JP6224462B2 - Method for detecting operating characteristics of machining feed mechanism in laser machining apparatus and laser machining apparatus - Google Patents

Description

  The present invention relates to a method for detecting an operation characteristic of a processing feed mechanism in a laser processing apparatus for performing laser processing on a workpiece such as a semiconductor wafer and a laser processing apparatus.

  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.

  Further, as a method of dividing a wafer such as a semiconductor wafer, a laser processing groove is formed along the planned dividing line by irradiating the wafer with a pulse laser beam having a wavelength that absorbs the wafer along the planned dividing line. There has been proposed a technique for dividing a wafer by applying an external force along a planned division line in which a laser processed groove is formed.

  The laser processing apparatus for performing the laser processing described above includes a workpiece holding means for holding a workpiece, a laser beam irradiation means for irradiating the workpiece held by the workpiece holding means with a laser beam, and a workpiece A machining feed mechanism for moving the holding means and the laser beam irradiation means relative to the machining feed direction (X-axis direction), and an index feed direction (Y-axis) perpendicular to the X-axis direction between the workpiece holding means and the laser beam irradiation means. And an image pickup means for picking up an image of the work piece held by the work piece holding means and detecting a region to be machined. (For example, refer to Patent Document 1.)

JP 2008-12666 A

  Therefore, a ball screw type moving mechanism is generally used as a machining feed mechanism for moving a moving base supporting a holding table as a workpiece holding means along the guide rail in the machining feed direction (X-axis direction). If the ball screw or the guide rail has a distortion of about several μm, the holding table supported by the moving base is swung in the Y-axis direction. As a result, there is a problem in that the laser beam is irradiated to a position shifted from the division planned line of the wafer held on the holding table, and the device is damaged.

  In addition, a jig with a highly accurate side surface without distortion is placed on the holding surface of the holding table, and the displacement in the Y-axis direction is measured with a micrometer while operating the machining feed mechanism to obtain a correction value. Although a method of canceling the distortion in the Y-axis direction by the mechanism by a correction value is also employed, there are problems that the jig is expensive and it is difficult to measure the displacement with a micrometer.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is the Y-axis by the machining feed mechanism that moves the workpiece holding means for holding the workpiece in the machining feed direction (X-axis direction). It is an object of the present invention to provide a method for detecting an operation characteristic of a processing feed mechanism in a laser processing apparatus and a laser processing apparatus capable of easily detecting a directional distortion.

In order to solve the above-mentioned main technical problem, according to the present invention, a workpiece holding means for holding a workpiece, and a laser beam irradiation means for irradiating a workpiece held by the workpiece holding means with a laser beam A workpiece feed mechanism for moving the workpiece holding means and the laser beam irradiation means in the machining feed direction (X-axis direction), and the workpiece holding means and the laser beam irradiation means in the X-axis direction. Index feed mechanism that moves relatively in the orthogonal index feed direction (Y-axis direction), X-axis direction position detecting means for detecting the X-axis direction movement position by the machining feed mechanism, and Y-axis direction by the index feed mechanism Y-axis direction position detecting means for detecting the moving position, imaging means for picking up an image of the workpiece held by the workpiece holding means and detecting a region to be processed, the laser beam irradiation means, and the processing feed A working characteristic detection method of processing feed mechanism in the laser machining apparatus comprising a control unit, the controlling mechanisms and the indexing mechanism,
A plate-like object holding step of holding the plate-like object on the workpiece holding means;
A laser that moves the workpiece holding means that holds the plate-like object by operating the processing feed mechanism in the X-axis direction, and forms a linear laser processing mark on the plate-like object by operating the laser beam irradiation means. Processing mark formation process;
The plate-like object on which the laser machining trace forming step has been performed is removed from the workpiece holding means, and the line connecting the start point and the end point of the laser machining trace is reversed 180 degrees to the workpiece holding means. A plate-like object reversing step to hold,
The processing feed mechanism is actuated to move the workpiece holding means for holding the plate-like object subjected to the plate-like object reversing step, and the start point of the laser processing trace formed on the plate-like object is imaged. A laser processing mark positioning step for positioning the imaging region by means;
The processing feed mechanism is operated and the imaging means is operated to image from the start point to the end point of the laser processing trace formed on the plate-like object, and the displacement amount in the Y-axis direction in the X coordinate of the laser processing trace is determined. A displacement detection step to detect;
A display step of displaying on the display means the amount of displacement in the Y-axis direction at the X coordinate of the laser processing mark detected by the displacement detection step,
There is provided a method for detecting an operation characteristic of a machining feed mechanism in a laser machining apparatus.

In the display step, ½ of the amount of displacement in the Y-axis direction at the X coordinate of the laser processing trace is displayed as a correction value at the time of laser processing.
The plate-like object is a glass plate, and the displacement detection step images the laser processing trace formed on the surface of the glass plate from the back surface of the glass plate.
The plate-like object is a silicon plate, and in the displacement detection step, a laser processing mark formed on the surface of the silicon plate is imaged by infrared rays from the back surface of the silicon plate.
Alignment marks are provided on one end and the other end of the plate-like object, and a reference line extending in the X-axis direction is formed in the image pickup area of the image pickup means. The step includes a first alignment step of matching the alignment mark provided at one end of the plate-like object with the alignment mark provided at the other end of the plate-like object and the alignment mark provided at the other end, In the laser processing mark positioning step, the alignment mark provided at one end portion of the plate-like object matches the reference line with the alignment mark provided at the other end portion and the other end portion of the plate-like object. An alignment process is included.

Further, according to the present invention, a workpiece holding means for holding the workpiece, a laser beam irradiation means for irradiating the workpiece held by the workpiece holding means with a laser beam, and the workpiece holding means And a processing feed mechanism for moving the laser beam irradiation means relative to the processing feed direction (X-axis direction), and an indexing feed direction (Y that is orthogonal to the X-axis direction between the workpiece holding means and the laser beam irradiation means. An index feed mechanism that moves relatively in the axial direction), an X-axis direction position detection means that detects an X-axis direction movement position by the machining feed mechanism, and a Y-axis that detects a Y-axis direction movement position by the index feed mechanism A laser processing apparatus comprising: a direction position detection unit; and an imaging unit that detects an area to be processed by imaging the workpiece held by the workpiece holding unit;
The plate-like object is held by the workpiece holding means and the workpiece feed mechanism is operated to move the workpiece holding means holding the plate-like object in the X-axis direction and the laser beam irradiation means is operated to move the plate. Forming a linear laser-processed trace on the object, removing the plate-like object from the workpiece-holding means, and reversing it 180 degrees about the line connecting the start point and end point of the laser-processed mark as the rotation axis The image is taken from the start point to the end point of the laser processing mark formed on the plate-like object by operating the processing feeding mechanism and operating the processing feed mechanism. Control means comprising a memory for detecting the amount of displacement in the axial direction and storing the amount of displacement in the Y-axis direction at the X coordinate of the detected laser processing trace;
Display means for displaying the amount of displacement in the Y-axis direction at the X coordinate of the laser processing mark stored in the memory of the control means,
A laser processing apparatus is provided.

  The control means stores ½ of the amount of displacement in the Y-axis direction in the X coordinate of the laser processing trace as a correction value at the time of laser processing in the memory.

  The method for detecting the operating characteristics of the processing feed mechanism in the laser processing apparatus according to the present invention includes a plate-like object holding step for holding the plate-like object on the workpiece holding means, and a workpiece holding the plate-like object by operating the processing feed mechanism. Laser processing trace forming step of moving the workpiece holding means in the X-axis direction and operating the laser beam irradiation means to form a linear laser processing trace on the plate-like material, and a plate shape on which the laser processing trace forming step is performed The plate-like object reversing step of removing the workpiece from the workpiece holding means and reversing it 180 degrees around the line connecting the start point and end point of the laser machining trace and holding it on the workpiece holding means, and the processing feed mechanism are operated. The laser processing trace which moves the workpiece holding means for holding the plate-like object subjected to the plate-like object reversing step and positions the start point of the laser processing trace formed on the plate-like object in the imaging area by the imaging means Displacement amount in the Y-axis direction in the X coordinate of the laser processing trace by imaging the installation process and the processing feed mechanism and the imaging means to image the laser processing trace from the start point to the end point And a display step for displaying on the display means the amount of displacement in the Y-axis direction at the X coordinate of the laser processing mark detected by the displacement detection step, an expensive jig is used. The displacement amount in the Y-axis direction of the X-coordinate of the laser processing trace can be easily detected. Therefore, the operator can confirm the operation characteristics of the machining feed mechanism by the amount of displacement in the Y-axis direction in the X coordinate of the laser machining trace displayed on the display means, and whether or not correction is necessary when performing laser machining. Can be judged.

The perspective view of the laser processing apparatus comprised according to this invention. The block block diagram of the laser beam irradiation means with which the laser processing apparatus shown in FIG. 1 is equipped, and an imaging means. 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 plate-shaped object used for the operating characteristic detection method of the X-axis moving mechanism in the laser processing apparatus by this invention. Explanatory drawing of the laser processing trace formation process in the operating characteristic detection method of the X-axis moving mechanism by this invention. Explanatory drawing of the plate-shaped object inversion process in the operating characteristic detection method of the X-axis moving mechanism by this invention. Explanatory drawing of the displacement detection process in the operating characteristic detection method of the X-axis moving mechanism by this invention. The operating characteristic map of the X-axis movement mechanism created by the operating characteristic detection method of the X-axis movement mechanism by this invention.

  Hereinafter, preferred embodiments of a method for detecting an operation characteristic of a machining feed mechanism in a laser machining apparatus and a laser machining apparatus 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 constructed according to the present invention. A laser processing apparatus shown in FIG. 1 includes a stationary base 2 and a chuck table mechanism 3 that 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 and holds a workpiece. And a laser beam irradiation unit 4 as a laser beam irradiation means disposed on the stationary base 2.

  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 slide block 32 provided, and a second slide arranged on the first slide block 32 so as to be movable in an index feed direction (Y-axis direction) indicated by an arrow Y orthogonal to the X-axis direction. A block 33, a support table 35 supported by a cylindrical member 34 on the second sliding block 33, 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 a disk-shaped semiconductor wafer, for example, a workpiece is placed on a holding surface, which is the upper surface of the suction chuck 361, by suction means (not shown). It comes to hold. 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 that supports a workpiece such as a semiconductor wafer via a protective tape.

  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 a processing feed mechanism 37 for moving the first sliding block 32 along the pair of guide rails 31, 31 in the X-axis direction. The processing feed mechanism 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 rotationally driving the male screw rod 371. 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 X-axis direction position of the chuck table 36. 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. The control means described later detects the position of the chuck table 36 in the X-axis direction by counting the input pulse signals. When the pulse motor 372 is used as a drive source for the machining feed mechanism 37, the drive pulse of the control means (described later) that outputs a drive signal to the pulse motor 372 is counted, so that the X-axis direction of the chuck table 36 is counted. The position can also be detected. When a servo motor is used as a drive source for the machining feed mechanism 37, a pulse signal output from a rotary encoder that detects the rotation speed of the servo motor is sent to a control means described later, and the pulse signal input by the control means. Can be detected to detect the position of the chuck table 36 in the X-axis direction.

  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 has an index feed mechanism 38 for moving the second slide block 33 in the Y-axis direction along a pair of guide rails 322 and 322 provided in the first slide block 32. It has. The index feeding mechanism 38 includes a male screw rod 381 disposed in parallel between the pair of guide rails 322 and 322, and a drive source such as a pulse motor 382 for rotationally driving the male screw rod 381. One end of the male screw rod 381 is rotatably supported by a bearing block 383 fixed to the upper surface of the first sliding 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 penetrating female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the second sliding block 33. Therefore, by driving the male screw rod 381 forward and backward by the pulse motor 382, the second slide block 33 is moved along the guide rails 322 and 322 in the Y-axis direction.

  The laser processing apparatus in the illustrated embodiment includes Y-axis direction position detecting means 384 for detecting the Y-axis direction position of the second sliding block 33. The Y-axis direction position detecting means 384 is a linear scale 384a disposed along the guide rail 322, and a reading which is disposed along the linear scale 384a together with the second sliding block 33 disposed along the second sliding block 33. And a 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 detects the position of the chuck table 36 in the Y-axis direction by counting the input pulse signals. When the pulse motor 382 is used as the drive source of the index feed mechanism 38, the drive pulse of the control means (described later) that outputs a drive signal to the pulse motor 382 is counted, so that the Y axis direction of the chuck table 36 is counted. The position can also be detected. When a servo motor is used as the drive source of the index feed mechanism 38, a pulse signal output from a rotary encoder that detects the rotation speed of the servo motor is sent to a control means described later, and the pulse signal input by the control means Can be detected to detect the position of the chuck table 36 in the Y-axis direction.

The laser beam irradiation unit 4 includes a support member 41 disposed on the stationary base 2, a casing 42 supported by the support member 41 and extending substantially horizontally, and a laser beam disposed on the casing 42. Irradiation means 5 is provided. The laser beam irradiation means 5 will be described with reference to FIG.
The laser beam irradiation means 5 includes a pulse laser beam oscillation means 51 disposed in the casing 42, an output adjustment means 52 for adjusting the output of the pulse laser beam oscillated by the pulse laser beam oscillation means 51, and the output adjustment means 52. The direction change mirror 53 which changes the direction of the pulse laser beam whose output is adjusted by the direction downward toward the holding surface of the chuck table 36, and the pulse laser beam whose direction is changed by the direction change mirror 53 is condensed to the chuck table. A condenser 54 having a condenser lens 541 for irradiating the workpiece W held by 36 is provided. The concentrator 54 thus configured is attached to the tip of the casing 42 as shown in FIG.

  The description will be continued with reference to FIG. 2. In the casing 42, an optical path changing means 61 disposed between the direction changing mirror 53 and the condenser 54, and a chuck table via the optical path changing means 61. An imaging means 62 for detecting a processing region to be laser processed of the workpiece W held on 36 is provided. The optical path changing means 61 includes a reflection mirror 611 disposed so as to be able to advance and retreat in the optical path between the direction conversion mirror 53 and the condenser 54, and the reflection mirror 611 between the direction conversion mirror 53 and the condenser 54. And a mirror positioning means 612 for operating the retracted position retracted from the optical path. In the illustrated embodiment, the imaging unit 62 includes an infrared illuminating unit that irradiates a workpiece with infrared rays in addition to a normal imaging device (CCD) that captures images with visible light, and infrared rays that are irradiated by the infrared illuminating unit. The optical system includes a capturing optical system and an image sensor (infrared CCD) that outputs an electrical signal corresponding to the infrared light captured by the optical system. The captured image signal is sent to a control unit described later. The imaging unit 62 has a reference line 621 extending in the X-axis direction in the imaging region.

  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 in accordance with a control program, a read-only memory (ROM) 72 that stores a control program and the like, and a readable and writable data that stores arithmetic results and the like. A random access memory (RAM) 73, a counter 74, an input interface 75 and an output interface 76 are provided. Detection signals from the X-axis direction position detection unit 374, the Y-axis direction position detection unit 384, the imaging unit 62, and the like are input to the input interface 75 of the control unit 7. A control signal is output from the output interface 76 of the control means 7 to the pulse motor 372, the pulse motor 382, the pulse laser beam oscillation means 51, the output adjustment means 52, the mirror positioning means 612, the display means 70, and the like. The random access memory (RAM) 73 includes a first storage area 73a for storing an operation characteristic value of the machining feed mechanism 37, which will be described later, and other storage areas.

The processing feed mechanism 37 for moving the first sliding block 32 supporting the chuck table 36 constituting the laser processing apparatus described above in the X-axis direction along the guide rails 31, 31 uses a screw type moving mechanism, If the screw or the guide rail has a distortion of about several μm, the chuck table 36 supported by the first sliding block 32 is swung in the Y-axis direction. As a result, there is a problem that the laser beam is irradiated to a position shifted from the set processing region of the workpiece held on the chuck table 36, and the device is damaged when the workpiece is a wafer.
Therefore, the laser processing apparatus in the illustrated embodiment detects the amount of displacement in the Y-axis direction in the X-coordinate when the chuck table 36 is moved in the X-axis direction by the processing feed mechanism 37, and Y in the detected X-coordinate is detected. The axial displacement amount is detected as an operation characteristic of the machining feed mechanism 37 and stored in a random access memory (RAM) 73, and displayed on the display means 70 (monitor) so that the operation characteristics of the machining feed mechanism 37 can be confirmed. To.

Hereinafter, a method of detecting the displacement amount in the Y-axis direction in the X coordinate when the chuck table 36 is moved in the X-axis direction by the machining feed mechanism 37 will be described.
FIG. 4 shows a perspective view of a plate-like object for detecting a displacement amount in the Y-axis direction in the X coordinate when the chuck table 36 is moved in the X-axis direction. The plate-like object 10 shown in FIG. 4 is formed in a disk shape, and alignment marks 101 and 102 are provided on the outer periphery of the surface 10a at positions opposite to each other by 180 degrees. The plate-like object 10 may be formed of a transparent glass plate or a non-transparent silicon plate.

  In order to detect the displacement amount in the Y-axis direction in the X coordinate when the chuck table 36 is moved in the X-axis direction by the processing feed mechanism 37 using the plate-like object 10 described above, the chuck of the laser processing apparatus shown in FIG. The back surface is placed on the table 36 with the front surface 10a of the plate-like object 10 facing upward. Then, by operating a suction means (not shown), the plate-like object 10 is sucked and held on the chuck table 36 (plate-like object holding step).

  If the plate-like object holding step described above is performed, the control means 7 operates the processing feed mechanism 37 to suck and hold the plate-like object 10 in the image pickup area of the image pickup means 62, that is, the condenser 54. Move directly below. Next, the control means 7 operates the mirror positioning means 612 to position the reflecting mirror 611 at the operating position indicated by the two-dot chain line in FIG. 2, and operates the imaging means 62. Then, the alignment mark 101 provided on the plate-like object 10 on the chuck table 36 is positioned immediately below the condenser 54. Next, the control means 7 operates the processing feed mechanism 37 to position the alignment mark 102 provided on the plate-like object 10 immediately below the condenser 54. At this time, if the alignment mark 101 and the alignment mark 102 are not located on the same line in the X-axis direction (a reference line 621 formed on the imaging means 62), the control means 7 is disposed in the cylindrical member 34. The chuck motor 36 is rotated by operating a pulse motor (not shown) and adjusted so that the alignment mark 101 and the alignment mark 102 are positioned on the same line in the X-axis direction (reference line 621 formed on the imaging means 62). (First alignment step).

  When the first alignment step is performed as described above, the control means 7 operates the machining feed mechanism 37 to provide the plate-like object 10 held on the chuck table 36 as shown in FIG. The alignment mark 101 thus positioned is positioned immediately below the condenser 54, and the mirror positioning means 612 is operated to position the reflecting mirror 611 at the retracted position indicated by the solid line in FIG. Next, while operating the pulse laser beam oscillating means 51 and the output adjusting means 52 to irradiate the pulse laser beam from the condenser 54, the machining feed mechanism 37 is operated to move the chuck table 36 in a direction indicated by Xa. Move with. Then, as shown in FIG. 5B, when the irradiation position of the condenser 54 reaches the position of the alignment mark 102, the irradiation of the pulse laser beam is stopped and the movement of the chuck table 36 is stopped. As a result, a laser processing mark 103 is formed between the alignment mark 101 and the alignment mark 102 on the surface 10a of the plate-like object 10 as shown in FIG. 5C (laser processing mark forming step).

  Next, the plate-like object 10 on which the laser processing mark forming step has been performed is removed from the chuck table 36, and the start point (alignment mark 101) and end point (alignment mark 102) of the laser processing mark 103 are shown in FIG. ) Is rotated 180 degrees around the rotation axis, placed on the chuck table 36 as shown in FIG. 6B, and suction means (not shown) is operated to hold the suction. Accordingly, in the plate-like object 10 placed on the chuck table 36, the front surface 10a in which the laser processing mark 103 is formed between the alignment mark 101 and the alignment mark 102 is on the lower side, and the rear surface 10b is on the upper side ( Plate-like material inversion step).

  If the plate-like object reversing step described above is performed, the control means 7 operates the processing feed mechanism 37 to bring the chuck table 36 that sucks and holds the plate-like object 10 into the image pickup area of the image pickup means 62, that is, the condenser 54. Move directly below. Next, the control means 7 operates the mirror positioning means 612 to position the reflecting mirror 611 at the operating position indicated by the two-dot chain line in FIG. 2, and operates the imaging means 62. Then, the starting point (alignment mark 101) of the laser processing mark 103 formed on the plate-like object 10 on the chuck table 36 is positioned immediately below the condenser 54. Next, the control means 7 operates the processing feed mechanism 37 to position the end point (alignment mark 102) of the laser processing mark 103 formed on the plate-like object 10 directly below the condenser 54. At this time, when the start point (alignment mark 101) of the laser processing mark 103 and the end point (alignment mark 102) of the laser processing mark 103 are not located on the same line in the X-axis direction (reference line 621 formed on the imaging means 62). Then, the control means 7 operates a pulse motor (not shown) disposed in the cylindrical member 34 to rotate the chuck table 36, so that the starting point of the laser processing mark 103 (alignment mark 101) and the laser processing mark 103 are Adjustment is made so that the end point (alignment mark 102) is positioned on the same line in the X-axis direction (reference line 621 formed in the image pickup means 62) (second alignment step).

  Next, the control means 7 operates the processing feed mechanism 37 to set the start point (alignment mark 101) of the laser processing mark 103 formed on the plate-like object 10 on the chuck table 36 as shown in FIG. Positioning directly below the condenser 54 (laser processing mark positioning step). Then, the image pickup means 62 is operated and the processing feed mechanism 37 is operated to move the chuck table 36 in the direction indicated by Xa at a predetermined moving speed (displacement detecting step). Then, as shown in FIG. 7B, when the position of the condenser 54 (image area by the image pickup means 62) reaches the end point (alignment mark 102) of the laser processing mark 103, the movement of the chuck table 36 is stopped. (Displacement detection step). In this displacement detection step, the control means 7 corresponds to the starting point (alignment mark 101) of the laser processing mark 103 as shown in FIG. 7C based on the detection signal from the X-axis direction position detection means 374. A displacement amount (ΔY) in the Y-axis direction (a displacement amount ΔY from the reference line 621 formed in the imaging means 62) between the Xn coordinates corresponding to the end point (alignment mark 102) of the laser processing mark 103 is obtained from the X1 coordinate. Then, as shown in FIG. 8, the control means 7 controls the Y axis between the X1 coordinate corresponding to the start point (alignment mark 101) of the laser processing mark 103 and the Xn coordinate corresponding to the end point (alignment mark 102) of the laser processing mark 103. An operation characteristic map of the machining feed mechanism 37 indicating the displacement amount (ΔY) in the direction and the correction amount in the case of laser machining is created.

That is, the amount of displacement in the Y-axis direction that occurs when the chuck table 36 moves from the X1 coordinate to the Xn coordinate is recorded in the laser processing mark 103 shown in FIG. 5C formed in the laser processing mark forming step. ing. However, even if the laser processing mark 103 is imaged from the X1 coordinate to the Xn coordinate by the imaging means 62, it coincides with the reference line and the displacement amount in the Y-axis direction recorded on the laser processing mark 103 cannot be detected. Therefore, the plate-like object 10 is inverted 180 degrees and held on the chuck table 36 with a line connecting the alignment mark 101 that is the start point of the laser processing mark 103 and the alignment mark 102 that is the end point of the laser processing mark 103 being rotated, After that, when the plate-like object 10 is imaged from the X1 coordinate to the Xn coordinate by the imaging means 62 from the back surface, the displacement amount in the Y-axis direction recorded in the laser processing mark 103 is actually relative to the reference line 621 formed in the imaging means 62. A value obtained by multiplying twice the amount of displacement by minus (−) is imaged as an inverted coordinate. Accordingly, the displacement amount (ΔY) in the Y-axis direction detected by the imaging means 62 is recorded in the operating characteristic map by multiplying the actual displacement amount by minus (−). Further, in order to form a linear laser mark in which the distortion of the laser processing mark 103 shown in FIG. 5C is eliminated, the actual displacement is performed so as to cancel the displacement amount in the Y-axis direction from the X1 coordinate to the Xn coordinate. It is necessary to operate the indexing feed mechanism 38 using a value obtained by multiplying the amount by minus (−) as a correction value, and ΔY / 2 is recorded in the operation characteristic map as the correction value.
Next, the control means 7 stores the operating characteristic map shown in FIG. 8 in the first storage area 73 a of the random access memory (RAM) 73 and displays it on the display means 70.

  In the displacement detection step described above, the surface 10a of the plate-like object 10 on which the laser processing mark 103 is formed is positioned on the lower side. However, when the plate-like object 10 is a transparent glass plate, it is visible from the back surface. Imaging can be performed with light. On the other hand, when the plate-like object 10 is a silicon plate, the back surface is imaged by infrared rays.

  As described above, the operation characteristic map shown in FIG. 8 is stored in the first storage area 73a of the random access memory (RAM) 73 and displayed on the display means 70, whereby the operator operates the machining feed mechanism 37. The characteristics can be confirmed, and it can be determined whether or not correction is necessary when performing laser processing. When it is determined that correction is necessary, the index feed mechanism 38 is controlled using the correction value described in the operation characteristic map during laser processing.

Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the embodiment, and various modifications are possible within the scope of the gist of the present invention. In the above-described embodiment, the example using the plate-like object 10 on which the alignment mark 101 and the alignment mark 102 are formed is shown. However, laser processing traces are formed on the plate-like object on which the alignment mark is not formed, and laser is used. The line connecting the processing mark start point and the laser processing mark end point is reversed 180 degrees, and the amount of displacement in the Y-axis direction (ΔY) with the laser processing mark start point as the X1 coordinate and the laser processing mark end point as the Xn coordinate. May be detected.
In the above-described embodiment, an example in which a monitor is used as the display unit 70 has been described. However, a configuration for printing on paper may be used.
Furthermore, in the above-described embodiment, the example in which the chuck table 36 as the workpiece holding means is moved in the X axis direction and the Y axis direction has been shown, but the laser beam irradiation means 5 is moved in the X axis direction and the Y axis direction. It may be configured. Therefore, the workpiece holding means and the laser beam irradiation means move relatively in the X-axis direction and the Y-axis direction.

2: Stationary base 3: Chuck table mechanism 36: Chuck table 37: Processing feed mechanism 374: X-axis direction position detection means 38: Index feed mechanism 384: Y-axis direction position detection means 4: Laser beam irradiation unit 5: Laser beam irradiation means 51: Pulse laser beam oscillation means 52: Output adjustment means 54: Light collector 61: Optical path changing means 62: Imaging means 7: Control means 10: Plate

Claims (7)

Processing a workpiece holding means for holding a workpiece, a laser beam irradiation means for irradiating a workpiece held by the workpiece holding means with a laser beam, and processing the workpiece holding means and the laser beam irradiation means The work feed mechanism that moves relatively in the feed direction (X-axis direction), the workpiece holding means, and the laser beam irradiation means move relatively in the index feed direction (Y-axis direction) perpendicular to the X-axis direction. An index feed mechanism that detects the X-axis direction position detected by the machining feed mechanism, a Y-axis direction position detect means that detects a Y-axis direction move position by the index feed mechanism, An image pickup means for picking up an image of the work piece held by the work piece holding means and detecting a region to be processed; a control means for controlling the laser beam irradiation means, the work feed mechanism and the index feed mechanism; A working characteristic detection method of processing feed mechanism in the laser processing apparatus comprising,
A plate-like object holding step of holding the plate-like object on the workpiece holding means;
A laser that moves the workpiece holding means that holds the plate-like object by operating the processing feed mechanism in the X-axis direction, and forms a linear laser processing mark on the plate-like object by operating the laser beam irradiation means. Processing mark formation process;
The plate-like object on which the laser machining trace forming step has been performed is removed from the workpiece holding means, and the line connecting the start point and the end point of the laser machining trace is reversed 180 degrees to the workpiece holding means. A plate-like object reversing step to hold,
The processing feed mechanism is actuated to move the workpiece holding means for holding the plate-like object subjected to the plate-like object reversing step, and the start point of the laser processing trace formed on the plate-like object is imaged. A laser processing mark positioning step for positioning the imaging region by means;
The processing feed mechanism is operated and the imaging means is operated to image from the start point to the end point of the laser processing trace formed on the plate-like object, and the displacement amount in the Y-axis direction in the X coordinate of the laser processing trace is determined. A displacement detection step to detect;
A display step of displaying on the display means the amount of displacement in the Y-axis direction at the X coordinate of the laser processing mark detected by the displacement detection step,
An operating characteristic detection method for a machining feed mechanism in a laser machining apparatus.   2. The operation characteristic detection of the machining feed mechanism in the laser machining apparatus according to claim 1, wherein the display step displays ½ of the amount of displacement in the Y-axis direction in the X coordinate of the laser machining trace as a correction value at the time of laser machining. Method.   The plate-like object is a glass plate, and the displacement detecting step images the laser processing trace formed on the surface of the glass plate from the back surface of the glass plate. Operating characteristic detection method.   3. The processing feed in the laser processing apparatus according to claim 1, wherein the plate-like object is a silicon plate, and the displacement detection step images the laser processing trace formed on the surface of the silicon plate with infrared rays from the back surface of the silicon plate. Mechanism operating characteristic detection method. An alignment mark is provided on one end and the other end of the plate-like object,
A reference line extending in the X-axis direction is formed in the imaging area of the imaging means,
In the laser processing mark forming step, the alignment mark provided at one end of the plate-like object and the alignment mark provided at the other end of the plate-like object are matched with the reference line. 1 alignment step,
In the laser processing mark positioning step, the alignment mark provided at one end of the plate-like object and the alignment mark provided at the other end of the plate-like object are matched with the reference line. 5. A method for detecting an operation characteristic of a machining feed mechanism in a laser machining apparatus according to claim 1, comprising two alignment steps. Processing a workpiece holding means for holding a workpiece, a laser beam irradiation means for irradiating a workpiece held by the workpiece holding means with a laser beam, and processing the workpiece holding means and the laser beam irradiation means The work feed mechanism that moves relatively in the feed direction (X-axis direction), the workpiece holding means, and the laser beam irradiation means move relatively in the index feed direction (Y-axis direction) perpendicular to the X-axis direction. An index feed mechanism that detects the X-axis direction position detected by the machining feed mechanism, a Y-axis direction position detect means that detects a Y-axis direction move position by the index feed mechanism, An imaging means for detecting an area to be imaged by processing the workpiece held by the workpiece holding means, and a laser processing apparatus comprising:
The plate-like object is held by the workpiece holding means and the workpiece feed mechanism is operated to move the workpiece holding means holding the plate-like object in the X-axis direction and the laser beam irradiation means is operated to move the plate. Forming a linear laser-processed trace on the object, removing the plate-like object from the workpiece-holding means, and reversing it 180 degrees about the line connecting the start point and end point of the laser-processed mark as the rotation axis The image is taken from the start point to the end point of the laser processing mark formed on the plate-like object by operating the processing feeding mechanism and operating the processing feed mechanism. Control means comprising a memory for detecting the amount of displacement in the axial direction and storing the amount of displacement in the Y-axis direction at the X coordinate of the detected laser processing trace;
Display means for displaying the amount of displacement in the Y-axis direction at the X coordinate of the laser processing mark stored in the memory of the control means,
Laser processing equipment characterized by that.   The laser processing apparatus according to claim 6, wherein the control means stores in the memory half of the amount of displacement in the Y-axis direction of the X-coordinate of the laser processing trace as a correction value during laser processing.

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