JP5766566B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus, for example, a grinding apparatus that grinds a workpiece with ultrasonic vibration.

  In a manufacturing process of various devices such as a mobile phone and a personal computer, a substantially disk-shaped wafer provided with an integrated circuit (IC) such as an LSI (Large Scale Integration) is used. The wafer is partitioned into a plurality of regions by division lines arranged in a lattice pattern on the surface, and an integrated circuit is formed in each of the partitioned regions. And each device used for various apparatuses is manufactured by cut | disconnecting a wafer along a division | segmentation planned line. Before the wafer is divided into individual devices, the back surface is ground and adjusted to a desired thickness by a grinding apparatus having a grinding wheel having a grinding wheel.

  By the way, when the back surface of a wafer is ground by a grinding apparatus, clogging may occur in the grinding wheel due to grinding waste generated along with grinding. In particular, when a brittle hard material such as sapphire, silicon nitride, lithium tantalate, or altic is ground, the grinding wheel is likely to be clogged, and it takes a long time to grind and the productivity may decrease. Focusing on these problems, the present applicant suppresses clogging of the grinding wheel due to grinding debris by arranging an annular ultrasonic vibrator on the grinding wheel and ultrasonically vibrating the grinding wheel during grinding. A grinding device that can be used has been developed and a patent application has been filed (see Patent Document 1).

  In such a grinding apparatus, power supply means for supplying power to the ultrasonic vibrator is connected to an end of a rotating spindle coupled to a wheel mount that supports the grinding wheel. The rotary spindle has a cavity formed in the longitudinal direction of the axis, and a conductive wire connected to the power supply means is disposed through the cavity. This conductive wire is connected to a concave connector provided on the wheel mount. In the grinding device described in Patent Document 1, when a grinding wheel is mounted on a wheel mount, an ultrasonic wave is obtained by connecting a convex connector connected to an ultrasonic transducer to a concave connector provided on the wheel mount. High frequency power is supplied to the vibrator and the grinding wheel vibrates ultrasonically.

  However, in the grinding apparatus described in Patent Document 1, when the grinding wheel is attached to and detached from the wheel mount, the concave connector and the convex connector must be attached and detached, and it takes time to attach and remove the grinding wheel. There is. Paying attention to such problems, the present applicant electrically connects the ultrasonic vibrator of the grinding wheel and the power supply means without going through the concave connector and the convex connector, thereby providing a grinding wheel for the wheel mount. Has been developed and a patent application has already been filed (see Patent Document 2).

  In such a grinding apparatus, two annular electrodes are disposed around an annular ultrasonic vibrator provided on the grinding wheel, and the annular electrode and the ultrasonic vibrator are electrically connected to each other, and power supply means is provided. A pair of electrically connected pressing electrodes is disposed on the wheel mount. In the grinding device described in Patent Document 2, when the grinding wheel is mounted on the wheel mount, the pair of pressing electrodes protrudes toward the two annular electrodes, and the pair of pressing electrodes and the two annular electrodes come into contact with each other. With this configuration, since the ultrasonic vibrator and the power supply means can be electrically connected without using the concave connector and the convex connector, the grinding wheel can be easily attached to and detached from the wheel mount.

JP 2008-23893 A JP 2010-194650 A

  However, in the grinding apparatus described in Patent Document 2, since the pair of pressing electrodes protrudes toward the two annular electrodes to electrically connect the pair of pressing electrodes and the annular electrode, There may be a contact failure between the pair of pressing electrodes and the annular electrode due to an error in the arrangement positions of the two annular electrodes. In addition, because it is electrically connected at the contact point between the pair of pressing electrodes and the two annular electrodes, it is a region where the vibration is canceled during processing due to ultrasonic vibration due to wear of the grinding wheel and changes in the rotation speed of the grinding wheel. When a certain node region changes, a contact failure between electrodes may occur.

  The present invention has been made in view of such points, and in the case of using a grinding wheel for grinding with ultrasonic vibration mounted on a wheel mount, high precision electrode position accuracy is unnecessary, It is an object of the present invention to provide a grinding apparatus that does not cause electrode contact failure even when a node region is changed during ultrasonic vibration machining, and can easily attach and detach a grinding wheel.

  A grinding apparatus according to the present invention comprises a chuck table for holding a workpiece, a grinding means for grinding the workpiece held on the chuck table, and a grinding wheel used for the grinding means. The grinding means includes a spindle housing, a spindle rotatably accommodated in the spindle housing, a wheel mount fixed to the tip of the spindle, and a drive source for rotationally driving the spindle. The grinding wheel is fastened by the wheel mount and a screw and formed of a conductive member, a plurality of grinding wheels disposed in an annular shape at a free end of the wheel base, and the wheel base. An annular ultrasonic transducer disposed thereon, an annular electrode disposed on the annular ultrasonic transducer, and the wheel A receiving portion opened in the center of the base; and a movable electrode portion accommodated in the accommodating portion. The movable electrode portion is formed of a material attracted by a magnetic force; A receiving portion inserted through the opening; a restricting portion for restricting the receiving portion so that the movable electrode protrudes from the opening; and a conductive flexible conductor connected from the movable electrode portion to the annular electrode. The movable electrode portion is housed in the housing portion of the wheel base so as to be able to advance and retreat, and the wheel mount is disposed in the vicinity of a central free end surface, and the grinding wheel is fastened with screws in the movable electrode portion. The grinding wheel has a fixed electrode disposed at a position facing the wheel, and when the grinding wheel is fastened to the wheel mount by a screw, the magnetic force of the fixed electrode Wherein the movable electrode portion is energized to the annular electrode in contact with the fixed electrode, the movable electrode portion is characterized by comprising a non-contact with the wheel base.

  According to this grinding apparatus, a fixed electrode having a magnetic force is disposed on the wheel mount, and a movable electrode portion including a movable electrode formed of a material attracted by the magnetic force is disposed in the housing portion of the wheel base. Since the portion is housed in the housing portion of the wheel base so as to be able to advance and retreat, when the grinding wheel is fastened and attached to the wheel mount, the movable electrode portion is attracted by the magnetic force of the fixed electrode and comes into contact with the fixed electrode. As a result, since the fixed electrode and the movable electrode are automatically connected by magnetic force only by mounting the grinding wheel to the wheel mount without using a connector or the like, the grinding wheel can be easily connected. Further, since the movable electrode portion is brought into a non-contact state from the wheel base of the grinding wheel, the vibration of the wheel base is not transmitted to the movable electrode portion, and the contact failure of the electrode due to the vibration can be avoided. Furthermore, since the movable electrode and the fixed electrode come into contact with each other by the magnetic force of the fixed electrode, it is possible to electrically connect the fixed electrode and the movable electrode without requiring high-precision electrode position accuracy, Even when the node region, which is a region in which vibration is canceled at the time of processing accompanied by vibration, changes, it is possible to suppress a contact failure between the fixed electrode and the movable electrode. In addition, since the fixed electrode having magnetic force is disposed on the wheel mount away from the workpiece, the influence of the magnetic force on the workpiece can be reduced. Furthermore, since a fixed electrode having a magnetic force is disposed on the wheel mount without using a magnet in the grinding wheel, the grinding wheel that is a consumable can be configured at low cost. Further, since the fixed electrode and the movable electrode portion are disposed in the center portion of the wheel mount, the connection state can be stably maintained without being affected by the centrifugal force accompanying the rotation of the grinding wheel.

  A grinding apparatus according to the present invention comprises a chuck table for holding a workpiece, a grinding means for grinding the workpiece held on the chuck table, and a grinding wheel used for the grinding means. The grinding means includes a spindle housing, a spindle rotatably accommodated in the spindle housing, a wheel mount fixed to the tip of the spindle, and a drive source for rotationally driving the spindle. The grinding wheel is fastened by the wheel mount and a screw and formed of a conductive member, a plurality of grinding wheels disposed in an annular shape at a free end of the wheel base, and the wheel base. An annular ultrasonic transducer disposed thereon, an annular electrode disposed on the annular ultrasonic transducer, and the wheel A housing portion opened in the center of the base; and a movable electrode portion housed in the housing portion. The movable electrode portion includes a movable electrode having a magnetic force, and a contained member that holds the movable electrode and is inserted into the opening. A receiving portion, a restricting portion for restricting the receiving portion so that the movable electrode protrudes from the opening, and a conductive flexible conductive line connecting the annular electrode from the moving electrode portion. Is housed in the housing portion of the wheel base so as to be able to advance and retreat, and the wheel mount is disposed in the vicinity of a central free end surface and is disposed at a position facing the movable electrode in a state where the grinding wheel is fastened with a screw. A fixed electrode made of a material attracted by magnetic force, and when the grinding wheel is fastened to the wheel mount by a screw, the magnetic force of the movable electrode Serial with the movable electrode portion is energized to the annular ultrasonic transducer in contact with the fixed electrode, the movable electrode portion is characterized by comprising a non-contact with the wheel base.

  In the grinding apparatus of the present invention, the surface of the chuck table is formed in a horizontal plane, the wheel mount of the grinding means is disposed facing the chuck table, and the wheel mount is free of the fixed electrode and the wheel mount. A space that opens to the free end surface side between the end surface and a conductive plate that is made of a material that closes the opening from the inside and cannot be attracted by magnetic force, and the conductive plate is a stretchable waterproof sheet The conductive plate is fixed to the inner wall of the space and can be moved back and forth between the opening and the fixed electrode.When the grinding wheel is not attached, the conductive plate hangs down on the inner wall of the space by its own weight and closes the opening. When the grinding wheel is fastened to the wheel mount with a screw, the movable electrode is driven by the magnetic force of the fixed electrode or the movable electrode. There is preferably energized to the annular electrode in contact with the fixed electrode via the conductive plate.

  The grinding wheel of the present invention is a grinding wheel used in the grinding apparatus, wherein the restricting portion has conductivity, has a larger diameter than the opening of the wheel base, and the movable electrode protrudes from the opening. The accommodated part is suspended so as to be installed, and the flexible conductor is connected to the annular electrode laminated on the annular ultrasonic transducer from the restricting part having conductivity, and when separated from the wheel mount, The restricting portion having conductivity connected to an annular electrode comes into contact with the wheel base, and electric charges charged in the annular ultrasonic transducer are discharged.

  According to this grinding wheel, the restricting portion made of a conductive material is formed with a larger diameter than the opening of the wheel base and is suspended from the receiving portion, and the restricting portion and the annular electrode are connected to the flexible conductor. Therefore, the restricting portion and the annular electrode are electrically connected. As a result, the annular electrode provided on the annular ultrasonic vibrator is short-circuited via the restricting portion, so that the electric charge charged to the annular ultrasonic vibrator by the piezoelectric effect can be discharged, and the grinding wheel can be safely It can be handled.

  According to the present invention, when a grinding wheel that performs grinding with ultrasonic vibration is mounted on a wheel mount and used, high-precision electrode position accuracy is not necessary, and node region change during ultrasonic vibration machining is achieved. Therefore, it is possible to provide a grinding apparatus that does not cause poor electrode contact and can easily attach and detach the grinding wheel.

It is an external appearance perspective view of the grinding device concerning this embodiment. It is sectional drawing which shows roughly the structure of a part of grinding apparatus which concerns on this Embodiment. It is a perspective view of the wheel mount periphery of the grinding device according to the present embodiment. It is a perspective view of the grinding wheel of the grinding device concerning this embodiment. It is a cross-sectional schematic diagram of the wheel mount and grinding wheel of the grinding device according to the present embodiment. It is a cross-sectional schematic diagram of the wheel mount and grinding wheel of the grinding device according to the present embodiment. It is a cross-sectional schematic diagram which shows the other structure of the wheel mount and grinding wheel of the grinding apparatus which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the other structure of the wheel mount and grinding wheel of the grinding apparatus which concerns on this Embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an external perspective view showing an example of a grinding apparatus 1 according to the present embodiment. In the following, for the sake of convenience of explanation, the lower left side shown in FIG. 1 is called the front side of the grinding apparatus 1, and the upper right side shown in FIG. 1 is called the rear side of the grinding apparatus 1. In the following, for convenience of explanation, the vertical direction shown in FIG.

  As shown in FIG. 1, a grinding apparatus 1 according to the present embodiment has a base 100 that constitutes a housing of the apparatus. The base 100 includes a main portion 101 extending in the front-rear direction of the grinding apparatus 1 and a wall portion 102 provided to extend upward at the rear end portion of the main portion 101. On the front side of the upper surface of the main part 101, an operation panel 103 that receives instructions for the grinding apparatus 1 is provided. On the rear side of the operation panel 103, there is provided a table support base 105 that supports a chuck table 104 holding a workpiece W (workpiece) so as to be movable back and forth. On the other hand, a pair of guide rails 106 extending in the vertical direction are provided on the front surface of the wall portion 102. A grinding unit 21 (grinding means) is mounted on these guide rails 106 so as to be movable in the vertical direction.

  The grinding unit 21 is driven by the grinding feed mechanism 11 and can be moved up and down. The grinding feed mechanism 11 includes a ball screw 111 that is arranged in parallel to the guide rail 106 and extends in the vertical direction, a motor 112 that is connected to one end of the ball screw 111 and rotates the ball screw 111 in both forward and reverse directions, and an interior that is screwed into the ball screw 111. And a support base 114 connected to the transfer base 113 and supporting the grinding unit 21. The support base 114 is connected to the transfer base 113. The grinding feed mechanism 11 raises and lowers the grinding unit 21 by rotating the ball screw 111 driven by the motor 112 and moving the moving base 113 up and down guided by the guide rail 106.

  The grinding unit 21 includes a spindle unit 22 mounted on the moving base 113. The spindle unit 22 is supported by the support portion 114. The spindle unit 22 includes a spindle housing 221 supported by the support portion 114, and a rotating spindle 222 (not shown in FIG. 1, refer to FIG. 2) rotatably disposed in the spindle housing 221. . The lower end portion of the rotating spindle 222 protrudes downward beyond the lower end portion of the spindle housing 221, and a disc-shaped wheel mount 31 is connected to the tip end of the lower end portion. A grinding wheel 41 used for grinding by the grinding unit 21 is fixed to the wheel mount 31. The wheel mount 31 is disposed so as to be able to face the chuck table 104 whose upper surface (surface) is formed in a horizontal plane.

  FIG. 2 is a cross-sectional view schematically showing a partial configuration of the grinding apparatus 1 according to the present embodiment. As shown in FIG. 2, the rotary spindle 222 is rotatably supported by the spindle housing 221 in a non-contact state.

  The grinding unit 21 includes an electric motor 23 as a drive source that rotationally drives the rotary spindle 222. The electric motor 23 includes a rotor 231 connected to an intermediate portion of the rotary spindle 222 and a stator coil 232 disposed on the outer peripheral side of the rotor 231. The electric motor 23 operates by receiving power supply from the power supply means 51.

  The power supply means 51 includes a voltage adjustment means 512 interposed between the AC power source 511 and the power supply coil 242b of the power supply means 242, a frequency adjustment means 513 for adjusting the frequency of the AC power supplied to the power supply coil 242b, The control unit 514 controls the adjustment unit 512 and the frequency adjustment unit 513, and the input unit 515 is used to input the amplitude of the ultrasonic vibration.

  The AC power supply 511 is connected to the stator coil 232 of the electric motor 23 via the control circuit 516 and the wiring 517. The rotor 231 and the rotating spindle 222 can be rotated by supplying AC power to the stator coil 232.

  A small-diameter tip 223 is provided at one end (lower end) of the rotary spindle 222. The wheel mount 31 is fixed to the lower end portion of the small diameter tip portion 223. A rotary transformer 24 is provided at the other end (upper end) of the rotary spindle 222. The rotary transformer 24 includes a power receiving unit 241 connected to the upper end of the rotary spindle 222 and a power feeding unit 242 located on the outer peripheral side of the power receiving unit 241.

  The power receiving unit 241 includes a rotor core 241a connected to the rotary spindle 222 and a power receiving coil 241b wound around the rotor core 241a. The power feeding unit 242 includes a stator core 242a disposed on the outer peripheral side of the rotor core 241a constituting the power receiving unit 241 and a power feeding coil 242b disposed on the stator core 242a. Note that AC power is supplied to the power supply coil 242b through the wiring 518.

  A conductive wire 25 is connected to the power receiving coil 241 b of the power receiving means 241. A part of the conductive wire 25 passes through a through hole 222a formed in the axial direction of the rotary spindle 222 and is connected to a fixed electrode 62 (not shown in FIG. 2, see FIG. 3) of the wheel mount 31 described later. .

  Here, the configuration of the wheel mount 31 fixed to the lower end portion of the rotary spindle 222 and the grinding wheel 41 attached to the wheel mount 31 will be described. FIG. 3 is a perspective view of the periphery of the wheel mount 31 of the grinding apparatus 1 according to the present embodiment. In FIG. 3, the wheel mount 31 with the grinding wheel 41 removed is shown from below. FIG. 4 is a perspective view of the grinding wheel 41 of the grinding apparatus 1 according to the present embodiment. In FIG. 4, the grinding wheel 41 is shown from above.

  As shown in FIG. 3, the wheel mount 31 is made of a conductive metal material and has a generally disc shape. A circular hole 31 a that communicates with the through hole 222 a of the rotary spindle 222 is provided at the center of the lower surface of the wheel mount 31. As will be described in detail later, an insulating member 61 having a hole 61a provided in the center is attached to the circular hole 31a. Inside the insulating member 61, the fixed electrode 62 is held with a part thereof exposed from the hole 61a. In addition, a plurality of (six in this embodiment) screw holes 31 b penetrating the wheel mount 31 in the vertical direction are provided on the outer peripheral edge of the wheel mount 31.

  As shown in FIG. 4, the grinding wheel 41 is made of a conductive metal material and has a generally disc shape. The grinding wheel 41 has an annular shape, a mounting ring 411 fixed to the wheel mount 31, a wheel base 413 formed integrally with the mounting ring 411 via an annular coupling portion 412, and a wheel base 413. And a plurality of grinding wheels 414 arranged annularly at the free end.

  A plurality (six in this embodiment) of screw holes 411 a that penetrates in the vertical direction of the grinding wheel 41 are provided on the outer peripheral edge of the mounting ring 411. The screw hole 411 a is disposed at a position corresponding to the screw hole 31 b provided in the wheel mount 31. The grinding wheel 41 is attached to the wheel mount 31 by fastening the screw hole 31b of the wheel mount 31 and the screw hole 411a of the attachment ring 411 with a screw 31c (see FIG. 2).

  At the center of the wheel base 413, a circular accommodating portion 413a is provided that opens upward. More specifically, the accommodating part 413a is comprised by the through-hole which penetrates the wheel base 413 to an up-down direction. An annular ultrasonic transducer 415 is disposed around the accommodating portion 413a on the wheel base 413 so as to be concentric with the circular opening constituting the accommodating portion 413a.

As the annular ultrasonic transducer 415, for example, barium titanate (BaTiO ₃ ), lead zirconate titanate (Pb (Zi, Ti) O ₃ ), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO) ₃ ), potassium sodium niobate (K, N) (KNbO ₃ ) and the like can be used.

  An annular electrode 416 having substantially the same shape as the annular ultrasonic transducer 415 is laminated and disposed above the annular ultrasonic transducer 415. For example, the annular electrode 416 is fixed to the annular ultrasonic transducer 415 with an adhesive or the like. The annular electrode 416 is electrically connected to a later-described movable electrode portion 71 (more specifically, a restriction portion 712 constituting the movable electrode portion 71) via a flexible conductive wire 417.

  The mounting ring 411 and the wheel base 413 are connected by an annular connecting portion 412. The annular connecting portion 412 is provided with a plurality of slits 412 a along the circumferential direction of the wheel base 413. These slits 412 a are provided so as to penetrate the annular coupling portion 412 in the vertical direction (see FIG. 5), and play a role of suppressing transmission of ultrasonic vibrations by the annular ultrasonic transducer 415 to the wheel mount 31.

  The movable electrode portion 71 is accommodated in the accommodating portion 413a of the wheel base 413 so as to be able to advance and retract in the vertical direction. The movable electrode portion 71 penetrates the substantially cylindrical portion 711 to be inserted through the opening of the housing portion 413a, a disc-shaped restriction portion 712 provided on the upper surface of the portion 711 to be received, and the restriction portion 712. And a movable electrode 713 held by the receiving portion 711 and a disk-shaped engaging portion 714 (not shown in FIG. 4, refer to FIG. 5) provided on the lower surface of the receiving portion 711. Composed.

  5 and 6 are schematic cross-sectional views of the wheel mount 31 and the grinding wheel 41 of the grinding apparatus 1 according to the present embodiment. 5 shows a state before mounting (the grinding wheel 41 is separated from the wheel mount 31) in which the grinding wheel 41 is disposed opposite to the wheel mount 31, and in FIG. The state where is attached is shown.

  As shown in FIG. 5, a mounting ring 411 is connected to the upper side of the wheel base 413 via an annular connecting portion 412. Therefore, a predetermined space is formed between the upper surface 413b of the wheel base 413 and the lower surface 31d of the wheel mount 31 when the grinding wheel 41 is mounted on the wheel mount 31 (see FIG. 6). The movable electrode portion 71 described above is accommodated in the space so as to be able to advance and retreat in an accommodating portion 413 a provided on the wheel base 413.

  The restricting portion 712 constituting the movable electrode portion 71 is formed to have a slightly larger width dimension in the radial direction than the opening of the wheel base 413 (the opening of the accommodating portion 413a). That is, it has a larger diameter than the opening of the wheel base 413 and is arranged so as to cover the opening. The restricting portion 712 moves the movable electrode portion 71 (more specifically, the accommodated portion 711) in a state where the outer peripheral edge of the lower surface of the restricting portion 712 and the opening edge of the accommodating portion 413a of the wheel base 413 are in contact. Suspend and regulate the drop of the movable electrode portion 71 into the housing portion 413a. When the restricting portion 712 restricts the fall of the accommodated portion 711 into the accommodating portion 413a, the movable electrode 713 is maintained in a state of protruding from the opening of the wheel base 413 (the opening of the accommodating portion 413a).

  The restricting portion 712 is made of a conductive metal material. A flexible conductive wire 417 is connected between the restricting portion 712 and the annular electrode 416 laminated on the annular ultrasonic transducer 415. That is, in a state where the grinding wheel 41 is separated from the wheel mount 31, the annular ultrasonic transducer 415 and the wheel base 413 are electrically connected via the flexible conductor 417 and the restricting portion 712. On the other hand, since the back surface side of the annular ultrasonic transducer 415 is in contact with the wheel base 413 made of a conductive member, the upper surface side and the lower surface side of the ultrasonic transducer 415 are short-circuited.

  When the grinding wheel 41 is not attached to the wheel mount 31 as in storage, the grinding wheel 41 can expand and contract according to the surrounding atmosphere. Such expansion and contraction of the grinding wheel 41 may be caused by factors such as a temperature change when moving from outside air in midsummer to a room whose temperature is controlled by an air conditioning facility. An external stress typified by expansion and contraction of the grinding wheel 41 causes a piezoelectric action in the annular ultrasonic vibrator 415. Under a situation where an external stress is applied, the surface of the annular ultrasonic transducer 415 may be charged by the piezoelectric action of the annular ultrasonic transducer 415. When such a situation occurs, it becomes difficult to handle the grinding wheel 41 safely, for example, when the wheel mount 31 is attached. In order to cope with such a situation, in the grinding wheel 41 according to the present embodiment, the regulating portion 712 made of a conductive metal material is electrically connected to the annular ultrasonic transducer 415, and the wheel mount The upper surface side and the lower surface side of the annular ultrasonic transducer 415 are short-circuited by bringing the regulating portion 712 into contact with the wheel base 41 while the grinding wheel 41 is separated from the wheel 31. As a result, the electric charge charged to the annular ultrasonic vibrator 415 by the piezoelectric action can be discharged (that is, charging due to the piezoelectric action by the annular ultrasonic vibrator 415 can be prevented), and the grinding wheel 41 removed after grinding can be safely used. Can be handled.

  The movable electrode 713 is made of a material that is attracted by magnetic force, for example, iron. The movable electrode 713 is disposed at a substantially central portion of the restricting portion 712 and is provided so that at least a part protrudes upward from the upper surface of the restricting portion 712. A flat portion is provided at the upper end of the movable electrode 713. This flat portion constitutes an attracting surface of a magnet 621 constituting a fixed electrode 62 described later.

  The engaging portion 714 is provided on the lower surface of the accommodated portion 711 and is disposed in the accommodating portion 413a. Similar to the restricting portion 712, the engaging portion 714 has a slightly larger width in the radial direction than the opening of the wheel base 413 (the opening of the accommodating portion 413a), and the accommodated portion 711 is located above the accommodating portion 413a. It plays a role of preventing separation to the side or the lower side.

  On the other hand, an insulating member 61 is attached to the circular hole 31 a provided in the center of the wheel mount 31. The insulating member 61 includes an insertion portion 611 inserted into the circular hole 31a and a flat portion 612 having a disk shape provided at the lower end of the insertion portion 611. The lower surface of the planar portion 612 is disposed on the same plane as the lower surface 31 d of the wheel mount 31 in a state where the insulating member 61 is completely attached to the wheel mount 31. A hole 61 a is provided in the center of the flat portion 612.

  The fixed electrode 62 is accommodated in the insertion portion 611. The fixed electrode 62 is accommodated in the insertion portion 611 so that a part thereof is exposed from the hole 61 a of the flat portion 612. The fixed electrode 62 includes a magnet 621 and a conductive member 622 that covers the magnet 621. By providing the magnet 621 inside, the fixed electrode 62 functions as a fixed electrode having magnetic force. A part of the conductive member 622 that covers the lower surface of the magnet 621 is provided thinner than a portion that covers the other surface (for example, the upper surface or side surface of the magnet 621). By providing a thin part of the conductive member 622 corresponding to the lower surface of the magnet 621, the magnetic force of the magnet 621 is appropriately applied to the movable electrode portion 71 (more specifically, the movable electrode 713) disposed on the wheel base 413. It is configured to work.

  The conductive member 622 is insulated by the insulating member 61. The conductive wire 25a disposed in the through hole 222a formed in the rotary spindle 222 is connected to the conductive member 622 via the insulating member 26, and the other conductive wire 25b different from the conductive wire 25a is connected to the wheel mount 31. Connected to itself.

  A movable electrode portion 71 housed in a housing portion 413a opened in the center of the wheel base 413, a fixed electrode 62 held in an insulating member 61 attached to a circular hole 31a near the center of the free end surface of the wheel mount 31, Are arranged at positions facing each other in a state where the grinding wheel 41 is fastened to the wheel mount 31 by screws 31c. As shown in FIG. 5, in a state before the grinding wheel 41 is fastened to the wheel mount 31 by the screw 31 c, the magnetic force of the fixed electrode 62 does not act, and the movable electrode portion 71 has a receiving portion 711 that has a receiving portion. It is maintained in the state accommodated in 413a.

  On the other hand, when the grinding wheel 41 is fastened to the wheel mount 31 with the screw 31c, the movable electrode 713 is attracted by the magnetic force of the fixed electrode 62 as shown in FIG. ) As a result, the movable electrode 713 comes into contact with the fixed electrode 62, and the restricting portion 712 is separated from the opening edge of the housing portion 413 a of the wheel base 413, so that the movable electrode portion 71 is not in contact with the wheel base 413.

  In addition, the restricting portion 712 maintains a state where it is electrically connected to the annular ultrasonic transducer 415 (annular electrode 416) via the flexible conductive wire 417. Therefore, the fixed electrode 62 and the movable electrode 713 are electrically connected, and the annular ultrasonic transducer 415 electrically connected to the movable electrode 713 via the flexible conductive wire 417 is electrically connected to the fixed electrode 62. Connected. As a result, power is supplied from the power supply means 51 to the annular ultrasonic vibrator 415 via the fixed electrode 62, and grinding by the grinding wheel 41 accompanied by ultrasonic vibration becomes possible.

  In the state where the fixed electrode 62 and the movable electrode 713 are connected, the electric charge generated on the back surface side of the annular ultrasonic transducer 415 is a wheel base 413 made of a conductive member and a wheel fastened to the wheel base 413. The signal is output through the conductive wire 25 b connected to the mount 31 and the wheel mount 31. Then, it is grounded via the ground terminal of the grinding device 1.

  As described above, in the grinding apparatus 1 according to the present embodiment, the fixed electrode 62 having magnetic force is disposed on the wheel mount 31 and the material attracted by the magnetic force into the accommodating portion 413a of the wheel base 413 of the grinding wheel 41. Since the movable electrode portion 71 including the movable electrode 713 formed in the above is disposed and the movable electrode portion 71 is housed in the housing portion 413a of the wheel base 413 so as to be able to advance and retreat, the grinding wheel 41 is mounted on the wheel mount 31. At this time, the movable electrode portion 71 is attracted by the magnetic force of the fixed electrode 302 and automatically contacts the fixed electrode 62. Thereby, since the ultrasonic transducer | vibrator 415 and the electric power supply means 51 can be electrically connected without going through a connector etc., it becomes possible to attach or detach the grinding wheel 41 easily.

  In particular, since the movable electrode 713 and the fixed electrode 62 come into contact with each other by the magnetic force of the fixed electrode 62, the fixed electrode 62 and the movable electrode 713 can be electrically connected without requiring high-precision electrode position accuracy, and the ultrasonic wave Even when a node region, which is a region in which vibration is canceled during processing involving vibration, changes, contact failure between the fixed electrode 62 and the movable electrode 713 can be suppressed.

  Further, since the fixed electrode 62 having magnetic force is disposed on the wheel mount 31 away from the workpiece W (workpiece), the influence of the magnetic force on the workpiece W can be reduced. Further, since the grinding wheel 41 does not use a magnet and the wheel mount 31 is provided with the fixed electrode 62 having a magnetic force, the grinding wheel 41 that is a consumable can be configured at low cost. Furthermore, since the movable electrode portion 71 is disposed at the center portion of the wheel mount 31, the connection state can be stably maintained without being affected by the centrifugal force accompanying the rotation of the grinding wheel 41.

  Next, the operation of the grinding apparatus 1 when the workpiece (workpiece) W is ground using the grinding apparatus 1 shown in FIG. 1 will be described. The workpiece W is held on the chuck table 104 with the tape T attached to the held surface. Then, when the chuck table 104 moves rearward, the workpiece W is positioned in the lower region of the grinding unit 21.

  Next, while rotating the chuck table 2 at a rotational speed of about 300 RPM and rotating the rotary spindle 222, the grinding feed mechanism 11 rotates the grinding unit 21 while rotating the grinding wheel 41 at a rotational speed of about 6000 RPM, for example. Is lowered, the rotating grinding wheel 414 can be brought into contact with the workpiece W for grinding. Then, when the workpiece W reaches a desired thickness, the grinding unit 21 is raised and the grinding is finished.

  Next, another configuration example of the grinding apparatus 1 according to the present embodiment will be described. 7 and 8 are diagrams showing another configuration example of the grinding apparatus 1 according to the present embodiment, and schematically show a partial cross section corresponding to FIGS. 5 and 6. In the following, only differences in other configuration examples of the grinding apparatus 1 according to the present embodiment will be described. In the following description, for convenience of explanation, a grinding apparatus according to another configuration example is referred to as a grinding apparatus 10. 7 and 8, the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the grinding apparatus 10, as shown in FIGS. 7 and 8, the restricting portion 712 of the movable electrode portion 71 is made of a non-conductive material, and the flexible conductive wire 417 connected to the annular electrode 416 is connected to the movable electrode 713. This is different from the grinding apparatus 1 according to the present embodiment.

  The grinding apparatus 10 is different from the grinding apparatus 1 according to the present embodiment in the configuration of the insulating member 61 attached to the circular hole 31a of the wheel mount 31. In the insulating member 61, a space 63 opened to the free end face side (downward side) is provided between the free end face of the wheel mount 31 and the fixed electrode 62. In this space 63, a conductive plate 641 that closes the hole 61a from the inside is disposed. The conductive plate 641 is formed of a material that is not attracted by magnetic force, and has, for example, a disk shape. For this reason, the conductive plate 641 is not attracted by the magnet 621 constituting the fixed electrode 62.

  The conductive plate 641 is fixed to the inner wall surface of the space 63 by a waterproof sheet 642 having elasticity at the outer peripheral edge thereof. More specifically, the conductive plate 641 is fixed to the side wall surface that defines the space 63 in the insulating member 61 via the waterproof sheet 642. Since the conductive plate 641 is fixed via the stretchable waterproof sheet 642, the conductive plate 641 is configured to be movable back and forth between the hole 61 and the fixed electrode 62 in the space 63. As shown in FIG. 7, when the grinding wheel 41 is not mounted, the conductive plate 641 hangs down on the inner wall surface of the space 63 by its own weight and closes the hole 61a. In other words, the conductive plate 641 is placed on the upper surface of the inner wall surface that defines the hole 61a in the insulating member 61 and covers the hole 61a.

  On the other hand, as shown in FIG. 8, when the grinding wheel 41 is fastened to the wheel mount 31 by screws 31c, the movable electrode 713 is attracted against gravity by the magnetic force of the fixed electrode 62. Then, the movable electrode 713 automatically contacts the fixed electrode 62 while pushing up the conductive plate 641 after contacting the conductive plate 641. As a result, as with the grinding apparatus 1 shown in FIGS. 5 and 6, by attaching the grinding wheel 41 to the wheel mount 31, the power supply means 51 and the annular ultrasonic transducer 415 (annular electrode 416) are electrically connected. Therefore, the grinding wheel 41 can be easily attached and detached. When the grinding wheel 41 is removed from the wheel mount 31, the conductive plate 641 hangs down by its own weight and closes the hole 61 a constituting the opening of the insulating member 61. Intrusion of grinding water, etc. can be prevented. The same applies to the case where the fixed electrode 62 is made of a material attracted by a magnet, while the movable electrode 713 is made to have a magnetic force.

  As described above, also in the grinding apparatus 10 shown in FIGS. 7 and 8, the movable electrode 713 and the fixed electrode 62 automatically contact each other via the conductive plate 641 by attaching the grinding wheel 41 to the wheel mount 31. On the other hand, since the movable electrode 713 is separated from the fixed electrode 62 by removing the grinding wheel 41 from the wheel mount 31, the contact state between the movable electrode 713 and the fixed electrode 62 is different from the attachment / detachment of the grinding wheel 41 with respect to the wheel mount 31. It is not necessary to operate, and the grinding wheel 41 can be easily attached and detached. Further, since the fixed electrode 62 and the movable electrode 713 are attracted and contacted by magnetic force, high positional accuracy is not required, and contact failure due to electrode position error does not occur.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the above embodiment, the movable electrode 713 is made of a material that can be attracted by a magnet, while the magnet 621 is arranged on the fixed electrode 62 side to electrically connect the movable electrode 713 and the fixed electrode 62. Explains. However, the configuration for electrically connecting the movable electrode 713 and the fixed electrode 62 is not limited to this, and can be changed as appropriate. For example, while the fixed electrode 62 is made of a material that can be attracted by a magnet, the movable electrode 713 is given a magnetic force, and the movable electrode 713 is moved to the fixed electrode 62 side to electrically connect the movable electrode 713 and the fixed electrode 62. It is good also as a structure to connect.

  Further, in the above-described embodiment, the movable electrode portion 71 of the accommodated portion 711 is protruded from the opening of the wheel base 41 by the restriction portion 712 provided on the upper surface of the accommodated portion 711. Although the case of restricting movement is described, the configuration of the restricting portion 712 that restricts the movement of the accommodated portion 711 is not limited to this, and can be changed as appropriate. For example, the engaging portion 714 provided on the lower surface of the accommodated portion 711 can also function as the restricting portion 712.

  As described above, the present invention eliminates the need for high-precision electrode position accuracy when using a grinding wheel for grinding with ultrasonic vibration mounted on a wheel mount, and at the time of ultrasonic vibration machining. It has the effect of preventing electrode contact failure even when the node region changes, and the grinding wheel can be easily attached and detached. Especially, grinding of brittle hard materials such as sapphire, silicon nitride, lithium tantalate, and Altic. It can be suitably used as an apparatus.

DESCRIPTION OF SYMBOLS 1, 10 Grinding device 11 Grinding feed mechanism 100 Base 101 Main part 102 Wall part 103 Operation panel 104 Chuck table 105 Table support base 106 Guide rail 111 Motor screw 113 Motor 113 Moving base 114 Support part 21 Grinding unit (grinding means)
22 Spindle unit 221 Spindle housing 222 Rotating spindle 222a Through hole 223 Small diameter tip 23 Electric motor 231 Rotor 232 Stator coil 24 Rotary transformer 241 Power receiving means 242 Power feeding means 241a Rotor core 241b Power receiving coil 242a Stator core 242b Power feeding coil 25 Conductive wire 31 Mount 31 Circular hole 31b Screw hole 31c Screw 41 Grinding wheel 411 Mounting ring 411a Screw hole 412 Annular connecting part 412a Slit 413 Wheel base 413a Housing part 414 Grinding wheel 415 Annular ultrasonic vibrator 416 Annular electrode 417 Flexible lead 51 Power supply means 511 512 Voltage adjusting means 513 Frequency adjusting means 514 Control means 515 Input means 516 Control circuit 517 wiring 518 wiring 61 insulating member 61a hole 611 insertion portion 612 flat portion 62 fixed electrode 621 magnet 622 conductive member 641 conductive plate 642 tarp 71 movable electrode portion 711 installed portion 712 restricting portion 713 movable electrode 714 engaging part

Claims (4)

A grinding apparatus comprising: a chuck table for holding a workpiece; a grinding means for grinding a workpiece held on the chuck table; and a grinding wheel used for the grinding means,
The grinding means includes a spindle housing, a spindle rotatably accommodated in the spindle housing, a wheel mount fixed to the tip of the spindle, and a drive source for rotationally driving the spindle,
The grinding wheel is fastened with the wheel mount and a screw and is formed of a conductive member, a plurality of grinding wheels arranged in an annular shape at a free end of the wheel base, and a wheel base. An annular ultrasonic transducer provided; an annular electrode disposed on the annular ultrasonic transducer; a housing portion opened in the center of the wheel base; and a movable electrode portion housed in the housing portion Including
The movable electrode portion includes a movable electrode formed of a material attracted by magnetic force, a receiving portion that holds the movable electrode and is inserted into the opening, and the received electrode so that the movable electrode protrudes from the opening. A restricting portion for restricting a portion, and a conductive flexible conductive wire connected to the annular electrode from the movable electrode portion, and the movable electrode portion is accommodated in the accommodating portion of the wheel base so as to be capable of moving forward and backward.
The wheel mount has a fixed electrode having a magnetic force disposed at a position facing the movable electrode in a state in which the grinding wheel is fastened by a screw and disposed near the free end surface of the center,
When the grinding wheel is fastened to the wheel mount with a screw, the movable electrode portion is brought into contact with the fixed electrode by the magnetic force of the fixed electrode, and the annular electrode is energized. Grinding device characterized in that it is non-contact. A grinding apparatus comprising: a chuck table for holding a workpiece; a grinding means for grinding a workpiece held on the chuck table; and a grinding wheel used for the grinding means,
The grinding means includes a spindle housing, a spindle rotatably accommodated in the spindle housing, a wheel mount fixed to the tip of the spindle, and a drive source for rotationally driving the spindle,
The grinding wheel is fastened with the wheel mount and a screw and is formed of a conductive member, a plurality of grinding wheels arranged in an annular shape at a free end of the wheel base, and a wheel base. An annular ultrasonic transducer provided; an annular electrode disposed on the annular ultrasonic transducer; a housing portion opened in the center of the wheel base; and a movable electrode portion housed in the housing portion Including
The movable electrode portion includes a movable electrode having a magnetic force, a contained portion that holds the movable electrode and is inserted into the opening, and a restriction portion that restricts the contained portion so that the movable electrode protrudes from the opening. And a conductive flexible conductor that connects the annular electrode from the movable electrode portion, and the accommodated portion is accommodated in the accommodating portion of the wheel base so as to be able to advance and retreat,
The wheel mount includes a fixed electrode formed of a material that is disposed near a free end surface at a center and is disposed at a position facing the movable electrode in a state where the grinding wheel is fastened by a screw and is attracted by a magnetic force.
When the grinding wheel is fastened to the wheel mount by a screw, the movable electrode portion is brought into contact with the fixed electrode by the magnetic force of the movable electrode, and the annular ultrasonic transducer is energized. A grinding apparatus characterized by being in non-contact with the wheel base.   A surface of the chuck table is formed in a horizontal plane, and the wheel mount of the grinding means is disposed to face the chuck table, and the wheel mount is on a free end surface side between the fixed electrode and a free end surface of the wheel mount. And a conductive plate made of a material that closes the opening from the inside and cannot be attracted by magnetic force, and the conductive plate is fixed to the inner wall of the space with a stretchable waterproof sheet. The conductive plate can be moved back and forth between the opening and the fixed electrode, and when the grinding wheel is not mounted, the conductive plate hangs down on the inner wall of the space by its own weight and closes the opening. When fastened to the wheel mount, the movable electrode portion is interposed through the conductive plate by the magnetic force of the fixed electrode or the movable electrode. Grinding apparatus according to claim 1 or claim 2, wherein when energized to the annular electrode in contact with the fixed electrode.   It is a grinding wheel used for the grinding apparatus in any one of Claims 1-3, Comprising: The said control part has electroconductivity, is larger diameter than the said opening of the said wheel base, and the said movable electrode And the flexible conductor is connected to the annular electrode stacked on the annular ultrasonic transducer from the restricting portion having conductivity, and the wheel mount is suspended from the opening. The grinding wheel is characterized in that, when separated from each other, the regulating portion having conductivity connected to the annular electrode comes into contact with the wheel base, and electric charges charged in the annular ultrasonic vibrator are discharged.

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