JP2011240383A - Pulse laser-machining apparatus, shading correction apparatus, and pulse laser-machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse laser-machining apparatus which improves positioning accuracy of an irradiation spot to enable stable micromachining and increase machining speed, and effectively corrects shading caused in a scanning optical system.SOLUTION: The pulse laser-machining apparatus includes a reference clock oscillator circuit, a laser oscillator which emits a pulsed laser beam, a laser beam scanner, a stage on which a workpiece can be placed, a pulse picker which switches passage and blocking of the pulsed laser beam, a pulse picker controller which controls the pulse picker, a correction table storage unit for storing a correction table which defines a correlation between an image height and light quantity loss in the laser beam scanner, a machining pattern generation unit which generates a machining table in which a three-dimensional shape of the workpiece is expressed by the number of optical pulses of the pulsed laser beam using machining data which define the three-dimensional shape and the correction table. The pulse picker controller controls the pulse picker based on the machining table.

Description

  The present invention relates to a pulse laser processing apparatus, a shading correction apparatus, and a pulse laser processing method for processing a workpiece surface with a pulse laser beam.

  In recent years, flat panel displays (FPDs) such as liquid crystal panels, for example, have been required to have a member that has been subjected to high-precision microfabrication on a large area, for example, on the order of μm or less, with an increase in size. . Various studies have been made on microfabrication of large roll molds for sheet creation, molds having fine shapes for blind grooves and deep microlenses, difficult-to-cut materials, etc., which are difficult to produce by conventional machining.

  On the other hand, it is known that, for example, a fine pattern of 1 μm or less can be easily formed on a metal surface by ablation processing using an ultrashort pulse laser beam having a pulse width of the order of picoseconds (ps) or less. Until now, various methods have been proposed for techniques for processing the surface of a workpiece made of a polymer material containing a resin, a semiconductor material, a glass material, a metal material, and the like by this ultrashort pulse laser processing.

  In laser processing, there is a technique for finely processing a required region by scanning a laser beam with a laser beam scanner such as a galvanometer scanner (see, for example, Patent Document 1). According to the galvanometer scanner, the scanning speed can be improved as compared with the case of using the stage.

  However, in processing using a pulsed laser beam, the positioning accuracy of the irradiation spot is still insufficient, and it is difficult to realize stable micromachining of a large workpiece surface and its high speed.

  Further, in a processing apparatus using a laser beam scanner, shading with a scanning lens, that is, unevenness in the amount of light due to the beam irradiation position may be a problem. For example, in the case of a laser beam scanner using an fθ lens, the amount of laser beam may change depending on the image height (h) represented by the product of the focal length f and the incident angle θ. If the amount of light changes, even if the workpiece is scanned with the pulse laser beam in the same manner, there arises a problem that different processed shapes are obtained.

  The image height is a value that represents the image position as a distance from the optical axis on the evaluation surface of the optical system. In this specification, it means the distance from the optical axis of the condensing point position of the laser beam when the laser beam is scanned by the laser beam scanner.

  FIG. 15 is a diagram illustrating an example of the correlation between the image height h and the light amount of the scanning optical system. FIG. 16 shows a processed cross-sectional shape of the workpiece when the workpiece is processed by the scanning optical system having the characteristics shown in FIG.

  As shown in FIG. 15, the scanning optical system using the galvanometer mirror and the fθ lens exemplified here has a characteristic that the light amount loss increases as the absolute value of the image height h increases. In this case, as shown in FIG. 16, when the laser beam is scanned on the surface to be processed under uniform conditions, the processed cross-sectional shape that should ideally be indicated by the dotted line is actually due to the loss of light amount. In this case, the cross-sectional shape is as shown by the solid line.

  In order to solve this problem, conventionally, for example, attempts have been made to suppress the change in the amount of light due to the image height by devising the configuration of an fθ lens in which a plurality of lenses are combined.

Japanese Patent Laid-Open No. 2002-160086

  In view of the above circumstances, the present invention improves the positioning accuracy of the irradiation spot of the pulse laser beam, enables stable fine processing of the surface of a large workpiece and its speed increase, and shading generated in the scanning optical system. An object is to provide a pulse laser processing apparatus, a shading correction apparatus, and a pulse laser processing method that effectively correct.

  The pulse laser processing apparatus of one embodiment of the present invention includes a reference clock oscillation circuit that generates a clock signal, a laser oscillator that emits a pulse laser beam synchronized with the clock signal, and the pulse laser beam synchronized with the clock signal. A laser beam scanner that scans only in a one-dimensional direction, a stage on which a workpiece can be placed and moves in a direction perpendicular to the one-dimensional direction, and an optical path between the laser oscillator and the laser beam scanner A pulse picker that switches between passing and blocking the pulse laser beam in synchronization with the clock signal, a pulse picker control unit that controls the pulse picker, and a correlation between image height and light loss in the laser beam scanner. A correction table storage unit that stores a correction table to be processed, and a three-dimensional shape of the workpiece. A processing pattern generation unit that generates a processing table in which the three-dimensional shape is described by the number of optical pulses of the pulse laser beam using the processing data to be processed and the correction table, and the pulse picker control based on the processing table The unit controls the pulse picker.

  In the pulse laser processing apparatus of the above aspect, a measurement unit that measures a correlation between an image height and a light amount loss in the laser beam scanner, and a correction table generation unit that generates the correction table based on a result of the measurement unit, It is desirable to have.

  In the pulse laser processing apparatus of the above aspect, when the correction table generated outside the pulse laser processing apparatus is used for the correction table used in the processing pattern generation unit, the correction table generated by the correction table generation unit is It is desirable to further include a correction method selection unit that switches between use and non-use.

  In the pulse laser processing apparatus according to the above aspect, the processing pattern generation unit uses the processing data and the correction table to generate corrected processing data that defines the three-dimensional shape in which the correlation between the image height and the light amount loss is corrected. It is desirable to create and generate the machining table from the modified machining data.

  The pulse laser processing apparatus according to the above aspect includes a correction mechanism that corrects a processing origin position for each scan based on a scanning position signal from the laser beam scanner, and the correction mechanism uses the pulse based on the scanning position signal. It is desirable to control the passage and blocking of the pulsed laser beam in the picker.

  In the pulse laser processing apparatus according to the above aspect, it is preferable that the stage is controlled to move in a direction orthogonal to the one-dimensional direction based on a scanning position signal of the laser beam scanner.

  A shading correction apparatus according to one embodiment of the present invention includes a processing data input unit that inputs processing data that defines a three-dimensional shape of a workpiece, and an image height and light amount in a laser beam scanner of a pulse laser beam processing apparatus that has been acquired in advance. A correction table input unit for inputting a correction table for defining a correlation of loss, and a processing for generating a processing table in which the three-dimensional shape is described by the number of optical pulses of a pulsed laser beam using the processing data and the correction table It has a pattern generation unit.

  In the shading correction apparatus according to the aspect described above, the processing pattern generation unit uses the processing data and the correction table to create correction processing data that defines the three-dimensional shape in which the correlation between image height and light amount loss is corrected It is desirable to generate the machining table from the corrected machining data.

  In the pulse laser processing method of one embodiment of the present invention, a workpiece is placed on a stage, a clock signal is generated, a pulse laser beam synchronized with the clock signal is emitted, and the clock is applied to the surface of the workpiece. The pulse laser beam is scanned in a one-dimensional direction in synchronization with a signal, the pulse laser beam is scanned in the one-dimensional direction, the stage is moved in a direction orthogonal to the one-dimensional direction, and the clock is further moved. A pulse laser processing method for scanning the pulse laser beam in the one-dimensional direction in synchronization with a signal, wherein a correlation between an image height and a light amount loss in the laser beam scanner is evaluated in advance, and 3 of the workpiece is measured. The machining data defining the three-dimensional shape is corrected based on the correlation, and the three-dimensional shape is added by describing the number of optical pulses of the pulse laser beam. When a table is generated and the pulse laser beam is scanned in the one-dimensional direction, irradiation and non-irradiation of the pulse laser beam are performed in synchronization with the clock signal based on the number of optical pulses described in the processing table. It is characterized by switching.

  According to the present invention, the positioning accuracy of the irradiation spot of the pulse laser beam is improved, stable fine processing of the surface of a large workpiece and high speeding thereof are possible, and shading generated in the scanning optical system is effectively prevented. It is possible to provide a pulse laser processing apparatus, a shading correction apparatus, and a pulse laser processing method for correction.

It is a block diagram of the pulse laser processing apparatus of 1st Embodiment. It is explanatory drawing of the laser beam scanner of the pulse laser processing apparatus of 1st Embodiment. It is explanatory drawing of the scanning of the laser beam scanner of the pulse laser processing apparatus of 1st Embodiment. It is explanatory drawing of the process control part of the pulse laser processing apparatus of 1st Embodiment. It is explanatory drawing of the process pattern production | generation part of the pulse laser processing apparatus of 1st Embodiment. It is explanatory drawing of the process pattern signal generation part of the pulse laser processing apparatus of 1st Embodiment. It is a signal waveform diagram explaining the timing control of the laser processing apparatus of 1st Embodiment. It is a signal waveform diagram explaining timing control of the pulse picker operation of the pulse laser processing apparatus according to the first embodiment. It is a figure which shows the example of 1 process by the pulse laser processing apparatus of 1st Embodiment. It is a figure which shows the scanning of the specific one-dimensional direction in the process of FIG. It is a figure which shows the two-dimensional process about the specific layer in the process of FIG. It is a processing example of the metal mold | die formed by the manufacturing method of 2nd Embodiment. It is a block diagram of the pulse laser processing apparatus of 3rd Embodiment. It is a block diagram of the pulse laser processing apparatus of 4th Embodiment. It is a figure which shows an example of the correlation of the image height h of a scanning optical system, and light quantity. FIG. 16 is a processed cross-sectional shape of a workpiece when the workpiece is processed by a scanning optical system having characteristics as shown in FIG.

  Hereinafter, a pulse laser processing apparatus and a pulse laser processing method according to embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
The pulse laser processing apparatus of this embodiment includes a reference clock oscillation circuit that generates a clock signal, a laser oscillator that emits a pulse laser beam synchronized with the clock signal, and a one-dimensional pulse laser beam synchronized with the clock signal. A laser beam scanner that scans only in a direction, a stage that can place a workpiece and moves in a direction perpendicular to the one-dimensional direction, and an optical path between the laser oscillator and the laser beam scanner. A pulse picker that switches between passing and blocking of the pulse laser beam in synchronization and a pulse picker control unit that controls the pulse picker are provided. Furthermore, using the correction table storage unit that stores a correction table that defines the correlation between the image height and the light loss in the laser beam scanner, the processing data that defines the three-dimensional shape of the workpiece, and the correction table, the above 3 And a machining pattern generation unit that generates a machining table in which the dimensional shape is described by the number of light pulses of the pulse laser beam. Then, the pulse picker control unit controls the pulse picker based on the processing table.

  The pulse laser processing apparatus according to the present embodiment synchronizes the pulse of the laser oscillator, the scanning of the laser beam scanner, and the passage and blocking of the pulse laser beam directly or indirectly with the same clock signal. In this way, the positioning accuracy of the irradiation spot of the pulse laser beam is improved by maintaining the synchronization between the laser system and the beam scanning system.

  Further, it is possible to control the passage and blocking of the pulse laser beam based on the number of light pulses of the pulse laser beam. This facilitates the synchronization of the pulse of the laser oscillator, the scanning of the laser beam scanner, and the passage and blocking of the pulsed laser beam. Further, the configuration of the control circuit can be simplified. The pulse laser processing apparatus according to the present embodiment further improves the positioning accuracy of the irradiation spot of the pulse laser beam, and easily realizes stable fine processing of the surface of a large workpiece and its speed increase.

  Furthermore, it is possible to generate a processing table using the processing data and a correction table that defines the correlation between the image height and the light loss, and it is possible to effectively correct shading that occurs in the scanning optical system. .

  FIG. 1 is a configuration diagram of a pulse laser processing apparatus according to the present embodiment. The pulse laser processing apparatus 100 includes a laser oscillator 12, a pulse picker 14, a beam shaper 16, a laser beam scanner 18, an XY stage unit 20, a pulse picker control unit 22, and a processing control unit 24 as main components. . The processing control unit 24 includes a reference clock oscillation circuit 26 that generates a desired clock signal S1.

  Further, the processing control unit 24 stores a correction table storage unit 102 that stores a correction table that defines the correlation between the image height and the light loss in the laser beam scanner 18, and the correction table and processing data stored in the correction table storage unit 102. A processing pattern generation unit 40 is used to generate a processing table. The pulse laser processing apparatus 100 further includes a correction table input unit 106 for inputting a correction table generated outside the apparatus and a processing data input unit 108 for inputting processing data from outside the apparatus. Yes. The correction table input unit 106 and the processing table input unit 108 are readers such as a magnetic memory and a magnetic disk, for example.

  The laser oscillator 12 is configured to emit a pulsed laser beam PL1 synchronized with the clock signal S1 generated by the reference clock oscillation circuit 26. The laser oscillator 12 desirably oscillates a ps (picosecond) laser beam or fs (femtosecond) laser beam which is an ultrashort pulse.

  Here, the laser wavelength emitted from the laser oscillator 12 is selected in consideration of the light absorptivity, light reflectance, etc. of the workpiece. For example, in the case of a workpiece made of a metal material including Cu, Ni, difficult-to-cut material SKD11, or diamond-like carbon (DLC), use the second harmonic (wavelength: 532 nm) of an Nd: YAG laser. Is desirable.

  The pulse picker 14 is provided in the optical path between the laser oscillator 12 and the laser beam scanner 18. And it is comprised so that processing and non-processing of a workpiece (workpiece W) may be switched by switching passage and interception (on / off) of pulse laser beam PL1 synchronizing with clock signal S1. In this way, the pulse laser beam PL1 becomes the modulated pulse laser beam PL2 which is controlled to be turned on / off for processing the workpiece by the operation of the pulse picker 14.

  The pulse picker 14 is preferably composed of, for example, an acousto-optic element (AOM). Further, for example, a Raman diffraction type electro-optic element (EOM) may be used.

  The beam shaper 16 converts the incident pulse laser beam PL2 into a pulse laser beam PL3 shaped into a desired shape. For example, a beam expander that expands the beam diameter at a constant magnification. Further, for example, an optical element such as a homogenizer for making the light intensity distribution in the beam cross section uniform may be provided. Further, for example, an element that makes the beam cross section circular or an optical element that makes the beam circularly polarized light may be provided.

  The laser beam scanner 18 is configured to scan the pulsed laser beam PL4 only in the one-dimensional direction in synchronization with the clock signal S1. As described above, by scanning the pulse laser beam PL4 in synchronization with the clock signal S1, the positioning accuracy of the irradiation spot of the pulse laser beam is improved.

  In addition, it is possible to improve the positioning accuracy of the irradiation spot of the pulse laser beam by performing scanning only in the one-dimensional direction. This is because a laser beam scanner that scans in a two-dimensional direction is structurally deteriorated with respect to a laser beam scanner that scans only in a one-dimensional direction.

  As the laser beam scanner 18, for example, a galvanometer scanner provided with a uniaxial scan mirror can be cited. FIG. 2 is an explanatory diagram of a laser beam scanner using a galvanometer scanner.

  The galvanometer scanner has a uniaxial scan mirror 28, a galvanometer 30, and a laser beam scanner controller 32. Here, the galvanometer 30 is provided with a scanning mirror rotation drive mechanism such as servo control by feedback from the scanning angle sensor 36, for example.

  A scanning command signal S2 synchronized with the clock signal S1 is sent from the processing control unit 24. The galvanometer 30 is configured to be driven and controlled by a driving signal S3 from the laser beam scanner control unit 32 based on the scanning command signal S2. The galvanometer scanner scans the pulsed laser beam PL3 totally reflected by the uniaxial scanning mirror 28 according to the rotational movement (swinging) of the scanning mirror as shown by the arrow in FIG.

  The laser beam scanner 18 is provided with a scanning angle sensor 36. In the case of a galvanometer scanner, the rotation position of the single-axis scan mirror 28 is detected by a rotary encoder or the like. Then, the scanning angle sensor 36 sends the detected scanning angle detection signal S4 to the laser beam scanner control unit 32 and is used for driving control of the galvanometer 30. Further, the laser beam scanner control unit 32 transmits a scanning angle signal S5 to the processing control unit 24 based on the scanning angle detection signal S4.

  Then, the pulse laser beam PL3 reflected by the uniaxial scan mirror 28 passes through the fθ lens 34 and is scanned in a one-dimensional direction in parallel at a constant speed V, for example, a pulse laser beam PL4 having an image height H = fθ. It becomes. Then, the pulse laser beam PL4 is projected onto the workpiece W as irradiation pulse light for finely processing the surface of the workpiece W held on the XY stage unit 20.

  In addition to the galvanometer scanner, for example, a polygon scanner, a piezo scanner, a resonant scanner, or the like can be applied to the laser beam scanner 18.

  In any of the above laser beam scanners, it is important from the viewpoint of improving the processing accuracy that the laser beam scanner is configured to be controlled so as to ensure a constant scanning speed V within a processing range. FIG. 3 is a diagram for explaining scanning of the laser beam scanner of the pulse laser processing apparatus according to the present embodiment. As shown in FIG. 3, the position range corresponding to the scan end position from the scan start position in the scan angle range of the scan mirror includes an acceleration period, a stable region, and a deceleration period. In order to increase the processing accuracy, it is important that the apparatus is configured to control the scanning speed V to be constant within a stable range including the actual processing range.

  The XY stage unit 20 can place a workpiece (work) W, and can freely move in the XY direction including a direction orthogonal to the one-dimensional direction in which the pulse laser beam is scanned, its drive mechanism unit, For example, a position sensor having a laser interferometer for measuring the position of the XY stage is provided. Here, the XY stage can be moved continuously or stepped in a two-dimensional wide range, for example, a distance range in the X direction and Y direction of about 1 m. And it is comprised so that the positioning accuracy and movement error may become the high precision of the range of a submicron.

  The processing control unit 24 is configured by hardware such as a microcomputer (MCU), a microprocessor (MPU), a digital signal processor (DSP), a semiconductor memory, a circuit board, or the like including a semiconductor integrated circuit, or a combination of these hardware and software. It is configured. Integrated control of processing by pulse laser processing equipment.

  FIG. 4 is an explanatory diagram of a machining control unit of the pulse laser machining apparatus according to the present embodiment. The processing control unit 24 includes a laser system / beam scanning system control unit 36, a processing data setting unit 38, and a processing pattern generation unit 40.

  The laser system / beam scanning system control unit 36 controls a laser system such as the laser oscillator 12 and the pulse picker 14 and a beam scanning system such as the laser beam scanner 18. The laser system / beam scanning system control unit 36 generates a laser / beam condition setting unit 68 for setting conditions of the laser system and the beam scanning system, and a clock signal S1 for maintaining synchronization of the laser system and the beam scanning system. A reference clock oscillation circuit 26 is provided. Further, in order to maintain synchronization of the laser system and the beam scanning system, a phase synchronization processing circuit 42, a laser beam scanner control circuit 32, a synchronization position setting unit 44, a synchronization detection circuit 46, and the like are provided.

  The processing control unit 24 determines the movement timing of the XY stage unit 20 based on the scanning angle signal S5 that is a scanning position signal from the laser beam scanner 18, and generates a stage movement signal based on the two-dimensional processing data and the movement timing. To do. The scanning angle signal S5 in this case is from the scanning angle detection signal obtained by detecting the processing end position at which the processing described with reference to FIG. Then, the XY stage unit 20 operates as instructed by the stage movement signal.

  As described above, the movement of the XY stage unit in the direction orthogonal to the scanning direction of the laser beam scanner is controlled based on the scanning position signal of the laser beam scanner. As a result, the time to the next scanning is shortened, and further high speed of laser beam processing is realized.

  In the machining pattern generation unit 40, for example, the machining data input from the machining data input unit 108 is converted into parameter data in accordance with the actual machining. The machining data input from the machining data input unit 108 is data that defines the three-dimensional shape of the workpiece. For example, the designation of the three-dimensional shape, dimensions, the number of shapes, the arrangement, the material name of the workpiece, It consists of dimensions.

  FIG. 5 is an explanatory diagram of a machining pattern generation unit of the pulse laser machining apparatus according to the present embodiment. The processing pattern generation unit 40 uses the input processing data and correction table to generate correction processing data that defines three-dimensional shape data in which the correlation between image height and light amount loss is corrected. Is provided.

  And the process data analysis part 48 which analyzes correction process data is provided. In addition, a table generation unit 49 that generates a processing table and a stage movement table based on the analysis by the processing data analysis unit 48 is provided. The processing table describes the standby length, processing length, and non-processing length of the three-dimensional shape of the workpiece based on the number of light pulses of the pulse laser beam. In other words, the machining table generation unit 49 generates a pulse picker machining table based on the machining length and non-machining length of the corrected machining data and the spot diameter of the pulse laser beam. The stage movement table describes the movement distance of the XY stage unit and the like for the three-dimensional shape of the workpiece. In the present embodiment, the processing table includes a pulse picker processing table and a stage moving table.

  Moreover, the process pattern production | generation part 40 is provided with the pulse picker process table part 50 provided with a pulse picker process table. Moreover, the stage movement table part 52 provided with a stage movement table is provided.

  The machining pattern generation unit 40 includes a machining origin (SYNC) register 54 (hereinafter also simply referred to as a machining origin register) to which information regarding the machining origin output from the pulse picker machining table unit 50 is input. Further, a standby length output from the pulse picker processing table unit 50, a standby length register 56 to which information on processing length and non-processing length is input, a processing length register 58, and a non-processing length register 60 are provided.

  The machining pattern signal generation unit 62 receives values of the machining origin register 54, the standby length register 56, the machining length register 58, and the non-machining length register 60, and is sent to the pulse picker control unit 22. The movement signal generation unit 64 is configured to generate a stage movement signal S15 based on the data from the stage movement table unit 52 and output it to the stage control unit 66.

  The data generated by the processing pattern generation unit 40 is also output to the laser system / beam scanning system control unit 36, and is used for maintaining synchronization between the laser system and the beam scanning system.

  FIG. 6 is an explanatory diagram of a machining pattern signal generation unit of the pulse laser machining apparatus according to the present embodiment. The machining pattern signal generation unit 62 includes a machining origin counter 70, a standby length counter 72, a machining length counter 74, and a non-machining length counter 76. These counters are configured to start counting in response to a counter control signal S8 output from the timing forming circuit 88.

  Further, a machining origin comparator 80, a standby length comparator 82, a machining length comparator 84, and a non-machining length comparator 86 having a function of comparing values of the register and the counter are provided. These comparators are configured to output coincidence signals a to d to the timing forming circuit 88 when the values of the register and the counter coincide.

  The timing forming circuit 88 is configured to output an output control signal S10 to the processing pattern output circuit 90 based on the input synchronization detection signal S9, coincidence signals a to d, and the scanning end code.

  The machining pattern output circuit 90 is configured to generate a machining pattern signal S7 based on the output from the machining length comparator 84 and the output control signal S10 from the timing forming circuit 88.

  In this embodiment, it is desirable to have a correction mechanism for correcting the processing origin position for each scan based on the scan position signal (scan angle signal) from the laser beam scanner. This is because by having this correction mechanism, variations in scanning speed during the acceleration period of the laser scanner for each scan (see FIG. 3) are compensated, and processing with higher accuracy becomes possible.

  Next, a pulse laser processing method using the pulse laser processing apparatus 100 will be described. In this pulse laser processing method, a workpiece is placed on a stage, a clock signal is generated, a pulse laser beam synchronized with the clock signal is emitted, and a pulse laser is synchronized with the clock signal on the surface of the workpiece. The beam is scanned in the one-dimensional direction, the pulse laser beam is scanned in the one-dimensional direction, the stage is moved in the direction orthogonal to the one-dimensional direction, and the pulse laser beam is further synchronized with the clock signal in the one-dimensional direction. To scan. Then, the correlation between the image height and the light loss in the laser beam scanner is evaluated in advance, the processing data including the three-dimensional shape data of the processing pattern of the workpiece is corrected based on the above correlation, and the processing pattern is converted into a pulse laser. A processing table described by the number of light pulses of the beam is generated. Then, when scanning the pulse laser beam in a one-dimensional direction, irradiation and non-irradiation of the pulse laser beam are switched in synchronization with the clock signal based on the number of optical pulses described in the processing table.

  FIG. 7 is a signal waveform diagram illustrating timing control of the pulse laser processing apparatus according to the present embodiment. When machining the workpiece W placed on the stage, the laser oscillator 12 operates autonomously with the majority of laser oscillation controlled by a built-in control unit. However, as shown in FIG. 7A, the pulse oscillation timing is controlled by the clock signal S1 having the period Tp generated by the reference clock oscillation circuit, and the pulse laser beam PL1 having the period Tp synchronized with the clock signal S1. Is emitted.

  The laser beam scanner 18 starts scanning at the scanning start position (scanning origin) shown in FIG. 6 based on the scanning start signal S11. At this time, as shown in FIG. 7A, the laser beam scanner 18 is instructed by a scan command signal S2 having a cycle Ts generated by the processing control unit 24 in synchronization with the rising edge (or falling edge) of the clock signal S1. Receive. The laser beam scanner control unit 32 controls driving of the galvanometer 30 based on the scanning command signal S2.

  As described above, the laser beam scanner 18 scans the pulse laser beam in the one-dimensional direction in synchronization with the clock signal S1. At this time, a pattern is processed on the surface of the workpiece W by switching between irradiation and non-irradiation of the pulse laser beam. Note that the scan command signal S2 conforms to the XY2-100 protocol, and follows an absolute scan angle command based on the position of the scan angle “0 degree” of the galvanometer 30 at, for example, 100 kHz (Ts = 10 μsec).

  FIG. 7A shows a clock signal at the start of scanning when the oscillation frequency of the pulse laser beam is 500 kHz (Tp = 2 μsec), the beam diameter of the pulse laser beam is 16 μm, and the scanning speed V is 4000 mm / sec. An example of the scan command signal S2 synchronized with the rising edge of S1 is shown.

  After scanning the pulse laser beam in the one-dimensional direction, the stage is moved in a direction orthogonal to the one-dimensional direction, and the pulse laser beam is scanned in the one-dimensional direction in synchronization with the clock signal. In this way, the scanning of the pulse laser beam in the one-dimensional direction and the movement of the stage are alternately performed in the direction orthogonal to the one-dimensional direction.

  Here, the scanning angle signal (scanning position signal) S5 from the laser beam scanner 18 indicates the movement timing of the XY stage unit. Assuming that the one-dimensional scanning direction of the laser beam scanner 18 is the X-axis direction, step movement or continuous movement of a predetermined width in the Y-axis direction is performed according to the movement timing. Thereafter, the pulse laser beam is scanned in the X direction.

  Here, in the acceleration period of FIG. 3, the laser beam scanner 18 is controlled by the scanning command signal S2 so that the scanning speed becomes a stable scanning speed V at an early stage. It is empirically clear that the reproducibility of the scanning angle of the uniaxial scanning mirror 28 under the optimum condition is about 10 μrad / pp in the stable region. This value becomes a scanning position reproducibility of 1 μm / pp when an fθ lens having a focal length of 100 mm is used.

  However, the repeated stability of the scanning speed V during the acceleration period deteriorates to about 10 times in the long-term scanning. For this reason, the position of the processing origin in FIG. 3 may vary from scan to scan.

  Therefore, the processing origin position for each scanning is corrected based on the scanning position signal (scanning angle signal) from the laser beam scanner by the correction mechanism described above. For example, a synchronization angle (θsy) for synchronizing the oscillation of the pulsed laser beam PL1 and the beam scanning is set in a sufficiently stable region after the acceleration period ends. The scanning angle range until reaching a sufficiently stable region is, for example, about 2.3 degrees to 3.4 degrees when an fθ lens having an acceleration period of 1 msec to 1.5 msec and a focal length of 100 mm is used.

Then, as shown in FIG. 7B, the scanning angle sensor 36 detects this synchronization angle. Then, a phase difference θi between the scan command signal S2 corresponding to the scanning angle theta ₀ from the scanning start position in detecting the synchronization angle. Then, based on this phase difference θ _i , the distance to the processing origin with respect to the scanning command signal S2 is corrected.

As the correction value of the distance to the processing origin, the first scanning (i = 1) at the time of processing is stored as a reference correction value. Then, each time scanning from the n-th scanning start position where i = n thereafter, the difference between the phase difference θ _n and the phase difference θ ₁ is processed for the scanning command signal S2 for the first scanning of the n-th scanning. The distance correction value to the origin is used. The determined distance correction value, the scanning command signal to the scanning angle theta ₀ from the scanning start position: By giving the (S2 absolute scanning angle command) after the scanning command signal (S2), machining origin position is corrected. In this way, even if the scanning speed varies during the acceleration period of the laser beam scanner 18, it is possible to match the processing origin positions during the first scan and the n-th scan.

  As described above, after scanning the pulse laser beam in the one-dimensional direction, the stage is moved in the direction orthogonal to the one-dimensional direction, and the pulse laser beam is further moved in the one-dimensional direction in synchronization with the clock signal S1. In the case of scanning, the machining origin position for each scan is matched, and the machining accuracy is improved.

  When the laser beam scanner 18 is composed of the galvanometer scanner described in FIG. 2, the scanner clock signal drives the servo control motor as a drive signal from the laser beam scanner control unit 32. However, the laser beam scanner 18 may have a phase shift due to its autonomous operation. Therefore, the synchronization angle detection signal that becomes the scanning position signal generated every time the scanning operation is repeated synchronizes the passage / blocking of the oscillation pulse light with the scanning operation of the beam, that is, the timing is adjusted, so that the laser is extremely stable. Processing becomes possible.

  Specifically, for example, the correction mechanism controls passage and blocking of the pulse laser beam in the pulse picker based on the scanning position signal (scanning angle signal). That is, the timing of the driving signal of the pulse picker is designated based on the phase difference detected from the scanning position signal for detecting the synchronous position (angle) of the rotational position of the scanning mirror. Thereby, the processing origin position for each scan of the pulse laser beam is corrected.

  Alternatively, for example, the correction mechanism gives a distance correction value obtained from the phase difference detected from the scanning position signal to the scanning command signal after the scanning command signal to the laser beam scanner for θo at the scanning angle from the scanning start position. Thus, the processing origin position for each scan of the pulse laser beam is corrected.

  When the pulse laser beam is scanned in the one-dimensional direction, irradiation and non-irradiation of the pulse laser beam are switched in synchronization with the clock signal S1 based on the number of light pulses of the pulse laser beam. Irradiation and non-irradiation of the pulse laser beam are performed using a pulse picker.

As shown in FIG.
S _L : Distance from synchronous angle detection position to workpiece W _L : Work length W ₁ : Distance from workpiece edge to machining origin W ₂ : Machining range W ₃ : Distance from machining end to workpiece edge.

here,
Machining origin = synchronous angle detection position + S _L + W ₁
Next, the workpiece to be placed in a fixed position on the stage, S _L becomes a fixed distance. Furthermore, the machining origin on the workpiece with the synchronization angle detection position as a reference (hereinafter also referred to as machining origin (SYNC)) is
Machining origin (SYNC) = S _L + W ₁
It becomes. The processing origin (SYNC) is managed by performing the correction as described above, and processing is always started from a stable position for each scan. Note that, as shown in FIG. 3, the actual machining is performed in a range that falls within the machining range (W ₂ ).

For example, when scanning is performed under the processing conditions of the beam spot diameter D (μm) and the beam frequency F (kHz), the processing speed: V (m / sec) shifts the irradiation position of the beam by 1 / n of the spot diameter. If
V = D × 10 ⁻⁶ × F × 10 ³ / n
It becomes.

When processing is performed by controlling the light pulse with the pulse picker, the pulse picker drive signal S6 created by the pulse picker defines the actual processing region by the processing length and the repetitive processing pitch by the non-processing length. Is possible. Here, assuming that the machining length is L ₁ and the non-machining length is L ₂ , the machining length register setting is based on the number of light pulses of the pulse laser beam.
Number of machining pulses = (L ₁ / (D / n)) − 1
Non-processing length register setting is
Number of non-machined pulses = (L ₂ / (D / n)) + 1
It can be.

Moreover, the start position for each machining shape is set by defining the position where machining is actually started from the machining origin (SYNC) as the standby length. Here, when the waiting length and _{L W,} machining origin (SYNC) register settings,
Processing origin (SYNC) number of light pulses = (S _L + W ₁ ) / (D / n)
The standby length register setting is
Standby light pulse count = L _W / (D / n)
It can be.

  Note that the set values in each register for the machining length, non-machining length, standby length, and machining origin (SYNC) are the number of optical pulses corresponding to each. The number of light pulses is a value that takes into account the number of light pulses for correction determined in advance based on the beam profile to be used.

  The register setting value is managed by the number of light pulses to be emitted. Further, the processing standby section after the synchronization angle detection is also managed by the number of light pulses. By managing the pulse picker by the number of optical pulses in this way, synchronization between the reference clock signal S1 and the pulse picker can be easily maintained, and stable repeatability is maintained. By maintaining the synchronization between the clock signal S1 and the pulse picker 14, highly accurate laser processing can be easily realized.

  FIG. 8 is a signal waveform diagram for explaining timing control of the pulse picker operation of the pulse laser processing apparatus according to the present embodiment. The machining pattern signal S7 generated from the machining data and managed by the number of light pulses is output from the machining pattern output circuit 62 of the machining pattern signal generation unit 40.

As shown in FIG. 8, the pulsed laser beam was t ₁ delayed from the clock signal S1 periods Tp (PL1) is cut off / passage is controlled based on the pulse picker drive signal S6. The scanning of the laser beam scanner 18 is synchronized with the blocking / passing of the pulse laser beam by synchronizing the generation timing of the scanning angle command signal (S2) with the clock signal (S1).

For example, the pulse picker driving signal S6 samples the processing pattern signal S7 at the rising edge of the clock signal S1. Then, it rises with a delay from the rise of one clock of the clock signal S1 t ₂ hours. After the number of clocks corresponding to the number of desired pulses, the state of machining pattern signal S7 becomes inactive sampled at the rising edge of the clock signal S1, it falls with a delay t ₃ hours.

By this pulse picker driving signal S6, the operation of the pulse pickers 14 occurs after a delay time t ₄ and t ₅ elapses. By the operation of the pulse picker 14, the pulse laser beam (PL1) is extracted as a modulated pulse laser beam (PL2).

  Here, the correlation between the image height and the light loss in the laser beam scanner is evaluated, the machining data defining the three-dimensional shape of the workpiece is corrected based on this correlation, and the three-dimensional shape of the workpiece is pulsed. A method for generating a processing table described by the number of light pulses of a laser beam will be described.

  In the present embodiment, the workpiece is scanned and processed with a laser beam scanner under the same conditions using a laser beam scanner, and the processing depth is measured to evaluate the correlation between the image height and the light loss.

As described above, when scanning is performed under the processing conditions of the beam spot diameter D (μm) and the beam frequency F (kHz), the processing speed: V (m / sec) is irradiated with the beam by 1 / n of the spot diameter. When shifting the position,
V = D × 10 ⁻⁶ × F × 10 ³ / n
It becomes.

  Here, for example, when processing is performed on Cu, if the operation is performed under the processing conditions of the beam spot diameter D = 15 μm, the repetition frequency F = 500 kHz, and the beam irradiation movement ratio n = 2, the processing speed V is V = 3. .75 m / sec. When the workpiece feed unit in the Y-axis direction is 7.5 μm and the irradiation pulse energy is 1 μJ / pulse, a machining depth of 0.1 μm is obtained as a result of actual machining.

  For example, as shown in FIG. 15, the light amount loss of a laser beam scanner constituted by an fθ scanning optical system has the smallest image height: h = 0 and the largest image height: h = ± Lmax. Then, for example, when processing is performed with the number of scans n = 200 while the height of the stage in the Z direction is fixed under the above conditions, the processing depth: Dp = 20 μm is obtained at the image height: h = 0. can get.

  At this time, as shown in FIG. 15, the loss of light quantity depends on the image height, so that it becomes deepest at the center (image height: h = 0) that coincides with the optical axis of the scanning optical system as shown by the solid line in FIG. Image height: It becomes the shallowest at the end where h = ± Lmax. Therefore, the processing depth with respect to the image height of the processing shape is measured using a known depth measuring means.

  For example, if the light loss at image height: h = ± Lmax is set to 10%, the processing depth: Dp = 20 μm, h = 0 and the processing at h = ± Lmax have a maximum difference of 2 μm. Will occur.

A correction table for shading correction (hereinafter also referred to as a shading correction table) is generated from the processing depth with respect to the measured image height of the processed shape. The shading correction table is composed of the following correction coefficients. Here, the suffix h is the image height position.
Correction coefficient at each image height position: Rh
Machining depth at h = 0 (maximum value): Dp0
Processing depth at each image height position: Dph
Then,
Rh = Dp0 / Dph
Here, if the required machining accuracy is ± 0.2 μm, the machining depth loss distribution displacement point may be 0.2 μm, so Dph is 20 points (h = −10 to −1, +1 to +10). It becomes. As a result, the shading correction table is created in the form shown in Table 1, for example.

  In addition, when a change in the material of the workpiece or a change in required machining accuracy occurs, a change in machining conditions such as irradiation pulse energy, scanning speed, and stage feed amount occurs. In that case, the shading correction table may be changed by grasping in advance the processing amount at the image height: h = 0 according to each processing condition.

  In order to facilitate the creation of corrected machining data in the later machining pattern generation unit 40, the shading correction intermediate in which the distance from the machining origin in the shading correction table is converted into the number of light pulses of the pulse laser of the laser machining apparatus. It is desirable to edit the table.

  Here, the processing data that defines the three-dimensional shape of the workpiece includes, for example, designation of the three-dimensional shape, dimensions, the number of shapes, an arrangement position, a workpiece material name, a workpiece dimension, and the like. For the machining data, the machining data correction unit 110 of the machining pattern generation unit 40 forms correction machining data using the correction table. Also for the machining data, in order to facilitate the creation of the corrected machining data, the distance from the machining origin of the three-dimensional shape of the workpiece may be defined by the number of light pulses of the pulse laser of the laser machining apparatus. desirable.

  In the correction by the processing data correction unit 110 (FIG. 5), for example, with reference to the shading correction intermediate table, processing depth correction processing for the beam scanning direction component is performed on the three-dimensional shape of the processing data. This correction calculation processing is based on taking the product of the Z-axis direction component (depth direction component) and the correction coefficient of the shading correction intermediate table. By this correction calculation processing, corrected processing data that defines the three-dimensional shape of the workpiece in which the correlation between the image height and the light loss is corrected is created. In the case of the present embodiment, the three-dimensional shape of the modified data is such that the depth of the central portion (h = 0) is the shallowest and the depth of the end portion (h = ± Lmax) is the deepest. It will be prescribed.

  Next, the modified machining data is analyzed by the machining data analysis unit 48. The processing amount of the unit light pulse can be obtained empirically from conditions such as the operation of the laser oscillator used for processing, the irradiation pulse energy, which is the beam scanning condition, the beam spot diameter, the repetition frequency, the scanning speed, and the stage feed amount. .

  Based on the above conditions, the three-dimensional shape is further decomposed into two-dimensional layers, and converted into two-dimensional data using bitmap data for each layer. This two-dimensional data is converted into operation data (number of machining pulses, number of non-machining pulses, number of standby length pulses) of the pulse picker 14.

  For example, as described above, when processing a Cu material, if the operation is performed under the processing conditions of a beam spot diameter D = 15 μm, a repetition frequency F = 500 kHz, and a beam irradiation movement ratio n = 2, the processing speed V is V = 3.75 m / sec. If the irradiation pulse energy is 1 μJ / pulse, the processing depth per pulse is 0.1 μm. Therefore, the layer decomposition width of the processed shape may be set to 0.1 μm. The number of layers decomposed in this way is referred to as a layer number Rn. About the above conditions, it is possible to change suitably according to processing time and the required processing quality.

  Next, pulse picker operation data for each layer, that is, the number of machining pulses, the number of non-machining pulses, and the number of standby length pulses will be described. FIG. 9 is a diagram showing an example of processing by the pulse laser processing apparatus of the embodiment. FIG. 10 is a diagram showing scanning in a specific one-dimensional direction in the processing of FIG. FIG. 11 is a diagram showing two-dimensional processing for a specific layer in the processing of FIG.

As shown in FIG. 9, for example, LX ₁ (horizontal) × LY ₁ (vertical) × Dp (depth), specifically, for example, a pocket of 52.5 μm × 37.5 μm × 0.1 Rn μm It is formed at the top nine locations. In this machining example, the machining direction of LX ₁ and the non-machining length of LX ₂ are performed in the X direction that is the beam scanning direction, and the machining length of LY ₁ is performed in the Y direction that is the stage moving direction. _2. Processing of non-processed length of LY ₃ is performed.

FIG. 10 shows one-dimensional scanning of one line in the region corresponding to LY ₁ in the Y direction. S _L + W ₁ from the sync angle detection position, the number of light pulses is (S _L + W ₁ ) / (D / n) Lw based on the processing origin (SYNC) separated by (D / n), and the number of light pulses is L _W / (D / The workpiece is irradiated with a pulsed laser beam with a waiting length of n). The irradiation with the number of light pulses _{(LX 1 / (D / n} )) - 1. Thereafter, the number of light pulses is not irradiated for (LX ₂ / (D / n)) + 1, and irradiation and non-irradiation controlled by the number of light pulses are repeated in the same scan.

  When the line scan in the specific X direction is completed by the laser beam scanner 18 scanned only in the one-dimensional direction, the stage is moved in the Y direction orthogonal to the X direction, and further the X direction scan is performed by the laser beam scanner 18. I do. That is, the workpiece is processed by alternately repeating the scanning in the one-dimensional direction of the pulse laser beam by the laser beam scanner 18 and the movement of the stage in the direction orthogonal to the one-dimensional direction following the scanning.

  In this way, two-dimensional processing for a specific layer as shown in FIG. 11 is performed. Further, another layer generated by layer decomposition is subjected to two-dimensional processing by the same method as shown in FIG. Such processing for each layer is repeated to finally complete the three-dimensional pocket processing as shown in FIG.

  Next, the operation of the machining control unit 24 will be described in detail with reference to FIGS. 5 and 6. In the machining pattern generation unit 40 in the machining control unit 24, when the synchronization detection signal S <b> 9 generated when the synchronization detection is performed by the phase synchronization circuit 42 is input to the timing forming circuit 88, the table is sent to the pulse picker machining table unit 50. The selection signal S13 “machining origin (SYNC)” is output. Then, information on the machining origin is output from the pulse picker machining table unit 50 and loaded into the machining origin register 54. At the same time, the machining origin (SYNC) counter 70 (hereinafter also simply referred to as a machining origin counter) starts counting the clock signal S1.

  The comparator control signal S14 enables a machining origin (SYNC) comparator 80 (hereinafter also simply referred to as a machining origin comparator), and compares the value of the machining origin counter 70 with the value of the machining origin register 54. When they match, the machining origin comparator 80 outputs a coincidence signal a to the timing forming circuit 88. At this time, the pulse laser beam is scanned to the processing origin position.

  Next, the timing forming circuit 88 outputs a counter control signal S8 and stops the counting of the machining origin counter 70. Then, the table selection signal S13 “standby length” is output from the timing forming circuit 88 to the pulse picker processing table unit 50. Standby length information is output from the pulse picker processing table section 50 and loaded into the standby length register 56. At the same time, the standby length counter 72 starts counting the clock signal S1 by the counter control signal S8.

  The comparator control signal S14 enables the standby length comparator 82, and compares the value of the standby length counter 72 with the value of the standby length register 56. If they match, the standby length comparator 82 outputs a match signal b to the timing forming circuit 88. At this time, the pulse laser beam is scanned to the actual machining start position.

  Next, the timing formation circuit 88 outputs a counter control signal S8 and stops the counting of the standby length counter 72. Then, the table selection signal S13 “machining length” is output from the timing forming circuit 88 to the pulse picker machining table unit 50. Processing length information is output from the pulse picker processing table unit 50 and loaded into the processing length register 58. At the same time, the machining length counter 74 starts counting the clock signal S1 by the counter control signal S8.

  The comparator control signal S14 enables the machining length comparator 84 and compares the value of the machining length counter 74 with the value of the machining length register 58. When they match, the machining length comparator 84 outputs a coincidence signal c to the timing forming circuit 88. At this time, the pulsed laser beam is scanned to the position where the processing is completed.

  Next, the timing forming circuit 88 outputs a counter control signal S8, and stops counting of the machining length counter 74. Then, the table selection signal S13 “non-processing length” is output from the timing forming circuit 88 to the pulse picker processing table unit 50. Information on the non-machining length is output from the pulse picker machining table unit 50 and loaded into the non-machining length register 60. At the same time, the non-machining length counter 76 starts counting the clock signal S1 by the counter control signal S8.

  The comparator control signal S14 enables the non-machining length comparator 86 and compares the value of the non-machining length counter 76 with the value of the non-machining length register 60. When they match, the non-machining length comparator 86 outputs a coincidence signal d to the timing forming circuit 88. At this time, the pulse laser beam is scanned to the non-processed end. Then, scanning is performed up to one light pulse before the position at which actual machining is started.

  Next, the timing forming circuit 88 outputs a counter control signal S8 and stops the counting of the non-machining length counter 76. Then, the table selection signal S13 “machining length” is output from the timing forming circuit 88 to the pulse picker machining table unit 50. Processing length information is output from the pulse picker processing table unit 50 and loaded into the processing length register 58. At the same time, the machining length counter 74 starts counting the clock signal S1 by the counter control signal S8.

  The comparator control signal S14 enables the machining length comparator 84 and compares the value of the machining length counter 74 with the value of the machining length register 58. When they match, the machining length comparator 84 outputs a coincidence signal c to the timing forming circuit 88. At this time, the pulsed laser beam is scanned to the position where the processing is completed.

  Next, the timing forming circuit 88 outputs a counter control signal S8, and stops counting of the machining length counter 74. Then, the table selection signal S13 “non-processing length” is output from the timing forming circuit 88 to the pulse picker processing table unit 50. Information on the non-machining length is output from the pulse picker machining table unit 50 and loaded into the non-machining length register 60. At the same time, the non-machining length counter 76 starts counting the clock signal S1 by the counter control signal S8.

  The comparator control signal S14 enables the non-machining length comparator 86 and compares the value of the non-machining length counter 76 with the value of the non-machining length register 60. When they match, the non-machining length comparator 86 outputs a coincidence signal d to the timing forming circuit 88. At this time, the pulse laser beam is scanned to the non-processed end. Then, scanning is performed up to one light pulse before the position at which actual machining is started.

  In the above process, the machining pattern output circuit 90 recognizes the machining execution period according to the output of the machining length comparator 84, and further outputs the machining pattern signal S7 by the output control signal S10 from the timing forming circuit 88. The timing control of the pulse picker operation based on the machining pattern signal S7 is as shown in FIG.

  As described above, the processing pattern generation unit 40 performs one-dimensional scanning of the pulse laser beam as shown in FIG. 10 according to the pulse picker processing table provided in the pulse picker processing table unit 50. The pulse picker processing table unit 50 is provided with a scanning end code, and is output to the timing forming circuit 88 after the end of the specific beam scanning.

  When the timing forming circuit 88 recognizes the scanning end code, stage movement is performed, the stage movement amount is read from the stage movement table unit 52, and the stage movement amount and stage movement are transferred from the movement signal generation unit 64 to the stage control unit 66. A stage movement signal S15 including a start command is output. By moving to the stage moving process, it is recognized that the processing of the line has been completed.

  When the stage movement in the direction orthogonal to the line scan is completed and the preparation for the next line beam scan is completed, the next line beam scan is started. Processing by one-dimensional beam scanning is performed according to the same process as described above. When the predetermined number of beam scans and stage movements are finished, the processing of the two-dimensional layer is finished.

  The determination of the processing end of the two-dimensional layer is performed based on the movement end code provided in the stage movement table unit 52. When the movement end code is confirmed, the stage is controlled to move to the first line.

  As described above, beam scanning and stage movement are performed according to the data of the “pulse picker processing table” and “stage movement table”, and processing of each layer is executed. Then, a predetermined number of layers given by Rn is processed.

Table 2 is an example of the processing table of the embodiment. Although a table for one layer is shown here, when the processing data (or correction processing data) is decomposed into a plurality of layers, information of the same format is provided for each layer. Table 2 is an example in which the pulse picker processing table and the stage movement table are described in the same table. In Table 2, the standby length, processing length, and non-processing length are described in terms of the number of light pulses. Note that the pulse picker processing table and the stage movement table may exist as separate tables.

  As described above, according to the present embodiment, it is possible to perform stable fine processing of a large-sized workpiece surface and increase the speed thereof.

  Further, a processing table can be generated using a correction table that defines the correlation between the processing data, the image height, and the light loss. For this reason, it is possible to effectively correct the shading generated in the scanning optical system by generating an appropriate processing table without adjusting the amount of light loss to be minimized by the lens configuration of the scanning optical system. It becomes. In addition, for example, even if a temporal change occurs in the correlation between the image height of the scanning optical system and the light loss, an appropriate shading correction can be performed by newly creating a shading correction table and inputting it to the pulse laser processing apparatus. Can be done.

(Second Embodiment)
The present embodiment is a microlens mold manufacturing method using the pulse laser processing apparatus and pulse laser processing method of the first embodiment, a microlens mold manufactured using the same, and this This is a method of manufacturing a microlens using a microlens mold.

  For example, a microlens used for a flat panel display is required to have a large area and high processing accuracy. Therefore, when manufacturing this microlens using a metal mold, the metal mold inevitably requires a large area and high processing accuracy. FIG. 12 shows an example of processing a mold formed by the manufacturing method of the present embodiment.

  As shown in FIG. 12, for example, dimples having a diameter R and a depth Dp are formed at nine locations with a spacing I on a Cu workpiece. Laser processing is performed in the same manner as in the first embodiment. By using a table conforming to the three-dimensional shape of FIG. 12 as the processing table, the processing of FIG. 12 can be realized. According to the present embodiment, it is possible to manufacture a microlens mold having a large area and high accuracy.

  The microlens mold is useful for manufacturing a large-area and high-precision microlens. According to the microlens manufacturing method using this microlens mold, it is possible to manufacture a large-area and high-precision microlens.

(Third embodiment)
The pulse laser processing apparatus according to the present embodiment includes a measurement unit that measures the correlation between the image height and the light amount loss in the laser beam scanner, and a correction table generation unit that generates a shading correction table based on the result of the measurement unit. In the first embodiment, the mode in which the correlation between the image height and the light amount loss is acquired by actually performing the processing has been described. In the present embodiment, the correlation is acquired by providing a measurement unit that measures the amount of light of the pulse laser in the pulse laser processing apparatus. Hereinafter, description of contents overlapping with those of the first embodiment will be omitted.

  FIG. 13 is a configuration diagram of the pulse laser processing apparatus according to the present embodiment. The pulse laser processing apparatus 200 includes a measurement unit 122 that measures the correlation between the image height and the light amount loss in the laser beam scanner 18. As the measuring unit 122, for example, a measuring device in which photodiodes are arranged in an array in the scanning direction of the laser beam scanner 18 can be applied.

  In addition, the pulse laser processing apparatus 200 includes a correction table generation unit 124 that generates a shading correction table based on the result of the measurement unit 122. The shading correction table generated by the correction table generation unit 124 is input to the correction table storage unit 102 of the processing control unit 24.

  The configuration other than the generation of the shading correction table by the correction table generation unit 124 based on the result of the measurement unit 122 is the same as that of the first embodiment.

  According to the present embodiment, the shading correction table can be easily generated by the measurement unit 122 and the correction table unit 124 provided in the pulse laser processing apparatus 200. Therefore, the correlation between the image height and the light amount loss in the laser beam scanner can be evaluated in a short time. Therefore, even when the correlation between the image height and the light loss in the scanning optical system is expected to be changed, the shading correction table can be easily re-created, and shading can be corrected more effectively. Become.

(Fourth embodiment)
The pulse laser processing apparatus according to the present embodiment uses a correction table generated outside the pulse laser processing apparatus and a correction table generated by the correction table generation section as a correction table used by the processing pattern generation section. A correction method selection unit for switching between the case and the case. Hereinafter, the description overlapping with the first to third embodiments is omitted.

  FIG. 14 is a configuration diagram of the pulse laser processing apparatus according to the present embodiment. As in the second embodiment, the pulse laser processing apparatus 300 includes a measuring unit 122 and a correction table generating unit 124. Moreover, the correction table input part 106 is provided similarly to 1st Embodiment.

  Further, regarding a correction table used in the processing pattern generation unit, a correction method selection for switching between using a correction table generated outside the pulse laser processing apparatus and using a correction table generated by the correction table generation unit 124 is used. Part 130 is provided.

  The correction method selection unit is configured by hardware or a combination of hardware and software, and the correction data input unit 106 generates a correction table generated outside the pulse laser processing apparatus by a selection signal input from a keyboard terminal or the like. Switching between reading and using or using a correction table measured by the measuring unit 122 and created by the correction table generating unit 124 is performed.

As described above, the laser processing apparatus 300 according to the present embodiment includes the correction method selection unit 130, so that the correction table to be used can be easily switched. Therefore,
It is possible to select an optimal correction table according to the status of the laser oscillator and the scanning optical system, the workpiece, and the like, and it is possible to perform more effective shading correction.

(Fifth embodiment)
In the pulse laser processing apparatus of this embodiment, when the processing pattern is generated by the processing pattern generation unit 40 (FIG. 1), the three-dimensional shape is temporarily converted into a pulse laser beam light by using the input processing data. A temporary machining table described by the number of pulses is generated. Thereafter, a processing table is generated using the provisional processing table and the correction table. Except for this point, the second embodiment is the same as the first embodiment, and thus description of the overlapping contents is omitted.

  In the present embodiment, a temporary machining table is first generated in which the three-dimensional shape of the machining data of the workpiece is described by the number of optical pulses of the pulse laser beam. This provisional processing table is assumed to have been processed up to the layer decomposition processing as in the final processing table.

  Thereafter, for example, a final processing table is generated using the shading intermediate correction table described in the first embodiment and the provisional processing table. Specifically, the number of irradiation pulses at each processing position described by the number of light pulses in the provisional correction table is multiplied by the correction coefficient in the shading intermediate correction table.

  For example, when the shading correction table is as shown in Table 1, since the correction coefficient is 1 or more, multiplying the correction coefficient increases the number of irradiation pulses at the processing position. As a result, if it is necessary to increase the number of layers, a processing table with an increased number of layers may be generated. Alternatively, a preliminary blank layer (all non-irradiated layers) may be provided in advance in the temporary processing table, and the number of irradiations may be increased using this blank layer.

(Sixth embodiment)
The shading correction apparatus according to the present embodiment includes a machining data input unit that inputs machining data that defines a three-dimensional shape of a workpiece by a pulse laser beam, and an image obtained in advance by a laser beam scanner of the pulse laser beam machining apparatus. Processing that generates a processing table that describes a three-dimensional shape by the number of light pulses of a pulsed laser beam, using a correction table input unit that inputs a correction table that defines the correlation between high and light loss, and processing data and the correction table A pattern generation unit and a processing data output unit that outputs a generated processing table are provided.

  That is, in the first embodiment, the shading correction apparatus includes only the shading correction function incorporated in the pulse laser processing apparatus. According to the shading correction apparatus of the present embodiment, shading generated in the scanning optical system is effective for a pulse laser processing apparatus that processes a three-dimensional processing shape using a processing table that describes the number of optical pulses of a pulse laser beam. It is possible to generate a machining table corrected to the above.

  In the generation of the processing table, for example, the processing pattern generation unit uses the processing data and the correction table to create correction processing data that defines a three-dimensional shape in which the correlation between the image height and the light amount loss is corrected, and this correction A processing table is generated from the processing data.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In the pulse laser processing apparatus, the shading correction apparatus, the pulse laser processing method, etc., the description of the parts that are not directly necessary for the explanation of the present invention is omitted, but the necessary pulse laser processing apparatus, shading correction apparatus, and pulse laser processing are omitted. A method can be appropriately selected and used. In addition, all pulse laser processing apparatus shading correction apparatuses and pulse laser processing methods that include elements of the present invention and can be appropriately modified by those skilled in the art are included in the scope of the present invention.

  For example, in the embodiment, the case of processing pockets and dimples has been described as an example. However, the present invention is not limited to these shapes. For example, a cone shape for manufacturing a rib for electronic paper, a triangular pyramid, a square shape, or the like. It may be a pulse laser processing apparatus or a pulse laser processing method for processing an arbitrary shape such as a weight, a V groove, a concave groove, an R groove, or a combination thereof.

  Moreover, although Cu material was mainly demonstrated to the example as a to-be-processed object, even if it is other materials, such as metal materials, such as Ni material and SKD11, DLC material, a polymer material, a semiconductor material, a glass material, for example, I do not care.

Further, the laser oscillator is not limited to the YAG laser, but is a single wavelength band laser such as a second harmonic (wavelength: 532 nm) of other Nd: YVO ₄ laser suitable for processing a workpiece. Or you may output a multiple wavelength band laser.

DESCRIPTION OF SYMBOLS 12 Laser oscillator 14 Pulse picker 18 Laser beam scanner 20 XY stage part 22 Pulse picker control part 26 Clock oscillation circuit 40 Processing pattern generation part 49 Table generation part 100 Pulse laser processing apparatus 102 Correction table storage part 106 Correction table input part 108 Processing data Input unit 122 Measuring unit 124 Correction table generation unit 200 Pulse laser processing device 300 Pulse laser processing device

Claims (9)

A reference clock oscillation circuit for generating a clock signal;
A laser oscillator that emits a pulsed laser beam synchronized with the clock signal;
A laser beam scanner that scans the pulse laser beam only in a one-dimensional direction in synchronization with the clock signal;
A stage on which a workpiece can be placed and moves in a direction perpendicular to the one-dimensional direction;
A pulse picker that is provided in an optical path between the laser oscillator and the laser beam scanner, and switches between passing and blocking of the pulse laser beam in synchronization with the clock signal;
A pulse picker control unit for controlling the pulse picker;
A correction table storage unit that stores a correction table that defines the correlation between image height and light loss in the laser beam scanner;
A machining pattern generation unit that generates a machining table in which the three-dimensional shape is described by the number of optical pulses of the pulsed laser beam, using machining data that defines a three-dimensional shape of the workpiece and the correction table;
The pulse laser processing apparatus, wherein the pulse picker control unit controls the pulse picker based on the processing table. A measurement unit for measuring a correlation between an image height and a light loss in the laser beam scanner;
A correction table generation unit that generates the correction table based on the result of the measurement unit;
The pulse laser processing apparatus according to claim 1, further comprising:   Correction method selection for switching between using the correction table generated outside the pulse laser processing apparatus and using the correction table generated by the correction table generation unit for the correction table used in the processing pattern generation unit The pulse laser processing apparatus according to claim 2, further comprising a section.   The processing pattern generation unit creates correction processing data defining the three-dimensional shape in which the correlation between the image height and the light amount loss is corrected using the processing data and the correction table, and the correction processing data from the correction processing data The pulse laser processing apparatus according to any one of claims 1 to 3, wherein a processing table is generated.   Based on a scanning position signal from the laser beam scanner, a correction mechanism that corrects a processing origin position for each scanning, and the correction mechanism, based on the scanning position signal, passes the pulse laser beam through the pulse picker. The pulse laser processing apparatus according to any one of claims 1 to 4, wherein the interruption is controlled.   The pulse laser according to any one of claims 1 to 5, wherein the stage is controlled to move in a direction orthogonal to the one-dimensional direction based on a scanning position signal of the laser beam scanner. Processing equipment. A machining data input unit for inputting machining data defining the three-dimensional shape of the workpiece;
A correction table input unit for inputting a correction table that defines the correlation between the image height and the light loss in the laser beam scanner of the pulse laser beam processing apparatus acquired in advance;
A shading correction apparatus comprising: a processing pattern generation unit configured to generate a processing table in which the three-dimensional shape is described by the number of light pulses of a pulse laser beam using the processing data and the correction table.   The processing pattern generation unit creates correction processing data defining the three-dimensional shape in which the correlation between the image height and the light amount loss is corrected using the processing data and the correction table, and the correction processing data from the correction processing data The shading correction apparatus according to claim 7, wherein a processing table is generated. Place the work piece on the stage,
Generate a clock signal,
A pulse laser beam synchronized with the clock signal is emitted,
Scanning the surface of the workpiece in a one-dimensional direction with the pulsed laser beam in synchronization with the clock signal,
After scanning the pulse laser beam in the one-dimensional direction, the stage is moved in a direction orthogonal to the one-dimensional direction, and the pulse laser beam is scanned in the one-dimensional direction in synchronization with the clock signal. A pulse laser processing method,
Evaluate the correlation between image height and light loss in the laser beam scanner in advance.
Correcting the processing data defining the three-dimensional shape of the workpiece based on the correlation, and generating a processing table describing the three-dimensional shape by the number of light pulses of the pulse laser beam;
When the pulse laser beam is scanned in the one-dimensional direction, irradiation and non-irradiation of the pulse laser beam are switched in synchronization with the clock signal based on the number of optical pulses described in the processing table. Pulse laser processing method.

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