Laser processing equipment

Abstract

To provide a laser processing device that enables grasping a state of a laser beam without deteriorating productivity.SOLUTION: A laser processing device comprises: a laser oscillator 30 that generates a laser beam 21; a condensing lens 32 that condenses the laser beam 21 generated by the laser oscillator 30; a separating member 33 that separates the laser beam 21 generated by the laser oscillator 30 into a laser beam 22 for inspection and a laser beam 22 for processing for condensing the beam onto a work-piece 100; a beam receiving part 40 that receives the laser beam 22 for inspection separated by the separating member 33; a detecting unit 50 that obtains, from the laser beam 22 received by the beam receiving part 40, information concerning intensity of the laser beam 22 and information concerning a pulse waveform of the laser beam 22; and a control part 54 that outputs the information obtained by the detecting unit 50.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus.

Background Art

[0002] In order to divide a plate-shaped object such as a semiconductor wafer into chips, a method of forming a modified layer by condensing and irradiating laser light having a wavelength that is transmissive to the plate-shaped object inside the plate-shaped object and dividing starting from this modified layer, or a method of dividing by irradiating laser light having a wavelength that is absorptive to the plate-shaped object and causing ablation, etc. are known (see Patent Documents 1 and 2). In order to stabilize the processing quality in such a processing method, it is very important to grasp the state of the laser light of the laser processing apparatus.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, conventionally, a power meter for measuring the intensity of laser light needs to be installed so as to block the laser light. Therefore, it is necessary to stop the processing for measurement, and there is a problem that productivity decreases. Further, in order to observe the pulse waveform, pulse dropout, etc. of the laser light, it is necessary to install a photodiode at a position where scattered light can be received, connect it to an oscilloscope, and visually confirm it. Not only does productivity decrease as in the case of intensity measurement, but it is also a troublesome operation.

[0005] The present invention has been made in view of such problems, and an object thereof is to provide a laser processing apparatus capable of grasping the state of laser light without reducing productivity. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, the laser processing apparatus of the present invention comprises: a laser oscillator that generates laser light; a focusing lens that focuses the laser light generated by the laser oscillator; a separating member that separates the laser light generated by the laser oscillator into an inspection laser light and a processing laser light for focusing onto a workpiece; a light receiving unit that receives the inspection laser light separated by the separating member; a detection unit that acquires information regarding the intensity of the laser light and information regarding the pulse waveform of the laser light from the laser light received by the light receiving unit; and a control unit that outputs the information acquired by the detection unit. The information regarding the pulse waveform of the laser light acquired by the detection unit includes information regarding the presence or absence of pulse dropouts, and the control unit automatically sets a threshold for detecting pulse dropouts based on the average output of the laser light. It is characterized by the following.

[0007] Furthermore, the laser processing apparatus of the present invention may further include a branching mirror for branching the inspection laser light separated by the separation member, and the light receiving unit may include a thermal sensor that receives one of the laser beams branched by the branching mirror and measures the average output of the laser beam, and a photodetector that receives the other laser beam branched by the branching mirror and acquires information regarding the pulse waveform of the laser beam.

[0008] Furthermore, in the laser processing apparatus of the present invention, the thermal sensor may be arranged to receive the laser light reflected by the branching mirror, and the photodetector may be arranged to receive the laser light that has passed through the branching mirror.

[0009] Furthermore, in the laser processing apparatus of the present invention, an ND filter may be placed between the branching mirror and the photodetector. [Effects of the Invention]

[0011] This invention makes it possible to understand the state of laser light without reducing productivity. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a perspective view showing an example of the configuration of a laser processing apparatus according to an embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the general configuration of the laser light irradiation unit shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing another example of the configuration of a laser light irradiation unit. [Figure 4] Figure 4 is a schematic diagram showing another example of the light-receiving unit's configuration. [Figure 5] Figure 5 is a graph showing an example of the trend in the average output of the laser light received by the thermal sensor shown in Figure 4. [Figure 6] Figure 6 is a graph showing an example of the change in the output power of the laser light received by the photodetector shown in Figure 4. [Modes for carrying out the invention]

[0013] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. Moreover, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0014] [Embodiment] First, the overall configuration of the laser processing apparatus 1 according to an embodiment of the present invention will be described based on the drawings. Figure 1 is a perspective view showing an example of the configuration of the laser processing apparatus 1 according to an embodiment. In the following description, the X-axis direction is a single direction in the horizontal plane. The Y-axis direction is a direction perpendicular to the X-axis direction in the horizontal plane. The Z-axis direction is a direction perpendicular to both the X-axis and Y-axis directions. In the laser processing apparatus 1 of this embodiment, the processing feed direction is the X-axis direction, the indexing feed direction is the Y-axis direction, and the focusing point position adjustment direction is the Z-axis direction.

[0015] As shown in Figure 1, the laser processing apparatus 1 comprises a holding table 10, a laser beam irradiation unit 20, a moving unit 60, an imaging unit 70, and a display unit 80. The laser processing apparatus 1 according to this embodiment is a device that processes a workpiece 100 by irradiating the workpiece 100 with laser light 21. The processing of the workpiece 100 by the laser processing apparatus 1 includes, for example, a modified layer formation process that forms a modified layer inside the workpiece 100 by stealth dicing, a groove processing that forms grooves on the surface of the workpiece 100, or a cutting process that cuts the workpiece 100 along a planned division line.

[0016] The workpiece 100 is, for example, a disc-shaped semiconductor device wafer, optical device wafer, or other wafer with a substrate made of silicon (Si), sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), or lithium tantalate (LiTaO3). In this embodiment, the workpiece 100 is disc-shaped, but in this invention, it does not have to be disc-shaped. The workpiece 100 is transported and processed while supported within the opening of the frame 110, with, for example, an annular frame 110 attached to it and a tape 111 with a diameter larger than the outer diameter of the workpiece 100 attached to the back surface of the workpiece 100.

[0017] The holding table 10 holds the workpiece 100 on its holding surface 11. The holding surface 11 is a disc shape formed from porous ceramic or the like. In this embodiment, the holding surface 11 is a plane parallel to the horizontal direction. The holding surface 11 is connected to a vacuum suction source, for example, via a vacuum suction path. The holding table 10 holds the workpiece 100 placed on the holding surface 11 by suction. Multiple clamping parts 12 are arranged around the holding table 10 to hold an annular frame 110 that supports the workpiece 100.

[0018] The holding table 10 is rotated about an axis parallel to the Z-axis direction by the rotation unit 13. The rotation unit 13 is supported by the X-axis direction moving plate 14. The rotation unit 13 and the holding table 10 are moved in the X-axis direction by the X-axis direction moving unit 61, which will be described later, via the X-axis direction moving plate 14. The rotation unit 13 and the holding table 10 are moved in the Y-axis direction by the Y-axis direction moving unit 62, which will be described later, via the X-axis direction moving plate 14, the X-axis direction moving unit 61, and the Y-axis direction moving plate 15.

[0019] The laser light irradiation unit 20 is a unit that irradiates the workpiece 100 held on the holding surface 11 of the holding table 10 with the laser light 21. At least the condenser lens 32 (see FIG. 2) of the laser light irradiation unit 20 is supported by the Z-axis direction moving unit 63, which will be described later, installed on the column 3 erected from the apparatus main body 2 of the laser processing apparatus 1. A specific configuration example of the laser light irradiation unit 20 will be described in detail later.

[0020] The moving unit 60 is a unit that relatively moves the condensing point of the laser light 21 with respect to the workpiece 100 held on the holding table 10. The moving unit 60 includes an X-axis direction moving unit 61, a Y-axis direction moving unit 62, and a Z-axis direction moving unit 63.

[0021] The X-axis direction moving unit 61 is a unit that relatively moves the holding table 10 and the condensing point of the laser light irradiation unit 20 in the X-axis direction, which is the processing feed direction. In the embodiment, the X-axis direction moving unit 61 moves the holding table 10 in the X-axis direction. In the embodiment, the X-axis direction moving unit 61 is installed on the apparatus main body 2 of the laser processing apparatus 1. The X-axis direction moving unit 61 supports the X-axis direction moving plate 14 so as to be movable in the X-axis direction.

[0022] The Y-axis movement unit 62 is a unit that moves the holding table 10 and the focusing point of the laser beam irradiation unit 20 relative to each other in the Y-axis direction, which is the indexing feed direction. In the embodiment, the Y-axis movement unit 62 moves the holding table 10 in the Y-axis direction. In the embodiment, the Y-axis movement unit 62 is installed on the main body 2 of the laser processing apparatus 1. The Y-axis movement unit 62 supports the Y-axis movement plate 15 so that it can move freely in the Y-axis direction.

[0023] The Z-axis movement unit 63 is a unit that moves the holding table 10 and the focal point of the laser beam irradiation unit 20 relative to each other in the Z-axis direction, which is the direction for adjusting the focal point position. In the embodiment, the Z-axis movement unit 63 moves at least the focusing lens 32 of the laser beam irradiation unit 20 in the Z-axis direction. In the embodiment, the Z-axis movement unit 63 is installed on a column 3 that is erected from the main body 2 of the laser processing apparatus 1. The Z-axis movement unit 63 supports at least the focusing lens 32 of the laser beam irradiation unit 20 so that it can move freely in the Z-axis direction.

[0024] The X-axis movement unit 61, the Y-axis movement unit 62, and the Z-axis movement unit 63 each, in embodiments, include a well-known ball screw, a well-known pulse motor, and a well-known guide rail. The ball screw is rotatably mounted around its axis. The pulse motor rotates the ball screw around its axis. The guide rail of the X-axis movement unit 61 supports the X-axis movement plate 14 so as to be movable in the X-axis direction. The guide rail of the X-axis movement unit 61 is fixedly mounted on the Y-axis movement plate 15. The guide rail of the Y-axis movement unit 62 supports the Y-axis movement plate 15 so as to be movable in the Y-axis direction. The guide rail of the Y-axis movement unit 62 is fixedly mounted on the main body 2 of the device. The guide rail of the Z-axis movement unit 63 supports at least the focusing lens 32 of the laser beam irradiation unit 20 so as to be movable in the Z-axis direction. The guide rail of the Z-axis movement unit 63 is fixedly mounted on the column 3.

[0025] The imaging unit 70 images the workpiece 100 held on the holding table 10. The imaging unit 70 includes a CCD (Charge Coupled Device) camera or an infrared camera. The imaging unit 70 is fixed, for example, adjacent to the focusing lens 32 (see Figure 2) of the laser beam irradiation unit 20. The imaging unit 70 images the workpiece 100 to obtain an image for performing alignment between the workpiece 100 and the laser beam irradiation unit 20, and outputs the obtained image.

[0026] The display unit 80 is a display unit composed of a liquid crystal display device or the like. The display unit 80 displays, for example, the setting screen for processing conditions, the state of the workpiece 100 captured by the imaging unit 70, the state of the processing operation, etc., on its display surface. If the display surface of the display unit 80 includes a touch panel, the display unit 80 may also include an input unit. The input unit can accept various operations from the operator, such as registering processing content information. The input unit may also be an external input device such as a keyboard. The information and images displayed on the display surface of the display unit 80 can be switched by operations from the input unit or the like.

[0027] Next, the specific configuration of the laser light irradiation unit 20 will be described. Figure 2 is a schematic diagram showing an example of the general configuration of the laser light irradiation unit 20 shown in Figure 1. As shown in Figure 2, the laser light irradiation unit 20 includes a laser oscillator 30 and a focusing lens 32.

[0028] The laser oscillator 30 generates and emits laser light 21 having a predetermined wavelength for processing the workpiece 100. The laser light 21 irradiated by the laser light irradiation unit 20 is laser light with a wavelength that is transparent to or absorbs the workpiece 100. The laser oscillator 30 has a laser oscillation unit 31 which includes a laser medium that oscillates and amplifies the laser light 21. In addition, the laser oscillator 30 of this embodiment is provided with a separation member 33, a light receiving unit 40, a detection unit 50, and a control unit 54 inside the housing.

[0029] The separation member 33 is provided in the optical path of the laser beam 21 between the laser oscillator 31 and the focusing lens 32. The separation member 33 separates the laser beam 21 generated in the laser oscillator 31 into a laser beam 22 for inspection and a laser beam 23 for processing.

[0030] The separation member 33 of the embodiment includes, for example, glass, and transmits 99% or more of the laser light 21 while reflecting less than 1 percent. That is, the separation member 33 of the embodiment guides the reflected laser light 21 to the light receiving unit 40 as inspection laser light 22, and guides the transmitted laser light 21 to the focusing lens 32 as processing laser light 23. The separation member 33 may also include a reflective mirror, in which case it should be arranged so that the reflected laser light 21 is guided to the focusing lens 32 as processing laser light 23, and the transmitted laser light 21 is guided to the light receiving unit 40 as inspection laser light 22.

[0031] The light-receiving unit 40 receives the inspection laser light 22 separated by the separation member 33. The light-receiving unit 40 in this embodiment includes a photodetector that detects light by converting the optical signal into an electrical signal. A filter that attenuates the amount of light may be placed before the light-receiving unit 40. The filter may include, for example, an ND (Neutral Density) filter that reduces the amount of light transmitted by a certain amount without selecting a wavelength in a predetermined wavelength band. The light-receiving unit 40 outputs an electrical signal corresponding to the received light to the detection unit 50.

[0032] The detection unit 50 is a unit that acquires information about the inspection laser light 22 received by the light receiving unit 40. The detection unit 50 includes a signal amplification unit 51, a pulse waveform information acquisition unit 52, and a light intensity information acquisition unit 53. The signal amplification unit 51 amplifies the electrical signal acquired from the light receiving unit 40 and outputs it to the pulse waveform information acquisition unit 52 and the light intensity information acquisition unit 53.

[0033] The pulse waveform information acquisition unit 52 acquires an electrical signal of light intensity corresponding to information about the pulse waveform of the laser light 22. The light intensity information acquisition unit 53 acquires an electrical signal of light intensity corresponding to information about the intensity of the laser light 22. The pulse waveform information acquisition unit 52 and the light intensity information acquisition unit 53 acquire their respective information as analog signals. The pulse waveform information acquisition unit 52 and the light intensity information acquisition unit 53 output the analog signals corresponding to each acquired piece of information to the control unit 54.

[0034] The control unit 54 is a computer that includes an arithmetic processing unit as an arithmetic means, a storage device as a storage means, and an input / output interface device as a communication means. The arithmetic processing unit includes, for example, a microprocessor such as a CPU (Central Processing Unit). The storage device has memory such as an HDD (Hard Disk Drive), ROM (Read Only Memory), or RAM (Random Access Memory). The arithmetic processing unit performs various calculations based on a predetermined program stored in the storage device. The arithmetic processing unit outputs various control signals to the above-mentioned components via the input / output interface device according to the calculation results.

[0035] The control unit 54 performs AD conversion on the analog signals acquired from the pulse waveform information acquisition unit 52 and the light intensity information acquisition unit 53. Furthermore, the control unit 54 converts the AD value of the light intensity into a power value. As a result, the control unit 54 obtains time-series information of the peak output from the electrical signal of the light intensity corresponding to the information on the pulse waveform of the laser light 22 acquired by the pulse waveform information acquisition unit 52. In addition, the control unit 54 obtains time-series information of the average output from the electrical signal of the light intensity corresponding to the information on the intensity of the laser light 22 acquired by the light intensity information acquisition unit 53.

[0036] The control unit 54 acquires the time progression of the average output of the laser beam 22 based on the information regarding the intensity of the inspection laser beam 22 acquired by the detection unit 50. Since the inspection laser beam 22 and the processing laser beam 23 are separated at a predetermined ratio by the separation member 33, it is possible to estimate the time progression of the average output of the processing laser beam 23 from the time progression of the average output of the laser beam 22. In other words, based on the time progression of the average output of the processing laser beam 23, it is possible to detect abnormalities in the device, such as an unexpected decrease in the intensity of the laser beam 23.

[0037] Furthermore, the control unit 54 acquires the time progression of the peak output of the laser beam 22 based on the information regarding the pulse waveform of the inspection laser beam 22 acquired by the detection unit 50. Since the inspection laser beam 22 and the processing laser beam 23 are separated at a predetermined ratio by the separation member 33, it is possible to estimate the time progression of the peak output of the processing laser beam 23 from the time progression of the peak output of the laser beam 22. In other words, the control unit 54 can detect abnormalities in the device, such as pulse dropouts of the laser beam 23, based on the time progression of the peak output of the processing laser beam 23.

[0038] Here, the information regarding the pulse waveform of the laser light 22 acquired by the pulse waveform information acquisition unit 52 of the detection unit 50 may include information regarding the presence or absence of pulse dropouts. The presence or absence of pulse dropouts is detected by determining whether the peak output of each pulse falls below a predetermined threshold. The control unit 54 of this embodiment automatically sets the threshold for detecting pulse dropouts based on the time progression of the average output of the laser light 22. This makes it possible to handle cases where the processing conditions are changed during irradiation of the laser light 21, causing the appropriate threshold to change.

[0039] The focusing lens 32 focuses the laser beam 21 emitted from the laser oscillator 30 onto the workpiece 100 held on the holding surface 11 of the holding table 10, and irradiates the workpiece 100 with it. The focusing lens 32 focuses the processing laser beam 23 that has passed through the separating member 33 from the laser beam 21 emitted from the laser oscillator 31 and incident on the separating member 33 onto the workpiece 100.

[0040] In the laser light irradiation unit 20 of the embodiment shown in Figure 2, the light receiving unit 40 and the detection unit 50 are arranged inside the laser oscillator 30, but the present invention is not limited to this configuration. Figure 3 is a schematic diagram showing another schematic configuration example of the laser light irradiation unit 20-1. As shown in Figure 3, the laser light irradiation unit 20-1 differs from the laser light irradiation unit 20 of the embodiment in that it includes a laser oscillator 30-1 instead of the laser oscillator 30.

[0041] The laser oscillator 30-1 does not have a separation member 33, a light receiving unit 40, a detection unit 50, and a control unit 54 inside. That is, the laser beam irradiation unit 20-1 has a separation member 33, a light receiving unit 40, a detection unit 50, and a control unit 54 outside the laser oscillator 30-1. The separation member 33 separates the laser beam 21 emitted from the laser oscillator 30-1 into a laser beam 22 for inspection and a laser beam 23 for processing. The other components are the same as those of the laser beam irradiation unit 20 shown in Figure 2, so their description is omitted.

[0042] The light-receiving unit 40 in this embodiment includes a photodetector, but the present invention may further include a thermal sensor. Figure 4 is a schematic diagram showing another schematic configuration example of the light-receiving unit 40-1. The light-receiving unit 40-1 includes a thermal sensor 42 and a photodetector 43, which receive the laser beams 24 and 25 that have been branched by the branching mirror 41, respectively.

[0043] The branching mirror 41 branches the inspection laser beam 22 that has been separated by the separation member 33. The branching mirror 41 guides one branch of the laser beam 22 as laser beam 24 to the thermal sensor 42, and the other branch of the laser beam 22 as laser beam 25 to the photodetector 43. The branching mirror 41 is, for example, a reflective mirror that reflects about 99% of the laser beam 22. The branching mirror 41 reflects about 99% of the laser beam 22 and guides it as laser beam 24 to the thermal sensor 42, and transmits the remaining 1 percent or so to the photodetector 43.

[0044] The thermal sensor 42 receives one of the laser beams 24 that has been split by the branching mirror 41 and measures the average output of the laser beam 24. In this embodiment, the thermal sensor 42 receives the laser beam 24 that has been reflected by the branching mirror 41.

[0045] The photodetector 43 receives the other laser beam 25 that has been branched by the branching mirror 41 and acquires information about the pulse waveform of the laser beam 25. In this embodiment, the photodetector 43 receives the laser beam 25 that has passed through the branching mirror 41.

[0046] As shown in Figure 4, a focusing lens 44 and a wavelength-selective filter 45 are placed before the branching mirror 41. An ND filter 46 is also placed between the branching mirror 41 and the photodetector 43.

[0047] The focusing lens 44 focuses the inspection laser beam 22, separated by the separation member 33, toward the light-receiving surface of the photodetector 43. The laser beam 22 that has passed through the focusing lens 44 passes through the wavelength-selective filter 45, the branching mirror 41, and the ND filter 46, and is incident on the photodetector 43.

[0048] The wavelength-selective filter 45 is positioned in the optical path of the inspection laser beam 22 between the focusing lens 44 and the branching mirror 41. The wavelength-selective filter 45 is a filter that transmits only predetermined wavelengths of the inspection laser beam 22. The wavelength-selective filter 45 is, for example, a bandpass filter, a dichroic filter, a long-pass filter, or a short-pass filter, or a combination thereof. A bandpass filter is a filter that arbitrarily selects and transmits specific wavelengths. A dichroic filter is a filter that reflects light in a specific wavelength range and transmits light in the remaining wavelength range. A long-pass filter is a filter that transmits light with wavelengths longer than a predetermined wavelength. A short-pass filter is a filter that transmits light with wavelengths shorter than a predetermined wavelength. In this embodiment, the wavelength-selective filter 45 transmits only wavelengths that can be measured by the thermal sensor 42 and the photodetector 43.

[0049] The ND filter 46 reduces the amount of light from the laser beam 25, which is branched by the branching mirror 41, by a certain amount before transmitting it. This reduces the amount of light from the laser beam 25 that enters the photodetector 43.

[0050] Here, we will describe a method for automatically setting a threshold 93 for detecting pulse dropouts in a laser processing apparatus 1 equipped with a light receiving unit 40 having both a thermal sensor 42 and a photodetector 43. Figure 5 is a graph showing an example of the change in the average output of the laser light 24 received by the thermal sensor 42 shown in Figure 4. Figure 6 is a graph showing an example of the change in the output of the laser light 25 received by the photodetector 43 shown in Figure 4. In the example shown in Figures 5 and 6, the laser processing conditions are changed from the first processing condition 91 to the second processing condition 92 midway through the process.

[0051] The control unit 54 estimates the trend of the average output of the processing laser beam 23, as shown in Figure 5, based on the average output of the laser beam 24 acquired by the thermal sensor 42. As shown in Figure 5, the average output of the laser beam 23 is approximately constant while laser processing is being performed under the first processing condition 91. Similarly, the average output of the laser beam 23 is approximately constant while laser processing is being performed under the second processing condition 92. Furthermore, the average output of the laser beam 23 changes when transitioning from the first processing condition 91 to the second processing condition 92 (it decreases in one example shown in Figure 5).

[0052] Furthermore, the control unit 54 estimates the transition of the peak output of the laser beam 23 for processing based on waveform data, including the peak output of the laser beam 25, acquired by the photodetector 43 as shown in Figure 6. While laser processing is being performed under the first processing condition 91, the pulse waveform of the laser beam 23 is generally constant. Similarly, while laser processing is being performed under the second processing condition 92, the pulse waveform of the laser beam 23 is also generally constant. However, when transitioning from the first processing condition 91 to the second processing condition 92, the pulse waveform of the laser beam 23 changes (in one example shown in Figure 6, the peak value decreases).

[0053] The control unit 54 sets a value obtained by multiplying the average output of the laser beam 24 acquired by the thermal sensor 42 shown in Figure 5 by a predetermined coefficient as the pulse drop threshold 93 for the waveform data of the laser beam 25 acquired by the photodetector 43 shown in Figure 6. Therefore, the set threshold 93 changes at the timing when the average output of the laser beam 23 changes, that is, at the timing when transitioning from the first processing condition 91 to the second processing condition 92.

[0054] As described above, in the laser processing apparatus 1 according to the embodiment, a portion of the laser beam 21 is separated as inspection laser beam 22, and by receiving this laser beam 22, it is possible to simultaneously measure the intensity of the laser beam 22 and observe the pulse. In this method, a portion of the laser beam 21 is separated as detection laser beam 22, while the majority of the laser beam 21 is used as processing laser beam 23. This makes it possible to understand the state of the laser beam 21 while processing, thereby improving productivity.

[0055] For example, based on the trend of the average output and output of the detected laser beam 22, if these fall below a preset threshold, a decrease in the output of the processing laser beam 23 and pulse dropouts can be estimated. If the output of the laser beam 22 decreases or pulse dropouts are observed, processing can be stopped to avoid total loss of the workpiece 100. It is also possible to save various sensor values ​​before and after the moment an abnormality is observed as a log and use it for abnormality analysis. Here, various sensor values ​​include information such as voltage, current, and temperature applied to the optical elements inside the laser oscillator 30, and information such as temperature and humidity inside the optical box. Furthermore, by accumulating this data, it can be used to predict and prevent the occurrence of defects.

[0056] Furthermore, by detecting the average output and output trends of the laser beam 23 and automatically setting a threshold for detecting pulse dropouts based on the average output, this method can also be applied when processing conditions are changed during processing and the appropriate threshold changes.

[0057] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core of the present invention. For example, the control unit 54 may only output the information acquired by the detection unit 50, and the operator may determine whether the device is operating normally based on the output information. For example, the control unit 54 may only output a threshold for detecting pulse dropouts set based on the average output acquired by the thermal sensor 42, and waveform data acquired by the photodetector 43, and the operator may determine whether or not there are pulse dropouts based on the output information. [Explanation of Symbols]

[0058] 1. Laser processing device 10 Retention Table 20, 20-1 Laser beam irradiation unit 21, 22, 23, 24, 25 Laser light 30, 30-1 Laser Oscillator 31 Laser Oscillator 32 Focusing lenses 33 Separation member 40, 40-1 Light receiving section 41 Branching mirror 42 Thermal Sensors 43 Photo Detector 44 Focusing lenses 45 Wavelength Selective Filter 46 ND filter 50 detection units 51 Signal Amplification Section 52 Pulse waveform information acquisition unit 53 Light intensity information acquisition unit 54 Control Unit 91 First processing conditions 92 Second processing conditions 93 threshold 100 Workpiece

Claims

1. A laser processing device, A laser oscillator that generates laser light, A focusing lens that focuses the laser light generated by the laser oscillator, A separating member separates the laser beam generated by the laser oscillator into a laser beam for inspection and a laser beam for processing to focus onto the workpiece. A light receiving unit that receives the inspection laser light separated by the separating member, A detection unit that acquires information regarding the intensity of the laser light and information regarding the pulse waveform of the laser light from the laser light received by the light receiving unit, A control unit that outputs the information acquired by the detection unit, Equipped with, The information regarding the pulse waveform of the laser light acquired by the detection unit includes information regarding the presence or absence of pulse dropouts. The control unit is characterized by automatically setting a threshold for detecting pulse dropouts based on the average output of the laser light. Laser processing equipment.

2. The separation member further comprises a branching mirror for branching the inspection laser light that has been separated by the separation member, The light receiving unit is, A thermal sensor that receives one of the laser beams split by the branching mirror and measures the average output of the laser beam, A photodetector that receives the other laser beam branched by the branching mirror and acquires information about the pulse waveform of the laser beam, A feature having The laser processing apparatus according to claim 1.

3. The thermal sensor receives the laser light reflected by the branching mirror, The photodetector is characterized by being arranged to receive laser light that has passed through the branching mirror. The laser processing apparatus according to claim 2.

4. The invention is characterized by arranging an ND filter between the branching mirror and the photodetector. The laser processing apparatus according to claim 3.

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