JP2011152605A - Grinding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding device applying ultrasonic vibration of a vibration mode suitable for a workpiece to a grinding wheel. <P>SOLUTION: The grinding device includes a chuck table for holding the workpiece; a grinding wheel which grinds the workpiece retained on the chuck table and includes a wheel base fixed to a wheel mount disposed on one end of a rotating spindle, and the grinding wheel attached to the wheel base; an ultrasonic transducer disposed on the wheel base; and an electric power supply means for applying high frequency electric power to the ultrasonic transducer. The electric power supply means includes a control means for controlling the frequency of the high frequency electric power applied to the ultrasonic transducer; and an input means for inputting the vibration mode. The control means includes a memory for storing a first frequency generated by the first vibration mode by which the grinding wheel oscillates in the axial direction of the grinding wheel, and a second frequency generated by the second vibration mode by which the grinding wheel oscillates in the radial direction of the grinding wheel. The control means controls so that the high frequency electric power of the frequency corresponding to the vibration mode inputted from the input means is applied to the ultrasonic transducer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a grinding apparatus for grinding a workpiece such as a semiconductor wafer, and more particularly to a grinding apparatus that performs grinding while applying ultrasonic vibration to a grinding wheel.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially wafer-shaped semiconductor wafer, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. Then, the semiconductor wafer is cut along the streets to divide the region in which the device is formed to manufacture individual semiconductor devices. In addition, optical device wafers with gallium nitride compound semiconductors laminated on the surface of a sapphire substrate are also divided into individual optical devices such as light emitting diodes and laser diodes by cutting along the streets, and are widely used in electrical equipment. ing. The wafer divided in this way is ground to a predetermined thickness by a grinding device before being cut along the street.

  The grinding apparatus includes a chuck table that holds a workpiece, and a grinding unit that grinds the workpiece held on the chuck table. The grinding means includes a rotating spindle, a wheel mount provided at the lower end of the rotating spindle, and a grinding wheel that is detachably attached to the lower surface of the wheel mount. And a plurality of grinding wheels mounted on the outer peripheral grinding wheel mounting portion on the lower surface of the wheel base, and the grinding wheel is pressed against the workpiece held on the chuck table while rotating the grinding wheel. Grind the workpiece.

  However, when the back surface of the wafer is ground with the grinding wheel of the grinding device, the grinding wheel is clogged and the grinding ability is lowered. Especially when grinding hard materials with high Mohs, such as silicon substrates, sapphire substrates with optical devices formed on the surface, and Altic substrates with magnetic heads formed, productivity is reduced due to a decrease in grinding ability due to clogging of grinding wheels. There is a problem that it drops significantly.

  In order to solve the above-mentioned problems, ultrasonic vibration means is mounted on a wheel base on which a grinding wheel of a grinding wheel for grinding a workpiece held on a chuck table holding a workpiece such as a wafer is mounted. There has been proposed a grinding wheel that applies ultrasonic vibration to a grinding wheel mounted on a wheel base by applying high-frequency power to the ultrasonic vibration means. (For example, refer to Patent Document 1.)

JP 2009-107065 A

Thus, even if grinding is performed by applying ultrasonic vibration to the grinding wheel, the grinding efficiency may not always be improved depending on the workpiece.
According to the study by the present inventors, when the ultrasonic vibration means is attached to the wheel base on which the grinding wheel of the grinding wheel is attached, and high frequency power is applied to the ultrasonic vibration means, the grinding wheel is driven by the frequency of the high frequency power. It has been found that a first vibration mode in which the grinding wheel vibrates in the axial direction and a second vibration mode in which the grinding wheel vibrates in the radial direction of the grinding wheel are generated. Therefore, when a workpiece suitable for the first vibration mode is ground in the second vibration mode, the grinding efficiency cannot be improved even if grinding is performed while applying ultrasonic vibration. In addition, even if a work piece suitable for the second vibration mode is ground in the first vibration mode, the grinding efficiency cannot be improved in the same manner.

  This invention is made | formed in view of the said fact, The main technical subject is to provide the grinding device which can provide the grinding wheel with the ultrasonic vibration of the vibration mode suitable for a workpiece.

In order to solve the above main technical problems, according to the present invention, a chuck table for holding a workpiece, a wheel base attached to a wheel mount provided at one end of a rotary spindle, and a wheel base attached to the wheel base. A grinding wheel for grinding a workpiece held on the chuck table, an ultrasonic vibrator disposed on the wheel base of the grinding wheel, and the ultrasonic vibrator In a grinding apparatus comprising a power supply means for applying high-frequency power,
The power supply means comprises a control means for controlling the frequency of the high frequency power applied to the ultrasonic transducer and an input means for inputting a vibration mode to the control means,
The control means includes a first frequency at which a first vibration mode in which the grinding wheel vibrates in the axial direction of the grinding wheel and a second vibration in which the grinding wheel vibrates in the radial direction of the grinding wheel. A memory for storing a second frequency at which the mode is generated, and controlling so as to apply high-frequency power of a frequency corresponding to the vibration mode input from the input means to the ultrasonic transducer;
A grinding device is provided.

  In the grinding apparatus according to the present invention, the power supply means for applying the high frequency power to the ultrasonic vibrator disposed on the wheel base of the grinding wheel controls the frequency of the high frequency power applied to the ultrasonic vibrator, and The control means includes an input means for inputting a vibration mode, and the control means performs grinding in a first frequency at which a first vibration mode in which the grinding wheel vibrates in the axial direction of the grinding wheel and in a radial direction of the grinding wheel. A memory is provided for storing a second frequency at which a second vibration mode in which the grinding wheel vibrates is generated, and high frequency power having a frequency corresponding to the vibration mode input from the input means is applied to the ultrasonic vibrator. Therefore, it is possible to perform grinding efficiently with a vibration mode suitable for the workpiece.

1 is a perspective view of a grinding apparatus constructed according to the present invention. Sectional drawing of the spindle unit with which the grinding apparatus shown in FIG. 1 is equipped. The disassembled perspective view of the wheel mount and the grinding wheel which comprise the spindle unit shown in FIG. The expanded sectional view of the grinding wheel shown in FIG. FIG. 4 is a bottom view of the grinding wheel shown in FIG. 3. The figure which shows the vibration mode provided to the grinding wheel of the grinding wheel shown in FIG. The principal part side view which shows the state which is grinding the workpiece by the grinding apparatus shown in FIG.

Preferred embodiments of a grinding apparatus constructed according to the present invention will be described below in more detail with reference to the accompanying drawings.
FIG. 1 shows a perspective view of a grinding apparatus constructed in accordance with the present invention. The grinding apparatus shown in FIG. 1 is provided with an apparatus housing generally indicated by numeral 2. This device housing 2 has a rectangular parallelepiped main portion 21 that extends long and an upright wall 22 that is provided at the rear end portion (upper right end in FIG. 1) of the main portion 21 and extends substantially vertically upward. ing. A pair of guide rails 221 and 221 extending in the vertical direction are provided on the front surface of the upright wall 22. A grinding unit 3 as grinding means is mounted on the pair of guide rails 221 and 221 so as to be movable in the vertical direction.

  The grinding unit 3 includes a moving base 31 and a spindle unit 4 mounted on the moving base 31. The movable base 31 is provided with a pair of legs 311 and 311 extending in the vertical direction on both sides of the rear surface. The pair of legs 311 and 311 is slidably engaged with the pair of guide rails 221 and 221. Guided grooves 312 and 312 are formed. As described above, a support portion 313 protruding forward is provided on the front surface of the movable base 31 slidably mounted on the pair of guide rails 221 and 221 provided on the upright wall 22. The spindle unit 4 is attached to the support portion 313.

  The spindle unit 4 includes a spindle housing 41 attached to the support portion 313 and a rotating spindle 42 that is rotatably disposed on the spindle housing 41. The spindle unit 4 will be described with reference to FIG. A spindle housing 41 constituting the spindle unit 4 shown in FIG. 2 is formed in a substantially cylindrical shape and includes a shaft hole 411 penetrating in the axial direction. A rotary spindle 42 that is inserted through a shaft hole 411 formed in the spindle housing 41 is provided with a thrust bearing flange 421 formed in the central portion so as to protrude in the radial direction. In this way, the rotary spindle 42 disposed through the shaft hole 411 formed in the spindle housing 41 is rotatably supported by high-pressure air supplied between the inner wall of the shaft hole 411. One end (lower end in FIG. 1) of the rotary spindle 42 rotatably supported by the spindle housing 41 is disposed so as to protrude from the lower end of the spindle housing 41, and a wheel mount is mounted on one end (lower end in FIG. 1). 43 is provided. Then, the grinding wheel 5 is attached to the lower surface of the wheel mount 43.

The wheel mount 43 and the grinding wheel 5 will be described with reference to FIGS.
As shown in FIG. 3, the wheel mount 43 is formed in a disc shape integrally with the lower end of the rotary spindle 42. The wheel mount 43 is provided with four bolt insertion holes 43a. A connector insertion hole 43 b is formed at the center of the wheel mount 43.

  A grinding wheel 5 shown in FIGS. 3 to 5 includes a disk-shaped wheel base 51, an annular grinding wheel 52 mounted on the lower surface of the wheel base 51, and an annular grinding wheel on the wheel base 51. And an annular ultrasonic vibration means 6 disposed at a position corresponding to the inner side of 52. The wheel base 51 includes a base body 511 having a grindstone mounting portion 511a formed on the lower surface and mounted with the grinding wheel 52 and an ultrasonic vibration means mounting portion 511b formed on the upper surface and mounted with the ultrasonic vibration means 6. It comprises an annular side wall 512 formed upright from the outer periphery of the base body 511 and an annular mounting portion 513 formed inward from the upper end of the annular side wall 512. A plurality of arc-shaped slits 511c are formed in the base body 511 constituting the wheel base 51 so as to penetrate from the upper surface to the lower surface in the circumferential direction between the annular side wall 512 and the grindstone mounting portion 511a. An annular grinding stone 52 composed of a plurality of grinding stone segments is attached to the grinding stone attachment portion 511a of the base body 511 formed in this manner with an appropriate adhesive. In addition, the annular ultrasonic vibration means 6 is attached to the ultrasonic vibration means mounting portion 511b of the base body 511 with an appropriate adhesive. On the other hand, in the annular mounting portion 513, four female screw holes 513a are formed at positions corresponding to the bolt insertion holes 43a provided in the wheel mount 43.

  Annular ultrasonic vibration means 6 attached to the ultrasonic vibration means attachment part 511b of the base body 511 includes an annular ultrasonic vibrator 61 and a pair attached to both polarization surfaces of the ultrasonic vibrator 61, respectively. Electrode plates 62a and 62b. The ultrasonic transducer 61 is formed in an annular shape from a piezoelectric ceramic such as barium titanate, lead zirconate titanate, or lithium tantalate. In the thus configured annular ultrasonic vibration means 6, one electrode plate 62a of the pair of electrode plates is attached to the ultrasonic vibration means attachment portion 511b with an insulating bond agent such as epoxy resin. In this way, one end of each of the conductive wires 63a and 63b is connected to the pair of electrode plates 62a and 62b constituting the annular ultrasonic vibration means 6 mounted on the ultrasonic vibration means mounting portion 511b of the base body 511. Has been. The other end of each conductive wire 63a, 63b is connected to the convex connector 64. The convex connector 64 is detachably connected to a power supply means described later.

  In the grinding wheel 5 configured as described above, the fastening bolts 53 respectively inserted into the four bolt insertion holes 43 a provided in the wheel mount 43 are provided on the annular attachment portion 513 of the wheel base 51. By screwing into the respective screw holes 513a, the wheel mounts 43 are detachably mounted.

  Returning to FIG. 2 and continuing the description, the spindle unit 4 in the illustrated embodiment includes an electric motor 7 for rotationally driving the rotary spindle 42. The illustrated electric motor 7 is constituted by a permanent magnet motor. The permanent magnet type electric motor 7 is disposed in the spindle housing 41 on the outer peripheral side of the rotor 71 and a rotor 71 made of a permanent magnet mounted on a motor mounting portion 422 formed in an intermediate portion of the rotary spindle 42. The stator coil 72 is included. In the electric motor 7 configured as described above, the rotor 71 is rotated by applying AC power to the stator coil 72 by power supply means described later, and the rotating spindle 42 to which the rotor 71 is mounted is rotated.

The spindle unit 4 in the illustrated embodiment includes power supply means 8 that applies high-frequency power to the ultrasonic transducer 6 and applies AC power to the electric motor 7.
The power supply means 8 includes a rotary transformer 80 disposed at the rear end of the spindle unit 4. The rotary transformer 80 includes a power receiving unit 81 disposed at the other end of the rotary spindle 42 and a power feeding unit 82 disposed opposite to the power receiving unit 81 and disposed at the rear end portion of the spindle housing 41. is doing. 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. A conductive wire 813 is connected to the power receiving coil 812 of the power receiving means 81 configured as described above. The conductive wire 813 is disposed in a hole 423 formed in the axial direction at the center of the rotary spindle 42, and its tip is connected to a concave connector 814 (see FIG. 3) that fits the convex connector 64. ing. The power supply means 82 includes a stator side core 821 disposed on the outer peripheral side of the power reception means 81 and a power supply coil 822 disposed on the stator side core 821. The power supply coil 822 of the power supply means 82 configured as described above is supplied with high-frequency power via the electrical wiring 83.

  The power supply means 8 in the illustrated embodiment includes an AC power supply 84 of high frequency power supplied to the power supply coil 822 of the rotary transformer 80, a voltage adjustment means 85 as power adjustment means, and a high frequency power supplied to the power supply means 82. Frequency adjusting means 86 for adjusting the frequency of the power, control means 87 for controlling the voltage adjusting means 85 and the frequency adjusting means 86, and vibration modes of ultrasonic vibration applied to the plurality of grinding wheels 52 are input to the control means 87. Input means 88 is provided. The power supply means 8 shown in FIG. 2 supplies AC power to the stator coil 72 of the electric motor 7 via the control circuit 89 and the electric wiring 821.

The spindle unit 4 in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
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 and the rotary spindle 42 rotates, and the grinding wheel 5 attached to the tip of the rotary spindle 42 is rotated.

  On the other hand, the power supply means 8 controls the voltage adjustment means 85 and the frequency conversion means 86 by the control means 87 to control the voltage of the high frequency power to a predetermined voltage (for example, 20V), and the frequency of the high frequency power will be described later. Thus, the frequency is set to a predetermined frequency and supplied to the power supply coil 822 of the power supply means 82 constituting the rotary transformer 80. When high-frequency power having a predetermined frequency is applied to the feeding coil 822 in this way, the power receiving coil 812 of the rotating power receiving means 81, the conductive wire 813, the concave connector 814, the convex connector 64, and the conductive wires 63a and 63b are used. High frequency power is applied to the pair of electrode plates 62a and 62b constituting the sonic vibration means 6. As a result, the ultrasonic vibrator 61 is ultrasonically vibrated by being repeatedly displaced in the axial direction or the radial direction depending on the frequency of the applied high-frequency power. This ultrasonic vibration is transmitted to the plurality of grinding wheels 52 via the grinding wheel mounting portions 511a of the base body 511 constituting the wheel base 51, and the plurality of grinding wheels 52 are ultrasonically vibrated in the axial direction or the radial direction. . In the illustrated embodiment, a plurality of arc-shaped slits 511c are formed in the circumferential direction between the annular side wall 512 and the grindstone mounting portion 511a in the base body 511 constituting the wheel base 51. Transmission of ultrasonic vibration generated from the ultrasonic vibration means 6 to the wheel mount 43 via the annular side wall 512 is suppressed. Therefore, the ultrasonic vibration generated from the ultrasonic vibration means 6 is effectively transmitted to the plurality of grinding wheels 52 via the grinding wheel mounting portion 511a.

  FIG. 6 shows a vibration mode in which ultrasonic vibration is performed in the axial direction or the radial direction at the frequency of the high-frequency power applied to the ultrasonic vibrator 61 disposed on the wheel base 51 of the grinding wheel 5. . In FIG. 6, the horizontal axis represents the frequency (kHz) of the high-frequency power applied to the ultrasonic transducer 61, the vertical axis represents the amplitude (μm) of the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5, and the line A Represents vibration in the axial direction of the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5, and line B represents vibration in the radial direction of the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5.

  In the example shown in FIG. 6, the vibration A in the axial direction of the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5 has a high amplitude at a frequency of 27 (kHz), and the frequency is 27 ( The amplitude of kHz) is the first vibration mode. Further, the vibration B in the radial direction of the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5 has a high amplitude at a frequency of 22.6 (kHz) and a frequency of 30.5 (kHz). However, since the amplitude of the frequency is 30.5 (kHz) is large, in this embodiment, the amplitude of 30.5 (kHz) is set as the second vibration mode. In the example shown in FIG. 6, a high amplitude is present in the axial vibration A and radial vibration B of the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5 at a frequency of 37.4 (kHz). It has occurred and is referred to as a third vibration mode (composite vibration mode). In this way, the first vibration mode, the second vibration mode, and the third vibration mode (in the vibration applied to the grinding wheel 52 mounted on the wheel base 51 of the grinding wheel 5 mounted on the wheel mount 43 ( If the composite vibration mode) is measured, the frequency 27 (kHz) (first frequency) at which the first vibration mode is generated and the frequency 30.5 (kHz) (second frequency at which the second vibration mode is generated). Frequency) and the frequency 37.4 (kHz) at which the third vibration mode (composite vibration mode) occurs are stored in the memory 871 of the control means 87. The frequency at which each vibration mode is generated differs depending on the grinding wheel mounted on the wheel mount 43. Therefore, the frequency at which each vibration mode is generated is measured when the grinding wheel is mounted on the wheel mount 43. Store in the memory 871.

  Referring back to FIG. 1, the grinding apparatus in the illustrated embodiment moves the grinding unit 4 in the vertical direction (perpendicular to the holding surface of the chuck table described later) along the pair of guide rails 221 and 221. A grinding unit feed mechanism 10 that is moved in the direction). The grinding unit feed mechanism 10 includes a male screw rod 101 that is disposed on the front side of the upright wall 22 and extends substantially vertically. The male screw rod 101 is rotatably supported by bearing members 102 and 103 whose upper end and lower end are attached to the upright wall 22. The upper bearing member 102 is provided with a pulse motor 104 as a drive source for rotationally driving the male screw rod 101, and an output shaft of the pulse motor 104 is connected to the male screw rod 101 by transmission. A connecting portion (not shown) protruding rearward from the widthwise central portion is also formed on the rear surface of the movable base 31, and a through female screw hole (not shown) extending in the vertical direction is formed in this connecting portion. ) And the male screw rod 101 is screwed into the female screw hole. Accordingly, when the pulse motor 104 rotates in the forward direction, the moving base 31, that is, the grinding unit 3 is lowered or moved forward, and when the pulse motor 104 rotates in the reverse direction, the moving base 31, that is, the grinding unit 3 is raised or moved backward.

  Continuing the description with reference to FIG. 1, the chuck table mechanism 11 is disposed in the main portion 21 of the housing 2. The chuck table mechanism 11 includes a chuck table 12, a cover member 13 that covers the periphery of the chuck table 12, and bellows means 14 and 15 disposed in front of and behind the cover member 13. The chuck table 12 is configured to be rotated by a rotation driving unit (not shown), and is configured to suck and hold a wafer as a workpiece on its upper surface by operating a suction unit (not shown). Further, the chuck table 12 is moved between a workpiece placing area 24 shown in FIG. 1 and a grinding area 25 facing the grinding wheel 5 constituting the spindle unit 4 by a chuck table moving means (not shown). The bellows means 14 and 15 can be formed from any suitable material such as campus cloth. The front end of the bellows means 14 is fixed to the front wall of the main portion 21, and the rear end is fixed to the front end surface of the cover member 13. The front end of the bellows means 15 is fixed to the rear end surface of the cover member 13, and the rear end is fixed to the front surface of the upright wall 22 of the apparatus housing 2. When the chuck table 12 is moved in the direction indicated by the arrow 23a, the bellows means 14 is expanded and the bellows means 15 is contracted. When the chuck table 12 is moved in the direction indicated by the arrow 23b, the bellows means 14 is The bellows means 15 is expanded by contraction.

The grinding apparatus equipped with the grinding wheel in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
When carrying out the grinding operation, the operator selects a vibration mode suitable for grinding the wafer W (see FIG. 1) as a workpiece and inputs it from the input means 88. For example, when the wafer W is a sapphire wafer, the operator inputs the first vibration mode, and when the wafer W is a silicon wafer, the operator inputs the second vibration mode. In addition, in the case of a workpiece in which the third vibration mode (composite vibration mode) is suitable, the operator inputs the third vibration mode (composite vibration mode).

  In order to grind the wafer W, the wafer W is placed on the chuck table 12 positioned in the workpiece placement area 24 of the grinding apparatus as shown in FIG. A protective tape T is attached to the surface on which the wafer W device is formed, and the protective tape T side is placed on the chuck table 12. The wafer W placed on the chuck table 12 in this way is sucked and held on the chuck table 12 by suction means (not shown).

  As described above, when the wafer W is sucked and held on the chuck table 12, the chuck table moving means (not shown) is operated to move the chuck table 12 in the direction indicated by the arrow 23a and position it in the grinding zone 25. Then, as shown in FIG. 7, the outer peripheral edges of the plurality of grinding wheels 52 of the grinding wheel 5 are positioned so as to pass through the rotation center P of the chuck table 12, that is, the center of the wafer W.

  When the wafer W held on the grinding wheel 5 and the chuck table 12 is set in the positional relationship shown in FIG. 7, the chuck table 12 is rotated in the direction indicated by the arrow 12a in FIG. At the same time, the grinding wheel 5 is rotated in the direction indicated by the arrow 5a, for example, at a rotational speed of 6000 rpm. That is, by supplying AC power from the power supply means 8 to the stator coil 72 of the electric motor 7, the electric motor 7 rotates and the rotating spindle 42 rotates, and the grinding wheel attached to the tip of the rotating spindle 42. 5 is rotated. Then, the grinding wheel 5 is lowered to press the plurality of grinding wheels 52 against the back surface (surface to be ground), which is the upper surface of the wafer W, with a predetermined pressure. As a result, the surface to be ground of the wafer W is ground over the entire surface.

  At the time of grinding described above, the control means 87 of the power supply means 8 selects the frequency corresponding to the vibration mode input from the input means 88 as described above from the data stored in the memory as described above, and the frequency The converter 86 is controlled and the voltage regulator 85 is controlled. As a result, a pair of electrode plates 62a constituting the annular ultrasonic vibration means 6 via the power receiving coil 812, the conductive wire 813, the concave connector 814, the convex connector 64, and the conductive wires 63a and 63b of the rotating power receiving means 81, The high frequency power of the selected frequency is applied to 62b, and the annular ultrasonic vibration means 6 is ultrasonically vibrated. The ultrasonic vibration generated by the annular ultrasonic vibration means 6 is transmitted to the plurality of grinding wheels 52 via the grinding wheel mounting portions 511a of the base body 511 constituting the wheel base 51, and the plurality of grinding wheels 52 are super The sound wave vibrates. The ultrasonic vibration of the grinding wheel 52 vibrates in the axial direction when the vibration mode input from the input means 88 is the first vibration mode as described above, and the vibration mode input from the input means 88 is the first vibration mode. In the case of the second vibration mode, it vibrates in the radial direction, and when the vibration mode input from the input means 88 is the third vibration mode (composite vibration mode), it vibrates in the axial direction and the radial direction. Thus, since the grinding wheel 52 is ground while vibrating in a vibration mode suitable for the workpiece, the workpiece can be ground efficiently.

2: device housing 3: grinding unit 31: moving base 4: spindle unit 41: spindle housing 42: rotating spindle 43: wheel mount 5, 50: grinding wheel 51: wheel base 52: grinding wheel 6: ultrasonic vibration means 61: Ultrasonic vibrators 62a, 62b: A pair of electrode plates 7: Electric motor 8: Power supply means 80: Rotary transformer 81: Power reception means 82: Power supply means 84: AC power supply 85: Voltage adjustment means 86: Frequency adjustment means 87 : Control means 88: Input means 10: Grinding unit feed mechanism 11: Chuck table mechanism 12: Chuck table

Claims (1)

A work piece held on the chuck table, comprising a chuck table for holding a work piece, a wheel base attached to a wheel mount provided at one end of a rotary spindle, and a grinding wheel attached to the wheel base. A grinding wheel for grinding an object, an ultrasonic vibrator disposed on the wheel base of the grinding wheel, and power supply means for applying high-frequency power to the ultrasonic vibrator. In grinding equipment,
The power supply means comprises a control means for controlling the frequency of the high frequency power applied to the ultrasonic transducer and an input means for inputting a vibration mode to the control means,
The control means includes a first frequency at which a first vibration mode in which the grinding wheel vibrates in the axial direction of the grinding wheel and a second vibration in which the grinding wheel vibrates in the radial direction of the grinding wheel. A memory for storing a second frequency at which the mode is generated, and controlling so as to apply high-frequency power of a frequency corresponding to the vibration mode input from the input means to the ultrasonic transducer;
A grinding apparatus characterized by that.

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