JP7297385B2 - Cutting device and cutting blade management method - Google Patents

Description

The present invention relates to a cutting apparatus for cutting workpieces such as semiconductor wafers, package substrates, ceramic substrates, and glass substrates with a cutting blade, and a cutting blade management method for managing the cutting blades attached to the cutting apparatus.

A device chip on which a semiconductor device is mounted is formed from a semiconductor wafer, a package substrate, a ceramic substrate, a glass substrate, or the like. The surface of a semiconductor wafer or the like is partitioned by a plurality of intersecting dividing lines called streets, semiconductor devices are formed in each of the partitioned regions, and then the semiconductor wafer or the like is divided along the dividing lines to form individual devices. Chips can be formed.

A cutting device having a cutting unit equipped with an annular cutting blade, for example, is used to divide a semiconductor wafer or the like. The cutting blade has, on the outer peripheral side, a cutting edge that includes a binder made of resin, metal, or the like, and a plurality of abrasive grains fixed to the binder. Some of the abrasive grains are exposed from the bonding material forming the cutting edge. When cutting a workpiece with a cutting device, the cutting blade is rotated in a plane perpendicular to the surface of the workpiece such as a semiconductor wafer, and the abrasive grains are brought into contact with the workpiece to rotate the cutting blade. Cut into the workpiece.

The abrasive grains of the cutting blade are worn out when the cutting equipment is repeatedly used for cutting. Maintained above standard. This action is called self-sharpening. As cutting is repeatedly performed, the diameter of the cutting blade becomes smaller and the height of the lower end of the cutting edge of the cutting blade gradually deviates from the predetermined height position. Therefore, the height of the lower end of the tip of the cutting blade is periodically measured and the height of the cutting unit is adjusted so that the depth of cut does not change significantly.

For example, a detection mechanism capable of measuring the height of the lower end of the cutting edge of a cutting blade is known (see, for example, Patent Document 1). The detection mechanism includes a light emitting portion and a light receiving portion facing each other. When using the detection mechanism, the cutting blade is moved in the cutting feed direction (height direction) so that the cutting edge of the cutting blade enters between the light emitting part and the light receiving part, and the light emitted by the light emitting part is received. detected in the part. At this time, since the cutting blade gradually blocks the light, the amount of received light detected by the light receiving unit gradually decreases according to the height position of the cutting blade.

Therefore, the detection mechanism detects the height of the cutting unit when the amount of received light becomes a reference value and the lower end of the cutting edge reaches a height suitable for cutting. By using the detection mechanism, the height of the cutting unit can be adjusted so that the lower end of the cutting edge of the cutting blade is at a predetermined height even if the cutting blade is worn and the diameter is reduced. Furthermore, there is known a cutting blade monitoring device that includes a light emitting portion and a light receiving portion and is capable of monitoring wear and chipping of the cutting blade (see, for example, Patent Document 2).

Japanese Patent Application Laid-Open No. 2001-298001 Japanese Patent Application Laid-Open No. 2002-370140

The monitoring device for the cutting blade detects the occurrence of chipping at an early stage when chipping occurs on the cutting edge of the cutting blade, and notifies the manager or user of the cutting device of the chipping and recommends replacement of the cutting blade. prompt. However, the cutting device must be stopped while the cutting blade is being replaced, and there is time during which the workpiece cannot be cut. Therefore, if the cutting blades are frequently replaced, the efficiency of machining the workpiece is reduced.

In addition, depending on the degree of chipping occurring in the cutting blade, a member called a dressing board used for promoting the self-sharpening of the cutting blade is cut by the cutting blade, so that the cutting blade is appropriately worn out. In some cases, chipping can be removed in the field. In spite of this, all of the cutting blades for which chipping was detected were removed from the cutting device, which unnecessarily increased the consumption of the cutting blades and increased the cost of the cutting blades. That is, the machining efficiency of the workpiece was further reduced.

The present invention has been made in view of such problems, and its object is to provide a cutting apparatus and a cutting blade that can evaluate the depth of chipping occurring in a cutting blade and prevent unnecessary replacement of the cutting blade. It is to provide management methods.

According to one aspect of the present invention, a chuck table that holds a workpiece and a spindle to which a cutting blade is attached are provided, and the workpiece held on the chuck table is cut by the cutting blade attached to the spindle. and a management unit for managing the cutting blade mounted on the spindle, wherein the management unit includes a light emitting section that emits light, and the light emitted from the light emitting section that faces the light emitting section. a light-receiving portion that receives light; and the cutting edge of the cutting blade from the amount of light received by the light-receiving portion emitted from the light-emitting portion while the cutting blade is positioned between the light-emitting portion and the light-receiving portion. a chipping measuring unit that measures the depth of the chipping that occurs in the chipping measurement unit; The determination unit measures the depth of the chipping based on the height of the peak appearing in the waveform of the time change of the amount of light received by the light receiving unit when the cutting blade rotates once, and is a threshold value registration unit in which a first threshold value set for the depth of the chipping of the cutting blade and a second threshold value larger than the first threshold value are registered; a comparison unit that compares the measurement result of the chipping depth with the first threshold value and the second threshold value registered in the threshold value registration unit, and the result of the comparison performed by the comparison unit determining that the workpiece can be cut by the cutting blade when the depth of the chipping of the cutting blade measured by the chipping measuring unit is less than the first threshold; As a result of the comparison performed by the comparison unit, if the depth of the chipping of the cutting blade measured by the chipping measuring unit is greater than or equal to the first threshold value and is less than the second threshold value, the cutting When it is determined that the blade is in a state requiring dressing, and as a result of the comparison performed by the comparison unit, the depth of the chipping of the cutting blade measured by the chipping measurement unit is greater than or equal to the second threshold and determining that the cutting blade is in a state in which further cutting of the workpiece should not be performed.

Preferably, the apparatus further includes a sub-chuck table holding a dressing board for dressing the cutting blade mounted on the spindle, and when the determination unit determines that the cutting blade requires dressing, the The dressing board held on the sub-chuck table is cut by the cutting blade.

Preferably, the apparatus further includes a notification section connected to the determination section, the notification section being capable of reporting the result of the determination performed by the determination section. More preferably, the first threshold and the second threshold derived by the management unit are registered in the threshold registration unit.

According to another aspect of the present invention, a cutting unit having a chuck table for holding a workpiece and a cutting blade for cutting the workpiece held by the chuck table with the cutting blade; A cutting blade management method for managing the cutting blade in a cutting apparatus comprising: a light receiving part facing the light emitting part; and a management unit for managing the cutting blade, the cutting blade managing method comprising: a threshold value registration step of setting a first threshold value and a second threshold value larger than the first threshold value with respect to the depth of chipping and registering them in the management unit; Before, during, or after cutting a workpiece, the cutting blade is positioned between a light-emitting portion and a light-receiving portion, the light-emitting portion emits light, the light-receiving portion receives the light, and the light-receiving portion receives the light. a chipping measurement step of measuring the depth of the chipping formed on the cutting edge of the cutting blade based on the amount of light received by the chipping measuring step; a management step of comparing the determined first threshold value and the second threshold value to determine the state of the cutting blade, and managing the cutting blade based on the determined state of the cutting blade; In the chipping measurement step, the depth of the chipping is measured based on the height of the peak appearing in the waveform of the time change of the amount of light received by the light receiving unit when the cutting blade rotates once. and in the managing step, if the chipping depth of the cutting blade measured in the chipping measuring step is less than the first threshold value, cutting of the workpiece with the cutting blade is possible and the depth of the chipping of the cutting blade measured in the chipping measurement step is equal to or greater than the first threshold value and less than the second threshold value, the cutting blade is not dressed It is determined that it is in a necessary state, the cutting blade is dressed until the amount of wear of the cutting blade reaches the depth of the chipping or more, and the depth of the chipping of the cutting blade measured in the chipping measurement step is If it is equal to or greater than the second threshold, it is determined that the cutting blade is in a state in which further cutting of the workpiece should not be performed, and the cutting blade is replaced. is provided.

Preferably, prior to the chipping measurement step, a water drainer removes from the cutting blade cutting water that is supplied to the cutting blade and rotates together with the cutting blade when cutting the workpiece held on the chuck table. Have a step. More preferably, in the threshold registration step, the management unit derives the first threshold and the second threshold.

When the cutting blade is arranged between the light emitting part and the light receiving part, part of the light emitted from the light emitting part is blocked by the cutting blade. At this time, the light reaching the light receiving portion changes depending on the shape of the cutting blade. For example, if the cutting edge of the cutting blade is chipped, light is transmitted through the chipped chip, so the amount of light received by the light-receiving unit increases accordingly. By using the light-emitting portion and the light-receiving portion, the depth of the chip formed on the cutting blade can be measured.

If the depth of chipping can be measured, is the cutting blade able to cut the work piece? Is dressing necessary? , the state of the cutting blade can be determined. By dressing the cutting blade in a state in which the performance of the cutting blade can be recovered by dressing, it is possible to restart the machining of the workpiece without replacing the cutting blade.

Therefore, according to the cutting device and the cutting blade management method according to an aspect of the present invention, the number of times the cutting blade is replaced can be reduced, and the time during which the cutting device is stopped can be shortened. Moreover, the number of cutting blades consumed can be reduced. That is, it becomes possible to efficiently cut the workpiece.

Therefore, according to one aspect of the present invention, there is provided a cutting apparatus and a cutting blade management method capable of evaluating the depth of a chip formed in a cutting blade and preventing unnecessary replacement of the cutting blade.

It is a perspective view which shows a cutting device typically. FIG. 4 is a perspective view schematically showing a cutting unit; FIG. 3(A) is a front view schematically showing a cutting blade, FIG. 3(B) is a front view schematically showing an enlarged cutting edge of the cutting blade, and FIG. It is a front view schematically showing an enlarged cutting edge of a cutting blade with a chipped outer periphery, and FIG. 3 (D) schematically shows an enlarged cutting edge of a cutting blade with a relatively large chipped outer periphery It is a front view showing. FIG. 2 is a side view schematically showing a cutting unit and a block diagram schematically showing the configuration of a management unit; FIG. FIG. 5A is a graph schematically showing the temporal change in the amount of received light, and FIG. 5B is a graph schematically showing the relationship between the depth of chipping and the threshold. FIG. 6A is a side view schematically showing the cutting edge detection unit and a block diagram schematically showing the configuration of the management unit, and FIG. is a graph shown in FIG. 4 is a flow chart showing the flow of each step of the cutting blade management method.

An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. First, a cutting apparatus according to this embodiment will be described with reference to FIG. FIG. 1 shows a cutting device 2 for cutting a workpiece 1. As shown in FIG. The workpiece 1 is, for example, a substantially disk-shaped substrate made of materials such as silicon, SiC (silicon carbide), or other semiconductors, or materials such as sapphire, glass, or quartz.

A plurality of division lines that intersect each other are set on the surface of the workpiece 1, and a device such as an IC (Integrated Circuit) is formed in each region partitioned by the division lines. Finally, individual device chips are formed by cutting and dividing the workpiece 1 along the dividing lines.

For example, when a region extending from the front surface to the back surface of the workpiece 1 is cut along the dividing line, a dividing groove extending from the front surface to the back surface is formed to divide the workpiece 1 . However, when cutting the workpiece 1, it is not necessary to form a dividing groove extending from the front surface to the back surface of the workpiece 1, and a groove not extending to the back surface may be formed by cutting. When a groove that does not reach the back surface is formed by cutting, a dividing groove or the like extending from the bottom of the groove to the back surface of the workpiece 1 is further formed by cutting or a method other than cutting to divide the workpiece 1. .

For example, the workpiece 1 is integrated with the adhesive tape 3 stretched on the annular frame 5 to form the frame unit 7 . The workpiece 1 is conveyed and cut in the state of the frame unit 7 .

As shown in FIG. 1, the cutting device 2 includes a base 4 that supports each component. An X-axis moving table 6, an X-axis moving mechanism for moving the X-axis moving table 6 in the X-axis direction (processing feed direction), and a drainage channel covering the X-axis moving mechanism are provided at the upper center of the base 4. 20 and are provided. The X-axis movement mechanism has a pair of X-axis guide rails 12 parallel to the X-axis direction, and an X-axis movement table 6 is slidably attached to the X-axis guide rails 12 .

A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 6, and an X-axis ball screw 14 parallel to the X-axis guide rail 12 is screwed into this nut portion. An X-axis pulse motor 16 is connected to one end of the X-axis ball screw 14 . When the X-axis ball screw 14 is rotated by the X-axis pulse motor 16, the X-axis moving table 6 moves along the X-axis guide rail 12 in the X-axis direction.

A chuck table 8 for sucking and holding the workpiece 1 is provided on the X-axis moving table 6 . The chuck table 8 is connected to a rotation drive source (not shown) such as a motor, and is rotatable around a rotation axis perpendicular to the upper surface of the chuck table 8 . Also, the chuck table 8 is fed in the X-axis direction by the above-described X-axis direction moving mechanism.

The surface (upper surface) of the chuck table 8 serves as a holding surface 8a for sucking and holding the workpiece 1 . The holding surface 8 a is connected to a suction source (not shown) through a suction path (not shown) formed inside the chuck table 8 . A clamp 10 for fixing an annular frame 5 holding the workpiece 1 via a tape is arranged around the holding surface 8a.

A support structure 22 that supports two cutting units 18 that cut the workpiece 1 is arranged on the upper surface of the base 4 so as to straddle the X-axis movement mechanism. A cutting unit moving mechanism for moving the two cutting units 18 in the Y-axis direction (index feed direction) and the Z-axis direction is provided on the upper front surface of the support structure 22 .

The cutting unit moving mechanism includes a pair of Y-axis guide rails 24 arranged in front of the support structure 22 and parallel to the Y-axis direction. Two Y-axis movement plates 26 corresponding to the cutting units 18 are slidably attached to the Y-axis guide rail 24 . A nut portion (not shown) is provided on the back side of each Y-axis moving plate 26, and a Y-axis ball screw 28 parallel to the Y-axis guide rail 24 is screwed into this nut portion. .

One end of the Y-axis ball screw 28 is connected to a Y-axis pulse motor 28a. When the Y-ball screw 28 is rotated by the Y-axis pulse motor 28a, the corresponding Y-axis moving plate 26 moves along the Y-axis guide rail 24 in the Y-axis direction. A pair of Z-axis guide rails 30 parallel to the Z-axis direction are provided on the surface (front surface) of the Y-axis moving plate 26 . A Z-axis movement plate 32 is slidably attached to each Z-axis guide rail 30 .

A nut portion (not shown) is provided on the back side (rear side) of the Z-axis moving plate 32, and a Z-axis ball screw 34 parallel to the Z-axis guide rail 30 is screwed into this nut portion. ing. A Z-axis pulse motor 36 is connected to one end of the Z-axis ball screw 34 . When the Z-axis ball screw 34 is rotated by the Z-axis pulse motor 36, the Z-axis moving plate 32 moves along the Z-axis guide rail 30 in the Z-axis direction (infeed direction).

A cutting unit 18 for processing the workpiece 1 and an imaging unit (camera) 38 capable of imaging the workpiece 1 held on the chuck table 8 are fixed below each of the two Z-axis moving plates 32 . It is When the Y-axis moving plate 26 is moved in the Y-axis direction, the cutting unit 18 and the imaging unit 38 are moved in the Y-axis direction (index feed direction), and when the Z-axis moving plate 32 is moved in the Z-axis direction, The cutting unit 18 and imaging unit 38 move in the Z-axis direction (infeed direction).

The cutting unit 18 will be described with reference to FIG. The cutting unit 18 includes a spindle 54 forming a rotating shaft parallel to the Y-axis direction. A blade mount 56 is attached to the tip of the spindle 54 , and an annular cutting blade 58 is attached to the tip of the spindle 54 by the blade mount 56 .

A rotary drive source (not shown) such as a motor housed in a spindle housing 54a (see FIG. 4, etc.) is connected to the other end of the spindle 54 . When the spindle 54 is rotated using the rotary drive source, a cutting blade 58 mounted on the spindle 54 can be rotated.

FIG. 3 is a front view schematically showing the cutting blade 58. FIG. The cutting blade 58 has, for example, a disk-shaped base 58b and an annular cutting edge 58a fixed to the outer peripheral portion of the base 58b. A substantially circular mounting hole is provided in the center of the base 58b to pass through the base 58b. When mounting the cutting blade 58 to the cutting unit 18, the spindle 54 is mounted in the mounting hole. The boss portion of the blade mount 56 is penetrated.

The cutting edge 58a constituting the outer circumference 66 of the cutting blade 58 includes a binder made of metal, resin, or the like, and a plurality of abrasive grains made of diamond or the like fixed to the binder. Called. Abrasive grains are exposed from the bonding material, and when the cutting blade 58 is rotated to cut into the workpiece 1, the exposed abrasive grains come into contact with the workpiece 1 and the workpiece 1 is cut. be done.

When cutting the workpiece 1 by cutting, the height of the cutting unit 18 is adjusted so that the lower end of the cutting edge 58 a of the cutting blade 58 reaches below the lower surface of the workpiece 1 . When forming a groove that does not reach the lower surface of the workpiece 1, the height of the cutting unit 18 is adjusted so that the lower end of the cutting edge 58a is positioned between the upper and lower surfaces of the workpiece 1. be.

When the workpiece 1 is cut with the cutting blade 58, the abrasive grains are chipped or dropped. However, since the binding material is gradually consumed and new abrasive grains are exposed one after another, the cutting ability of the cutting blade 58 is maintained. At this time, the diameter of the cutting blade 58 gradually decreases. Therefore, the height of the lower end of the cutting edge 58a of the cutting blade 58 changes.

Therefore, in the cutting device 2, the position of the lower end of the cutting edge 58a of the cutting blade 58 is detected, and the Z-axis direction moving mechanism is arranged so that the lower end of the cutting edge 58a of the cutting blade 58 reaches below the lower surface of the workpiece 1. is performed at a predetermined timing. Below the cutting unit 18, as shown in FIG. 1, a cutting edge detection unit 40 used in the setup process is provided. The cutting edge detection unit 40 will be detailed later.

As shown in FIG. 2, the cutting unit 18 includes a blade cover 50 that encloses a cutting blade 58. As shown in FIG. The blade cover 50 is slidable, and when the cutting blade 58 is replaced, it slides and retreats so as not to interfere with the replacement work. The blade cover 50 incorporates a cutting water supply mechanism that supplies cutting water to the workpiece 1 and the cutting blade 58 during cutting of the workpiece 1 .

When the workpiece 1 is cut by the cutting blade 58 , heat is generated due to friction between the workpiece 1 and the cutting blade 58 . Moreover, the workpiece 1 that has been cut produces chips. Therefore, cutting water is supplied to the workpiece 1 and the cutting blade 58 while cutting is performed in order to remove the heat and processing debris generated by cutting. The cutting water is pure water, for example.

Cutting water is supplied at high pressure from a cutting water supply source (not shown) outside the cutting unit 18 through a cutting water supply channel (not shown). The blade cover 50 is provided with a connecting portion 52d to which one end of the cutting water supply path is connected. The cutting unit 18 includes a pair of cutting water supply nozzles 52a each extending along either side of the cutting blade 58 such that the cutting blade 58 is disposed therebetween. The pair of cutting water supply nozzles 52a are formed with a plurality of ejection ports (not shown) facing the cutting blade 58. As shown in FIG.

The cutting unit 18 also includes a cutting water supply nozzle 52c that jets cutting water toward the workpiece 1 on the front side of the cutting blade 58 in the feed direction. Further, the cutting unit 18 includes a cutting water supply nozzle 52b that jets cutting water toward the cutting blade 58 from the front. The cutting water supply nozzle 52b has a spout (not shown) facing the cutting blade 58. As shown in FIG. When the workpiece 1 is cut by the cutting blade 58, cutting water is supplied to the workpiece 1 and the cutting blade 58 from the cutting water supply nozzles 52a, 52b, and 52c.

When cutting the workpiece 1 held on the chuck table 8, the cutting device 2 lowers the cutting unit 18 along the Z-axis direction to position the cutting unit 18 at a predetermined height position. Then, the cutting blade 58 is rotated and the X-axis direction moving mechanism is operated to move the chuck table 8 in the processing feed direction, and the cutting blade 58 is cut into the workpiece 1 to cut the workpiece 1. .

Before cutting the workpiece 1, a setup process using the cutting edge detection unit 40 shown in FIG. 1 is performed so that the lower end of the cutting edge 58a of the cutting blade 58 is positioned at a predetermined height. be. The cutting edge detection unit 40 is provided below the cutting unit 18, for example. FIG. 6A shows a side view of the cutting unit 18, a side view of the cutting edge detection unit 40, and a block diagram schematically showing an example of the configuration of the setup unit 104. FIG.

The main body 40a of the cutting edge detection unit 40 is provided with a groove-shaped cutting blade entry portion 40b that opens upward. The cutting blade 58 is advanced to 40b.

A window-shaped light-emitting portion 76b is provided on one side wall of the main body 40a of the cutting edge detection unit 40 facing the cutting blade entry portion 40b, and a window-shaped light-receiving portion is provided on the other side wall at a position facing the light-emitting portion 76b. 78b is provided. A light source 62b is connected to the light emitting portion 76b via an optical fiber or the like, and light is emitted from the light emitting portion 76b when the light source 62b is operated. The light source 62b may be connected to a dimmer (not shown) having a function of adjusting the amount of light emitted.

The light receiving section 78b is connected to the light receiving element 64b via an optical fiber or the like. The light reaching the light receiving portion 78b is received by the light receiving element 64b. The light-receiving element 64b includes a photoelectric conversion section 80b, from which an electric signal having a voltage corresponding to the amount of light received is output. The photoelectric conversion section 80 b is electrically connected to the setup unit 104 and sends the electrical signal to the setup unit 104 .

The light emitting portion 76b and the light receiving portion 78b are provided at substantially the same height position. The height position is the height position near the lower end 66a of the cutting edge 58a of the cutting blade 58 when the cutting unit 18 is positioned at a predetermined height position. The cutting edge detection unit 40 is provided with an openable/closable cover 40c that protects the light emitting section 76b and the light receiving section 78b when the cutting edge detection unit 40 is not in use. When using the cutting edge detection unit 40, the cover 40c is opened in advance to expose the main body 40a.

When the cutting edge detection unit 40 detects the lower end 66a of the cutting edge 58a of the cutting blade 58, the light source 62b is operated to emit light from the light emitting portion 76b, the light receiving portion 78b is irradiated with the light, and the light receiving element 64b is irradiated with the light. The light is received. The photoelectric converter 80 b converts the light into an electric signal having a voltage corresponding to the amount of light received, and sends the electric signal to the setup unit 104 .

When the cutting blade 58 is lowered toward the cutting blade entry portion 40b, the light emitted from the light emitting portion 76b is gradually blocked by the cutting blade 58, reaches the light receiving portion 78b, and is received by the light receiving element 64b. The amount of received light gradually decreases. The electrical signal output from the photoelectric conversion unit 80b is analyzed by the setup unit 104, and when the voltage value of the electrical signal reaches a predetermined voltage value, the lower end 66a of the cutting edge 58a of the cutting blade 58 is suitable for cutting. It is confirmed that the predetermined height has been reached.

A more detailed description will be given. The setup unit 104 includes a voltage comparator 106 that compares the voltage values of the electrical signals. The voltage comparison unit 106 includes a reference voltage setting unit 108. The reference voltage setting unit 108 is configured to adjust the height of the lower end 66a of the cutting edge 58a of the cutting blade 58 to a height suitable for cutting the workpiece 1. The voltage of the electrical signal is registered as the value of the reference voltage. Also, the voltage comparison section 106 is connected to the edge position detection section 110 .

When an electric signal is sent from the photoelectric conversion unit 80b to the voltage comparison unit 106 of the setup unit 104, the voltage comparison unit 106 compares the voltage value of the electric signal with the reference voltage value registered in the reference voltage setting unit 108. compare. The descent of the cutting unit 18 is continued until the voltage comparing section 106 detects that the voltage value of the electrical signal and the value of the reference voltage match. When the voltage value of the electrical signal and the value of the reference voltage match, the voltage comparator 106 sends to the edge position detector 110 information that the two match.

The edge position detector 110 acquires the height of the cutting unit 18 at this time from the Z-axis direction movement mechanism. When cutting the workpiece 1, the cutting unit 18 should be positioned at this height. The end position detection section 110 is connected to a calculation section 112, and the calculation section 112 calculates the height of the cutting unit 18 specified by the end position detection section 110 and the position of the cutting unit 18 during cutting up to that point. The difference between the height of the

The calculator 112 is connected to the position corrector 114 . The calculator 112 sends the correction value to the position corrector 114 . The position correction unit 114 corrects the height at which the cutting unit 18 should be positioned during cutting with the correction value. When cutting the workpiece 1 with the cutting blade 58, the Z-axis pulse motor 36 constituting the Z-axis movement mechanism is controlled based on the corrected value, and the cutting unit 18 is positioned at an appropriate height position. be done.

For example, FIG. 6B schematically shows a change 116 in the voltage value of the electric signal output from the photoelectric conversion section 80b as a change in the amount of light received by the light receiving element 64b in the setup process. . In this example, the voltage value in the initial state is 5V, and the voltage value when the light is completely blocked by the cutting blade 58 is 0V. The value of the reference voltage 118 corresponding to the reference amount of received light is set to 3V.

In this example, the height position of the cutting unit 18 is detected when the voltage value of the electric signal becomes 3V. The height position of the cutting unit 18 at this time is, for example, the height position of the cutting unit 18 when the lower end 66a of the cutting edge 58a of the cutting blade 58 is positioned at a predetermined height position. Thus, when cutting the workpiece 1 with the cutting blade 58, a setup process is carried out in advance using the setup unit 104. FIG.

Further, the cutting device 2 will be described with reference to FIG. The cutting device 2 has a sub-chuck table 42 adjacent to the chuck table 8 . A suction mechanism including a suction path (not shown) communicating with the upper surface of the sub-chuck table 42 is arranged inside the sub-chuck table 42 . A dressing board 9 described below is placed on the upper surface of the sub-chuck table 42 and held by the sub-chuck table 42 by suction.

Even if the abrasive grains contained in the cutting edge 58a are consumed by repeated cutting using the cutting blade 58, the binding material is consumed and new abrasive grains are exposed one after another. 58 cutting ability is maintained. However, there are cases where the binding material is not sufficiently consumed and the action of self-sharpening is insufficient. In addition, the cutting blade 58 may be unevenly worn and the diameter may not be uniform, and the shape of the cutting blade 58 may become unsuitable for cutting. Therefore, in the cutting device 2 , dressing is performed to actively wear the cutting blade 58 .

Dressing is performed by cutting the dressing board 9 held on the sub-chuck table 42 with the cutting blade 58 . However, the cutting device 2 does not have to include the sub-chuck table 42 . In this case, for example, the dressing board 9 is held by suction on the chuck table 8 . The dressing board 9 includes, for example, a binder and abrasive grains fixed to the binder. The materials of the binder and the abrasive grains, the size and shape of the abrasive grains, etc. are appropriately selected according to the type of the cutting blade 58, the purpose of dressing, and the like.

The cutting device 2 further comprises a control unit 48 . The control unit 48 has a function of controlling each component of the cutting device 2 such as the cutting unit 18, the chuck table 8, each moving mechanism, the imaging unit 38, the cutting edge detection unit 40, and the like. The functions of the control unit 48 are implemented as software in, for example, a device control computer including a CPU and a storage medium. Furthermore, the functions of the setup unit 104 and the functions of the management units 90a and 90b described below may be implemented by the control unit 48. FIG.

Further, as shown in FIG. 1 , the cutting device 2 has a display section 44 . The display unit 44 is electrically connected to the control unit 48 and displays the result of cutting, various warnings, and the like. The display unit 44 may be a display panel with a touch panel. In this case, the user or administrator of the cutting device 2 can input information such as processing conditions to the control unit 48 using the touch panel.

An alarm lamp 46 electrically connected to a control unit 48 is provided on the upper portion of the cutting device 2 . The alarm lamp 46 has, for example, a green lamp and a red lamp. The control unit 48 turns on the green lamp when the cutting device 2 is in a normal operating state to notify the user or administrator that the cutting device 2 is normal. On the other hand, when some problem occurs in the cutting device 2, the control unit 48 lights a red lamp to inform the user or administrator of the fact.

The display unit 44 and the alarm lamp 46 can function as a notification unit that issues warnings and various types of information to the user or administrator of the cutting device 2 . Note that the notification unit is not limited to this, and may issue a warning or the like to the user or administrator by other methods. For example, the cutting device 2 may be equipped with a buzzer to emit a warning sound to issue a warning or the like.

When the workpiece 1 is cut with the cutting blade 58 , a large load is applied to the cutting blade 58 , and chipping may occur at the cutting edge 58 a of the cutting blade 58 . 3(B), 3(C), and 3(D) each show an example of a front view schematically showing an enlarged lower end region 68 of the cutting edge 58a. The location of region 68 on cutting blade 58 is shown in FIG.

FIG. 3B schematically shows a cutting edge 58a with no chipping. The workpiece 1 can be properly cut by using the cutting blade 58 whose cutting edge 58a is free from damage such as chipping. FIG. 3(C) schematically shows a cutting edge 58a with a relatively small chip 70a, and FIG. 3(D) schematically shows a cutting edge 58a with a relatively large chip 70b. shown in

Note that the positions of the chips 70a and 70b that occur on the cutting edge 58a are not necessarily at the lower end of the cutting edge 58a. In the first place, since the cutting blade 58 is used while rotating at high speed, the positions of the chips 70a and 70b in the circumferential direction are of little significance. On the other hand, the depth 72a, 72b of the chip 70a, 70b from the outer circumference 66 of the cutting blade 58 is significant. Here, the chip depths 72a, 72b refer to the distance from the point of the chip 70a, 70b closest to the center of the cutting blade 58 to the outer circumference 66 of the cutting blade 58. As shown in FIG.

For example, if the depth of the chip is sufficiently small, cutting of the workpiece 1 can be performed with a sufficient quality by the cutting blade 58 . On the other hand, if the depth of the chip exceeds a predetermined level, cutting the workpiece 1 with the cutting blade 58 does not reach the required level of machining accuracy, and the workpiece 1 is damaged. It is possible to give. Therefore, when chipping occurs in the cutting edge 58a of the cutting blade 58, it is desirable to detect the chipping at an early stage.

A chipping detector 60 provided in the cutting unit 18 is used, for example, to determine whether the cutting edge 58a is chipped. The chipping detector 60 is provided on the upper portion of the blade cover 50 as shown in FIG. Next, the chipping detector 60 will be described. The chipping detection unit 60 is configured in the same manner as the cutting edge detection unit 40 described above. The chipping detector 60 is connected to an external light source 62a and a light receiving element 64a via an optical fiber or the like.

FIG. 4 shows a side view schematically showing the cutting unit 18 including the chipping detector 60 and a block diagram of a management unit 90a that manages the cutting blade 58. As shown in FIG. A groove-like main body 60a of the chipping detector 60 is incorporated in the upper portion of the blade cover 50, and is disposed so as to sandwich the upper end 66b of the cutting edge 58a of the cutting blade 58 for cutting the workpiece 1. As shown in FIG. The main body 60a of the chipping detector 60 can be moved up and down by an elevating mechanism 74, and is positioned at a height at which chipping can be appropriately detected according to the diameter of the cutting blade 58 to be detected for chipping.

A window-shaped light-emitting portion 76a is provided on one inner wall facing the cutting edge 58a of the cutting blade 58 of the groove-shaped main body 60a, and a window-shaped light-receiving portion is provided on the other inner wall at a position facing the light-emitting portion 76a. 78a is provided. A light source 62a is connected to the light emitting portion 76a via an optical component such as an optical fiber, and light is emitted from the light emitting portion 76a when the light source 62a is operated. The light source 62a may be connected to a dimmer (not shown) having a function of adjusting the amount of light emitted.

The light receiving section 78a is connected to the light receiving element 64a via an optical component such as an optical fiber. The light reaching the light receiving portion 78a is received by the light receiving element 64a. The light-receiving element 64a includes a photoelectric conversion section 80a from which an electric signal having a voltage corresponding to the amount of light received is output. The photoelectric conversion section 80a is electrically connected to the chipping measuring section 82a, and sends the electric signal to the chipping measuring section 82a.

The chipping measuring unit 82a analyzes the electric signal to determine whether the cutting edge 58a of the cutting blade 58 is chipped, and if chipping occurs, measures the depth of the chipping. With the cutting blade 58 positioned between the light emitting portion 76a and the light receiving portion 78a, the chipping measuring portion 82a measures the cutting edge 58a of the cutting blade 58 based on the amount of light received by the light receiving portion 78a which is emitted from the light emitting portion 76a. Measure the depth of chipping that occurs in

Here, the chipping measurement using the chipping measuring unit 82a is performed while the workpiece 1 is being cut, or while the cutting of the workpiece 1 is temporarily stopped. For example, the cutting blade 58 rotates at a rotational speed of about 20,000 to 100,000 rpm when cutting the workpiece 1 . In order not to reduce the machining efficiency of the workpiece 1, when detecting chipping of the cutting blade 58, acceleration and deceleration are not performed before and after detection, and chipping detection is performed for the cutting blade 58 rotating at high speed. be done.

When chipping of the cutting edge 58a of the cutting blade 58 is detected, the cutting edge 58a of the cutting blade 58 is continuously irradiated with light from the light emitting section 76a, and the light reaching the light receiving section 78a is received by the light receiving element 64a. continue. Then, the chipping measuring unit 82a analyzes the change in the amount of received light over time to determine the presence or absence of chipping, and measures the depth of the chipping based on the time change in the amount of received light when a chipping occurs.

Here, in order to detect the depth of chipping in each region of the outer circumference 66 of the cutting blade 58 rotating at high speed, the amount of received light is also measured with high frequency. For example, the sampling frequency for measuring the amount of received light is about 250 kHz. The graph exemplified in FIG. 5(A) represents the change over time in the amount of light received upon reaching the light receiving portion 78a. etc. are detected. However, the change over time in the voltage value of the electrical signal output from the photoelectric conversion unit 80a may be used for detection instead of the amount of light received.

FIG. 5A is a graph showing an example of temporal change in the amount of light received by the light receiving portion 78a. A waveform 92 shown in FIG. 5(A) represents a time change in the amount of light received when the cutting blade 58 rotates once. The amount of light received by reaching the light receiving portion 78a is determined by the amount of light emitted from the light emitting portion 76a that is blocked by the cutting edge 58a of the cutting blade 58. FIG.

Here, when the cutting blade 58 is attached to the cutting unit 18, due to a slight deviation between the rotation axis of the cutting blade 58 and the center of the cutting blade 58, the diameter from the rotation axis to the outer circumference 66 of the cutting blade 58 is It is not constant all around. In addition, uneven wear may occur on the cutting edge 58a during the process of cutting the workpiece 1. As shown in FIG. Therefore, even when the cutting edge 58a is not chipped, the amount of received light is unlikely to be constant as shown in the waveform 92 illustrated in FIG. 5(A).

A maximum portion 94 of the waveform 92 represents the amount of light received when the outer circumference 66 of the cutting blade 58 with the smallest diameter is positioned between the light emitting portion 76a and the light receiving portion 78a. A minimum portion 96 of the waveform 92 represents the amount of light received when the outer circumference 66 of the cutting blade 58 having the largest diameter is positioned between the light emitting portion 76a and the light receiving portion 78a.

A difference 98 between the amount of light received at the maximum portion 94 and the amount of light received at the minimum portion 96 of the waveform 92 is the difference in the amount of light received corresponding to the amount of eccentricity of the cutting blade 58 . When the cutting blade 58 is dressed with the dressing board 9, the eccentricity of the cutting blade 58 is reduced, the difference 98 is reduced, and the waveform 92 becomes flat.

When the cutting edge 58a of the cutting blade 58 is chipped, the chip transmits light, so the amount of light received by reaching the light receiving portion 78a increases. Therefore, if the cutting edge 58a is chipped, peaks 100a and 100b appear in the waveform 92 shown in FIG. For example, height 102a of peak 100a corresponds to the depth of the chip. That is, the depth of the chipping can be evaluated from the height 102a of the peak 100a appearing in the waveform 92. FIG.

Therefore, the chipping measurement unit 82a can detect the chipping of the cutting edge 58a of the cutting blade 58 from the amount of light received by the light receiving unit 78a emitted from the light emitting unit 76a. The depth of the chip from the perimeter 66 of the cutting blade 58 can be measured.

By using the chipping detector 60, when the cutting edge 58a of the cutting blade 58 is chipped, it can be detected as described above. Conventionally, when the cutting edge 58a of the cutting blade 58 is found to be chipped, the cutting blade 58 is promptly replaced.

However, depending on the depth of the chip formed on the cutting edge 58 a of the cutting blade 58 , the chip may be removed by dressing the cutting blade 58 with the dressing board 9 . That is, the reproducible cutting blade 58 has also been removed from the spindle 54 and replaced due to chipping.

The cutting device 2 must be stopped while the cutting blade 58 is being replaced, and there is a time during which the workpiece 1 cannot be cut. Therefore, if the cutting blade 58 is frequently replaced, the machining efficiency of the workpiece 1 will be reduced. In addition, since the cutting blades 58 that can be regenerated by cutting the dressing board 9 are discarded, the consumption of the cutting blades 58 increases unnecessarily and the cost of the cutting blades 58 increases. That is, the machining efficiency of the workpiece 1 was further reduced.

Therefore, the cutting device 2 according to the present embodiment includes a management unit 90a that manages the cutting blade 58, and the cutting blade 58 is managed according to the depth of chipping. The management unit 90a evaluates the depth of chipping occurring in the cutting blade 58 and determines whether the cutting blade 58 is in a reproducible state. Then, when the cutting blade 58 can be regenerated by dressing, the cutting blade 58 is caused to cut the dressing board 9 to perform dressing, and the cutting blade 58 is regenerated.

The management unit 90a, as shown in FIG. 4, includes a determination section 84a. The judging section 84a judges the state of the cutting blade 58 from the measurement result of the chipping depth of the cutting edge 58a by the chipping measuring section 82a. The determination unit 84a includes a threshold registration unit 86a and a comparison unit 88a. A first threshold set for the depth of chipping of the cutting blade 58 and a second threshold larger than the first threshold are registered in the threshold registration unit 86a.

Even if the cutting blade 58 is chipped, the workpiece 1 can be cut with sufficient accuracy if the depth of the chip is sufficiently small. Therefore, the first threshold value is set as a value corresponding to the upper limit of the chipping depth at which it can be determined that the chipping depth of the cutting blade 58 is sufficiently small to cut the workpiece 1 as it is.

If the depth of the chip formed on the cutting edge 58a of the cutting blade 58 is greater than or equal to the first threshold value, the workpiece 1 cannot be cut with sufficient accuracy as it is. However, if the depth of the chipping is not too large, the cutting blade 58 can be regenerated by dressing the cutting blade 58, and the workpiece 1 can be properly cut. The second threshold is set as a value corresponding to the upper limit of the chipping depth that allows regeneration of the cutting blade 58 by dressing.

If the depth of chipping on the cutting edge 58a of the cutting blade 58 is equal to or greater than the second threshold value, it is impossible to regenerate by dressing, so it is desired that the cutting blade 58 be promptly replaced. .

Note that the first threshold value and the second threshold value are, for example, determined in advance by the operator of the cutting device 2 or the like and registered in the threshold value registration unit 86a. The first threshold and the second threshold may differ depending on the type of the cutting blade 58, the type of the workpiece 1, and the details of cutting to be performed. It may also be influenced by variations in the quality of individual cutting blades 58 . Furthermore, it may change depending on the usage history of the cutting blade 58, that is, the amount of wear. Therefore, the first threshold and the second threshold may be appropriately changed according to the situation and registered in the threshold registration section 86a.

When chipping of the cutting edge 58a of the cutting blade 58 is detected, the light-emitting portion 76a and the light-receiving portion 78a are positioned at a predetermined height position by the elevating mechanism 74. FIG. The height position is the height position near the upper end 66b of the cutting edge 58a of the cutting blade 58 attached to the spindle 54. As shown in FIG.

When the chipping detection unit 60 detects a chipping on the cutting edge 58a of the cutting blade 58, the light source 62a is operated to emit light from the light emitting unit 76a, and the light receiving unit 78a is irradiated with the light. to receive the light. The photoelectric conversion section 80a converts the light into an electric signal having a voltage corresponding to the amount of received light, and sends the electric signal to the chipping measuring section 82a. The chipping measuring unit 82a detects the presence or absence of chipping based on the voltage value of the electrical signal, and measures the depth of the chipping when the chipping has occurred.

The comparing unit 88a compares the measurement result of the chipping depth of the cutting edge 58a of the cutting blade 58 by the chipping measuring unit 82a and the first threshold value and the second threshold value registered in the threshold registering unit 86a. compare. Then, when the depth of chipping of the cutting blade 58 measured by the chipping measuring unit 82a is less than the first threshold as a result of the comparison performed by the comparing unit 88a, the determining unit 84a It is determined that the workpiece 1 is ready for cutting.

On the other hand, the determining unit 84a determines that the depth of chipping of the cutting blade 58 measured by the chipping measuring unit 82a is equal to or greater than the first threshold value as a result of the comparison performed by the comparing unit 88a, and is less than the threshold value, the cutting blade 58 is determined to be in a state requiring dressing. Further, as a result of the comparison performed by the comparison unit 88a, if the chipping depth of the cutting blade 58 measured by the chipping measuring unit 82a is equal to or greater than the second threshold value, the cutting blade 58 is further removed from the workpiece 1. It is determined that cutting should not be performed.

Using the bar graph shown in FIG. 5B, the relationship between the depth of chipping occurring in the cutting blade 58 and the first threshold value 126 and the second threshold value 128 will be described. For example, when chipping A occurs in the cutting blade 58 and the chipping depth 120 is equal to or greater than the second threshold value 128, the cutting blade 58 is determined to be in a state in which further cutting of the workpiece 1 should not be performed. be done.

When a chip having a depth of 128 or more is detected while cutting the workpiece 1, the cutting of the workpiece 1 may be immediately interrupted and the cutting blade 58 may be replaced. . Alternatively, the cutting blade 58 may be exchanged after the cutting blade 58 completes the cutting of the workpiece 1 in the process of cutting.

Further, for example, when chipping B occurs in the cutting blade 58 and the depth 122 of the chipping is greater than or equal to the first threshold value and less than the second threshold value 128, it is determined that the cutting blade 58 needs dressing. be done. In this case, for example, the cutting of the workpiece 1 may be interrupted immediately and the cutting blade 58 may be dressed. Alternatively, the cutting blade 58 may be dressed after the cutting blade 58 completes the cutting of the workpiece 1 in the process of cutting.

For example, when chipping C occurs in the cutting blade 58 and the depth 124 of the chipping is less than the first threshold value, it is determined that the cutting blade 58 can cut the workpiece 1 . In this case, it is not necessary to stop the workpiece 1 by the cutting blade 58 .

Further, when a plurality of chips are generated in the cutting blade 58, it is preferable that the determination unit 84a makes a determination based on the chip with the largest depth among the plurality of chips. Furthermore, when a plurality of chippings occur in the cutting blade 58, the determination result may be corrected according to the number of chippings. For example, even if the depth of all chippings generated on the cutting edge 58a of the cutting blade 58 is less than the second threshold value, if the number of chippings is equal to or greater than a predetermined number, the cutting blade 58 cuts the workpiece 1. A determination may be made that no further cutting should be performed.

The cutting device 2 causes the cutting blade 58 to cut the dressing board 9 held by the sub-chuck table 42 when the determination unit 84a determines that the cutting blade 58 needs dressing. That is, the cutting blade 58 is dressed. When the cutting edge 58a of the cutting blade 58 is worn by dressing and the chipped portion of the cutting edge 58a is removed, the cutting blade 58 can be used again.

After the cutting blade 58 is dressed, the management unit 90a may irradiate the cutting edge 58a of the cutting blade 58 again with light using the chipping detector 60 to detect the amount of wear of the cutting edge 58a due to dressing. . If the amount of wear can be detected, it can be determined whether or not the amount of wear of the cutting edge 58a exceeds the depth of chipping occurring in the cutting edge 58a. If the amount of wear exceeds the depth of the chip, it is likely that the chip has been removed by dressing.

The determination unit 84a may be connected to a notification unit such as the display unit 44 and the alarm lamp 46 . The notification unit may notify the user, administrator, or the like of the cutting device 2 of the result of the determination performed by the determination unit 84a. If the user or the like can be notified of the determination result, for example, when the cutting blade 58 has a relatively large chipping and it becomes necessary to stop the cutting device 2 and replace the cutting blade 58, the user or the like can be notified at an early stage. can be warned.

According to the cutting device 2 according to the present embodiment, even if chipping occurs in the cutting edge 58a of the cutting blade 58, the cutting blade 58 can be regenerated depending on the depth of the chipping. In the cutting device 2, since the cutting blades 58 are not replaced unnecessarily, the downtime of the cutting device 2 can be minimized and the number of cutting blades 58 consumed can be reduced. Therefore, the workpiece 1 can be cut with high efficiency.

The cutting device 2 may detect that the cutting edge 58a of the cutting blade 58 is chipped using the cutting edge detection unit 40, and may measure the depth of the chipping. In this case, as shown in FIG. 6A, the cutting device 2 includes a management unit 90b connected to a setup unit 104, and the setup unit 104 includes a chipping measuring section 82b. The management unit 90b is configured similarly to the management unit 90a.

The chipping measuring unit 82b analyzes the electrical signal sent from the photoelectric conversion unit 80b to the voltage comparing unit 106 to determine whether chipping has occurred in the cutting edge 58a of the cutting blade 58, and if chipping has occurred, the chipping is detected. Measure depth. With the cutting blade 58 positioned between the light-emitting portion 76b and the light-receiving portion 78b, the chipping measuring portion 82b measures the cutting edge 58a of the cutting blade 58 based on the amount of light received by the light-receiving portion 78b. Measure the depth of chipping that occurs in The chipping measuring section 82b is connected to the management unit 90b.

A management unit 90b configured similarly to the management unit 90a evaluates the depth of chipping in the cutting blade 58 to determine whether the cutting blade 58 is in a reproducible state. Then, when the cutting blade 58 can be regenerated by dressing, the cutting blade 58 is caused to cut the dressing board 9 to perform dressing, and the cutting blade 58 is regenerated.

The management unit 90b includes a determination section 84b, as shown in FIG. 6(A). The judging section 84b judges the state of the cutting blade 58 from the measurement result of the chipping depth of the cutting edge 58a by the chipping measuring section 82b. The determination unit 84b includes a threshold registration unit 86b and a comparison unit 88b.

A first threshold set for the depth of chipping of the cutting blade 58 and a second threshold larger than the first threshold are registered in the threshold registration unit 86b. The comparing unit 88b compares the measurement result of the chipping depth of the cutting edge 58a of the cutting blade 58 by the chipping measuring unit 82b and the first threshold value and the second threshold value registered in the threshold value registering unit 86b. A comparison is made to determine the condition of the cutting blade 58 .

Note that the chipping measurement using the chipping measuring unit 82b may be performed together with the setup process. In this case, it is performed before the cutting of the workpiece 1 is performed. Alternatively, it may be performed after the cutting blade 58 is moved to the cutting edge detection unit 40 after the workpiece 1 has been completely cut. As described above, in the cutting device 2 according to this embodiment, the cutting edge detection unit 40 may be used to determine the state of the cutting blade 58 .

Next, a method for managing cutting blades in this embodiment, which is carried out using the cutting device 2, will be described. FIG. 7 is a flow chart showing the flow of each step of the cutting blade management method according to this embodiment. For the description of each step, the description regarding the cutting device 2 can be appropriately referred to.

In the cutting blade management method, first, a first threshold value and a second threshold value larger than the first threshold value are set with respect to the depth of chipping occurring in the cutting edge 58a of the cutting blade 58, and a management unit A threshold registration step S1 for registering in 90a and 90b is performed. As described above, the first threshold value and the second threshold value may differ depending on the type and individual difference of the cutting blade 58, so every time a new cutting blade 58 is attached to the spindle 54 preferably.

After performing the threshold registration step S1, before, during, or after cutting the workpiece 1 held on the chuck table 8, a chipping measurement step S2 for measuring the depth of chipping generated at the cutting edge 58a of the cutting blade 58. to implement.

The chipping measurement step S2 is performed using, for example, the chipping detector 60 and the management unit 90a. In this case, the chipping measurement step S2 is performed while the cutting blade 58 is cutting the workpiece 1 . Also, the chipping measurement step S2 is performed using, for example, the cutting edge detection unit 40 and the management unit 90b. In this case, the chipping measurement step S2 is performed before or after cutting the workpiece 1 with the cutting blade 58 .

In the chipping measurement step S2, light is emitted from the light emitting portions 76a and 76b and the light receiving portions 78a and 78b with the cutting blade 58 positioned between the light receiving portions 78a and 78b. is received. Then, chipping measuring units 82a and 82b measure the depth of chipping generated in the cutting edge 58a of the cutting blade 58 based on the amount of light received by the light receiving units 78a and 78b.

Here, the depth of chipping of the cutting edge 58a may be measured by directly analyzing the amount of received light. The voltage value may be analyzed and measured.

After performing the chipping measurement step S2, a management step S3 of determining the state of the cutting blade 58 and managing the cutting blade 58 based on the determined state of the cutting blade 58 is performed. In the management step S3, the depth of the chipping measured in the chipping measurement step S2, the first threshold and the second threshold registered in the threshold registration units 86a and 86b of the management units 90a and 90b are combined. A comparison is made to determine the condition of the cutting blade 58 .

The determination performed in the management step S3 will be further explained using FIG. In the management step S3, first, it is determined whether or not the depth of the chip formed on the cutting edge 58a of the cutting blade 58 is equal to or greater than a first threshold (S4). As a result, if the chipping depth of the cutting blade 58 measured in the chipping measurement step S2 is less than the first threshold value or is zero, cutting of the workpiece 1 by the cutting blade 58 is possible. state.

If the chipping depth of the cutting blade 58 measured in the chipping measurement step S2 is greater than or equal to the first threshold, then it is determined whether or not the chipping depth is greater than or equal to the second threshold ( S5). If the chipping depth of the cutting blade 58 measured in the chipping measurement step S2 is greater than or equal to the first threshold value and less than the second threshold value, the cutting blade 58 is in a state requiring dressing. Determine that there is.

In this case, the chipping is removed by dressing the cutting blade 58 until the wear amount of the cutting blade 58 reaches or exceeds the depth of the chipping (S7). When dressing the cutting blade 58 , the dressing board 9 is held by the sub-chuck table 42 or the chuck table 8 , and the dressing board 9 is cut by the cutting blade 58 .

When performing dressing by cutting the dressing board 9 with the cutting blade 58, a confirmation step for confirming that the dressing has been properly performed may be further performed. In the confirmation step, the cutting edge detection unit 40 or the management unit 90b is used to measure the amount of wear of the cutting edge 58a of the cutting blade 58 due to dressing, as in the chipping measurement step S2.

When it is confirmed that the amount of wear is equal to or greater than the depth of the chipped portion of the cutting edge 58a, it is expected that the chipped portion has been removed. Alternatively, the chipping measurement step S2 and the management step S3 may be further performed after the dressing is performed to determine whether or not the cutting edge 58a of the cutting blade 58 is chipped.

Further, when the chipping depth of the cutting blade 58 measured in the chipping measurement step S2 is equal to or greater than the second threshold value, the cutting blade 58 is in a state in which further cutting of the workpiece 1 should not be performed. Determine that there is. In this case, the cutting blade 58 is removed from the spindle 54, and a new cutting blade 58 is mounted on the spindle 54 to replace the cutting blade 58 (S6).

When measuring the depth of chipping of the cutting blade 58 using the cutting edge detection unit 40, the cutting water accompanying the cutting blade 58 is removed from the outer periphery of the cutting blade 58 before the chipping measurement step S2. A draining step may be performed.

When cutting the workpiece 1 with the cutting blade 58, the cutting blade 58 is rotated at high speed, and the cutting water supply nozzles 52a, 52b, 52c (see FIG. 2) supply water to the cutting blade 58 and the workpiece 1. Cutting water is supplied. When cutting water is supplied to the cutting blade 58 rotating at high speed, a phenomenon is observed in which a portion of the cutting water clings to the cutting blade 58 and rotates together with the cutting blade 58 .

Since the cutting water continues to rotate with the cutting blade 58 even after the cutting of the workpiece 1 is completed, when the chipping measurement step S2 is performed after cutting the workpiece 1 using the cutting blade 58, the chipping The cutting water may interfere with depth measurements. That is, when the light emitted from the light emitting portion 76b is irradiated toward the outer circumference 66 of the cutting blade 58 and the light not blocked by the cutting blade 58 reaches the light receiving portion 78b and is received, the light is accompanied by the cutting blade 58. Spinning cutting water can affect the travel of the light.

Therefore, a water draining step is performed to remove the cutting water entrained in the cutting blade 58 so that the depth of chipping of the cutting blade 58 can be properly measured. In the draining step, for example, the Z-axis movement mechanism is operated to move the cutting blade 58 into and out of the groove-shaped cutting blade entry portion 40b (see FIG. 6A) of the main body 40a of the cutting edge detection unit 40 at high speed.

When the cutting blade 58, which continues to rotate at a high speed without deceleration even after finishing the cutting of the workpiece 1, is moved in and out of the cutting blade entry portion 40b at a high speed, the cutting blade 58 rotates as the cutting blade 58 rotates. The air flow around it changes. Due to this change in air flow, the cutting water that is entrained in the cutting blade 58 is separated from the cutting blade 58 and removed. Therefore, when the water draining step is performed, the depth of chipping of the cutting blade 58 can be measured without being affected by the cutting water.

As described above, according to the method for managing the cutting blade 58 according to the present embodiment, the depth of chipping occurring in the cutting blade 58 is evaluated, and the cutting blade 58 can be managed based on the depth of the chipping. . Even if chipping occurs in the cutting edge 58a of the cutting blade 58, the cutting blade 58 will not be discarded if the chipping can be removed by dressing the cutting blade 58 and regenerated.

Therefore, the cutting blades 58 are not replaced unnecessarily, the time during which the cutting device 2 is stopped can be minimized, and the number of cutting blades 58 consumed can be reduced. That is, according to the cutting blade management method according to the present embodiment, the workpiece 1 can be cut with high efficiency using the cutting blade.

In the above embodiment, the case where the first threshold value and the second threshold value are set and registered by the user or administrator of the cutting device 2 has been described. The management method is not limited to this. That is, in the cutting device 2, the management units 90a and 90b may derive the first threshold and the second threshold. Then, in the threshold registration step S1, a threshold derivation step may be further performed.

When the management units 90a and 90b derive the first threshold value, for example, a first cutting blade for test that is formed in advance on the cutting edge is prepared. At this time, the depth of the chip formed in the first test cutting blade is the depth of the chip that serves as a boundary for determining whether or not the cutting blade requires dressing. Then, the first test cutting blade is irradiated with light to measure the depth of the chipping, and the depth of the chipping is registered as the first threshold in the threshold value registration units 86a and 86b.

Also, when the second threshold value is derived by the management units 90a and 90b, for example, a second test cutting blade formed in advance on the cutting edge is prepared. At this time, the depth of the chipping formed on the second test cutting blade is the boundary for determining whether or not the cutting blade should not further cut the workpiece 1. Depth. Then, the second test cutting blade is irradiated with light to measure the depth of the chipping, and the depth of the chipping is registered as a second threshold in the threshold value registration units 86a and 86b.

If the first threshold value and the second threshold value can be derived by the cutting device 2 by performing the threshold value derivation step, the first threshold value can be obtained without depending on the knowledge, experience, and skill of the user or manager of the cutting device 2. and a second threshold is determined. Therefore, the state of the cutting blade 58 can be determined more uniformly.

In addition, the structures, methods, and the like according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention.

1 workpiece 3 adhesive tape 5 annular frame 7 frame unit 9 dressing board 2 cutting device 4 base 6 X-axis movement table 8 chuck table 8a holding surface 10 clamp 12, 24, 30 guide rail 14, 28, 34 ball screw 16, 28a, 36 pulse motor 18 cutting unit 20 drainage channel 22 support structure 26, 32 moving plate 38 imaging unit (camera)
40 cutting edge detection unit 40a main body 40b cutting blade entry portion 42 sub-chuck table 44 display portion 46 alarm lamp 48 control unit 50 blade cover 52a, 52b, 52c cutting water supply nozzle 52d connection portion 54 spindle 54a spindle housing 56 blade mount 58 cutting blade 58a cutting edge 58b base 60 chipping detector 60a main body 62a, 62b light source 64a, 64b light receiving element 66 outer periphery 66a lower end 66b upper end 68 area 70a, 70b chipping 72a, 72b depth of chipping 74 lift mechanism 76a, 76b light emitting unit 78a, 78b Light receiving unit 80a, 80b Photoelectric conversion unit 82a, 82b Chipping measurement unit 84a, 84b Determination unit 86a, 86b Threshold registration unit 88a, 88b Comparison unit 90a, 90b Management unit 92 Waveform 94 Maximum portion 96 Minimum portion 98 Difference 100a, 100b Peak 102a Peak height 104 Setup unit 106 Voltage comparison unit 108 Reference voltage setting unit 110 Edge position detection unit 112 Calculation unit 114 Position correction unit 116 Change 118 Reference voltage 120, 122, 124 Chipping depth 126 First threshold 128 Second threshold of 2

Claims (7)

a chuck table for holding a workpiece;
a cutting unit having a spindle on which a cutting blade is mounted, and cutting a workpiece held on the chuck table with the cutting blade mounted on the spindle;
a management unit that manages the cutting blade attached to the spindle,
The management unit is
a light emitting unit that emits light;
a light receiving unit that faces the light emitting unit and receives the light emitted by the light emitting unit;
The depth of chipping occurring at the cutting edge of the cutting blade is determined from the amount of light received by the light-receiving portion emitted from the light-emitting portion while the cutting blade is positioned between the light-emitting portion and the light-receiving portion. a chipping measuring unit to measure;
a determination unit that determines the state of the cutting blade from the measurement result of the chipping depth of the cutting edge by the chipping measuring unit;
The chipping measuring unit measures the depth of the chipping based on the height of the peak appearing in the waveform of the time change of the amount of light received by the light receiving unit when the cutting blade makes one revolution,
The determination unit
a threshold registration unit in which a first threshold set for the depth of the chipping of the cutting blade and a second threshold larger than the first threshold are registered;
a comparison unit that compares the measurement result of the chipping depth of the cutting blade with the first threshold value and the second threshold value registered in the threshold value registration unit;
If the result of the comparison performed by the comparison unit is that the chipping depth of the cutting blade measured by the chipping measuring unit is less than the first threshold value, cutting of the workpiece by the cutting blade is possible. determined to be in a state of
As a result of the comparison performed by the comparison unit, if the chipping depth of the cutting blade measured by the chipping measuring unit is greater than or equal to the first threshold value and less than the second threshold value, Judging that the cutting blade needs dressing,
As a result of the comparison performed by the comparison unit, if the chipping depth of the cutting blade measured by the chipping measuring unit is equal to or greater than the second threshold value, the cutting blade performs further cutting of the workpiece. A cutting device characterized by determining that it is in a state that should not be performed. The cutting device according to claim 1,
further comprising a sub-chuck table holding a dressing board for dressing the cutting blade mounted on the spindle;
A cutting device, wherein when the determination unit determines that the cutting blade needs dressing, the cutting blade is caused to cut the dressing board held on the sub-chuck table. Further comprising a notification unit connected to the determination unit,
3. The cutting apparatus according to claim 1, wherein the reporting section can report the result of the determination performed by the determining section. 4. The method according to any one of claims 1 to 3, wherein the first threshold value and the second threshold value derived by the management unit are registered in the threshold value registration unit. cutting equipment. A chuck table holding a workpiece, a cutting unit having a cutting blade, and cutting the workpiece held on the chuck table with the cutting blade, a light emitting part, and a light receiving part facing the light emitting part , a management unit for managing the cutting blade, and a cutting blade management method for managing the cutting blade in a cutting device comprising:
a threshold value registration step of setting a first threshold value and a second threshold value larger than the first threshold value for the depth of chipping occurring on the cutting edge of the cutting blade and registering them in the management unit;
Before, during, or after cutting the workpiece held on the chuck table, the cutting blade is positioned between the light-emitting portion and the light-receiving portion to emit light from the light-emitting portion and the light-receiving portion. a chipping measurement step of causing a portion to receive the light and measuring the depth of the chip formed on the cutting edge of the cutting blade based on the amount of light received by the light receiving portion;
The state of the cutting blade is determined by comparing the depth of the chipping measured in the chipping measurement step with the first threshold value and the second threshold value registered in the management unit, and determined a managing step of managing the cutting blade based on the state of the cutting blade;
In the chipping measurement step, the depth of the chipping is measured based on the height of the peak appearing in the waveform of the time change of the amount of light received by the light receiving unit when the cutting blade rotates once,
The management step includes:
determining that cutting of the workpiece by the cutting blade is possible when the depth of the chipping of the cutting blade measured in the chipping measurement step is less than the first threshold;
If the chipping depth of the cutting blade measured in the chipping measuring step is greater than or equal to the first threshold and less than the second threshold, the cutting blade is in a state requiring dressing. and dressing the cutting blade until the amount of wear of the cutting blade is equal to or greater than the depth of the chip,
If the chipping depth of the cutting blade measured in the chipping measuring step is equal to or greater than the second threshold value, it is determined that the cutting blade is in a state in which further cutting of the workpiece should not be performed. and replacing the cutting blade. Before the chipping measurement step, a draining step is provided for removing from the cutting blade cutting water supplied to the cutting blade and accompanying the cutting blade when cutting the workpiece held on the chuck table. The cutting blade management method according to claim 5 , characterized in that: 7. The cutting blade management method according to claim 5, wherein in the threshold registration step, the management unit derives the first threshold and the second threshold.

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