JPH08215875A - Laser beam machine - Google Patents

Abstract

PURPOSE: To improve processing capacity in laser machining by providing plural objective lenses. CONSTITUTION: A first and a second objective lenses 26A and 26B respectively are provided; on and off of light modulators 25A, 25B is each controlled by a controller 18; and the irradiation timing is independently controlled of laser beams L1 ', L1 " from the objective lenses 26A, 26B. As a result, in the case of simultaneous irradiation of these laser beams L1 ' L1 ", machining is made possible at plural places simultaneously with a shortened machining time. In addition, in the case of different irradiation timing of the laser beams L1 ', L1 " from the objective lenses 26A, 26B, it is possible to change a machining length at each machining place and to machine the objects simultaneously which have a different pitch for each machining place in the machining direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus,
More specifically, a laser for processing a workpiece on a stage by using a laser beam while positioning the stage at the processing position of the workpiece based on the moving position data of the stage that moves two-dimensionally and predetermined processing position data. Regarding processing equipment.

[0002]

2. Description of the Related Art A laser processing apparatus of this type is disclosed, for example, in Japanese Patent Laid-Open No. 5-115992 and Japanese Patent Laid-Open No. 6-277864.
As disclosed in Japanese Patent Laid-Open Publication No. 1989-331, an objective lens which is fixed in the apparatus and constitutes an optical system for irradiating laser light, and an XY stage which moves in a two-dimensional direction within a reference plane orthogonal to the optical axis of the objective lens. It has and. Then, in the control means, based on the moving position data of the stage detected by the position detecting means such as an interferometer and the processing position data of the workpiece on the stage stored in advance in the memory, the processing point of the workpiece is processed. The workpiece was processed on the stage by using the laser beam while positioning the stage so that the laser beam was on the optical axis of the objective lens.

[0003]

However, in the above-mentioned conventional laser processing apparatus, since there is only one laser irradiation system for irradiating the laser beam for processing the workpiece, the processing capacity is limited. there were.

The present invention has been made under the above circumstances, and an object thereof is to provide a laser processing apparatus capable of improving the processing capacity.

[0005]

The present invention comprises a stage that moves in a two-dimensional direction within a reference plane, and position detection means that detects the moving position of the stage, and provides predetermined machining position data and the position detection. A laser processing apparatus for irradiating a workpiece placed on the stage with laser light through the objective lens while positioning the stage on the optical axis of the objective lens based on position data from the means, It has a plurality of objective lenses and control means for independently controlling the irradiation timing of laser light from each objective lens.

In this case, all of the plurality of objective lenses may be fixed, but at least one of them may be fixed to the apparatus and the remaining objective lenses may be movable.
In such a case, a lens position detecting means for detecting the moving position of each movable objective lens, and an objective lens fixed by independently driving each movable objective lens based on the output of the lens position detecting means. A lens interval setting means for arbitrarily setting an interval with each movable objective lens may be further provided.

The laser light source may be single or plural. When there is only one laser light source, a light splitting means for splitting the laser light emitted from this laser light source, and the incidence / non-incidence of each laser light split by this light splitting means on the respective objective lens It is desirable that a setting means for independently setting the state is provided and the control means controls the setting means.

On the other hand, when a plurality of laser light sources are provided,
The number of light sources is set to a number corresponding to the objective lens, and the laser light emitted from each laser light source is configured to be emitted from each objective lens, and the control unit controls the emission timing of the laser light of each laser light source. You may make it control independently.

[0009]

According to the above construction, a plurality of objective lenses are provided, and the irradiation timing of the laser beam from each objective lens is independently controlled by the control means. Therefore, when the control means simultaneously irradiates laser light from a plurality of objective lenses, it is possible to perform processing at a plurality of positions at the same time, and the processing time is shortened. Further, when the control means changes the irradiation timing of the laser light from the plurality of objective lenses, the processing length is changed at each processing location,
Simultaneous processing is possible even for workpieces having different pitches in the processing direction at each processing location.

At least one of the objective lenses is fixed to the apparatus, the remaining objective lenses are movable, and when the lens position detecting means and the lens interval setting means are further provided, the lens interval setting means uses the lens position. Each movable objective lens is independently driven based on the output of the detection means to arbitrarily set the distance between the fixed objective lens and each movable objective lens. For this reason, it is possible to set the distance between the objective lenses according to the pitch of the workpiece in the non-machining direction, change the machining length at each machining location, and of course the machining direction, as well as the pitch of the machining location in the non-machining direction. It is possible to process workpieces of different types.

When the laser light source is single and the light splitting means and the setting means are provided, the laser light emitted from the single laser light source is split by the light splitting means, and the setting means controls the means. The state of incidence / non-incidence of each of the divided laser beams on each objective lens is independently set.
In this way, the irradiation timing of the laser light from each objective lens is independently controlled via the setting means. In this case, since the laser light source is single, downsizing of the device,
The cost can be reduced.

On the other hand, when the number of laser light sources corresponding to the objective lenses is provided and the laser light emitted from each laser light source is irradiated from each objective lens, the control means has each laser light source. By directly and independently controlling the emission timing of the laser light, the irradiation timing of the laser light from each objective lens is independently controlled.

[0013]

【Example】

<< First Embodiment >> A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic structure of a laser processing apparatus 10 according to the first embodiment. This laser processing apparatus 10 is for processing an XY stage 12 as a stage that moves in a two-dimensional direction within a reference plane orthogonal to the paper surface of FIG. 1 and a workpiece 14 placed on the XY stage 12. The first and second irradiation optical systems (which will be described later) for irradiating the laser beam, the optical system for observing the processed part (which will be described later), and the moving position of the XY stage 12. A stage coordinate reading device 16 as position detecting means and a controller 18 as control means for controlling the moving position of the XY stage 12 and the emission timing of laser light are provided.

The first irradiation optical system is a half mirror (beam splitter) 23 as a light splitting means for splitting the laser light L1 emitted from the laser light source 20, and one of the lasers split by the half mirror 23. Light (transmitted light) L
The XY stage 1 receives the light quantity adjusting unit 22A of 1'and the laser light L1 '.
A dichroic mirror 24 that reflects toward 2 and a first objective lens 26A whose optical axis is arranged in a direction orthogonal to the reference plane ahead of the traveling direction of the laser light L1 ′ reflected by the dichroic mirror 24; It is configured to include. Here, the first objective lens 26A is fixed to the apparatus main body.

A first optical modulator 25A is arranged on the optical path of the laser beam L1 'between the half mirror 23 and the dichroic mirror 24. This first optical modulator 25A
Is provided for setting the incident / non-incident state of the laser beam L1 ′ to the first objective lens 26A (this will be described later), and is controlled to be turned on / off by the controller 18. .

In the present embodiment, this first optical modulator 25A
A so-called acousto-optic modulator (AOM) is used as the. As is well known, when the acousto-optic modulator is driven by a high frequency signal of frequency f, a compressional wave corresponding to the frequency is generated so as to traverse the optical path of the laser beam L1 ', and the compressional wave is passed by the laser beam L1'. Then, since the 0th-order light traveling straight and the 1st-order diffracted light deflected by the diffraction angle determined by the frequency f by Bragg diffraction are generated, only the 0th-order light traveling straight is adjusted by adjusting the frequency f.
The first-order diffracted light can be prevented from entering the first objective lens 26A. Therefore, in the present embodiment, when laser processing is performed, the first optical modulator 2
When 5A is turned off and the laser beam L1 'incident on the first optical modulator 25A is incident on the first objective lens 26A without being attenuated (decreased in intensity), on the contrary, when laser processing is not performed, The first light modulator 25A is turned on to greatly attenuate the laser beam L1 'so that it is incident on the first objective lens 26A.

As described above, strictly speaking, even if the first optical modulator 25A is in the ON state, the 0th order light of the laser beam L1 'is incident on the first objective lens 26A. Is irradiating the work piece 14 through the first objective lens 26A, it does not damage the work piece 14, so if the first optical modulator 25A is in the ON state,
It can be considered that the laser beam L1 'is not incident on the first objective lens 26A, and this state is referred to as a non-incident state in the description of the present embodiment. Thinking this way
For example, if multiple AOMs are arranged in series, the AO at the final stage
Since the amount of 0th-order light emitted from M can be made almost zero, there is no problem in practice.

The second irradiation optical system is the half mirror 2
3, a light quantity adjusting unit 22B for the other laser light (reflected light) L1 ″ split into two by the half mirror 23, and a laser light L
Two mirrors 27, 28 that sequentially reflect 1 "toward the XY stage 12, and laser light L1" reflected by the mirror 28
And a second objective lens 26B whose optical axis is arranged in a state of being orthogonal to the reference plane in the traveling direction of the above. A second optical modulator 25B is arranged on the optical path of the laser beam L1 ″ between the half mirror 23 and the mirror 27. The second optical modulator 25B is the first optical modulator 25A. It is composed of an AOM having the same function as the above, and is provided to set the incident / non-incident state of the laser beam L1 ″ to the second objective lens 26B. The second optical modulator 25B is also on / off controlled by the controller 18.

The mirror 28 and the second objective lens 26B are integrally held by a holding member (not shown),
With these, the drive unit 3 movable in the direction of arrow A in FIG. 1 (the same as the X-axis direction which is the moving direction of the XY stage 12)
0 is configured. Although not shown in FIG. 1, the drive unit 30 is actually provided with a lens position detecting means 32 as shown in FIG. The lens position detecting means 32 is a pair of reflecting surfaces 33A and 33B similar to a so-called right-angle prism provided on one end surface of the driving unit 30.
And the interferometer laser light source 36 that oscillates the interferometer laser light L toward the reflection mirror 34.
And the laser beam L and the first and second reflecting surfaces 3 of the reflecting mirror 34.
Laser interferometer 38 that interferes with reflected light L ′ of laser light L that is sequentially reflected by 3A and 33B and travels in the opposite direction, and the interference light interfered by this laser interferometer 38 is converted into an electric signal according to its intensity. And a light receiver 40 for conversion.

The lens position detecting means 32 having such a structure
According to the above, an electric signal having a different intensity depending on the distance between the drive unit 30 and the laser interferometer 38 is obtained from the photodetector 40. In the first embodiment, the output of the photodetector 40 is sent to the controller 18. It has become so. Therefore, the controller 18 can always monitor the moving position of the drive unit 30 based on the output signal waveform of the light receiver 40.

The observation optical system includes a half mirror 44 that reflects the observation illumination light L2 from the illumination light source 42 toward the first objective lens 26A, and the observation illumination light L2 is the same as the laser light L1 '. The first objective lens 26A that irradiates the work piece 14 with the optical axis of and the surface of the work piece that receives the reflected light from the work piece 14 through the first objective lens 26A, the dichroic mirror 24, and the half mirror 44. And a CCD camera 46 placed on it.
A television monitor 48 is attached to the CCD camera 46.

According to this observation optical system, the illumination light L2
Is reflected by the half mirror 44, and then is processed by the first objective lens 26A along the same optical axis as the laser beam L1 '.
Is irradiated. Illumination light L2 applied to the workpiece 14
Is reflected by the workpiece 14, the reflected light is detected by the CCD camera 46, and the processing state can be observed by the television monitor 48.

The workpiece 1 is placed on the XY stage 12.
An energy meter 50 for detecting the light amount of the laser light with which the laser beam 4 is irradiated is provided, and the output of the energy meter 50 is input to the controller 18.

The controller 18 comprises a microcomputer, and the stage coordinate reading device 1
Positioning of the XY stage 12 by driving and controlling the motor 52 for driving the stage based on the output (6, X, Y coordinates) of 6 and the data of the processed portion on the workpiece 14 stored in the internal memory (not shown). That is, the processing portion (processing point) of the workpiece 14 is positioned with respect to the optical axes of the first objective lens 26A and the second objective lens 26B.

Further, the controller 18 sets the light amount adjusting units 22A, 2A so that a predetermined set energy is obtained based on the output of the energy meter 50 on the XY stage 12.
It also has the function of adjusting 2B. Further, the controller 18 also has a function of controlling the stage movement position and controlling the emission timing of the laser light by performing on / off control of each of the first and second optical modulators 25A and 25B described above. That is, in this embodiment, the objective lenses 26A and 26B of the laser beams L1 'and L1 "split by the half mirror 23 by the first and second optical modulators 25A and 25B are used.
Setting means for independently setting the incident / non-incident state on / off is configured.

Next, the overall operation of the laser processing apparatus 10 thus constructed will be described.

First, the controller 18 monitors the moving position of the drive unit 30 via the lens position detecting means 32 described above according to the set interval information (which is a part of the processing position data) stored in advance in the internal memory. At the same time, the drive unit 30 is driven to a set position via a drive mechanism (not shown),
The distance between the optical axes of the first objective lens 26A and the second objective lens 26B is set according to the pitch of the processed portion on the workpiece 14. That is, in this embodiment, the lens interval setting means is realized by the drive mechanism and the controller (not shown).

Next, the controller 18 drives the motor 52 while monitoring the output coordinate values of the stage coordinate reading device 16 and drives the motor 52 to an XY position until the center position of the energy meter 50 coincides with the optical axis of the first objective lens 26A. The stage 12 is moved. In this state, the controller 18 sends a trigger signal to the laser light source 20 to oscillate the processing laser beam L1, and at the same time, turns off the first optical modulator 25A and turns on the second optical modulator 25B. As a result, the laser light L1 emitted from the laser light source 20 is split into the laser lights L1 'and L1 "by the half mirror 23. The laser light L1' is reflected by the dichroic mirror 24 and then the first objective lens. The energy meter 50 is irradiated through 26A, and the energy amount of the laser light L1 'is detected by the energy meter 50.
Based on the detected light intensity, the light intensity adjusting unit 22A is adjusted so that the light intensity is appropriate for the processing of the workpiece 14. At this time, since the second light modulator 25B is turned on, the laser light L1 "is not incident on the second objective lens 26B, and the laser light is not emitted from the second objective lens 26B. The controller 18 uses the same method as the laser beam L1 ″ from the second objective lens 26B.
The light amount adjusting unit 22B is adjusted so that the light amount of is also an appropriate light amount.

When the adjustment of the distance between the objective lenses and the amount of light are completed in this manner, the controller 18 drives the motor 52 based on the processing position data stored in the internal memory while monitoring the output coordinates of the stage coordinate output device 16. Then, the movement control of the XY stage 12 is started. Here, since the workpiece 14 is processed, the XY stage 12 is moved to the Y direction.
If it is moved in the axial direction, this XY stage 1
When the workpiece 14 is located at a predetermined processing position during the movement of 2 in the Y-axis direction, the controller 18 sends a trigger signal to the laser light source 20 to generate the processing laser light L1.
At this time, in the controller 18, when processing is simultaneously performed using the first and second irradiation optical systems, both optical modulators 2 are processed.
Turn off 5A and 25B. As a result, the laser light L
1'and L1 "are irradiated from the objective lenses 26A and 26B constituting the respective irradiation optical systems to the respective processed parts on the workpiece 14, and the respective processed parts are simultaneously processed.

On the other hand, when the irradiation timing of the laser light from each objective lens is changed, the controller 1
8, the trigger signal is sent to the laser light source 20 for each processing point, and the optical modulator (2
5A or 25B) is turned on, and the optical modulator (25A or 25B) on the side used for processing is kept off. in this case,
With the optical modulator set to ON, the laser light (L1 'or L1 ") is changed to the objective lens (26A or 26B) as described above.
Is set to the non-incident state.

The state of the processed portion during processing can be observed by the television monitor 48 via the observation optical system as described above.

As described above, according to the first embodiment, it is possible to irradiate the workpieces 14 with the laser beams L1 'and L1 "from the first and second objective lenses 26A and 26B simultaneously or separately. Therefore, it is possible to change the processing length at each processing location or perform simultaneous processing even on a workpiece having a different pitch in each processing location in the processing direction (Y direction in this case).
Moreover, since the distance between the objective lenses can be adjusted, it is possible to set the distance between the objective lenses according to the pitch of the processing portion in the non-processing direction of the workpiece (in this case, the X-axis direction). Thus, it becomes possible to process workpieces having different pitches at the processing points. Therefore, it becomes possible to perform high-speed processing according to the processing pattern,
The processing capacity can be improved.

Further, in the case of the present embodiment, since the laser light source 20 for processing is single, it is possible to reduce the size and cost of the apparatus.

In the first embodiment, the setting means for setting the incident / non-incidence state of the laser light on the objective lens is exemplified by the optical modulator which is an acousto-optic modulator. Although it is possible to configure the setting means by a liquid crystal plate, a rotary shutter, etc., it is desirable to use an optical modulator that can turn on / off the laser light irradiation at high speed from the viewpoint of responsiveness. As the optical modulator, in addition to AOM, it is also possible to use an electro-optical modulator (EOM) of a phase modulation system utilizing the so-called Pockels effect.

<< Second Embodiment >> Next, a second embodiment of the present invention will be described with reference to FIG. Here, the same or equivalent components as those of the first embodiment described above are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 3 shows the configuration of a laser processing apparatus 60 according to the second embodiment. This laser processing device 60
Then, the optical modulators 25A and 2A in the first embodiment described above
5B and the half mirror 23 are omitted, and two laser light sources for processing are provided.

That is, the laser processing apparatus 60 includes a first irradiation optical system for irradiating the workpiece 14 with the first processing laser beam L1 through the first objective lens 26A, and the second processing laser. A second irradiation optical system for irradiating the workpiece 14 with the light L3 through the second objective lens 26B.

The first irradiation optical system is the first laser light source 2
A laser beam L1 for processing which is oscillated by 0A into a larger parallel beam, a first light amount adjusting unit 22A including a beam expander, a dichroic mirror 24, and a first
It is composed of an objective lens 26A.

On the other hand, the second irradiation optical system includes a second light quantity adjusting section 22B including a beam expander for expanding the processing laser light L3 oscillated by the second laser light source 20B into a larger parallel light. It is composed of a mirror 28 that reflects the laser light L3 that has passed through the light quantity adjusting section 22B, and a second objective lens 26B that irradiates the workpiece 14 with the laser light L3 that is reflected by the mirror 28.

The laser light sources 20A and 20B are controlled to be turned on / off by a trigger signal from the controller 18, whereby the objective lenses 26A and 26B are controlled.
The irradiation timings of the laser beams L1 and L3 from B are controlled independently. The configuration of the other parts is the same as that of the first embodiment described above.

In the laser processing apparatus 60 of the second embodiment constructed as described above, the controller 18 sends the trigger signals to the laser light sources 20A and 20B separately, so that the first and second laser light sources 20A and 20B are supplied. The laser light L1 and the laser light L3 are independently emitted from the objective lens, that is, the laser light emission timing is controlled by a trigger signal from the controller 18 to the laser light source. Only the difference from the first embodiment in which the irradiation timing of the laser light from 26A and 26B is controlled, and the other actions are the same as in the first embodiment.

Therefore, according to the laser processing apparatus 60 of the second embodiment, the same effect as that of the first embodiment can be obtained. Further, in this laser processing device 60, since two laser light sources are provided, it becomes possible to arbitrarily set the intensity of the laser light emitted from each objective lens.
It is possible to perform processing with an appropriate amount of light for each processing location of the workpiece.

In the first and second embodiments, two objective lenses, a first objective lens and a second objective lens, are provided, one objective lens is fixed to the apparatus, and the other objective lens is movable. Although the case has been illustrated, the present invention is not limited to this, and a plurality of objective lenses may be fixed to the apparatus at predetermined intervals, or three or more objective lenses may be provided. . When three or more objective lenses are provided, if three or more objective lenses are arranged on the same straight line or arranged in a cross shape in accordance with the moving direction of the XY stage 12, the moving direction of the XY stage 12 is determined. It is possible to always process at three or more locations simultaneously.

Although not particularly described in the first and second embodiments, it is possible to change the distance between the objective lenses by driving the drive unit 30 during processing (moving the stage). .

[0046]

As described above, according to the present invention,
By irradiating the workpiece with laser light from multiple objective lenses at the same time, it is possible to process multiple locations at the same time, which can shorten the processing time and the timing of laser light emission from multiple objective lenses. When different, the processing length is changed at each processing point,
There is an unprecedented excellent effect that simultaneous processing is possible even for a workpiece having a different pitch in each processing direction in the processing direction.

In particular, according to the second aspect of the invention, it is possible to set the distance between the objective lenses according to the pitch of the workpiece in the non-machining direction, and to change the machining length at each machining point. Not only the machining direction but also the non-machining direction can be machined even for workpieces having different machining pitches, and there is also an effect that machining according to the machining pattern can be performed at high speed.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a laser processing apparatus according to a first embodiment.

FIG. 2 is a diagram showing a configuration example of a lens position detecting means for monitoring a moving position of a drive unit in FIG.

FIG. 3 is a diagram showing a schematic configuration of a laser processing apparatus according to a second embodiment.

[Explanation of symbols]

10 Laser Processing Device 12 XY Stage (Stage) 14 Workpiece 16 Stage Coordinate Output Device (Position Detection Means) 18 Controller (Control Means, Lens Interval Setting Means) 23 Half Mirror (Light Splitting Means) 25A First Optical Modulator (Setting means) 25B Second light modulator (setting means) 26A First objective lens 26B Second objective lens 32 Lens position detecting means 60 Laser processing device

Claims (4)

[Claims] 1. A stage which moves in a two-dimensional direction within a reference plane, and position detection means for detecting the movement position of the stage, based on predetermined processing position data and position data from the position detection means. A laser processing apparatus for irradiating a workpiece mounted on the stage with laser light through the objective lens while positioning the stage on the optical axis of the objective lens, comprising: a plurality of objective lenses; A laser processing apparatus comprising: a control unit that independently controls the irradiation timing of laser light from the lens. 2. At least one of the plurality of objective lenses is fixed to the apparatus, the remaining objective lenses are movable, and lens position detection is performed to detect the moving position of each movable objective lens. Means, and a lens interval setting for independently driving each of the movable objective lenses based on the output of the lens position detection means to arbitrarily set an interval between the fixed objective lens and each movable objective lens. The laser processing apparatus according to claim 1, further comprising: 3. A single laser light source, a light splitting means for splitting the laser light emitted from this laser light source, and an incidence / non-incidence of each laser light split by this light splitting means on each objective lens. 3. The laser processing apparatus according to claim 1, further comprising a setting unit that independently sets the incident state, and the control unit controls the setting unit. 4. The number of laser light sources corresponding to the objective lens is provided, and the laser light emitted from each laser light source is irradiated from each objective lens. 3. The emission timing of the laser light of 1 is independently controlled.
The laser processing device described.