JP7148233B2 - Workpiece cutting method and cutting device - Google Patents

Description

The present invention relates to a cutting method and a cutting apparatus for cutting a workpiece with a cutting blade.

A plate-shaped workpiece such as a semiconductor wafer is cut by a rotatable cutting blade while being held on a holding table provided in a cutting device, and divided into individual chips or the like, which are used in various electronic devices. .

During cutting of a workpiece, the center of the holding table may not be completely aligned with the center of the workpiece held by the holding table. This is due to misalignment in the application of the tape to the work piece and the tape to the frame to enable handling of the work piece using the annular frame, or the sticking of the holding table. This is caused by a transport deviation or the like when the workpiece is transported. Therefore, since the holding position of the workpiece on the holding table differs for each workpiece, the cutting blade is relatively fed for cutting and index-feeding over an area larger than the actual size of the workpiece. is doing. Specifically, cutting is started from a position further outside the outer peripheral edge of the workpiece, and the actual cutting of the workpiece is started after several lines of idle cutting by the cutting blade.

In the cutting device, the cutting feed operation of the holding table is temporarily stopped during cutting, the cutting groove formed by the cutting blade is imaged, and the formed image is used to correct the cutting position (cut position correction) and confirmation of whether cutting is normal (kerf check) (see, for example, Patent Documents 1 and 2).

JP 2012-028635 A JP-A-6-326187

Since the positions of the cutting grooves formed in the workpiece vary slightly depending on the thickness of the workpiece and the state of the cutting blade, it is preferable to correct the cutting position, for example, at the beginning of machining for each workpiece. Therefore, the imaging position for forming the captured image showing the cutting groove is set to, for example, the position of the fifth line after the start of the cutting feed of the holding table holding the workpiece, that is, the relatively early stage when the machining is started. position. However, due to deviation of the holding position of the workpiece on the holding table, etc., the position of the 5th line becomes the position where the cutting blade performs idle cutting. If cut position correction or kerf check is performed based on this, an error will occur and various operations of the apparatus will stop. As a result, there is a problem that it takes time and effort to recover and the productivity of cutting is lowered.

Therefore, in view of the above problems, in a cutting device for cutting a workpiece, the number of lines where the workpiece actually started to be cut is accurately detected so that the position of the workpiece can be specified. There is a problem of

The present invention for solving the above-mentioned problems is a cutting method for cutting, with a cutting blade, a workpiece attached to a dicing tape having an outer peripheral portion attached to an annular frame, wherein the workpiece is cut by a holding table. a holding step for holding, a cutting step for cutting a workpiece by performing a cutting operation with the cutting blade on an allowable area in which the workpiece can be placed within the holding surface of the holding table, and the cutting blade detects that the cutting blade has cut into the workpiece and started cutting, detects the coordinate position at which the cutting blade starts cutting into the workpiece, and is orthogonal to the cutting feed direction of the holding table in the horizontal plane. a cutting start detection step of detecting the number of the line on which cutting of the workpiece by the cutting blade is started after index feed of the cutting blade in the index feed direction is started, and Identifying the position of the workpiece based on the number of the lines detected in the cutting start detection step, including the line where the dicing tape is cut outside the workpiece in the index feeding direction. The method.

Preferably, in the cutting start detection step, it is detected that the cutting blade has cut into the workpiece from a change in the load current value of the spindle on which the cutting blade is mounted.

Preferably, in the cutting start detection step, an elastic wave detection sensor provided in the cutting means having the cutting blade detects that the cutting blade has cut into the workpiece.

The present invention for solving the above problems is a holding table for holding a workpiece attached to a dicing tape having an outer peripheral portion attached to an annular frame, and cutting the workpiece held by the holding table. A cutting device comprising a cutting blade, moving means for relatively moving the cutting blade with respect to the holding table, and detecting that the cutting blade has cut into the workpiece held by the holding table. and cutting start detection means, wherein the cutting start detection means detects that the cutting blade has cut into the workpiece and started cutting, and the coordinates at which the cutting blade has cut into the workpiece and started cutting. The position is detected, and the cutting in the index feed direction is performed, including the line where the dicing tape is cut outside the work piece in the index feed direction perpendicular to the cutting feed direction of the holding table in the horizontal plane. A cutting device that detects the number of the line where the cutting blade starts cutting the workpiece after index feed of the blade is started, and specifies the position of the workpiece based on the line number. is.

The cutting method according to the present invention detects that the cutting blade has cut into the workpiece and started cutting, detects the coordinate position at which the cutting blade has cut into the workpiece and started cutting, and further detects the position of the holding table. A cutting start detection step of detecting the number of the line on which cutting of the workpiece by the cutting blade is started after the index feed of the cutting blade is started in the index feed direction perpendicular to the cutting feed direction in the horizontal plane. Therefore, the position of the workpiece can be accurately specified based on the line number detected in the cutting start detection step, and the cutting position can be corrected based on the information about the line number. Alternatively, it is possible to determine the position of the workpiece to be subjected to the kerf check, and to prevent the cut position correction or the kerf check from being performed on the line on which the cutting blade has performed the idle cutting. In addition, when the cutting blade is defective in cutting the workpiece, it is possible to easily grasp the number of the line in which the cutting defect occurred, from the number of the line where cutting was started.

Further, the cutting apparatus according to the present invention includes cutting start detection means for detecting that the cutting blade has cut into the workpiece held by the holding table, and the cutting start detection means detects when the cutting blade has cut into the workpiece. By detecting the start of cutting, the coordinate position at which the cutting blade starts cutting into the workpiece is detected, and furthermore, the cutting blade is moved in the index feed direction perpendicular to the cutting feed direction of the holding table in the horizontal plane. The number of the line on which cutting of the workpiece by the cutting blade is started after the start of the index feed is detected, and the position of the workpiece is accurately specified based on the line number . Then, the position of the workpiece to be subjected to cut position correction or kerf check can be determined based on the information about the number of the line, and the cut position correction or kerf check can be performed on the line on which idle cutting is performed by the cutting blade. It is possible to prevent it from being carried out. In addition, in the case where a cutting blade causes a poor cutting of a workpiece, it is possible to easily grasp the number of the line on which the cutting was started and the number of the line on which the cutting failure occurred. .

It is a perspective view which shows an example of a cutting device. 1 is a perspective view showing an example of a wafer to be cut; FIG. It is an exploded perspective view showing an example of a cutting means. FIG. 4 is a cross-sectional view showing an example of the structure of cutting start detection means and cutting means having an elastic wave detection sensor; FIG. 4 is a cross-sectional view showing a state in which a workpiece is held by a holding table; FIG. 10 is a cross-sectional view showing a state in which cutting of the workpiece by the cutting blade is started from a position spaced apart from the outer peripheral edge of the workpiece in the index feed direction; FIG. 4 is an explanatory diagram for explaining a cutting start detection step; It is explanatory drawing of the captured image which the cutting groove formed by the imaging means reflected.

A cutting device 1 shown in FIG. 1 is a device that cuts a workpiece W held on a holding table 30 by a cutting means 6 having a cutting blade 60 that rotates.
An X-axis movement means (cutting feed means) 12 for relatively moving the holding table 30 in the X-axis direction with respect to the cutting blade 60 is arranged in front of the base 10 of the cutting device 1 (on the -Y direction side). there is The X-axis moving means 12 includes a ball screw 120 having an axis in the X-axis direction, a pair of guide rails 121 arranged parallel to the ball screw 120, a motor 122 for rotating the ball screw 120, and a nut inside the ball screw. 120 and a movable plate 123 whose bottom is in sliding contact with the guide rail 121 . When the motor 122 rotates the ball screw 120, the movable plate 123 is guided by the guide rail 121 and moves in the X-axis direction. is fed in the X-axis direction along with the movement of .

The holding table 30 shown in FIG. 1 has, for example, a circular outer shape, and includes a suction portion 300 that suctions the workpiece W and a frame 301 that supports the suction portion 300 . The suction unit 300 communicates with a suction source (not shown), and suction-holds the workpiece W on a holding surface 300 a that is an exposed surface of the suction unit 300 and flush with the upper surface of the frame 301 . The holding table 30 is surrounded by a cover 32 and is rotatable about the axis in the Z-axis direction by a rotating means 33 arranged on the bottom side of the holding table 30 . Around the frame 301, four fixing clamps 34 for fixing the annular frame F supporting the workpiece W are arranged evenly in the circumferential direction.

The workpiece W shown in FIGS. 1 and 2 sucked and held by the holding table 30 is, for example, a semiconductor wafer having a circular outer shape and made of silicon as a base material. A device D is formed in a grid-like region. For example, the back surface Wb of the workpiece W is attached to the attachment surface of the dicing tape T, and the outer peripheral portion of the dicing tape T is attached to the annular frame F. As shown in FIG. As a result, the workpiece W can be handled using the annular frame F. As shown in FIG. In addition, the workpiece W is not limited to the device wafer as described above, and may be a wafer or plate-shaped object on which no device is formed, a rectangular package substrate in which the device is sealed with resin, or the like. .

As shown in FIG. 1, Y-axis movement means (index feed means) for reciprocating the cutting means 6 in the Y-axis direction perpendicular to the X-axis direction on the horizontal plane is provided from the center to the rear of the base 10 of the cutting device 1. ) 13 are provided. The Y-axis moving means 13 includes a ball screw 130 having an axial center in the Y-axis direction, a pair of guide rails 131 arranged parallel to the ball screw 130, a motor 132 for rotating the ball screw 130, and a nut inside the ball screw. 130 and a movable plate 133 whose bottom portion is in sliding contact with the guide rail 131 . When the motor 132 rotates the ball screw 130, the movable plate 133 is guided by the guide rail 131 and moves in the Y-axis direction, and is disposed on the movable plate 133 via the Z-axis moving means 14, which will be described later. The cutting means 6 is index-fed in the Y-axis direction as the movable plate 133 moves.

A column 145 is integrally erected on the movable plate 133, and a side surface of the column 145 is provided with a Z-axis moving means (cutting feed means) 14 for reciprocating the cutting means 6 in the Z-axis direction. . The Z-axis moving means 14 includes a ball screw (not shown) having a Z-direction axis, a pair of guide rails 141 arranged parallel to the ball screw, a motor 142 for rotating the ball screw, and an internal nut screwed onto the ball screw. and a holder 143 whose mating side portion is in sliding contact with the guide rail 141 . When the motor 142 rotates the ball screw, the holder 143 is guided by the guide rail 141 and moved in the Z-axis direction, and the cutting means 6 supported by the holder 143 is cut and fed in the Z-axis direction.

The cutting device 1 comprises control means 9 for controlling the entire device. A control means 9 composed of a memory element such as a CPU and a memory is electrically connected to the X-axis moving means 12, the Y-axis moving means 13, the Z-axis moving means 14, etc., and controls the control means 9. , the cutting feed operation of the holding table 30 by the X-axis moving means 12, the index feeding operation of the cutting means 6 by the Y-axis moving means 13, and the like are controlled.

For example, the motor 122 of the X-axis moving means 12 and the motor 132 of the Y-axis moving means 13 are pulse motors operated by driving pulses supplied from a pulse oscillator (not shown). By counting the number of driving pulses supplied to the X-axis moving means 12 and the Y-axis moving means 13, the control means 9 controls the position of the holding table 30 in the X-axis direction and the index of the cutting means 6 in the Y-axis direction. It is possible to detect the feed position.
For example, the motor 122 of the X-axis moving means 12 and the motor 132 of the Y-axis moving means 13 may be servo motors instead of pulse motors, and a rotary encoder may be connected to the servo motors. In this case, the rotary encoder is connected to a control means 9 that also functions as a servo amplifier, and after an operation signal is supplied from the control means 9 to the servomotor, an encoder signal (servomotor rotation speed) is output. Output to the control means 9 . Based on the received encoder signal, the control means 9 calculates the amount of movement of the holding table 30 in the X-axis direction and the amount of movement of the cutting means 6 in the Y-axis direction. Detects the index feed position in the Y-axis direction.

FIG. 3 is an exploded perspective view showing each configuration of the cutting means 6. The cutting means 6 includes, for example, a spindle housing 61, a spindle 62 having an axis in the Y-axis direction and driven to rotate by a motor (not shown), a spindle It has a mount flange 63 detachably attached to 62 , a circular cutting blade 60 and an annular front flange 64 .

The spindle housing 61 includes a cylindrical housing body 610 held by the holder 143 of the Z-axis moving means 14 shown in FIG. there is Two screw holes 610a are formed in the front surface (surface on the -Y direction side) of the housing body 610 at intervals of 180 degrees in the circumferential direction.

A spindle 62 is rotatably accommodated in the housing body 610, the spindle 62 protrudes from the housing body 610, and has a bolt hole 620 formed at its tip. A motor (not shown) is connected to the rear end of the spindle 62 .

A spindle insertion hole 611a is formed in the center of the housing cover 611, into which a rear end portion 632 of a mount flange 63, which will be described later, is inserted and through which the spindle 62 is inserted. An annular inductor receiving groove 611b is formed in the front surface of the housing cover 611 . Two mounting portions 611c having screw insertion holes extend radially outward from the side surface of the housing cover 611. As shown in FIG.

The mount flange 63 attached to the outer periphery of the tip of the spindle 62 includes a flange portion 630 formed at an intermediate position in the thickness direction, and a flange portion 630 formed with a smaller diameter than the flange portion 630 and extending forward (-Y direction) from the flange portion 630. It has a protruding boss portion 631 and a rear end portion 632 formed to have a smaller diameter than the flange portion 630 and protruding rearward (+Y direction) from the flange portion 630 . A through hole 633 into which the spindle 62 is inserted is formed in the center of the mount flange 63 .

The cutting blade 60 is, for example, a hub blade. The cutting edge 601 is formed by fixing diamond abrasive grains or the like with an appropriate binder. The cutting blade provided in the cutting means 6 may be an annular washer type hubless blade provided with only a cutting edge.

As shown in FIG. 4, the screw hole 610a of the housing main body 610 and the screw insertion hole of the mounting portion 611c of the housing cover 611 are superimposed, and the fixing screw 67 is inserted into the screw insertion hole and screwed into the screw hole 610a. By tightening, the housing cover 611 is fixed to the front surface of the housing body 610, and the tip portion of the spindle 62 protrudes from the spindle insertion hole 611a of the housing cover 611. As shown in FIG. Further, the rear end portion 632 of the mount flange 63 is inserted into the spindle insertion hole 611 a of the housing cover 611 , and the tip portion of the spindle 62 is fitted into the through hole 633 of the mount flange 63 . The mount flange 63 can be attached to the spindle 62 by screwing the fixing bolt 66 through the flat washer 65 into the bolt hole 620 of the spindle 62 .

Next, the mounting hole of the cutting blade 60 is fitted to the boss portion 631 of the mount flange 63 , and the rear surface of the cutting blade 60 is brought into contact with the flange portion 630 of the mount flange 63 . Furthermore, by screwing the front flange 64 onto the screw formed on the side surface of the boss portion 631 and tightening it, the cutting blade 60 is clamped and fixed between the mount flange 63 and the front flange 64 and attached to the spindle 62. Become.

As shown in FIG. 1, a blade cover 69 is attached to the cutting means 6 so as to straddle the cutting blade 60 from above. A cutting water supply nozzle 68 is attached to the blade cover 69 to supply cutting water to a machining point where the cutting blade 60 contacts the workpiece W. As shown in FIG.

The cutting device 1 includes alignment means 18 arranged on the side surface of the tip portion of the housing body 610 . The alignment means 18 includes an imaging means 180. The imaging means 180 includes, for example, a light irradiation unit that irradiates the workpiece W with light, an optical system that captures the reflected light from the workpiece W, and the reflected light. and a camera composed of an imaging device (CCD) or the like that outputs a corresponding electrical signal. The alignment means 18 performs image processing such as pattern matching based on the captured image of the surface Wa of the workpiece W formed by the imaging means 180, and detects the planned cutting line S along which the cutting blade 60 should cut. can be done. The alignment means 18 and the cutting means 6 are integrally constructed, and move together in the Y-axis direction and the Z-axis direction.

The cutting device 1 includes, for example, a touch panel monitor 19 . An input screen and a display screen are displayed on the monitor 19, and various information such as processing conditions and an image captured by the imaging means 180 are displayed on the display screen, and various information such as processing conditions can be input from the input screen. is possible.

The cutting apparatus 1 includes cutting start detection means 7 shown in FIG. 4 for detecting that the cutting blade 60 has cut into the workpiece W held by the holding table 30 . The cutting start detection means 7 includes, for example, an elastic wave detection sensor (AE sensor) 71 arranged on the mount flange 63 of the cutting means 6 and a non-contact transmission line 72 .

The elastic wave detection sensor 71 has, for example, an annular outer shape, and is fitted into an annular groove formed on the rear side of the flange portion 630 of the mount flange 63 . The elastic wave detection sensor 71 is made of piezoelectric ceramics such as barium titanate (BaTiO ₃ ), lead zirconate titanate (Pb(Zi,Ti)O ₃ ), lithium niobate (LiNbO ₃ ) or lithium tantalate (LiTaO ₃ ). and is intended to detect elastic waves in a predetermined ultrasonic range. The elastic wave detection sensor 71 converts the elastic wave generated when the rotating cutting blade 60 contacts the object to be cut into an electric signal and detects it.

The non-contact type transmission line 72 is arranged in the first inductor 721 arranged so as to be connected to the elastic wave detection sensor 71 in the flange portion 630 of the mount flange 63 and in the inductor accommodation groove 611b of the housing cover 611. The second inductor 722 faces the first inductor 721 with a predetermined gap in the Y-axis direction. In this embodiment, the first inductor 721 and the second inductor 722 are ring-shaped coils around which conductive wires are wound.

Since the first inductor 721 and the second inductor 722 facing each other are magnetically coupled, the electrical signal (detection signal) about the elastic wave detected by the elastic wave detection sensor 71 is transmitted through the first inductor 721 is transmitted to the second inductor 722 side due to mutual induction between and the second inductor 722 . The control means 9 is electrically connected to the second inductor 722 , and the detection signal transmitted to the second inductor 722 is sent to the control means 9 . The detection signal sent from the second inductor 722 is amplified by, for example, a preamplifier or the like so as to facilitate subsequent signal processing. , the control means 9 may be reached.

The cutting start detection means for detecting that the cutting blade 60 has cut into the workpiece W held by the holding table 30 is not limited to the cutting start detection means 7 constituted by the elastic wave detection sensor 71 and the like. do not have. For example, the cutting start detection means 7A shown in FIG. It is detected as a current value, and it is configured to detect that the cutting blade 60 has cut into the workpiece W from a change in the load current value of the spindle 62 .
The cutting device 1 may include either the cutting start detection means 7 or the cutting start detection means 7A.

Each step and the operation of the cutting device 1 when cutting the workpiece W using the cutting device 1 described above will be described below.

(1) Input and storage of processing conditions and workpiece information For example, first, an input screen is displayed on the monitor 19 shown in FIG. , or the length and thickness of the workpiece W), the shape of the workpiece W (circular or rectangular), the allowance width, and the index size of the workpiece W (the center line in the width direction of a certain planned cutting line S shown in FIG. 2 The distance from Sc to the center line Sc of the next scheduled cutting line S) is input and stored in the condition storage unit 90 of the control means 9 . The allowance width is set in the X-axis direction and the Y-axis direction in order to cut the cutting blade 60 at a predetermined position further outside the outer peripheral edge of the workpiece W at the start of cutting to perform idle cutting. predetermined distance. The margin width value is determined in consideration of the allowable area in which the workpiece W can be placed within the holding surface 300 a of the holding table 30 .

The same circuit pattern is formed on the surface of each device D of the workpiece W shown in FIG. Then, one of the circuit patterns having a characteristic shape is selected in advance as the target pattern P, and information about this target pattern P is stored in the condition storage section 90 . Note that the target pattern P is formed at the same position, for example, at the corner portion of the device D for each of the plurality of devices D. As shown in FIG. Although the target pattern P in the example of FIG. 2 is formed in an L shape, it is not limited to this shape. Also, in FIG. 2, only the target patterns P of the three devices D are shown, and the target patterns P of the other devices D are omitted. Then, a distance L1 from a certain target pattern P to the center line Sc of the line to be cut S adjacent to the target pattern P (hereinafter referred to as a reference distance L1) is stored in the condition storage unit 90 .

(2) Holding Step As shown in FIG. 5, the workpiece W supported by the annular frame F is placed on the holding surface 300a of the holding table 30 with the dicing tape T facing downward. A suction force generated by a suction source (not shown) communicating with the holding surface 300a is transmitted to the holding surface 300a, whereby the workpiece W is held by the holding table 30 by suction. Further, the annular frame F is clamped and fixed by each fixing clamp 34 . Note that the center of the holding surface 300a and the center of the workpiece W coincide to some extent.

(3) Alignment of θ and Alignment of Scheduled Cutting Line After the workpiece W is sucked and held by the holding table 30, the holding table 30 is moved, for example, in the −X direction (back side of the paper surface in FIG. 5) by the X-axis moving means 12. After the workpiece W on the holding table 30 is positioned directly below the imaging means 180 , the surface Wa of the workpiece W is imaged by the imaging means 180 . The actual imaging by the imaging means 180 is performed by aligning the planned cutting line S of the workpiece W in parallel with the X-axis direction (parallelization), and determining the cutting coordinate position of the cutting blade 60 based on the alignment of the planned cutting line S. carried out for

The imaging by the imaging means 180 is performed by, for example, targeting two devices D located adjacent to one planned cutting line S extending in the X-axis direction and separated from each other in the X-axis direction, and capturing two images of the devices D. A captured image is formed. Then, the alignment means 18 performs matching between the pattern formed on the surface of the device D in the two captured images and the target pattern P shown in FIG. Detect each target pattern P in . Also, the X-axis and Y-axis coordinate positions of each target pattern P in the captured image are detected from the position of the imaging means 180 . Then, by rotating the holding table 30 by a predetermined angle θ so that the coordinates of the two target patterns P in the Y-axis direction match, the planned cutting line S extending in the X-axis direction is made parallel to the X-axis direction. can be matched.

The control means 9 always grasps the X-axis and Y-axis coordinate positions of the center of the holding surface 300 a of the holding table 30 . For example, after the θ adjustment is performed as described above, the margin width L2 is added to the size of the workpiece W stored in the condition storage unit 90 with reference to the center coordinates of the holding surface 300a of the holding table 30. The permissible area (the area inside the circle indicated by the two-dot chain line in FIG. 7), that is, the cutting feed range in the X-axis direction of the holding table 30 by the X-axis moving means 12 and the Y of the cutting means 6 by the Y-axis moving means 13 An index feed range in the axial direction is calculated. Furthermore, among the Y-axis coordinate positions separated from the Y-axis coordinate position of the target pattern P detected by the alignment means 18 by a distance of integral multiples of the index size stored in the condition storage section 90, The Y-axis coordinate position on the dicing tape T which is located at the position and is closest to the outer periphery of the allowable area is determined as the index feed position for starting cutting. Further, the X-coordinate position of the extreme end in the X-axis direction within the allowable area corresponding to the determined index feed position (Y-axis coordinate position) for starting cutting is used as the cutting start position on the dicing tape T in the X-axis direction. It is determined.

(4-1) Dry cutting by the cutting blade in the cutting step and initial cutting of the cutting blade into the workpiece As shown in FIG. The blade 60 is positioned at the index feed position at the beginning of cutting in the Y-axis direction. As the spindle 62 rotates clockwise when viewed from the -Y direction, the cutting blade 60 also rotates in the same direction. Further, the holding table 30 holding the workpiece W is sent out in the X-axis direction, and the cutting start position on the dicing tape T in the X-axis direction is positioned directly below the cutting blade 60 . Furthermore, the Z-axis moving means 14 (not shown in FIG. 6) cuts and feeds the cutting means 6 in the -Z direction, and the lowest end of the cutting blade 60 completely cuts the workpiece W to the dicing tape T. A cutting means 6 is positioned at a predetermined height position for cutting. The cutting height position of the cutting blade 60 may be a height position at which the workpiece W is not completely cut.

The holding table 30 holding the workpiece W is sent out in the -X direction (back side of the paper surface in FIG. 6) at a predetermined cutting feed rate, so that the holding table 30 and the cutting blade 60 are moved relative to each other at a predetermined speed in the X direction. While moving in the axial direction and rotating at high speed, the cutting blade 60 cuts into the dicing tape T around the workpiece W and cuts only the dicing tape T, that is, dry cutting by the cutting blade 60 is performed. . As a result, cutting marks K1 are formed on the dicing tape T as shown in FIG.

-X direction where the cutting blade 60 finishes cutting one line in the allowable area where the workpiece W can be placed within the holding surface 300a of the holding table 30 (the area inside the circle indicated by the two-dot chain line in FIG. 7). When the holding table 30 is sent to the predetermined position, the cutting feed of the holding table 30 in the -X direction is stopped, and the cutting blade 60 is lifted above the height position of the surface Wa of the workpiece W. As shown in FIG. Next, the holding table 30 is moved in the +X direction and returned to the origin position. Then, the cutting blade 60 is index-fed in the +Y direction by the interval of the index size stored in the condition storage unit 90 .

The cutting blade 60 is positioned at the cutting height position, and the holding table 30 is fed in the -X direction for cutting, so that a cutting mark K2 is formed on the dicing tape T in the same manner as the previous idle cutting by the cutting blade 60. After that, the holding table 30 moves again in the +X direction and is returned to the origin position. Again, the cutting blade 60 is index-fed in the +Y direction by the interval of the index size, and the holding table 30 is fed out in the -X direction at a predetermined cutting feed rate, so that the cutting blade 60 cuts only the dicing tape T for a predetermined distance. After the cutting mark K3 is formed, the cutting blade 60 cuts into the workpiece W for the first time.

(5) Embodiment 1 of cutting start detection step
Embodiment 1 of the cutting start detection step for detecting that the cutting blade 60 has cut into the workpiece W and started cutting will be described below. In the cutting start detection step of Embodiment 1, the cutting start detection means 7 provided in the cutting means 6 shown in FIG. 4 detects that the cutting blade 60 has cut into the workpiece W.

When dry cutting by the cutting blade 60 in the cutting step (4-1) described above is started, the elastic wave detection sensor 71 detects the sound (elastic wave) generated by the cutting blade cutting the object to be cut. Begin to. Then, the elastic wave detection sensor 71 converts the detected elastic wave value into an electric signal and sequentially sends the electric signal to the control means 9 via the transmission line 72 . The value of the elastic wave generated when the cutting blade 60 cuts the dicing tape T made of polymer resin or the like, and the elastic wave generated when the cutting blade 60 cuts the workpiece W having silicon as the base material. different from wave values. Therefore, when the cutting blade 60 cutting only the dicing tape T cuts into the workpiece W, the detection signal sent from the elastic wave detection sensor 71 to the control means 9 changes. cutting into the workpiece W is detected.

When it is detected that the cutting blade 60 has started cutting the workpiece W, the coordinate position Q(x1 , y1) are detected. The coordinate position Q (x1, y1) is, for example, the number of driving pulses supplied to the X-axis moving means 12 counted by the control means 9 and the Y-axis moving means at the time when the cutting blade 60 cuts the workpiece W. It is detected from the number of driving pulses supplied to 13. Furthermore, the time when the cutting blade 60 cuts into the workpiece W and the cutting is started is also detected.
The coordinate position Q(x1, y1) may be detected from the coordinate position of the holding table 30, the coordinate position of the spindle 62, and the size of the cutting blade 60.

Also, the line where the cutting of the workpiece W by the cutting blade 60 is started is the line of what number (the third line in the first embodiment) after the index feed of the cutting means 6 by the Y-axis moving means 13 is started. line) is detected. Then, the coordinate position Q (x1, y1) and the line number (third line) where cutting of the workpiece W is started are stored in the control means 9, so that the control means 9 can control the workpiece After the third line where cutting of W is started, cutting is performed while counting the number of lines of cutting grooves formed in the workpiece W, in other words, cutting of the workpiece W It is possible to carry out the cutting while specifying the position of the workpiece W with reference to the line where .

(5) Embodiment 2 of cutting start detection step
The cutting start detection step may be performed as in Embodiment 2 described below instead of being performed as in Embodiment 1 above. In the cutting start detection step of the second embodiment, it is detected that the cutting blade 60 has cut into the workpiece W based on a change in the load current value of the spindle 62 to which the cutting blade 60 is attached.

When the cutting blade 60 starts idle cutting in the cutting step (4-1) described above, the spindle load current value detection means 79 shown in FIG. Begin to. For example, in a state in which the cutting blade 60 cuts (idle cuts) only the dicing tape T, the motor current value detected by the spindle load current value detection means 79 is about 1.8A. Then, the spindle load current value detection means 79 sequentially sends information about the detected motor current value (the load current value of the spindle 62) to the control means 9, and the control means 9 detects the current of the motor that rotationally drives the spindle 62. Start monitoring values. That is, the control means 9 calculates the difference by subtracting the current value detected a unit time ago from the newly detected current value, and monitors the change in the current value for each unit time.

Since the workpiece W is harder than the dicing tape T, the cutting blade 60 cutting only the dicing tape T cuts into the workpiece W, increasing the load on the cutting blade 60 . While the cutting blade 60 is rotating, electric power continues to be supplied to the motor from a power source (not shown), and even if the load acting on the cutting blade 60 due to cutting into the workpiece W increases, the spindle 62 continues to operate. Since the motor is feedback-controlled so as to rotate at a constant number of revolutions, the current value of the motor increases. That is, for example, the motor current value detected by the spindle load current value detecting means 79 suddenly rises to about 2.5A. Then, the control means 9, which sequentially monitors changes in the current value of the motor that drives the spindle 62 per unit time, detects that the cutting blade 60 has cut into the workpiece W from the rapid increase in the current value. do.
After that, the coordinate position Q (x1, y1) shown in FIG. The line number (third line) and the like are detected, and the detected information is stored in the control means 9 .

Conventionally, for example, at the time of inputting the above-mentioned (1) processing conditions and workpiece information, the operator instructs the control means 9 to set the execution position where the cutting position correction or kerf check is performed on the line at the beginning of processing. was set to be On the other hand, for example, in the cutting device 1 according to the present invention, information about the coordinate position Q (x1, y1) where cutting of the workpiece W is started and the line where cutting of the workpiece W is started Based on the information about the number (third line), the control means 9 determines the execution position where the cut position correction or the kerf check is executed. Therefore, in the cutting device 1, the line on which the cutting blade 60 performs idle cutting is no longer the position where the cutting position correction or the kerf check is performed. Prevents outages.

The position where the cutting position correction or the kerf check is performed is, for example, the +Y direction side from the third line shown in FIG. It is determined on one of the 1st to 5th planned cutting lines, that is, for example, on one planned cutting line SM shown in FIG.

(4-2) Cutting Workpiece with Cutting Blade in Cutting Step After the cutting blade 60 first cuts into the workpiece W, the holding table 30 shown in FIG. The cutting blade 60 is sent out in the X direction and cuts the workpiece W while rotating at high speed. After that, the cutting feed of the holding table 30 and the index feed of the cutting means 6 corresponding to the interval of the index size are repeated a plurality of times, so that the workpiece W is cut along the planned cutting line S extending in the X-axis direction, Cutting grooves (full-cut grooves) are formed in the workpiece W. As shown in FIG.

After the cutting blade 60 finishes cutting the workpiece W along the planned cutting line SM shown in FIG. 7, the cutting feed of the holding table 30 is once stopped. Then, the cutting groove formed on the surface Wa of the workpiece W along the scheduled cutting line SM is imaged by the imaging means 180 (not shown in FIG. 7), and the formed image G (see FIG. 8) is obtained. A cut position correction and a kerf check are performed. The captured image G shown in FIG. 8 is displayed, for example, on the output screen of the monitor 19 shown in FIG. Note that the captured image G displayed on the output screen of the monitor 19 is subjected to filtering using, for example, a sharpening filter that emphasizes edges, or the filtered image is further subjected to binarization. It may be something that has been done or done.

In the cutting position correction, the cutting groove M formed along the planned cutting line SM in the captured image G and the target pattern P formed on the device D adjacent to the planned cutting line SM are detected. Furthermore, a distance L3 from the center line Mc of the cutting groove M to the target pattern P on the device D adjacent to the line to be cut SM is calculated by counting pixels or the like. Next, the difference L3-L1 (or L1-L3) between the reference distance L1 stored in advance in the condition storage unit 90 shown in FIG. be.

Then, the cutting blade 60 is aligned in the Y-axis direction with the planned cutting line SN (see FIG. 7) that is adjacent to the planned cutting line SM that has been cut and that has not been cut. Here, the amount of index feed of the cutting means 6 in the +Y direction by the Y-axis moving means 13 is corrected in accordance with the amount of deviation described above. Specifically, a correction amount corresponding to the above-described shift amount is added (or subtracted) to the feed amount that has already been set (the feed amount for the interval of the index size). Then, the cutting means 6 is sent in the +Y direction by the corrected index feed amount, so that the cutting blade 60 after the index feed is aligned with the center line in the width direction of the planned cutting line SN. .

On the other hand, in the kerf check, the average chipping Me This is done by judging whether the magnitude of (chipping) and the number of chippings Me are within the allowable value. Also, it is determined whether or not the groove width L5 of the cutting groove M is within the allowable range. For example, if the groove width L5 of the cutting groove M is less than the allowable value, there is a possibility that the cutting blade 60 is abnormally worn such as side surface thinning.
If it is determined that the value is not within the allowable value range in each of the above determinations, the cutting of the scheduled cutting line SN shown in FIG. 7 is stopped under the control of the control means 9 . Alternatively, a warning is issued from a speaker or the like, or a warning is displayed on the monitor 19 shown in FIG. 1 so that the operator can recognize the determination result.

After the cutting position correction is performed as described above, the holding table 30 holding the workpiece W is sent out in the -X direction at a predetermined cutting feed rate, so that the center line in the width direction of the planned cutting line SN. The cutting blades 60 positioned together cut the workpiece W. As shown in FIG. After the cutting blade 60 finishes cutting one line along the planned cutting line SN in the allowable area where the workpiece W can be placed within the holding surface 300a of the holding table 30, the holding table 30 moves in the +X direction. Move and return to the origin position. Then, the cutting blade 60 is index-fed in the +Y direction by the interval of the index size stored in the condition storage unit 90 . That is, the workpiece W is cut by returning to the original index feed amount (the index feed amount before correction).

After all the planned cutting lines S in the X-axis direction are cut, the holding table 30 is further rotated by 90 degrees and the same cutting as described above is performed, so that all the planned cutting lines S are cut vertically and horizontally. to divide the workpiece W into chips with the devices D thereon.

The cutting method according to the present invention detects when the cutting blade 60 cuts into the workpiece W and starts cutting, and detects the position where the cutting blade 60 cuts into the workpiece W and starts cutting. Since the step is provided, based on the position Q (x1, y1) detected in the cutting start detection step and the number of the line where cutting of the workpiece W is started, the workpiece W on the holding table 30 position can be specified accurately.

Further, the cutting apparatus 1 according to the present invention includes cutting start detection means 7 (or cutting start detection means 7A) for detecting that the cutting blade 60 has cut into the workpiece W held by the holding table 30. Therefore, the position Q (x1, y1) where the workpiece W actually started to be cut and the number of the line where the machining of the workpiece W started are detected, and the workpiece W on the holding table 30 is detected. position can be specified accurately. That is, for example, in the present cutting apparatus 1, the position Q (x1, y1) where the workpiece W actually started to be cut and the number of the line (3rd line) where cutting of the workpiece W started are Since the cutting process is performed while the control means 9 accurately specifies the position of the workpiece W on the holding table 30 after the detection, when the cutting blade 60 fails to cut the workpiece W. In such cases, the control means 9 can easily grasp the number of the line on which the cutting failure occurred from the number of the line on which cutting was started.

The cutting method according to the present invention is not limited to the above examples, nor is the configuration of the cutting apparatus 1 illustrated in the accompanying drawings limited to this, and the effects of the present invention can be exhibited. It can be changed as appropriate within the range.

1: cutting device 10: base
12: X-axis moving means
120: Ball screw 122: Motor 123: Movable plate
30: Holding table 300a: Holding surface 34: Fixed clamp 33: Rotating means 13: Y-axis moving means 130: Ball screw 132: Motor 133: Movable plate
14: Z-axis movement means 142: Motor 143: Holder 145: Column 18: Imaging means 19: Monitor 6: Cutting means 60: Cutting blade 600: Base 601: Cutting edge 61: Spindle housing 610: Housing body
611: housing cover 611a: spindle insertion hole 611b: inductor housing groove 62: spindle
63: Mount flange 630: Flange portion 631: Boss portion 632: Rear end portion 64: Front flange 65: Plain washer 66: Fixing bolt 68: Cutting water supply nozzle 69: Blade cover 7: Cutting start detection means 71: Elastic wave detection Sensor 72: Transmission path 7A: Cutting start detection means 79: Spindle load current value detection means 9: Control means 90: Condition storage unit W: Workpiece Wa: Surface of work piece Wb: Back side of work piece S: Cutting Scheduled line D: device T: dicing tape F: annular frame P: target pattern M: cutting groove

Claims (4)

A cutting method for cutting, with a cutting blade, a workpiece attached to a dicing tape having an outer peripheral portion attached to an annular frame ,
a holding step of holding the workpiece with a holding table;
a cutting step of cutting the workpiece by performing a cutting operation with the cutting blade on an allowable area on which the workpiece can be placed within the holding surface of the holding table;
Detecting that the cutting blade has cut into the workpiece and started cutting, detecting the coordinate position at which the cutting blade has cut into the workpiece and started cutting, and furthermore, detecting a coordinate position at which the cutting blade has cut into the workpiece and started cutting; a cutting start detection step of detecting the number of the line where cutting of the workpiece by the cutting blade is started after index feed of the cutting blade in the index feed direction orthogonal to is started in
The position of the workpiece, including the line where the dicing tape is cut outside the workpiece in the allowable area in the index feeding direction, based on the number of the line detected in the cutting start detection step Specifying the cutting method. 2. The cutting method according to claim 1, wherein said cutting start detection step detects that said cutting blade has cut into the workpiece from a change in a load current value of a spindle on which said cutting blade is mounted. 2. The cutting method according to claim 1, wherein said cutting start detection step detects that said cutting blade has cut into the workpiece with an elastic wave detection sensor provided in said cutting means having said cutting blade. A cutting device comprising a holding table for holding a workpiece attached to a dicing tape having an outer peripheral portion attached to an annular frame, and a cutting blade for cutting the workpiece held by the holding table. ,
moving means for relatively moving the cutting blade with respect to the holding table;
cutting start detection means for detecting that the cutting blade has cut into the workpiece held by the holding table;
When the cutting start detection means detects that the cutting blade has cut into the workpiece and started cutting, the cutting blade detects the coordinate position at which the cutting blade starts cutting into the workpiece , and After the index feed of the cutting blade in the index feed direction is started, including the line where the dicing tape is cut on the outer side of the dicing tape perpendicular to the cutting feed direction of the holding table in the horizontal plane from the object A cutting device that detects the number of a line on which cutting of a workpiece by the cutting blade is started, and specifies the position of the workpiece based on the number of the line.

Images