JP2001071160A - High speed laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute fine working of high accuracy at high speed. SOLUTION: The machine is equipped with a laser beam oscillator 14 having a Q-switch emitting laser beam by Qswitch oscillation, an incident optical system to make the laser beam enter a fiber, an working optical system to converge the transmission fiber and the transmitted laser beams, and a high speed X-Y table mounting a work piece irradiated with the converged laser beams, and further is equipped with a controller which puts the Q-switch into oscillation operation at a desired repeated cycle at a desired position while this X-Y table is in running and with a counter 12a attached with a comparator which executes position indexing of high speed X-Y table in this controller and generates timing pulse of the Q-switch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a laser oscillator with a Q switch and an apparatus for performing high-precision and high-speed fine laser processing using a high-speed XY table.

[0002]

2. Description of the Related Art For example, when a fine peeling of a thin film is to be performed with high precision, specifically, ITO (Indium Tin Oxide) formed by vapor deposition on an insulating material such as a polymer, glass, or ceramics such as a touch panel. In the case of obtaining a panel on which an electrode pattern is formed by finely peeling a thin film with high precision, it is common practice to form a desired pattern by etching using a conventional semiconductor manufacturing technique. Alternatively, in consideration of reducing waste liquids and shortening long working steps, there is a tendency to apply dry thin film removal processing using a laser beam.

[0003] For this purpose, there has hitherto been known one in which a workpiece mounted on a processing stage of, for example, an XY table is irradiated with a laser beam by, for example, an excimer laser to peel off a thin film. That is, there is a technique in which a desired position is irradiated with a laser beam and separated to form an insulating portion by controlling the position and speed of the XY table while controlling the frequency and pulse of the laser oscillator.

[0004]

However, there are various problems in such laser processing, and it is not satisfactory in both processing accuracy and processing speed. That is, the repetition frequency of the excimer laser is, for example, 200 Hz or 4 Hz.
On the other hand, the XY table that moves using a ball screw has a moving amount of, for example, 250 mm / sec. In actual processing, the work is moved by the XY table, and the laser is stopped at a desired position. Processing is performed by irradiating a beam, and after the processing is completed, the XY table is driven to move to the next processing position.

The present invention has been made in view of the above problems, and provides a high-speed laser processing apparatus capable of performing high-speed laser processing when performing fine processing with high processing accuracy.

[0006]

The present invention that achieves the above object has the following matters specifying the invention. The first invention is Q
A laser oscillator with a Q switch for emitting a laser beam by switch oscillation, an incident optical system for entering the laser beam into a fiber, a transmission fiber thereof, and a processing optical system for narrowing the transmitted laser beam; High-speed XY with a workpiece to be irradiated with a focused laser beam
A controller for causing a Q switch to oscillate at a desired repetition frequency at a desired position during traveling of the XY table, and a position index of the high-speed XY table and a timing pulse of the Q switch in the controller. And a counter with a comparator for generating

According to a second aspect of the present invention, in the first aspect, the laser oscillator with the Q switch is a YAG laser oscillator with the Q switch, and the high-speed XY table is an XY table of a linear motor drive.

In a third aspect based on the first or second aspect, the controller includes a controller for controlling a laser oscillator with a Q switch, an automatic focusing mechanism for focusing a laser beam on a surface of a workpiece, It comprises a loader and an unloader for a workpiece, an assist gas supply unit for the workpiece, and a processing apparatus controller for controlling a traveling high-speed XY table.

In a fourth aspect based on the first or second aspect, the laser beam condensed on the workpiece by a lens system is provided between the high-speed XY table and the workpiece. By placing a thick underlay that fully considers the depth of focus, the above XY
This avoids processing the table surface.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an example of an embodiment of the present invention will be described with reference to FIGS. In the present invention,
For example, a YAG laser is used. This YAG laser can perform Q-switch oscillation by adding a Q-switch, and can obtain a repetition frequency of, for example, about 50 kHz. Further, since the laser beam can be transmitted through the fiber, the processing machine can be arranged without being affected by the layout in the factory, as well as the equipment arrangement in the processing machine can be designed flexibly.

On the other hand, a high-speed XY table on which a workpiece is mounted is of a direct drive type using, for example, a linear motor as a drive source, has a speed of about 2 m / sec, and has a positioning reproduction accuracy of 0.1 to 0. 0.5 μm. In this high-speed XY table, the amount of movement for 1 μsec is 2
μm.

In order to perform high-precision fine processing at a high speed with a repetition frequency of 50 kHz by such a laser oscillator having a Q switch and a high-speed movement amount of 2 m / sec by a high-speed XY table, the Q switch is used. Mutual control between the laser oscillator and the high-speed XY table is required.

In this case, in this embodiment, the high-speed XY table is constantly driven during the processing, in other words, the high-speed XY table is driven so that the workpiece is relatively scanned by the laser device. At this position, on / off control of the laser oscillator is to be performed. And, for example, 2m / sec
High-speed XY table with the speed of
Even if the switch oscillates, fine processing can be performed sufficiently as described later.

The processing accuracy relates to the control of the timing of the Q switch oscillation and the number of pulses thereof, but the high speed causes a problem of signal delay in the control system. The Q-switch oscillation timing and the number of pulses will constitute a controller depending on the accuracy of this 50 kHz, but the control system needs to consider the delay individually. For example, in order to secure an absolute positioning accuracy of ± 50 μm at a high processing speed of 2 m / sec, only a delay of 25 μsec is allowed.

FIG. 1 is a block diagram from the drive and detection portion of the high-speed XY table to the drive portion of the YAG laser oscillator. The linear encoder 10 for detecting the position of the high-speed XY table and the linear motor drive of the high-speed XY table are driven. The signal delay by the encoder 10 and the servo driver 11 is fixed at the order of several tens to several hundreds of nsec.

A controller 1 to which a detection position signal is input
2 has a built-in comparator (comparator) 12b therein. The comparator 12b includes a count value, which is position information taken from the counter 12a, and a CPU 12b.
Compare with the setting value received from c. Here, if they match, an interrupt is issued to the CPU 12c and a match signal is output to the F / F circuit (Flip Flop circuit) 13a. C
In the calculation by the PU 12c, time variation is apt to occur. Therefore, the output is performed by hardware by the comparator 12b, and the output is set in the order of several tens to several hundreds of nsec and is fixed. Next, the F / F receiving the coincidence signal
The circuit 13a gives an ON signal (synchronous signal) to the repetition frequency generation circuit 13b, and the repetition frequency generation circuit 13b gives the laser oscillator (Q-SW) 14 ON / OFF of a Q switch.
A timing pulse for performing the operation is output. F / F circuit 13a
Signal delay in the order of tens of nanoseconds, the repetition generation circuit 13b
The signal delay from the laser oscillator 14 to the laser oscillator 14 is fixed to the order of several μsec. Further, the interrupted CPU 12c gives the next set value and the interrupt release signal to the comparator 12b. Although the above is the concept of the start of synchronization, the concept of the end of synchronization is the same.

In this way, by fixing the signal delay near the fixed value by means of the counter with comparator 12a or the synchronization at the place where the variation is likely to occur, the delay of the whole control can be grasped. Correction is also possible, and fine high-precision processing can be performed by suppressing variations.

That is, the Q switch on / off of the YAG laser oscillator can be controlled on the order of several microseconds even while the high-speed XY table is running, so that a high-speed XY table can be used to increase the speed and turn on / off the Q switch. Fine processing can be performed with high accuracy in a few microseconds.

FIG. 1 mainly shows a control system, while FIG. 2 shows the entire processing apparatus. In FIG. 2, a YAG laser oscillator 14 with a Q switch 1a, an optical fiber 1c for transmitting a laser beam,
An optical system including a processing optical system 1e having an automatic focusing mechanism 1d, an XY table 2 on which the workpiece is mounted and capable of moving at high speed, a workpiece to be mounted from a magazine on a processing stage of the XY table 2, and a magazine. The laser oscillator controller 5 for controlling the loader 3a and the unloader 3b, the assist gas supply unit 4, and the YAG laser oscillator 14, which are stored in the XY table 2, the movement of the XY table 2, the on / off control of the assist gas, and the automatic A processing device controller 6 for performing each control of the focus control is provided.

The configuration shown in FIG. 1 described above mainly shows a portion extending over the processing apparatus controller 6 and the laser oscillator controller 5 shown in FIG. Here, the position control and speed control of the high-speed XY table by the processing device controller 6 can be performed by numerical control, and the frequency control and pulse control by the laser oscillator controller 5 can also be performed by numerical control.

In the optical system, the processing optical system focuses the laser beam including the lens system so as to focus on the surface of the workpiece on the high-speed XY table 2. Depending on the workpiece, An auto focus mechanism 1d is provided for focusing. In this case, the focus is strictly focused on, for example, the surface of the workpiece, but the focus is fixed over a certain thickness due to the depth of focus of the lens system. At this time, if the workpiece is a thin transparent electrode such as the above-described ITO thin film, the laser beam is processed not only to the workpiece but also to a processing stage thereunder, and the back surface of the workpiece is processed into processing debris. May be damaged. For this reason, a transparent spacer is interposed between the workpiece and the processing stage in consideration of the depth of focus. Further, it is preferable to interpose a spacer in consideration of the sealing property in the fixed stage using the vacuum chuck.

The diameter of the focused laser beam is also related to the processing accuracy.
When a beam of m is used, for example, an XY table moving at 2 m / sec has a movement amount of 2 μm per 1 μsec. Therefore, control is performed on the order of 300/2 = 150 μsec.
Even if there is a signal delay of several tens of microseconds due to the above, it is possible to perform a sufficient and accurate control such as a process of continuing the laser beam without separating it.

[0023]

As described above, the present invention has the following effects. According to the first invention, a Q-switched laser oscillator for emitting a laser beam by Q-switch oscillation, an incident optical system for entering the laser beam into a fiber, its transmission fiber, and the transmitted laser beam A high-speed XY table on which a workpiece to be irradiated with the focused laser beam is mounted, and a Q-switch oscillation at a desired repetition frequency at a desired position during traveling of the XY table. And a counter in the controller for determining the position of the high-speed XY table and generating the timing pulse of the Q switch.
High-speed laser processing associated with the XY table becomes possible, and high-precision processing can be achieved even when the processing control is fine processing using a Q switch and a counter with a comparator. Further, since the laser beam can be transmitted through the fiber, the processing machine can be arranged without being affected by the layout in the factory, as well as the equipment arrangement in the processing machine can be designed flexibly.

According to the second invention, based on the first invention, the laser oscillator with the Q switch is replaced with the YAG with the Q switch.
By using a laser oscillator and the high-speed XY table as an XY table of a linear motor drive, specifically, a Q switch having a repetition frequency of about 50 kHz
A workpiece on a linear XY table having a movement amount of about / sec can be machined.

According to a third aspect, based on the first or second aspect, the controller includes a controller for controlling a laser oscillator with a Q switch, and an automatic focusing mechanism for focusing a laser beam on a surface of a workpiece. The loader and unloader of the workpiece, the assist gas supply unit to the workpiece, and a processing apparatus controller that controls the traveling high-speed XY table, respectively, in addition to the above-described effects, environmentally friendly as a high-speed laser processing apparatus, It is possible to obtain an apparatus which is economical and excellent in workability.

According to the fourth aspect of the invention, based on the first or second aspect, between the XY table and the workpiece, a laser beam focused on the workpiece by a lens system is provided. By placing an underlay with a thickness that fully considers the depth of focus,
By preventing the surface of the Y table from being processed, defective processing of the workpiece can be prevented in addition to the above-described effects.

[Brief description of the drawings]

FIG. 1 is a simplified block diagram showing a portion from a drive / detection portion of an XY table to a drive portion of a laser oscillator in an example of an embodiment of the present invention.

FIG. 2 is a simplified block diagram showing the entire laser processing system.

[Explanation of symbols]

 1a Q switch 1e Processing optical system 1d Autofocus mechanism 2 High-speed XY table 3a Loader 3b Unloader 4 Assist gas supply unit 5 Laser oscillator controller 6 Processing device controller 12 Controller 12a Counter with comparator 12b Comparator (comparator) 12c CPU 13a F / F circuit 13b Repetition frequency generation circuit 14 Laser oscillator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Takahashi 1-1-1, Wadazakicho, Hyogo-ku, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Seiichi Morimoto Hyogo-ku, Kobe-shi, Hyogo 1-1-1 Wadazakicho Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Yoshio Hashimoto 2-1-1, Araimachi Shinhama, Takasago-shi, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd.Takasago Research Laboratory (72) Inventor Makoto Kinoshita Tottori 10-3 Kitamura, Tottori City, Ricoh Microelectronics Co., Ltd. (72) Inventor Joji Kobayashi 10-3, Kitamura, Tottori City, Tottori Prefecture F-term (reference) 4E068 AA00 CA03 CA11 CB02 CC06 CE03 CK01 5F072 AB01 GG05 GG07 KK30 MM04 YY06

Claims (4)

[Claims] 1. A laser oscillator with a Q-switch for emitting a laser beam by Q-switch oscillation, an incident optical system for entering the laser beam into a fiber, a transmission fiber thereof, and a throttle for transmitting the transmitted laser beam. And a high-speed XY table on which a workpiece to be irradiated with the focused laser beam is mounted, and a Q-switch oscillation is performed at a desired repetition frequency at a desired position during traveling of the XY table. A high-speed laser processing apparatus comprising: a controller; and a counter in the controller for determining the position of the high-speed XY table and generating a timing pulse of the Q switch. 2. The laser oscillator with a Q switch is a YAG laser oscillator with a Q switch, and the high-speed XY table is an XY table of a linear motor drive.
A high-speed laser processing apparatus as described in the above. 3. A controller for controlling a laser oscillator with a Q switch, an automatic focusing mechanism for focusing a laser beam on a surface of a workpiece, a loader and an unloader for the workpiece, and an assist gas for the workpiece. 3. The high-speed laser processing apparatus according to claim 1, further comprising a processing apparatus controller that controls the supply unit and the traveling high-speed XY table. 4. An underlay having a thickness sufficiently considering a focal depth of a laser beam focused on the workpiece by a lens system between the high-speed XY table and the workpiece. 3. The high-speed laser processing apparatus according to claim 1, wherein the high-speed laser processing apparatus has a structure that does not process the XY table surface.