JPS63171286A - Laser beam machining device - Google Patents

Abstract

PURPOSE:To detect the occurrence of the defective machining by providing a photosensor to detect the intensity of visible light or infrared light generated from the machining area of a work when a laser beam irradiates an object to be worked. CONSTITUTION:In irradiating the laser beam 2, since pale light is emitted from the surface of the work 6 and the temperature is a rised, the infrared light is also emitted. The photosensor 20 detects the intensity of the visible light or the infrared light emitted from the machining area of the work 6 and converts it into the voltage. A detector 30 process and output signal from the photosensor 20 and outputs a control signal when it is lower than a predetermined set level. In other words, when the defective machining takes place, the output signal of the photosensor 20 becomes lower than that at the normal time and a defective detected signal 31 is outputted. In this way, defective machining is detected and can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a laser processing device that removes or alters a part of a workpiece using a laser beam.

[Conventional technology]

Figure 5 shows Toshiba Review (Vol. 39, No. 12) “TEA
This is a configuration diagram showing a laser marking device disclosed in ``CO, Laser Device'', in which a laser beam is irradiated onto a mask cut into a desired shape, and the beam that passes through the mask is focused by a lens to form a mask pattern. An image is formed on the workpiece at an appropriate magnification, and a part of the workpiece is removed or altered to form an inscription. In the figure, (1) is a laser oscillator.

(2) is a laser beam, (3) is a pend mirror for transmitting the laser beam (2) to the processing position, (4)
(5) is a mask that cuts out a desired pattern, and (5) is a processing lens that images the pattern of the mask (4) onto the workpiece (6).

Laser beam (2) extracted from laser oscillator (1)
is bent by a pend mirror (3) and guided to a predetermined position. This laser beam (2) is irradiated onto the mask (4).

The patterned laser beam (2) passing through this mask (4) is imaged onto the workpiece (6) by the processing lens (5). The workpiece (6) is irradiated or altered by the energy of the laser beam (2) to perform marking.

[Problem that the invention seeks to solve]

In the conventional laser processing equipment as mentioned above, the processing lens (
5) The energy density of the beam focal point is 10”W/c
/, and is absorbed or scattered by dust and water vapor in the atmosphere, and almost no energy is transmitted. This is called an air break phenomenon, and there is a problem in that desired machining cannot be performed and machining defects occur. Also,
There is a problem in that the laser beam (2) is not outputted from the laser oscillation W (11) at all, or even if it is outputted, the value is lower than a predetermined value, so that sufficient processing cannot be performed and processing defects occur.

This invention has been made to solve the above-mentioned problems, and provides a laser processing device that can detect processing defects by detecting air break phenomena and occurrence of laser beam output abnormalities. The purpose is to

[Means for Solving the Problems] A laser processing apparatus according to the present invention includes a mask for patterning a laser beam emitted from a laser oscillator, and a processing lens for forming an image of the patterned laser beam on a workpiece. , and an optical sensor that detects the intensity of visible light or infrared light generated from the processing area of the workpiece when the workpiece is irradiated with a laser beam.

[For production]

The optical sensor according to the present invention detects the light emitted by the material that has been turned into plasma and evaporated from the processing area of the workpiece, and the intensity of the reflected light of the laser beam in the processing area.

When an air brake phenomenon occurs or when the output of the laser beam decreases or is not output, the output of the optical sensor becomes small, so processing defects can be detected from the output of the optical sensor.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing a laser processing apparatus according to an embodiment of the present invention. In FIG. 2, (20) is a workpiece (
6) is an optical sensor that detects the intensity of visible light or infrared light generated from the processing area of the workpiece (6) when the laser beam is irradiated, and does not detect light at the wavelength of the laser beam (2). For example, a photodiode.

A Si sensor with a measurement wavelength of 0.9 μm or the like that converts detected light into voltage is used. (30) is a detection device that processes the output signal from the optical sensor (20) and outputs a control signal when the output signal is smaller than a predetermined setting level; (31) is a detection bag! The control signal from (30) is shown. FIG. 2(a) shows laser oscillation v! (1) This shows the output of the laser beam oscillated.

The horizontal axis shows time, and the tU axis shows laser output (energy).

FIGS. 2(b) and 2(e) each show the output signal from the optical sensor (2o), where the horizontal axis shows time and the m-axis shows the sensor output, in this case the voltage value. Also, Fig. 3(a),
Figure 4 (凰) shows the output of the laser beam emitted from the laser oscillator (1).

The horizontal axis shows time and the a-axis shows laser output (energy), and FIGS. 3(b) and 4(b) are respectively shown in FIG. 3(a).

In the output signal from the optical sensor (20) in response to the output in FIG. 4(a), the horizontal axis represents time, ! ! The axis shows the sensor output (voltage).

As in the prior art, a laser beam (2) as shown in FIG. 2(a) is output from a laser oscillator (1) as a pulsed beam to process a workpiece (6). Laser beam (
2), a bluish-white light is generated from the surface of the workpiece (6) and the temperature is high (so infrared light is also generated.The optical sensor (20) detects the processing of the workpiece (6). When the intensity of visible or infrared light emitted from the area is detected,
The output signal has a waveform as shown in FIG. 2(b). However, if energy loss occurs during transmission due to the occurrence of an air break phenomenon, the output from the optical sensor (20) decreases as shown in FIG. 2(e). If A is determined in advance as a set value, machining defects will occur when the laser value is less than A. Furthermore, the waveforms shown in Figures 3(a) and (b) are those when the laser output is normal;
As shown in Figure 4(a), when the laser output becomes low, the output signal from the optical sensor (20) becomes lower than normal and below level A, as shown in Figure 4(b), which may cause machining defects. Occur. That is, when a processing defect occurs, the output signal of the optical sensor (20) becomes lower than when it is normal. Therefore, in the detection device (30), the optical sensor (20
) is below a preset value 1, eg, level A, it is determined that a processing defect has occurred, and a defect detection signal (31) is output. In this way, after detecting the occurrence of machining defects using this detection signal (31), the workpiece can be automatically removed. Furthermore, if a processing defect is detected, it is possible to eliminate the processing defect by irradiating the laser beam (2) again.

In this way, according to this embodiment, the optical sensor (20) can detect insufficient laser output, energy loss during transmission, etc., and can detect and prevent processing defects. Furthermore, the inspection process after processing can be omitted.

Note that any type of laser may be used.

Further, although the optical sensor (20) in the above embodiment is one that does not detect light at the wavelength of the laser beam, even if it detects the laser beam, it is possible to detect the occurrence of machining defects in the output signal. If there is, the same effect as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, a mask for patterning a laser beam emitted from a laser oscillator;
A processing lens focuses this patterned laser beam on the workpiece, and detects the intensity of visible light or infrared light generated from the processing area of the workpiece when the workpiece is irradiated with the laser beam. By including the optical sensor, it is possible to obtain a laser processing apparatus that can detect the occurrence of processing defects.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a laser processing apparatus according to an embodiment of the present invention, FIG. 2(a) is an output waveform diagram of a laser beam oscillated by a laser oscillator, and FIGS. 2(b) and (e)
are waveform diagrams showing the output signals from the optical sensor, respectively.
Figure (aL (b), Figure 4 (a), (b) is a waveform diagram showing the output waveform of the laser beam and the corresponding output signal from the optical sensor, respectively, and Figure 5 is a waveform diagram showing the output signal from the optical sensor. It is a configuration diagram showing. (1)... Laser oscillator, (2)... Laser beam. (41... Mask, (51... Processing lens. (6)... Workpiece # ( 20)... Optical sensor. Note that the same reference numerals in the two figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A mask for patterning a laser beam emitted from a laser oscillator, a processing lens for focusing the patterned laser beam on a workpiece, and a mask for forming an image on the workpiece when the workpiece is irradiated with the laser beam. A laser processing device equipped with an optical sensor that detects the intensity of visible light or infrared light generated from the processing area of a workpiece.