Multi-band laser confocal silicon carbide crystal ingot processing equipment and processing method

Abstract

The invention relates to a multi-band laser confocal silicon carbide crystal ingot processing device and method, the multi-band laser confocal silicon carbide crystal ingot processing device comprises an objective table and a laser assembly, the laser assembly comprises a first laser, a second laser, a first reflecting mirror, a second reflecting mirror and a laser focusing mirror, the second wavelength laser and the second wavelength laser reflected by the second reflector and emitted by the second laser device are output in a common light path mode, and a to-be-machined crystal ingot on the objective table is machined through the laser focus lens; the objective table comprises an X-axis moving module, a Y-axis moving module, a C-axis module and a B-axis module, the C-axis module is used for driving the to-be-machined crystal ingot to rotate around the vertical center axis of the to-be-machined crystal ingot, and the B-axis module is used for driving the to-be-machined crystal ingot to swing in the vertical plane. The device can improve the laser processing efficiency, can cut the cylindrical crystal ingot, is simple in structure, easy to operate and control, low in cost and particularly suitable for cutting the silicon carbide crystal ingot with large thickness, high hardness and high precision.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and in particular to a multi-band laser confocal silicon carbide ingot processing device and a processing method. Background Art

[0002] Laser processing uses the energy of light to reach a very high energy density at the focal point after being focused by a lens, and relies on the photothermal effect for processing. It uses the high energy and high focusing properties of the laser beam to heat, melt, evaporate, and burn the surface of the workpiece to achieve operations such as cutting, engraving, welding, drilling, surface modification, and grinding of materials. It has the advantages of fast processing speed, small surface deformation, and the ability to process a variety of materials. Therefore, it is widely used in various industrial manufacturing fields.

[0003] With the development of laser processing technology, the method of processing workpieces using only single-wavelength laser is difficult to meet the increasingly stringent requirements for workpiece processing efficiency and processing quality. Instead, it is more inclined to use dual-wavelength or multi-band lasers to process workpieces. However, the existing dual-wavelength or multi-band laser processing technology is not yet mature, and there are still some problems that are not conducive to meeting complex processing needs.

[0004] Meanwhile, in the existing laser processing technology, in conventional laser processing, since the conventional laser beam is a conical laser beam 14, it is difficult to achieve taper-free cutting, such as Figure 1 As shown, the inner wall 82 or the cutting edge processed by the laser is not vertical, forming an inclined surface, and it is difficult to obtain a cylindrical shape with the side and the bottom completely vertical, forming a frustum. Although the laser micro-water jet technology can be used to solve this problem and obtain high-quality processed walls and cutting edges, the equipment cost is high, and the high-power density laser in the water beam will cause a large loss of laser beam energy due to continuous reflection and absorption, resulting in its limitation in high-power applications and slow cutting speed; during the processing, due to the high energy density of the laser and the rapid heating and cooling process, microcracks may be generated inside the material, affecting the quality and strength of the processed parts, especially precision workpieces, such as semiconductor silicon wafers, which directly affect the quality of the finished product; and the current water-guided laser processing technology is difficult to further improve its cutting accuracy due to the stability of the water beam, the effective length, and the size control of the laser spot, and its adaptability under different materials and thickness conditions is poor. Therefore, it is necessary to seek new solutions for the processing of silicon carbide ingots. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a multi-band laser confocal silicon carbide ingot processing equipment with high laser energy, high processing efficiency, good processing quality, simple structure, easy operation and control, and low cost, as well as a multi-band laser confocal silicon carbide ingot processing method, which are particularly suitable for the processing of silicon carbide ingots with large thickness, high hardness, high precision and high price.

[0006] The present invention is achieved through the following technical solutions:

[0007] A multi-band laser confocal silicon carbide ingot processing equipment, comprising a stage and a laser assembly, wherein the stage is used to carry the ingot to be processed, the laser assembly comprises a first laser, a second laser, a first reflector, a second reflector and a laser focusing mirror, the first reflector is used to reflect a first wavelength laser emitted by the first laser, the second reflector is used to reflect a second wavelength laser emitted by the second laser, the reflected first wavelength laser and the reflected second wavelength laser are output in a common optical path, and the ingot to be processed on the stage is processed through the laser focusing mirror; the stage comprises an X-axis moving module, a Y ... The invention relates to a crystal ingot to be processed, wherein the crystal ingot is provided with a Y-axis moving module, the B-axis module is provided on the Y-axis moving module, the C-axis module is provided on the B-axis module, the C-axis module is connected to the crystal ingot to be processed, the C-axis module is used for driving the crystal ingot to be processed to rotate around its vertical center axis, and the B-axis module is used for driving the crystal ingot to be processed to swing in a vertical plane so that the vertical center axis of the crystal ingot to be processed is inclined relative to the vertical direction (Z-axis direction) to eliminate the cutting effect of the conical laser beam focused by the laser focusing mirror on the side surface of the crystal ingot, thereby processing a cylindrical crystal ingot whose side surface is completely perpendicular to the bottom surface.

[0008] Furthermore, the laser assembly also includes a laser cutting head and a first Z-axis moving module, the laser focusing mirror is arranged in the laser cutting head, the output end of the laser cutting head is facing the crystal ingot to be processed, the laser cutting head is installed on the first Z-axis moving module, and moves up and down in the vertical direction through the first Z-axis moving module, the parallel laser beam emitted by the first laser or the second laser is focused by the laser focusing mirror on the laser cutting head, and the laser focus is focused on the crystal ingot to be processed through the up and down movement of the first Z-axis moving module.

[0009] Furthermore, the first reflector and the second reflector are arranged in parallel up and down, the first reflector is located above the second reflector, the first reflector is a total reflector, and the second reflector is a coated semi-transparent semi-reflective mirror, which reflects the second wavelength laser while allowing the first wavelength laser to pass through. The first wavelength laser emitted by the first laser is reflected by the first reflector, and then passes through the second reflector, and is output in the same optical path as the second wavelength laser emitted by the second laser and reflected by the second reflector, and converges on the laser focusing mirror.

[0010] Furthermore, the B-axis module is used to drive the ingot to be processed to swing in a vertical plane, so that the vertical center axis of the ingot to be processed is deflected by an angle α relative to the vertical direction (Z-axis direction), α=θ / 2, where θ is the cone angle of the conical laser beam, D is the diameter of the beam incident on the laser focusing mirror, W D It is the distance between the laser focusing mirror and the laser focus, and can also be replaced by focal length.

[0011] Furthermore, it also includes a positioning area, above which are arranged a plurality of concentric annular positioning lights for projecting a plurality of positioning rings for positioning the stage and the crystal ingot to be processed in the positioning area, wherein the stage includes a processing seat and a circular vacuum suction cup, wherein the processing seat is mounted on the C-axis module, and the C-axis module drives the processing seat to rotate around its rotating axis, and the vacuum suction cup is arranged on the processing seat, and the vacuum suction cup is connected to a vacuum generating device for fixing the crystal ingot to be processed in the form of vacuum adsorption, and the center of the vacuum suction cup is located on the rotating axis of the processing seat, and the processing seat, driven by the X-axis moving module and the Y-axis moving module, positions the vacuum suction cup and the center of the crystal ingot to be processed at the center of the corresponding positioning ring for positioning.

[0012] Furthermore, a support column is provided on the positioning area, a second Z-axis movable module is provided on the support column, a plurality of the annular positioning lights are installed on the second Z-axis movable module, and the second Z-axis movable module drives the annular positioning lights to move up and down along the support column to project positioning rings with the same center but different diameters to accommodate the processing of ingots with different diameters.

[0013] Furthermore, the B-axis module includes a swing motor, a swing plate and a swing arm, one end of the swing plate is vertically connected to the output shaft of the swing motor, and the other end is vertically connected to the swing arm; the C-axis module includes a rotating motor and a processing seat, the rotating motor is installed on the swing arm, the processing seat is drive-connected to the rotating motor, and the rotating axis of the processing seat is perpendicular to the rotating axis of the swing motor.

[0014] A multi-band laser confocal silicon carbide ingot processing method, using the multi-band laser confocal silicon carbide ingot processing equipment, comprises the following steps:

[0015] S1. Setting parameters on the control system, including the diameter and thickness of the final ingot product, the parameters of the V-shaped cutting groove, the laser parameters and the speed n of the C-axis module. The control system calculates the deflection angle α of the B-axis module according to the set parameters, automatically plans the laser cutting path for layered processing, and calculates the processing time;

[0016] The parameters of the V-shaped cutting groove include the maximum width L of the V-shaped cutting groove, the angle β of the two sides of the V-shaped cutting groove and the laser depth step H, wherein the laser depth step H is the distance between two adjacent layers in layered processing, and the laser parameters include laser power, laser frequency, pulse width and duty cycle; the deflection angle α=θ / 2, wherein θ is the cone angle of the conical laser beam, D is the diameter of the beam incident on the laser focusing mirror, W D is the distance between the laser focusing mirror and the laser focus, which can also be replaced by the focal length of the laser focusing mirror;

[0017] S2, move and position the ingot to be processed to the processing area through the X-axis moving module and the Y-axis moving module, and then control the B-axis module according to the deflection angle α to make the ingot to be processed swing in the vertical direction, so that the angle between its vertical center axis and the vertical direction is α; then focus the laser generated by the laser component on the surface of the ingot to be processed through the CCD automatic focusing system, and cut the side of the ingot according to the planned laser cutting path;

[0018] S3. After the side cutting of the crystal ingot is completed, the control system controls the B-axis module to swing the crystal ingot in the vertical direction, so that its vertical center axis returns to the vertical direction, focuses the laser on the surface of the crystal ingot to be processed, and cooperates with the movement of the X-axis moving module, the Y-axis moving module and the C-axis module to process the top or bottom surface of the crystal ingot according to the planned laser processing path.

[0019] Furthermore, in the laser cutting path of the layered processing described in step S1, the width of each layer gradually narrows from top to bottom, and the V-shaped cutting groove is finally formed on the vertical section. The angle β between the two sides of the V-shaped cutting groove is θ, where θ is the cone angle of the conical laser beam. Where D is the diameter of the beam incident on the laser focusing mirror, W D It is the distance between the laser focusing mirror and the laser focus. When processing each layer, a path is adopted from the inside to the outside or from the outside to the inside, one ring at a time.

[0020] The parameters of the laser cutting path include the processing width L of each layer n , laser width step amount M, laser moving speed V, the processing width L of each layer is the processing width of each layer during layered processing, the laser width step amount M is the step amount between two adjacent rings when the laser processes one ring at a time on each layer, and the laser moving speed V is the cutting linear speed when the laser processes one ring at a time, V=πr·n / 30, mm / s, wherein r is the rotation radius at the cutting point, mm; π is a constant of 3.14, dimensionless; and n is the rotation speed of the C-axis, revolutions / min.

[0021] Furthermore, in step S2, the method for moving and positioning the ingot to be processed to the processing area by means of the X-axis moving module and the Y-axis moving module is as follows: a plurality of concentric annular positioning lights that can be raised and lowered are arranged above the positioning area, the stage comprises a processing seat and a circular vacuum suction cup, the processing seat is mounted on the C-axis module, the vacuum suction cup is arranged on the processing seat, and is used to fix the ingot to be processed by vacuum adsorption, and the center of the vacuum suction cup is located on the rotating shaft of the processing seat; the height of the annular positioning lights is adjusted according to the size of the ingot to be processed, and positioning rings corresponding to the sizes of the vacuum suction cup and the ingot are projected in the positioning area respectively, the vacuum suction cup is first moved to the corresponding positioning ring by controlling the X-axis moving module and the Y-axis moving module, so that the center of the vacuum suction cup is aligned with the center of gravity of the positioning ring corresponding to the suction cup, and then the ingot to be processed is placed on the vacuum suction cup, so that the center of the ingot to be processed is aligned with the center of gravity of the positioning ring corresponding to the suction cup, and then the ingot to be processed is fixed by vacuum adsorption, and then the Y-axis moving module is controlled to move the ingot to be processed to the processing area under the laser assembly.

[0022] The present invention realizes the coupling of dual-band lasers by arranging a first laser, a second laser, a first reflector, a second reflector and a laser focusing mirror, and can integrate the advantages of two or more bands of lasers, improve the intensity of laser output, and improve the laser processing efficiency, and is particularly suitable for laser cutting of materials with large thickness and high hardness such as silicon carbide ingots; by arranging a B-axis module on the basis of a conventional processing platform, the processing platform is driven to swing in a vertical direction, so that the ingot to be processed is tilted and placed, and its central axis is parallel to the side of the conical laser beam, so that the side of the cut ingot is parallel to the central axis and perpendicular to the bottom of the ingot, so as to obtain a cylindrical ingot, and the defect of the cut side being tilted due to the conical edge of the conical laser beam when the conventional laser is cutting the side is overcome, and the water-guided laser technology has the problems of high equipment cost, large laser energy loss, slow cutting speed, easy generation of micro cracks inside the precision material, and poor stability Compared with the problems of the present invention, which are difficult to control, the present invention has many advantages such as simple structure, easy operation and control, low cost, etc., and is especially suitable for cutting silicon carbide ingots with large thickness, high hardness and high precision. For silicon carbide ingot materials, a layered step-by-step processing method is adopted for cutting the side of the ingot, and the width becomes narrower layer by layer from top to bottom, and finally a V-shaped processing groove is formed on the vertical cross section, which can save the material to be cut and removed to the maximum extent, and also improve the processing efficiency, which is suitable for the processing of silicon carbide ingots with high price, large thickness and high hardness. For each layer, a ring-by-ring processing method is adopted, and the C-axis module is used to move inward or outward one ring at a time, which is easy to carry out automatic control. By setting a ring-shaped positioning lamp that can be raised and lowered, positioning rings of different diameters can be obtained, and in conjunction with the X-axis moving module and the Y-axis moving module, the positioning and coaxial processing of the workpiece can be realized, further improving the efficiency and accuracy of laser processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the prior art in the background technology of the present invention.

[0024] Figure 2 It is a schematic structural diagram of an embodiment of the present invention.

[0025] Figure 3 Schematic diagram of the optical path of an embodiment of the present invention.

[0026] Figure 4 It is an enlarged view of part of the structure of an embodiment of the present invention.

[0027] Figure 5 It is a schematic diagram of the structure of the C-axis module and the B-axis module in an embodiment of the present invention.

[0028] Figure 6 It is a side schematic diagram of the C-axis module and the B-axis module in an embodiment of the present invention.

[0029] Figure 7 Schematic diagram of the structure of the conical laser beam and the processed workpiece in an embodiment of the present invention.

[0030] Figure 8 FIG. 4 is a schematic diagram of processing a conical laser beam on a workpiece according to an embodiment of the present invention.

[0031] Fig. 9 Schematic diagram of the installation position of the annular positioning light in an embodiment of the present invention.

[0032] Fig.10 It is a schematic diagram of workpiece positioning in an embodiment of the present invention.

[0033] Fig.11 Schematic diagram of a positioning ring in an embodiment of the present invention.

[0034] Fig.12 Schematic diagram of the path for cutting the side of the ingot in an embodiment of the present invention.

[0035] Fig.13 Schematic diagram of the path in the depth direction when the side of the ingot is cut in an embodiment of the present invention.

[0036] Fig.14 Schematic diagram of the path in the width direction when the side of the ingot is cut in an embodiment of the present invention.

[0037] Fig.15 The figure is a workflow diagram of the processing method according to the embodiment of the present invention.

[0038] Figure markings: 1-first laser; 2-second laser; 3-first reflector; 4-second reflector; 5-laser focusing mirror; 6-laser cutting head; 7-first Z-axis moving module; 8-ingot 8; 9-processing seat; 10-rotating motor; 11-B-axis module; 12-X-axis moving module; 13-Y-axis moving module; 14-conical laser beam; 15-annular positioning lamp; 16-support column; 17-second Z-axis moving module; 18-positioning ring; 19-vacuum suction cup; 111-swing motor; 112-swing plate; 113-swing arm; 81-vertical center axis; 82-side; 83-V-shaped cutting groove. DETAILED DESCRIPTION

[0039] A multi-band laser confocal silicon carbide ingot processing equipment, such as Figure 2 As shown, it includes a stage and a laser assembly. The stage is used to carry the ingot 8 to be processed, and the laser assembly includes a first laser 1, a second laser 2, a first reflector 3, a second reflector 4, a laser cutting head 6, a laser focusing mirror 5 and a first Z-axis moving module 7. The first laser 1 emits a first wavelength laser, the first reflector 3 is used to reflect the first wavelength laser emitted by the first laser 1, and the second reflector 4 is used to reflect the second wavelength laser emitted by the second laser 2. The reflected first wavelength laser and the reflected second wavelength laser are output in the same optical path, and the ingot 8 to be processed on the stage is processed through the laser focusing mirror 5.

[0040] The laser focusing mirror 5 is arranged in the laser cutting head 6, the output end of the laser cutting head 6 faces the ingot 8 to be processed, and the laser cutting head 6 is mounted on the first Z-axis moving module 7, and moves up and down in the vertical direction through the first Z-axis moving module 7 to adjust the distance between the laser cutting head 6 and the ingot 8 to be processed on the stage, so as to facilitate the focus and realize the precise control of the processing depth of the ingot 8. The parallel laser beam emitted by the first laser 1 or the second laser 2 is focused by the laser focusing mirror 5 on the laser cutting head 6, and the laser focus is placed on the ingot 8 to be processed through the up and down movement of the first Z-axis moving module 7.

[0041] The stage includes an X-axis moving module 12, a Y-axis moving module 13, a C-axis module and a B-axis module 11, wherein the Y-axis moving module 13 is arranged on the X-axis moving module 12, the B-axis module 11 is arranged on the Y-axis moving module 13, the C-axis module is arranged on the B-axis module 11, the C-axis module is connected to the ingot 8 to be processed, and the C-axis module is used to drive the ingot 8 to be processed to perform a rotational motion around its vertical central axis 81, as shown in FIG. Figures 6 to 8The B-axis module 11 is used to drive the crystal ingot 8 to be processed to swing in the vertical plane, so that the vertical center axis 81 of the crystal ingot 8 to be processed is inclined relative to the vertical direction (Z-axis direction) to eliminate the cutting effect of the conical laser beam 14 focused by the laser focusing mirror 5 on the side surface 82 of the crystal ingot 8, thereby processing a cylindrical crystal ingot 8 with the side surface 82 completely perpendicular to the bottom surface.

[0042] As one of the implementation methods, Figures 4 to 6 The B-axis module 11 includes a swing motor 111, a swing plate 112 and a swing arm 113. One end of the swing plate 112 is vertically connected to the output shaft of the swing motor 111, and the other end is vertically connected to the swing arm 113. The C-axis module includes a rotary motor 10 and a processing seat 9. The rotary motor 10 is mounted on the swing arm 113. The processing seat 9 is drivingly connected to the rotary motor 10, and the rotation axis of the processing seat 9 is perpendicular to the rotation axis of the swing motor 111. The rotary motor 10 and the processing seat 9 can be arranged on the swing arm 113, and the output shaft of the rotary motor 10 is parallel to the rotation axis of the processing seat 9 (such as Figure 5 ) or vertical (such as Figure 4 ), the output shaft of the rotating motor 10 can be connected to the rotating shaft of the processing seat 9 through gear transmission. The swing motor 111 drives the swing plate 112 to rotate on the vertical plane, thereby driving the swing arm 113 and the C-axis module to swing in the vertical direction, and the rotating motor 10 drives the processing seat 9 and the ingot 8 to be processed thereon to rotate around the central axis of the processing seat 9.

[0043] The cooperation between the X-axis moving module 12, the Y-axis moving module 13 and the first Z-axis moving module 7 can realize the accurate positioning of the ingot 8 to be processed and the precise focusing of the laser focus on the ingot 8. The C-axis module rotates the ingot 8 and can cooperate with the laser to cut the side 82 of the ingot 8. The B-axis module 11 tilts the ingot 8 during processing. The central axis of the ingot 8 is tilted at an angle relative to the vertical direction, which can eliminate the phenomenon that the side 82 of the processed ingot 8 has a certain taper due to the conical laser beam 14 and cannot be completely perpendicular to the bottom surface, and the ingot 8 presents a cone-shaped phenomenon with a small top and a large bottom (such as Figure 1 ). Specifically, Figure 7 , Figure 8 , a B-axis module 11 is set to drive the ingot 8 to be processed to swing in the vertical plane, so that the vertical center axis 81 of the ingot 8 to be processed is deflected by an angle α relative to the vertical direction (Z-axis direction), α=θ / 2, where θ is the cone angle of the conical laser beam 14, and θ can be To calculate, then D is the diameter of the beam incident on the laser focusing mirror 5, W Dis the distance between the laser focusing mirror 5 and the laser focus, which can also be replaced by the focal length. In this way, the vertical center axis 81 of the ingot 8 and the side of the conical laser beam 14 close to the ingot 8 are parallel to each other. When the ingot 8 rotates around its vertical center axis 81, the area where the side of the conical laser beam 14 sweeps on the ingot 8 forms the side 82 of the ingot 8. The side 82 of the ingot 8 can be parallel to its vertical center axis 81, and the vertical center axis 81 of the ingot 8 is perpendicular to its bottom surface. In this way, the side 82 of the ingot 8 can be completely perpendicular to the bottom surface.

[0044] In this embodiment, the coupling structure of the dual-band laser is specifically as follows: Figure 3 , the first reflector 3 and the second reflector 4 are arranged in parallel up and down, and are both arranged at a 45-degree inclination. The first laser 1 and the second laser 2 both emit horizontal laser beams. The first reflector 3 is located above the second reflector 4. The first reflector 3 is a full reflector, and the second reflector 4 is a coated semi-transparent semi-reflector, which reflects the second wavelength laser while allowing the first wavelength laser to pass through. Specifically, referring to the prior art, the first wavelength laser anti-reflection film is coated on the side of the second reflector 4 facing the first reflector 3. If the first wavelength laser is infrared light, it is an infrared anti-reflection film. The second wavelength laser high-reflection film is coated on the side of the second reflector 4 facing the second laser 2. If the second wavelength laser is blue light, it is a blue light high-reflection film. The horizontal first wavelength laser emitted by the first laser 1 is reflected by the first reflector 3 and then goes vertically downward, and then passes through the second reflector 4. After merging with the horizontal second wavelength laser emitted by the second laser 2 and reflected by the second reflector 4 and then going vertically downward, they are output in the same optical path, converged on the laser focusing mirror 5, and then focused vertically downward onto the ingot 8. The laser beam obtained in this way can combine the processing advantages of two wavelengths, enhance the intensity of laser output, further improve the efficiency and quality of laser processing, meet various quality requirements of laser processing, and is especially suitable for laser processing of materials with large thickness and high hardness such as silicon carbide ingot 8.

[0045] The first wavelength laser and the second wavelength laser can be set according to actual needs. For example, the first wavelength laser can be infrared light, and the first laser 1 corresponds to an infrared fiber laser. The second wavelength laser can be green light, and the second laser 2 corresponds to a green light laser. According to actual conditions, the same method can be used to couple more lasers of other wavelengths, such as blue light, to output multi-band composite lasers. The lasers of each wavelength laser are set independently, and the parameters of each wavelength laser can be adjusted independently to meet various processing needs.

[0046] The first reflector 3 and the second reflector 4 are detachably connected to facilitate installation and replacement of the first reflector 3 and the second reflector 4. The first laser 1 and the second laser 2 can also be detachably connected to facilitate installation and replacement of the first laser 1 and the second laser 2.

[0047] In order to accurately position the ingot 8 to be processed in the processing area under the laser assembly, as Fig. 9 , Fig.10 The present invention further provides a positioning area, which is located in the area covered by the X-axis moving module 12 and the Y-axis moving module 13. A plurality of concentric annular positioning lights 15 are provided above the positioning area, which are used to project a plurality of positioning rings 18 for positioning the stage and the crystal ingot 8 to be processed in the positioning area. The stage includes a processing seat 9 and a circular vacuum suction cup 19. The processing seat 9 is installed on the C-axis module, and the C-axis module drives the processing seat 9 to rotate around its rotation axis. The vacuum suction cup 19 is arranged on the processing seat 9. The vacuum suction cup 19 is connected to a vacuum generating device, which is used to fix the crystal ingot 8 to be processed in the form of vacuum adsorption, and the center of the vacuum suction cup 19 is located on the rotation axis of the processing seat 9. Under the drive of the X-axis moving module 12 and the Y-axis moving module 13, the processing seat 9 positions the vacuum suction cup 19 and the center of the crystal ingot 8 to be processed to the center of the corresponding positioning ring 18 for positioning, which can ensure the accurate positioning of the workpiece to be processed, and keep it coaxial with the rotation axis of the processing seat 9, so as to realize coaxial processing and improve processing accuracy.

[0048] In order to adapt to the processing of ingots 8 of different sizes including non-standard sizes, a support column 16 is provided on the positioning area, and a second Z-axis moving module 17 is provided on the support column 16. A plurality of annular positioning lights 15 are installed on the second Z-axis moving module 17, and the second Z-axis moving module 17 drives the annular positioning lights 15 to move up and down along the support column 16. Fig.11 , a positioning ring 18 with the same center but different diameters can be projected, corresponding to the sizes of 4, 6, 8, 10, and 12 inches of conventional ingots 8, and can be changed at will according to the size of the ingots 8. The second Z-axis moving module 17 can be in manual moving mode, such as Fig. 9 As shown, the height of the annular positioning light 15 can be manually adjusted by turning the hand wheel.

[0049] A multi-band laser confocal silicon carbide ingot processing method, using the multi-band laser confocal silicon carbide ingot processing equipment, such as Fig.15 , including the following steps:

[0050] S1. Parameters are set on the control system. The set parameters include the diameter and thickness of the final ingot product, the parameters of the V-shaped cutting groove, the laser parameters and the speed n of the C-axis module. The control system calculates the deflection angle α of the B-axis module 11 according to the set parameters and automatically plans the laser cutting path for layered processing (such as Fig.12 ), calculate the processing time.

[0051] like Fig.13The parameters of the V-shaped cutting groove include the maximum width L of the V-shaped cutting groove, the angle β of the two sides of the V-shaped cutting groove and the laser depth step H, the laser depth step H is the distance between the upper and lower adjacent layers during layered processing, and the laser parameters include laser power, laser frequency, pulse width and duty cycle; Figure 7 , Figure 8 , the deflection angle α = θ / 2, where θ is the cone angle of the conical laser beam, D is the diameter of the beam incident on the laser focusing mirror, W D It is the distance between the laser focusing mirror and the laser focus, and can also be replaced by the focal length of the laser focusing mirror.

[0052] As one embodiment, in the laser cutting path of the layered processing, such as Fig.13 The width of each layer gradually narrows from top to bottom, and the V-shaped cutting groove is finally formed on the vertical section. In order to make the width of the V-shaped cutting groove 83 as narrow as possible and to reduce the material removed by cutting as little as possible to improve the utilization rate of raw materials, the angle β of the two sides of the V-shaped cutting groove 83 is made to be equal to θ, where θ is the cone angle of the conical laser beam 14. Where D is the diameter of the beam incident on the laser focusing mirror, W D is the distance between the laser focusing mirror and the laser focus; when processing each layer, Fig.14 , using a path that processes from the inside to the outside or from the outside to the inside, one ring at a time.

[0053] The parameters of the laser cutting path include the processing width L of each layer n , laser width step amount M, laser moving speed V, the processing width L of each layer is the processing width of each layer during layered processing, the laser width step amount M is the step amount between two adjacent rings when the laser processes one ring at a time on each layer, and the laser moving speed V is the cutting linear speed when the laser processes one ring at a time, V=πr·n / 30, mm / s, wherein r is the rotation radius at the cutting point, mm; π is a constant of 3.14, dimensionless; and n is the rotation speed of the C-axis, revolutions / min.

[0054] S2, the ingot to be processed is moved and positioned to the processing area by the X-axis moving module and the Y-axis moving module, and then the B-axis module is controlled according to the deflection angle α to make the ingot to be processed swing in the vertical direction, so that the angle between its vertical center axis and the vertical direction is α; then the laser generated by the laser assembly is focused on the surface of the ingot to be processed by the CCD automatic focusing system, and cutting is performed according to the planned laser cutting path, including the rotation of the C-axis module, the movement of the X-axis moving module 12, the Y-axis moving module 13 and the first Z-axis moving module 7. By tilting the ingot 8 to be processed so that its inclination is adapted to the inclination of the tapered side of the tapered laser beam 14, a cylinder without taper is cut on the ingot 8, thereby realizing taper-free processing.

[0055] Specifically, the positioning method of the ingot 8 to be processed can be as follows: Fig.10 A plurality of concentric annular positioning lamps 15 that can be lifted and lowered are arranged above the positioning area. The stage includes a processing seat 9 and a circular vacuum suction cup 19. The processing seat 9 is installed on the C-axis module. The vacuum suction cup 19 is arranged on the processing seat 9 and is used to fix the crystal ingot 8 to be processed in the form of vacuum adsorption. The center of the vacuum suction cup 19 is located on the rotating shaft of the processing seat 9. The vacuum suction cup 19 rotates coaxially with the processing seat 9. The height of the annular positioning lamp 15 is adjusted according to the size of the crystal ingot 8 to be processed, and the corresponding concentric vacuum suction cup 19 and the positioning ring corresponding to the size of the crystal ingot 8 are projected in the positioning area. 18, firstly, by controlling the X-axis moving module 12 and the Y-axis moving module 13, the vacuum suction cup 19 is moved to the corresponding positioning ring 18, so that the center of the vacuum suction cup 19 is aligned with the center of gravity of the positioning ring 18 corresponding to the vacuum suction cup 19 (the edge of the vacuum suction cup 19 can be overlapped with the edge of the corresponding positioning ring 18), and then the crystal ingot 8 to be processed is placed on the vacuum suction cup 19, so that the center of the crystal ingot 8 to be processed is overlapped with the center of the positioning ring 18 corresponding to the crystal ingot, and then the crystal ingot 8 to be processed is fixed by vacuum adsorption, and then the Y-axis moving module 13 is controlled to move the crystal ingot 8 to be processed to the processing area under the laser assembly. In this way, the accurate positioning of the crystal ingot can be ensured, and the rotating axis of the crystal ingot and the processing seat can be ensured to be coaxial, so as to realize coaxial processing and ensure the processing accuracy.

[0056] S3. After the side cutting of the ingot is completed, the control system controls the B-axis module to swing the ingot in the vertical direction, so that its vertical center axis returns to the vertical direction, focuses the laser on the surface of the ingot to be processed, and cooperates with the movement of the X-axis moving module, the Y-axis moving module and the C-axis module to process the top or bottom surface of the ingot according to the planned laser processing path. The surface (top or bottom surface) of the ingot 8 can be processed by conventional methods, such as grinding and polishing the surface of the ingot 8 in a circular outward or inward manner.

[0057] The laser cutting and laser processing are fully controlled by the control system (industrial computer), including: controlling the movement of the X-axis moving module 12 and the Y-axis moving module 13 to position and coordinate the movement of the crystal ingot 8 to be processed; controlling the movement of the first Z-axis moving module 7 to adjust the focal position of the laser to achieve focusing and stepping in the direction of processing depth; controlling the CCD autofocus system to automatically capture the processing area information through visual technology to facilitate focusing; controlling the movement of the C-axis module to rotate the crystal ingot 8 to be processed; controlling the movement of the B-axis module 11 to tilt or straighten the crystal ingot 8, which is mainly used to cut out a cylindrical crystal ingot 8 with a vertical side 82; planning the cutting path of the side 82 of the crystal ingot 8 and the processing path of the surface of the crystal ingot 8, including various processing parameters.

[0058] The above detailed description is a specific description of a feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the patent scope of this case.

Claims

1. A multi-band laser confocal silicon carbide ingot processing equipment, characterized in that: The invention comprises a stage and a laser assembly, wherein the stage is used to carry a crystal ingot to be processed, the laser assembly comprises a first laser, a second laser, a first reflector, a second reflector and a laser focusing mirror, the first reflector is used to reflect a first wavelength laser emitted by the first laser, the second reflector is used to reflect a second wavelength laser emitted by the second laser, the reflected first wavelength laser and the reflected second wavelength laser are output in a common optical path, and the crystal ingot to be processed on the stage is processed through the laser focusing mirror; the stage comprises an X-axis moving module, a Y-axis moving module, a C-axis moving module, a The Y-axis moving module is arranged on the X-axis moving module, the B-axis module is arranged on the Y-axis moving module, the C-axis module is arranged on the B-axis module, the C-axis module is connected with the crystal ingot to be processed, the C-axis module is used to drive the crystal ingot to be processed to rotate around its vertical center axis, and the B-axis module is used to drive the crystal ingot to be processed to swing in a vertical plane, so that the vertical center axis of the crystal ingot to be processed is inclined relative to the vertical direction, so as to eliminate the cutting effect of the conical laser beam focused by the laser focusing mirror on the side of the crystal ingot, so as to process a cylindrical crystal ingot whose side surface is completely perpendicular to the bottom surface.

2. The multi-band laser confocal silicon carbide ingot processing equipment according to claim 1, characterized in that: The laser assembly also includes a laser cutting head and a first Z-axis moving module. The laser focusing mirror is arranged in the laser cutting head. The output end of the laser cutting head faces the crystal ingot to be processed. The laser cutting head is installed on the first Z-axis moving module and moves up and down in the vertical direction through the first Z-axis moving module. The parallel laser beam emitted by the first laser or the second laser is focused by the laser focusing mirror on the laser cutting head, and the laser focus is focused on the crystal ingot to be processed through the up and down movement of the first Z-axis moving module.

3. The multi-band laser confocal silicon carbide ingot processing equipment according to claim 1, characterized in that: The first reflector and the second reflector are arranged in parallel up and down, the first reflector is located above the second reflector, the first reflector is a total reflector, and the second reflector is a coated semi-transparent semi-reflective mirror, which reflects the second wavelength laser while allowing the first wavelength laser to pass through. The first wavelength laser emitted by the first laser is reflected by the first reflector, and then passes through the second reflector, and is output in the same optical path as the second wavelength laser emitted by the second laser and reflected by the second reflector, and converges on the laser focusing mirror.

4. The multi-band laser confocal silicon carbide ingot processing equipment according to claim 1, characterized in that: The B-axis module is used to drive the ingot to be processed to swing in a vertical plane, so that the vertical center axis of the ingot to be processed is deflected by an angle α relative to the vertical direction, α=θ / 2, where θ is the cone angle of the conical laser beam, D is the diameter of the beam incident on the laser focusing mirror, W D is the distance between the laser focusing mirror and the laser focus.

5. The multi-band laser confocal silicon carbide ingot processing equipment according to claim 1, characterized in that: It also includes a positioning area, above which are arranged a number of concentric annular positioning lights for projecting a number of positioning rings for positioning the stage and the crystal ingot to be processed in the positioning area, the stage includes a processing seat and a circular vacuum suction cup, the processing seat is mounted on the C-axis module, the vacuum suction cup is arranged on the processing seat, and is used to fix the crystal ingot to be processed in the form of vacuum adsorption, and the center of the vacuum suction cup is located on the rotating shaft of the processing seat, and the processing seat is driven by the X-axis moving module and the Y-axis moving module to position the vacuum suction cup and the center of the crystal ingot to be processed to the center of the corresponding positioning ring for positioning.

6. The multi-band laser confocal silicon carbide ingot processing equipment according to claim 5, characterized in that: A support column is provided on the positioning area, and a second Z-axis movable module is provided on the support column. Several annular positioning lights are installed on the second Z-axis movable module. The second Z-axis movable module drives the annular positioning lights to move up and down along the support column to project positioning rings with the same center but different diameters to adapt to the processing of ingots with different diameters.

7. The multi-band laser confocal silicon carbide ingot processing equipment according to claim 1, characterized in that: The B-axis module includes a swing motor, a swing plate and a swing arm, one end of the swing plate is vertically connected to the output shaft of the swing motor, and the other end is vertically connected to the swing arm; the C-axis module includes a rotating motor and a processing seat, the rotating motor is installed on the swing arm, the processing seat is drive-connected to the rotating motor, and the rotating axis of the processing seat is perpendicular to the rotating axis of the swing motor.

8. A multi-band laser confocal silicon carbide ingot processing method, using the multi-band laser confocal silicon carbide ingot processing equipment according to any one of claims 1 to 7, characterized in that: The steps include: S1. Setting parameters on the control system, including the diameter and thickness of the final ingot product, the parameters of the V-shaped cutting groove, the laser parameters and the speed n of the C-axis module. The control system calculates the deflection angle α of the B-axis module according to the set parameters, automatically plans the laser cutting path for layered processing, and calculates the processing time; The parameters of the V-shaped cutting groove include the maximum width L of the V-shaped cutting groove, the angle β of the two sides of the V-shaped cutting groove and the laser depth step H, wherein the laser depth step H is the distance between two adjacent layers in layered processing, and the laser parameters include laser power, laser frequency, pulse width and duty cycle; the deflection angle α=θ / 2, wherein θ is the cone angle of the conical laser beam, D is the diameter of the beam incident on the laser focusing mirror, W D is the distance between the laser focusing mirror and the laser focus; S2, move and position the ingot to be processed to the processing area through the X-axis moving module and the Y-axis moving module, and then control the B-axis module according to the deflection angle α to make the ingot to be processed swing in the vertical direction, so that the angle between its vertical center axis and the vertical direction is α; then focus the laser generated by the laser component on the surface of the ingot to be processed through the CCD automatic focusing system, and cut the side of the ingot according to the planned laser cutting path; S3. After the side cutting of the crystal ingot is completed, the control system controls the B-axis module to swing the crystal ingot in the vertical direction, so that its vertical center axis returns to the vertical direction, focuses the laser on the surface of the crystal ingot to be processed, and cooperates with the movement of the X-axis moving module, the Y-axis moving module and the C-axis module to process the top or bottom surface of the crystal ingot according to the planned laser processing path.

9. The multi-band laser confocal silicon carbide ingot processing method according to claim 8, characterized in that: In the laser cutting path of the layered processing described in step S1, the width of each layer gradually narrows from top to bottom, and the V-shaped cutting groove is finally formed on the vertical section. The angle β between the two sides of the V-shaped cutting groove is θ, where θ is the cone angle of the conical laser beam. Where D is the diameter of the beam incident on the laser focusing mirror, W D It is the distance between the laser focusing mirror and the laser focus. When processing each layer, the processing path is from the inside to the outside or from the outside to the inside, one ring at a time. The parameters of the laser cutting path include the processing width L of each layer n , laser width step amount M, laser moving speed V, the processing width L of each layer is the processing width of each layer during layered processing, the laser width step amount M is the step amount between two adjacent rings when the laser processes one ring at a time on each layer, and the laser moving speed V is the cutting linear speed when the laser processes one ring at a time, V=πr·n / 30, mm / s, wherein r is the rotation radius at the cutting point, mm; π is a constant of 3.14, dimensionless; and n is the rotation speed of the C-axis, revolutions / min.

10. The multi-band laser confocal silicon carbide ingot processing method according to claim 8, characterized in that: In step S2, the method for moving and positioning the ingot to be processed to the processing area by the X-axis moving module and the Y-axis moving module is as follows: a plurality of concentric annular positioning lights that can be raised and lowered are arranged above the positioning area, the stage comprises a processing seat and a circular vacuum suction cup, the processing seat is mounted on the C-axis module, the vacuum suction cup is arranged on the processing seat, and the center of the vacuum suction cup is located on the rotating shaft of the processing seat; the height of the annular positioning lights is adjusted according to the size of the ingot to be processed, and the corresponding concentric vacuum suction cups and the positioning rings corresponding to the size of the ingot are projected in the positioning area respectively, the vacuum suction cups are first moved to the corresponding positioning rings by controlling the X-axis moving module and the Y-axis moving module, so that the center of the vacuum suction cups is aligned with the center of gravity of the positioning ring corresponding to the vacuum suction cups, and then the ingot to be processed is placed on the vacuum suction cup, so that the center of the ingot to be processed coincides with the center of the positioning ring corresponding to the ingot, and then the ingot to be processed is fixed by vacuum adsorption, and then the Y-axis moving module is controlled to move the ingot to be processed to the processing area under the laser assembly.

Images