JP6125867B2 - Cutting method - Google Patents

Description

  The present invention relates to a cutting method using a cutting blade.

  For example, in a semiconductor device manufacturing process, a plurality of circuit elements such as ICs and LSIs are formed on the surface of a wafer. The wafer on which the circuit elements are formed is ground to a predetermined thickness by grinding the back surface, cut by a cutting device, and divided into individual semiconductor chips. The cutting device includes, for example, a cutting blade that cuts a workpiece, and state detection means that detects the state (breakage (chip), wear amount, etc.) of the cutting blade (for example, Patent Document 1 or 2). reference). The cutting device performs cutting by rotating a cutting blade having a thickness of about 30 μm into the workpiece while rotating the cutting blade at a high speed of about 3000 rpm, and relatively moving the cutting blade and the workpiece.

  As state detection means, blade detection means fixed to the spindle housing that supports the spindle and mounted on a wheel cover that covers the upper half of the cutting blade, and reference position detection means arranged alongside the chuck table are often used. Is done. Since the blade detection means is attached to the wheel cover, the state of the cutting blade can be detected in real time even during processing, but because it is affected by cutting water injected toward the cutting blade, The detection accuracy of the blade edge (tip of the cutting blade) becomes unstable. On the other hand, the reference position detection means is arranged side by side with the chuck table, and since the cutting water is stopped during the reference position detection operation, the cutting edge (tip of the cutting blade) is not affected by cutting water or the like. However, during the detection, the processing of the workpiece is temporarily interrupted.

  Since such a cutting apparatus performs processing while wearing the cutting blade of the cutting blade, it is normal to correct the position of the tip of the cutting blade by using the reference position detecting means every time a certain distance is processed. It is. At that time, the cutting apparatus narrows the interval for correcting the position of the cutting blade using the reference position detecting means so that the division failure due to the insufficient cutting amount does not occur.

Japanese Utility Model Publication No. 7-7854 JP 2009-83072 A

  In the cutting method having the reference position detection means, if the interval for correcting the position of the cutting blade using the reference position detection means is narrowed, the number of times the correction of the position of the cutting blade is increased. Since the number of times of interruption is increased, the processing amount per unit time may be reduced.

  The present invention has been made in view of the above, and can correct the position of the tip of the cutting blade using the reference position detection means while suppressing a decrease in the processing amount per unit time. An object is to provide a cutting method.

In order to solve the above-described problems and achieve the object, the cutting method of the present invention has a chuck table for holding a workpiece and a cutting blade for cutting the workpiece held on the chuck table on the outer periphery. Cutting means provided with a cutting blade, machining feed means for relatively feeding the chuck table and the cutting means, cutting feed means for cutting and feeding the cutting blade in a cutting feed direction perpendicular to the machining feed direction, and machining feed The reference position detection means for detecting the reference position of the cutting blade in the cutting feed direction by operating the cutting means and the cutting feed means to approach the cutting blade, and the light emitting portion and the light receiver A blade detecting means for detecting the position of the cutting blade and measuring the amount of wear during cutting while supplying cutting water, and the reference position detecting means A cutting method of cutting a workpiece using a cutting device that detects the position of the cutting blade with high accuracy in a state where no cutting water is supplied, and the amount of wear of the cutting blade detected by the blade detecting means is allowable. The wear amount allowable value setting step for setting the value and the reference position detection for detecting the reference position of the tip of the cutting blade by operating the processing feed means and the cutting feed means to bring the cutting blade of the cutting blade closer to the reference position detection means After the step and the reference position detecting step, the workpiece held on the chuck table is measured with a cutting blade positioned based on the reference position detected in the reference position detecting step while measuring the wear amount by the blade detecting means. A cutting step for cutting, and a reference position detecting step when the blade detecting means detects that the wear amount of the cutting blade has reached the set wear amount tolerance during the cutting step. And a re-detection step of performing again, does not reach the wear amount allowable value wear amount is set for the cutting blades during the cutting step performed is subjected to cutting continuously to the workpiece It is characterized by that.

  According to the cutting method of the present invention, when the blade detecting means detects that the wear amount of the cutting blade has reached the set wear amount allowable value during the cutting step, the reference position detecting step is performed again. Therefore, if the cutting blade is difficult to wear, the interval until the correction of the cutting blade position using the reference position detection means can be increased, and the number of times that machining is temporarily interrupted can be reduced. it can. Accordingly, it is possible to correct the position of the tip of the cutting blade using the reference position detection means while suppressing a decrease in the processing amount per unit time.

FIG. 1 is a perspective view illustrating a configuration example of a cutting apparatus according to an embodiment. FIG. 2 is an enlarged view of the blade detection means. FIG. 3 is a block diagram illustrating a configuration example of the blade detection unit. FIG. 4 is an explanatory diagram of the reference voltage. FIG. 5 is an enlarged view of the reference position detecting means. FIG. 6 is a block diagram illustrating a configuration example of the reference position detection unit. FIG. 7 is a block diagram showing a configuration example of the control means. FIG. 8 is a flowchart showing the cutting method according to the embodiment.

  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 and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. In addition, various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment
FIG. 1 is a perspective view illustrating a configuration example of a cutting apparatus according to an embodiment. FIG. 2 is an enlarged view of the blade detection means. FIG. 3 is a block diagram illustrating a configuration example of the blade detection unit. FIG. 4 is an explanatory diagram of the reference voltage. FIG. 5 is an enlarged view of the reference position detecting means. FIG. 6 is a block diagram illustrating a configuration example of the reference position detection unit. FIG. 7 is a block diagram showing a configuration example of the control means.

  As shown in FIG. 1, the cutting device 1 according to the embodiment includes a chuck table 10, a cutting unit 20, an imaging unit 30, a processing feeding unit 40, an indexing feeding unit 50, a cutting feeding unit 60, and wear. The quantity setting means 70, the blade detection means 80, the reference position detection means 90, and the control means 100 are configured. The cutting apparatus 1 includes a cassette elevator 3, a cassette 4, a temporary placement unit 5, a transport unit 6, a cleaning unit 7, and a carry-in / out unit 8. The cutting apparatus 1 processes the workpiece W by relatively moving the chuck table 10 that holds the workpiece W and the two cutting means 20. In the present embodiment, the cutting device 1 is a facing dual type processing device in which two cutting means 20 are arranged to face each other in the indexing feed direction (Y-axis direction). In addition, the cutting device 1 can drive the two cutting means 20 synchronously and can drive the two cutting means 20 asynchronously.

The workpiece W is not particularly limited, but for example, a plate-like semiconductor wafer or optical device wafer based on silicon, gallium arsenide (GaAs) or the like, ceramic, glass, sapphire (Al ₂ O ₃ ) -based material. Various processing materials such as a plate-like inorganic material substrate and a plate-like ductile material such as metal or resin. In the present embodiment, the workpiece W has an adhesive tape T (also referred to as a dicing tape) attached to the back surface where devices such as IC (Integrated Circuit) and LSI (Large Scale Integration) are not formed. The adhesive tape T is also fixed to the frame F by being attached to the annular frame F.

  The cassette elevator 3 is movable up and down in the Z-axis direction with respect to the apparatus main body 2. The cassette 4 is moved up and down by the cassette elevator 3 to store the workpieces W one by one. The temporary placement means 5 temporarily places the workpiece W before and after processing on a pair of rails. The conveying means 6 is a so-called frame conveying means having a chuck means for chucking the frame F, and conveys the workpiece W processed by the two cutting means 20 from the chuck table 10 to the cleaning means 7. The cleaning means 7 cleans the surface of the workpiece W by spraying a cleaning liquid onto the surface of the workpiece W from a cleaning nozzle (not shown) while rotating the spinner table 7 a that holds the workpiece W. The carry-in / out means 8 takes out one workpiece W before cutting from the cassette 4 and transports it to the temporary placement means 5, and feeds one workpiece W after cleaning after the cutting from the spinner table 7 a. Carry it into the cassette 4.

  The chuck table 10 has a disk shape in which a portion constituting the holding surface 11 is formed of porous ceramic or the like, and sucks and holds the workpiece W placed on the holding surface 11 by a vacuum suction source (not shown).

  As shown in FIGS. 1 and 2, the cutting means 20 includes a cutting blade 21, a spindle 22, a spindle housing 23, a cutting fluid supply nozzle 24, and a cleaning fluid supply nozzle 25. The cutting means 20 performs cutting while supplying a cutting fluid to the workpiece W held on the chuck table 10. In addition, the cutting unit 20 processes the region to be processed of the workpiece W based on the image data captured by the imaging unit 30. The cutting blade 21 is an annular ultra-thin cutting grindstone. As shown in FIG. 2, the cutting blade 21 has a cutting edge 21 a for cutting the workpiece W on the outer periphery. The cutting blade 21 is detachably attached to one end of the spindle 22. The cutting fluid supply nozzle 24 supplies the cutting fluid to a processing point of the workpiece W during processing of the workpiece W by the cutting blade 21. The cleaning liquid supply nozzle 25 supplies the cleaning liquid to the cutting blade 21 a during the processing of the workpiece W by the cutting blade 21.

  The imaging means 30 is, for example, a camera using a CCD (Charge Coupled Device) image sensor. The imaging unit 30 captures the surface of the workpiece W to generate alignment adjustment image data, and outputs the image data to the control unit 100.

  As shown in FIG. 1, the machining feed means 40 corresponds to an X-axis moving means for machining and feeding the chuck table 10 relative to the apparatus body 2 in the X-axis direction, and the chuck table 10 and the cutting means 20 are connected. Process feed relatively. The machining feed means 40 rotates and drives the X-axis ball screw by the rotational force of the X-axis pulse motor, thereby guiding the X-axis moving base with a pair of X-axis guide rails in the X-axis direction. Move to. In the present embodiment, the X-axis direction is a direction orthogonal to the rotation axis of the cutting blade 21 and is a direction orthogonal to the vertical direction.

  Further, the machining feed means 40 includes an X-axis position detection mechanism (not shown) that detects the position of the chuck table 10 in the X-axis direction. The X-axis position detection mechanism includes, for example, an X-axis position detection scale and an X-axis position detection sensor.

  The index feeding means 50 corresponds to a Y-axis moving means for indexing and feeding the cutting means 20 relative to the apparatus body 2 in the Y-axis direction, and relatively indexes and feeds the cutting means 20. The index feeding means 50 rotates and drives the Y-axis ball screw 51 by the rotational force of the Y-axis pulse motor 52, thereby guiding the Y-axis moving base 54 with the pair of Y-axis guide rails 53, with respect to the apparatus main body 2. To move in the Y-axis direction. In the present embodiment, the Y-axis direction is the direction of the rotation axis of the cutting blade 21 and is a direction orthogonal to the vertical direction.

  Further, the index feeding means 50 includes a Y-axis position detection mechanism (not shown) that detects the position of the cutting means 20 in the Y-axis direction. The Y-axis position detection mechanism includes, for example, a Y-axis position detection scale and a Y-axis position detection sensor.

  The cutting and feeding means 60 corresponds to a Z-axis moving means that relatively cuts and feeds the cutting means 20 relative to the apparatus body 2 in the Z-axis direction, that is, the direction in which the cutting blade 21 approaches and leaves the chuck table 10. Cut 20 and feed. The notch feeding means 60 rotates the Z-axis ball screw 61 by the rotational force of the Z-axis pulse motor 62, thereby guiding the Z-axis moving member 64 with the pair of Z-axis guide rails 63 with respect to the apparatus main body 2. Move in the Z-axis direction. Thereby, the cutting feed means 60 cuts and feeds the cutting blade 21a of the cutting blade 21 in a direction orthogonal to the machining feed direction (X-axis direction). In the present embodiment, the Z-axis direction is the vertical direction.

  Further, the cutting feed means 60 includes a Z-axis position detection mechanism (not shown) that detects the position of the cutting means 20 in the Z-axis direction. The Z-axis position detection mechanism includes, for example, a Z-axis position detection scale and a Z-axis position detection sensor.

  The wear amount setting means 70 is a display panel that is disposed at a position that is easy to operate for an operator such as an operator and that is easy to see, displays various types of information associated with the processing, and the like. It is also an input panel having a touch panel configuration for inputting and setting an allowable wear amount.

  The blade detection means 80 detects the position of the cutting blade 21a during the cutting process on the workpiece W, and measures the wear amount of the cutting blade 21a. As shown in FIG. 3, the blade detection unit 80 includes a blade detection unit 110. The blade detection unit 80 includes a wheel cover 81, a light emitting unit 82, and a light receiving unit 83. The wheel cover 81 is fixed to the spindle housing 23 that rotatably supports the spindle 22, and is disposed above the cutting blade 21 (+ Z axis direction). The wheel cover 81 has a mounting hole 84 (see FIG. 2) expanded in the vertical direction. The wheel cover 81 can adjust the relative position in the vertical direction with respect to the cutting blade 21 by loosening or tightening the fastening member 85 attached to the attachment hole 84. The wheel cover 81 includes a first wall portion 81a and a second wall portion 81b that extend vertically downward, that is, in the −Z axis direction. The first wall portion 81a and the second wall portion 81b are opposed to each other with an interval in the Y-axis direction. A gap between the first wall portion 81a and the second wall portion 81b is a blade intrusion portion 86 that can enter without the cutting blade 21a of the cutting blade 21 coming into contact therewith. The blade intrusion portion 86 is formed at an interval at which the cutting blade 21a of the cutting blade 21 having the maximum blade thickness that can be used by the cutting means 20 can enter without contacting. For this reason, during the processing of the workpiece W, the relative distance between the rotation axis of the cutting blade 21 and the light emitting portion 82 and the light receiving portion 83 does not change, so the blade detecting means 80 can determine the wear amount of the cutting blade 21a in real time. Can be detected.

  The light emitting part 82 is provided on the first wall part 81a. The light receiving portion 83 is provided on the second wall portion 81b. The light emitting unit 82 and the light receiving unit 83 are arranged to face each other in the Y-axis direction. The light emitting unit 82 includes, for example, a light emitting element as the light source 87 and irradiates light toward the light receiving unit 83. The light receiving part 83 has, for example, a light receiving element. The light receiving unit 83 outputs a light reception signal corresponding to the intensity of the received light to the blade detection unit 110.

  The blade detection unit 110 detects an allowable wear amount. The blade detection unit 110 includes a photoelectric conversion unit 111, a reference voltage setting unit 112, a voltage comparison unit 113, and a wear amount allowable value detection unit 114.

  The photoelectric conversion unit 111 converts the amount of light received by the light receiving unit 83 into a voltage and outputs the voltage. The photoelectric conversion unit 111 outputs a voltage corresponding to the amount of light received by the light receiving unit 83. When the amount of received light is small, the photoelectric conversion unit 111 outputs a higher voltage than when the amount of received light is large. As shown in FIG. 4, the photoelectric conversion unit 111 outputs a voltage of 5 V (maximum voltage) when the light reception rate is 0% and 0 V (minimum voltage) when the light reception rate is 100%.

  The reference voltage setting unit 112 sets and outputs a reference voltage. The reference voltage setting unit 112 outputs a voltage lower than the maximum voltage output from the photoelectric conversion unit 111. In this embodiment, the reference voltage output from the reference voltage setting unit 112 is 3V. Here, the reference voltage is set such that, for example, when the wear amount of the cutting blade 21 reaches a wear amount allowable value described later, the voltage output from the photoelectric conversion unit 111 is reduced to 3V. For this reason, the reference voltage may be changed according to the set wear amount allowable value.

  The voltage comparison unit 113 compares the voltage output from the photoelectric conversion unit 111 with the reference voltage output from the reference voltage setting unit 112, and outputs a comparison result signal. For example, the voltage comparison unit 113 outputs different signals depending on whether the voltage output from the photoelectric conversion unit 111 is higher than the reference voltage or lower than the reference voltage.

  The wear amount allowable value detection unit 114 detects that the wear amount of the cutting blade 21a of the cutting blade 21 has reached the wear amount allowable value based on the signal output from the voltage comparison unit 113. In this embodiment, the wear amount allowable value detection unit 114 receives a signal when the voltage output from the photoelectric conversion unit 111 is equal to or lower than the reference voltage from the voltage comparison unit 113, thereby obtaining the wear amount allowable value. Detect that it has been reached. Further, when the wear amount allowable value detection unit 114 detects that the wear amount allowable value has been reached, it outputs a signal to a reference position detection unit 120 described later, and the reference position detection unit 90 described later detects the reference position. Make it.

  As shown in FIGS. 5 and 6, the reference position detection unit 90 detects the tip position (lower end position) of the cutting blade 21 a in the cutting feed direction of the cutting blade 21. The reference position detector 90 detects the reference position of the cutting blade 21a in the cutting feed direction (Z-axis direction) by operating the machining feed means 40 and the cutting feed means 60 to bring the cutting blade 21a of the cutting blade 21 closer. But there is. As shown in FIG. 6, the reference position detection unit 90 includes a reference position detection unit 120. In the present embodiment, the reference position detection means 90 is provided on the movable table 12 (see FIG. 1) that holds the chuck table 10. The reference position detection unit 90 includes a light emitting unit 91, a light receiving unit 92, and a support member 93. The support member 93 is fixed to the upper surface of the movable table 12. The support member 93 has a first protrusion 93a and a second protrusion 93b that protrude vertically upward, that is, in the + Z-axis direction. The first protrusion 93a and the second protrusion 93b are opposed to each other with a gap in the Y-axis direction. A gap between the first protrusion 93a and the second protrusion 93b is a blade intrusion portion 96 that can be intruded without the cutting blade 21a of the cutting blade 21 coming into contact therewith. The blade intrusion portion 96 is a substantially U-shaped space portion, and is formed with an interval at which at least the cutting blade 21 having the maximum blade thickness that can be used by the cutting means 20 can enter without contacting. The bottom of the blade intrusion portion 96 has an inclination that goes downward in the vertical direction as it goes in the -X direction.

  The light emitting part 91 is provided in the first protrusion 93a. The light receiving part 92 is provided in the second protrusion 93b. The light emitting unit 91 and the light receiving unit 92 are arranged to face each other in the Y-axis direction. The light emitting unit 91 has, for example, a light emitting element as the light source 97, and irradiates light toward the light receiving unit 92. For example, the light receiving unit 92 includes a light receiving element. The light receiving unit 92 outputs a light reception signal corresponding to the intensity of the received light to the reference position detection unit 120.

  The support member 93 is provided with a cleaning water supply nozzle 94 and an air supply nozzle 95. The cleaning water supply nozzle 94 supplies cleaning water to the light emitting unit 91 and the light receiving unit 92 to clean the light emitting unit 91 and the light receiving unit 92. The air supply nozzle 95 supplies air to the light emitting unit 91 and the light receiving unit 92 and blows away cleaning water to dry the light emitting unit 91 and the light receiving unit 92. Thereby, even if cutting waste adheres to the light emitting part 91 and the light receiving part 92, it is washed away, so that the tip of the cutting blade 21a of the cutting blade 21 can be accurately detected.

  The reference position detector 120 detects the reference position of the cutting blade 21 a of the cutting blade 21. The reference position detection unit 120 includes a photoelectric conversion unit 121, a reference voltage setting unit 122, a voltage comparison unit 123, an end position detection unit 124, a calculation unit 125, and a position correction unit 126.

  The photoelectric conversion unit 121 converts the amount of light received by the light receiving unit 92 into a voltage and outputs the voltage. The photoelectric conversion unit 121 outputs a voltage corresponding to the amount of light received by the light receiving unit 92. When the amount of received light is small, the photoelectric conversion unit 121 outputs a higher voltage than when the amount of received light is large. As shown in FIG. 4, the photoelectric conversion unit 121 outputs a voltage of 5 V (maximum voltage) when the light reception rate is 0% and 0 V (minimum voltage) when the light reception rate is 100%.

  The reference voltage setting unit 122 sets and outputs a reference voltage. The reference voltage setting unit 122 outputs a voltage lower than the maximum voltage output from the photoelectric conversion unit 121. As shown in FIG. 4, the reference voltage output from the reference voltage setting unit 122 is 3V in the present embodiment. Here, the reference voltage is obtained when, for example, the cutting blade 21 enters the blade intrusion portion 96 and the tip of the cutting blade 21 a of the cutting blade 21 reaches the optical axis of the light emitting portion 91. The voltage output from the voltage rises to 3V. For this reason, the reference voltage may be changed in accordance with the amount of penetration of the cutting blade 21a into the blade entry portion 96.

  The voltage comparison unit 123 compares the output voltage of the photoelectric conversion unit 121 with the reference voltage output from the reference voltage setting unit 122, and outputs a comparison result signal. For example, the voltage comparison unit 123 outputs different signals depending on whether the output voltage of the photoelectric conversion unit 121 is higher than the reference voltage or lower than the reference voltage.

  The end position detection unit 124 cuts the cutting blade 21 based on a signal output from the voltage comparison unit 123 and a position signal in the Z-axis direction acquired from a Z-axis position detection mechanism (not shown) of the cutting feed unit 60. The tip position (lower end position) of the blade 21a is detected. Specifically, the end position detection unit 124 lowers the cutting blade 21 (moves in the −Z axis direction) via the control unit 100 to cause the cutting blade 21 a to enter the blade intrusion unit 96, and the light from the light emitting unit 91. , The position in the Z-axis direction acquired from the Z-axis position detection mechanism at the time when the signal output from the voltage comparison unit 123 is different is used as the tip position (lower end position) of the cutting blade 21a of the cutting blade 21. To detect. That is, the end position detection unit 124 detects the Z-axis position of the Z-axis position detection mechanism when the tip of the cutting blade 21a of the cutting blade 21 is detected as the reference position.

  The calculation unit 125 calculates a correction amount of the position of the cutting blade 21 in the cutting feed direction based on the reference position detected by the end position detection unit 124.

  The position correction unit 126 corrects the position of the cutting blade 21 in the cutting feed direction based on the correction amount calculated by the calculation unit 125. For this reason, the position of the cutting blade 21 when processing the workpiece W is controlled based on the corrected position. In the present embodiment, correcting the position of the cutting blade 21 in the cutting feed direction is to match the tip of the cutting blade 21a of the cutting blade 21 to the origin position, that is, the reference position.

  The control means 100 is an electronic control device having a computer. As shown in FIG. 7, the control unit 100 includes a blade detection unit 110, a reference position detection unit 120, and a drive control unit 130. The control means 100 is connected to each device of the cutting device 1 described above. The control means 100 includes a wear amount allowable value set by the wear amount setting means 70, a wear amount of the cutting edge 21 a detected by the blade detection means 80, and a reference of the cutting edge 21 a detected by the reference position detection means 90. Each means 20, 40, 50, 60 is controlled via the drive control unit 130 based on the position.

  As shown in FIG. 1, the cutting apparatus 1 configured as described above captures the workpiece W sucked and held by the chuck table 10 by the imaging means 30 to generate alignment adjustment image data, and this image data After adjusting the alignment between the cutting means 20 and the workpiece W based on the above, the cutting means 20 is cut into the chuck table 10 while rotating the cutting blade 21 of the cutting means 20 at a high speed, and the Z-axis direction is fed by the feed means 60. The chuck table 10 is processed and fed relative to the cutting means 20 in the X-axis direction by the machining feed means 40, and the cutting means 20 is indexed and fed to the chuck table 10 by the index feed means 50. By relatively indexing and feeding in the axial direction, it is possible to form a cutting groove by cutting the division planned line of the workpiece W. Further, the cutting device 1 cuts all the planned division lines in the same direction, and then rotates the chuck table 10 by 90 degrees with a rotating means (not shown), and repeats the same cutting process with the cutting means 20, thereby processing the workpiece. Cutting grooves can be formed in a grid pattern on the workpiece W, and the workpiece W can be divided into individual devices.

  Next, the cutting method according to the embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the cutting method according to the embodiment.

  First, the cutting device 1 sets a wear amount allowable value of the cutting blade 21 (step ST1). The step ST1 will be described in detail. The control means 100 of the cutting device 1 detects the wear amount allowable value input to the wear amount setting means 70 by a worker such as an operator, and the cutting blade according to the detected input operation. The wear amount allowable value of the wear amount of 21 is set. That is, the control unit 100 performs the “wear amount allowable value setting step” for setting the wear amount allowable value of the wear amount of the cutting blade 21 a detected by the blade detection unit 80. In the present embodiment, the wear amount allowable value of the amount of wear of the cutting blade 21 is, for example, full-cut the workpiece W by cutting the cutting blade 21a by 10 μm into the adhesive tape T attached to the back surface of the workpiece W. In this case, it is set to 5 μm. As a result, when the wear amount of the cutting blade 21 reaches 5 μm, which is a wear amount allowable value, a re-detection step (step ST5 affirmation, step ST2) described later can be performed. By cutting the cutting edge 21a into the tape T by at least 5 μm, the workpiece W can be fully cut.

  In this wear amount allowable value setting step, the blade detection means 80 is positioned at the initial position in the Z-axis direction. Here, the initial position is a position where the voltage output from the photoelectric conversion unit 111 is less than the maximum voltage of 5 V and higher than the reference voltage of 3 V, that is, a position where the light receiving unit 83 receives at least light. Thereby, when the cutting blade 21a of the cutting blade 21 is worn, the voltage output from the photoelectric conversion unit 111 is decreased. The adjustment of the initial position of the blade detection unit 80 is performed by, for example, displaying the voltage output from the photoelectric conversion unit 111 in real time on the wear amount setting unit 70 having a touch panel configuration, and changing the voltage displayed on the wear amount setting unit 70. While confirming by the operator, the position of the blade detection means 80 is adjusted in the Z-axis direction, and the fastening member 85 is tightened at the position where the voltage output from the photoelectric conversion unit 111 is less than the maximum voltage of 5V. Is done.

  Next, the cutting device 1 detects the reference position of the cutting blade 21 (step ST2). The step ST2 will be described in detail. The control unit 100 of the cutting apparatus 1 operates the processing feed unit 40 and the cutting feed unit 60 to bring the cutting blade 21a of the cutting blade 21 closer to the reference position detection unit 90, thereby entering the blade. The penetration of the cutting blade 21a into the part 96 is detected, and the Z-axis position of the Z-axis position detection mechanism when this penetration is detected is set as the reference position (origin position) of the tip of the cutting blade 21a. That is, the control means 100 performs a “reference position detection step” for detecting the reference position of the tip of the cutting blade 21a.

  In this reference position detection step, the processing feed means 40 and the index feed means 50 are operated so that the optical axis connecting the light emitting portion 91 and the light receiving portion 92 and the rotation axis of the cutting blade 21 overlap on the Z axis. .

  Next, the cutting device 1 cuts the workpiece W (step ST3). This step ST3 will be described in detail. The control unit 100 of the cutting apparatus 1 detects the amount of wear of the cutting blade 21a of the cutting blade 21 with the blade detection unit 80, and is detected in the above step ST2 (reference position detection step). The workpiece W held on the chuck table 10 is cut by the cutting blade 21a positioned based on the reference position (origin position). That is, the control means 100 performs a “cutting step” for cutting the workpiece W held on the chuck table 10 after the reference position detecting step (step ST2).

  In this cutting step, the cutting fluid is sprayed from the cutting fluid supply nozzle 24 of the cutting means 20 toward the processing point, and the cleaning fluid is sprayed from the cleaning fluid supply nozzle 25 toward the cutting blade 21a. Further, the cutting feeding means 60 is operated so as to cut 10 μm into the adhesive tape T adhered to the back surface of the workpiece W.

  Next, the cutting device 1 determines whether or not to end the cutting process (step ST4). The step ST4 will be described in detail. The control unit 100 of the cutting apparatus 1 determines whether or not to end the cutting process, for example, depending on whether or not the workpiece W that has been subjected to the cutting process has reached a predetermined number of workpieces. To do. Moreover, the cutting apparatus 1 will complete | finish a cutting process, if it judges that the cutting process with respect to the workpiece W is complete | finished (step ST4 affirmation).

  Further, when the cutting device 1 determines that the cutting process on the workpiece W is not finished (No in step ST4), the cutting apparatus 1 determines whether or not the wear amount of the cutting blade 21a of the cutting blade 21 has reached the wear amount allowable value. (Step ST5). If this step ST5 is demonstrated in detail, the control means 100 of the cutting device 1 is the signal when the wear amount tolerance detection part 114 reaches | attains 3V as a reference voltage when the voltage which the photoelectric conversion part 111 outputs falls, and reaches | attains (3V). Whether or not the wear amount allowable value has been reached is determined based on whether or not the wear amount allowable value detection signal) is received from the voltage comparison unit 113.

  Further, when the cutting device 1 determines that the wear amount of the cutting blade 21a of the cutting blade 21 has not reached the wear amount allowable value (No in step ST5), the cutting device 1 performs the above-described step ST3 (cutting step). That is, the cutting device 1 can continuously perform the cutting process on the plurality of workpieces W if the wear amount of the cutting blade 21a does not reach the wear amount allowable value.

  Further, when the cutting device 1 determines that the wear amount of the cutting blade 21a of the cutting blade 21 has reached the wear amount allowable value (Yes in step ST5), the cutting device 1 performs the above-described step ST2 (reference position detection step). The step ST5 affirmation will be described in detail. When the voltage comparison unit 113 outputs the wear amount allowable value detection signal, the control unit 100 of the cutting apparatus 1 indicates that the wear amount allowable value detection unit 114 has reached the wear amount allowable value. And the reference position detecting means 90 detects the reference position (origin position) of the cutting blade 21a of the cutting blade 21. That is, the control means 100 confirms that the wear amount of the cutting blade 21a has reached the wear amount allowable value set in step ST1 (wear amount allowable value setting step) during the execution of step ST3 (cutting step). When the blade detection means 80 detects (Yes in step ST5), a “redetection step” is performed in which the step ST2 (reference position detection step) is performed again. Thereby, since the reference position (origin position) of the cutting blade 21a of the cutting blade 21 is corrected, the cutting blade 21a can be cut by 10 μm into the adhesive tape T adhered to the back surface of the workpiece W. The object W can be fully cut.

  In addition, when the wear amount of the cutting blade 21a reaches the wear amount allowable value as a result of step ST5 affirmation, the cutting device 1 performs the step ST2 (reference position detection step) again, so that the step ST2 (reference step) is performed. The number of executions of the position detection step) can be reduced.

  As described above, according to the cutting method of the cutting apparatus 1 according to the present embodiment, the wear amount of the cutting blade 21a is set in the wear amount allowable value setting step (step ST1) during the cutting step (step ST3). When the blade detection means 80 detects that the wear amount allowable value has been reached, the reference position detection step (step ST2) is performed again. For this reason, when it is hard to wear the cutting blade 21, the space | interval until it implements a reference position detection step (step ST2) again can be extended.

  Moreover, since the interval until the reference position detection step (step ST2) is performed again can be increased, the number of times that the cutting process is temporarily interrupted to perform the reference position detection step (step ST2) is reduced. Can do. Therefore, it is possible to correct the position of the tip of the cutting blade 21a using the reference position detecting means 90 while suppressing a decrease in the processing amount per unit time. That is, the throughput of the cutting process 1 can be increased.

  Further, the blade detection means 80 capable of detecting the wear amount of the cutting blade 21a at any time during the processing, that is, during the cutting step (step ST3), the wear amount up to a certain level (the wear amount allowable value in this embodiment) ( Since the reference position detecting means 90 is used for correcting the position of the cutting blade 21 when the wear amount of the cutting blade 21a reaches a certain level while being used for the measurement of the amount of wear), the workpiece W due to wear of the cutting blade 21 is used. Can be prevented from occurring.

  In the division (full cut) of the silicon wafer as the workpiece W, the reference position detection is usually performed once every time one of the division planned lines is processed. In many cases, the detected value is about 0 to 2 μm. For this reason, the cutting method of the cutting apparatus 1 according to the present embodiment is particularly effective when dividing the workpiece W to which the cutting blade 21 is unlikely to wear, such as a silicon wafer (full cut).

  In the above embodiment, the cutting apparatus 1 is a dicer having two spindles 22, a so-called dual dicer, but may be a dicer having one spindle.

  Further, in the above embodiment, the reference position detection unit 90 is provided on the moving table 12, but even if the reference position detection unit 90 is disposed on the X axis around the chuck table 10, It may be arranged directly below. That is, the reference position detection unit 90 can be arranged at an appropriate position according to the arrangement form of the cutting unit 20 in the cutting apparatus 1.

  In the above embodiment, the reference position detection means 90 detects the reference position of the cutting blade 21, but detects the wear amount of the cutting blade 21a from the displacement of the Z-axis position detected by the Z-axis position detection mechanism. You can also As a result, the operator can grasp the amount of wear of the cutting blade 21.

DESCRIPTION OF SYMBOLS 1 Cutting device 10 Chuck table 20 Cutting means 21 Cutting blade 21a Cutting blade 40 Processing feed means 60 Cutting feed means 80 Blade detection means 82 Light emitting part 83 Light receiving part 90 Reference position detection means W Workpiece X Work feed direction Z Cutting feed direction

Claims (1)

A chuck table for holding a workpiece, a cutting means having a cutting blade having a cutting blade for cutting the workpiece held by the chuck table on its outer periphery, and the chuck table and the cutting means are relatively A machining feed means for machining and feeding, a cutting feed means for cutting and feeding the cutting blade in a cutting feed direction perpendicular to the machining feed direction, and operating the machining feed means and the cutting feed means to cut the cutting blade. Reference position detection means for detecting a reference position of the cutting blade in the cutting feed direction close to the blade, and a light emitting portion and a light receiving portion that are disposed across the cutting blade of the cutting blade and supply cutting water. Blade detecting means for detecting the position of the cutting blade and measuring the amount of wear during cutting, and the reference position detecting means A cutting method for cutting a workpiece with a cutting device for detecting a position of high accuracy the cutting blade in a state in which no sheet, and
A wear amount allowable value setting step for setting a wear amount allowable value of the wear amount of the cutting blade detected by the blade detecting means;
A reference position detection step of operating the processing feed means and the cutting feed means to bring the cutting blade of the cutting blade closer to the reference position detection means and detecting a reference position of the tip of the cutting blade;
After the reference position detection step, the amount of wear is measured by the blade detection means, and the cutting blade positioned on the basis of the reference position detected in the reference position detection step is held on the chuck table. A cutting step for cutting the workpiece;
When the blade detection means detects that the wear amount of the cutting blade has reached a set wear amount allowable value during the cutting step, a re-detection step that performs the reference position detection step again;
Equipped with a,
If the amount of wear of the cutting blade does not reach a set wear amount allowable value during the cutting step, the workpiece is continuously cut.

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