CN104889868A - Cutting device - Google Patents

Abstract

The present invention provides a cutting device capable of appropriately detecting abnormalities during cutting. The cutting device includes: a vibration signal generating member (68) that generates a vibration signal corresponding to the vibration of the cutting tool (60); and a control member (78) that determines whether cutting is performed based on the vibration signal generated by the vibration signal generating member. The state of the tool, the vibration signal generating member is composed of the following parts: the ultrasonic vibrator (70), which is arranged on the first flange member (46), generates a voltage corresponding to the vibration signal corresponding to the vibration of the cutting tool; and transmits member (72), which is connected to the ultrasonic vibrator and transmits the voltage to the control member, and a plurality of ultrasonic waves with different resonant frequencies connected in parallel with the first coil member (74) constituting the transmission member are arranged on the first flange member. Vibrator (70a, 70b, 70c).

Description

cutting device

technical field

The present invention relates to a cutting device for cutting a plate-shaped workpiece.

Background technique

For example, a plate-shaped workpiece represented by a semiconductor wafer is cut and divided into a plurality of chips by a cutting device provided with an annular cutting blade. During the cutting of the workpiece, the cutting tool vibrates when abnormalities such as breakage of the cutting tool, reduction in cutting performance, contact with foreign matter, or change in machining load occur.

Therefore, in order to detect such an abnormality, various methods have been studied. For example, breakage of a cutting tool can be detected by a method using an optical sensor (for example, refer to Patent Document 1). Furthermore, a change in the machining load can also be detected by a method of monitoring the current of the spindle (motor) to which the cutting tool is attached.

Patent Document 1: Japanese Patent No. 4704816

However, in the above-mentioned method using an optical sensor, there is a problem that abnormalities other than breakage of the cutting tool cannot be properly detected. On the other hand, the current monitoring method can detect various abnormalities that affect the rotation of the cutting tool, but it is not suitable for detection of minute abnormalities because of a certain degree of measurement error.

Contents of the invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting device capable of appropriately detecting abnormalities during cutting.

According to the present invention, there is provided a cutting device including: a chuck table holding a workpiece; and a cutting member including a cutting tool for cutting the workpiece held on the chuck table , the cutting member includes: a main shaft, which is rotatably supported on the main shaft housing; and a first flange member and a second flange member, which are mounted on the end of the main shaft and hold the cutting tool, the The cutting device is characterized in that the cutting device includes: a vibration signal generating means that generates a vibration signal corresponding to the vibration of the cutting tool; In the state of the cutting tool, the vibration signal generating member is composed of the following parts: an ultrasonic vibrator, which is arranged on the first flange member, and generates a voltage corresponding to the vibration signal corresponding to the vibration of the cutting tool; and a transmission member, It is connected with the ultrasonic vibrator, and transmits the voltage to the control member. The transmission member includes: a first coil member, which is installed on the first flange part; and a second coil member, which is connected with the first coil member. The plurality of ultrasonic vibrators connected in parallel to the first coil member and having different resonance frequencies are arranged on the spindle housing so as to be opposed to each other at intervals.

In addition, in the present invention, it is preferable that the control means performs Fourier transform analysis on the waveform corresponding to the time change of the vibration signal, and determines the change in the state of the cutting tool based on the change in the vibration component.

Invention effect

The cutting device of the present invention is equipped with: a vibration signal generating member that generates a vibration signal corresponding to the vibration of the cutting tool, and a control member that determines the state of the cutting tool based on the vibration signal generated by the vibration signal generating member. Abnormalities in cutting accompanied by vibration of the cutting tool.

Description of drawings

FIG. 1 is a perspective view schematically showing a configuration example of a cutting device according to this embodiment.

Fig. 2 is an exploded perspective view schematically showing the structure of a cutting unit.

Fig. 3 is a diagram schematically showing a section of a cutting unit and the like.

(A) of FIG. 4 is a diagram schematically showing the arrangement of an ultrasonic vibrator and a first inductor, and (B) of FIG. 4 is a circuit diagram showing a connection relationship between an ultrasonic vibrator and a first inductor.

(A) of FIG. 5 is a graph showing an example of the waveform (waveform in the time domain) of the voltage transmitted to the control device, and (B) in FIG. 5 is a waveform (waveform in the frequency domain) after Fourier transform. The graph of the example.

FIG. 6 is a graph showing an example of waveforms (waveforms in the frequency domain) before and after an abnormality occurs.

Label description

2: cutting device;

4: Base;

4a: opening;

6: X-axis mobile table;

8: waterproof cover;

10: chuck table;

10a: holding surface;

12: holder;

14: cutting unit (cutting member);

16: supporting structure;

18: Cutting unit moving mechanism;

20: Y-axis guide rail;

22: Y-axis mobile table;

24: Y-axis ball screw;

26: Z-axis guide rail;

28: Z-axis mobile table;

30: Z-axis ball screw;

32: Z-axis pulse motor;

34: camera;

36: spindle housing;

38: shell main body;

38a: threaded hole;

40: shell cover;

40a: opening;

40b: threaded hole;

40c: locking part;

42: spindle;

42a: opening;

44: screw;

46: the first flange part;

46a: opening;

48: flange part;

48a: abutment surface;

50: the first raised portion;

50a: outer peripheral surface;

52: the second raised portion;

56: washer;

58: bolt;

58a: outer peripheral surface;

60: cutting tool;

60a: opening;

62: support base;

64: cutting edge;

66: the second flange part;

66a: opening;

66b: contact surface;

68: Vibration signal generating device (vibration signal generating component);

70: ultrasonic vibrator;

70a: the first ultrasonic vibrator;

70b: the second ultrasonic vibrator;

70c: the third ultrasonic vibrator;

72: transmission path (transmission component);

74: 1st inductor (1st coil member);

76: 2nd inductor (2nd coil member);

78: control device (control member);

O: axis.

Detailed ways

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing a configuration example of a cutting device according to this embodiment. As shown in FIG. 1 , the cutting device 2 includes a base 4 that supports each structure.

On the upper surface of the base 4, a rectangular opening 4a long in the X-axis direction (front-rear direction, machining feed direction) is formed. An X-axis moving table 6, an X-axis moving mechanism (not shown) for moving the X-axis moving table 6 in the X-axis direction, and a waterproof cover 8 covering the X-axis moving mechanism are provided in the opening 4a.

The X-axis moving mechanism includes a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and the X-axis moving table 6 is slidably provided on the X-axis guide rails. A nut portion (not shown) is fixed to the lower surface side of the X-axis movable table 6, and an X-axis ball screw (not shown) parallel to the X-axis guide rail is screwed to the nut portion.

An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. By rotating the X-axis ball screw with the X-axis pulse motor, the X-axis moving table 6 moves in the X-axis direction along the X-axis guide rail.

A chuck table 10 for sucking and holding a plate-shaped workpiece (not shown) is provided on the X-axis movable table 6 . The workpiece is, for example, a disk-shaped semiconductor wafer, a resin substrate, a ceramic substrate, etc., and the lower surface side of the workpiece is sucked and held on the chuck table 10 .

The chuck table 10 is connected to a rotation mechanism (not shown) such as a motor, and rotates around a rotation axis extending in the Z-axis direction (vertical direction). Then, the chuck table 10 moves in the X-axis direction by the above-mentioned X-axis moving mechanism. A clamper 12 for clamping and fixing an annular frame (not shown) supporting a workpiece is provided around the chuck table 10 .

The surface (upper surface) of the chuck table 10 serves as a holding surface 10 a for suction holding a workpiece. This holding surface 10 a is connected to a suction source (not shown) through a flow path (not shown) formed inside the chuck table 10 .

On the upper surface of the base 4, a gate-type support structure 16 for supporting the cutting unit (cutting member) 14 is arranged so as to straddle the opening 4a. A cutting unit moving mechanism 18 for moving the cutting unit 14 in the Y-axis direction (index feed direction) and the Z-axis direction is provided on the upper front surface of the support structure 16 .

The cutting unit moving mechanism 18 includes a pair of Y-axis guide rails 20 arranged on the front surface of the support structure 16 and parallel to the Y-axis direction. A Y-axis moving table 22 constituting the cutting unit moving mechanism 18 is slidably provided on the Y-axis guide rail 20 .

A nut portion (not shown) is fixed to the back side (rear surface side) of the Y-axis movable table 22 , and the Y-axis ball screw 24 parallel to the Y-axis guide rail 20 is screwed to the nut portion. A Y-axis pulse motor (not shown) is connected to one end of the Y-axis ball screw 24 . When the Y-axis ball screw 24 is rotated by the Y-axis pulse motor, the Y-axis moving table 22 moves in the Y-axis direction along the Y-axis guide rail 20 .

A pair of Z-axis guide rails 26 parallel to the Z-axis direction is provided on the surface (front surface) of the Y-axis moving table 22 . A Z-axis moving table 28 is slidably provided on the Z-axis guide rail 26 .

A nut portion (not shown) is fixed to the back side (rear surface side) of the Z-axis movable table 28 , and the Z-axis ball screw 30 parallel to the Z-axis guide rail 26 is screwed to the nut portion. A Z-axis pulse motor 32 is connected to one end of the Z-axis ball screw 30 . When the Z-axis ball screw 30 is rotated by the Z-axis pulse motor, the Z-axis moving table 28 moves in the Z-axis direction along the Z-axis guide rail 26 .

A cutting unit 14 for cutting a workpiece is provided below the Z-axis movable table 28 . Furthermore, a camera 34 for imaging the upper surface side of the workpiece is provided at a position adjacent to the cutting unit 14 . As described above, by moving the Y-axis moving table 22 and the Z-axis moving table 28 , the cutting unit 14 and the camera 34 move in the Y-axis direction and the Z-axis direction.

FIG. 2 is an exploded perspective view schematically showing the structure of the cutting unit 14 , and FIG. 3 is a diagram schematically showing a cross section of the cutting unit 14 and the like. In addition, in FIGS. 2 and 3 , a part of the structure of the cutting unit 14 is omitted.

The cutting unit 14 includes a spindle housing 36 fixed to the lower portion of the Z-axis movable table 28 . The spindle housing 36 includes a substantially rectangular parallelepiped housing main body 38 and a cylindrical housing cover 40 fixed to one end side of the housing main body 38 .

A main shaft 42 that rotates around the Y-axis is accommodated inside the housing main body 38 . One end side of the main shaft 42 protrudes outward from the housing main body 38 . A motor (not shown) for rotating the main shaft 42 is connected to the other end side of the main shaft 42 .

A circular opening 40 a is formed at the center of the outer case 40 . Furthermore, a locking portion 40c is provided on the side of the housing body 38 of the housing cover 40, and a screw hole 40b is formed in the locking portion 40c. The housing cover 40 can be fixed to the housing body 38 by inserting one end of the main shaft 42 through the opening 40 a and screwing a screw 44 through the screw hole 40 b of the locking portion 40 c and into the screw hole 38 a of the housing body 38 .

An opening 42 a is formed at one end of the main shaft 42 , and a screw groove is provided on an inner wall surface of the opening 42 a. A first flange member 46 is attached to one end of the main shaft 42 .

The first flange member 46 includes a flange portion 48 protruding outward in the radial direction, and a first protrusion 50 and a second protrusion 52 protruding from the front and rear surfaces of the flange 48 , respectively. At the center of the first flange member 46, an opening 46a penetrating the first protrusion 50, the flange 48, and the second protrusion 52 is formed.

One end portion of the spindle 42 is fitted into the opening 46 a of the first flange member 46 from the rear side (the spindle housing 36 side). In this state, when the washer 56 is positioned in the opening 46 a and the fixing bolt 58 is screwed into the opening 42 a through the washer 56 , the first flange member 46 is fixed to the main shaft 42 . In addition, screw threads corresponding to the screw grooves of the opening 42 a are provided on the outer peripheral surface 58 a of the bolt 58 .

The front surface on the outer peripheral side of the flange portion 48 serves as an abutment surface 48 a that abuts on the back surface of the cutting insert 60 . The abutting surface 48 a is formed in an annular shape when viewed from the Y-axis direction (axis center direction of the main shaft 42 ).

The first boss portion 50 is formed in a cylindrical shape, and thread threads are provided on the outer peripheral surface 50a on the distal end side. A circular opening 60 a is formed at the center of the cutting blade 60 . The cutting insert 60 is attached to the first flange member 46 by inserting the first boss portion 50 into the opening 60a.

The cutting blade 60 is a so-called hub blade, and an annular cutting edge 64 for cutting a workpiece is fixed to the outer periphery of a disc-shaped support base 62 . The cutting edge 64 is formed by mixing abrasive grains such as diamond or CBN (Cubic Boron Nitride, cubic boron nitride) into a bonding material (bonding material) such as metal or resin to have a predetermined thickness. In addition, as the cutting blade 60, a washer blade composed of only cutting edges can be used.

In a state where the cutting insert 60 is attached to the first flange member 46 , an annular second flange member 66 is disposed on the front side of the cutting insert 60 . A circular opening 66 a is formed at the center of the second flange member 66 , and thread grooves corresponding to the thread ridges formed on the outer peripheral surface 50 a of the first boss 50 are provided on the inner wall surface of the opening 66 a.

The back surface on the outer peripheral side of the second flange portion 66 is a contact surface 66b ( FIG. 3 ) that contacts the front surface of the cutting insert 60 . The contact surface 66 b is provided at a position corresponding to the contact surface 48 a of the first flange member 46 .

By screwing the tip of the first boss 50 into the opening 66 a of the second flange member 66 , the cutting tool 60 is sandwiched between the first flange member 46 and the second flange member 66 .

The cutting unit 14 configured in this way is provided with a vibration detection mechanism for detecting the vibration of the cutting tool 60 . The vibration detection mechanism includes a vibration signal generating device (vibration signal generating means) 68 ( FIG. 3 ) that generates a vibration signal corresponding to the vibration of the cutting tool 60 .

The vibration signal generator 68 includes a plurality of ultrasonic transducers 70 fixed inside the first flange member 46 . The ultrasonic vibrator 70 is formed of materials such as barium titanate (BaTiO ₃ ), lead zirconate titanate (Pb(Zi,Ti)O ₃ ), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), etc. The vibration of the cutter 60 is converted into a voltage (vibration signal).

Usually, the ultrasonic vibrator 70 is configured to resonate with vibration of a predetermined frequency. Therefore, the frequency of the vibration that can be detected by the vibration detection means is determined based on the resonance frequency of the ultrasonic vibrator 70 . In this embodiment, in order to be able to detect vibrations in a wide frequency range, a plurality of ultrasonic transducers 70 having different resonance frequencies are used.

A non-contact transmission path (transmission member) 72 ( FIG. 3 ) for transmitting a voltage generated by the ultrasonic vibrator 70 is connected to the ultrasonic vibrator 70 . The transmission path 72 includes a first inductor (first coil member) 74 connected to the ultrasonic vibrator 70 and a second inductor (second coil member) 76 facing the first inductor 74 at a predetermined interval. .

Typically, the first inductor 74 and the second inductor 76 are annular coils wound with conductive wires, and are fixed to the first flange member 46 and the housing cover 40, respectively.

4(A) is a diagram schematically showing the arrangement of the ultrasonic vibrator 70 and the first inductor 74 , and FIG. 4(B) is a circuit diagram showing the connection relationship between the ultrasonic vibrator 70 and the first inductor 74 .

In this embodiment, as shown in (A) of FIG. 4 , two ultrasonic vibrators 70 are arranged at positions overlapping with the first inductor 74 when viewed from the Y-axis direction (the direction of the axis O of the main shaft 42 ). The ultrasonic vibrator 70 includes three types of ultrasonic vibrators (first ultrasonic vibrator 70a, second ultrasonic vibrator 70b, and third ultrasonic vibrator 70c) having different resonance frequencies.

For example, the frequency ranges of the vibrations detected by the first ultrasonic vibrator 70 a , the second ultrasonic vibrator 70 b , and the third ultrasonic vibrator 70 c are 50 kHz to 100 kHz, 100 kHz to 300 kHz, and 300 kHz to 500 kHz, respectively. In this way, by using a plurality of ultrasonic vibrators 70 having different resonant frequencies, vibrations in a wide frequency range can be detected. In the above case, vibrations in the frequency range of 50 kHz to 500 kHz can be appropriately detected.

The two first ultrasonic vibrators 70 a are arranged symmetrically with respect to the axis O of the main shaft 42 . In addition, the two second ultrasonic vibrators 70 b are arranged symmetrically with respect to the axis O of the main shaft 42 . Similarly, the two third ultrasonic transducers 70 are arranged symmetrically with respect to the axis O of the main shaft 42 .

Thus, by arranging the plurality of ultrasonic vibrators 70 symmetrically with respect to the axis O of the spindle 42 , it is possible to detect the vibration of the cutting tool 60 with high precision. In addition, the number, arrangement, shape, etc. of the ultrasonic transducers 70 are not limited to those shown in (A) of FIG. 4 .

As shown in FIG. 4(B) , the first ultrasonic vibrator 70 a , the second ultrasonic vibrator 70 b , and the third ultrasonic vibrator 70 c are connected in parallel to the first inductor 74 . In addition, the first inductor 74 and the second inductor 76 face each other and are magnetically coupled. Therefore, the voltage generated by each ultrasonic vibrator 70 is transmitted to the second inductor 76 side through mutual induction between the first inductor 74 and the second inductor 76 .

A control device (control means) 78 is connected to the second inductor 76 . The control device 78 determines the vibration state of the cutting tool based on the voltage transmitted from the second inductor 76 . Specifically, spectrum analysis is performed on a waveform corresponding to a time change (waveform in the time domain) of a voltage transmitted per arbitrary unit of time by Fourier transform (for example, fast Fourier transform), and from the obtained waveform in the frequency domain to determine the state of the cutting tool 60. As unit time, the time required to cut one line (per cutting line), the time required to cut one workpiece (per workpiece), the time required to cut an arbitrary distance (each cutting distance ) and other methods.

(A) of FIG. 5 is a graph showing an example of the waveform (waveform in the time domain) of the voltage transmitted to the control device 78, and (B) in FIG. 5 is a graph showing a waveform after Fourier transform (waveform in the frequency domain). ) graph of an example. 5(A), the vertical axis represents voltage (V), and the horizontal axis represents time (t), and in FIG. 5(B), the vertical axis represents amplitude and the horizontal axis represents frequency (f).

In this way, when the waveform of the voltage (vibration signal) from the vibration signal generator 68 is Fourier transformed by the control device 78, the vibration of the cutting tool 60 is divided into main frequency components as shown in FIG. 5(B). , can easily analyze the abnormalities that occur during cutting. Thereby, abnormality during cutting can be detected with high precision in real time.

FIG. 6 is a graph showing an example of waveforms (waveforms in the frequency domain) before and after occurrence of an abnormality. In FIG. 6 , the vertical axis represents the amplitude, and the horizontal axis represents the frequency (f). In addition, in FIG. 6 , the waveform before the abnormality occurs is shown by a solid line, and the waveform after the abnormality is shown by a dotted line.

As shown in FIG. 6 , in the waveform after the occurrence of the abnormality, there is a high-frequency vibration mode (vibration component) that was not seen in the waveform before the abnormality occurred. The control device 78 compares, for example, waveforms (waveforms in the frequency domain) before and after the occurrence of the abnormality, and determines that an abnormality corresponding to a vibration pattern seen only in the waveform after the abnormality has occurred has occurred.

As described above, the cutting device 2 of the present embodiment includes: the vibration signal generating device (vibration signal generating member) 68 that generates a vibration signal corresponding to the vibration of the cutting tool 60; The control device (control means) 78 that determines the state of the cutting tool 60 can therefore appropriately detect abnormalities in cutting accompanied by vibrations of the cutting tool 60 .

In addition, in the cutting device 2 of the present embodiment, Fourier transform is performed on the waveform (time-domain waveform) of the voltage (vibration signal) corresponding to the time change. The analysis of the abnormality that occurs becomes easy. Thereby, abnormality during cutting can be detected with high precision.

In addition, this invention is not limited to description of said embodiment. For example, the voltage (vibration signal) may not be analyzed by Fourier transform. In addition, the structures, methods, and the like of the above-described embodiments can be appropriately changed and implemented without departing from the scope of the purpose of the present invention.

Claims (2)

1. a topping machanism, it comprises: chuck table, and it keeps machined object; And cutting member, it possesses cutting tool, and this cutting tool cuts the machined object being held in this chuck table,

This cutting member possesses: main shaft, and it is supported on main shaft shell in the mode that can rotate; And the 1st vibrating part and the 2nd vibrating part, they are installed on the end of this main shaft, and clamp this cutting tool,

The feature of described topping machanism is,

Described topping machanism possesses:

Vibration signal produces component, and it produces the vibration signal corresponding with the vibration of this cutting tool; And

Control member, it judges the state of this cutting tool according to the vibration signal being produced component generation by this vibration signal,

This vibration signal produces component and is formed by with lower part:

Ultrasonic oscillator, it is disposed on the 1st vibrating part, produces the voltage suitable with this vibration signal of the vibration corresponding to this cutting tool; And

Transmission member, it is connected with this ultrasonic oscillator, and this voltage is sent to this control member,

This transmission member comprises: the 1st coil member, and it is installed on the 1st vibrating part; And the 2nd coil member, it is opposed at spaced intervals with the 1st coil member, and is disposed in this main shaft shell,

1st vibrating part is equipped multiple this ultrasonic oscillators different from the resonant frequency that the 1st coil member is connected in parallel.

2. topping machanism according to claim 1, is characterized in that,

Described control member to described vibration signal and waveform that time variations is suitable carry out Fourier transformation and resolve, judge the change of the state of cutting tool according to the change of vibration component.