JP6215558B2 - Processing equipment - Google Patents

Description

  The present invention relates to a processing apparatus for performing processing along a plurality of division lines set on a workpiece such as a semiconductor wafer.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by division lines arranged in a lattice pattern on the surface of a substantially disc-shaped semiconductor wafer, and devices such as ICs and LSIs are formed in the partitioned regions. . Then, by cutting the semiconductor wafer along the planned dividing line, the region where the device is formed is divided to manufacture individual devices.

  As a method of dividing a wafer such as the semiconductor wafer described above, there is a laser processing method using a pulsed laser beam having a wavelength that is transparent to the wafer, and irradiating the pulsed laser beam with a focusing point positioned inside the region to be divided. It has been put into practical use. The division method using this laser processing method is to divide the inside of the work piece by irradiating a pulse laser beam having a wavelength that is transparent to the wafer by positioning a condensing point from one side of the wafer inside. This is a technique for dividing a wafer by continuously forming a modified layer along a line and applying an external force along a line to be divided whose strength is reduced by forming the modified layer. (For example, refer to Patent Document 1.)

  A laser processing apparatus for forming a modified layer along a division line inside a workpiece includes a workpiece holding means for holding the workpiece, and a workpiece held by the workpiece holding means. Laser beam irradiating means provided with a condenser for irradiating a laser beam, processing feed means for processing and feeding the workpiece holding means and laser beam irradiating means relative to the processing feed direction, workpiece holding means and laser beam irradiating means Are fed in an indexing feed direction orthogonal to the machining feed direction, and an imaging means for detecting a region to be machined of the workpiece held by the workpiece holding means. (For example, see Patent Document 2.)

Japanese Patent No. 3408805 JP 2010-52014 A

While laser processing is being performed on the workpiece held by the workpiece holding means using the laser processing device described above, the work is interrupted due to power interruption or machine trouble, etc. However, when the work is recovered and the work is resumed, the work is automatically resumed from the state where the work is interrupted.
In other words, the laser processing apparatus is operated to warm each component mechanism, and is cooled until the operation is resumed when the operation is interrupted due to power interruption, machine trouble, or the like. Therefore, when the work is resumed from a state where the work is interrupted, there is a problem that the laser beam is irradiated to an area that is out of the division planned line to be machined and the device is damaged.
Such a problem may also occur in a cutting apparatus that cuts a workpiece with a cutting blade.

  The present invention has been made in view of the above facts, and its main technical problem is to provide a processing apparatus that can reliably perform processing along a set division schedule line even if the processing operation is interrupted and resumed. It is to provide.

In order to solve the above main technical problem, according to the present invention, a processing apparatus that performs processing along a plurality of division scheduled lines set on a workpiece,
A workpiece holding means for holding the workpiece, a processing means for processing the workpiece held by the workpiece holding means, and the workpiece holding means and the processing means in the X-axis direction. X-axis moving means for relatively machining and feeding, Y-axis moving means for indexing and feeding the workpiece holding means and the machining means in the Y-axis direction orthogonal to the X-axis direction, and X by the X-axis moving means X-axis direction position detection means for detecting the axial movement position, Y-axis direction position detection means for detecting the Y-axis direction movement position by the Y-axis movement means, and the workpiece held by the workpiece holding means An imaging means for detecting a division-scheduled line set to the X-axis direction position detecting means, the Y-axis direction position detecting means, and the processing means, the X-axis moving means, and the Control means for controlling the Y-axis moving means,
The control means includes a first recording area for recording the coordinates of a plurality of scheduled division lines set on the workpiece, and a memory having a second recording area for recording the coordinates of the scheduled division lines that have been processed. And time measuring means, and performing the machining operation by executing the alignment for detecting the machining area of the workpiece held by the workpiece holding means by operating the imaging means. When resuming the machining operation after the interruption, it is determined whether or not a predetermined time has elapsed from the time when the machining operation timed by the time measuring means is interrupted to the time when the machining operation is resumed. When the elapsed time exceeds a predetermined time, the processing information recorded in the second recording area and the coordinate information of the plurality of scheduled division lines set in the workpiece recorded in the first recording area Raw splitting plan based on After performing the realignment to detect the unscheduled division line set on the workpiece that is held by the workpiece holding unit and the machining operation is interrupted by operating the imaging unit When the X-axis moving means, the Y-axis moving means and the machining means are controlled to process along the unscheduled division line of the workpiece and the elapsed time has not reached the predetermined time Is processed along the unscheduled division lines of the workpiece without the realignment based on the information recorded in the first recording area and the second recording area ,
The processing apparatus characterized by this is provided.

In the machining apparatus according to the present invention, the control unit records a first recording area for recording the coordinates of a plurality of scheduled division lines set on the workpiece and a second recording for recording the coordinates of the scheduled division lines subjected to the machining. A memory having a region and a timing unit are provided, and the processing is performed by executing the alignment that detects the processing region of the workpiece held by the workpiece holding unit by operating the imaging unit. When the machining operation is resumed after the machining operation is interrupted, it is determined whether the elapsed time from the time when the machining operation timed by the timing means is interrupted to the time when the machining operation is resumed has passed a predetermined time. When the predetermined time has passed, the processing information recorded in the second recording area and the coordinates of the plurality of scheduled division lines set in the workpiece recorded in the first recording area Not added based on information Re-alignment was performed to identify the unscheduled division line set on the workpiece that was held by the workpiece holding means and the machining operation was interrupted by operating the imaging means Thereafter, by controlling the X-axis moving means, the Y-axis moving means, and the processing means, the workpiece is processed along the unscheduled division line , and when the elapsed time does not reach the predetermined time, Based on the information recorded in the first recording area and the second recording area, the processing is performed along the unscheduled division lines of the workpiece without performing the realignment. Even if the component mechanism is cooled, it can be reliably processed along the unscheduled dividing line.

The perspective view of the laser processing apparatus comprised according to this invention. The block block diagram of the control means with which the laser processing apparatus shown in FIG. 1 is equipped. The perspective view of the semiconductor wafer as a to-be-processed object. The perspective view which shows the state which affixed the semiconductor wafer shown in FIG. 3 on the dicing tape with which the cyclic | annular flame | frame was mounted | worn. FIG. 5 is an explanatory diagram showing a relationship with a coordinate position in a state where the semiconductor wafer shown in FIG. 4 is held at a predetermined position of a chuck table as a workpiece holding means of the laser processing apparatus shown in FIG. 1. Explanatory drawing of the modified layer formation process implemented by the laser processing apparatus shown in FIG. Explanatory drawing of the re-alignment process implemented by the laser processing apparatus shown in FIG. Explanatory drawing of the rework process in the modified layer formation process implemented by the laser processing apparatus shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a processing apparatus configured according to the present invention will be described in more detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a laser processing apparatus as a processing apparatus configured according to the present invention. The laser processing apparatus shown in FIG. 1 includes a stationary base 2 and a chuck for holding a wafer as a workpiece, which is disposed on the stationary base 2 so as to be movable in a machining feed direction (X-axis direction) indicated by an arrow X. A table mechanism 3, a laser beam irradiation unit support mechanism 4 disposed on the stationary base 2 so as to be movable in an indexing feed direction (Y axis direction) indicated by an arrow Y orthogonal to the X axis direction, and the laser beam irradiation unit support mechanism 4 includes a laser beam irradiation unit 5 disposed so as to be movable in a condensing point position adjustment direction (Z-axis direction) indicated by an arrow Z.

  The chuck table mechanism 3 includes a pair of guide rails 31 and 31 disposed in parallel along the X-axis direction on the stationary base 2, and is arranged on the guide rails 31 and 31 so as to be movable in the X-axis direction. A first sliding block 32 provided, a second sliding block 33 movably disposed on the first sliding block 32 in the Y-axis direction, and a cylindrical member on the second sliding block 33 A cover table 35 supported by 34 and a chuck table 36 as a workpiece holding means are provided. The chuck table 36 includes a suction chuck 361 formed of a porous material, and holds, for example, a disk-shaped semiconductor wafer, which is a workpiece, on the suction chuck 361 by suction means (not shown). . The chuck table 36 configured as described above is rotated by a pulse motor (not shown) disposed in the cylindrical member 34. The chuck table 36 is provided with a clamp 362 for fixing an annular frame described later.

  The first sliding block 32 has a pair of guided grooves 321 and 321 fitted to the pair of guide rails 31 and 31 on the lower surface thereof, and is parallel to the upper surface along the Y-axis direction. A pair of formed guide rails 322 and 322 are provided. The first sliding block 32 configured in this manner moves in the X-axis direction along the pair of guide rails 31, 31 when the guided grooves 321, 321 are fitted into the pair of guide rails 31, 31. Configured to be possible. The chuck table mechanism 3 in the illustrated embodiment includes an X-axis moving means 37 for moving the first slide block 32 along the pair of guide rails 31 and 31 in the X-axis direction. The X-axis moving means 37 includes a male screw rod 371 disposed in parallel between the pair of guide rails 31 and 31, and a drive source such as a pulse motor 372 for rotating the male screw rod 371. Yes. One end of the male screw rod 371 is rotatably supported by a bearing block 373 fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 372 by transmission. The male screw rod 371 is screwed into a penetrating female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the first sliding block 32. Therefore, the first slide block 32 is moved in the X-axis direction along the guide rails 31 and 31 by driving the male screw rod 371 forward and backward by the pulse motor 372.

  The laser processing apparatus in the illustrated embodiment includes X-axis direction position detecting means 374 for detecting the processing feed amount of the chuck table 36, that is, the X-axis direction position. The X-axis direction position detecting means 374 is a linear scale 374a disposed along the guide rail 31 and a reading that is disposed along the linear scale 374a together with the first sliding block 32 disposed along the first sliding block 32. It consists of a head 374b. In the illustrated embodiment, the reading head 374b of the X-axis direction position detecting means 374 sends a pulse signal of one pulse every 1 μm to the control means described later. Then, the control means described later detects the machining feed amount of the chuck table 36, that is, the position in the X-axis direction by counting the input pulse signals. When the pulse motor 372 is used as the drive source of the machining feed means 37, the machining feed amount of the chuck table 36 is counted by counting the drive pulses of the control means to be described later that outputs a drive signal to the pulse motor 372. That is, the position in the X-axis direction can also be detected.

  The second sliding block 33 is provided with a pair of guided grooves 331 and 331 which are fitted to a pair of guide rails 322 and 322 provided on the upper surface of the first sliding block 32 on the lower surface thereof. By fitting the guided grooves 331 and 331 to the pair of guide rails 322 and 322, the guided grooves 331 and 331 are configured to be movable in the Y-axis direction. The chuck table mechanism 3 in the illustrated embodiment includes a first Y for moving the second slide block 33 along the pair of guide rails 322 and 322 provided in the first slide block 32 in the Y-axis direction. An axis moving means 38 is provided. The first Y-axis moving means 38 includes a drive source such as a male screw rod 381 disposed in parallel between the pair of guide rails 322 and 322, and a pulse motor 382 for rotationally driving the male screw rod 381. Is included. One end of the male screw rod 381 is rotatably supported by a bearing block 383 fixed to the upper surface of the first slide block 32, and the other end is connected to the output shaft of the pulse motor 382. The male screw rod 381 is screwed into a through female screw hole formed in a female screw block (not shown) provided on the lower surface of the center portion of the second sliding block 33. Therefore, the second sliding block 33 is moved in the Y-axis direction along the guide rails 322 and 322 by driving the male screw rod 381 forward and backward by the pulse motor 382.

  The laser processing apparatus in the illustrated embodiment includes Y-axis direction position detection means 384 for detecting the indexing processing feed amount of the second sliding block 33, that is, the Y-axis direction position. The Y-axis direction position detecting means 384 moves along the linear scale 384a together with the linear scale 384a disposed along the guide rail 322 and the second sliding block 33. And a reading head 384b. In the illustrated embodiment, the reading head 384b of the Y-axis direction position detecting means 384 sends a pulse signal of one pulse every 1 μm to the control means described later. The control means described later counts the input pulse signal to detect the index feed amount of the chuck table 36, that is, the position in the Y-axis direction. When the pulse motor 382 is used as the drive source of the first Y-axis moving means 38, the chuck table 36 is counted by counting the drive pulses of the control means to be described later that outputs a drive signal to the pulse motor 382. It is also possible to detect the index feed amount, that is, the position in the Y-axis direction.

  The laser beam irradiation unit support mechanism 4 includes a pair of guide rails 41 and 41 disposed in parallel along the Y-axis direction on the stationary base 2 and a direction indicated by an arrow Y on the guide rails 41 and 41. A movable support base 42 is provided so as to be movable. The movable support base 42 includes a movement support portion 421 that is movably disposed on the guide rails 41, 41, and a mounting portion 422 that is attached to the movement support portion 421. The mounting portion 422 is provided with a pair of guide rails 423 and 423 extending in the Z-axis direction on one side surface in parallel. The laser beam irradiation unit support mechanism 4 in the illustrated embodiment includes second Y-axis moving means 43 for moving the movable support base 42 along the pair of guide rails 41 and 41 in the Y-axis direction. . The second Y-axis moving means 43 includes a male screw rod 431 disposed in parallel between the pair of guide rails 41, 41, and a drive source such as a pulse motor 432 for rotationally driving the male screw rod 431. Is included. One end of the male screw rod 431 is rotatably supported by a bearing block (not shown) fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 432. The male screw rod 431 is screwed into a female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the moving support portion 421 constituting the movable support base 42. Therefore, the movable support base 42 is moved in the Y-axis direction along the guide rails 41 and 41 by driving the male screw rod 431 forward and backward by the pulse motor 432.

  The laser beam irradiation unit 5 in the illustrated embodiment includes a unit holder 51 and laser beam irradiation means 52 attached to the unit holder 51. The unit holder 51 is provided with a pair of guided grooves 511 and 511 that are slidably fitted to a pair of guide rails 423 and 423 provided in the mounting portion 422. By being fitted to the guide rails 423 and 423, the guide rails 423 and 423 are supported so as to be movable in the Z-axis direction.

  The laser beam irradiation unit 5 in the illustrated embodiment includes a condensing point position adjusting means 53 for moving the unit holder 51 along the pair of guide rails 423 and 423 in the Z-axis direction. The condensing point position adjusting means 53 includes a male screw rod (not shown) disposed between the pair of guide rails 423 and 423, and a drive source such as a pulse motor 532 for rotationally driving the male screw rod. Thus, the unit holder 51 and the laser beam irradiation means 52 are moved along the guide rails 423 and 423 in the Z-axis direction by driving the male screw rod (not shown) by the pulse motor 532 in the normal direction and the reverse direction. In the illustrated embodiment, the laser beam irradiation means 52 is moved upward by driving the pulse motor 532 forward, and the laser beam irradiation means 52 is moved downward by driving the pulse motor 532 in reverse. Yes.

  The illustrated laser beam irradiation means 52 includes a cylindrical casing 521 that is fixed to the unit holder 51 and extends substantially horizontally, and a laser beam oscillation means such as a YAG laser oscillator or a YVO4 laser oscillator disposed in the casing 521. (Not shown) and a condenser 524 that is disposed at the tip of the casing 521 and collects the pulse laser beam emitted from the laser beam oscillation means and irradiates the workpiece held on the chuck table 36. ing.

  An imaging unit 6 for detecting a processing region to be laser processed by the laser beam irradiation unit 52 is disposed at the tip of the casing 521 constituting the laser beam irradiation unit 52. In the illustrated embodiment, the imaging unit 6 includes an infrared illumination unit that irradiates a workpiece with infrared rays, and an infrared ray that is irradiated by the infrared illumination unit, in addition to a normal imaging device (CCD) that captures visible light. And an imaging device (infrared CCD) that outputs an electrical signal corresponding to infrared rays captured by the optical system, and sends the captured image signal to a control means described later.

  The laser processing apparatus in the illustrated embodiment includes a control means 7 shown in FIG. The control means 7 is constituted by a computer, and a central processing unit (CPU) 71 that performs arithmetic processing according to a control program, a read only memory (ROM) 72 that stores a control program and the like, and a design value of a workpiece to be described later. A readable / writable random access memory (RAM) 73 for storing data, calculation results, and the like, a counter 74, a timer 75 as a time measuring means, an input interface 76, and an output interface 77 are provided. Detection signals from the X-axis direction position detection unit 374, the Y-axis direction position detection unit 384, the imaging unit 6, and the like are input to the input interface 76 of the control unit 7. A control signal is output from the output interface 77 of the control means 7 to the pulse motor 372, the pulse motor 382, the pulse motor 432, the pulse motor 532, the laser beam irradiation means 52, and the like. The random access memory (RAM) 73 has a first recording area 73a for recording the coordinates of a planned division line set on a semiconductor wafer, which will be described later by the imaging means 6, and a planned division line which has been processed later. Are provided with a second recording area 73b for recording the coordinates and other storage areas.

  The control means 7 described above is connected to a power source 8 and a backup power source 80 for supplying electric power to each of the mechanisms and devices constituting the laser processing apparatus. Therefore, even if the power supply 8 is cut off, power is supplied to the control means 7 from the backup power supply 80.

Next, laser processing for forming a modified layer inside a wafer as a workpiece using the above-described laser processing apparatus will be described.
FIG. 3 is a perspective view of a semiconductor wafer as a workpiece. A semiconductor wafer 10 shown in FIG. 3 is made of, for example, a silicon wafer having a thickness of 100 μm, and a plurality of division lines 101 are formed in a lattice pattern on the surface 10a. In the semiconductor wafer 10 configured as described above, the surface 10a is attached to the surface of the dicing tape T attached to the annular frame F as shown in FIG. 4 (wafer attaching step). Therefore, the back surface 10b of the semiconductor wafer 10 adhered to the front surface of the dicing tape T is on the upper side.

  If the wafer sticking step described above is performed, the dicing tape T side of the semiconductor wafer 10 is placed on the chuck table 36 of the laser processing apparatus shown in FIG. Then, the semiconductor wafer 10 is sucked and held on the chuck table 36 via the dicing tape T by operating a suction means (not shown) (wafer holding step). Therefore, the back surface 10b of the semiconductor wafer 10 held on the chuck table 36 via the dicing tape T is on the upper side. The annular frame F is fixed by a clamp 362.

  As described above, the chuck table 36 that sucks and holds the semiconductor wafer 10 is positioned directly below the imaging unit 6 by the X-axis moving unit 37. When the chuck table 36 is positioned immediately below the image pickup means 6 in this way, an alignment operation for detecting a processing region to be laser processed on the semiconductor wafer 10 is executed by the image pickup means 6 and the control means 7. That is, the imaging unit 6 and the control unit 7 constitute a division line 101 formed in a predetermined direction on the surface 10 a of the semiconductor wafer 10 and a laser beam irradiation unit 52 that irradiates a laser beam along the division line 101. Image processing such as pattern matching for alignment with the condenser 524 is performed, and alignment of the laser beam irradiation position is performed (alignment process). Similarly, alignment of the laser beam irradiation position is also performed on the division line 101 formed in the direction orthogonal to the predetermined direction formed on the surface 10a of the semiconductor wafer 10 (alignment process). At this time, the surface 10a on which the plurality of division lines 101 of the semiconductor wafer 10 are formed is positioned on the lower side. However, as described above, the imaging unit 6 has the infrared illumination unit and the optical system that captures infrared rays and the infrared ray. Since the image pickup device is provided with an image pickup device (infrared CCD) or the like that outputs a corresponding electric signal, it is possible to pick up an image of the planned division line 101 through the back surface 10b.

  As described above, when the alignment process is performed, the semiconductor wafer 10 on the chuck table 36 is positioned at the coordinate position shown in FIG. FIG. 5B shows a state in which the chuck table 36, that is, the semiconductor wafer 10, is rotated by 90 degrees from the state shown in FIG.

  As described above, the design coordinates of the plurality of scheduled division lines 101 in the semiconductor wafer 10 positioned at the coordinate positions shown in FIGS. 5A and 5B are the random access memory of the control means 7. It is recorded in the first recording area 73 a of (RAM) 73.

  When the alignment process is performed as described above, the chuck table 36 is moved so that the lowest division line 101 is positioned immediately below the condenser 524 of the laser beam irradiation means 52 in FIG. Further, as shown in FIG. 6A, one end of the planned division line 101 (the left end in FIG. 6A) is positioned directly below the condenser 524. Then, the condensing point P of the pulse laser beam irradiated through the condenser 524 is positioned at an intermediate position in the thickness direction of the semiconductor wafer 10.

  Next, the laser beam irradiating means 52 is operated to irradiate a pulse laser beam having a wavelength that is transmissive to the silicon wafer through the condenser 524, and the X-axis moving means 37 is operated to move the chuck table 36 to the position shown in FIG. In a), it is moved at a predetermined machining feed rate in the direction indicated by the arrow X1. When the irradiation position of the condenser 524 of the laser beam irradiation means 52 reaches the position of the other end (the right end in FIG. 6B) as shown in FIG. 6B, the pulse laser beam. Is stopped and the movement of the chuck table 36 is stopped (modified layer forming step). As a result, the modified layer 110 is formed on the wafer 10 along the planned division line 101 as shown in FIG.

The processing conditions in the modified layer forming step are set as follows, for example.
Light source: Semiconductor-excited solid-state laser (Nd: YAG)
Laser beam wavelength: 1064 nm
Repetition frequency: 100 kHz
Average output: 0.3W
Condensing spot diameter: φ1μm
Processing feed rate: 400 mm / sec

  As described above, when the modified layer forming step is performed along the lowest division line 101 in FIG. 5A of the semiconductor wafer 10, the first Y-axis moving unit 38 is operated. Then, the chuck table 36 is moved in the Y-axis direction by the interval of the scheduled division lines 101, and the second lowest divisional line 101 from the lowest position is positioned directly below the condenser 524 of the laser beam irradiation means 52. Then, the modified layer forming step is performed along the second scheduled division line 101 from the bottom. Then, the modified layer forming step is sequentially performed along the upper division line 101. When performing the above-described modified layer forming step, the control unit 7 performs the modified layer forming process based on the detection signals from the X-axis direction position detecting unit 374 and the Y-axis direction position detecting unit 384. Are recorded in the second recording area 73 b of the random access memory (RAM) 73.

  As described above, when the modified layer forming step is being performed, the work may be interrupted due to the interruption of the power supply 8 or mechanical troubles. Then, when the power source 8 and the trouble are recovered, the operation is resumed. When the power supply 8 is cut off, power is supplied to the control means 7 by the backup power supply 80, so that data recorded in the random access memory (RAM) 73 or the like will not disappear. However, each component mechanism of the laser processing apparatus is warmed by continuing the above-described processing, and is cooled when the operation is interrupted. For this reason, if the time from when the work is interrupted to when the work is resumed is, for example, 5 minutes or longer, the amount of cooling of each constituent mechanism and the displacement increases, so that the semiconductor wafer 10 held on the chuck table 36 is increased. Incorrect machining position. Therefore, in the laser processing apparatus described above, when a signal for resuming the work is input to the control means 7, the control means 7 reads the processing information recorded in the second recording area 73b and the first recording area 73a. An unprocessed division planned line is specified based on the coordinate information of a plurality of division planned lines set in the semiconductor wafer 10 recorded in the above. Then, the control means 7 determines whether or not the elapsed time from the time when the work timed by the timer 75 as the time measuring means is interrupted to the time when the work is resumed is, for example, 5 minutes or more, and the elapsed time is 5 minutes or more. In some cases, the X-axis moving means 37 is operated to move the chuck table 36 that sucks and holds the semiconductor wafer 10 to the image pickup area of the image pickup means 6, and the semiconductor wafer 10 held on the chuck table 36 as shown in FIG. The position at which the work is interrupted is positioned directly below the imaging means 6. And the control means 7 operates the imaging means 6, and performs the realignment which detects the coordinate of the unscheduled division | segmentation scheduled line 101 (realignment process). This realignment process can be implemented similarly to the alignment process mentioned above.

  When the realignment process is performed as described above, the control means 7 controls the X-axis moving means 37 and the first Y-axis moving means 38 to move the chuck table 36, and as shown in FIG. The position where the operation of the unscheduled division line 101 in the semiconductor wafer 10 held on the table 36 is interrupted is positioned immediately below the condenser 524. Then, the control means 7 positions the condensing point P of the pulse laser beam irradiated through the condenser 524 at the intermediate position in the thickness direction of the semiconductor wafer 10.

  Next, the control means 7 operates the laser beam irradiating means 52 to irradiate a pulse laser beam having a wavelength that is transmissive to the silicon wafer through the condenser 524, and operates the X-axis moving means 37 to move the chuck table 36. In FIG. 7, the above-described modified layer forming step is carried out by moving at a predetermined processing feed rate in the direction indicated by the arrow X1. Thereafter, the modified layer forming process is performed along all unprocessed division lines 101 (rework process).

  As described above, when the elapsed time from the time when the work is interrupted to the time when the work is resumed is, for example, 5 minutes or longer, the processing information recorded in the second recording area 73b and the first recording area 73a. Based on the recorded coordinate information of the plurality of division lines set on the semiconductor wafer 10, an unprocessed division line is specified, and the imaging means 6 is operated to be held on the chuck table 36 and the machining operation is interrupted. After the re-alignment for detecting the unprocessed division planned line 101 set in the semiconductor wafer 10 is executed, the re-processing is performed along the unprocessed division planned line 101. Can be processed reliably.

  When a signal for resuming the work is input to the control means 7 and the elapsed time from the time when the work is interrupted to the time when the work is resumed is less than 5 minutes, each component mechanism of the laser processing apparatus Since the displacement due to cooling is slight, the line to be divided as an unprocessed line to be divided based on the information recorded in the first recording area 73a and the second recording area 73b of the random access memory (RAM) 73 A modified layer forming step is performed along the line 101.

  In the above, an example in which the present invention is applied to a laser processing apparatus has been shown. However, the same effect can be obtained even if the present invention is applied to a cutting apparatus that cuts a wafer along a plurality of division lines.

2: stationary base 3: chuck table mechanism 36: chuck table 37: X-axis moving means 38: first Y-axis moving means 4: laser beam irradiation unit support mechanism 43: second Y-axis moving means 5: laser beam irradiation unit 52: Laser beam irradiation means 524: Condenser 53: Condensing point position adjusting means 6: Imaging means 7: Control means 8: Power supply 80: Backup power supply 10: Semiconductor wafer F: Ring frame T: Dicing tape

Claims (1)

A processing device that performs processing along a plurality of scheduled division lines set on a workpiece,
A workpiece holding means for holding the workpiece, a processing means for processing the workpiece held by the workpiece holding means, and the workpiece holding means and the processing means in the X-axis direction. X-axis moving means for relatively machining and feeding, Y-axis moving means for indexing and feeding the workpiece holding means and the machining means in the Y-axis direction orthogonal to the X-axis direction, and X by the X-axis moving means X-axis direction position detection means for detecting the axial movement position, Y-axis direction position detection means for detecting the Y-axis direction movement position by the Y-axis movement means, and the workpiece held by the workpiece holding means An imaging means for detecting a division-scheduled line set to the X-axis direction position detecting means, the Y-axis direction position detecting means, and the processing means, the X-axis moving means, and the Control means for controlling the Y-axis moving means,
The control means includes a first recording area for recording the coordinates of a plurality of scheduled division lines set on the workpiece, and a memory having a second recording area for recording the coordinates of the scheduled division lines that have been processed. And time measuring means, and performing the machining operation by executing the alignment for detecting the machining area of the workpiece held by the workpiece holding means by operating the imaging means. When resuming the machining operation after the interruption, it is determined whether or not a predetermined time has elapsed from the time when the machining operation timed by the time measuring means is interrupted to the time when the machining operation is resumed. When the elapsed time exceeds a predetermined time, the processing information recorded in the second recording area and the coordinate information of the plurality of scheduled division lines set in the workpiece recorded in the first recording area Raw splitting plan based on After performing the realignment to detect the unscheduled division line set on the workpiece that is held by the workpiece holding unit and the machining operation is interrupted by operating the imaging unit When the X-axis moving means, the Y-axis moving means and the machining means are controlled to process along the unscheduled division line of the workpiece and the elapsed time has not reached the predetermined time Is processed along the unscheduled division lines of the workpiece without the realignment based on the information recorded in the first recording area and the second recording area ,
A processing apparatus characterized by that.

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