Linear motor

Abstract

To provide a linear motor which can prevent softening of wiring due to heat evolution in electric conduction to a coil, dissolve the problem that it becomes impossible to fix the wiring due to the heat evolution, and reduce man-hour of wiring processing.SOLUTION: In a linear motor 10 in which a stator and a mover can relatively move, the mover includes wiring which has a multi-phase coil 6 and supplies current to the multi-phase coil, and the wiring is formed on a multilayer printed board 12 formed by laminating a plurality of boards. The multilayer printed board has a contact 7 for connecting the wiring with the multi-phase coil and connecting the wiring with external wiring, and each contact of each printed board may be connected via through holes so that the contact is arranged to at least one of the multilayer printed boards.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a linear motor.

Background Art

[0002] In semiconductor manufacturing equipment, liquid crystal manufacturing equipment, or inspection equipment for semiconductor elements, liquid crystal displays, etc., a two-axis stage device, a so-called X-Y stage, is used as a transfer device for various components. The X-Y stage includes an X stage that moves in a predetermined direction (X direction) with respect to the base plate and a Y stage that moves in a direction (Y direction) orthogonal to the X direction. The X stage and the Y stage include drive units driven by a linear motor or the like. The linear motor includes a magnetic field generating member having a U-shaped cross-section with a permanent magnet supported by a yoke such that the N pole and the S pole face each other, and a coil member having a coil that crosses the magnetic field. The linear motor can relatively move the magnetic field generating member and the coil member by the interaction between the magnetic field by the permanent magnet and the magnetic field generated in the coil when an electric current is passed through the coil.

[0003] The linear motor as described above generally has a structure in which the magnetic field generating member is a stator and the coil member is a mover, and in order to increase the speed of the transfer device, the current flowing through the coil is generally increased. Patent Document 1 and Patent Document 2 disclose a technique for supplying current to each coil of a linear motor by electrical wiring. Patent Document 3 discloses a technique for performing wiring of the current supplied to the coil on a printed circuit board.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] When wiring is performed on a coil using the method described in Patent Document 1 or Patent Document 2, if a large current is passed through the wiring, there is a concern that the wiring itself may soften due to heat generation. Furthermore, in cases where the wiring itself is not molded and fixed, as described in Patent Document 2, adhesives are used to fix the wiring, which leads to problems such as insufficient fixing of the wiring due to evaporation of the adhesive due to heat generation or a decrease in adhesive strength.

[0006] Patent Document 3 does not mention how to handle the intersections of wiring. If the intersections are handled with jumper wires or the like, there is a concern that the handling of the jumper wires will be time-consuming.

[0007] This invention has been made in view of the above circumstances, and aims to provide a linear motor that can prevent the softening of wiring due to heat generated when current is supplied to the coil, solve the problem of wiring becoming impossible to fix due to heat generation, and reduce the man-hours required for wiring processing. [Means for solving the problem]

[0008] The linear motor of the present invention is a linear motor in which a stator and a movable element are relatively movable, wherein the movable element has a multiphase coil and includes wiring that supplies current to the multiphase coil, and the wiring comprises a plurality print Formed on a multilayer printed circuit board by stacking substrates. so Furthermore, a contact for connecting the wiring and the external wiring is located at one end of the movable part in the direction of movement on one end face of the plurality of substrates in the stacking direction of the multilayer printed circuit board. It is characterized by being present.

[0009] The aforementioned multilayer printed circuit board is The aforementioned contact and, The aforementioned wiring and The aforementioned Multiphase coil of Contacts for connection and Having the above each contact but , the multilayer printed circuit board either main surface so as to be arranged at Each of the aforementioned contacts is each contact of each printed circuit board and is characterized by being through-hole connected.

[0010] The mover has a coil member having a polyphase coil and a holder, and the multilayer printed circuit board is arranged in the holder.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a linear motor that can solve the problems of softening due to heat generation of coil wiring and instability of wiring when a large current flows through the coil, and can reduce the man-hours of wiring processing.

Brief Description of the Drawings

[0012] [Figure 1] It is a top view of a linear motor according to an embodiment of the invention. [Figure 2] It is a sectional view taken along line A-A of FIG. 1. [Figure 3] It is a perspective view of a mover according to an embodiment of the invention. [Figure 4] It is an explanatory view of a mover according to an embodiment of the invention, where (a) is a plan view (partially transparent view) and (b) is a side view (partially transparent view). [Figure 5] It is a perspective view showing a wiring structure of a multilayer printed circuit board according to an embodiment of the invention. [Figure 6] It is a perspective view showing a wiring structure of a multilayer printed circuit board according to another embodiment.

Modes for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described based on its embodiments.

[0014] FIG. 1 is a top view of a linear motor 10 according to an embodiment of the invention. FIG. 2 is a sectional view taken along line A-A of FIG. 1. FIG. 3 is a perspective view of a mover according to an embodiment of the invention.

[0015] The linear motor of the present invention comprises a stator and a movable element. Specifically, the linear motor 10 of the present invention comprises a stator 1 having a plurality of segmented units 2 including a magnetic field generating member 22, and a movable element 3 having a coil member 4 having a multiphase coil and a holder 5. The movable element 3 is driven within a magnetic gap g formed inside the stator 1. The linear motor 10 of the present invention is constructed by connecting a plurality of segmented units 2 along the direction of movement of the movable element 3 (the vertical (X) direction in Figure 1), and each segmented unit 2 has a similar structure. However, the lengths do not need to be the same. As shown in Figure 2, the movable element 3 includes a coil member 4 having a multiphase coil, which will be described later, and a holder 5 that supports it. According to the linear motor 10 of the present invention, by providing a magnetic field detection element such as a Hall element on the movable element 3 to detect the magnetic pole position and changing the direction of the current flowing through each coil, the movable element 3 can be moved in the movable direction. In other words, the linear motor 10 of the present invention is a movable coil type linear motor.

[0016] The divided units 2 that make up the stator 1 include a non-magnetic frame 21 and a permanent magnet which is a magnetic field generating member 22. The non-magnetic frame 21 has a base member 211 and a pair of side members 212. The base member 211 is prismatic in shape, and the flat side members 212 are arranged on its sides. The non-magnetic frame 21 has a U-shaped cross-section. The base member 211 and side members 212 that make up the non-magnetic frame 21 are made of a non-magnetic material such as an aluminum alloy. A groove 213 is formed in the base member 211, extending in the direction of movement of the movable element 3 (see Figure 2). The groove 213 is located in the center of the base member 211 in the width direction. The depth and width of the groove 213 are set to accommodate a portion of the coil member 4, which will be described later.

[0017] The magnetic field generating member 22 includes a yoke 23, a main magnet 24, and an auxiliary magnet 25. The yoke 23 is flat and made of a ferromagnetic material such as SS material. Multiple main magnets 24 are fixed at predetermined intervals on one surface of the yoke 23 along the direction of movement of the movable element 3. The magnetization method of the main magnets 24 is in the thickness direction (a direction perpendicular to the direction of movement of the movable element 3). The magnetization direction of the auxiliary magnet 25 is parallel to the direction of movement of the movable element 3 and perpendicular to the magnetization direction of the main magnet 24. The auxiliary magnet 25 is positioned so that its like poles face the main magnet 24. The other side of the yoke 23 is fixed to the side member 212 of the non-magnetic frame 21. The magnetic field generating member 22 has the above configuration and a U-shaped cross-section. The main magnet 24 and auxiliary magnet 25, facing each other across a magnetic gap, are arranged in a Halbach configuration with opposite poles facing each other. The direction of the magnetic field in the magnetic gap g is in the direction of opposition between the magnets. The main magnet 24 and auxiliary magnet 25 can be known permanent magnets. One example is a rare earth magnet. As a rare earth magnet, an RTB-type sintered magnet is preferred, in which R (where R is an element consisting of at least one selected from rare earth elements such as Nd), T (where T is Fe or Fe and Co), and B (boron) are essential components. In order to make linear motors smaller, lighter, more efficient, and more energy-efficient (improved energy efficiency), it is preferable to use RTB-type sintered magnets for the main magnet 24 and auxiliary magnet 25.

[0018] The movable element 3 includes a coil member 4 and a holder 5. The coil member 4 of the movable element 3 is positioned within a magnetic gap g formed in the stator 1. The holder 5 is connected to a driven member (not shown). The driven member is, for example, a linear-type bearing. The coil 6 (see Figure 3) is molded and fixed to the coil member 4 using resin.

[0019] Embodiment 1 The wiring structure of the multilayer printed circuit board in the linear motor of the present invention will be described in detail below. Figure 4 is an explanatory diagram of a movable element according to an embodiment of the invention, where (a) is a plan view (partially transparent) and (b) is a side view (partially transparent). Figure 5 is a perspective view showing the wiring structure of a multilayer printed circuit board according to an embodiment of the invention. In Figure 4, the three-phase coils (U, V, W) are arranged in parallel along the direction of movement of the movable part. Each coil is connected by printed wiring (connection patterns) formed on the multilayer printed circuit board 12. The multilayer printed circuit board 12 is placed inside the holder 5. For example, wiring 8 (8b) connects U phases in series, wiring 9 connects V phases in series, and wiring 10 connects W phases in series. 11 is the neutral wire. Current is supplied to the U-phase from wiring 8a to the starting point (beginning of winding) of the left U-phase coil (U1), and from the end point of coil U1 to the starting point of coil U2 via wiring 8b. Contact 7 is a contact for soldering to external wiring (not shown) to supply current to wirings 8, 9, and 10. It is also a contact for connecting the wiring to a portion of the coil winding (for example, 14). The multilayer printed circuit board 12 has a four-layer structure consisting of printed circuit boards 12a, 12b, 12c, and 12d. 12a has wiring printed to supply current to the U phase, 12b has wiring printed to supply current to the V phase, 12c has wiring printed to supply current to the W phase, and 12d has wiring printed for the neutral wire. As shown in Figure 5, printed circuit boards 12a, 12b, 12c, and 12d are stacked with printed wiring. The width of printed circuit boards 12a, 12b, 12c, and 12d is increased in that order (the height can be varied in Figure 5 so that each contact always lies on a single plane). The multilayer printed circuit board 12 can be formed by individually manufacturing each printed circuit board and then fixing them together with adhesive or the like, or by forming the laminated board by pressing. Note that the connections between each contact, each coil, and the external components shown in Figure 5 may be made by first connecting the wiring to the contacts before stacking them.

[0020] Embodiment 2 Figure 6 shows the wiring structure of a multilayer printed circuit board according to another embodiment. As shown in Figure 6, contacts 7 and 13 are all provided on board 12a, and external power supply to the printed wiring of 12b, 12c, and 12d, or connection to the coil, may be made from 12a through through holes. In Figure 6, the dashed line 15 indicates that the contact point 13b of the neutral wire 11 on substrate 12d penetrates substrates 12b and 12c to form a contact point 13a on the surface of 12a.

[0021] The disclosed embodiments should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of symbols]

[0022] 10 Linear motor 1 Stator 2-part unit 3 Mover 22 Magnetic field generating member 4. Coil members 5 holders 6 coils 7, 13 Contacts (electrodes to be soldered) 8 U phase wiring 9 V phase wiring 10 W phase wiring 11 Neutral Line 12 Multilayer Printed Circuit Boards 14. Coil Wiring

Claims

1. A linear motor in which a stator and a movable element are relatively movable, wherein the movable element has a multiphase coil and includes wiring that supplies current to the multiphase coil, the wiring is formed on a multilayer printed circuit board formed by stacking a plurality of printed circuit boards, and a contact for connecting the wiring to external wiring is arranged at one end of the movable element in the direction of movement on one end face of the multilayer printed circuit board in the stacking direction of the plurality of boards.

2. The linear motor according to claim 1, wherein the multilayer printed circuit board has the contacts and contacts for connecting the wiring and the multiphase coil, and each contact is through-hole connected to each contact of each printed circuit board such that each contact is arranged on the main surface of any of the multilayer printed circuit boards.

3. The linear motor according to claim 1 or 2, characterized in that the movable element has a coil member having the multiphase coil and a holder, and the multilayer printed circuit board is disposed within the holder.

Images