This application claims priority to Japanese Patent Application No. 2022-030921, filed on Mar. 1, 2022, which is incorporated by reference herein in its entirety.
Certain embodiments of the present invention relate to an armature and a driving device suitable for use in a vacuum environment.
The related art discloses an armature of a linear motor including coil arrays on both sides of a plate-shaped cooling unit. Further, the related art discloses a driving device that drives a stage in an X-axis direction and a Y-axis direction that are perpendicular to each other by a linear motor.
According to an embodiment of the present invention, there is provided an armature including: a plurality of coils that generate power according to a flowing current; and a covering member that covers the plurality of coils from an outside, insulates the plurality of coils from each other, and reduces outgas to the outside.
Another aspect of the present invention is a driving device. This device includes a plurality of coils that generate power according to a flowing current; a covering member that covers the plurality of coils from an outside, insulates the plurality of coils from each other, and reduces outgas to the outside, and a vacuum chamber that accommodates the plurality of coils and the covering member inside the vacuum chamber in a vacuum state.
When the above linear motor or driving device is applied to an apparatus such as a semiconductor manufacturing apparatus that performs fine processes in a vacuum environment, outgas from the insulation coating for preventing a short circuit of the coil itself and between adjacent coils can cause pollution or contamination of the vacuum environment in the vacuum chamber. In such a case, it is necessary to perform immediate shutdown of an apparatus, bulk disposal of semiconductor wafers in process, and labor and time consuming re-setup of the vacuum environment of the vacuum chamber, which causes a huge economic loss.
It is desirable to provide an armature suitable for use in a vacuum environment.
In this aspect, since outgas from the covering member itself or a coil covered with the covering member is reduced, pollution or contamination due to outgas when used in a vacuum environment can be effectively prevented.
Any combination of the above components and conversion of the expression of the present invention between methods, devices, systems, recording media, computer programs, and the like are also effective as aspects of the present invention.
Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description or drawings, the same or equivalent components, members, and processes are designated by the same reference numerals, and duplicate description thereof will be omitted. The scale and shape of shown each portion is set for convenience in order to facilitate the description, and is not limitedly interpreted unless otherwise specified. The embodiments are examples, and the scope of the present invention is not limited in any way. All the features and combinations thereof described in the embodiments are not always essential to the invention.
Of the configurations of the stage driving device 100, at least the table 200, the X-axis actuator 120, and the Y-axis actuator 130 are accommodated in a vacuum chamber whose inside is kept in a vacuum state. In the present specification, the term “vacuum” represents a state of a space filled with a gas having a pressure lower than the normal atmospheric pressure. Vacuum is categorized into low vacuum (100 kPa to 100 Pa), medium vacuum (100 Pa to 0.1 Pa), high vacuum (0.1 Pa to 10−5 Pa), ultra-high vacuum (10−5 Pa to 10−8 Pa), extremely high vacuum (10−8 Pa or less), or the like, depending on the pressure range. The stage driving device 100 of the present embodiment may be used in a vacuum environment of any of the above categories. However, according to the linear motor described later, pollution or contamination of the vacuum environment due to outgas can be effectively prevented, so that the present embodiment is suitable for a stage driving device 100 that operates in a vacuum environment of a low pressure range (for example, a pressure range of high vacuum or lower) in which a vacuum chamber is required to have a high degree of cleanliness.
The X-axis actuator 120 and the Y-axis actuators 130A and 130B are respectively provided with a linear motor to be described later. The linear power in an X-axis direction or a Y-axis direction generated by each linear motor linearly drives the table 200 serving as a driven body in the X-axis direction or the Y-axis direction. The X-axis actuator 120 includes a square shaft or an X-axis guide 122 extending in the X-axis direction, and an X-axis slider 124 that is movable in the X-axis direction along the X-axis guide 122. Similarly, the Y-axis actuator 130 includes a square shaft or a Y-axis guide 132 extending in the Y-axis direction, and a Y-axis slider 134 that is movable in the Y-axis direction along the Y-axis guide 132. By supplying gas such as pressurized air between the outer peripheral surface of the X-axis guide 122 and the inner peripheral surface of the X-axis slider 124, the X-axis slider 124 floated from the X-axis guide 122 may move smoothly and precisely with extremely low friction. At this time, to prevent the supplied pressurized air or the like from leaking into the vacuum environment in the vacuum chamber, an exhaust port or exhaust groove connected to an exhaust device such as a vacuum pump that exhausts the pressurized air or the like is preferably provided between the outer peripheral surface of the X-axis guide 122 and the inner peripheral surface of the X-axis slider 124. Similarly, these gas supply portions and exhaust portions may be provided between the outer peripheral surface of the Y-axis guide 132 and the inner peripheral surface of the Y-axis slider 134.
Both end portions of the X-axis guide 122 are fixed to the Y-axis sliders 134 of the Y-axis actuators 130A and 130B. When the linear motors in the Y-axis actuators 130A and 130B drive the Y-axis slider 134 in the Y-axis direction in synchronization with each other, the X-axis actuator 120 moves in the Y-axis direction together with the X-axis guide 122 fixed to the Y-axis slider 134. Since the table 200 is fixed to the X-axis slider 124 of the X-axis actuator 120, the table 200 as a driven body is driven in the Y-axis direction by the linear motor of the Y-axis actuator 130. Further, the linear motor of the X-axis actuator 120 drives the X-axis slider 124 together with the table 200 in the X-axis direction. In this way, the stage driving device 100 drives the table 200 as a driven body in the XY plane, by the linear motors of the X-axis actuator 120 and the Y-axis actuator 130.
A position sensor 140 measures the position of the table 200 in the X-axis direction, and a position sensor 142 measures the position of the table 200 in the Y-axis direction. By differentiating the measured positions in the X-axis direction and the Y-axis direction with respect to time, the velocities in the X-axis direction and the Y-axis direction are obtained. Further, by differentiating the velocities in the X-axis direction and the Y-axis direction with respect to time, accelerations in the X-axis direction and the Y-axis direction are obtained. The table 200 as a driven body is driven with high accuracy by the feedback-control based on the measurement data of the position, the velocity, and the acceleration.
For example, in the semiconductor manufacturing apparatus such as an exposure apparatus, an ion implanter, a heat treatment apparatus, an asking apparatus, a sputtering apparatus, a dicing apparatus, an inspection apparatus, and a cleaning apparatus or a flat panel display (FPD) manufacturing apparatus, the stage driving device 100 of the present embodiment, which can realize high-precision driving under the vacuum environment as described above, is suitable for applications in which the table 200 on which a semiconductor wafer or the like to be processed is placed is used as a driven body.
A linear power generated by a magnetic field generated by each coil array in which a drive current such as a three-phase alternating current has flowed is exerted on field magnets (not shown) with permanent magnets or electromagnets facing each coil array and/or each coil array itself. The direction of this linear power is substantially the same as the arrangement direction of each coil array (that is, the longitudinal direction of the armature 2 or the substantially left-right direction in
Further, the field magnets on both sides may be integrally driven by the coil arrays on both sides of the armature 2 by connecting or integrally forming the field magnets respectively facing the coil arrays on the first surface side and the second surface side of the armature 2. In this case, substantially the same drive current is applied to each coil 4 on the first surface side of the armature 2 and each coil 4 on the second surface side located behind the first surface. Alternatively, the field magnet on the first surface side and the field magnet on the second surface side may be driven independently of each other, by applying different drive currents to the coil arrays on the first surface side and the second surface side of the armature 2.
The cooling unit 10 for cooling the plurality of coils 4 of the armature 2 is interposed between the coil array on the first surface side and the coil array on the second surface side of the armature 2. The cooling unit 10 has a long substantially rectangular plate shape, and is disposed such that one end surface or an inner end surface of each coil array described above is in contact with both a first surface and a second surface thereof. The cooling unit 10 includes a flat plate cooling portion 12 having a substantially rectangular plate shape that supports each coil array on each surface (first surface and second surface), an inflow portion 14 provided at one end portion of the flat plate cooling portion 12 in the arrangement direction of the coils 4, and an outflow portion 16 provided at the other end portion of the flat plate cooling portion 12 in the arrangement direction of the coils 4.
The inflow portion 14 is provided at a position deviated from the arrangement direction of the coils 4, specifically, above the coil 4 at one end (left end in
As described above, the refrigerant flowing through the flow path in the flat plate cooling portion 12 simultaneously cools two coil arrays disposed so as to be in contact with both surfaces of the flat plate cooling portion 12. In addition, the coil array may be provided on only one surface of the flat plate cooling portion 12. In this case, the refrigerant flowing through the flow path in the flat plate cooling portion 12 cools one coil array disposed so as to be in contact with one surface of the flat plate cooling portion 12.
The first flat plate member 20 is a substantially rectangular flat plate. The second flat plate member 22 is a substantially rectangular flat plate having substantially the same size and shape as the first flat plate member 20. The frame member 24 is a frame-shaped member having substantially the same outer peripheral shape as the first flat plate member 20 and the second flat plate member 22. The frame member 24 can also be said to be a flat plate member having one large opening portion 24a defined by the frame. The first flat plate member 20, the frame member 24, and the second flat plate member 22 are stacked in this order and joined over the entire outer periphery. As shown in
As shown in
As shown in
The plurality of linear protrusions 20d and 22d provided substantially in the center of the first flat plate member 20 and the second flat plate member 22 (or the opening portion 24a of the frame member 24) in the vertical direction are arranged substantially in a straight line along the longitudinal direction of the respective flat plate cooling portion 12. As shown in
A plurality of point-like protrusions 20e and 22e are provided in the flow path 30 (inside the first divided flow path 32a in the illustrated example) at substantially constant intervals along the longitudinal direction of the flat plate cooling portion 12. By joining the protrusion 20e and the protrusion 22e, the joining intensity of the first flat plate member 20 and the second flat plate member 22 can be increased. This can prevent deformation of the first flat plate member 20 and the second flat plate member 22 due to the pressure of the refrigerant flowing in the flow path 30 between the first flat plate member 20 and the second flat plate member 22.
The inflow port 14a of the inflow portion 14 in
As shown in
When a drive current such as a three-phase alternating current flows to each coil 4 to drive a field magnet (not shown) facing the outer end surfaces of each coil 4 (the right end surface of the right coil 4 and the left end surface of the left coil 4 in
In addition, the coating film 41 preferably reduces outgassing to a vacuum environment. The outgas is gases such as water, oxygen, and hydrocarbons, or fine particles that can scatter in the form of a gas that are released from constituent materials of the coil 4 or the flat plate cooling portion 12 covered with the coating film 41 (including an adhesive therebetween), and causes serious pollution or contamination when released into the vacuum environment outside coating film 41. In order to reduce such outgassing to a vacuum environment, the coating film 41 can confine the gas and fine particles released by the internal coil 4 and the flat plate cooling portion 12 in the coating film 41, and it is preferable that the coating film 41 itself is made of a material that does not substantially release gases or fine particles that contaminate the vacuum environment. In addition, in the same manner that the refrigerant in the flat plate cooling portion 12 is taken out from the outflow portion 16 (
The coating film 41 having both insulation properties and an outgas reduction function as described above is made of an inorganic material such as glass or ceramics (formed by Electro Ceramic Coating (ECC), or the like) and/or an organic material such as fluororesin (polytetrafluoroethylene (PTFE) and perfluoroalkoxy fluorine resin (PFA)) or polyimide. The above inorganic materials have high insulation properties and an outgas reduction function (the amount of outgas of the inorganic materials is small), and are not easily deformed by the heat of the coil 4 or the like. In addition, the above organic materials have high insulation properties and an outgas reduction function (the amount of outgas in the organic materials is small). The coating film 41 made of these organic materials is formed by firing, curing with ultraviolet rays, or the like.
The plurality of coils 4 forming the coil arrays on the first surface side and the second surface side of the armature 2 or the flat plate cooling portion 12 are covered from the outside with an insulating member 42 (not shown in
The armature 2 as described above is assembled, for example, by the following procedure. First, the flat plate cooling portion 12 in which coil arrays are formed on both surfaces is attached to the holder 50 such that the protrusion portions at both end portions of the flat plate cooling portion 12 in a longitudinal direction (direction perpendicular to the paper surface in
In the first embodiment of
Here, the insulating material forming the insulating member 42 can be a source of outgas, but since the metal case 43 having a high outgas reduction function covers the insulating member 42 from the outside, it is possible to effectively reduce the release of outgas into the vacuum environment. The metal member that covers the insulating member 42 from the outside is not limited to the metal case 43 shown in
In the second embodiment as described above, since the plurality of coils 4 and the flat plate cooling portion 12 are covered with the insulating member 42, even in a case where the temperature and pressure of the refrigerant in the flat plate cooling portion 12 are significantly different from the external vacuum environment, the deformation of the flat plate cooling portion 12 can be reduced. Therefore, it is possible to increase the flow rate and/or decrease the temperature of the refrigerant flowing through the flat plate cooling portion 12, thereby improving the cooling efficiency of the cooling unit 10 and the operating efficiency of the armature 2 or the linear motor.
The present invention has been described based on the embodiments. Embodiments are examples, and it is understood by those skilled in the art that various modifications are possible for each of the components and combinations of the respective processing processes, and that such modifications are also within the scope of the present invention.
In addition, the functional configuration of each device described in the embodiment can be implemented by hardware resources or software resources, or by the cooperation between the hardware resources and the software resources. A processor, a ROM, a RAM, or other LSIs can be used as the hardware resource. Programs such as operating systems and applications can be used as software resources.
It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the spirit of the invention. Additionally, the modifications are included in the scope of the invention.
Number | Date | Country | Kind |
---|---|---|---|
2022-030921 | Mar 2022 | JP | national |