JP2008016679A - Laser equipment, laser machining device, and dust removing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove dust in a chamber. <P>SOLUTION: In a laser equipment, a preset laser gas is guided into a chamber, and laser beam is emitted by discharging an electrode, with a dust results from it being removed. The laser equipment comprises a laser gas guiding means for guiding the laser gas into the chamber, a purge gas guiding means for guiding a purge gas consisting of inert gas that is heavier than the laser gas into the chamber, a blower for circulating the laser gas and the purge gas in the chamber, and a gas exhausting means for exhausting the laser gas and the purge gas out of the chamber for resolving issues. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser device, a laser processing device, and a dust removal method, and more particularly, to a laser device, a laser processing device, and a dust removal method for efficiently removing dust in a chamber.

  2. Description of the Related Art Conventionally, in a discharge type gas laser apparatus, a laser gas is sealed in a container (chamber), and a laser beam is generated by being discharged by an electrode therein. For example, in the case of an excimer laser device used for industrial purposes, an ionized gas is generated between a pair of main electrodes by a mechanism that causes preliminary ionization in a gas enclosed in a chamber, Light generated when an atom excited by a discharge between main electrodes applied with a high voltage returns to the original atom is extracted and used as laser light.

  Here, the surface of the electrode described above is scraped by the influence of evaporation due to an instantaneous temperature rise, sputtering due to discharge, and the like. Moreover, since the electrode is generally made of metal, it reacts with, for example, a halogen gas in an excimer laser gas to generate metal halide dust.

  Dust in the laser device causes a decrease in output and stability due to a decrease in the transmittance of laser light due to absorption of laser gas and adhesion to the window material, insulation failure due to adhesion to the inner wall of the chamber, and the like. That is, since dust generated by sputtering due to discharge deteriorates the laser performance, the laser apparatus needs to clean the chamber periodically to remove the dust.

  In general, dust is discharged together with laser gas during maintenance such as laser gas exchange.However, dust that adheres to and accumulates on the inner wall of the chamber and the components provided in the chamber, such as electrodes, heat exchangers, and blowers, It cannot be completely removed and remains. In view of this, there has been proposed a method of removing dust by providing a gas blowing mechanism for blowing purge gas or the like in the chamber to blow (see, for example, Patent Document 1).

In Patent Document 1, a blowing port for blowing purge gas toward the heat exchanger installed in the laser chamber is provided, and a suction port for sucking the purge gas blown to the opposite side across the heat exchanger Is provided.
JP-A-6-252481

  However, according to the above-described prior art, in order to blow the entire chamber including the components other than the heat exchanger, a plurality of air outlets are required or a large number of pipes or the like must be routed. Don't be. Further, in order to realize the above-described configuration, it is necessary to provide a mechanism such as a compressor. Therefore, it is necessary to prepare a laser device having a special specification in consideration of durability, which is expensive.

  As a chamber cleaning operation method, there is a disassembly cleaning method in which each chamber is disassembled and cleaned. In that case, at the time of cleaning, each chamber needs to be replaced with another chamber and transported to a well-equipped place for cleaning. Therefore, the cost is increased by the provision of the replacement chamber. In addition, there is a problem that it takes time including transportation time because dust that has adhered and accumulated in the chamber is cleaned manually or by a machine. Therefore, it is preferable that the laser apparatus improve the dust removal time and the removal efficiency in the chamber as much as possible.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a laser device, a laser processing device, and a dust removal method for efficiently removing dust in a chamber.

  In order to achieve the above-mentioned object, the present invention provides a laser apparatus for removing dust generated when a laser gas set in advance in a chamber is introduced and laser light is emitted by discharge of an electrode. Laser gas introduction means for introducing into the chamber, purge gas introduction means for introducing a purge gas made of an inert gas heavier than the laser gas into the chamber, a blower for circulating the laser gas and the purge gas in the chamber, and the laser gas And a gas exhaust means for exhausting the purge gas from the chamber. Thereby, the inert gas heavier than the laser gas is circulated in the chamber, so that the dust accumulated in the chamber or dust adhering to the inner wall of the chamber rises and is efficiently removed by exhausting the dust. it can. In addition, the maintenance interval can be extended and the chamber cleaning operation can be shortened, so that the operating rate of the laser device itself can be improved.

  Furthermore, in the laser apparatus, it is preferable that the blower has a higher speed than a wind speed for circulating the laser gas when the purge gas is introduced into the chamber. Thereby, the dust in the chamber can be efficiently lifted by increasing the wind speed.

  Further, the laser apparatus preferably includes a pressure measuring unit that measures the pressure in the chamber, and a gas control unit that controls introduction or discharge of the laser gas and the purge gas in the chamber. This makes it possible to more efficiently remove dust in the chamber at a pressure that can be withstood by the chamber in consideration of a pressure difference from the atmosphere.

  According to the present invention, in the laser processing apparatus, laser processing is performed on the object to be processed using the laser beam emitted from the laser apparatus according to any one of the first to third aspects. To do. Thereby, dust can be efficiently removed. In addition, the maintenance interval can be extended and the chamber cleaning operation can be shortened, so that the operating rate of the laser processing apparatus itself can be improved.

  According to another aspect of the present invention, there is provided a dust removal method for removing dust generated when a laser gas set in advance in a chamber is introduced and laser light is emitted by discharge of an electrode, from an inert gas heavier than the laser gas. A purge gas introduction step for introducing the purge gas into the chamber, a circulation step for circulating the purge gas with a blower in the chamber, and a gas exhaust step for exhausting the laser gas and the purge gas from the chamber. Features. Thereby, the inert gas heavier than the laser gas is circulated in the chamber, so that the dust accumulated in the chamber or dust adhering to the inner wall of the chamber rises and is efficiently removed by exhausting the dust. it can. In addition, the maintenance interval can be extended and the chamber cleaning operation can be shortened, so that the operating rate of the laser device itself can be improved.

  Further, it is preferable that the circulation step is performed at a speed higher than a wind speed for circulating the laser gas when the purge gas is introduced into the chamber. Thereby, the dust in the chamber can be efficiently lifted by increasing the wind speed.

  Furthermore, it is preferable to have a pressure measurement step for measuring the pressure in the chamber and a gas control step for controlling introduction or discharge of the laser gas and the purge gas in the chamber. This makes it possible to more efficiently remove dust in the chamber at a pressure that can be withstood by the chamber in consideration of a pressure difference from the atmosphere.

  According to the present invention, dust in the chamber can be efficiently removed.

  Hereinafter, embodiments in which a laser device, a laser processing device, and a dust removal method according to the present invention are suitably implemented will be described with reference to the drawings.

<Embodiment>
FIG. 1 is a cross-sectional view showing an example of a schematic configuration of a laser apparatus according to the present invention. A laser apparatus 10 shown in FIG. 1 includes a chamber 11, a laser gas inlet 12, a purge gas inlet 13, a blower 14, a dust collecting means 15, a main discharge electrode pair 16, and preliminary discharge electrode pairs 17a and 17b. The high voltage applying means 18, the ground 19, the heat exchanger 20, and the gas exhaust port 21 are configured.

  In addition, although the laser apparatus 10 demonstrates the laser apparatus which generates an excimer laser beam as an example, in this invention, the kind of laser beam which a laser apparatus oscillates is not limited to this.

  The chamber 11 is filled with a predetermined amount of laser gas inside and excited by discharge or the like to oscillate laser light. The laser gas inlet 12 introduces a laser gas for generating preset excimer laser light. As the laser gas to be introduced, for example, at least one gas or a mixed gas of rare gases such as argon, krypton, and xenon, halogen gases such as fluorine and hydrogen chloride, and diluted gases such as helium and neon are used. can do. The type of gas is not limited to this.

  The purge gas inlet 13 introduces an inert gas that is heavier (has a higher molecular weight) than the laser gas introduced from the laser gas inlet. An example of introducing purge gas will be described later.

  The blower 14 is a fan for gas circulation (blow), and is supported in the chamber 11 so as to rotate at a predetermined speed about an axis. Thereby, the gas in the chamber 11 is circulated at a predetermined wind speed in a predetermined direction (for example, an arrow direction in the chamber 11 shown in FIG. 1). The blower 14 introduces fresh laser gas introduced from the laser gas inlet 12 between the main discharge electrode pair 16 or between the preliminary discharge electrode pairs 17a and 17b.

  Further, when the purge gas is introduced into the chamber 11, the blower 14 is preferably set at a higher speed than the wind speed for circulating the laser gas. By increasing the wind speed when introducing the purge gas, the dust in the chamber can be efficiently raised.

  The dust collecting means 15 is a mechanism for removing the dust that has risen in the chamber 11. For example, a dust collecting filter (chemical filter or the like), an electric dust collector, a dust collector using magnetic force, or the like. Can be used. The dust collecting means 15 may not be provided in the chamber 11, and for example, a path for circulating gas may be provided outside, and the dust collecting means may be provided in the path.

  One of the main discharge electrode pair 16 and the preliminary discharge electrode pairs 17 a and 17 b is a discharge electrode, and the other is a ground electrode connected to the ground 19. Further, the main discharge electrode pair 16 and the preliminary discharge electrode pairs 17a and 17b discharge by applying a high voltage by the high voltage applying means 18 between the discharge electrode and the ground electrode. Further, the main discharge electrode pair 16 and the preliminary discharge electrode pairs 17a and 17b excite the laser gas introduced from the laser gas introduction port 12 by this discharge to generate laser light.

  Further, the heat exchanger 20 cools the temperature of the laser gas that has risen due to the discharge by the main discharge electrode pair 16 and the preliminary discharge electrode pairs 17a and 17b, and makes the temperature of the laser gas in the chamber 11 constant. The heat exchanger 20 may not be provided in the chamber 11. For example, a separate path for circulating the laser gas may be provided outside, and the temperature of the laser gas may be cooled by providing the heat exchanger 20 on the path. Good.

  Further, the gas exhaust port 21 exhausts the laser gas and purge gas circulated in the chamber 11. At this time, the dust that has risen into the chamber 11 according to the present invention is also discharged from the gas exhaust port 21 together with the gas. In the present invention, the diameter of the gas exhaust port 21 is made larger than that of the conventional exhaust port, the laser gas inlet 12 or the purge gas inlet 12. Thereby, the gas in the chamber 11 can be discharged instantly and more dust can be discharged.

  Next, a gas introduction / exhaust mechanism in the laser apparatus 10 described above will be specifically described. FIG. 2 is a diagram illustrating an example of a schematic configuration in introducing and discharging gas in the laser apparatus. Here, the inside of the laser apparatus 10 shown in FIG. 2 shows a configuration of the configuration shown in FIG. 1 viewed from the side. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The laser apparatus 10 shown in FIG. 2 includes a laser gas introduction means 31, a purge gas introduction means 32, a gas exhaust means 33, a valve 34, a pressure measurement means 35, and a gas control as a gas introduction / exhaust mechanism to the chamber 11. And means 36.

  The laser gas introduction means 31 opens and closes the valve 34-1 and introduces a predetermined amount of laser gas into the chamber 11 from a gas cylinder (not shown) in which laser gas for oscillating excimer laser light from the laser gas introduction port 12 is stored. Let

  Further, the purge gas introduction means 32 opens and closes the valve 34-2 to introduce a predetermined amount of inert gas heavier than the laser gas into the chamber 11 from the purge gas introduction port 13. Further, the gas exhaust means 33 opens and closes the valve 34-3 and exhausts the gas filling the chamber 11 from the gas exhaust port 21. The valves 34-1 to 34-3 can seal or open the chamber 11.

  The pressure measuring means 35 measures the pressure of the gas introduced by the laser gas introducing means 31 and the purge gas introducing means 32 and discharged by the gas exhausting means 33. Further, the pressure measuring means 35 outputs the measurement result to the gas control means 36.

  The gas control unit 36 controls the entire configuration of the laser device 10. Specifically, a predetermined amount of gas is introduced by the laser gas introduction unit 31 and the purge gas introduction unit 32 based on the measurement result obtained by the pressure measurement unit 35, and a predetermined amount of gas is discharged by the gas exhaust unit 33. Thereby, the inside of the chamber 11 can be set to a predetermined pressure with a predetermined gas. Further, the gas control unit 36 performs processing such as rotating the blower 14 at a predetermined speed to circulate the gas in the chamber 11 or discharging the electrodes 16 and 17 to oscillate laser light.

  The laser light causes laser oscillation by an optical resonator that includes optical windows 41 a and 41 b provided in the chamber 11 and a total reflection mirror 42 and a partial reflection mirror 43 provided outside the chamber 11. The laser beam is output from the partial reflection mirror 43.

<Purge gas introduction example>
Here, an example of introducing purge gas in the present invention will be specifically described. The dust in the chamber 11 is in the form of powder, and can be broadly divided into those floating in the chamber 11 and those deposited and adhered. At this time, the accumulated dust adheres to the inside of the chamber 11 where the laser gas is circulated by the blower and is not discharged from the gas discharge port 21. This is because the wind power of the blower is insufficient and the attached dust cannot be removed because it is light even when the laser gas molecules collide with the attached dust.

  Therefore, in the present invention, an inert gas heavier than the laser gas (having a higher molecular weight) is introduced into the chamber 11. In addition, as purge gas in this invention, argon, krypton, etc. can be used, for example.

  When introducing the purge gas, the chamber 11 is filled with, for example, about 0.1 Mpa of purge gas. In the present invention, the pressure is not limited to this, and it is better to increase the pressure. However, considering the resistance in the chamber and the difference from the atmospheric pressure, it is preferable to set the pressure to about 0.1 to 1.0 MPa.

  Further, the pressure of the chamber 11 in the present invention is appropriately adjusted depending on the volume in the chamber 11, the heat exchanger, the arrangement of the electrodes, etc., but is at least equal to the density of the laser gas introduced to oscillate the laser beam. Is preferred.

  In the present invention, the purge gas may be circulated for about 1 hour at a pressure of about 0.1 Mpa, for example. These pressures are measured by the pressure measuring means 35 for measuring the pressure in the chamber 11, and the amount of purge gas introduced by the purge gas introducing means 32, the pressure, and the blower 14 are obtained by the gas control means 36 that acquires the measurement result. Wind speed, circulation time, etc. are controlled.

  Further, it is preferable that a gas line for introducing the purge gas is separately provided in addition to the normal laser gas introduction line as described above. As a result, the laser gas and the purge gas can be easily controlled, and unintended gas mixing can be prevented and the gas components can be maintained.

  Further, it is preferable that the wind speed of the purge gas in the chamber 11 by the blower 14 is as high as possible. Furthermore, in the present invention, since the purge gas is heavier than the laser gas, for example, a plurality of blowers may be installed in the chamber 11 or the rotational speed may be increased several times. As a result, it is possible to raise the deposited or adhered dust that could not be removed by the laser gas.

  In this way, when dust is in a state of floating in the chamber 11, the dust collecting means 15 such as a dust filter can be easily taken. Further, dust can be discharged to the outside by exhausting from the gas exhaust port 21 having a large diameter at once.

  Moreover, it is preferable that the above-described dust removal method by introducing and discharging the purge gas is periodically executed before the cleaning operation or at a period earlier than that. By performing the dust removal operation described above, dust accumulated in the chamber 11 or adhered to the inner wall of the chamber 11 causes the gas in the chamber to circulate through the blower for circulating the laser gas at a predetermined speed and time, so that the dust rises. By exhausting, it can be removed out of the chamber, and the amount of dust in the chamber 11 can be reduced.

  Therefore, the amount of dust in the chamber 11 can be reduced by performing the above-described dust removal processing of the laser apparatus before or periodically during a cleaning operation in maintenance or the like. In addition, the maintenance interval can be extended and the chamber cleaning operation can be shortened, so that the operating rate of the laser device itself can be improved.

<Application example of laser device>
Next, a laser processing apparatus to which the above-described laser apparatus is applied will be described with reference to the drawings. FIG. 3 is a diagram illustrating an example of a schematic configuration of a laser processing apparatus to which the laser apparatus according to the present invention is applied. A laser processing apparatus 50 shown in FIG. 3 is configured to include the laser apparatus 10 described above, a reflection mirror 51, a beam forming optical system 52, a stage driving unit 53, a stage 54, and a control unit 55. .

  The laser device 10 performs laser beam at a predetermined timing based on each irradiation condition such as the frequency and power of the laser beam obtained from the control means 55, the number of shots, the pulse width, the irradiation timing, and the irradiation position. Irradiate. Further, the laser apparatus 10 outputs an irradiation completion signal to the control means 55 after irradiating the laser beam based on the set irradiation condition.

  The reflection mirror 51 guides the laser light emitted from the laser device 10 in the direction of a predetermined processing target 56. Further, the beam forming optical system 52 forms the laser beam from the input reflection mirror 51 into a predetermined shape and outputs it to the workpiece 56.

  Based on the stage movement information obtained from the control means 55, the stage driving means 53 has a predetermined height (Z direction) corresponding to the machining conditions of the stage 54 on which the workpiece 56 to be laser machined is placed and the stage 54. / Or move to a position on the plane (XY direction). Further, the stage driving unit 53 outputs a movement completion signal to the control unit 55 when the movement of the stage 54 is completed.

  The control means 55 controls the entire configuration of the laser processing apparatus 50. Specifically, each piece of control information (irradiation conditions, stage movement information, etc.) for processing the processing target 56 is generated, and control information corresponding to each of the corresponding laser device 10 and stage driving means 53 is generated. Output.

  Further, the control means 55 generates control information for performing dust removal in the present invention and outputs it to the laser apparatus 10. The laser device 10 outputs the dust removal completion signal to the control means 55 after performing the dust removal described above according to the control information for removing the dust.

  By using the laser processing apparatus 50 described above, it is possible to perform predetermined processing on the processing object 56. The laser processing apparatus according to the present invention can be applied to general laser processing such as drilling, welding, cutting, and annealing of a workpiece.

  Thus, by applying the laser device according to the present invention to the laser processing device, the dust removal time and removal efficiency in the chamber can be improved. In addition, the maintenance interval can be extended and the chamber cleaning operation can be shortened, so that the operating rate of the laser processing apparatus itself can be improved.

  As described above, according to the present invention, dust in the chamber can be efficiently removed. Specifically, by circulating the gas in the chamber with a purge gas heavier than the laser gas, more dust deposited in the chamber or adhering to the inner wall of the chamber can be peeled off, and can be raised in the gas. Therefore, by exhausting this dust, more dust can be exhausted out of the chamber. In addition, the maintenance interval can be extended and the chamber cleaning operation can be shortened, so that the operating rate of the laser device itself can be improved. Therefore, costs such as labor costs can be reduced.

Note that the laser device described above can be applied to a pulse discharge type gas laser device. For example, laser light output from the laser device is used for laser processing such as a CO ₂ laser in addition to the excimer laser described above. The present invention can be applied to all types of laser devices.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Can be changed.

It is sectional drawing which shows an example of schematic structure of the laser apparatus in this invention. It is a figure which shows an example of schematic structure in introduction and discharge | emission of the gas of a laser apparatus. It is a figure which shows an example of schematic structure of the laser processing apparatus to which the laser apparatus in this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laser apparatus 11 Chamber 12 Laser gas inlet 13 Purge gas inlet 14 Blower 15 Dust collection means 16 Main discharge electrode pair 17 Preliminary discharge electrode pair 18 High voltage addition means 19 Ground 20 Heat exchanger 21 Gas exhaust port 31 Laser gas introduction means 32 Purge gas Introduction means 33 Gas exhaust means 34 Valve 35 Pressure measuring means 36 Gas control means 41 Optical window 42, 43, 51 Reflection mirror 50 Laser processing device 52 Beam forming optical system 53 Stage drive means 54 Stage 55 Control means 56 Work object

Claims (7)

In a laser apparatus for removing dust generated when a laser gas set in advance in a chamber is introduced and laser light is emitted by discharge of an electrode,
Laser gas introduction means for introducing the laser gas into the chamber;
Purge gas introduction means for introducing a purge gas made of an inert gas heavier than the laser gas into the chamber;
A blower for circulating the laser gas and the purge gas in a chamber;
And a gas exhaust unit for exhausting the laser gas and the purge gas from the chamber. The blower is
The laser apparatus according to claim 1, wherein when the purge gas is introduced into the chamber, the laser speed is higher than a wind speed for circulating the laser gas. Pressure measuring means for measuring the pressure in the chamber;
The laser apparatus according to claim 1, further comprising a gas control unit that controls introduction or discharge of the laser gas and the purge gas in the chamber.   The laser processing apparatus which laser-processes to a process target object using the laser beam radiate | emitted from the laser apparatus of any one of the said Claim 1 thru | or 3. In a dust removing method for removing dust generated when a laser gas set in advance in a chamber is introduced and laser light is emitted by discharging an electrode,
A purge gas introduction step for introducing a purge gas made of an inert gas heavier than the laser gas into the chamber;
A circulation step for circulating the purge gas by a blower in the chamber;
And a gas exhausting step of exhausting the laser gas and the purge gas from the chamber. The circulation step includes
6. The dust removal method according to claim 5, wherein when the purge gas is introduced into the chamber, the purge gas is set at a higher speed than a wind speed for circulating the laser gas. A pressure measuring step for measuring the pressure in the chamber;
The dust removal method according to claim 5, further comprising a gas control step for controlling introduction or discharge of the laser gas and the purge gas in the chamber.

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