TW201932223A - Laser device using a blower to create an atmospheric flow in the space that contains therein the optical components - Google Patents

Abstract

The present invention provides a laser device capable of maintaining a stable beam profile. Optical components are disposed in a beam path through which a laser beam passes. A blower creates an atmospheric flow in the space that contains therein the optical components. In addition, the laser device further includes a cover that covers the optical path and the space that contains the optical components.

Description

Laser device

The present invention relates to a laser device.

A laser beam transmission path filled with a non-absorptive gas in the body of the laser beam transmission path having airtightness is known (Patent Document 1). The transmission path body disclosed in Patent Document 1 has a shape along a propagation path of a laser beam, and is air-tight. A non-absorbent gas inlet is provided near the starting point of the transfer path body, and an outlet is provided near the end point.
[Prior technical literature]
[Patent Literature]

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

[Questions to be Solved by the Invention]

In general, when a laser beam is used for drilling or the like of a printed wiring board, a beam profile adjustment mechanism such as a lens or an aperture is arranged in a path of the laser beam. It is difficult to arrange the optical axis adjustment of such a beam profile adjustment mechanism inside the transmission path body having a high airtightness. Based on experiments by the inventors of the present application, it was found that when the propagation path of the laser beam is used as an open space without airtightness, a stable beam profile may not be obtained.

An object of the present invention is to provide a laser device capable of maintaining a stable beam profile.

[Means for solving problems]

According to an aspect of the present invention, a laser device is provided, including:
The optical components are arranged in the beam path through which the laser beam passes; and the blower is used to generate atmospheric flow in the space containing the optical components.

[Inventive effect]

By making the space inside the optical component an atmospheric state, it is not necessary to maintain the airtightness, so that the optical axis of the optical component can be easily adjusted. Moreover, by generating an atmospheric flow, the temporal profile of the beam profile can be stabilized.

1 to 3B, a laser device according to an 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 can be used, such as a carbon dioxide laser oscillator.

Optical components such as a beam expander 11, mirrors 12, 14, 16, an aperture 13, and a branch optical system 15 are arranged on a beam path of a laser beam output from the laser oscillator 10. The beam expander 11 changes a beam diameter and a divergence angle of a laser beam output from the laser oscillator 10. The laser beam that has passed through the beam expander 11 is reflected by the mirror 12 and is incident on 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 reflecting mirror 14 and is incident on 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 branching optical system 15 branches the incident laser beam into two beam paths. As the branch optical system 15, a translucent mirror, a polarizing beam splitter, or the like can be used.

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

The laser beam that is branched by the branch optical system 15 and propagates through one of the beam paths (the beam path facing downward) passes through the beam scanner 17A and the lens 18A and is incident on the processing object 20A. The laser beam that propagates through another beam path (the beam path in the horizontal direction) is reflected downward by the mirror 16 and then enters the processing 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 a function of scanning a pulsed laser beam in a two-dimensional direction. The lenses 18A and 18B focus the pulsed laser beams on the surfaces of the processing objects 20A and 20B, respectively. Alternatively, the aperture 13 may be formed on the surfaces of the processing objects 20A and 20B.

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

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

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

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

Next, an excellent effect obtained by employing the configuration of the laser device according to the above-mentioned embodiment will be described.

In the above embodiment, optical components such as the beam expander 11, the mirrors 12, 14, 16, the aperture 13, the branch optical system 15, and the light detector 19 are arranged in a space on the optical base 25 (FIGS. 2A and 2B). The space is open in the atmosphere, not to ensure air tightness. Therefore, compared with a structure in which optical components are arranged in a highly airtight space, the optical axis adjustment and the like of various optical components can be easily performed.

Next, referring to FIG. 3A and FIG. 3B, an excellent effect obtained by generating an atmospheric flow will be described.

FIG. 3A is a gray scale diagram and a graph showing a measurement result of a beam profile at a position of the photodetector 19 of the laser device according to the embodiment. The graphs on the left and lower sides of the grayscale diagram show the beam profiles along the straight lines passing through the center of the beam cross section in the vertical direction and the horizontal direction, respectively. In this embodiment, the beam profile shown in FIG. 3A is obtained over time.

FIG. 3B is a gray scale diagram and a graph showing a profile of a light beam measured in a state where the atmosphere of a space where optical components are arranged is almost stationary without generating atmospheric flow. Between the beam profile shown on the left of FIG. 3B and the beam profile shown on the right, the beam profile changes with time as a result.

From the measurement results shown in FIGS. 3A and 3B, it can be seen that the beam profile can be stabilized by generating an atmospheric flow in the space where the optical components are arranged. From various evaluation experiments by the inventors of the present application, it can be seen 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 will be studied by generating an atmospheric flow. The atmosphere on the beam path is slightly heated by the laser beam. At this time, if the atmosphere is stagnated, the temperature of the beam path rises significantly, and density fluctuations occur in the atmosphere. As a result, the refractive index of light changes. Since the beam profile is affected by the refractive index distribution throughout the entire beam path, the beam profile is considered to be unstable in time and space. If atmospheric flow occurs in this embodiment, it is considered that the atmospheric fluctuation caused by the local temperature rise of the beam path will disappear, and the temporal stability of the beam profile will be improved.

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

FIG. 4 is a perspective view of an optical room of the laser device according to the embodiment. The cover case 27 covers a space where the optical components on the optical base 25 are accommodated. For example, in a plan view, the cover case 27 includes: a side wall that surrounds the space where the optical components are housed; and a top plate that blocks above the side wall. A blower 30 is attached to a 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 a side wall opposite to the side wall on which the blower 30 is installed.

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

Next, a description will be given of an excellent effect obtained by using the configuration of the laser device based on the embodiment shown in FIG. 4. In the embodiment shown in FIG. 4, the optical axis of the optical component can be easily adjusted by removing the cover case 27 from the optical base 25. In addition, it is possible to suppress the intrusion of dust into the optical room where the optical components are arranged.

Each of the above embodiments is an example, and it is self-evident that a partial replacement or combination of the structures shown in different embodiments can be performed. The same effects on the same configuration based on a plurality of embodiments are not described in each of the embodiments. The present invention is not limited to the above embodiments. For example, it is obvious to those skilled in the art that various changes, improvements, and combinations can be made in the technical field to which the present invention belongs.

10‧‧‧laser oscillator

11‧‧‧ Beam Expander

12‧‧‧Mirror

13‧‧‧ orifice

14‧‧‧Mirror

15‧‧‧ branch optical system

16‧‧‧Reflector

17A, 17B‧‧‧Beam Scanner

18A, 18B‧‧‧ lens

19‧‧‧ light detector

20A, 20B‧‧‧ Objects to be processed

21‧‧‧ carrier

25‧‧‧ Optical Block

26‧‧‧ base

27‧‧‧ cover

30‧‧‧ blower

31‧‧‧ opening

[Fig. 1] Fig. 1 is a schematic diagram of a laser device according to an embodiment.

[Fig. 2] Figs. 2A and 2B are a schematic front view and a schematic top view, respectively, based on the laser device shown in the embodiment shown in Fig. 1. [Fig.

[Fig. 3] Fig. 3A is a gray scale diagram and a graph showing a measurement result of a light beam profile at a position of a photodetector of the laser device of the embodiment shown in Fig. 1. Fig. 3B is a graph showing a state where no atmospheric flow is generated. Gray scale diagram and graph of the measurement result of the beam profile measured in the state.

4 is a perspective view of an optical room of a laser device according to another embodiment.

Claims (4)

A laser device includes: (i) an optical component arranged in a beam path through which a laser beam passes; and (ii) a blower that generates atmospheric flow in a space containing the aforementioned optical component inside. The laser device according to claim 1, further comprising: a cover shell, which covers the aforementioned beam path and a space where the aforementioned optical components are arranged; The blower generates an atmospheric flow in a space covered by the cover case. The laser device of claim 2, wherein: the aforementioned blower ventilates the space covered by the aforementioned cover. If the laser device of any one of items 1 to 3 is requested, in which The air blower generates an air flow with a wind speed of 0.5 m / s or more in a space containing the optical components therein.