JP2008093784A - Amplitude measuring device of cutting blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an amplitude measuring device of a cutting blade capable of precisely detecting an amplitude of a cutting blade caused by ultrasonic vibrations corresponding to a frequency of an alternating-current power applied to an ultrasonic transducer. <P>SOLUTION: This amplitude measuring device of a cutting blade applies ultrasonic vibrations by applying an alternating-current power of a predetermined frequency to an ultrasonic vibration means arranged on a rotary spindle 42 mounted with a cutting blade 45. This device comprises an amplitude detection means 110 optically detecting amplitude of the cutting blade 45 with a light emission means 112 and a light reception means 113, a frequency variable band pass filter 120 for passing only amplitude signals in a set frequency area out of amplitude signals outputted from the amplitude detection means, and a control means 130 setting and controlling a frequency area of the frequency variable band pass filter and calculating the amplitude of the cutting blade based on the amplitude signals from the frequency variable band pass filter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an amplitude measuring apparatus for a cutting blade that cuts a workpiece such as a semiconductor wafer or an optical device wafer while applying ultrasonic vibration.

  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 chips. In addition, optical device wafers with gallium nitride compound semiconductors laminated on the surface of sapphire substrates are divided into individual light emitting diodes, laser diodes, CCDs and other optical devices by cutting along the streets. It's being used.

  The above-described cutting along the wafer street is usually performed by a cutting device called a dicer. This cutting apparatus includes a chuck table for holding a workpiece such as a wafer, a cutting means for cutting the workpiece held on the chuck table, and a cutting for relatively moving the chuck table and the cutting means. And feeding means. The cutting means includes a cutting tool having a rotating spindle and a cutting blade mounted on the spindle, and a spindle unit having a drive mechanism for driving the rotating spindle to rotate. In such a cutting apparatus, the cutting tool and the work piece held on the chuck table are relatively cut and fed while rotating the cutting tool at a rotational speed of 20000 to 40000 rpm.

  However, brittle hard materials such as silicon, sapphire, silicon nitride, glass, and lithium tantalate are used for the wafer on which the device is formed. There is a problem of lowering. Also, a wafer with high Mohs hardness such as sapphire is very difficult if not impossible to cut with a cutting blade.

In order to solve the above-described problem, an ultrasonic vibrator is disposed on a rotary spindle on which a cutting tool equipped with a cutting blade is mounted, and an AC power is applied to the ultrasonic vibrator, so that an ultrasonic power is applied to the cutting blade. There has been proposed a cutting method in which cutting is performed while applying sonic vibration. A cutting tool used in this cutting method includes a vibration transmission member attached to a rotary spindle, and a cutting blade attached to the vibration transmission member, and transmits ultrasonic vibration that vibrates in the axial direction of the rotary spindle. Is converted into radial vibration, and radial ultrasonic vibration is applied to the cutting blade. (For example, refer to Patent Document 1.)
Japanese Patent No. 3469516

  Thus, since vibration due to rotation of the rotary spindle acts on the cutting blade, the amplitude of the vibration applied to the cutting blade is equal to the amplitude of the ultrasonic vibration corresponding to the frequency of the AC voltage applied to the ultrasonic vibrator. The amplitude of vibration due to rotation of the rotary spindle is a composite amplitude. Therefore, in order to set the power value of the AC power applied to the ultrasonic transducer, it is necessary to detect only the amplitude of the ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic transducer. However, in order to detect only the amplitude of the ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic vibrator in the vibration applied to the cutting blade, the frequency of the AC power applied to the ultrasonic vibrator is recognized in advance. I have to keep it. However, since the cutting blade amplitude measuring device independent of the cutting device does not know the frequency of the AC power applied to the ultrasonic vibrator, the frequency of the AC power applied to the ultrasonic vibrator in the vibration applied to the cutting blade. It is impossible to detect only the amplitude of the ultrasonic vibration corresponding to.

  The present invention has been made in view of the above facts, and its main technical problem is to accurately determine the amplitude of the cutting blade by ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic vibrator. An object of the present invention is to provide an amplitude measuring device for a cutting blade.

In order to solve the above-mentioned main technical problem, according to the present invention, ultrasonic vibration means is disposed on a rotary spindle to which a cutting tool having a cutting blade is attached, and AC power of a predetermined frequency is supplied to the ultrasonic vibration means. In the cutting blade amplitude measuring device to which the ultrasonic vibration is applied by applying,
Amplitude detecting means for detecting the amplitude of the cutting blade of the cutting tool attached to the rotary spindle;
A frequency variable band-pass filter that passes only the amplitude signal in the set frequency region among the amplitude signals output from the amplitude detection means;
Control means for controlling the frequency region of the frequency variable bandpass filter and calculating the amplitude of the cutting blade based on the amplitude signal from the frequency variable bandpass filter;
The control means includes a counter for counting the frequency of the amplitude signal output from the frequency variable bandpass filter, and a memory for storing the frequency counted by the counter, and a predetermined frequency region of the frequency variable bandpass filter is obtained. Set and count the frequency of the amplitude signal, set the minute amplitude detection frequency region around the counted frequency, control the frequency variable bandpass filter, and output from the frequency variable bandpass filter Calculate the amplitude of the cutting blade based on the amplitude signal,
There is provided an apparatus for measuring an amplitude of a cutting blade.

Further, according to the present invention, the ultrasonic vibration means is disposed on the rotary spindle to which the cutting tool having the cutting blade is attached, and the ultrasonic vibration is applied by applying AC power of a predetermined frequency to the ultrasonic vibration means. In the amplitude measuring device of the cutting blade to which is given,
Amplitude detecting means for detecting the amplitude of the cutting blade of the cutting tool attached to the rotary spindle;
A frequency variable band-pass filter that passes only an amplitude signal in a set frequency region among the amplitude signals output from the amplitude detection means;
A frequency variable filter that passes only an amplitude signal of a predetermined frequency among the amplitude signals that have passed through the frequency variable bandpass filter;
Control means for controlling the frequency region of the frequency variable bandpass filter and the frequency variable filter and calculating the amplitude of the cutting blade based on the frequency variable bandpass filter and the amplitude signal from the frequency variable filter. ,
The control means includes a counter for counting the frequency of the amplitude signal output from the frequency variable bandpass filter, and a memory for storing the frequency counted by the counter, and a predetermined frequency region of the frequency variable bandpass filter is obtained. Set and count the frequency of the amplitude signal, control the frequency variable filter using the counted frequency as the amplitude detection frequency, and calculate the amplitude of the cutting blade based on the amplitude signal output from the frequency variable filter.
There is provided an apparatus for measuring an amplitude of a cutting blade.

According to the cutting blade amplitude measuring apparatus of the present invention, the variable frequency band-pass filter that passes only the amplitude signal in the set frequency region among the amplitude signals output from the amplitude detecting means for detecting the amplitude of the cutting blade is provided. Then, the frequency of the AC power applied to the ultrasonic vibration means can be detected by counting the frequency of the amplitude signal that has passed through the frequency variable bandpass filter. Then, an amplitude detection frequency region in a minute range is set around the counted frequency, the frequency variable bandpass filter is controlled, and the cutting blade amplitude is calculated based on the amplitude signal output from the frequency variable bandpass filter. Therefore, the amplitude of the cutting blade by ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic vibrator can be accurately obtained.
Also, according to the present invention, the frequency variable filter is controlled using the frequency counted as described above as the amplitude detection frequency, and the amplitude of the cutting blade is calculated based on the amplitude signal output from the frequency variable filter. It is possible to accurately obtain the amplitude of the cutting blade by ultrasonic vibration corresponding to the frequency of the AC power applied to the acoustic vibrator.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a cutting blade amplitude measuring apparatus constructed according to the present invention will be described in more detail with reference to the accompanying drawings.

First, a cutting apparatus for cutting a workpiece such as a semiconductor wafer or an optical device wafer while applying ultrasonic vibration to a cutting blade will be described with reference to FIGS.
The illustrated cutting device 1 includes a device housing 2 having a substantially rectangular parallelepiped shape. In the apparatus housing 2, a chuck table 3 that holds a workpiece is disposed so as to be movable in a direction indicated by an arrow X that is a cutting feed direction. The chuck table 3 includes a suction chuck support 31 and a suction chuck 32 disposed on the suction chuck support 31. A workpiece is illustrated on a holding surface which is the upper surface of the suction chuck 32. Suction holding is performed by operating a suction means that does not. The chuck table 3 is configured to be rotatable by a rotation mechanism (not shown). The chuck table 31 is provided with a clamp 33 for fixing a support frame for supporting a wafer, which will be described later, as a workpiece through a protective tape. The chuck table 3 configured as described above can be moved in a cutting feed direction indicated by an arrow X by a cutting feed means (not shown).

  A cutting apparatus 1 shown in FIG. 1 includes a spindle unit 4 as cutting means. The spindle unit 4 is mounted on a moving base (not shown) and is moved in an indexing direction indicated by an arrow Y perpendicular to the cutting feed direction indicated by the arrow X by indexing feeding means (not shown), and a cutting direction by a notch feeding means (not shown). It can be moved in the direction indicated by the arrow Z. The spindle unit 4 will be described with reference to FIG.

  The spindle unit 4 shown in FIG. 2 includes a spindle housing 41, a rotating spindle 42 that is rotatably disposed in the spindle housing 41, and a cutting tool 43 that is attached to the tip of the rotating spindle 42. . The spindle housing 41 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 includes a tool mounting portion 422 provided with a screw hole 421 at a front end portion thereof, and a central portion thereof in a radial direction. A protruding thrust bearing flange 423 is provided. 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.

  A cutting tool 43 mounted on a tool mounting portion 422 provided at the tip of the rotary spindle 42 includes a vibration transmission member 44 as a blade base, and an annular cutting blade 45 mounted on the vibration transmission member 44. It is made up of. The vibration transmitting member 44 is made of aluminum in the illustrated embodiment, and has a central large-diameter portion 441, a first small-diameter portion 442 formed so as to protrude coaxially from one end surface of the central large-diameter portion 441, The second small-diameter portion 443 is formed so as to protrude coaxially from the other end surface of the large-diameter portion 441. Note that the first small diameter portion 442 and the second small diameter portion 443 are formed to have the same dimensions. The thus formed vibration transmission member 44 is formed with a through hole 444 that penetrates the center of the shaft. In the illustrated embodiment, the cutting blade 45 attached to the vibration transmission member 44 is bonded to the end face of the vibration transmission member 44 on the first small diameter portion 442 side of the central large diameter portion 441 by metal plating such as nickel. An electroformed blade, a resin bond grindstone blade in which abrasive grains are bonded by resin bond, a metal bond grindstone blade in which abrasive grains are bonded by metal bond, and a vitrified bond grindstone blade in which abrasive grains are bonded by vitrified bond can be used.

  The illustrated cutting tool 43 includes a first end surface 442a facing the rotary spindle 42 and a left end in FIG. 2 of the second small diameter portion 443 in FIG. 2 of the first small diameter portion 442 constituting the vibration transmitting member 44. Spacers 46, 46 made of synthetic resin are mounted on the surface, that is, the second end surface 443a facing the fixing member described later. The cutting tool 43 configured in this way is screwed into a screw hole 421 provided in the tool mounting portion 422 of the rotary spindle 42 with a fastening bolt 46 as a fixing member disposed through the through hole 444. Thus, the rotary spindle 42 is mounted. At this time, spacers 46 and 46 made of synthetic resin are mounted on the first end surface 442a of the first small-diameter portion 442 and the second end surface 443a of the second small-diameter portion 443 constituting the vibration transmitting member 44, respectively. Therefore, it is easy to attach the vibration transmitting member 44 to the rotating spindle 42, and it is possible to reliably prevent forgetting to interpose the spacers 46 and 46.

  The illustrated spindle unit 4 includes an electric motor 5 for rotationally driving a rotary spindle 42. The illustrated electric motor 5 is constituted by a permanent magnet motor. The permanent magnet type electric motor 5 is disposed in a spindle housing 41 on the outer peripheral side of the rotor 51 and a rotor 51 made of a permanent magnet mounted on a motor mounting portion 424 formed in an intermediate portion of the rotary spindle 42. The stator coil 52 is included. In the electric motor 5 configured in this manner, the rotor 51 is rotated by applying AC power to the stator coil 52 by power supply means described later, and the rotating spindle 42 to which the rotor 51 is mounted is rotated.

  The illustrated spindle unit 4 includes an ultrasonic transducer 6 that is disposed on the rotary spindle 42 and applies ultrasonic vibration to the cutting blade 45. The ultrasonic vibrator 6 includes an annular piezoelectric body 61 polarized in the axial direction of the rotary spindle 42 and two annular electrode plates 62 and 63 attached to both side polarization surfaces of the piezoelectric body 61. It has become. The piezoelectric body 61 is made of piezoelectric ceramics such as barium titanate, lead zirconate titanate, and lithium tantalate. The ultrasonic transducer 6 configured as described above is mounted on the rotary spindle 42, and generates ultrasonic vibration when AC power having a predetermined frequency is applied to the electrode plates 62 and 63 by power supply means described later. A plurality of ultrasonic transducers 6 may be arranged in the axial direction.

The illustrated spindle unit 4 includes power supply means 7 that applies AC power to the ultrasonic transducer 6 and applies AC power to the electric motor 5.
The power supply means 7 includes a rotary transformer 8 disposed at the rear end of the spindle unit 4. The rotary transformer 8 includes a power receiving unit 81 disposed at the rear 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. One end of the power receiving coil 812 of the power receiving means 81 configured as described above is connected to the electrode plate 62 of the ultrasonic transducer 6, and the other end is connected to the electrode plate 63. 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 in this way is supplied with AC power via the electrical wirings 73 and 74.

  The power supply means 7 shown in the figure has an AC power supply 91 for AC power supplied to the power supply coil 822 of the rotary transformer 8, a current adjustment means 92 as power adjustment means, and a frequency of AC power supplied to the power supply means 82. A frequency adjusting means 93 for adjusting, a control means 94 for controlling the current adjusting means 92, the frequency adjusting means 93, and the like, and an input means 95 for inputting the type of the cutting tool 43 provided with the cutting blade 45 to the control means 94, etc. It has. The power supply means 7 shown in FIG. 2 supplies AC power to the stator coil 52 of the electric motor 5 through the control circuit 96 and the electric wirings 521 and 522.

The illustrated spindle unit 4 is configured as described above, and the operation thereof will be described below.
When performing the cutting operation, AC power is supplied from the power supply means 7 to the stator coil 52 of the electric motor 5. As a result, the electric motor 5 rotates and the rotary spindle 42 rotates, and the cutting blade 45 attached to the vibration transmitting member 44 of the cutting tool 43 attached to the front end of the rotary spindle 42 is rotated.

  On the other hand, the power supply means 7 controls the current adjusting means 92 and the frequency converting means 93 by the control means 94 to control the voltage of the AC power to a predetermined voltage, and the frequency of the AC power is set to a predetermined frequency (for example, 53 kHz). And is supplied to the power supply coil 822 of the power supply means 82 constituting the rotary transformer 8. When AC power having a predetermined frequency is applied to the feeding coil 822 as described above, AC power having a predetermined frequency is interposed between the electrode plate 62 and the electrode plate 63 of the ultrasonic transducer 6 via the power receiving coil 812 of the rotating power receiving means 81. Is applied. As a result, the ultrasonic transducer 6 is repeatedly displaced in the radial direction and vibrates ultrasonically. This ultrasonic vibration is transmitted to the vibration transmission member 44 of the cutting tool 43 via the rotary spindle 42, and the vibration transmission member 44 ultrasonically vibrates in the radial direction. Accordingly, the cutting blade 45 attached to the vibration transmitting member 44 vibrates ultrasonically in the radial direction.

  Referring back to FIG. 1, the illustrated cutting apparatus 1 captures an image of the surface of the workpiece held on the chuck table 3 and detects an area to be cut by the grindstone blade 45. Means 12 are provided. The alignment unit 12 includes an imaging unit including an optical unit such as a microscope or a CCD camera. In addition, the cutting apparatus includes a display unit 13 that displays an image or the like captured by the alignment unit 12.

  In the cassette mounting area 14a of the apparatus housing 2, a cassette mounting table 14 for mounting a cassette for storing a workpiece is disposed. The cassette mounting table 14 is configured to be movable in the vertical direction by lifting means (not shown). On the cassette mounting table 14, a cassette 15 for storing a semiconductor wafer W as a workpiece is placed. The semiconductor wafer W accommodated in the cassette 15 has a grid-like street formed on the surface of the wafer, and devices such as capacitors, LEDs and circuits are formed in a plurality of rectangular areas partitioned by the grid-like street. ing. The semiconductor wafer W thus formed is accommodated in the cassette 15 with the back surface adhered to the front surface of the protective tape T mounted on the annular support frame F.

  The illustrated cutting apparatus temporarily places a semiconductor wafer W (supported on an annular frame F via a protective tape T) accommodated in a cassette 15 placed on a cassette placement table 14. The unloading means 17 for unloading to the table 16, the transfer means 18 for transferring the semiconductor wafer W unloaded to the temporary table 16 onto the chuck table 3, and the semiconductor wafer W cut on the chuck table 3 are cleaned. A cleaning means 19 and a cleaning and conveying means 20 for conveying the semiconductor wafer W cut on the chuck table 3 to the cleaning means 19 are provided.

  In the cutting apparatus 1 configured as described above, it is necessary to set the amplitude of the ultrasonic vibration applied to the cutting blade 45 to a predetermined amplitude. In order to set the amplitude of the ultrasonic vibration applied to the cutting blade 45 to a predetermined amplitude, it is necessary to set the power value of the AC power applied to the ultrasonic transducer 6 to a predetermined power value. However, the amplitude of the vibration applied to the cutting blade 45 is an amplitude obtained by combining the amplitude of the ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic vibrator 6 and the amplitude of the vibration due to the rotation of the rotary spindle 42 or the like. Become. Therefore, in order to set the power value of the AC power applied to the ultrasonic transducer 6, it is necessary to detect only the amplitude of the ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic transducer 6.

A cutting blade amplitude measuring apparatus for detecting only the amplitude of ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic transducer 6 will be described below with reference to FIG.
The cutting blade amplitude measuring apparatus 10 in the embodiment shown in FIG. 3 includes an amplitude detecting unit 110 that detects the amplitude of the cutting blade 45, and only an amplitude signal in a predetermined frequency region among the amplitude signals output from the amplitude detecting unit 110. A controller 130 for controlling the frequency region of the frequency variable bandpass filter 120 (BPF) that passes through and outputs the cutting blade 45 and measuring the amplitude of the cutting blade 45 based on the amplitude signal from the frequency variable bandpass filter 120 (BPF). It has. The amplitude detecting means 110 is formed between the detector main body 111, the light emitting means 112 and the light receiving means 113 disposed opposite to the detector main body 111, and the cutting blade 45 formed between the light emitting means 112 and the light receiving hand 113. And a blade receiving portion 114 for receiving the outer peripheral portion of the blade. The light emitting means 112 is connected to a light source 116 via an optical fiber 115 and emits light from the light source 116 toward the light receiving means 113. The light receiving means 113 receives the light emitted from the light emitting means 112 and sends the received light to the photoelectric converter 118 via the optical fiber 117.

  The photoelectric converter 118 converts the optical signal received by the light receiving means 113 into a voltage signal and outputs it to the frequency variable bandpass filter 120 (BPF). The frequency variable band pass filter 120 (BPF) passes only the amplitude signal in a predetermined frequency region out of the voltage signal (amplitude signal) output from the photoelectric converter 118 and sends it to the controller 130.

  The controller 130 includes a central processing unit (CPU) 131 that performs arithmetic processing according to a control program, a read-only memory (ROM) 132 that stores a control program and the like, and a read / write random access memory (RAM) that stores arithmetic results and the like. 133, a counter 134, an input interface 135, and an output interface 136. An amplitude signal is input from the frequency variable bandpass filter 120 to the input interface 135 of the controller 130. In addition, the output interface 136 of the controller 130 outputs a control signal to the frequency variable bandpass filter 120 (BPF) and also outputs a control signal to the display means 140 (DSP).

The cutting blade amplitude measuring apparatus 10 in the embodiment shown in FIG. 3 is configured as described above, and the operation thereof will be described below.
In order to measure the amplitude of the cutting blade 45 by the cutting blade amplitude measuring device 10, the detector main body 111 of the amplitude detecting means 110 is disposed so as to surround the chuck table 3 of the cutting device 1 as shown in FIG. It is arranged on the cover member 30. Then, the detector main body 111 disposed on the cover member 30 is moved directly below the cutting blade 45. Next, as shown in FIG. 3, the cutting blade 45 is lowered to enter the blade receiving portion 114 of the detector main body 111. And it positions so that the lower end of the cutting blade 45 may be located in the center of the light emission means 112 and the light-receiving means 113. FIG. Next, AC power is supplied from the power supply means 7 to the stator coil 52 of the electric motor 5. As a result, the electric motor 5 rotates and the rotary spindle 42 rotates, and the cutting blade 45 attached to the vibration transmission member 44 of the cutting tool 43 attached to the tip of the rotary spindle 42 is rotated.

  On the other hand, the power supply unit 7 supplies AC power of a predetermined voltage (for example, 50 V) and a predetermined current (for example, 300 mA) to the power supply coil 822 of the power supply unit 82 constituting the rotary transformer 8. At this time, the control means 94 outputs a control signal to the frequency adjusting means 93 so that the frequency of the AC power is a predetermined frequency. The predetermined frequency commanded to the frequency adjusting means 93 is a resonance frequency set in advance for the cutting blade 45 attached to the rotary spindle 42, and is set to 53 kHz, for example. When AC power having a predetermined frequency is applied to the feeding coil 822 as described above, AC power having a predetermined frequency is applied to the ultrasonic transducer 6 via the power receiving coil 812 of the rotating power receiving means 81. As a result, the ultrasonic transducer 6 is repeatedly displaced in the radial direction and vibrates ultrasonically. This ultrasonic vibration is transmitted to the vibration transmission member 44 of the cutting tool 43 via the rotary spindle 42, and the vibration transmission member 44 ultrasonically vibrates in the radial direction. Accordingly, the cutting blade 45 attached to the vibration transmitting member 44 vibrates ultrasonically in the radial direction.

  As described above, the amplitude of the cutting blade 45 that is rotated and applied with the ultrasonic vibration is equal to the amplitude of the ultrasonic vibration corresponding to the frequency of the AC voltage applied to the ultrasonic vibrator 6 and the rotary spindle 42 as described above. The amplitude of vibration due to rotation of the rotation is a composite amplitude. Therefore, it is necessary to measure only the amplitude of the cutting blade 45 by ultrasonic vibration corresponding to the frequency of the AC power applied to the ultrasonic vibrator 6. However, when the frequency of the AC power applied to the ultrasonic transducer 6 is not known, it is necessary to detect this frequency. A procedure for measuring the amplitude of the ultrasonic vibration of the cutting blade 45 corresponding to the frequency of the AC power applied to the ultrasonic vibrator 6 using the cutting blade amplitude measuring apparatus 10 shown in FIG. This will be described with reference to the flowchart shown.

  The controller 130 sets the frequency region of the frequency variable bandpass filter 120 (BPF) as an initialization set value (f1, f2) (step S1). The frequency region initialization set values (f1, f2) are known in advance that the resonance frequency is in the range of 50 to 60 kHz in the cutting tool 43 provided with the cutting blade 45 as described above. f1) is set to 50 kHz, and (f2) is set to 60 kHz.

  If the frequency region of the frequency variable filter 120 (BPF) is set to the initialization set value (f1, f2) in step S1, the controller 130 proceeds to step S2 and the amplitude output from the frequency variable bandpass filter 120 (BPF). Based on the signal, the counter 134 counts the frequency (f0). Here, the amplitude signal output from the frequency variable bandpass filter 120 (BPF) will be described with reference to FIG. As described above, the amplitude of the ultrasonic vibration applied to the cutting blade 45 is detected by the amplitude detecting means 110. That is, a voltage signal corresponding to the amount of light received by the light receiving means 113 that receives the light emitted from the light emitting means 112 of the amplitude detecting means 110 is output from the photoelectric conversion means 118. The amplitude signal output from the photoelectric conversion means 118 is an amplitude signal in which the amplitude of the ultrasonic vibration of the cutting blade 45 at a frequency of, for example, 53 kHz and the amplitude of vibration caused by the rotation of the rotary spindle 42 are combined as described above. . The amplitude signal output from the photoelectric conversion means 118 in this way passes through the frequency variable bandpass filter 120 (BPF). At this time, since the frequency domain of the frequency variable filter 120 (BPF) is set to the initialization set value (f1: 50 kHz, f2: 60 kHz) in step S1, the amplitude signal output from the photoelectric conversion means 118 is Only amplitude signals with a frequency of 50-60 kHz are passed. The frequency range of 50 to 60 kHz set in the frequency variable filter 120 (BPF) does not include the frequency of vibration due to rotation of the rotary spindle 42 (the frequency of vibration due to rotation of the rotary spindle 42 or the like is 50 to 60 kHz). Therefore, the frequency that passes through the variable frequency filter 120 (BPF) is the ultrasonic vibration of the cutting blade 45 corresponding to the frequency of the AC power applied to the ultrasonic vibrator 6. Accordingly, the amplitude signal output from the frequency variable bandpass filter 120 (BPF) is an amplitude signal corresponding to ultrasonic vibration having a frequency of 53 kHz in the illustrated embodiment. Based on the amplitude signal from the frequency variable bandpass filter 120 (BPF) output in this way, the controller 130 counts the frequency (f0) by the counter 134.

  Next, the controller 130 proceeds to step S3 and checks whether or not the frequency (f0) has been counted by the counter 134 in step S2. If the frequency (f0) cannot be counted, the controller 130 determines that the frequency of the AC power applied to the ultrasonic transducer 6 is not in the range of the initialization setting values (f1: 50 kHz, f2: 60 kHz). In step S4, the frequency region of the frequency variable bandpass filter 120 (BPF) is expanded. For example, f1 is f1−0.2 kHz, and f2 is f2 + 0.2 kHz. Then, the controller 130 returns to step S2.

  When the frequency (f0) can be counted by the counter 134 in step S3, the controller 130 stores the counted value in the random access memory (RAM) 133 as the frequency (f0) (step S5). In the case of the illustrated embodiment, since the amplitude signal output from the frequency variable band pass filter 120 (BPF) is 53 kHz as described above, the count value is 53 kHz.

  Next, the controller 130 proceeds to step S6 and confirms whether or not the frequency (f0) counted by the counter 134 in the step S3 is in the range of the initialization setting values (f1: 50 kHz, f2: 60 kHz). To do. If the counted frequency (f0) is not in the range of the initialization setting values (f1: 50 kHz, f2: 60 kHz), the controller 130 proceeds to step S4. If the frequency (f0) counted in step S6 is within the range of the initialization setting values (f1: 50 kHz, f2: 60 kHz), the controller 130 proceeds to step S7 and the frequency variable bandpass filter 120 (BPF). The frequency region is narrowed to the amplitude detection frequency region. In this amplitude detection frequency region, for example, f1 is set to f0−0.2 kHz, and f2 is set to f0 + 0.2 kHz. In this way, the frequency detection band of the frequency variable bandpass filter 120 (BPF) is narrowed and the frequency (f0) that is counted is set in the minute amplitude detection frequency region around the counted frequency (f0). This is to accurately measure the amplitude of the cutting blade 45 by the signal. That is, the amplitude of the amplitude signal that has passed through the frequency variable bandpass filter 120 (BPF) in the range of the initialization setting values (f1: 50 kHz, f2: 60 kHz) is the frequency of the AC power applied to the ultrasonic transducer 6. This is because there is a high possibility that amplitudes due to vibrations other than the vibration corresponding to (f0) are combined.

  The frequency variable bandpass filter 120 (BPF) in which the frequency domain is narrowed to the amplitude detection frequency domain in step S7 corresponds to the frequency (f0) of the AC power applied to the ultrasonic transducer 6 as shown in FIG. Output an amplitude signal. Next, the controller 130 proceeds to step S8, and calculates the amplitude of the ultrasonic vibration applied to the cutting blade 45 based on the amplitude signal output from the frequency variable bandpass filter 120 (BPF). That is, the controller 130 detects the maximum value and the minimum value based on the amplitude signal output from the frequency variable bandpass filter 120 (BPF), and obtains the amplitude of the cutting blade 45 from the maximum value and the minimum value. Then, the controller 130 proceeds to step S9, and displays the measured amplitude of the cutting blade 45 on the display means 140 (DSP).

  As described above, in the cutting blade amplitude measuring apparatus 10 in the embodiment shown in FIG. 3, even when the frequency of the AC power applied to the ultrasonic transducer 6 is not known, it is applied to the ultrasonic transducer 6. The amplitude of the cutting blade 45 by ultrasonic vibration corresponding to the frequency of the AC power can be accurately obtained.

Next, another embodiment of the cutting blade amplitude measuring apparatus 10 will be described with reference to FIG.
The amplitude measurement apparatus 10 shown in FIG. 5 is a synchronous detection circuit or lock that can set a frequency to be passed between the frequency variable bandpass filter 120 (BPF) and the controller 130 in the amplitude measurement apparatus 10 shown in FIG. A frequency variable filter 150 such as an in-amplifier is provided. Other configurations in the amplitude measuring apparatus 10 shown in FIG. 5 are the same as those in the amplitude measuring apparatus 10 shown in FIG.

  In the amplitude measuring apparatus 10 shown in FIG. 5, the controller 130 controls steps S1 to S6 in the flowchart shown in FIG. 4 based on the amplitude signal directly input from the frequency variable bandpass filter 120 (BPF). In step S7, the controller 130 sets the frequency (f0) counted in step S5 to the frequency variable filter 150 as the amplitude detection frequency. In the illustrated embodiment, the counted frequency (f0) has an amplitude signal of 53 kHz, and therefore the frequency variable filter 150 is set to 53 kHz as the amplitude detection frequency. Next, the controller 130 performs step S9 based on the amplitude signal corresponding to the frequency of 53 kHz as the amplitude detection frequency that has passed through the frequency variable filter 150, calculates the amplitude of the cutting blade 45, and proceeds to step S10. Then, the calculated amplitude of the cutting blade 45 is displayed on the display means 140 (DSP).

  Based on the amplitude of the cutting blade 45 measured by the amplitude measuring device 10 as described above, the cutting device 1 applies the amplitude of the cutting blade 45 to the ultrasonic transducer 6 so as to obtain a target amplitude (for example, 10 μm). The power value of AC power to be adjusted can be adjusted. That is, when the amplitude of the cutting blade 45 displayed on the display means 140 (DSP) of the amplitude measuring apparatus 10 is smaller than the target amplitude (for example, 10 μm), the current adjusting means 92 of the amplitude measuring apparatus 10 is controlled to control the ultrasonic wave. The current value of AC power applied to the vibrator 6 is increased by, for example, 10 mA. Then, the control means 94 of the cutting apparatus 1 stores the current value in which the amplitude of the cutting blade 45 displayed on the display means 140 (DSP) of the amplitude measuring apparatus 10 matches the target amplitude (for example, 10 μm) as a set current value. To store. On the other hand, when the amplitude of the cutting blade 45 displayed on the display means 140 (DSP) of the amplitude measuring apparatus 10 is larger than the target amplitude (for example, 10 μm), the current adjusting means 92 of the amplitude measuring apparatus 10 is controlled to control the ultrasonic wave. The current value of the AC power applied to the vibrator 6 is decreased by 10 mA, for example. Then, the control means 94 of the cutting apparatus 1 stores the current value in which the amplitude of the cutting blade 45 displayed on the display means 140 (DSP) of the amplitude measuring apparatus 10 matches the target amplitude (for example, 10 μm) as a set current value. To store. In this way, if the current value of the AC power applied to the ultrasonic vibrator 6 of the cutting apparatus 1 is set to a value at which the amplitude of the cutting blade 45 becomes the target amplitude, and stored in the memory 941 as the set current value Then, the amplitude measuring device 10 is removed from the cutting device 1.

The cutting apparatus 1 in which the setting current value of the AC power applied to the ultrasonic vibrator 6 for the cutting tool 43 attached to the tip of the rotary spindle 42 as described above is stored in the memory 941 of the control means 94 is the setting. Perform ultrasonic vibration cutting based on the current value.
That is, the semiconductor wafer W accommodated in a predetermined position of the cassette 15 placed on the cassette placement table 14 is positioned at the carry-out position when the cassette placement table 14 moves up and down by a lifting means (not shown). Next, the unloading means 17 moves forward and backward to unload the semiconductor wafer W positioned at the unloading position onto the temporary placement table 16. The semiconductor wafer W carried out to the temporary placement table 16 is transferred onto the chuck table 3 by the turning operation of the transfer means 18. When the semiconductor wafer W is placed on the chuck table 3, suction means (not shown) is operated to suck and hold the workpiece W on the chuck table 3. Further, the support frame F that supports the workpiece W via the protective tape T is fixed by the clamp 33. In this way, the chuck table 3 holding the semiconductor wafer W is moved to just below the alignment means 12. When the chuck table 3 is positioned immediately below the alignment means 12, the street formed on the semiconductor wafer W is detected by the alignment means 12, and the spindle unit 4 is moved and adjusted in the direction of the arrow Y, which is the indexing direction. A precision alignment operation with the cutting blade 45 of the tool 43 is performed.

  Thereafter, while the cutting blade 45 is cut and fed by a predetermined amount in the direction indicated by the arrow Z and rotated in the predetermined direction, the chuck table 3 that sucks and holds the semiconductor wafer W is moved in the direction indicated by the arrow X (cutting blade 45). The semiconductor wafer W held on the chuck table 3 is cut along a predetermined street by the cutting blade 45 by moving at a predetermined cutting feed speed in a direction perpendicular to the rotation axis of the magnetic head. In this cutting step, the control means 94 outputs a control signal having a preset frequency to the frequency adjusting means 93 and outputs a control signal having the set current value to the current adjusting means 92. Therefore, the power supply means 7 applies AC power having a set current value set as described above to the ultrasonic transducer 6. As a result, as described above, the ultrasonic transducer 6 is ultrasonically vibrated by being repeatedly displaced in the radial direction. This ultrasonic vibration is transmitted to the vibration transmission member 44 of the cutting tool 43 via the rotary spindle 42, and the vibration transmission member 44 ultrasonically vibrates in the radial direction. Accordingly, the cutting blade 45 attached to the vibration transmitting member 44 ultrasonically vibrates in the radial direction with a target amplitude (for example, 10 μm). For this reason, even if the semiconductor wafer W is a difficult-to-cut material such as sapphire, which can effectively reduce the cutting resistance by the cutting blade 45, it can be easily cut.

The perspective view of the cutting device which cuts a workpiece which gives ultrasonic vibration to a cutting blade. Sectional drawing of the spindle unit with which the cutting apparatus shown in FIG. 1 is equipped. The block diagram which shows one Embodiment of the amplitude measuring apparatus of the cutting blade comprised according to this invention. The flowchart which shows the operation | movement procedure of the controller with which the amplitude measuring apparatus of the cutting blade shown in FIG. 3 is equipped. The block diagram which shows other embodiment of the amplitude measuring device of the cutting blade comprised according to this invention.

Explanation of symbols

1: Cutting device 2: Device housing 3: Chuck table mechanism 30: Chuck table 4: Spindle unit 41: Spindle housing 42: Rotary spindle 43: Cutting tool 44: Vibration transmitting member 45: Grinding wheel blade 5: Electric motor 6: Ultrasonic Vibrator 7: Power supply means 8: Rotary transformer 81: Power reception means 82: Power supply means 91: AC power supply 92: Current adjustment means 93: Frequency adjustment means 94: Control means 95: Input means 10: Amplitude measuring device 110 for cutting blade : Amplitude detecting means 112: Light emitting means 113: Light receiving means 116: Light source 118: Photoelectric converter 120: Frequency variable band pass filter (BPF)
130: Controller 140: Display means (DSP)
150: Frequency variable filter 12: Alignment means 13: Display means 34: Cassette placing table 15: Cassette 16: Temporary placing table 17: Unloading means 18: Conveying means 19: Cleaning means

Claims (2)

An ultrasonic vibration means is disposed on a rotary spindle to which a cutting tool having a cutting blade is attached, and the amplitude of the cutting blade is applied with an ultrasonic power by applying an AC power of a predetermined frequency to the ultrasonic vibration means. In the measuring device,
Amplitude detecting means for detecting the amplitude of the cutting blade of the cutting tool attached to the rotary spindle;
A frequency variable band-pass filter that passes only an amplitude signal in a set frequency region among the amplitude signals output from the amplitude detection means;
Control means for controlling the frequency region of the frequency variable bandpass filter and calculating the amplitude of the cutting blade based on the amplitude signal from the frequency variable bandpass filter;
The control means includes a counter for counting the frequency of the amplitude signal output from the frequency variable bandpass filter, and a memory for storing the frequency counted by the counter, and a predetermined frequency region of the frequency variable bandpass filter is obtained. Set and count the frequency of the amplitude signal, set the amplitude detection frequency region in a minute range around the counted frequency, control the frequency variable bandpass filter, and output from the frequency variable bandpass filter Calculate the amplitude of the cutting blade based on the amplitude signal
A device for measuring an amplitude of a cutting blade. An ultrasonic vibration means is disposed on a rotary spindle to which a cutting tool having a cutting blade is attached, and the amplitude of the cutting blade is applied with an ultrasonic power by applying an AC power of a predetermined frequency to the ultrasonic vibration means. In the measuring device,
Amplitude detecting means for detecting the amplitude of the cutting blade of the cutting tool attached to the rotary spindle;
A frequency variable band-pass filter that passes only an amplitude signal in a set frequency region among the amplitude signals output from the amplitude detection means;
A frequency variable filter that passes only an amplitude signal of a predetermined frequency among the amplitude signals that have passed through the frequency variable bandpass filter;
Control means for controlling the frequency region of the frequency variable bandpass filter and the frequency variable filter and calculating the amplitude of the cutting blade based on the frequency variable bandpass filter and the amplitude signal from the frequency variable filter. ,
The control means includes a counter for counting the frequency of the amplitude signal output from the frequency variable bandpass filter, and a memory for storing the frequency counted by the counter, and a predetermined frequency region of the frequency variable bandpass filter is obtained. Set and count the frequency of the amplitude signal, control the variable frequency filter using the counted frequency as an amplitude detection frequency, and calculate the amplitude of the cutting blade based on the amplitude signal output from the variable frequency filter ,
A device for measuring an amplitude of a cutting blade.

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