KR101367737B1 - Grinding wheel - Google Patents

Abstract

An object of this invention is to provide the grinding wheel which can transmit the ultrasonic wave of an ultrasonic vibrator enough and uniformly with respect to a grinding grindstone, and can grind efficiently even a non-grinding abrasive material.

In the wheel base 51 including a ring-shaped connecting portion 511 connected to the wheel mount and a disk-shaped grindstone mounting portion 512 connected to the inner circumference of the connecting portion 511, the grinding wheel mounting portion 512 is The upper surface, which is the wheel mount side, is relatively in contact with the wheel mount, and the grinding grindstone 52 is mounted on the lower surface side, and the grinding grindstone is disposed around the center of the grinding wheel 5 on the inner circumferential side of the grinding grinder 52. A plurality of circular arc-shaped slits 513 having an annular ultrasonic vibrator 6 disposed at a position concentric with the 52 and positioned at the boundary between the connecting portion 511 and the grindstone mounting portion 512 and formed in the circumferential direction. It was to be provided.

Description

GRINDING WHEEL [0002]

The present invention provides a grinding wheel comprising a wheel base attached to a wheel mount provided at one end of a rotating spindle constituting a grinding means for grinding a workpiece held on a chuck table, and an annular grinding wheel attached to the wheel base. It is about.

In the semiconductor device manufacturing process, a plurality of regions are partitioned by a division scheduled line called a street arranged in a lattice shape on the surface of a semiconductor wafer having a substantially disk shape, and devices such as IC and LSI are formed in the partitioned region. have. Subsequently, the semiconductor wafer is cut along the street to divide the region where the device is formed to manufacture individual semiconductor chips. In addition, optical device wafers in which gallium nitride compound semiconductors and the like are laminated on the surface of a sapphire substrate are also cut along the street to be divided into optical devices such as individual light emitting diodes and laser diodes, and are widely used in electronic devices.

In the wafer divided in this manner, the back surface is ground by a grinding apparatus and processed to a predetermined thickness before being cut along the street. When the back surface of the wafer is ground by the grinding grindstone of the grinding device, the grinding ability is lowered due to the clogging of the grinding grindstone and the smooth discharge of contaminants. In particular, when brittle hard materials such as sapphire, silicon nitride, lithium tantalate, and altic are ground, there is a problem in that the productivity is remarkably lowered due to a decrease in the grinding ability due to clogging of the grinding wheel.

In order to solve such a problem, at least one of the chuck table for holding the workpiece and the grindstone holding member for holding the grinding wheel for grinding the workpiece held on the chuck table is provided in the grinding part of the workpiece by the grinding wheel. There is proposed a grinding device in which ultrasonic application means for imparting ultrasonic vibration is arranged (see Patent Document 1, for example).

[Patent Document 1] Japanese Patent Application Laid-Open No. 2-232164

However, in the grinding apparatus of patent document 1, although the specific example which arrange | positioned the ultrasonic wave application means in the chuck table in order to give ultrasonic vibration to a chuck table is disclosed, it is sufficient for the grinding grindstone which targets the ultrasonic wave which an ultrasonic vibrator produces | generates. Since it is not described about the specific structure for carrying out uniformly, it is a problem that it is not able to transmit ultrasonic vibration uniformly enough to a grinding grindstone, and that a flame-retardant material cannot be ground smoothly.

This invention is made | formed in view of the above, Comprising: It aims at providing the grinding wheel which can transmit the ultrasonic wave of an ultrasonic vibrator enough and uniformly with respect to a grinding grindstone, and can grind efficiently even a non-grinding abrasive material.

In order to solve the above problems and achieve the object, the grinding wheel according to the present invention, the wheel base attached to one end of the rotary spindle constituting the grinding means for grinding the workpiece held on the chuck table, A grinding wheel comprising an annular grinding grindstone mounted to the wheel base, wherein the wheel base includes a ring-shaped connecting portion connected to the wheel mount, and a disc shaped grindstone mounting portion connected to an inner circumferential portion of the connecting portion. The grindstone mounting portion is configured such that the upper surface on the wheel mount side is relatively non-contact with the wheel mount, the grinding grindstone is mounted on the lower surface side, and is formed concentric with the grinding grindstone around the center of the grinding wheel on the inner circumferential side than the grinding grindstone. An annular ultrasonic vibrator disposed at a position, positioned at a boundary between the connecting portion and the grindstone mounting portion, It characterized in that it comprises a plurality of arcuate slits are formed.

In the above-described invention, the grinding wheel according to the present invention is characterized in that the grindstone mounting portion is formed in a donut shape, and the ultrasonic vibrator is disposed at a central position between the inner circumferential portion of the donut-shaped grindstone mounting portion and the arc-shaped slit. do.

The grinding wheel according to the present invention is also characterized in that in the above invention, a plurality of arc-shaped slits are alternately positioned on circumferences of different radii.

Moreover, in the grinding wheel which concerns on this invention, in the said invention, the upper surface side of a grindstone mounting part is formed in concave shape with respect to a connection part, It is characterized by being comprised by non-contact with a wheel mount.

The grinding wheel according to the present invention has a wheel base including a ring-shaped connecting portion connected to a wheel mount and a disk-shaped grindstone mounting portion connected to an inner circumferential portion of the connecting portion, wherein the upper surface of the grinding wheel mounting portion is a wheel mount side. It has a relatively non-contact with respect to the grinding wheel is mounted on the lower surface side, and has an annular ultrasonic vibrator arranged in a position concentric with the grinding wheel around the center of the grinding wheel on the inner peripheral side than the grinding wheel, And the configuration and arrangement are designed to include a plurality of arc-shaped slits positioned in the boundary portion of the grindstone mounting portion and formed in the circumferential direction, so that ultrasonic vibration generated by the ultrasonic vibrator can be sufficiently and uniformly transmitted to the grinding grindstone located on the outer circumferential side. As a result, a larger vibration amplitude can be obtained in the grinding wheel than in the prior art. This eliminates clogging of the stone and exhibits an effect that even a non-grinded abrasive can be ground efficiently.

EMBODIMENT OF THE INVENTION Hereinafter, the grinding wheel of the preferable form for implementing this invention is demonstrated with reference to drawings.

1 is a perspective view showing an example of a configuration of an entire grinding device including the grinding wheel of the present embodiment, and FIG. 2 is a longitudinal side view of the spindle unit included in the grinding device together with the electric field control system. The grinding apparatus of this embodiment is equipped with the apparatus housing 2. The device housing 2 is a thin and long rectangular parallelepiped main part 21 and a pair of uprights which are provided at the rear end of the main part 21 (upper right corner in FIG. 1) and extend substantially vertically. Has a wall 22. On the front surface of the upstanding wall 22, a pair of guide rails 221 extending in the vertical direction are provided. The grinding means 3 is attached to this pair of guide rails 221 so that a movement to an up-down direction is possible.

The grinding means 3 is equipped with the movement base 31 and the spindle unit 4 attached to this movement base 31. The moving base 31 is provided with a pair of leg portions 311 extending in the vertical direction on both sides of the rear surface, and the pair of leg portions 311 are slidably movable with a pair of guide rails 221. Guided grooves 312 to be engaged are formed. The front part of the movable base 31 is provided with the support part 313 which protrudes forward, and the spindle unit 4 is attached to this support part 313. As shown in FIG.

The spindle unit 4 is provided with the spindle housing 41 attached to the support part 313, and the rotating spindle 42 rotatably arrange | positioned at this spindle housing 41. As shown in FIG. Here, as shown in FIG. 2, the spindle housing 41 is formed in substantially cylindrical shape, and has the axial hole 411 which penetrates to an axial direction. The thrust bearing flange 421 which protruded in the radial direction is provided in the center part of the rotating spindle 42 inserted into the axial hole 411 formed in the spindle housing 41, and is provided. As a result, the rotating spindle 42 is rotatably supported by the high pressure air supplied between the inner wall of the shaft hole 411. As for the rotary spindle 42, the one end part (lower end part of FIG. 2) protrudes from the lower end of the spindle housing 41, and the wheel mount 43 is provided in the one end. The grinding wheel 5 according to the present embodiment is attached to the lower surface of the wheel mount 43. The wheel mount 43 and the grinding wheel 5 will be described later.

Moreover, the grinding apparatus is equipped with the grinding unit feed mechanism 10 which moves the spindle unit 4 to an up-down direction along a pair of guide rail 221. As shown in FIG. The grinding unit feed mechanism 10 is provided with the external threaded rod 101 arrange | positioned in front of the upstanding wall 22, and extending substantially vertically. The male threaded rod 101 is rotatably supported by bearing members 102 and 103 whose upper and lower ends are attached to the upstanding wall 22. On the upper bearing member 102, a pulse motor 104 for rotationally driving the male threaded rod 101 is arranged. A through female screw hole (not shown) is formed in the rear surface of the movable base 31 from the widthwise center portion to the rear, and the male screw rod 101 is screwed into the through female screw hole. Therefore, when the pulse motor 104 rotates forward, the moving base 31, that is, the grinding means 3, moves down (forwarding), and when the pulse motor 104 reversely rotates, the moving base 31, that is, the grinding means ( 3) rises (retreats).

Moreover, the chuck table mechanism 11 is arrange | positioned at the main part 21 of the apparatus housing 2. The chuck table mechanism 11 includes a chuck table 12, a cover member 13 covering the circumference of the chuck table 12, and bellows means 14 and 15 disposed before and after the cover member 13. Equipped. The chuck table 12 is rotated by a rotating means (not shown), and is configured to suck and hold the workpiece W on its upper surface by operating a suction means (not shown). In addition, the chuck table 12 opposes the workpiece loading area 24 shown in FIG. 1 by the chuck table moving means (not shown) and the grinding wheel 5 constituting the spindle unit 4. It is moved between the grinding areas 25. The bellows means 14, 15 are formed of a suitable material, such as a campus cloth. The front end of the bellows means 14 is fixed to the front wall of the main part 21, and the rear end is fixed to the front face of the cover member 13. The front end of the bellows means 15 is fixed to the rear end face of the cover member 13, and the rear end is fixed to the front surface of the upstanding wall 22 of the device housing 2. When the chuck table 12 moves in the direction indicated by arrow 23a , the bellows means 14 extends and the bellows means 15 contracts. On the contrary, when the chuck table 12 moves in the direction indicated by arrow 23b . The bellows means 14 contract and the bellows means 15 extend.

Next, the wheel mount 43 and the grinding wheel 5 will be described with reference to FIGS. 3 to 6. 3 is an exploded perspective view showing the wheel mount and the grinding wheel, FIG. 4 is a bird's eye view showing the grinding wheel, FIG. 5 is a longitudinal front view showing the grinding wheel, and FIG. 6 is a schematic bottom view showing the grinding wheel. to be.

First, as shown in FIG. 3, the wheel mount 43 is integrally formed in the disk shape at the lower end of the rotating spindle 42. As shown in FIG. A plurality of bolt insertion holes 43a are formed in this wheel mount 43. In addition, a connector insertion hole 43b is formed in the center of the wheel mount 43.

Meanwhile, the grinding wheel 5 is made of SUS or the like, and as shown in FIGS. 3 to 6, the wheel base 51 attached to the wheel mount 43 and the lower surface of the wheel base 51 are rounded. A plurality of grinding grindstones 52 are mounted in an annular shape. The wheel base 51 is formed in a size corresponding to the wheel mount 43, a ring-shaped connecting portion 511 is located on the outer peripheral portion and connected to the wheel mount 43, and a disc connected to the inner peripheral portion of the connecting portion 511 The grindstone mounting part 512 of a shape is included. In the connecting portion 511, a plurality of screw holes 511a corresponding to the plurality of bolt insertion holes 43a formed in the wheel mount 43 are formed.

The grindstone mounting part 512 is formed in the recessed part 53 so that the upper surface side may become concave shape with respect to the connection part 511, and the upper surface of the grindstone mounting part 512 in the state in which the connection part 511 is connected to the wheel mount 43 is carried out. The side is comprised so that it may become non-contact with respect to the wheel mount 43. As shown in FIG. That is, the grindstone mounting part 512 is formed sufficiently thin compared with the thickness of the connection part 511. As shown in FIG. In addition, as for the grindstone mounting part 512, the wiring insertion hole 512a is formed in the center part, and is formed in the donut shape as a whole. In the appropriate radial position on the lower surface side of the grindstone mounting portion 512, a plurality of grinding grindstones 52 are appropriately mounted in an annular shape by an adhesive in the circumferential direction.

Further, in the grindstone mounting portion 512, an annular grinding grindstone 52 and a concentric circle are arranged around the center of the grinding wheel 5 (wiring insertion through hole 512a), which is located at an inner circumferential side of the grinding grindstone 52. The annular ultrasonic vibrator 6 mounted with the appropriate adhesive agent is arrange | positioned at the up-and-down both sides which comprise. These ultrasonic vibrators 6 are for imparting ultrasonic vibration to the grinding grindstone 52, and are formed by piezoelectric ceramics such as barium titanate, lead zirconate titanate (PZT), lithium tantalate, and the like. As the ultrasonic vibrator 6 of the present embodiment, for example, a PZT vibrator is used. In this way, one end of the conductive wire 61 is connected to the + and-terminals of the front and back surfaces of the ultrasonic vibrator 6 mounted on the upper and lower surfaces of the grindstone mounting portion 512, respectively. In addition, the conductive wire 61 is connected to the + and-terminals of the ultrasonic vibrator 6 on the lower surface side through the wiring insertion hole 512a. The other end of the conductive wire 61 is connected to the convex connector 62. This convex connector 62 is detachably connected to a power supply means described later.

Moreover, in the grindstone mounting part 512, it is located in the boundary part of the connection part 511 which becomes the outer peripheral side position rather than the grinding grindstone 52, and the grindstone mounting part 512, and the several arc-shaped slits 513 are circumferentially formed. Formed. The arcuate slits 513 are formed in a plurality of rows, for example, in two rows on two circumferences of different radii, and the arcuate slits 513 in two rows are formed in a staggered staggered arrangement so that they overlap evenly in the radial direction. have. In addition, in FIG. 6, these arc-shaped slits 513 and some grinding grindstone 52 are simplified and shown in the state which continued on the circumference.

The grinding wheel 5 configured as described above is mounted by mounting the fastening bolts 55 respectively inserted through the bolt insertion holes 43a formed in the wheel mount 43 into the screw holes 511a, respectively, to thereby mount the mounting wheels. Removably attached to (43).

2, the spindle unit 4 is equipped with the electric motor 7 for rotationally driving the rotating spindle 42. As shown in FIG. The electric motor 7 is made of, for example, a permanent magnet motor, and includes a rotor 71 including a permanent magnet attached to a motor mounting portion 422 formed at an intermediate portion of the rotary spindle 42, and the rotor 71. It includes a stator coil 72 disposed in the spindle housing 41 on the outer peripheral side of the. This electric motor 7 rotates the rotor 71 by supplying alternating current power to the stator coil 72 by the electric power supply means mentioned later, and rotates the rotating spindle 42 which mounted this rotor 71. FIG. .

Moreover, the spindle unit 4 is equipped with the electric power supply means 8 which supplies AC electric power to the ultrasonic vibrator 6, and supplies AC electric power to the electric motor 7. As shown in FIG. The electric power supply means 8 is equipped with the rotary transformer 80 arrange | positioned at the rear end of the spindle unit 4. The rotary transformer 80 includes a power receiving means 81 disposed at the rear end of the rotary spindle 42 and a power feeding means disposed at the rear end of the spindle housing 41 so as to face the power receiving means 81. 82). The power receiving means 81 includes a rotor side core 811 attached to the rotary spindle 42 and a power receiving coil 812 wound around the rotor side core 811. The conductive wire 813 is connected to the power receiving coil 812. This conductive wire 813 is disposed in the hole 423 formed in the axial direction at the center of the rotating spindle 42, and the concave connector 814 whose tip is fitted with the convex connector 62 (see Fig. 3). Is connected to. The power feeding means 82 includes a stator side core 821 disposed on the outer circumferential side of the power receiving means 81 and a power feeding coil 822 disposed on the stator side core 821. The power supply coil 822 is supplied with alternating current power through the wiring 83.

In addition, the power supply means 8 supplies the AC power supply 91 of the AC power supplied to the power supply coil 822 of the rotary transformer 80, the voltage adjusting means 92, and the power supply means 82. A frequency adjusting means 93 for adjusting the frequency of the AC power, a control means 94 for controlling the voltage adjusting means 92 and a frequency adjusting means 93, and a plurality of grinding grindstones ( The input means 95 which inputs the amplitude of the ultrasonic vibration of the ultrasonic vibrator 6 attached to 52, etc. is provided. In addition, the power supply means 8 supplies AC power to the stator coil 72 of the electric motor 7 through the control circuit 96 and the wiring 721.

Here, the operation of the spindle unit 4 will be described. When grinding, AC power is supplied from the power supply means 8 to the stator coil 72 of the electric motor 7. As a result, the electric motor 7 rotates, the rotary spindle 42 rotates, and the grinding wheel 5 attached to the tip of the rotary spindle 42 rotates.

On the other hand, the electric power supply means 8 controls the voltage adjusting means 92 and the frequency adjusting means 93 by the control means 94, controls the voltage of AC power to a predetermined voltage, and changes the frequency of AC power. It converts into a predetermined frequency and supplies it to the power supply coil 822 of the power supply means 82 which comprises the rotary transformer 80. As shown in FIG. When AC power having a predetermined frequency and a predetermined voltage is supplied to the power feeding coil 822, the power receiving coil 812, the conductive wire 813, the concave connector 814, and the convex connector 62 of the power receiving means 81 that rotates. And alternating current power of a predetermined voltage and a predetermined frequency is applied to the annular ultrasonic vibrator 6 via the conductive line 61. As a result, the ultrasonic vibrator 6 vibrates in the radial direction. The ultrasonic vibration generated by the ultrasonic vibrator 6 is transmitted to the plurality of grinding grindstones 52 through the grindstone mounting portion 512.

Next, the operation of the grinding device of the present embodiment will be described. First, as shown in FIG. 1, the to-be-processed object W, such as a semiconductor wafer, is mounted on the chuck table 12 located in the to-be-processed object loading area 24 of a grinding apparatus. In addition, when the workpiece W is a semiconductor wafer, a protective tape T is adhered to the surface on which the device is formed, and the protective tape T side is placed on the chuck table 12. The workpiece W placed on the chuck table 12 is sucked and held on the chuck table 12 by suction means (not shown). Then, the chuck table moving means (not shown) is operated to move the chuck table 12 in the direction indicated by the arrow 23a, and to position it in the grinding region 25. And the outer peripheral edge of the grinding grindstone 52 in the grinding wheel 5 is located so that it may pass through the center of rotation of the chuck table 12 (namely, the center of the workpiece W).

After positioning in this positional relationship, the chuck table 12 is rotated at a rotational speed of, for example, 300 rpm, and the grinding wheel 5 is rotated in the same direction at a rotational speed of, for example, 6000 rpm. That is, by supplying alternating current power to the stator coil 72 from the electric power supply means 8, the electric motor 7 rotates, the rotary spindle 42 rotates, and the grinding wheel attached to the front-end | tip of the rotary spindle 42 is carried out. (5) rotates. Then, the grinding wheel 5 is lowered, and the grinding grindstone 52 is pressed against the back surface (grinded surface) which is the upper surface of the workpiece W at a predetermined pressure. As a result, the to-be-grinded surface of the to-be-processed object W is ground over the whole surface. At this time, the grinding liquid is supplied to the grinding processing part by the plurality of grinding grindstones 52.

At the time of such a grinding process, the electric power supply means 8 supplies AC power of predetermined voltage and predetermined frequency to the power supply coil 822 of the power supply means 82 which comprises the rotary transformer 80. As shown in FIG. As a result, the ultrasonic transducer 6 is fixed to the ultrasonic vibrator 6 through the power receiving coil 812, the conductive wire 813, the concave connector 814, the convex connector 62, and the conductive wire 61 of the rotating power receiving means 81. Voltage, AC power of a predetermined frequency is applied. As a result, the ultrasonic vibrator 6 repeatedly displaces in the radial direction and vibrates ultrasonically. Such ultrasonic vibration is transmitted to the plurality of grinding grindstones 52 through the grindstone mounting portion 512, so that the plurality of grinding grindstones 52 oscillate in the radial direction.

Here, in the grinding wheel 5 of this embodiment, the grindstone mounting part 512 to which the some grinding grindstone 52 which transmits ultrasonic vibration is mounted is formed thinner than the connection part 511, and the upper wheel mount 43 is carried out. Since it is in contact with the connection part and the some circular arc slit 513 is formed in the boundary part with the connection part 511, it is an intermittent connection state which is easy to deform | transform with respect to the connection part 511. As shown in FIG. Therefore, it becomes possible to transmit ultrasonic vibration to a grinding | polishing grindstone 52 with sufficient amplitude through the grindstone mounting part 512 which is easy to deform | transform when ultrasonically vibrating the ultrasonic vibrator 6 arrange | positioned at this grindstone mounting part 512. In particular, since the arc-shaped slits 513 are alternately arranged in two rows, the grindstone mounting portion 512 is easily deformed with a high degree of freedom with respect to the fixed connecting portion 511, which is more effective. Moreover, since the ultrasonic vibrator 6 is arrange | positioned at the inner peripheral side position rather than the grinding grindstone 52, the radial ultrasonic vibration which the ultrasonic vibrator 6 generate | occur | produces is efficient for the grinding grindstone 52 located in the outer peripheral side. Can be delivered as In particular, since the ultrasonic vibrator 6 is also disposed in a ring-shaped position concentrically with respect to the grinding grindstone 52 which is generally annular, the ultrasonic vibration can be uniformly transmitted to the plurality of grinding grindstones 52. .

When the plurality of grinding grindstones 52 are ultrasonically vibrated in the radial direction as described above, grinding debris generated by grinding and remaining between the abrasive grains of the grinding grindstone 52 and causing clogging acts on the grinding grindstone 52. The flow is removed by the micro vibration. Therefore, clogging of the grinding grindstone 52 can be prevented, and even a flame-retardant material like brittle hard material can be ground efficiently.

Here, specific examples according to the present embodiment will be described. For example, as shown in FIG. 5, the diameter d of the wiring insertion through hole 512a is d = 30 mm, and the diameter of the grindstone mounting portion 512 (the diameter of the portion of the outer arc-shaped slit 513) is D = 170. The diameter R, which defines the size of the ultrasonic vibrator 6, is set to R = 100 mm, and the AC power of 35 kHz, 100 V, for example, is applied to the ultrasonic vibrator (PZT vibrator) as the ultrasonic vibrator 6. When applied to 6), the vibration amplitude of about 8 micrometers in the radial direction was obtained in the grinding grindstone 52 part by the frequency of 35 kHz. In addition, the radial vibration amplitude in the case where the diameter R of the ultrasonic vibrator 6 is increased to R = 125 mm is about 4.9 µm, and the radial vibration amplitude in the case where the diameter R is reduced to R = 75 mm is 5.6 µm. It becomes about. Therefore, the ultrasonic vibrator 6 has a central position (i.e., the grindstone mounting portion) between the inner circumferential portion of the donut shaped grindstone mounting portion 512 (the edge portion of the wiring insertion through hole 512a) and the arc-shaped slit 513. 512) its own radial center position] is considered to be the most efficient.

This invention is not limited to embodiment mentioned above, A various deformation | transformation is possible within the range which does not deviate from the meaning of this invention. For example, in the present embodiment, the top surface side of the grindstone mounting portion 512 is formed in a cup shape to form a concave shape with respect to the connecting portion 511 on the wheel base 51 side, whereby the grindstone mounting portion 512 is wheel mounted ( 43), it is configured to be non-contact, but only relatively non-contact, the upper surface side of the grindstone mounting portion 512 is flat, the lower surface side of the wheel mount 43 to form a concave shape with respect to the connecting portion 511. The configuration, such as forming in a shape, may also be used.

In addition, in this embodiment, although the several grinding grindstones 52 are arrange | positioned on the same circumference and make it annular, you may use one grinding grindstone originally formed in an annular shape.

In addition, in this embodiment, although the several circular arc-shaped slits 513 of two rows are arrange | positioned in staggered staggered manner so that it may overlap evenly in a radial direction, you may arrange | position in staggered staggered manner without overlapping. It is also possible to use one row of arc-shaped slits. In these cases, the number or length of each arc-shaped slit, and the space | interval between arc-shaped slits can be set suitably.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the structural example of the whole grinding apparatus containing the grinding wheel which concerns on embodiment of this invention.

Fig. 2 is a longitudinal side view of the spindle unit included in the grinding apparatus together showing the electric field control system.

3 is an exploded perspective view illustrating the wheel mount and the grinding wheel.

4 is a bird's eye view showing the grinding wheel.

5 is a longitudinal front view illustrating the grinding wheel.

6 is a schematic bottom view illustrating the grinding wheel.

<Explanation of symbols for the main parts of the drawings>

3: grinding means

5: grinding wheel

6: ultrasonic vibrator

12: Chuck Table

42: rotating spindle

43: Wheel Mount

51: wheel base

52: grinding stone

511: connection

512: grindstone mount

513: arc slit

W: Workpiece

Claims (4)

A grinding wheel comprising a wheel base attached to a wheel mount provided on one end of a rotating spindle constituting a grinding means for grinding a workpiece held on a chuck table, and an annular grinding wheel mounted on the wheel base, The wheel base includes a ring-shaped connecting portion connected to the wheel mount, and a discoid grindstone mounting portion connected to an inner circumferential portion of the connecting portion. The grindstone mounting portion, The upper surface on the wheel mount side is relatively in contact with the wheel mount, The grinding grindstone is mounted on the lower surface side, An annular ultrasonic vibrator disposed at a position concentric with the grinding grindstone around a center of the grinding wheel on an inner circumferential side of the grinding grindstone, Grinding wheel, characterized in that located in the boundary between the connecting portion and the grindstone mounting portion, a plurality of arc-shaped slits formed in the circumferential direction. According to claim 1, wherein the grindstone mounting portion is formed in a doughnut shape, The said ultrasonic vibrator is arrange | positioned at the center position between the inner peripheral part of the said grindstone mounting part of donut shape, and the said arc-shaped slit. The grinding wheel according to claim 1 or 2, wherein the plurality of arc-shaped slits are formed to be alternately positioned on circumferences of different radii. The grinding wheel according to claim 1 or 2, wherein an upper surface side of the grindstone mounting portion is formed in a concave shape with respect to the connecting portion, and is configured to be in non-contact with the wheel mount.

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