Optical system and processing method for realizing two light spots in XY two dimensions at focus

Abstract

The present application relates to a kind of optical systems that two light spots can be realized in XY two dimensions at focus, it includes laser, first half-wave plate, first photoelectric crystal, second half-wave plate, second photoelectric crystal, first mirror group, second mirror group, scanner and focusing field mirror;Laser provides processing laser beam, processing laser beam is incident to first photoelectric crystal after first half-wave plate, is divided into first light beam, second light beam, then is incident to second photoelectric crystal after second half-wave plate, and second photoelectric crystal divides first light beam into first light beam and third light beam;First light beam, second light beam and third light beam are incident to scanner, and focus processing after passing through focusing field mirror, focusing field mirror is used to converge into first light spot, second light spot and third light spot processing first light beam, second light beam and third light beam.The optical system and laser processing method of the present application, processing light spot can change with processing profile, increase processing line spacing, to improve efficiency.

Description

Technical Field

[0001] This invention pertains to laser precision machining systems and laser machining methods, specifically an optical system and its laser machining method that can realize two light spots in both the X and Y dimensions at the focal point. Background Technology

[0002] Currently, laser processing equipment is used to process the surface layer of copper-layer and PI composite circuit boards, or other types of composite circuit boards, to form specific patterns. Laser processing uses a laser beam, which is focused by a focusing lens to form a focal spot for processing. Existing laser processing equipment typically uses a single focal spot, and the processing method generally involves a galvanometer controlling the focused spot to process lines and then surfaces. The processing efficiency depends on the diameter of the focal spot. In the laser processing of copper-layer and PI composite circuit boards, a very small focal spot is required during the removal of the surface layer according to the designed shape, resulting in a large number of processed lines and low efficiency. In existing multi-spot laser processing equipment systems, due to the limitations of the optical path design, the distance between the two focal spots is too large to be used for processing, and most are arranged in a single direction, failing to achieve XY two-dimensional spot arrangement that can change according to the processing drawing. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technology in processing efficiency and to provide a laser processing method and optical system that can realize two light spots in both the X and Y dimensions at the focal point. It can meet the requirements of a small number of wires, as well as special wire requirements. It can also meet the requirement that the light spot arrangement changes with the processing drawing, increasing the line spacing during processing, thereby improving efficiency.

[0004] The technical problem solved by this invention is achieved through the following technical solution:

[0005] An optical system that can realize two light spots in both the X and Y dimensions at the focal point is 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 mirror group, a second mirror 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 splits the processing laser beam into a first beam and a second beam. Then, the laser beam passes through a second half-wave plate and is incident on a second photoelectric crystal, which splits the first beam into a first beam and a third beam. After passing through a first set of mirrors, the second beam's relative position with the first beam is reduced to a lens area and at a small relative angle. After passing through a second set of mirrors, the third beam's relative position with the first beam is reduced to a lens area and at a small relative angle. The first, second, and third beams are incident on a scanner and focused for processing after passing through a focusing lens. The scanner is used to provide processing scanning, and the focusing lens is used to converge the first, second, and third beams into a first spot, a second spot, and a third spot for processing.

[0007] Furthermore, the first reflector group includes two reflector lenses; the second reflector group includes two reflector 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, used to control the oscillation and processing of the first beam, the second beam, and the third beam.

[0010] Moreover, the focusing field lens is an F-θ lens or objective lens, which serves to focus the image.

[0011] Moreover, the distance between the first light spot and the second light spot can be tangent, intersect, or be a certain distance apart.

[0012] Moreover, the distance between the first light spot and the third light spot can be tangent, intersect, or be a certain distance apart.

[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 in which two light spots can be realized in both the X and Y dimensions at the focal point includes the following steps:

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

[0017] 2) After passing through the second half-wave plate, the first beam is incident on the second photoelectric crystal and splits into the first beam and the third beam on the vertical plane;

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

[0019] 4) Adjust the first reflector group so that the first and second light spots are tangent, intersecting, or separated by a certain distance to meet the processing requirements; adjust the second reflector group so that the first and third light spots are tangent, intersecting, or separated by a certain distance to meet the processing requirements.

[0020] Moreover, in step 4):

[0021] When processing the vertical line in the middle of the material, keep the first photoelectric crystal on to emit the first and second beams, keep the second photoelectric crystal off to make the energy of the third beam zero, and make the first and second beams horizontally arranged, tangent, intersecting or separated by a distance to process synchronously or alternately.

[0022] When processing the horizontal line in the middle of the material, keep the second photoelectric crystal on to emit the first and third beams, keep the first photoelectric crystal off to make the energy of the second beam zero, and make the first and third beams vertically arranged, tangent, intersecting or separated by a distance to process synchronously or alternately.

[0023] When processing the edge of the material, the first and second photoelectric crystals are kept off, and only the first beam is used for processing, which meets the processing requirements of small edge taper and neatness.

[0024] The advantages and beneficial effects of this invention are as follows:

[0025] 1. The optical system of the present invention can realize two light spots in both the X and Y dimensions at the focal point. The laser provides a processing laser beam. The processing laser beam is incident on a first photoelectric crystal after passing through a first half-wave plate. The first photoelectric crystal splits the processing laser beam into a first beam and a second beam. The energy of the two beams is adjustable under the control of the first photoelectric crystal. Then, it is incident on a second photoelectric crystal after passing through a second half-wave plate. The second photoelectric crystal splits the first beam into a first beam and a third beam. The energy of the two beams is adjustable under the control of the second photoelectric crystal. After passing through a first reflector group, the relative position of the second beam and the first beam is reduced to a lens range and at a small relative angle. After passing through a second reflector group, the relative position of the third beam and the first beam is reduced to a lens range and at a small relative angle. The first beam, the second beam and the third beam are incident on a scanner and focused for processing 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.

[0026] 2. The optical system of this invention enables the realization of two light spots in both the X and Y dimensions at the focal point. A first or second set of mirrors is used to reduce the relative positions of the two beams to within a single lens area, maintaining a small relative angle. The two light spots at the focal point can be processed simultaneously or separately, and the distance between the two spots can be tangent, intersecting, or separated by a certain distance. Existing laser processing systems cannot achieve the tangent or intersecting effect between the two light spots.

[0027] 3. The present invention discloses a laser processing method for an optical system that can realize two light spots in both the X and Y dimensions at the focal point. The laser processing method and optical system that can realize two focused light spots in both the X and Y dimensions at the focal point can meet the requirements of a small number of wirings, and can also meet special wiring requirements. Furthermore, the light spot arrangement can be changed according to the processing drawing, increasing the line spacing and thus improving efficiency. Existing laser processing systems cannot realize two light spots in both the X and Y dimensions. Attached Figure Description

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

[0029] Figure 2 This refers to the arrangement of light spots when the intermediate processing position drawing is a vertical line (the first light spot 13 and the second light spot 14 form a horizontal ellipse);

[0030] Figure 3 This refers to the arrangement of light spots when the intermediate processing position drawing is a horizontal line (the first light spot 13 and the second light spot 15 form a vertical ellipse);

[0031] Figure 4aThis is a schematic diagram of the light spot distribution at the focal point when the intermediate processing position drawing is a vertical line (the first light spot 13 and the second light spot 14 are a distance apart);

[0032] Figure 4b This is a schematic diagram of the light spot distribution at the focal point when the intermediate processing position drawing is a vertical line (the first light spot 13 and the second light spot 14 intersect);

[0033] Figure 4c This is a schematic diagram of the light spot distribution at the focal point when the intermediate processing position drawing is a vertical line (the first light spot 13 and the second light spot 14 are tangent);

[0034] Figure 5a This is a schematic diagram of the light spot distribution at the focal point when the intermediate processing position drawing is a horizontal line (the first light spot 13 and the second light spot 15 are a distance apart);

[0035] Figure 5b This is a schematic diagram of the light spot distribution at the focal point when the intermediate processing position drawing is a horizontal line (the first light spot 13 and the second light spot 15 intersect);

[0036] Figure 5c This is a schematic diagram of the light spot distribution at the focal point when the intermediate processing position drawing 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 location;

[0038] Figure 7a This is a schematic diagram of the previous wiring method (requiring 10 lines in the middle);

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

[0040] Icon labels:

[0041] 1-Laser, 2-First half-wave plate, 3-First photoelectric crystal, 4-Second half-wave plate, 5-Second photoelectric crystal, 6-First reflecting mirror group, 7-Second reflecting mirror group, 8-Scanner, 9-Focusing field lens, 10-First beam, 11-Second beam, 12-Third beam, 13-First spot, 14-Second spot, 15-Third spot. Detailed Implementation

[0042] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0043] Example 1

[0044] An optical system that can realize two light spots in both the X and Y dimensions at the focal point 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 mirror group 6, a second mirror group 7, a scanner 8, and a focusing field lens 9.

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

[0046] The first 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 splits the first beam 10 into a first beam 10 and a third beam 12. The two beams propagate in a vertical plane, and the energy of the two beams can be adjusted by the second photoelectric crystal 5. That is, the plane formed by the first beam 10 and the second beam 11 is perpendicular to the plane formed by the first beam 10 and the third 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, an acousto-optic modulator is used.

[0048] The second beam 11, after passing through the first reflecting mirror group 6, is reduced in relative position to the first beam 10 within a lens area and at a small relative angle. The third beam 12, after passing through the second reflecting mirror group 7, is also reduced in relative position to the first beam 10 within a lens area and at a small relative angle. The first beam 10, the second beam 11, and the third beam 12 are all incident on the scanner 8 and converged for processing after passing through the focusing field lens 9. The scanner 8 is used to provide processing scanning; the scanner 8 can be a galvanometer or a fast-reflecting mirror, etc. In this embodiment, a galvanometer is used to control the oscillation of the first beam 10, the second beam 11, and the third beam 12 for processing. The focusing field lens 9 is used to converge the first beam 10, the second beam 11, and the third beam 12 into a first spot 13, a second spot 14, and a third spot 15 for processing. The focusing field lens 9 is an F-θ lens or an objective lens, which serves to focus the light; 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, individually, or alternately. The scanner 8 is located relatively far from the first reflector group, positioned at a point where the first beam 10 and the second beam 11 can nearly intersect. During processing, the angle of the first reflector group 6 is adjusted to regulate the angle between the first beam 10 and the second 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] By adjusting the second reflector group 7, the distance between the first light spot 13 and the third light spot 15 can be tangent, intersecting, or separated by a certain distance. The first light spot 13 and the third light spot 15 can be processed simultaneously, individually, or alternately.

[0051] A laser processing method for an optical system in which two light spots can be realized in both the X and Y dimensions at the focal point includes the following steps:

[0052] 1) The laser 1 emits a first beam 10, which passes through the first half-wave plate 2 and is incident on the first photoelectric crystal 3, where it is split into the first beam 10 and the second beam 11 on the horizontal plane;

[0053] 2) After passing through the second half-wave plate 4, the first beam 10 is incident on the second photoelectric crystal 5 and splits into the first beam 10 and the third beam 12 on the vertical plane;

[0054] 3) After the second beam 11 is adjusted by the first reflector group 6, its relative position with the first beam 10 on the horizontal plane is reduced to within a lens range and at a small relative angle; after the third beam 12 is adjusted by the second reflector group 7, its relative position with the first beam 10 on the vertical plane is reduced to within a lens range and at a small relative angle. The three beams of light are incident on the scanner 8 and form three light spots through the focusing field lens 9: 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, intersecting, 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, intersecting, 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, while a single light spot is used to process the edge. At the same time, efficiency is reduced and the overlap rate is increased to achieve effects such as small edge taper and neatness.

[0058] When processing the vertical line in the middle of the material, keep the first photoelectric crystal 3 on, emitting the first beam 10 and the second beam 11; keep the second photoelectric crystal 5 off, making the energy of the third beam 12 zero; and arrange the first beam spot 13 and the second beam spot 14 laterally, processing synchronously or alternately in a state where they are tangent, intersecting, or separated by a certain distance. Figure 2 As shown, the first spot 13 and the second spot 14 form a long, horizontally elliptical vertical line for processing the spot.

[0059] When processing the horizontal line in the middle of the material, keep the second photoelectric crystal 5 on, emitting the first beam 10 and the third beam 12. Keep the first photoelectric crystal 3 off, making the energy of the second beam 11 zero. This allows the first beam spot 13 and the third beam spot 15 to be vertically aligned, tangent, intersecting, or spaced apart, processing synchronously or alternately. Figure 3 As shown, the first spot 13 and the third spot 15 form a long, vertically elliptical processing line;

[0060] Assuming that the diameter of a single light spot in the prior art is 20 μm, processing a width of 200 μm requires 10 lines. The diameters of the first light spot 13, the second light spot 14, and the third light spot 15 of the present invention are all 20 μm. When they are tangent to each other, the processing width is 40 μm. A width of 200 μm would require 5 passes, thus doubling the efficiency.

[0061] When processing the edge of the material, the first photoelectric crystal 3 and the second photoelectric crystal 5 are kept off, and only the first beam 10 processes the material, which meets the processing requirements of small edge taper and neatness.

[0062] Examples with machining parameters:

[0063] On a copper layer and PI composite material, a picosecond ultraviolet laser is used to process patterns to remove PI without damaging the copper layer. The method of this invention is used for processing, with the following parameters applied to the edge and center regions:

[0064] Horizontal line in the middle area 5.4W 1200k 500mm / s 2 intersecting 5 Vertical lines in the middle area 5.4W 1200k 500mm / s 2 intersecting 5 Edge area 1.7W 1200k 250mm / s 1

[0065] When using traditional single-spot processing for edge and center areas, the following parameters are used respectively:

[0066] Horizontal line in the middle area 2.7W 1200k 500mm / s 1 10 Vertical lines in the middle area 2.7W 1200k 500mm / s 1 10 Edge area 1.7W 1200k 250mm / s 1

[0067] As can be seen, in the middle area, the present invention can process the line with two focal spots while keeping the processing speed constant. When processing horizontal lines, the two spots are arranged vertically; when processing vertical lines, the two spots are arranged horizontally, which reduces the number of lines in the same area by half, thereby reducing the time by half.

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

[0069] Although the embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for fabricating an optical system in which two light spots can be realized in both the X and Y dimensions at the focal point, characterized in that: The optical system 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 mirror group (6), a second mirror group (7), a scanner (8), and a focusing field lens (9); the laser (1) provides a first processing beam (10), which passes through the first half-wave plate (2) and is incident on the first photoelectric crystal (3), which splits the first beam (10) into a first beam (10) and a second beam (11), which propagate in a horizontal plane and whose energy distribution is controlled by the first photoelectric crystal (3); the first beam (10) passes through the second half-wave plate (4) and is incident on the second photoelectric crystal (5), which splits the first beam (10) into a first beam (10) and a third beam (12), which propagate in a vertical plane and whose energy distribution is controlled by the second photoelectric crystal (5); the first half-wave plate (4) passes through the second half-wave plate (4) and is incident on the second photoelectric crystal (5), which splits the first beam (10) into a first beam (10) and a third beam (12), which propagate in a vertical plane and whose energy distribution is controlled by the second photoelectric crystal (5); the first half-wave plate (2) passes through the first half-wave plate (4), ... After being adjusted by the first reflector group (6), the second beam (11) and the first beam (10) are reduced to a lens range in the horizontal plane and have a small relative angle. After being adjusted by the second reflector group (7), the third beam (12) and the first beam (10) are reduced to a lens range in the vertical plane and have a small relative angle. The three beams, the first beam (10), the second beam (11) and the third beam (12), are incident on the scanner (8) and focused by the focusing field lens (9). The first beam (10) converges into the first spot (13), the second beam (11) converges into the second spot (14), and the third beam (12) converges into the third spot (15). The scanner (8) is used to provide processing scanning. During processing, when the processing drawing is a vertical line, the first spot (13) and the second spot (14) are processed in the X direction. When the processing drawing is a horizontal line, the first spot (13) and the third spot (15) are processed in the Y direction. The second photoelectric crystal (5) is placed orthogonally to the first photoelectric crystal (3). The second photoelectric crystal (5) divides the first beam (10) into a first beam (10) and a third beam (12). The two beams are transmitted in a vertical plane, and the energy of the two beams can be adjusted by the second photoelectric crystal (5). That is, the plane formed by the first beam (10) and the second beam (11) is perpendicular to the plane formed by the first beam (10) and the third beam (12). The processing method includes the following steps: 1) The laser (1) emits a first beam (10), which passes through the first half-wave plate (2) and is incident on the first photoelectric crystal (3) and splits into a first beam (10) and a second beam (11) on the horizontal plane. 2) After passing through the second half-wave plate (4), the first beam (10) is incident on the second photoelectric crystal (5) and splits into the first beam (10) and the third beam (12) on the vertical plane. 3) After the second beam (11) is adjusted by the first reflector group (6), its relative position with the first beam (10) on the horizontal plane is reduced to within a lens range and at a small relative angle; after the third beam (12) is adjusted by the second reflector group (7), its relative position with the first beam (10) on the vertical plane is reduced to within a lens range and at a small relative angle. The three beams of light are incident on the scanner (8) and form three light spots through the focusing field lens (9): the first light spot (13), the second light spot (14), and the third light spot (15). 4) Adjust the first reflector group (6) so that the first light spot (13) and the second light spot (14) are tangent, intersecting, 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, intersecting, or separated by a certain distance to meet the processing requirements; In step 4): When processing the vertical line in the middle of the material, keep the first photoelectric crystal (3) on and emit the first beam (10) and the second beam (11), keep the second photoelectric crystal (5) off and make the energy of the third beam (12) zero, so that the first light spot (13) and the second light spot (14) are arranged horizontally, and are processed synchronously or alternately in a state of being tangent, intersecting or separated by a distance. The first light spot (13) and the second light spot (14) form a long strip horizontal elliptical light spot to process the vertical line; When processing the horizontal line in the middle of the material, keep the second photoelectric crystal (5) on and emit the first beam (10) and the third beam (12). Keep the first photoelectric crystal (3) off and make the energy of the second beam (11) zero. Make the first light spot (13) and the third light spot (15) vertically arranged, tangent, intersecting or separated by a distance, to process synchronously or alternately. The first light spot (13) and the third light spot (15) form a long strip vertical elliptical light spot to process the horizontal line. 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 beam (10) is used for processing, which meets the processing requirements of small edge taper and neat effect.

2. The processing method of an optical system that can realize two light spots in both the X and Y dimensions at the focal point according to claim 1, characterized in that: The first reflector group (6) contains two lenses, and the second reflector group (7) contains two lenses.

3. The processing method of an optical system that can realize two light spots in both the X and Y dimensions at the focal point according to claim 1, 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. The processing method of an optical system that can realize two light spots in both the X and Y dimensions at the focal point according to claim 1, characterized in that: The scanner (8) is a galvanometer or a fast-reflecting mirror, used to control the oscillation of the first beam (10), the second beam (11) and the third beam (12) for processing.

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

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

7. The processing method of an optical system that can realize two light spots in both the X and Y dimensions at the focal point according to claim 1, characterized in that: The first light spot (13) and the second light spot (14) are processed simultaneously, individually, or alternately; the first light spot (13) and the third light spot (15) are processed simultaneously, individually, or alternately.

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