JP3211206B2 - Laser processing apparatus and processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a laser pressurized <br/> machining apparatus and machining method for machining a workpiece by a laser beam having a non-uniform laser intensity distribution, high in particular energy loss is small homogeneous The present invention relates to a laser processing apparatus and a processing method capable of performing precision processing.

[0002]

2. Description of the Related Art Generally, an excimer laser is used as shown in FIG.
When drilling a hole in the workpiece 2 through the mask 1 as shown in FIG. 1A, the beam intensity of the laser beam has a non-uniform distribution that is large at the center and small at both ends as shown in FIG. I have. Therefore, the beam intensity 3 of the laser beam passing through the mask 1 as shown in FIGS. 3A and 3C also has the same intensity distribution as shown in FIG. On the other hand, the processing speed of the excimer laser varies depending on the beam intensity as shown in FIG. 7. Therefore, as shown in FIG. Become uniform.

Conventionally, in order to improve the processing characteristics, only a portion having a small difference in the intensity distribution of the laser light of the excimer laser is used, or the shape of the laser light itself is made uniform using an optical element called a homogenizer. The technique was being taken. Although various configurations have been implemented for this method, basically the laser beam is split into several beams,
By concentrating these beams at one place, the difference in the intensity distribution of the beams is reduced.

[0004] As another method for improving the above processing characteristics, a method described in Japanese Patent Application Laid-Open No. 4-242644 is known. In this method, as shown in FIG. 8, the mask is scanned through a mirror that moves in a direction in which the intensity distribution of the laser beam is non-uniform, and the laser beam is superimposed to perform uniform processing. . According to this method, FIG.
By processing the fixed workpiece 1 with laser light scanned at _three positions E ₁ , E ₂ , and E ₃ as shown in FIG. it can.

[0005]

However, when only the portion having a small difference in the intensity distribution of the laser beam is used in the above method, the energy efficiency is deteriorated and a high-output laser is required. In addition, when a homogenizer is used, energy loss is small, but adjustment is difficult, and there is a disadvantage that the NA value of the beam is increased and processing accuracy is deteriorated.

On the other hand, according to the method described in the above-mentioned publication, it is necessary to sufficiently increase the emission area of the laser beam with respect to the mask, and there is a problem that the energy efficiency is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a laser processing apparatus and a processing apparatus capable of performing uniform and high-precision processing with a small energy loss of laser light. And

[0008]

To achieve the above object, according to the solution to ## laser machining apparatus of the present invention according to claim 1, trout
The workpiece and the workpiece relative to the laser beam
Depending on the driving means and beam reduction or magnification,
Drive means for driving the disk and the workpiece in conjunction with each other
And control means for controlling

A monitoring means for monitoring the intensity distribution of the laser light
Further steps can be provided, and the control means
Means that, in addition to beam reduction or magnification,
Depending on the measured laser light intensity distribution,
It can be controlled to be driven in conjunction with the object
You.

[0010] A laser processing method according to the present invention as set forth in claim 3.
Drives the mask and the workpiece relatively to the laser beam.
Move, mask according to beam reduction or magnification
And the workpiece to be driven in conjunction with each other
It is characterized by .

[0011]

[0012]

According to the present invention , there is provided a laser processing apparatus according to the present invention .
In its, relative to the mask and the workpiece and the laser beam
The beam is driven by
The disk and the workpiece are controlled so as to be driven in conjunction with each other.
You.

[0013] In addition to beam reduction or magnification,
The mask and the workpiece are linked according to the intensity distribution of the laser light
It is controlled to be driven.

A laser processing method according to the present invention as set forth in claim 3.
In this case, the mask and the workpiece
Driven oppositely, depending on beam reduction or magnification
Control so that the mask and the work
Is controlled .

[0015]

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an excimer laser processing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of the first embodiment of the present invention. A laser beam 12 emitted from a laser oscillator 11 enters a projection optical system 14 through an aperture pattern 13a regularly arranged on a projection mask 13 as a mask. The laser beam 12 incident on the projection optical system 14 is
The beam is reduced, and the workpiece 16 mounted and fixed on the processing stage 15 is irradiated. A trimming mask 17 that blocks the laser beam 12 outside the processing range is provided above the workpiece 16.

The processing stage 15 is driven and controlled in the direction of arrows AA by the control device 18 in synchronization with the laser oscillator 11. The control device 18 has a built-in memory 19,
The memory 19 stores a driving pattern for moving the processing stage 15 to a predetermined position. Then, as shown in FIG. 2, the processing stage 15 is moved with respect to the mask 13 according to a predetermined driving pattern, and the laser light 12 is
9 is overlapped with the work piece 15 through
In the same manner as in the conventional example shown in FIG. 1, a hole with a uniform depth can be formed by the superposition effect.

According to the present embodiment, the projection optical system 14 can be fixed and can have a simple structure, and it is possible to perform hole drilling of a uniform depth with good energy efficiency. In addition, it is not necessary to increase the NA value of the laser beam 12, and high-accuracy processing can be maintained.

In the above embodiment, the case where the projection optical system 14 reduces the beam of the laser beam 12 is shown. However, the beam of the laser beam 12 may be expanded by the projection optical system 14 as shown in FIG.

FIG. 4 shows a configuration of an excimer laser processing apparatus according to a second embodiment of the present invention. In FIG. 4, parts corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This embodiment is characterized in that a mask driving device 2 for driving the mask 13 in conjunction with the movement of the processing stage 15 and monitoring means for monitoring the intensity distribution of the laser light 12 emitted from the laser oscillator 11 are provided. .

The mask driving device 21 is linked with the processing stage 15 by the control device 18 and moves along the arrow A as shown in FIG.
-Move in the A direction. In this case, the moving amount of the mask 13 is an amount obtained by multiplying the moving amount of the processing stage 15 by the beam reduction or enlargement ratio of the projection optical system 14. The monitoring means includes a beam splitter 22, an imaging optical system 23, and an image sensor 24. The beam splitter 22 is a laser oscillator 11
The laser light 12 emitted from the light source is branched and reflected in a right angle direction, and forms an image on an image sensor 24 via an image forming optical system 23. The image of the laser beam 12 received by the image sensor 24 is input to the control device 18 and the intensity distribution of the laser beam 12 is measured. The drive pattern stored in the memory 19 is selected according to the measurement result, an optimum laser overlap pattern is obtained, and the processing stage 15 and the mask 13 are driven according to the drive pattern.

By moving the mask 13 in conjunction with the processing stage 15 according to the present embodiment, even if the opening patterns 13a formed in the mask 13 are not regularly arranged, the same as in the first embodiment. The effect can be obtained.

By providing a means for monitoring the intensity distribution of the laser beam 12, an optimum superimposition pattern corresponding to the intensity distribution of the laser beam 12 can be selected from the memory 19. Further, a new superimposed pattern can be generated by the control device 18 according to the intensity distribution.

[0025]

As described above, according to the first aspect,
According to the laser processing device, the mask and the workpiece are
Driven relative to the light, the beam contracts or expands.
The mask and the workpiece are driven in conjunction with each other
Since so as to control the so that the machining energy efficient homogeneous depth by the projection optical system of a simple structure, mass
Make sure that the opening patterns formed in the
It can be performed with high accuracy even without it .

According to the laser processing apparatus of the second aspect, in addition to the beam reduction or the magnification, the laser beam
The mask and workpiece are driven in conjunction with each other according to the intensity distribution
So that the optimal superposition pattern of the laser light is selected according to the intensity distribution of the laser light,
It can also be generated.

The laser processing method of the present invention according to claim 3
According to the above, the mask and the workpiece are
Driven according to the beam reduction or expansion ratio,
Control so that the mask and the workpiece are driven in conjunction.
As a result, the effects described in the above sections can be obtained.

[0028]

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a method of driving a workpiece with respect to the laser beam of FIG.

FIG. 3 is an explanatory diagram showing a beam optical system according to another example of the projection optical system of FIG. 1;

FIG. 4 is a block diagram showing a configuration of a second embodiment of the excimer laser processing apparatus according to the present invention.

FIG. 5 is an explanatory diagram showing a method of driving a workpiece and a mask with respect to the laser beam of FIG. 4;

FIG. 6 is an explanatory view showing a processing example by a conventional excimer laser processing method.

FIG. 7 is a diagram showing the relationship between laser beam intensity and processing speed.

FIG. 8 is an explanatory view of the principle in the case where a conventional workpiece is fixed and laser light is moved to achieve beam homogenization by superposition of laser light.

9 is a cross-sectional view showing a processed shape when a workpiece is processed using a mask according to the principle shown in FIG. 8;

[Explanation of symbols]

 REFERENCE SIGNS LIST 12 laser beam 13 mask 15 processing stage (drive means) 16 workpiece 18 control device (control means) 19 memory (storage means) 21 mask drive device (drive means) 24 image sensor (monitoring means)

Claims (3)

(57) [Claims] 1. A laser having a non-uniform laser intensity distribution.
Light has a partial aperture pattern to limit the processing range
In a laser processing apparatus that irradiates a mask and processes a workpiece according to the opening pattern, a driving unit that relatively drives the mask and the workpiece with respect to the laser light ; Laser processing , comprising: control means for controlling the driving means so that the mask and the workpiece are driven in conjunction with each other in accordance with a beam reduction or magnification ratio. apparatus. And a monitoring means for monitoring an intensity distribution of the laser beam, wherein the control means reduces or expands the beam.
In addition to the large ratio, the mask and the workpiece are interlocked according to the intensity distribution of the laser light measured by the monitoring unit.
2. The laser processing apparatus according to claim 1 , wherein the driving unit is controlled so as to be driven . 3. A laser having a non-uniform laser intensity distribution.
Light has a partial aperture pattern to limit the processing range
That is irradiated to the mask, in the laser processing method of the laser processing apparatus for processing a workpiece according to the opening pattern, the phase <br/> pair to thereby drive the said mask and said workpiece relative to the laser beam , Depending on beam reduction or magnification
The mask and the workpiece are driven in conjunction with each other.
Laser processing method according to claim and control child as.