Micropore machining device

Abstract

The utility model discloses a micropore processing device which comprises a laser system, a beam expanding system, a polarization device, a light beam shaping device, a first lens group, a light beam deflection system, a second lens group and a coaxial air blowing module which are arranged in sequence, the coaxial air blowing module is provided with an air inlet and a nozzle, the second lens group is installed in the coaxial air blowing module, and the coaxial air blowing module is provided with an air outlet. And the nozzle is positioned right below the lens group. The laser system, the beam expanding system, the polarization device and the beam shaping device form the beam shaping piece, the beam shaping piece, the focusing system, the two-dimensional galvanometer and the coaxial blowing module are combined for machining, the problem that the focus depth is short after Gaussian beam focusing is solved, zooming is not needed in the drilling process, and the machining efficiency is improved. Therefore, micro-hole processing with high depth-diameter ratio and low taper can be realized on a thick material.

Description

Technical Field

[0001] The utility model relates to the technical field of micro-hole processing, and particularly relates to a micro-hole processing device. Background Technique

[0002] Micro-hole processing technology is the key technology for the manufacturing of many precision parts. For example, drilling holes in the turbine blades of aerospace engines, drilling holes in the fuel injectors of automobile engines, precision drilling of PCB boards, TGV drilling of glass substrates, etc. Traditional processing methods include mechanical drilling, die punching, electric discharge drilling, etc. With the emergence of new materials and new processes, the requirements for micro-hole processing are getting higher and higher. Traditional processing methods all have certain problems in processing in some specific scenarios. For example, it is very difficult to drill holes with a diameter less than 200 microns and a large depth-to-diameter ratio by mechanical drilling; the stress generated by die punching is large, and the edge effect of the hole is poor, which is not suitable for drilling hard and brittle materials. Moreover, the cost of making dies is high, and new dies need to be processed for drilling samples with different hole diameters and different distributions; the thermal influence of electric discharge drilling is large, and a recast layer is likely to appear on the hole wall, affecting the service life of the device. Laser drilling has the advantages of high speed, high precision and flexible processing, and is more and more widely used in the field of precision manufacturing.

[0003] Currently, the mainstream laser drilling methods include pulsed percussion drilling, laser scanning rotary cutting, laser spiral scanning drilling, etc. Pulsed percussion drilling uses continuous or quasi-continuous laser to continuously heat the material in the hole, making it change from solid state to liquid state and gaseous state, and then cooperating with coaxial air blowing to quickly remove the material in the hole to form a small hole. This method is suitable for application scenarios with a huge number of holes but not high quality requirements; Scanning rotary cutting drilling is to control the laser to scan along the hole edge contour and directly cut the whole material in the hole, which is suitable for the processing of larger diameter holes; Laser spiral scanning drilling is to control the laser to ablate and remove the material in the hole. This method has high processing precision and small thermal effect, and is suitable for the processing of micro-holes with small diameters and high precision.

[0004] The above-mentioned laser drilling methods can realize the preparation of micro-holes in different scenarios and with different requirements. However, when drilling holes in thicker materials, due to the limitation of the focal depth of the focused light spot, it is necessary to use mechanical or optical zoom methods to move the laser focus or the sample up and down during the drilling process. The zoom processing method not only increases the drilling time, but also makes the whole processing system more complex, resulting in an increase in cost. Content of the Utility Model

[0005] The purpose of the utility model is to provide a micro-hole processing device, which solves the problems put forward in the above background technique.

[0006] To achieve the above object, the present utility model provides the following technical solution: A micro-hole processing device, comprising a laser system, a beam expander system, a polarization device, a beam shaping device, a first lens group, a beam deflection system, a second lens group, and a coaxial air blowing module arranged in sequence. It is characterized in that: an air inlet and a nozzle are provided on the coaxial air blowing module, the second lens group is installed inside the axial air blowing module, and the nozzle is located directly below the lens group.

[0007] Preferably, the laser system can be any one of a continuous laser, a quasi-continuous laser, a nanosecond laser, a picosecond laser, and a femtosecond laser.

[0008] Preferably, the working wavelength of the laser system is 200nm - 2000nm.

[0009] Preferably, the beam expander system is a laser beam expander.

[0010] Preferably, the polarization device is a quarter-wave plate corresponding to the working wavelength of the laser system 1.

[0011] Preferably, the beam shaping device can be any one of a spatial light modulator, a cone lens, and a diffractive optical element.

[0012] Preferably, the first lens group, the beam deflection system, and the second lens group cooperate to form a focusing system.

[0013] Preferably, the beam deflection system is a two-dimensional scanning galvanometer, and its installation position is between the lens groups.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] The laser system, beam expander system, polarization device, and beam shaping device of the present utility model form a beam shaping component. Combining the beam shaping component, focusing system, two-dimensional galvanometer, and coaxial air blowing module for processing, it solves the problem of short focal depth after Gaussian beam focusing. During the drilling process, there is no need to perform zooming, and micro-hole processing with a high aspect ratio and low taper can be achieved on thick materials. Description of the Drawings

[0016] Figure 1 It is a structural schematic diagram of the micro-hole processing device of the present utility model;

[0017] Figure 2 It is an optical principle diagram of the micro-hole processing device of the present utility model;

[0018] Figure 3 It is a laser scanning trajectory diagram in the two-dimensional plane of the micro-hole processing of the present utility model;

[0019] Figure 4 It is a micro-hole processing principle diagram of the present utility model;

[0020] Figure 5 This is the method flowchart of the micro-hole processing device of the present utility model. Specific embodiments

[0021] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0022] Please refer to Figures 1 to 5 , an embodiment provided by the present utility model: a micro-hole processing device, including a laser system 1, a beam expander system 2, a polarization device 3, a beam shaping device 4, a first lens group 5, a beam deflection system 6, a second lens group 7, a coaxial air blowing module 8, and a processing sample 9.

[0023] The beam expander system 2 is a laser beam expander. The linearly polarized light emitted by the laser system 1 first passes through the beam expander system 2. The function of the beam expander system 2 is to adjust the diameter of the laser spot so that it meets the incident spot size requirements of the beam shaping device 4.

[0024] Furthermore, the laser system 1 can be any one of a continuous laser, a quasi-continuous laser, a nanosecond laser, a picosecond laser, and a femtosecond laser; the working wavelength of the laser system 1 is 200 nm - 2000 nm.

[0025] The expanded beam passes through the polarization device 3. The polarization device 3 is a quarter-wave plate, which can change the linearly polarized light emitted by the laser into circularly polarized light to improve the roundness of micro-hole processing. The beam after passing through the polarization device enters the beam shaping device 4. The beam shaping device 4 can shape the Gaussian beam into a Bessel distribution or a longitudinal multi-focus distribution, so that the focused spot has a longer focal depth and a more uniform energy distribution in the propagation direction. The first lens group 5, the beam deflection system 6, and the second lens group 7 cooperate to form a focusing system.

[0026] The beam shaping device 4 can be any one of a spatial light modulator, a cone lens, and a diffractive optical element.

[0027] The shaped beam is focused on the material surface through a 4f focusing system. The 4f focusing system is composed of the lens group 4 and the second lens group 7.

[0028] The optical principles of the beam shaping device and the 4f focusing system are as Figure 2As shown, after passing through the beam shaping device 4, the laser forms an approximate Bessel beam, and the central spot diameter and transverse light intensity distribution can be basically unchanged within the propagation direction L range. Under the condition of the same beam diameter, the focal depth length formed by the Bessel beam is much larger than that of the Gaussian beam.

[0029] The Bessel beam formed by the beam shaping device 4 has a long focal depth, but the spot diameter is large, and the energy density cannot reach the damage threshold of the material. It is necessary to further compress the diameter of the Bessel beam. Here, the 4f focusing system composed of the lens group one 5 and the lens group two 7 is used to focus the formed Bessel beam. The rear focus of the lens 5 coincides with the front focus of the lens 7, and the focused focus is located at the rear focus position of the lens 7. The 4f focusing system can proportionally compress the spot size and focal depth of the Bessel beam without changing the laser energy distribution.

[0030] The beam deflection system 6 is a two-dimensional scanning galvanometer, which is between the lens group one 5 and the lens group two 7. The galvanometer can control the laser to scan and process in the XY plane, and the optical path is deflected by a mirror inside, so the optical path between the lens group one 5 and the lens group two 7 will not be changed. The lens group two 7 is hermetically installed inside the coaxial gas blowing module 8. There is an air inlet 81 and a nozzle 82 below the lens. The laser is focused at the position directly below through the nozzle 82. During the drilling process, the compressed gas enters the coaxial gas blowing structure from the air inlet 81 and is quickly ejected from the nozzle 82, which can quickly remove the dust and heat generated by laser ablation, improve the quality and processing efficiency of the micro-holes, and at the same time prevent surface oxidation. The processed sample 9 is placed near the focus to ensure that both its upper and lower surfaces are within the range of the focal depth l.

[0031] Furthermore, the air inlet 81 is arranged at the side end of the coaxial gas blowing module 8, and the air pressure of the compressed gas used during the processing is 0 - 0.5 MPa.

[0032] First, both the upper and lower surfaces of the sample to be processed 9 are placed within the range of the focal depth l. The beam deflection system 6 controls the focused spot to perform a spiral scan, and the single movement trajectory of the spot is as Figure 3 shown. The diameter of the spiral is determined by the diameter of the hole to be processed, and the pitch of the spiral is determined by the size of the focused spot and the physical properties of the material to be processed; during the spot scanning process, the compressed gas is always in an open state, and the gas is quickly ejected from the nozzle 82, quickly removing the dust and heat generated during the scanning process; the beam deflection system controls the laser to continuously repeat the scan along the spiral trajectory until all the material in the hole is removed, completing the micro-hole processing.

[0033] The entire drilling process is as Figure 4 shown. Since the focal depth l after focusing is greater than the thickness of the material, it is not necessary to move the sample position or the laser focus up and down during the processing.

[0034] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present utility model, the present utility model can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present utility model. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A micro-hole machining device, comprising a laser system, a beam expander system, a polarization device, a beam shaping device, a first lens group, a beam deflection system, a second lens group, and a coaxial air blowing module arranged in sequence, characterized in that: An air inlet and a nozzle are provided on the coaxial air blowing module. The second lens group is installed in the coaxial air blowing module, and the nozzle is located directly below the lens group.

2. The micro-hole processing device according to claim 1, wherein: The laser system can be any one of a continuous laser, a quasi-continuous laser, a nanosecond laser, a picosecond laser, and a femtosecond laser.

3. A micro-hole processing device according to any one of claims 1 or 2, characterized in that: The working wavelength of the laser system is 200 nm - 2000 nm.

4. A micro-hole processing device according to claim 1, characterized in that: The beam expander system is a laser beam expander.

5. A micro-hole machining device according to claim 1, characterized in that: The polarization device is a quarter-wave plate corresponding to the working wavelength of the laser system (1).

6. A micro-hole processing device according to claim 1, characterized in that: The beam shaping device can be any one of a spatial light modulator, a cone lens, and a diffractive optical element.

7. A micro-hole machining device according to claim 1, characterized in that: The first lens group, the beam deflection system, and the second lens group cooperate to form a focusing system.

8. A micro-hole processing device according to claim 1, characterized in that: The beam deflection system is a two-dimensional scanning galvanometer, and its installation position is between the lens groups.

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