JPH01273683A - Laser beam machining device - Google Patents

Abstract

PURPOSE:To simplify the device and to improve machining accuracy by provid ing optical systems for varying laser light which can change an energy level to the levels for illumination and machining and executing the laser beam ma chining in accordance with the detection and storage of the quantity of the light reflected from a pattern. CONSTITUTION:A laser oscillator 30 which can vary the energy level to the two stages; high and low, is provided and the 1st and 2nd scanning optical systems 32, 33 are disposed. Further, a partial reflecting mirror 35, a photodetec tor 36 and a control section 40 contg. a CPU 44 are respectively disposed to the optical system 32. The oscillator 30 is changed to the low level for illumina tion and a pattern master plate 50 is scanned by the laser light 31. The quantity of the light detected by a photodetector 37 is stored in a memory circuit 43. The oscillator 30 is then changed to the level for machining and the laser beam machining is executed in accordance with the signal of a memory circuit 43. Since the same optical system is used for the profiling of the master plate 50 and the machining, the device is simplified and since the optical aberrations are decreased, the machining accuracy is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a laser processing device, and particularly to a tracing control type device.

(Conventional technology) As a laser processing device using a scanning control method,
A device disclosed in Japanese Patent No. 4-31899 is known. This device has the configuration shown in FIG. That is, it has a laser oscillator (1), and the optical path of the laser beam (2) emitted from this oscillator includes a laser beam (2a) with high output density used for processing, and a laser beam (2a) with high output power used for detection. A beam splitter (3) is provided that separates the light into a low-density laser beam (2b). A modulator (4) and a reflecting mirror (5) are provided in the optical path of the laser beam (2a), and the laser beam (2a) is reflected at right angles by the reflecting mirror (5).
a) is made incident on the first condensing lens (6a).

On the other hand, the laser beam (2b) is reflected by the reflecting mirror (7),
After being made into an optical path parallel to the laser beam (2a), it is further reflected by a reflecting mirror (8) at right angles so as to be coaxial with the laser beam (2a), and then enters a condenser lens (6b). There is. Above 1. The second condensing lens is integrally supported by the support (9). The support (9) is connected to a feed mechanism (11) which converts the rotational movement of the motor (10) into linear movement. a pair of discs (10a) located below each of the condenser lenses (6a) and (8b), and whose outer peripheral surfaces are rotated across the optical axis of the lenses;
(10b) are provided in a stepped manner. These disks are commonly attached to a rotating shaft (11) and driven by a motor (13) via a speed reducer (12). Lower disk (
A mask (15) made of a transparent material and having a desired pattern (14) formed thereon is fixed to the outer surface of 10a). A part of the outer periphery of the disk (10a) to which the mask (15) is fixed has a passage hole (1B) for illuminating the mask (15).
) is formed. The support (9) has a photodetector (
18) is attached and faces the passage hole (16).

A detection signal from the photodetector (18) is sent to a control circuit (20) that controls the modulator (4).

Further, the motor (lO) for the support (9) is connected to the feed speed control circuit (21).

With the above configuration, processing is performed as follows. A plurality of workpieces (22
) are arranged radially at a predetermined pitch. Master (15)
The same number of workpieces (22) are arranged facing each other. The pair of discs (10a) and (10b) are rotated at a constant speed, while the support (9) is reciprocated in the radial direction at a constant speed by a motor (10) and a feed mechanism (11). The photodetector (18) detects the master (15) during the above rotation and reciprocation.
) is detected, and the amount of light is sent to the control circuit (20). The control circuit (2o) turns on and off the modulator (4) based on the difference in the amount of light when the pattern (14) in the master (15) is irradiated and the amount of light when the part other than the pattern (14) is irradiated. Control. In other words, when detecting the amount of light irradiated onto the pattern (14), the laser light (2a) is applied to the workpiece (2).
2) is irradiated and processed into the same shape as the pattern (14).

In addition to the above-mentioned conventional example, a pattern is programmed as described in Utility Model Application Publication No. 60-11187, and based on this program, a reflecting mirror that scans the laser beam and an XY table are controlled to perform laser processing. is known to do.

(Issue 8 to be solved by the invention) In the former case, two tables are required, one for arranging the masks and the other for arranging the workpieces, and two types of optical systems, one for detection and one for processing, are required. Furthermore, two drive systems for these optical systems are required, which has the disadvantage of increasing the size of the apparatus. Moreover, in the latter case, not only is it difficult to process fine patterns, but also the program is extremely complicated. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a laser device that can process fine patterns with high precision without increasing the size of the device.

Structure of invention C] (Means and effects for solving the order of assignments) A variable optical system that two-dimensionally scans a predetermined range with two laser beams whose energy level can be changed to an illumination level and a processing level, and a reference. A pattern original plate having a pattern and irradiated with a laser beam at the illumination level that has passed through the variable optical system, and an amount of reflected light from an area including the reference pattern that has been irradiated with the two-dimensional scanning of the laser beam at the illumination level. a detection means for detecting the processing level, and a detection means for transmitting a drive signal to the variable optical system, storing the reference pattern from the detected amount of reflected light, and applying the laser beam of the processing level to the workpiece based on the stored signal in the reference pattern. Since the optical system used during scanning and processing of the reference pattern is the same, extremely good reproducibility is achieved.

(Example) EMBODIMENT OF THE INVENTION Hereinafter, this invention will be explained based on drawing which shows an Example.

Figure 1 shows an embodiment of the present invention, which consists of a continuous wave YAG laser whose energy level can be switched between high and low levels for illumination and processing. provided in a predetermined position. This oscillator (30
) is emitted from a first scanning optical system (32) that scans in the X direction, and a second scanning optical system (33) that is paired with this optical system and scans in the Y direction. The light is then condensed by a first condensing lens (34) for recording and processing. A partial reflecting mirror (35) is provided in the optical path of the laser beam (31) in the oscillator (30) and the first scanning optical system (32) located on the oscillator side. The partially reflecting mirror (35) is connected to the first scanning optical system (3
The reflecting surface is tilted so as to reflect the reflected light from 2) toward the oscillator (30) at right angles to the optical path within the same plane.

A second condenser lens (36) and a photodetector (37) are sequentially provided on the optical path of the reflected light from the partial reflecting mirror (35). The photodetector (37) is the pattern original plate (50)
The installation position is determined by the position of and the positions of the condenser lenses (34) and (3B). Its position is the pattern original plate (50)
The position must be conjugate to the position of . In order to control the first and second scanning optical systems, a control section (40) is provided which inputs a detection signal from the photodetector (37). As shown in FIG. 2, the control unit (40) inputs the detection signal and outputs "1" and "0" to this input signal as compared with the reference light amount.
A comparator circuit (4) that adds and outputs an on or off signal
1), a memory circuit (43) that stores the signal output from the comparison circuit (41) through the input/output circuit (42), and a bus (45) common to the input/output circuit (42) and the memory circuit (43). a central processing unit (44) connected to the first scanning optical system (32), a first D/A converter (46) that commands the swing angle of the first scanning optical system (32), and an X-axis driver (46) that drives based on the command. 47), a second D/A converter (48) that commands the swing angle of the second scanning optical system (33), and a Y-axis driver (49) that drives based on the command. has been done. The central processing unit (44) processes a pattern original plate (
The scanning range for 50) and the scanning signal stored in the storage circuit (43) are transmitted to the oscillator (3
It is designed to control commands sent to the 0) side. The input/output circuit (42) outputs an oscillator (3) when irradiating the reference pattern (51) formed on the pattern original plate (50).
The circuit has a circuit configuration that sends a control signal to open a Q switch (not shown) consisting of an acoustic element etc. incorporated in the 0).

Next, the operation of the above configuration will be explained. Oscillator (30)
is switched to a low energy level and a weak laser light is prepared to be emitted. First, the pattern original plate (50) is placed at the focal position of the first condensing lens (34) by a known positioning means. Next, the weak laser beam is emitted, and the central processing unit (44) emits the first laser beam (31) onto the pattern original plate (5o). A predetermined range is scanned by a second scanning optical system,
The reference pattern (51) is determined from the amount of light detected by the photodetector (37).
The part is stored as "1#" and the other parts are stored as "θ" in the memory circuit (43). After the above scanning, the oscillator (3o)
is switched to a high energy level and prepared for machining.

That is, the pattern original plate (50) is removed and the workpiece (52) is placed in the same position. Central processing unit (44
) so that the first and second scanning optical systems are connected to the first. 2nd D/A
The swing angle is controlled by converters (4G) and (48), respectively.

It is scanned in XY by Y-axis drivers (47) and (49). During this scanning, among the signals stored in the memory circuit (43), a signal of "1" at the position of the reference pattern (51), that is, the above-mentioned Q switch (not shown) is opened, and the laser beam being oscillated is The light is emitted from the oscillator (30) and incident on the first scanning optical system (32). As a result, the workpiece (5
A pattern having the same shape as the reference pattern (51) is processed on the processed surface of 2).

Note that if an index table, a switching table that reciprocates in the horizontal direction, or the like is used to position the pattern original plate (5o) and the workpiece (52), it is possible to efficiently process a plurality of the same patterns. In addition, after memorizing the reference pattern (51), the laser beam transmitted through the first condensing lens (34) can be guided to a completely different location using a reflecting mirror or an optical fiber, and the beam can be condensed again. Things (52)
There is no need to place it at the same location as the pattern original plate (5o). Furthermore, in the above embodiment, the oscillator was controlled to switch the energy level of the laser light, but the invention is not limited to this; for example, two oscillators, one for processing and one for illumination, may be provided, and the two oscillators emitted from these oscillators may be The laser beams may be configured to be superimposed on the same optical axis using a guichroic mirror or the like.

[Effects of the Invention] Since the same optical system is used for copying and processing the pattern on the pattern original plate, the configuration of the device can be greatly simplified and miniaturization can be achieved. Furthermore, since the optical systems are the same, distortion of the pattern due to lens aberrations is canceled out, making it possible to process the reference pattern with extremely high precision and good reproducibility. Therefore, not only general copying processing but also marking processing can now be performed extremely well.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing the control section in FIG. 1, and FIG. 3 is a block diagram showing a conventional example. (30>... Laser oscillator (32)... First scanning optical system (variable optical system) (33
)...Second scanning optical system (variable optical system) (37)...
・Photodetector (detection means) (40)...Control unit (50)...Pattern original plate

Claims (1)

[Claims] A variable optical system that two-dimensionally scans a predetermined range with two laser beams whose energy level can be changed to illumination level and processing level, and a laser beam of the above certification level that has a reference pattern and passes through the variable optical system. a detection means for detecting an amount of reflected light from a pattern original plate to be irradiated, a region including the reference pattern irradiated by the two-dimensional scanning of the laser beam at the illumination level, and a drive signal to the variable optical system. and a control unit that stores the reference pattern from the detected amount of reflected light and controls the irradiation of the laser beam at the processing level to the workpiece based on the stored signal in accordance with the reference pattern. Laser processing equipment.