Optical system for two focus light spots at focus

Abstract

The utility model relates to an optical system for two focus light spots at a focus. The optical system comprises a laser, a first half-wave plate, a beam splitter, a beam combiner, a light path adjusting system, a scanner and a focusing field lens, the laser provides a laser beam for processing, the laser beam for processing enters the beam splitter after passing through the first half-wave plate, the beam splitter divides the laser beam for processing into a first light beam and a second light beam, the first light beam and the second light beam enter the beam combiner after passing through the light path adjusting system, and the first light beam and the second light beam are shrunk to be within a lens range at relative positions and are transmitted in parallel. The combined first light beam and the second light beam enter the scanner together and are focused and processed after passing through the focusing field lens, the scanner is used for providing processing scanning, and the focusing field lens is used for focusing the first light beam and the second light beam into a first focus light spot and a second light spot for focus processing. The optical system provided by the utility model can meet the requirement of small wiring quantity, can meet the special wiring requirement at the same time, and increases the processing line spacing, thereby improving the efficiency.

Description

Technical Field

[0001] The utility model belongs to a laser precision processing system and a laser processing method, in particular to an optical system with two focal spots at a focal point. Background Art

[0002] Laser processing equipment is a device that transmits the light beam emitted by the laser to the focusing field lens through the light beam, and forms a small light spot for processing after the light beam is focused. In laser processing equipment, the laser generally emits a laser beam, which passes through several reflectors and then enters the galvanometer, and then enters the field lens. After being focused by the field lens, a circular focused light spot is formed, and the galvanometer controls the processing of this focused light spot. The processing method is generally a single-line scanning method. For some surface treatment processes, the processing material is generally composed of multiple layers of different materials. It is required to remove a piece of material in one layer without damaging the underlying substrate material. The light spot at the focus is very small, and the processing wiring spacing must be very small, otherwise the energy is high and the substrate will be damaged, and the energy is low and there will be residual phenomenon. This results in a large number of processing lines and low efficiency. In the existing multi-spot laser processing equipment system, due to the influence of the optical path design, the distance between the two focal points is very far and cannot be used for processing. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings of the processing efficiency of the prior art and to provide a laser processing method and an optical system with two focusing spots at the focal point, which can meet the requirements of a smaller number of wirings and also meet the requirements of special wirings, increase the processing line spacing, and thus improve efficiency.

[0004] The utility model solves the technical problem through the following technical solutions:

[0005] An optical system with two focal spots at a focus, comprising a laser, a first half-wave plate, a beam splitter, an optical path adjustment system, a beam combiner, a scanner and a focusing field lens; the laser provides a processing laser beam, the processing laser beam is incident on the beam splitter after passing through the first half-wave plate, the beam splitter divides a processing laser beam into a first beam and a second beam, the first half-wave plate is used to adjust the energy distribution of the first beam and the second beam separated by the beam splitter, the first beam and the second beam enter the beam combiner after passing through the optical path adjustment system, the optical path adjustment system adjusts the relative position of the two beam paths after beam combination, the relative position of the first beam and the second beam is reduced to within a lens range, and the first beam and the second beam are transmitted in parallel, after beam combination, the first beam and the second beam are incident on the scanner together through a fourth reflector, and are focused and processed after passing through the focusing field lens, the scanner is used to provide processing scanning, and the focusing field lens is used to focus the first beam and the second beam into a first focal spot and a second focal spot for processing.

[0006] Moreover, the optical path adjustment system includes a first reflector, a second reflector, a third reflector and a second half-wave plate. The first light beam enters the beam combiner after passing through the first reflector and the third reflector, and the second light beam enters the beam combiner after passing through the second reflector and the second half-wave plate.

[0007] Moreover, the beam splitter is an acousto-optic modulator, an electro-optic modulator, a beam splitter or a polarization beam splitter.

[0008] Moreover, the beam combiner is a reflective lens or a polarization cube that transmits one wavelength for different wavelengths.

[0009] Moreover, the scanner is a galvanometer or a fast-reflecting mirror, which is used to control the swing processing of the first light beam and the second light beam.

[0010] Moreover, the focusing field lens is an F-θ lens or an objective lens, which plays a focusing role.

[0011] Moreover, the distance between the first focal light spot and the second focal light spot can be tangent, intersecting, overlapping or separated by a certain distance.

[0012] Moreover, the first focal spot and the second focal spot can be processed simultaneously, individually, or alternately.

[0013] Moreover, the processing laser beam is incident on the beam splitter after passing through the beam shaper, and the beam shaper changes the energy distribution state of the first focal spot and the second focal spot, so that the first focal spot and the second focal spot are distributed in the form of flat top light, ring light, or square light.

[0014] The advantages and beneficial effects of the utility model are:

[0015] 1. The utility model is an optical system with two focal spots at the focus. The processing laser is incident on the beam splitter after passing through the first half-wave plate. The beam splitter divides a laser beam into two beams of light. The first half-wave plate is used to adjust the energy distribution of the two beams of light separated by the beam splitter; then it is incident on the beam combiner after passing through the optical path adjustment system. The optical path adjustment system is used to adjust the relative position of the two light paths after beam combination. The beam combiner is used to reduce the relative position of the two light beams within the range of a lens and make the two light beams relatively parallel to each other. After beam combination, the two laser beams are incident on the scanner together and are focused after passing through the focusing field lens for processing. The focusing field lens is used to focus the two light beams into two focal spots for processing.

[0016] 2. In the optical system of the utility model with two focal spots at the focus, the beam combiner is used to reduce the relative position of the two beams of light to a lens range. The two spots at the focus can be processed simultaneously or not at the same time. The distance between the two spots can be tangent, intersecting, overlapping, or separated by a certain distance. In the existing laser processing system, the two spots of light cannot achieve the effect of overlapping, tangent, and intersecting.

[0017] 3. In the optical system with two focal spots at the focus of the utility model, the processing laser beam is incident on the beam splitter after passing through the shaper, and the beam shaper changes the energy distribution state of the first focal spot and the second focal spot, so that the first focal spot and the second focal spot are distributed in the form of flat top light, ring light, or square light.

[0018] 4. The optical system with two focal spots at the focus of the utility model, the laser processing method and the optical system with two focal spots at the focus, can meet the requirements of a smaller number of wirings, and can also meet special wiring requirements, increase the processing line spacing, and thus improve efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an optical structure diagram of an optical system of two focal spots at the focus of the utility model.

[0020] Figure 2 It is an optical structure diagram combined with a beam shaper (Example 2).

[0021] Figure 3 a is a schematic diagram of the light spot distribution at the focus (the first focus spot and the second focus spot are separated by a certain distance);

[0022] Figure 3 b is a schematic diagram of the light spot distribution at the focus (the first focus spot and the second focus spot intersect);

[0023] Figure 3 c is a schematic diagram of the light spot distribution at the focus (the first focus spot and the second focus spot are tangent);

[0024] Figure 3 d is a schematic diagram of the light spot distribution at the focus (the first focus spot and the second focus spot overlap);

[0025] Figure 4 It is a processing schematic diagram of the utility model.

[0026] Figure 5 a is a schematic diagram of the previous processing and wiring method (10 wires are required in the middle);

[0027] Figure 5 b is a schematic diagram of the processing and wiring method of the utility model (5 wires are required in the middle).

[0028] Figure Number:

[0029] 1-laser, 2-processing laser beam, 3-first half-wave plate, 4-light beam, 5-beam splitter acousto-optic modulator, 6-first light beam, 7-first reflector, 8-second light beam, 9-second reflector, 10-second half-wave plate, 11-beam combiner, 12-third reflector, 13-fourth reflector, 14-scanner, 15-focusing field lens, 16-first focal spot, 17-second focal spot, 18-beam shaper. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not restrictive, and the protection scope of the present invention cannot be limited by them.

[0031] Example 1

[0032] An optical system with two focal spots at a focus comprises a laser 1, a first half-wave plate 3, a beam splitter 5, a beam combiner 11, an optical path adjustment system, a scanner 14 and a focusing field lens 15.

[0033] The laser 1 provides a processing laser beam 2, which is a beam of light. The processing laser beam 2 passes through the first half-wave plate 3, and then the beam 4 is incident on the beam splitter 5. The beam splitter 5 splits the processing laser beam 2 into a first beam 6 and a second beam 8. The first half-wave plate 3 is used to adjust the energy distribution of the first beam 6 and the second beam 8 split by the beam splitter 5.

[0034] The beam splitter 5 is a beam splitter acousto-optic modulator, an electro-optic modulator, a beam splitter or a polarization beam splitter. In this embodiment, a beam splitter acousto-optic modulator is used.

[0035] The first light beam 6 and the second light beam 8 enter the beam combiner 11 after passing through the optical path adjustment system, and the optical path adjustment system adjusts the relative position of the two light paths after the beam combination. The optical path adjustment system includes a first reflector 7, a second reflector 9, a third reflector 12 and a second half-wave plate 10. The first light beam 6 enters the beam combiner 11 after passing through the first reflector 7 and the third reflector 12, and the second light beam 8 enters the beam combiner 11 after passing through the second reflector 9 and the second half-wave plate 10. The beam combiner 11 transmits a wavelength reflector lens or a polarization cube at the same wavelength. This embodiment is a polarization cube of the beam combiner 11. The reflector 12 can be replaced with an electrically adjustable reflector to achieve rapid adjustment of the relative position of the light spots 16 and 17. The second light beam 8 changes its polarization state after passing through the second half-wave plate 10, and the light beam 6 is incident on the beam combiner polarization splitter crystal 11 for reflection. The light beam 8 is transmitted after passing through the beam combiner 11, and the relative distance between the first light beam 6 and the second light beam 8 becomes smaller, and they are transmitted in parallel or nearly in parallel.

[0036] The relative positions of the first light beam 6 and the second light beam 8 are reduced to a range of a lens, and the first light beam 6 and the second light beam 8 are transmitted in parallel. After the beams are combined, the first light beam 6 and the second light beam 8 are incident on the scanner 14 through the fourth reflector 13, and are focused and processed after passing through the focusing field lens 15. The scanner 14 is used to provide processing scanning. The scanner 14 is a galvanometer or a fast reflection mirror, which is used to control the swing processing of the first light beam 6 and the second light beam 8. The focusing field lens 15 is used to focus the first light beam 6 and the second light beam 8 into the first focal spot 16 and the second focal spot 17 for processing. The focusing field lens 15 is an F-θ lens or an objective lens, which plays a focusing role.

[0037] Through the adjustment of the optical path adjustment system, the distance between the first focal spot 16 and the second focal spot 17 can be tangent, intersecting, overlapping or separated by a certain distance. The first focal spot 16 and the second focal spot 17 can be processed simultaneously, separately or alternately.

[0038] Example 2

[0039] Figure 2 It is an extended application combined with a beam shaper. The processing laser emitted by the laser 1 is first incident on the beam shaper 18, and then passes through the beam splitter, which can change the energy distribution state of the first focal spot 16 and the second focal spot 17, so that the distribution can achieve flat top light, ring light or square light and other forms.

[0040] The laser processing method of the optical system based on two focal spots at the focus of the present invention comprises the following processing steps:

[0041] The laser 1 emits a processing laser beam 2, which is adjusted to a polarization state after passing through a first half-wave plate 3, and is divided into a first beam 6 and a second beam 8 by a beam splitter 5; 2) the first beam 6 and the second beam 8 are formed into two parallel beams after passing through an optical path adjustment system and a beam combiner 11; the first beam 6 and the second beam 8 are incident on a scanner 14, and are formed into two focal spots, a first focal spot 16 and a second focal spot 17, by a focusing field lens 15; the first focal spot 16 and the second focal spot 17 are adjusted to be tangent, intersecting, overlapping or at a distance to meet the processing requirements, in step 4): when processing a material area, the two tangent spots are processed in the middle to improve efficiency, and the edges are processed by a single spot or overlapping spots, while reducing efficiency and increasing overlap rate to meet the effects of small edge taper and neatness.

[0042] like Figure 4As shown, when processing the middle part of the material, the first reflector (7) and the third reflector (12) are adjusted so that the first focal spot (16) and the second focal spot (17) are tangent, intersecting or spaced a certain distance apart, so as to meet the processing needs of improving processing efficiency. As shown in the figure, the first focal spot (16) and the second focal spot (17) in the middle part intersect. Assuming that the diameter of a single spot in the prior art is 20um, 10 lines are required to process 200um width. The diameters of the first focal spot (16) and the second focal spot (17) of the utility model are both 20um. When they are tangent, the processing width is 40um, and 200um width requires 5 passes, so the efficiency can be doubled.

[0043] When processing the edge of a material, the first reflector (7) and the third reflector (12) are adjusted so that the first focal spot (16) and the second focal spot (17) overlap, and the power can be adjusted to a low level to meet the processing requirements of small edge taper, neatness, etc.; or only one of the two focal spots can be used to meet the same processing effect.

[0044] In another embodiment, the processing laser emitted by the laser 1 first passes through the beam shaper 18 and then passes through the beam splitter, which can change the energy distribution state of the first focal spot 16 and the second focal spot 17 so that the distribution can achieve flat top light, ring light or square light.

[0045] When flat top light processing is required, the beam shaper (18) is replaced so that the first focal spot and the second focal spot are distributed in a flat top light form; when annular light processing is required, the beam shaper (18) is replaced so that the first focal spot and the second focal spot are distributed in annular light form; when square light processing is required, the beam shaper (18) is replaced so that the first focal spot and the second focal spot are distributed in a square light form. This meets the processing needs of surface treatment processes such as opening blind holes or blind grooves.

[0046] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. An optical system with two focal spots at the focus, characterized in that: The invention comprises a laser (1), a first half-wave plate (3), a beam splitter (5), an optical path adjustment system, a beam combiner (11), a scanner (14) and a focusing field lens (15); the laser (1) provides a processing laser beam (2); the processing laser beam (2) passes through the first half-wave plate (3) and is incident on the beam splitter (5); the beam splitter (5) splits the processing laser beam (2) into a first beam (6) and a second beam (8); the first half-wave plate (3) is used to adjust the energy distribution of the first beam (6) and the second beam (8) separated by the beam splitter (5); the first beam (6) and the second beam (8) pass through the optical path adjustment system. The light beams (6) and (8) enter the beam combiner (11) and the optical path adjustment system adjusts the relative positions of the two optical paths after the beam combination, so that the relative positions of the first light beam (6) and the second light beam (8) are reduced to within a lens range, and the first light beam (6) and the second light beam (8) are transmitted in parallel. After the beam combination, the first light beam (6) and the second light beam (8) are incident on the scanner (14) via the fourth reflector (13) and are focused and processed after passing through the focusing field lens (15). The scanner (14) is used to provide processing scanning, and the focusing field lens (15) is used to focus the first light beam (6) and the second light beam (8) into a first focal spot (16) and a second focal spot (17) for processing.

2. The optical system with two focal spots at the focus according to claim 1, characterized in that: The optical path adjustment system comprises a first reflector (7), a second reflector (9), a third reflector (12) and a second half-wave plate (10); the first light beam (6) enters a beam combiner (11) after passing through the first reflector (7) and the third reflector (12); and the second light beam (8) enters the beam combiner (11) after passing through the second reflector (9) and the second half-wave plate (10).

3. The optical system with two focal spots at the focus according to claim 1, characterized in that: The beam splitter (5) is an acousto-optic modulator, an electro-optic modulator, a beam splitter or a polarization beam splitter.

4. The optical system with two focal spots at the focus according to claim 1 or 2, characterized in that: The beam combiner (11) is a lens or a polarization cube that transmits and reflects different wavelengths one wavelength at a time.

5. The optical system with two focal spots at the focus according to claim 1, characterized in that: The scanner (14) is a galvanometer or a fast-reflecting mirror, and is used to control the first light beam (6) and the second light beam (8) to perform oscillating processing.

6. The optical system with two focal spots at the focus according to claim 1, characterized in that: The focusing field lens (15) is an F-θ lens or an objective lens, and plays a focusing role.

7. The optical system with two focal spots at the focus according to claim 1, characterized in that: The distance between the first focal light spot (16) and the second focal light spot (17) can be tangent, intersecting, overlapping or separated by a certain distance.

8. The optical system with two focal spots at the focus according to claim 1, characterized in that: The first focal light spot (16) and the second focal light spot (17) can be processed simultaneously, individually, or alternately.

9. The optical system with two focal spots at the focus according to claim 1, characterized in that: The processing laser beam (2) is incident on the beam splitter (5) after passing through the shaper. The beam shaper (18) changes the energy distribution state of the first focal light spot (16) and the second focal light spot (17), so that the first focal light spot (16) and the second focal light spot (17) are distributed in the form of flat top light, ring light, or square light.

Images