JP3381885B2 - Laser processing method and laser processing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method and a laser processing apparatus, and more particularly to a laser processing method capable of forming a solid having an arbitrary shape from a desired material such as metal or organic resin. Also, the present invention relates to a laser processing apparatus, which is particularly suitable for high-speed molding of a minute solid body having an arbitrary shape, and can be used for micro-machining (micromachining).

[0002]

2. Description of the Related Art Conventionally, as a processing method for molding an arbitrary three-dimensional shape from a desired material such as a metal or an organic resin, for example, machining by a blade using a machine lathe or the like is used. It has been known.

In machining with such a blade,
Since it is difficult to control the position of a blade with large inertia at high speed, and there is a limit to the improvement of the accuracy of the blade itself,
There is a problem that it is not possible to process a minute object whose one side is about 1 mm or less.

In particular, when a mechanical lathe is used, it has been pointed out that the machined three-dimensional shape is limited to the rotating body, and therefore it cannot be machined into an arbitrary shape.

Further, as a processing method for processing a metal material to form an arbitrary three-dimensional shape, in addition to the above-described mechanical processing by a mechanical lathe, electric discharge processing is generally performed. It is known that electric discharge machining can process a minute three-dimensional shape.

However, such electric discharge machining has a problem that the material to be machined is limited to a conductive material.

The present invention has been made in view of the above-mentioned various problems of the prior art, and the purpose thereof is not to limit the material to be processed but to obtain a desired material. An object of the present invention is to provide a laser processing method and a laser processing device capable of forming a minute three-dimensional solid body.

[0008]

In order to achieve the above object, a laser processing method and a laser processing apparatus according to the present invention include a laser beam (pulse laser beam) instead of a conventional blade for machine processing such as a mechanical lathe. And continuous laser light, and any of them may be used.
In the case of pulsed laser light, the wavelength may be any wavelength. ) Is the material to be processed (hereinafter referred to as "workpiece").
Concentrate on the top and remove the substance by the irradiation effect of laser light at the focus part (This substance removal is laser evaporation or laser etching when irradiated with pulsed laser light, and when irradiated with continuous laser light Laser melting, etc.), and the processed product is molded into an arbitrary shape by removing such substances.

[0009]

[Function] By controlling the irradiation site of the laser beam to the work piece, it becomes possible to remove the substance at any part on the work piece, and it is possible to form not only the rotating body but also a solid body of any shape. Like

Further, the laser light is focused on a minute point on the workpiece, and the intensity of the laser light (in the case of pulsed laser light, the quantity of light per pulse, the number of irradiation pulses, etc., is used. , The average amount of light and the irradiation time are controlled.) It is possible to accurately control the amount of the substance removed by the substance removal by the irradiation effect of the laser light, so that it is possible to control any minute three-dimensional object. The shape can be molded.

[0011]

Embodiments of a laser processing method and a laser processing apparatus according to the present invention will be described in detail below with reference to the drawings. The laser processing apparatus according to the present invention can be installed not only in a vacuum but also in the air or in a liquid, and the installation location is not limited.

FIG. 1 is a schematic structural explanatory view of a laser processing apparatus according to a first embodiment for carrying out the laser processing method according to the first embodiment of the present invention.

The laser processing apparatus according to the first embodiment is used in the air, and is used for the workpiece 10
The vertical moving stage 12 for mounting the The vertical movement stage 12 is attached to a base 14 so as to be vertically movable, and is movable in a vertical direction which is an optical axis direction of a laser beam 16 described later by the operation of a drive system (not shown). The focus of the laser light 16 condensed by the condenser lens 38 can be positioned at a predetermined portion of the workpiece 10.

The laser light 16 which is vertically irradiated onto the workpiece 10 from above is generated by a laser irradiation system 18.

The laser irradiation system 18 adjusts the light amount of the processing laser 20 and the processing laser light emitted from the processing laser 20 to adjust the amount of material removed from the workpiece 10. 22, a correction optical system device 24 for adjusting the focal position of the processing laser beam,
A surface shape measuring device 26 that measures the shape of the surface of the workpiece 10 in real time by incorporating a measuring laser that emits a weak measuring laser beam, and the workpiece 10 measured by the surface shape measuring device 26 in real time. In order to obtain a target three-dimensional shape to be formed by processing by comparing them based on shape information indicating the surface shape of the target and shape information indicating a target three-dimensional shape to be formed by processing stored in advance. And a control device 28 for controlling the light quantity adjuster 22 based on the light quantity control information so that the light quantity of the processing laser light necessary for calculating the light quantity of the processing laser light becomes the calculated light quantity. There is.

The processing laser light emitted from the correction optical system device 24 is reflected by the semi-transmissive mirror 30 and is incident on the total reflection mirror 32, is reflected by the total reflection mirror 32 and is incident on the movable mirror pair 34. It

On the other hand, the measuring laser beam emitted from the surface shape measuring device 26 is reflected by the total reflection mirror 36, is incident on the semi-transmission mirror 30, is further transmitted through the semi-transmission mirror, and is reflected by the total reflection mirror 32. It is incident on the movable mirror pair 34.

Then, the processing laser light and the measurement laser light reflected by the movable mirror pair 34 are condensed as laser light 16 on the surface of the workpiece 10 by the condenser lens 38.

The pair of movable mirrors 34 is used for the laser light 1
6 is a device for scanning 6 in the XY directions at a high speed, but since it is a known technique, its detailed description is omitted.

The condenser lens 38 is composed of the movable mirror pair 3
In order to always collect the laser beam 16 scanned at a high speed in the XY directions by 4 in the best state,
It can move at high speed in the XY directions in response to the scanning of the laser 16 in the XY directions.

The correction optical system device 24 adjusts the focal points of the processing laser light and the measurement laser light focused by the same condenser lens 38 to the surface of the workpiece 10. , For adjusting the focal position of the processing laser light to the focal position of the measuring laser light for the purpose of matching the focal positions of the processing laser light and the measuring laser light in the optical axis direction. It is an apparatus, and may not be provided when the processing laser light and the measurement laser light have the same focal position in the optical axis direction in advance.

The movable mirror pair 34 and the condenser lens 38
The vertical movement stage 12 can be moved to a position required to obtain a target three-dimensional shape to be formed by processing through a drive system (not shown) under the control of the control device 28. That is, in order to obtain a target three-dimensional shape to be formed by machining from the workpiece 10, the workpiece 10
The controller 28 controls the movements of the movable mirror pair 34, the condenser lens 38, and the vertical movement stage 12 so that the focal point of the laser beam 16 is located at the region where the substance should be removed from the surface.

In the above structure, the processing laser light emitted from the processing laser 20 which constitutes the laser light 16 is incident on the light quantity controller 22, and the correction optical system device 2 is operated.
4 → semi-transmissive mirror 30 → total reflection mirror 32 → movable mirror pair 34 → condensing lens 38
By the control of 8, a predetermined position on the surface of the workpiece 10 is focused and irradiated.

At this time, when a pulse laser is used as the processing laser 20, for example, the amount of light adjusted by the light quantity controller 22 is caused by laser evaporation or laser etching due to the irradiation effect of the processing laser light. A corresponding amount of material will be removed from the surface of the work piece 10 focused by the laser light 16.

At the same time, the measuring laser light emitted from the measuring laser of the surface shape measuring device 26 which constitutes the laser light 16 is also reflected from the total reflection mirror 36 → semi-transmissive mirror 30.
→ total reflection mirror 32 → movable mirror pair 34 → condenser lens 3
Through the route of 8, the surface of the workpiece 10 is focused and irradiated under the control of the control device 28.

Then, this measuring laser beam is used for the workpiece 1.
The light is reflected on the surface 0, and enters the surface shape measuring device 26 through a path opposite to the above, that is, the movable mirror pair 34 → total reflection mirror 32 → semitransmissive mirror 30 → total reflection mirror 36. In this way, the surface shape measuring device 26 on which the measuring laser beam reflected on the surface of the workpiece 10 is incident,
The incident measurement laser light is analyzed, the shape of the surface of the workpiece 10 is measured, and the measurement result is input to the control device 28 as shape information.

The control device 28 thus stores the shape information input from the surface shape measuring device 26, and the target three-dimensional object to be formed by the shape information input from the surface shape measuring device 26 and the previously stored processing. When it is necessary to remove the substance on the surface of the workpiece 10 by comparing the target three-dimensional shape to be formed by processing with the current shape of the workpiece 10 based on the shape information indicating the shape, the workpiece is processed. 10 Light intensity adjuster 2 so as to emit a light intensity capable of removing substances on the surface
2 is controlled, and when it is not necessary to remove the substance on the surface of the workpiece 10, the light amount controller 22 is controlled to reduce the light amount so that the substance on the surface of the workpiece 10 is not removed.

That is, the laser irradiation system 18 is configured to accurately obtain a target three-dimensional shape to be molded by laser processing by using feedback control.

The processing laser light and the measuring laser light are scanned on the surface of the workpiece 10 by the operation of the movable mirror pair 34 under the control of the control device 28 as described above. Further, as the material on the surface of the workpiece 10 is removed by the processing laser light, the vertical movement stage 12 is moved upward in the vertical direction by the operation of the drive system (not shown), so that the processing laser light and the measurement laser light are moved. Focusing can be performed, and laser processing with a large processing depth can be performed.

Next, as an operation example of the processing method according to the first embodiment using the laser processing apparatus according to the above-described first embodiment, a processing method for forming a triangular pyramid on the surface of a workpiece whose upper surface is a flat surface will be described. explain. That is, the rectangular parallelepiped workpiece 100 shown in FIG. 2 is used as the workpiece, and
A processing method for forming the triangular pyramid 102 shown in (a) and (b) will be described step by step.

(First stage) The vertical moving stage 12 is moved by a drive system (not shown) so that the focus of the focusing lens 38 is located on the processing surface 1 (see FIG. 2). Then, the measurement laser of the surface shape measuring device 26 emits the measurement laser light (the processing laser light from the processing laser 20 is not emitted), and the movable mirror pair 34 is operated to emit the measurement laser light. The surface shape is measured by scanning the surface of 100 and measuring the surface shape at each scanning point.
Measure in real time according to 6. Then, the measurement result is output to the control device 28 as shape information and stored in the control device 28.

Even in each step described later, the measurement laser of the surface shape measuring device 26 is always emitted from the measurement laser to measure the surface shape of the workpiece 100 at each scanning point by the operation of the movable mirror 34. Shape measuring device 2
6, the light amount of the processing laser light is adjusted by controlling the light amount adjuster 22 by the control device 28 in order to measure in real time and form the triangular pyramid 102.

(Second stage) The vertical moving stage 12 is moved upward by a drive system (not shown) so that the focus of the condenser lens 38 is located on the processing surface 2 (see FIG. 2).

(Third step) A processing laser beam is emitted from the processing laser 20, and the processing laser beam (and the measurement laser beam) is emitted by the movable mirror pair 34.
The surface material of the workpiece 100 is removed up to the processed surface 2 by scanning the surface of the workpiece (FIG. 4A).

At this time, the processing laser beam (and the measuring laser beam) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular pyramid 102, the control device 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to “0”, and the substance removal by irradiation of the processing laser light occurs. Control not to.

When the scanning point of the processing laser light (and the measuring laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular pyramid 102, the surface shape measured in the first step is obtained. Based on this, the control device 28 controls the light quantity adjuster 22 to adjust the light quantity of the processing laser light, adjust the amount of substance removed by the irradiation of the processing laser light, and create the processed surface 2.

The machining depth at each scanning point is measured in real time by the surface profile measuring device 26 in parallel with the machining, and is output to the control device 28 for storage.

(Fourth stage) The focal point of the condenser lens is the processed surface 3
(See FIG. 2) The vertical movement stage 12 is moved upward by a drive system (not shown) so as to be positioned above.

(Fifth stage) A processing laser beam is emitted from the processing laser 20, and the processing laser beam (and the measurement laser beam) is applied by the movable mirror pair 34.
The surface substance of the workpiece 100 is removed up to the processed surface 3 by scanning the surface of the workpiece (FIG. 4B).

At this time, the processing laser beam (and the measuring laser beam) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular pyramid 102, the control device 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to “0”, and the substance removal by irradiation of the processing laser light occurs. Control not to.

When the scanning point of the processing laser light (and the measuring laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular pyramid 102, the surface shape measured in the third stage is obtained. Based on this, the control device 28 controls the light quantity adjuster 22 to adjust the light quantity of the processing laser light and adjust the amount of substance removed by the irradiation of the processing laser light so that the processing surface 3 becomes a flat surface. .

The processing depth at each scanning point is measured in real time by the surface shape measuring device 26 in parallel with the processing, and is output to the control device 28 for storage.

After that, the processes of the above steps may be sequentially repeated until the final processed surface n (FIG. 4C) is obtained.

The surface of the triangular pyramid 102 after the laser processing has a stepped shape as shown in FIG. 5, but this step indicates the resolution of the laser processing apparatus according to the first embodiment. It corresponds to the focused diameter of the laser light for use. However, since this converging diameter can be made as small as the wavelength of the processing laser beam, the step-like step as shown in FIG. 5 can be an extremely minute step, so that the processing can be performed according to the desired processing accuracy. By selecting the wavelength of the laser light for use, it can be practically ignored.

Next, a laser processing apparatus according to the second embodiment for carrying out the laser processing method according to the second embodiment of the present invention will be described.

FIG. 6 is a schematic structural explanatory view of a laser processing apparatus according to the second embodiment for carrying out the laser processing method according to the second embodiment of the present invention, which is shown in FIG. Constituent members which are the same as or corresponding to those of the laser processing apparatus according to the first embodiment are designated by the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted.

The laser processing apparatus shown in FIG. 6 is attached to a rotating device 40 that rotates the workpiece 10 at a predetermined rotation speed (angular velocity ω) under the control of the control device 28. The rotating device 40 is attached to a horizontal moving stage 42 which is reciprocated in the horizontal direction by a drive system (not shown) under the control of the control device 28. The movement of the horizontal moving stage 42 is advanced by about the processing width (laser beam spot diameter: diameter of the converging point of the processing laser beam on the surface of the processing object 10) during one rotation of the processing object 10. It is set.

Further, the horizontal moving stage 42 is attached to the vertical moving stage 44, and the vertical moving stage 44 is attached to the base 14 so as to be movable up and down, and is shown under the control of the controller 28. It is possible to move vertically by the drive system.

In the laser processing apparatus according to the second embodiment, the laser beam 1 applied to the workpiece 10
6 is 2 in the vertical direction and the horizontal direction with respect to the workpiece 10.
The laser light emitted from two directions, that is, the vertical direction and the horizontal direction with respect to the workpiece 10 is generated by two sets of laser irradiation systems 18a and 18b (however, Of the laser irradiation system 18b, a processing laser 20, a light quantity controller 22,
The correction optical system device 24, the surface shape measuring device 26, the control device 28, the semi-transmissive mirror 30, and the total reflection mirror 36 are
It is also possible to share it with the corresponding configuration of the laser irradiation system 18a. ). That is, the laser irradiation system 1
The laser beam 16 that is emitted from the vertical direction to the workpiece 10 is generated by 8a, and the laser irradiation system 1
The laser beam 16 that is emitted from the horizontal direction to the workpiece 10 is generated by 8b.

The laser irradiation systems 18a and 18b and the laser irradiation system 18 used in the laser processing apparatus according to the first embodiment described above are different in that the laser irradiation systems 18a and 18b include a total reflection mirror 32 and a movable mirror pair 34. However, the processing laser light is directly incident on the condenser lens 38 via the semi-transmissive mirror 30, and thus the laser irradiation system 18 is provided.
Is different from.

Therefore, in the laser processing apparatus according to the second embodiment, the workpiece 10 is rotated by the rotating device 40, the horizontal moving stage 42 is moved in the horizontal direction, and the vertical moving stage 44 is moved in the vertical direction. By moving, the scanning of the laser beam 16 on the workpiece 10 is realized.

Next, as an operation example of the processing method using the laser processing apparatus according to the second embodiment described above, a processing method of processing a side surface of a cylinder to form a triangular prism will be described. That is, as a processed product, a cylindrical processed product 20 shown in FIG.
The processing method for forming the triangular prism 202 by using 0 is
Each step will be described in order. A laser irradiation system 18a is used for the side surface processing of the columnar workpiece 200 described below.

(First stage) The vertical moving stage 44 is moved by a driving system (not shown) so that the focus of the focusing lens 38 is located on the processing surface 1 (see FIG. 8). Then, the measuring laser beam of the surface shape measuring device 26 is emitted from the measuring laser beam (the processing laser beam from the processing laser 20 is not emitted), the rotating device 40 is rotated, and the horizontal movement stage 42 is moved. The surface of the workpiece 100 is scanned with the measuring laser beam, and the surface shape measuring device 26 measures the surface shape at each scanning point in real time. Then, the measurement result is output to the control device 28 as shape information and stored in the control device 28.

Even in each step described later, the measuring laser of the surface profile measuring device 26 is always emitted from the measuring laser, the rotating device 40 is rotated, and the horizontal moving stage 42 is moved to move at each scanning point. The surface shape of the workpiece 200 is measured in real time by the surface shape measuring device 26, and the control device 2 is used to form the triangular prism 202.
By controlling the light quantity controller 22 by 8, the light quantity of the processing laser light is adjusted.

(Second stage) The vertical moving stage 44 is moved upward by a driving system (not shown) so that the focal point of the condenser lens 38 is located on the processing surface 2 (see FIG. 8).

(Third stage) The processing laser light is emitted from the processing laser 20 and the rotation device 40 and the horizontal movement stage 42 are operated to apply the processing laser light (and the measurement laser light) to the surface of the workpiece 200. By scanning up, the surface material of the work piece 200 up to the work surface 2 will be removed (see FIG. 8). The relationship between the amount of processing laser light and the rotation angle of the workpiece 200 by the rotation device 40 at this time is as shown in FIG.

At this time, the processing laser beam (and the measuring laser beam) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular prism 202, the control device 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to “0”, and the substance removal by the irradiation of the processing laser light does not occur. To control.

When the scanning point of the processing laser light (and the measuring laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular prism 202, it is based on the surface shape measured in the first step. Then, the control device 28 controls the light quantity adjuster 22 to adjust the light quantity of the processing laser light and adjust the amount of substance removed by the irradiation of the processing laser light so that the processed surface 2 becomes a circumferential surface. To do.

The machining depth at each scanning point is measured in real time by the surface shape measuring device 26 in parallel with the machining, and is output to the control device 28 for storage.

(Fourth stage) The focal point of the condenser lens is the processed surface 3
(See FIG. 8) The vertical movement stage 44 is moved upward by a drive system (not shown) so as to be positioned above.

(Fifth stage) The processing laser light is emitted from the processing laser 20 and the rotation device 40 and the horizontal movement stage 42 are operated to apply the processing laser light (and the measurement laser light) to the surface of the workpiece 200. By scanning up, the surface material of the work piece 200 up to the work surface 3 will be removed (see FIG. 8). The relationship between the amount of processing laser light and the rotation angle of the workpiece 200 by the rotation device 40 at this time is as shown in FIG. 9B.

At this time, the processing laser beam (and the measuring laser beam) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular prism 202, the control device 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to “0”, and the substance removal by the irradiation of the processing laser light does not occur. To control.

Further, when the scanning point of the processing laser light (and the measuring laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular prism 202, it is based on the surface shape measured in the third step. Then, the control device 28 controls the light quantity adjuster 22 to adjust the light quantity of the processing laser light and adjust the amount of substance removed by the irradiation of the processing laser light so that the processing surface 3 becomes a circumferential surface. To do.

The processing depth at each scanning point is measured in real time by the surface profile measuring device 26 in parallel with the processing, and is output to the control device 28 for storage.

After that, the processes of the above steps may be sequentially repeated until the final processed surface n (see FIG. 8) is obtained.

The surface of the triangular prism 202 after laser processing is also stepwise like the surface of the triangular pyramid 102 shown in FIG. 5, but this step indicates the resolution of the laser processing apparatus according to the second embodiment. And corresponds to the focused diameter of the processing laser light. However, since this converging diameter can be made as small as the wavelength of the processing laser beam, the step-like steps as shown in FIG. 5 can be extremely minute steps. By selecting the wavelength of the laser light, it can be practically ignored.

Furthermore, when processing the end face 200a or the end face 200b of the rotating device 40 of the workpiece 200 in the direction of the rotation axis, laser processing may be performed by using the laser irradiation system 18b in the same manner as described above. In this way, when performing laser processing using the laser irradiation system 18b, the focus position of the laser light 16 on the surface of the workpiece 200 is adjusted by the horizontal movement stage 4.
2 and the scanning of the laser beam 16 on the surface of the workpiece 200 may be performed using the rotating device 40 and the vertical moving stage 44.

In each of the above-mentioned embodiments, the amount of material removed by the irradiation of the processing laser light is generally very small, so it takes a long time to mold a large workpiece. Become. However, the amount of material removal required to obtain the desired shape is proportional to the cube of the representative length of the workpiece, so the time required for machining is also reduced accordingly, and the representative length of the target workpiece is reduced. In the case of a minute object having a diameter of 1 mm or less, the desired three-dimensional shape can be obtained by laser processing in a sufficiently short time for practical use.

Further, it is known that when rotating a workpiece whose mass distribution is not axisymmetric at a high speed, the deviation of the workpiece due to the centrifugal force due to the eccentric motion causes a reduction in the machining accuracy. The relative amount of blurring (blurring length / representative value of workpiece) is inversely proportional to the square of the relative amount of eccentricity (eccentricity length / representative value of workpiece). Therefore, when the workpiece is very small,
When the representative length of the work piece becomes 1 mm or less, the deterioration of the working accuracy due to the blurring is remarkably alleviated, and it becomes practically negligible. For this reason, when the workpiece is very small, the laser processing method and the laser processing apparatus according to the present invention can be used to perform accurate laser processing using various materials.

As the processing laser, the above-mentioned pulsed laser or continuous laser may be appropriately selected according to the condition of the processed product. The removal of substances when using a pulsed laser is laser evaporation or laser etching, and the removal of substances when using a continuous laser is laser melting.

The control of the light quantity by the light quantity adjuster is performed not only by narrowing down the irradiation light quantity but also by turning on / off the operation of the optical shutter or the processing laser itself so that the laser light is conducted / blocked. You may make it adjust the light amount irradiated to.

Further, the processing accuracy of the laser processing depends on the converging diameter of the condensing lens that condenses the laser light on the surface of the work as described above, and the converging diameter is as small as the wavelength of the laser light. Therefore, when an ultraviolet laser is used, the processing accuracy can be increased to 1 μm or less.

Furthermore, in each of the above-described embodiments, the case where the laser processing apparatus is used in air has been described, but it may be used in vacuum or in liquid. For example, when the workpiece is used by immersing it in an etching solution, by irradiating a continuous laser beam as a processing laser beam, it is possible to increase the etching effect in the continuous laser beam irradiation portion. The laser processing by the laser processing apparatus according to the present invention and the etching act synergistically, so that a solid having a desired shape can be obtained at higher speed.

Further, in the above-mentioned second embodiment, the laser irradiation system includes laser light irradiation from the vertical direction and laser light irradiation from the horizontal direction.
Although different laser irradiation systems were used, laser light emitted from a single laser irradiation system was appropriately branched using a single laser irradiation system, and laser light was irradiated from the vertical direction and from the horizontal direction. It may be shared with the irradiation of the laser light.

Further, in the above-mentioned second embodiment, three or more sets of laser irradiation systems may be used to irradiate the workpiece with laser light from an appropriate direction (angle).

Further, in each of the above-described embodiments, the measuring laser beam and the processing laser beam are the same focusing optical system (semi-transmissive mirror 30, total reflection mirror 32, movable mirror pair 34, total reflection mirror 36). , The condensing lens 38) was used to condense the light on the surface of the workpiece, but the present invention is not limited to this, and the measuring laser light and the processing laser light are separately condensed by a converging optical system. It may be condensed on the surface.

Further, in the laser irradiation system in each of the above-mentioned embodiments, the light quantity control information from the control device is given to the light quantity adjuster, and the target three-dimensional shape to be shaped by laser processing is accurately used by using feedback control. However, the feedback control is not limited to such a configuration, and another configuration may be adopted.

Further, in the laser irradiation system in each of the above-mentioned embodiments, the light amount control information from the control device is given to the light amount adjuster, and the target three-dimensional shape to be formed by laser processing is accurately used by using feedback control. However, the present invention is not limited to this, and the laser irradiation system may be controlled so that laser processing with a preset shape is performed without using feedback control.

As described above, when laser processing is performed without using feedback control, if a reference surface of a workpiece to be processed into a desired shape is formed in advance with high accuracy, there is no error and high accuracy. Processing can be performed.

The laser processing method according to the present invention can also be used to form the reference surface of such a processed object. For example, there are two methods as described below.

[Horizontal Irradiation Method] For example, in order to obtain a highly accurate cylinder as a workpiece for forming a desired shape, a lens 300 having a relatively long focal length fl is used as shown in FIG. The processing laser light is condensed, and the outer edge 302 of the processing laser light near the focal point f is set so as to come into contact with the side surface of the workpiece 304 having a substantially cylindrical shape.

With the above-mentioned structure, the workpiece 304
Is rotated about the central axis O, and the processing laser light is scanned once or repeatedly in the central axis O direction.
As a result, the substance on the side surface of the workpiece 304 in contact with the outer edge 302 of the processing laser beam is removed.

Then, the processing laser light and the workpiece 304 are relatively moved so that the outer edge 302 near the focal point f of the processing laser light comes into contact with the side surface of the workpiece 304,
By performing the above-described operation while shortening the distance l, it is possible to obtain a highly accurate cylinder whose cross section is extremely close to a perfect circle. That is, it is possible to obtain a workpiece 304 having a side surface whose cross section is extremely close to a perfect circle as a reference surface. By performing laser processing with this reference surface as a reference, high processing is possible without performing feedback control. Precision can be achieved.

The lens 3 having a relatively long focal length fl
00 is the diameter d and the focal length f of the processing laser beam.
It is preferable that the F value (F = fl / d) representing the relationship with l is 10 or more.

[Vertical Irradiation Method] For example, in order to obtain a highly accurate cylinder as a workpiece for forming a desired shape, a lens 400 having a relatively short focal length fl is used as shown in FIG. , The laser beam for processing is focused so that the optical axis thereof is perpendicular to the side surface of the workpiece 404 having a substantially cylindrical shape, and the irradiation position 40 having the maximum irradiation intensity density on the focal point f thereof.
Only in No. 2, the output of the laser beam for processing is adjusted and set so that the surface substance of the workpiece 404 is removed.

With the above-described structure, the work piece 404
Is rotated about the central axis O, and the processing laser light is scanned once or repeatedly in the central axis O direction.
As a result, only the surface substance on the side surface of the workpiece 404 that is in contact with the irradiation position 402 where the focal point f of the processing laser light is located is removed.

Then, the processing laser light and the workpiece 404 are relatively moved so that the irradiation position 402 where the focal point f of the processing laser light is located contacts the side surface of the workpiece 404, and the distance 1 is shortened. By performing the above-mentioned operation while performing, it is possible to obtain a highly accurate columnar section whose cross section is very close to a perfect circle. That is, it is possible to obtain a workpiece 404 having a side surface whose cross section is extremely close to a perfect circle as a reference surface. By performing laser processing with this reference surface as a reference, high processing is possible without performing feedback control. Precision can be achieved.

The lens 4 having a relatively short focal length fl
00 is the diameter d and the focal length f of the processing laser beam.
It is preferable that the F value (F = fl / d) representing the relationship with l is about 1.

In general, in order to irradiate a substance with a laser to remove it, there is a threshold for the intensity of laser irradiation. That is, the substance can be removed by laser irradiation if laser irradiation is performed at a laser irradiation intensity density of a threshold value or more, but even if laser irradiation is performed at a laser irradiation intensity density of a threshold value or less, the substance is removed by laser irradiation. It is known that it cannot be removed.

For this reason, in the horizontal irradiation method and the vertical irradiation method described above, when it is desired to form the reference plane with higher accuracy, the laser beam for processing is applied to the workpiece at a laser irradiation intensity density that slightly exceeds the threshold value. Irradiation is preferred. As described above, when the processing laser beam is irradiated to the workpiece with the laser irradiation intensity density that slightly exceeds the threshold value, in the horizontal irradiation method, the workpiece 304 with which the outer edge 302 near the focal point f of the processing laser beam contacts. It is possible to reliably remove only the substance on the surface of the workpiece 304 without affecting other parts of the workpiece 304. Further, in the vertical irradiation method, the focus f of the laser beam for processing is f.
It is possible to reliably remove only the substance on the surface of the work piece 404 that is in contact with the irradiation position 402 where is located without affecting other parts of the work piece 404.

Further, in the above description of the horizontal irradiation method and the vertical irradiation method, the case where a columnar workpiece having a side surface of a perfect circle as a reference surface is formed has been described. In addition to the above, a processed product having a plane as a reference plane such as a rectangular parallelepiped or a flat plate can be obtained.

Further, the horizontal irradiation method and the vertical irradiation method described above are used not only for forming the reference surface of the workpiece, but also in the same manner as in the first and second embodiments described above. It may be used to obtain the desired shape from.

The first embodiment and the second embodiment described above
When performing laser processing without using the feedback control that monitors the processing surface of the workpiece in real time as described in the example of 1., the output of the processing laser light is monitored and the processing laser is based on the output. The output of light may be controlled to improve the processing accuracy.

That is, the output of the laser light such as the processing laser light is constantly changing, and when the output of the processing laser light is changed during the laser processing of the workpiece by the processing laser light, this change causes Will have a negative effect on the finish. Therefore, the output of the laser beam for processing is constantly monitored, and at all laser processing points of the workpiece,
Calculate the integrated value of the output intensity (irradiation intensity density, irradiation intensity, etc.) of the processing laser light at the laser processing point,
If this integrated value is higher than the value required to obtain the processed surface at the laser processing point, when performing laser processing at the laser processing point by the next scan of the processing laser light, at the laser processing point The intensity of the output of the processing laser light is reduced to eliminate the influence of the fluctuation of the output of the processing laser light.

On the other hand, when the integrated value of the output intensities of the processing laser light at the laser processing point is lower than the value required to obtain the processing surface at the laser processing point, the next scanning of the processing laser light is performed. When performing the laser processing at the laser processing point, the intensity of the output of the processing laser light at the laser processing point is increased to eliminate the influence of the fluctuation of the output of the processing laser light.

In order to change the intensity of the laser light output at such a laser processing point, in the case of pulsed laser light, it is sufficient to change the light quantity per pulse or the number of irradiation pulses. In that case, the average light amount, the irradiation time, and the like may be changed.

That is, in order to reduce the output intensity of the pulsed laser light, for example, the number of irradiation pulses at the laser processing point may be decreased, and conversely, to increase the output intensity, the laser processing may be performed. The number of irradiation pulses at the point may be increased, and such control can be easily realized by on / off control of the processing laser.

In order to reduce the output intensity of the continuous laser beam, for example, the irradiation time at the laser processing point may be reduced, and conversely, to increase the output intensity, the laser processing point may be increased. The irradiation time may be increased, and such control can be easily realized by turning on / off the processing laser.

[0099]

Since the present invention is constructed as described above, it has the following effects.

Instead of a blade in the conventional machining such as a mechanical lathe, a laser beam is focused on the workpiece, a substance is removed by the irradiation effect of the laser beam at a focal portion, and the workpiece is molded by such a substance removal. By doing so, it becomes possible to remove the substance at any part on the work by selectively controlling the irradiation part of the laser light to the work, and to form not only a rotating body but also a solid of any shape. Moreover, by controlling the intensity of the laser beam, the amount of the substance removed by the substance removal due to the irradiation effect of the laser beam can be accurately controlled, so that a minute three-dimensional shape is formed. Will be able to.

Therefore, according to the present invention, it is possible to form a minute three-dimensional solid from the material without limiting the material to be processed.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory diagram of a laser processing apparatus according to a first embodiment for carrying out a laser processing method according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a processed surface when forming a triangular pyramid on a rectangular parallelepiped processed product.

3A and 3B show a state in which a triangular pyramid is formed on a rectangular parallelepiped workpiece, FIG. 3A is a top view, and FIG. 3B is a front view.

FIG. 4 is a top view showing the progress of laser processing,
(A) shows a state where the processed surface 2 is processed, (b) shows a state where the processed surface 3 is processed, and (c) shows a state where the final processed surface n is processed.

FIG. 5 is an enlarged explanatory view showing a surface state of a processed surface.

FIG. 6 is a schematic structural explanatory view of a laser processing apparatus according to a second embodiment for carrying out the laser processing method according to the second embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between a cylindrical workpiece and a triangular prism formed from the workpiece.

FIG. 8 is an explanatory view showing a processing surface when forming a triangular prism from a cylindrical workpiece.

9A and 9B show the relationship between the amount of processing laser light and the rotation angle of the workpiece by the rotating device, where FIG. 9A shows the case where the processed surface 2 is formed, and FIG. 9B shows the case where the processed surface 3 is formed. Indicates.

FIG. 10 is an explanatory view of a main part for explaining a horizontal irradiation method.

FIG. 11 is an explanatory diagram of a main part for explaining a vertical irradiation method.

[Explanation of symbols]

10, 100, 200, 304, 404 Workpiece 12, 44 Vertical movement stage 14 Base 16 Laser light 18, 18a, 18b Laser irradiation system 20 Processing laser 22 Light quantity controller 24 Correction optical system device 26 Surface shape measuring device 28 Control device 30 Semi-transmissive mirror 32 Total reflection mirror 34 Movable mirror pair 36 Total reflection mirror 40 Rotating device 42 Horizontal movement stage 102 Triangular pyramid 202 Triangular prisms 200a, 200b End face 300 Lens 302 with relatively long focal length 302 Laser light for processing Outer edge 400 Lens 402 with relatively short focal length Irradiation position

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-224887 (JP, A) JP-A-3-35890 (JP, A) JP-A 54-69896 (JP, A) JP-A 59- 215290 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B23K 26/00-26/42 B81C 5/00

Claims (18)

(57) [Claims] 1. A laser beam for processing, which removes a substance on a surface of a workpiece by irradiating the surface of the workpiece, is focused on the surface of the workpiece using a focusing optical system, and the light is focused on the surface of the workpiece. A point is scanned on the surface of the work piece and sequentially moved inward from the surface of the work piece in a stepwise manner, and only the substance in a desired portion from the surface of the work piece is controlled in intensity of the processing laser beam. Meanwhile, the laser processing method is characterized in that the material is removed by a substance removing action by irradiation of the processing laser beam, and the processed product is molded into a desired three-dimensional shape. 2. A laser beam for processing, which removes a substance on the surface of the workpiece by irradiation of the workpiece, is focused on the surface of the workpiece by using a focusing optical system, and the rotation of the workpiece and the surface of the workpiece. By the relative movement of the laser beam for processing and the workpiece relative to each other, the focal point of the laser beam for processing is scanned on the surface of the workpiece and is directed inward from the surface of the workpiece. The material is removed from the surface of the workpiece by a substance removing action by irradiation of the laser light for processing while controlling the intensity of the laser light for processing, Forming a desired three-dimensional shape. 3. A material for measuring a laser beam for measuring a shape of a surface of a workpiece is focused on the surface of the workpiece using a first focusing optical system, and the surface of the workpiece is irradiated with the laser beam for measurement. A laser beam for processing that removes light on the surface of the workpiece by using a second condensing optical system, and a first condensing point on the surface of the workpiece by condensing the first condensing optical system. And a second converging point on the surface of the workpiece by the condensing of the second condensing optical system is scanned on the surface of the workpiece, and is moved stepwise inward from the surface of the workpiece. According to the surface shape of the workpiece measured based on the measurement laser light, only the substance of a desired portion from the workpiece surface is irradiated with the processing laser light while controlling the intensity of the processing laser light. The material is removed by the substance removal action by the A laser processing method characterized by forming into a body shape. 4. The measurement laser beam for measuring the shape of the surface of the workpiece and the laser beam for processing for removing the substance on the surface by irradiating the surface of the workpiece by using the same focusing optical system. The measurement laser is focused on the surface of the workpiece, and the focusing point on the surface of the workpiece by the focusing is scanned on the surface of the workpiece and is gradually moved inward from the surface of the workpiece. According to the surface shape of the workpiece measured based on light, only the substance at a desired site from the workpiece surface is controlled by the irradiation of the laser beam for processing while controlling the intensity of the laser beam for processing. A laser processing method, which comprises removing and shaping the processed product into a desired three-dimensional shape. 5. A material for measuring a laser beam for measurement for measuring the shape of the surface of a workpiece is focused on the surface of the workpiece using a first focusing optical system, and the surface of the workpiece is irradiated with the laser light for measurement. A laser beam for processing that removes light is condensed on the surface of the workpiece by using a second condensing optical system, and is rotated by the first condensing optical system and condensed on the surface of the workpiece by the first condensing optical system. By the relative movement of the laser beam for measurement and the workpiece, which is performed, the focusing point of the laser beam for measurement is scanned and sequentially moved inward from the surface of the workpiece, Rotation of the workpiece,
The converging point of the processing laser beam is scanned by the relative movement of the processing laser beam and the workpiece, which are focused on the surface of the workpiece by the second focusing optical system, and While gradually moving inward from the surface of the workpiece, according to the surface shape of the workpiece measured based on the laser beam for measurement, only the substance at a desired portion from the surface of the workpiece is processed. A laser processing method, characterized in that the material is removed by a substance removing action by irradiation of the processing laser light while controlling the intensity of the laser light, and the processed product is molded into a desired three-dimensional shape. 6. The measurement laser beam for measuring the shape of the surface of the workpiece and the laser beam for processing to remove the substance on the surface by irradiating the surface of the workpiece by using the same focusing optical system. The measurement is performed by converging on the surface of the workpiece, rotating the workpiece, and measuring laser light focused on the surface of the workpiece and relative movement of the laser light for machining and the workpiece. Shape of the workpiece measured based on the measurement laser beam while scanning the focusing point of the laser beam for processing and the converging point of the laser beam for processing and sequentially moving inward from the surface of the workpiece. According to the above, only the substance at a desired portion is removed from the surface of the workpiece by the substance removing action by the irradiation of the laser beam for processing while controlling the intensity of the laser beam for processing, and the workpiece is cut into a desired three-dimensional shape. Laser processing method characterized by forming the Jo. 7. The control of the intensity of the processing laser light is
The method according to claim 1 or 2, wherein operation / stop of laser oscillation is performed.
7. The laser processing method according to any one of 3, 4, 5 and 6. 8. A laser beam for processing, which removes substances on the surface of a workpiece by irradiation, is condensed using a condensing optical system having a relatively long focal length, and the laser beam for processing in the vicinity of the focal point of the laser beam for processing is collected. The outer edge of the laser beam for processing is brought into contact with the surface of the workpiece, the contact position by the contact is scanned on the surface of the workpiece and is moved stepwise inward from the surface of the workpiece, A laser processing method, characterized in that only a substance on the surface of the workpiece that is in contact with the outer edge of the laser light is removed by a substance removing action by irradiation of the processing laser light, and a reference plane is formed on the surface of the workpiece. . 9. The processing laser collects processing laser light for removing a substance on the surface of the processing object by irradiating the surface of the processing object with a focusing optical system having a relatively long focal length, The outer edge of the laser beam for processing near the focal point of light is brought into contact with the surface of the workpiece, and the contact position by the contact is scanned on the surface of the workpiece and is sequentially stepwise inward from the surface of the workpiece. A reference surface is previously formed on the surface of the workpiece by moving and removing only the substance on the surface of the workpiece which the outer edge of the laser beam for contact comes into contact with by removing the substance by irradiation of the laser beam for processing. Any one of items 1, 2, 3, 4, 5, 6 or 7
Laser processing method according to item. 10. A laser beam for processing for removing a substance on the surface of a workpiece by irradiating the surface of the workpiece with a focusing optical system having a relatively short focal length, and an optical axis of the laser beam for processing is the surface of the workpiece. Condensed so as to be perpendicular to, the irradiation position where the intensity of the processing laser light on the focus of the processing laser light is high is brought into contact with the surface of the workpiece, and the contact position by the contact is Scanning on the surface of the workpiece and moving in a stepwise manner inward from the surface of the workpiece, only the substance on the surface of the workpiece with which the irradiation position of the laser beam for processing comes into contact with the laser beam for processing. A method of laser processing, characterized in that a reference surface is formed on the surface of the workpiece by removing by a substance removing action by irradiation. 11. The workpiece includes a laser beam for processing for removing a substance on the surface of the workpiece by irradiating the surface of the workpiece, using a focusing optical system having a relatively short focal length. The light is focused so that its axis is perpendicular to the surface of the workpiece, and the irradiation position where the intensity of the laser beam for processing is high on the focus of the laser beam for processing is brought into contact with the surface of the workpiece, and the contact is made. Scanning the contact position by the surface of the workpiece and gradually moving inward from the surface of the workpiece in a stepwise manner so that only the substance on the surface of the workpiece with which the irradiation position of the processing laser light comes into contact. 2. A reference surface is previously formed on the surface of the workpiece by removing it by a substance removing action by irradiation of the laser beam for processing.
The laser processing method according to any one of 2, 3, 4, 5, 6 or 7. 12. A processing laser that emits a processing laser beam that removes a substance on the surface of a workpiece by irradiation of the workpiece surface, and a condensing optical system that condenses the processing laser beam on the surface of the workpiece. Scanning means for scanning the surface of the workpiece with a focus point on the surface of the workpiece by the light collection of the focusing optical system; and the step of collecting the workpiece surface stepwise inward from the surface of the workpiece. A moving means for moving the light spot, and with the scanning and moving of the condensing point by the scanning means and the moving means, only the substance at a desired portion is removed from the surface of the workpiece by irradiation with the processing laser light. As described above, the laser processing apparatus is provided with a control means for controlling the intensity of the processing laser light. 13. A processing laser that emits a processing laser beam for removing a substance on the surface of a workpiece by irradiation of the workpiece surface, and the processing laser beam emitted from the processing laser is collected on the surface of the workpiece. By a converging optical system that emits light, rotation of the workpiece, and relative movement of the processing laser light focused on the surface of the workpiece and the workpiece,
Scanning means for scanning the converging point of the processing laser light on the workpiece surface, and moving means for moving the converging point of the workpiece surface stepwise inward from the surface of the workpiece, With the scanning and moving of the converging point by the scanning means and the moving means, the processing is performed so that only the substance at a desired portion is removed from the surface of the workpiece by the substance removing action by the irradiation of the processing laser beam. Processing device for controlling the intensity of laser light for use in laser processing. 14. A measuring laser that emits a measuring laser beam for measuring the shape of a surface of a workpiece, and a processing laser that emits a laser beam for processing that removes substances on the surface by irradiating the workpiece surface. A laser, a first condensing optical system that focuses the measurement laser light emitted from the measurement laser on the surface of the workpiece, and the processing laser light emitted from the processing laser to the workpiece A second condensing optical system for condensing on a surface, and a first condensing point on the surface of the workpiece due to the condensing of the first condensing optical system is scanned on the surface of the workpiece,
Scanning means for scanning the second condensing point on the surface of the workpiece by the light condensing by the second condensing optical system on the surface of the workpiece; and stepwise inward from the surface of the workpiece toward the inside. Moving means for moving the first focus point and the second focus point on the surface of the workpiece, and the first focus point and the second focus point of the scanning means and the moving means. Along with scanning and movement, according to the surface shape of the workpiece measured based on the measuring laser light, only the substance of a desired portion is removed from the workpiece surface by a substance removing action by irradiation of the processing laser light. As described above, the laser processing apparatus is provided with a control means for controlling the intensity of the processing laser light. 15. A measuring laser that emits a measuring laser beam for measuring the shape of a surface of a workpiece, and a processing laser that emits a laser beam for processing that removes a substance on the surface by irradiating the workpiece surface. A laser, a condensing optical system that condenses the measuring laser light emitted from the measuring laser and the processing laser light emitted from the processing laser on the surface of the workpiece, and the condensing optical system. Scanning means for scanning the light condensing point on the surface of the workpiece by the light condensing, and moving the light condensing point on the surface of the workpiece stepwise inward from the surface of the workpiece. A moving means, the scanning means and the moving means scans and moves the condensing point, and according to the surface shape of the workpiece measured based on the measuring laser beam, the workpiece table Only material of a desired site to remove a material removing action by irradiation of the processing laser light from the laser processing apparatus characterized by a control means for controlling the intensity of the processing laser light. 16. A measuring laser that emits a measuring laser beam for measuring the shape of the surface of a workpiece, and a processing laser that emits a laser beam for processing that removes substances on the surface by irradiating the workpiece surface. A laser, a first condensing optical system that focuses the measurement laser light emitted from the measurement laser on the surface of the workpiece, and the processing laser light emitted from the processing laser to the workpiece A second condensing optical system for condensing on the surface; a rotation of the work piece; and the measuring laser beam and the work piece condensed on the surface of the work piece by the first condensing optical system. The relative movement scans the converging point of the measurement laser beam on the surface of the workpiece, and the rotation of the workpiece and the condensing on the surface of the workpiece by the second condensing optical system. With laser light for processing By means of relative movement with respect to the workpiece, a scanning means for scanning the converging point of the processing laser light on the surface of the workpiece, and the step of the surface of the workpiece sequentially inward from the surface of the workpiece. Moving means for moving the focusing point of the measuring laser beam and the focusing point of the processing laser beam, and the focusing point of the measuring laser beam and the collecting point of the processing laser beam by the scanning means and the moving means. Along with the scanning and movement of the light spot, according to the surface shape of the workpiece measured based on the measuring laser light, only the substance of a desired portion is removed from the workpiece surface by irradiation with the processing laser light. And a control means for controlling the intensity of the processing laser light so that the laser processing apparatus removes the laser. 17. A measuring laser that emits a measuring laser beam for measuring the shape of the surface of a workpiece, and a processing laser that emits a laser beam for processing that removes substances on the surface by irradiating the workpiece surface. A laser, a condensing optical system that condenses the measurement laser light emitted from the measurement laser and the processing laser light emitted from the processing laser on the surface of the workpiece, and rotation of the workpiece. And the relative movement of the measurement laser beam and the processing laser beam and the workpiece that are focused on the surface of the workpiece, the converging point of the measurement laser beam and the processing laser beam Scanning means for scanning on the surface of the workpiece, and moving the converging point of the measurement laser light and the processing laser light on the workpiece surface in a stepwise manner inward from the surface of the workpiece. Moving means for moving the surface of the workpiece measured based on the measuring laser light in accordance with the scanning and moving of the condensing point of the measuring laser light and the processing laser light by the scanning means and the moving means. A control means for controlling the intensity of the processing laser light so as to remove only a substance at a desired portion from the surface of the workpiece according to the shape by a substance removing action by irradiation of the processing laser light. And laser processing equipment. 18. The moving means moves the workpiece in the optical axis direction of the processing laser light.
The laser processing apparatus according to any one of 3, 14, 15, 16 or 17.