JP7122559B2 - LASER PROCESSING METHOD AND LASER PROCESSING APPARATUS - Google Patents

Description

The present invention relates to a laser processing method and a laser processing apparatus for laser cutting an object to be processed such as a resin film.

2. Description of the Related Art Processing methods and devices for cutting, drilling, etc., of various objects to be processed (that is, workpieces) by laser irradiation are already known.

A laser processing device mainly consists of a drive stage, a galvanometer scanner, a laser oscillator, and optical components. A common method is to apply Also, two-dimensional processing includes a method of scanning an arbitrary trajectory with a stage having a drive shaft or a galvanometer scanner.

For example, there is a method of scanning laser light only with a galvanometer scanner. In this case, since the scanning speed of the galvanometer scanner is fast, the thermal influence of the workpiece can be reduced, and high-quality processing can be achieved.

In addition to the above method, there is a method of processing by pitch-moving the drive stage. In this case, it is effective for large-area workpieces and processing. In this way, various techniques have been proposed.

In recent years, for the purpose of high speed and high quality, there has been proposed a processing method in which a driving stage and a galvanometer scanner are combined and under coordinated control (see, for example, Patent Document 1).

JP 2017-196652 A

However, in the conventional configuration, the following operation is performed in order to process a large area larger than the scanning area of the f.theta. lens. First, the object to be processed is divided within the range of the scanning area of the fθ lens. Next, laser processing is performed on the first processing area of the workpiece on the stopped driving stage. After that, the drive stage is driven to move the workpiece to the second machining area adjacent to the first machining area. After that, the processing is stopped, and laser processing is performed on the second processing region of the processing object. These machining operations are then repeated in sequence. That is, it is necessary to perform machining by a step-and-repeat system in which the drive stage is repeatedly moved by the machining pitch. Therefore, there is a problem that a seam is generated in the processing marks at the boundary of the scanning range, and processing accuracy and productivity are lowered due to excessive processing or insufficient processing.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a laser processing method and a laser processing which are capable of suppressing a decrease in processing accuracy and productivity in order to solve the above problems.

In order to achieve the above object, a laser processing method according to one aspect of the present invention comprises:
In a laser processing method for laser processing an object having a processing area larger than a scanning area scanned with a laser beam,
holding the workpiece in a first drive that moves the workpiece in a first direction;
Next, while the first driving device moves the object to be processed in the first direction, the galvano scanner irradiates the object to be processed with the laser beam passing through the galvano scanner and the fθ lens. When scanning an object to be processed by reciprocating in the first direction and in a direction opposite to the first direction,
Let Vt be the moving speed of the object to be processed, Vs be the scanning speed of the laser beam, and while moving the object to be processed at the moving speed Vt, a part of the planned processing line of the object to be processed is on the same straight line. and irradiating the laser beam by continuously scanning the laser beam three or more times at the scanning speed Vs,
The _linear velocity V0 of the scanning of the laser light is controlled by the control unit so as to be relatively constant, and of the reciprocating scanning at the scanning velocity _Vs , the galvanometer scanner forward scanning velocity of the forward scanning is set to Vs1. Assuming that the backward scanning speed of the galvano-scanner backward scanning is Vs ₂ ,
The linear velocity _V0 in the forward scanning is
V ₀ =Vs ₁ -Vt and
The linear velocity _V0 in the backward scanning is
V ₀ =Vs ₂ +Vt and
Since the linear velocity _V0 is controlled to be relatively constant,
Vt=(Vs ₁ -Vs ₂ )/2 and
In the galvano scanner, the _galvano scanner forward scanning speed Vs1 is faster _than the _galvano scanner backward scanning speed Vs2, and _Vs1 >Vs2,
The scanning speed Vs of the galvanometer scanner is twice or more faster than the moving speed Vt, and Vs>2Vt.
A laser processing method is provided.

As described above, according to the above aspect of the present invention, it is possible to suppress the deterioration of processing accuracy and productivity, and to joint a large area in an arbitrary shape and in a wider range on a processing object at high speed. Homogeneous processing is possible.

Explanatory diagram of equipment configuration in the embodiment of the present invention Explanatory drawing of the detailed optical system of FIG. 1 in the embodiment of the present invention Explanatory drawing of the object to be processed in the embodiment of the present invention Explanatory drawing of the trajectory of laser processing in the embodiment of the present invention Explanatory diagram of laser beam scanning in the embodiment of the present invention Explanatory diagram of galvanometer scanner reciprocating motion in the embodiment of the present invention In the description of the processing depth accompanying laser beam scanning in the embodiment of the present invention, the upper side is a plan view, and the lower side is an explanatory diagram represented as a cross-sectional view. Explanatory diagram of the plane and cross section of the object to be processed in the operation of the number of reciprocating motions N = 1 at the processing depth accompanying the laser beam scanning in the embodiment of the present invention Explanatory diagram of the plane and cross section of the object to be processed when the number of reciprocating motions N = 2 at the processing depth accompanying laser beam scanning in the embodiment of the present invention Explanatory diagram of the plane and cross section of the object to be processed in the operation of the number of reciprocating operations N=3 at the processing depth accompanying the laser beam scanning in the embodiment of the present invention Explanatory diagram of the plane and cross section of the object to be processed in the operation of the number of reciprocating motions N=4 at the processing depth accompanying the laser beam scanning in the embodiment of the present invention Explanatory diagram of the plane and cross section of the object to be processed when the number of reciprocating motions N=5 in the processing depth accompanying the laser beam scanning in the embodiment of the present invention In the description of the overlap amount of the processing end in the embodiment of the present invention, the upper side is a plan view, and the lower side is an explanatory diagram represented as a cross-sectional view. Explanatory diagram of f-theta lens maximum scanning range and laser beam scanning trajectory in the embodiment of the present invention

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a diagram of the configuration of a laser processing apparatus 90 according to an embodiment of the present invention.

In the laser processing method using the laser processing apparatus 90, the processing area (see the scanning locus 402 and the planned processing line 402a in FIG. 4) is larger than the scanning area 401 (see FIG. 4) scanned with the laser beam L. This is a method of laser processing 101 . Here, the scanning locus 402 is generated by scanning the laser beam L, and the line that generates the scanning locus 402 is referred to as a planned processing line 402a.

The laser processing apparatus 90 includes at least a driving stage 102 for an object to be processed as an example of a first driving device, a laser emitting section, a galvanometer scanner 202, an fθ lens 203, and a scanning device as an example of a second driving device. and a control unit 100.

An example drive stage for the workpiece is the X-axis drive stage 102 . In FIG. 1, an X-axis driving stage 102 is arranged on a base 91, and a workpiece 101 is held by the X-axis driving stage 102. By driving the X-axis driving stage 102, the workpiece 101 moves forward and backward in the X-axis direction. Moving.

The galvanometer scanner 202 and the fθ lens 203 are provided on the processing head 103 .

The drive stage for scanning is configured by at least the Y-axis drive stage 105 as an example. Preferably, the drive stage for laser light may further include a Z-axis drive stage 104 . Y-axis drive stage 105 and Z-axis drive stage 104 are arranged on base 91 . Specifically, the Y-axis drive stage 105 is attached to an inverted U-shaped gate post 106 fixed to the base 91 .

The machining head 103 is supported by a Z-axis drive stage 104, and driven by the Z-axis drive stage 104, the machining head 103 moves forward and backward in the direction of the Z-axis that intersects the X-axis and the Y-axis. Also, the Z-axis drive stage 104 is supported by the Y-axis drive stage 105, and the Y-axis drive stage 105 drives the Z-axis drive stage 104 and the machining head 103 to move forward and backward in the direction of the Y-axis that intersects the X-axis.

As another example, the object drive stage may be a Y-axis drive stage, and the scanning drive stage may be an X-axis drive stage.

The galvanometer scanner 202 drives and controls X-axis and Y-axis galvanometer mirrors 202a and 202b, shaft rotation motors 202c and 202d for adjusting the tilt angles of the galvanometer mirrors 202a and 202b, and shaft rotation motors 202c and 202d. and a rotation angle control unit 202e.

The X-axis driving stage 102 and the Y-axis driving stage 105 are configured to have the ability to sufficiently secure the operating speed (for example, 500 mm/sec or more). In the present embodiment, as an example, the X-axis drive stage 102 and the Y-axis drive stage 105 are each moved forward and backward by a linear motor (not shown) driven and controlled by a drive control unit (not shown) and a linear motor. and a moving guide (not shown).

The Z-axis drive stage 104 is used for focus adjustment of laser light irradiation, and does not need to satisfy the above-mentioned high-speed drive capability, and is configured so as to ensure repeatable positioning accuracy. In this embodiment, as an example of the Z-axis drive stage 104, a servomotor (not shown) driven and controlled by a drive control unit (not shown), a ball screw (not shown), a guide (not shown) ), the ball screw is rotated forward and backward by the forward and reverse rotation drive of the servomotor, and the guide connected to the ball screw by a screw advances and retreats in the axial direction of the ball screw, that is, in the Z-axis direction. A machining head 103 is supported by the guide.

If the Y-axis drive stage 105 satisfies the above-described configuration, it may be arranged on the X-axis drive stage 102 so as not to drive the processing head 103 . That is, in this case, the X-axis drive stage 102 and the Y-axis drive stage 105 constitute the driving stage for the object to be processed, and the Z-axis driving stage 104 constitutes the scanning drive stage.

The control unit 100 controls the rotation angle of the laser emission unit, the drive control unit of the X-axis drive stage 102, the drive control unit of the Y-axis drive stage 105, the drive control unit of the Z-axis drive stage 104, and the galvanometer scanner 202. 202e are controlled so as to carry out laser processing while performing cooperative control.

FIG. 2 is a detailed view of the configuration of part of FIG. Galvanometer mirrors 202 a and 202 b of a galvanometer scanner 202 are irradiated with laser light L from a laser oscillator 201 as an example of a laser emitting unit. The laser beam L emitted from the laser oscillator 201 is reflected by the galvanometer mirrors 202 a and 202 b of the galvanometer scanner 202 and condensed by the fθ lens 203 . The laser beam L condensed by the fθ lens 203 is transmitted through the fθ lens 203 and applied to the processing object 101 to process the processing object 101 . At that time, the X-axis driving stage 102, the galvanometer scanner 202, and the Y-axis driving stage 105 scan an arbitrary planned processing line 402a to form a predetermined scanning locus 402 and cut the cut product into a predetermined shape. 301 can be obtained. In this embodiment, the X-axis drive stage 102 and the galvanometer scanner 202 are cooperatively controlled by the control unit 100, so the above operation can be realized.

Note that the control unit 100 performs coordinated control of not only the X-axis driving stage 102 but also the Y-axis driving stage 105 in the same manner as the X-axis driving stage 102 .

As shown in FIG. 3, the object 101 to be processed is cut into a cut product 301 having a predetermined cut shape by processing with the laser beam L. As shown in FIG.

FIG. 3 shows a method of cutting out a plurality of shapes from a large-area workpiece. is.

The size of the cut product 301 is a processing area larger than the scanning area 401 of the galvano scanner 202 as shown in FIG. Meanwhile, the galvanometer scanners 202 are cooperatively controlled by the control unit 100 to operate on the processing planned line 402a in a simultaneous series.

The control unit 100
The galvanometer scanner 202 is controlled by the respective drive controllers of the X-axis drive stage 102 and the Y-axis drive stage 105 so that the laser beam L can scan the desired processing line 402a at a constant speed and in one direction. The rotation angle control unit 202e controls the relative linear velocity to be constant while reciprocating the galvanometer scanner 202 within the scanning area 401 on the planned processing line 402a.

A laser oscillator 201 oscillates laser light L with ultrashort pulses (eg, picoseconds to femtoseconds) and a maximum frequency of 1 MHz or higher. The laser beam L from the laser oscillator 201 is spatially transmitted by a plurality of reflecting mirrors (not shown) and the galvanometer scanner 202 until it irradiates the planned processing line 402a of the object 101, and is condensed. An fθ lens 203 is used as the lens.

The wavelength, output, parameter setting, etc. of the laser oscillator 201 may be appropriately selected according to the material and processing method of the object 101 to be processed. For example, for metallic materials, it is preferable to use a laser wavelength of around 1064 nm.

The galvanometer scanner 202 has the ability to sufficiently secure a scanning speed for reciprocating motion, that is, reciprocating scanning (for example, a galvanometer scanner having a scanning speed of about 5000 mm/sec). A laser that meets the conditions such as the wavelength band, power, and beam diameter of the laser oscillator 201 is selected. Reflecting mirrors other than the galvanometer mirrors 202a and 202b and optical system members (for example, collimator lenses and beam expanders) are also configured to satisfy the above conditions.

The configuration of the galvanometer scanner 202 can be a polygon mirror, a single element such as a piezo element, or a biaxial configuration having galvanometer mirrors 202a and 202b as reflection mirrors.

As the fθ lens 203, one having an F value of 45 or more and 110 or less is used according to the required processing accuracy. The smaller the F value, the higher the precision, and the larger the F value, the better the productivity. In addition, the focal length and diameter of the light beam of the fθ lens 203 are set to the theoretical value by using a beam expander and a collimator lens with reference to the fθ lens 203 having the selected F value.

FIG. 5 is a diagram showing a laser processing method using a laser processing device 90 according to an embodiment of the present invention.

This embodiment is a processing method for laser processing the workpiece 101 having a processing area larger than the laser scanning area 401. At the same time as the X-axis driving stage 102 and the Y-axis driving stage 105 are operated, the galvanometer scanner 202 scans the laser light L. can be processed without being affected by seams. Further, under the control of the control unit 100, by controlling the scanning linear velocity _V0 of the laser light L to be relatively constant, highly productive processing can be realized.

In order to keep the linear velocity of the laser scanning constant, the drive stage scanning 501 of the X-axis drive stage 102 and the galvano-scanner scanning 502 of the galvano-scanner 202 are cooperatively controlled by the controller 100 . In the driving stage scanning 501, the laser light L is scanned along the planned processing line 402a of the given laser beam L in one direction (for example, the upward direction in FIG. 5), and reflected by the galvanometer scanner 202 on the planned processing line 402a of the driving stage in a simultaneous series. The laser beam L that has been applied scans back and forth a plurality of times. FIG. 5 shows a synchronous scanning trajectory 503 as a result of cooperative control of drive stage scanning 501 and galvano scanner scanning 502, and also shows a synchronous scanning trajectory decomposition image 504. FIG.

The driving of the galvanometer scanner 202 is controlled by the controller 100 so that the scanning linear velocity V0 of the laser light L in the _{galvanoscanner} scanning 502 is kept relatively constant.

Here, the drive stage speed of the X-axis drive stage 102 moving in one direction along the given planned processing line 402a is Vt, which is the same as the movement direction of the X-axis drive stage 102 (for example, the direction toward the front side in FIG. 1). Let Vs1 be the galvano _- scanner forward scanning speed of the galvano-scanner 202 moving in the direction, and let the moving direction of the X-axis drive stage 102 be the first direction. At this time, the scanning line speed V ₀ is V ₀ = Vs ₁ - Vt
becomes.

As the moving direction of the X-axis driving stage 102, the driving stage speed in one direction along the given planned processing line 402a is Vt. Assume that the scanner return scanning speed is Vs2 and the opposite direction is the _second direction (that is, the direction opposite to the first direction). At this time, the scanning line speed V ₀ is V ₀ = Vs ₂ + Vt
becomes.

Here, in galvano scanning, the first direction scanning in the same direction as the X-axis drive stage 102 is more effective than the second direction scanning in the opposite direction to the first direction, which is the movement direction of the X-axis drive stage 102. ,fast. For this reason,
_Vs1 > _Vs2 .

Since the scanning line speed _V0 is controlled by the controller 100 so as to be relatively constant,
Vs1 _- Vt>Vs2 ₊ Vt
and
(Vs1 _- Vs2)/Vt> ₂
becomes.

Therefore, the scanning speed Vs of the galvanometer scanner 202 is twice or more faster than the drive stage speed (that is, movement speed) Vt of the X-axis drive stage 102 .

Although FIG. 5 is described with a linear shape, the same concept applies to a shape having a right angle or an arc.

According to such a processing method, while the X-axis drive stage 102 moves the processing object 101 in the X-axis direction, the galvano scanner 202 moves the processing object 101 through the galvano scanner 202 and the fθ lens 203 . can scan the workpiece 101 by reciprocating in a first direction along the X-axis direction and a second direction opposite to the first direction. Therefore, the irradiation power of the laser oscillator 201 can be set relatively low (for example, about 20% of the conventional one), and the thermal influence on the workpiece 101 during laser processing is reduced. Further, since the scanning speed is high and the reciprocating scanning is performed a plurality of times, even if the irradiation power of the laser oscillator 201 is small, the cutting amount in the laser processing is large, which has the effect of shortening the processing time. For example, when the scanning distance is about 391 mm and the object to be processed is equivalent to 6 inches, processing can be performed at a speed about 1.5 to 2.0 times faster than conventionally.

FIG. 6 shows a planned processing line 402a, that is, a scanning locus 402 of the galvanometer scanner 202, which is mainly a reciprocating motion and is assumed to be performed multiple times. Specifically, the number N of reciprocating motions derives process conditions related to linear velocity and power that satisfy the number of scans that is 3 or more and an odd number. If the number of reciprocating motions N is less than 2, it is not preferable because it is a mere reciprocating motion and the shape scanning becomes simple. In addition, if the number of reciprocating motions N is set to an even number, the galvanoscan ends in the return pass (see FIG. 7E) in the cross-sectional shape of the workpiece 101, which will be described later, which may cause processing defects. . For this reason, that is, in order to suppress deterioration in machining accuracy and productivity, the number of reciprocating operations N is set to 3 or more and an odd number.

The shape of the planned processing line 402a, that is, the locus 402 is not limited to a straight line, and may be an arc or other shape. Further, the length of the planned processing line 402a, that is, the locus 402, may be set arbitrarily as long as it does not exceed the maximum scanning range of the f.theta.

As described above, the X-axis drive stage 102 moves at a constant linear velocity in one direction along the X-axis. By combining the movement of the X-axis driving stage 102 and the galvanometer scanner scanning in the cooperative control by the control unit 100, the scanning locus 402 is changed to the cross-sectional shape of the workpiece 101 in the depth direction of laser processing as shown in FIG. 7A. It becomes a staircase shape like FIG. 7A shows a working edge area 701 and a cutting line 702 .

As a result, the workpiece 101 is gradually cut along the scanning locus 402, and high-quality machining becomes possible.

Specifically, it will be described with reference to FIGS. 7B to 7F.

FIG. 7B is a cross section of the workpiece 101 in operation with the number of reciprocating motions N=1. This operation indicates forward movement of the X-axis drive stage 102 and the galvanometer scanner 202 .

FIG. 7C is a cross section of the workpiece 101 in motion with the number of reciprocating motions N=2. This operation adds a return trip operation of the galvanometer scanner 202 to the operation of FIG. 7B. However, the X-axis drive stage 102 moves only in one direction, so the amount of movement is short.

FIG. 7D is a cross section of the workpiece 101 in motion with the number of reciprocating motions N=3. In this motion, the X-axis drive stage 102 moves in one direction, and the galvanometer scanner 202 performs forward motion in addition to reciprocating motion.

When the motion is repeated multiple times, FIG. 7E is a cross section of the workpiece 101 in motion with the number of reciprocating motions N=4, and FIG. 7F is a cross section of the workpiece 101 in motion with the number of reciprocating motions N=5. The object 101 to be processed is processed in this manner and subjected to laser cutting.

It is preferable to determine the number of repetitions of the reciprocating motion of 3 or more by deriving process conditions from the relationship between the linear velocity and the power of the laser oscillator 201 .

Further, in the scanning operation, as shown in FIG. 7F, a step 701a in the depth direction remains in a processing end area 701 between the processing start point and the processing end point. Therefore, in order to eliminate the step 701a in the processing end area 701, the processing end area 701 should be scanned so as to generate a scanning locus 402 in which the loci 402 intentionally overlap.

The amount of overlap at this time is, as shown in FIG. 402 is scanned. Note that FIG. 8 shows a start point overlap 801 , an end point overlap 802 , a start edge 803 and an end edge 804 .

As described above, the laser beam L is condensed via the fθ lens 203 and then irradiated onto the workpiece 101 . The more the laser light L passes through the center of the fθ lens 203, the more the laser light L is condensed, and the more accurately the laser light L can be processed. Therefore, the planned processing line 402a scanned by the galvanometer scanner 202 generates a scanning locus 402 so as to pass through the center 203a of the fθ lens 203 and is scanned.

As an example, as shown in FIG. 9, the fθ lens 203 has a maximum scanning range (in other words, maximum scanning area) 901 . For example, when the F value is 100, the range within a circle with a diameter of about 70 mm (a square area of 50 mm*50 mm within a circle with a diameter of 70 mm) is effective as the maximum scanning range 901, and the size varies depending on the type of fθ lens 203. However, the maximum scan range 901 is circular. As described above, the trajectory 402 passing through the circular center of the maximum scanning range 901 to be scanned is a cross centered on the fθ lens 203 within the trajectory passing range width 902 in (a) of FIG. 9 . Dotted line 902 a indicates the trajectory passing range, ie, the edge of the workpiece that is separated by cutting with scanning trajectory 402 .

With the maximum scanning diameter Ds, the locus passing range width A is given by the following formula.

Width A = Ds*sinπ/4*0.06
As described above, since it passes through the center 203a of the fθ lens 203, it can be processed with high precision, and since it has a cross-shaped trajectory passing range width A, it can be used up to the upper limit of the maximum scanning range 901, and the scanning distance can be lengthened, which reduces the processing time. Since it is shortened, it is possible to achieve both processing accuracy and productivity in laser processing.

9B to 9E show a part of the scanning trajectory pattern 903 of the trajectory passage range width A passing through the center 203a of the fθ lens 203. The galvanometer scanner 202 reciprocally scans a scanning locus pattern 903 as shown in (e) of 9.

FIG. 9(b) shows a trajectory pattern 903a of the trajectory 402 generated by scanning in the horizontal direction of FIG. 9(b). FIG. 9(c) shows a trajectory pattern 903b of the trajectory 402 generated by scanning in the vertical direction of FIG. 9(c). FIG. 9(d) shows a locus pattern 903c of the locus 402 generated by scanning in an L-shape to the right hand side passing through the center from the top of FIG. 9(d). In this trajectory pattern 903c, right-angled corners can be formed at the corners of the cutting shape. (e) of FIG. 9 shows a locus pattern 903d, which does not bend at a right angle at the center but gently curves near the center, among the locus patterns 903c of (d) of FIG. In this trajectory pattern 903d, curved R portions can be formed at the corners of the cut shape.

According to the laser processing method and apparatus having the configuration described above, the object 101 or the laser scanning optical systems 202 and 203 are driven to move the object 101 and the laser beam L to the X-axis and Y-axis drive stages 102, 102, and 203. 105 can be driven in the XY axis direction, and has a laser scanning optical system that can position and irradiate the laser beam L within the scanning range, for example, a galvanomirror Gx and Gy axes. By simultaneously operating the XY axes of the Y-axis drive stages 102 and 105 and the X-axis and Y-axis galvanometer mirrors 202a and 202b of the laser scanning optical systems 202 and 203, the laser scanning speed is controlled to be constant. Laser processing can be performed without controlling the laser intensity.

According to the above-described embodiment, while moving the object 101 at the moving speed Vt, the laser beam L is continuously emitted three times at the scanning speed Vs on the same straight line as a part of the planned processing line 402a of the object 101. Since the reciprocating scanning is performed at least once and an odd number of times, it is possible to suppress the deterioration of the machining accuracy and productivity, and it is possible to form an arbitrary shape and a large area on the workpiece 101 at a high speed. Seamless and homogeneous processing is possible.

By appropriately combining any of the various embodiments or modifications described above, the respective effects can be obtained. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, as well as combinations of features in different embodiments or examples.

The laser processing apparatus and laser processing method according to the above aspect of the present invention can process an object to be processed in any shape and in a wide range at high speed, and can be used to cut objects other than resin films (for example, iron-based materials). Alternatively, it can also be applied to cutting applications.

90 laser processing device 91 base 100 control unit 101 object to be processed 102 X-axis drive stage 103 processing head 104 Z-axis drive stage 105 Y-axis drive stage 106 portal 201 laser oscillator 202 galvano scanner 202a, 202b for X-axis and Y-axis 202c, 202d Motor for axis rotation 202e Rotation angle control unit 203 fθ lens 203a Center of fθ lens 301 Cut product 401 Scanning area of galvano scanner 402 Laser scanning trajectory 402a Planned processing line 501 Drive stage scanning 502 Galvano scanner scanning 503 Synchronization Scan trajectory 504 Synchronous scanning trajectory resolution image 701 Processing edge area 701a Step 702 Cutting line 801 Start point overlap 802 End point overlap 803 Start edge 804 End edge 901 Galvano scanner maximum scanning range 902 Locus passage range width 902a Locus passage range 903 Scanning trajectory pattern 903a, 903b, 903c, 903d Trajectory pattern

Claims (11)

In a laser processing method for laser processing an object having a processing area larger than a scanning area scanned with a laser beam,
holding the workpiece in a first drive that moves the workpiece in a first direction;
Next, while the first driving device moves the object to be processed in the first direction, the galvano scanner irradiates the object to be processed with the laser beam passing through the galvano scanner and the fθ lens. When scanning an object to be processed by reciprocating in the first direction and in a direction opposite to the first direction,
Let Vt be the moving speed of the object to be processed, Vs be the scanning speed of the laser beam, and while moving the object to be processed at the moving speed Vt, a part of the planned processing line of the object to be processed is on the same straight line. and irradiating the laser beam by continuously scanning the laser beam three or more times at the scanning speed Vs,
The _linear velocity V ₀ of scanning of the laser light is controlled by the control unit so as to be relatively constant. Assuming that the backward scanning galvano scanner backward scanning speed is Vs ₂ ,
The linear velocity V ₀ in the forward scanning is
V ₀ =Vs ₁ -Vt and
The linear velocity V ₀ in the backward scanning is
V ₀ =Vs ₂ +Vt and
Since the linear velocity V ₀ is controlled to be relatively constant,
Vt = (Vs ₁ -Vs ₂ )/2,
Laser processing method. In the reciprocating scanning, a scanning trajectory is formed by reciprocating motion of the galvanometer scanner along the planned processing line,
The number of reciprocating motions is 3 or more and an odd number of times,
The laser processing method according to claim 1 . In the control unit, by cooperatively controlling and combining the reciprocating scanning by the galvanometer scanner and the movement at a constant speed in one direction along the first direction by the first driving device, the scanning trajectory is In the depth direction of laser processing, it becomes a stepped shape,
The laser processing method according to claim 2 . The control unit generates and scans the scanning trajectory that overlaps and scans so as to eliminate steps in the cross section of the object to be processed in the processing end area of the processing start point and the processing end point by the laser beam. control to
The laser processing method according to claim 3 . scanning so as to generate the scanning trajectory so that the laser light from the galvanometer scanner passes through the center of the fθ lens;
Assuming that the scanning trajectory is within the trajectory passing range of the fθ lens, the maximum scanning diameter of the fθ lens is Ds, and the width of the trajectory passing range is A,
A = Ds*sinπ/4*0.06
performing the scanning to generate the scanning trajectory under the condition of
The laser processing method according to any one of claims 2 to 4 . In a laser processing apparatus for laser processing an object having a processing area larger than a laser scanning area scanned with a laser beam,
a driving stage that moves in a first direction at a moving speed Vt while holding the workpiece;
a laser emission unit that emits the laser light;
changing the scanning direction of the laser beam emitted from the laser emitting part, and scanning the laser beam so as to reciprocate the object to be processed in the first direction and in a direction opposite to the first direction; a galvanometer scanner that scans at a speed Vs;
an fθ lens that transmits the laser beam emitted from the galvanometer scanner and irradiates the object to be processed at an arbitrary predetermined angle;
By controlling the driving of the drive stage and the galvano-scanner respectively, the object to be processed is moved in the first direction by the drive stage, and the galvano-scanner moves the galvano-scanner through the galvano-scanner and the fθ lens. When the object to be processed is irradiated with the laser beam for scanning, the moving speed of the object to be processed is Vt, the scanning speed of the laser beam is Vs, and the object to be processed is moved at the moving speed Vt. A control unit for performing control so that the laser beam is continuously scanned three times or more back and forth at the scanning speed Vs on the same straight line as a part of the planned processing line of the object to be processed while the laser beam is irradiated. and
When controlled by the control unit,
The _linear velocity _V0 of the scanning of the laser light is controlled to be relatively constant. Assuming that the galvanometer scanner return scanning speed is Vs ₂ ,
The linear velocity V ₀ in the forward scanning is
V ₀ =Vs ₁ -Vt and
The linear velocity V ₀ in the backward scanning is
V ₀ =Vs ₂ +Vt and
Since the linear velocity V ₀ is controlled to be relatively constant,
Vt = (Vs ₁ -Vs ₂ )/2,
Laser processing equipment. The drive stage is an X-axis drive stage that holds the workpiece and moves it along the X-axis that is the first direction,
The laser processing device is
a processing head having the galvanometer scanner and the fθ lens;
a Z-axis drive stage for moving the machining head in a Z-axis direction that intersects with the X-axis;
a Y-axis drive stage to which the Z-axis drive stage is attached and which moves the machining head and the Z-axis drive stage in a Y-axis direction that intersects the X-axis and the Z-axis;
The control unit also controls the driving of the Z-axis drive stage and the Y-axis drive stage, respectively.
The laser processing apparatus according to claim 6 . The control unit cooperatively controls the driving stage and the galvanometer scanner to perform the reciprocating scanning, and scans the workpiece by generating a predetermined scanning locus, thereby cutting the workpiece into cut pieces having a predetermined shape. do,
The laser processing apparatus according to claim 6 or 7 . The controller controls the galvanometer scanner while controlling the X-axis driving stage and the Y-axis driving stage so that the laser beam can scan the desired processing line at a constant speed and in one direction. While reciprocating on the planned processing line within the scanning area, control is performed so that the relative linear velocity is constant.
The laser processing apparatus according to claim 7 . The laser emitting unit is a laser oscillator that oscillates the laser light at a picosecond to femtosecond ultrashort pulse and a maximum frequency of 1 MHz or higher.
The laser processing apparatus according to any one of claims 6-9 . The f-theta lens is an f-theta lens having an F value of 45 or more and 110 or less,
The laser processing apparatus according to any one of claims 6-10 .

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