JP7286254B2 - Laser processing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laser processing apparatus for drilling holes by irradiating a laser onto a printed circuit board, for example.

In recent years, as a laser processing apparatus, there is a problem that dust in the air adheres to an optical component such as a reflecting mirror provided inside. Therefore, for example, as shown in Japanese Patent Application Laid-Open No. 2002-200313, a technique is disclosed in which dry air is blown onto a reflecting mirror during transmission of a laser beam to prevent dust from adhering to the reflecting mirror.

However, in the method disclosed in Patent Document 1, since dry air is always blown, certain types of laser (for example, UV laser) fluctuate the laser beam and change the hole shape, resulting in machining. Poor quality. In addition, the risk of failure of the air supply mechanism is high and the life of the mechanism is shortened. Further, when the air supply mechanism fails during the machining operation, it is necessary to stop the machining operation, but Patent Document 1 does not mention stopping the machining operation. Furthermore, there is no mention of restarting the machining operation when the machining operation is stopped.

JP-A-62-003894

Therefore, the present invention secures processing quality and reduces the risk of failure of an air supply mechanism for removing dust adhering to optical components to extend the life of the mechanism. To provide a user-friendly laser processing apparatus that can quickly interrupt a processing operation when it cannot be maintained and then automatically restart the processing operation.

Among the inventions disclosed in the present application, a typical laser processing apparatus includes a scanner unit that scans a substrate with a laser beam in a two-dimensional direction, and a laser for guiding the laser beam emitted from a laser oscillator to the scanner unit. In a laser processing apparatus having a plurality of optical components for sequentially passing light and a controller for controlling processing operations using laser light, a part of the laser light passing through at least one of the optical components is received and an electrical signal is received. , a nozzle for blowing gas onto the at least one optical component, and a gas supply mechanism for supplying the gas to the nozzle, wherein the controller controls the electrical signal from the photodetector to be a threshold When the following conditions are met, the processing operation is stopped, the at least one optical component is sprayed with gas from the nozzle, and after the spraying is completed, when the electrical signal from the photodetector exceeds the threshold value, the It is characterized by controlling to restart the machining operation.

The typical features of the invention disclosed in the present application are as described above, but the features not described here are described in the detailed description below, and also in the claims. It is as shown also in the range.

According to the present invention, the machining quality is ensured, the risk of failure of the air supply mechanism is reduced, and the life of the air supply mechanism is lengthened. It is possible to obtain a user-friendly laser processing apparatus that automatically restarts the processing operation after that.

It is a figure for demonstrating the structure of the laser unit of the laser processing apparatus which concerns on one Example of this invention. It is a figure for demonstrating the compressor of the laser processing apparatus which concerns on one Example of this invention. It is a figure which shows the structure of the laser processing apparatus based on one Example of this invention. 4 is a flow chart for explaining the operation of the laser processing apparatus according to one embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described along with examples with reference to the drawings. note that,
In the following description, the same reference numerals are assigned to equivalent parts, and description thereof is omitted.

FIG. 3 is a diagram showing the structure of a laser processing apparatus according to one embodiment of the present invention. Numeral 1 denotes a laser unit provided with a plurality of optical components inside for irradiating a scanner unit 3 with a laser beam L1. A telescopic duct 2 is provided to prevent entry into the interior of 3. The expandable duct 2 expands and contracts as the scanner unit 3 moves in the Z direction. The scanner unit 3 is provided with a pair of galvanometer scanners and a condenser lens (not shown), and the substrate 4 is scanned two-dimensionally with the emitted laser light L2.

Reference numeral 4 denotes a substrate to be processed, and 5 denotes a table on which the substrate 4 is placed. The table 5 can be moved relative to the laser unit 1 and the scanner unit 3 by moving in the X and Y directions in the figure. The substrate 4 is divided into processing areas determined based on the practical diameter of the condensing lens. After finishing processing in one processing area, the table 5 is moved horizontally to move the center of the next processing area. It is positioned on the central axis of the condensing lens. Reference numeral 6 denotes a control section for controlling the operation of each section such as the laser unit 1, the scanner unit 3, the table 5, etc., and is realized by, for example, a program-controlled processing device.

FIG. 1 is a diagram for explaining the structure of a laser unit 1 according to one embodiment of the invention, and FIG. 2 is a diagram for explaining a compressor of the laser unit 1 according to one embodiment of the invention. The same numbers are given to the same parts as in FIG. 3, and only the parts necessary for explaining the embodiment of the present invention are shown.

Inside the laser unit 1 , the laser beam emitted from the laser oscillator 7 is guided to the scanner unit 3 after passing through an optical system composed of a plurality of optical components that pass sequentially. The optical system here includes a mirror 8 that reflects the laser beam L3 emitted from the laser oscillator 7, a mirror 9 that reflects the laser beam L3 reflected by the mirror 8, and a damper 10 that reflects the laser beam L3 reflected by the mirror 9. Acousto-optic element 11 that deflects laser light L4 for non-processing and laser light L5 for processing that is absorbed by acousto-optic element 11, beam diameter adjustment lens 12 that receives laser light L5 deflected by acousto-optic element 11, beam diameter adjustment A splitter 13 that splits part of the processing laser beam L5 from the lens 12 and a transmission plate 14 that prevents dust from entering the laser unit 1 from the outside are included. Note that the laser unit 1 constitutes a container housing the optical system, the laser oscillator 7, and the like.
In addition, the beam diameter adjusting lens 12 is shown as a single lens, but it is actually composed of a plurality of lenses.

A laser beam L1 that has passed through the transmission plate 14 in the laser unit 1 is incident on the scanner unit 3 via the expansion duct 2 . A blower 15 blows outside air into the laser unit 1 and is always in operation while the power of the apparatus is turned on. A filter 16 removes dust from outside air that is blown into the laser unit 1 by the blower 15 .
It should be noted that the external air that flows in from the blower 15 has a wind pressure that does not cause the laser light to fluctuate even if it is blown against the optical components. An exhaust port 17 is connected to a dust collector (not shown) to exhaust the gas in the laser unit 1 to the outside. Therefore, the inside of the laser unit 1 is kept at a positive pressure to prevent dust from entering from the outside.

A compressor 18 sends out dry air from which water and oil are removed from the outside air around the laser unit 1 . A solenoid valve 19 controls the flow rate of dry air from the compressor 18 to the pipe 20 . A nozzle 21 is for blowing dry air onto the mirrors 8 and 9, the acoustooptic element 11, the beam diameter adjusting lens 12, the splitter 13 and the transmission plate .
The nozzle 21 serves as the laser light reflecting surface of the mirrors 8 and 9, the laser light input/output surface of the acousto-optic element 11, the laser light input/output surface of the beam diameter adjusting lens 12, the laser light input/output surface of the splitter 13, and the laser light of the transmission plate 14. An exit port is provided facing each of the light incident surfaces, and dry air is blown from the pipe 20 by opening the electromagnetic valve 19 .
Here, the compressor 18, the solenoid valve 19 and the pipe 20 constitute an air supply mechanism to the nozzle 21. As shown in FIG. Although dry air is blown onto the optical system here, nitrogen gas may be blown instead of dry air.

A photodetector 22 receives the laser beam L6 split by the splitter 13, converts the received laser beam L6 into an electrical signal, and outputs the signal to the control unit 6. The photodetector 22 comprises, for example, a photodiode. be done.
The controller 6 compares the signal input from the photodetector 22 with the threshold. If dust adheres to any one of the mirrors 8 and 9, the acousto-optic element 11, the beam diameter adjustment lens 12, or the splitter 13, the light intensity detected by the photodetector 22 is weakened. When the control unit 6 determines that the value is equal to or less than the threshold value, the emission of the laser beam L3 from the laser oscillator 7, the deflection of the acousto-optic device 11, and the driving of the scanner unit 3 and the table 5 are stopped to stop processing. Dry air is blown from a nozzle 21. - 特許庁
Note that the threshold serves as a boundary as to whether or not the processing quality can be guaranteed, and is obtained by experiments in advance prior to processing.

FIG. 4 is a flow chart for explaining the operation of the laser processing apparatus according to one embodiment of the present invention. Laser processing is performed by the following processing steps described in the flow chart.
Step 401: A laser beam L3 is emitted from the laser oscillator 7. FIG.
Step 402: The laser beam L3 is deflected in the processing direction by the acousto-optic element 11 and made incident on the beam diameter adjusting lens 12 as the laser beam L5. Also, the laser beam L6 from the splitter 13 is received by the photodetector 22, and it is determined whether the signal from the photodetector 22 is below the threshold. Transition. If the signal from photodetector 22 is greater than the threshold, go to step 406 .
Step 403: An alarm is issued to stop the emission of the laser beam L3 from the laser oscillator 7, the deflection of the acoustooptic device 11, and the driving of the scanner unit 3 and the table 5, thereby stopping the machining operation.

Step 404: Open the electromagnetic valve 19 and blow dry air from the compressor 18 onto the mirrors 8 and 9, the acoustooptic element 11, the beam diameter adjusting lens 12, the splitter 13 and the transmission plate .
Step 405: After finishing the spraying, continue to stop the processing for several minutes (preferably about 3 minutes) until the dust that has risen up in the laser unit 1 is exhausted. It should be noted that even if the machining operation is stopped, the blower 15 is still in operation, so the air is exhausted. After finishing the continuation of the machining stop, the process moves to step 401 again.
Step 406: Deflect the acoustooptic device 11, drive the galvano unit 3 and the table 5, and perform the processing operation of the substrate 4. FIG.
Step 407: Determine the end of machining by determining whether there are any other holes to be machined. If there are no more holes to be machined, end the machining operation. .

According to the above embodiment, since the dry air is blown onto the optical parts after the laser beam has stopped being emitted from the laser oscillator, it is possible to prevent the fluctuation of the laser beam and ensure the processing quality. becomes. In addition, since dust adhering to the optical parts is removed only when necessary, the load on the air supply mechanism can be reduced, and the life of the air supply mechanism can be extended. Furthermore, dust adheres to any of the mirrors 8 and 9, the acousto-optic element 11, the beam diameter adjustment lens 12, or the splitter 13, and the intensity of the laser beam emitted to the scanner unit becomes so weak that the processing quality cannot be guaranteed. Immediately interrupt the machining operation when the machining quality cannot be maintained. Therefore, it is possible to prevent the processing failure from spreading, and the processing operation is automatically restarted after the dust adhering to the optical component is removed, so that a user-friendly laser processing apparatus can be obtained.

Although the present invention has been described above based on the embodiments, it goes without saying that the present invention is not limited to the embodiments, and various modifications can be made without departing from the scope of the invention. is included.

1: Laser unit 2: Expansion duct 3: Scanner unit 4: Substrate 5: Table 6: Control unit 7: Laser oscillator 8, 9: Mirror 10: Damper 11: Acoustooptic device 12: Beam diameter adjustment lens 13: Splitter 14: Transmission plate 15: Blower 16: Filter 17: Exhaust port 18: Compressor 19: Solenoid valve 20: Piping 21: Nozzle 22: Photodetector

Claims (3)

A scanner unit that scans a substrate with a laser beam in two-dimensional directions, a plurality of optical components that sequentially pass the laser beam to guide the laser beam emitted from a laser oscillator to the scanner unit, and a processing operation using the laser beam. In a laser processing device having a control unit that controls
a photodetector that receives a portion of the laser light passing through at least one of the optical components and converts it into an electrical signal;
a nozzle for blowing gas onto the at least one optical component;
a gas supply mechanism that supplies gas to the nozzle,
The control unit stops the processing operation when the electric signal from the photodetector becomes equal to or less than a threshold value, blows gas from the nozzle onto the at least one optical component, and after the blowing is completed, the A laser processing apparatus, wherein control is performed to restart the processing operation when an electrical signal from a photodetector exceeds a threshold value. In the laser processing apparatus according to claim 1,
The optical component is housed inside the housing,
a blower that allows outside air to flow into the interior of the housing through a filter provided in the housing;
an exhaust port provided in the container for exhausting outside air that has flowed into the container to the outside of the container;
A laser processing device comprising: In the laser processing apparatus according to claim 1 or 2,
a nozzle for blowing gas to each of the optical components through which the laser beam passes before being incident on the at least one optical component;
The control unit stops the processing operation when the electric signal from the photodetector becomes equal to or less than a threshold value, and controls each of the at least one optical component and the optical component that passes before being incident on the optical component. A laser processing apparatus characterized in that it is controlled so that the gas is blown from the nozzle to the.

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