TWM622708U - Laser apparatus - Google Patents

Abstract

[Subject] The present invention provides a laser device capable of maintaining a stable beam profile. [Solution] Optical parts are arranged in the beam path through which the laser beam passes. The blower creates an atmospheric flow in the space containing the optical components inside.

Description

Laser device

This new type relates to a laser device.

There is known a laser beam transmission channel in which a non-absorptive gas is filled in an airtight laser beam transmission channel main body (Patent Document 1). The transmission path body disclosed in Patent Document 1 has a shape along the propagation path of the laser beam and is airtight. An inlet of the non-absorbable gas is arranged near the starting point of the conveying passage body, and an outlet is arranged near the end point. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 59-206804

[The new problem to be solved]

Generally, when a laser beam is used for drilling processing of printed wiring boards, etc., a beam profile adjustment mechanism such as a lens and an aperture is arranged in the path of the laser beam. It is difficult to arrange these beam profile adjustment mechanisms to adjust the optical axis inside the airtight transmission channel main body. According to the experiments of the present inventors and others, it has been found that a stable beam profile may not be obtained when the propagation path of the laser beam is an open space without airtightness.

The purpose of the present invention is to provide a laser device capable of maintaining a stable beam profile. [Means of Solving Problems]

According to an aspect of the present invention, a laser device is provided, which has: Optical components disposed in the beam path through which the laser beam passes; and The blower generates air flow in the space containing the optical components. [new effect]

By setting the space included in the inside of the optical component into an atmospheric state, since it is not necessary to maintain airtightness, the optical axis adjustment of the optical component can be easily performed. In addition, by generating atmospheric flow, the beam profile can be stabilized temporally.

Referring to FIGS. 1 to 3B , the laser device according to the embodiment will be described. FIG. 1 is a schematic diagram of a laser device according to an embodiment. The laser oscillator 10 outputs a laser beam. As the laser oscillator 10 , a laser oscillator that outputs a laser beam in a wavelength region that is not substantially absorbed by the atmosphere, such as a carbon dioxide laser oscillator, can be used.

Optical components such as a beam expander 11 , mirrors 12 , 14 , 16 , an aperture 13 , and a branch optical system 15 are arranged on the beam path of the laser beam output from the laser oscillator 10 . The beam expander 11 changes the beam diameter and divergence angle of the laser beam output from the laser oscillator 10 . The laser beam passing through the beam expander 11 is reflected by the mirror 12 and then enters the aperture 13 . The aperture 13 shapes the beam profile of the laser beam. The laser beam that has passed through the aperture 13 is reflected by the mirror 14 to enter the branch optical system 15 . The beam path from the laser oscillator 10 to the branch optical system 15 is almost parallel to the horizontal plane.

The branch optical system 15 branches the incident laser beam into two beam paths. As the branch optical system 15, a half mirror, a polarizing beam splitter, or the like can be used.

A part of the laser beam incident on the mirror 12 passes through the mirror 12 and enters the photodetector 19 . The photodetector 19 outputs an electrical signal corresponding to the light intensity of the incident laser beam. The detection result detected by the photodetector 19 is used for feedback to the laser oscillator 10 , confirmation of the normality of the operation of the laser oscillator 10 , and the like, for example.

The laser beam branched by the branch optical system 15 and propagated through one of the beam paths (beam path toward the downward direction) is incident on the object 20A via the beam scanner 17A and the lens 18A. The laser beam propagating on the other beam path (the beam path in the horizontal direction) is reflected downward by the mirror 16 and then enters the object 20B through the beam scanner 17B and the lens 18B. The beam scanners 17A and 17B include, for example, a pair of galvanometer mirrors, and have the function of scanning the pulsed laser beam in two-dimensional directions. The lenses 18A and 18B condense the pulsed laser beams on the surfaces of the objects 20A and 20B, respectively. Moreover, you may comprise so that the aperture 13 may be imaged on the surfaces of the objects 20A and 20B.

The objects to be processed 20A and 20B are, for example, printed wiring boards, and are held on the holding surface of the stage 21 . For example, drilling is performed by injecting a pulsed laser beam into a printed wiring board. The holding surface of the stage 21 is, for example, horizontal. The stage 21 can move the objects 20A and 20B to be processed in two directions in the horizontal plane. As the stage 21, for example, an XY stage can be used.

The blower 30 generates air flow in a space including optical components such as the beam expander 11 , mirrors 12 , 14 , 16 , the aperture 13 , the branch optical system 15 , and the photodetector 19 . As the blower 30, for example, a fan can be used. Thereby, atmospheric flow is generated in the beam path and the space containing the optical components.

2A and 2B are a schematic front view and a schematic plan view of the laser device according to the present embodiment, respectively.

The optical base 25 and the stage 21 are supported by the base 26 . Optical components such as the beam expander 11 , the mirrors 12 , 14 , 16 , the aperture 13 , the branch optical system 15 , and the photodetector 19 are supported on the optical base 25 . The beam scanners 17A and 17B and the lenses 18A and 18B are supported under the optical base 25 . The blower 30 generates air flow in the space where the optical components are arranged on the optical base 25 .

Next, the excellent effect obtained by using the structure of the laser apparatus based on the said Example is demonstrated.

In the above embodiment, optical components such as beam expander 11, mirrors 12, 14, 16, aperture 13, branch optical system 15, and photodetector 19 are arranged in the space on optical base 25 (FIG. 2A, FIG. 2B). The space is open to the atmosphere without ensuring airtightness. Therefore, compared with the structure which arrange|positions an optical component in the space with high airtightness, adjustment of the optical axis of various optical components, etc. can be performed easily.

Next, with reference to FIGS. 3A and 3B , the excellent effect obtained by generating the air flow will be described.

FIG. 3A is a grayscale diagram and a graph showing the measurement result of the beam profile at the position of the photodetector 19 of the laser apparatus of the present embodiment. The graphs on the left and the lower side of the grayscale graph represent the beam profiles along the vertical and horizontal lines, respectively, passing through the center of the beam profile. In this embodiment, the beam profile shown in FIG. 3A is obtained with temporal stability.

FIG. 3B is a grayscale diagram and a graph showing the beam profile measured in a state where no atmospheric flow is generated and the atmosphere in the space where the optical components are arranged is almost still. Between the beam profile shown on the left side of FIG. 3B and the beam profile shown on the right side, the beam profile varies with the time results.

As can be seen from the measurement results shown in FIGS. 3A and 3B , the beam profile can be stabilized by generating atmospheric flow in the space where the optical components are arranged. According to various evaluation experiments by the inventors of the present application, it has been found that a sufficient effect of stabilizing the beam profile cannot be obtained when the wind speed is 0.2 m/s or less. In addition, it was found that in order to obtain a sufficient effect of stabilizing the beam profile, it is preferable to set the wind speed to 0.5 m/s or more.

Next, the reason why the beam profile can be stabilized by generating atmospheric flow is studied. The atmosphere in the beam path is slightly heated by the laser beam. At this time, when the atmosphere is stagnant, the temperature of the beam path rises significantly, and density fluctuations occur in the atmosphere. Along with this, the refractive index of light also changes. The beam profile is considered to be temporally and spatially unstable due to the influence of the refractive index distribution throughout the entire beam path. If the atmospheric flow is generated in this embodiment, it is considered that the fluctuation of the atmosphere caused by the local temperature rise of the beam path will disappear, and the temporal stability of the beam profile will be improved.

Next, referring to FIG. 4 , a laser device based on another embodiment will be described. Hereinafter, the description of the configuration common to the configuration of the laser device based on the embodiment shown in FIGS. 1 to 2B is omitted.

FIG. 4 is a perspective view of an optical chamber of the laser device according to the present embodiment. The cover 27 covers the space in which the optical components on the optical base 25 are accommodated. For example, in a plan view, the cover case 27 includes: a side wall, which surrounds the space in which the optical components are accommodated; and a top plate, which blocks the upper part of the side wall. A blower 30 is attached to the side wall of the cover case 27 . A filter is attached to the air inlet of the blower 30 . An opening 31 is provided on the side wall at a position opposite to the side wall on which the blower 30 is mounted.

The blower 30 introduces the outside air into the optical chamber surrounded by the cover case 27 . The atmosphere introduced into the optical chamber flows in the optical chamber and flows out through the opening 31 to the outside. As described above, the blower 30 has a function of ventilating the inside of the optical chamber surrounded by the cover case 27 .

Next, the excellent effect obtained by using the structure of the laser apparatus based on the Example shown in FIG. 4 is demonstrated. In the embodiment shown in FIG. 4 , by removing the cover 27 from the optical base 25 , the optical axis adjustment of the optical components can be easily performed. In addition, the invasion of dust into the optical chamber in which the optical components are arranged can be suppressed.

The above-described embodiments are examples, and it goes without saying that partial replacement or combination of the configurations shown in different embodiments can be performed. The same functions and effects of the same configuration based on a plurality of embodiments are not described in each embodiment. In addition, the present invention is not limited to the above-mentioned embodiments. For example, it is obvious to those having ordinary knowledge in the technical field to which the present invention pertains that various changes, improvements, combinations and the like can be made.

10: Laser oscillator 11: Beam Expander 12: Reflector 13: Orifice 14: Reflector 15: Branch Optical System 16: Reflector 17A, 17B: Beam Scanner 18A, 18B: Lenses 19: Photodetector 20A, 20B: object to be processed 21: Carrier 25: Optical seat 26: Pedestal 27: cover shell 30: Blower 31: Opening

[ Fig. 1] Fig. 1 is a schematic diagram of a laser device according to an embodiment. 2A and 2B are a schematic front view and a schematic plan view of the laser device based on the embodiment shown in FIG. 1 , respectively. [ Fig. 3] Fig. 3A is a grayscale diagram and a graph showing a measurement result based on the beam profile in the position of the photodetector of the laser device of the embodiment shown in Fig. 1 , and Fig. 3B is a graph showing a situation where no atmospheric flow is generated. Grayscale images and graphs of the measurement results of the beam profile measured in the state. [ Fig. 4] Fig. 4 is a perspective view of an optical chamber of a laser device according to another embodiment.

10: Laser oscillator

11: Beam Expander

12: Reflector

13: Orifice

14: Reflector

15: Branch Optical System

16: Reflector

17A, 17B: Beam Scanner

18A, 18B: Lens

19: Photodetector

20A, 20B: Object to be processed

21: Carrier

30: Blower

Claims (6)

A laser device has: Optical parts, which are arranged on the beam path through which the laser beam passes; The optical parts are arranged on the optical base; The laser device further has: a blower, which is used to configure the optical parts Space produces atmospheric flow. The laser device according to claim 1, further comprising: an outflow portion for causing the air introduced into the optical chamber by the blower to flow out to the outside. The laser device according to claim 1 or 2, further comprising: a side wall, which is a space around the beam path and the space where the optical parts are arranged; the blower is installed on the side wall, and the blower is installed in the side wall. An opening is provided at the position opposite to the position. The laser device of claim 3, further comprising: a top plate that blocks the upper part of the side wall; the blower that ventilates the space covered by the side wall and the top plate. The laser device of claim 1 or 2, wherein The said air blower generates the said air flow with a wind speed of 0.5 m/s or more in the space containing the said optical component. A laser device, comprising: an optical part, which is arranged in a beam path through which a laser beam passes; a blower, which makes the space where the optical part is arranged to generate atmospheric flow; a side wall, which is installed with the blower and surrounds the light beam The path and the space in which the aforementioned optical components are arranged; The aforementioned optical components are arranged on the optical seat; The atmospheric flow is a flow that is not parallel to the beam path.

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