CN116803580A

CN116803580A - cutting device

Info

Publication number: CN116803580A
Application number: CN202310273269.6A
Authority: CN
Inventors: 饭田贵大
Original assignee: Tokyo Seimitsu Co Ltd
Current assignee: Tokyo Seimitsu Co Ltd
Priority date: 2022-03-25
Filing date: 2023-03-20
Publication date: 2023-09-26
Also published as: JP2023143278A

Abstract

The invention provides a cutting device capable of detecting elastic waves generated from a blade with high precision. The cutting device (1) is provided with a processing table (22), a main shaft (24), a blade (26) mounted on a blade mounting portion (60) of the main shaft (24), and an elastic wave detection portion (90) for detecting an elastic wave generated from the blade (26). An elastic wave detection unit (90) is provided with an AE sensor (92) which is mounted on at least one of the main shaft (24), the blade mounting unit (60) and the processing table (22); a transmission-side coil (94) which is attached to at least one of the spindle (24), the blade attachment unit (60), and the machining table (22) and is connected to the AE sensor (92); and a receiving-side coil (96) disposed opposite to the transmitting-side coil (94) and magnetically coupled to the transmitting-side coil (94), wherein a signal output from the AE sensor (92) is transmitted to the receiving-side coil (96) through the transmitting-side coil (94) by mutual induction between the transmitting-side coil (94) and the receiving-side coil (96).

Description

Cutting device

Technical Field

The present invention relates to a cutting device, and more particularly, to a cutting device for cutting a workpiece or forming a slot in the workpiece by a rotating blade.

Background

In a cutting device (so-called blade cutter) that cuts a workpiece or cuts a groove in the workpiece with a blade (extremely thin outer peripheral edge) attached to the tip of a spindle that rotates at a high speed, when an abnormality such as a blade jam occurs, a machining failure (e.g., chipping) of the workpiece occurs.

Patent document 1 describes a device in which an AE sensor is mounted on a fixed work table. The device described in patent document 1 detects an elastic wave generated when a workpiece is cut by a blade using an AE sensor, and measures the sharpness of the blade based on the sensor output.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 4-99946

Disclosure of Invention

Problems to be solved by the invention

Elastic waves propagate in a substance, but have the characteristic of being greatly attenuated among different objects. Therefore, when the work table rotates, the elastic wave may be greatly attenuated at the bearing portion or the like in the middle depending on the position where the AE sensor is mounted, and high-precision detection may not be performed.

The present invention has been made in view of such circumstances, and an object thereof is to provide a cutting device capable of detecting an elastic wave generated from a blade with high accuracy.

Means for solving the problems

In order to solve the above problems, a cutting device of the present invention includes: a table that holds a workpiece; a spindle that moves relatively with respect to the table; a blade mounting portion integrally mounted to the spindle; a blade mounted on the blade mounting portion; and an elastic wave detection unit that detects an elastic wave, the elastic wave detection unit including: an AE sensor mounted on at least one of the spindle, the blade mounting portion, and the table; a transmitting-side coil which is mounted on at least one of the spindle, the blade mounting section, and the table, and is connected to the AE sensor; and a receiving-side coil disposed opposite to the transmitting-side coil and magnetically coupled to the transmitting-side coil, wherein a signal output from the AE sensor is transmitted to the receiving-side coil by mutual induction between the transmitting-side coil and the receiving-side coil via the transmitting-side coil.

In one aspect of the present invention, the table, the spindle, and the blade attachment portion are preferably rotating bodies.

In one aspect of the present invention, the cutting device preferably includes: a contact detection unit that detects contact between the blade and the table based on the signal output from the elastic wave detection unit; and a reference position setting unit that sets a reference position of the blade, wherein the reference position setting unit sets a position at which the spindle moves from a position at which the blade is separated from the table toward the table and the contact detection unit detects contact as the reference position of the blade.

In one aspect of the present invention, it is preferable that the cutting device further includes an estimating unit that estimates a state of the blade and/or the workpiece based on a signal output from the elastic wave detecting unit during processing of the workpiece.

In one aspect of the present invention, the estimating unit preferably estimates occurrence of the collapse based on the signal output from the elastic wave detecting unit.

In one aspect of the present invention, the estimating unit preferably estimates the state of clogging of the blade based on the signal output from the elastic wave detecting unit.

In one aspect of the present invention, the estimating unit preferably estimates the state of the insert and/or the workpiece by comparing the state with the signal output from the elastic wave detecting unit during stable cutting.

In one aspect of the present invention, the AE sensor and the transmission side coil are preferably attached to the blade attachment portion.

In one aspect of the present invention, the AE sensor and the transmission side coil are preferably attached to the main shaft.

In one aspect of the present invention, the blade attachment portion is preferably provided at a front end portion of the spindle, and the AE sensor is preferably built in the front end portion of the spindle, and the transmission side coil is preferably attached to a base end portion of the spindle.

In one aspect of the present invention, the AE sensor and the transmission side coil are preferably mounted on a table.

In one aspect of the present invention, the receiving-side coil and the transmitting-side coil are preferably disposed so as to be wound around a rotation shaft of at least one of the spindle, the blade attachment portion, and the table.

In one aspect of the present invention, it is preferable that a balance weight is provided on at least one of the spindle, the blade attachment portion, and the table.

Effects of the invention

According to the present invention, the elastic wave generated from the blade can be detected with high accuracy.

Drawings

Fig. 1 is a perspective view showing a schematic configuration of a cutting device.

Fig. 2 is a perspective view showing a schematic configuration of the processing section.

Fig. 3 is a sectional view showing the structure of the blade fitting portion.

Fig. 4 is a rear view of the rear flange.

Fig. 5 is a front view of the front end cap.

Fig. 6 is a block diagram of the main functions of the system controller with respect to tool setting.

Fig. 7 is a graph showing an example of the output of the AE sensor.

Fig. 8 is a flowchart showing the processing steps of the tool setting.

Fig. 9 is a diagram showing an example of a mounting structure of the AE sensor to the spindle.

Fig. 10 is a diagram showing an example of a mounting structure of the AE sensor to the processing table.

Fig. 11 is a bottom view of the sensor base.

Fig. 12 is a top view of the coil base.

Fig. 13 is a schematic view of a cutting line in a plan view.

Fig. 14 is a schematic diagram of occurrence of breakage.

Fig. 15 is a graph showing an example of the output of the AE sensor during processing.

Fig. 16 is a graph showing an example of the output of the AE sensor during processing.

Fig. 17 is a schematic view of an in-process blade.

Fig. 18 is a graph showing an example of the output of the AE sensor during processing.

Fig. 19 is a block diagram of functions of the system controller with respect to estimation.

Description of the reference numerals

10 cutting apparatus, 12 supply and recovery unit, 14 processing unit, 16 cleaning unit, 18 carrying unit, 20 loading port, 22 processing table, 22A work holding surface, 24 spindle, 24A spindle body, flange fitting portion of 24B spindle, screw hole of 24C spindle, hole of 24D spindle, 26 blade, fitting hole of 26A blade, 28 cleaning table, 30 arm, 32 saddle, 34 gate post, 36X axis table, 38 v axis guide rail, 40 table unit, 42 table driving unit, housing of 42A table driving unit, 44Y axis table, 46Y axis guide rail, 48Z axis table, 48M Z axis motor, 48S Z axis sensor, 50 processing unit, 52 spindle driving unit, housing of 52A spindle driving unit, 60 blade fitting portion, 70 rear flange, 70A rear flange body, flange portion of 70B rear flange, and blade fitting portion of 70C rear flange, male screw portion of 70D rear flange, AE sensor mounting portion of 70E rear flange, balance weight mounting portion of 70F rear flange, transmitting side coil mounting portion of 70G rear flange, 72 fixing screw, 74 front flange, hole of 74A front flange, 76 fixing nut, front end cap of housing of 80 spindle driving portion, 80A opening portion, 80B receiving side coil mounting portion, 82 bolt, 84 end cap, 86 sensor base, AE sensor mounting portion of 86A sensor base, balance weight mounting portion of 86B sensor base, transmitting side coil mounting portion of 86C sensor base, 88 coil base, receiving side coil mounting portion of 88A coil base, 90 elastic wave detecting portion, 92 AE sensor, 93 wire, 94 transmitting side coil, 94a … transmit side coil form, 96 … receive side coil form, 96a … receive side coil form, 98 … balance weight, 100 … system controller, 102 … storage unit, 110 … spindle rotation control unit, 112 … plunge feed control unit, 114 … contact detection unit, 116 … reference position setting unit, 120 … workpiece state estimation unit, 122 … blade state estimation unit, AC … abrasive grain, C … break, CL … cutting fluid, CP … chip flute, DT … cutting tape, KC … cut center, SW … cut, st … interval, stC … interval center, W … workpiece, epsilon … center offset.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

(first embodiment)

[ overall Structure of cutting device ]

Fig. 1 is a perspective view showing a schematic configuration of a cutting device. In fig. 1, X-direction, Y-direction, and Z-direction are shown. The X direction and the Y direction are intersected with each other. For example, the X direction and the Y direction are mutually orthogonal. The Z direction intersects the X direction and the Y direction. For example, the Z direction is orthogonal to the X direction and the Y direction. Hereinafter, the length in the X direction and the Y direction may be referred to as thickness or width. The length in the Z direction is sometimes referred to as thickness, depth, and height. The direction of the tip side of the arrow in the Z direction may be referred to as an upward direction, an upper side, or an upper side, and the direction opposite to the upward direction may be referred to as a downward direction, a lower side, or a lower side. Hereinafter, an axis parallel to the X-direction may be referred to as an X-axis, an axis parallel to the Y-direction may be referred to as a Y-axis, and an axis parallel to the Z-direction may be referred to as a Z-axis. The plane including the X axis and the Y axis is sometimes referred to as a horizontal plane.

The cutting device 10 of the present embodiment is a so-called blade cutter. The blade cutting machine cuts or cuts a workpiece W with a blade attached to the front end of a spindle rotating at a high speed. The workpiece W is, for example, a semiconductor wafer.

As shown in fig. 1, the cutting apparatus 10 of the present embodiment includes a supply/recovery unit 12 that supplies and recovers a workpiece W, a processing unit 14 that processes the workpiece W, a cleaning unit 16 that cleans the processed workpiece W, a conveying unit 18 that conveys the workpiece W to each unit, and the like.

The supply/recovery unit 12 includes a loading port 20, and supplies the workpiece W to be processed from a cassette (not shown) attached to the loading port 20. The processed workpiece W is collected into a cassette (not shown) through the loading port 20. The workpiece W is processed while being attached to a dicing frame (not shown). The workpiece W is mounted to the cutting frame via a cutting belt.

The processing unit 14 holds the workpiece W on the processing table 22 and processes the workpiece W. The processing table 22 is rotatable about the θ axis shown in fig. 1, and is movable in the X direction. The θ axis is an axis passing through the center of the processing table 22 and parallel to the Z axis. The processing unit 14 makes a blade 26 attached to the tip of a spindle 24 rotating at a high speed contact with the workpiece W, and cuts the workpiece W or cuts a groove in the workpiece W. In the example shown in fig. 1, the cutting device 10 has two spindles 24, and can simultaneously machine two parts. The structure of the processing unit 14 will be described later.

The cleaning unit 16 holds and rotates the workpiece W after processing by the cleaning table 28. Specifically, the cleaning unit 16 supplies the cleaning liquid to the workpiece W while rotating the cleaning table 28, thereby cleaning the workpiece W. After the cleaning, the cleaning unit 16 rotates the cleaning table 28 and blows air to the workpiece W to dry the workpiece W (so-called spin drying).

The carrying section 18 includes a robot arm 30, and carries the workpiece W to each section by the robot arm 30. Specifically, the conveying section 18 conveys the workpiece W supplied from the supply/recovery section 12 to the processing section 14 by the robot arm 30. Then, the conveying section 18 conveys the workpiece W processed by the processing section 14 to the cleaning section 16 by the robot arm 30. Then, the conveying section 18 conveys the workpiece W cleaned by the cleaning section 16 to the supply/recovery section 12 by the robot arm 30.

As shown in fig. 2, the working portion 14 includes a saddle 32 and a gate post 34. The saddle 32 and the gate post 34 are provided on a stand not shown.

The X-axis guide 38 is provided to the saddle 32. The X-axis table 36 is mounted to an X-axis guide rail 38. The X-axis table 36 is guided by an X-axis guide 38 and supported so as to be movable in the X-direction. The X-axis table 36 is driven to move by an X-axis motor. The X-axis motor is constituted by a linear motor, for example. In addition, the position of the X-axis table 36 on its movement axis (position in the X-direction) is detected by an X-axis sensor. The X-axis sensor is constituted by a linear scale, for example.

The X-axis table 36 is provided with a table unit 40. The table unit 40 includes a processing table 22 that holds the workpiece W, and a table driving section 42 that rotates the processing table 22. The processing table 22 has a disk-like shape, and has a work holding surface 22A for holding the work W on the upper surface portion. The workpiece W is held on the workpiece holding surface 22A by vacuum suction, for example. The workpiece W is held horizontally. The table driving unit 42 includes a motor, and rotates the processing table 22 by the motor.

The door type column 34 is provided with a pair of Y-axis tables 44 that move in the Y direction. Each Y-axis table 44 is guided by a common Y-axis guide 46 disposed on the gate post 34, and is supported so as to be movable in the Y-direction. The Y-axis tables 44 are driven by, for example, Y-axis motors, respectively, and move. The Y-axis motor is constituted by a linear motor, for example. Further, the positions of the respective Y-axis tables 44 on the movement axes thereof (positions in the Y-direction) are detected by Y-axis sensors, respectively. The Y-axis sensor is constituted by a linear scale, for example.

Each Y-axis table 44 is provided with a Z-axis table 48 that moves in the Z direction. Each Z-axis table 48 is guided by a Z-axis guide rail, not shown, disposed on the Y-axis table 44, and is supported so as to be movable in the Z-direction. The Z-axis tables 48 are driven by, for example, Z-axis motors, respectively, and move. The Z-axis motor is constituted by a linear motor, for example. The positions of the Z-axis tables 48 on the movement axes (positions in the Z direction) are detected by Z-axis sensors. The Z-axis sensor is constituted by a linear scale, for example.

Each Z-axis table 48 is provided with a processing unit 50 for processing the workpiece W. The machining unit 50 includes a spindle 24, a spindle drive unit 52 that rotates the spindle 24, and a cutting fluid supply unit (not shown) that supplies a cutting fluid. In the example shown in fig. 2, the two processing units 50 are opposed in the direction Y. The two processing units 50 are arranged, for example, opposite to each other in the direction Y. For example, the two processing units 50 are symmetrically arranged so as to sandwich the saddle 32 (or the X-axis guide rail 38). The spindle 24 is arranged along the Y direction. The spindle 24 has a blade fitting portion at a front end. The blade 26 is detachably mounted to the blade mounting portion. The structure of the blade attachment portion will be described later. The spindle driving unit 52 includes a motor, and rotates the spindle 24 by the motor. The cutting fluid supply portion includes a nozzle, and supplies the cutting fluid from the nozzle to a contact portion between the blade 26 and the workpiece W.

According to the processing unit 14 configured as described above, the processing table 22 is fed in the X direction by driving the X-axis table 36. Thereby, the workpiece W is cut and fed. In addition, by driving the Y-axis table 44, the processing unit 50 is fed in the Y direction. Thereby, the blade 26 is index fed. Further, by driving the Z-axis table 48, the processing unit 50 is fed in the Z direction. Thereby, the blade 26 is cut into the feed. The orientation (rotational position) of the workpiece W is switched by rotating the processing table 22. By the operation of the processing portion 14, the workpiece W is cut or a notch is processed in the workpiece W.

[ blade mounting portion ]

Fig. 3 is a sectional view showing the structure of the blade fitting portion. In fig. 3, the insert mounting portion 60 of the machining unit 50 disposed on the front end side of the arrow in the Y direction of the two machining units 50 shown in fig. 2 is described. The structure of the blade fitting portion 60 of the processing unit 50 shown in fig. 3 can also be applied to the blade fitting portions of other processing units 50.

In the present embodiment, a so-called handle-less blade is used as the blade 26. A shank-less blade is a blade without a base metal (shank). It is to be noted that a structure using a shank insert having a base metal can also be employed. The blade 26 has a disk-like shape, and has a circular fitting hole 26A in a central portion.

As described above, the blade 26 is detachably mounted to the front end portion of the spindle 24 via the blade mounting portion 60.

The blade attachment portion 60 includes a flange attachment portion 24B provided at the front end of the spindle 24, a rear flange 70 attached to the flange attachment portion 24B, fixing screws 72 for fixing the rear flange 70 to the flange attachment portion 24B, a front flange 74 for sandwiching and fixing the blade 26 between the rear flange and the rear flange 70, and a fixing nut 76 for fixing the front flange 74. The blade mounting portion 60 rotates in response to the rotation of the spindle 24.

The flange fitting portion 24B has a tapered shape (truncated cone shape) in which the diameter decreases toward the tip. The flange fitting portion 24B is integrally provided at the front end of the main shaft body 24A. The spindle 24 is disposed such that the flange fitting portion 24B protrudes from the front end of the housing 52A of the spindle driving portion 52. More specifically, the main shaft 24 is disposed such that the flange fitting portion 24B protrudes from the opening 80A of the front cover 80 attached to the front end of the housing 52A. The front end cover 80 is fixed to the front end of the housing 52A of the spindle drive 52 by bolts 82.

The rear flange 70 is mainly composed of a rear flange main body 70A and a flange portion 70B. The rear flange body 70A has a cylindrical shape. The rear flange body 70A has a hole on its inner side into which the flange fitting portion 24B fits. The hole formed on the inner side of the rear flange body 70A has a shape conforming to the shape of the flange fitting portion 24B. That is, the inner peripheral portion of the hole of the rear flange main body 70A has a tapered shape corresponding to the shape of the flange fitting portion 24B. The flange portion 70B has a disk-like shape, and is integrally provided on the outer periphery of the base end portion of the rear flange main body 70A. The flange portion 70B is provided with a blade fitting portion 70C on an end surface on the opposite side (hereinafter, may be referred to as a front side or a front end side) to the front end of the arrow in the Y direction. The blade fitting portion 70C has a shape corresponding to the fitting hole 26A of the blade 26. The blade 26 is held on the axis of the rear flange 70 by fitting the fitting hole 26A thereof to the blade fitting portion 70C.

The fixing screw 72 is screwed to the tip end of the flange fitting portion 24B. The flange fitting portion 24B is provided with a screw hole 24C to which the fixing screw 72 is screwed. A screw hole 24C is formed along the axis of the main shaft 24 at the front end of the flange fitting portion 24B.

The rear flange 70 is fitted on the flange fitting portion 24B coaxially with the flange fitting portion 24B by fitting the inner peripheral portion thereof. After the assembly, the fixing screws 72 are fitted into the screw holes 24C of the flange fitting portion 24B and fastened, whereby the rear flange 70 is pressed by the flange fitting portion 24B and is fixed integrally with the flange fitting portion 24B.

The front flange 74 has a disk-like shape, and has a circular hole 74A in a central portion. The front flange 74 is fitted to the rear flange 70 by fitting the hole 74A to the rear flange body 70A.

The fixing nut 76 is screwed to the front end portion of the rear flange body 70A. The front end portion of the rear flange body 70A is provided with a male screw portion 70D to which a fixing nut 76 is screwed.

The blade 26 is mounted to the blade mounting portion 60. A method of attaching the blade 26 to the blade attachment portion 60 will be described. First, the rear flange 70 is assembled to the main shaft 24. The rear flange 70 is fitted to the flange fitting portion 24B by fitting its inner peripheral portion to the flange fitting portion 24B. After the assembly, the rear flange 70 is fixed to the flange fitting portion 24B by fixing screws 72. Next, the blade 26 is assembled to the rear flange 70. The blade 26 is fitted to the rear flange 70 by fitting the fitting hole 26A thereof to a blade fitting portion 70C provided in the flange portion 70B of the rear flange 70. The front flange 74 is then assembled to the rear flange 70. The front flange 74 is fitted to the rear flange 70 by passing the rear flange body 70A through the central hole 74A. After the front flange 74 is assembled, the fixing nut 76 is fitted and fastened to the male screw portion 70D of the rear flange 70. Thereby, the blade 26 is sandwiched and fixed between the rear flange 70 and the front flange 74.

[ elastic wave detection section ]

The cutting device 10 of the present embodiment includes an elastic wave detection unit 90 that detects an elastic wave generated from the blade 26. The elastic wave detection section 90 includes an AE sensor 92.AE is a slight name for acoustic emission (acoustic emission). Acoustic emission is a phenomenon in which strain energy accumulated in a material is released as elastic waves (AE waves) when the material is deformed or broken. AE waves have very high frequency components of several kHz to MHz. Signals with higher frequencies are greatly attenuated in air, so AE waves propagate mainly in objects. The AE sensor 92 detects the AE wave, converts the AE wave into an electrical signal, and outputs the electrical signal. AE sensors typically use a piezoelectric element such as PZT (lead zirconate titanate) to detect AE waves. Since the AE sensor itself is a well-known structure, a detailed description thereof will be omitted.

In the cutting device 10 of the present embodiment, the AE sensor 92 is attached to the blade attachment portion 60. Since the blade mounting portion 60 is a rotating body, in the present embodiment, a coil is used to transmit the signal of the AE sensor 92 to the outside. The structure and mounting structure of the acoustic wave sensor 90 will be described below.

As shown in fig. 3, the elastic wave detection unit 90 includes an AE sensor 92, a transmission-side coil 94 electrically connected to the AE sensor 92, and a reception-side coil 96 magnetically coupled to the transmission-side coil 94. The AE sensor 92 and the transmitting-side coil 94 are attached to the rear flange 70 as a rotating body. On the other hand, the receiving-side coil 96 is attached to the front cover 80 fixed to the front end of the housing 52A without rotating. The object that does not rotate with respect to the rotating body is sometimes referred to as a "fixed body".

Fig. 4 is a rear view of the rear flange.

As shown in the figure, an AE sensor mounting portion 70E, a counterweight mounting portion 70F, and a transmitting side coil mounting portion 70G are provided on the back surface portion of the flange portion 70B of the rear flange 70.

The AE sensor mounting portion 70E and the balance weight mounting portion 70F are formed of concave portions of the same shape, and are arranged symmetrically with respect to the axis of the rear flange 70. The AE sensor 92 is accommodated in the AE sensor mounting portion 70E, and is mounted on the rear flange 70.

A balance weight 98 is attached to the balance weight attachment portion 70F. The balance weight 98 is a weight that balances the rotation of the rear flange 70. By installing the balance weight 98, stable rotation without wobble can be ensured even when the main shaft 24 is rotated at high speed.

The transmitting-side coil mounting portion 70G is formed of an annular recess, and is disposed coaxially with the axis of the rear flange 70 serving as a rotation axis. The transmitting-side coil 94 is accommodated in the transmitting-side coil mounting portion 70G and is mounted on the rear flange 70. The transmitting-side coil 94 attached to the rear flange 70 is disposed so as to be wound around the shaft (rotation shaft) of the rear flange 70 as a rotating body.

Fig. 5 is a front view of the front end cap.

As shown in fig. 5, a receiving-side coil mounting portion 80B is provided on a front end-side surface of the front cover 80. The receiving-side coil mounting portion 80B is formed of an annular concave portion, and is disposed coaxially with the transmitting-side coil mounting portion 70G. The receiving-side coil 96 is accommodated in the receiving-side coil mounting portion 80B, and is mounted on the front cover 80. The receiving-side coil 96 and the transmitting-side coil 94 attached to the front cover 80 are coaxially arranged. Therefore, the transmission-side coil 94 is disposed so as to be wound around the axis (rotation axis) of the rear flange 70.

With the above configuration, the transmitting-side coil 94 and the receiving-side coil 96 are disposed so as to face each other with a predetermined gap therebetween, and are magnetically coupled in a non-contact state. In addition, with this configuration, the signal output from the AE sensor 92 is transmitted to the receiving-side coil 96 by mutual induction of the transmitting-side coil 94 and the receiving-side coil 96.

[ cutter setting ]

In the cutting device 10, in order to achieve high-precision machining, the height of the blade 26 is managed with high precision with respect to the machining table 22. The height of the blade 26 is controlled by detecting the position of the blade 26 in contact with the surface of the processing table 22. This process is called tool setting, and is performed periodically. The detected position is set as a reference position of the blade 26, and the cutting feed of the blade 26 is controlled based on information of the reference position. In addition, the wear amount of the blade 26 is measured based on the information of the reference position. That is, the change amount (wear amount) of the diameter of the blade 26 is calculated from the change amount of the reference position.

In the cutting device 10 of the present embodiment, when the cutter is set, contact of the blade 26 with the processing table 22 is detected based on the output of the elastic wave detection unit 90.

The tool setting is performed by the system controller 100 according to an execution instruction of the tool setting. Executing the instruction includes both manual and automatic. In the case of manual operation, an operator manually inputs the operation through an operation unit (not shown) of the cutting device 10. In the case of automation, input is automatically performed at a specific timing. For example, the execution instruction is automatically input when a certain time has elapsed since the replacement of the insert 26, when a certain number of workpieces have been machined since the replacement of the insert 26, or the like.

The system controller 100 is a control unit that integrally controls the operation of the entire cutting apparatus 10, and is configured by a computer including a processor, a memory, and the like, for example. The processor is constituted by CPU (central processing unit), for example. The memory includes RAM (random access memory) and ROM (read only memory).

The system controller 100 controls driving of the spindle driving unit 52 and the Z-axis motor 48M, and executes processing of setting the tool.

As shown in fig. 6, the system controller 100 has functions of a spindle rotation control unit 110, an plunge feed control unit 112, a contact detection unit 114, a reference position setting unit 116, and the like, with respect to tool setting. Each function is realized by a processor by executing a predetermined control program by the processor. The control program is stored in the memory or storage unit 102. The storage unit 102 is constituted by, for example, a flash memory.

The spindle rotation control unit 110 controls the driving of the spindle driving unit 52, thereby controlling the rotation of the blade 26.

The plunge feed control unit 112 controls driving of the Z-axis motor 48M, and thereby controls feeding (plunge feed) of the blade 26 in the Z-axis direction.

The contact detection unit 114 processes the signal output from the elastic wave detection unit 90 (the output signal of the AE sensor 92) to detect contact of the blade 26 with the processing table 22.

Fig. 7 is a graph showing an example of the output of the AE sensor. In the graph shown in the figure, the horizontal axis is time, and the vertical axis is the output of the AE sensor (output voltage V of the piezoelectric element). Fig. 7 (a) shows an example of the output of the AE sensor in the case where the blade idles. Fig. 7 (B) shows an example of the output of the AE sensor when the intermediate blade is in contact with the processing table. Fig. 7 (B) shows an example of the case where the insert is in contact with the processing table at time T1.

As shown in fig. 7 (a), when the blade 26 is idling, that is, when nothing is touching the blade 26, the output of the AE sensor 92 is lower than that in the touching state, and shifts in a substantially constant range.

On the other hand, as shown in fig. 7 (B), when the blade 26 is in contact with the processing table 22 in the middle, the output of the AE sensor 92 increases.

The contact detection unit 114 monitors the signal output from the elastic wave detection unit 90, and detects that the blade 26 has contacted the processing table 22. Specifically, the signal output from the elastic wave detection unit 90 is compared with the threshold Th, and when the signal output from the elastic wave detection unit 90 exceeds the threshold, it is determined that the blade 26 is in contact with the processing table 22.

The reference position setting unit 116 sets the reference position of the blade 26 based on the output of the contact detection unit 114 and the output of the Z-axis sensor 48S. Specifically, the position of the Z-axis table 48 detected at the point in time when the contact of the blade 26 with the processing table 22 is detected is set as the reference position of the blade 26. Information of the set reference position is recorded in the storage unit 102.

[ processing of tool setting ]

Fig. 8 is a flowchart showing the processing steps of the tool setting.

First, the presence or absence of an execution instruction for tool setting is determined (step S1). As described above, the tool setting is automatically input at a specific timing in addition to being manually input via the operation unit.

When the execution instruction of the tool setting is input, the blade 26 is set at the origin position (step S2). The origin position is set at a position where the blade 26 does not contact the processing table 22, that is, at a separated position.

Subsequently, the cutting blade 26 is rotated, and simultaneously, the cutting feed is performed toward the processing table 22 (step S3).

When the cutting feed of the blade 26 is started, the contact detection unit 114 detects the contact of the blade 26. The contact detection unit 114 determines whether or not the blade 26 has contacted the processing table 22 based on the output of the AE sensor 92 (step S4). In more detail, it is determined whether the output of the AE sensor 92 exceeds a threshold value, thereby determining whether the blade 26 is in contact with the processing table 22.

When contact of the blade 26 is detected, the reference position is set (step S5). That is, information on the position of the Z-axis table 48 at the time point when the contact of the blade 26 is detected is acquired, and the acquired position is set as the reference position of the blade 26. Information of the set reference position is stored in the storage unit 102.

When contact of the blade 26 is detected, the blade 26 returns to the origin position, and rotation of the blade 26 is stopped (step S6).

Through the above series of steps, the process of setting the tool is completed. Thereafter, the cutting feed of the blade 26 is controlled with the set reference position as a reference. In addition, the wear amount of the blade 26 is measured based on the information of the set reference position.

Since the cutting device 10 of the present embodiment is provided with two processing units 50, a tool setting is performed for each processing unit 50.

As described above, according to the cutting device 10 of the present embodiment, the contact of the blade 26 is detected based on the output of the AE sensor 92, and therefore, the height relationship between the blade 26 and the processing table 22 can be managed with high accuracy regardless of the type of the blade 26. Therefore, for example, a blade having no conductivity can be used.

In addition, according to the cutting device 10 of the present embodiment, since the AE sensor 92 is attached to the blade attachment portion 60, it is possible to detect the elastic wave generated from the blade 26 (the elastic wave generated by the blade) with high accuracy. That is, since the AE sensor 92 is attached to a member that directly holds the blade 26, the elastic wave generated from the blade 26 can be detected with little attenuation. In addition, even when a plurality of processing units 50 are provided, the elastic wave generated from the blade 26 of each processing unit 50 can be detected with high accuracy. Further, by providing a dedicated mounting portion on the rear flange 70 and mounting the AE sensor 92 and the transmission-side coil 94, the AE sensor 92 and the transmission-side coil 94 can be firmly fixed to the rear flange 70 as a rotating body. This enables safe use even when the spindle 24 is rotated at a high speed.

In the above embodiment, the blade 26 is in direct contact with the processing table 22, but a configuration may be adopted in which a member for setting a tool (a member whose positional relationship with the processing table 22 is known) is attached to the processing table 22, and the blade 26 is brought into contact with the member to set the tool. This case is also included in the structure in which the blade 26 is brought into contact with the processing table 22.

(modification)

In the above embodiment, the AE sensor 92 is mounted to the blade mounting portion 60 and detects the elastic wave generated from the blade 26, but the portion where the AE sensor 92 is mounted is not limited thereto. Hereinafter, another example of the attachment site of the AE sensor 92 will be described.

[ example of mounting to Main shaft ]

The blade 26 is integrated with the spindle 24 via the blade fitting portion 60. Accordingly, the elastic wave generated from the blade 26 also propagates toward the spindle 24. Therefore, even when the AE sensor 92 is attached to the spindle 24, the elastic wave generated from the blade 26 can be detected.

As shown in the figure, in this example, the AE sensor 92 is incorporated in the front end (end on the blade mounting portion 60 side) of the spindle 24.

The spindle 24 is provided with a hole 24D extending along the shaft from the base end portion to the tip end portion. The hole 24D is arranged coaxially with the rotation axis of the spindle 24. The AE sensor 92 is accommodated in a hole 24D provided in the spindle 24, and is fixed to and attached to a tip end portion of the hole 24D.

A transmission-side bobbin 94A including a transmission-side coil 94 is attached to the base end portion of the spindle 24. The transmitting-side coil 94 is disposed so as to be wound around the rotation axis of the main shaft 24 as a rotating body. The AE sensor 92 is electrically connected to the transmission-side coil 94 via a wire 93 disposed in the hole 24D.

An end cap 84 is attached to the base end portion of the housing 52A of the spindle drive section 52 as a fixing section. A receiving-side bobbin 96A having a receiving-side coil 96 on an inner surface thereof is attached to the end cover 84. The receiving-side coil 96 is disposed so as to be wound around the rotation axis of the spindle 24, and is disposed so as to face the transmitting-side coil 94 with a predetermined gap therebetween. Thereby, the transmitting side coil 94 and the receiving side coil 96 are magnetically coupled in a noncontact state.

With the above configuration, the AE sensor 92 is mounted to the spindle 24. The signal output from the AE sensor 92 is transmitted to the receiving-side coil 96 by mutual induction of the transmitting-side coil 94 and the receiving-side coil 96.

As described above, since the blade 26 is integrated with the spindle 24 via the blade attachment portion 60, even when the AE sensor 92 is attached to the spindle 24, it is possible to detect the elastic wave generated from the blade 26. In particular, in the present example, since the AE sensor 92 is mounted on the tip end side (blade mounting portion side) of the spindle 24, the elastic wave generated from the blade 26 can be detected with little attenuation. In this example, the AE sensor 92 and the transmission-side coil 94 are mounted on the same axis of the spindle 24, so that the spindle 24 can be rotated stably. Since the AE sensor 92 is built in the spindle 24, it can be firmly fixed.

[ example of mounting on a processing Table ]

As described above, in the tool setting, the AE sensor 92 detects the elastic wave of the specific pattern generated when the blade 26 is in contact with the processing table 22, and detects the contact between the blade 26 and the processing table 22. The elastic wave of the specific pattern also propagates toward the processing table 22. Therefore, even when the AE sensor 92 is mounted on the processing table 22, the contact of the blade 26 can be detected from the output of the AE sensor 92.

As shown in the figure, an AE sensor 92 and a transmitting-side coil 94 are mounted on the machining table 22 as a rotating body, and a receiving-side coil 96 is mounted on the table driving unit 42 as a fixed body. The AE sensor 92 and the transmitting-side coil 94 are mounted on the processing table 22 via the sensor mount 86. The receiving-side coil 96 is attached to the table driving unit 42 via the coil base 88.

Fig. 11 is a bottom view of the sensor base.

As shown in fig. 11, the sensor base 86 has an annular shape. An AE sensor mounting portion 86A, a balance weight mounting portion 86B, and a transmission-side coil mounting portion 86C are provided on the lower surface portion of the sensor base 86.

The AE sensor mounting portion 86A and the counterweight mounting portion 86B are formed of concave portions of the same shape, and are symmetrically arranged with respect to the axis (=the rotation axis of the processing table 22) of the sensor base 86. The AE sensor 92 is accommodated in the AE sensor mounting portion 86A, and is mounted on the sensor base 86.

A balance weight 98 is attached to the balance weight attachment portion 86B. The balance weight 98 is a weight that balances the rotation of the sensor base 86.

The transmitting-side coil mounting portion 86C is formed of an annular recess, and is disposed coaxially with the axis of the sensor base 86. The transmission-side coil 94 is accommodated in the transmission-side coil mounting portion 86C, and is mounted on the sensor base 86. Thus, the transmitting-side coil 94 is disposed so as to be wound around the axis of the sensor base 86.

As shown in fig. 10, the sensor base 86 of the above structure is mounted coaxially on the lower surface of the processing table 22, and is integrated with the processing table 22. Since the sensor base 86 is attached to the processing table 22, the transmitting-side coil 94 is disposed coaxially with the rotation axis of the processing table 22 and is wound around the same.

Fig. 12 is a top view of the coil base.

As shown in fig. 12, the coil base 88 has an annular shape. A receiving-side coil mounting portion 88A is provided on an upper surface portion of the coil base 88. The receiving-side coil mounting portion 88A is formed of an annular recess, and is disposed coaxially with the coil base 88. The receiving-side coil 96 is accommodated in the receiving-side coil mounting portion 88A, and is mounted on the coil base 88. Thereby, the receiving-side coil 96 is disposed so as to be wound around the axis of the coil base 88.

As shown in fig. 10, the coil base 88 having the above-described structure is attached to the upper end portion of the housing 42A of the table driving unit 42, and is disposed coaxially with the rotation axis of the processing table 22. Thus, the receiving coil 96 is disposed coaxially with the rotation axis of the processing table 22 and is wound around the same. The receiving-side coil 96 and the transmitting-side coil 94 are disposed on the same circumference.

When the blade 26 is in contact with the processing table 22, an elastic wave generated at the time of the contact is detected by the AE sensor 92. This enables detection of contact of the blade 26.

(second embodiment)

As described above, since the elastic wave detection unit 90 is provided in the cutting device 10, the contact between the blade 26 and the processing table 22 can be detected. Thus, the contact type tool setting can be performed regardless of the type of the blade 26.

In the cutting apparatus 10 including the elastic wave detection unit 90, the state of the workpiece W and the blade 26 can be estimated by monitoring the elastic wave generated from the blade 26 during processing. The estimation of the states of the workpiece W and the insert 26 using the elastic wave will be described below.

[ estimation of the State of the workpiece ]

Fig. 13 is a schematic view of a cutting line in a plan view.

Typically, the workpiece W is cut at the center of the streets St (streets center). Fig. 13 shows an example of a case where the center (notch center) KC of the notch (Kerf; kerf) K is cut so as to be offset from the center StC of the street. When the spacer center StC is offset from the kerf center KC, a center offset occurs. The offset of the spacer center StC from the kerf center KC is the center offset epsilon.

Fig. 14 is a schematic diagram of occurrence of breakage. Fig. 14 shows a state when a wafer (workpiece W) adhered to the dicing tape DT is diced. Reference FB in fig. 14 is a foreign matter. Collapse C occurs at the edge of the cut (boundary with the spacer). The chipping refers to unexpected cracking or chipping occurring at the corners or edges of the notch line of the work. Breakage occurs due to various factors such as clogging of the insert, fluctuation of the amount of the cutting fluid, deterioration of the condition of the workpiece material, and setting errors by the operator.

When the chipping occurs, there is a case where the chipping is deformed or broken differently from the usual cutting, and therefore, an elastic wave different from that in the stabilizing is generated. Therefore, by monitoring the elastic wave generated from the blade, the occurrence of the breakage (breakage exceeding the allowable value) can be detected.

Fig. 15 is a graph showing an example of the output of the AE sensor during processing. Fig. 15 (a) shows an example of the output of the AE sensor at the time of stable cutting. Fig. 15 (B) shows an example of the output of the AE sensor when a burst loss occurs. Fig. 15 (B) shows an example of the case where a breakdown occurs at time T2 and time T3.

As shown in fig. 15 (a), when machining (cutting) is stable, the output of the AE sensor 92 shifts within a substantially constant range. That is, the output is substantially uniform.

On the other hand, as shown in fig. 15 (B), when sudden collapse occurs, the output of the AE sensor 92 greatly fluctuates from the stability tendency.

Fig. 16 is a graph showing an example of the output of the AE sensor during processing. The figure shows an example of the output of the AE sensor in the case where the collapse continues to occur.

A breakage exceeding an allowable value may continue to occur due to a difference in the amount of the cutting fluid, a setting error of an operator, or the like. In this case, the output of the AE sensor 92 continues to take a value different from that at the time of stabilization. Therefore, by comparing the output with the output at the time of stabilization (see fig. 15 a), an abnormality can be detected.

[ estimation of blade State ]

Fig. 17 is a schematic view of an in-process blade.

The insert 26 achieves optimal machining (cutting) by balancing the abrasive grains (cutting particles) AC, the binder (binder) BO that binds the abrasive grains AC, and the concentration (chip pocket) CP that separates them by how much space to bind.

The machining of the workpiece W is performed by applying the cutting fluid CL to the insert 26. When the workpiece W is cut, so-called cutting powder (cutting powder) SW is generated. In addition, the abrasive grains AC are also slightly detached from the blade 26. When the cutting powder SW and the detached abrasive grains are properly detached from the insert 26 together with the cutting fluid CL, good cutting is achieved. On the other hand, if the balance is broken, foreign matter is blocked in the chip pocket of the insert 26.

This phenomenon is referred to as "clogging". When clogging occurs in the blade 26, the output of the AE sensor 92 fluctuates.

Fig. 18 is a graph showing an example of the output of the AE sensor during processing. In fig. 18, a graph G1 shown by a thick line is a graph showing an example of the output of the AE sensor 92 when the blade is clogged. On the other hand, a graph G2 shown by a thin line is a graph showing an example of the output of the AE sensor 92 at the time of stabilization without clogging.

As shown in fig. 18, when clogging of the blade 26 occurs, the output of the AE sensor 92 changes in a stepwise manner as compared with that in the steady state. Therefore, by comparing the output of the AE sensor 92 at the time of stabilization, the occurrence state of clogging can be estimated.

[ device Structure ]

The cutting device 10 of the present embodiment has a function of estimating the state of the workpiece W based on the elastic wave generated from the blade 26 and a function of estimating the state of the blade 26. This function is implemented by the system controller 100.

The device configuration is substantially the same as that of the cutting device 10 of the first embodiment. Therefore, only the above-described functions of the system controller 100 will be described here.

As shown in fig. 19, the system controller 100 includes a workpiece state estimating unit 120 that estimates the state of the workpiece W and a blade state estimating unit 122 that estimates the state of the blade 26, in regard to the estimated process. Each unit is realized by a processor by executing a predetermined program by the processor. The program is stored in the memory or storage unit 102.

The work state estimating unit 120 obtains a signal (output signal of the AE sensor 92) output from the elastic wave detecting unit 90, and estimates the state of the work W, in particular, whether or not chipping occurs. In the present embodiment, the state of the workpiece W is estimated by comparison with a signal obtained at the time of stable cutting.

As described above, when a breakdown exceeding the allowable value occurs suddenly, the output of the AE sensor 92 greatly fluctuates from the stability tendency (see fig. 15 (B)). When the collapse exceeding the allowable value continues to occur, the output of the AE sensor 92 continues to take a value different from that at the time of stabilization (see fig. 16).

Therefore, the work state estimating unit 120 compares the output signal of the AE sensor 92 obtained during machining with the output signal obtained from the AE sensor 92 during stable cutting, and detects (estimates) the occurrence of chipping. For example, a signal exceeding a threshold value is detected based on a threshold value set on an output signal obtained at the time of stable cutting, and burst breakage is detected (estimated). For example, when the threshold is set based on the output signal obtained at the time of stable cutting and the number of times the signal exceeding the threshold is detected within a predetermined time is equal to or more than a predetermined number of times, the continuous chipping is detected (estimated).

The blade state estimating unit 122 obtains the signal output from the elastic wave detecting unit 90, and estimates the state of the blade 26, in particular, the occurrence state of clogging. In the present embodiment, the occurrence state of clogging is estimated by comparison with a signal obtained at the time of stable cutting.

As described above, when clogging of the blade 26 occurs, the output of the AE sensor 92 fluctuates stepwise as compared with when it is stable. Therefore, by comparing the output signal of the AE sensor 92 at the time of stabilization, the occurrence state of clogging can be estimated.

The blade state estimating unit 122 calculates the tendency of fluctuation of the output signal of the AE sensor 92 by a statistical method, for example, and estimates occurrence of clogging by comparing the tendency of fluctuation of the output signal obtained at the time of stabilization. That is, if the calculated tendency to change is different from the tendency to change at the time of stabilization (particularly, if the output signal deviates from the output signal at the time of stabilization with the lapse of time), it is estimated that clogging exceeding the allowable amount has occurred.

Information of the output signal of the AE sensor 92 obtained at the time of stable cutting is acquired in advance and stored in the storage unit 102. The output signal of the AE sensor 92 obtained at the time of stable cutting is different depending on the machining conditions (such as the type of the insert used), and is thus prepared according to the machining conditions.

As described above, according to the cutting device 10 of the present embodiment, the state of the workpiece W and the blade 26 can be estimated by the elastic wave detection unit 90.

The estimation result is displayed on a display unit (not shown). When the breakage and the jam exceeding the allowable values are detected (estimated), a warning is issued.

In the present embodiment, the state of both the workpiece W and the insert 26 is estimated, but only one of them may be estimated.

In the above embodiment, the configuration is adopted in which the machining unit 50 side is moved relative to the machining table 22 when the blade 26 is cut and fed, but the configuration may be adopted in which the machining table 22 side is moved. Alternatively, a configuration may be adopted in which both sides are moved. That is, the spindle 24 and the processing table 22 may be moved relatively.

Claims

1. A cutting device, wherein,

the cutting device is provided with:

a table that holds a workpiece;

a spindle that moves relatively with respect to the table;

a blade mounting portion integrally mounted to the spindle;

a blade mounted to the blade mounting portion; and

an elastic wave detection unit for detecting an elastic wave,

the elastic wave detection unit is provided with:

an AE sensor attached to at least one of the spindle, the blade attachment portion, and the table;

A transmitting-side coil which is attached to at least one of the spindle, the blade mounting section, and the table, and which is connected to the AE sensor; and

a receiving-side coil disposed opposite to the transmitting-side coil and magnetically coupled to the transmitting-side coil,

the signal output from the AE sensor is transmitted to the receiving side coil through the transmitting side coil by mutual induction of the transmitting side coil and the receiving side coil.

2. The cutting device of claim 1, wherein,

the table, the spindle, and the blade mounting portion are rotating bodies.

3. The cutting device according to claim 1 or 2, wherein,

the cutting device is provided with:

a contact detection unit that detects contact between the blade and the table based on a signal output from the elastic wave detection unit; and

a reference position setting unit that sets a reference position of the blade,

the reference position setting unit sets a position at which the spindle is moved from a position at which the blade is separated from the table toward the table and contact is detected by the contact detecting unit as the reference position of the blade.

4. A cutting device according to any one of claims 1 to 3, wherein,

the cutting device further includes an estimating unit that estimates a state of the blade and/or the workpiece based on a signal output from the elastic wave detecting unit during processing of the workpiece.

5. The cutting device of claim 4, wherein,

the estimating unit estimates occurrence of collapse based on the signal output from the elastic wave detecting unit.

6. The cutting device of claim 4, wherein,

the estimating unit estimates a state of clogging of the blade based on a signal output from the elastic wave detecting unit.

7. The cutting device according to any one of claims 4 to 6, wherein,

the estimating unit estimates the state of the insert and/or the workpiece by comparing the state with a signal output from the elastic wave detecting unit during stable cutting.

8. The cutting device according to any one of claims 1 to 7, wherein,

the AE sensor and the transmitting-side coil are attached to the blade attachment portion.

9. The cutting device according to any one of claims 1 to 7, wherein,

the AE sensor and the transmitting-side coil are mounted on the spindle.

10. The cutting device of claim 9, wherein,

the blade assembly part is arranged at the front end part of the main shaft,

the AE sensor is built in the front end of the spindle,

the transmission-side coil is attached to a base end portion of the spindle.

11. The cutting device according to any one of claims 1 to 7, wherein,

the AE sensor and the transmitting-side coil are mounted on the table.

12. The cutting device according to any one of claims 1 to 11, wherein,

the receiving-side coil and the transmitting-side coil are disposed so as to be wound around a rotation shaft of at least one of the spindle, the blade attachment portion, and the table.

13. The cutting device according to any one of claims 1 to 12, wherein,

at least one of the spindle, the blade mounting portion, and the table is provided with a balance weight.