JP3006348B2 - Laser processing equipment - 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 apparatus for performing hole processing, pattern processing, cutting, and the like using a laser beam.

[0002]

2. Description of the Related Art In recent years, research and development of processing using a laser beam has been actively carried out mainly on a carbon dioxide gas laser and a YAG laser. It is being established as.

Further, recently, processing applications of excimer lasers having an oscillation wavelength in the ultraviolet region have been studied.

[0004] This excimer laser is a carbon dioxide gas laser,
Since the wavelength is shorter than that of a YAG laser or the like, it is suitable for fine processing.

The mechanism of the processing is not so-called thermal processing but non-thermal processing using high photon energy (so-called ablation processing). Therefore, the processing shape is extremely beautiful, and processing by pulse oscillation is performed. The feature is that the amount of processing can be easily controlled by the number of pulses.

[0006] In view of mass production, a processing apparatus in which one laser has a plurality of processing heads has been developed.

As an example, Japanese Patent Application Laid-Open No. 61-193794 is disclosed.
There is a configuration shown in Japanese Unexamined Patent Publication (Kokai) No. H10-26095. FIG. 3 shows a specific configuration thereof.

In FIG. 3, reference numeral 701 denotes a laser light source;
2 is a condenser lens, 703 is a mixing rod, 704,
705 is an optical fiber bundle, 706 is a processing head, 707 is a control table, 708 is a focus lens, 709 is a work material, 710 is an NC controller, and 711 is a positioning table.

In such a configuration, first, the light oscillated from the laser light source 701 is introduced into the mixing rod 703 through the condenser lens 702.

The other end of the mixing rod 703 becomes an optical fiber bundle 704, which is a bundle of a number of optical fibers.
It is fixed, and the fixed tip has a focusing lens 708
Are installed respectively.

The positioning table 711 can be moved up and down, and the mixing rod 703 and the optical fiber bundle 70
It is configured so that the workpiece 709 can be positioned on the focal point of the laser beam that has passed through the lens 4, 705, and the focusing lens 708.

On the other hand, the processing head 706 is held at an arbitrary position on the control table 707 in advance, and the contour is controlled by moving the control table 707 by the NC control device 710.

In the structure of this conventional example, it is possible to simultaneously process the workpieces by the number of heads continuously.

Furthermore, several methods of focusing a laser beam on a workpiece have been conventionally proposed.

For example, a method of detecting the intensity of reflected laser light by re-reflecting the reflected laser light (Japanese Patent Application Laid-Open No. 59-73192), a method of arranging a light projecting means and a light receiving means on a working head (Japanese Patent Application Laid-Open No. 61-73192). 108484) and the like.

Here, the former will be described as an example. FIG.
The specific configuration is shown in FIG.

Reference numeral 801 denotes a laser oscillator, 802 denotes a laser beam, 803 denotes a beam splitter, 804 denotes a power meter, 805 denotes a mirror, 806 denotes a lens, 806 denotes a workpiece, 808 denotes a power meter, 809 denotes an adjustment screw, and 809 denotes an adjustment screw.
Reference numeral 10 denotes a workpiece mounting table.

In such a configuration, the laser oscillator 8
When the laser beam 802 is emitted from the light source 01, a part thereof is reflected by the beam splitter 803,
Incident on.

This incident light is used for measuring the intensity of the laser light 802. On the other hand, the laser beam 802 transmitted through the beam splitter 803 is reflected by a mirror 805 and condensed on a surface of a workpiece 807 via a lens 806.

When the workpiece 807 is not located at the focal position of the laser beam 802 and the light intensity received by the workpiece is low, the laser beam 802 is reflected by the workpiece 807 and returns to the beam splitter 803. Are reflected again by the beam splitter 803 and enter the power meter 808.

Here, by appropriately adjusting the adjusting screw 809, the detection value of the power meter 808 is set to the maximum value, and the laser light 802 is adjusted by adjusting the detection value to the maximum value.
Is precisely focused on the surface of the workpiece 807, and the processing is performed.

[0022]

In a processing apparatus having a plurality of processing heads, one laser shown in FIG.
The positioning of the focal point, which is important for the processing accuracy, is performed by driving the positioning table 711 up and down.

However, in practice, due to variations in individual characteristics of the focus lens 708, mounting accuracy of each head 706, or variations in characteristics of the small bundle optical fiber 705, etc.
Although slightly, the focal position varies in each case.

Further, even if the accuracy of the positioning table 711 can be obtained, the processing surface under each head 706 may vary depending on the mounting accuracy at the time of replacement of the work material 709 mounted thereon and the shape variation of the material itself. Usually, it cannot be kept the same as the focal position.

Therefore, in order to obtain high processing accuracy, an independent adjustment mechanism is required for each head including the small bundle optical fiber.

However, as the number of processing heads increases, the configuration shown in FIG. 4 or the configuration disclosed in Japanese Patent Application Laid-Open No. 61-108484 requires a complicated and large-scale focus adjustment mechanism, and the size of the processing apparatus itself becomes large. Now, problems arise in terms of cost.

Also, during the adjustment, the shape of the beam emitted from the optical fiber may change due to the movement of the optical fiber, which may lead to a deterioration in processing quality.

On the other hand, the depth of focus also poses a problem in terms of processing accuracy. That is, in the configuration as shown in FIG. 3, it is general that the spread angle of the light from the small bundle optical fiber 705 is different due to the variation of the characteristic. In such a case, the condensing angle of each of the focus lenses 708 becomes smaller. It means different.

This means a variation in the depth of focus, and as a result, the processed shapes are different from each other.

In particular, when processing a thick material, the change in shape increases in the depth direction.

Therefore, in order to keep a good processed shape uniform between the heads, it is necessary to keep the light divergence angle of each optical fiber small and constant.

[0032]

[0033]

[0034]

[0035]

[Means for Solving the Problems] In order to solve the above-mentioned problems
The present invention also relates to a laser processing apparatus using a plurality of fibers, the laser processing apparatus having a configuration in which the spread diameter of laser light entering the lens system from the fiber at the lens position in the processing head is larger than the lens effective diameter. It is.

Further, in this case, the laser light that should pass outside the effective diameter of the lens is shielded by the inner surface of the processing head.

[0037]

[0038]

According to the above arrangement, the converging angles of the focus lenses of the plurality of processing heads become constant, and as a result, variations in processing characteristics among the heads are suppressed.

Further, by reducing the lens diameter, processing with a high aspect ratio becomes possible.

[0040]

Embodiment ( Reference Example 1 ) Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a processing head of a laser processing apparatus according to a reference example of the present invention. This is done by moving 107 up and down.

In FIG. 1, reference numeral 101 denotes an optical fiber,
02 is a fiber holder, 103 is a fiber mounting plate, 104 is a support plate, 105 is a vertical adjustment mechanism, 106 is a processing head mounting plate, 107 is a processing head, 108 is a focusing lens, 109 is a workpiece, and 110 is a table. is there.

In this configuration, first, a laser beam oscillated from a laser oscillator (not shown) is shaped into a beam by a uniform optical system (not shown).
Will be introduced.

At the tip of each optical fiber 101,
A fiber holder 102 is provided. The fiber holder 102 is fixed to a fiber mounting plate 103 and is finally fixed to a common processing head mounting plate 106 via a support plate 104.

The fiber mounting plate 103 is provided with a rotary up-down adjustment mechanism 105.

A processing head 107 is mounted on the vertical adjustment mechanism 105, and inside the processing head 107,
A focusing lens 108 is incorporated so as to be coaxial with the center of the fiber 101.

The vertical adjustment mechanism 105 is configured to transmit a small vertical displacement to the processing head 107 by rotating.

The workpiece 109 is set on the table 110 corresponding to each head 107.

Here, the table 110 is moved to a desired position in the X and Y directions by a control device (not shown) in accordance with the data of the processing position, and the light emitted from the fiber 101 is passed through the focusing lens 108 to the workpiece 109. To process the workpiece 109 to a desired position.

In the above configuration, the adjustment of the focal position is performed by
This is performed by rotating the vertical adjustment mechanism 105 and moving the processing head 107 up and down.

At this time, the end face of the fiber 101 is fixed without moving. With this configuration, the conventional method of moving the table 110 up and down and adjusting the focal position cannot sufficiently cope with the variation, that is, each processing head 10
Variations that occur depending on the characteristics, shape, mounting, assembly, etc. of the components constituting the workpiece 7 and the workpiece can be dealt with, and the focal position can be accurately adjusted for each workpiece 109.

On the other hand, in the case of this embodiment, a method is also conceivable in which the entire processing head including the fiber system is moved up and down to adjust the focus. However, in this system, the fiber itself also moves and is ejected from the fiber. The beam shape may change, which is not preferable.

Further, since the entire processing head must be moved mechanically, the structure becomes complicated.

On the other hand, according to the structure of this embodiment,
An extremely simple configuration enables highly accurate focal point alignment, and the beam shape does not change, so that the processed shape of the workpiece can be obtained as expected.

When the present embodiment is strictly studied, it is conceivable that the processing shape of the workpiece 109 changes slightly when the end face of the optical fiber 101 is fixed and the focus is adjusted.

However, within the range of adjustment for absorbing variations occurring in the characteristics, shape, mounting, assembly, etc. of the components and workpieces constituting the processing head 107 described above, as a practical problem, A negligible level with little effect.

As described above, according to the present embodiment, as a focus adjusting mechanism of a laser processing apparatus using a plurality of optical fibers, a processing head having a lens system inside is vertically moved with respect to a fixed fiber end face. By providing a rotary adjustment mechanism for fine adjustment, it is possible to obtain a simple focus adjustment mechanism with uniform processing characteristics.

In the present embodiment, a configuration having a plurality of processing heads corresponding to a plurality of optical fibers has been described. Of course, the position adjustment mechanism is realized.

( Embodiment 1 ) A first embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a sectional view showing a processing head portion in the laser processing apparatus according to the first embodiment of the present invention.

Reference numeral 201 denotes an optical fiber, 202 denotes a fiber holder, 203 denotes a focus lens, 204 denotes a processing head, 205 denotes a processing head mounting plate, 206 denotes a workpiece, and 207 denotes a table.

In such a configuration, after a laser beam oscillated from a laser oscillator (not shown) is shaped by a uniform optical system (not shown), a plurality of optical fibers 201 are formed.
It is divided and introduced.

At the end of the optical fiber 201, a fiber holder 202 is provided, and the fiber holder 202 is fixed to a processing head 204.

A focusing lens 203 is provided inside the processing head 204, and the focusing lens 203
The image of the exit end face of the optical fiber 201 is transferred to the workpiece 206.
Processing is performed by reducing and projecting on the surface to be processed.

Generally, the divergence angle of the light emitted from the plurality of optical fibers 201 depends on the dimensions of the optical fibers 201,
There is variation depending on the arrangement shape and the like. Due to this variation, the emission angles are different from each other as typically represented by θ ₁ , θ ₂ , and θ ₃ .

Therefore, in this embodiment, the effective diameter of the condenser lens 203 is smaller than the diameter of the light emitted from the exit end of the optical fiber 201 to the focus lens 203 at the position of the focus lens 203. Set as follows.

By setting in this way, even if the spread angles of the light emitted from the plurality of optical fibers 201 vary, the spread diameter of the focus lens 203 becomes larger than the effective diameter of the focus lens 203. The laser beam located outside the effective diameter is blocked by the inner surface of the processing head 204, and only the laser beam located inside the effective diameter passes through the focusing lens 203. Equal at 204.

As described above, when the converging angle θ is constant, the change of the shape of each workpiece 207 in the depth direction becomes constant,
Processing quality uniformity is greatly improved.

Therefore, the configuration of the present embodiment is an effective configuration in a case where a plurality of processings are performed simultaneously using a plurality of processing heads.

Indeed, from the viewpoint of effective use of light, it is preferable to set all the light from the optical fiber 201 to enter the focusing lens 203. However, in the configuration of this embodiment, the amount of light kicked by the focusing lens 203 is , Not to the extent that it substantially affects processing speed, accuracy, etc.
In addition, the focusing angle θ is more consistent between the processing heads,
As a result, the merit of uniform processing quality is greater.

In the present embodiment, by realizing a configuration in which the variation of the spread angle of light from the fiber is substantially suppressed, the processing quality can be extremely effectively stabilized in the multi-axis processing using the optical fiber. ing.

The effective diameter of the focusing lens 203 can also be reduced, which is advantageous in terms of size and cost.

As described above, according to this embodiment, the effective diameter of the focusing lens in the processing head of the laser processing apparatus using a plurality of optical fibers is smaller than the diameter of the light spread from each optical fiber at that position. This is advantageous in that the processing quality can be made uniform, and that the size and cost can be reduced. Further, as for the aspect ratio of the processed shape, an aspect ratio in which the depth direction is larger than the width can be realized.

Although the reference example and the first embodiment of the present invention have been described separately, a laser processing apparatus having both of them may be used if necessary.

[0075]

[0076]

As described above, according to the present invention, the effective diameter of the focusing lens in the processing head of the laser processing device using a plurality of optical fibers is determined by the spread diameter of light from each optical fiber at that position. The setting is made smaller, whereby the processing quality can be made uniform, and the size and cost are also advantageous, and the effect is great.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a processing head portion of a laser processing apparatus according to a reference example of the present invention.

FIG. 2 is a sectional view showing a processing head of the laser processing apparatus according to the first embodiment of the present invention;

FIG. 3 is an overall schematic diagram showing a conventional laser processing apparatus.

FIG. 4 is an overall schematic view showing a conventional laser processing apparatus.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-36787 (JP, A) JP-A-59-73192 (JP, A) JP-A-61-193794 (JP, A) 73612 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 26/00-26/08

Claims (4)

(57) [Claims] 1. A laser light source, a plurality of optical fibers into which laser light emitted from the laser light source is incident, a plurality of processing heads including a lens system connected to each of the optical fibers, and the processing A laser processing apparatus comprising: a workpiece mounting table opposed to a head, wherein a spread diameter of light incident on the lens system from the optical fiber is larger than an effective diameter of the lens system at the position of the lens system. In the position of 2. A lens system, the laser beam is located outside the effective diameter of the lens system, the laser processing apparatus of claim 1 further comprising means for substantially shielding. 3. The laser processing apparatus according to claim 2 , wherein the means for blocking the laser light located outside the effective diameter of the lens system is an inner surface of the processing head. 4. A plurality including a laser light source, a plurality of optical fibers into which the laser light emitted from the laser light source is incident, and a lens system connected to the optical fiber and into which the laser light emitted from the optical fiber is incident. A processing head, and a workpiece mounting table that can be moved to a desired position on a plane facing the processing head, fixing an output end of the optical fiber, and an output end of the fixed optical fiber. In contrast, at least the lens system of the processing head is provided with adjusting means capable of relatively moving in a direction intersecting with the plane, and the spread diameter of light incident on the lens system from the optical fiber is determined by the position of the lens system. 3. The laser processing apparatus according to claim 1, wherein the laser processing apparatus is larger than an effective diameter of the lens system.