JP5389604B2 - Method for managing consumption of cutting blade in cutting apparatus - Google Patents

Description

  The present invention relates to a cutting blade consumption control method in a cutting apparatus.

  Various electronic components that require precision cutting, such as semiconductor wafers, ceramics, and glass, are divided into individual chips by a cutting device called a dicing saw. The processing of these electronic parts requires precise cutting in micron units, and not only the chip size but also the cutting depth is important.

  For example, a semiconductor wafer is fixed to a dicing tape, and a cutting blade is cut into the dicing tape by about 10 to 30 μm to completely cut the semiconductor wafer. However, if the cutting amount into the dicing tape is not sufficient, the wafer is cut incompletely. Thus, the lower cut edge is notched.

  In addition, the cutting blade used for cutting has a property of being consumed (abraded) as it is cut, and it is necessary to correct the cutting depth variation due to the consumption of the cutting blade as needed.

  Such variation of the cutting edge position of the cutting blade is detected at any time by a position detecting means called an optical sensor, and correction of the height position of the cutting blade (origin position correction) is performed based on the detection result (for example, (See JP-A-11-214334). With this technique, it is possible to easily detect the height position of the cutting blade without damaging the cutting blade without cutting the chuck table for fixing the workpiece or the workpiece.

JP-A-11-214334

  However, due to recent advances in processing technology and product diversification, chipping of chipped edges (chipping) using a processing method such as shallow cutting with a thick cutting blade in advance and then splitting with a thin cutting blade is performed. The processing method to suppress is adopted.

  In addition, by cutting the resin film formed on the upper surface of the silicon wafer and the base silicon with a separate cutting blade, it is possible to perform optimal cutting for either material, and there are many processing methods that suppress the chipping size. It is used.

  In these cutting processes, especially when performing a half cut for processing the upper surface side of a semiconductor wafer, a good cutting result cannot be obtained even if the cutting depth is above or below the required level. Control is required.

  In the conventional setup of the cutting blade (detection of the reference position of the cutting blade), since the setup was performed at the position in the X direction set visually, when the setup was performed at a position shifted from the end of the lowest point of the cutting blade, There has been a problem that the detection error of the reference position tends to be large.

  The present invention has been made in view of these points, and the object of the present invention is to reduce the amount of wear of the cutting blade in a cutting apparatus that can be set up at the exact bottom end position of the cutting blade. It is to provide a management method.

According to the present invention, a cutting blade and an optical sensor for detecting the position of the outer peripheral end of the cutting blade are provided, and the cutting blade moves up and down relatively in a vertical direction (Z direction) relative to the optical sensor. The optical sensor is a consumption management method of a cutting blade in a cutting apparatus configured to move in a horizontal direction (X direction) relative to the cutting blade, and the optical sensor is fixed to the cutting blade. When assuming that the cutting blade moves in the Z direction, the optical sensor is moved in the X direction and the Z direction to detect the outer peripheral edge of the cutting blade at at least three different points in the X direction. A detecting step, a center calculating step of calculating the rotation center coordinates (X ₀ , Z ₀ ) of the cutting blade from the detected X, Z coordinates of the plurality of outer peripheral end portions, and a rotation center coordinate of the cutting blade ( X ₀ , Z ₀ ) and the radius of the cutting blade is calculated based on the X and Z coordinates of at least one of the outer peripheral ends of the cutting blade detected in the multiple end detecting step Performing the center calculation step and the radius calculation step after appropriately cutting the workpiece with the cutting blade, comparing with the radius of the cutting blade determined last time, There is provided a method for managing the amount of consumption of a cutting blade in a cutting apparatus, comprising a consumption amount calculating step for calculating the amount of consumption of the cutting blade.

  Preferably, the cutting blade consumption amount management method further includes a position correction step of correcting the origin position of the cutting blade in the Z direction based on the cutting blade consumption amount calculated from the consumption amount calculation step.

  Preferably, in the cutting blade consumption management method, the sum of the consumption calculated up to the previous time and the addition value of the cutting blade consumption calculated in the consumption calculation step can use a predetermined cutting blade. If the maximum consumable amount that is the limit criterion is exceeded, a limit determination step for stopping the use of the cutting blade is further provided.

  According to the present invention, since the radius of the cutting blade is determined from the positions of at least three cutting blade outer peripheral ends, the exact radius of the cutting blade can be calculated, and the accurate consumption amount of the cutting blade can be calculated. it can.

  Further, if the X coordinate of the rotation center position is stored and the setup is performed at the next and subsequent times, the setup at the stored rotation center position does not need to be performed every time.

It is a perspective view of a cutting device. It is a surface side perspective view of the semiconductor wafer supported by the annular frame via the dicing tape. It is a partial cross section side view of a blade detection means and a chuck table part. It is a perspective view of the principal part of a blade detection means. It is a block diagram of a blade edge part detection mechanism. FIG. 6A is a diagram showing the positional relationship between the lowest point of the cutting blade and the optical sensor, and FIG. 6B is an explanatory diagram of the multiple edge detection step. It is a graph which shows the change of the output voltage of a blade edge part detection mechanism according to the position of the cutting direction of a cutting blade. It is a figure explaining the calculation method of X and Z coordinates of a plurality of ends.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration diagram of the cutting device 2. The cutting device 2 includes a pair of guide rails 6 that are mounted on a stationary base 4 and extend in the X-axis direction.

  Reference numeral 8 denotes a table base (X-axis movement block). The table base 8 is moved in the machining feed direction, that is, the X-axis direction by an X-axis feed mechanism 14 including a ball screw 10 and a pulse motor 12. A chuck table 20 is mounted on the table base 8 via a cylindrical support member 22. A motor for rotating the chuck table 20 is accommodated in the cylindrical support member 22.

  The chuck table 20 has a suction part (suction chuck) 24 formed of porous ceramics and the like, and a frame 23 formed of metal such as SUS surrounding the suction chuck 24. The suction surface of the suction portion 24 and the upper surface of the frame body 23 are formed flush with each other. The chuck table 20 is provided with a plurality (four in this embodiment) of clampers 26 that clamp the annular frame F shown in FIG. Reference numeral 25 denotes a waterproof cover.

  As shown in FIG. 2, the first street S1 and the second street S2 are formed orthogonal to each other on the surface of the semiconductor wafer W to be processed by the cutting apparatus 2, and the first street S1 A device D is formed in each of the areas partitioned by the second street S2.

  The wafer W is attached to a dicing tape T that is an adhesive tape, and the outer periphery of the dicing tape T is attached to an annular frame F. As a result, the wafer W is supported by the annular frame F via the dicing tape T, and is clamped on the chuck table 20 by clamping the annular frame F by the clamper 26 shown in FIG.

  The X-axis feed mechanism 14 includes a linear scale 16 disposed on the stationary base 4 along the guide rail 6 and a reading head 18 disposed on the lower surface of the table base 8 that reads the X coordinate value of the linear scale 16. Including. The read head 18 is connected to the controller of the cutting device 2.

  A pair of guide rails 28 extending in the Y-axis direction are further fixed on the stationary base 4. The Y-axis moving block 30 is moved in the Y-axis direction by a Y-axis feed mechanism (index feed mechanism) 36 composed of a ball screw 32 and a pulse motor 34.

  Although not particularly illustrated, the Y-axis feed mechanism 36 is arranged on the linear scale disposed on the stationary base 4 along the guide rail 28 and the lower surface of the Y-axis moving block 30 that reads the Y coordinate value of the linear scale. The reading head is provided, and the reading head is connected to the controller of the cutting device 2.

  The Y-axis moving block 30 is formed with a pair of guide rails 38 (only one is shown) extending in the Z-axis direction. The Z-axis moving block 40 is moved in the Z-axis direction by a Z-axis feed mechanism 44 including a ball screw (not shown) and a pulse motor 42.

  Although not specifically illustrated, the Z-axis feed mechanism 44 is disposed on the linear scale disposed on the Y-axis movement block 30 along the guide rail 38 and the Z-axis movement block 40 that reads the Z coordinate value of the linear scale. The read head is connected to the controller of the cutting device 2.

  Reference numeral 46 denotes a cutting unit (cutting means), and a spindle housing 48 of the cutting unit 46 is inserted into and supported by the Z-axis moving block 40. A spindle 49 (see FIG. 5) is accommodated in the spindle housing 48 and is rotatably supported by an air bearing. The spindle 49 is rotationally driven by a motor (not shown) housed in a spindle housing 48, and a cutting blade 50 is detachably attached to the tip of the spindle 49.

  An alignment unit (alignment means) 52 is mounted on the spindle housing 48. The alignment unit 52 has an imaging unit (imaging means) 54 that images the wafer W held on the chuck table 20. The cutting blade 50 and the imaging unit 54 are arranged in alignment in the X-axis direction.

  As shown in FIGS. 3 and 4, the blade detection means 56 for detecting the reference position in the cutting direction of the cutting blade 50 is a vertical support member 78 erected from the table base 8 and a vertical support member fixed to the vertical support member 78. The horizontal support member 72 extends so as to protrude from the member 78 to the side of the chuck table 20, and the blade end detection mechanism 58 mounted at the tip of the horizontal support member 72. As best shown in FIG. 4, the horizontal support member 72 is secured to the vertical support member 78 by a plurality of screws 76.

  As shown in FIG. 3, the waterproof cover 25 is fixed to the vertical support member 78 by a plurality of screws 77. In FIG. 4, the waterproof cover 25 is omitted. A packing 27 is disposed between the cylindrical support member 22 of the chuck table 20 and the waterproof cover 25. Reference numeral 80 denotes a bellows, which is omitted in FIG.

  The blade end detection mechanism 58 includes an attachment member 60 having a horizontal portion 60a and a vertical portion 60b. The front end of the vertical portion 60 b of the attachment member 60 is formed in a U shape that defines the blade intrusion portion 62, and the light emitting portion 64 and the light receiving portion 66 that receives light from the light emitting portion 64 across the blade intrusion portion 62. An optical sensor 65 is provided. As shown in FIG. 5, the light emitting unit 64 is connected to the light source 82 via the optical fiber 81, and the light receiving unit 66 is connected to the photoelectric conversion unit 84 via the optical fiber 83.

  In the horizontal portion 60 a of the mounting member 60, cleaning water supply nozzles 68 a and 68 b that supply constant temperature-controlled cleaning water to the end surfaces of the light emitting unit 64 and the light receiving unit 66, and air are supplied to the end surfaces of the light emitting unit 64 and the light receiving unit 66. Air supply nozzles 70a and 70b to be supplied are disposed.

  Next, the cutting blade 50 is cut into the frame 23 of the chuck table 20 made of metal to establish conduction, thereby detecting the origin position detection mechanism for detecting the origin position of the cutting blade 50 and the reference position of the cutting blade 50. The operation of the blade end detection mechanism 58 that detects the amount of wear (amount of wear) of the cutting blade will be described.

  When a new chuck table 20 is mounted or when the chuck table 20 is disassembled and reassembled after cleaning, the cutting blade 50 is first cut into the frame 23 of the chuck table 20 by the origin position detection mechanism. Then, the origin position of the cutting blade 50 is detected, and this origin position is stored in the memory of the controller of the cutting apparatus 2.

  Next, the reference position detection for detecting the reference position in the cutting direction of the cutting edge of the cutting blade 50 by the blade end detection mechanism 56 is performed. This reference position detection will be described with reference to FIG. The light from the light source 82 is conveyed by the optical fiber 81 and emitted from the light emitting unit 64 in the form of a beam. The light receiving unit 66 receives the light emitted by the light emitting unit 64 and sends the received light to the photoelectric conversion unit 84 via the optical fiber 83.

  The photoelectric conversion unit 84 outputs a voltage corresponding to the amount of light transmitted from the light receiving unit 66 to the voltage comparison unit 88. On the other hand, a reference voltage (for example, 3 V) set by the reference voltage setting unit 86 is input to the voltage comparison unit 88.

  The voltage comparison unit 88 compares the output from the photoelectric conversion unit 84 with the reference voltage set by the reference voltage setting unit 86, and when the output from the photoelectric conversion unit 84 reaches the reference voltage, a signal indicating that is given. Output to the reference position detector 90.

  More specifically, when the reference position of the cutting blade 50 in the cutting direction is detected, the pulse motor 42 of the Z-axis feed mechanism 44 is driven to connect the cutting blade 50 to the blade entry portion 62 of the blade end detection mechanism 58. Invade from above.

  At this time, when the cutting blade 50 does not block between the light emitting part 64 and the light receiving part 66 of the optical sensor 65, the light quantity received by the light receiving part 66 is the maximum, and from the photoelectric conversion part 84 corresponding to this light quantity. Is set to 5 V, for example, as shown in FIG.

  As the cutting blade 50 enters the blade intrusion portion 62, the amount by which the cutting blade 50 blocks the light beam emitted from the light emitting portion 64 gradually increases, so the amount of light received by the light receiving portion 66 gradually decreases. The output voltage from the photoelectric conversion unit 84 gradually decreases as indicated by reference numeral 92 in FIG.

  And when the cutting blade 50 reaches the position which connects the center of the light emission part 64 and the light-receiving part 66, it sets so that the output voltage from the photoelectric conversion part 84 may be set to 3V, for example. Therefore, when the output voltage of the photoelectric conversion unit 84 reaches 3V, the voltage comparison unit 88 outputs a signal indicating that the output voltage of the photoelectric conversion unit 84 has reached the reference voltage to the end position detection unit 90.

  The end position detection unit 90 transmits a signal indicating that the reference position (end position) has been detected to the pulse motor 42 and stops driving the pulse motor 42. At this time, the end position detection unit 90 stores the value of the linear scale that detects the position of the cutting blade 50 in the cutting direction (Z-axis direction) as a reference position.

  As shown in FIG. 3, there is a predetermined height direction (cutting direction) between the holding surface position of the suction portion 24 of the chuck table 20 and the reference position of the cutting blade 50 detected by the blade end detection mechanism 58. There is a difference.

  Therefore, since the origin position of the cutting blade 50 detected by the origin position detection mechanism and the reference position of the cutting blade 50 detected by the blade end detection mechanism 58 are both stored in the memory, they are detected by the blade end detection mechanism 58. By correcting the determined reference position by the difference between the origin position and the reference position, the origin position where the cutting blade 50 contacts the upper surface of the frame body 23 of the chuck table 20 based on the reference position detected by the blade end detection mechanism 58 is determined. Can be detected.

  In FIG. 3, an arrow P indicates a case where the cutting blade 50 is performing the reference position detection operation, and an arrow Q indicates a case where the cutting blade 50 is performing the cutting operation of the wafer W. In both the reference position detection operation and the cutting operation, the cutting blade 50 is rotated in the direction of arrow A at a high speed (for example, 30000 rpm).

  Since the difference between the origin position of the cutting blade 50 and the reference position of the cutting blade 50 detected by the blade end detection mechanism 58 varies due to assembly errors of the cutting device, the difference is obtained for each cutting device and this difference is stored in the memory. Remembered.

  Therefore, when it becomes necessary to re-detect the origin position of the cutting blade 50 during normal cutting, the blade edge detection mechanism 58 detects the reference position of the cutting blade 50 and stores this reference position in advance. The origin position of the cutting blade 50 is corrected by the corrected value.

  Accordingly, it is possible to minimize the necessity of cutting the top surface of the frame body 23 of the chuck table 20 with the cutting blade 50 to detect the origin position, and it is possible to suppress damage to the top surface of the frame body 23.

  When the cutting blade 50 is worn, its cutting edge gradually descends. Therefore, by continuously detecting the reference position of the cutting blade 50 using the blade end detection mechanism 58, the amount of wear (amount of wear) of the cutting blade 50 is detected. Can be detected.

  However, in the conventional setup of the cutting blade (detection of the reference position of the cutting blade), the setup was performed at the position in the X direction set visually, so the setup was performed at a position slightly deviated from the end of the lowest point of the cutting blade. There was a problem that it was easy.

  Hereinafter, the cutting blade consumption management method of the present invention that solves this problem will be described mainly with reference to FIGS. Referring to FIG. 6A, the positional relationship between the cutting blade 50 and the optical sensor 65 when the cutting blade 50 is set up is shown.

  The cutting blade 50 is movable in the arrow Z direction, and the optical sensor 60 is movable in the X direction orthogonal to the Z direction. The cutting blade 50 needs to be set up by detecting the lowest point end portion 57, which is the intersection of the outer peripheral end portion of the cutting blade 50 and the perpendicular line from the rotation center 55, with the optical sensor 65.

  In the cutting blade consumption management method of the present invention, as shown in FIG. 6B, the optical sensor 65 is set up at at least three locations moved in the X direction, and the X coordinate of the rotation center 55 of the cutting blade 50 is set. It is characterized by being obtained accurately. In FIG. 6B, reference numeral 93 is a first X-direction setup position, 94 is a second X-direction setup position, and 96 is a third X-direction setup position.

  When the optical sensor 65 is positioned at the first X-direction setup position 93, the optical sensor 65 detects the outer peripheral end position of the cutting blade 50, and the optical sensor 65 is positioned at the second X-direction setup position. If the optical sensor 65 is positioned at the third X-direction setup position 96, the optical sensor 65 detects the outer peripheral end position of the cutting blade 50a. The outer peripheral end position of 50b is detected.

  Since the optical sensor 65 is fixed in the Z direction and the cutting blade 50 moves in the Z direction, the outer peripheral end position of the cutting blade 50 detected at the three X-direction setup positions 93, 94, 96 described above is set to P, Q. , R, the relative relationship of the feed amount of the Z-axis feed mechanism 44 when these three points are detected is schematically shown in FIG.

  Here, since the optical sensor 65 and the cutting blade 50 move relative to each other in the Z direction, the cutting blade 50 is fixed, and it is assumed that the optical sensor 65 moves in the Z direction with respect to the cutting blade 50. 50 rotation center positions are detected.

  As shown in FIG. 8, when the optical sensor 65 passes the Z coordinate value at the time of P point detection and a straight line parallel to the X direction is 98, the cutting blade 50 is fixed and the optical sensor 65 is moved in the Z direction. The positions of the outer peripheral ends of the cutting blade 50 detected by the optical sensor 65 at the second X-direction setup position 94 and the third X-direction setup position 96 are symmetrical positions of points Q and R with respect to the straight line 98. Some Q ', R'.

  Therefore, when the intersection 104 between the vertical bisector 100 of the line segment PQ ′ and the vertical bisector 102 of the line segment Q′R ′ is obtained, this point 104 is the rotation of the cutting blade 50 when the P point is detected. Become the center.

  Actually, since the position of the cutting blade 50 in the Z direction is detected by counting the number of pulses of the pulse motor 42 of the Z-axis feed mechanism 44, the sign of the count value when the points Q and R are detected , The points Q ′ and R ′ that are symmetrical with respect to the straight line 98 of the points Q and R are obtained. The rotation center position 104 of the cutting blade 50 is calculated by the center coordinate calculation unit 106 in accordance with the output signal from the end position detection unit 90 shown in FIG.

Assuming that the coordinates of the rotation center 104 calculated in this way are (X ₀ , Z ₀ ), at least one of the rotation center coordinates (X ₀ , Z ₀ ) and the P point, the Q ′ point, and the R ′ point. The radius of the cutting blade 50 can be easily calculated based on the X and Z coordinates. The calculated radius of the cutting blade 50 is stored in the memory of the cutting apparatus.

  Therefore, in the cutting blade wear amount management method of the present embodiment, after the semiconductor wafer W is appropriately cut by the cutting blade 50, the rotation center calculation step and the radius calculation step described above are performed, and are calculated and stored last time. The consumption amount calculation step of calculating the consumption amount of the cutting blade 50 is performed by comparing the radius of the cutting blade 50 thus calculated with the radius calculated this time.

  Then, based on the consumption amount of the cutting blade 50 calculated from the consumption amount calculation step, the position correction unit 108 corrects the origin position of the cutting blade 50 in the Z direction. By correcting the origin position, the tip of the cutting blade 50 can be brought into a position where it contacts the upper surface of the frame body 23 of the chuck table 20.

  In the cutting blade consumption management method according to the present embodiment, the sum of the amount of consumption calculated up to the previous time and the amount of consumption of the cutting blade 50 calculated in the consumption calculation step are determined in advance. If it exceeds the maximum consumable amount that is the criterion of 50 usable limits, it is determined that the cutting blade is usable, and the use of the cutting blade 50 is stopped and replaced with a new cutting blade.

  According to this embodiment described above, the radius of the cutting blade is calculated from the coordinates of the rotation center of the cutting blade and the coordinates of the outer peripheral edge of at least three cutting blades, so that an accurate radius can be calculated and detected last time. By comparing the radius of the cutting blade with the radius calculated this time, the wear amount of the cutting blade can be easily calculated.

  Preferably, the X coordinate of the rotation center position is stored in the memory of the cutting device 2. As a result, at the next and subsequent setups, if setup is performed with the stored X-coordinate of the rotation center position, it is not necessary to perform setup at a plurality of points every time.

2 Cutting device 8 Table base 20 Chuck table 50 Cutting blade 56 Blade detection means 58 Blade end detection mechanism 62 Blade intrusion portion 64 Light emitting portion 65 Optical sensor 66 Light receiving portion 93 First X direction setup position 94 Second X direction setup Position 96 Third X direction setup position 100, 102 Vertical bisector 104 Center of rotation

Claims (3)

A cutting blade and an optical sensor for detecting the position of the outer peripheral end of the cutting blade, the cutting blade moving up and down in the vertical direction (Z direction) relative to the optical sensor, the optical sensor A consumption management method of a cutting blade in a cutting device configured to move in a horizontal direction (X direction) relative to the cutting blade,
When it is assumed that the cutting blade is fixed and the optical sensor is moved in the Z direction with respect to the cutting blade, the optical sensor is moved in the X direction and the Z direction, and the cutting is performed at at least three different points in the X direction. A plurality of end detection steps for detecting the outer peripheral end of the blade;
A center calculating step of calculating the rotation center coordinates (X ₀ , Z ₀ ) of the cutting blade from the detected X, Z coordinates of the plurality of outer peripheral end portions;
Based on the rotation center coordinates (X ₀ , Z ₀ ) of the cutting blade and the X, Z coordinates of at least one outer peripheral end of the plurality of outer peripheral ends detected in the multiple end detecting step. A radius calculating step for calculating a radius of the cutting blade;
After the workpiece is appropriately cut with the cutting blade, the center calculation step and the radius calculation step are performed, and compared with the radius of the cutting blade calculated last time, the consumption amount of the cutting blade is calculated. A consumption calculation step to calculate,
A method for managing the amount of wear of a cutting blade in a cutting apparatus.   The cutting blade consumption in the cutting apparatus according to claim 1, further comprising a position correction step of correcting the origin position of the cutting blade in the Z direction based on the consumption amount of the cutting blade calculated from the consumption amount calculation step. Quantity management method.   The maximum consumable amount for which the sum of the consumable amounts calculated up to the previous time and the sum of the consumable amounts of the cutting blades calculated in the consumable amount calculating step is a predetermined criterion for the usable limit of the cutting blades. The cutting blade wear amount management method in the cutting apparatus according to claim 1, further comprising a limit determination step of stopping the use of the cutting blade when the cutting blade is used.

Images