Cross-medium intelligent self-adaptive laser cleaning system and method based on plasma

Abstract

The invention discloses a plasma-based cross-medium intelligent self-adaptive laser cleaning system and method, and belongs to the technical field of laser cleaning. A laser control module of the system dynamically adjusts output pulsed light, the pulsed light enters a transmission optical fiber through a coupling system, and beam shaping and emergent are performed on the end face of the optical fiber; and emergent light spots on the end face of the optical fiber penetrate through the medium and are focused to the target surface, and when focusing light spot energy exceeds a breakdown threshold value, plasma shock waves are generated to remove impurities on the target surface. Laser emitted by the laser control module breaks down any surrounding medium (gas, liquid and solid) to generate plasma shock waves, and non-contact pollutant removal is achieved. According to the method, direct contact with the target is not needed, damage to the surface of the target is avoided, the pulse laser clearing efficiency is high, and the method can be widely applied to multi-medium cleaning scenes in the fields of semiconductors, medical treatment, energy and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser cleaning, and in particular relates to a plasma-based cross-medium intelligent adaptive laser cleaning system and method. Background Art

[0002] Traditional surface cleaning technologies, such as chemical etching, mechanical grinding, and ultrasonic cleaning, have limitations in terms of environmental pollution, object damage, and cleaning efficiency. Chemical etching produces hazardous waste and pollutes the environment; mechanical grinding creates stress, scratches, and deformation, affecting material properties; and ultrasonic cleaning is inefficient and difficult to clean on surfaces with complex shapes. In recent years, laser cleaning has garnered widespread attention as a novel surface cleaning technology. Laser cleaning utilizes the high energy density and short pulse duration of laser light to provide non-contact, non-destructive, and highly efficient cleaning of target surfaces.

[0003] However, existing laser cleaning technologies have limitations. Traditional laser cleaning techniques utilize spatial focusing, which is difficult to adjust due to optical path limitations. The cleaning range is limited by the laser beam diameter, making it difficult to clean narrow or deep holes. In practical applications, excessive energy from pulsed lasers can easily damage samples during the cleaning process. Existing laser cleaning technologies are mostly based on the thermal effects of pulsed lasers or acousto-optic transduction, resulting in low energy conversion efficiency and high requirements for the environmental media during the cleaning process. For example, the cleaning system disclosed in Chinese Patent Application No. 202210620984.8, "A Tunable Multi-Pulse Laser Cleaning System and Operating Method thereof," utilizes a spatial optical path and a pulse delay generation control system for laser cleaning. However, due to optical path limitations, this system cannot operate in narrow or curved spaces. The laser cleaning principle described in Chinese Patent Application No. 202411297382.9, "A Dual-Path Laser Cleaning Device," utilizes the thermal effects of high-energy lasers to remove dirt, rust, coatings, or other attachments. This method requires a high laser energy level, and high laser energy levels can cause damage to the target. The Chinese patent application number CN112317450A, "An ultrasonic fixed-point cleaning device and method based on photoacoustic jet effect", uses the photoacoustic effect to clean objects. The cleaning device has specific requirements for the cleaning environment and needs to be used in an ultrasonic cleaning solution. Summary of the Invention

[0004] In view of the limitation of the cleaning system having high requirements for the environmental medium, the present invention provides a cross-medium adaptive, high-efficiency, non-contact laser plasma intelligent adaptive cleaning system and working method, which can effectively remove impurities on the surfaces of various materials.

[0005] The present invention provides a plasma-based cross-medium intelligent adaptive laser cleaning system, which is characterized by comprising: a laser control module, a coupling system, a transmission optical fiber, and an optical fiber end face; the laser control module dynamically adjusts the output pulse light, enters the transmission optical fiber through the coupling system, and performs beam shaping and emission at the optical fiber end face; the light spot emitted from the optical fiber end face penetrates the medium and is focused to the target surface. When the energy of the focused light spot exceeds its breakdown threshold, a plasma shock wave is generated to remove impurities on the target surface.

[0006] Furthermore, the medium is a transparent medium selected from one of solid, gas or liquid. When the medium is liquid, cavitation effect occurs to wash the target.

[0007] Furthermore, the pulse light output by the laser control module is one of ultraviolet light of 100-400nm, visible light of 400-700nm, near infrared light of 700-2500nm, mid-infrared light of 2500-10000nm, and far infrared light of >10000nm.

[0008] Furthermore, the transmission optical fiber is a single optical fiber or an optical fiber bundle; the optical fiber is a single-mode optical fiber, a multi-mode optical fiber or a special optical fiber.

[0009] Furthermore, it also includes a monitoring system, which is located at the top of the transmission optical fiber and is used for real-time collection and feedback of the impurity removal effect on the target surface.

[0010] Furthermore, the monitoring system includes a light source module, an optical imaging module, an optical fiber sensor array, and an optical signal processing module; the light source module includes a supercontinuum light source and an LED light source; the optical imaging module includes an illumination optical fiber array and a miniature camera; the optical fiber sensor array includes an optical fiber humidity sensor, an optical fiber temperature sensor, an optical fiber refractive index sensor, and an optical fiber pressure sensor; the optical signal processing module is composed of a spectrum analyzer and a photodetector; the optical fiber sensor array acquires the humidity, temperature, refractive index, and pressure parameters of the target, impurities, and medium in real time, the optical imaging module synchronously acquires the surface morphology image of the medium, the signal processing module converts the optical signal acquired by the optical imaging module into an electrical signal and transmits it to the processing center, and realizes intelligent identification of the target, impurities, and medium status and adaptive adjustment of the cleaning parameters through multimodal data fusion.

[0011] Furthermore, it also includes an execution module; the execution module includes a multi-degree-of-freedom robotic arm and an autonomous navigation and obstacle avoidance system, which is used to move the transmission optical fiber, optical fiber end face and detection system to the front end of the medium and adjust the position of the light spot emitted from the optical fiber end face.

[0012] Furthermore, the optical fiber end face is one of a flat head, a tapered end face, and a spherical end face.

[0013] The present invention also provides a control method for a plasma-based cross-medium intelligent adaptive laser cleaning system, comprising:

[0014] Step 1: The execution module carries the transmission fiber and monitoring system into the work area. The monitoring system collects and identifies the target, impurities, and medium data, and feeds the data back to the processing center to set the cleaning plan;

[0015] Step 2: The processing center identifies and determines the state of the target, calls the model to match the dielectric breakdown threshold, generates laser parameters, and applies a low voltage to enable the laser control module to emit a positioning pulse laser;

[0016] Step 3: The execution module adjusts the position of the light spot emitted from the fiber end face according to the location of the target impurities, and the processing center pre-scans and locates all clean areas of the target;

[0017] Step 4: The laser control module applies high voltage. When the fiber end face removes impurities from the target surface according to the set cleaning plan, the light spot emitted from the fiber end face penetrates the medium and focuses on the target surface. When the energy of the focused light spot exceeds its breakdown threshold, a plasma shock wave is generated to achieve cleaning. If the medium is liquid, cavitation effect occurs to enhance the cleaning effect.

[0018] Step 5: The processing center records, evaluates and processes the target impurity cleaning effect through the monitoring system;

[0019] Step 6: If the cleaning requirements are not met, repeat steps 1 to 5 to perform the next impurity cleaning on the target until the cleaning requirements are met.

[0020] The beneficial effects of the present invention are:

[0021] The present invention proposes a plasma-based, cross-medium intelligent adaptive laser cleaning system. When the energy density of a focused pulsed laser transmitted by an optical fiber exceeds the dielectric breakdown threshold in the focal region, it induces a coupled process of photoionization and avalanche ionization, causing the dissociation of dielectric molecules or atoms to form a transient expanding plasma. This generates a high-temperature, high-pressure plasma shock wave, which impacts and strips impurities from the target surface. Specifically, in liquid media, the plasma formation process is accompanied by the periodic evolution of cavitation bubbles. The dynamic process of bubble expansion and collapse produces a dual cleaning mechanism of collapse shock waves and microjet effects, further enhancing the cleaning effect. Compared with traditional laser cleaning technologies, the present method's multi-medium adaptability supports adaptive operation in gas / liquid / solid environments. Furthermore, the flexible optical fiber transmission significantly enhances operational flexibility, enabling deep-hole cleaning. Furthermore, the present invention provides non-contact, non-destructive cleaning without affecting material properties. Furthermore, the cross-medium adaptive system combines operational flexibility, non-contact cleaning, and deep learning neural networks, significantly improving ease of use and applicability. The present invention can be widely applied in medical, industrial and scientific fields, such as precise tissue removal in surgery, nanoscale etching in electronic component manufacturing, and surface modification in materials science research. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of a plasma-based cross-medium intelligent adaptive laser cleaning system;

[0023] Figure 2 Schematic diagram of a monitoring system for a plasma-based cross-medium intelligent adaptive laser cleaning system;

[0024] Figure 3 This is a processing center workflow diagram of a plasma-based cross-medium intelligent adaptive laser cleaning system;

[0025] Figure 4 It is an intelligent neural network that serves as the processing center of a plasma-based cross-medium intelligent adaptive laser cleaning system.

[0026] The figures are marked as follows: 1. Laser control module; 2. Coupling system; 3. Transmission optical fiber; 4. Execution module; 5. Optical fiber end face; 6. Target; 7. Monitoring system; 8. Processing center; 9. Medium; 7-1. Supercontinuum light source; 7-2. LED light source; 7-3. Illumination optical fiber array; 7-4. Miniature camera; 7-5. Optical fiber humidity sensor; 7-6. Optical fiber temperature sensor; 7-7. Optical fiber refractive index sensor; 7-8. Optical fiber pressure sensor; 7-9. Spectrum analyzer; 7-10. Photodetector. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] The present invention discloses a plasma-based cross-medium intelligent adaptive laser cleaning system, such as Figure 1 、 Figure 2 As shown, it includes a laser control module 1, a coupling system 2, a transmission optical fiber 3, an execution module 4, an optical fiber end face 5, a monitoring system 7, a processing center 8, and a medium 9; the processing center 8 presets the impurity cleaning plan for the target 6, controls the laser control module 1 to generate pulsed light, enters the transmission optical fiber 3 through the coupling system 2, and performs beam shaping and emission at the optical fiber end face 5; the execution module 4 is used to carry the transmission optical fiber 3 and the monitoring system 7 to the specified position, adjust the position of the output light spot of the optical fiber end face 5, and realize directional cleaning of the pulsed laser output; the monitoring system 7 collects and feeds back the surface cleaning effect of the target 6 in real time, and the feedback signal is input to the processing center 8 for judgment, and plans the next cleaning plan.

[0029] The laser control module 1 can dynamically adjust the parameters of the output pulse laser; the transmission optical fiber 3 is a single optical fiber or an optical fiber bundle; the optical fiber is a single-mode optical fiber, a multi-mode optical fiber or a special optical fiber; the optical fiber end face 5 can be a flat head, a cone, a spherical or other shaped end face; the execution module 4 includes a multi-degree-of-freedom robotic arm and an autonomous navigation and obstacle avoidance system, which is used to carry the transmission optical fiber 3 and the monitoring system 7 to the specified position, adjust the output spot position of the optical fiber end face 5, and realize the directional and precise removal of the pulse laser; the monitoring system 7 includes a supercontinuum light source 7-1, an LED light source 7-2, an illumination optical fiber array 7-3, a micro camera 7-4, an optical fiber humidity sensor 7-5, an optical fiber temperature sensor 7-6, an optical fiber optic sensor 7-7, an optical fiber optic sensor 7-8, an optical fiber optic sensor 7-9, an optical fiber optic sensor 7-10, an optical fiber optic sensor 7-11, an optical fiber optic sensor 7-12, an optical fiber optic sensor 7-13, an optical fiber optic sensor 7-14, an optical fiber optic sensor 7-15, an optical fiber optic sensor 7-16, an optical fiber optic sensor 7-17, an optical fiber optic sensor 7-18, an optical fiber optic sensor 7-19, an optical fiber optic sensor 7-21, an optical fiber optic sensor 7-22, an optical fiber optic sensor 7-23, an optical fiber optic sensor 7-24, an optical fiber optic sensor 7-35, an optical fiber optic sensor 7-36, an optical fiber optic sensor 7-37, an optical fiber optic sensor 7-38, an optical fiber optic sensor 7-39, an optical fiber optic sensor 7-45, an optical fiber optic sensor 7-46 Fiber optic refractive index sensor group 7-7, fiber optic pressure sensor 7-8, spectrum analyzer 7-9, photoelectric detector 7-10; fiber optic humidity sensor 7-5, fiber optic temperature sensor 7-6, fiber optic refractive index sensor group 7-7 and fiber optic pressure sensor 7-8 are used to obtain the humidity, temperature, refractive index and pressure parameters of the target and the medium in real time. The lighting fiber array 7-3 and the micro camera 7-4 synchronously collect the surface morphology image of the medium. After the signal is transmitted to the processing center 8, the multimodal data fusion is used to realize the intelligent recognition of the target medium state and the adaptive adjustment of the cleaning parameters, and the surface cleaning effect of the target 6 is collected and fed back in real time. The working process of the processing center 8 is as follows Figure 3 As shown; the processing center 8 is used to preset the cleaning plan, control the cleaning process and determine the cleaning effect. The processing center 8 adopts a deep learning neural network, and the structure is as follows Figure 4 shown.

[0030] Example 1

[0031] A plasma-based cross-medium intelligent adaptive laser cleaning system comprises: a laser control module 1, a coupling system 2, a transmission optical fiber 3, an optical fiber end face 5, a medium 9, and a target 6, which are arranged in sequence; wherein the coupling system 2 is constructed using a lens group, and a 4× optical microscope objective lens is used to couple the light generated by the laser into the transmission optical fiber 3; the transmission optical fiber 3 is a fiber bundle, and the optical fiber type is a graded refractive index multimode optical fiber with a cladding diameter of 125μm and a core diameter of 62.5μm; the optical fiber end face 5 is a flat end face; the target 6 is on a silicon substrate, and the impurity is photoresist under a polyimide coating on the silicon substrate; and the medium 9 is a polyimide coating.

[0032] A plasma-based cross-medium intelligent adaptive laser cleaning method, comprising:

[0033] S1: The execution module 4 carries the transmission optical fiber 3 and the monitoring system 7 into the operation area. The monitoring system 7 collects and identifies the target 6, the medium 9, the impurities and the environment data, and feeds the data back to the processing center 8;

[0034] S2: The processing center 8 matches the breakdown threshold of the cross-medium (air-polyimide cover) model, generates laser parameters, determines the laser wavelength to be 532nm, the output energy to be 1mJ, and the repetition frequency to be 1Hz, and transmits the laser parameter information to the laser control module 1, which then emits a low-energy pulsed laser.

[0035] S3: The execution module 4 adjusts the position of the light spot emitted from the optical fiber end face 5;

[0036] S4: The laser control module 1 emits a high-energy pulsed laser, and the laser emitted from the optical fiber end face 5 converges on the photoresist layer after passing through the air-polyimide cover layer. When the laser energy at the convergence point exceeds the breakdown threshold of the photoresist layer, a plasma shock wave is generated, which impacts and strips the photoresist layer of the target 6;

[0037] S5: The cleaning effect of the target 6 is detected by the monitoring system 7, and the signal is transmitted to the processing center 8 for decision-making. If the cleaning requirements are not met, the laser emission parameters are adjusted by the processing center 8. The laser control module 1 receives the laser parameter signal and emits the laser. The control execution module 4 adjusts the position of the output light spot and performs the next cleaning of the target 6;

[0038] S6: Repeat steps S1 to S5 until the cleaning requirements are met.

[0039] In summary, the laser control module of the system of the present invention emits a pulsed laser, which is focused and incident on the transmission optical fiber through the coupling system; the output end face of the transmission optical fiber can realize laser shaping; the execution module irradiates the laser spot emitted by the optical fiber to the specified position; the monitoring system can accurately locate the cleaning position, and collect and monitor the cleaning effect and cleaning environment of the target surface in real time; the processing center identifies and determines the cleaning status, and inputs further cleaning operations to the laser control module in the form of feedback signals to ensure the stability of cross-medium cleaning. The plasma-based cross-medium intelligent adaptive laser cleaning system proposed in the present invention uses laser pulses to generate plasma on the end face of the optical fiber, and uses plasma shock waves and cavitation bubbles to remove impurities on the target surface. It does not require direct contact with the target, avoids damage to the target surface, and has high pulse laser cleaning efficiency; and the optical fiber is small in size and can be accurately cleaned in complex environments by controlling the execution module; the laser control module dynamically adjusts the laser parameters to match the breakdown threshold of different media, solving the scene limitation problem caused by traditional laser cleaning relying on medium ablation.

[0040] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A plasma-based cross-medium intelligent adaptive laser cleaning system, characterized in that: include: Laser control module (1), coupling system (2), transmission optical fiber (3), optical fiber end face (5); The laser control module (1) dynamically adjusts the output pulse light, enters the transmission optical fiber (3) through the coupling system (2), and performs beam shaping and emission at the optical fiber end face (5); the light spot emitted from the optical fiber end face (5) penetrates the medium (9) and is focused onto the surface of the target (6); when the energy of the focused light spot exceeds its breakdown threshold, a plasma shock wave is generated to remove impurities on the surface of the target (6).

2. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 1, characterized in that: The medium (9) is a transparent medium selected from solid, gas or liquid. When the medium (9) is liquid, a cavitation effect occurs to wash the target (6).

3. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 1, characterized in that: The pulse light output by the laser control module (1) is one of ultraviolet light of 100-400nm, visible light of 400-700nm, near infrared light of 700-2500nm, mid-infrared light of 2500-10000nm, and far infrared light greater than 10000nm.

4. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 1, characterized in that: The transmission optical fiber (3) is a single optical fiber or an optical fiber bundle; the optical fiber is a single-mode optical fiber, a multi-mode optical fiber or a special optical fiber.

5. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 1, characterized in that: It also includes a monitoring system (7), which is located at the top of the transmission optical fiber (3) and is used for real-time collection and feedback of the impurity removal effect on the surface of the target (6).

6. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 5, characterized in that: The monitoring system (7) includes a light source module, an optical imaging module, an optical fiber sensor array, and an optical signal processing module; The light source module includes a supercontinuum light source (7-1) and an LED light source (7-2); the optical imaging module includes an illumination fiber array (7-3) and a micro camera (7-4); the optical fiber sensor array includes an optical fiber humidity sensor (7-5), an optical fiber temperature sensor (7-6), an optical fiber refractive index sensor (7-7) and an optical fiber pressure sensor (7-8); and the optical signal processing module includes a spectrum analyzer (7-9) and a photodetector (7-10); The optical fiber sensor array acquires the humidity, temperature, refractive index and pressure parameters of the target (6), impurities and medium (9) in real time; the optical imaging module synchronously acquires the surface morphology image of the medium; the signal processing module converts the optical signal acquired by the optical imaging module into an electrical signal and transmits it to the processing center (8), thereby realizing intelligent recognition of the state of the target (6), impurities and medium (9) and adaptive adjustment of cleaning parameters through multimodal data fusion.

7. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 5, characterized in that: The invention also includes an execution module (4); the execution module (4) includes a multi-degree-of-freedom mechanical arm and an autonomous navigation and obstacle avoidance system, which is used to move the transmission optical fiber (3), the optical fiber end face (5) and the detection system (7) to the front end of the medium (9) and adjust the position of the light spot emitted by the optical fiber end face (5).

8. The plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 1, characterized in that: The optical fiber end face (5) is one of a flat head, a tapered end face and a spherical end face.

9. A control method for the plasma-based cross-medium intelligent adaptive laser cleaning system according to claim 1, characterized in that: include: Step 1: The execution module (4) carries the transmission optical fiber (3) and the monitoring system (7) into the operation area. The monitoring system (7) collects and identifies the data of the target (6), impurities and medium (9), and feeds the data back to the processing center (8) to set the cleaning plan; Step 2: The processing center (8) identifies and determines the state of the target (6), calls a model to match the dielectric breakdown threshold, generates laser parameters, applies a low voltage, and causes the laser control module (1) to emit a positioning pulse laser; Step 3: The execution module (4) adjusts the position of the light spot emitted from the optical fiber end face (5) according to the impurity position of the target (6), and the processing center (8) pre-scans and positions all clean areas of the target (6); Step 4: The laser control module (1) applies a high voltage, and when the optical fiber end face (5) removes impurities from the surface of the target (6) according to the set cleaning scheme, when the light spot emitted from the optical fiber end face (5) penetrates the medium (9) and is focused on the surface of the target (6), when the energy of the focused light spot exceeds its breakdown threshold, a plasma shock wave is generated to achieve cleaning, and when the medium (9) is a liquid, a cavitation effect occurs to enhance the cleaning effect; Step 5: The processing center (8) records, evaluates and processes the impurity cleaning effect of the target (6) through the monitoring system (7); Step 6: If the cleaning requirements are not met, repeat steps 1 to 5 to perform the next impurity cleaning on the target (6) until the cleaning requirements are met.

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