A method and apparatus for water jet assisted laser and mechanical compound drilling

Abstract

The present application relates to laser processing technology and precision cutting technology field, concretely is a kind of water jet assisted laser and mechanical compound drilling method and device, including the following steps: S1, the silicon carbide material to be processed is clamped and fixed above the infrared coaxial alignment sensor of device guide rail platform, after laser lens calibration focal length, water jet device is opened, and the controller receives the transmittance change of the infrared light beam emitted by the infrared coaxial alignment sensor in the processing process through signal receiving unit to determine the processing termination opportunity by bringing into penetration determination formula;S2, after pre-processing, switching position is carried out through device guide rail platform, and the coaxial calibration of pre-hole and PCD drill bit is completed by means of infrared coaxial alignment sensor;S3, after calibration, PCD drill bit is driven by drilling device according to pre-set parameter, and pre-hole is processed by pecking drill type sizing and reaming, and high-quality silicon carbide through-hole meeting the requirements of size and precision is obtained.

Description

Technical Field

[0001] This invention relates to the fields of laser processing technology and precision cutting technology, specifically to a method and apparatus for water jet-assisted laser and mechanical composite drilling. Background Technology

[0002] Silicon carbide (SiC) is a third-generation wide-bandgap semiconductor material. Compared with traditional silicon-based semiconductor materials, it has many outstanding advantages, such as a large bandgap, high breakdown electric field strength, excellent thermal conductivity, and extremely strong chemical stability. It can meet the requirements of use under extreme conditions such as high frequency, high voltage, high temperature, and high power. It has been widely used in high-frequency power electronic equipment, new energy vehicle power devices, aerospace core components, 5G communication radio frequency components and other high-end manufacturing fields. It is a key core material to promote the iterative upgrade of the next generation of semiconductor devices, and its market application prospects and industrialization value are very broad.

[0003] In the fabrication process of various silicon carbide-based semiconductor devices, micro-hole precision machining is an indispensable key process. Micro-hole machining of silicon carbide substrates is characterized by a large number of holes, small hole diameters, stringent precision requirements, and high hole quality standards. The forming quality, surface finish, and structural integrity of the micro-holes directly determine the compatibility of subsequent device assembly, electrical performance stability, and long-term reliability. It is an important link affecting the yield and core performance of silicon carbide devices.

[0004] However, silicon carbide itself possesses extremely high hardness and significant brittleness, with a hardness approaching that of conventional cemented carbide materials. It is a typical example of a difficult-to-machine, hard, and brittle material. Traditional micro-hole machining methods using cemented carbide drills suffer from numerous insurmountable technical drawbacks in actual processing. Firstly, the high hardness of silicon carbide exacerbates tool wear, making cemented carbide drills prone to chipping, dulling, and breakage. This not only results in extremely low processing efficiency but also necessitates frequent tool replacements, significantly increasing material costs and processing time. Secondly, the continuous cutting forces and concentrated cutting heat generated during machining cause irreversible damage to the highly brittle silicon carbide substrate, easily leading to defects such as edge chipping at the hole opening, micro-cracks in the hole wall, and large diameter deviations. These microscopic defects directly damage the structural integrity and semiconductor performance of the silicon carbide material, significantly reducing the overall quality and lifespan of the device, failing to meet the performance requirements of high-end devices. Furthermore, the intense frictional wear between the tool and the silicon carbide workpiece further shortens tool life, causing a sharp increase in overall processing costs, making it difficult to meet the cost control requirements of mass production of silicon carbide devices.

[0005] To address the issues of tool wear and substrate mechanical damage in traditional machining, laser processing technology, with its high precision, high flexibility, and non-contact processing characteristics, has been gradually applied to the field of silicon carbide micro-hole machining. This technology avoids direct contact with the workpiece, effectively preventing tool wear and chipping, while improving the precision and efficiency of micro-hole machining, and is suitable for various complex hole diameters and processing scenarios. However, laser processing of silicon carbide materials still has unavoidable technical shortcomings: the highly concentrated energy during laser processing generates instantaneous high temperatures in localized areas of the silicon carbide substrate, causing significant thermal effects. This leads to the formation of a recast layer on the hole wall, and induces microcracks on the inner wall and surrounding area of ​​the hole, forming a large heat-affected zone that directly damages the original crystal structure and physicochemical properties of the silicon carbide substrate. In addition, the thermal effect also results in poor hole shape consistency and excessive surface roughness of the hole wall, failing to meet the stringent quality standards for micro-holes in high-end silicon carbide semiconductor devices, thus limiting the large-scale industrial promotion and application of laser processing technology in the field of silicon carbide devices. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a method and apparatus for water jet-assisted laser and mechanical composite drilling. This method solves the problems that concentrated laser energy can easily lead to the formation of a recast layer, microcracks, and heat-affected zone on the hole wall, which damages material properties. Furthermore, the hole shape consistency and hole wall surface quality are difficult to meet the stringent requirements of high-end devices, making it difficult to achieve large-scale industrial applications.

[0007] This invention provides a method for water jet-assisted laser-mechanical composite drilling, comprising the following steps:

[0008] S1. The silicon carbide material to be processed is clamped and fixed above the infrared coaxial alignment sensor on the guide rail platform of the device. After the laser lens is calibrated, the water jet device is turned on. The water jet parameters are dynamically adjusted to assist the laser in completing the pre-through hole processing of the target diameter. During the processing, the controller receives the transmittance change of the infrared beam emitted by the infrared coaxial alignment sensor through the signal receiving unit and uses it to determine the processing termination time by inputting it into the penetration judgment formula. During the water jet-assisted laser processing, the controller drives the nozzle bracket to adjust the water jet nozzle in linkage with the drilling depth fed back by the laser lens sensor in real time, dynamically optimizing the offset distance and offset angle of the water jet, and synchronously adjusting the water jet pressure of the water pressure system. Specifically, it is obtained from the following formula:

[0009]

[0010]

[0011]

[0012] In the formula, This represents the offset distance of the water jet; The angle between the axis of the water jet nozzle and the vertical direction; The pressure of the water jet; To detect borehole depth; This represents the initial offset distance of the water jet; The target diameter for pre-machined holes; This is the vertical distance from the nozzle outlet to the workpiece surface; This is the initial water pressure;

[0013] S2. After pre-processing, the work station is switched through the device guide rail platform, and the coaxial calibration of the pre-through hole and the PCD drill bit is completed with the help of the infrared coaxial alignment sensor.

[0014] S3. After calibration, the PCD drill bit driven by the drilling device performs a pecking-type sizing and enlarging process on the pre-through hole according to the preset parameters to obtain a high-quality silicon carbide through hole that meets the requirements in terms of both size and accuracy.

[0015] Preferably, the step of determining the processing termination time in step S1 is as follows: During the pre-processing process, the infrared coaxial alignment sensor continuously emits an infrared beam. The controller calculates the real-time transmittance of the infrared beam based on the infrared light intensity detected by the sensor in real time, and then determines whether the pre-through hole is completely penetrated using a dual-condition penetration determination formula. The formula is:

[0016]

[0017]

[0018] In the formula: for Real-time transmittance of the infrared beam at any given moment; for Effective light intensity collected by the time sensor receiver; for The rated emitted light intensity of the time sensor's transmitter; The transmittance threshold is used to determine penetration. This represents the step change in transmittance per unit time. The sensor sampling interval; The threshold for step change is set; when both conditions are met simultaneously, the controller determines that the pre-through hole has been completely penetrated and then shuts down the laser device and the water pressure system, ending the pre-processing.

[0019] Preferably, in step S2, the infrared coaxial alignment sensor emits an infrared beam. After the beam passes through the pre-through hole, it is collected by the signal receiving unit. By identifying the center of the light spot and the intensity distribution of the beam passing through the hole, the geometric center coordinates of the pre-through hole are obtained. The controller compares the geometric center coordinates with the axis coordinates of the PCD drill bit and then makes fine adjustments to achieve coaxial positioning of the pre-through hole and the PCD drill bit, ensuring that the axes of the two coincide and avoiding hole position displacement during subsequent hole enlargement processing.

[0020] Preferably, a laser wavelength cutoff filter is fitted at the front end of the detection end of the infrared coaxial alignment sensor.

[0021] Preferably, the preset parameter in step S3 is the target pre-through hole diameter quantitatively calculated using the optimal value formula for hole enlargement allowance. Specifically, the target diameter of the pre-through hole is determined using the optimal value formula for single-sided hole enlargement allowance, with the final target hole diameter and the maximum heat-affected zone thickness of laser-processed silicon carbide as constraints. The formula is as follows:

[0022]

[0023]

[0024] in, This is the allowance for single-sided hole expansion; The final target hole diameter; Pre-diameter of the through hole for laser processing; The controller first determines the single-sided hole enlargement allowance to ensure coverage of the heat-affected zone, based on the maximum heat-affected zone thickness generated during laser processing of silicon carbide. Combined with the final target aperture The diameter of the pre-through hole is obtained by reverse calculation. With regard to processing range.

[0025] A device for water jet-assisted laser-mechanical composite drilling employs the water jet-assisted laser-mechanical composite drilling method described above. Specifically, it includes a laser device, a water jet device, an infrared coaxial alignment sensor, a signal receiving unit, a drilling device, a PCD drill bit, silicon carbide, and a controller. The water jet device includes a water jet nozzle, a nozzle support, and a water pressure system, providing water jet assistance for laser processing. The water jet device is controlled by the controller. During drilling using the laser emitted from the laser device, the controller, based on the real-time drilling depth of the drill bit in the drilling device, drives the nozzle support to adjust the water jet nozzle in a coordinated manner, dynamically optimizing the water jet's offset angle and distance, while simultaneously regulating the water jet output pressure of the water pressure system.

[0026] This invention offers the following advantages: It employs a composite processing method combining waterjet-assisted laser pre-machining and PCD drill bit mechanical reaming. First, waterjet-assisted laser machining efficiently completes low-damage pre-hole machining. Then, the PCD drill bit sizing and reams the pre-hole, significantly improving the dimensional accuracy, roundness, and surface quality of silicon carbide holes, effectively suppressing micro-cracks, edge chipping, and thermal damage. Furthermore, the device boasts a high degree of automation, precise positioning, and strong processing stability, fundamentally solving the technical problems of severe tool wear, low processing efficiency, and poor accuracy and insufficient surface integrity in traditional mechanical drilling, as well as single laser processing. It is particularly suitable for high-precision, high-quality drilling of hard and brittle silicon carbide materials. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a device for water jet-assisted laser and mechanical composite drilling.

[0029] Figure 2 This is a schematic diagram illustrating the steps of using a method and apparatus for water jet-assisted laser and mechanical composite drilling.

[0030] Figure 3 A schematic diagram of water jet-assisted laser processing.

[0031] Figure 4 This is a schematic diagram of drill bit reaming.

[0032] In the diagram: 1-Laser device; 2-Lens; 3-Silicon carbide; 4-Water jet nozzle; 5-Nozzle support; 6-Hydraulic system; 7-Drilling device; 8-PCD drill bit; 9-Infrared coaxial alignment sensor; 10-Device guide rail platform; 11-Controller; 12-Signal receiving unit. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example

[0035] The following are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the following embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention.

[0036] Please refer to the attached instruction manual. Figure 1-4 The present invention provides a method and apparatus for water jet-assisted laser and mechanical composite drilling, comprising a laser device 1, a water jet device, an infrared coaxial alignment sensor 9, a signal receiving unit 12, a drilling device 7, a PCD drill bit 8, a silicon carbide 3, and a controller 11.

[0037] The silicon carbide 3 has a cubic structure and its processing thickness is set to 5mm. The PCD drill bit 8 adopts a composite material structure design, with the drill shank and drill rod both made of cemented carbide, and the drill tip made of polycrystalline diamond (PCD). The drill bit diameter is 1mm, which is suitable for drilling silicon carbide.

[0038] The water jet device adjusts the distance and angle between the water jet nozzle 4 and the workpiece via the nozzle bracket 5. The water pressure system 6 is activated after being set to a suitable pressure value, ensuring a stable water jet is sprayed onto the predetermined processing area. Laser processing is then performed after the water flow stabilizes, preventing water flow fluctuations from interfering with the laser beam path and ensuring processing stability. The water used is deionized water, which effectively avoids energy absorption and scattering of the laser during transmission in water, ensuring processing accuracy and preventing ion contamination and water stains from remaining on the workpiece surface.

[0039] The laser device adjusts the focal length of the laser lens 2 to align the laser focus with the initial position of the silicon carbide workpiece to be processed. After the water jet stabilizes, the laser device 1 is activated according to preset laser parameters for pre-processing until a pre-through hole with a diameter of 0.8 mm is formed. During processing, the controller can drive the nozzle bracket to adjust the water jet nozzle in conjunction with the real-time drilling depth of the lens, dynamically optimizing the offset angle and offset distance of the water jet, while simultaneously controlling the water jet output pressure of the water pressure system. It can adaptively cool the processing area in real time, flush away molten silicon carbide debris, effectively suppress the generation of recast layers, microcracks, and heat-affected zones, achieving low-damage pre-drilling and providing a foundation for subsequent hole enlargement processes.

[0040] The infrared coaxial alignment sensor 9 and signal receiving unit 12 are described above. The signal receiving unit is mounted around the circumference of the laser lens 2 housing and is coaxial with the laser optical path. During laser pre-processing, the infrared coaxial alignment sensor continuously emits an infrared detection beam upwards. The signal receiving unit 12 receives the signal, and the controller collects the transmittance data of the infrared beam using a real-time transmittance calculation formula. Then, it uses a dual-condition penetration determination formula to determine whether the pre-through hole is completely penetrated. When the penetration determination condition is met, the controller determines that the pre-through hole has been completely penetrated, immediately shuts down the laser device and the water pressure system, and terminates the pre-processing.

[0041] After pre-machining is completed, the controller 11 controls the guide rail platform 10 to move to the right by a specified distance, so that the workpiece reaches the station below the PCD drill bit, and the pre-machined hole and the PCD drill bit are coaxially aligned.

[0042] The infrared coaxial alignment sensor 9 emits an infrared detection beam upwards. After passing through the pre-through hole, the beam is collected by the sensor signal receiving unit 12. By identifying the center of the light spot and the intensity distribution of the beam passing through the hole, the geometric center coordinates of the pre-through hole are obtained. The controller compares and compensates these center coordinates with the axis coordinates of the PCD drill bit to achieve high-precision coaxial positioning of the pre-through hole and the PCD drill bit, ensuring that their axes coincide and avoiding hole position offset during subsequent hole reaming.

[0043] After coaxial positioning is completed, the spindle of the drilling device 7 performs pecking-type sizing and enlarging machining on the pre-through hole according to the set rotation speed and downward feed speed. This corrects the form and position errors caused by water jet-assisted laser pre-machining, reduces the surface roughness and thermal damage of the hole wall, and finally obtains a high-quality through hole that meets the requirements in terms of size and accuracy.

[0044] In a preferred embodiment, the steps of using the water jet-assisted laser-mechanical composite drilling device and method for silicon carbide processing are as follows:

[0045] Step 1:

[0046] The silicon carbide material 3 is clamped onto the infrared coaxial alignment sensor 9 of the device guide rail platform 10 and fixed. Using the material surface as the positioning reference, the position of the clamped material is moved so that the area to be processed is aligned directly below the laser beam path.

[0047] Turn on the laser device.

[0048] The controller 11 drives the laser lens 2 to move along the Z-axis until the focus falls on the silicon carbide surface. The focus is calibrated to complete the focusing. The target diameter of the pre-through hole is quantitatively calculated using the formula of the optimal value of the hole enlargement allowance, with the final target hole diameter of 1mm as the reference.

[0049] The method of quantitatively calculating the target pre-through hole diameter using the optimal value formula for hole enlargement allowance specifically involves: using the final target hole diameter and the maximum heat-affected zone thickness of laser-processed silicon carbide as constraints, determining the target diameter of the pre-through hole using the optimal value formula for single-sided hole enlargement allowance. The formula is as follows:

[0050]

[0051]

[0052] In the formula, The allowance for single-sided hole enlargement ranges from 0.05mm to 0.15mm. The final target hole diameter; Pre-diameter of the through hole for laser processing; The controller first determines the single-sided hole enlargement allowance to ensure coverage of the heat-affected zone, based on the maximum heat-affected zone thickness generated during laser processing of silicon carbide. Combined with the final target aperture The diameter of the pre-through hole is obtained by reverse calculation. With regard to processing range.

[0053] The machining range refers to the target diameter range of the pre-drilled hole being 0.7mm to 0.9mm; and the allowance range. R = 0.05mm - 0.15mm.

[0054] The maximum heat-affected zone thickness Zmax can be determined through preliminary experiments. A heat-affected zone will be formed on the surface of the material after laser processing. The surface quality of this area is relatively low, so it is removed by a drill bit in this invention. The thickness of this heat-affected zone in the pre-hole in this invention is 0.05 mm.

[0055] In this embodiment, the maximum heat-affected zone thickness during silicon carbide laser processing =50 =0.05mm, therefore the minimum single-sided enlargement allowance is =0.05mm, the optimal allowance upper limit is 0.15mm, and the corresponding target diameter range of the pre-through hole is 0.7mm~0.9mm. In this embodiment, the target diameter of the pre-through hole is selected as 0.8mm, and the laser processing parameters are set simultaneously to ensure that the processed hole diameter meets the target range.

[0056] Laser parameters: Select infrared picosecond pulsed laser, pulse frequency 1000kHz, single pulse energy 35. J, pulse width 10ps, continuous laser processing.

[0057] Step Two:

[0058] The PCD drill bit 8 is clamped on the spindle of the drilling device 7, and the tool setting is completed by the control controller 11. Tool setting is used to establish the axial machining zero point and radial initial coordinates of the PCD drill bit, eliminate the form and position errors caused by the drill bit clamping, unify the machining coordinate system of laser pre-machining and mechanical reaming processes, calibrate the rotational accuracy of the drill bit spindle, and ensure the feed accuracy and coaxiality of subsequent reaming processes.

[0059] Step 3:

[0060] Adjust the nozzle bracket 5 to adjust the angle of the water jet nozzle 4 aligned with the workpiece. After preseting the initial water pressure to 10MPa in the water pressure system 6, start the system to ensure a stable water jet sprayed onto the predetermined processing area. Once the water flow stabilizes, the controller records the water jet offset angle and distance before proceeding with laser processing. This avoids water flow fluctuations interfering with the laser beam path and ensures processing stability. The water used is deionized water, which effectively avoids energy absorption and scattering of the laser during transmission in water, ensuring processing accuracy and preventing ion contamination and water stains on the workpiece surface.

[0061] Step Four:

[0062] After the water jet is stably sprayed into the processing area, the laser device 1 is turned on, and the silicon carbide material is pre-processed by drilling according to the preset parameters. During the processing, the controller 11 drives the nozzle bracket 5 to adjust the water jet nozzle 4 in conjunction with the drilling depth fed back in real time by the confocal displacement sensor built into the laser lens 2, dynamically optimizing the offset distance and offset angle of the water jet, and synchronously controlling the output pressure of the water pressure system.

[0063]

[0064]

[0065]

[0066] In the formula, This represents the offset distance of the water jet; The angle between the axis of the water jet nozzle and the vertical direction; The pressure of the water jet; To detect borehole depth; The initial offset distance of the water jet is 5mm. The target diameter for pre-machined holes is 0.7-0.9 mm. This is the vertical distance from the nozzle outlet to the workpiece surface, with a value of 20mm. The initial water pressure is 10 MPa.

[0067] The process parameters are adaptive throughout the entire deep hole machining process. Real-time water jet cooling of the machining area promptly removes molten silicon carbide debris, effectively suppressing the formation of recast layers, microcracks, and heat-affected zones.

[0068] Step 5:

[0069] During laser pre-processing, an infrared coaxial alignment sensor continuously emits an infrared detection beam upwards. The transmittance data of the infrared beam is collected using a real-time transmittance calculation formula. Then, a dual-condition penetration determination formula is used to determine whether the pre-through hole is completely penetrated. The formula is as follows:

[0070]

[0071]

[0072] In the formula: for Real-time transmittance of the infrared detection beam; for The effective light intensity collected by the signal receiving unit at any given time; for The rated emitted light intensity of the time sensor's transmitter; The transmittance threshold for penetration determination is set to 80% in this example; This represents the step change in transmittance per unit time. The sensor sampling interval is fixed at 1ms; The threshold for a step change is set to 70% in this example.

[0073] When both conditions are met, the controller determines that the pre-through hole has been completely penetrated, forming a pre-through hole with a diameter of 0.8mm, shuts down the laser device and the water pressure system, and ends the pre-processing.

[0074] Step Six:

[0075] After pre-machining, the controller 11 moves the guide platform 10 of the control device a specified distance to the right, moving the silicon carbide workpiece and the pre-through hole to a position directly below the PCD drill bit 8. The infrared coaxial alignment sensor 9 is activated, emitting an infrared detection beam upwards. The beam passes through the pre-through hole and is collected by the receiving unit. By identifying the center position and intensity distribution of the transmitted light spot, the geometric center coordinates of the pre-through hole are obtained. The controller 11 compares these center coordinates with the axis coordinates of the PCD drill bit 8, driving the guide platform 10 to complete coordinate compensation and fine-tuning, ensuring that the center of the pre-through hole precisely coincides with the axis of the PCD drill bit, completing coaxial calibration and preventing hole position misalignment during subsequent hole enlargement processing.

[0076] Step Seven:

[0077] After coaxial positioning is completed, the controller 11 drives the spindle of the drilling device 7 to start. The spindle drives the PCD drill bit 8 to perform pecking drilling and sizing hole enlargement on the pre-through hole according to the preset spindle speed and downward feed speed.

[0078] The spindle speed is 12000 r / min, the feed rate is 5 mm / min, the depth of cut per pecking stroke is 0.01 mm, and the machining depth is 5.1 mm. Pecking-drilling achieves efficient chip removal, reduces axial cutting force, and suppresses silicon carbide chipping and micro-cracks. The low feed rate combined with the small depth of cut reduces cutting load, ensuring machining accuracy and surface quality, and extending tool life. The machining depth exceeding the workpiece thickness by 0.1 mm ensures complete penetration, eliminates exit machining defects, and guarantees through-hole continuity.

[0079] Mechanical drilling can correct hole diameter deviation, hole taper and roundness errors caused by waterjet-assisted laser pre-processing, remove the recast layer and thermal damage layer of the hole wall, and reduce the surface roughness of the hole wall.

[0080] Step 8:

[0081] The final machining process forms a through hole with a diameter of 1mm, and the dimensional accuracy and geometric tolerances meet the requirements. The controller 11 immediately pauses the spindle movement to complete the composite drilling of silicon carbide material.

[0082] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A method for water jet-assisted laser and mechanical composite drilling, characterized in that, Includes the following steps: S1. The silicon carbide material to be processed is clamped and fixed above the infrared coaxial alignment sensor on the guide rail platform of the device. After the laser lens is calibrated, the water jet device is turned on. The water jet parameters are dynamically adjusted to assist the laser in completing the pre-through hole processing of the target diameter. During the processing, the controller receives the transmittance change of the infrared beam emitted by the infrared coaxial alignment sensor through the signal receiving unit and uses it to determine the processing termination time by inputting it into the penetration judgment formula. During the water jet-assisted laser processing, the controller drives the nozzle bracket to adjust the water jet nozzle in linkage with the drilling depth fed back by the laser lens sensor in real time, dynamically optimizing the offset distance and offset angle of the water jet, and synchronously adjusting the water jet pressure of the water pressure system. Specifically, it is obtained from the following formula: In the formula, This represents the offset distance of the water jet; The angle between the axis of the water jet nozzle and the vertical direction; The pressure of the water jet; To detect borehole depth; This represents the initial offset distance of the water jet; The target diameter for pre-machined holes; This is the vertical distance from the nozzle outlet to the workpiece surface; This is the initial water pressure; S2. After pre-processing, the work station is switched through the device guide rail platform, and the coaxial calibration of the pre-through hole and the PCD drill bit is completed with the help of the infrared coaxial alignment sensor. S3. After calibration, the PCD drill bit driven by the drilling device performs a pecking-type sizing and enlarging process on the pre-through hole according to the preset parameters to obtain a high-quality silicon carbide through hole that meets the requirements in terms of both size and accuracy.

2. The method for water jet-assisted laser and mechanical composite drilling according to claim 1, characterized in that, The determination step for determining the processing termination time in step S1 is as follows: During the pre-processing process, the infrared coaxial alignment sensor continuously emits an infrared beam. The controller calculates the real-time transmittance of the infrared beam based on the infrared light intensity detected by the sensor, and then determines whether the pre-through hole is completely penetrated using a dual-condition penetration determination formula. The formula is as follows: In the formula: for Real-time transmittance of the infrared beam at any given moment; for Effective light intensity collected by the time sensor receiver; for The rated emitted light intensity of the time sensor's transmitter; The transmittance threshold is used to determine penetration. This represents the step change in transmittance per unit time. The sensor sampling interval; The threshold for step change is set; when both conditions are met simultaneously, the controller determines that the pre-through hole has been completely penetrated and then shuts down the laser device and the water pressure system, ending the pre-processing.

3. The method for water jet-assisted laser and mechanical composite drilling according to claim 1, characterized in that, In step S2, the infrared coaxial alignment sensor emits an infrared beam. After the beam passes through the pre-through hole, it is collected by the signal receiving unit. By identifying the center of the light spot and the intensity distribution of the beam passing through the hole, the geometric center coordinates of the pre-through hole are obtained. The controller compares the geometric center coordinates with the axis coordinates of the PCD drill bit and then makes fine adjustments to achieve coaxial positioning of the pre-through hole and the PCD drill bit, ensuring that the axes of the two coincide and avoiding hole position displacement during subsequent hole enlargement processing.

4. The method for water jet-assisted laser and mechanical composite drilling according to claim 3, characterized in that, The front end of the detection end of the infrared coaxial alignment sensor is equipped with a laser wavelength cutoff filter.

5. The method for water jet-assisted laser and mechanical composite drilling according to claim 1, characterized in that, The preset parameters in step S3 are used to quantitatively calculate the target pre-through hole diameter using the optimal value formula for hole enlargement allowance. Specifically, the target diameter of the pre-through hole is determined using the optimal value formula for single-sided hole enlargement allowance, with the final target hole diameter and the maximum heat-affected zone thickness of laser-processed silicon carbide as constraints. The formula is as follows: in, This is the allowance for single-sided hole expansion; The final target hole diameter; Pre-diameter of the through hole for laser processing; The controller first determines the single-sided hole enlargement allowance to ensure coverage of the heat-affected zone, based on the maximum heat-affected zone thickness generated during laser processing of silicon carbide. Combined with the final target aperture The diameter of the pre-through hole is obtained by reverse calculation. With regard to processing range.

6. A device for water jet-assisted laser and mechanical composite drilling, characterized in that, Drilling is performed using the water jet-assisted laser and mechanical composite drilling method as described in any one of claims 1-5, specifically including a laser device, a water jet device, an infrared coaxial alignment sensor, a signal receiving unit, a drilling device, a PCD drill bit, silicon carbide, and a controller; the water jet device includes a water jet nozzle, a nozzle support, and a water pressure system, providing water jet assistance for laser processing; the water jet device is controlled by the controller; during the drilling process using the laser emitted from the laser device, the controller drives the nozzle support to adjust the water jet nozzle in conjunction with the drilling depth fed back in real time by the laser lens sensor, dynamically optimizing the offset angle and offset distance of the water jet, while simultaneously regulating the water jet output pressure of the water pressure system.

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