A laser engraving device for chip preparation

Abstract

This invention relates to the field of laser engraving technology for microfluidic chips, and more particularly to a laser engraving apparatus for chip fabrication. The apparatus includes a laser engraving unit that engraves microfluidic chip material according to engraving parameters using a preset scanning trajectory and number of scans; a side-bottom quality analysis unit that determines and adjusts a preset height value based on the relationship between the side-bottom quality index and a preset quality index; and a bottom-layer evaluation unit that acquires blind groove image data of the target number of engraving passes for the marked points to determine bottom-layer evaluation parameters, and adjusts the initial laser power based on the relationship between the bottom-layer evaluation parameters and preset evaluation parameters, adjusting the initial laser power based on the excess value of the evaluation parameters. This invention improves the quality and yield of laser engraving by comprehensively and multidimensionally judging the engraving quality of marked points during multiple laser engraving passes and dynamically adjusting the laser engraving parameters and thresholds in the judgment process.

Description

Technical Field

[0001] This invention relates to the field of laser engraving technology for microfluidic chips, and more particularly to a laser engraving apparatus for chip fabrication. Background Technology

[0002] The prevalence of various viral diseases has created a huge demand for high-throughput, low-cost testing. For example, a certain biological cervical cancer diagnostic chip can screen for 12 pathogens at once, and DaAn Gene's PCR amplification chip can screen for 8 pathogens at once. These examples reflect the market's strong reliance on rapid, multi-pathogen detection, and also provide a broad space for the development of microfluidic chips. Microfluidic chip technology integrates the basic operational units of biological, chemical, and medical analysis processes, such as sample preparation, reaction, separation, and detection, onto a chip at the micrometer scale, automatically completing the entire analysis process. Most domestic companies are still in the design and verification stage for microfluidic chips and cannot promote mass production. In the process of mass-producing microfluidic chips, there are problems such as high costs of molds, equipment, and materials, long development cycles, incompatibility with mass production, low standardization, low efficiency, and low manufacturing yield.

[0003] Chinese Patent Publication No. CN116100164A discloses a microfluidic chip processing method based on laser cutting. The method uses computer-aided software to draw the microfluidic chip structure, generating a design graphic file readable by a laser engraving and cutting device. The design graphic file is imported into the laser engraving and cutting device, and the substrate is sequentially laser-cut to obtain the various structures of the microfluidic chip. The substrate for the flow channel layer is double-sided adhesive. The various structures of the microfluidic chip are sequentially overlapped from bottom to top, and bonded together using the double-sided adhesive of the flow channel to obtain the finished microfluidic chip.

[0004] Therefore, the microfluidic chip processing method based on laser cutting has the following problems: it is difficult to comprehensively determine the engraving quality of the marker points in the multiple laser engraving process through multiple dimensions, and to dynamically adjust the laser engraving parameters and the threshold in the judgment process in order to improve the quality and yield of laser engraving. Summary of the Invention

[0005] Therefore, the present invention provides a laser engraving device for chip fabrication, which overcomes the problem in the prior art that it is difficult to comprehensively determine the engraving quality of marker points in multiple laser engraving processes from multiple dimensions, and to dynamically adjust the laser engraving parameters and thresholds in the determination process, so as to improve the quality and yield of laser engraving.

[0006] To achieve the above objectives, the present invention provides a laser engraving apparatus for chip fabrication, comprising: The accumulation analysis unit is used to acquire image data of the molten pool at the marked point to determine the accumulation height value, and to adjust the blowing pressure of the auxiliary blowing according to the height excess value based on the relationship that the accumulation height value is greater than the preset height value. The height excess value is determined based on the difference between the accumulation height value and the preset height value. The side bottom quality analysis unit is used to acquire image data of the blind groove of the marked point to determine the side bottom quality index, and to determine the adjustment of the preset height value according to the insufficient value of the index based on the relationship that the side bottom quality index is less than the preset quality index. The bottom evaluation unit is used to acquire blind groove image data of the target engraving pass of the marked points to determine the bottom evaluation parameters, and to determine the adjustment of the initial laser power according to the value of the evaluation parameters exceeding the preset evaluation parameters based on the relationship between the bottom evaluation parameters and the preset evaluation parameters. The comprehensive analysis unit responds when the underlying evaluation parameter is less than or equal to the preset evaluation parameter, and determines the taper tolerance constant based on the roughness value being greater than the critical roughness value. The laser engraving unit engraves microfluidic chip materials according to engraving parameters, which include laser power, focal depth, and scanning speed. The auxiliary blowing unit transports and removes material according to the blowing pressure adjusted based on the height excess value, with the blowing angle on the coaxial axis. The side bottom quality index is determined based on the first depth error value and the side wall taper value. The preset quality index is determined based on the first depth error tolerance constant and the taper tolerance constant. The index deficiency value is determined based on the side bottom quality index and the preset quality index. The bottom layer evaluation parameter is determined based on the second depth error value and the roughness value. The evaluation parameter excess value is determined based on the bottom layer evaluation parameter and the preset evaluation parameter.

[0007] Furthermore, the stacking analysis unit is used to compare the stacking height value with the preset height value to determine the passability of the single-layer scan quality. In response to the single-layer scan quality failure determination, the blowing pressure of the auxiliary blowing is increased according to the height exceeding the value.

[0008] Furthermore, the stacking analysis unit, in response to the fact that simply increasing the blowing pressure does not meet the single-layer scan quality compliance requirements, adjusts the scan speed to increase based on the height exceeding the value.

[0009] Furthermore, the side bottom quality analysis unit is used to compare the side bottom quality index with the preset quality index to determine the side bottom quality compliance. In response to the side bottom quality non-compliance judgment, the preset height value is adjusted to decrease according to the insufficient index value.

[0010] Furthermore, the side bottom quality analysis unit, in response to the side bottom quality non-compliance determination, adjusts the laser focus position downward according to the side wall taper value, and determines the laser power adjustment direction according to the deviation direction of the first depth error value.

[0011] Furthermore, the underlying evaluation unit is used to compare the underlying evaluation parameters with the preset evaluation parameters to determine the passability of the underlying quality. In response to the determination that the underlying quality is unqualified, the initial laser power is adjusted to decrease according to the evaluation parameters exceeding the value.

[0012] Furthermore, the bottom evaluation unit, in response to the fact that simply adjusting the initial laser power to decrease does not meet the bottom quality compliance requirements, adjusts the scanning speed to increase based on the roughness value.

[0013] Furthermore, the comprehensive analysis unit responds to redetermining the taper tolerance constant, which is negatively correlated with the roughness value.

[0014] Furthermore, the compensation processing unit responds to re-determining the taper tolerance constant to determine the plasma processing time based on the roughness value.

[0015] Furthermore, a linear drive unit is used to drive the laser engraving unit to engrave the flow channel blind groove of the microfluidic chip according to a preset scanning trajectory and a determined scanning speed.

[0016] Compared with the prior art, the beneficial effect of the laser engraving device for chip fabrication of the present invention is that it improves the quality and yield of laser engraving by comprehensively judging the engraving quality of the marker points in the multiple laser engraving process in a multi-dimensional manner and dynamically adjusting the laser engraving parameters and the threshold in the judgment process.

[0017] Furthermore, by comparing the molten material accumulation height with a preset threshold, the dynamic balance between laser heat input, material removal rate, and auxiliary air blowing slag removal capability during the current laser engraving process can be determined. When the molten material accumulation height exceeds expectations, it indicates that the laser energy input is too high or the air blowing pressure is insufficient to blow the molten material away from the processing area in time, causing the molten material to accumulate on both sides of the groove. The accumulation of molten material will affect the effective utilization of heat input in subsequent engraving processes, resulting in a decrease in engraving quality. Excessive repeated melting and solidification of molten material will cause unevenness on the surface of the microfluidic chip material. After laser engraving, when encapsulating with the upper plate, uneven areas are prone to poor sealing, leading to a decrease in the quality of the microfluidic chip. Controlled accumulation height indicates that the processing parameters are reasonably matched and slag removal is smooth. Real-time monitoring of molten material accumulation can also quantitatively identify process instability states, avoiding batch defects caused by relying on post-inspection. At the same time, by increasing the detection frequency for easily accumulated markers such as corners and start / end points, the process reliability of critical areas can be further improved. To prevent molten material from blocking the laser pulse, ensuring the laser continuously acts on the surface of fresh material rather than repeatedly melting solidified deposits, thus maintaining a stable etching depth and reducing sidewall taper; to avoid localized overheating caused by heat insulation from deposits, protecting the bottom roughness of the groove to meet the laminar flow requirements of the microfluidic chip; in cases where the single-layer scanning quality is deemed unqualified, adjusting the blowing pressure to enhance the delivery capacity of the removed material; when adjusting the blowing pressure alone cannot guarantee the molten material accumulation height, increasing the scanning speed to reduce heat input, thereby ensuring the single-layer scanning quality of laser engraving, and thus ensuring the single-layer scanning quality of subsequent layer-by-layer laser engraving and the overall quality of laser engraving.

[0018] Furthermore, during the laser engraving process, monitoring of markers with large process fluctuations allows for rapid determination of quality changes in the laser engraving. By monitoring the taper of the sidewall and the error in engraving depth during a single scan, the quality of the bottom edge after laser engraving is assessed. When the bottom edge of the currently engraved blind groove exceeds expectations, the focal position of the laser engraving is adjusted to ensure uniform heat input distribution and fully meet expectations. This reduces the risk of the upper engraving width being greater than the lower engraving width due to the laser beam's heat input dispersion during the laser engraving process caused by the focal position not meeting the requirements for stable heat input. Sudden changes in the flow channel cross-section can lead to deviations between the actual flow rate and the design value, with errors exceeding 20%, severely affecting the repeatability of the test results and causing quality and performance loss of control of the microfluidic chip itself. Secondly, irregular trapezoidal cross-sections can cause irregular refraction of the optical path. In fluorescence detection, this can cause focus shift and signal intensity unevenness, interfering with quantitative analysis and leading to complete loss of control of the microfluidic chip, making it unable to meet performance requirements. By monitoring the taper of the sidewall, when there is a defect in the quality of the side bottom but no sidewall tilt that cannot be reduced, the focus position can be quickly adjusted to suppress and improve the deterioration trend of the sidewall taper, thereby ensuring that the flow channel of the microfluidic chip can meet the performance requirements in the sidewall taper direction.

[0019] Furthermore, when the error in the engraving depth is detected to exceed expectations, the laser power is adjusted according to the direction of the error deviation to quickly respond to the situation where the engraving depth deviates, so as to avoid the continuous accumulation of engraving depth error causing the depth of the blind groove to exceed expectations. If the depth of the blind groove exceeds expectations, the actual flow rate will be seriously inconsistent with the design expectation. For experiments such as immunoassay and cell stimulation that rely on precise flow rates, completely erratic reaction times can lead to unreliable results, severely impacting the performance consistency of microfluidic chips. If the error of engraving depth exceeding expectations continues to accumulate without adjustment of laser power, it will cause severe loss of control over the flow channels of the microfluidic chip, ultimately resulting in defective microfluidic chips. Furthermore, unstable processes can lead to a sharp deterioration in product defect rates, affecting the overall fabrication of microfluidic chips. By monitoring markers with large process fluctuations, a rapid response can be made to adjust the laser power when the engraving depth error exceeds expectations, preventing the continuous accumulation of engraving depth errors. Multiple laser engravings are used to achieve the expected blind groove depth, ensuring the performance stability of the microfluidic chip's flow channels. This ensures the performance stability of the microfluidic chip. Intelligent automatic identification of defective situations and corresponding adjustments increase process stability and improve the yield of laser-engraved microfluidic chips.

[0020] Furthermore, by comprehensively constructing a side-bottom quality index by monitoring the errors of sidewall taper and engraving depth, the quality of the side-bottom is determined. Compared with traditional single-direction monitoring and independent single-direction adjustment, the comprehensive judgment can better monitor the condition of the sidewall and engraved bottom during the laser engraving process from an overall perspective. By judging the overall condition of the side-bottom during the laser engraving process, the laser engraving quality is monitored based on the overall abnormality of the side-bottom in both directions. This avoids new quality problems caused by occasional misjudgments in single-direction monitoring, which may lead to adjustments in laser beam focus or laser power. It also avoids the response delay that occurs when determining laser beam focus or laser power adjustment based on multiple abnormality judgments. Thus, a comprehensive, complete, and accurate judgment is achieved to quickly suppress the degradation that occurs during the laser engraving process and ensure the stability of the laser engraving quality and performance of the microfluidic chip.

[0021] Furthermore, when a side-bottom quality defect is triggered, the threshold for judging the molten material accumulation height is tightened to apply a more stringent standard to the single-layer scan quality acceptance. This is to prevent the molten material accumulation height from approaching the expected boundary, which would exacerbate the side-bottom quality defect. The side-bottom quality defect would then feed back to the dispersion of heat input during laser engraving, leading to a continuous deterioration of the single-layer scan quality, causing a cyclical deterioration of the laser engraving process and ultimately resulting in downtime. By monitoring the side-bottom quality defect and applying stringent single-layer scan quality acceptance criteria, a more rapid response can be made to situations where the molten material accumulation height exceeds the limit. To address unexpected situations, the system reduces side-bottom quality defects caused by molten material accumulation. This is achieved through a coordinated monitoring and judgment process, comprehensively regulating laser power, focal position, and scanning speed to achieve integrated control. This avoids abnormalities in the laser engraving process caused by singular adjustments to laser power, focal position, and scanning speed. Different suppression and reduction techniques are employed for different abnormal situations and degrees to ensure the stability of the laser engraving process for microfluidic chips and the stability of the microfluidic chip's performance. Furthermore, intelligent control of the microfluidic chip engraving process improves the yield rate of laser engraving.

[0022] Furthermore, by monitoring the second depth error value and roughness value to construct bottom-level evaluation parameters, a comprehensive judgment is made on the deep laser engraving of the flow channel. After the pre-processing laser engraving, a comprehensive judgment is made on the bottom surface of the flow channel to avoid the one-sidedness and randomness of judgment in a single direction, and also to avoid the redundancy caused by exhaustively judging all directions. The second depth error value and roughness value are used to ensure the stability of the flow channel dimensions and performance. In the case of bottom-level quality abnormalities, the initial laser power is reduced to comprehensively reduce roughness abnormalities and excessive engraving depth at the same time. This reduces laser engraving abnormalities from multiple aspects simultaneously, providing a comprehensive and rapid response to reduce possible abnormalities in multiple directions, avoiding targeted treatment based on abnormalities in a single direction. In cases where the technical means of suppressing abnormalities in the laser engraving are used incorrectly, such as detecting excessive roughness and individually reducing the laser power to reduce the roughness abnormality caused by excessive heat input, the actual roughness abnormality is caused by uneven laser beam energy distribution due to abnormal sidewall taper. In this case, continuous adjustment of laser power will lead to new problems such as abnormal engraving depth. However, by jointly judging the synchronous deterioration of the second depth error value and roughness value by constructing the bottom-level evaluation parameters, targeted adjustment can more accurately determine the cause of the bottom-level quality abnormality and carry out comprehensive adjustment to simultaneously reduce laser engraving abnormalities from multiple directions, so as to ensure the quality of laser engraving microfluidic chips.

[0023] Furthermore, by setting up multi-level control methods to avoid new anomalies caused by excessive adjustment in a single direction, different control strategies are adopted for different degrees of anomalies through multiple directions to effectively suppress abnormal situations, increase the stability and continuity of laser engraving, and avoid the situation of stopping for maintenance after the single-direction control reaches the boundary, thereby ensuring the processing cycle of laser engraving and avoiding the decrease in laser engraving efficiency due to the interruption of the continuity of laser engraving.

[0024] Furthermore, by monitoring the relationship between the underlying evaluation parameters and preset evaluation parameters to determine the quality compliance of the underlying layer, the system accurately identifies abnormal situations where the underlying quality failure judgment is not triggered, but the roughness value exceeds the critical roughness value. The taper tolerance constant is then adjusted accordingly. This taper tolerance constant is used to feedback and adjust preset quality indicators to increase the stringency of the side-bottom quality compliance judgment. This further optimizes the laser engraving process, reducing underlying quality failures caused by sidewall taper and situations where the roughness value exceeds expectations due to the failure to trigger the underlying quality failure judgment. This intelligently optimizes the impact of single-layer scanning quality on side-bottom and underlying quality, as well as the impact of side-bottom quality on underlying quality. This ensures continuous optimization of the laser engraving process to guarantee the dimensional and performance compliance of the microfluidic chip channels after multiple laser engraving passes, as well as the stability of the laser engraving process. It prevents unavoidable channel quality anomalies caused by excessively large quality tolerances in shallow and middle layer laser engraving, which could lead to a decrease in the yield rate of microfluidic chip laser engraving. By continuously optimizing the laser engraving process, the yield rate of microfluidic chip laser engraving is improved.

[0025] Furthermore, the plasma treatment time is adjusted for blind grooves with acceptable dimensions but abnormal roughness. This ensures that the microfluidic chip material with acceptable dimensions but unacceptable processing performance can be repaired to improve the flow channel performance, thus avoiding material waste and improving the yield and utilization rate of microfluidic chips. The subsequent processing of the compensation unit provides greater tolerance for laser engraving, reduces the difficulty of laser engraving microfluidic chip material, and improves the standardization and intelligence level of laser engraving. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the laser engraving device used for chip fabrication according to an embodiment of the present invention; Figure 2 This is a functional block diagram of the laser engraving device according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the process of adjusting the laser focus position and laser power based on the defective side bottom quality in an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the process of adjusting the initial laser power and scanning speed based on the substandard quality of the underlying layer in an embodiment of the present invention.

[0027] In the figure: Linear drive unit 11, laser engraving unit 12. Detailed Implementation

[0028] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0029] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0030] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0031] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] Please see Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the laser engraving device used for chip fabrication according to an embodiment of the present invention; Figure 2 This is a functional block diagram of the laser engraving device according to an embodiment of the present invention; The laser engraving apparatus for chip fabrication according to embodiments of the present invention includes, The laser engraving unit 12 engraves the microfluidic chip material according to the engraving parameters, which include laser power, focal depth and scanning speed. The laser engraving unit 12 includes a laser source module for emitting a laser beam, a beam transmission and focusing module for adjusting and transporting the emitted laser beam, and a scanning galvanometer module for controlling the laser beam to perform laser engraving according to a preset scanning trajectory and number of scans. The scanning galvanometer module is used to fine-tune the scanning path of the laser beam. The laser engraving unit 12 includes, but is not limited to, the structure in this embodiment.

[0033] The linear drive unit 11 is used to drive the laser engraving unit 12 to engrave the flow channel blind groove of the microfluidic chip according to a preset scanning trajectory and a determined scanning speed. The linear drive unit 11 is used to realize the long-distance movement of the laser engraving unit 12. Through the synergistic effect of the linear drive unit 11 and the scanning galvanometer module in the laser engraving unit 12, the laser beam is refined and standardized for laser engraving.

[0034] The linear drive unit 11 drives the laser engraving unit 12 to move linearly on the horizontal plane, thereby enabling the laser engraving unit 12 to scan and move on the microfluidic chip material according to a preset scanning trajectory. Combined with the heat input of the laser engraving unit 12, blind groove engraving is achieved on the microfluidic chip material.

[0035] The linear drive unit 11 includes a first linear module, a second linear module, and a frame. The first linear module is mounted on the frame, and the second linear module is mounted on the first linear module. The linear module includes... The guide rail and the sliding frame that slides on the guide rail are fixedly connected to the sliding frame. A lead screw nut is provided on the lead screw nut. The lead screw is fixedly connected to the output shaft of the servo motor and is driven to rotate by the rotation of the servo motor. The rotation of the lead screw drives the lead screw nut to drive the linear movement of the sliding frame. The guide rail, servo motor and lead screw of the first linear module are set on the main frame. The guide rail, servo motor and lead screw of the second linear module are set on the sliding frame of the first linear module. The degrees of freedom of the sliding frame of the first linear module and the sliding frame of the second linear module are perpendicular. The laser engraving unit 12 is fixedly connected to the sliding frame of the second linear module. The laser engraving unit 12 moves along any scanning trajectory in a plane parallel to the microfluidic chip material through the linear movements of the sliding frames of the first linear module and the second linear module.

[0036] It also includes a visual inspection unit, which is set to detect the image data of the laser engraving process of the marked points. A visual inspection unit can also be set on the laser engraving unit 12 to acquire the image data after laser engraving in real time.

[0037] An auxiliary air blowing unit is installed on the laser engraving unit 12, and the air blown out is coaxially arranged with the laser beam used for engraving to ensure the auxiliary air blowing has the ability to transport the removed material.

[0038] The accumulation analysis unit is used to acquire image data of the molten pool at the marked point to determine the accumulation height value, and to adjust the blowing pressure of the auxiliary blowing according to the relationship that the accumulation height value is greater than the preset height value, wherein the height excess value is determined based on the accumulation height value and the preset height value. The visual inspection unit acquires image data of the molten pool through a coaxial CMOS or CCD camera and analyzes the image features of the molten pool using a lightweight deep learning model.

[0039] The stacking analysis unit acquires image data from the visual inspection unit to determine the molten material stacking height; based on the molten material stacking height, the stacking height value is determined, and the stacking height value is compared with the preset height value to determine the quality qualification of the single-layer scan. When acquiring image data of the molten pool, the acquisition frequency of image data is increased for pre-classified marker points in order to focus on judging the carving quality; The marker points include calibration points for positioning, points where the path changes abruptly, points where the size changes abruptly, and points where there are branching paths; for example, turning corners, the start and end points of a flow channel, and points where flow channels intersect or branch.

[0040] Several typical molten pool image data sets were collected and labeled, for example, to determine the accurate boundaries of the molten pool in the image data. Then, a lightweight classification network based on the data with the accurate boundaries of the molten pool was used to analyze image data acquired through coaxial CMOS or CCD cameras to determine the molten material accumulation height.

[0041] Preferred CMOS industrial cameras with a resolution of 2 megapixels or higher and a frame rate of 50-200fps or higher are used. They are mounted coaxially with the laser head and fixed by a beam splitter.

[0042] Narrow-band filters are used to block the corresponding laser wavelength, filtering out laser reflection interference and only collecting the molten pool radiation light to increase the accuracy of molten pool image features.

[0043] To reduce interference from strong light, smoke, plasma and other factors during laser processing on the image data acquired by the CMOS camera, the following methods are used: exposure time of less than 100μs, freezing of the molten pool shape, coaxial blowing to reduce smoke obstruction, and averaging of 3-5 consecutive frames to suppress random noise.

[0044] The preferred laser is a 355nm ultraviolet nanosecond laser with a 25μm spot diameter, a laser power of 4W, a scanning speed of 100mm / s, a pulse frequency of 80kHz, and 7 scan passes. The auxiliary blowing air is 0.25MPa air.

[0045] The scanning pass is 7 times, with a different scanning depth each time, set sequentially to 6μm, 6μm, 8μm, 8μm, 7μm, 8μm and 7μm, to carve a material with a flow channel layer and a blind groove with a depth of 50μm and a width of 80μm. Later, a plate is used to encapsulate it to form a two-layer precision microfluidic DNA sequencing chip.

[0046] Since the engraving material is a three-dimensional mesh framework structure based on polysiloxane, filled with different functional materials to meet the needs of different scenarios, and the three-dimensional mesh framework structure is prone to backflow, the shallow layer needs to be scanned multiple times. The scanning depth of the first two scans is set to 6μm. The scanning depth is increased in subsequent scans to ensure the speed and quality of laser engraving blind grooves. The laser focal depth is determined according to the different scanning depths. For example, when the scanning depth is 6μm, the focal depth can be determined to be 15μm, and when the scanning depth is 12μm, the focal depth can be determined to be 20μm. This allows for matching appropriate heat input according to the different scanning depths of each laser engraving pass, thus ensuring the quality of laser engraving.

[0047] If the stacking height is less than or equal to the preset height, the single-layer scan quality is deemed acceptable. If the stacking height value is greater than the preset height value, the single-layer scan quality is deemed unqualified. The preset height value is set comprehensively based on the process tolerance of subsequent taper and depth errors, material melting characteristics, and the balance point between processing efficiency and quality. It typically ranges from 2 to 5 μm. In this embodiment, the preset height value is 3 μm. This is to ensure that subsequent taper and depth error requirements are met while balancing processing efficiency and process stability, achieving a final yield of over 95%. It also avoids frequent false alarms and production stoppages due to overly strict thresholds (e.g., 1 μm) or overly wide thresholds leading to quality control issues (e.g., 4-5 μm). It is known that different preset height values ​​are set for different scanning depths; the 3 μm preset height value in this embodiment is for an engraving process with a scanning depth of 6-8 μm.

[0048] The molten material buildup height reflects the dynamic balance between heat input and slag removal capacity during the laser-material interaction process. A buildup height controlled within a preset threshold indicates that the laser energy input and the rates of material vaporization, melting, and removal are reasonably matched during the scanning process of this layer. The laser energy is sufficient to effectively remove the material, while the auxiliary air blowing can promptly blow the molten material away from the processing area, preventing excessive accumulation on both sides of the groove.

[0049] This indicates that the channel outline is clear and not obstructed by deposits, allowing subsequent laser pulses to continuously act on the material surface rather than on the accumulated molten material, ensuring stable depth processing and processing according to the expected results. The deposits will not be repeatedly melted and re-solidified in subsequent scans, avoiding the formation of irregular sidewalls or increased sidewall taper. The heat accumulation at the bottom of the channel is controllable, and local overheating caused by the deposits will not affect the bottom surface roughness or the flow of fluid within the channel.

[0050] When the stacking height is less than or equal to the preset height, the single-layer scanning quality is deemed acceptable, indicating that the heat input of laser engraving, the speed of material removal, and the conveying capacity of the removed material are all within the expected range during the current single-layer scanning process; no parameter adjustment is required.

[0051] Specifically, the stacking analysis unit is used to compare the stacking height value with the preset height value to determine the pass rate of single-layer scanning quality. In response to the single-layer scanning quality failure determination, the blowing pressure of the auxiliary blowing is increased according to the height exceeding the value.

[0052] The auxiliary blowing unit transports and removes material according to the blowing pressure adjusted based on the height excess value, with the blowing angle being coaxial.

[0053] The initial state is 0.25 MPa of auxiliary air to fully transport the removed material and prevent excessive accumulation on both sides of the blind groove, which would affect the quality of subsequent laser engraving. In response to the height exceeding the value, the blowing pressure of the auxiliary air is increased to blow air out at the adjusted pressure to enhance the transport capacity of the auxiliary air unit for the removed material, thereby reducing the problem of the molten material accumulation height exceeding the expectation.

[0054] When the stacking height value is greater than the preset height value, the single-layer scanning quality is deemed unqualified. This indicates that during the current single-layer scanning process, the heat input of laser engraving is too large, or the speed of material removal is too fast, or the conveying capacity of the removed material is too low, i.e., the auxiliary blowing pressure is too low.

[0055] The pressure of the auxiliary air blowing is adjusted according to the height excess value. For every 1μm increase in the height excess value, the blowing pressure of the auxiliary air blowing increases by 0.5MPa. It can be seen that different adjustment values ​​of the blowing pressure can also be set according to the process requirements of different materials and the yield rate to meet different laser engraving needs.

[0056] The maximum upper limit of the auxiliary blowing pressure is 5.0 MPa. If the blowing pressure continues to increase, it may blow away the molten pool, cause uneven edges, or blow away molten material, causing secondary pollution. The part of the height exceeding the value by less than 1 μm shall be calculated as 1 μm.

[0057] This invention compares the molten material accumulation height with a preset threshold to determine the dynamic balance between laser heat input, material removal rate, and auxiliary air blowing slag removal capability during the laser engraving process. When the molten material accumulation height exceeds expectations, it indicates that the laser energy input is too high or the air blowing pressure is insufficient to blow the molten material away from the processing area in time, causing the molten material to accumulate on both sides of the groove. The accumulation of molten material affects the effective utilization of heat input in subsequent engraving processes, resulting in a decrease in engraving quality. Excessive repeated melting and solidification of molten material causes unevenness on the surface of the microfluidic chip material. After laser engraving, when encapsulating with the upper plate, uneven areas are prone to poor sealing, leading to a decrease in the quality of the microfluidic chip. Controlled accumulation height indicates that the processing parameters are reasonably matched and slag removal is smooth. Furthermore, by monitoring the molten material accumulation in real time, the process instability state can be quantitatively identified, avoiding batch defects caused by relying on post-inspection. At the same time, by increasing the detection frequency for easily accumulated markers such as corners and start / end points, the process reliability of critical areas is further improved. To prevent molten material from blocking the laser pulse, ensuring the laser continuously acts on the surface of fresh material rather than repeatedly melting solidified deposits, thus maintaining a stable etching depth and reducing sidewall taper; to avoid localized overheating caused by heat insulation from deposits, protecting the bottom roughness of the groove to meet the laminar flow requirements of the microfluidic chip; in cases where the single-layer scanning quality is deemed unqualified, adjusting the blowing pressure to enhance the delivery capacity of the removed material; when adjusting the blowing pressure alone cannot guarantee the molten material accumulation height, increasing the scanning speed to reduce heat input, thereby ensuring the single-layer scanning quality of laser engraving, and thus ensuring the single-layer scanning quality of subsequent layer-by-layer laser engraving and the overall quality of laser engraving.

[0058] The accumulation height value was compared with the critical height value. The critical height value was determined based on the degree of abrupt change in the quality of the subsequent engraving process caused by the molten material accumulation height. After multiple statistical analyses of historical data, it was found that the quality of the subsequent engraving process was severely reduced after the molten material accumulation height reached 4.5 μm.

[0059] If the accumulation height value is less than or equal to the critical height value, it indicates that the current molten material accumulation does not meet the current single-layer scanning quality requirements, but has not reached the point of causing a sudden drop in quality in the subsequent engraving process. At this time, the blowing pressure of the auxiliary blowing is adjusted to reduce the single-layer scanning quality failure.

[0060] Specifically, the stacking analysis unit responds to the fact that simply increasing the blowing pressure does not meet the single-layer scan quality qualification requirements, by increasing the scan speed according to the height exceeding the value.

[0061] If the molten material buildup exceeds the critical height, it indicates that the current molten material buildup has reached a point where it will cause a sudden drop in quality during the subsequent engraving process. In this case, simply adjusting the auxiliary air pressure cannot fundamentally solve the problem of excessive molten material buildup. Simultaneously, the material removal speed (i.e., the scanning speed) should be increased. If the initial scanning speed is 100 mm / s, then for every 0.5 μm increase in the height exceeding the critical height, the scanning speed should be increased by 5 mm / s to reduce the heat input for laser engraving and decrease the molten material generation rate, thereby reducing the degree of single-layer scan quality defects. The maximum scanning speed can be adjusted to 120 mm / s. If adjusting to 120 mm / s still fails to meet the single-layer scan quality requirements, it indicates that the cause of the single-layer scan quality defects is not a problem with the scanning speed. The laser power needs to be re-determined to avoid uncontrolled laser engraving due to excessive heat input. Alternatively, a stop height value can be set for the molten material buildup height to exceed the critical height. When the buildup height reaches the stop height value, the machine will directly enter a stop state, indicating that the current laser power is severely deviating from the expected situation and is out of control, making effective laser engraving impossible.

[0062] This invention sets different thresholds for the height of molten material accumulation and sets different responses for the degree of single-layer scanning quality failure. This diversified approach addresses situations where molten material accumulation exceeds expectations, preventing the ineffective suppression of single-layer scanning quality failures by a single response and avoiding the occurrence of new negative effects due to over-adjustment of a single response. Under the condition that there is no serious deviation in heat input, the molten material accumulation height is kept at the expected state by reducing the transport capacity of the removed material and reducing heat input, thereby ensuring the reliability of subsequent packaging and subsequent laser engraving processes.

[0063] The side bottom quality analysis unit is used to acquire image data of the blind grooves marked with points to determine the side bottom quality index, and adjust the preset height value according to the relationship that the side bottom quality index is less than the preset quality index. Among them, the side bottom quality index is determined based on the first depth error value and the side wall taper value, the preset quality index is determined based on the first depth error tolerance constant and the taper tolerance constant, and the index deficiency value is determined based on the side bottom quality index and the preset quality index.

[0064] Please see Figure 3 As shown, it is a schematic diagram of the process of adjusting the laser focus position and laser power according to the defective side bottom quality in an embodiment of the present invention; Specifically, the side bottom quality analysis unit responds to the side bottom quality non-compliance judgment by adjusting the laser focus position downward according to the side wall taper value, and determines the laser power adjustment direction according to the deviation direction of the first depth error value.

[0065] Acquire image data of blind grooves marked points, determine sidewall taper value and first depth error value, construct side bottom quality index, compare side bottom quality index with preset quality index, and determine the side bottom quality qualification; If the quality index of the side bottom is greater than or equal to the preset quality index, the quality of the side bottom is deemed to be qualified. If the quality index of the side bottom is less than the preset quality index, the quality of the side bottom is deemed unqualified. The side bottom quality index is determined based on the side wall taper value and the depth error value. Let the side bottom quality index be C, the side wall taper value be Z, the taper tolerance constant be Zb, the first depth error value be S, the first depth error tolerance constant be Sb, and the preset quality index be Cb. C=[Zb / (Zb+Z)]×[Sb / (Sb+S)]; Wherein, Z is the actual obtained sidewall taper value, Zb is the maximum allowable sidewall taper value, S is the actual obtained depth error value, Sb is the maximum allowable depth error value, and S is the absolute value of the corresponding data to ensure it is always positive. The value of Sb is determined according to different scanning depths. For example, when the laser engraving depth is the first or second pass (shallow scanning depth), Sb can be 3μm, 4μm, or 5μm; when the laser engraving depth is the fourth or fifth pass (medium scanning depth), Sb can be 2.5μm, 3μm, or 4μm; and when the laser engraving depth is the sixth or seventh pass (deep scanning depth), Sb can be 1μm, 1.5μm, or 2μm. Different depth error tolerance constant values ​​are determined according to different process requirements and different scanning depths. In Zb / (Zb+Z), the closer the sidewall taper value is to 0, meaning the sidewall is close to being perpendicular to the bottom groove, the closer the result of Zb / (Zb+Z) is to 1. Conversely, the larger the sidewall taper value, the less perpendicular the sidewall is to the bottom groove, the greater the slope of the sidewall, and the smaller the result of Zb / (Zb+Z). In Sb / (Sb+S), the closer the first depth error value is to 0, the more accurate the laser engraving depth is, and the closer it is to the target depth, the closer the result of Sb / (Sb+S) is to 1. Conversely, the larger the first depth error value, the less accurate the laser engraving depth is, and the more likely it is to affect the yield rate of subsequent products, the closer the result of Sb / (Sb+S) is to 0. For example, the laser engraving depth at this time is the scanning depth of the middle layer, and the value of Zb is 2°, and the value of Sb is 3μm; Based on the target product's 80μm wide and 50μm deep microchannel, with a taper of 2°, the width difference between the top and bottom of the channel is approximately 3.5μm, which is within the expected range for the impact on fluid velocity and pressure drop.

[0066] The target depth is 50±1μm. During the laser engraving process, the depth error is controlled within ±3μm, which is also within the expected range, leaving enough room for fine-tuning for laser engraving with a depth between 40-50μm.

[0067] The preset quality index is a value determined by adding the corresponding safety margin to the calculation result of [Zb / (Zb+Z)]×[Sb / (Sb+S)] based on the good condition. The ideal condition is that Z is half of Zb, i.e., 1°, and S is half of Sb, i.e., 1.5μm; C=[2 / (2+1)]×[3 / (3+1.5)]=0.445; Taper measurement has an error of ±0.2°. The actual taper is 1°, but the measured value may be 0.8° or 1.2°. The depth measurement has an error of 0.5 μm, the actual depth error is 1.5 μm, and the measured value may be 1.0 μm or 2.0 μm; In this embodiment, C under good condition is determined as a preset quality index through corresponding correction. It is generally corrected to 1.5 to 1.6 times that of C under good condition to prevent process defects caused by the maximum error. Therefore, Cb is determined to be 0.7, which is used as the threshold for judging the quality of the side bottom.

[0068] During the laser engraving process, the marker points are the calibration points of the laser engraving, the points where the path changes abruptly, the points where the size changes abruptly, or the points where there are branching paths. Compared with the points where the laser engraving is continuous and without abrupt changes, these points are the points where the process is unstable. Therefore, by monitoring the parameters of the marker points, a better judgment and monitoring effect can be achieved. When the side bottom quality index is less than the preset quality index, it is determined that the side bottom quality is unqualified. This indicates that the current blind groove is in a situation that exceeds expectations. The side wall taper value and depth error value are seriously deviated. There is a situation where the side wall of the blind groove is excessively tilted or the laser engraving depth is seriously inaccurate. At this time, it is necessary to determine the control strategy based on the side wall taper value and depth error value relative to the side wall taper value and depth error value under good conditions. If the sidewall taper value is greater than 1°, the focus is lowered. Whenever the sidewall taper value increases by 0.1°, the focus is lowered by 20μm to ensure that the sidewall of the blind groove for laser engraving is more vertical by adjusting the focus downward. Adjusting the focus redistributes the laser beam energy so that the lower middle part of the engraving receives more energy to reduce the situation where the blind groove is wider at the top and narrower at the bottom due to energy attenuation during laser engraving.

[0069] If the first depth error value exceeds 1.5μm under good conditions, the laser power is adjusted. Whenever the first depth error value increases by 0.1μm, the laser power is adjusted by 1%. The direction of laser power adjustment is determined according to the deviation direction of the first depth error value. For example, when the first depth error is +1.8μm, it indicates that the current laser engraving scanning depth exceeds the expected depth by 1.8μm, so the laser power adjustment is reduced by 3%. If the first depth error is -1.8μm, it indicates that the current laser engraving scanning depth is still 1.8μm away from the expected depth, that is, the scanning depth needs to be increased by 1.8μm to reach the expected depth, so the laser power adjustment is increased by 3%. When acquiring the first depth error value, the source data of the first depth error value is also recorded, and the positive and negative values ​​of the first depth error are recorded.

[0070] This invention monitors markers with large process fluctuations during laser engraving to quickly determine quality changes. It assesses the quality of the finished sidewall by monitoring the taper of the sidewall and the error in engraving depth during a single scan. When the sidewall of the engraved blind groove exceeds expectations, the focal point of the laser engraving is adjusted to ensure uniform heat input distribution and achieve the desired results. This reduces issues caused by the focal point not meeting the requirements for stable heat input during laser engraving, leading to uneven heat input and a wider upper engraving width than the lower part. Abrupt changes in the flow channel cross-section can cause deviations between actual and design flow rates, with errors exceeding 20%, severely impacting the repeatability of test results and causing quality and performance issues with the microfluidic chip itself. Furthermore, irregular trapezoidal cross-sections can cause irregular refraction of the optical path. In fluorescence detection, this can cause focus shift and signal intensity unevenness, interfering with quantitative analysis and leading to complete loss of control of the microfluidic chip, making it unable to meet performance requirements. By monitoring the taper of the sidewall, when there is a defect in the quality of the side bottom but no sidewall tilt that cannot be reduced, the focus position can be quickly adjusted to suppress and improve the deterioration trend of the sidewall taper, thereby ensuring that the flow channel of the microfluidic chip can meet the performance requirements in the sidewall taper direction.

[0071] When the error in the engraving depth exceeds expectations, the laser power is adjusted according to the direction of the error deviation to quickly respond to the situation where the engraving depth deviates, so as to avoid the continuous accumulation of engraving depth error and the blind groove depth exceeding expectations. If the depth of the blind groove exceeds expectations, the actual flow rate will be seriously inconsistent with the design expectation. For experiments such as immunoassay and cell stimulation that rely on precise flow rates, completely erratic reaction times can lead to unreliable results, severely impacting the performance consistency of microfluidic chips. If the error of engraving depth exceeding expectations continues to accumulate without adjustment of laser power, it will cause severe loss of control over the flow channels of the microfluidic chip, ultimately resulting in defective microfluidic chips. Furthermore, unstable processes can lead to a sharp deterioration in product defect rates, affecting the overall fabrication of microfluidic chips. By monitoring markers with large process fluctuations, a rapid response can be made to adjust the laser power when the engraving depth error exceeds expectations, preventing the continuous accumulation of engraving depth errors. Multiple laser engravings are used to achieve the expected blind groove depth, ensuring the performance stability of the microfluidic chip's flow channels. This ensures the performance stability of the microfluidic chip. Intelligent automatic identification of defective situations and corresponding adjustments increase process stability and improve the yield of laser-engraved microfluidic chips.

[0072] By comprehensively constructing a side-bottom quality index by monitoring the errors of sidewall taper and engraving depth, the quality of the side-bottom is determined. Compared with traditional single-direction monitoring and independent single-direction adjustment, the comprehensive judgment can better monitor the condition of the sidewall and engraved bottom during the laser engraving process from an overall perspective. By judging the overall condition of the side-bottom during the laser engraving process, the laser engraving quality is monitored based on the overall abnormality of the side-bottom in both directions. This avoids the occasional misjudgment caused by single-direction monitoring, which may lead to new quality problems in laser beam focus adjustment or laser power adjustment. It also avoids the response delay caused by determining laser beam focus adjustment or laser power adjustment based on multiple abnormality judgments. Thus, it achieves a comprehensive, complete, and accurate judgment to quickly suppress the degradation that occurs during the laser engraving process and ensure the stability of the laser engraving quality and performance of the microfluidic chip.

[0073] Specifically, the side bottom quality analysis unit is used to compare the side bottom quality indicators with preset quality indicators to determine the side bottom quality compliance. In response to the side bottom quality non-compliance determination, the preset height value is adjusted to decrease according to the insufficient value of the indicator.

[0074] If the side bottom quality index is less than the preset quality index, the side bottom quality is deemed unqualified. The preset height value is then reduced based on the insufficient value determined by the side bottom quality index being less than the preset quality index. Insufficient indicator value = Preset quality indicator - Side bottom quality indicator; Whenever the index value increases by 0.03, the preset height value decreases by 0.1μm. Based on the value of Zb being 2° and Sb being 3μm, the corresponding actual side bottom quality index is 0.25. Considering process error and detection error, and through corresponding corrections, the critical side bottom quality index corresponding to Zb being 2° and Sb being 3μm is determined to be 0.4. The critical side bottom quality index = 1.6 × actual side bottom quality index. When the side bottom quality index is less than the preset quality index, and the side bottom quality is deemed unqualified, the preset height value is adjusted to reduce the side bottom quality failure caused by molten material accumulation. When the side bottom quality index is less than the critical side bottom quality index, laser engraving cannot continue. The current engraving quality is seriously deviating from the expected engraving state, and the laser engraving is out of control. Immediately stop the laser engraving, readjust the laser engraving device, and then proceed with the laser engraving of the blind groove.

[0075] This invention, upon triggering a side-bottom quality defect determination, tightens the threshold for judging the molten material accumulation height, applying a more stringent standard to determine the single-layer scan quality compliance. This is to prevent the molten material accumulation height from approaching the expected boundary, which would exacerbate the side-bottom quality defect. Side-bottom quality defects, in turn, feed back to the dispersion of laser engraving heat input, leading to continuous degradation of the single-layer scan quality, causing a cyclical deterioration of the laser engraving process and ultimately resulting in shutdown. By monitoring side-bottom quality defects and implementing stringent single-layer scan quality compliance determination, this invention can respond more quickly to situations where the molten material accumulation height exceeds expectations, reducing side-bottom quality defects caused by molten material accumulation. This linkage between monitoring and judgment processes allows for comprehensive control of laser power, focal position, and scanning speed, achieving integrated control and avoiding malfunctions in the laser engraving process caused by singular control of laser power, focal position, and scanning speed. Different suppression and reduction techniques are employed for different abnormal situations and degrees of abnormality to ensure the stability of the laser engraving process and the performance stability of the microfluidic chip. Furthermore, intelligent control of the microfluidic chip engraving process improves the yield rate of laser engraving.

[0076] The bottom evaluation unit is used to acquire blind groove image data of the target engraving pass of the marked points to determine the bottom evaluation parameters, and adjust the initial laser power according to the relationship between the bottom evaluation parameters and the preset evaluation parameters.

[0077] Among them, the bottom evaluation parameters are determined based on the second depth error value and the roughness value, and the evaluation parameter excess value is determined based on the bottom evaluation parameters and the preset evaluation parameters.

[0078] Please see Figure 4As shown, it is a schematic diagram of the process of adjusting the initial laser power and scanning speed according to the unqualified underlying quality in an embodiment of the present invention; Specifically, the bottom-level evaluation unit is used to compare the bottom-level evaluation parameters with the preset evaluation parameters to determine the quality of the bottom layer. In response to the bottom-level quality failure determination, the initial laser power is adjusted to decrease according to the evaluation parameters exceeding the value.

[0079] The second depth error value and roughness value of the blind groove in the deep scan are obtained to construct the bottom layer evaluation parameters and determine the quality qualification of the bottom layer. If the underlying evaluation parameter is less than or equal to the preset evaluation parameter, the underlying quality is deemed acceptable. If the underlying evaluation parameters are greater than the preset evaluation parameters, the underlying quality is deemed unqualified. Let the bottom evaluation parameter be D, the preset evaluation parameter be Dp, the roughness value be R, and the second depth error value be Si; D = Ws × Si + Wr × R, where Ws is the depth error weight and Wr is the roughness weight. Ws and Wr are determined based on the importance of evaluating the bottom layer quality of the blind trench. In the process of evaluating the bottom layer quality, the flow resistance of the microfluidic channel is inversely proportional to the cube of the blind trench depth. Deviations in blind trench depth exceeding expectations are dimensional defects that directly affect whether the chip is qualified. Roughness reflects the flatness of the bottom surface of the blind trench. Excessive roughness will scatter excitation light or fluorescence signals, reduce the signal-to-noise ratio, increase the specific surface area, and easily adsorb biomolecules, leading to fluorescence signal attenuation and inaccurate detection of weak signals, which is a functional defect. Therefore, when evaluating the bottom layer quality of the blind trench, the depth error weight Ws is greater than the roughness weight Wr. Ws is set to a value of 0.6 and Wr is set to a value of 0.4. The preset evaluation parameters are determined based on the depth error and roughness values ​​under good conditions of deep scanning; When the deep scan is in good condition, the second depth error value is half of the depth error tolerance constant Sb when it is 2μm, i.e., 1μm, and the roughness value is 1. Dp = 0.6 × 1 + 0.4 × 1 = 1; Sb is the maximum allowable depth error value. In this case, it is a deep scan, and Sb is set to 2μm. The maximum allowable roughness value is the critical roughness value. The critical roughness value is determined statistically based on several roughness values ​​that meet the performance requirements of the microfluidic chip. According to statistics, when the second depth error value is less than 1μm, microfluidic chips with a roughness value less than or equal to 1.5μm meet the performance requirements. In microfluidic chips with a roughness value greater than 1.5μm, the yield of microfluidic chips that meet the performance requirements drops rapidly and deteriorates sharply as the roughness value continues to increase. Therefore, in this embodiment, the critical roughness value is set to 1.5μm. When the bottom evaluation parameter is less than or equal to the preset evaluation parameter, the bottom quality is deemed to be qualified, indicating that the bottom of the laser-engraved blind groove is in a qualified state, the quality of the bottom surface processing of the blind groove is within expectations, and the quality of the laser-engraved blind groove meets the expected requirements. At this time, even if the second depth error value or the roughness value deviates too much from the good state, it is still within the expected range. The material obtained by laser engraving can meet the performance requirements of the microfluidic chip. When the bottom evaluation parameter is greater than the preset evaluation parameter, and the bottom quality is deemed unqualified, it indicates that the current laser engraving blind groove processing exceeds expectations, and there is a risk of loss of control over the processing quality of the bottom of the blind groove. At this time, the second depth error value and roughness value both exceed expectations, resulting in the bottom quality being deemed unqualified. In this case, laser engraving adjustment is required. Typically, increased roughness is caused by excessive laser power during laser engraving, leading to excessive material melting, the formation of a recast layer, and spatter adhesion, resulting in a rapid increase in roughness. Insufficient scanning speed and excessively high energy density per unit area can also cause the molten pool to expand, resulting in a rough surface after solidification. Excessive energy input and slow scanning speed are also common causes of excessive second-depth error values. Excessive energy input or slow scanning speed leads to excessive material melting, resulting in an excessively deep laser engraving scan depth and an excessively deep blind groove, exceeding 50μm and its corresponding margin. Therefore, when the bottom layer quality is deemed unqualified, the initial laser power needs to be adjusted according to the evaluation parameters. Whenever the bottom layer evaluation parameters exceed the preset evaluation parameters by 0.1, the initial laser power is reduced by 0.05W.

[0080] This invention comprehensively assesses deep laser engraving of flow channels by constructing bottom-level evaluation parameters through monitoring second depth error values ​​and roughness values. Following the initial laser engraving process, a comprehensive assessment of the flow channel's bottom surface is performed, avoiding the bias and randomness of assessments from a single direction, as well as the redundancy caused by exhaustively considering all directions. The second depth error value and roughness value ensure the stability of flow channel dimensions and performance. In cases of bottom-level quality abnormalities, the initial laser power is reduced to comprehensively mitigate both roughness anomalies and excessive engraving depth, thereby simultaneously reducing laser engraving anomalies from multiple aspects. This comprehensive and rapid response reduces potential anomalies from multiple directions, avoiding targeted treatment based on anomalies in a single direction. In cases where the adjustment techniques for suppressing anomalies are used incorrectly, such as detecting excessive roughness and individually reducing the laser power to mitigate roughness anomalies caused by excessive heat input, the actual roughness anomaly may be due to uneven laser beam energy distribution caused by abnormal sidewall taper. In such situations, continuous adjustment of the laser power may lead to new problems such as abnormal engraving depth. However, by jointly determining the synchronous degradation of the second depth error value and roughness value using bottom-level evaluation parameters constructed from the second depth error value and roughness value, targeted adjustments can more accurately identify the cause of bottom-level quality anomalies and perform comprehensive adjustments to simultaneously reduce laser engraving anomalies from multiple directions, thereby ensuring the quality of laser-engraved microfluidic chips.

[0081] Specifically, the bottom evaluation unit responds to the fact that simply adjusting the initial laser power to reduce it does not meet the bottom quality compliance requirements, and adjusts the scanning speed to increase based on the roughness value.

[0082] When individually adjusting the laser power fails to meet the processing requirements of the bottom layer of the blind groove, the scanning speed is increased. Whenever the bottom layer evaluation parameter exceeds the preset evaluation parameter by 0.1, the scanning speed increases by 2 mm / s.

[0083] This invention avoids new anomalies caused by excessive adjustment in a single direction by setting up a multi-level control mode. By controlling in multiple directions, different control strategies are adopted for different degrees of anomalies to effectively suppress abnormal situations, increase the stability and continuity of laser engraving, and avoid the situation of stopping for maintenance after the control in a single direction reaches the boundary. This ensures the processing cycle of laser engraving and avoids the decrease in laser engraving efficiency due to the interruption of the continuity of laser engraving.

[0084] The comprehensive analysis unit responds when the underlying evaluation parameter is less than or equal to the preset evaluation parameter, and redetermines the taper tolerance constant based on the roughness value being greater than the critical roughness value. Specifically, the comprehensive analysis unit responds to redetermining the taper tolerance constant, which is negatively correlated with the roughness value.

[0085] If the underlying evaluation parameter is less than or equal to the preset evaluation parameter, and the roughness value is greater than the critical roughness value, it indicates that the roughness exceeds expectations, while the second depth error value is within the expected range. This situation occurs because the sidewall taper of the blind groove is too large, causing the laser beam to be blocked and consuming part of the heat input of the laser beam, so that the second depth error value does not exceed expectations. However, due to the deformation of the laser spot, the surface at the bottom of the blind groove experiences uneven heating, either due to energy dispersion or excessive local energy concentration, leading to a sharp deterioration in roughness. In this case, the taper tolerance constant should be reduced during the previous laser engraving process to avoid the quality control failure at the bottom of the blind groove during deep scanning caused by the excessive sidewall taper during the previous laser engraving process. Whenever the roughness value exceeds the critical roughness value by 0.1, the value of the taper tolerance constant decreases by 0.1°.

[0086] This invention determines the quality compliance of the underlying layer by monitoring the relationship between the underlying evaluation parameters and preset evaluation parameters. Simultaneously, it accurately identifies anomalies where the underlying quality failure judgment is not triggered, but the roughness value exceeds the critical roughness value. The taper tolerance constant is then adjusted accordingly. This taper tolerance constant is used to feedback and adjust preset quality indicators to increase the stringency of the sidewall quality compliance judgment, further optimizing the laser engraving process. This reduces underlying quality failures caused by sidewall taper and situations where the roughness value exceeds expectations due to the failure judgment not being triggered. This intelligently optimizes the impact of single-layer scanning quality on the sidewall and underlying quality, and optimizes the impact of sidewall quality on the underlying quality. This ensures continuous optimization of the laser engraving process, guaranteeing the dimensional and performance compliance of the microfluidic chip's channels after multiple laser engraving passes, as well as the stability of the laser engraving process. It prevents irreducible channel quality anomalies caused by excessively large quality tolerances in shallow and middle layer laser engraving, which would lead to a decrease in the yield rate of microfluidic chip laser engraving. By continuously optimizing the laser engraving process, the yield rate of microfluidic chip laser engraving is improved.

[0087] Specifically, the compensation processing unit responds to re-determining the taper tolerance constant to determine the plasma processing time based on the roughness value.

[0088] The compensation processing unit is preferably a plasma processing device, which can perform plasma processing on microfluidic chip materials that meet the size requirements but not the roughness requirements, thereby reducing the roughness of the microfluidic chip material packaging surface, increasing the sealing performance, and can also perform plasma processing on laser-engraved blind grooves to reduce roughness, ensuring the performance of the microfluidic chip flow channels, thereby increasing the yield of microfluidic chips. At the same time, the plasma processing time is determined for different roughness values. For example, the plasma processing time is set to 5 minutes for roughness values ​​less than 1.5 μm, and the plasma processing time is increased by 1 minute for every 0.1 μm of roughness value exceeding the critical roughness value, so as to ensure that the roughness of the blind grooves can be reduced sufficiently.

[0089] This invention addresses the adjustment of plasma treatment time for blind grooves with acceptable dimensions but abnormal roughness. This ensures the repair of flow channel performance for laser-engraved microfluidic chip materials with acceptable dimensions but unacceptable processing performance, thus avoiding material waste and improving the yield and utilization rate of microfluidic chip materials. The subsequent processing of the compensation unit provides greater tolerance for laser engraving, reduces the difficulty of laser engraving microfluidic chip materials, and improves the standardization and intelligence level of laser engraving.

[0090] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A laser engraving apparatus for chip fabrication, characterized in that, include, The accumulation analysis unit is used to acquire image data of the molten pool at the marked point to determine the accumulation height value, and to adjust the blowing pressure of the auxiliary blowing according to the height excess value based on the relationship that the accumulation height value is greater than the preset height value. The height excess value is determined based on the difference between the accumulation height value and the preset height value. The side bottom quality analysis unit is used to acquire image data of the blind groove of the marked point to determine the side bottom quality index, and to determine the adjustment of the preset height value according to the insufficient value of the index based on the relationship that the side bottom quality index is less than the preset quality index. The bottom evaluation unit is used to acquire blind groove image data of the target engraving pass of the marked points to determine the bottom evaluation parameters, and to determine the adjustment of the initial laser power according to the value of the evaluation parameters exceeding the preset evaluation parameters based on the relationship between the bottom evaluation parameters and the preset evaluation parameters. The comprehensive analysis unit responds when the underlying evaluation parameter is less than or equal to the preset evaluation parameter, and determines the taper tolerance constant based on the roughness value being greater than the critical roughness value. The laser engraving unit engraves microfluidic chip materials according to engraving parameters, which include laser power, focal depth, and scanning speed. An auxiliary blowing unit transports and removes material according to the blowing pressure adjusted based on the height exceeding the specified value, using a coaxial blowing angle. The side bottom quality index is determined based on the first depth error value and the side wall taper value. The preset quality index is determined based on the first depth error tolerance constant and the taper tolerance constant. The index deficiency value is determined based on the side bottom quality index and the preset quality index. The bottom layer evaluation parameter is determined based on the second depth error value and the roughness value. The evaluation parameter excess value is determined based on the bottom layer evaluation parameter and the preset evaluation parameter.

2. The laser engraving apparatus for chip fabrication according to claim 1, characterized in that, The stacking analysis unit is used to compare the stacking height value with the preset height value to determine the pass rate of single-layer scanning quality. In response to the single-layer scanning quality failure determination, the blowing pressure of the auxiliary blowing is increased according to the height exceeding the value.

3. The laser engraving apparatus for chip fabrication according to claim 2, characterized in that, The stacking analysis unit responds to the fact that simply increasing the blowing pressure does not meet the single-layer scan quality compliance requirements, and adjusts the scan speed according to the height exceeding the value.

4. The laser engraving apparatus for chip fabrication according to claim 1, characterized in that, The side bottom quality analysis unit is used to compare the side bottom quality indicators with the preset quality indicators to determine the side bottom quality compliance. In response to the side bottom quality non-compliance judgment, the preset height value is adjusted to decrease according to the insufficient value of the indicators.

5. The laser engraving apparatus for chip fabrication according to claim 4, characterized in that, The side bottom quality analysis unit responds to the side bottom quality non-compliance judgment by adjusting the laser focus position downward according to the side wall taper value, and determines the laser power adjustment direction according to the deviation direction of the first depth error value.

6. The laser engraving apparatus for chip fabrication according to claim 1, characterized in that, The bottom-level evaluation unit is used to compare the bottom-level evaluation parameters with the preset evaluation parameters to determine the passability of the bottom-level quality. In response to the bottom-level quality failure determination, the initial laser power is adjusted to decrease according to the evaluation parameters exceeding the value.

7. The laser engraving apparatus for chip fabrication according to claim 6, characterized in that, The bottom-level evaluation unit responds to the fact that simply adjusting the initial laser power to decrease does not meet the bottom-level quality compliance requirements, and adjusts the scanning speed to increase based on the roughness value.

8. The laser engraving apparatus for chip fabrication according to claim 1, characterized in that, The comprehensive analysis unit responds to the redetering of the taper tolerance constant, which is negatively correlated with the roughness value.

9. The laser engraving apparatus for chip fabrication according to claim 1, characterized in that, It also includes, The compensation processing unit responds to the re-determination of the taper tolerance constant to determine the plasma processing time based on the roughness value.

10. The laser engraving apparatus for chip fabrication according to claim 1, characterized in that, It also includes, A linear drive unit is used to drive a laser engraving unit to engrave blind grooves in the flow channel of a microfluidic chip at a predetermined scanning speed along a preset scanning trajectory.

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