JP2010000517A - Device and program for working workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform a high-quality working by which a working position from a surface to be worked of a workpiece is made uniform without scanning the whole surface to be worked of the workpiece to which the working is scheduled. <P>SOLUTION: The Z coordinate points of the respective surfaces to be worked of the workpiece are detected in a plurality of sampling positions S<SB>ij</SB>(S<SB>21</SB>, S<SB>22</SB>, etc.) on the workpiece 200 and the predetermined position to be worked, for example, the Z coordinate points Z<SB>A</SB>of the surface to be worked of the workpiece at the intersecting point P<SB>A</SB>is calculated and recognized by arithmetic processing on the base of the Z coordinate points in the plurality of sampling positions S<SB>ij</SB>and each predetermined positions to be worked, for sample, the X and Y coordinate points of an intersecting point P<SB>A</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a workpiece machining apparatus and a workpiece machining program for machining a workpiece such as a semiconductor wafer.

  In the semiconductor device manufacturing process, a plurality of regions are defined by streets (scheduled cutting lines) arranged in a lattice pattern on the surface of a substantially disk-shaped workpiece, and circuits such as IC and LSI are formed in the partitioned regions. By cutting the formed work along the streets, each semiconductor chip is manufactured by being divided into circuits. Cutting along the work street is usually performed by a cutting device called a dicer. A processing method for cutting a workpiece by irradiating it with a laser beam has also been attempted (for example, see Patent Document 1).

  As a cutting method using a laser beam, a pulsed laser beam having a wavelength that passes through the workpiece is focused on the inside of the workpiece along the planned cutting line, a modified region is formed inside the workpiece, and the modified region is formed. As a starting point, there is one that is cut by breaking or cracking along a planned cutting line (for example, see Patent Document 2).

  Thus, in the processing method for forming the modified region in the workpiece, in order to perform high-quality processing, it is necessary to make the processing position (position for forming the modified region) from the workpiece processing surface uniform. Is done. Here, as a technique for processing a workpiece whose main surface is uneven, as a processing preparation, the flatness of all portions to be processed is measured by flatness measuring means, for example, a flatness having a projector and a reflected light receiver. After measuring with a measuring instrument, there is one in which a workpiece is processed based on the measured flatness (for example, see Patent Documents 3 and 4).

JP-A-10-305420 JP-A-2005-95952 JP-A-11-345785 JP 2005-193286 A

  However, in the case of the method using the flatness measuring means as shown in Patent Documents 3 and 4, etc., it is necessary to scan all the workpiece machining surfaces to be machined and measure the surface state. It takes a lot of time to measure the degree of processing, and the processing efficiency is poor.

  The present invention has been made in view of the above, and efficiently performs high-quality machining that can make the machining position uniform from the workpiece machining surface without scanning all workpiece machining surfaces to be machined. An object of the present invention is to provide a workpiece machining apparatus and a workpiece machining program.

  In order to solve the above-described problems and achieve the object, a workpiece machining apparatus according to the present invention includes a holding unit that holds a workpiece, a machining unit that processes the workpiece held by the holding unit, and a workpiece machining surface. A first feeding means for relatively moving the holding means and the processing means in the X direction on the XY coordinate plane set on the same plane; and the holding means and the processing means in the Y direction on the XY coordinate plane. A second feeding means for relatively moving, a third feeding means for relatively moving the holding means and the processing means in the Z direction orthogonal to the XY coordinate plane, the holding means and the processing A first position detecting means for detecting a relative X-direction position with respect to the means; a second position detecting means for detecting a relative Y-direction position between the holding means and the processing means; and the holding means; The Z-direction position relative to the processing means A third position detecting means for taking out the workpiece, and processing the workpiece held by the holding means on the basis of each Z coordinate of the workpiece machining surface at a plurality of machining scheduled positions, Z-coordinate detection means for sequentially detecting the Z-coordinate of the workpiece machining surface at each sampling position by being sequentially positioned by the first and second feeding means at a plurality of sampling positions on the workpiece which are set to be roughly distributed from the planned machining position. Storage means for storing the Z coordinates at each sampling position detected by the Z coordinate detection means; Z coordinates at a plurality of sampling positions stored in the storage means; and X and Y coordinates of the respective processing scheduled positions; Based on the calculation means for sequentially calculating the Z coordinate of the workpiece machining surface at each of the planned machining positions, and the X, Y, Z coordinates of the intended machining position. The first, second and third feeding means are controlled to move the holding means and the processing means relative to each other, and the processing schedule to be processed according to the first, second and third position detection means Machining control means for positioning and machining the machining means at a position.

  In the workpiece machining apparatus according to the present invention, in the above invention, the planned machining position is a street in which the same X coordinate position continues in the Y direction on the XY coordinate plane, and the calculation means The intersection points on the streets based on the Z coordinates at a plurality of sampling positions on the straight lines and the X coordinates of the intersection points where the streets and the straight lines intersect. Intersection position Z coordinate calculation means for sequentially calculating the Z coordinate of the workpiece machining surface for each street, and the street based on the Z coordinates at the plurality of intersection points on the same street calculated by the intersection position Z coordinate calculation means. An on-street Z-coordinate distribution calculating means for sequentially calculating the Z-coordinate distribution of the workpiece machining surface on the street for each street. And butterflies.

  In the workpiece machining apparatus according to the present invention as set forth in the invention described above, the intersection position Z-coordinate calculating means includes the Z-coordinates at a plurality of sampling positions on each straight line, the respective X-coordinates at the plurality of sampling positions, and the straight line. The Z coordinate of the workpiece machining surface at the intersection is calculated by a linear approximation linear function using the X coordinates of the intersections of the intersections, and the Z coordinate distribution calculation means on the street calculates each Y at the intersections on the same street. The Z coordinate distribution of the workpiece machining surface on the street is calculated as a linear function of linear approximation using the Z coordinate.

  The workpiece machining apparatus according to the present invention is characterized in that, in the above invention, the plurality of sampling positions on each straight line are sampling positions of coordinates sandwiching intersecting streets.

  In the workpiece processing apparatus according to the present invention, in the above invention, the sampling positions are distributedly set along the X and Y directions on the XY coordinate plane, and each straight line intersecting the street is orthogonal to the street. It is a straight line along the X direction.

  Moreover, the workpiece processing apparatus according to the present invention is characterized in that, in the above invention, the processing means is a laser irradiation means for irradiating a laser beam with a focus inside the workpiece.

  The workpiece machining program according to the present invention includes a holding means for holding a workpiece, a machining means for machining the workpiece held by the holding means, and an XY coordinate plane set on the same plane as the workpiece machining surface. A first feeding means for relatively moving the holding means and the processing means in the X direction, and a second feeding for relatively moving the holding means and the processing means in the Y direction on the XY coordinate plane. Detecting a relative X-direction position between the holding means and the processing means, a third feeding means for moving the holding means and the processing means relative to each other in the Z direction orthogonal to the XY coordinate plane; First position detecting means, second position detecting means for detecting a relative Y-direction position between the holding means and the processing means, and a relative Z-direction position between the holding means and the processing means. Third position detecting means for detecting A plurality of workpieces on the workpiece, the workpieces being held by the holding means, which are coarsely distributed from the plurality of scheduled machining positions in a machining apparatus that processes the workpiece based on each Z coordinate of the workpiece machining surface at a plurality of scheduled machining positions. A Z coordinate detection procedure in which the Z coordinate detection means is sequentially positioned at the sampling position by the first and second feeding means, and the Z coordinate of the workpiece machining surface at each sampling position is detected and stored in the storage means; A calculation procedure for sequentially calculating the Z coordinate of the workpiece machining surface at each planned machining position based on the Z coordinates at the plurality of sampling positions and the X and Y coordinates of each of the planned machining positions, and the machining to be processed Based on the X, Y, and Z coordinates of the planned position, the first, second, and third feeding means are controlled to move the holding means and the processing means relative to each other. Second, characterized in that to execute a machining control procedure for processing to position the processing means to the planned processing position of interest in accordance with the third position detecting means.

  The workpiece machining apparatus and the workpiece machining program according to the present invention detect the Z coordinate of the workpiece machining surface at each of a plurality of sampling positions on the workpiece, and the Z coordinates at the plurality of sampling positions and the X, Y of each planned machining position. With the calculation processing based on the coordinates, the Z coordinate of the workpiece machining surface at the scheduled machining position can be grasped, so that the machining position from the workpiece machining surface can be made uniform without scanning the entire workpiece machining surface to be machined High processing can be efficiently performed.

  Hereinafter, a workpiece machining apparatus and a workpiece machining program that are the best mode for carrying out the present invention will be described with reference to the drawings. In this embodiment, as a workpiece processing apparatus, a modified region is formed by irradiating the inside of a workpiece with a pulsed laser beam along a street (scheduled cutting line) that is a desired processing planned position of the workpiece. An example of application to a laser processing apparatus to be cut will be described.

  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 holding unit 2, a laser beam irradiation unit 3 that is a processing unit and a laser irradiation unit, a first feeding unit 4, a second feeding unit 5, and a third unit. Feeding means 6, first position detecting means 4 a, second position detecting means 5 a, third position detecting means 6 a, Z coordinate detecting means 7, imaging means 8, and control means 10. I have.

  The holding means 2 includes a suction chuck 21 made of a porous material, holds a workpiece 200 to be processed on the suction chuck 21 by a suction means (not shown), and is disposed in the cylindrical member 22. It can be rotated by a pulse motor that does not. The holding means 2 is provided with a clamp 23 for fixing an annular frame 210 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 holding means 2 from above. The pulse laser beam is irradiated from The imaging unit 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, faces the holding unit 2, and holds the workpiece 200 held by the holding unit 2. Is for imaging. The imaging unit 8 includes an illuminating unit that illuminates the workpiece 200, 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. The processed image signal is sent to the control means 10.

  In addition, the same surface as the workpiece processing surface held by the holding means 2 in the laser processing apparatus 1 of the present embodiment is defined as an XY coordinate plane, and the X direction and the Y direction are the directions indicated by the arrows in FIG. When the direction perpendicular to the surface is the Z direction, the first feeding means 4 is for moving the holding means 2 in the X direction with respect to the laser beam irradiation unit 3, and the second feeding means 5 is The third feeding means 6 moves the holding means 2 in the Z direction with respect to the workpiece on the holding means 2. It is for moving. Here, the second feeding means 5 includes a sliding block 51 on which the first feeding means 4 is mounted together with the holding means 2, a pair of guide rails 52 for moving the sliding block 51 in the Y direction, and a pair of A ball screw 53 disposed in parallel between the guide rails 52 and a drive source such as a pulse motor 54 for rotating the ball screw 53 are configured. 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 holding means 2 is mounted moves in the Y direction along the guide rail 52.

  On the other hand, the first feeding means 4 includes a sliding block 41 on which the holding means 2 is mounted, a pair of guide rails 42 provided on the sliding block 51 for moving the sliding block 41 in the X direction, and a pair of A ball screw 43 disposed in parallel between the guide rails 42 and a drive source such as a pulse motor 44 for rotating the ball screw 43 are configured. 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 holding means 2 is mounted moves in the X direction along the guide rail 42.

  The third feeding means 6 includes a sliding block 61 on which the laser beam irradiation unit 3 and the like are mounted, and a pair of guide rails 63 provided on the side surface of the support base 62 for moving the sliding block 61 in the Z direction. A ball screw 64 disposed in parallel between the pair of guide rails 63 and a drive source such as a pulse motor 65 for rotating the ball screw 64 are configured. One end of the ball screw 64 is rotatably supported by a bearing block 66 fixed to the support body 62, and the other end is connected to the output shaft of the pulse motor 65. The ball screw 64 is screwed into a through female screw hole formed in a female screw block (not shown) that protrudes from the back of the central portion of the sliding block 61, and the ball motor 64 is driven to rotate forward and backward by a pulse motor 65. As a result, the sliding block 61 on which the laser beam irradiation unit 3 is mounted moves in the Z direction along the guide rail 63.

  The first position detection means 4 a is attached to the first feeding means 4 and detects the relative X-direction position between the holding means 2 and the laser beam irradiation unit 3. The first position detecting means 4 a includes an X-axis linear scale 47 disposed along the guide rail 42 on the sliding block 51, and an X-axis linear scale 47 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 47. The X 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 direction position of the laser beam irradiation unit 3 with respect to the holding means 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 holding means 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 direction position of the laser beam irradiation unit 3 with respect to the holding means 2 by counting a pulse signal.

  Similarly, the second position detection means 5 a is attached to the second feeding means 5 and detects the relative Y direction position between the holding means 2 and the laser beam irradiation unit 3. The second position detecting means 5 a includes a Y-axis linear scale 57 disposed along the guide rail 52 on the stationary base 11, and a Y-axis linear scale 57 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 57. The Y 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. And the control means 10 detects the relative Y direction position of the laser beam irradiation unit 3 with respect to the holding means 2 by counting the input pulse signal.

  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 in the Y direction of the laser beam irradiation unit 3 with respect to the holding means 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 direction position of the laser beam irradiation unit 3 with respect to the holding means 2 by counting a pulse signal.

  The third position detection means 6 a is attached to the third feeding means 6 and detects the relative Z-direction position between the holding means 2 and the laser beam irradiation unit 3. The third position detecting means 6 a includes a Z-axis linear scale 67 disposed along the guide rail 63 on the side of the support base 62, and a Z-axis linear scale 67 together with the sliding block 61 disposed along the sliding block 61. And a Z-axis reading head (not shown) that moves along the Z-axis linear scale 67. The Z coordinate value that is the result read by the Z-axis reading head is output to the control means 10. The Z-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 Z direction position of the laser beam irradiation unit 3 with respect to the holding means 2 by counting the input pulse signal.

  When the pulse motor 65 is used as the driving source of the third feeding unit 6 as in the present embodiment, the driving pulse of the control unit 10 that outputs a driving signal to the pulse motor 65 is counted. The relative position of the laser beam irradiation unit 3 with respect to the holding means 2 may be detected. If a servo motor is used as a drive source for the third feeding means 6, 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 input by the control means 10. You may make it detect the relative Z direction position of the laser beam irradiation unit 3 with respect to the holding means 2 by counting a pulse signal.

  Further, the Z coordinate detection means 7 is arranged so as to face the holding means 2 from above similarly to the condenser 31 and is held in the XY coordinate plane by the first and second feeding means 4 and 5. By moving the workpiece facing position on the means 2, as will be described later, the workpiece 2 is sequentially positioned at a plurality of sampling positions on the workpiece 200, and the Z coordinate of the workpiece machining surface at each sampling position is detected. This Z coordinate detection means 7 is mounted on the slide block 61 in a fixed arrangement relationship with the laser beam irradiation unit 3 and the imaging means 8 and is provided so as to be movable in the Z direction by the third feed means 6. It is. The Z coordinate detection means 7 is, for example, a laser light irradiation means for condensing and irradiating a workpiece processing surface with laser light so that the focal point coincides with the workpiece processing surface at the target sampling position. The Z-direction position of the Z-coordinate detection means 7 is moved by the third feeding means 6, and a signal at the time of matching is sent to the control means 10, and the control means 10 is in the Z-direction of the third position detection means 6a at the time of matching. By acquiring the position, the Z coordinate (machined surface height position) of the workpiece machining surface with respect to a predetermined reference position in the Z direction is detected.

  The control means 10 is constituted by a computer, and includes a central processing unit (CPU) 101 that performs arithmetic processing according to a control program, a read-only memory (ROM) 102 that stores a workpiece machining program, and the like, and a workpiece that will be described later. A random access memory (RAM) 103 capable of storing design value data, calculation results, and the like, a counter 104, an input interface 105, and an output interface 106. Detection signals from the first, second and third position detecting means 4a, 5a and 6a, the Z coordinate detecting means 7, the imaging means 8 and the like are input to the input interface 105. The output interface 106 outputs a control signal to the pulse motors 44, 54, 65, the laser beam irradiation unit 3, and the like. The RAM 103 is a first memory 103a that is a storage unit that stores each Z coordinate at each sampling position, which will be described later, and a second memory that is a storage area that stores a linear function indicating the Z coordinate distribution on each street. 103b and other storage areas. In addition, the CPU 101 of the present embodiment includes functions of a calculation unit 101a and a machining control unit 101b that are executed according to a workpiece machining program.

  FIG. 2 is a plan view showing a configuration example of a workpiece 200 used in the laser processing apparatus 1 of the present embodiment. The workpiece 200 is not particularly limited. For example, a wafer such as a semiconductor wafer, an adhesive member such as DAF (Die Attach Film) provided on the back surface of the wafer for chip mounting, or a semiconductor product package, ceramic, glass or silicon Examples of the processing substrate include various types of processing materials that require accuracy of the order of μm. The workpiece 200 of the present embodiment is, for example, a semiconductor wafer, and a plurality of areas are partitioned by a plurality of streets 201 arranged in a lattice pattern on the surface 200a, and a device 202 such as an IC or LSI is formed in the partitioned areas. Each is formed. All the devices 202 have the same configuration.

  In such a laser processing apparatus 1, first, a basic operation for laser processing along the street 201 of the workpiece 200 will be described. As shown in FIG. 3, the workpiece 200 configured as described above is attached to a protective tape 220 made of a synthetic resin sheet such as polyolefin and attached to an annular frame 210 with the back surface 200 b facing upward. The workpiece 200 supported by the annular frame 210 via the protective tape 220 places the protective tape 220 on the holding means 2. Then, the work 200 is sucked and held on the holding means 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 holding means 2 that sucks and holds the workpiece 200 is positioned immediately below the imaging means 8 by the first and second feeding means 4 and 5. Then, a pre-alignment operation is performed to determine whether or not the grid-like streets 201 formed on the workpiece 200 held by the holding unit 2 are arranged in parallel with each other in the X direction and the Y direction. That is, the workpiece 200 on the holding unit 2 is imaged by the imaging unit 8 and image processing such as pattern matching is performed to perform pre-alignment work so that the street 201 matches the XY coordinate plane. Thereby, the workpiece 200 is positioned on the XY coordinate plane on the holding means 2 as shown in FIG.

  Next, an alignment operation for detecting a processing region of the workpiece 200 to be laser processed by the imaging unit 8 and the control unit 10 is executed. That is, the imaging unit 8 and the control unit 10 perform pattern matching for aligning the street 201 formed in the Y direction of the workpiece 200 with the condenser 31 that irradiates the pulse laser beam along the street 201. The image processing such as the above is executed to align the laser beam irradiation position. At this time, the alignment of the laser beam irradiation position is similarly performed on the street 201 in the X direction orthogonal to the Y direction formed on the workpiece 200.

  When alignment of the laser beam irradiation position is performed, the holding unit 2 is moved by the first and second feeding units 4 and 5 to the laser beam irradiation region where the condenser 31 for irradiating the pulsed laser beam is located, One end of a predetermined street 201 in the Y direction is positioned directly below the condenser 31. Then, the holding means 2, that is, the workpiece 200 is moved in the Y direction at a predetermined processing feed speed while irradiating a pulse laser beam having a wavelength having transparency from the condenser 31. When the irradiation position of the condenser 31 reaches the position of the other end of the street 201, the irradiation of the pulse laser beam by the laser beam irradiation unit 3 is stopped and the movement of the holding means 2, that is, the workpiece 200 is stopped. . The machining feed amount in the Y direction by the second feeding means 5 is controlled by the counter 104 in the control means 10 counting the detection signal from the Y-axis reading head of the second position detecting means 5a.

  In such a laser processing step, as shown in FIG. 5, the modified region 203 is formed by irradiating the focused point P of the pulsed laser beam within the region of the workpiece 200 with respect to the street 201. . In other words, the laser beam irradiation unit 3 is moved in the Z direction by the third feeding means 6, and a collection of pulsed laser beams to be irradiated from the condenser 31 toward the workpiece 200 according to the position detection by the third position detection means 6 a. Control is performed so that the position of the light spot P is a predetermined depth position from the workpiece processing surface (in the case of the present embodiment, the back surface 200b). Similarly, the modified region 203 is formed inside all the streets 201 in the Y direction. At this time, the index 104 feed amount corresponding to the street interval in the X direction by the first feed means 4 is counted by the counter 104 in the control means 10 as a detection signal from the X-axis reading head of the first position detection means 4a. Is controlled.

  Thereafter, by rotating the holding means 2 by 90 °, the workpiece 200 is rotated by 90 °, and all streets 200 in the X direction are positioned in the Y direction as in the case of FIG. Similarly, the modified region 203 is formed. By applying an external force to the workpiece 200 along the street 201 whose strength has been reduced by continuously forming such a modified region 203, the workpiece 200 is divided along the street 201, and individual devices are separated. It can be divided into 202.

  Here, the basic operation described above is based on the premise that the machining surface of the workpiece 200 to be machined is a flat surface without unevenness, and all the workpiece machining surfaces exhibit the same Z coordinate (machining surface height position). It is. However, in reality, the processed surface of the workpiece 200 is not a little uneven, and the Z coordinate value varies depending on the location. In order to make the converging position from the processing surface uniform when condensing and irradiating the laser beam onto the street 201 that is the planned processing position, it is necessary to acquire the Z coordinate corresponding to the unevenness of the processing surface on the street 201. is there. Therefore, in the present embodiment, the Z coordinate of the processed surface on each street 201 that is the planned processing position is efficiently acquired, and appropriate laser processing corresponding to the Z coordinate value can be performed.

  FIG. 6 is a schematic flowchart showing a control example of the workpiece machining method in the present embodiment. First, as described above, after the alignment process of the workpiece 200 held on the holding means 2 is executed (step S1), the CPU 101 operates the Z coordinate detection means 7 to perform the Z coordinates of the workpiece machining surface at a plurality of sampling positions. Is stored in the first memory 103a (step S2: Z coordinate detection procedure).

In the present embodiment, for example, as shown in FIG. 7A, a plurality of sampling positions S _ij are distributedly set for the workpiece 200 held by the holding means 2. Here, the sampling positions S _ij are set to be evenly distributed at equal pitches and equal intervals in the XY coordinate plane, and the X and Y coordinates on the XY coordinate plane after the alignment processing are set in advance. FIG. 8 is an arrangement diagram showing the X and Y coordinates of each sampling position _Sij . In the present embodiment, the dispersion is set along the X and Y directions on the XY coordinate plane. The number of such sampling positions S _ij is set as appropriate, but is set so as to be coarser than the number of streets 201 serving as processing scheduled positions. In the illustrated example, i = 5 and j = 5 are set, and 22 sampling positions that can be accommodated in the workpiece 200 are set.

In step S2, firstly, positioned Z-coordinate detection unit 7 to the sampling position S ₁₂ by the first, second feed means 4 and 5, the laser light is condensed and irradiated to the workpiece processing surface of the sampling position S ₁₂ Then, the Z-direction position of the Z-coordinate detecting means 7 is moved by the third feeding means 6 so that the focal point coincides with the workpiece processing surface. Then, a signal at the time when the condensing point coincides with the workpiece processing surface is sent to the control means 10. Control means 10 detects the Z coordinate Z ₁₂ of the workpiece machining surface by acquiring the Z direction position of the third position detection means 6a of the matched points in the sampling position S _12. The Z coordinate of the workpiece machining surface is based on the Z-direction position (height position) detected by the third position detection means 6a at appropriate locations such as the reference point on the work 200, the reference point on the holding means 2, and the like. It is what. In the present embodiment, the height information is detected as Z ₁₂ = 10 [μm].

Similarly, with respect to the other sampling positions S _ij , the Z coordinate detection means 7 is sequentially positioned at each sampling position S _ij by the first and second feeding means 4 and 5 to perform the Z coordinate detection operation. Each Z coordinate _Zij of the workpiece machining surface at the sampling position _Sij is detected. The detected value of each Z coordinate Z _ij is stored in the first memory 103a in association with each sampling position S _ij . FIG. 9 is an explanatory diagram showing a storage example in the first memory 103a of the Z coordinate _Zij detected for each sampling position _Sij .

After detecting the Z coordinate Z _ij for each sampling position S _ij, the Z coordinate calculation processing of the planned processing position is performed by the function of the calculation means 101a executed by the CPU 101 (steps S3 and S4: calculation procedure). That is, based on the Z coordinate Z _ij at the plurality of sampling positions S _ij stored in the first memory 103a and the X and Y coordinates of the planned machining position, the Z coordinate of the workpiece machining surface at the planned machining position is calculated. To do. Here, in the present embodiment, the planned machining position is a street 201 in which the same X coordinate continues in the Y direction on the XY coordinate plane, and the function of the computing means 101a is the same as the intersection position Z coordinate calculating means and the street. It is divided into Z coordinate distribution calculating means, and is calculated for each street 201 as the Z coordinate distribution of the workpiece machining surface on the street 201.

First, the intersection position Z coordinate calculation unit identifies a calculation target street 201, the straight line L _A crossing through a plurality of sampling positions determined for this street 201, the two on the straight line L _A each Z coordinate in the sampling position, and calculates the Z coordinates Z _a of the workpiece machining surface at the intersection point P _a on the basis of the X-coordinate of the intersection point P _a to the this street 201 and the straight line L _a cross (step S3).

For example, in FIG. 7 (a), and calculates the specified target the X-coordinate = _{X N} becomes Street 201 _N. That, Street 201 _N is represented by X = _{X N.} In this case, for example, to a straight line along the X direction through the sampling position _{S 33, S 43} intersect so as to be orthogonal to the street 201 _N and _{L A.} That is, the straight line _{L A} is a straight line represented by Y = _{Y A.} Therefore, as shown extracted in FIG. 7 (b), the street on the straight line _{L A} crossing the 201 _N 2 two sampling on straight line closest _{L A} to the street 201 across the _N Street 201 _N based each Z coordinate in the position _{S 33, S 43 (Z 33} = 40, Z 43 = 50), the X coordinate of the intersection point _{P a} to the this street 201 _N and the straight line _{L a} cross (X = _{X N)} to Te to calculate the Z-coordinate _{Z a} of the workpiece machining surface at the intersection point _{P a.}

That is, the intersection position Z coordinate calculating means, the straight line _L each Z coordinates in two sampling positions _{S 33, S 43} on _{A (Z 33 = 40, Z} 43 = 50) and the two sampling positions _{S 33, S 43} each X-coordinate _{(X = X 3, X =} X 4) and the straight line _L X-coordinate of the intersection point _{P a} on _a (X = _{X N)} and the intersection point _{P a} by proportional distribution by a linear function of the linear approximation with the calculating the Z-coordinate Z _a of the workpiece machining surface at. For example, Z coordinates _{Z A} of the workpiece processed surface in accordance with the X-coordinate _{X N} of intersection _{P A} on the straight line _{L A,}
Z _A = aX _N + b
It is calculated | required by the linear function of the following linear approximation. Here, the proportional coefficient a _is determined from _{(Z 43 -Z 33) / (} X 4 -X 3). b is a predetermined constant. When the intersection point P _A is the midpoint between the two sampling positions S ₃₃ and S ₄₃ , the calculation is performed such that Z _A = 45. Z-coordinate _{Z A} of the calculated intersection point _{P A} is Street 201 _N, X of intersection _{P A,} in correspondence with the Y-coordinate is stored in the second memory 103b in the RAM 103.

Intersection position Z coordinate calculating means, like for other straight line passing through a plurality of sampling positions intersect at a position different from the intersection point P _A against the calculated target street 201 _N, and the straight line and the street 201 _N is the Z coordinate of the workpiece machining surface at the intersection of intersecting, each Z coordinate in the nearest two sampling positions Street 201 _N across the street 201 _N on a straight line, the intersection of X, calculated on the basis of the Y coordinate. For example, in the example shown in FIG. 7 (a), as indicated by the broken lines, street 201 intersection with respect to _{N P B (X = X N} , Y = Y B) linearly represented by Y = _{Y B} intersect at L Set _B. Then, each of the two X-coordinate of the sampling position _{S 34,} the Z coordinates in _{S 44 (Z 34 = 50,} Z 44 = 60) and the two sampling positions _{S 34, S 44} on the straight line _{L B} the intersection _{P B (X = X 3, X =} X 4) and workpiece machining surface at the intersection point _{P B} by proportional distribution by a linear function of the linear approximation using the X-coordinate of the intersection point _{P B} on the straight line _{L B (X} = X _N) to the calculated Z coordinate _{Z B.} When the intersection point P _B is the midpoint between the two sampling positions S ₃₄ and S ₄₄ , the calculation is performed as Z _B = 55. Z-coordinate _{Z B} of the calculated intersection point _{P B} is Street 201 _N, X of intersection _{P B,} in association with the Y-coordinate is stored in the first memory 103a in the RAM 103.

  The intersection position Z-coordinate calculating means also sets two or more intersections where the straight lines passing through the sampling positions intersect on each street 201 for the other streets 201 of the workpiece 200, and the workpiece machining surface at the intersection for each intersection. The Z coordinate is calculated in the same manner, and the calculated Z coordinate of the intersection is stored in the first memory 103 a in the RAM 103 in association with the X and Y coordinates of the street 201 and the intersection P.

  Next, the Z coordinate distribution calculating unit on the street specifies the street 201 to be calculated, and the Z coordinate at each of a plurality of intersections on the same street 201 calculated by the intersection position Z coordinate calculating unit with respect to the street 201 is determined. Based on this, the Z coordinate distribution of the workpiece machining surface on the street 201 is sequentially calculated for each street (step S4).

For example, in FIG. 10 (a), and calculates the specified target the X-coordinate = _{X N} becomes Street 201 _N. Then, a plurality of intersections on the street 201 _N intersection _P A, and _{P B.} Here, the Z coordinate Z _N between the intersections P _A and P _B on the street 201 _N is linearly approximated to the Z coordinates Z _A and Z _B of the intersections P _A and P _B as shown in FIG. The Z coordinate distribution of the workpiece machining surface on this street 201 _N is regarded as being proportional,
Z _N = cY + d
The calculated linear function is stored in the second memory 103 b in the RAM 103.

That is, the on-street Z coordinate distribution calculating means calculates the Y and Z coordinates (Y = Y _A , Z = Z _A , Y = Y _B , Z = Z) at a plurality of intersections P _A and P _B on the same street 201 _N. calculating the Z-coordinate distribution of the workpiece machining surface on the street 201 _N as a linear function _Z N = cY + d of the linear approximation with reference to _B). Here, the proportionality coefficient c is obtained from (Z _B −Z _A ) / (Y _B −Y _A ) as shown in FIG. d is a predetermined constant. The calculated linear function Z _N = cY + d is stored in the second memory 103 b in the RAM 103 in association with the street 201 _N.

  The Z coordinate distribution calculation unit on the street also linearly approximates the Z coordinate distribution of the workpiece machining surface on the street 201 based on the Z coordinates at a plurality of intersections on each street 201 with respect to the other streets 201. The calculation is similarly performed as a linear function and stored in the second memory 103 b in the RAM 103.

  When the Z coordinate distribution of the workpiece machining surface is calculated for all the streets 201, the machining control unit 101 b executed by the CPU 101 performs processing based on the X, Y, Z coordinates of the target street (scheduled machining position). The first, second and third position detecting means 4a, 5a and 6a are controlled by controlling the first, second and third feeding means 4, 5 and 6 to relatively move the holding means 2 and the condenser 31. Accordingly, the condenser 31 is positioned on the target street (scheduled processing position), and the processing is performed by irradiating the laser beam while always controlling the position of the laser focusing point from the workpiece processing surface to be the same ( Step S5: Processing control procedure). That is, when the street 201 to be processed is irradiated with a laser beam, the Y coordinate continuously changing on the street 201 according to a linear function of linear approximation indicating the Z coordinate distribution of the workpiece processing surface on the street 201 In accordance with the Z position detection result of the third position detecting means 6a, the Z coordinate position of the condenser 31 by the third feeding means 6 is changed so that the Z coordinate also changes in accordance with.

As described above, according to the workpiece machining apparatus 1 of the present embodiment, the Z coordinate Z _ij of the workpiece machining surface is detected at each of the plurality of sampling positions S _ij on the workpiece 200, and the Z at the plurality of sampling positions S _ij is detected. coordinate Z _ij and X each street 201 (planned processing position), the arithmetic processing based on a Y-coordinate, it is possible to grasp the Z coordinate of the workpiece machining surface in Street 201 (planned processing position), workpiece machining plan subjected to processing It is possible to efficiently perform high-quality processing that can make the processing position from the workpiece processing surface uniform without scanning the entire surface.

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, as the two sampling positions on the straight line intersecting the street 201, the two positions closest to the street 201 across the street 201 are selected to improve the accuracy of the linear approximation. It may not be the sampling position closest to the street 201, and three or more sampling positions may be selected. Furthermore, a plurality of sampling positions located on one side with respect to the street 201 may be selected. For example, in FIG. 7 (a), in order to calculate the Z-coordinate _{Z A} of intersection _{P A,} using the sampling position _{S 23, S 33,} be calculated by proportional distribution in accordance with a linear function of the linear approximation Good. This is particularly effective when the sampling position exists only on one side of the street 201 to be calculated.

In the present embodiment, a plurality of sampling positions _Sij are set to be distributed in a state orthogonal to the X and Y directions on the XY coordinate plane. However, the present invention is not necessarily limited to an array in a state orthogonal to the X and Y directions. The straight line that intersects the street 201 may also be a straight line that intersects obliquely as long as it passes through a plurality of sampling positions and can specify the coordinates of the intersection with the street 201.

Further, in the present embodiment, the Z coordinate is calculated by linear approximation using the Z coordinate information of the two sampling positions with respect to the processing planned position to be calculated. However, the present invention is not limited to the two sampling positions. The Z coordinate may be calculated using the Z coordinate information of three or more surrounding sampling positions surrounding the planned processing position to be calculated. For example, the Z coordinate of the sampling position of a desired machining scheduled position is used, and the Z coordinate of the machining scheduled position is calculated by polynomial approximation using a three-dimensional Bezier curve or the like that is a curved surface equation. Also good.

Furthermore, the mapping data regarding the Z coordinate of the sampling position S _ij of the entire workpiece 200 as shown in FIG. 7A is acquired, and the tendency of the surface height (Z coordinate) of the entire sampling position S _ij is detected. For sampling positions that deviate from the overall trend, the surface height (Z coordinate) may be modified to follow the overall trend. For example, when the surface height (Z coordinate) of a certain sampling position is unnaturally high or conversely low, the Z coordinate of this sampling position is matched with the Z coordinates of the surrounding sampling positions. By correcting so as to equalize, the sampling data can be optimized.

  Further, the present embodiment has been described in the application example of the processing example in which the modified region 203 is formed by irradiating the laser beam with the laser beam irradiation unit 3 focused on the inside of the workpiece 200. The present invention is not limited to this application example, and can be similarly applied as long as the machining is performed at a desired machining scheduled position based on the Z coordinate of the workpiece machining surface. 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 desired processing planned position of a workpiece is cut using a disk-shaped blade. .

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 perspective view which shows the workpiece | work with which the flame | frame was mounted | worn. It is explanatory drawing which shows the relationship with XY coordinate in the state in which the workpiece | work was hold | maintained at the predetermined position of the holding means. It is a schematic diagram which shows the irradiation state of a laser beam in sectional drawing. It is a schematic flowchart which shows the example of control of the workpiece | work processing method in this Embodiment. It is a schematic diagram for demonstrating the intersection Z coordinate calculation process example. It is an arrangement | positioning figure which shows the X and Y coordinate of each sampling position. It is explanatory drawing which shows the example of storage in the memory of Z coordinate detected for every sampling position. It is a schematic diagram for demonstrating the on-street Z coordinate distribution calculation processing example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser processing apparatus 2 Holding means 3 Laser beam irradiation unit 4 1st sending means 4a 1st position detecting means 5 2nd sending means 5a 2nd position detecting means 6 3rd sending means 6a 3rd position detection It means 7 Z-coordinate detection unit 101a computing unit 101b machining control means 103a first memory 200 work 200b backside 201 Street S _ij sampling position P _{a, P B} intersection L _{a, L B} linear

Claims (7)

Holding means for holding a workpiece, machining means for machining the workpiece held by the holding means, and the holding means and the machining means in the X direction on the XY coordinate plane set on the same plane as the workpiece machining surface. A first feeding means for relatively moving; a second feeding means for relatively moving the holding means and the processing means in the Y direction on the XY coordinate plane; and a Z direction orthogonal to the XY coordinate plane. A third feed means for relatively moving the holding means and the processing means; a first position detecting means for detecting a relative X-direction position between the holding means and the processing means; and the holding means. And a second position detecting means for detecting a relative Y-direction position between the processing means and a third position detecting means for detecting a relative Z-direction position between the holding means and the processing means. A plurality of workpieces held by the holding means A processing apparatus for processing based on each Z coordinate of the workpiece machining surface at the planned processing position,
Z coordinates that are sequentially positioned by the first and second feeding means at a plurality of sampling positions on the workpiece coarsely distributed from the plurality of machining scheduled positions and detect the Z coordinate of the workpiece machining surface at each sampling position. Detection means;
Storage means for storing the Z coordinate at each sampling position detected by the Z coordinate detection means;
Arithmetic means for sequentially calculating the Z coordinate of the workpiece machining surface at each of the scheduled machining positions based on the Z coordinates at the plurality of sampling positions stored in the storage means and the X and Y coordinates of each of the scheduled machining positions; ,
The first, second, and third feeding means are controlled based on the X, Y, and Z coordinates of the target machining position, and the holding means and the machining means are moved relative to each other. Machining control means for positioning and machining the machining means at the intended machining position according to second and third position detection means;
A workpiece machining apparatus comprising: The planned processing position is a street in which the same X coordinate position continues in the Y direction on the XY coordinate plane,
The computing means is
A plurality of straight lines intersecting the street at different positions on the street based on Z coordinates at a plurality of sampling positions on the straight lines and X coordinates of intersections of the street and the straight lines. Intersection position Z coordinate calculation means for sequentially calculating the Z coordinate of the workpiece machining surface at each intersection of each street,
On-street Z-coordinate distribution calculation for sequentially calculating the Z-coordinate distribution of the workpiece machining surface on the street for each street based on the Z-coordinates at the plurality of intersections on the same street calculated by the intersection position Z-coordinate calculating means. Means,
The workpiece processing apparatus according to claim 1, comprising: The intersection position Z coordinate calculating means is a linear function of linear approximation using each Z coordinate at a plurality of sampling positions on each straight line, each X coordinate of the plurality of sampling positions, and the X coordinate of the intersection on the straight line. To calculate the Z coordinate of the workpiece machining surface at the intersection,
The on-street Z coordinate distribution calculating means calculates the Z coordinate distribution of the workpiece machining surface on the street as a linear function of linear approximation using the Y and Z coordinates at the plurality of intersections on the same street. The workpiece machining apparatus according to claim 2, wherein the workpiece machining apparatus is a workpiece machining apparatus.   4. The workpiece machining apparatus according to claim 2, wherein the plurality of sampling positions on each straight line are sampling positions at coordinates sandwiching intersecting streets. The sampling positions are distributedly set along the X and Y directions on the XY coordinate plane,
5. The workpiece machining apparatus according to claim 2, wherein each straight line intersecting with the street is a straight line along an X direction orthogonal to the street.   The workpiece processing apparatus according to claim 1, wherein the processing unit is a laser irradiation unit that irradiates a laser beam while focusing on the inside of the workpiece. Holding means for holding a workpiece, machining means for machining the workpiece held by the holding means, and the holding means and the machining means in the X direction on the XY coordinate plane set on the same plane as the workpiece machining surface. A first feeding means for relatively moving; a second feeding means for relatively moving the holding means and the processing means in the Y direction on the XY coordinate plane; and a Z direction orthogonal to the XY coordinate plane. A third feed means for relatively moving the holding means and the processing means; a first position detecting means for detecting a relative X-direction position between the holding means and the processing means; and the holding means. And a second position detecting means for detecting a relative Y-direction position between the processing means and a third position detecting means for detecting a relative Z-direction position between the holding means and the processing means. A plurality of workpieces held by the holding means A processing apparatus for processing based on each Z coordinate of the workpiece machining surface at the planned processing position,
The Z coordinate detection means is sequentially positioned by the first and second feeding means at a plurality of sampling positions on the workpiece which are set to be roughly dispersed from the plurality of machining scheduled positions, and the Z coordinate of the workpiece machining surface at each sampling position is obtained. A Z coordinate detection procedure for detection and storage in the storage means;
A calculation procedure for sequentially calculating the Z coordinate of the workpiece machining surface at each of the planned machining positions based on the stored Z coordinates at the plurality of sampling positions and the X and Y coordinates of each of the planned machining positions;
The first, second, and third feeding means are controlled based on the X, Y, and Z coordinates of the target machining position, and the holding means and the machining means are moved relative to each other. A machining control procedure for positioning the machining means at the intended machining position according to the second and third position detection means and machining the workpiece,
A program for machining a workpiece characterized by causing

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