Real-time monitoring acousto-optic deflection laser drilling system, method, equipment and medium

Abstract

The invention relates to the technical field of laser drilling, in particular to a real-time monitoring acousto-optic deflection laser drilling system, method, equipment and medium, and the system comprises a laser light source, a power monitoring module, an acousto-optic deflector, a galvanometer, a three-light coaxial device and a control system. The power monitoring module collects a power signal of a machining laser beam in real time, and the control system compares the power signal with a preset threshold value and dynamically adjusts laser output parameters. The three-light coaxial device carries out in-situ imaging on the surface of a workpiece while transmitting laser to obtain a drilling morphology image, and a control system recognizes defects such as fused heap or hole shape distortion based on the image and dynamically adjusts laser machining parameters or light beam deflection parameters. According to the system, through a double-closed-loop feedback mechanism, synchronous regulation and control of laser energy and machining morphology are achieved, and the consistency and precision of micropore machining are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of laser drilling technology, and in particular to a laser drilling system, method, equipment and medium for real-time monitoring of acousto-optic deflection. Background Technology

[0002] With the rapid development of microelectronics, flexible printed circuit boards (FPC), advanced packaging, and precision medical devices, increasingly stringent requirements have been placed on the precision, efficiency, and consistency of micro-hole processing in high-density interconnect structures. Laser drilling, due to its advantages of being non-contact, having high energy density, and being highly programmable, has become one of the mainstream processes for manufacturing micron-level through-holes / blind holes. However, in practical applications, traditional laser drilling systems still face several key technical bottlenecks: on the one hand, the laser output power is easily affected by factors such as thermal drift and optical loss, leading to fluctuations and uncontrollable energy acting on the workpiece, affecting hole consistency; on the other hand, vision systems used to observe drilling results often employ a side-axis arrangement, with illumination, imaging, and the laser optical path being non-axial, resulting in parallax and making it difficult to accurately acquire key information such as hole shape and edge melting state, thus failing to support reliable feedback; simultaneously, the scanning mechanism either relies on mechanical galvanometers, causing response lag, or uses only acousto-optic deflectors limited by the deflection angle, making it difficult to balance positioning accuracy and processing efficiency. These defects make existing technologies prone to problems such as melt accumulation, hole shape distortion, and depth loss in micro-hole processing. The aforementioned defects make existing technologies prone to problems such as molten material buildup, distorted hole shape, and uncontrolled depth in micro-hole fabrication.

[0003] Therefore, the existing laser drilling process lacks a closed-loop control mechanism based on real-time energy monitoring and coaxial visual feedback, resulting in technical problems such as poor processing consistency, easy melting and hole shape defects that urgently need to be solved. Summary of the Invention

[0004] The main objective of this application is to provide a laser drilling system, method, equipment, and medium for real-time monitoring of acousto-optic deflection, aiming to solve the technical problems of existing laser drilling processes lacking a closed-loop control mechanism based on real-time energy monitoring and coaxial visual feedback, resulting in poor processing consistency and easy occurrence of melt accumulation and hole shape defects.

[0005] To achieve the aforementioned objectives, the first aspect of this application proposes a real-time monitoring system for acoustic-optical deflection laser drilling, comprising: Laser source, used to output the laser beam for processing; A power monitoring module is installed in the output optical path of the laser source to collect the power signal of the processing laser beam in real time. An acousto-optic deflector is used to receive the processing laser beam transmitted through the power monitoring module and to deflect the processing laser beam non-mechanically based on a control signal. A galvanometer, located downstream of the acousto-optic deflector, is used to scan the deflected processing laser beam to guide the processing laser beam to different processing positions on the workpiece. The three-optical-coaxial device includes a laser transmission channel, an illumination optical path, and an imaging optical path with the same main optical axis. It is used to perform in-situ imaging of the workpiece surface while transmitting the processing laser beam to obtain a drilling morphology image. The control system is electrically connected to the power monitoring module, the acousto-optic deflector, the galvanometer, and the imaging camera. The control system is used to compare the power signal with a preset power threshold. If there is a deviation, the output parameters of the laser source are adjusted. The control system is also used to identify hole defects based on the borehole topography image and dynamically adjust the laser processing parameters or beam deflection parameters to suppress molten material buildup or hole distortion.

[0006] Furthermore, a first focusing lens, an aperture, and a second focusing lens are sequentially provided between the acousto-optic deflector and the galvanometer, wherein the aperture is located at the back focal plane of the first focusing lens, and the second focusing lens is used to image the light field formed by the aperture onto the incident surface of the galvanometer.

[0007] Furthermore, the focal length of the first focusing lens is f1, the focal length of the second focusing lens is f2, and f2>f1; the distance between the first focusing lens and the second focusing lens is L=f1+f2.

[0008] Furthermore, the three-optical coaxial device includes multiple reflectors, and the laser transmission channel, illumination optical path, and imaging optical path share the same main optical axis in space through the multiple reflectors.

[0009] Furthermore, the system also includes a height measuring device, which is disposed beside the three-optical coaxial device and emits a measuring beam toward the workpiece surface in a direction parallel to the main optical axis, for real-time acquisition of the height information of the workpiece surface and transmission of the height information to the control system to dynamically adjust the laser focus position.

[0010] A second aspect of this application proposes a method for real-time monitoring of acousto-optic deflection laser drilling, the method being executed by the system described in any one of the above-mentioned methods, comprising: The laser beam is output from a laser source, and the power signal of the laser beam is collected in real time by a power monitoring module. The processing laser beam is input into an acousto-optic deflector, and the processing laser beam is deflected non-mechanically based on a control signal; The deflected processing laser beam is scanned by a galvanometer and guided to the target processing position on the workpiece. While transmitting the processing laser beam, the workpiece surface is imaged in situ using a three-optical coaxial device to obtain a drilling morphology image. The power signal is compared with a preset power threshold. If there is a deviation, the output parameters of the laser source are adjusted. Based on the borehole morphology image, hole defects are identified, and laser processing parameters or beam deflection parameters are dynamically adjusted to suppress molten deposits or hole distortion.

[0011] Further, the step of comparing the power signal with a preset power threshold and adjusting the output parameters of the laser source if a deviation exists includes: The power signal of the current processing laser beam is acquired in real time, and the power signal is compared with a preset power threshold. When the power signal deviates from the preset power threshold by more than the allowable error range, a power adjustment command is generated; The output power or pulse energy of the laser source is adjusted according to the power adjustment command.

[0012] Furthermore, the step of identifying hole shape defects based on the borehole topography image and dynamically adjusting laser processing parameters or beam deflection parameters includes: Real-time image analysis is performed on the borehole morphology images to determine whether there is molten rock, borehole shrinkage, or borehole shape distortion. If a hole-shaped defect is identified, the target parameter to be adjusted is determined based on the defect type; Based on the target parameters, a parameter correction command is sent to the laser source or acousto-optic deflector. A third aspect of this application also includes a computer device comprising a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of any of the methods described above.

[0013] The fourth aspect of this application also includes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0014] Beneficial effects By integrating a power monitoring module, an acousto-optic deflector, a galvanometer, a three-optical-coaxial device, and a control system into a laser processing system, a dual-closed-loop real-time control mechanism was constructed. On the one hand, the control system compares the processing laser beam power signal collected by the power monitoring module with a preset threshold and dynamically adjusts the laser source output parameters to ensure energy stability. On the other hand, the three-optical-coaxial device performs in-situ imaging of the workpiece surface while transmitting the processing laser beam, acquiring drilling morphology images. Based on image recognition, hole defects are identified, and laser processing parameters or beam deflection parameters are dynamically adjusted. Through the synergy of these structures, real-time perception and feedback adjustment of laser power fluctuations and hole shape anomalies are achieved, effectively suppressing melt accumulation and hole shape distortion, significantly improving the consistency and reliability of micro-hole processing, and overcoming the problem of unstable processing quality caused by the lack of online monitoring and closed-loop control capabilities in existing technologies. Attached Figure Description

[0015] Figure 1 This is a schematic block diagram of a real-time monitoring acoustic-optical deflection laser drilling system according to an embodiment of this application; Figure 2 This is a flowchart illustrating a real-time monitoring method for laser drilling based on acousto-optic deflection, according to an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a three-optical coaxial device in a real-time monitoring acousto-optic deflection laser drilling system according to an embodiment of this application; Figure 4 This is a comparison image of the borehole surface morphology obtained after dynamically adjusting the laser power parameters according to an embodiment of this application; Figure 5 This is a schematic block diagram of the structure of a computer device according to an embodiment of this application.

[0016] The components include: 1. Laser source; 2. Beam expander; 3. Power monitoring module; 4. Acousto-optic deflector; 5. First focusing lens; 6. Aperture stop; 7. Second focusing lens; 8. Galvanometer; 9. Illumination source; 10. Imaging camera; 11. Altitude ranging device. The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of features, integers, steps, operations, elements, modules, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, modules, components, and / or groups thereof. It should be understood that when an element is referred to as “connected” or “coupled” to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein may include wireless connection or wireless coupling. The term “and / or” as used herein includes all or any modules and all combinations of one or more associated listed items.

[0019] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0020] Reference Figure 1 and Figure 3 This invention provides a real-time monitoring system for acousto-optic deflection laser drilling, comprising: Laser source 1, used to output the processing laser beam; The power monitoring module 3 is located on the output optical path of the laser source 1 and is used to collect the power signal of the processing laser beam in real time. The acousto-optic deflector 4 is used to receive the processing laser beam transmitted through the power monitoring module 3, and to deflect the processing laser beam in a non-mechanical manner based on the control signal; The galvanometer 8, located downstream of the acousto-optic deflector 4, is used to scan the deflected processing laser beam to guide the processing laser beam to different processing positions on the workpiece. The three-optical-coaxial device includes a laser transmission channel, an illumination optical path, and an imaging optical path with the same main optical axis. It is used to perform in-situ imaging of the workpiece surface while transmitting the processing laser beam to obtain a drilling morphology image. The control system is electrically connected to the power monitoring module 3, the acousto-optic deflector 4, the galvanometer 8, and the imaging camera 10, respectively. The control system is used to compare the power signal with a preset power threshold. If there is a deviation, the output parameters of the laser source 1 are adjusted. The control system is also used to identify hole defects based on the borehole topography image and dynamically adjust the laser processing parameters or beam deflection parameters to suppress molten material buildup or hole distortion.

[0021] As described above, this invention provides a real-time monitoring system for acousto-optic deflection laser drilling, which deeply integrates laser energy monitoring, high-speed beam deflection, coaxial in-situ imaging, and intelligent closed-loop control. Through multi-module collaboration, it achieves synchronous perception and dynamic control of laser energy state and processing morphology.

[0022] First, the system starts with laser source 1, which typically uses a nanosecond or picosecond pulsed fiber laser. The output wavelength is selected based on the absorption characteristics of the workpiece material. The processing laser beam output from laser source 1 first passes through power monitoring module 3, which is precisely positioned on the output optical path of laser source 1, immediately after the laser exit, to ensure that the acquired signal accurately reflects the energy state entering the subsequent optical path. In some embodiments, the original laser beam output from laser source 1 first passes through a variable-magnification beam expander 2. The beam expansion ratio of beam expander 2 can be adjusted from 1× to 4× (e.g., by moving an embedded lens group) to expand the initial spot diameter to the target size. This design allows the system to flexibly adapt to the incident spot diameter requirements of different types of acousto-optic deflectors 4, while optimizing the beam filling factor entering the subsequent 4f system, avoiding low energy utilization due to an excessively small spot size or edge diffraction of the AOD crystal due to an excessively large spot size. The power monitoring module 3 consists of a low-reflectivity beam splitter (e.g., a partial mirror or wedge-shaped beam splitter with 98% transmittance and 2% reflectivity) and a high-response photodetector (e.g., a silicon photodiode or InGaAs detector). The beam splitter separates a very small percentage (typically <5%) of the laser energy in the main beam and guides it to the photodetector. The photodetector converts this energy into an analog electrical signal proportional to the laser power, which is then transmitted to the control system after analog-to-digital conversion. This design achieves millisecond-level real-time monitoring of the laser output power with almost no impact on the main optical path energy, providing a reliable data source for subsequent closed-loop energy regulation. To meet the compact design requirements of practical applications, the processed laser beam after beam expansion can be reflected to the power monitoring module 3 via a mirror, and the processed laser beam after passing through the power monitoring module 3 can be reflected to the acousto-optic deflector 4 via a mirror. The specific placement and reflection angle can be adjusted according to the actual application.

[0023] The main laser beam, after being transmitted through the power monitoring module 3, enters the acousto-optic deflector 4 (AOD). The acousto-optic deflector 4 is a non-mechanical beam deflection device based on the acousto-optic effect, containing an acousto-optic crystal (such as TeO2) and a piezoelectric transducer. When the control system applies a specific frequency radio frequency drive signal to the piezoelectric transducer, traveling ultrasonic waves are generated inside the crystal, forming a periodic refractive index grating. The incident laser beam undergoes Bragg diffraction through this grating, and its diffraction angle changes continuously with the drive frequency. Because there are no moving parts, the deflection response time of the AOD can reach the microsecond level, facilitating high-speed fine-tuning and positioning of individual micro-holes or achieving precise scanning within a small range. However, the beam output by the AOD typically has a certain divergence angle and may carry high-frequency spatial noise (originating from unstable drive signals or crystal defects). If directly input to the galvanometer 8, it will cause focusing spot distortion and uneven energy distribution, thus affecting the roundness and repeatability of the drill hole.

[0024] To address this, this application features a specially designed improved dual-lens spatial filtering structure between the acousto-optic deflector 4 and the galvanometer 8—a non-standard "4f optical system." It should be noted that the "4f system" in this invention is not a traditional symmetrical structure where the distance between the two lenses is strictly equal to f1+f2 and their focal lengths are equal. Instead, it uses a combination of a first focusing lens 5 (focal length f1) and a second focusing lens 7 (focal length f2), where f2>f1, and the actual distance L between the two lenses is equal to f1+f2. In this configuration, the beam output from the AOD is first converged by the first focusing lens 5, forming a Fourier spectrum surface at its rear focal plane. A circular aperture 6 (usually no larger than 2mm) is positioned at this location to block high-frequency stray components and edge noise, allowing only the central low-frequency dominant mode to pass through, thus achieving effective spatial filtering. The filtered light field, acting as an "object," propagates a distance in free space before being re-imaged onto the incident plane of the galvanometer 8 by the second focusing lens 7. Since f2 > f1 and L = f1 + f2, the system not only performs spatial filtering but also achieves controllable beam expansion and divergence angle compression, resulting in a higher collimation and more uniform intensity distribution in the output beam. This design significantly optimizes the quality of the light spot entering the galvanometer 8, ensuring that the processed light spot after focusing by the galvanometer 8 and the field lens is close to the diffraction limit, thereby improving the roundness, edge sharpness, and processing consistency of the micro-aperture.

[0025] The galvanometer 8 typically consists of two orthogonal high-speed mirrors (X-axis and Y-axis), mounted at the output of the improved 4f system. After a high-quality collimated beam is incident, the galvanometer 8 deflects the beam at a large angle, and then the beam is focused onto the workpiece surface by an f-theta field mirror. The galvanometer 8 has a large stroke scanning capability (deflection angle can reach ±20° or more), and when used with the field mirror, it can cover an effective processing area of ​​tens of millimeters. By combining the microsecond-level high-speed fine-tuning capability of the AOD with the large-area scanning capability of the galvanometer 8, the system can quickly and accurately locate the center of the microhole, and efficiently complete large-area array drilling, balancing processing speed and positioning accuracy.

[0026] Crucially, this system integrates a three-optical-coaxial device, which uses multiple mirrors to spatially connect the laser transmission channel, illumination path, and imaging path to the same principal optical axis Z. Specifically, the processing laser beam is directed vertically downwards along the principal optical axis and projected directly onto the workpiece through a transmission window; visible light emitted from the illumination source 9 is obliquely illuminated onto the workpiece surface by a first mirror (such as a 45° high-reflection mirror), providing uniform diffuse illumination; the light reflected from the workpiece is guided by a second mirror to the imaging camera 10, forming a clear image on the imaging plane. This spatial coaxial layout ensures that the laser's point of action is always located at the center of the field of view, providing a distortion-free imaging basis for defect identification.

[0027] The core of the intelligent control system lies in the control system, which establishes high-speed electrical connections with the power monitoring module 3, the acousto-optic deflector 4, the galvanometer 8, and the imaging camera 10. The control system dynamically adjusts the laser output parameters based on the power signal, and identifies defects such as molten lava, hole shrinkage, or hole shape distortion based on the borehole morphology image, correcting the laser or deflection parameters in real time, forming a dual closed loop. This system effectively solves the problem of unstable processing quality caused by beam degradation and lack of real-time feedback in existing technologies, achieving high consistency and high precision micro-hole laser drilling.

[0028] In one embodiment, a first focusing lens 5, an aperture 6, and a second focusing lens 7 are sequentially disposed between the acousto-optic deflector 4 and the galvanometer 8, wherein the aperture 6 is located at the rear focal plane of the first focusing lens 5, and the second focusing lens 7 is used to image the light field formed by the aperture 6 onto the incident surface of the galvanometer 8.

[0029] In this embodiment, a first focusing lens 5, an aperture 6, and a second focusing lens 7 are sequentially arranged between the acousto-optic deflector 4 and the galvanometer 8, forming an improved spatial filtering structure. Specifically, the laser beam output from the acousto-optic deflector 4 first enters the first focusing lens 5 (focal length f1 = 250 mm), which converges the laser beam and forms a Fourier spectrum surface at its rear focal plane. A circular aperture 6 (inner diameter 2 mm) is provided here to filter out high-frequency stray components, allowing only the central low-frequency dominant mode to pass through, thus achieving effective spatial filtering. The filtered light field, as an "object," propagates a certain distance in free space and is received by the second focusing lens 7 (focal length f2 = 500 mm, with a focal length ratio of 2:1 to that of the first focusing lens 5), which then images the light field onto the incident surface of the galvanometer 8. Optionally, the actual distance L between the first focusing lens 5 and the second focusing lens 7 can be set to 750 mm, satisfying the condition L = f1 + f2, and f2 > f1. This asymmetric long-distance design not only achieves approximately twice the beam expansion ratio but also significantly compresses the divergence angle of the output beam, thereby improving the spot quality and energy uniformity entering the galvanometer 8. In the actual optical path layout, to meet the requirements of equipment compactness, one or more plane mirrors can be introduced between the first focusing mirror 5 and the second focusing mirror 7 to deflect the beam (e.g., using a 45° high-reflection mirror to change the propagation direction). Such mirrors are optional optical elements used to optimize the system spatial arrangement without changing the imaging relationship. Through the above parameter configuration and structural design, this embodiment effectively ensures the stability and focusing accuracy of the beam during laser drilling, providing key optical support for high-consistency micro-hole processing.

[0030] In one embodiment, the focal length of the first focusing lens 5 is f1, and the focal length of the second focusing lens 7 is f2; the distance between the first focusing lens 5 and the second focusing lens 7 is L = f1 + f2.

[0031] In this embodiment, the focal length of the first focusing lens 5 is f1, and the focal length of the second focusing lens 7 is f2, satisfying f2>f1 in this scheme; the distance L between the first focusing lens 5 and the second focusing lens 7 is equal to f1+f2, constituting a non-standard, long-spacing improved 4f optical system used for spatial filtering and beam shaping of the laser beam output from the acousto-optic deflector 4 (AOD). For example, the incident spot diameter of the AOD output is 4.5mm, and the focal lengths of the first focusing lens 5 (f1=250mm) and the second focusing lens 7 (f2=500mm) are configured with a beam expansion ratio of 1:2. The distance from the AOD exit surface to the first focusing lens 5 is a = 250 mm, ensuring the incident beam enters the lens in a near-collimated state. After being converged by the first focusing lens 5, a Fourier spectrum surface is formed at its rear focal plane (i.e., 250 mm from the lens), and a circular aperture 6 with an inner diameter of 2 mm is placed at this position to filter out high-frequency noise and stray light components. The actual optical path between the first focusing lens 5 and the second focusing lens 7 is designed to be b + c + d = 750 mm, i.e., L = 750 mm = f1 + f2. After propagating in this 750 mm free space, the filtered light field is received by the second focusing lens 7 and imaged onto the incident surface of the galvanometer 8 at a position e + f + g + h = 500 mm (equal to f2). This parameter combination not only achieves approximately twice the beam expansion (increasing the output spot diameter to approximately 9 mm) but also significantly reduces the divergence angle of the output beam, improving energy distribution uniformity and spatial coherence. Furthermore, to accommodate a compact equipment layout, one or more planar mirrors can be introduced in segments b–d or e–h to fold the optical path. These mirrors are merely optical path guiding elements and do not alter the aforementioned imaging relationship or total optical path length. Through this specific implementation, the system effectively ensures the beam quality entering the galvanometer 8, providing a reliable optical foundation for high-precision, low-thermal-affect micro-hole laser drilling.

[0032] In one embodiment, the three-optical coaxial device includes multiple reflectors, and the laser transmission channel, illumination optical path and imaging optical path share the same main optical axis in space through the multiple reflectors.

[0033] In this embodiment, the three-optical coaxial device includes multiple reflectors, and the laser transmission channel, illumination optical path, and imaging optical path share the same principal optical axis in space through the multiple reflectors. Specifically, the device adopts a discrete but cooperative optical path design: the processing laser beam propagates vertically downward along the principal optical axis Z direction and is directly projected onto the workpiece surface through a transmission window (such as the central light-transmitting area of ​​the field lens or a high-transparency flat window); at the same time, the visible light emitted by the independent illumination source 9 is reflected by the first reflector (such as a high-reflectivity plane mirror placed at a 45° angle) and then illuminates the workpiece surface at an oblique angle (such as 30°–60°), forming uniform diffuse reflection illumination and enhancing the contrast between the hole edge and the background; the imaging light reflected from the workpiece surface returns near the original path, is deflected by the second reflector (which can be another 45° reflector or a partially transmission / reflection beam splitter) by 90°, and is guided to the photosensitive chip of the imaging camera 10, finally forming a clear image on the imaging plane. Although the three beams do not share the same physical medium (such as a single optical fiber or a single lens aperture), the precise arrangement of the aforementioned reflectors ensures that the laser application point, illumination center, and imaging field of view are strictly aligned on the same point on the principal optical axis on the workpiece surface, thus achieving true "spatial coaxiality." This structure avoids parallax errors caused by traditional off-axis observation, ensuring that the acquired borehole morphology image accurately reflects the actual state of the laser processing position, providing high-fidelity visual evidence for subsequent image-based defect identification and closed-loop control. The number and angle of the reflectors can be flexibly adjusted according to system compactness and optical path length, but their core function remains the same: achieving coaxial alignment of the three beams in space.

[0034] In one embodiment, the system further includes a height measuring device 11, which is disposed beside the three-optical coaxial device and emits a measuring beam toward the workpiece surface in a direction parallel to the main optical axis, for real-time acquisition of the height information of the workpiece surface and transmission of the height information to the control system to dynamically adjust the laser focus position.

[0035] In this embodiment, the system further includes a height measuring device 11, which is disposed beside the three-optical coaxial device and emits a measuring beam towards the workpiece surface in a direction parallel to the main optical axis. This is used to acquire the height information of the workpiece surface in real time and transmit the height information to the control system to dynamically adjust the laser focus position. Specifically, the height measuring device 11 can be a laser displacement sensor, a confocal displacement sensor, or a triangulation module. Its installation position is close to the outside of the three-optical coaxial device (e.g., fixed on the same mounting bracket), but it does not obstruct the laser transmission channel, illumination path, or imaging path. The measuring beam is perpendicularly irradiated onto the workpiece surface in an attitude strictly parallel to the main optical axis, ensuring that the measured height data accurately reflects the local morphology at the laser processing point, which is particularly suitable for curved surfaces, warped plates, or workpieces with uneven thickness. During drilling, the device continuously acquires the Z-axis position (i.e., the direction perpendicular to the workpiece) of the workpiece surface at millisecond-level frequency and transmits the height signal to the control system in real time. Based on this, the control system calculates the offset of the current workpiece surface relative to the preset machining reference surface and drives the Z-axis adjustment mechanism of the galvanometer 8 or the electrically adjustable focusing field lens to dynamically compensate for the focal plane position, ensuring that the laser focus is always precisely focused on the material surface or the set blind hole depth layer. By introducing this height feedback mechanism, the system effectively solves the defocusing problem caused by workpiece clamping errors, thermal deformation, or material fluctuations, significantly improving the consistency of blind hole depth and the reliability of through-hole penetration.

[0036] Reference Figure 2 In one embodiment, this application also proposes a method for real-time monitoring of acousto-optic deflection laser drilling, the method being executed by the system described in any of the above claims, including steps S1-S6, specifically: S1. A processing laser beam is output through the laser source 1, and the power signal of the processing laser beam is collected in real time by the power monitoring module 3; S2. Input the processing laser beam into the acousto-optic deflector 4, and deflect the processing laser beam non-mechanically based on the control signal; S3. The deflected processing laser beam is scanned by galvanometer 8 and guided to the target processing position on the workpiece; S4. While transmitting the processing laser beam, the workpiece surface is imaged in situ using a three-optical coaxial device to obtain a drilling morphology image. S5. Compare the power signal with a preset power threshold. If there is a deviation, adjust the output parameters of the laser source 1. S6. Identify hole shape defects based on the borehole morphology image and dynamically adjust laser processing parameters or beam deflection parameters to suppress molten pile-up or hole shape distortion.

[0037] As described in step S1, a processing laser beam is output from laser source 1, and the power signal of the processing laser beam is acquired in real time by power monitoring module 3. In a specific implementation, for example, laser source 1 uses a pulsed fiber laser, outputting ultraviolet laser with a wavelength of 355nm, a repetition frequency of 100kHz, and adjustable single-pulse energy. Power monitoring module 3 consists of a wedge-shaped beam splitter with a transmittance of 98% and a silicon-based photodiode detector. The beam splitter reflects 2% of the main beam energy to the detector, which outputs an analog voltage signal that is converted into a digital power value (unit: W) by a 16-bit ADC, with a sampling frequency of 1kHz. This power signal serves as a feedback data source input to the power closed-loop engine in the control system. The preset power threshold is dynamically set according to the material type. For example, for a glass substrate of a certain thickness, the target power is 8.0W, with an allowable error range of ±0.3W (i.e., deviation threshold δ=0.3W). When the measured power P_measured exceeds the range [P_target-δ, P_target+δ], an adjustment command is triggered. For example, when drilling the 50th microhole, the laser temperature rise caused P_measured to drop to 7.5W. The system immediately identified the deviation and initiated compensation. This step, through high-frequency, low-intrusion energy monitoring, provides a reliable input for subsequent energy stability control, forming the first closed-loop control foundation in the overall process and effectively suppressing problems such as inconsistent hole depth or insufficient ablation caused by laser source fluctuations.

[0038] As described in step S2, the processing laser beam is input into the acousto-optic deflector 4, and the processing laser beam is deflected non-mechanically based on the control signal. In specific implementation, the path planning module in the control system calculates the required deflection angle θ according to the target micro-hole coordinates and maps it to the DDS output frequency. This step utilizes the high-speed, inertia-free deflection characteristics of AOD to achieve sub-microsecond positioning switching between micro-holes, significantly improving the array drilling efficiency; at the same time, as a pre-fine adjustment unit for the large-stroke scanning of the galvanometer 8, it forms a "coarse-fine" two-level positioning architecture with the subsequent galvanometer 8, undertaking the high-speed and precision pointing function in the overall process, avoiding the positioning lag caused by mechanical inertia in the pure galvanometer 8 solution.

[0039] As described in step S3, the deflected laser beam is scanned by galvanometer 8 and guided to the target machining position on the workpiece. After being output by AOD, the deflected laser beam enters a modified 4f system consisting of lenses with f1=250 mm and f2=500 mm for filtering and beam expansion, and then is incident on the center of galvanometer 8. The trajectory synchronization module in the control system receives the mapping relationship between the AOD deflection command and the workpiece coordinate system, generates a galvanometer 8 driving voltage signal, and drives the lens deflection via a servo amplifier. For example, when machining 1000 microholes in a 5×5 mm area, galvanometer 8 is responsible for area-level hopping (step size > 0.5 mm), while AOD is responsible for fine-tuning within the holes (step size < 50 μm). This step compensates for the limited deflection range of AOD by utilizing the large stroke coverage capability of galvanometer 8, and the two work together to achieve high-density drilling across the entire area. In the overall process, galvanometer 8, as the final beam guiding actuator, ensures that the laser is accurately focused on the preset machining point, which is a key link in achieving accurate spatial positioning.

[0040] As described in step S4, while transmitting the processing laser beam, an in-situ imaging of the workpiece surface is performed using a three-beam coaxial device to acquire an image of the drilled hole morphology. Specifically, the three-beam coaxial device includes, for example, two 45° high-reflection plane mirrors: the illumination beam is a white LED that illuminates the workpiece obliquely (45° incident) through the first reflector; the imaging beam is diffuse reflection from the workpiece surface that is deflected 90° by the second reflector and enters a CMOS industrial camera (resolution 2448×2048, frame rate 120 fps). The laser beam passes perpendicularly through the transmission window along the principal optical axis and acts on the workpiece. The three beams share the same principal optical axis in space, ensuring that the center of the imaging field of view coincides with the laser's point of action. Image acquisition is strictly synchronized with the laser pulses, triggered by a vision trigger module in the control system within 50 μs after each drilling cycle. For example, after drilling a 50 μm diameter through-hole, the system captures an image of the hole opening for subsequent analysis. This step eliminates parallax through coaxial layout, providing high-fidelity, distortion-free real-time topographic data. It constitutes the source of visual feedback in the overall process, providing an objective basis for aperture quality assessment.

[0041] As described in step S5, the power signal is compared with a preset power threshold. If a deviation exists, the output parameters of the laser source 1 are adjusted. Specifically, the control system has a built-in power adjustment engine, employing a proportional-integral (PI) control algorithm: adjustment amount ΔI (current adjustment amount) = K_p (proportional gain)·e(t) (power deviation) + K_i (integral gain)·∫e(t)dt (cumulative power deviation), where e(t) = P_target (target power) - P_measured (measured power), K_p = 0.8, K_i = 0.05. When |e(t)| (absolute value of power deviation) is greater than a specified value, such as 0.3 watts (W), and continues for more than a specified number of sampling periods (e.g., three sampling periods), the system determines it as a valid deviation and triggers the adjustment action. The output parameters are adjusted based on the laser's pump current or Q-switching delay time. For example, when P_measured (measured power) is 7.4 W and P_target (target power) is set to 8.0 W, the control system gradually increases the pump current, allowing the laser output power to recover to 7.95 W within 10 milliseconds. This step establishes a closed-loop control mechanism in the energy dimension, ensuring the consistency of energy received by each micro-hole throughout the entire process, effectively preventing processing defects such as blind holes not being penetrated, holes with residue at the bottom, or excessive taper in through holes caused by laser power attenuation.

[0042] Reference Figure 4 The image shows a comparison of the surface morphology of the drilled holes obtained after real-time monitoring and dynamic adjustment of the laser power parameters by this system, demonstrating the changes in the micro-hole processing effect under different pulse energies. The three holes in the image correspond to three different laser pulse energy settings: (1) 35 μJ, (2) 26 μJ, and (3) 18 μJ. Under the condition of 35 μJ, due to the excessive energy, obvious molten accumulation and edge roughness appeared around the hole opening, indicating that the heat-affected zone was too large; when the energy was reduced to 26 μJ, the molten accumulation was significantly reduced, the hole wall tended to be smooth, the hole shape was close to the ideal cylindrical shape, and the processing quality was significantly improved; when further reduced to 18 μJ, the hole diameter slightly shrank, the bottom ablation was insufficient, and there was a risk of incomplete penetration. In this process, this system can effectively suppress molten accumulation and optimize the hole shape by real-time monitoring and closed-loop adjustment of laser parameters, thereby achieving precise control of the micro-hole processing process.

[0043] As described in step S6, based on the drilled hole morphology image, hole shape defects are identified, and the laser processing parameters or beam deflection parameters are dynamically adjusted to suppress melt buildup or hole shape distortion. In a specific implementation, the control system calls the image analysis module and adopts a morphological processing flow based on OpenCV. For example, first, Gaussian filtering (standard deviation σ = 1.0) and Canny edge detection are performed on the image, and then the hole contour is fitted by the Hough circle transform to calculate the hole diameter D (the diameter of the hole), the roundness C (the roundness of the hole contour, defined as C = 4πA / P², where A is the actual area of the hole and P is the perimeter of the hole contour), and the average bottom brightness B (the average pixel gray value of the hole bottom area). The preset defect criteria include: melt buildup (when B > threshold B0 and D < D_target - 5 microns, where B0 is the preset brightness threshold with a value of 120; D_target is the target hole diameter); hole shape distortion (when C < 0.85, that is, when the roundness is lower than 0.85, it is determined as shape distortion). If melt buildup is recognized, the system calls the parameter correction strategy library to reduce the laser pulse number of the next micro-hole by 10% or extend the pulse interval by 20%; if it is recognized as hole shape distortion, the driving frequency of the acousto-optic deflector 4 (AOD) is finely adjusted by ±0.2 MHz to correct the actual action position of the light spot on the workpiece surface. For example, after slight melt buildup occurs in 3 consecutive micro-holes, the system automatically reduces the laser power from 8.0 W to 7.6 W. This step realizes the dynamic optimization of process parameters through an image-driven adaptive control mechanism, significantly improving the batch processing yield.

[0044] In one embodiment, the step of comparing the power signal with a preset power threshold and adjusting the output parameters of the laser source 1 if there is a deviation includes: S10. Obtain the power signal of the current processing laser beam in real time and compare the power signal with a preset power threshold; S11. Generate a power adjustment command when the power signal deviates from the preset power threshold beyond the allowable error range; S12. Adjust the output power or pulse energy of the laser source 1 according to the power adjustment command.

[0045] In this embodiment, the process of comparing the power signal with a preset power threshold and adjusting the output parameters of the laser source 1 when a deviation exists is specifically achieved by real-time acquisition of power data at the laser output and execution of closed-loop feedback. The power monitoring module 3 acquires the measured power value of the currently processed laser beam at a specified frequency and compares it with a target power preset according to the material process (e.g., 8.0 W). When the measured power deviates from the target value by more than the allowable error range (e.g., ±0.3 W) and the duration exceeds a specified number of sampling cycles, the control system determines it as a valid deviation and generates a power adjustment command. This command calculates the required pump current or Q-switching parameter correction amount using a proportional-integral (PI) control algorithm and applies it to the laser source 1, dynamically adjusting its output power or single-pulse energy so that the laser output recovers to the set tolerance range within a specified time. This ensures that each microhole receives a consistent energy dose throughout the overall drilling process, thereby avoiding uneven processing depth or abnormal heat-affected zones caused by power fluctuations.

[0046] In one embodiment, the step of identifying hole shape defects based on the borehole topography image and dynamically adjusting laser processing parameters or beam deflection parameters includes: S20. Perform real-time image analysis on the borehole morphology image to determine whether there is molten accumulation, borehole diameter shrinkage, or borehole shape distortion. S21. If a hole-shaped defect is identified, determine the target parameter to be adjusted based on the defect type. S22. Based on the target parameters, send a parameter correction command to the laser source 1 or the acousto-optic deflector 4.

[0047] In this embodiment, the process of identifying hole defects and dynamically adjusting parameters based on borehole morphology images is automatically judged and feedback executed through an image analysis module on the micro-hole images acquired in real time by the three-optical coaxial device. The system adopts an OpenCV-based image processing flow, performing Gaussian filtering, Canny edge detection, and Hough circle transform on the image after each hole is processed, extracting key features such as hole diameter D, roundness C, and average bottom brightness B, and judging whether there is melting, hole shrinkage, or hole shape distortion based on preset criteria. Once a specific defect is identified, the system matches the corresponding control scheme from the parameter correction strategy library: for example, for melting, reducing the number of pulses or extending the pulse interval for subsequent holes; for hole shape distortion, fine-tuning the driving frequency of the acousto-optic deflector 4 to correct the spot position. The relevant control commands are sent to the laser source 1 or the acousto-optic deflector 4 to achieve closed-loop optimization of processing parameters, adaptively correcting process parameters according to actual processing results, effectively suppressing repetitive defects, and improving the consistency and yield of batch micro-holes.

[0048] Reference Figure 5 This application also provides a computer device, which may be a server, and its internal structure may be as follows: Figure 5 As shown, the computer device includes a processor, internal memory, storage medium (non-volatile storage medium), and network interface connected via a system bus. The processor provides computing and control capabilities. The computer device's memory includes the aforementioned storage medium (non-volatile storage medium) and internal memory. The storage medium (non-volatile storage medium) stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the storage medium (non-volatile storage medium). The computer device's database stores usage data, such as data from a real-time monitoring process of an acousto-optic deflection laser drilling method. The computer device's network interface is used for communication with external terminals via a network connection. Furthermore, the computer device may also include input devices and a display screen. When the aforementioned computer program is executed by a processor, it implements a real-time monitoring method for acousto-optic deflection laser drilling, comprising the following steps: outputting a processing laser beam through a laser source and acquiring the power signal of the processing laser beam in real time via a power monitoring module; inputting the processing laser beam into an acousto-optic deflector and non-mechanically deflecting the processing laser beam based on a control signal; scanning the deflected processing laser beam with a galvanometer and guiding it to the target processing position on the workpiece; simultaneously transmitting the processing laser beam and performing in-situ imaging of the workpiece surface using a three-optical coaxial device to obtain a drilling morphology image; comparing the power signal with a preset power threshold, and adjusting the output parameters of the laser source if a deviation exists; identifying hole shape defects based on the drilling morphology image and dynamically adjusting the laser processing parameters or beam deflection parameters to suppress melt accumulation or hole shape distortion. Those skilled in the art will understand that... Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer equipment on which the present application is applied.

[0049] One embodiment of this application also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements a real-time monitoring method for acousto-optic deflection laser drilling, comprising the following steps: outputting a processing laser beam through a laser source and acquiring the power signal of the processing laser beam in real time via a power monitoring module; inputting the processing laser beam into an acousto-optic deflector and non-mechanically deflecting the processing laser beam based on a control signal; scanning the deflected processing laser beam with a galvanometer and guiding it to a target processing position on the workpiece; simultaneously transmitting the processing laser beam and performing in-situ imaging of the workpiece surface using a three-optical coaxial device to obtain a drilling morphology image; comparing the power signal with a preset power threshold, and adjusting the output parameters of the laser source if a deviation exists; identifying hole shape defects based on the drilling morphology image and dynamically adjusting the laser processing parameters or beam deflection parameters to suppress melt accumulation or hole shape distortion. It is understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.

[0050] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in this application and in the embodiments can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual-speed SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0051] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0052] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A real-time monitoring acousto-optic deflection laser drilling system, characterized in that, The system comprises: a laser light source for outputting a machining laser beam; a power monitoring module arranged on an output light path of the laser light source for collecting a power signal of the machining laser beam in real time; an acousto-optic deflector for receiving the machining laser beam transmitted through the power monitoring module and non-mechanically deflecting the machining laser beam based on a control signal; a galvanometer mirror located downstream of the acousto-optic deflector for scanning the deflected machining laser beam to guide the machining laser beam to different machining positions on a workpiece; a three-light coaxial device comprising a laser transmission channel, an illumination light path and an imaging light path with the same main optical axis for in-situ imaging of the workpiece surface while transmitting the machining laser beam to obtain a hole topography image; a control system electrically connected with the power monitoring module, the acousto-optic deflector, the galvanometer mirror and the imaging camera, wherein the control system is configured to compare the power signal with a preset power threshold value, adjust the output parameters of the laser light source if there is a deviation, identify hole shape defects based on the hole topography image, and dynamically adjust the laser machining parameters or the beam deflection parameters to suppress the molten pile or hole shape distortion.

2. The real-time monitoring acousto-optic deflection laser drilling system of claim 1, wherein, The acousto-optic deflector and the galvanometer mirror are sequentially provided with a first focusing mirror, a diaphragm and a second focusing mirror, wherein the diaphragm is located at the back focal plane of the first focusing mirror, and the second focusing mirror is configured to image the light field formed by the diaphragm to the entrance surface of the galvanometer mirror.

3. The real-time monitoring acousto-optic deflection laser drilling system of claim 2, wherein, The focal length of the first focusing mirror is f1, the focal length of the second focusing mirror is f2, and f2>f1; the distance L between the first focusing mirror and the second focusing mirror is f1+f2.

4. The real-time monitoring acousto-optic deflection laser drilling system of claim 1, wherein, The three-light coaxial device comprises a plurality of mirrors, and the laser transmission channel, the illumination light path and the imaging light path share the same main optical axis in space through the plurality of mirrors.

5. The real-time monitoring acousto-optic deflection laser drilling system of claim 1, wherein, The system further comprises a height ranging device arranged beside the three-light coaxial device and emitting a ranging light beam to the workpiece surface in a direction parallel to the main optical axis for obtaining height information of the workpiece surface in real time and transmitting the height information to the control system to dynamically adjust the laser focal point position.

6. A method of real-time monitoring of acousto-optic deflection laser drilling, the method being performed by the system of any one of claims 1 to 5, characterized in that, The system comprises: outputting a machining laser beam by a laser light source and collecting a power signal of the machining laser beam in real time through a power monitoring module; inputting the machining laser beam into an acousto-optic deflector and non-mechanically deflecting the machining laser beam based on a control signal; scanning the deflected machining laser beam through a galvanometer mirror to guide the machining laser beam to a target machining position on a workpiece; in-situ imaging the workpiece surface through a three-light coaxial device while transmitting the machining laser beam to obtain a hole topography image; comparing the power signal with a preset power threshold value and adjusting the output parameters of the laser light source if there is a deviation; identifying hole shape defects based on the hole topography image and dynamically adjusting the laser machining parameters or the beam deflection parameters to suppress the molten pile or hole shape distortion.

7. The method of real-time monitoring of acousto-optic deflection laser drilling of claim 6, wherein, The step of comparing the power signal with a preset power threshold value and adjusting the output parameters of the laser light source if there is a deviation comprises: acquire a power signal of the current machining laser beam in real time, and compare the power signal with a preset power threshold; generate a power adjustment instruction when the power signal deviates from the preset power threshold by more than an allowable error range; adjust the output power or pulse energy of the laser light source according to the power adjustment instruction.

8. The method of real-time monitoring of acousto-optic deflection laser drilling of claim 6, wherein, The step of identifying hole shape defects based on the hole profile image and dynamically adjusting laser machining parameters or beam deflection parameters comprises: performing real-time image analysis on the hole profile image to determine whether there is a molten pool, hole diameter shrinkage, or hole shape distortion; if a hole shape defect is identified, determining a target parameter to be adjusted according to the defect type; sending a parameter correction instruction to the laser light source or the acousto-optic deflector based on the target parameter. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The processor executes the computer program to implement the steps of the method of any one of claims 6 to 8.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 6 to 8.

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