JP2017124416A - Laser processing apparatus and laser processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the work of positioning between a plurality of laser beams when the same point on a processing object with a plurality of laser beams having laser characteristics different from each other.SOLUTION: A laser beam irradiation means 11 that irradiates a processing object with laser beams emits a plurality of laser beams having laser characteristics different from each other out of a common emitting part 72, where a control means that controls the laser beam irradiation means 11 controls the laser beam irradiation means so that a point to be processed on the processing object may be irradiated with one laser beam of the plurality of laser beams, and then the same point as the point to be processed with another laser beam of the plurality of laser beams.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laser processing apparatus and a laser processing method.

  2. Description of the Related Art Conventionally, there is known a laser processing apparatus that processes a workpiece by irradiating a laser beam from a laser oscillator.

  For example, Patent Document 1 discloses a laser processing apparatus that processes a processing object in which a resin layer is formed so as to cover a metal wiring formed on a substrate. In this laser processing apparatus, first, a resin layer is formed by irradiating a laser beam for drilling with an infrared wavelength region (wavelength of 780 nm or more) carbon dioxide laser or an ultraviolet wavelength region (wavelength of 380 nm or less) excimer laser. A hole is formed in the hole, and the metal wiring is exposed on the bottom surface of the hole. At this time, a residue such as a resin that has been melted and remained solid without being ablated remains on the bottom surface of the hole. Therefore, in this laser processing apparatus, a residue removing laser beam that is the second harmonic (wavelength 523 nm) of the Nd: YLF laser is then obtained by a residue removing laser optical system that is prepared separately from the drilling laser optical system. To the bottom of the hole. Thereby, the residue remaining on the bottom surface of the hole is removed together with the surface layer portion of the metal wiring.

  In conventional laser processing equipment, laser processing is performed using multiple laser beams with different laser characteristics (wavelength, pulse width, repetition frequency, average output, power density, transmission mode (continuous wave or pulse wave), etc.). When performing, the said several laser beam is irradiated from each optical system which has an individual radiation | emission part, respectively. Therefore, when laser processing the same spot on the workpiece (the same workpiece spot) with the plurality of laser beams, the position of the energy distribution center position and the imaging position in the beam spot on the workpiece for each laser beam is positioned. Difficult alignment work of aligning is required.

  In order to solve the above-described problems, the present invention provides a laser beam irradiation apparatus including a laser beam irradiation unit that irradiates a workpiece with a laser beam and a control unit that controls the laser beam irradiation unit. The means emits a plurality of laser beams having mutually different laser characteristics from a common emitting portion, and the control means applies one of the plurality of laser lights to a processing location on the workpiece. After irradiating the laser beam, the laser beam irradiating means is controlled so as to irradiate another laser beam of the plurality of laser beams to the same location as the processing location.

  According to the present invention, a plurality of laser beams having different laser characteristics (pulse width, repetition frequency, average output, power density, transmission mode (continuous wave or pulse wave), etc.) are emitted from a common emission part. When the same location (the same location to be processed) on the workpiece is laser-processed by the plurality of laser beams, an excellent effect is obtained that the alignment operation between the plurality of laser beams is not necessary.

It is a schematic diagram which shows the structure of the principal part of the laser processing apparatus in embodiment. It is a schematic diagram which shows one structural example of the laser oscillator in the laser processing apparatus. It is a schematic diagram which shows one structural example of the workpiece conveyance part in the laser processing apparatus. It is explanatory drawing which shows the optical path of a laser beam when the carriage in the said laser processing apparatus is each located in the position where a main scanning direction differs. FIG. 10 is an explanatory diagram illustrating an optical path of laser light when the carriage is positioned at different positions in the main scanning direction in a modification in which the galvano scanner is not mounted on the carriage. It is a flowchart which shows an example of the process by the laser processing apparatus of embodiment. It is explanatory drawing which shows an example of the shift | offset | difference of the center position and alignment position of the alignment mark in the state which the workpiece | work stopped. It is explanatory drawing which shows distribution of the optimal pulse width and power density of a pulsed laser beam by the difference in processing content. (A) is a timing chart which shows an example of the timing which outputs the 1st pulse laser beam for ablation processing, (b) is a timing which shows an example of the timing which outputs the 2nd pulse laser beam for melt processing. It is a chart. It is explanatory drawing for demonstrating an ablation process and a melt process. It is explanatory drawing for demonstrating the ablation process and the fusion | melting process at the time of the groove processing of the micro flow path in the modification 1. FIG. 10 is a timing chart showing an example of timing for outputting a second pulse laser beam for melt processing in Modification 2.

Hereinafter, an embodiment in which the laser processing apparatus according to the present invention is applied to a laser processing apparatus that forms nozzle holes in a nozzle plate of a liquid discharge head used in an apparatus for discharging liquid such as an ink jet printer will be described.
The laser processing apparatus according to the present invention is as in the present embodiment as long as it laser-processes the same place (worked place) on the object to be processed with a plurality of laser beams oscillated at different repetition frequencies. The present invention is not limited to a simple hole processing device, and can be applied to other laser processing devices such as a cutting device and a groove processing device.

FIG. 1 is a schematic diagram showing a configuration of a main part of a laser processing apparatus according to the present embodiment.
The laser processing apparatus according to the present embodiment includes a laser output unit 1, a laser scanning unit 2, a work transfer unit 3, and a control unit 4.
The laser output unit 1 includes a laser oscillator 11 as laser light irradiation means that oscillates at a predetermined repetition frequency, and a beam expander 12 that expands the beam diameter of the laser light L output from the laser oscillator 11.
The laser scanning unit 2 rotates the two galvanometer mirrors 21a for reflecting the laser light L in the X-axis direction and the Y-axis direction by a stepping motor 21b to emit the laser light L in the X-axis direction and the Y-axis direction. A galvano scanner 21 which is an optical scanning means for scanning, and a laser beam L scanned by the galvano scanner 21 inside the workpiece (work surface, such as an interface between the surface of the workpiece 35 (surface to be processed) or a film formed on the substrate) And an fθ lens 22 as a condensing means for condensing light at a position offset by a predetermined depth from the surface.
The workpiece transfer unit 3 includes a processing table 32 on which the workpiece 35 is placed. The processing table 32 is configured to be movable in the sub-scanning direction (Y-axis direction) along the linear guide 38 by the stepping motor 31.

  The laser oscillator 11 of the laser output unit 1 is controlled by the laser driver unit 10. The laser driver unit 10 controls the light emission of the laser oscillator 11 in conjunction with the scanning operation of the galvano scanner 21 of the laser scanning unit 2. The laser oscillator 11 is, for example, one that oscillates a pulsed laser beam having a pulse width (time width) of 1 μsec or less, and is preferably 100 [nsec] or less with little damage due to thermal influence on the substrate. Is used that oscillates a pulse fiber laser (picosecond fiber laser) with a pulse oscillation of 100 [p seconds] or less, but other laser oscillators may be used.

FIG. 2 is a schematic diagram showing a configuration example of the laser oscillator 11 of the present embodiment.
The laser oscillator 11 of the present embodiment is a pulse fiber laser called MOPA (Master Oscillator Power Amplifier). For example, the laser oscillator 11 oscillates a pulse fiber laser by pulse oscillation of 100 [n seconds] or less with little damage due to thermal influence on the base material. The laser oscillator 11 generates a seed beam by oscillating a seed LD 74 with a pulse generator 73 and amplifies the laser beam L output from the pulse engine unit 70 in a plurality of stages with an optical fiber amplifier. An output fiber 71 that guides light and an output head unit 72 that emits laser light L as a substantially parallel light beam by a collimating optical system 83 as a parallel light beam forming unit. In the present embodiment, only the output head unit 72 is provided in the laser output unit 1.

  The pulse engine unit 70 includes a preamplifier unit having an optical fiber 78, a pumping LD 76 and a coupler 77, and a main amplifier unit having an optical fiber 82, a pumping LD 80 and a coupler 81. An optical fiber having a double clad structure in which a core is doped with a rare earth element is used, and laser light is repeatedly reflected between mirrors installed at the output end and the incident end of the fiber by absorption of pumping light from the pumping LD 76. It reaches. Reference numeral 75 in FIG. 2 is an isolator that blocks light in the reverse direction, and reference numeral 79 in FIG. 2 is a bandpass filter that removes ASE light.

In this embodiment, the wavelength of the seed LD 74 is set to 1064 [nm] in the near infrared, but the work material such as 532 [nm] which is the second harmonic and 355 [nm] which is the third harmonic is used. A suitable wavelength can be selected accordingly. In general, it is known that by shortening the pulse width, the thermal diffusion distance is shortened, and laser processing with less thermal damage to the workpiece is possible. By instantaneously irradiating a laser beam having a high pulse intensity of a GW (gigawatt) level, there is an advantage that even a transparent material having little light absorption, for example, can be processed. The laser oscillator 11 may be a solid laser such as a YVO ₄ laser that generates laser oscillation by irradiating a laser medium made of yttrium vanadate crystal with excitation light.

  The galvano scanner 21 of the laser scanning unit 2 is controlled by the galvano scanner control unit 20 for each stepping motor 21b that rotates the galvano mirrors 21a for X-axis direction scanning and Y-axis direction scanning. The galvano scanner control unit 20 tilts the laser beam incident on the reflecting surface with respect to the reflecting surface of the galvano mirror 21a in accordance with line segment element data (line segment start point coordinates and line segment end point coordinates) constituting the processing pattern. Each stepping motor 21b is controlled such that the angle of inclination of the reflecting surface with respect to the optical axis of the light changes in a direction corresponding to the X-axis direction or a direction corresponding to the Y-axis direction. Thereby, each galvanometer mirror 21a can be rotated from the scanning start inclination angle to the scanning end inclination angle corresponding to the XY coordinates of the start point and the end point of the line segment element.

  In the present embodiment, as the optical scanning unit, both the X-axis direction scanning and the Y-axis direction scanning are configured by galvano scanners, but not limited to this, widely known optical scanning units can be used. In addition, the optical scanning unit for scanning in the X-axis direction and the optical scanning unit for scanning in the Y-axis direction may be optical scanning units having different configurations. For example, a galvano scanner may be used as the scanning means for Y-axis direction scanning, and a polygon scanner that rotates a polygon mirror with a motor may be used as the scanning means for X-axis direction scanning. The optical scanning control in the X-axis direction can be performed based on the light reception timing at which the laser light L reflected by the polygon mirror is received by the optical sensor via the lens.

  The laser scanning unit 2 is mounted on a carriage 25 that can move in the main scanning direction (X-axis direction). The carriage 25 is mounted on a timing belt 27 that is stretched over a driving pulley 27a and a driven pulley 27b. By driving the stepping motor 26 connected to the drive pulley 27a, the timing belt 27 moves, and the carriage 25 on the timing belt 27 performs main scanning along a linear guide 29 (see FIG. 3) extending in the main scanning direction. Move in the direction (X-axis direction). The position of the carriage 25 in the main scanning direction can be detected based on an output signal (address signal) from the linear encoder 28. The stepping motor 26 is controlled by the main scanning control unit 24.

  In this embodiment, a moving means using a timing belt is used as a moving means of the carriage 25 on which the laser scanning unit 2 is mounted. However, the moving means using a timing belt is not limited to this, and a linearly movable means such as a linear stage is also used. Alternatively, a moving means for moving in a two-dimensional direction may be used.

  The workpiece transfer unit 3 includes a linear stage that moves the processing table 32 in the sub-scanning direction (Y-axis direction). This linear stage moves the processing table 32 in the sub-scanning direction (Y-axis direction) along the linear guide 38 by the driving force transmitted from the stepping motor 31 via the timing belt 31a. The stepping motor 31 is controlled by the sub-scanning control unit 30 to move the machining table 32 on the linear stage to the target feed position in the sub-scanning direction (Y-axis direction), and thereby the workpiece 35 held on the machining table 32. Can be moved to the target feed position in the sub-scanning direction (Y-axis direction). The workpiece conveyance unit 3 intermittently conveys the workpiece so as to sequentially feed the portion to be processed on the workpiece 35 to the processing region 36 that is the scanning range of the laser light L emitted from the laser scanning unit 2.

  Specifically, the workpiece transport unit 3 includes a first monitor camera 34 as a position detection unit that captures an alignment mark 37 as a detection mark formed on the workpiece surface in the vicinity of both ends of the workpiece 35 in the main scanning direction, and a first monitor camera 34. A second monitor camera 33 is provided as a second position detecting means. The sub-scanning control unit 30 sequentially captures the image data output from the monitor cameras 33 and 34 while stepping the workpiece 35 by the stepping motor 31 in small steps in the workpiece feeding direction B (sub-scanning direction). Then, the alignment mark 37 is detected by pattern matching processing or the like, the amount of workpiece movement to the target feed position is calculated, the stepping motor 31 is controlled based on the calculation result, and the position of the workpiece 35 in the sub-scanning direction is determined. Move to the feed position.

FIG. 3 is a schematic diagram illustrating a configuration example of the workpiece transfer unit 3.
In the present embodiment, the processing table 32 of the workpiece transfer unit 3 is configured to be drawable from the front surface of the laser processing apparatus. When setting the workpiece 35 on the processing table 32, the user P pulls out the processing table 32 from the front surface of the laser processing apparatus, sets the workpiece 35 on the extracted processing table 32, and sets the processing table 32 to the laser. Push into the processing equipment. The same applies when the workpiece 35 after processing is taken out.

  Innumerable pores are formed in the processing table 32, and the work 58 is adsorbed on the surface of the processing table 32 by sucking the air in the cavity 32 a formed on the back surface of the processing table 32 by the pump 58. The work 35 in the region 36 is held while ensuring flatness.

  The control unit 4 includes a control PC 40 that manages and controls the entire laser processing apparatus. The control PC 40 is connected to the laser driver unit 10, the galvano scanner control unit 20, the main scanning control unit 24, the sub-scanning control unit 30 and the like, and manages each status and controls the processing sequence.

The beam expander 12 of the laser output unit 1 is composed of a plurality of lenses, and the position of the lens 39 closest to the fθ lens 22 of the laser scanning unit 2 on the laser beam path is movable in the optical axis direction of the laser beam. It is configured. By moving the position of the lens 39, the carriage on which the laser scanning unit 2 is mounted can be finely adjusted so that the converging distances when the carriage stops at each stop target position in the main scanning direction are aligned as will be described later. That is, the beam expander 12 has a focusing function that finely adjusts the laser light L incident on the galvano scanner 21 to be a parallel light flux.
In addition, an actuator that individually moves and adjusts the position of the lens 39 according to each stop target position in the main scanning direction is provided, and by changing the condensing distance for each stop target position, the movement direction of the carriage relative to the processing surface can be changed. Even when the parallelism is slightly deviated, the imaging position of the fθ lens 22 can be accurately adjusted.

In the present embodiment, the maximum lengths L in the X-axis direction and the Y-axis direction of the processing region 36 that is the scanning range of the laser beam L with respect to the workpiece 35 are the respective galvanometer mirrors 21a when the focal length of the fθ lens 22 is f. Is obtained from the following equation (1) using the maximum inclination angle θ (for example, ± 20 °).
L = f × θ (1)

  As shown in this equation (1), the width of the processing region 36 is limited by the scanning range of the galvano scanner 21 (the maximum inclination angle of the galvano mirror 21a). Here, as the scanning range of the galvano scanner 21 increases, it becomes more difficult to properly collect light on the work 35, so that it becomes difficult to maintain the processing uniformity in the processing region 36. Therefore, there is a limit in increasing the scanning range of the galvano scanner 21, that is, the maximum inclination angle θ of the galvano mirror 21a. Therefore, there is a limit in expanding the width of the processing region 36 by expanding the scanning range of the galvano scanner 21 (the maximum inclination angle θ of the galvano mirror 21a).

  On the other hand, according to the above formula (1), if the focal length f of the fθ lens 22 is increased, the width of the processing region 36 can be increased. However, the longer the focal length f is, the more it is necessary to dispose the fθ lens 22 away from the workpiece 35, which causes a problem that the present laser processing apparatus becomes larger.

In addition, each processing resolution σ in the X-axis direction and the Y-axis direction can be obtained from the following equation (2), where P is the number of pulses of the stepping motor 21b.
σ = f × (2π / P) (2)
As shown in Expression (2), the processing resolution σ decreases as the focal length f of the fθ lens 22 increases. Therefore, the realization of high-definition machining with a high machining resolution σ and the realization of a wider machining area are in a trade-off relationship. Therefore, when the processing resolution σ is taken into consideration, there is a limit to extending the processing area 36 by increasing the focal length f.

  On the other hand, a method of providing a moving mechanism for moving the work 35 not only in the sub-scanning direction (Y-axis direction) but also in the main scanning direction (X-axis direction) by the work transport unit 3 is also conceivable. According to this method, since the processing portion can be processed on each processing portion while sequentially replacing the processing portion of the workpiece 35 in the main scanning direction with respect to the processing region 36, the main scanning exceeding the processing region 36 is performed. Machining can be performed on a workpiece having a length in the direction.

  However, providing a moving mechanism that moves the workpiece not only in the sub-scanning direction (Y-axis direction) but also in the main-scanning direction (X-axis direction) causes an increase in the size of the laser processing apparatus. Moreover, since such a large work 35 has a large weight, there is a problem that inertia force is large, high-speed movement is difficult to realize, and productivity is low.

  Therefore, in the present embodiment, a configuration is adopted in which the scanning range of the laser light L is moved in the main scanning direction instead of moving the workpiece 35 in the main scanning direction (X-axis direction). Specifically, the laser scanning unit 2 is mounted on the carriage 25, and the laser scanning unit 2 is configured to be movable in the main scanning direction. As a result, the range in which the laser beam L scanned by the galvano scanner 21 scans the surface of the workpiece, that is, the processing region 36 is moved in the main scanning direction with respect to the workpiece 35 without moving the workpiece 35 in the main scanning direction (X-axis direction). Can be moved relative to each other. As a result, the processing region 36 can be sequentially moved to each processing portion of the workpiece 35 to perform processing, and even if the width of the processing region 36 in the main scanning direction (X-axis direction) is narrow, it exceeds that width. Processing can be performed on the large workpiece 35.

  As a result, since the machining process can be performed on the large workpiece 35 exceeding the machining area 36 without forcibly expanding the machining area 36, a high machining resolution σ can be maintained, so that the large workpiece 35 is highly finely processed. Can be realized. Moreover, in the present embodiment, the load mounted on the carriage 25 as the moving means that moves in the main scanning direction (X-axis direction) is substantially only the laser scanning unit 2, that is, the galvano scanner 21 and fθ. Only the lens 22 is provided. Since the weight of the mounted object is much lighter than that of the workpiece 35, the carriage 25 can be moved at high speed in the main scanning direction, and high productivity can be obtained.

  It should be noted that the mounted object mounted on the carriage 25 only needs to include at least the fθ lens 22 as the light condensing means constituting the machining light emitting unit. Therefore, the lightest configuration is a configuration in which only the fθ lens 22 is mounted on the carriage 25. On the other hand, as long as the component is light with respect to the workpiece 35, other components may be mounted on the carriage 25 together with the fθ lens 22. For example, as in the present embodiment, optical scanning means such as the galvano scanner 21 may be mounted on the carriage, or part or all of the laser output unit 1 may be mounted on the carriage.

  In the present embodiment, the optical path of the laser light L incident on the carriage 25 moving in the main scanning direction, that is, the optical path of the laser light L output from the laser output unit 1 is parallel to the X-axis direction. Therefore, as shown in FIG. 4, the laser light L output from the laser output unit 1 is incident from the same position of the carriage 25 regardless of the position of the carriage 25 in the main scanning direction (X-axis direction). Therefore, even if the carriage 25 moves in the main scanning direction (X-axis direction), the optical path of the laser light L after entering the carriage 25 is the same, and the processing regions 36-1 and 36-2 are different from each other in the main scanning direction. The same processing can be realized even when the processing is performed with.

  However, in this embodiment, when the carriage 25 moves, the optical path length of the laser light L until it enters the carriage 25 changes. Therefore, if the laser beam L incident on the carriage 25 is non-parallel convergent, the focal point of the laser beam L applied to the workpiece 35 changes depending on the position of the carriage 25 in the main scanning direction, and the laser beam L on the workpiece 35 changes. The processing accuracy is affected, for example, the spot diameter changes.

  In the present embodiment, the laser beam L output from the laser oscillator 11 is a substantially parallel light beam, is emitted from the beam expander 12 via the two reflecting mirrors 14 and 15, is reflected by the reflecting mirror 16, and is output as a laser beam. The laser beam L output from the unit 1 is also a substantially parallel light beam. Therefore, if the laser light L incident on the carriage 25 is substantially parallel and converged, the focal point of the laser light L applied to the workpiece 35 is substantially changed even if the carriage 25 moves and the position in the main scanning direction changes. Therefore, there is no influence such as a change in the spot diameter of the laser beam L on the workpiece 35. Therefore, even when processing is performed in processing regions 36-1 and 36-2 that are different from each other in the main scanning direction, the processing can be performed with the same processing accuracy without performing operations such as focus adjustment, resulting in higher production. Can be realized.

  However, if the laser output unit 1 is entirely mounted on the carriage 25 in addition to the laser scanning unit 2, that is, if the light source itself such as the laser oscillator 11 is mounted on the carriage 25, the carriage 25 Does not change the focal point of the laser beam L applied to the workpiece 35. However, it is necessary to consider that it is difficult to realize high-speed movement of the carriage 25 because the weight of the load on the carriage 25 increases.

  On the other hand, in order to further reduce the weight of the mounted object on the carriage 25, a configuration in which the optical scanning means such as the galvano scanner 21 is not mounted on the carriage 25 as shown in FIG. In the configuration shown in FIG. 5, the laser light L output from the laser output unit 1 ′ corresponds to the direction corresponding to the X-axis direction and the Y-axis direction by the galvano scanner 21 of the laser scanning unit 2 ′ that is fixedly arranged. Scan in the direction. The laser beam L scanned in this manner is converted into a parallel beam so as to become a parallel beam parallel to the X-axis direction by a parallel beam forming unit such as the coupling lens 61, and is output from the laser scanning unit 2 ′. The The laser beam L after scanning, which is a substantially parallel light beam output from the laser scanning unit 2 ′, enters the carriage 25 from the X-axis direction and is reflected by the reflecting mirror 16 ′ on the carriage 25 as a condensing unit. Are guided by the fθ lens 22 and focused on the work 35.

  Even in the configuration as shown in FIG. 5, the laser beam L incident on the carriage 25 has a substantially parallel convergence, so that the laser irradiated to the workpiece 35 even if the carriage 25 moves and the position in the main scanning direction changes. The focal point of the light L is not substantially changed, and there is no influence such as a change in the spot diameter of the laser light L on the workpiece 35. Therefore, even when processing is performed in processing regions 36-1 and 36-2 that are different from each other in the main scanning direction, the processing can be performed with the same processing accuracy without performing operations such as focus adjustment, resulting in higher production. Can be realized.

FIG. 6 is a flowchart showing an example of processing by the laser processing apparatus of this embodiment.
When the user P sets the workpiece 35 on the machining table 32, the control PC 40 operates the pump 58 to suck out air from the cavity 32 a formed on the back surface of the machining table 32, and places the workpiece 35 on the surface of the machining table 32. The workpiece 35 is held so that the position of the workpiece 35 does not move easily (S1). Thereafter, in accordance with a control command from the control PC 40, the sub-scanning control unit 30 controls the stepping motor 31 to move the work 35 in the work transport direction B along the sub-scanning direction (S2). Then, when the alignment mark 37 formed on the surface of the workpiece 35 moves to the imaging area of the monitor cameras 33 and 34, the alignment mark 37 is detected from the image data of the monitor cameras 33 and 34 (S3). The control PC 40 calculates the workpiece movement amount from the detection result of the alignment mark 37 to the target feed position, and causes the sub-scanning control unit 30 to control the stepping motor 31 based on the calculation result. As a result, the workpiece 35 moving in the sub-scanning direction stops near the target feed position.

The control PC 40 captures the image data output from the monitor cameras 33 and 34 after the work is stopped, and the amount of misalignment between the center position of the alignment mark 37 and the target position (X-axis direction work misalignment amount Δx _w , Y-axis direction work misalignment). Amount Δy _w , tilt work deviation amount Δφ _w ). The calculated workpiece deviation amounts Δx _w , Δy _w , Δφ _w are stored in a memory in the control PC 40 for use as a correction value (offset value) of the machining target position.

FIG. 7 is an explanatory diagram showing an example of a deviation between the center position of the alignment mark 37 and the target position O in a state where the workpiece is stopped.
The amount of deviation between the center position of the alignment mark 37 and the target position O when the workpiece is stopped is the difference between the center position O of the image captured by the monitor cameras 33 and 34 and the center position of the alignment mark 37 displayed on the image. Calculated from the amount of deviation. In the present embodiment, the Wakuzure amount, the X-axis direction and the X-axis direction Wakuzure amount [Delta] x _w is a shift amount in (the main scanning direction), the Y-axis direction Wakuzure amount is a shift amount in the Y-axis direction (sub scanning direction) Tilt workpiece deviation amount Δφ which is an angle formed between Δy _w and a straight line connecting two alignment marks 37 formed at the same position in the sub-scanning direction at both ends of the work 35 in the main scanning direction and the X-axis direction (main scanning direction) It is represented by _w .

  The shape of the alignment mark 37 in the present embodiment is circular, but is not limited to this, and a shape advantageous for detection by pattern matching by image processing, such as a cross line shape in which two line segments are orthogonal to each other, is suitable. is there. The shape of the alignment mark 37 is appropriately selected according to the detection method of the alignment mark 37 and the like.

  Then, the control PC 40 sets the processed part number N for specifying the processed part on the workpiece 35 to zero (S4), and then controls the stepping motor 26 by the main scanning control unit 24 to set the standby position. The waiting carriage 25 is moved along the main scanning direction in the carriage feed direction A (in the direction away from the laser output unit 1), and the carriage position is initialized at a predetermined home position (S5).

  In this initialization process, the control PC 40 acquires the position in the main scanning direction of the carriage 25 stopped at the home position based on the address signal from the linear encoder 28. Based on the address signal from the linear encoder 28, the difference between the home position managed by the control PC 40 and the position of the carriage 25 actually stopped is detected, and this is used for the subsequent position control of the carriage 25 in the main scanning direction. Use. This difference may also be used as a correction value (offset value) for the processing target position.

Next, the control PC 40 calculates the following formulas (3-1) to (3) from the above-described work shift amounts Δx _w , Δy _w , Δφ _w and other shift amounts (such as carriage posture shift amounts) δxi, δyi, δφi. From 3-3), offset values ΔDxi, ΔDyi, ΔDφi, which are correction values of the processing target position for correcting the processing data, are derived. Note that other deviation amounts δxi, δyi, and δφi such as a carriage posture deviation amount are measured in advance, and the measured values are stored in a memory in the control PC 40. In the following formulas (3-1) to (3-3), “i” represents each stop position in the main scanning direction of the carriage (first stop position i = 1, second stop position i = 2, third). This is a number indicating stop position i = 3 and fourth stop position i = 4).
_{ΔDxi = Δx w + (d0 +} (i-1) × d) × (cosΔφ-1) + δxi
... (3-1)
ΔDyi = Δy _w + (d0 + (i−1) × d) × (sinΔφ−1) + δyi
... (3-2)
_{ΔDφi = Δφ w + δφi ··· (} 3-3)

  Next, the control PC 40 sets the workpiece part number N of the workpiece 35 to 1 (S6). Thereafter, the control PC 40 controls the stepping motor 26 by the main scanning control unit 24 to move the carriage 25 located at the home position in the carriage feed direction A, so that the first processing on the workpiece 35 on which the processing is performed first. The machined part N = 1 is stopped at the first stop position for processing (S7).

  In this embodiment, in order to realize a high processing resolution with a positional accuracy of 5 μm or less, the laser beam scanning range on the workpiece scanned by the galvano scanner 21, that is, the size of the processing region 36 is set to 150 [mm] × 150 [mm]. It is set. Therefore, when a machining process is performed on the workpiece 35 in which the machining target on the workpiece is, for example, 600 [mm] (main scanning direction) × 300 [mm] (sub-scanning direction) as a whole, Dividing into 4 pieces in the main scanning direction and dividing into 2 pieces in the sub scanning direction. Then, the entire processing object is processed by sequentially processing these eight pieces (processed portion N = 1 to 8).

  Here, in general, the laser beam to be irradiated by the laser processing apparatus has an optimal power density and an optimal pulse width (time) due to differences in processing contents such as cutting, drilling, and welding, and differences in materials to be processed. The optimum laser beam conditions such as (width) are different. For example, in the case of processing content that removes the processing target such as cutting, drilling, etc., normal processing is usually realized by applying high energy in a short time called ablation to instantly evaporate the processing target. The Therefore, as shown in FIG. 8, a laser beam having a pulse width of 10 [p seconds] or less as typified by a femtosecond laser is preferable. On the other hand, in the case of processing contents for melting a processing target such as welding or welding, as shown in FIG. 8, a laser beam having a long pulse width of 1 [μsec] or more is used and a temperature slightly higher than the melting point is used. The conditions are preferably such that they can be maintained only for a time during which sufficient penetration by heat conduction is obtained.

  The laser processing apparatus in this embodiment performs laser processing for forming nozzle holes in a nozzle plate of a liquid discharge head used in an apparatus for discharging liquid such as an ink jet printer. Since the material of the nozzle plate in the present embodiment is polyimide resin, the laser processing apparatus of the present embodiment performs hole processing by ablation using an excimer laser, YAG laser, or the like. There is a possibility that unwanted matter such as scattered matter is generated in or around the nozzle hole and adversely affects the ink ejection characteristics (ink fluid characteristics, etc.) of the liquid ejection head. Therefore, in this embodiment, after performing an ablation process that forms a nozzle hole using a laser beam having an optimum condition for ablation, it is optimal for melting unnecessary materials generated in and around the processed nozzle hole. A melting step of removing unnecessary materials from the nozzle holes using a laser beam under various conditions is performed.

  By performing the melting step after the ablation step in this manner, it is possible to suppress the unnecessary matter from remaining in or around the nozzle hole, and it is possible to suppress the deterioration of the ink discharge characteristics of the liquid discharge head due to the remaining unnecessary matter. In addition, such a melting process is not limited to removal of unnecessary materials generated during the ablation process, but also has an effect of smoothing the roughness of the processed surface during the previous processing process such as the ablation process. For this reason, it is possible to suppress a decrease in ink discharge characteristics (such as ink fluid characteristics) of the liquid discharge head due to the rough surface.

  In addition to the formation of ink holes, for example, micro-channel processing (μTAS) used for biopsy, die processing of micro optical elements such as DOE (Diffractive Optical Element) and light guides The same applies to the above. That is, in micro-channel processing (μTAS), acrylic resin (PMMA: Polymethyl methacrylate) or the like is used as the material of the object to be processed, but the unnecessary material adhering to the processed surface and the surface roughness of the processed surface greatly affect the fluid characteristics. Therefore, it is preferable to perform the melting step after the previous processing step such as an ablation step. Further, in the mold processing, since the specularity of the processed surface greatly affects the optical characteristics, it is preferable to perform the melting step after the previous processing step such as an ablation step.

  However, a conventional laser processing apparatus uses a plurality of laser beams having different laser characteristics (wavelength, pulse width, repetition frequency, average output, power density, transmission mode (continuous wave or pulse wave), etc.). When processing, each laser beam is irradiated from each optical system having an individual emitting portion. Therefore, as in this embodiment, two laser beams having different laser characteristics, that is, laser characteristics suitable for ablation processing (non-thermal processing) and laser characteristics suitable for melt processing (thermal processing), are identical on the workpiece 35. When laser processing is to be performed on a location (the same location to be processed), it is necessary to perform a difficult alignment operation of aligning the energy distribution center position and the imaging position in the beam spot on the workpiece with each laser beam. If the alignment accuracy is insufficient, the roundness and symmetry of the nozzle holes are impaired, and the ink discharge characteristics of the liquid discharge head are deteriorated. In particular, in the present embodiment, the diameter of each nozzle hole drilled by laser light is 10 [μm] or less, and in order to suppress such a variation in nozzle diameter between the nozzle holes, a position on the submicron level is used. Matching is required.

  In addition, in the configuration in which a plurality of laser beams are irradiated from each optical system having an individual emitting part for each laser beam, even if the alignment can be performed with high accuracy at the initial stage, the optical axis shift with time and the pulse characteristics of the optical system can be reduced. The alignment may shift due to fluctuations. Therefore, with such a configuration, it is difficult to obtain a stable processing quality over time.

  Various problems due to such a decrease in alignment accuracy are not limited to laser processing of ink holes, but laser processing is performed on the same location (the same location to be processed) on a workpiece by using a plurality of laser beams having different laser characteristics. In some cases, this can occur with any laser processing.

  Therefore, in the present embodiment, two pulsed laser beams having different repetition frequencies (laser characteristics) are emitted from the output head unit 72, which is a common emitting unit, and the same location on the workpiece by each laser beam. It is configured to laser-process (the same processed part). This eliminates the need for alignment work between the two pulse laser beams, which is necessary in the configuration in which such two pulse laser beams are emitted from the optical systems having the individual emission portions.

FIGS. 9A and 9B are timing charts showing an example of timing for outputting two pulsed laser beams in the present embodiment.
The pulse generation timing of the pulse laser beam, in other words, the repetition frequency of the pulse oscillation is determined by the reference clock PCLOCK generated by the pulse generator 73 provided in the laser oscillator 11. The galvano scanner control unit 20 generates a lighting signal (trigger signal) for the seed LD 74 so as to be synchronized with the reference clock PCLOCK from the pulse generator 73. Since the seed LD 74 is lit only during the period when the trigger signal is rising, the pulse laser beam is oscillated and output only during the period when the trigger signal is rising (laser irradiation possible period).

  In the present embodiment, the reference clock PCLOCK from the pulse generator 73 can be switched in two stages according to the oscillation condition received from the control PC 40. Specifically, the pulse generator 73 can generate, for example, a first reference clock PCLOK1 of 100 k [Hz] and a second reference clock PCLOK2 of 100 M [Hz]. Thereby, the second pulse laser beam output by the second reference clock PCLOK2 has a repetition frequency that is 1000 times the repetition frequency of the first pulse laser beam output by the first reference clock PCLOK1.

If the average output is 10 [W], the energy per pulse is 0.01 [μJ], the pulse width is 100 [p seconds], and the beam spot diameter is 30 [μm]. Is 34 G [W / cm ² ]. Therefore, in the present embodiment, the first reference clock PCLOK1 having a repetition frequency of 100 k [Hz] is irradiated with the first pulse laser beam having a power density of 34 G [W / cm ² ], and the repetition frequency is 100 M [Hz]. The second reference clock PCLOK2 can be irradiated with a first pulse laser beam having a power density of 34M [W / cm ² ]. That is, in this embodiment, since the average output and the pulse width are set in common, the power density of the second pulse laser beam by the second reference clock PCLOK2 having a repetition frequency 1000 times larger than that of the first reference clock PCLOCK1 is This is 1/1000 of the first pulse laser beam by the first reference clock PCLOK1.

  In the present embodiment, an ablation process is performed in which nozzle holes are formed by ablation using a first pulse laser beam having a high power density by the first reference clock PCLOK1. After that, the reference clock is switched to the second reference clock PCLOK2, and a melting process is performed to melt and remove unnecessary materials generated in and around the formed nozzle holes with a second pulse laser beam having a low power density. To do.

  In this embodiment, the average output and the pulse width are made common, only the repetition frequency is changed, and the first pulse laser light for ablation processing and the second pulse laser light for melt processing are used as a common output head unit. Although it is the structure radiate | emitted from 72, it is not restricted to this. For example, the first pulse laser beam for ablation processing and the second pulse laser beam for the melting process can be changed by changing other laser characteristics such as average output and pulse width in place of the repetition frequency or in combination with the repetition frequency. May be emitted from the common output head unit 72.

The first pulse laser beam used in the ablation process is not particularly limited as long as it has laser characteristics that can be ablated, but the power density is preferably 5 G [W / cm ² ] or more. Also, the second pulse laser beam used in the melting step is not particularly limited as long as it has laser characteristics capable of melting processing, but the power density is 1 M [W / cm ² ] or more and 1 G [W / cm ^2]. It is preferable that

In the present embodiment, the first pulse laser beam for ablation processing has a repetition frequency of 1 M [Hz] or less and a power density of 5 G [W / cm ² ] or more. At this time, the energy density (fluence) ) Is preferably 5 [J / cm ² ] or less. The second pulse laser beam for melt processing has a repetition frequency of 5 M [Hz] or more and a power density of 1 G [W / cm ² ] or less, and the energy density (fluence) at this time is 1 [ J / cm ² ] or less is preferable. The second pulse laser beam for melting processing can be increased in temperature up to a threshold value at which heat is accumulated in the work 35 in the beam spot and the work 35 is melted by increasing the repetition frequency extremely.

In the present embodiment, the same portion of the workpiece 35 is laser processed using the two pulse laser beams as described above. Specifically, as described above, the control PC 40 stops the carriage 25 at the first stop position for processing the first processed portion N = 1 on the workpiece 35 (S7), and then the carriage 25 The main scanning direction position is acquired based on the address signal from the linear encoder 28. Then, to detect the difference between the position of the carriage 25 which control PC40 has actually stopped the target stop position which manages, which was the carrier position deviation amount [Delta] x _c, is temporarily stored in the memory. Thereafter, the control PC 40 reads the work shift amounts Δx _w , Δy _w , Δφ _w and the carriage position shift amount Δx _c from the memory, and uses the offset values ΔDxi, ΔDyi from the equations (3-1) to (3-3) described above. , ΔDφi is calculated (S8).

  Subsequently, the control PC 40 reads the nozzle hole machining data, and offsets the coordinate origin of the machining data using the calculated offset values ΔDxi, ΔDyi, ΔDφi. Then, at the first stop position, the control PC 40 performs nozzle hole drilling (ablation) on the first workpiece portion N = 1 on the workpiece 35 based on the machining data based on the coordinate origin after the offset. Processing) is performed under the processing conditions for ablation processing (S9).

  Specifically, the galvano scanner control unit 20 scans the galvano scanner 21 so that the beam spot is positioned at the processing target position of the first nozzle hole based on the processing data based on the coordinate origin after the offset. To fix. Thereafter, the first reference clock PCLOK1 is output from the pulse generator 73 to oscillate a first pulse laser beam having a high power density, and the first pulse laser beam causes the first processed portion N = 1 on the workpiece 35 to be first. Ablation processing is performed to form nozzle holes.

  After finishing the ablation processing for forming the first nozzle hole in this way, the control PC 40 then switches the processing conditions to the processing conditions for melt processing, and toward the same nozzle hole, this time in the nozzle hole or Melt processing for removing unnecessary unnecessary objects is performed under the processing conditions for melt processing (S10). That is, as described above, the second reference clock PCLOK2 is output from the pulse generator 73 to oscillate a second pulse laser beam having a low power density, and the first processed portion N = Melting processing is performed to melt and remove unnecessary materials in and around the first nozzle hole formed in 1.

FIG. 10 is an explanatory diagram for explaining ablation processing and melt processing.
When the nozzle hole is drilled by ablation, as shown by the dotted line in FIG. 10, unwanted objects such as scattered matter accompanying laser ablation (explosion of the laser absorbing portion) adhere to the processed surface 35a. Periodic unevenness due to the laser pulse is formed, or debris 35b is deposited on the periphery of the nozzle hole. In the present embodiment, after the ablation process for forming the first nozzle hole is finished, the melt process is subsequently performed on the first nozzle hole under the process conditions for the melt process. As a result, as shown by the solid line in FIG. 10, the nozzle hole penetrates completely, and unnecessary objects, debris 35b, and uneven portions are dissolved, and the processed surface 35a becomes a smooth mirror surface 35c without unevenness.

  In the first processed portion N = 1 on the work 35, the galvano scanner control unit 20 sequentially changes the scan angle of the galvano scanner 21, and the above-described ablation processing and fusion processing are performed on the processing target position of each nozzle hole. Are carried out sequentially. When the drilling of all the nozzle holes for the first processed portion N = 1 on the workpiece 35 is finished, the control PC 40 sets the processed portion number N of the workpiece 35 to 2 (S6), and the main scanning The control unit 24 controls the stepping motor 26 to move the carriage to the second stop position for processing the second processed portion N = 2 on the workpiece 35 (S7). Thereafter, as in the case of the first stop position, at the second stop position, the above-described ablation processing and melting processing are sequentially performed on the processing target positions of the respective nozzle holes (S9, S10). When the processing at the second stop position is finished, similarly, the above-described ablation processing and melt processing are sequentially performed on the processing target positions of the nozzle holes at the third stop position and the fourth stop position ( S9, 10). When the processing at the fourth stop position is completed (Yes in S11), the home position is restored.

  On the other hand, in the sub-scanning direction, after the carriage 25 moves to the fourth stop position and finishes the processing process (Yes in S11), the control PC 40 starts until the next processing process at the first stop position is started. Then, the sub-scanning control unit 30 controls the stepping motor 31 to move the workpiece 35 by 150 [mm] in the workpiece conveyance direction B (S13). Then, again, the carriage 25 is sequentially moved to the first stop position, the second stop position, the third stop position, and the fourth stop position, and both the ablation process and the melting process are performed (S5 to S11).

  As long as the parts to be processed on the workpiece 35 are independent from each other, the stop positions of the carriage 25 may be positions where the respective processing regions 36 are separated from each other. However, when the parts to be processed are not independent, but are to be processed by a plurality of parts to be processed, each stop position of the carriage 25 and each stop position of the workpiece are respectively adjacent to the respective processing regions 36 or It is necessary to set the position so as to partially overlap. In such a case, an overlap region of about several tens [μm] is provided between the eight pieces (processed parts), and each piece (processed part) is overlapped so that adjacent process parts partially overlap each other. A processing portion) may be set.

  When the processing for the eight pieces (the processed portion N = 1 to 8) is completed while moving in the main scanning direction and the sub-scanning direction as described above (Yes in S12), 600 [mm] × Processing of the entire processing target of 300 [mm] is completed. Therefore, the user P pulls out the processing table 32 from the front surface of the laser processing apparatus, takes out the workpiece 35 on the extracted processing table 32, and transfers the processed workpiece 35 to the next process.

  In this embodiment, the same part on the workpiece 35 is laser-processed by two pulsed laser beams having different laser characteristics, and the same material is processed stepwise. In the present embodiment, since the first pulse laser beam for ablation processing and the second pulse laser beam for the melting process are emitted from the common output head unit 72, such two pulse laser beams are individually supplied. The alignment work between the two pulse laser beams, which is necessary in the configuration in which the light is emitted from each optical system having the light emitting portion, becomes unnecessary.

  In particular, in the present embodiment, since the entire optical system including the galvano scanner 21 is fixed, the ablation processing by the first pulse laser light and the melting processing by the second pulse laser light are continuously performed. Processing position shift does not occur between ablation processing and melt processing, and high-precision laser processing can be realized.

Not limited to this, for example, after forming all nozzle holes by ablation while sequentially changing the scan angle of the galvano scanner 21 for each part to be processed on the workpiece 35, the carriage 25 remains fixed. Again, melt processing may be performed on each nozzle hole while sequentially changing the scan angle of the galvano scanner 21 for the same processed portion again.
Further, for example, after all the nozzle holes are formed by ablation processing from the first processed portion on the work 35 to the fourth processed portion by moving the carriage 25 sequentially, the fourth processed portion is again moved from the first processed portion to the fourth processed portion. You may make it implement a melt process with respect to each nozzle hole with respect to a to-be-processed part.

[Modification 1]
Next, a modified example of the laser processing in the present embodiment (hereinafter referred to as “modified example 1”) will be described.
In the above-described embodiment, the processing for forming the nozzle holes in the nozzle plate of the liquid ejection head used in the apparatus for ejecting liquid such as an ink jet printer is used. However, the first modification is used for biopsy or the like. This is a processing process for performing micro-channel groove processing. Since the basic configuration and operation are the same as those in the above-described embodiment, the description below will focus on differences from the above-described embodiment.

FIG. 11 is an explanatory diagram for explaining ablation processing and melt processing at the time of groove processing of the microchannel according to the first modification.
When performing the groove processing of the micro flow path, first, the control PC 40 stops the carriage 25 at the first stop position for processing the first processed portion N = 1 on the workpiece 35, and offset values ΔDxi, ΔDyi. , ΔDφi is read, the processing data for groove processing is read out, and the coordinate origin of the processing data is offset using the calculated offset values ΔDxi, ΔDyi, ΔDφi. Then, at the first stop position, the control PC 40 sets the groove under the processing conditions for ablation processing on the first processed portion N = 1 on the workpiece 35 based on the processing data based on the coordinate origin after the offset. Perform processing (ablation processing).

  Specifically, the galvano scanner control unit 20 fixes the scan angle of the other galvanometer mirror 21a in a state where the scan angle of one galvanometer mirror 21a is fixed based on the processing data based on the coordinate origin after the offset. While changing, the first reference clock PCLOK1 is output from the pulse generator 73 to oscillate the first pulse laser beam with high power density, and the first pulse laser beam causes the first processed portion N = 1 on the workpiece 35 to be oscillated. In contrast, a groove for one line is formed by ablation.

  When the ablation processing for one line for the first workpiece portion N = 1 on the workpiece 35 is completed in this way, the control PC 40 then switches the processing conditions to the processing conditions for melting and processing for the same line. This time, melt processing for removing unnecessary materials in and around the groove is performed under the processing conditions for melt processing. That is, the second reference clock PCLOK2 is output from the pulse generator 73 to oscillate a second pulse laser beam having a low power density, and the second pulse laser beam forms the first processed portion N = 1 on the workpiece 35. A melting process is performed to melt and remove unnecessary materials in and around the groove.

  In the first processed part N = 1 on the workpiece 35, the galvano scanner control unit 20 sequentially changes the scan angle of one galvano scanner 21 to perform the above-described ablation and melting processes on all the lines. Implement sequentially. Then, when all the grooving for the first processed portion N = 1 on the workpiece 35 is finished, the grooving is performed for all the processed portions as in the above-described embodiment.

  Also in this modification 1, when performing groove processing by ablation processing, as shown by a dotted line in FIG. 11, the processing surface 35 a is free of unwanted materials such as scattered matter due to laser ablation (explosion of the laser absorbing portion). Adhering or periodic irregularities due to laser pulses may be formed. In the first modification, after the ablation process for forming the groove for one line is finished, the melt process is subsequently performed on the groove under the process conditions for the melt process. As a result, as shown by a solid line in FIG. 11, unnecessary parts and uneven portions are dissolved, and the processed surface 35 a becomes a smooth mirror surface 35 c without uneven portions.

[Modification 2]
Next, another modified example of the laser processing in the present embodiment (hereinafter, this modified example is referred to as “modified example 2”) will be described.
The above-described embodiment is configured such that the pulse laser beam continues to oscillate during the period in which the trigger signal output from the galvano scanner control unit 20 rises (the laser irradiation possible period). Generally, melt processing is difficult to control. For example, if a heat storage state exceeding the melting point continues even after processing, the processing shape is deformed. Even when the melting point is not exceeded, scorching due to oxidation may occur and the work surface may be deteriorated. Therefore, in order to obtain high processing quality, it is desired to control the power density or energy density during the period when the trigger signal rises (the period during which laser irradiation is possible).

FIG. 12 is a timing chart showing an example of timing for outputting the second pulse laser beam for melt processing in the second modification.
In the second modification, a burst gate signal generated under the control of the control PC 40 is used. That is, in the second modification, even if the trigger signal from the galvano scanner controller 20 is rising (laser irradiation possible period), the seed LD 74 is not lit during the period when the burst gate signal is not rising, Pulse laser light is not output. Therefore, in the second modification, by appropriately changing the rising period of the burst gate signal, even if the period during which the trigger signal from the galvano scanner control unit 20 is rising is constant, the pulse laser beam within the period is fixed. The output time (laser beam irradiation time) can be adjusted. That is, even if the period during which the trigger signal from the galvano scanner control unit 20 rises is constant, the power density or energy density of the second pulse laser beam for melt processing can be adjusted.

  In the second modification, by appropriately changing the rising period of the burst gate signal, a part of the laser beam irradiation time is obtained from the period (laser irradiation possible period) in which the trigger signal from the galvano scanner control unit 20 is rising. Can be thinned out. This makes it possible to adjust to an appropriate melt processing condition that solidifies instantaneously after the melt processing and suppresses the progress of deterioration, and high processing quality is obtained.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
In a laser processing apparatus having a laser beam irradiation unit such as a laser oscillator 11 that irradiates a workpiece with a laser beam, and a control unit such as a control PC 40 or a laser driver unit 10 that controls the laser beam irradiation unit, the laser beam The irradiating means emits a plurality of laser beams such as a first pulse laser beam and a second pulse laser beam having laser characteristics such as different repetition frequencies from a common emitting portion such as the output head portion 72, and the like. The control means irradiates one of the plurality of laser beams on the workpiece on the workpiece, and then another laser of the plurality of laser beams at the same location as the workpiece. The laser light irradiation means is controlled so as to irradiate light.
According to this aspect, a plurality of laser beams having different laser characteristics (wavelength, pulse width, repetition frequency, average output, power density, transmission mode (continuous wave or pulse wave), etc.) are emitted from a common emission part. And the same location (same processing location) on a processing object can be laser-processed by each laser beam. Thereby, the alignment operation between the plurality of laser beams, which is necessary in the conventional configuration in which the plurality of laser beams are emitted from the respective optical systems having the individual emission units, becomes unnecessary.

(Aspect B)
In the aspect A, the plurality of laser beams include a first laser beam oscillated at a first repetition frequency such as at least 100 k [Hz] and a second repetition frequency such as 100 M [Hz] higher than the first repetition frequency. A second laser beam that oscillates, and the control means irradiates the first laser beam on a portion to be processed on the workpiece and then irradiates the second laser beam on the same portion as the portion to be processed. Thus, the laser beam irradiation means is controlled.
According to this, melting processing (thermal processing) using the second laser light is performed to remove unwanted materials and roughened surface of the processed surface where ablation processing (non-thermal processing) has been performed by the first laser light. The stepwise laser processing of removing the first laser beam and the second laser beam can be realized with high processing accuracy due to the high alignment accuracy between the first laser beam and the second laser beam.

(Aspect C)
In the aspect B, the power density of the first laser light is 5 G [W / cm ² ] or more.
Thereby, high-quality ablation processing (non-thermal processing) can be realized.

(Aspect D)
In the aspect B or C, the power density of the second laser light is 1 G [W / cm ² ] or less.
Thereby, high-quality melt processing (thermal processing) can be realized.

(Aspect E)
In any one of the aspects A to D, the laser beam irradiation means uses the laser oscillator 11 that can generate the plurality of laser beams from light emitted from a common light source such as a seed LD 74, and the plurality of lasers. The light is a pulse laser beam having a time width of 1 μsec or less.
According to this, it is easy to obtain a laser beam suitable for ablation processing (non-thermal processing) and a laser light suitable for melt processing (thermal processing) using a common light source.

(Aspect F)
In any one of the aspects A to E, the apparatus includes an optical scanning unit such as a galvano scanner 21 that scans the laser beam from the laser beam irradiation unit.
According to this, quick and accurate processing can be performed.

(Aspect G)
In any one of the aspects A to F, the control unit performs control to adjust at least one laser beam irradiation time of the plurality of laser beams during a laser irradiation possible period with respect to the processing site. And
In the configuration in which the laser beam is irradiated all the time during which the laser beam can be irradiated on the part to be processed, it may be difficult to obtain a stable processing quality. According to this aspect, by adjusting the laser beam irradiation time, it is possible to thin out the time during which the laser beam is not irradiated from the laser irradiation possible period for the portion to be processed. Thereby, even if the laser irradiation possible period with respect to a to-be-processed part is fixed, the laser beam irradiation time in the said laser irradiation possible period can be adjusted, and it becomes easy to obtain the stable processing quality.

(Aspect H)
A laser processing method for processing a workpiece by sequentially irradiating the workpiece with a plurality of laser beams having different laser characteristics from a common emitting section. Then, after irradiating a portion to be processed on the object to be processed with one of the plurality of laser beams emitted from the common emitting portion in the laser beam irradiation means, The other laser beam is emitted from the common emitting portion and irradiated to the same portion as the portion to be processed, so that the portion to be processed is processed by the plurality of laser beams.
According to this aspect, a plurality of laser beams having different laser characteristics (wavelength, pulse width, repetition frequency, average output, power density, transmission mode (continuous wave or pulse wave), etc.) are emitted from a common emission part. And the same location (same processing location) on a processing object can be laser-processed by each laser beam. Thereby, the alignment operation between the plurality of laser beams, which is necessary in the conventional configuration in which the plurality of laser beams are emitted from the respective optical systems having the individual emission units, becomes unnecessary.

DESCRIPTION OF SYMBOLS 1 Laser output part 2 Laser scanning part 3 Work conveyance part 4 Control part 10 Laser driver part 11 Laser oscillator 12 Beam expander 20 Galvano scanner control part 21 Galvano scanner 24 Main scanning control part 25 Carriage 30 Sub-scanning control part 32 Processing table 32a Cavity 33, 34 Monitor camera 35 Work 37 Alignment mark 38 Linear guide 70 Pulse engine 71 Output fiber 72 Output head 73 Pulse generator

JP 2004-74211 A

Claims (8)

Laser light irradiation means for irradiating the workpiece with laser light;
In a laser processing apparatus having a control means for controlling the laser light irradiation means,
The laser beam irradiation means emits a plurality of laser beams having mutually different laser characteristics from a common emitting portion,
The control means irradiates one portion of the plurality of laser beams on the portion to be processed on the object to be processed, and then applies another portion of the plurality of laser beams to the same portion as the portion to be processed. A laser processing apparatus, wherein the laser beam irradiation means is controlled so as to irradiate a laser beam. In the laser processing apparatus of Claim 1,
The plurality of laser beams include at least a first laser beam oscillated at a first repetition frequency and a second laser beam oscillated at a second repetition frequency higher than the first repetition frequency,
The control unit is configured to irradiate the laser beam irradiation unit so as to irradiate the second laser beam to the same part as the processing part after irradiating the processing part on the processing object with the first laser beam. A laser processing apparatus characterized by controlling. In the laser processing apparatus of Claim 2,
The power density of said 1st laser beam is 5 G [W / cm < ² >] or more, The laser processing apparatus characterized by the above-mentioned. In the laser processing apparatus according to claim 2 or 3,
The power density of said 2nd laser beam is 1 G [W / cm < ² >] or less, The laser processing apparatus characterized by the above-mentioned. The laser processing apparatus according to any one of claims 1 to 4,
The laser beam irradiation means uses a laser oscillator capable of generating the plurality of laser beams from light emitted from a common light source,
The laser processing apparatus, wherein the plurality of laser beams are pulsed laser beams having a time width of 1 μsec or less. The laser processing apparatus according to any one of claims 1 to 5,
A laser processing apparatus comprising: an optical scanning unit that scans the laser beam from the laser beam irradiation unit. In the laser processing apparatus of any one of Claims 1 thru | or 6,
The laser processing apparatus, wherein the control means performs control to adjust at least one laser beam irradiation time of the plurality of laser beams during a laser irradiation possible period with respect to the processing site. A laser processing method for processing a workpiece by sequentially irradiating the workpiece with a plurality of laser beams having different laser characteristics from a common emitting section. And
After irradiating the part to be processed on the object to be processed with one laser light of the plurality of laser lights emitted from the common emission part in the laser light irradiation means, of the plurality of laser lights A laser processing method characterized in that another laser beam is emitted from the common emitting portion and irradiated to the same spot as the workpiece, thereby processing the workpiece with the plurality of laser beams.

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