JP2003080388A - Laser beam machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining device in which a plurality of divided mask patters are simultaneously projected upon a work and machining for different depths in a plurality of areas on the work are simultaneously performed. SOLUTION: The laser machining device is provided with at least one laser oscillator 1 which generates a laser beam, a plurality of first optical systems 5 and 6 which are so arranged to correspond to a plurality of masks 3 and 4 for receiving laser beams which are generated by at least one laser oscillator and passed through the plurality of masks and a second optical system 7 for forming images on the work by receiving the laser beams emitted from the plurality of first optical systems.

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 used for processing an object to be processed using laser light, and more particularly to a laser processing apparatus used to process an object to be processed using a plurality of masks. Laser processing device.

[0002]

2. Description of the Related Art Conventionally, a laser has been used for forming grooves and holes in a printed board, cutting, pattern formation of a semiconductor device, IC
It has been used for marking molds. Further, it is also possible to evaporate the surface of the material using a laser to perform the surface processing. These processes are performed by condensing laser light emitted from a laser oscillator with a condensing lens or the like and irradiating the object to be processed.

In laser processing, a desired pattern to be formed on a workpiece is divided into a plurality of patterns to create respective masks, and while these masks are sequentially used, laser light is radiated to produce the workpiece. A desired pattern may be formed by connecting a plurality of divided patterns on an object. In such a case, a plurality of masks are sequentially replaced and arranged in the optical system to perform processing by irradiating with a laser beam, and the patterns formed on the respective masks are projected onto the workpiece to obtain a desired pattern. Form a pattern. Alternatively, after the pattern formed on one mask is projected, the workpiece is sequentially moved under another mask to project the pattern formed on another mask. However, in the method of sequentially replacing and arranging a plurality of masks,
The optical system must be adjusted every time the mask is replaced, which is complicated and the optical system is likely to be misaligned. Furthermore, it is not easy to superimpose a plurality of patterns. On the other hand, in the method of sequentially moving the workpiece, the stage scans overlap and the processing speed decreases.

In the laser processing, deep hole processing may be performed in the first region of the workpiece and shallow groove processing may be performed in the second region. In such a case, it is conceivable to irradiate a laser beam having a beam profile in which the energy density is changed in multiple stages and perform processing in two steps. Further, in Japanese Laid-Open Patent Publication No. 63-273587, two or more kinds of laser beams having different wavelengths are applied to the same region of a workpiece, and first, a surface portion of the workpiece is irradiated with laser light of a short wavelength. There is disclosed a method of performing processing such as melting, removal of a surface layer, and the like to make a state in which long-wavelength laser light is easily absorbed, and then irradiating with long-wavelength laser light. However, these methods cannot rapidly perform machining with different depths in a plurality of regions of the workpiece.

[0005]

Therefore, in view of the above points, the present invention is to project a plurality of divided mask patterns on a work piece at the same time, and to set a depth in a plurality of areas on the work piece. An object of the present invention is to provide a laser processing apparatus capable of simultaneously performing different processing.

[0006]

In order to solve the above problems, the laser processing apparatus according to the present invention is arranged so as to correspond to at least one laser oscillator for generating a laser beam and a plurality of masks. A plurality of first optical systems for respectively receiving laser light generated by at least one laser oscillator and passing through a plurality of masks; and a plurality of first optical systems A second optical system for receiving the emitted laser light and forming an image on the workpiece.

In the laser processing apparatus according to the present invention,
Since the patterns of the plurality of masks are transmitted through the plurality of first optical systems arranged corresponding to the respective masks and then are collectively projected by the second optical system onto the workpiece,
Even if there are three or more patterns, they can be quickly combined. At this time, since it is not necessary to replace the mask and dispose the mask, there is no misalignment of the optical system. Also, in principle,
No energy loss occurs in the optical system.

In the laser processing apparatus according to the present invention,
A plurality of divided patterns obtained by dividing a desired pattern may be formed on a plurality of masks. In that case, a complicated pattern can be processed by dividing a complicated pattern into a plurality of divided patterns to prepare a mask and synthesizing these divided patterns on a workpiece.

A laser processing apparatus according to the present invention comprises a plurality of optical systems or laser oscillators for irradiating a desired mask with laser beams having different energy densities, or a plurality of laser oscillators for generating laser beams having different wavelengths. May be. At that time, a plurality of patterns corresponding to processing with different depths can be formed on the plurality of masks.
In that case, it is possible to form a laser intensity distribution in the processing region, and it is possible to realize different processing depths for each processing region in the workpiece.

In the laser processing apparatus according to the present invention,
The plurality of first optical systems can be composed of a plurality of field lenses, and the second optical system can be composed of at least one objective lens. In that case, the laser light that has passed through the plurality of masks can be received by the plurality of field lenses, and the laser light emitted from these field lenses can be imaged on the workpiece by at least one objective lens. it can.

Further, in the laser processing apparatus according to the present invention, at least one mirror that reflects the laser light emitted from at least one of the plurality of first optical systems and makes it enter the second optical system. May be further provided. In that case, a large number of first optical systems can be provided in a narrow area.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Referring to the accompanying drawings,
An embodiment of the present invention will be described. In addition, the same reference numerals are given to the same components and the description thereof will be omitted. Figure 1
FIG. 1 is a diagram showing a configuration of a laser processing device according to a first embodiment of the present invention. In the present embodiment, a case will be described in which the divided patterns formed on the two masks are projected onto the workpiece and combined. The laser processing apparatus shown in FIG. 1 includes a laser oscillator 1 that generates a laser beam 10 and a mirror 2 that divides the laser beam and irradiates each of the masks 3 and 4.
6 and 27, and a plurality of field lenses 5 and 6 arranged below the mask 3 having the mask pattern A and the mask 4 having the mask pattern B, respectively, for receiving the laser beams passing through these masks. Is arranged below the first optical system and the field lenses 5 and 6,
A second optical system including an objective lens 7 for receiving the laser light emitted from these field lenses and forming an image on the workpiece 8, and a moving stage for mounting and moving the workpiece 8. 9 and. Here, one lens is illustrated as each optical system, but two or more lenses and mirrors may be arranged.

The two field lenses 5 and 6 are convex lenses arranged near the masks 3 and 4, respectively, so that the laser light 10 passing through the masks 3 and 4 is incident on the objective lens 7. Refract. Here, the plurality of field lenses are arranged such that the central axis of at least one field lens deviates from the central axis of the objective lens. In this embodiment, the central axes of both field lenses are deviated from the central axis of the objective lens 7,
Two field lenses 5 and 6 are arranged.

On the mask 3 and the mask 4, a desired pattern is divided into two patterns A and B, respectively. Laser light generated by laser oscillator 10
Is split and reflected by the partial reflection mirror 26 and the total reflection mirror 27, and is irradiated on the masks 3 and 4. The laser light 10 that has passed through the mask 3 on which the pattern A is formed is incident on the left portion of the objective lens 7 and projected onto the workpiece 8. The laser light 10 that has passed through the mask 4 on which the pattern B is formed is incident on the right portion of the objective lens 7 and is projected onto the workpiece. As a result, the pattern A and the pattern B are connected to each other on the workpiece to form a desired pattern.

The state will be described with reference to FIGS. 1 and 2. FIG. 2A is a diagram showing the positional relationship between the two field lenses 5 and 6 and the objective lens 7. The central axes of the field lenses 5 and 6 are deviated from the central axis of the objective lens 7. . In FIG. 2B, the pattern A and the pattern B are connected to each other to form a desired pattern C before division.
FIG. 6 is a diagram for explaining the formation of The image of the pattern A projected on the left field lens 5 passes through the objective lens 7 and then moves to the vicinity of the central axis of the objective lens. Pattern B projected on the field lens 6 on the right side
After passing through the objective lens 7, the image of moves to the vicinity of the central axis of the objective lens. In this manner, the pattern A and the pattern B are combined to form a ring shape, which is a desired pattern C before division, on the workpiece as shown in FIG. 2B.

According to this embodiment, the masks having a plurality of divided patterns are simultaneously arranged in the optical system, so that replacement of the masks is unnecessary. Therefore, there is no need to readjust the optical system that occurs when the mask is replaced, and no misalignment of the optical system occurs. Moreover, since it is not necessary to move the workpiece for each mask pattern, the stage scans do not overlap. Furthermore, since a plurality of patterns are simultaneously projected at once, the processing speed can be improved.

In the present embodiment, the optical system is composed of a combination of a field lens and an objective lens, and since it is not necessary to use a partial reflection mirror for combining laser beams, the loss of the laser beam to be irradiated is lost. Does not occur. Also,
Since it is not necessary to use a polarizing reflector for combining the laser lights, the structure is simple and it is possible to combine three or more kinds of laser lights.

In FIG. 1, the structure of the laser processing apparatus for simultaneously projecting two mask patterns is illustrated, but by increasing the number of masks and the number of field lenses arranged below these masks. It is also possible to project three or more mask patterns simultaneously. For example, 4
FIG. 3 shows a laser processing apparatus according to the second embodiment of the present invention capable of simultaneously projecting individual mask patterns.

As shown in FIG. 3, in the second embodiment of the present invention, four field lenses are arranged above the objective lens. FIG. 3A is a diagram showing the positional relationship between the four field lenses 11 and the one objective lens 12. FIG. 3B is a diagram for explaining that four types of patterns are superposed to form a desired pattern before division. Here, the desired pattern 17 is divided into four, and four different patterns 1
A mask on which 3, 14, 15, and 16 are formed is created. These four masks are arranged on the four field lenses 11, respectively.

When the four masks are irradiated with laser light, 4
The laser light that has passed through the masks passes through the four field lenses 11 and then the objective lens 12
And is imaged on the workpiece placed on the moving stage by the objective lens 12. The patterns are joined on the workpiece to form the figure 17 before division.

Here, the laser light to be irradiated may have different energy density for each mask. In this case, the depth of the groove formed on the surface of the workpiece to be processed can be varied.
Moreover, you may irradiate the laser beam with a different wavelength for every mask. By using two types of laser light, it is possible to process the workpiece by utilizing the characteristics of the respective laser lights.

Next, a laser processing apparatus according to the third embodiment of the present invention will be described. FIG. 4 shows a laser processing apparatus according to the third embodiment of the present invention. In the present embodiment, the laser light 10 emitted from the laser oscillator 1
And a laser beam 20 emitted from the laser oscillator 2 are used, and a part of the laser beam 10 further passes through the dimmer 28.

In FIG. 4, field lenses 5 and 6 are arranged below the mask 23 having the pattern D and the mask 24 having the pattern E, respectively. Below these field lenses, an objective lens 7 for forming images of the pattern D and the pattern E on the workpiece is arranged.

On the other hand, on the right side of the figure, a mask 25 having a pattern F is arranged. The field lens 21 and the mirror 22 are provided on the left side of the mask 25 in order to make the laser light passing through the mask 25 enter the objective lens 7.
Are arranged in this order. The mirror 22 is located above the objective lens 7, and the image of the pattern F is formed on the workpiece by the objective lens 7. By disposing the mirror 22 at a position close to the focus of the objective lens 7, it is possible to provide a large number of optical systems in a narrow area.

In the present embodiment, the laser light 10 emitted from the laser oscillator 1 is supplied with the mask 23 and the mask 24.
Through the field lenses 5 and 6 disposed therebelow, and enters the objective lens 7.
The laser light 20 incident from the laser oscillator 2 passes through the mask 25, the field lens 21, and
Further, the objective lens 7 is totally reflected by the mirror 22.
Incident on. As a result, the laser light 10 that has passed through the masks 23 and 24 and the laser light 20 that has passed through the mask 25 are
All are incident on the objective lens 7. The laser light 10 that has passed through the masks 23 and 24 forms an image of the pattern D and the pattern E on the workpiece 8 by the objective lens 7.
The laser light 20 that has passed through the mask 25 forms an image of the pattern F on the workpiece 8 by the objective lens 7.

According to the present embodiment, it is possible to suitably cope with the case where a plurality of laser beams having different energy densities and wavelengths are used. For example, by irradiating laser light having a high energy density as the laser light 10 and irradiating laser light having a low energy density as the laser light 20, deep hole processing and shallow groove processing can be performed at the same time. Further, by changing the energy density of one of the split laser beams with the dimmer 28, laser beams having different energy densities can be emitted.

[Brief description of drawings]

FIG. 1 is a diagram showing a laser processing apparatus according to a first embodiment of the present invention.

FIG. 2A is a diagram showing a positional relationship between a field lens and an objective lens in the laser processing apparatus according to the first embodiment of the present invention, and FIG. 2B is a diagram in which two patterns are joined together. It is a figure for demonstrating that a desired pattern is formed.

FIG. 3A is a diagram showing a positional relationship between a field lens and an objective lens in a laser processing apparatus according to a second embodiment of the present invention, and FIG. 3B is a diagram showing four patterns joined together. It is a figure for demonstrating that a desired pattern is formed.

FIG. 4 is a diagram showing a laser processing apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

1, 2 laser oscillator 3 Mask (Pattern A) 4 Mask (Pattern B) 5, 6, 11, 21 field lens 7, 12 Objective lens 8 Workpiece 9 Moving stage 10, 20 laser light 13, 14, 15, 16 mask pattern 17 desired pattern 22 mirror 23 Mask (Pattern D) 24 Mask (Pattern E) 25 Mask (Pattern F) 26 Partial reflection mirror 27 Total reflection mirror 28 Dimmer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hironobu Ishima             1200 Manda, Hiratsuka-shi, Kanagawa Made by Komatsu Ltd.             Seisakusho Research Headquarters F-term (reference) 4E068 CD02 CD03 CD05 CD10

Claims (7)

[Claims] 1. At least one laser oscillator for generating laser light, and a plurality of first optical systems arranged so as to correspond to a plurality of masks, the plurality of first optical systems being generated by the at least one laser oscillator. A plurality of the first optical systems for respectively receiving the laser beams that have passed through the mask, and a laser beam emitted from the plurality of the first optical systems for forming an image on a workpiece. A laser processing apparatus comprising: a second optical system. 2. The laser processing apparatus according to claim 1, wherein a plurality of division patterns obtained by dividing a desired pattern are formed on the plurality of masks, respectively. 3. The laser processing apparatus according to claim 1, further comprising a plurality of optical systems or laser oscillators for irradiating a desired mask with laser beams having different energy densities. 4. The laser processing apparatus according to claim 1, further comprising a plurality of laser oscillators that generate laser beams having different wavelengths. 5. The laser processing apparatus according to claim 3, wherein a plurality of patterns corresponding to processing with different depths are formed on the plurality of masks, respectively. 6. The plurality of first optical systems are composed of a plurality of field lenses, and the second optical system comprises:
The laser processing device according to claim 1, wherein the laser processing device is configured by at least one objective lens. 7. The optical system according to claim 1, further comprising at least one mirror that reflects the laser light emitted from at least one of the plurality of first optical systems and makes the laser light incident on the second optical system. 6. The laser processing device according to claim 6.