JP2009223440A - Workpiece machining method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform high-accuracy machining without being affected by orthogonal displacement of axial feeding of an X-axis direction and a Y-axis direction. <P>SOLUTION: A plurality of Y-direction reference patterns disposed in a Y-direction of an XY-orthogonal coordinate system on a chuck table apart from each other at a prescribed distance are used, at least two Y direction reference patterns PY6, PY8 are moved by a prescribed distance α, are positioned in visual field ranges E1, E2 of an imaging means, and are imaged to obtain their position information, and an orthogonal displacement angle of the Y-axis direction to the X-axis direction is obtained based on the obtained position information and the movement distance α. When machining a workpiece that is a target, a design coordinate value of a desired machining position is corrected based on the orthogonal displacement angle, and a machining means is positioned. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a workpiece machining method and a workpiece machining apparatus, such as forming a pore at a desired position of a workpiece.

  In the semiconductor device manufacturing process, a plurality of regions are defined by division lines on the surface of a substantially disk-shaped semiconductor wafer, and devices such as ICs and LSIs are formed in the partitioned regions. Such semiconductor wafers are divided along the division lines to manufacture individual semiconductor chips. Here, in order to reduce the size and increase the functionality of a product, a module structure in which a plurality of semiconductor chips are created and electrodes of stacked semiconductor chips are connected has been put into practical use. In this module structure, a structure is used in which a through hole (via hole) is formed at a position where an electrode of a semiconductor wafer is formed, and a conductive material such as aluminum connected to the electrode is embedded in the through hole (for example, Patent Document 1).

  A laser processing apparatus that can efficiently form a process for forming such a through hole has also been proposed (see, for example, Patent Document 2). In such a laser processing apparatus, an X-axis direction feeding unit that relatively moves a chuck table that holds a workpiece and a laser beam irradiation unit that irradiates the workpiece with a laser beam in the X-axis direction, a chuck table, and laser beam irradiation. And a Y-axis direction feeding means for relatively moving the means in the Y-axis direction, and the laser beam irradiation means is positioned at a desired position of the workpiece to form a through hole.

JP 2003-163323 A JP 2006-247664 A

  However, such a laser processing apparatus is designed and manufactured so that the feed directions of the X-axis direction feed means and the Y-axis direction feed means are orthogonal to each other, but in reality, the orthogonal accuracy is sufficiently adjusted and maintained. There are cases where it is not possible.

  Therefore, when there is an orthogonal shift in the feeding means in the X-axis direction and the Y-axis direction, when the through hole is formed at a desired position on the workpiece, it is affected by the orthogonal shift from the desired position. A through-hole will be formed in the shifted | deviated location, and it will become a thing which cannot respond to a highly accurate process request.

  The present invention has been made in view of the above, and provides a workpiece machining method and a workpiece machining apparatus capable of high-precision machining without being affected by the orthogonal shift of the axis feed in the X-axis direction and the Y-axis direction. The purpose is to do.

  In order to solve the above-described problems and achieve the object, a workpiece machining method according to the present invention includes a chuck table for holding a workpiece, a machining means for machining the workpiece held on the chuck table, and the chuck table. A first feed means for relatively moving the machining means in the X-axis direction parallel to the X direction of the XY orthogonal coordinate system, and a Y-axis direction substantially orthogonal to the X-axis direction between the chuck table and the machining means Relative to the chuck table and the machining means, a second feed means that moves relative to the first table, a first position detection means that detects a relative position in the X-axis direction between the chuck table and the machining means, and A second position detecting means for detecting a typical position in the Y-axis direction, and an imaging means for picking up an image of the work held on the chuck table with a fixed positional relationship with the processing means; A workpiece machining method for machining a workpiece held by the chuck table to a desired machining position in an XY rectangular coordinate system by the machining means using a machining device provided, wherein the workpiece is Y in the XY rectangular coordinate system on the chuck table. A plurality of Y-direction reference patterns spaced apart by a predetermined distance in the direction are positioned and used so as to be orthogonal to the X-axis direction, and the chuck table and the processing means are sequentially moved by a predetermined distance to Orthogonal that obtains position information of at least two of the Y-direction reference patterns sequentially imaged by the imaging means, and obtains an orthogonal displacement angle in the Y-axis direction with respect to the X-axis direction based on the obtained positional information and movement distance of the Y-direction reference patterns. A workpiece including a deviation angle calculating step and a desired machining position in which a design coordinate value in an XY orthogonal coordinate system is set; A workpiece holding step to be held on the chuck table, and machining of a desired machining position of the workpiece held on the chuck table, the desired machining position is determined based on the orthogonal deviation angle calculated in the orthogonal deviation angle calculating step. A machining control step of correcting the design coordinate value and moving the chuck table and the machining means relative to each other based on the corrected design coordinate value to position the machining means at the machining position of the design coordinate value. It is characterized by including these.

  Further, in the work machining method according to the present invention, in the above invention, the machining control step corrects an X coordinate value of a design coordinate value of a desired machining position based on the orthogonal deviation angle, and the first feeding unit. Is controlled in accordance with the first position detecting means, and the feed amount by the second feeding means is linearly controlled in one dimension based on the Y coordinate value of the design coordinate value of the desired machining position. Features.

  Further, in the work machining method according to the present invention, in the above invention, the machining control step corrects an X coordinate value and a Y coordinate value of a design coordinate value of a desired machining position based on the orthogonal deviation angle, The feed amount by one feeding means and the second feeding means is controlled according to the first position detecting means and the second position detecting means.

  The workpiece machining apparatus according to the present invention includes a chuck table for holding a workpiece, a machining unit for machining the workpiece held on the chuck table, and the chuck table and the machining unit in the X direction of an XY orthogonal coordinate system. A first feeding means for relatively moving in the X-axis direction parallel to the second feeding means, and a second feeding means for relatively moving the chuck table and the processing means in the Y-axis direction substantially orthogonal to the X-axis direction; First position detecting means for detecting a relative position in the X-axis direction between the chuck table and the processing means, and a second position for detecting a relative position in the Y-axis direction between the chuck table and the processing means. An image pickup means for picking up an image of a work held on the chuck table with a positional relationship between the position detection means and the processing means fixed, and held on the chuck table. A workpiece machining apparatus for machining a workpiece at a desired machining position in an XY orthogonal coordinate system by a plurality of Y-direction references spaced apart from each other by a predetermined distance in the Y direction of the XY orthogonal coordinate system on the chuck table. At least two Y-direction reference patterns that are sequentially imaged by the imaging unit by sequentially moving the chuck table and the processing unit by a predetermined distance while positioning the pattern so as to be orthogonal to the X-axis direction. And an orthogonal deviation angle calculating means for obtaining an orthogonal deviation angle in the Y-axis direction with respect to the X-axis direction based on the obtained positional information and movement distance of the Y-direction reference pattern, and design coordinate values in the XY orthogonal coordinate system In the machining of the desired machining position of the workpiece held on the chuck table. The design coordinate value of the desired machining position is corrected based on the orthogonal deviation angle calculated by the orthogonal deviation angle calculating means, and the chuck table and the machining means are corrected based on the corrected design coordinate value. And a machining control means for moving the machining means relative to the machining position of the design coordinate value.

  According to the workpiece machining method and the workpiece machining apparatus according to the present invention, at least two Y-direction reference patterns are used by using a plurality of Y-direction reference patterns spaced apart by a predetermined distance in the Y direction of the XY orthogonal coordinate system on the chuck table. Is positioned on the imaging means to obtain the position information thereof, and based on the obtained position information and movement distance, an orthogonal deviation angle in the Y-axis direction with respect to the X-axis direction is obtained. Since the design coordinate value of the desired machining position is corrected based on the angle and the machining means is positioned, the desired machining position is not affected by the orthogonal shift of the axial feed in the X-axis direction and the Y-axis direction. Thus, there is an effect that machining can be performed with high accuracy.

  Hereinafter, a workpiece processing method and a workpiece processing apparatus which are the best mode for carrying out the present invention will be described with reference to the drawings. The present embodiment will be described as an example of application to a laser processing apparatus that forms a via hole (through hole) by irradiating a laser beam at a desired processing position of the work as the work processing apparatus. It is not limited to a laser processing apparatus.

  FIG. 1 is an external perspective view showing a main part including a part of a control system of the laser processing apparatus of the present embodiment. The laser processing apparatus 1 according to the present embodiment includes a chuck table 2, a laser beam irradiation unit 3 that is a processing means, a first feeding means 4, a second feeding means 5, and a first position detecting means 6. And a second position detection means 7, an imaging means 8, and a control means 10.

  The chuck table 2 includes a suction chuck 21 made of a porous material, holds a workpiece to be processed on the suction chuck 21 by a suction unit (not shown), and is disposed in the cylindrical member 22 (not shown). It can be rotated by a pulse motor. The chuck table 2 is provided with a clamp 23 for fixing an annular frame described later.

  The laser beam irradiation unit 3 is fixedly arranged on the fixed base 11 so that the condenser 31 attached to the tip faces the chuck table 2 from above. The pulse laser beam is irradiated from In addition, the imaging means 8 is disposed in a part of the laser beam irradiation unit 3 in a state where the positional relationship with the condenser 31 is fixed, opposes the chuck table 2, and holds the workpiece held on the chuck table 2. It is for imaging. The imaging unit 8 includes an illuminating unit that illuminates the workpiece, an optical system that captures an area illuminated by the illuminating unit, an imaging device (CCD) that captures an image captured by the optical system, and the like. An image signal is sent to the control means 10.

  Further, when the X direction and Y direction of the XY orthogonal coordinate system in the laser processing apparatus 1 of the present embodiment are taken in the directions indicated by the arrows in FIG. 1, the first feeding means 4 moves the chuck table 2 to the laser beam. This is for moving the irradiation unit 3 in the X-axis direction parallel to the X-direction, and the second feeding means 5 is substantially orthogonal to the X-axis direction of the chuck table 2 with respect to the laser beam irradiation unit 3. It is for moving in the Y-axis direction. Here, the second feeding means 5 includes a sliding block 51 on which the first feeding means 4 is mounted together with the chuck table 2, a pair of guide rails 52 for moving the sliding block 51 in the Y-axis direction, and a pair of Are constituted by a ball screw 53 disposed in parallel between the guide rails 52 and a drive source such as a pulse motor 54 for rotationally driving the ball screw 53. One end of the ball screw 53 is rotatably supported by a bearing block 55 fixed to the stationary base 11, and the other end is connected to the output shaft of the pulse motor 54. The ball screw 53 is screwed into a through female screw hole formed in a female screw block (not shown) provided so as to protrude from the lower surface of the central portion of the sliding block 51, and the ball screw 53 is driven forward and reverse by a pulse motor 54. As a result, the sliding block 51 on which the chuck table 2 is mounted moves in the Y-axis direction along the guide rail 52.

  On the other hand, the first feeding means 4 includes a sliding block 41 on which the chuck table 2 is mounted, a pair of guide rails 42 provided on the sliding block 51 for moving the sliding block 41 in the X-axis direction, A ball screw 43 disposed in parallel between the guide rails 42 and a drive source such as a pulse motor 44 for driving the ball screw 43 to rotate. One end of the ball screw 43 is rotatably supported by a bearing block 45 fixed to the sliding block 51, and the other end is connected to the output shaft of the pulse motor 44. The ball screw 43 is screwed into a through female screw hole formed in a female screw block (not shown) that protrudes from the lower surface of the central portion of the sliding block 41, and the ball motor 43 is driven to rotate forward and backward by a pulse motor 44. As a result, the sliding block 41 on which the chuck table 2 is mounted moves in the X-axis direction along the guide rail 42.

  The first position detecting means 6 is attached to the first feeding means 4 and detects a relative X-axis direction position between the chuck table 2 and the laser beam irradiation unit 3. The first position detecting means 6 includes an X-axis linear scale 61 disposed along the guide rail 42 on the sliding block 51 and an X-axis linear scale 61 disposed on the sliding block 41 together with the sliding block 41. And an X-axis reading head (not shown) that moves along the X-axis and reads the X-axis linear scale 61. The X-axis coordinate value that is the result read by the X-axis reading head is output to the control means 10. The X-axis reading head is set so as to output a pulse signal of one pulse every 1 μm, for example. And the control means 10 detects the relative X-axis direction position of the laser beam irradiation unit 3 with respect to the chuck table 2 by counting the input pulse signal.

  When the pulse motor 44 is used as the driving source of the first feeding unit 4 as in the present embodiment, the driving pulse of the control unit 10 that outputs a driving signal to the pulse motor 44 is counted. The relative position of the laser beam irradiation unit 3 relative to the chuck table 2 may be detected. If a servo motor is used as the drive source of the first feeding means 4, a pulse signal output from a rotary encoder that detects the rotation speed of the servo motor is sent to the control means 10, and the control means 10 inputs the pulse signal. You may make it detect the relative X-axis direction position of the laser beam irradiation unit 3 with respect to the chuck table 2 by counting a pulse signal.

  Similarly, the second position detection means 7 is attached to the second feeding means 5 and detects the relative position in the Y-axis direction between the chuck table 2 and the laser beam irradiation unit 3. The second position detection means 7 includes a Y-axis linear scale 71 disposed along the guide rail 52 on the stationary base 11, and a Y-axis linear scale 71 disposed on the sliding block 51 together with the sliding block 51. And a Y-axis reading head (not shown) that reads the Y-axis linear scale 71. The Y-axis coordinate value that is the result read by the Y-axis reading head is output to the control means 10. The Y-axis reading head is set to output a pulse signal of one pulse every 1 μm, for example. Then, the control means 10 detects the relative position in the Y-axis direction of the laser beam irradiation unit 3 with respect to the chuck table 2 by counting the input pulse signals.

  When the pulse motor 54 is used as the drive source of the second feeding unit 5 as in the present embodiment, the drive pulse of the control unit 10 that outputs a drive signal to the pulse motor 54 is counted. The relative position of the laser beam irradiation unit 3 with respect to the chuck table 2 may be detected. If a servo motor is used as the drive source of the second feeding means 5, a pulse signal output from a rotary encoder that detects the rotation speed of the servo motor is sent to the control means 10, and the control means 10 inputs the pulse signal. You may make it detect the relative Y-axis direction position of the laser beam irradiation unit 3 with respect to the chuck table 2 by counting a pulse signal.

  The control means 10 is constituted by a computer, and includes a central processing unit (CPU) 101 that performs arithmetic processing in accordance with a control program, a read-only memory (ROM) 102 that stores a control program for processing, and the like. A random access memory (RAM) 103 that stores design value data and calculation results of the workpiece to be read, a counter 104, an input interface 105, and an output interface 106 are provided. Detection signals from the first position detection unit 6, the second position detection unit 7, the imaging unit 8, and the like are input to the input interface 105. The output interface 106 outputs control signals to the pulse motors 44 and 54, the laser beam irradiation unit 3, and the like. The RAM 103 includes a memory 103a that is a storage area for storing coordinate values of a captured Y-direction reference pattern, which will be described later, as position information, and other storage areas. In addition, the CPU 101 of the present embodiment includes functions of an orthogonal deviation angle calculation unit and a processing control unit that are executed according to a processing control program.

  FIG. 2 is a plan view showing a configuration example of the workpiece 200 used in the laser processing apparatus 1 of the present embodiment, and FIG. 3 is a plan view showing a part thereof enlarged. The workpiece 200 is mainly a silicon wafer, a sapphire wafer, a chip package, a substrate, DAF, glass or the like, and requires a processing accuracy of the order of several μm. The workpiece 200 of the present embodiment is, for example, a semiconductor wafer, and a plurality of regions are partitioned by a plurality of division lines 201 arranged in a lattice pattern on the surface 200a, and a device such as an IC or LSI is divided into the partitioned regions. 202 are formed. All the devices 202 have the same configuration. A plurality of electrodes 203 (203a to 203j) are formed on the surface of the device 202 as shown in FIG. In this embodiment, the electrodes 203a and 203f, the electrodes 203b and 203g, the electrodes 203c and 203h, the electrodes 203d and 203i, and the electrodes 203e and 203j have the same position in the Y direction (Y coordinate value) in the XY orthogonal coordinate system. The via holes (through holes) are respectively formed in these electrode 203 (203a to 203j) portions.

  The distance A in the Y direction (left and right direction in FIG. 3) of the electrodes 203 (203a to 203j) in each device 202, and the electrodes adjacent in the Y direction across the scheduled division line 201 in the electrodes 203 formed in each device 202, That is, the interval B between the electrodes 203e and 203a is set to be the same interval. Further, the distance C in the X direction (vertical direction in FIG. 3) of the electrodes 203 in each device 202 and the electrodes adjacent to each other in the X direction across the planned division line 201 in the electrodes 203 formed in each device, that is, the electrodes 203f and 203a. The intervals D are set to be the same interval. With respect to the workpiece 200 composed of the semiconductor wafer thus configured, the number of devices 202 arranged in each row E1, E2,..., En and each column F1, F2,. In A, B, C, and D, design value data is stored in a predetermined storage area in the RAM 103. Accordingly, each electrode 203 is a desired processing position on the workpiece 200. In a state where the electrode 203 is held on the chuck table 2 and aligned as described later, the design coordinate value in the XY orthogonal coordinate system is set for each electrode 203. It will be set in advance.

  In such a laser processing apparatus 1, first, a basic operation of forming a via hole by laser processing on the electrode 203 (203 a to 203 j) portion of each device 202 formed on the workpiece 200 will be described.

  First, as shown in FIG. 4, the workpiece 200 configured as described above is attached to a protective tape 220 made of a synthetic resin sheet such as polyolefin attached to an annular frame 210 with the surface 200 a facing upward. The workpiece 200 supported by the annular frame 210 via the protective tape 220 places the protective tape 220 on the chuck table 2. The work 200 is sucked and held on the chuck table 2 via the protective tape 220 by operating a suction means (not shown). The frame 210 is fixed by the clamp 23.

  As described above, the chuck table 2 that sucks and holds the workpiece 200 is positioned directly below the imaging unit 8 by the first and second feeding units 4 and 5. In this state, an alignment operation is performed to determine whether or not the grid-like division planned lines 201 formed on the workpiece 200 held on the chuck table 2 are arranged parallel to the X direction and the Y direction, respectively. To do. That is, the workpiece 200 on the chuck table 2 is imaged by the imaging unit 8, and image processing such as pattern matching is executed, and alignment work is performed so that the planned division line 201 matches the XY orthogonal coordinate system.

  Next, the chuck table 2 is moved, and the leftmost device 202 in FIG. 5 in the uppermost row E1 in the device 202 formed on the workpiece 200 is positioned directly below the imaging means 8, and further formed on the device 202. The upper left electrode 203a in FIG. 5 of the electrode 203 (203a to 203j) is positioned directly below the imaging means 8. When the imaging means 8 detects this electrode 203a in this state, the X and Y coordinate values (a1) are sent to the control means 10. The control means 10 stores this X, Y coordinate value (a1) as a first feed start position coordinate value in a predetermined storage area in the RAM 103. At this time, since the imaging unit 8 and the condenser 31 of the laser beam irradiation unit 3 are arranged at a predetermined interval in the Y-axis direction, the Y coordinate value is determined between the imaging unit 8 and the condenser 31. A value with an interval added is stored (coordinate values based on imaging are processed in the same manner below).

  In this way, when the first feed start position coordinate value (a1) in the device 202 in the uppermost row E1 in FIG. 5 is detected, the chuck table 2 is fed in the X-axis direction at intervals of the scheduled division lines 201, and Y By moving in the axial direction, the leftmost device 202 in the second row E2 from the top in FIG. 5 is positioned immediately below the image pickup means 8, and further, a diagram of electrodes 203 (203a to 203j) formed on the device 202. 5, the upper left electrode 203 a is positioned directly below the imaging means 8. When the imaging means 8 detects the electrode 203a in this state, the X and Y coordinate values (a2) are sent to the control means 10. The control means 10 stores this X, Y coordinate value (a2) as a second feed start position coordinate value in a predetermined storage area in the RAM 103.

  Thereafter, the above-described feed in the X-axis direction and feed start position detection process in the Y-axis direction are repeatedly executed up to the lowest row En in FIG. 5, and the Y-axis feed start position coordinate value of the device 202 formed in each row ( a3-an) is detected and stored in a predetermined storage area in the RAM 103.

  Next, a drilling step of drilling a via hole in each electrode 203 (203a to 203j) formed on each device 202 of the workpiece 200 is performed. In the punching step, first, the first and second feeding means 4 and 5 are operated based on the first feed start position coordinate value (a1) stored in the RAM 103 to move the chuck table 2, and 1. Position the position of the first feed start position coordinate value (a1) according to the second position detection means 6, 7 immediately below the condenser 31. In this state, the laser beam irradiation unit 3 is controlled so as to irradiate a pulse laser beam for a predetermined pulse necessary for performing desired processing from the condenser 31 and the chuck table 2 is moved in a predetermined direction in the Y-axis direction. The second feeding means 5 is controlled to feed at the moving speed. Therefore, a pulse laser beam for a predetermined pulse is applied to the electrode 203a portion of the first feed start position coordinate value (a1).

  On the other hand, the control means 10 receives a detection signal from the Y-axis reading head of the second position detection means 7 and counts this detection signal by the counter 104. When the count value reaches a value corresponding to the distance A in the Y direction in FIG. 3 of the electrode 203, the laser beam irradiation unit 3 is operated so that a pulse laser beam of a predetermined pulse is irradiated from the condenser 31. Control. After this, the control means 10 causes the laser beam irradiation unit 3 to irradiate a pulse laser beam of a predetermined pulse from the condenser 31 every time the count value by the counter 104 reaches the interval A and the interval B in the Y direction. To control.

  Then, when the rightmost electrode 203j formed on the rightmost device 202 in the E1 row of the workpiece 200 reaches the condenser 31, the laser beam is applied so that a pulse laser beam corresponding to a predetermined pulse is emitted from the condenser 31. After controlling the irradiation unit 3, the operation of the second feeding means 5 is stopped and the movement of the chuck table 2 is stopped. As a result, laser processing holes for via holes are formed in the work 200 at each electrode 203 (not shown).

  Next, the control means 10 controls the first feeding means 4 so as to send the chuck table 2 to the condenser 31 in the X-axis direction. The control means 10 receives a detection signal from the X-axis reading head of the first position detection means 6, and counts this detection signal by the counter 104. When the count value reaches a value corresponding to the distance C between the electrodes 203 in the X direction, the operation of the first feeding means 4 is stopped. As a result, the condenser 31 is positioned immediately above the electrode 203j in the same row as the electrode 203e.

  In this state, the control means 10 controls the laser beam irradiation unit 3 so as to irradiate a pulse laser beam for a predetermined pulse from the condenser 31, and sends the chuck table 2 at a predetermined moving speed in the Y-axis direction. Thus, the second feeding means 5 is controlled. Then, the control means 10 counts the detection signal from the Y-axis reading head of the second position detection means 7 by the counter 104, and each time the count value reaches the interval A and the interval B in the Y direction, the concentrator The laser beam irradiation unit 3 is controlled so as to irradiate a pulse laser beam corresponding to a predetermined pulse from 31.

  Then, when the electrode 203f formed on the rightmost end of the E1 row of the workpiece 200 reaches the condenser 31, the laser beam irradiation unit 3 is controlled so that a pulse laser beam of a predetermined pulse is emitted from the condenser 31. Thereafter, the operation of the second feeding means 5 is stopped and the movement of the chuck table 2 is stopped. As a result, a laser processing hole is formed in the work 200 at each electrode 203 portion.

  As described above, when the laser processing hole is formed in the electrode 203 portion formed in the device 202 in the E1 row of the workpiece 200, the control means 10 determines the second feed start position coordinate value stored in the RAM 103. The position of the second feed start position coordinate value (a2) for the electrode 203 formed on the device 202 of the E2 row of the workpiece 200 by operating the first and second feed means 4 and 5 based on (a2). Is positioned directly below the condenser 31. Then, the laser beam irradiation unit 3 and the first and second feeding means 4 and 5 are controlled, and the above-described perforation process is performed on the electrode 203 portion formed on the E2 row device of the workpiece 200. Thereafter, the above-described drilling process is performed also on the electrode 203 portion formed on the device 202 in the E3 to En rows of the workpiece 200. As a result, laser processing holes are formed in all electrode 203 portions formed in each device 202 of the workpiece 200.

  Here, the basic operation described above is based on the premise that the X-axis direction that is the feeding direction by the first feeding means 4 and the Y-axis direction that is the feeding direction by the second feeding means 5 are orthogonal to each other as in the XY orthogonal coordinate system. Is due to. However, in reality, when the accuracy of orthogonality between the X-axis direction and the Y-axis direction cannot be sufficiently adjusted and maintained (the X-axis direction and the Y-axis direction are originally designed to be orthogonal to each other, but deviate from the orthogonal state) Therefore, in the present invention, the Y-axis direction is defined as a direction substantially perpendicular to the X-axis direction), and an error due to deviation in the feed direction may occur due to the orthogonal deviation. In the present embodiment, in consideration of such circumstances, an appropriate correction process is added to the basic operation so that a through hole can be accurately formed in each electrode 203 portion at a desired processing position. .

  FIG. 6 is a schematic flowchart showing a control example of the workpiece machining method in the present embodiment. First, the orthogonal deviation angle calculation step is executed by the function of the orthogonal deviation angle calculation means executed by the CPU 101. In this step, generally, a plurality of Y-direction reference patterns PY1 to PYm that are spaced apart from each other by a predetermined distance in the Y direction of the XY orthogonal coordinate system on the chuck table 2 are used while being positioned in the X direction. At least two Y-direction reference patterns, for example, a first Y-direction reference pattern PY6 and a second Y-direction, which are sequentially picked up by the image pickup means 8 by sequentially moving the table 2 and the laser beam irradiation unit 3 by a predetermined distance α. A coordinate value in the imaging visual field range of the direction reference pattern PY8 is obtained as position information, and an orthogonal deviation angle θ in the Y-axis direction with respect to the X-axis direction is obtained based on the obtained position information and movement distance α.

  In the present embodiment, as shown in FIG. 7, a workpiece-like gauge work 300 including Y-direction reference patterns PY <b> 1 to PYm is prepared in advance, and the gauge work 300 is sucked and held on the chuck table 2. As described above, when the gauge work 300 is set on the chuck table 2 (step S1; Yes), the orthogonal deviation angle calculation process is started.

  Here, the Y-direction reference patterns PY1 to PYm are arranged in a line in the Y direction of the XY orthogonal coordinate system in a state where the gauge work 300 is aligned with respect to the XY orthogonal coordinate system (therefore, the same X in the XY orthogonal coordinate system). Are arranged at regular intervals (for example, α / 2) at a coordinate position), and are formed in a rectangular shape with the same size that is sufficiently within the imaging range of the imaging means 8, for example. . In this embodiment, m = 9 and nine Y-direction reference patterns are provided. However, at least two patterns are sufficient. On the gauge work 300, X-direction reference patterns PX1 to PXm that are spaced apart at equal intervals in a row in the X direction are also provided. For example, as shown in FIG. 7, the gauge work 300 held on the chuck table 2 is imaged so that the X direction of the XY orthogonal coordinate system is parallel to the X axis direction which is the feeding direction by the first feeding means 4. Alignment processing is performed by image processing using captured images of the X-direction reference patterns PX1 to PXm by means 8. By such an alignment process, the Y-direction reference patterns PY1 to PYm are positioned so as to be orthogonal to the X direction and the X-axis direction.

  When the gauge work 300 is set and aligned, for example, the Y-direction reference pattern PY6 is moved by moving the chuck table 2 by the first and second feeding means 4 and 5 with the Y-direction reference pattern PY6 on the gauge work 300 as a target. The imaging unit 8 is positioned within the first visual field range E1, and the imaging unit 8 captures an image including the Y-direction reference pattern PY6. Then, as shown in FIG. 9, for example, the coordinate value (X1, Y1) of a corner point A of the Y-direction reference pattern PY6 is detected (step S2). Data of the detected coordinate value (X1, Y1) of the point A is stored in the memory 103a.

  Next, as shown in FIG. 10, for example, the Y-direction reference pattern PY8 that is a predetermined distance α away from the Y-direction reference pattern PY6 on the gauge work 300 is used as a target, and the chuck table 2 is moved by the second feeding means 5 to move the chuck table 2. In accordance with the detection result of the moving position by the position detecting means 2 of the second position, the movement is stopped at the position moved in the Y-axis direction by a predetermined distance α, the Y-direction reference pattern PY8 is positioned within the second visual field range E2 of the imaging means 8, and imaging is performed. The means 8 captures an image including the Y-direction reference pattern PY8. Then, as shown in FIG. 11, for example, the coordinate value (X2, Y2) of the corresponding corner point B of the Y-direction reference pattern PY8 is detected (step S3). Data of the detected coordinate value (X2, Y2) of the point B is stored in the memory 103a.

At this time, if there is no orthogonal shift between the X-axis direction and the Y-axis direction, the points A and B within the field of view of the imaging means 8 should have the same coordinate values, that is, X2 = X1, Y2 = Y1. However, as shown in FIG. 7 and the like, if there is an orthogonal shift in the Y-axis direction with respect to the X-axis direction, X2 ≠ X1 and Y2 ≠ Y1. Therefore, referring to FIG. 12 showing this relationship, even if the visual field range of the imaging means 8 is moved by a predetermined distance α in the Y-axis direction from the point A to the point B, the Y-axis direction is not Y direction. Due to the orthogonal deviation angle θ of the Y axis, the point B is located at a coordinate position (X2, Y2) that is shifted from the desired point B ′ (X1, Y1). Here, according to the relationship between the triangles shown in FIG. 12, when X1−X2 = β, the orthogonal deviation angle (tilt angle in the Y axis direction with respect to the Y direction) θ with respect to the X axis direction is the XY coordinate value. By using the position information of X1, X2 and movement distance α in the middle,
θ = sin (β / α)
(Step S4). Here, the orthogonal deviation angle θ is determined to be a right upward direction (θ> 0) if β> 0 (X1> X2), and a right downward direction (θ <0) if β <0 (X1 <X2). Is done.

  In the orthogonal deviation angle calculation step, the calculation of the orthogonal deviation angle θ is not limited to the above-described trigonometric formula, but the position information of the points A, B, B ′, The orthogonal deviation angle θ may be calculated based on a trigonometric function or a linear function appropriately using the movement distance information.

  In addition, when a desired Y-direction reference pattern cannot be recognized by the imaging unit 8 due to a missing Y-direction reference pattern, another Y-direction reference pattern may be used as a target.

  When the orthogonal deviation angle calculation step (steps S1 to S4) is completed, the gauge workpiece 300 is removed, and then the workpiece 200 to be processed is conveyed onto the chuck table 2 by the workpiece conveying means (not shown), and the suction means is operated. (Step S5: workpiece holding step). The workpiece 200 held on the chuck table 2 is arranged according to the XY orthogonal coordinate system as shown in FIG. 5 by the alignment process (the X-axis direction as the feeding direction by the first feeding means 4 is X To be parallel to the direction).

  In such a holding and setting state of the workpiece 200, a drilling step of forming a through hole (via hole) by irradiating a laser beam to the desired processing position of the workpiece 200 by the laser beam irradiation unit 3 is executed. Since this process is accompanied by a correction control process, it is executed as a machining control step by the function of the machining control means executed by the CPU 101. First, a target machining position on the workpiece 200 is set (step S6), and the design coordinate value of the target machining position is corrected based on the orthogonal deviation angle θ calculated as described above (step S7). . Then, the chuck table 2 is relatively moved by the first and second feeding means 4 and 5 based on the corrected design coordinate value, and according to the position detection result by the first and second position detecting means 6 and 7. By performing the positioning, a desired processing position is positioned directly below the condenser 31 of the laser beam irradiation unit 3 (step S8). At this position, the movement of the chuck table 2 is stopped, and a laser beam is irradiated from the condenser 31 to execute a processing process for forming a through hole (via hole) at the processing position (electrode portion) (step S9, S10). Such processing control is similarly repeated for the remaining other machining positions (step S11).

  Here, correction of the design coordinate value will be described with reference to FIG. For example, when processing is performed at a processing position P having a desired design coordinate value (X, Y), the chuck table 2 is moved by the first and second feeding means 4 and 5 with the design coordinate value (X, Y) as a target. When the movement position is managed by the first and second position detecting means 6 and 7, this design coordinate value (X, Y) is caused by the orthogonal deviation angle θ in the Y-axis direction with respect to the X-axis direction. The position deviated from the position will be positioned with respect to the condenser 31. Therefore, the positioning target position in actual machining is corrected so as to be (X−Y / tan θ, Y / cos θ) when, for example, θ> 0, considering the shift amount due to the orthogonal deviation angle θ. The first feed means 4 feeds the chuck table 2 relatively by XY / tan θ, and the second feed means 5 feeds the chuck table 2 by Y / cos θ relatively. By controlling according to the detection results of the position detection means 6, 7, the processing position P of the design coordinate value (X, Y) can be controlled just below the condenser 31. If θ <0, correction may be made so that (X + Y / tan θ, Y / cos θ).

  Thereby, it is possible to perform the machining with respect to the desired machining position P with high accuracy without being affected by the orthogonal deviation angle in the Y axis direction with respect to the X axis direction. When correction is not performed as in the prior art, there was an error of about 3 to 10 μm / 200 mm. However, the orthogonal deviation angle was calculated using the Y-direction reference pattern set at intervals of 5 mm as in the present embodiment. When correction was performed as described above, an error of 1 μm / 200 mm or less could be accommodated.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the present embodiment, the dedicated gauge work 300 having the Y-direction reference patterns PY1 to PYm is used to calculate the orthogonal deviation angle θ, but an XY orthogonal coordinate system of a plurality of Y-direction reference patterns is used. As long as the design coordinate value is fixed, for example, a normal workpiece having such a Y-direction reference pattern may be used. Furthermore, the orthogonal deviation angle may be calculated by using the machining trace of the workpiece as the Y-direction reference pattern. Alternatively, the Y-direction reference pattern may be provided directly on the surface of the chuck table 2 without using a workpiece.

  In the present embodiment, the gauge work 300 is aligned so that the X direction is parallel to the X axis direction as shown in FIG. 7 and the like, but the tilt angle between the X direction and the X axis direction is known. If the Y-direction reference pattern is positioned so as to be orthogonal to the X-axis direction, alignment may be performed so that the X direction has an inclination with respect to the X-axis direction. However, in order to simplify the calculation process of the orthogonal deviation angle θ, it is preferable to set the X direction to be parallel to the X axis direction.

  Further, if the processing for calculating the orthogonal deviation angle θ using such Y-direction reference patterns PY1 to PYm is performed every time the workpiece is processed, the orthogonality between the X axis and the Y axis changes during operation of the apparatus. It is possible to deal with such a time-dependent axial feed error, and the machining accuracy is improved, but the tact is reduced. Therefore, the timing for calculating and storing the reference pattern deviation amount using the reference pattern is determined for each workpiece machining, for each group of workpieces set in the cassette, in consideration of required accuracy, efficiency, etc. What is necessary is just to set suitably at the time of the processing start of a day.

In this embodiment, the orthogonal deviation angle θ is calculated by imaging the Y-direction reference patterns PY6 and PY8 by the imaging unit 8, but the other two Y-direction reference patterns are captured by the imaging unit 8. By doing so, the orthogonal deviation angle θ may be calculated. When calculating the orthogonal deviation angle θ using two Y-direction reference patterns, the accuracy of the calculated orthogonal deviation angle θ can be improved by selecting two Y-direction reference patterns that are as far apart as possible in the Y direction. . Further, not only two Y-direction reference patterns but also three or more Y-direction reference patterns as targets, the imaging means 8 is relatively moved sequentially and images are taken to calculate respective orthogonal deviation angles θ. The orthogonal deviation angle may be calculated based on an average value of a plurality of orthogonal deviation angles θ. Furthermore, even when the inclination in the Y-axis direction varies depending on the position of the Y coordinate, if the orthogonal deviation angle is calculated using only two Y-direction reference patterns, an orthogonal deviation angle θ as shown in FIG. On the other hand, as shown in FIG. 14B, the imaging unit 8 is relatively moved sequentially with the Y-direction reference patterns PY1 to PYm as targets, and the Y-direction between the Y-direction reference patterns PY1 to PYm is captured. orthogonal deviation angle theta ₁ corresponding to the coordinate _position, theta _2, ..., theta _8, calculates ..., these orthogonal shift angle _{θ 1, θ 2, ...,} θ 8, ... and used in accordance with the Y coordinate position If correction is performed, proper correction is possible even if the inclination in the Y-axis direction varies depending on the position of the Y coordinate.

  In the present embodiment, the X and Y coordinate values of the design coordinate value of the desired machining position are corrected based on the calculated orthogonal deviation angle θ, and the first and second feeding means 4 and 5 are corrected. Is controlled in accordance with the first and second position detecting means 6 and 7, but the X coordinate value of the design coordinate value of the desired machining position is corrected based on the orthogonal deviation angle, and the first The feed amount by the feed means 4 is controlled according to the first position detection means 6, and the feed amount by the second feed means 4 is determined by laser length measurement (not shown) based on the Y coordinate value of the design coordinate value of the desired machining position. You may make it control linearly in one dimension using a container etc.

  This is because the second feeding means 5 that is positioned below and feeds in the Y-axis direction and the first feeding means 4 that is mounted on the second feeding means 5 and feeds in the X-axis direction are There is a difference in the magnitude of the mechanical error that occurs during the axis feeding, and the feeding by the second feeding means 5 is linear and relatively stable in the Y-axis direction, whereas the first feeding means This is because the feed by 4 is easy to shake. Therefore, the feed control in the Y-axis direction may be performed by one-dimensional linear control using a laser length measuring device or the like that has been conventionally performed.

  Moreover, although this Embodiment demonstrated by the application example about the process example which forms a through-hole (via hole) by laser processing, it will not be restricted to such an application example but will process to a desired process position. It is equally applicable. For example, the present invention can also be applied to a broken line cut along the planned division line 201 of the workpiece 200 and an inner cut that cuts between predetermined positions in the workpiece 200 along the planned division line 201. Further, the processing means is not limited to the laser processing using the laser beam irradiation unit 3, and can be similarly applied to, for example, a case where a chopper cut is performed at a desired processing position of a workpiece using a disk-shaped blade. is there.

It is an external appearance perspective view which shows the principal part including a part of control system of the laser processing apparatus of embodiment of this invention. It is a top view which shows the structural example of the workpiece | work used for the laser processing apparatus of this Embodiment. It is a top view which expands and shows a part of workpiece | work. It is a perspective view which shows the workpiece | work with which the flame | frame was mounted | worn. It is explanatory drawing which shows the relationship with the coordinate in the state in which the workpiece | work was hold | maintained at the predetermined position of the chuck table. It is a schematic flowchart which shows the example of control of the workpiece | work processing method in this Embodiment. It is explanatory drawing which shows the Y direction reference | standard pattern example in a gauge work. It is explanatory drawing which shows the example of the visual field range E1 located in the Y direction reference pattern PY6. It is explanatory drawing which shows the example of imaging of the visual field range E1. It is explanatory drawing which shows the example of the visual field range E2 which moved the predetermined distance (alpha) and was located in the Y direction reference pattern PY8. It is explanatory drawing which shows the example of imaging of the visual field range E2. It is explanatory drawing regarding calculation of orthogonal deviation angle (theta). It is explanatory drawing which shows the example of correction | amendment of the feed amount based on orthogonal deviation angle | corner (theta). It is explanatory drawing which compares and shows the 2 point | piece correction example and the multipoint correction example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser processing apparatus 2 Chuck table 3 Laser beam irradiation means 4 1st feed means 5 2nd feed means 6 1st position detection means 7 2nd position detection means 8 Imaging means 200 Workpiece 300 Gauge work

Claims (4)

A chuck table for holding a workpiece, a machining means for machining the workpiece held on the chuck table, and the chuck table and the machining means are relatively moved in the X-axis direction parallel to the X direction of the XY orthogonal coordinate system. Relative to the chuck table and the processing means, the second feeding means for moving the chuck table and the processing means relative to each other in the Y-axis direction substantially orthogonal to the X-axis direction. Positions of a first position detecting means for detecting a typical X-axis direction position, a second position detecting means for detecting a relative Y-axis direction position of the chuck table and the processing means, and the processing means An XY orthogonal seat of the workpiece held on the chuck table using a processing device having an imaging means for imaging the workpiece held on the chuck table with a fixed relationship A workpiece machining method for machining at said processing means to a desired processing position in the system,
A plurality of Y-direction reference patterns spaced apart from each other by a predetermined distance in the Y direction of the XY orthogonal coordinate system on the chuck table are positioned so as to be orthogonal to the X-axis direction, and the chuck table and the processing means are used. Position information of at least two Y-direction reference patterns sequentially moved by a predetermined distance and sequentially imaged by the imaging means is obtained, and the X-axis direction is determined based on the obtained position information and movement distance of these Y-direction reference patterns. An orthogonal deviation angle calculating step for obtaining an orthogonal deviation angle in the Y-axis direction with respect to
A workpiece holding step of holding a workpiece including a desired machining position in which a design coordinate value is set in an XY orthogonal coordinate system on the chuck table;
When machining a desired machining position of the workpiece held on the chuck table, the design coordinate value of the desired machining position is corrected based on the orthogonal deviation angle calculated in the orthogonal deviation angle calculating step, and corrected. A machining control step of moving the chuck table and the machining means relative to each other based on the designed coordinate values and positioning the machining means at a machining position of the design coordinate values; and
A workpiece machining method comprising:   The machining control step corrects the X coordinate value of the design coordinate value of a desired machining position based on the orthogonal deviation angle, and controls the feed amount by the first feed means according to the first position detection means. The workpiece machining method according to claim 1, wherein the feed amount by the second feeding means is linearly controlled in a one-dimensional manner based on a Y coordinate value of a design coordinate value of a desired machining position.   The machining control step corrects the X coordinate value and the Y coordinate value of the design coordinate value of a desired machining position based on the orthogonal deviation angle, and sets the feed amounts by the first feeding means and the second feeding means. 2. The workpiece machining method according to claim 1, wherein control is performed according to the first position detection means and the second position detection means. A chuck table for holding a workpiece, a machining means for machining the workpiece held on the chuck table, and the chuck table and the machining means are relatively moved in the X-axis direction parallel to the X direction of the XY orthogonal coordinate system. Relative to the chuck table and the processing means, the second feeding means for moving the chuck table and the processing means relative to each other in the Y-axis direction substantially orthogonal to the X-axis direction. Positions of a first position detecting means for detecting a typical X-axis direction position, a second position detecting means for detecting a relative Y-axis direction position of the chuck table and the processing means, and the processing means Imaging means for imaging the workpiece held on the chuck table with a fixed relationship, and a desired workpiece in the XY orthogonal coordinate system of the workpiece held on the chuck table. A workpiece machining apparatus for machining by the machining means Engineering position,
A plurality of Y-direction reference patterns spaced apart from each other by a predetermined distance in the Y direction of the XY orthogonal coordinate system on the chuck table are positioned so as to be orthogonal to the X-axis direction, and the chuck table and the processing means are used. Position information of at least two Y-direction reference patterns sequentially moved by a predetermined distance and sequentially imaged by the imaging means is obtained, and the X-axis direction is determined based on the obtained position information and movement distance of these Y-direction reference patterns. Orthogonal deviation angle calculating means for obtaining an orthogonal deviation angle in the Y-axis direction with respect to
The orthogonal deviation calculated by the orthogonal deviation angle calculation means is included when machining a desired machining position of the workpiece held on the chuck table, including a desired machining position in which design coordinate values are set in an XY orthogonal coordinate system. The design coordinate value of the desired machining position is corrected based on the angle, and the chuck table and the machining means are relatively moved based on the corrected design coordinate value, and the machining means is moved to the design coordinate value. Processing control means for processing at a processing position;
A workpiece machining apparatus comprising:

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