JP2013110321A - Cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting device that is capable of starting a cutting operation under a state where a dimensional change ascribable to a temperature change of a spindle, a cutting blade driving source, or the like due to an idling operation is within an allowable range.SOLUTION: Control means 6 of a cutting device 1 performs control so that when a determination part 6PB determines that an error between a first position coordinate stored in a first coordinate storage part 6MA and a second position coordinate stored in a second coordinate storage part 6MB is within an allowable range, an operation for cutting a workpiece is started and when the determination part 6PB determines that the error between the first position coordinate stored in the first coordinate storage part 6MA and the second position coordinate stored in the second coordinate storage part 6MB is outside the allowable range, an idling operation is repeated.

Description

  The present invention relates to a cutting apparatus that performs an idling operation when starting a cutting operation.

  The cutting apparatus includes at least a chuck table that holds a workpiece such as a semiconductor wafer, and a cutting means that rotatably supports a cutting blade that cuts the workpiece held on the chuck table and supplies cutting water. In addition, it is possible to cut a very narrow division line with a width of several tens of μm with high accuracy. However, when the cutting apparatus is restarted after stopping the operation for a long time (for example, more than a dozen hours), due to the heat generated by the spindle (cutting blade driving source) that rotates the cutting blade via the spindle and the spindle constituting the cutting means, Since the spindle extends in the index direction and the spindle stops extending in combination with the cooling effect of the supplied cutting water, an error in the index feed direction of about several μm may occur in the cutting process. For this reason, there is a technique for performing an idling operation by rotating a spindle for a predetermined time prior to cutting in a cutting apparatus having a cutting water supply nozzle (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-114949

  However, even if the product is processed with the intention of sufficiently performing the idling operation, there is a problem that the expansion or contraction of the spindle or the cutting blade drive source due to the temperature change is difficult to understand until the product is actually processed.

  An object of the present invention is to provide a cutting apparatus capable of starting a cutting operation in a state in which a dimensional change due to a temperature change of a spindle or a cutting blade drive source due to an idling operation is allowable.

  The present invention relates to a chuck table for holding a workpiece having a characteristic region formed on the surface on the upper surface, a cutting means for performing machining while supplying a cutting fluid to the workpiece held on the chuck table, and the chuck An index feed means for indexing and feeding the cutting means to the table, a cutting feed means for cutting and feeding the chuck table so as to move in a cutting feed direction orthogonal to the index feed direction, Cutting feed means for cutting and feeding to a position; imaging means arranged in the vicinity of the cutting means for picking up an image of a feature area of the work piece held by the chuck table; chuck table, index feed means and cutting feed means A control device that controls the image of the feature region of the workpiece by the imaging device. A first coordinate storage unit that stores the position coordinates of the feature region detected based on the obtained image information as a first position coordinate, and the feature region of the workpiece after the idling operation is performed by the imaging unit. A second coordinate storage unit for storing the position coordinates of the feature region detected based on the captured image information as the second position coordinates, and the first position coordinates and the second position coordinates. A determination unit that determines whether the error is within an allowable value, and the determination unit stores the first position coordinate stored in the first coordinate storage unit and the second coordinate storage unit. When it is determined that the error from the stored second position coordinate is within an allowable value, the control unit starts a cutting operation of the workpiece, and the determination unit performs the first operation. Stored in the first coordinate stored in the coordinate storage unit and in the second coordinate storage unit If the error between said second coordinates is determined not to fall within the allowable value, the control means is a cutting device and controls so as to repeat the idling operation.

  In the present invention, the idling operation may be performed by cutting the workpiece while supplying the cutting fluid in a state where the cutting means is raised to a position where the cutting means is not cut into the workpiece. preferable.

  The present invention can provide a cutting apparatus capable of starting a cutting operation in a state in which a dimensional change due to a temperature change of a spindle or a cutting blade drive source due to an idling operation can be allowed.

FIG. 1 is a diagram illustrating a configuration example of cutting according to the present embodiment. FIG. 2 is a perspective view showing a tray on which a workpiece is placed. FIG. 3 is a flowchart showing a control procedure during an idling operation of the cutting apparatus. FIG. 4 is a diagram illustrating an example of an idling operation. FIG. 5 is a diagram for explaining the error. FIG. 6 is a diagram for explaining the error. FIG. 7 is a diagram illustrating another example of a method for obtaining an error in the position coordinates of the feature region before and after the idling operation. FIG. 8 is a diagram illustrating another example of a method for obtaining an error in the position coordinates of the feature region before and after the idling operation.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that are so-called equivalent ranges. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

  FIG. 1 is a diagram illustrating a configuration example of cutting according to the present embodiment. FIG. 2 is a perspective view showing a tray on which a workpiece is placed. The cutting apparatus 1 according to the present embodiment cuts the workpiece W by relatively moving the cutting means 20 having the cutting blade 21 and the chuck table 10 holding the workpiece W. As shown in FIG. 1, the cutting apparatus 1 is a dicer having one spindle, but may be a dicer having two spindles, a so-called twin dicer. The cutting apparatus 1 includes a chuck table 10, a cutting unit 20, a Y-axis moving unit 50, an X-axis moving unit 40, a Z-axis moving unit 60, a θ-axis rotating unit 70, an imaging unit 30, and a control unit. 6 is included. Next, each component which the cutting device 1 has is demonstrated.

  The chuck table 10 holds the workpiece W (see FIG. 2) having the characteristic region CP formed on the surface on the upper surface. The characteristic region CP is a part of an electronic circuit formed on the surface of the workpiece W. Only one feature region CP is provided for each device W, and a region having a pattern (pattern such as an electronic circuit) suitable for pattern matching used for extraction of the feature region CP described later is selected. The chuck table 10 has a holding part 11. The holding unit 11 holds the workpiece W on a surface that is a horizontal plane. In the present embodiment, the holding unit 11 holds the workpiece W by placing the workpiece W on the tray 12 shown in FIG. 2 with a tape or the like, and sucking the tray 12 from its back surface. The portion constituting the surface of the holding portion 11 has a disk shape made of porous ceramic or the like, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). The workpiece W is a workpiece to be processed by the cutting device 1. The cutting device 1 is used, for example, when cutting out a test piece to be used for testing an electronic circuit of an electronic component or a semiconductor wafer or when fine processing such as FIB (Focused Ion Beam) pre-processing is required. The workpiece W includes a semiconductor wafer or an FIB processing target before cutting out the above-described test piece. However, the workpiece W is not limited to the semiconductor wafer before cutting out such a test piece, and may be, for example, a wafer having silicon, sapphire, gallium, or the like as a base material.

  The cutting means 20 performs processing while supplying a cutting fluid to the workpiece W held on the chuck table 10. At this time, the cutting unit 20 processes the region to be processed of the workpiece W imaged by the imaging unit 30. More specifically, the cutting unit 20 cuts the workpiece W held on the chuck table 10 by the cutting blade 21 based on the position information of the region to be processed of the workpiece W imaged by the imaging unit 30. . The cutting blade 21 is an extremely thin cutting grindstone having a substantially ring shape. The cutting blade 21 is detachably attached to the spindle 22. The spindle 22 is rotatably supported by a cylindrical housing 23. Further, the spindle 22 is connected to a motor (not shown) serving as a cutting blade drive source housed in the housing 23. The cutting blade 21 is rotationally driven by the rotational force generated by the cutting blade drive source. The cutting means 20 is mounted on the cutting blade moving base 8 via the wall portion 5 and the support portion 4. The cutting means 20 includes a cutting fluid supply nozzle 24 that supplies a cutting fluid to the workpiece W during processing of the workpiece W by the cutting blade 21. During the processing of the workpiece W, the cutting fluid is supplied from the cutting fluid supply nozzle 24 to the processing point.

  The Y-axis moving unit 50 corresponds to an index feeding unit that indexes and feeds the cutting unit 20 to the chuck table 10. For this reason, as shown in FIG. 1, the Y-axis moving means 50 relatively moves the workpiece W held on the chuck table 10 and the cutting blade 21 in the Y-axis direction. The Y-axis moving means 50 includes a Y-axis pulse motor 51, a Y-axis ball screw 52, a pair of Y-axis guide rails 53, 53, a Y-axis position detection scale 54, and a Y-axis position detection sensor 55. Contains. The Y-axis ball screw 52 is disposed in the Y-axis direction, and is screwed with a nut (not shown) provided inside the cutting blade moving base 8, and the Y-axis pulse motor 51 is connected to one end. ing. The Y-axis moving means 50 moves the cutting blade moving base 8 in the Y-axis direction with respect to the apparatus main body 3 by rotationally driving the Y-axis ball screw 51 by the rotational force generated by the Y-axis pulse motor 51.

  The X-axis moving means 40 corresponds to a cutting feed means for cutting and feeding the chuck table 10 so as to move in a cutting feed direction orthogonal to the index feed direction. For this reason, the X-axis moving means 40 relatively moves the workpiece W held with respect to the cutting blade 21 in the X-axis direction. The X-axis moving means 40 includes an X-axis pulse motor 41, an X-axis ball screw 42, a pair of X-axis guide rails 43, 43, an X-axis position detection scale 44, and an X-axis position detection sensor 45. Contains. The X-axis ball screw 42 is disposed in the X-axis direction, is screwed with a nut (not shown) provided at the lower part of the table moving base 2, and is connected to the X-axis pulse motor 41 at one end. . The pair of X-axis guide rails 43, 43 are arranged in parallel with the X-axis ball screw 42, and the table moving base 2 on which the θ-axis rotating means 70 and the chuck table 10 are mounted is slidably mounted. The X-axis moving means 40 guides the table moving base 2 (chuck table 10) with a pair of X-axis guide rails by rotationally driving the X-axis ball screw 42 by the rotational force generated by the X-axis pulse motor 41. While moving in the X-axis direction with respect to the apparatus main body 3.

  The Z-axis moving unit 60 corresponds to a cutting feed unit that moves the cutting unit 20 up and down and cuts and feeds it to a predetermined position. For this reason, the Z-axis moving means 60 moves the cutting blade 21 relative to the workpiece W held on the chuck table 10 in the Z-axis direction, that is, in the direction in which the spindle 22 approaches and separates from the chuck table 10. The Z-axis moving means 60 is provided on the cutting blade moving base 8 and includes a Z-axis ball screw 61, a Z-axis pulse motor 62, and a pair of Z-axis guide rails 63. The Z-axis ball screw 61 is disposed in the Z-axis direction on the wall portion 5 and is screwed with a nut (not shown) provided inside the support portion 4. A Z-axis pulse motor 62 is connected to one end of the Z-axis ball screw 61. Has been. The pair of Z-axis guide rails 63 are provided in parallel with the Z-axis ball screw 61, and the support portion 4 is slidably mounted on the wall portion 5. The Z-axis moving means 60 rotates and drives the Z-axis ball screw 61 by the rotational force generated by the Z-axis pulse motor 62, thereby guiding the support unit 4 with the pair of Z-axis guide rails 63 and the apparatus body 3. Move in the Z-axis direction.

  The θ-axis rotating means 70 includes a θ-axis rotating motor 71 and a table 72. The table 72 carries the chuck table 10. The table 72 is supported by the apparatus main body 3 via a θ-axis rotation motor 71 so that the table 72 can rotate around the central axis of the chuck table 10. The table 72 is connected to a θ-axis rotation motor 71 mounted on the table moving base 2. The rotation center axis of the θ-axis rotation motor 71 coincides with the center axis of the chuck table 10. The table 72 can be rotated at an arbitrary angle, for example, 90 degrees or continuously by the rotational force generated by the θ-axis rotating means 70. With such a structure, the table 72 can cause the chuck table 10 to rotate at any angle or continuous rotation with respect to the cutting blade 21 around the central axis.

  The imaging unit 30 includes a plurality of pixels, images the workpiece W held on the chuck table 10, and generates an image. More specifically, the imaging unit 30 images the feature region CP of the workpiece W that is disposed in the vicinity of the cutting unit 20 and is held by the chuck table 10. The imaging unit 30 is, for example, a camera using a CCD (Charge Coupled Device) image sensor, but is not limited thereto.

  The control means 6 controls each of the above-described components of the cutting apparatus 1 to cause the cutting apparatus 1 to perform a machining operation on the workpiece W. For example, the control unit 6 controls the chuck table 10, the Y-axis moving unit 50 as an indexing feeding unit, and the X-axis moving unit 40 as a cutting feeding unit. In addition to this, the control means 6 controls the operations of the Z-axis moving means 40, the θ-axis rotating means 70, and the like as the cutting and feeding means. As the control means 6, for example, a microcomputer is used. The control means 6 is connected to a display means for displaying the state of the machining operation and an operation means 7 used when the operator registers machining content information and the like.

  The control means 6 includes, for example, a processing unit 6P using a CPU (Central Processing Unit) or the like and a storage unit 6M using a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), or the like. Have. The processing unit 6P includes a device control unit 6PA and a determination unit 6PB that performs control during idling of the cutting device 1. The storage unit 6M includes a first coordinate storage unit 6MA and a second coordinate storage unit 6MB.

  The first coordinate storage unit 6MA captures the feature region CP (see FIG. 2) of the workpiece W by the imaging unit 30, and the position coordinates of the feature region CP detected based on the captured image information are set to the first. Is stored as the position coordinate P1. The second coordinate storage unit 6MB captures the feature region CP of the workpiece W after performing the idling operation (idling operation of the cutting apparatus 1) by the imaging unit 30, and the feature detected based on the captured image information. The position coordinates of the area CP are stored as the second position coordinates P2.

  The device controller 6PA controls the operation of the cutting device 1. For example, when the Y-axis moving unit 50 is controlled and the cutting unit 20 is indexed and fed to the chuck table 10, the apparatus control unit 6PA reads the Y-axis position detecting sensor 55 from the Y-axis position detecting scale 54. The Y-axis pulse motor 51 is rotated based on the Y-axis position, and the cutting blade moving base 8 on which the cutting means 20 is mounted is moved in the Y-axis direction. In this way, the cutting means 20 is indexed and fed to the chuck table 10.

  When cutting and feeding the cutting means 20 to the chuck table 10, the apparatus control unit 6PA is configured to use the X-axis pulse motor 41 based on the X-axis position read from the X-axis position detection scale 44 by the X-axis position detection sensor 45. And the table moving base 2 on which the chuck table 10 is mounted is moved in the X-axis direction. In this way, the cutting means 20 is indexed and fed to the chuck table 10. When the cutting means 20 is moved up and down and cut and sent to a predetermined position, the apparatus control unit 6PA rotates the Z-axis pulse motor 62 to move the support part 4 supporting the cutting means 20 in the Z-axis direction. In this way, the cutting means 20 is cut and fed to a predetermined position.

  The determination unit 6PB determines whether or not the error ΔE between the first position coordinate P1 and the second position coordinate P2 is within the allowable value ΔEc. The determination unit 6PB has an error ΔE between the first position coordinate P1 stored in the first coordinate storage unit 6MA and the second position coordinate P2 stored in the second coordinate storage unit 6MB within an allowable value ΔEc. If it is determined that the workpiece W is, the control means 6, more specifically, the apparatus control unit 6PA starts a cutting operation of the workpiece W. The determination unit 6PB has an error ΔE between the first position coordinate P1 stored in the first coordinate storage unit 6MA and the second position coordinate P2 stored in the second coordinate storage unit 6MB within an allowable value ΔEc. If it is determined that it is not, the control means 6, more specifically, the apparatus control unit 6PA controls to repeat the idling operation.

  In addition to these, the cutting device 1 may include a cassette elevator (not shown), temporary placement means (not shown), and cleaning / drying means (not shown). The cassette elevator stores a plurality of workpieces W at a time. The temporary placement means has a pair of rails, and temporarily places the workpiece W before and after processing on the pair of rails. The cleaning / drying means has a spinner table, and the workpiece W after processing is placed on and held by the spinner table. Next, the control during the idling operation of the cutting apparatus 1 will be described.

  FIG. 3 is a flowchart showing a control procedure during an idling operation of the cutting apparatus. FIG. 4 is a diagram illustrating an example of an idling operation. 5 and 6 are diagrams for explaining the error. X and Y in FIGS. 5 and 6 indicate the X axis and the Y axis of the cutting device 1, respectively (the same applies hereinafter). When the cutting apparatus 1 performs an idling operation in the present embodiment, the imaging unit 30 illustrated in FIG. 1 captures the feature region CP of the workpiece W illustrated in FIG. 2 (Step S101). When extracting the feature region CP, a key pattern (not shown) having the same shape as the feature region CP stored in the storage unit 6M is used. For example, the control unit 6 extracts the feature region CP of the workpiece W by detecting the feature region CP having a high similarity to the key pattern from the image captured by the imaging unit 30 by pattern matching. When the feature region CP is extracted, the imaging unit 30 images the feature region CP of the workpiece W.

  FIG. 5 shows the image information PS1 of the feature region CP of the workpiece W imaged by the imaging unit 30 in step S101. The image information PS1 is such that the center of the feature region CP coincides with the intersection of the target lines TLX and TLY. In the present embodiment, the intersection of the target lines TLX and TLY coincides with the center of the field of view of the imaging unit 30. The image information PS1 includes position information in the X-axis direction and position information in the Y-axis direction (feature area position information) of the feature area CP. X shown in FIG. 5 is the X-axis position (position in the cutting apparatus 1) read by the X-axis position detection sensor 45 from the X-axis position detection scale 44, and the Y-axis position detection sensor 55 detects the Y-axis position. This is the Y-axis position (position in the cutting device 1) read from the scale 54 (the same applies to the following examples). In this example, the X-axis position and the Y-axis position are both 0.000. For example, these are feature region position information. The processing unit 6P obtains the position coordinates of the detected feature region CP based on the image information PS1 of the captured feature region CP. The first coordinate storage unit 6MA stores this position coordinate as the first position coordinate P1 (step S102). In this example, the position coordinates of the feature region CP are the above-described X-axis position and Y-axis position, that is, P1 (0.000, 0.000).

  Next, the control means 6 makes the cutting device 1 perform an idling operation (step S103). In the idling operation, the cutting blade 21 is moved while supplying the cutting fluid prior to the cutting operation of the workpiece W in order to suppress the dimensional change caused by the temperature change of the spindle 22 or the cutting blade that contributes to the cutting operation. This is a preliminary operation to rotate and operate the drive mechanism such as the X-axis moving unit 40 and the Y-axis moving unit 50. In the present embodiment, as shown in FIG. 4, the cutting of the workpiece W while supplying the cutting fluid in a state where the cutting blade 21 is raised to a position where the cutting blade 21 is not cut into the workpiece W by the Z-axis moving means. Perform machining operations. In this case, a predetermined gap S is formed between the cutting blade 21 and the workpiece W. By doing so, the idling operation can be performed without wasting the workpiece W. The idling operation is not limited to such an operation. For example, the idling operation may be such that the cutting means 20 actually cuts the workpiece W while supplying the cutting fluid at the position where the workpiece W is cut. The idling operation may be an operation in which the cutting blade 21 cuts the dressing board, that is, an operation in which the cutting blade 21 is dressed. Further, the idling operation may be an operation of cutting a dummy of the workpiece W.

  When the idling operation is completed, the imaging unit 30 images the feature region CP of the workpiece W (step S104). In this case, as shown in FIG. 6, the control means 6 moves the imaging means 30 so that the center of the visual field of the imaging means 30, that is, the intersection of the target lines TLX and TLY coincides with the center of the feature region CP. When expansion / contraction of the spindle 22 or expansion / contraction of the cutting blade drive source due to temperature change occurs, the position of the cutting means 20 is deviated from that before expansion / contraction. The imaging means 30 is configured such that the cutting blade 21 of the cutting means 20 is located at the center of the visual field. Therefore, in order to image the feature region CP in the same state as before the idling operation, that is, in the state where the center of the field of view of the image pickup device 30 coincides with the center of the feature region CP, At least one of the position and the position on the Y-axis changes with respect to that before the idling operation.

  FIG. 6 shows the image information PS2 of the feature region CP obtained as a result of imaging the feature region CP in a state where the center of the field of view of the imaging unit 30 coincides with the center of the feature region CP after the idling operation. 6 is 0.052 before the idling operation, that is, X (= 0.000) shown in FIG. 5, and Y is 0 with respect to Y (= 0.000) before the idling operation. .076. As described above, after the idling operation, the position of the imaging means 30, that is, the cutting blade 21, is changed from that before the idling operation. The processing unit 6P obtains the position coordinates of the detected feature region CP based on the image information PS2 of the captured feature region CP. The second coordinate storage unit 6MB stores this position coordinate as the second position coordinate P2 (step S105). In this example, the position coordinates of the feature region CP are the X-axis position and the Y-axis position after idling described above, that is, P2 (0.052, 0.076).

  Next, the determination unit 6PB of the processing unit 6P included in the control unit 6 obtains an error ΔE (position error ΔE) of the position coordinates of the feature region CP before and after the idling operation (step S106). The position error ΔE is | P2−P1 |. When the first position coordinate P1 and the second position coordinate P2 are generalized to P1 (X1, Y1) and P2 (X2, Y2), for example, the position error ΔE is (ΔEX, ΔEY) = (| X2-X1 |, | Y2-Y1 |). In this case, the position error ΔEX is the position error of the feature region CP in the X direction before and after idling, and the position error ΔEY is the position error of the feature region CP in the Y direction before and after idling. The position error ΔE is not limited to this, and may be a moving distance of the feature region CP before and after idling. In this case, the position error ΔE is √ {(X2−X1) + (Y2−Y1)}. The determination unit 6PB reads the first position coordinate P1 from the first coordinate storage unit 6MA, reads the second position coordinate P2 from the second coordinate storage unit 6MB, and obtains the position error ΔE. Next, another method for obtaining an error (position error) ΔE of the position coordinates of the feature region CP before and after the idling operation will be described.

  7 and 8 are diagrams showing another example of a method for obtaining an error in the position coordinates of the feature region before and after the idling operation. In the above example, the position of the cutting blade 21, that is, the center of the field of view of the imaging unit 30 is made to coincide with the center of the feature region CP. However, in this example, the center of the field of view of the imaging unit 30 When returned, the position error ΔE is obtained by obtaining the deviation between the center of the feature region CP in the field of view of the imaging unit 30 and the field of view of the imaging unit 30.

  The first position coordinate P1 of the image information PS1a before the idling operation shown in FIG. 7 and the second position coordinate P2 of the image information PS2a after the idling operation shown in FIG. 8 both have the same value. Yes. That is, the image information PS2a after the idling operation is captured at the same position as the image information PS1a before the idling operation. In the image information PS1a before the idling operation, the center of the field of view of the imaging unit 30 coincides with the center of the feature region CP. On the other hand, in the image information PS1b after the idling operation, the center of the field of view of the imaging unit 30 is shifted from the feature region CP. Specifically, the feature region CP is shifted from the target line TLX by ΔX in the X-axis direction and by ΔY from the target line TLY. This deviation becomes a position error ΔE (= (ΔX, ΔY)). Thus, before and after the idling operation, the first position coordinate P1 and the second position coordinate P2 obtained from the image information PS1a and PS2a when the same feature region CP is imaged at the same position with respect to the cutting device 1. The position error ΔE may be obtained from the above.

  When the position error ΔE is obtained, the determination unit 6PB determines whether or not the error between the first position coordinate P1 and the second position coordinate P2, that is, the position error ΔE is within the allowable value ΔEc (step). S107). ΔEc is set to a size that allows the expansion / contraction of the spindle 22 or the dimensional change of the cutting blade drive source due to a temperature change, and is stored in the storage unit 6M. The allowable value ΔEc is appropriately determined depending on the required processing accuracy of the workpiece W and the like. When ΔE ≦ ΔEc is satisfied (step S107, Yes), it can be determined that the expansion / contraction of the spindle 22 or the dimensional change of the cutting blade drive source is within an allowable range. In this case, the control means 6 starts the cutting operation of the workpiece W (step S108). That is, the workpiece W is cut while the cutting blade 21 is rotated in a state where the tray 12 on which the workpiece W to be processed is attached is held by the holding portion 11 of the chuck table 10.

  When ΔE ≦ ΔEc is not satisfied, that is, when ΔE> ΔEc (step S107, No), it can be determined that the expansion / contraction of the spindle 22 or the dimensional change of the cutting blade drive source is outside the allowable range. In this case, the control means 6 stores the current second position coordinate P2 in the first coordinate storage unit 6MA as the first position coordinate P1. Thereafter, the control means 6 repeats Steps S103 to S107 until ΔE ≦ ΔEc. In this case, the position error ΔE is obtained as an error between the first position coordinate P1 and the second position coordinate P2 before and after the latest idling operation.

  As described above, in the present embodiment, the idling operation is repeated until the position error becomes a size that allows the extension / contraction of the spindle or the dimensional change of the cutting blade drive source due to the temperature change. For this reason, even if the product is processed with the intention of performing idling sufficiently, the expansion / contraction of the spindle, cutting blade drive source (motor), chuck table, etc. due to temperature change is difficult to understand until the product is actually processed. Can be avoided. As a result, this embodiment can stabilize the dimensional change of the spindle or the cutting blade drive source caused by the temperature change with the necessary and sufficient idling operation, and can allow the dimensional change by the idling operation. Can be confirmed. For this reason, the cutting operation can be started in a state where the dimensional change is allowed. As a result, highly accurate machining can be realized more reliably. Also, in product processing, even if the stroke is fine with a small diameter product, etc., and it is difficult to determine that the dimensional change of the spindle or cutting blade drive source is stable, the dimensional change is surely made. Can be stabilized.

DESCRIPTION OF SYMBOLS 1 Cutting apparatus 2 Table movement base 3 Apparatus main body 6 Control means 6M Storage part 6MA First coordinate storage part 6MB Second coordinate storage part 6P Processing part 6PA Apparatus control part 6PB Judgment part 8 Cutting blade movement base 7 Operation means 10 Chuck Table 11 Holding section 12 Tray 20 Cutting means 21 Cutting blade 22 Spindle 23 Housing 24 Cutting fluid supply nozzle 30 Imaging means 40 X-axis moving means 50 Y-axis moving means 60 Z-axis moving means 70 θ-axis rotating means

Claims (2)

A chuck table for holding a workpiece having a characteristic area on the surface on the upper surface;
Cutting means for performing processing while supplying a cutting fluid to the workpiece held on the chuck table;
Index feeding means for indexing and feeding the cutting means to the chuck table;
Cutting feed means for cutting and feeding the chuck table to move in a cutting feed direction orthogonal to the index feed direction;
Cutting and feeding means for raising and lowering the cutting means and cutting and feeding to a predetermined position;
An imaging means for imaging a feature area of the workpiece disposed in the vicinity of the cutting means and held by the chuck table;
A control device for controlling the chuck table, the index feed means and the cutting feed means, and a cutting device comprising:
The control means includes
A first coordinate storage unit that captures the feature area of the workpiece by the imaging unit and stores the position coordinates of the feature area detected based on the captured image information as a first position coordinate;
A second coordinate memory that stores the position coordinates of the feature area detected based on the image information obtained by imaging the feature area of the workpiece after the idling operation by the imaging unit as the second position coordinates. And
A determination unit that determines whether an error between the first position coordinate and the second position coordinate is within an allowable value;
An error between the first position coordinate stored in the first coordinate storage unit and the second position coordinate stored in the second coordinate storage unit is within an allowable value by the determination unit. If it is determined, the control means starts the cutting operation of the workpiece,
An error between the first position coordinate stored in the first coordinate storage unit and the second position coordinate stored in the second coordinate storage unit is not within an allowable value. If it is determined, the control means controls to repeat the idling operation. The idling operation is
The cutting apparatus according to claim 1, wherein the cutting means performs a cutting operation of the workpiece while supplying a cutting fluid in a state where the cutting means is raised to a position where the cutting means is not cut into the workpiece.

Images