Laser micro-nano machining method and device

Abstract

The invention discloses a laser micro-nano machining method and device. The laser micro-nano machining method comprises the steps of S1, S2, S3, S4, S5 and S6. According to the invention, real-time measurement and data feedback are carried out on the processing depth through the detection feedback system, so that the engraving depth can be accurately controlled, and the smoothness and uniformity of the depth of the micro-nano structure are effectively ensured; process parameters are adjusted in time through micro-nano machining control software, the forming precision of the micro-nano structure can be optimized, and the matching degree of an actual machining shape and a designed shape is greatly improved; by means of real-time observation of the visual system on the heat accumulation state in the machining process, technological parameters can be adjusted in a targeted mode, machining defects caused by excessive heat residues are avoided from the source, and the machining quality is guaranteed; meanwhile, the device can automatically adjust technological parameters according to machining unstable states such as laser power fluctuation, self-adaptive optimization of the machining process is achieved, and the quality stability of micro-nano machining is further improved.

Description

Technical Field

[0001] This invention relates to the field of micro-nano precision machining technology, and in particular to a laser micro-nano machining method and apparatus. Background Technology

[0002] The pulse width of ultrafast lasers is much smaller than the thermal relaxation time of materials. The laser energy removes the material before thermal diffusion occurs inside the material, resulting in a very small heat-affected zone in the processing area and almost no thermally induced defects such as melting, recasting, or cracking. This enables the manufacturing of ultra-precise micro- and nano-structures. At the same time, the ultra-high peak power density allows transparent materials to absorb laser energy through nonlinear optical processes such as multiphoton absorption and tunneling ionization, breaking through the material's absorption limitation to specific wavelengths and further expanding the material application range of laser micro- and nano-processing.

[0003] However, existing ultrafast laser micro / nano fabrication technologies still face several technical challenges in practical applications: First, when processing micro / nano structures with ultrafast lasers, the processing depth is difficult to control precisely due to differences in material surface properties and uneven laser energy distribution. Second, issues such as laser focusing deviation and material removal rate fluctuations during processing can lead to deviations between the actual processed shape and the design model. Third, repeated processing can easily generate residual heat, which can alter the physicochemical properties of the material and affect the material removal efficiency of subsequent processing steps. Fourth, fluctuations in laser output power and insufficient optical path transmission stability can lead to unstable processing results, thereby reducing the yield rate of micro / nano fabrication and increasing production costs. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings mentioned above by providing a laser micro / nano processing method and apparatus that can adjust the processing state in a timely manner and ensure processing quality.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a laser micro / nano fabrication method, comprising the following steps: S1. Conduct engraving depth tests on the target material with different parameters, associate the obtained parameters with the corresponding engraving depth data and name them to form a process parameter resource library; S2. Perform layered slicing on the pre-defined micro-nano three-dimensional structure, with the process parameters for each layer set independently and selected from the process parameter resource library. S3. Ultrafast lasers are emitted through an ultrafast laser emission system to perform micro-nano processing on the material surface according to the process parameters of each layer after layering. S4. The detection feedback system is used to measure the processing depth of each layer at multiple points and calculate the average value. The depth feedback value is transmitted to the micro-nano processing control software. The micro-nano processing control software adjusts the number of layers and process parameters for subsequent processing based on the difference between the depth feedback value and the preset depth value. S5. The processing status information is collected in real time through the vision system and matched with the pre-stored qualified status information. If the match is inconsistent, the processing is suspended and the manual parameter intervention is waited until the processing status returns to normal. S6. Repeat steps S3-S5 until all layers of micro / nano fabrication are completed.

[0006] Furthermore, in step S4, the number of multi-point measurements in the detection feedback system is at least 3. The specific method for adjusting process parameters in the micro-nano fabrication control software is as follows: the micro-nano three-dimensional structure slice is divided into M layers, and the difference in processing depth between the (N-1)th layer and the (N-2)th layer is compared. If the difference is within a preset range, the Nth layer uses the process parameters of the previous layer; if the difference exceeds the preset range, the optimal process parameters are called from the process parameter resource library for the processing of the Nth layer, until the Mth layer is processed, where N is a positive integer greater than 2, and the maximum value of N is equal to the total number of layers M.

[0007] Furthermore, in step S5, the processing status information collected by the vision system includes at least one of the following: processing edge burrs, surrounding heat-affected zone, and processing splashes. The pre-set qualified status information of the vision system includes the status of the processing edge and the status information within 1mm around the processing area.

[0008] A laser micro / nano fabrication device, applied to any one of the laser micro / nano fabrication methods described herein, comprising: An ultrafast laser emission system, including a laser and optical mirrors, is used to emit ultrafast lasers and perform micro- and nano-fabrication on materials; The detection feedback system is connected to the micro-nano fabrication control software and is used to measure the processing depth during laser processing and to feed the depth data back to the micro-nano fabrication control software in real time. The vision system is connected to the micro-nano fabrication control software and is used to collect fabrication status information in real time and match it with preset qualified status information. The motion control system is connected to the micro-nano fabrication control software and is used to drive the ultrafast laser emission system to move and adjust the laser focusing point.

[0009] Furthermore, the laser is a picosecond laser or a femtosecond laser.

[0010] Furthermore, the optical lens assembly includes a beam expander, a scanning galvanometer, and a focusing lens. The beam expander is used to reduce the laser divergence angle and increase the laser beam diameter. The scanning galvanometer is used to change the laser deflection trajectory. The focusing lens is used to focus the laser onto the material surface.

[0011] Furthermore, the depth measurement method of the detection feedback system is either white light interferometer measurement or laser measurement.

[0012] The beneficial effects of this invention are reflected in: This invention utilizes a detection feedback system to measure and provide data feedback on the processing depth in real time, enabling precise control of the engraving depth and effectively ensuring the smoothness and uniformity of the micro / nano structure's depth. By relying on micro / nano processing control software to adjust process parameters in a timely manner, the forming accuracy of the micro / nano structure can be optimized, significantly improving the match between the actual processed shape and the designed shape. Furthermore, by using a vision system to observe the heat accumulation state during processing in real time, process parameters can be adjusted in a targeted manner, avoiding processing defects caused by excessive heat residue from the source and ensuring processing quality. Simultaneously, the device can automatically adjust process parameters based on processing instability states such as laser power fluctuations, achieving adaptive optimization of the processing process and further improving the quality stability of micro / nano processing. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the system of the present invention. Detailed Implementation

[0014] 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, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. 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.

[0015] Please see Figure 1 This invention discloses a laser micro / nano fabrication method, comprising the following steps: S1. Conduct engraving depth tests on the target material with different parameters, associate the obtained parameters with the corresponding engraving depth data and name them to form a process parameter resource library; S2. Perform layered slicing on the pre-defined micro-nano three-dimensional structure, with the process parameters for each layer set independently and selected from the process parameter resource library. S3. Ultrafast lasers are emitted through an ultrafast laser emission system to perform micro-nano processing on the material surface according to the process parameters of each layer after layering. S4. The detection feedback system is used to measure the processing depth of each layer at multiple points and calculate the average value. The depth feedback value is then transmitted to the micro-nano processing control software. The micro-nano processing control software adjusts the number of layers and process parameters for subsequent processing based on the difference between the depth feedback value and the preset depth value. S5. The processing status information is collected in real time through the vision system and matched with the pre-stored qualified status information. If the match is inconsistent, the processing is suspended and the manual parameter intervention is waited until the processing status returns to normal. S6. Repeat steps S3-S5 until all layers of micro / nano fabrication are completed.

[0016] This invention utilizes a detection feedback system to measure and provide data feedback on the processing depth in real time, enabling precise control of the engraving depth and effectively ensuring the smoothness and uniformity of the micro / nano structure's depth. By relying on micro / nano processing control software to adjust process parameters in a timely manner, the forming accuracy of the micro / nano structure can be optimized, significantly improving the matching degree between the actual processed shape and the designed shape. Through a vision system to observe the heat accumulation state during processing in real time, process parameters can be adjusted in a targeted manner, avoiding processing defects caused by excessive heat residue from the source and ensuring processing quality. Simultaneously, the device can automatically adjust process parameters based on processing instability states such as laser power fluctuations, achieving adaptive optimization of the processing process and further improving the quality stability of micro / nano processing. The synergistic effect of these multiple technologies allows for strict control over the quality of micro / nano processing, significantly improving product yield and reducing time losses due to parameter debugging and rework, effectively saving the overall time consumption of micro / nano processing.

[0017] In one embodiment, in step S4, the number of multi-point measurements of the detection feedback system is at least 3. The specific method for adjusting process parameters in micro-nano fabrication control software is as follows: the micro-nano three-dimensional structure slice is divided into M layers. The difference in processing depth between the (N-1)th layer and the (N-2)th layer is compared. If the difference is within the preset range, the Nth layer uses the process parameters of the previous layer. If the difference exceeds the preset range, the optimal process parameters are called from the process parameter resource library for the processing of the Nth layer, until the Mth layer is processed, where N is a positive integer greater than 2, and the maximum value of N is equal to the total number of layers M.

[0018] This design, by setting multi-point measurement rules of at least 3 points in the detection feedback system and establishing adaptive adjustment logic for process parameters based on the depth difference between adjacent layers, aims to eliminate single-point measurement errors, dynamically respond to processing variables to avoid the accumulation of depth deviations, reduce manual intervention, improve the degree of processing automation, and ultimately ensure the depth uniformity of micro-nano structures. This design not only improves the accuracy of depth detection and prevents the accumulation of deviations layer by layer, but also improves the efficiency of processing automation. It is also suitable for 3D micro-nano structure processing scenarios with any number of layers, and has good versatility and adaptability.

[0019] In practice, the detection points are distributed according to the principle of "center + four corners" to improve detection accuracy.

[0020] In one embodiment, in step S5, the processing status information collected by the vision system includes at least one of the following: processing edge burrs, surrounding heat-affected zone, and processing splashes. The pre-set pass / fail status information of the vision system includes the status of the processing edge and the status information within 1mm around the processing area.

[0021] This design enables precise judgment and real-time monitoring of processing quality by targeting key defects in the process and defining the detection area. This design can not only comprehensively capture the core defect types in the process, but also ensure the accuracy of monitoring through a clear acceptance range. At the same time, it can promptly identify processing anomalies to avoid the expansion of defects, effectively improving the stability of micro-nano processing quality.

[0022] A laser micro / nano fabrication device, applied to any one of the laser micro / nano fabrication methods, comprising: An ultrafast laser emission system, including a laser and optical mirrors, is used to emit ultrafast lasers and perform micro- and nano-fabrication on materials; The detection feedback system is connected to the micro-nano fabrication control software to measure the processing depth during laser processing and to feed the depth data back to the micro-nano fabrication control software in real time. The vision system is connected to the micro-nano fabrication control software to collect real-time processing status information and match it with preset qualified status information. The motion control system is connected to the micro-nano fabrication control software and is used to drive the ultrafast laser emission system to move and adjust the laser focusing point.

[0023] Preferably, the laser is a picosecond laser or a femtosecond laser.

[0024] It should be noted that the optical lens group includes a beam expander, a scanning galvanometer, and a focusing lens. The beam expander is used to reduce the laser divergence angle and increase the laser beam diameter, the scanning galvanometer is used to change the laser deflection trajectory, and the focusing lens is used to focus the laser onto the material surface.

[0025] In practice, the scanning galvanometer can be selected according to the user's needs, using a three-dimensional scanning galvanometer, a two-dimensional scanning galvanometer matched with a lead screw motion, or a direct two-dimensional galvanometer scanning method, to meet the needs of different processing precision and processing costs.

[0026] Preferably, the depth measurement method of the detection feedback system is white light interferometer measurement or laser measurement.

[0027] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0028] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0029] Additionally, "multiple" refers to two or more.

[0030] The above description is only a preferred embodiment of the present invention and is 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 within the protection scope of the present invention.

Claims

1. A method of laser micro- and nanofabrication, characterized in that, The method comprises the following steps: S1, testing the target machining material with different parameters of engraving depth, associating and naming the parameters obtained by testing with corresponding engraving depth data to form a process parameter library; S2, layering the pre-set micro-nano three-dimensional structure, independently setting the process parameters of each layer, and selecting the process parameters from the process parameter library; S3, emitting ultrafast laser through an ultrafast laser emitting system, and performing micro-nano machining on the material surface according to the process parameters of each layer after layering; S4, measuring the machining depth of each layer by a detection feedback system and calculating the average value, and transmitting the depth feedback value to a micro-nano machining control software, wherein the micro-nano machining control software adjusts the layering number and process parameters of subsequent machining according to the difference between the depth feedback value and the pre-set depth value; S5, collecting the machining state information in real time through a visual system, and matching it with the pre-stored qualified state information, if the matching is inconsistent, the machining is suspended and waits for manual parameter intervention until the machining state returns to normal; S6, repeating steps S3-S5 until the micro-nano machining of all layers is completed. 2.The laser micro-nano processing method according to claim 1, wherein: In step S4, the number of multi-point measurements of the detection feedback system is at least 3 points; The specific way of adjusting the process parameters by the micro-nano machining control software is that the micro-nano three-dimensional structure slice is divided into M layers, the difference value of the machining depth of the N-1 layer and the N-2 layer is compared, if the difference value is within the pre-set range, the process parameters of the N-1 layer are used for the N layer, if the difference value exceeds the pre-set range, the optimal process parameters are called from the process parameter library for the N layer machining, until the M layer is machined, wherein N is a positive integer greater than 2, and the maximum value of N is equal to the total number of layers M. 3.The laser micro-nano processing method of claim 1, wherein: In step S5, the machining state information collected by the visual system includes at least one of the machining edge burr, the surrounding heat affected zone and the machining spatter; The pre-set qualified state information of the visual system includes the state information of the machining edge and the state information within 1mm range around the machining area.

4. A laser micro-nano processing device applied to the laser micro-nano processing method of any one of claims 1-3, wherein, It comprises: an ultrafast laser emitting system comprising a laser and an optical lens group, used for emitting ultrafast laser and implementing micro-nano machining on the material; a detection feedback system, signal connected with the micro-nano machining control software, used for measuring the machining depth in the laser machining process and feeding back the depth data to the micro-nano machining control software in real time; a visual system, signal connected with the micro-nano machining control software, used for collecting the machining state information in real time and matching it with the pre-set qualified state information; a motion control system, signal connected with the micro-nano machining control software, used for driving the ultrafast laser emitting system to move and adjusting the laser focusing point. 5.The laser micro-nano processing device according to claim 4, characterized in that: The laser is a picosecond laser or a femtosecond laser. 6.The laser micro-nano processing device according to claim 4, characterized in that: The optical lens group comprises an expander, a scanning galvanometer and a focusing lens, the expander is used for reducing the laser divergence angle and increasing the laser beam diameter, the scanning galvanometer is used for changing the laser deflection trajectory, and the focusing lens is used for focusing the laser on the material surface. 7.The laser micro-nano processing device according to claim 4, characterized in that: The depth measurement method of the detection feedback system is white light interferometer measurement or laser measurement.

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