Circuit board metal layer integrated etching system based on multi-field coupling regulation and control

Abstract

The invention discloses a circuit board metal layer integrated etching system based on multi-field coupling regulation and control, which relates to the technical field of circuit board metal layer etching and comprises a multi-field coupling etching cavity module, a pulse current regulation and control module, a depth real-time monitoring module, a uniformity optimization module, an intelligent control module and an automatic overturning module. The multi-field coupling etching cavity module is integrated with a synergistic effect space of an electric field, an ultrasonic field and a temperature field, multi-energy field superposition is achieved through the adjustable electrode array and the ultrasonic vibration source, the pulse frequency, the duty ratio and the amplitude are dynamically adjusted by outputting one-way high-pulse current and combining with an instruction of the intelligent control module, and the multi-field coupling etching cavity module is obtained. And the depth real-time monitoring module monitors the etching depth in real time, and uniform etching of the surface of the circuit board is realized through a closed loop link which is accurately regulated and controlled by an energy field, dynamically fed back and corrected, actively optimized in uniformity and automatically and seamlessly connected.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of circuit board metal layer etching, and particularly relates to a circuit board metal layer integrated etching system based on multi-field coupling regulation. BACKGROUND

[0002] The circuit board metal layer etching system belongs to a part of semiconductor equipment manufacturing, such as a photoetching machine, an etching machine, a thin film deposition device, etc. The etching equipment occupies an important position in semiconductor manufacturing, has a high value, and closely cooperates with the photoetching machine to jointly complete pattern transfer. The circuit board etching system may be a kind of etching equipment, especially in the aspect of metal layer etching, which has commonalities with the metal etching process in semiconductor manufacturing.

[0003] At present, the circuit board metal layer etching method usually adopts a "etching-cleaning-flipping" cycle process, and the etching depth is strictly controlled within 1 / 4 of the thickness of the metal layer each time. The metal layer in the non-line region is gradually stripped through multiple front and back surface alternating etching. For example, a Chinese patent document application No. 201410219480.0 discloses a processing method and a circuit board processing system for fine and dense circuit board. The above method comprises: etching the non-line pattern area on the surface of the circuit board, and the etching depth is less than or equal to 1 / 4 of the thickness of the surface metal layer of the circuit board; cleaning the circuit board; flipping the circuit board to make the other side of the circuit board face up; repeatedly performing the above etching, cleaning and flipping steps until the surface metal layer of the non-line pattern area on the surface of the circuit board is completely etched and removed to form the required line pattern.

[0004] However, since the etching depth is less than or equal to 1 / 4 of the thickness of the surface metal layer of the circuit board each time the non-line pattern area on the surface of the circuit board is etched, the process cycle number is increased due to the limitation of the etching depth. However, the metal layer in the non-line region is gradually stripped through multiple front and back surface alternating etching, which causes the phenomenon of over-etching or under-etching on the surface of the circuit board, resulting in that the etching uniformity of the surface of the circuit board is not ideal, and the quality of the fine and dense line etching of the circuit board is affected. SUMMARY

[0005] The purpose of the present application is to provide a circuit board metal layer integrated etching system based on multi-field coupling regulation, which can improve the etching uniformity and realize high-precision and stable manufacturing of fine and dense lines to solve the problems in the above background.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] The circuit board metal layer integrated etching system based on multi-field coupling regulation comprises a multi-field coupling etching cavity module, a synergistic action space integrated with the synergistic action of electric field, ultrasonic field and temperature field, and a high-precision stripping of the circuit board metal layer is realized in the synergistic action space by means of a plurality of adjustable electrode arrays and an ultrasonic vibration source built in the synergistic action space.

[0008] A pulse current regulation module outputs a one-way high pulse current, and the one-way high pulse current is combined with a regulation instruction to selectively etch the circuit board metal layer.

[0009] A depth real-time monitoring module monitors the etching depth of the circuit board in real time and feeds back the monitored depth data in real time.

[0010] An uniformity optimization module regulates the etching liquid distribution based on the etching depth data through a magnetic field or a flow field, eliminates the edge effect, and improves the surface uniformity.

[0011] An intelligent control module is used for controlling the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module to work, and dynamically adjusting the regulation instructions of the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module based on the received depth data.

[0012] An automatic turnover module automatically alternately etches and cleans the front and back surfaces of the circuit board through a turnover device and a cleaning device.

[0013] Preferably, the multi-field coupling etching cavity module comprises a reaction cavity, an ultrasonic generator, a temperature control system and a gas injection system, the adjustable electrode array is connected with the pulse current regulation module through a high-voltage cable to receive the one-way high pulse current, the ultrasonic vibration source is connected with the ultrasonic generator through a BNC interface, and the synergistic action space is formed by the reaction cavity, the ultrasonic generator, the temperature control system and the gas injection system.

[0014] Preferably, the adjustable electrode array is composed of a plurality of independently controlled flat plate electrodes, each flat plate electrode is provided with an independently controlled spacing adjustment mechanism, and each spacing adjustment mechanism is connected through an array of connecting seats.

[0015] Preferably, the ultrasonic vibration source comprises a piezoelectric ceramic vibrator, a matching layer and a backing structure, metal electrodes are formed on the upper and lower surfaces of the piezoelectric ceramic vibrator through silver paste screen printing, lead wires are led out through low-temperature welding, the lead wires are connected with the ultrasonic generator, the matching layer is located on the surface of the metal electrode, and the backing structure is located at the rear end of the piezoelectric ceramic vibrator and forms a composite structure with the piezoelectric ceramic vibrator.

[0016] Preferably, the temperature control system comprises heating wires embedded in the inner wall of the reaction cavity, a circulating cooling liquid pipeline and a temperature sensor installed in the reaction cavity, and the temperature sensor, the heating wires and the circulating cooling liquid pipeline are electrically connected with the intelligent control module.

[0017] Preferably, the pulse current regulation module comprises: a programmable pulse power supply connected to the electrodes of the reaction cavity through a shielded cable;

[0018] a digital signal processor receiving instructions from the intelligent control module to generate corresponding pulse signals;

[0019] an impedance matching circuit that dynamically adjusts parameters according to the distance between the plate electrodes to ensure stable output waveform;

[0020] an overcurrent protection module that monitors the current in real time and immediately cuts off the power supply and triggers an alarm when an anomaly occurs.

[0021] Preferably, the real-time depth monitoring module comprises: a laser triangulation sensor installed on the top of the reaction cavity, which is used to monitor the etching depth of the surface of the circuit board in real time;

[0022] a data acquisition card that collects data collected by the laser triangulation sensor in real time and transmits it to the intelligent control module after digital filtering;

[0023] a calibration module for periodically automatically calibrating the laser triangulation sensor to eliminate errors caused by temperature drift.

[0024] Preferably, the calibration module performs the following calibration process:

[0025] A1. When the temperature fluctuation of the reaction cavity exceeds 5℃ or reaches the set period, trigger the calibration instruction, pause the etching work of the reaction cavity, and switch to calibration mode;

[0026] A2. Move a standard thickness silicon wafer to the laser triangulation sensor directly below it through an electric translation stage to ensure that the surface of the silicon wafer is completely aligned with the reference surface of the circuit board;

[0027] A3. The laser triangulation sensor emits laser light to the surface of the silicon wafer, and the data acquisition card collects 1000 groups of signals at a sampling frequency of 1MHz, and takes the average value as the zero reference signal V0;

[0028] A4. Move the silicon wafer down 100μm through the electric translation stage to simulate the etching depth, and collect the signal V1 at this time, and calculate the actual signal difference ΔV 差 , that is, ΔV 差 = V1-V0;

[0029] A5. Calculate the theoretical value of the etching depth according to the etching depth calculation formula, and then divide the theoretical value of the etching depth by the actual signal difference to obtain the gain correction coefficient;

[0030] A6, the smart control module compensates the etching depth according to the gain correction coefficient, and the compensated depth is the product of the zero-point reference signal and the gain correction coefficient;

[0031] A7, the silicon wafer is moved back to the initial position by the electric translation table, the signal after the silicon wafer is moved back is collected, and it is verified whether the signal after the silicon wafer is moved back is close to 0 or not, if yes, the calibration is qualified, and the etching mode is switched to, otherwise, the calibration is unqualified, and A3-A6 are repeatedly executed.

[0032] Preferably, the uniformity optimization module comprises a magnetic field regulation unit, a coil current is controlled through a PWM signal, and a smart control module adjusts a magnetic field direction and strength according to depth monitoring data to suppress an edge effect.

[0033] The flow field regulation unit comprises a magnetic drive pump and a microchannel array, the magnetic drive pump is installed on an etching circulating pipeline outside a reaction cavity, an inlet of the etching circulating pipeline is connected to a liquid return port of the reaction cavity, the etching circulating pipeline and an outlet are connected to a liquid inlet at the top of the reaction cavity, and a motor of the magnetic drive pump is connected to the smart control module through a frequency converter; the microchannel array is a microwell plate arranged at the bottom of the reaction cavity, a plurality of microwells with a diameter of 50-200 mu are arranged on the microwell plate, and uniform liquid flow distribution is formed in the reaction cavity through the microwell plate.

[0034] Preferably, the smart control module comprises a data receiving and processing unit, which is used for receiving actual depth data fed back by the depth real-time monitoring module, and calculating a deviation between the actual depth data and target depth data according to the target depth data;

[0035] The PID control unit calculates the required control amount of each module according to the calculated deviation value by using a PID algorithm;

[0036] The control instruction distribution unit distributes the control instruction to the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module according to the calculated control amount, and generates specific adjustment instructions;

[0037] The feedback correction unit continuously monitors the real-time change of the etching depth after each adjustment, if the deviation between the target depth data and the actual depth data continuously decreases, the current PID parameter is maintained, otherwise, the required control amount of each module needs to be recalculated, and the corresponding module is readjusted.

[0038] Compared with the prior art, the circuit board metal layer integrated etching system based on multi-field coupling regulation and control has the following advantages:

[0039] 1. The application realizes precise energy field regulation, dynamic feedback correction, uniformity active optimization and automatic seamless link of closed loop link through the synergistic cooperation of multi-field coupling etching cavity module, pulse current regulation module, depth real-time monitoring module, intelligent control module, uniformity optimization module and automatic turnover module, improves etching uniformity and realizes high-precision stable manufacturing of fine lines.

[0040] 2. The application utilizes the synergistic action space of the multi-field coupling etching cavity module integrated with electric field, ultrasonic field and temperature field, realizes multi-energy field superposition through adjustable electrode array and ultrasonic vibration source, dynamically adjusts pulse frequency, duty cycle and amplitude through output unidirectional high pulse current combined with the instruction of intelligent control module, so as to improve line edge roughness.

[0041] 3. The multi-field coupling etching cavity module of the application integrates the synergistic action space of electric field, ultrasonic field and temperature field, and the synergistic action space is built-in with adjustable electrode array and ultrasonic vibration source, so that the metal layer of the circuit board is stripped with high precision in the synergistic action space. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The system block diagram according to the embodiment of the application is shown;

[0043] Figure 2 The module block diagram of the multi-field coupling etching cavity module according to the embodiment of the application is shown;

[0044] Figure 3 The module block diagram of the pulse current regulation module according to the embodiment of the application is shown;

[0045] Figure 4 The module block diagram of the intelligent control module according to the embodiment of the application is shown. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. The specific embodiments described herein are only used to explain the application, and are not used to limit the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0047] The application provides a circuit board metal layer integrated etching system based on multi-field coupling regulation as shown in Figures 1-4 The application provides a circuit board metal layer integrated etching system based on multi-field coupling regulation as shown in

[0048] The multi-field coupling etching cavity module is integrated with a synergistic space of electric field, ultrasonic field and temperature field, and is internally provided with an adjustable electrode array and an ultrasonic vibration source, so that the metal layer of the circuit board is stripped with high precision in the synergistic space.

[0049] The multi-field coupling etching cavity module comprises a reaction cavity, an ultrasonic generator, a temperature control system and a gas injection system, the adjustable electrode array is connected with a pulse current regulation module through a high-voltage cable to receive unidirectional high pulse current, the ultrasonic vibration source is connected with the ultrasonic generator through a BNC interface to generate high-frequency vibration to promote cavitation effect of the etching liquid, wherein the BNC interface is a coaxial radio frequency connector interface, the temperature control system feeds back the temperature of the reaction cavity to an intelligent control module in real time through a temperature sensor, and the reaction temperature of the reaction cavity is controlled through a PID algorithm in the intelligent control module; the gas injection system communicates with the intelligent control module to dynamically adjust the type and flow of the gas according to the etching stage.

[0050] The reaction cavity is made of polytetrafluoroethylene, which has corrosion resistance, and the synergistic space of electric field, ultrasonic field and temperature field is integrated inside the reaction cavity.

[0051] The adjustable electrode array is composed of a plurality of independently controlled flat plate electrodes, each flat plate electrode is provided with an independently controlled spacing adjustment mechanism, and the spacing adjustment mechanisms are arranged in an array through a connecting seat array, the spacing adjustment mechanism comprises a mounting seat, a stepping motor, a lead screw and a sliding block screwed on the lead screw, the flat plate electrode is mounted on the sliding block, the lead screw is rotatably mounted in the mounting seat, the sliding block is slidably connected with the mounting seat, and the stepping motor is mounted on one end of the lead screw, the rotation of the lead screw is controlled by the stepping motor, so that the sliding block can move horizontally in the mounting seat to drive the flat plate electrode to adjust the position, thereby adjusting the distance between the flat plate electrodes.

[0052] The ultrasonic vibration source comprises a piezoelectric ceramic vibrator, a matching layer and a backing structure, metal electrodes are formed on the upper and lower surfaces of the piezoelectric ceramic vibrator through silver paste screen printing, and lead wires are led out through low-temperature welding, the lead wires are connected with the ultrasonic generator, the matching layer is located on the surface of the metal electrode, and the backing structure is located at the rear end of the piezoelectric ceramic vibrator and forms a composite structure with the piezoelectric ceramic vibrator, the ultrasonic vibration source breaks bubbles and enhances the propagation of substances.

[0053] Since the temperature of the multi-field coupling etching cavity can reach 40-80℃, materials with temperature resistance need to be selected: piezoelectric ceramic: PZT-8 material with Curie temperature ≥ 300℃; adhesive: high-temperature epoxy glue (such as EPO-TEK 377, temperature resistance 200℃); matching layer: polyimide (PI) based composite material with thermal expansion coefficient matching with ceramic (≤5ppm / ℃).

[0054] The temperature control system comprises a heating wire embedded in the inner wall of the reaction cavity, a circulating cooling liquid pipeline and a temperature sensor installed in the reaction cavity, the temperature sensor, the heating wire and the circulating cooling liquid pipeline are electrically connected with the intelligent control module, the temperature sensor monitors the temperature change in the reaction cavity in real time, the intelligent controller controls the heating wire or the circulating cooling liquid pipeline to work according to the real-time temperature change, so as to accurately control the temperature in the reaction cavity.

[0055] The gas injection system comprises a gas inlet pipe communicated in the reaction cavity and a flow controller for controlling the gas injection quality, the flow controller is installed on the gas inlet pipe, and the gas injected by the gas inlet pipe comprises oxygen and carbon tetrafluoride gas.

[0056] The reaction cavity, the ultrasonic generator, the temperature control system and the gas injection system cooperatively constitute a synergistic space, ion migration is accelerated by an electric field, bubbles are broken and propagation substances are enhanced by ultrasonic vibration, and the etching rate is adjusted by a temperature field, so that the stripping precision of the metal layer of the circuit board can reach ±1 um, and the electrode plate spacing, the ultrasonic frequency, the temperature and the gas composition can be independently controlled to adapt to the etching requirements of different metal materials.

[0057] The unidirectional high pulse current output by the pulse current regulation module is combined with the regulation instruction to selectively etch the metal layer of the circuit board.

[0058] The pulse current regulation module comprises a programmable pulse power supply, a digital signal processor, an impedance matching circuit and an overcurrent protection module, the programmable pulse power supply is connected with the electrode of the reaction cavity through a shielded cable, the digital signal processor generates corresponding pulse signals by receiving the instruction of the intelligent control module, the impedance matching circuit dynamically adjusts parameters according to the plate electrode spacing to ensure the stability of the output waveform, and the overcurrent protection module monitors the current in real time and immediately cuts off the power supply and triggers an alarm when an abnormality occurs.

[0059] The programmable pulse power supply supports unidirectional high pulse output, the voltage range is 6-30kV, the current is 1-30kA, the pulse width is 1us-999ms, and the duty cycle is adjustable at 1-99%; the digital signal processor is built-in FPGA chip, and generates pulse waveforms in real time, the pulse waveforms include square wave and sine wave; the impedance matching circuit comprises an LC resonance network, which ensures efficient transmission of pulse energy to the adjustable electrode array; the overcurrent protection module integrates a Hall current sensor and a fast fuse, and the response time is less than 1us; by adjusting the pulse parameters, a specific metal layer is preferentially etched, and the line edge roughness is less than 0.2um.

[0060] The depth real-time monitoring module monitors the etching depth of the circuit board in real time and feeds back the monitored depth data in real time.

[0061] The depth real-time monitoring module comprises a data acquisition card, a calibration module and a laser triangulation sensor installed on the top of the reaction cavity, the laser triangulation sensor is used for real-time monitoring of the etching depth of the circuit board surface, the data acquisition card acquires the data collected by the laser triangulation sensor in real time and transmits the data after digital filtering to the intelligent control module, the calibration module is used for periodically automatically calibrating the laser triangulation sensor to eliminate the error caused by temperature drift, improve the accuracy of the laser triangulation sensor, and the laser triangulation sensor is installed according to the actual size of the reaction cavity, and a plurality of laser triangulation sensors are used to monitor the circuit board surface from different directions in real time, so as to improve the accuracy of the etching depth monitoring of the circuit board.

[0062] The laser triangulation sensor comprises a laser emitter with a wavelength of 650 nm, an optical lens group, a PSD detector and a signal preprocessing circuit, wherein the optical lens group comprises a collimating lens at the transmitting end and a focusing lens at the receiving end, the laser emitter outputs parallel laser through the collimating lens, and the parallel laser is vertically irradiated to the circuit board surface below the top of the reaction cavity (the installation position of the laser emitter ensures that the laser covers the etching area without dead angle), the reflected laser of the circuit board surface is accurately projected to the photosensitive surface of the PSD detector through the focusing lens at the receiving end, and a stable light spot is formed, when the etching depth increases (the circuit board surface is lowered), the reflected light path is deviated, the light spot generates a horizontal displacement on the PSD detector, the difference between the two current signals output by the PSD detector appears, and the signal preprocessing circuit converts the difference into a voltage signal proportional to the displacement, for example, 1 μm of displacement corresponds to 1 mV of voltage change.

[0063] The data acquisition card triggers the ADC through the FPGA to continuously sample the voltage signal preprocessed by the sensor at a sampling rate of 1 MHz, and converts the voltage signal into a 16-bit digital signal; the FPGA has a built-in Kalman filtering algorithm, which filters the digital signal in real time by establishing a depth-signal state equation to eliminate random errors and improve the signal-to-noise ratio to ≥50 dB; the filtered signal is transmitted to the intelligent control module in the form of a data packet with 1000 sampling points per packet and an interval of 1 ms through the USB2.0 module; the intelligent control module calculates the etching depth according to the relationship between displacement and voltage after receiving the data packet, and the etching depth calculation formula is:

[0064]

[0065] Wherein, h is the etching depth, ΔV is the voltage change of the PSD detector output, K is the displacement-voltage proportional coefficient, unit mV / μm, the voltage proportional coefficient needs to be calibrated in advance by the calibration module, and different sensors and etching environments need to be recalibrated;

[0066] The calibration module executes the following calibration process:

[0067] A1, when the temperature of the reaction cavity fluctuates more than 5℃ or reaches the set period, a calibration instruction is triggered, the reaction cavity pauses the etching operation, and switches to the calibration mode;

[0068] A2, the standard thickness of the silicon wafer is moved to the laser triangulation sensor below by the electric translation table, and the surface of the silicon wafer is completely aligned with the reference surface of the circuit board;

[0069] A3, the laser triangulation sensor emits laser to the surface of the silicon wafer, and the data acquisition card collects 1000 groups of signals at a sampling frequency of 1MHz, and takes the average value as the zero point reference signal V0;

[0070] A4, the silicon wafer is moved down 100μm by the electric translation table to simulate the etching depth, and the signal V1 at this time is collected, and the actual signal difference ΔV is calculated 差 , that is, ΔV 差 =V1-V0;

[0071] A5, the etching depth theoretical value is calculated according to the etching depth calculation formula, and then the etching depth theoretical value is divided by the actual signal difference to obtain the gain correction coefficient; the etching depth theoretical value calculation formula is:

[0072]

[0073] Wherein, V 理 is the etching depth theoretical value, ΔH is the silicon wafer moving down distance, L is the horizontal distance from the laser emitting point to the PSD detector, and H base is the laser triangulation sensor reference distance;

[0074] A6, the intelligent control module compensates the etching depth according to the gain correction coefficient, and the compensated depth is the product of the zero point reference signal and the gain correction coefficient;

[0075] A7, the silicon wafer is moved back to the initial position by the electric translation table, the signal after the silicon wafer is moved back is collected, and it is verified whether the signal after the silicon wafer is moved back is close to 0 or not, if it is close to 0, the calibration is qualified, and switches to the etching mode, otherwise, the calibration is unqualified, and A3-A6 are repeatedly executed.

[0076] The uniformity optimization module adjusts the etching liquid distribution through the magnetic field or the flow field based on the etching depth data, eliminates the edge effect, and improves the surface uniformity;

[0077] The uniformity optimization module includes a magnetic field regulation unit and a flow field regulation unit, the magnetic field regulation unit controls the coil current through a PWM signal, and the intelligent control module adjusts the direction and strength of the magnetic field according to the depth monitoring data to suppress the edge effect;

[0078] The magnetic field regulation unit comprises an electromagnetic coil wound by copper wire and a Hall effect sensor for real-time monitoring of the magnetic field strength, the electromagnetic coil is wound on a support on the inner wall of the reaction cavity by copper wire with a diameter of 0.5 mm to form an annular coil array, the center of the electromagnetic coil is flush with the placement plane of the circuit board of the reaction cavity, ensuring that the magnetic field covers the entire etching area; the Hall effect sensor is closely attached to the inner side of the electromagnetic coil, 5 mm away from the surface of the circuit board, and two are arranged diagonally along the inner wall of the reaction cavity, connected to the intelligent control module through a differential signal line to collect magnetic field strength data in real time, guide the directional migration of ions through the stepped electromagnetic coil, and enhance the liquid disturbance of the flow field, thereby improving the uniformity of the thickness of the metal layer;

[0079] The flow field regulation unit comprises a magnetic drive pump and a microchannel array, the magnetic drive pump is installed on the etching circulating pipeline outside the reaction cavity, the inlet of the etching circulating pipeline is connected to the liquid return port of the reaction cavity, and the etching circulating pipeline and the outlet are connected to the liquid inlet at the top of the reaction cavity, the motor of the magnetic drive pump is connected to the intelligent control module through a frequency converter for receiving speed regulation instructions; the microchannel array is a microwell plate arranged at the bottom of the reaction cavity, and a plurality of micropores with a diameter of 50-200 μm are arranged on the microwell plate, and uniform liquid flow distribution is formed in the reaction cavity through the microwell plate.

[0080] The intelligent control module is used for controlling the working of the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module, and dynamically adjusting the regulation instructions of the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module based on the received depth data;

[0081] The intelligent control module comprises a data receiving and processing unit, a PID control unit, a control instruction distribution unit and a feedback correction unit, the data receiving and processing unit is used for receiving the actual depth data fed back by the depth real-time monitoring module, and calculating the deviation between the actual depth data and the target depth data according to the set target depth data;

[0082] The PID control unit calculates the required control amount of each module according to the calculated deviation value by using a PID algorithm, and the formula of the PID algorithm is as follows:

[0083]

[0084] Wherein, u(t) is the required control amount, K p is a proportional coefficient, K i is an integral coefficient, K d is a differential coefficient, which can be adjusted online through HMI, e(t) is the deviation between the target depth data and the actual depth data, is the integral term of the deviation, that is, the cumulative deviation from the start of etching to the current time, is a differential term of the deviation, i.e., a rate of change of the deviation;

[0085] The control instruction distribution unit distributes control instructions to the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module according to the calculated control amount, to generate specific adjustment instructions, specifically:

[0086] For the multi-field coupling etching cavity module, when the control amount increases, adjustment instructions of increasing ultrasonic power and increasing temperature are generated; when the control amount decreases, adjustment instructions of decreasing ultrasonic power and decreasing temperature are generated; when the control amount does not change, no adjustment instruction is generated;

[0087] For the pulse current regulation module, when the control amount increases, adjustment instructions of increasing pulse amplitude and increasing duty cycle are generated; when the control amount decreases, adjustment instructions of decreasing pulse amplitude and decreasing duty cycle are generated; when the control amount does not change, no adjustment instruction is generated;

[0088] For the uniformity optimization module, when the deviation between the target depth data and the actual depth data of the edge position of the metal layer is smaller than the deviation between the target depth data and the actual depth data of the center position of the metal layer, adjustment instructions of increasing magnetic field strength and increasing flow rate are generated; when the deviation between the target depth data and the actual depth data of the edge position of the metal layer is greater than the deviation between the target depth data and the actual depth data of the center position of the metal layer, adjustment instructions of decreasing magnetic field strength and decreasing flow rate are generated; when the deviation between the target depth data and the actual depth data of the edge position of the metal layer is equal to the deviation between the target depth data and the actual depth data of the center position of the metal layer, no adjustment instruction is generated;

[0089] The feedback correction unit continuously monitors the real-time change of the etching depth after each adjustment, and if the deviation between the target depth data and the actual depth data continuously decreases, the current PID parameters are maintained, otherwise, the control amount required by each module needs to be recalculated, and the corresponding module is adjusted again.

[0090] The automatic flipping module automatically alternately etches and cleans the circuit board by the flipping device and the cleaning device;

[0091] The flipping device includes a six-axis mechanical arm and a flipping table, the six-axis mechanical arm is installed on a support between the reaction cavity and the flipping table, the end of the six-axis mechanical arm is installed with a vacuum chuck, and the vacuum chuck is connected with a vacuum generator through an air pipe; the table top of the flipping table is consistent with the height of the reaction cavity material taking port, and the flipping table is driven to flip by a servo motor;

[0092] The cleaning device comprises a high-pressure spraying system and an ultrasonic cleaning tank, the ultrasonic cleaning tank is installed beside the turnover table, the tank bottom of the ultrasonic cleaning tank is embedded with a heating pipe, and the temperature sensor is used to realize temperature control of the ultrasonic cleaning tank; the six-axis mechanical arm takes out the circuit board from the reaction cavity, and then places the circuit board on the turnover table; after the turnover table rotates 180°, the circuit board enters the cleaning tank, the high-pressure spraying system washes the surface of the circuit board to remove the particles on the surface of the circuit board, the ultrasonic cleaning tank cleans and dissolves the residual etching liquid, and then the six-axis mechanical arm sends the circuit board back to the reaction cavity.

[0093] The high-pressure spraying system comprises a plurality of nozzles uniformly distributed above the ultrasonic cleaning tank, the plurality of nozzles are communicated with a deionized liquid storage tank through a high-pressure plunger pump, the plurality of nozzles are uniformly distributed along the inner wall of the ultrasonic cleaning tank, so that the spraying range covers the circuit board, and the high-pressure plunger pump adjusts the rotating speed through a frequency converter to realize pressure adjustment of the high-pressure spraying system.

[0094] Through the synergistic cooperation of the multi-field coupling etching cavity module, the pulse current regulation module, the depth real-time monitoring module, the intelligent control module, the uniformity optimization module and the automatic turnover module, the multi-energy field superposition is realized through the adjustable electrode array and the ultrasonic vibration source by utilizing the synergistic action space of the electric field, the ultrasonic field and the temperature field integrated in the multi-field coupling etching cavity module, the pulse frequency, the duty cycle and the amplitude are dynamically adjusted by combining the instructions of the intelligent control module to output the unidirectional high pulse current, so as to improve the line edge roughness, the depth real-time monitoring module monitors the etching depth in real time and feeds back the depth data to the intelligent control module, the uniformity optimization module regulates the etching liquid distribution through the magnetic field or the flow field to eliminate the edge effect and the local difference, the intelligent control module integrates the PID control algorithm to dynamically adjust the parameters of each module, realizes the global coordination and parameter optimization, and the automatic turnover module completes the automatic turnover of the circuit board, combines the high-pressure spraying and the ultrasonic cleaning to remove the residual etching liquid, realizes the seamless connection of the front and back surfaces, and realizes the uniform etching on the surface of the circuit board through the closed loop link of the energy field precise regulation, the dynamic feedback correction, the uniformity active optimization and the automatic seamless connection.

[0095] Finally, it should be noted that: the above only describes the preferred embodiments of the present application and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A circuit board metal layer integrated etching system based on multi-field coupling regulation, characterized in that: The application relates to a multi-field coupling etching cavity module. The module comprises a reaction cavity, an ultrasonic generator, a temperature control system and a gas injection system. The adjustable electrode array is connected with the pulse current regulation module through a high-voltage cable to receive unidirectional high pulse current. The ultrasonic vibration source is connected with the ultrasonic generator through a BNC interface. The adjustable electrode array is composed of a plurality of independently controlled plate electrodes. The temperature control system comprises heating wires and circulating cooling liquid pipelines embedded in the inner wall of the reaction cavity and a temperature sensor installed in the reaction cavity. The temperature sensor, the heating wires and the circulating cooling liquid pipelines are electrically connected with the intelligent control module.

2. The system for multi-field coupling regulated etching of metal layer integrated with circuit board according to claim 1, wherein: The pulse current regulation module comprises a programmable pulse power source connected with the electrodes of the reaction cavity through a shielding cable.

3. The system for multi-field coupling regulated etching of metal layers integrated with circuit board according to claim 2, wherein: A digital signal processor receives the instruction of the intelligent control module to generate corresponding pulse signals.

4. The system for multi-field coupling regulated etching of metal layers integrated on a circuit board according to claim 3, wherein: An impedance matching circuit dynamically adjusts parameters according to the interval of the plate electrodes to ensure the stability of the output waveform.

5. The system for multi-field coupling regulated etching of metal layers integrated on a circuit board according to claim 4, wherein: An overcurrent protection module monitors the current in real time and immediately cuts off the power supply and triggers an alarm when an abnormality occurs.

6. The system for multi-field coupling regulated etching of metal layers integrated on a circuit board according to claim 5, wherein: The depth real-time monitoring module comprises a laser triangulation sensor installed on the top of the reaction cavity. A data acquisition card collects the data collected by the laser triangulation sensor in real time and transmits the data to the intelligent control module after digital filtering. A calibration module is used for automatically calibrating the laser triangulation sensor periodically to eliminate the error caused by temperature drift. ​ 7. The system for multi-field coupling regulated etching of metal layers integrated on a circuit board according to claim 6, wherein: ​ ​ ​ 8. The system for multi-field coupling regulated etching of metal layers integrated with circuit board according to claim 7, wherein: The calibration module performs the following calibration process: A1. When the temperature of the reaction cavity fluctuates more than 5°C or reaches a set period, a calibration instruction is triggered, the reaction cavity pauses etching work, and switches to calibration mode; A2. The standard thickness of the silicon wafer is moved to the laser triangulation sensor by the electric translation table, ensuring that the silicon wafer surface is completely aligned with the circuit board reference surface; A3. The laser triangulation sensor emits laser to the surface of the silicon wafer, and the data acquisition card collects 1000 groups of signals at a sampling frequency of 1MHz, and takes the average value as the zero point reference signal V0; A4, the silicon wafer is moved down 100 μm by the electric translation table to simulate the etching depth, and the signal V1 at this time is collected to calculate the actual signal difference AV 差 , i.e. AV 差 = V1-V0; A5. The etching depth theoretical value is calculated according to the etching depth calculation formula, and then the etching depth theoretical value is divided by the actual signal difference value to obtain the gain correction coefficient; A6. The intelligent control module compensates the etching depth according to the gain correction coefficient, and the compensated depth is the product of the zero point reference signal and the gain correction coefficient; A7. The silicon wafer is moved back to the initial position by the electric translation table, the signal after the silicon wafer is moved back is collected, and it is verified whether the signal after the silicon wafer is moved back is close to 0, if it is close to 0, the calibration is qualified, and switches to etching mode, otherwise, the calibration is unqualified, and A3-A6 are repeatedly executed.

9. The system for multi-field coupling regulated etching of metal layers integrated with a circuit board according to claim 8, wherein: The uniformity optimization module includes: a magnetic field regulation unit controlled by PWM signals to control the coil current, and an intelligent control module adjusts the magnetic field direction and strength according to the depth monitoring data to suppress the edge effect; A flow field regulation unit including a magnetic drive pump and a microchannel array, the magnetic drive pump is installed on the etching circulating pipeline outside the reaction cavity, the inlet of the etching circulating pipeline is connected with the liquid return port of the reaction cavity, the etching circulating pipeline and the outlet are connected with the liquid inlet at the top of the reaction cavity, and the motor of the magnetic drive pump is connected with the intelligent control module through a frequency converter; the microchannel array is a microwell plate arranged at the bottom of the reaction cavity, and a plurality of micropores with a diameter of 50-200μm are arranged on the microwell plate, and uniform liquid flow distribution is formed in the reaction cavity through the microwell plate.

10. The system for multi-field coupling regulated etching of metal layers integrated with a circuit board according to claim 9, wherein: The intelligent control module includes: a data receiving and processing unit for receiving actual depth data fed back by the depth real-time monitoring module, and calculating the deviation between the target depth data and the actual depth data according to the set target depth data; A PID control unit calculates the required control amount of each module according to the calculated deviation value by using the PID algorithm; A control instruction distribution unit distributes the control instruction to the multi-field coupling etching cavity module, the pulse current regulation module and the uniformity optimization module according to the calculated control amount to generate specific adjustment instructions; A feedback correction unit continuously monitors the real-time change of the etching depth after each adjustment, if the deviation between the target depth data and the actual depth data continuously decreases, the current PID parameters are maintained, otherwise, the required control amount of each module needs to be recalculated, and the corresponding module is adjusted again.

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