Optical system capable of realizing two light spots at focal point in XY two dimensions and processing method

Abstract

The invention relates to an optical system capable of realizing two light spots in X and Y dimensions at a focal point. The optical system comprises a laser, a first half-wave plate, a first photoelectric crystal, a second half-wave plate, a second photoelectric crystal, a first reflector group, a second reflector group, a scanner and a focusing field lens, the laser provides a laser beam for processing, the laser beam for processing enters the first photoelectric crystal after passing through the first half-wave plate, is divided into a first light beam and a second light beam and then enters the second photoelectric crystal after passing through the second half-wave plate, and the second photoelectric crystal divides the first light beam into the first light beam and a third light beam; the first light beam, the second light beam and the third light beam enter the scanner together and are focused and processed after passing through the focusing field lens, and the focusing field lens is used for converging the first light beam, the second light beam and the third light beam into a first light spot, a second light spot and a third light spot for processing. According to the optical system and the laser processing method, the processing light spot can change along with the processing drawing file, and the processing line spacing is increased, so that the efficiency is improved.

Description

Technical Field

[0001] The invention belongs to a laser precision processing system and a laser processing method, in particular to an optical system capable of realizing two light spots in both X and Y dimensions at a focus and a laser processing method thereof. Background Art

[0002] At present, in the processing of copper layers and PI composite circuit boards or other types of composite circuit boards, laser processing equipment is used to process the surface layer to form a specific pattern. Laser processing uses a laser output beam, which is focused by a focusing field lens to form a focal spot for processing. Existing laser processing equipment usually uses a single focal spot, and the processing method is generally to control the focused spot with a galvanometer to process from point to line and from line to surface, and the processing efficiency depends on the diameter of the point spot. In the laser processing of copper layers and PI composite circuit boards, in the process of removing the surface layer according to the designed shape, the spot at the focus needs to be very small, resulting 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, and most of them are arranged in a single direction, and it is impossible to realize the XY two-dimensional spot arrangement that changes with the processing drawings. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the processing efficiency of the prior art and to provide a laser processing method and an optical system that can realize two light spots in both the X and Y dimensions at the focus. It can meet the requirements of a smaller number of wirings, as well as special wiring requirements. It can also meet the changes in the arrangement of light spots with the processing drawings, increase the processing line spacing, and thus improve efficiency.

[0004] The present invention solves the technical problem by the following technical solutions:

[0005] An optical system capable of realizing two light spots in both X and Y dimensions at a focus, characterized by comprising a laser, a first half-wave plate, a first photoelectric crystal, a second half-wave plate, a second photoelectric crystal, a first reflector group, a second reflector group, a scanner and a focusing field lens;

[0006] The laser provides a processing laser beam, which is incident on a first photoelectric crystal after passing through a first half-wave plate. The first photoelectric crystal divides a processing laser beam into a first beam and a second beam, and then passes through a second half-wave plate and is incident on a second photoelectric crystal. The second photoelectric crystal divides the first beam into a first beam and a third beam. The second beam passes through a first reflector group and is reduced to a lens range relative to the first beam, and presents a smaller relative angle. The third beam passes through a second reflector group and is reduced to a lens range relative to the first beam, and presents a smaller relative angle. The first beam, the second beam and the third beam are incident on a scanner together and are focused and processed after passing through a focusing field lens. The scanner is used to provide processing scanning, and the focusing field lens is used to converge the first beam, the second beam and the third beam into a first light spot, a second light spot and a third light spot for processing.

[0007] Moreover, the first reflector group includes two reflective lenses; and the second reflector group includes two reflective lenses.

[0008] Moreover, the photoelectric crystal is an acousto-optic modulator or an electro-optic modulator.

[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, the second light beam, and the third 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 first light spot and the second light spot may be tangent, intersecting, or separated by a certain distance.

[0012] Moreover, the first light spot and the third light spot may be tangent, intersecting, or separated by a certain distance.

[0013] Moreover, the first light spot and the second light spot can be processed simultaneously, individually, or alternately.

[0014] Moreover, the first light spot and the third light spot can be processed simultaneously, individually, or alternately.

[0015] A laser processing method for an optical system that can realize two light spots in both X and Y dimensions at a focus, comprising the following steps:

[0016] 1) The laser emits a first light beam, which passes through a first half-wave plate and enters a first photoelectric crystal to be divided into a first light beam and a second light beam on a horizontal plane;

[0017] 2) The first light beam passes through the second half-wave plate and is incident on the second photoelectric crystal to be divided into the first light beam and the third light beam on the vertical plane;

[0018] 3) After the second light beam is adjusted by the first reflector group, its relative position with the first light beam on the horizontal plane is reduced to a lens range, and presents a smaller relative angle; after the third light beam is adjusted by the second reflector group, its relative position with the first light beam on the vertical plane is reduced to a lens range, and presents a smaller relative angle. The three light beams are incident on the scanner and form three light spots through the focusing field, namely, the first light spot, the second light spot, and the third light spot;

[0019] 4) adjusting the first reflector group so that the first light spot and the second light spot are tangent, intersected or separated by a certain distance to meet the processing requirements; adjusting the second reflector group so that the first light spot and the third light spot are tangent, intersected or separated by a certain distance to meet the processing requirements;

[0020] Furthermore, in the step 4):

[0021] When processing a vertical line in the middle of the material, keep the first photoelectric crystal turned on to emit the first light beam and the second light beam, keep the second photoelectric crystal turned off to make the energy of the third light beam zero, and arrange the first light spot and the second light spot horizontally, so that they can be synchronously processed or alternately processed in a state of being tangent or intersecting or at a distance;

[0022] When processing the horizontal line in the middle of the material, keep the second photoelectric crystal turned on to emit the first light beam and the third light beam, keep the first photoelectric crystal turned off to make the energy of the second light beam zero, and make the first light spot and the third light spot arranged vertically, and process synchronously or alternately in a state of being tangent or intersecting or at a distance;

[0023] When processing the edge of the material, the first photoelectric crystal and the second photoelectric crystal are kept closed, and only the first light beam is processed, which meets the processing needs of small edge taper and neatness.

[0024] The advantages and beneficial effects of the present invention are:

[0025] 1. The optical system of the present invention can realize two light spots in both X and Y dimensions at the focus. The laser provides a processing laser beam, and the processing laser beam is incident on the first photoelectric crystal after passing through the first half-wave plate. The first photoelectric crystal divides a beam of processing laser beam into a first beam and a second beam, and the energy of the two beams is controlled and adjustable by the first photoelectric crystal. Then, the laser beam passes through the second half-wave plate and enters the second photoelectric crystal. The second photoelectric crystal divides the first beam into a first beam and a third beam, and the energy of the two beams is controlled and adjustable by the second photoelectric crystal. After passing through the first reflector group, the relative position of the second beam with the first beam is reduced to a lens range and presents a smaller relative angle. After passing through the second reflector group, the relative position of the third beam with the first beam is reduced to a lens range and presents a smaller relative angle. The first beam, the second beam and the third beam are incident on the scanner together 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 converge the first beam, the second beam and the third beam into the first light spot, the second light spot and the third light spot for processing.

[0026] 2. The optical system of the present invention can realize two light spots in both XY dimensions at the focus. The first reflector group or the second reflector group is used to reduce the relative position of the two beams of light to a lens range. And at a small relative angle, the two light spots at the focus can be processed simultaneously or not, and the distance between the two light spots can be tangent, intersecting, or separated by a certain distance. In the existing laser processing system, the two light spots cannot achieve the effect of tangent and intersecting.

[0027] 3 The present invention discloses a laser processing method for an optical system that can realize two light spots in both X and Y dimensions at the focus. The laser processing method and optical system that can realize two focused light spots in both X and Y dimensions at the focus can meet the requirement of a small number of wirings and also meet the requirements of special wirings. The arrangement of the light spots can be changed with the processing drawings, and the processing line spacing can be increased, thereby improving the efficiency. The existing laser processing system cannot realize two light spots in both X and Y dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is an optical structure diagram of an optical system of the present invention that can realize two light spots in both X and Y dimensions at the focus;

[0029] Figure 2 It is the light spot arrangement when the image file at the middle processing position is a vertical line (the first light spot 13 and the second light spot 14 form a horizontal ellipse);

[0030] Figure 3 It is the light spot arrangement when the middle processing position image is a horizontal line (the first light spot 13 and the second light spot 15 form a vertical ellipse);

[0031] Figure 4aSchematic diagram of the light spot distribution at the focus when the middle processing position image is a vertical line (the first light spot 13 and the second light spot 14 are separated by a certain distance);

[0032] Figure 4b Schematic diagram of the light spot distribution at the focus when the middle processing position image is a vertical line (the first light spot 13 and the second light spot 14 intersect);

[0033] Figure 4c Schematic diagram of the light spot distribution at the focus when the middle processing position image is a vertical line (the first light spot 13 and the second light spot 14 are tangent);

[0034] Figure 5a It is a schematic diagram of the light spot distribution at the focus when the middle processing position image is a horizontal line (the first light spot 13 and the second light spot 15 are separated by a distance);

[0035] Figure 5b Schematic diagram of the light spot distribution at the focus when the middle processing position image is a horizontal line (the first light spot 13 and the second light spot 15 intersect);

[0036] Figure 5c Schematic diagram of the light spot distribution at the focus when the middle processing position image is a horizontal line (the first light spot 13 and the second light spot 15 are tangent);

[0037] Figure 6 This is a schematic diagram of the light spot at the edge processing position;

[0038] Figure 7a This is a schematic diagram of the previous processing and wiring method (10 wires are required in the middle);

[0039] Figure 7b This is a schematic diagram of the processing and wiring method of the present invention (5 wires are required in the middle).

[0040] Figure Number:

[0041] 1-laser, 2-first half-wave plate, 3-first photoelectric crystal, 4-second half-wave plate, 5-second photoelectric crystal, 6-first reflector group, 7-second reflector group, 8-scanner, 9-focusing field lens, 10-first light beam, 11-second light beam, 12-third light beam, 13-first light spot, 14-second light spot, 15-third light spot. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0043] Example 1

[0044] An optical system capable of realizing two light spots in both X and Y dimensions at a focus includes a laser 1, a first half-wave plate 2, a first photoelectric crystal 3, a second half-wave plate 4, a second photoelectric crystal 5, a first reflector group 6, a second reflector group 7, a scanner 8 and a focusing field lens 9.

[0045] The laser 1 provides a first processing light beam 10, which is incident on the first photoelectric crystal 3 after passing through the first half-wave plate 2. The first photoelectric crystal 3 divides the first light beam 10 into a first light beam 10 and a second light beam 11. The two light beams are transmitted in a horizontal plane, and the energy of the two light beams can be adjusted by the first photoelectric crystal 3.

[0046] The first light beam 10 then passes through the second half-wave plate 4 and is incident on the second photoelectric crystal 5. The second photoelectric crystal 5 is placed orthogonally to the first photoelectric crystal 3. The second photoelectric crystal 5 divides the first light beam 10 into the first light beam 10 and the third light beam 12. The two light beams are transmitted in a vertical plane, and the energy of the two light beams can be adjusted by the second photoelectric crystal 5. That is, the plane formed by the first light beam 10 and the second light beam 11 is perpendicular to the plane formed by the first light beam 10 and the third light beam 12.

[0047] The first photoelectric crystal 3 and the second photoelectric crystal 5 are acousto-optic modulators or electro-optic modulators, etc. In this embodiment, acousto-optic modulators are used.

[0048] After passing through the first reflector group 6, the relative position of the second light beam 11 to the first light beam 10 is reduced to a lens range, and the relative angle is small. After passing through the second reflector group 7, the relative position of the third light beam 12 to the first light beam 10 is reduced to a lens range, and the relative angle is small. The first light beam 10, the second light beam 11 and the third light beam 12 are incident on the scanner 8 together, and converged and processed after passing through the focusing field lens 9. The scanner 8 is used to provide processing scanning. The scanner 8 is a galvanometer or a fast reflection mirror. In this embodiment, a galvanometer is used to control the first light beam 10, the second light beam 11, and the third light beam 12 to swing for processing. The focusing field lens 9 is used to converge the first light beam 10, the second light beam 11 and the third light beam 12 into the first light spot 13, the second light spot 14 and the third light spot 15 for processing. The focusing field lens 9 is an F-θ lens or an objective lens, which plays a focusing role. In this embodiment, an F-θ lens is used.

[0049] By adjusting the first reflector group 6, the distance between the first light spot 13 and the second light spot 14 can be tangent, intersecting or separated by a certain distance. The first light spot 13 and the second light spot 14 can be processed simultaneously, separately or alternately. The scanner 8 is far away from the first reflector group and is set at a position where the first light beam 10 and the second light beam 11 can achieve a near intersection. During the processing, the angle of the first reflector group 6 is adjusted to adjust the angle between the first light beam 10 and the second light beam 11, thereby adjusting the distance between the first light spot 13 and the second light spot 14 to make them tangent, intersecting or separated by a certain distance.

[0050] The first light spot 13 and the third light spot 15 can be tangent, intersecting or separated by a certain distance through the adjustment of the second reflector group 7. The first light spot 13 and the third light spot 15 can be processed simultaneously, separately or alternately.

[0051] A laser processing method for an optical system that can realize two light spots in both X and Y dimensions at a focus, comprising the following steps:

[0052] 1) The laser 1 emits a first light beam 10, which passes through a first half-wave plate 2 and enters a first photoelectric crystal 3 to be divided into a first light beam 10 and a second light beam 11 on a horizontal plane;

[0053] 2) The first light beam 10 passes through the second half-wave plate 4 and is incident on the second photoelectric crystal 5 and is divided into the first light beam 10 and the third light beam 12 on the vertical plane;

[0054] 3) After the second light beam 11 is adjusted by the first reflector group 6, its relative position with the first light beam 10 on the horizontal plane is reduced to a lens range, and presents a small relative angle; after the third light beam 12 is adjusted by the second reflector group 7, its relative position with the first light beam 10 on the vertical plane is reduced to a lens range, and presents a small relative angle. The three light beams are incident on the scanner 8 and form three light spots through the focusing field lens 9, namely, the first light spot 13, the second light spot 14, and the third light spot 15;

[0055] 4) Adjust the first reflector group 6 so that the first light spot 13 and the second light spot 14 are tangent, intersected or separated by a certain distance to meet the processing requirements; adjust the second reflector group 7 so that the first light spot 13 and the third light spot 15 are tangent, intersected or separated by a certain distance to meet the processing requirements;

[0056] In step 4):

[0057] When processing a material area, two tangent light spots are used to process the middle to improve efficiency, and a single light spot is used to process the edge, while reducing efficiency and increasing the overlap rate to achieve the effect of small edge taper and neatness.

[0058] When processing a vertical line in the middle of the material, keep the first photoelectric crystal 3 turned on to emit the first light beam 10 and the second light beam 11, keep the second photoelectric crystal 5 turned off, make the energy of the third light beam 12 zero, and make the first light spot 13 and the second light spot 14 arranged horizontally, and process synchronously or alternately in a state of being tangent or intersecting or at a distance, such as Figure 2 As shown, the first light spot 13 and the second light spot 14 form a long horizontal elliptical light spot to process the vertical line;

[0059] When processing the horizontal line in the middle of the material, keep the second photoelectric crystal 5 turned on to emit the first light beam 10 and the third light beam 12, keep the first photoelectric crystal 3 turned off, make the energy of the second light beam 11 zero, and make the first light spot 13 and the third light spot 15 arranged vertically, and process synchronously or alternately when they are tangent or intersecting or at a distance, such as Figure 3 As shown, the first light spot 13 and the third light spot 15 form a long vertical elliptical light spot processing horizontal line;

[0060] Assuming that the diameter of a single spot in the prior art is 20um, 10 lines are required to process 200um wide. The diameters of the first spot 13, the second spot 14, and the third spot 15 of the present invention are all 20um. When they are tangent, the processing width is 40um, and 200um width requires 5 passes, which doubles the efficiency.

[0061] When processing the edge of the material, the first photoelectric crystal 3 and the second photoelectric crystal 5 are kept closed, and only the first light beam 10 is used for processing, so as to meet the processing requirements of small edge taper and neatness.

[0062] Example with processing parameters:

[0063] On the copper layer and PI composite material, a picosecond ultraviolet laser is used to process the pattern to remove the PI without damaging the copper layer. The method of the present invention is used for processing, and the following parameters are used for the edge and middle areas respectively:

[0064] Processing area power frequency Processing speed Number of focal spots Number of wiring lines Middle area horizontal line 5.4W 1200k 500mm / s 2 intersecting 5 Middle area vertical line 5.4W 1200k 500mm / s 2 intersecting 5 Edge Area 1.7W 1200k 250mm / s 1

[0065] The following parameters are used for edge and middle area processing using traditional single spot:

[0066] Processing area power frequency Processing speed Number of focal spots Number of wiring lines Middle area horizontal line 2.7W 1200k 500mm / s 1 10 Middle area vertical line 2.7W 1200k 500mm / s 1 10 Edge Area 1.7W 1200k 250mm / s 1

[0067] It can be seen that the middle area of ​​the present invention can be processed by two focal spots under the condition of unchanged processing speed. When processing horizontal lines, the two spots are arranged vertically; when processing vertical lines, the two spots are arranged horizontally, so that the number of lines arranged in the same area is reduced by half, thereby reducing the time by half.

[0068] To meet the processing needs of surface treatment processes such as opening blind holes or blind grooves.

[0069] 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 that can realize two light spots in both X and Y dimensions at the focus, characterized by: The invention comprises a laser (1), a first half-wave plate (2), a first photoelectric crystal (3), a second half-wave plate (4), a second photoelectric crystal (5), a first reflector group (6), a second reflector group (7), a scanner (8) and a focusing field lens (9); the laser (1) provides a first processing light beam (10), the first processing light beam (10) is incident on the first photoelectric crystal (3) after passing through the first half-wave plate (2), the first photoelectric crystal (3) divides the first processing light beam (10) into a first light beam (10) and a second light beam (11), the two light beams are transmitted in a horizontal plane, and the energy distribution of the two light beams is controlled by the first photoelectric crystal (3); the first light beam (10) is incident on the second photoelectric crystal (5) after passing through the second half-wave plate (4), the second photoelectric crystal (5) divides the first light beam (10) into a first light beam (10) and a third light beam (12), the two light beams are transmitted in a vertical plane, and the energy distribution of the two light beams is controlled by the second photoelectric crystal (5); the second light beam After being adjusted by the first reflector group (6), the relative position of the third light beam (12) and the first light beam (10) in the horizontal plane is reduced to a lens range and presents a small relative angle; after being adjusted by the second reflector group (7), the relative position of the third light beam (12) and the first light beam (10) in the vertical plane is reduced to a lens range and presents a small relative angle; the first light beam (10), the second light beam (11) and the third light beam (12) are incident on the scanner (8) together and are focused after passing through the focusing field lens (9); the first light beam (10) is converged into a first light spot (13), the second light beam (11) is converged into a second light spot (14), and the third light beam (12) is converged into a third light spot (15); the scanner (8) is used to provide processing scanning; during processing, when the processing image is a vertical line, the first light spot (13) and the second light spot (14) are distributed in the X direction for processing; when the processing image is a horizontal line, the first light spot (13) and the third light spot (15) are distributed in the Y direction for processing.

2. An optical system capable of realizing two light spots in both X and Y dimensions at the focus according to claim 1, characterized in that: The first reflector group (6) comprises two lenses, and the second reflector group (7) comprises two lenses.

3. According to claim 1, an optical system capable of realizing two light spots in both X and Y dimensions at the focus, characterized in that: The first photoelectric crystal (3) or the second photoelectric crystal (5) is an acousto-optic modulator or an electro-optic modulator.

4. According to claim 1, an optical system capable of realizing two light spots in both X and Y dimensions at the focus, characterized in that: The scanner (8) is a galvanometer or a fast-reflecting mirror, and is used to control the oscillation processing of the first light beam (10), the second light beam (11) and the third light beam (12).

5. The optical system according to claim 1, which can realize two light spots in both X and Y dimensions at the focus, is characterized in that: The focusing field lens (9) is an F-θ lens or an objective lens, and plays a focusing role.

6. The optical system according to claim 1, which can realize two light spots in both X and Y dimensions at the focus, is characterized in that: The distance between the first light spot (13) and the second light spot (14) can be tangent, intersecting or separated by a certain distance; the distance between the first light spot (13) and the third light spot (15) can be tangent, intersecting or separated by a certain distance.

7. The optical system according to claim 1, which can realize two light spots in both X and Y dimensions at the focus, is characterized in that: The first light spot (13) and the second light spot (14) can be processed simultaneously, individually or alternately; the first light spot (13) and the third light spot (15) can be processed simultaneously, individually or alternately.

8. A method for processing an optical system capable of realizing two light spots in both X and Y dimensions at a focus according to any one of claims 1 to 7, characterized in that: The steps include: 1) A laser (1) emits a first light beam (10), which passes through a first half-wave plate (2) and then enters a first photoelectric crystal (3) and is divided into a first light beam (10) and a second light beam (11) on a horizontal plane; 2) the first light beam (10) passes through the second half-wave plate (4) and is incident on the second photoelectric crystal (5) to be divided into the first light beam (10) and the third light beam (12) on a vertical plane; 3) After the second light beam (11) is adjusted by the first reflector group (6), its relative position with the first light beam (10) on the horizontal plane is reduced to within a lens range and presents a relatively small relative angle; after the third light beam (12) is adjusted by the second reflector group (7), its relative position with the first light beam (10) on the vertical plane is reduced to within a lens range and presents a relatively small relative angle. The three light beams are incident on the scanner (8) and form three light spots through the focusing field lens (9), namely, a first light spot (13), a second light spot (14), and a third light spot (15); 4) adjusting the first reflector group (6) so that the first light spot (13) and the second light spot (14) are tangent to, intersect with, or are separated by a certain distance, so as to meet the processing requirements; adjusting the second reflector group (7) so that the first light spot (13) and the third light spot (15) are tangent to, intersect with, or are separated by a certain distance, so as to meet the processing requirements.

9. The method for processing an optical system capable of realizing two light spots in both X and Y dimensions at the focus according to claim 8, characterized in that: In the step 4): When processing a vertical line in the middle of the material, the first photoelectric crystal (3) is kept turned on to emit the first light beam (10) and the second light beam (11), and the second photoelectric crystal (5) is kept turned off to make the energy of the third light beam (12) zero, so that the first light spot (13) and the second light spot (14) are arranged horizontally, and synchronous processing or alternating processing is performed in a state of being tangent, intersecting or at a distance; When processing a horizontal line in the middle of the material, the second photoelectric crystal (5) is kept turned on to emit the first light beam (10) and the third light beam (12), and the second photoelectric crystal (3) is kept turned off to make the energy of the second light beam (11) zero, so that the first light spot (13) and the third light spot (15) are arranged vertically, and synchronously or alternately processed in a state of being tangent, intersecting or at a distance; When processing the edge of a material, the first photoelectric crystal (3) and the second photoelectric crystal (5) are kept closed, and only the first light beam (10) is processed, thereby meeting the processing requirements of small edge taper, neatness, etc.

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