An arrayed closed loop electropolishing method and system for probes

Abstract

The application discloses an array closed-loop electrolytic polishing method and system for probes, and the method comprises the following steps: fixing a probe card to be electrolytically polished on a clamp, and immersing probe tips into an electrolyte in an electrolytic tank; a flat plate cathode opposite to a probe array is arranged in the electrolytic tank; a dynamic electric field is constructed to electrolytically polish the probe tips by controlling the voltage between the flat plate cathode and the probe array; electrochemical parameters between the probe array and the flat plate cathode are monitored in real time during the electrolytic polishing process, and the electrolytic polishing process is closed-loop controlled according to the monitoring result; after the electrolytic polishing is completed, the probe card is separated from the electrolyte, and then cleaning and blow-drying treatments are sequentially performed. Through real-time monitoring and closed-loop control of the electrochemical parameters, accurate end point judgment of the polishing process of the probe tips is realized, over-polishing is effectively avoided, the polishing consistency and the tip quality of the probe array are improved, and the application is suitable for batch manufacturing of high-precision probe cards.

Description

Technical Field

[0001] This application belongs to the field of semiconductor testing technology, and specifically relates to an array-type closed-loop electropolishing method and system for probes. Background Technology

[0002] Chip test probe cards are core consumables for semiconductor wafer testing, and their probe arrays typically contain hundreds to tens of thousands of micro probes. The tip shape, surface finish, and high consistency of each probe within the array directly affect the stability of the test signal and the lifespan of the probe card.

[0003] Currently, probe tip forming mainly employs mechanical grinding, laser cutting, or electropolishing techniques. Among these, electropolishing has attracted widespread attention due to its absence of mechanical stress and high surface finish. However, existing electropolishing technologies still have the following shortcomings: Firstly, traditional methods often involve single-probe electropolishing or simple batch clamping. Due to differences in the microscopic position and surface state of each probe in the electrolyte, the radius of curvature of the tips of probes in the same batch can vary by 5-10 μm, making it difficult to meet the advanced process requirement of probe height difference less than 2 μm, resulting in poor array consistency. Secondly, traditional methods rely on operators visually observing the "neckback" phenomenon and then manually cutting off the power, which is not only inefficient and prone to human error but also makes it difficult to achieve precise control of tip curvature. Finally, during batch electropolishing, probes formed earlier are prone to over-polishing due to continued immersion in the electrolyte, leading to blunting or even dissolution and failure of the tips, affecting the finished product yield. Although some patents (such as CN218533094U) have solved the clamping problem through multi-station clamping devices, they do not involve real-time monitoring and feedback adjustment mechanisms. This makes it difficult for the processing to adapt to disturbances caused by differences in initial morphology or changes in electrolyte state, making it difficult to meet the manufacturing yield requirements of high-precision probe cards. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of the prior art and provide an array-type closed-loop electropolishing method and system for probes, so as to achieve fine control of probe electropolishing and significantly improve the electropolishing quality and uniformity within the array.

[0005] To achieve the above objectives, this application employs, in one aspect, an array-type closed-loop electropolishing method for probes, comprising: Step 1: Fix a number of probes to be electropolished in an array on an anode fixture to form a probe array, and immerse the tips of a number of probes in the probe array into the electrolyte in the electrolytic cell; Step 2: Provide a flat cathode, immerse it in the electrolytic cell and place it opposite the probe array; Step 3: Apply voltage to make the plate cathode and each of the probes conduct electricity respectively, so as to perform electrolytic polishing on each of the probes. The electrolytic polishing includes a rough polishing stage and a fine polishing stage. Step 4: During the fine polishing stage, the initial impedance Z0 between the probe array and the plate cathode is detected, and the impedance change between the probe array and the plate cathode is continuously monitored. The relative impedance change rate R = (Z0 - Z0) / (Z0 - Z0) is calculated. t When the relative impedance change rate is greater than or equal to the preset stop threshold, the voltage application is stopped to end the electrolytic polishing.

[0006] In one specific embodiment, in step 1, before immersing the probe array into the electrolyte, the tips of the probes are adjusted to be parallel to the electrolyte surface using a vision-assisted system.

[0007] In one specific embodiment, the electrolyte in step 1 is formulated as a neutral or weakly acidic salt solution, a corrosion inhibitor, a complexing agent, and / or a surfactant. The neutral or weakly acidic salt solution includes one or more of phosphate solution, sodium sulfate solution, sodium phosphate solution, or ammonium persulfate solution.

[0008] In one specific embodiment, the corrosion inhibitor is selected from citric acid or glycerin.

[0009] In one specific embodiment, the complexing agent is selected from citric acid or gluconic acid.

[0010] In one specific embodiment, the surfactant is selected from polyethylene glycol or sodium dodecyl sulfate.

[0011] In one specific embodiment, in step 1, the depth to which the tip of the probe is immersed below the surface of the electrolyte is controlled within the range of 1 mm to 2 mm.

[0012] In one specific embodiment, in step 3, the voltage includes a pulsed DC voltage or a modulated voltage; The coarse polishing stage uses a unidirectional pulsed DC voltage with an amplitude of 8V-15V, a frequency of 500Hz-1000Hz, and a duty cycle of 50%-70%. The fine polishing stage uses a bidirectional pulse voltage with an amplitude of 4V-6V, a frequency of 5kHz-10kHz, and a duty cycle of 15%-25%.

[0013] In one specific embodiment, the coarse polishing stage lasts for 0.5-5 minutes, followed by the fine polishing stage.

[0014] In one specific embodiment, if the tip of the probe is sharp, the stop threshold ranges from 1.5 to 2.5; if the tip of the probe is standard, the stop threshold ranges from 0.8 to 1.8; and if the tip of the probe is round, the stop threshold ranges from 0.4 to 1.0.

[0015] In a specific embodiment, in step 3, during the electropolishing process, the plate cathode is simultaneously driven to perform periodic oscillation or rotation in the horizontal plane, so that the position of the plate cathode relative to each probe changes dynamically, thereby homogenizing the electric field distribution between the probe array and the plate cathode.

[0016] On the other hand, this application employs an electropolishing system, comprising: An electrolytic cell, which contains an electrolyte and a flat cathode; The probe clamping mechanism, located above the electrolytic cell, includes an anode clamp and a motion platform for simultaneously fixing a number of probes. A driving device is installed on the side of the electrolytic cell and is connected to the plate cathode for driving the plate cathode to vibrate or rotate periodically in the horizontal plane. A pulsed power supply, the positive terminal of which is electrically connected to the probe to be polished, and the negative terminal of which is electrically connected to the plate cathode, the pulsed power supply being configured to form an electrolytic circuit between the probe and the plate cathode; A monitoring circuit, electrically connected to the electrolysis circuit, is used to monitor the impedance between the probe and the plate cathode in real time. The controller, electrically connected to both the monitoring circuit and the pulse power supply, is configured to: receive the real-time monitoring results of the impedance and calculate the relative impedance change rate between the initial time and the current time, wherein the relative impedance change rate R = (Z... t -Z0) / Z0, where Z0 is the initial impedance, Z t The impedance at the current moment; When the relative impedance change rate R reaches the preset stop threshold, the pulse power supply is disconnected to end the electropolishing process.

[0017] In one specific embodiment, the motion platform is configured to drive the anode clamp and probe array to move in a vertical direction.

[0018] In one specific embodiment, the cross-sectional area of ​​the flat cathode is larger than the projected area of ​​the probe array on the horizontal plane.

[0019] This application has the following advantages compared with the prior art: This application utilizes a clamping mechanism to perform electropolishing of multiple probes simultaneously, eliminating the need for individual probe trimming and improving production efficiency. Furthermore, by monitoring the relative impedance change rate in real time, this application achieves precise control of the electropolishing process, allowing for the setting of termination thresholds for probes with different tip types to prevent over-polishing. This electropolishing system solves the over-polishing problem caused by individual differences in traditional batch electropolishing, controlling the tip curvature radius difference of the probe array within ±0.5μm and the height difference within ±1μm, significantly improving the consistency of the probe array and ensuring high-precision electropolishing quality. Attached Figure Description

[0020] Figure 1 A schematic diagram of an electropolishing system according to an embodiment of this application is provided.

[0021] The components are: 100, electrolytic polishing system; 1, anode fixture; 2, probe array; 3, flat cathode; 4, electrolyte; 5, drive device; 6, pulse power supply; 7, monitoring circuit; 8, electrolytic cell. Specific Implementation

[0022] To illustrate the technical content, structural features, achieved objectives, and effects of the invention in detail, the technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. In the following description, for illustrative purposes, numerous specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of the invention. However, various exemplary embodiments may also be implemented independently without these specific details or in one or more equivalent arrangements. Furthermore, the various exemplary embodiments may differ, but are not necessarily exclusive. For example, the specific shape, construction, and characteristics of the exemplary embodiments may be used or implemented in another exemplary embodiment without departing from the inventive concept.

[0023] The present invention provides an array-type closed-loop electropolishing method and system for probes, which can simultaneously electropolish multiple probes and achieve closed-loop control of the electropolishing process through dynamic electric field control and real-time electrochemical parameter monitoring, thereby improving the efficiency, consistency and controllability of electropolishing.

[0024] Specifically, this application discloses an array-type closed-loop electropolishing method for probe tips, comprising the following steps.

[0025] Step 1: Fix several probes to be electropolished in an array on an anode fixture 1 to form probe array 2. (See attached diagram) Figure 1The anode clamp 1 is fixed on a motion platform (not shown in the figure). The motion platform can drive the anode clamp to rise and fall, thereby driving the probe array to be immersed in or leave the electrolyte. The anode clamp is electrically connected to the positive terminal of a pulse power supply 6, and several probes are electrically connected to the anode clamp.

[0026] Before electrolysis begins, the anode clamp 1 descends, immersing the tips of several probes in the probe array 2 into the electrolyte in the electrolytic tank 8. The immersion depth of the probes can be adjusted according to the required electrolytic polishing height. If only the probe tips need polishing, then only the probe tips need to be immersed in the electrolyte. For example, in one embodiment of this application, the depth of the probe tips immersed below the electrolyte surface is controlled within the range of 1 mm to 2 mm. This depth range ensures that the probe tips are fully electrolytically polished while avoiding excessive corrosion of the probe shaft. If the entire probe needs to be polished, then the entire probe needs to be immersed in the electrolyte.

[0027] Electrolytic cell 8 is located below anode clamp 1. Before electrolysis begins, the tips of several probes are roughly adjusted to be horizontal using a vision-assisted system, so that the tips of several probes are parallel to the surface of the electrolyte.

[0028] Step 2: Provide a flat cathode 3, immersing it in the electrolytic cell 8 and positioning it opposite the probe array 2. The flat cathode 3 is electrically connected to the negative terminal of the pulse power supply 6. The distance between each probe on the probe array 2 and the flat cathode 3 is kept equal to maintain the uniformity of the polishing process.

[0029] Meanwhile, to eliminate edge effects under a static electric field and ensure that probes located at the center and edges of the probe array maintain a consistent polishing rate, this application also drives the plate cathode 3 to perform periodic oscillation or rotational motion in the horizontal plane during the electrolytic polishing process through a drive device 5 and a transmission mechanism. This causes the position of the plate cathode 3 relative to each probe to dynamically change, thereby homogenizing the electric field distribution in the probe array area. The drive device 5 can typically be an electric motor, while the transmission mechanism can employ common gear and rack mechanisms, cam mechanisms, crank-slider mechanisms, etc., to convert rotation into periodic vibration; alternatively, a linkage mechanism or gear transmission can be used to achieve the rotational motion of the plate cathode. Since the aforementioned transmission mechanisms and drive devices are common structures in the prior art, this application will not describe them in detail.

[0030] Step 3: Turn on the pulse power supply to apply voltage, so that the plate cathode 3 is connected to each of the probes respectively, so as to perform electrolytic polishing on each of the probes.

[0031] The voltage applied by the pulsed power supply can be a pulsed DC voltage or a modulated voltage. By controlling the voltage waveform (pulse width, frequency, duty cycle), the dissolution rate and dissolution mode of the metal can be precisely controlled, preferentially dissolving the most prominent part of the probe tip to achieve probe tip polishing. Dissolution modes include uniform dissolution mode, preferential protrusion dissolution mode, or self-termination protection mode. In this embodiment, the dissolution mode is the preferential protrusion dissolution mode, which preferentially dissolves the most prominent part of the tip to achieve electrolytic polishing of the probe tip.

[0032] In one embodiment of this application, the electropolishing includes a rough polishing stage and a fine polishing stage; The rough polishing stage can quickly remove surface texture from the probe tip and initially correct its shape; The fine polishing stage is used to finely polish the tip of the probe to reduce surface roughness and obtain a uniform, smooth mirror finish. Precise control of the polishing stop time is especially important in the fine polishing stage to prevent over-polishing.

[0033] The coarse polishing stage uses a unidirectional pulsed DC voltage with an amplitude of 8V-15V, a frequency of 500Hz-1000Hz, a duty cycle of 50%-70%, and a polishing time of 0.5-5 minutes. The voltage amplitude can be selected from 8V, 9V, 10V, 12V, 13V, 14V, 15V, and intermediate values. The frequency can be selected from 500Hz, 550Hz, 600Hz, 650Hz, 700Hz, 750Hz, 800Hz, 850Hz, 900Hz, 950Hz, 1000Hz, and intermediate values. The duty cycle can be selected from 50%, 55%, 60%, 65%, 70%, and intermediate values. The polishing time can be selected from 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 minutes, and intermediate values. The coarse polishing time selected in this embodiment is an empirical value. In other embodiments, parameters such as monitoring current density, impedance, electrolyte concentration, or relative impedance change rate can be used to replace the coarse polishing time. When the coarse polishing reaches the threshold of the set parameters, the fine polishing stage begins.

[0034] In this embodiment, after the rough polishing stage reaches its designated time, the process transitions to the fine polishing stage. The fine polishing process employs a bidirectional pulse voltage with an amplitude of 4V-6V, a frequency of 5kHz-10kHz, and a duty cycle of 15%-25%. The voltage amplitude can be selected from 4V, 4.5V, 5V, 5.5V, 6V, and values ​​intermediate to these values. The frequency can be selected from 5kHz, 5.5kHz, 6kHz, 6.5kHz, 7kHz, 7.5kHz, 8kHz, 8.5kHz, 9kHz, 9.5kHz, 10kHz, and values ​​intermediate to these values. The duty cycle can be selected from 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, and values ​​intermediate to these values.

[0035] During electropolishing, as the probe tip gradually dulls from an initial cut bevel or rough state to a smooth arc surface, the change in its surface area triggers a regular change in electrochemical parameters. Therefore, closed-loop control can be achieved by real-time monitoring of the relative impedance change rate between the probe and the plate cathode, allowing for precise control of the polishing stop time.

[0036] Step 4: During the fine polishing stage, the initial impedance Z0 between the probe array 2 and the plate cathode 3 is detected. This initial impedance Z0 is the impedance measured at the start of the fine polishing process. During the fine polishing process, the impedance change between the probe array and the plate cathode is continuously monitored, and the relative impedance change rate R = (Z0 - Z0) / 2 is calculated. t -Z0) / Z0, where Z t The impedance at the current sampling moment is used, and the sampling period is typically 1-5 seconds. When the relative impedance change rate is detected to be greater than or equal to a preset stop threshold, the applied voltage is stopped to end the electropolishing process. This closed-loop control mechanism can automatically terminate the electropolishing process and avoid overpolishing.

[0037] The probe tips include sharp, standard, and rounded types, and each type of probe tip corresponds to a different range of stop thresholds.

[0038] In some embodiments of this application, the probe tip is sharp, and the stop threshold value ranges from 1.5 to 2.5. For example, the stop threshold can be selected from 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 and intermediate values.

[0039] In some embodiments of this application, the probe tip type is standard, and the stop threshold value ranges from 0.8 to 1.8. For example, the stop threshold can be selected from 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 and intermediate values.

[0040] In some embodiments of this application, the probe tip is rounded, and the stop threshold value ranges from 0.4 to 1.0. For example, the stop threshold can be selected from 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 and intermediate values.

[0041] Step 5: After electropolishing, the anode fixture rises to separate the probe array from the electrolyte, and the probes are cleaned and dried.

[0042] In one embodiment, the probe can be ultrasonically cleaned in deionized water and then dried with dry nitrogen gas.

[0043] In some embodiments of this application, the vision assistance system may employ an industrial camera, a CCD / CMOS image sensor, or a microscopic vision system, etc.

[0044] This application does not limit the electrolyte system. In this embodiment, the electrolyte formulation includes a mixed aqueous solution prepared from a neutral or weakly acidic salt solution with low corrosivity and high stability, a corrosion inhibitor, a complexing agent, and / or a surfactant. The ratio of the salt solution to the corrosion inhibitor and the complexing agent is 4:5:1. In some embodiments, the complexing agent can be replaced with a surfactant, or both a complexing agent and a surfactant can be added simultaneously.

[0045] In some embodiments, the low-corrosiveness, high-stability neutral or weakly acidic salt solution may be at least one of phosphate, sodium sulfate, or sodium phosphate solution. The purpose is to provide stable ionic conductivity, maintain the electrolyte pH within the neutral or weakly acidic range, avoid excessive chemical corrosion of non-tip areas of the probe (such as the shaft and mounting structure) by strong acids, and ensure stable current efficiency during the electropolishing process.

[0046] In some embodiments, citric acid or glycerol can be used as the corrosion inhibitor. Its function is to form an adsorption film or passivation film on the surface of non-polished areas such as the probe shaft, inhibiting the chemical corrosion of these areas by the electrolyte, thereby protecting the non-tip portions of the probe and preventing a decrease in probe strength or loss of dimensional accuracy due to excessive lateral corrosion.

[0047] In some embodiments, citric acid or gluconic acid can be used as the complexing agent. Its function is to form a stable, soluble complex with the metal ions dissolved during electropolishing, preventing metal ions from depositing on the cathode surface or forming precipitates under hydrolysis, thereby maintaining the long-term stability of the electrolyte and avoiding precipitates adhering to the probe surface and affecting the polishing quality.

[0048] In some embodiments, the surfactant may be polyethylene glycol or sodium dodecyl sulfate. Its function is to reduce the surface tension of the electrolyte, improve the wetting properties of the electrolyte on the microstructure of the probe tip, promote the rapid desorption of bubbles from the probe surface, and avoid localized uneven polishing or surface defects caused by bubble retention.

[0049] like Figure 1 As shown, this embodiment also provides an electropolishing system 100 for implementing the above method, comprising: Electrolytic cell 8: It contains electrolyte 4 and a flat cathode 3.

[0050] Probe clamping mechanism: Located above the electrolytic cell 8, it includes an anode clamp 1 for simultaneously fixing several probes and a motion platform (not shown in the figure). The motion platform can adopt a lifting mechanism commonly used in electrolytic polishing systems, which can drive the anode clamp 1 to move up and down in the vertical direction to control the immersion depth of the probe tip.

[0051] Several probes to be polished are fixed by an anode clamp 1 to form a probe array 2, and the tips of several probes are roughly flush and parallel to the horizontal plane.

[0052] Drive unit 5: Installed on the side of the electrolytic cell 8, and connected to the flat cathode 3 via a transmission mechanism, it drives the flat cathode 3 to perform periodic micro-vibration or rotation in the horizontal plane. The drive unit 5 can be a motor, cylinder, etc., and its output end can be directly connected to the flat cathode or connected through a transmission mechanism.

[0053] A transmission mechanism is used to connect the drive device 8 and the flat cathode 3. As mentioned above, the transmission mechanism can adopt a structure commonly found in the prior art, which only needs to convert the power provided by the drive device 5 into driving the flat cathode 3 to perform periodic oscillation or rotational motion in the horizontal plane.

[0054] Pulse power supply 6: Its positive terminal is electrically connected to probe array 2, and its negative terminal is electrically connected to plate cathode 3. Pulse power supply 6 is configured to form an electrolytic circuit between probe array 2 and plate cathode 3, and to control the dissolution rate and dissolution mode of probe tip by adjusting voltage waveform.

[0055] Monitoring circuit 7: It is electrically connected in the electrolysis circuit and is used to monitor the total current and impedance between the probe and the plate cathode 3 in real time.

[0056] The controller, electrically connected to the monitoring circuit 7 and the pulse power supply 6 respectively, is configured to: receive the real-time monitoring results of the impedance and calculate the relative impedance change rate between the initial time and the current time, wherein the relative impedance change rate R = (Z t -Z0) / Z0, where Z0 is the initial impedance, Z t The impedance at the current moment; When the relative impedance change rate R reaches the preset stop threshold, the pulse power supply is disconnected to end the electropolishing process.

[0057] The system may further include a vision assistance system, such as a high-resolution industrial camera, a CCD / CMOS image sensor, or a microscopic vision system, to assist in adjusting the parallelism between the probe array and the liquid surface before the probe is immersed.

[0058] Example 1: Electrolytic polishing of 500 tungsten probes (sharp type) simultaneously using the polishing method of this application. Prepare the electrolyte: a 5% sodium phosphate aqueous solution with citric acid added as a complexing agent and corrosion inhibitor. The mass ratio of sodium phosphate aqueous solution to citric acid is 4:6.

[0059] Several probes are mounted in an array on the anode fixture.

[0060] Using a vision-assisted system, the probe array is adjusted to be parallel to the electrolyte surface and then lowered so that the tips of all probes are immersed about 1.0 mm below the liquid surface.

[0061] Start the system to make the flat cathode rotate at a constant speed of 30 RPM.

[0062] A unidirectional pulsed DC voltage is applied, and the initial impedance Z0 between the detection probe and the plate cathode is 5Ω.

[0063] The initial coarse polishing begins with a voltage amplitude of 10V, a frequency of 500Hz, and a duty cycle of 50%. At this point, the tips of each probe begin to preferentially dissolve under a dynamically uniform electric field.

[0064] After 2 minutes of coarse polishing, fine polishing begins, using a bidirectional pulse voltage with an amplitude of 5V, a frequency of 5KHz, and a duty cycle of 20%.

[0065] The monitoring circuit samples every 5 seconds and calculates the relative impedance change rate R. When R ≥ 1.5, the system determines that the electrolytic polishing endpoint has been reached, automatically cuts off the power supply and stops the cathode rotation.

[0066] The probe array was lifted, ultrasonically cleaned in deionized water for 60 seconds, and then dried with dry nitrogen gas.

[0067] In Example 1, the probe surface is smooth and the height difference of the probe tips within the array is controlled within ±1μm, which meets the requirements of the probe card for polishing quality and consistency within the array.

[0068] This application uses the relative impedance change rate as the core monitoring indicator, which can eliminate the influence of initial contact resistance differences. Through periodic sampling, it achieves precise control of the polishing process and prevents over-polishing. Therefore, this method can significantly improve the electropolishing quality of probe tips and the uniformity within the array while simultaneously achieving efficient electropolishing of multiple probes.

[0069] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope. The scope of protection of the present invention is defined by the appended claims, specification, and their equivalents.

Claims

1. An array-type closed-loop electropolishing method for probes, characterized in that, Includes the following steps: Step 1: Fix a number of probes to be electropolished in an array on an anode fixture to form a probe array, and immerse the tips of a number of probes in the probe array into the electrolyte in the electrolytic cell; Step 2: Provide a flat cathode, immerse it in the electrolytic cell and place it opposite the probe array; Step 3: Apply voltage to make the plate cathode and each of the probes conduct electricity respectively, so as to perform electrolytic polishing on each of the probes. The electrolytic polishing includes a rough polishing stage and a fine polishing stage. Step 4: During the fine polishing stage, the initial impedance Z0 between the probe array and the plate cathode is detected, and the impedance change between the probe array and the plate cathode is continuously monitored. The relative impedance change rate R = (Z0 / Z0) is calculated. t When the relative impedance change rate is greater than or equal to the preset stop threshold, the voltage application is stopped to end the electrolytic polishing.

2. The method according to claim 1, characterized in that, In step 1, before immersing the probe array into the electrolyte, the tips of the probes are adjusted to be parallel to the electrolyte surface using a vision-assisted system.

3. The method according to claim 1, characterized in that, In step 1, the depth to which the tip of the probe is immersed below the surface of the electrolyte is controlled within the range of 1 mm to 2 mm.

4. The method according to claim 1, characterized in that, In step 3, the voltage includes a pulsed DC voltage or a modulated voltage; The coarse polishing stage uses a unidirectional pulsed DC voltage with an amplitude of 8V-15V, a frequency of 500Hz-1000Hz, and a duty cycle of 50%-70%. The fine polishing stage uses a bidirectional pulse voltage with an amplitude of 4V-6V, a frequency of 5kHz-10kHz, and a duty cycle of 15%-25%.

5. The method according to claim 4, characterized in that: The coarse polishing stage lasts for 0.5-5 minutes, after which the fine polishing stage begins.

6. The method according to claim 1, characterized in that, If the probe tip is sharp, the stop threshold ranges from 1.5 to 2.5; if the probe tip is standard, the stop threshold ranges from 0.8 to 1.8; if the probe tip is round, the stop threshold ranges from 0.4 to 1.

0.

7. The method according to claim 1, characterized in that, In step 3, during the electropolishing process, the plate cathode is simultaneously driven to perform periodic oscillation or rotation in the horizontal plane, so that the position of the plate cathode relative to each probe changes dynamically, thereby homogenizing the electric field distribution between the probe array and the plate cathode.

8. An electropolishing system, characterized in that, include: An electrolytic cell, which contains an electrolyte and a flat cathode; The probe clamping mechanism, located above the electrolytic cell, includes an anode clamp and a motion platform for simultaneously fixing a number of probes. A driving device is installed on the side of the electrolytic cell and is connected to the plate cathode for driving the plate cathode to vibrate or rotate periodically in the horizontal plane. A pulsed power supply, the positive terminal of which is electrically connected to the probe to be polished, and the negative terminal of which is electrically connected to the plate cathode, the pulsed power supply being configured to form an electrolytic circuit between the probe and the plate cathode; A monitoring circuit, electrically connected to the electrolysis circuit, is used to monitor the impedance between the probe and the plate cathode in real time. The controller, electrically connected to both the monitoring circuit and the pulse power supply, is configured to: receive the real-time monitoring results of the impedance and calculate the relative impedance change rate between the initial time and the current time, wherein the relative impedance change rate R = (Z... t -Z0) / Z0, where Z0 is the initial impedance, Z t The impedance at the current moment; When the relative impedance change rate R reaches the preset stop threshold, the pulse power supply is disconnected to end the electropolishing process.

9. The electropolishing system according to claim 8, characterized in that: The motion platform is configured to drive the anode clamp and probe array to move in the vertical direction.

10. The electropolishing system according to claim 8, characterized in that: The cross-sectional area of ​​the flat cathode is larger than the projected area of ​​the probe array on the horizontal plane.

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