Acousto-optic deflector unit for laser processing device

Abstract

The present invention easily incorporates an acousto-optic deflector into a laser processing device as compared with conventional technology. This acousto-optic deflector unit for a laser processing device comprises: a coordinate position movement stage on which a mask part is placed; a laser power detection unit that is disposed on an optical axis of a laser beam emitted from the acousto-optic deflector and detects a laser power of the laser beam; and a control unit that adjusts an operation amount of a coordinate position movement stage drive unit such that the laser power detected by the laser power detection unit is maximized.

Description

Acousto-optic deflector unit for laser processing apparatus

[0001] The present invention relates to an acousto-optic deflector unit for a laser processing apparatus.

[0002] Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2012-173427) describes an invention that, in a two-dimensional optical scanner including a first acousto-optic deflector and a second acousto-optic deflector, is provided with a driving unit that rotates the first acousto-optic deflector and the second acousto-optic deflector.

[0003] Patent Document 2 (Japanese Translation of PCT International Application Publication No. 2012-528011), Patent Document 3 (Japanese Unexamined Patent Application Publication No. 2020-171961), and Patent Document 4 (Republished WO2018 / 047823) describe an invention in which an acousto-optic deflector is arranged on the optical axis of a laser beam emitted from a laser light source to constitute a laser processing apparatus.

[0004] Japanese Unexamined Patent Application Publication No. 2012-173427 Japanese Translation of PCT International Application Publication No. 2012-528011 Japanese Unexamined Patent Application Publication No. 2020-171961 Republished WO2018 / 047823

[0005] A galvano scanner scans laser light by driving a motor to operate a reflecting mirror. For this reason, a laser processing apparatus using a galvano scanner has limits on high-speed and high-precision processing due to mechanical factors such as backlash and factors caused by acceleration and deceleration of the motor.

[0006] On the other hand, an acousto-optic deflector scans laser light using an optical element without using a motor or mechanical components. For this reason, although the scanning area of a laser processing apparatus using an acousto-optic deflector is narrower than that of a galvano scanner, the laser processing apparatus can perform processing at high speed and with high precision.

[0007] Accordingly, the present applicant has made attempts to configure a laser processing apparatus by combining a galvano scanner and an acousto-optic deflector.

[0008] The present disclosure aims to make it possible to easily incorporate an acousto-optic deflector into a laser processing apparatus, as compared with the prior art.

[0009] The first embodiment is an acoustic-optical deflector unit for a laser processing apparatus, comprising: an acoustic-optical deflector positioned on the optical axis of a laser beam emitted from a laser light source, which causes the laser beam to be incident at a predetermined optimal setting angle and deflects it to an angle corresponding to the frequency of input ultrasonic waves before emission; a rotating stage on which the acoustic-optical deflector is mounted so as to be rotatable in a rotational direction that allows adjustment of the optimal setting angle; and a rotating stage drive unit that drives the rotation of the rotating stage according to the amount of operation.

[0010] The second embodiment is an acoustic-optical deflector unit for a laser processing apparatus, wherein, in the first embodiment, the acousto-optical deflector is configured to include a first acousto-optical deflector and a second acousto-optical deflector arranged in series on the optical axis of a laser beam emitted from the laser light source, so that the laser beam is incident on it sequentially at a first optimal setting angle and a second optimal setting angle, and the laser beam is deflected in two mutually orthogonal axial directions by angles corresponding to the frequency of the input ultrasonic waves, and then emitted; the rotating stage is configured to include a first rotating stage on which the first acousto-optical deflector is mounted so as to be rotatable in a rotational direction in which the first optimal setting angle can be adjusted, and a second rotating stage on which the second acousto-optical deflector is mounted so as to be rotatable in a rotational direction in which the second optimal setting angle can be adjusted; and the rotating stage drive unit drives the rotation of the first rotating stage and the second rotating stage according to the amount of operation.

[0011] A third embodiment is an acousto-optic deflector unit for a laser processing apparatus, comprising, in the first or second embodiment, a laser power detection unit positioned on the optical axis of the laser beam emitted from the acousto-optic deflector and detecting the laser power of the laser beam, and a control unit that adjusts the manipulated amount so that the laser power detected by the laser power detection unit is maximized.

[0012] A fourth embodiment is an acoustic-optical deflector unit for a laser processing apparatus, comprising: an acoustic-optical deflector positioned on the optical axis of a laser beam emitted from a laser light source, which incident on the laser beam at a predetermined optimal setting angle and deflects it to an angle corresponding to the frequency of input ultrasonic waves; a mask section positioned on the optical axis of the laser beam emitted from the acoustic-optical deflector, which blocks n-th order diffracted light (n = 0, -1, ±2...) other than the first-order diffracted light from the laser beam emitted from the acoustic-optical deflector, and emits only the first-order diffracted light; a coordinate position movement stage on which the mask section is mounted, which is movable in a coordinate axis direction that allows adjustment of the relative position of the mask section to the optical axis of the laser beam passing through the mask section; and a coordinate position movement stage drive section that drives the movement of the coordinate position of the coordinate position movement stage according to the amount of operation.

[0013] A fifth embodiment is an acoustic-optical deflector unit for a laser processing apparatus, which in the fourth embodiment comprises a laser power detection unit positioned on the optical axis of the laser beam emitted from the mask portion and detecting the laser power of the laser beam, and a control unit that adjusts the manipulated amount so that the laser power detected by the laser power detection unit is maximized.

[0014] According to the first to fifth embodiments, an acousto-optic deflector can be easily incorporated into the laser processing apparatus compared to the prior art.

[0015] Figure 1 is a diagram showing the overall configuration of the laser processing apparatus of the embodiment. Figure 2 is a perspective view showing the configuration of the galvanometer scanner unit. Figure 3 is a diagram showing an example of laser processing performed by the laser processing apparatus of the embodiment. Figures 4(A) and 4(B) are diagrams illustrating examples of use of the acousto-optic deflector unit. Figure 5A is a diagram showing an example configuration of the acousto-optic deflector unit of the embodiment. Figure 5B is a diagram showing an example configuration of the acousto-optic deflector unit of the embodiment. Figure 6A is a diagram illustrating the control of the optimal installation angle of the first acousto-optic deflector. Figure 6B is a diagram illustrating the control of the optimal installation angle of the second acousto-optic deflector. Figure 6C is a diagram illustrating the diffraction control of the first and second acousto-optic deflectors. Figure 7A is a diagram illustrating the optimal installation angle of the first acousto-optic deflector. Figure 7B is a diagram illustrating the optimal installation angle of the second acousto-optic deflector. Figure 8 is a control block diagram of the control for adjusting the first and second acousto-optic deflectors to their optimal installation angles. Figures 9(A) and 9(B) illustrate the control of the position of the focal plane mask. Figure 10 is a control block diagram for adjusting the position of the focal plane mask to the optimal position. Figures 11(A) and 11(B) show the preparation process for setting the reference optical axis by installing the laser light source. Figures 12(A) and 12(B) show the process of adjusting the installation positions of the relay lens and the λ / 4 wave plate. Figures 13(A) and 13(B) show the process of adjusting the focal position of the relay lens. Figures 14(A) and 14(B) show the process of adjusting the position of the focal plane mask. Figures 15(A), 15(B), and 16(A) and 16(B) show the process of adjusting the installation position and angle of the second acousto-optic deflector. Figures 17(A) and 17(B) show the process of adjusting the installation position and angle of the first acousto-optic deflector. Figures 18(A) and 18(B) show the process of adjusting the optical system installation position of the pre-optical system unit. Figures 19(A) and (B) show the process of fine-tuning the installation angles of the first acousto-optic deflector, the second acousto-optic deflector, and the λ / 2 wave plate, as well as the installation position of the focal plane mask. Figures 20(A) and (B) show the process of connecting the acousto-optic deflector unit to the galvanometer scanner unit.

[0016] Embodiments of this disclosure will be described below with reference to the drawings.

[0017] Figure 1 shows the overall configuration of the laser processing apparatus 10 according to the embodiment.

[0018] Figure 2 is a perspective view showing the configuration of the galvanometer scanner unit 200.

[0019] (Laser processing device 10)

[0020] The laser processing apparatus 10 is composed of an acousto-optic deflector unit 100, a galvanometer scanner unit 200, a pre-optical system unit 300, and a control unit 500. Alternatively, the functions of the control unit 500 may be assigned to the acousto-optic deflector unit 100, the galvanometer scanner unit 200, and the pre-optical system unit 300, respectively.

[0021] The control unit 500 is connected to the terminal device 20 so that it can send and receive data.

[0022] The laser processing apparatus 10 irradiates the workpiece 400 with a laser beam L to perform processing such as cutting and marking. The workpiece 400 is placed and held on the XY stage 410. The directions of the orthogonal axes in the two-dimensional plane of the surface of the workpiece 400 are defined as the X-axis direction and the Y-axis direction. The direction perpendicular to the X-axis direction and the Y-axis direction is defined as the Z-axis direction. The two-dimensional position (X, Y) of the workpiece 400 can be adjusted by driving the XY stage 410 according to the control signals generated by the control unit 500.

[0023] The pre-optical system unit 300 comprises a laser light source 310, a first mirror 320, and a second mirror 330. The laser light source 310 comprises a laser oscillator. The laser light source 310 emits a laser beam L. The first mirror 320 and the second mirror 330 have their reflective surfaces 320A and 330A positioned at different attitude angles. The first mirror 320 and the second mirror 330 are supported by kinematic mounts 321 and 331, respectively, which allow for fine adjustment of their optical axes.

[0024] The laser beam L emitted from the laser light source 310 is reflected in different directions by the first mirror 320 and the second mirror 330, guided in a predetermined direction, and emitted from the pre-optical system unit 300.

[0025] The acousto-optic deflector unit 100 and the galvanometer scanner unit 200 constitute the laser processing apparatus unit 150.

[0026] The acousto-optic deflector unit 100 is configured to include a first acousto-optic deflector 110 and a second acousto-optic deflector 120, which are positioned on the optical axis S of the laser beam L emitted from the pre-optical system unit 300 and deflect the input ultrasonic wave at an angle θ corresponding to the frequency fa of the ultrasonic wave before emission. Other optical system components of the acousto-optic deflector unit 100 will be described later.

[0027] The first acousto-optic deflector 110 and the second acousto-optic deflector 120 each deflect the laser beam L in two mutually orthogonal axes.

[0028] The first acousto-optic deflector 110 is provided for scanning the laser beam L in the X-axis direction. The deflection angle of the first acousto-optic deflector 110 is adjusted according to the RF drive signal RF1 output from the control unit 500.

[0029] The second acousto-optic deflector 120 is provided to scan the laser beam L in the Y-axis direction. The deflection angle of the second acousto-optic deflector 120 changes in accordance with the RF drive signal RF2 output from the control unit 500.

[0030] The housing 200A of the galvanoscanner unit 200 includes an aperture 201 into which the laser beam L emitted from the acousto-optic deflector unit 100 is incident, and an exit port 202 from which the laser beam L is emitted. A galvanoscanner 210 is located inside the galvanoscanner unit 200. The galvanoscanner 210 is composed of a first galvano mirror 221, a second galvano mirror 222, a first motor 231, a second motor 232, and a focusing lens 240.

[0031] The laser beam L that has passed through aperture 201 is sequentially reflected at the center of the reflective surface 221A of the first galvanometer mirror 221 and at the center of the reflective surface 222A of the second galvanometer mirror 222, and is deflected in the X-axis and Y-axis directions, respectively. The deflected laser beam L passes through focusing lens 240 and is emitted from exit port 202 toward the workpiece 400 below.

[0032] The first galvanometer mirror 221 and the second galvanometer mirror 222 are combined such that the galvanometer mirrors rotate around axes perpendicular to each other.

[0033] The first galvanometer mirror 221 is provided for scanning the laser beam L in the X-axis direction. The second galvanometer mirror 222 is provided for scanning the laser beam L in the Y-axis direction.

[0034] The orientation of the reflective surface 221A of the first galvanometer mirror 221 changes in response to the drive of the first motor 231. The first galvanometer mirror 221 is supported by the drive shaft 231A and rotates around the drive shaft 231A as the axis of rotation.

[0035] The orientation of the reflective surface 222A of the second galvanometer mirror 222 changes in response to the driving of the second motor 232. The drive shaft 232A of the second motor 232 is positioned perpendicular to the drive shaft 231A of the first motor 231. The second galvanometer mirror 222 is supported by the drive shaft 232A and rotates around the drive shaft 232A as its axis of rotation.

[0036] The rotational position of the first galvanometer mirror 221 is adjusted according to the drive signal M1 output from the control unit 500 and applied to the first motor 231.

[0037] The rotational position of the second galvanometer mirror 222 is adjusted according to the drive signal M2 output from the control unit 500 and applied to the second motor 232.

[0038] A focusing lens 240 is positioned on the optical axis S between the second galvanometer mirror 222 and the workpiece 400 for adjusting the focus. The focusing lens 240 is an fθ lens and functions to cause the laser beam L to be incident perpendicularly to the focusing plane (image plane). The focusing lens 240 adjusts the focal position of the laser beam L reflected by the second galvanometer mirror 222, so that the laser beam L is imaged onto the workpiece 400 with the workpiece 400 as the focal plane.

[0039] Therefore, the laser beam L is sequentially irradiated in a spot manner at each position (X, Y) on the workpiece 400 corresponding to the rotational position of the first galvanometer mirror 221 and the rotational position of the second galvanometer mirror 222, and material melting, evaporation, etc., occurs at those positions (X, Y) on the workpiece 400 according to the laser energy.

[0040] The acousto-optic deflector unit 100 is provided with a bracket portion 190 for connecting the acousto-optic deflector unit 100 to the galvanoscanner unit 200.

[0041] An aperture 191 is formed in the bracket portion 190. The aperture diameter of the aperture 191 is preferably such that it can pass through the refracted light emitted from the second acousto-optic deflector 120.

[0042] The housing 200A of the galvanometer scanner unit 200 is mounted on the bracket portion 190 such that the aperture 191 of the bracket portion 190 and the aperture 201 of the housing 200A of the galvanometer scanner unit 200 are aligned.

[0043] The control unit 500 is a controller of the laser processing apparatus 10, and is composed of a microprocessor, a ROM, a RAM, and the like. The ROM of the control unit 500 stores control programs for controlling the acousto-optic deflector unit 100, the galvano scanner unit 200, and the front-stage optical system unit 300. The microprocessor executes the control programs stored in the ROM using the RAM which is a working memory, thereby controlling each control target such as the laser light source 310, the first acousto-optic deflector 110, the second acousto-optic deflector 120, the first galvano mirror 221 (the first motor 231), and the second galvano mirror 222 (the second motor 232).

[0044] The terminal device 20 is, for example, a personal computer, and is configured to include an input unit such as a keyboard, and a display 21 provided with a display screen 21A.

[0045] Note that the configuration may be such that the functions of the terminal device 20 and the functions of the control unit 500 are provided in the same unit.

[0046] The control unit 500 receives processing data DT from the terminal device 20 via a communication interface that transmits and receives data wirelessly or by wire, or via a network such as the Internet, and adjusts the deflection angle of the laser beam L by the first acousto-optic deflector 110, the deflection angle of the laser beam L by the second acousto-optic deflector 120, the rotational position of the first galvano mirror 221, and the rotational position of the second galvano mirror 222 in accordance with the received processing data DT, so as to control the drawing trajectory of the laser beam L on the workpiece 400.

[0047] Note that the control unit 500 may acquire the processing data DT generated by the terminal device 20 using a portable recording medium such as a USB memory or an SD card.

[0048] FIG. 3 shows an example of laser processing performed by the laser processing apparatus 10 of the embodiment.

[0049] On the workpiece 400, for example, marking can be sequentially performed with predetermined graphic patterns PT1, PT2, PT3, and PT4 for each area AR1, AR2, AR3, and AR4. For example, laser processing is performed in area AR1 by driving and controlling the first acousto-optic deflector 110 and the second acousto-optic deflector 120. When laser processing in area AR1 is completed, the laser beam irradiation position is moved from area AR1 to the next area AR2 by driving and controlling the first motor 231 and the second motor 232. Next, laser processing is performed in the next area AR2 by driving and controlling the first acousto-optic deflector 110 and the second acousto-optic deflector 120. Thereafter, the movement from area AR2 to area AR3, laser processing in area AR3, movement from area AR3 to area AR4, and laser processing in area AR4 are repeated sequentially in the same manner. Note that graphic patterns PT1, PT2, PT3, and PT4 may be the same graphic pattern. Thus, according to the laser processing apparatus 10 of this embodiment, the laser processing of predetermined graphic patterns PT1, PT2, PT3, and PT4 can be performed by operating the first acousto-optic deflector 110 and the second acousto-optic deflector 120, and movement between each area AR1, AR2, AR3, and AR4 can be performed by operating the galvanometer scanner 210.

[0050] (Example of use of the acousto-optic deflector unit 100)

[0051] Figures 4(A) and 4(B) illustrate examples of the use of the acousto-optic deflector unit 100.

[0052] Figure 4(A) illustrates a case where the laser processing apparatus 10 is configured without the acousto-optic deflector unit 100, and consists of a galvanoscanner unit 200, a pre-optical system unit 300, and a control unit 500'.

[0053] Figure 4(B) illustrates a case where an acousto-optic deflector unit 100 is incorporated into the laser processing apparatus 10 of Figure 4(A), and the laser processing apparatus 10 is configured with the acousto-optic deflector unit 100, a galvanometer scanner unit 200, a pre-optical system unit 300, and a control unit 500.

[0054] According to this embodiment, depending on the customer's request, a laser processing apparatus 10 equipped with an acousto-optic deflector unit 100 (Figure 4(B)) or a laser processing apparatus 10 without an acousto-optic deflector unit 100 (Figure 4(A)) can be selected.

[0055] Furthermore, by incorporating the acousto-optic deflector unit 100 into an existing laser processing apparatus 10 without the acousto-optic deflector unit 100 (Figure 4(A)), a laser processing apparatus 10 equipped with the acousto-optic deflector unit 100 (Figure 4(B)) can be easily constructed. The acousto-optic deflector unit 100 should be installed between the optical system unit 300 and the galvanoscanner unit 200 so that each optical element of the acousto-optic deflector unit 100 is aligned along the optical axis S between the pre-optical system unit 300 and the galvanoscanner unit 200.

[0056] (Acousto-optic deflector unit 100)

[0057] Figures 5A and 5B show an example configuration of the acoustic-optic deflector unit 100 according to the embodiment.

[0058] Figure 5A shows the acousto-optic deflector unit 100 as viewed in the XY plane.

[0059] Figure 5B shows the acousto-optic deflector unit 100 as viewed in the XZ plane.

[0060] In Figures 5A and 5B, the left side is referred to as the "upstream" side, and is the side where the pre-optical system unit 300 is located. In Figures 5A and 5B, the right side is referred to as the "downstream" side, and is the side where the galvanoscanner unit 200 is located.

[0061] The acousto-optic deflector unit 100 has a first acousto-optic deflector 110, a λ / 2 wave plate 130, a second acousto-optic deflector 120, a relay lens 140, a focal plane mask 150, a relay lens 160, and a λ / 4 wave plate 170 arranged in series from upstream to downstream.

[0062] The first acousto-optic deflector 110, the λ / 2 wave plate 130, the second acousto-optic deflector 120, the relay lens 140, the focal plane mask 150, the relay lens 160, and the λ / 4 wave plate 170 are mounted on a substrate 100B.

[0063] The first acoustic-optic deflector 110 is supported on a base 100B via a first rotating stage 111, a goniometer stage 112, a Y-stage 113, and a Z-stage 114, so that it can rotate around the Z-axis, swing in an arc, move in the Y-axis direction, and move in the Z-axis direction.

[0064] The λ / 2 wave plate 130 is supported on the base 100B so that it can rotate around the optical axis via a rotating holder 131. The λ / 2 wave plate 130 rotates 90° to match the polarization direction of the laser beam L emitted from the first acousto-optic deflector 110 to the incidence of the second acousto-optic deflector 120.

[0065] The second acoustic-optic deflector 120 is supported via the second rotating stage 121, rotating stage 122, Y stage 123, and Z stage 124 so as to be rotatable around the Y axis and rotatable around the Z axis, and movable in the Y direction and movable in the Z direction.

[0066] The relay lens 140 is located inside the lens barrel 141. The relay lens 140 is supported on the base 100B via the lens barrel 141.

[0067] The focal plane mask 150 is held by a holder 151. The focal plane mask 150 is supported on a base 100B via the holder 151, X stage 152, Y stage 153, and Z stage 154 so as to be movable in the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0068] The relay lens 160 is located inside the lens barrel 161. The relay lens 160 is supported on the base 100B so that it can move in the X-axis direction via the lens barrel 161 and the X-stage 162.

[0069] The λ / 4 wave plate 170 is supported on the substrate 100B so that it can rotate around the optical axis via a rotating holder 171.

[0070] A bracket portion 190 is provided at the downstream end of the base plate 100B.

[0071] A space 190S for arranging a power meter (output meter) 180, which will be described later, is provided between the λ / 4 wave plate 170 and the bracket portion 190.

[0072] (Control of the diffraction angle and optimal installation angle of the first acousto-optic deflector 110 and the second acousto-optic deflector 120)

[0073] Figures 6A and 6B illustrate the control of the optimal installation angles of the first acousto-optic deflector 110 and the second acousto-optic deflector 120, respectively.

[0074] The first acousto-optic deflector 110 and the second acousto-optic deflector 120 are arranged in series on the optical axis S of the laser beam L emitted from the pre-optical system unit 300.

[0075] The first acousto-optic deflector 110 and the second acousto-optic deflector 120 are each arranged to deflect and emit the laser beam L in two mutually orthogonal axes.

[0076] The first acoustic-optic deflector 110 is positioned on the optical axis S of the laser beam L emitted from the preceding optical system unit 300. The laser beam L is incident at a predetermined optimal setting angle θB1 and deflected at an angle (separation angle) θ1 corresponding to the input ultrasonic frequency fa1, causing the laser beam L to be emitted.

[0077] The first rotating stage 111 is rotatable around the Z-axis so as to allow adjustment of the optimal mounting angle θB1, and the first acousto-optic deflector 110 is mounted on it.

[0078] The rotary stage drive unit 510 drives the rotation of the first rotary stage 111 according to the manipulated amount S1. The rotary stage drive unit 510 is configured to include, for example, a motor that drives the first rotary stage 111. The manipulated amount S1 corresponds to an electrical signal that drives this motor.

[0079] The control unit 500 controls the drive of the rotary stage drive unit 510. The control unit 500 outputs an electrical signal corresponding to the manipulated amount S1 to the rotary stage drive unit 510.

[0080] The second acousto-optic deflector 120 is positioned on the optical axis S of the laser beam L emitted from the preceding optical system unit 300 and deflected by the first acousto-optic deflector 110. The laser beam L is incident at a predetermined optimal setting angle θB2 and is deflected at an angle θ2 corresponding to the input ultrasonic frequency fa2, causing the laser beam L to be emitted.

[0081] The second rotating stage 121 is rotatable around the Y-axis so as to allow adjustment of the optimal mounting angle θB2, and the second acousto-optic deflector 120 is mounted on it.

[0082] The rotary stage drive unit 520 drives the rotation of the second rotary stage 121 according to the manipulated amount S2. The rotary stage drive unit 520 is configured to include, for example, a motor that drives the second rotary stage 121. The manipulated amount S2 corresponds to an electrical signal that drives this motor. The control unit 500 controls the driving of the rotary stage drive unit 520.

[0083] The control unit 500 outputs an electrical signal corresponding to the manipulated amount S2 to the rotary stage drive unit 520.

[0084] Figure 6C illustrates the control of the diffraction angles of the first acousto-optic deflector 110 and the second acousto-optic deflector 120. Figure 6C shows the configuration of the first acousto-optic deflector 110 as a representative example.

[0085] The first acousto-optic deflector 110 is configured to include an acoustic medium 110A made of a material such as lead molybdate or tellurium dioxide, which produces an acousto-optic effect.

[0086] The first acousto-optic deflector 110 is configured by attaching a piezoelectric transducer 110B to an acoustic medium 110A. The piezoelectric transducer 110B generates ultrasonic waves that propagate within the acoustic medium 110A based on an RF (radio frequency) drive signal RF1 provided by the control unit 500.

[0087] In the first acousto-optic deflector 110, if no RF drive signal RF1 is supplied to the piezoelectric vibrator 110B from the control unit 500, the laser beam L passes through the acoustic medium 110A without diffraction. The laser beam L that has passed through the acoustic medium 110A without diffraction continues to propagate along the optical axis S as zero-order diffracted light L0.

[0088] When the control unit 500 provides an RF drive signal RF1 to the piezoelectric vibrator 110B of the first acousto-optic deflector 110, the laser beam L is diffracted by the acoustic medium 110A at an angle θ1 corresponding to the RF drive signal RF1, and emitted from the acoustic medium 110A as first-order diffracted light L1.

[0089] When the angle of diffraction (separation angle) relative to the incident laser beam L is denoted as θ1, sinθ1 is proportional to the frequency fa1 of the ultrasonic waves propagating within the acoustic medium 110A. The frequency fa1 of the ultrasonic waves propagating within the acoustic medium 110A is equal to the frequency of the RF drive signal RF1 supplied to the piezoelectric transducer 110B. Therefore, the angle θ1 at which the first diffracted light L1 is diffracted can be changed according to the frequency of the RF drive signal RF1, thereby deflecting the laser beam L to a desired angle.

[0090] As shown in Figure 6C, enclosed in parentheses and with the subscript 1 replaced by 2, the second acousto-optic deflector 120 can similarly change the diffraction angle θ2 of the primary diffracted light L1 according to the frequency of the RF drive signal RF2, thereby deflecting the laser beam L to a desired angle.

[0091] (Control of the optimal installation angles θB1 and θB2 of the first acousto-optic deflector 110 and the second acousto-optic deflector 120 using the power meter 180)

[0092] Figures 7A and 7B illustrate the optimal installation angles (Bragg angles) θB1 and θB2 of the first acousto-optic deflector 110 and the second acousto-optic deflector 120, respectively.

[0093] Figure 7A(A) is a diagram in the YZ plane showing how the installation angle of the first acousto-optic deflector 110 is adjusted to the optimal installation angle θB1 by the first rotating stage 111. Figure 7A(B) is a diagram in the XY plane showing how the installation angle of the first acousto-optic deflector 110 is adjusted to the optimal installation angle θB1 by the first rotating stage 111.

[0094] Figure 7B(A) shows, in the YZ plane, how the installation angle of the second acousto-optic deflector 120 is adjusted to the optimal installation angle θB2 by the second rotating stage 121. Figure 7B(B) shows, in the XZ plane, how the installation angle of the second acousto-optic deflector 120 is adjusted to the optimal installation angle θB2 by the second rotating stage 121.

[0095] The first acousto-optic deflector 110 and the second acousto-optic deflector 120 each have their own unique optimal installation angles (Bragg Angle) θB1 and θB2, which result in an ideal angle for the laser beam L incident on the sound wave plane. The optimal installation angles θB1 and θB2 may be the same. For example, the optimal installation angles θB1 and θB2 are 0.301°.

[0096] If the first acousto-optic deflector 110 and the second acousto-optic deflector 120 can be precisely set to the optimal angles θB1 and θB2, the output (power) of the first-order diffracted light L1 will be maximized. If the installation angles of the first acousto-optic deflector 110 and the second acousto-optic deflector 120 deviate from the optimal angles θB1 and θB2, the output of the zero-order diffracted light L0 will increase, reducing the quality and efficiency of laser processing.

[0097] Therefore, the first acousto-optic deflector 110 and the second acousto-optic deflector 120 are set at the optimal installation angles θB1 and θB2 predetermined in the specifications, respectively. Then, a laser beam L is incident on them, and the first diffracted light L1 is irradiated onto the power meter 180. The laser power (laser output) P detected by the power meter 180 is used as a feedback amount to fine-tune the operating amounts S1 and S2 given to the rotary stage drive unit 510 of the first rotary stage 111 and the rotary stage drive unit 520 of the second rotary stage 121, respectively, so that the laser power P is maximized. The power meter 180 detects the energy (in W) per unit time of the incident laser beam L.

[0098] As shown in Figures 5A and 5B, the power meter 180 is installed in the space 190S between the λ / 4 wave plate 170 and the bracket portion 190 of the acousto-optic deflector unit 100.

[0099] Figure 8 shows a control block diagram for adjusting the first acousto-optic deflector 110 and the second acousto-optic deflector 120 to their optimal installation angles. The functions of the optimal installation angle control unit 530 shown in Figure 8 are provided by the control unit 500.

[0100] The control to adjust the first acousto-optic deflector 110 and the second acousto-optic deflector 120 to the optimal installation angle can be performed by the following procedure.

[0101] Step ST11: The first rotating stage 111 is rotated around the Z-axis to adjust the installation angle of the first acousto-optic deflector 110 to the optimal installation angle θB1 (0.301°). This control may be performed manually or automatically. If automatic control is used, the optimal installation angle θB1 (0.301°) is set as the target value, and the current installation angle is used as the feedback amount to adjust the control variable S1 so that the deviation between the optimal installation angle (target value) and the current installation angle becomes zero. Fine adjustment of the optimal installation angle is then performed.

[0102] Step ST12: The laser beam L emitted from the pre-optical system unit 300 is directed into the first acousto-optic deflector 110, and the laser power P(W) of the laser beam L emitted from the first acousto-optic deflector 110 is detected by the power meter 180.

[0103] Step ST13: Using the current laser power detection value P detected by the power meter 180 as a feedback amount, the operating amount S1 given to the rotary stage drive unit 510 that drives the first rotary stage 111 is adjusted so that the laser power is maximized.

[0104] Step ST14: Store the rotation position of the first rotating stage 111 (the installation angle of the first acousto-optic deflector 110) when the current detected laser power value P reaches its maximum output.

[0105] Step ST15: Using the rotation position of the first rotating stage 111 (the installation angle of the first acoustic-optic deflector 110) stored in Step ST14 as the target value, the operating amount S1 given to the rotating stage drive unit 510 is adjusted so that the deviation between this target value and the current rotation position of the first rotating stage 111 (the installation angle of the first acoustic-optic deflector 110) becomes zero.

[0106] Although the first acousto-optic deflector 110 has been described, the second acousto-optic deflector 120 can also be controlled to adjust to the optimal installation angle using the same procedure as in steps ST11 to ST15.

[0107] (Control of the optimal position of the focal plane mask 150)

[0108] When the RF drive signal RF2 is applied to the second acousto-optic deflector 120, multiple laser beams are output, including the incident zero-order diffracted light L0, the refracted first-order diffracted light L1, as well as second-order diffracted light and -1st-order diffracted light.

[0109] When nth-order diffracted light (n=0, -1, ±2...) other than the first-order diffracted light L1 is irradiated onto the workpiece 400, there is a risk of deterioration that cannot be ignored in terms of quality and efficiency, especially in micro-machining.

[0110] Therefore, in the acousto-optic deflector unit 100 of this embodiment, the laser beam L is temporarily focused into the lens barrels 141 and 161 installed on the optical axis S, and the nth-order diffracted light (n=0, -1, ±2...) other than the first-order diffracted light L1 is masked by the focal plane mask 150, and the position of the focal plane mask 150 is adjusted to the optimal position so that only the first-order diffracted light L1 is irradiated onto the workpiece 400.

[0111] Figures 9(A) and 9(B) illustrate the control of the position of the focal plane mask 150.

[0112] Figure 9(A) shows, in the XY plane, how the coordinate position Y of the focal plane mask 150 is adjusted to the optimal position by the Y stage 153. Figure 9(B) shows, in the XZ plane, how the coordinate position Z of the focal plane mask 150 is adjusted to the optimal position by the Z stage 154. Figure 9(C) shows the focal plane mask 150 in the YZ plane. The focal plane mask 150 has a pinhole 150H formed therein to allow the laser beam L, which is the first diffracted light L1, to pass through.

[0113] The Y stage 153 and Z stage 154 each support the focal plane mask 150 so that it can move in the coordinate axis Y and Z directions, respectively. The Y stage 153 and Z stage 154 adjust the relative position of the pinhole 150H of the focal plane mask 150 with respect to the optical axis S of the laser beam L passing through the focal plane mask 150.

[0114] A power meter 180 is installed downstream of the base 100B. For example, as shown in Figures 5A and 5B, the power meter 180 is installed in the space 190S between the λ / 4 wave plate 170 and the bracket portion 190 of the acousto-optic deflector unit 100.

[0115] The control for adjusting the position of the focal plane mask 150 to the optimal position involves adjusting the position of the focal plane mask 150 so that the laser beam L passes through the pinhole 150H of the focal plane mask 150, then irradiating the power meter 180 with the first diffracted light L1, and using the laser power P detected by the power meter 180 as a feedback amount, the control fine-tunes the operation amounts S4 and S5 given to the coordinate position movement stage drive unit 540 of the Y stage 153 and the coordinate position movement stage drive unit 550 of the Z stage 154, respectively, so that the laser power P is maximized.

[0116] Figure 10 shows a control block diagram for adjusting the position of the focal plane mask 150 to the optimal position. The function of the optimal position control unit 560 shown in Figure 10 is provided by the control unit 500.

[0117] The coordinate position movement stage drive unit 540 drives the movement of the Y stage 153 in accordance with the manipulated amount S4. The coordinate position movement stage drive unit 540 is configured to include, for example, a motor that drives the Y stage 153. The manipulated amount S4 corresponds to the electrical signal that drives this motor.

[0118] The control unit 500 controls the drive of the coordinate position movement stage drive unit 540. The control unit 500 outputs an electrical signal corresponding to the manipulated amount S4 to the coordinate position movement stage drive unit 540.

[0119] The coordinate position movement stage drive unit 550 drives the movement of the Z-stage 154 in accordance with the manipulated amount S5. The coordinate position movement stage drive unit 550 is configured to include, for example, a motor that drives the Z-stage 154. The manipulated amount S5 corresponds to an electrical signal that drives this motor.

[0120] The control unit 500 controls the drive of the coordinate position movement stage drive unit 550. The control unit 500 outputs an electrical signal corresponding to the manipulated amount S5 to the coordinate position movement stage drive unit 550.

[0121] The control to adjust the position of the focal plane mask 150 to the optimal position can be performed by the following procedure.

[0122] Step ST21: The manipulated amounts S4 and S5 applied to the coordinate position movement stage drive unit 540 and the coordinate position movement stage drive unit 550 are adjusted so that the optical axis S of the laser beam L coincides with the center position of the pinhole 150H of the focal plane mask 150.

[0123] Step ST22: The laser power P(W) of the laser beam L emitted from the pre-optical system unit 300 and passing through the first acousto-optic deflector 110 and the second acousto-optic deflector 120 to the focal plane mask 150 is detected by the power meter 180.

[0124] Step ST23: The current laser power detection value P detected by the power meter 180 is used as a feedback amount to adjust the control amount S4 given to the coordinate position movement stage drive unit 540 that drives the Y stage 153 so that the laser power is maximized.

[0125] Step ST24: Store the coordinate position Yp of the Y-stage 153 (coordinate position Yp of the focal plane mask 150) when the current laser power detection value P reaches its maximum output.

[0126] Step ST25: The current laser power detection value P detected by the power meter 180 is used as a feedback amount to adjust the control amount S5 given to the coordinate position movement stage drive unit 550 that drives the Z stage 154 so that the laser power is maximized.

[0127] Step ST26: Store the coordinate position Zp of the Z-stage 154 (coordinate position Zp of the focal plane mask 150) when the current laser power detection value P reaches its maximum output.

[0128] Step ST27: Using the coordinate position Yp of the Y-stage 153 (coordinate position Yp of the focal plane mask 150) stored in Step ST24 and the coordinate position Zp of the Z-stage 154 (coordinate position Zp of the focal plane mask 150) stored in Step ST26 as target values, the operating amounts S4 and S5 given to the coordinate position movement stage drive units 540 and 550 are adjusted so that the deviations between these target values ​​Yp and Zp and the current coordinate position Y of the Y-stage 153 (coordinate position Y of the focal plane mask 150) and the current coordinate position Z of the Z-stage 154 (coordinate position Z of the focal plane mask 150) are zero.

[0129] (Examples)

[0130] The following describes the procedure for installing the acousto-optic deflector unit 100 between the optical system unit 300 and the galvanoscanner unit 200.

[0131] (preparation process)

[0132] Figures 11(A) and (B) show the preparation steps for setting the reference optical axis by installing the laser light source 310.

[0133] Figure 11(A) is a view in the XY plane. Figure 11(B) is a view in the XZ plane.

[0134] An adjustment mask 195 is provided at the downstream end of the base 100B of the acousto-optic deflector unit 100. Further downstream of the acousto-optic deflector unit 100, a second mirror 330, a first mirror 320, an adjustment λ / 2 wave plate 130', and a laser light source 310 are sequentially provided. The adjustment λ / 2 wave plate 130' is responsible for aligning the polarization direction of the laser beam L when adjusting the optimal installation angle of the second acousto-optic deflector 120, which will be described later.

[0135] A pinhole 195H with a predetermined diameter (3.0 ± 0.1 mm) is formed in the center of the adjustment mask 195. The pinhole 195H of the adjustment mask 195 serves as the reference for the optical system of the acousto-optic deflector unit 100.

[0136] The adjustment mask 195 is installed at the incident surface of the galvanoscanner 210, that is, at a position corresponding to the aperture 191 of the bracket portion 190. The adjustment mask 195 is installed so as to coincide with the design position and angle of the laser beam L incident on the galvanoscanner 210.

[0137] From the perspective of the laser light source 310, a mirror 196 is installed on the back surface of the adjustment mask 195.

[0138] A laser beam L is emitted from the laser light source 310 towards the upstream side. The optical axis S of the laser beam L emitted from the laser light source 310 is adjusted by the kinematic mounts 321 and 331 so that it passes through the adjustment λ / 2 wave plate 130', the first mirror 320, the second mirror 330, and the pinhole 195H of the adjustment mask 195, is reflected by the mirror 196 on the back of the adjustment mask 195, and returns to the emission position of the laser light source 310. The optical axis S of the laser beam L adjusted in this way becomes the reference optical axis in each subsequent adjustment process.

[0139] When the optical axis S of the laser beam L is adjusted to the reference optical axis by the kinematic mounts 321 and 331, the mirror 196 is removed from the adjustment mask 195.

[0140] (Step for adjusting the installation positions of relay lenses 140, 160 and λ / 4 wave plate 170)

[0141] Figures 12(A) and (B) show the process of adjusting the installation positions of the relay lenses 140, 160 and the λ / 4 wave plate 170.

[0142] Figure 12(A) is a view in the XY plane. Figure 12(B) is a view in the XZ plane.

[0143] The λ / 4 wave plate 170 is mounted on the substrate 100B with a predetermined mechanical precision (for example, ±0.2 mm).

[0144] The relay lenses 140 and 160 are installed on the substrate 100B with a predetermined tolerance (for example, ±0.1 mm) relative to the reference optical axis of the laser beam L.

[0145] The downstream relay lens 160 is mounted on the X-stage 162 so that its focal position can be adjusted in the direction of the optical axis S (X direction) by the X-stage 162. Alternatively, the focal position of the relay lens 160 may be adjusted by adjusting shims instead of the X-stage 162.

[0146] (Adjustment process for the focal position of relay lens 160)

[0147] Figures 13(A) and (B) show the process of adjusting the focal position of the relay lens 160.

[0148] Figure 13(A) is a view in the XY plane. Figure 13(B) is a view in the XZ plane.

[0149] A collimation checker 145 is installed on the substrate 100B, upstream of the relay lens 140. The collimation checker 145 measures the parallelism (collimation degree) of the laser beam L.

[0150] A laser beam L is emitted from the laser light source 310 towards the upstream side. The laser beam L passes through the adjustment λ / 2 wave plate 130', the first mirror 320, the second mirror 330, the pinhole 195H of the adjustment mask 195, the λ / 4 wave plate 170, the relay lens 160, and the relay lens 140, and is incident on the collimation checker 145. The focal position of the relay lens 160 is adjusted so that the parallelism of the laser beam L measured by the collimation checker 145 reaches a predetermined level. The focal position of the relay lens 160 is adjusted by driving the X stage 162 to move the relay lens 160 in the X direction.

[0151] (Adjustment process for the position of the focal plane mask 150)

[0152] Figures 14(A) and (B) show the process of adjusting the position of the focal plane mask 150.

[0153] Figure 14(A) is a view in the XY plane. Figure 14(B) is a view in the XZ plane.

[0154] Figures 15(A), (B), and (C) show the focal plane mask 150 in the YZ plane.

[0155] A focal plane mask 150 is installed on the substrate 100B between the relay lens 140 and the relay lens 160. The focal plane mask 150 is mounted on the Y stage 153 and Z stage 154 so that the relative position of the focal plane mask 150 and the optical axis S of the laser beam L passing through the focal plane mask 150 can be adjusted by the Y stage 153 and Z stage 154.

[0156] The focal plane mask 150 preferably has a structure in which a mask 150B, which has a small-diameter pinhole 150H' for alignment, is detachably superimposed on a mask 150A, which has a large-diameter pinhole 150H formed therein for laser processing. The diameter of the pinhole 150H for laser processing is, for example, 1 mm, and the diameter of the pinhole 150H' for alignment is, for example, 0.1 mm. In addition, the pinhole 150H of the focal plane mask 150 may be configured as a variable aperture to change the pinhole diameter during alignment and laser processing.

[0157] A laser beam L is emitted from the laser light source 310 towards the upstream side. The laser beam L passes through the adjustment λ / 2 wave plate 130', the first mirror 320, the second mirror 330, the pinhole 195H of the adjustment mask 195, the λ / 4 wave plate 170, the relay lens 160, the pinhole 150H' of the focal plane mask 150, and the relay lens 140, and is incident on the collimation checker 145. The focal position of the focal plane mask 150 is adjusted so that the parallelism of the laser beam L measured by the collimation checker 145 reaches a predetermined level. The focal position of the focal plane mask 150 is adjusted by driving the X stage 152 to move the focal plane mask 150 in the X-axis direction.

[0158] The same process as in step ST21 is performed. The Y-axis and Z-axis positions of the focal plane mask 150 are adjusted so that the laser beam L passes through the center of the pinhole 150H'. By driving the Y-stage 153 and Z-stage 154 to move the focal plane mask 150 in the Y-axis and Z-axis directions, the optical axis S of the laser beam L coincides with the center of the pinhole 150H'.

[0159] After adjusting the position of the focal plane mask 150, the collimation checker 145 is removed from the base 100B.

[0160] (Steps for adjusting the installation position and angle of the second acoustic-optic deflector 120)

[0161] Figures 16(A) and (B) show the process of adjusting the installation position and installation angle of the second acousto-optic deflector 120.

[0162] Figure 16(A) is a view in the XY plane. Figure 16(B) is a view in the XZ plane.

[0163] A second acousto-optic deflector 120 is installed on the substrate 100B, upstream of the relay lens 140. The second acousto-optic deflector 120 is mounted on the second rotating stage 121, rotating stage 122, Y stage 123, and Z stage 124 so that its rotational position can be adjusted around the Y axis, its rotational position can be adjusted around the Z axis, its position in the Y axis direction can be adjusted, and its position in the Z axis direction can be adjusted.

[0164] A mirror 126 is installed on the front surface of the second acousto-optic deflector 120, as viewed from the laser light source 310.

[0165] A laser beam L is emitted from the laser light source 310 towards the upstream side. The laser beam L passes through the adjustment λ / 2 wave plate 130', the first mirror 320, the second mirror 330, the pinhole 195H of the adjustment mask 195, the λ / 4 wave plate 170, the relay lens 160, the pinhole 150H' of the focal plane mask 150, and the relay lens 140, and is reflected by the mirror 126 on the front surface of the second acousto-optic deflector 120. The Y-axis and Z-axis positions of the second acousto-optic deflector 120 are adjusted so that the optical axis S of the laser beam L reflected by the mirror 126 coincides with the center of the output port 120H of the second acousto-optic deflector 120, and the laser beam L reflected by the mirror 126 returns to the output position of the laser light source 310. By driving the Y-stage 123 and the Z-stage 124, the Y-axis and Z-axis positions of the second acousto-optic deflector 120 are adjusted.

[0166] After adjusting the Y-axis and Z-axis positions of the second acousto-optic deflector 120, the mirror 126 is removed from the second acousto-optic deflector 120.

[0167] Next, the second rotating stage 121 is rotated around the Y-axis in the same manner as in step ST11, and the installation angle of the second acousto-optic deflector 120 is adjusted to the optimal installation angle θB2 (0.301°). As a result, the second acousto-optic deflector 120 is tilted by 2θB2 (0.602°) in the XZ plane.

[0168] (Steps for adjusting the installation position and installation angle of the first acoustic-optic deflector 110)

[0169] Figures 17(A) and (B) show the process of adjusting the installation position and installation angle of the first acousto-optic deflector 110.

[0170] Figure 17(A) is a view in the XY plane. Figure 17(B) is a view in the XZ plane.

[0171] The λ / 2 wave plate 130 and the second acousto-optic deflector 120 are sequentially installed on the substrate 100B, facing upstream of the second acousto-optic deflector 120. The λ / 2 wave plate 130 is installed on the substrate 100B with a predetermined mechanical precision (for example, ±0.2 mm).

[0172] The first acoustic-optic deflector 110 is mounted on the first rotating stage 111, goniometer stage 112, Y-stage 113, and Z-stage 114 so that its rotational position around the Z-axis, its oscillation position, its Y-axis position, and its Z-axis position can be adjusted, respectively.

[0173] A mirror 116 is installed on the front surface of the first acousto-optic deflector 110, as viewed from the laser light source 310.

[0174] A laser beam L is emitted from the laser light source 310 towards the upstream side. The laser beam L passes through the adjustment λ / 2 wave plate 130', the first mirror 320, the second mirror 330, the pinhole 195H of the adjustment mask 195, the λ / 4 wave plate 170, the relay lens 160, the pinhole 150H' of the focal plane mask 150, the relay lens 140, the second acousto-optic deflector 120, and the λ / 2 wave plate 130, and is reflected by the mirror 116 on the front surface of the first acousto-optic deflector 110. The Y-axis and Z-axis positions of the first acousto-optic deflector 110 are adjusted so that the optical axis S of the laser beam L reflected by the mirror 116 coincides with the center of the output port 110H of the first acousto-optic deflector 110, and the laser beam L reflected by the mirror 116 returns to the output position of the laser light source 310. By driving the Y-stage 113 and the Z-stage 114, the Y-axis position and Z-axis position of the first acousto-optic deflector 110 are adjusted.

[0175] After adjusting the Y-axis and Z-axis positions of the first acousto-optic deflector 110, the mirror 116 is removed from the first acousto-optic deflector 110.

[0176] Next, the first rotating stage 111 is rotated around the Z axis in the same manner as in step ST11, and the installation angle of the first acousto-optic deflector 110 is adjusted to the optimal installation angle θB1 (0.301°). As a result, the first acousto-optic deflector 110 is tilted by 2θB1 (0.602°) in the XY plane.

[0177] (Step for adjusting the installation position of the optical system of the preceding optical system unit 300)

[0178] Figures 18(A) and (B) show the process of adjusting the optical system installation position of the pre-optical system unit 300.

[0179] Figure 18(A) is a view in the XY plane. Figure 18(B) is a view in the XZ plane.

[0180] In the preparation steps shown in Figures 11(A) and (B), the laser light source 310, the first mirror 320, and the second mirror 330, which are installed downstream of the base 100B of the acousto-optic deflector unit 100, are removed along with the kinematic mounts 321 and 331 and installed upstream of the base 100B.

[0181] The laser light source 310, the first mirror 320, and the second mirror 330, which are installed on the upstream side of the substrate 100B, constitute the pre-optical system unit 300.

[0182] A mirror 196 is installed on the back surface of the adjustment mask 195 as viewed from the laser light source 310.

[0183] A laser beam L is emitted downstream from the laser light source 310. The laser beam L passes through the first mirror 320, the second mirror 330, the first acousto-optic deflector 110, the λ / 2 wave plate 130, the second acousto-optic deflector 120, the relay lens 140, the pinhole 150H' of the focal plane mask 150, the relay lens 160, and the λ / 4 wave plate 170, and is reflected by the mirror 196 on the back surface via the pinhole 195H of the adjustment mask 195. The pitch tilt angle and yaw tilt angle of the kinematic mounts 321 and 331 are adjusted so that the optical axis S of the laser beam L reflected by the mirror 196 coincides with the center of the pinhole 195H of the adjustment mask 195, and the laser beam L reflected by the mirror 196 returns to the emission position of the laser light source 310. The optical axis S of the laser beam L coincides with the center position (X0, Y0, Z0) of the pinhole 195H of the adjustment mask 195. This center position (X0, Y0, Z0) of the pinhole 195H of the adjustment mask 195 becomes the reference position when mounting the galvanometer scanner unit 200.

[0184] After adjusting the installation position of the optical system of the preceding optical system unit 300, the adjustment mask 195 is removed from the base 100B of the acousto-optic deflector unit 100 together with the mirror 196.

[0185] (Steps for fine-tuning the installation angles of the first acousto-optic deflector 110, the second acousto-optic deflector 120, and the λ / 2 wave plate 130, as well as the installation position of the focal plane mask 150)

[0186] Figures 19(A) and (B) show the process of fine-tuning the installation angles of the first acousto-optic deflector 110, the second acousto-optic deflector 120, and the λ / 2 wave plate 130, as well as the installation position of the focal plane mask 150.

[0187] Figure 19(A) is a view in the XY plane. Figure 19(B) is a view in the XZ plane.

[0188] The power meter 180 is installed in the space 190S between the λ / 4 wave plate 170 and the bracket portion 190 of the acousto-optic deflector unit 100.

[0189] The same processes as in steps ST12, ST13, ST14, and ST15 are executed sequentially. As a result, the installation angle of the first acousto-optic deflector 110 is finely adjusted so that the laser power detected value P detected by the power meter 180 becomes the maximum output. Similarly, the installation angle of the second acousto-optic deflector 120 is finely adjusted so that the laser power detected value P detected by the power meter 180 becomes the maximum output.

[0190] Furthermore, the rotation angle of the λ / 2 wave plate 130 around the optical axis is finely adjusted so that the laser power detected value P, detected by the power meter 180, reaches its maximum output.

[0191] The following processes are the same as those in steps ST22 to ST27.

[0192] As a result, the installation position of the focal plane mask 150 is finely adjusted so that the laser power detection value P detected by the power meter 180 becomes the maximum output.

[0193] The power meter 180 is removed from the base 100B of the acousto-optic deflector unit 100.

[0194] The rotation angle of the λ / 4 wave plate 170 around its optical axis is adjusted to a specified angle (45°).

[0195] (Connection process between the acousto-optic deflector unit 100 and the galvanometer scanner unit 200)

[0196] Figures 20(A) and (B) show the process of connecting the acousto-optic deflector unit 100 to the galvanoscanner unit 200.

[0197] Figure 20(A) is a view in the XY plane. Figure 20(B) is a view in the XZ plane.

[0198] The bracket portion 190 is attached to the acousto-optic deflector unit 100.

[0199] The bracket portion 190 is attached to the base 100B such that the center position of the aperture 191 coincides with the center position (X0, Y0, Z0) of the pinhole 195H of the adjustment mask 195. Preferably, the bracket portion 190 is equipped with a mounting position adjustment mechanism that allows it to be attached to the base 100B in an adjustable manner in the X-axis, Y-axis, and Z-axis directions relative to the base 100B.

[0200] The housing 200A of the galvanoscanner unit 200 is mounted on the bracket portion 190 such that the aperture 191 of the bracket portion 190 and the aperture 201 of the housing 200A of the galvanoscanner unit 200 are aligned. This allows the laser beam L emitted from the acousto-optic deflector unit 100 to be sequentially incident on the center position of the reflective surface 221A of the first galvanoscanner mirror 221 and then on the center position of the reflective surface 222A of the second galvanoscanner mirror 222.

[0201] (Generating processing data and controlling laser processing)

[0202] The process of generating processing data and controlling laser processing will be explained with reference to Figures 1 and 3.

[0203] The user can generate processing data using the terminal device 20. This processing data generation process and processing process are realized by the processor executing a processing data generation program stored in the ROM, storage, or other memory unit of the terminal device 20.

[0204] When the processing data generation program is started, a graphic pattern generation screen is displayed on the display screen 21A of the terminal device 20. The graphic pattern generation screen displays a two-dimensional coordinate axis that allows the user to specify coordinate positions such as the center position of a shape, the distance between elements constituting the shape, etc. The user can draw the desired graphic patterns PT1, PT2, PT3, and PT4 by operating an input unit such as a mouse or keyboard to specify the coordinate positions, distances, radii, etc. of points, lines, circles, etc. on the graphic pattern generation screen. Once the graphic patterns PT1, PT2, PT3, and PT4 are drawn, they are stored in the ROM as graphic data SD1, SD2, SD3, and SD4. Note that graphic patterns PT1, PT2, PT3, and PT4 may be graphic patterns of the same shape.

[0205] Next, a screen for indicating the distance to move is displayed on the display screen 21A of the terminal device 20. On the screen for indicating the distance to move between the graphic patterns generated on the graphic pattern generation screen, the user can specify the distance to move between them. For example, the distance to move between graphic patterns PT1, PT2, PT3, and PT4 can be specified using the following procedure.

[0206] The distance indication screen displays the representative points (e.g., center positions) P1, P2, P3, and P4 of each area AR1, AR2, AR3, and AR4, which correspond to the generated geometric patterns PT1, PT2, PT3, and PT4, respectively.

[0207] The user can specify the distances (ΔX1, ΔY1), (ΔX2, ΔY2), (ΔX3, ΔY3), and (ΔX4, ΔY4) between representative points P1, P2, P3, and P4 by operating input devices such as a mouse or keyboard on the distance instruction screen. The specified distances (ΔX1, ΔY1), (ΔX2, ΔY2), (ΔX3, ΔY3), and (ΔX4, ΔY4) between the table points P1, P2, P3, and P4 are stored in the ROM as movement data MD1, MD2, MD3, and MD4.

[0208] The graphic data SD1, SD2, SD3, SD4 and movement data MD1, MD2, MD3, MD4 stored in the ROM are transmitted from the terminal device 20 to the control unit 500 as processing data DT.

[0209] The control unit 500 reads the processing data DT in the order of SD1, MD1, SD2, MD2, SD3, MD3, and SD4, and executes control of the laser processing.

[0210] The control unit 500 outputs a laser oscillation command to the laser light source 310 and also outputs RF drive signals RF1 and RF2 corresponding to the graphic data SD1 to the first acousto-optic deflector 110 and the second acousto-optic deflector 120, respectively, to scan and irradiate the laser beam L within area AR1 and laser process the workpiece 400 with the graphic pattern PT1.

[0211] Next, the laser oscillation command to the laser light source 310 is turned off, and the irradiation of the laser beam L is stopped. The control unit 500 outputs drive signals M1 and M2 corresponding to the movement data MD1 to the first motor 231 and the second motor 232 of the galvanoscanner 210, causing the galvanoscanner 210's output optical axis to move from area AR1 to the next area AR2 by a distance (ΔX1, ΔY1).

[0212] Next, the control unit 500 outputs a laser oscillation command to the laser light source 310 and outputs RF drive signals RF1 and RF2 corresponding to the graphic data SD2 to the first acousto-optic deflector 110 and the second acousto-optic deflector 120, respectively, to scan and irradiate the laser beam L within area AR2 and laser process the workpiece 400 with the graphic pattern PT2.

[0213] Similarly, the following processes are repeated sequentially: moving the output optical axis of the galvanometer scanner 210 from area AR2 to area AR3 according to the movement data MD2, graphic data SD3, movement data MD3, and graphic data SD4; laser processing the workpiece 400 with graphic pattern PT13 in area AR3; moving the output optical axis of the galvanometer scanner 210 from area AR3 to area AR4; and laser processing the workpiece 400 with graphic pattern PT14 in area AR4.

[0214] Therefore, according to this embodiment, large-area laser processing can be performed at high speed and with high precision.

[0215] 10 Laser processing device 20 Terminal device 21 Display 21A Display screen 100 Acousto-optic deflector unit 100B Substrate 110 Acousto-optic deflector 110A Acoustic medium 110B Piezoelectric transducer 110H Output port 111 Rotating stage 112 Goniometer stage 113 Stage 114 Stage 116 Mirror 120 Acousto-optic deflector 120H Output port 121 Rotating stage 122 Rotating stage 123 Stage 124 Stage 126 Mirror 130 Waveplate 131 Rotating holder 140 Relay lens 141 Lens barrel 145 Collimation checker 150 Unit for laser processing device 150 Focal plane mask 150A Mask 150B Mask 150H Pinhole 151 Holder 152 Stage 153 Stage 154 Stage 160 Relay Lens 161 Lens Tube 162 Stage 170 Waveplate 171 Rotating Holder 180 Power Meter 190 Bracket Section 190S Space 191 Aperture 195 Adjustment Mask 195H Pinhole 196 Mirror 200 Galvanoscanner Unit 200A Housing 201 Aperture 202 Output Port 210 Galvanoscanner 221 Galvano Mirror 221A Reflecting Surface 222 Galvano Mirror 222A Reflecting Surface 231 Motor 231A Drive Shaft 232 Motor 232A Drive Shaft 240 Focusing Lens 300 Optical System Unit 300 Pre-Optical System Unit 310 Laser Light Source 320 Mirror 320A Reflecting surface 321 Kinematic mount 330 Mirror 400 Workpiece 400 Work object 410 Stage 500 Control unit 510 Rotary stage drive unit 520 Rotary stage drive unit 530 Optimal installation angle control unit 540 Coordinate position movement stage drive unit 550 Coordinate position movement stage drive unit 560 Optimal position control unit

Claims

1. Acoustic-optical deflector unit for laser processing apparatus, comprising: an acoustic-optical deflector positioned on the optical axis of a laser beam emitted from a laser light source, which causes the laser beam to be incident at a predetermined optimal setting angle and deflects it to an angle corresponding to the frequency of input ultrasonic waves before emission; a rotating stage on which the acoustic-optical deflector is mounted so as to be rotatable in a rotational direction in which the optimal setting angle can be adjusted; and a rotating stage drive unit that drives the rotation of the rotating stage according to the amount of operation.

2. The acousto-optic deflector is configured to include a first acousto-optic deflector and a second acousto-optic deflector, which are arranged in series on the optical axis of a laser beam emitted from a laser light source, so that the laser beam is incident on it sequentially at a first optimal setting angle and a second optimal setting angle, and deflects the laser beam in two mutually orthogonal axial directions at angles corresponding to the frequency of the input ultrasonic waves, causing the laser beam to be emitted; the rotating stage is configured to include a first rotating stage on which the first acousto-optic deflector is mounted so as to be rotatable in a rotational direction in which the first optimal setting angle can be adjusted, and a second rotating stage on which the second acousto-optic deflector is mounted so as to be rotatable in a rotational direction in which the second optimal setting angle can be adjusted; and the rotating stage drive unit drives the rotation of the first rotating stage and the second rotating stage according to the amount of operation; the acousto-optic deflector unit for a laser processing apparatus according to claim 1.

3. The acousto-optic deflector unit for a laser processing apparatus according to claim 1 or 2, comprising: a laser power detection unit positioned on the optical axis of the laser beam emitted from the acousto-optic deflector and detecting the laser power of the laser beam; and a control unit that adjusts the operating amount so that the laser power detected by the laser power detection unit is maximized.

4. Acoustic-optical deflector unit for laser processing apparatus, comprising: an acoustic-optical deflector positioned on the optical axis of a laser beam emitted from a laser light source, which incident on the laser beam at a predetermined optimal setting angle and deflects it to an angle corresponding to the frequency of input ultrasonic waves; a mask section positioned on the optical axis of the laser beam emitted from the acoustic-optical deflector, which blocks n-th order diffracted light (n=0, -1, ±2...) other than the first-order diffracted light from the laser beam emitted from the acoustic-optical deflector, and emits only the first-order diffracted light; a coordinate position movement stage on which the mask section is mounted, which is movable in a coordinate axis direction that allows adjustment of the relative position of the mask section to the optical axis of the laser beam passing through the mask section; and a coordinate position movement stage drive section that drives the movement of the coordinate position of the coordinate position movement stage according to the amount of operation.

5. The acoustic-optic deflector unit for a laser processing apparatus according to claim 4, comprising: a laser power detection unit positioned on the optical axis of the laser beam emitted from the mask portion and detecting the laser power of the laser beam; and a control unit that adjusts the operating amount so that the laser power detected by the laser power detection unit is maximized.

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