 Metal cases 80a-80f Component member 83 Clearance 90 Filling port

Claims (5)

A coil portion in which a plurality of coils are held by a resin material;
A magnet yoke portion arranged in parallel so that a plurality of permanent magnets face the coil portion;
A cover member covering the coil portion;
In the linear motor that is formed inside the cover member and has a cooling water flow path that cools the coil portion by supplying cooling water,
Provided inside the cover member is a metal case formed by welding a metal plate to a shape corresponding to the surface shape of the coil so as to cover the plurality of coils with a predetermined gap around the plurality of coils. ,
Filling the resin material in the gap formed between the metal case and the plurality of coils,
Both ends of the cover member are joined to a block by welding, and the cooling water flow path is formed between the metal case and the cover member.   The linear motor according to claim 1, wherein the metal plate is a nonmagnetic material.   The linear motor according to claim 1, wherein an insulating material is interposed between the inside of the metal case and the resin material. A first step of arranging a plurality of coils in parallel;
A second step of covering the periphery of the plurality of coils with a metal case formed by welding a metal plate to a shape corresponding to the surface shape of the coil via a predetermined gap;
A third step of filling a resin material into the gap formed between the metal case and the plurality of coils;
A fourth step of attaching a lead wire passage for drawing out the lead wire drawn out from the coil to the metal case;
A fifth step of covering the periphery of the metal case with a cover member forming a coil cooling water flow path to which cooling water is supplied and joining both ends of the cover member to the block by welding;
A sixth step of attaching a magnet yoke portion so that a plurality of permanent magnets face the coil;
A method for manufacturing a linear motor, comprising:   A stage apparatus using the linear motor according to claim 1 as a stage driving means.

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