The present invention relates to a processing apparatus and an article manufacturing method.
A laser processing apparatus is an apparatus that performs various kinds of processes (for example, hole machining) on a workpiece by scanning and condensing laser light on the workpiece using a movable mirror such as a galvano scanner and a condenser lens. In recent years, Germany Patent No. 102004053298 has proposed a laser processing apparatus that can control, with high accuracy, the hole diameter of a machined hole and the angle of a wall surface by controlling the incident angle of laser light condensed on a workpiece.
However, in the conventional laser processing apparatus, if the shape of the laser light condensed on the workpiece is distorted, this influences the machined hole formed in the workpiece, and it is difficult to form the machined hole having a desired shape.
The present invention provides a processing apparatus advantageous in processing a workpiece with high accuracy.
According to one aspect of the present invention, there is provided a processing apparatus that processes a workpiece by irradiating the workpiece with laser light, the apparatus including a rotation unit configured to rotate with a rotation axis as a center, thereby rotating an intensity distribution of the laser light emitted therefrom with the rotation axis as a center, a scanning unit configured to scan the laser light applied to the workpiece, and a control unit configured to irradiate the workpiece with the laser light while reducing at least one of an angular shift and a positional shift of the laser light entering the workpiece, which occur due to a shift between the rotation axis and a barycentric line of the laser light entering the rotation unit.
Further aspects of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made to an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.
The processing head unit 200 includes an image rotator 202, a first partial transmission mirror 203, a shifter unit 204, a first enlarging lens 205, a second enlarging lens 206, a scanner unit 207, and a condenser lens 209.
The image rotator 202 rotates coaxially with the laser light 201, and has a function of allowing the laser light 201 emitted therefrom to rotate on its axis. The image rotator 202 functions as a rotation unit that rotates around a rotation axis, thereby allowing the intensity distribution of the laser light 201 emitted therefrom to rotate around the rotation axis.
The first partial transmission mirror 203 branches (separates) the laser light 201 emitted from the image rotator 202 into laser light which enters the sensor unit 220, and laser light which enters the shifter unit 204. Accordingly, a part of the laser light 201 emitted from the image rotator 202 enters the sensor unit 220 via the first partial transmission mirror 203, and the remaining part enters the shifter unit 204.
The shifter unit 204 is provided on the subsequent stage of the image rotator 202. A movable mirror or a movable transparent substrate having a plurality of rotational degrees of freedom is included inside the shifter unit 204. The shifter unit 204 translates (shifts) the incident laser light 201 in the vertical and horizontal directions. In this embodiment, the shifter unit 204 functions as a first scanning unit that changes the position of the laser light 201 applied to (entering) the workpiece 210. By cooperating with the scanner unit 207 which functions as a second scanning unit that changes the angle of the laser light 201 applied to (entering) the workpiece 210, the shifter unit 204 also functions as a scanning unit that scans the laser light 201 applied to the workpiece 210.
Each of the first enlarging lens 205 and the second enlarging lens 206 enlarges the beam diameter of the laser light emitted from the shifter unit 204. The first enlarging lens 205 is provided so as to be movable along the traveling direction of the laser light 201.
The laser light 201 with the beam diameter enlarged by the first enlarging lens 205 and the second enlarging lens 206 is reflected by the scanner unit 207, and condensed on the workpiece 210 via the condenser lens 209. The scanner unit 207 is provided on the subsequent stage of the image rotator 202, and includes, for example, a reflection mirror M that reflects the laser light 201, and a first actuator 208A and a second actuator 208B configured to drive the reflection mirror M. The scanner unit 207 can adjust the reflection angle of the laser light 201 in two directions by driving the reflection mirror M by the first actuator 208A and the second actuator 208B.
The laser light 201 reflected (branched) by the first partial transmission mirror 203 enters the sensor unit 220. The sensor unit 220 includes a second partial transmission mirror 221, a first reflection mirror 224, a second reflection mirror 225, a third partial transmission mirror 226, and a sensor 227.
The second partial transmission mirror 221 branches (separates) the laser light 201 having entered the sensor unit 220 into laser light which passes through a first optical path 222, and laser light which passes through a second optical path 223. The laser light 201 passing through the first optical path 222 is reflected by the third partial transmission mirror 226 via the first reflection mirror 224 and the second reflection mirror 225, and enters the sensor 227. The laser light 201 passing through the second optical path 223 is transmitted through the third partial transmission mirror 226, and enters the sensor 227. The sensor 227 detects the respective positions of the two incident laser light beams 201, and transmits the positions to the control unit 230 as position information.
The control unit 230 is formed by a computer (information processing apparatus) including a CPU, a memory, and the like and, for example, operates the processing apparatus 1 by comprehensively controlling respective units of the processing apparatus 1 in accordance with a program stored in a storage unit. In this embodiment, the control unit 230 controls the image rotator 202, the shifter unit 204, the first enlarging lens 205 (actuator included therein), and the first actuator 208A and the second actuator 208B included in the scanner unit 207. Further, the control unit 230 has various kinds of calculation (arithmetic) functions and, based on the position information transmitted from the sensor 227, obtains the fluctuation of the laser light 201 and generates a driving signal for driving each actuator. In this embodiment, the control unit 230 performs a process of irradiating the workpiece 210 with the laser light 201 to process the workpiece 210.
With reference to
In this embodiment, the image rotation element 302 is formed by a prism having a trapezoid cuboid shape, and referred to as, for example, a dope prism or a dove prism. The image rotation element 302 has characteristics of inverting/rotating the laser light 201 inside it. For example, along with a rotation of the image rotation element 302, an incident image 303 (intensity distribution) of the laser light 201 is changed to an emission image 304 (intensity distribution). More specifically, it is known that when the image rotation element 302 (dope prism) rotates once, the emission image 304 rotates at twice the cycle (that is, rotates twice).
In this embodiment, the housing 301 is configured to be rotatable coaxially with the laser light 201 and integrally with the image rotation element 302. Accordingly, when the housing 301 rotates, the image rotation element 302 also rotates, and the laser light 201 emitted therefrom rotates (on its axis). The housing 301 (image rotator 202) is rotated using, for example, an electromagnetic or pneumatic actuator. A sensor provided in the actuator detects the rotation speed and the number of rotations, and they are transmitted to the control unit 230 as operation information.
With reference
In the processing head unit 200, by operating the shifter unit 204 and the scanner unit 207 interlockingly, the laser light 201 (condensed point thereof) is scanned along a trajectory 402 (that is, so as to draw the circular trajectory 402). With this, a machined hole 403 is formed in the workpiece 210. However, if the condensed shape 401 of the laser light 201 is distorted, this influences the shape of the machined hole 403 formed in the workpiece 210. In
In the processing head unit 200, by operating the shifter unit 204 and the scanner unit 207 interlockingly, the laser light 201 (condensed point thereof) is scanned along the trajectory 502. With this, a machined hole 503 is formed in the workpiece 210. Since the condensed shape 501 of the laser light 201 is averaged to the perfectly circular shape, the shape of the machined hole 503 formed in the workpiece 210 becomes similar to the shape of the trajectory 502. Therefore, even if the condensed shape of the laser light 201 is distorted, the shape of the machined hole 503 is not influenced by this, and no error occurs in the processed shape.
With reference to
Referring to
Referring to
An optical path 622 schematically expresses the optical path of the laser light 201 in the second optical path 223 after the fluctuation. An optical path 623 schematically expresses the optical path of the laser light 201 in the first optical path 222 after the fluctuation. In
d2 denotes the incident point movement amount on the first sensor surface 625 after the optical axis fluctuation. This schematically shows the change of the incident position, to the sensor 227, of the laser light passing through the first optical path 222 in
A series of steps concerning calculation (calculation method) of the amount of optical axis fluctuation in the control unit 230 will be described below. First, in the first step, the angle component of the optical axis fluctuation is calculated from the measurement results (respective positions of the two laser light beams having entered the sensor 227) of the sensor unit 220. In
Then, in the second step, the position component of the optical axis fluctuation is calculated from the measurement results of the sensor unit 220. In
With the series of steps (the first step and the second step) described above, the angle component (angular shift θ1) and position component (positional shift d1) of the optical axis fluctuation can be calculated from the measurement results of the sensor unit 220.
Note that the relative effective ratio between the angle component and the position component may be changed by providing, in the optical path of the sensor unit 220, an optical system whose optical magnification ratio is changed by a combination of lenses or the like. For example, if the optical system of 2× optical magnification is provided in the optical path of the sensor unit 220, the angle component and position component of the emitted laser light change ½ times and twice, respectively, with respect to the fluctuation of the incident laser light.
In this embodiment, as has been described above, the image rotator 202 is rotated coaxially with the laser light 201 entering the image rotator 202 by the electromagnetic or pneumatic actuator. However, if the optical axis of the laser light 201 entering the image rotator 202 fluctuates with time, a positional error (shift) and an angular error (shift) occur between the rotation center (rotation axis) of the image rotator 202 and the optical axis (barycentric line (the line through which the barycenter (center) of the laser light 201 passes)) of the laser light 201.
Referring to
Then, from the detection signal transmitted from the sensor unit 220, the control unit 230 extracts the positional error and the angular error between the optical axis of the laser light 201 and the rotation axis of the image rotator 202, that is, the revolution component serving as the fluctuation component generated due to the optical axis fluctuation of the laser light 201. For example, the control unit 230 analyzes the detection signal from the sensor unit 220 with the frequency component, thereby extracting the revolution component which is in synchronization with the number of rotations of the image rotator 202. Further, the control unit 230 separates the revolution component (fluctuation component) extracted from the detection signal into the angle component and the position component by the calculation described with reference to
Then, the control unit 230 generates an angle compensation signal (period and amplitude thereof) for canceling (reducing) the separated angle component, and a position compensation signal (period and amplitude thereof) for canceling (reducing) the separated position component. The control unit 230 superimposes the angle compensation signal on a processing signal for controlling the angle of the laser light 201 applied to the workpiece 210 upon processing the workpiece 210, thereby generating a driving signal for driving the scanner unit 207. Similarly, the control unit 230 superimposes the position compensation signal on a processing signal for controlling the position of the laser light 201 applied to the workpiece 210 upon processing the workpiece 210, thereby generating a driving signal for driving the shifter unit 204. Note that the processing signal for controlling the angle or position of the laser light 201 is a set signal prepared in advance without considering the revolution component (fluctuation component) generated due to the optical axis fluctuation of the laser light 201.
The driving signal generated by superimposing the angle compensation signal on the processing signal for controlling the angle of the laser light 201 applied to the workpiece 210 is given from the control unit 230 to the scanner unit 207. On the other hand, the driving signal generated by superimposing the position compensation signal on the processing signal for controlling the position of the laser light 201 applied to the workpiece 210 is given from the control unit 230 to the shifter unit 204. With this, in the processing head unit 200, the shifter unit 204 and the scanner unit 207 operate interlockingly. At this time, since the driving signals generated by respectively superimposing the compensation signals on the processing signals are used, the revolution component (fluctuation component) generated due to the optical axis fluctuation of the laser light 201 is canceled. Thus, it is possible to form the machined hole in the workpiece 210 with no processing error.
In this manner, in this embodiment, the sensor unit 220 detects the fluctuation in at least one of the angle and position of the laser light 201 entering the workpiece 210, which occurs due to a shift between the optical axis of the laser light 201 and the rotation axis of the image rotator 202 in synchronization with a rotation of the image rotator 202. Then, in the control unit 230, while reducing (compensating) the fluctuation detected by the sensor unit 220 using the shifter unit 204 and the scanner unit 207, a process of irradiating the workpiece 210 with the laser light 201 is performed. Therefore, according to the processing apparatus 1 of this embodiment, even if the optical axis of the laser light 201 fluctuates, it is possible to perform processing with reduced influence of the fluctuation. Thus, it is possible to process the workpiece 210 with high accuracy.
Note that in this embodiment, of the revolution component (fluctuation component) generated due to the optical axis fluctuation of the laser light 201, the position component is reduced by the shifter unit 204, and the angle component is reduced by the scanner unit 207. However, the present invention is not limited to this. For example, a unit having both the function of the shifter unit 204 and the function of the scanner unit 207 may be formed, and this unit may reduce both the position component and the angle component.
In this embodiment, the laser light 201 branched immediately after the image rotator 202 enters the sensor unit 220, but the branch position of the laser light 201 which enters the sensor unit 220 is not limited to the position immediately after the image rotator 202. For example, a part of the reflection mirror M of the scanner unit 207 may be formed as a partial transmission mirror, and the laser light 201 branched by the scanner unit 207 may enter the sensor unit 220.
Further, in this embodiment, the scanner unit 207 can adjust the reflection angle of the laser light 201 in two directions by driving the reflection mirror M by the first actuator 208A and the second actuator 208B. However, the present invention is not limited to this configuration. For example, the laser light 201 may be scanned using two sets of movable mirrors such as galvano scanners.
In the second embodiment, in a processing apparatus 1 shown in
In the processing head unit 200, by operating the shifter unit 204 and the scanner unit 207 interlockingly, the laser light 201 (condensed point thereof) is scanned along a trajectory 1202. With this, a machined hole 1203 is formed in the workpiece 210. However, if a condensed shape 1201 of the laser light 201 is distorted, this influences the shape of the machined hole 1203 formed in the workpiece 210.
To prevent this, in this embodiment, the image rotator 202 is rotated at ½ the cycle of the trajectory 1202 so as to allow the laser light 201 to rotate (on its own axis) in the same direction as the direction (revolution direction) along the trajectory 1202. In other words, the image rotator 202 is rotated half while the laser light 201 is scanned (revolves) once along the trajectory 1202. With this, the condensed shapes 1201 having the same intensity distribution (same intensity) in the radial direction of the circle defined by the trajectory 1202 are obtained. Accordingly, the shape of the machined hole 1203 formed in the workpiece 210 becomes similar to the shape of the trajectory 1202. Therefore, even if the condensed shape of the laser light 201 is distorted, the shape of the machined hole 1203 is not influenced by this, and no error occurs in the processed shape. Here, the shape of the machined hole formed in the workpiece 210 is a circle (circular shape). However, the present invention is not limited to this, and various shapes such as an ellipse, a rectangle, and a triangle are assumed in addition to the circle. If the machined hole to be formed in the workpiece 210 has a shape other than a circle, the center of the shape (for example, in a case of an ellipse, the position in the middle between two centers), the barycenter, the center of the inscribed circle, or the center of the circumcircle is read as the center of the circle in this embodiment. Accordingly, by reading the radial direction in this embodiment as the direction connecting the center (or barycenter) of the shape and the processing position, this embodiment can support various shapes other than the circle. The example of forming the machined hole having a shape other than the circle can be applied to all the description of this embodiment.
Also in this embodiment, if the optical axis of the laser light entering the image rotator 202 fluctuates with time, a positional error and an angular error occur between the rotation center (rotation axis) of the image rotator 202 and the optical axis (barycentric line) of the laser light. If the laser light fluctuates with respect to the rotation axis of the image rotator 202 and an error occurs, in accordance with the error, in addition to a rotation component, a revolution component in synchronization with the rotation cycle of the image rotator 202 is generated in the laser light emitted from the image rotator 202. As a result, a revolution component is also generated in the laser light condensed on the workpiece 210 shown in
With reference to
Then, from the detection signal transmitted from the sensor unit 220, the control unit 230 calculates a first direction a from the center position 1601 of the laser light 201 to the barycenter position 1602 of the light amount of the laser light 201. The control unit 230 also calculates a second direction β from the center position 1601 of the laser light 201 at the irradiation start position (processing start position) of irradiation of the workpiece 210 with the laser light 201 to a center 1611 of a trajectory 1612 (circle defined thereby) as shown in
The adjustment signal generated by the control unit 230 is given to the image rotator 202. With this, in the processing head unit 200, the image rotator 202 is operated (rotated), and adjusted such that the high intensity portion of the laser light 201 is located on the outer side of a machined hole 1613 as shown in
In this manner, according to the processing apparatus 1 of this embodiment, as in the first embodiment, even if the optical axis of the laser light 201 fluctuates, it is possible to perform processing with reduced influence of the fluctuation. Thus, it is possible to process the workpiece 210 with high accuracy. Further, in the processing apparatus 1 of this embodiment, before processing the workpiece 210 by irradiating the workpiece 210 with the laser light 201, the image rotator 202 is adjusted such that the high intensity portion of the laser light 201 is located on the outer side of the machined hole. With this, better processing can be implemented.
In the first embodiment and the second embodiment, the case in which the optical axis of the laser light 201 entering the image rotator 202 fluctuates with time has been taken as an example and described, but the present invention is not limited to this. For example, the present invention is also applicable to a case in which the optical axis of the laser light 201 entering the image rotator 202 is shifted from the rotation center (rotation axis) of the image rotator 202 in the assembly stage (initial stage) of the processing apparatus 1.
The processing apparatus 1 in the embodiment can be used for an article manufacturing method. The article manufacturing method includes a step of processing a workpiece (target object) using the processing apparatus 1, and a step of manufacturing an article by processing the workpiece processed in the processing step. The processing step includes at least one of, for example, processing different from the above-described processing, conveyance, inspection, sorting, assembly, and packaging. The article manufacturing method according to the embodiment is superior to a conventional method in at least one of the performance, quality, productivity, and production cost of the article.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent application No. 2022-072673, filed Apr. 26, 2022, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2022-072673 | Apr 2022 | JP | national |