Pressure regulating method and device, front-end module and storage medium

Abstract

The application provides a pressure regulation method and device, a front-end module and a storage medium, and belongs to the technical field of pressure regulation. The method comprises the following steps: acquiring an actual pressure difference value between the inside of a transmission chamber and the external environment and a motion state parameter of a mechanical hand when the mechanical hand moves in the transmission chamber; determining an initial air speed regulation instruction according to the deviation of the actual pressure difference value and a target pressure difference value; predicting a pressure difference disturbance caused by instantaneous airflow caused by the movement of the mechanical hand based on the motion speed parameter, the motion acceleration parameter and the internal volume of the transmission chamber; and correcting the initial air speed regulation instruction based on the pressure difference disturbance to obtain a target air speed regulation instruction. The pressure regulation method and device, the front-end module and the storage medium provided by the application can improve the yield of semiconductor manufacturing and the reliability of equipment operation.

Description

Technical Field

[0001] This application belongs to the field of pressure regulation technology, and more specifically, relates to a pressure regulation method and device, a front-end module and a storage medium. Background Technology

[0002] In semiconductor manufacturing, the transfer chamber of the Equipment Front End Module (EFEM) needs to maintain a stable, slightly positive pressure environment to prevent external particles from contaminating the wafers. Existing pressure regulation methods typically employ feedback control strategies, adjusting fan speed in real time based on the deviation between the actual pressure difference inside the chamber and the target pressure difference. However, when a robotic arm moves at high speed within the chamber to pick up and place wafers, its movement generates instantaneous airflow disturbances, causing drastic fluctuations in chamber pressure. Due to the inherent response lag in feedback control, adjustment often only begins after the pressure deviates from the target value, making it difficult to effectively suppress pressure changes instantaneously during disturbances. This results in a brief disruption of the slightly positive pressure state, allowing unfiltered external air to enter the chamber, increasing the risk of wafer contamination and ultimately hindering improvements in semiconductor manufacturing yield and equipment reliability. Summary of the Invention

[0003] The purpose of this application is to provide a pressure regulation method and apparatus, a front-end module and a storage medium, which improves the yield of semiconductor manufacturing and the reliability of equipment operation.

[0004] A first aspect of this application provides a pressure regulation method, executed by a front-end module. The front-end module includes a transfer chamber, in which a robotic arm is disposed for wafer transfer, comprising: Obtain the actual pressure difference between the inside of the transmission chamber and the external environment; The initial wind speed adjustment command is determined based on the deviation between the actual pressure difference value and the target pressure difference value. The target pressure difference value is a fixed value that is preset and located within the range of slight positive pressure. The motion state parameters of the robotic arm as it moves within the transfer chamber are acquired. These motion state parameters include motion velocity parameters and motion acceleration parameters. Based on motion velocity parameters, motion acceleration parameters, and the internal volume of the transmission chamber, the pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the robotic arm is predicted. The initial wind speed adjustment command is corrected based on the pressure difference disturbance to obtain the target wind speed adjustment command; the target wind speed adjustment command is used to control the fan speed inside the transmission chamber so that the pressure value inside the transmission chamber is kept within a slightly positive pressure range.

[0005] A second aspect of this application provides a pressure regulating device applied to a front-end module. The front-end module includes a transfer chamber, and a robotic arm is disposed within the transfer chamber for wafer transfer. The differential pressure acquisition module is used to acquire the actual differential pressure value between the inside of the transmission chamber and the external environment; The initial command determination module is used to determine the initial wind speed adjustment command based on the deviation between the actual pressure difference value and the target pressure difference value. The target pressure difference value is a fixed value that is preset and located within the range of slight positive pressure. The status acquisition module is used to acquire motion status parameters of the robot arm when it moves in the transmission chamber. The motion status parameters include motion velocity parameters and motion acceleration parameters. The disturbance prediction module is used to predict the amount of pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the robot arm, based on motion velocity parameters, motion acceleration parameters, and the internal volume of the transmission chamber. The instruction correction module is used to correct the initial wind speed adjustment instruction based on the pressure difference disturbance to obtain the target wind speed adjustment instruction; the target wind speed adjustment instruction is used to control the fan speed inside the transmission chamber so that the pressure value inside the transmission chamber is kept within the slightly positive pressure range.

[0006] A third aspect of this application provides a front-end module, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of the pressure regulation method described above.

[0007] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the pressure regulation method described above.

[0008] The beneficial effects of the pressure regulation method and apparatus, front-end module and storage medium provided in this application embodiment are as follows: This embodiment of the application achieves steady-state pressure control under a feedback closed loop by acquiring the actual pressure difference between the inside of the transmission chamber and the external environment in real time, and generating an initial wind speed adjustment command based on this actual deviation. Simultaneously, by acquiring the speed and acceleration parameters of the robotic arm's movement, and combining this with the chamber volume to predict the instantaneous airflow pressure difference disturbance caused by its movement, this disturbance is used as a feedforward quantity to correct the initial command. This allows the fan speed to respond in advance to pressure fluctuations caused by the robotic arm's movement, thus proactively adjusting the airflow before the disturbance actually occurs. This pressure regulation method, combining feedback and feedforward, overcomes the shortcomings of traditional wind speed control in handling instantaneous disturbances, ensuring effective suppression of transient pressure fluctuations inside the transmission chamber and maintaining the transmission chamber within a stable micro-positive pressure range. Consequently, unfiltered external air cannot enter the chamber through gaps, ensuring the wafer remains in an ultra-clean environment during transmission, effectively preventing particulate contamination, and improving the yield of semiconductor manufacturing and the reliability of equipment operation. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A schematic flowchart illustrating a pressure regulation method provided in an embodiment of this application; Figure 2 A timing diagram for feedforward compensation and advance control is provided for an embodiment of this application; Figure 3 This is a structural block diagram of a pressure regulating device provided in an embodiment of this application; Figure 4 This is a schematic block diagram of a front-end module provided in one embodiment of this application. Detailed Implementation

[0011] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0012] To make the objectives, technical solutions, and advantages of this application clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0013] Please refer to Figure 1, Figure 1 This is a schematic flowchart of a pressure regulation method provided in an embodiment of this application. The method can be executed by a front-end module, which includes a transmission chamber and a robotic arm configured in the transmission chamber for wafer transfer.

[0014] In this embodiment, the front-end module is a transition module in semiconductor manufacturing equipment connecting the wafer loading port and the main process equipment. It is primarily responsible for the clean transport of wafers in an atmospheric environment and for microenvironment control, serving as a key barrier to prevent particulate contamination. The transport chamber is a sealed physical space within the front-end module used for robotic arm movement and temporary wafer storage. The transport chamber requires airflow control to maintain a specific cleanliness level and pressure environment. The robotic arm refers to an automated handling device configured within the transport chamber, used for high-speed and precise gripping and transporting of wafers between various loading ports, alignment points, and process chambers. The method includes: S101: Obtain the actual pressure difference between the inside of the transmission chamber and the external environment.

[0015] In this embodiment, the actual pressure difference value is the real-time difference between the absolute pressure inside the transmission chamber and the absolute pressure of the external cleanroom environment.

[0016] In one embodiment of this application, obtaining the actual pressure difference between the inside of the transmission chamber and the external environment includes: Acquire the raw internal pressure signal collected by the pressure sensor located inside the transmission chamber, and acquire the raw external pressure signal collected by the pressure sensor located outside the transmission chamber; Obtain the current motion state identifier of the robot arm, which is used to indicate whether the robot arm is currently in motion or stationary. When the motion status indicator indicates that the robot is currently in motion, the original internal pressure signal is low-pass filtered using the first cutoff frequency to obtain the internal filtered pressure signal. The first cutoff frequency is used to filter out the high-frequency pneumatic noise generated by the robot's movement. When the motion status indicator indicates that the robot is currently in a stationary state, the original internal pressure signal is low-pass filtered using the second cutoff frequency to obtain the internal filtered pressure signal. The second cutoff frequency is greater than the first cutoff frequency. The original external pressure signal is filtered by moving average to obtain a smooth external pressure signal, so as to filter out the low-frequency pulsation caused by the airflow in the external environment. Calculate the difference between the internal filtered pressure signal and the external smoothed pressure signal, and use the difference as the actual pressure difference value.

[0017] In this embodiment, the internal raw pressure signal refers to the unprocessed electrical signal directly output by the pressure sensor installed inside the transmission chamber, which is linearly related to the absolute pressure of the chamber. The external raw pressure signal refers to the raw signal directly output by the pressure sensor installed on the outer wall of the transmission chamber or exposed to the external environment. The motion state indicator is a numerical indicator obtained from the robot controller; for example, a value of 1 indicates that the robot is currently in motion, and a value of 0 indicates that it is stationary. The first cutoff frequency refers to the -3dB cutoff frequency of the low-pass filter, for example, set to 10Hz, used to filter out the 50-200Hz high-frequency pressure fluctuations generated when the robot moves rapidly. High-frequency aerodynamic noise is mainly caused by high-frequency pressure pulsations generated by airflow turbulence induced by the high-speed movement of the robot. The second cutoff frequency refers to the filter cutoff frequency used in the stationary state, for example, set to 100Hz, which is greater than the first cutoff frequency to retain faster pressure changes.

[0018] In this embodiment, two identical piezoresistive pressure sensors are installed inside and outside the transmission chamber. Both sensors have a range of -100Pa to +100Pa and output a 4~20mA current signal. This signal is converted to a 1~5V voltage by a 250Ω precision resistor and then converted to a digital signal by an analog-to-digital converter at a 1000Hz sampling rate. The front-end module synchronously acquires the raw values ​​from both pressure sensors at a 1ms period and stores them in their respective circular buffers, each with a capacity of 200 sampling points.

[0019] When the absolute value of the velocity of any axis of the robot arm is greater than 0.005 m / s, the motion status flag is set to 1; otherwise, it is set to 0. The front-end module checks this flag in each control cycle (e.g., 10 ms).

[0020] When the motion state flag is 1, a first-order low-pass digital filter is applied to the original internal pressure signal sequence. The recursive formula for the first-order low-pass digital filter is: Where x[n] represents the nth sampling point of the original internal pressure signal input at the current sampling time, and y[n] represents the internal filtered pressure signal output at the current sampling time. This represents the internally filtered pressure signal output at the previous sampling time. These are the filter coefficients. From sampling period and filter time constant Decide: Sampling period It is 0.001s. Time constant. With cutoff frequency The relationship is If the first cutoff frequency is 10Hz, then ≈0.0159s, calculate =0.001 / (0.001+0.0159)≈0.059. Substituting into the recursive formula, we obtain the internal filtered pressure signal under motion conditions. Wherein, This is the specific time constant value when the cutoff frequency is the first cutoff frequency (10Hz). Is when The filter coefficient value at that time.

[0021] When the motion status indicator is 0, the second cutoff frequency of 100Hz is used. ≈0.00159s, =0.001 / (0.001+0.00159)≈0.386. Substituting into the same recursive formula, we obtain the internal filtered pressure signal under static conditions. Wherein, This is the specific time constant value when the cutoff frequency is the second cutoff frequency (100Hz). Is when The filter coefficient value at that time.

[0022] For the raw external pressure signal, a moving average filter is applied with a window length M equal to 200 sampling points, corresponding to a 0.2s time window. The mathematical expression for the moving average filter is: . Indicates the first The external raw pressure signal value at each sampling point M This represents the window length (number of sampling points) for the moving average filter. For the first k The external smooth pressure signal value after filtering at each sampling point. This moving average filter has its first attenuation zero point at 5Hz, which can attenuate pressure pulsation components at 5Hz and above, while retaining slow pressure changes in the external environment below 5Hz.

[0023] Finally, at the end of each 10ms control cycle, the front-end module reads the latest internal filter pressure signal. and external smooth pressure signal Calculate the difference The difference This is the actual pressure difference value.

[0024] As can be seen from the above, this embodiment solves the problem that a single filtering strategy cannot simultaneously suppress high-frequency noise and filter out low-frequency pulsations by dynamically switching the internal filter cutoff frequency and performing moving average processing on the external signal. This implementation effectively eliminates spurious differential pressure signals, providing extremely pure and realistic differential pressure feedback data for closed-loop control, reducing ineffective adjustments and mechanical wear of the fan caused by signal distortion, extending the service life of the equipment, and improving the anti-interference capability and dynamic response quality of the micro-positive pressure control system.

[0025] S102: Determine the initial wind speed adjustment command based on the deviation between the actual pressure difference value and the target pressure difference value. The target pressure difference value is a pre-set fixed value within the slightly positive pressure range.

[0026] In this embodiment, the target pressure difference value is a preset expected pressure difference value, which can be a fixed value greater than 0, such as +15Pa. This value is within the slightly positive pressure range (e.g., +10Pa to +30Pa). Setting this fixed value is to ensure that the inside of the transmission chamber is always in a slightly positive pressure state, thereby effectively isolating particulate pollutants in the external environment by utilizing the weak outward airflow.

[0027] The initial fan speed adjustment command is based on the deviation between the current actual pressure difference and the target pressure difference. It can be calculated by a basic feedback control algorithm (such as a traditional proportional-integral-derivative control algorithm) to generate an initial fan control signal (such as a basic speed setpoint or PWM duty cycle) to correct the pressure deviation under steady state.

[0028] For example: Assuming the actual pressure difference within the transmission chamber is 5 Pa, and the preset target pressure difference is 15 Pa, then the deviation e = 15 - 5 = 10 Pa. A proportional-integral-derivative (PID) control algorithm is used, where the proportional coefficient Kp = 0.3 rpm / Pa, the integral coefficient Ki = 0.05 rpm / (Pa·s), and the derivative coefficient Kd = 0.01 rpm·s / Pa. Sampling period. =0.02s, the cumulative value of the integral term in the previous cycle is 2rpm, the deviation in the previous cycle =8Pa. Therefore, the proportional term... =0.3×10=3rpm; Integral term =2 + 0.05 × 10 × 0.02 = 2.01 rpm; Differential term =0.01×(10-8) / 0.02=1rpm. Initial wind speed adjustment command. =3+2.01+1=6.01rpm, meaning the fan needs to increase its base speed by approximately 6rpm.

[0029] In this embodiment, the actual pressure difference value acquired in real time is compared with the target pressure difference value to obtain the pressure deviation value. Subsequently, an initial wind speed adjustment command is generated using a feedback control algorithm. The initial wind speed adjustment command represents the fan base speed required solely by the feedback action. It can independently respond to steady-state deviations and low-frequency disturbances, providing a stable reference for subsequent superposition of feedforward compensation.

[0030] S103: Acquire motion state parameters of the robot arm when it moves in the transmission chamber. The motion state parameters include motion speed parameters and motion acceleration parameters.

[0031] In this embodiment, motion state parameters are physical quantities that describe the current kinematic characteristics of the robot, specifically including motion velocity parameters (such as the linear velocity or angular velocity of each axis) and motion acceleration parameters (such as the linear acceleration or angular acceleration of each axis). These parameters directly determine the intensity of the robot's disturbance to the surrounding gas.

[0032] In this embodiment, due to the extremely high movement speed of the robotic arm when transferring wafers (such as Z-axis lifting and XY-axis translation), its body exerts a strong squeezing or suction effect on the gas inside the chamber. The front-end module accurately obtains the current movement speed and acceleration parameters of the robotic arm by reading the encoder data of the robotic arm in real time.

[0033] S104: Based on motion velocity parameters, motion acceleration parameters, and the internal volume of the transmission chamber, predict the pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the robot arm.

[0034] In this embodiment, the internal volume is the effective free space volume inside the transmission chamber that is not occupied by fixed hardware (such as inner walls, supports, etc.) and is available for gas flow and compression. The smaller the volume, the more drastic the pressure change will be under the same gas displacement. The pressure difference disturbance is the predicted value of the transient and drastic change in the internal pressure of the chamber caused by the high-speed movement of the manipulator in the sealed transmission chamber, which displaces or drags the surrounding gas.

[0035] In one embodiment of this application, the prediction of pressure differential disturbance caused by the instantaneous airflow triggered by the movement of the robotic arm, based on motion velocity parameters, motion acceleration parameters, and the internal volume of the transmission chamber, includes: The current pose of the robot is determined based on the motion state parameters, and the equivalent windward area corresponding to the current pose is obtained from the preset mapping table. The preset mapping table contains the mapping relationship between pose and windward area. The instantaneous volumetric flow rate caused by the movement of the manipulator is calculated based on the product of the motion speed parameter and the equivalent windward area. The rate of change of instantaneous volumetric flow rate is calculated based on the motion acceleration parameters, and then the rate of change is superimposed with the instantaneous volumetric flow rate according to the first formula to obtain the target volumetric flow rate. The pressure difference disturbance is calculated based on the rate of change of the target volumetric flow rate, the internal volume, and the gas density within the transmission chamber. The first formula is: ; in, Indicates the target volumetric flow rate. Indicates instantaneous volumetric flow rate. Indicates the inertial compensation time constant. It represents the rate of change of instantaneous volumetric flow rate.

[0036] In this embodiment, the current pose of the robotic arm can be obtained through feedback from the encoders of each joint. The pose parameters are used as indexes to look up the corresponding equivalent windward area in a preset mapping table. The preset mapping table can be established in advance through offline experiments: the workspace of the robotic arm is discretized into several poses, and the projected area along the motion direction under each pose is measured to establish the pose-area correspondence. For example, when the robotic arm is fully retracted, the equivalent windward area is 0.01m², and when it is fully extended, it is 0.03m². The intermediate poses are obtained through linear interpolation.

[0037] The inertial compensation time constant k (unit: s) is used to correct the response lag caused by gas inertia. The value of k can be calibrated through a step response experiment. For example, a known step change in volumetric flow rate is generated in the chamber, the pressure response curve is recorded, and the optimal time constant is obtained by fitting. The typical value range is 0.05s to 0.5s. In this embodiment, k=0.1s is determined through calibration experiments. According to the first formula... Obtain the target volumetric flow rate. Then, for... By performing time differentiation, we obtain The internal volume V is a known geometric parameter of the cavity, which can be obtained through measurement using a three-dimensional model, for example, 0.5 m³. Gas density... The pressure difference disturbance can be calculated in real time using temperature and humidity sensors installed within the transmission chamber, combined with the ideal gas law. A piston effect model is used to calculate the pressure difference disturbance. ,in This represents the pressure difference disturbance. To transmit the gas density within the chamber, The rate of change of the target volumetric flow rate, The internal volume of the transmission chamber. Comprehensive calibration coefficient (unit: It is used to comprehensively compensate for deviations caused by non-ideal factors such as gas inertia, gas vortex or wall friction in the actual cavity. It can be calibrated by inputting the known volume flow rate change rate into the cavity and measuring the actual pressure change.

[0038] In this embodiment, the frontal area is obtained by looking up the pose in a table, and then the instantaneous volumetric flow rate and its rate of change of the gas displaced by the manipulator are calculated by combining the velocity and acceleration. Since the gas has inertia, when the manipulator's acceleration is large, the gas's response to pressure changes exhibits phase lag. By introducing an experimentally calibrated inertial compensation time constant k, the weighted sum of the instantaneous volumetric flow rate and its rate of change is used as the target volumetric flow rate, making the predicted pressure change closer to the actual physical process. Finally, using a piston effect model, the rate of change of the target volumetric flow rate is correlated with the chamber volume and gas density to quantitatively calculate the pressure disturbance caused by the manipulator's movement.

[0039] As can be seen from the above, this embodiment avoids complex real-time fluid dynamics calculations and reduces the computational burden on the controller by using an offline calibrated pose-windward area mapping table; the inertia compensation time constant is experimentally calibrated, enabling the prediction model to accurately reflect the response lag caused by gas inertia and improving the prediction accuracy of pressure difference disturbance in dynamic processes.

[0040] S105: The initial wind speed adjustment command is corrected based on the pressure difference disturbance to obtain the target wind speed adjustment command; the target wind speed adjustment command is used to control the fan speed inside the transmission chamber so that the pressure value inside the transmission chamber is kept within the slightly positive pressure range.

[0041] In this embodiment, the target wind speed adjustment command is a comprehensive control command issued to the fan motor after superimposing a feedforward compensation amount for instantaneous airflow disturbance on the basis of the initial wind speed adjustment. The fan refers to the fan filter unit, which is installed on the top or side of the transmission chamber to blow filtered clean air into the chamber and dynamically controls the air volume in the chamber by adjusting its speed, thereby maintaining a slight positive pressure inside.

[0042] In one embodiment of this application, the initial wind speed adjustment command carries the fan's base speed. In this embodiment, the initial wind speed adjustment command is corrected based on the pressure difference disturbance to obtain the target wind speed adjustment command, including: Obtain the three-dimensional motion direction vector of the robotic arm within the current control cycle; The normal velocity is obtained by projecting the three-dimensional motion direction vector onto the normal vector of the equivalent windward surface of the manipulator. The instantaneous volume change rate of the gas displaced by the manipulator is calculated based on the product of the normal velocity and the equivalent frontal area. The feedforward speed compensation is calculated based on the instantaneous volume change rate and the preset fan flow calibration coefficient. Based on the pressure difference disturbance, internal volume, and fan flow calibration coefficient, calculate the speed correction amount, and add the speed correction amount to the feedforward speed compensation amount to obtain the corrected feedforward speed compensation amount. The target fan speed is obtained by superimposing the base speed with the corrected feedforward speed compensation. Replace the base speed with the target speed and add it to the initial wind speed adjustment command as the target wind speed adjustment command.

[0043] In this embodiment, the initial wind speed adjustment command carries the fan's base rotational speed value. This base rotational speed is generated by the feedback control algorithm in step S102 and is used to provide a reference for the steady-state pressure control of the chamber. For example, the current base rotational speed is 1200 rpm. The three-dimensional motion direction vector is provided in real time by the robot's motion controller and is represented as (Vx, Vy, Vz). The normal vector of the equivalent windward surface is a unit vector perpendicular to the windward surface and pointing forward in the direction of robot movement. The normal vector of the equivalent windward surface can be obtained from a mapping table with the same windward area based on the robot's current pose. The dot product between the three-dimensional motion direction vector and the normal vector of the equivalent windward surface is calculated, and the absolute value is taken. The resulting value is the normal motion velocity. Instantaneous volume change rate. ,in The normal velocity, It represents the equivalent windward area.

[0044] Fan flow rate calibration coefficient Pre-calibration is achieved through experiments, for example: on a fan test bench, a series of different speed commands are issued to the fan, the corresponding steady-state volumetric flow rate is measured using a flow meter, and the speed-flow rate curve is plotted; its slope is the [value / slope]. Based on instantaneous volume change rate and fan flow rate calibration coefficient The feedforward speed compensation amount can be determined through a preset conversion relationship. As a basic implementation method, the instantaneous volume change rate can be divided by the fan flow rate calibration coefficient, thus determining the feedforward speed compensation amount. It should be noted that this conversion relationship is not limited to a simple division operation. In practical applications, the instantaneous volume change rate can be directionally corrected according to the direction of the robot's movement before conversion, in order to further improve the accuracy of feedforward compensation.

[0045] Based on pressure difference disturbance Internal volume of the chamber and fan flow rate calibration coefficient Calculate the speed correction amount Among them, pressure difference disturbance This reflects the prediction deviation of chamber pressure caused by the movement of the robotic arm, and the internal volume. It characterizes the sensitivity of the chamber to pressure disturbances; the larger the volume, the more gas needs to be compensated for the same pressure difference disturbance.

[0046] In this embodiment, the rotational speed correction amount The calculation process is as follows: First, based on the isothermal gas law, the equivalent gas volume change caused by the manipulator's movement is determined by multiplying the pressure difference disturbance by the internal volume of the chamber. Then, this equivalent gas volume change is compared to the duration of the current control cycle to obtain the required fan flow rate. Finally, this flow rate is compared to the fan flow rate calibration coefficient to obtain the speed correction. Add the speed correction amount to the feedforward speed compensation amount to obtain the corrected feedforward speed compensation amount. .

[0047] base speed With the corrected feedforward speed compensation amount Algebraic addition yields the target rotational speed The sign of the compensation amount is determined by the direction of the robot's movement. If the robot moves into the chamber (compressing gas), then... If the pressure is positive, the fan speed needs to be increased to counteract the pressure rise; if the pressure is increasing outward (drawing in gas), then... A negative value indicates a need to reduce fan speed. (Speed ​​correction amount) The sign of the pressure difference disturbance The signs are consistent, when When positive (predicting rising pressure), To be positive, further enhance speed compensation; when When it is negative (predicting a decrease in pressure), If the value is negative, the speed compensation should be appropriately reduced. Finally, the target speed is used to replace the base speed in the original initial wind speed adjustment command to generate a new target wind speed adjustment command.

[0048] In this embodiment, the actual motion direction vector of the manipulator in three-dimensional space is first obtained. By projecting this vector onto the normal of the windward surface, the effective velocity component that actually causes gas displacement is extracted. The normal velocity is multiplied by the equivalent windward area to obtain the instantaneous volume change rate, which represents the volume of gas displaced by the manipulator per unit time. To convert this volume change rate into an adjustment amount for the fan speed, a linear mapping between volumetric flow rate and speed is established using a pre-calibrated fan flow rate calibration coefficient. Simultaneously, this embodiment also uses the predicted pressure difference disturbance, combined with the internal volume of the chamber and the fan flow rate calibration coefficient, to calculate the speed correction amount, and performs a secondary correction on the feedforward speed compensation amount obtained based on kinematic parameters. The calculated and corrected feedforward speed compensation amount is superimposed with the base speed given by feedback control to form the final target speed command. Throughout the process, the projection calculation ensures that only the motion component perpendicular to the windward surface participates in the compensation, avoiding interference from tangential motion.

[0049] As can be seen from the above, this embodiment eliminates the erroneous contribution of the manipulator's tangential motion to the compensation amount through directional projection processing, making the feedforward compensation more accurate. The fan flow rate calibration coefficient, obtained through offline experiments, accurately reflects the fan's flow rate-speed characteristics, providing a reliable physical basis for the conversion from volume change rate to speed compensation. By introducing pressure difference disturbance to calculate the speed correction, pressure prediction information is integrated into the speed compensation process, enabling the feedforward compensation to not only rely on kinematic parameters but also undergo secondary correction based on the predicted trend of chamber pressure changes, further improving compensation accuracy. The superimposed target speed command allows the fan to actively adjust its speed when the manipulator generates pressure fluctuations, reducing pressure overshoot and oscillation.

[0050] As can be seen from the above, this embodiment achieves steady-state pressure control under a feedback closed loop by acquiring the actual pressure difference between the inside of the transmission chamber and the external environment in real time, and generating an initial wind speed adjustment command based on this actual deviation. Simultaneously, by acquiring the speed and acceleration parameters of the robotic arm's movement, and combining this with the chamber volume to predict the instantaneous airflow pressure difference disturbance caused by its movement, this disturbance is used as a feedforward quantity to correct the initial command. This allows the fan speed to respond in advance to the pressure fluctuations caused by the robotic arm's movement, thus proactively adjusting the airflow before the disturbance actually occurs. This pressure regulation method, combining feedback and feedforward, overcomes the shortcomings of traditional wind speed control in dealing with instantaneous disturbances, ensuring that transient pressure fluctuations are effectively suppressed inside the transmission chamber, keeping the transmission chamber within a stable micro-positive pressure range. Therefore, unfiltered external air cannot enter the chamber through gaps, and the wafer remains in an ultra-clean environment during transmission, effectively preventing particulate contamination and improving the yield of semiconductor manufacturing and the reliability of equipment operation.

[0051] In one embodiment of this application, the feedforward speed compensation is calculated based on the instantaneous volume change rate and a preset fan flow calibration coefficient, including: Obtain the equivalent crosswind area corresponding to the current pose from the preset mapping table; The three-dimensional motion direction vector is decomposed into a vertical velocity component perpendicular to the bottom surface of the transmission chamber and a horizontal velocity component parallel to the bottom surface of the transmission chamber; the vertical velocity component includes the vertical velocity amplitude and the vertical direction polarity value, and the horizontal velocity component includes the horizontal velocity amplitude. When the vertical velocity amplitude is greater than the preset vertical threshold, the product of the vertical velocity amplitude and the equivalent windward area is used as the vertical volume change rate; the preset first compensation gain, the vertical volume change rate and the vertical polarity value are multiplied together to obtain the vertical feedforward compensation amount. When the horizontal velocity amplitude is greater than the preset horizontal threshold, the product of the horizontal velocity amplitude and the equivalent crosswind area is used as the horizontal volume change rate; the preset second compensation gain is multiplied by the horizontal volume change rate to obtain the horizontal feedforward compensation amount, and the first compensation gain is greater than the second compensation gain. The vertical feedforward compensation is added to the horizontal feedforward compensation to obtain the directional compensation. The base speed compensation is determined based on the instantaneous volume change rate and the fan flow calibration coefficient. The base speed compensation is then superimposed with the directional compensation to obtain the feedforward speed compensation.

[0052] In this embodiment, the equivalent crosswind area With equivalent windward area The area is stored together in a preset mapping table. This area is obtained through offline experiments. The projected area is measured or calculated along the horizontal movement direction of the robotic arm. For example, when the robotic arm is extended horizontally, the crosswind area is 0.005 m². The vertical velocity component Vz is directly taken from the Z-axis component of the three-dimensional direction vector, and the vertical velocity amplitude is... The vertical polarity value is sign(Vz) (+1 for upward motion, -1 for downward motion). The horizontal velocity amplitude... Both the vertical and horizontal thresholds were determined through the following experiments: the robotic arm was moved at different speeds (e.g., 0.001 m / s, 0.002 m / s, 0.005 m / s, 0.01 m / s) in the vertical or horizontal direction, and the peak value of the chamber pressure fluctuation was recorded. When the movement speed was below a certain value, the peak pressure fluctuation was less than 0.1 Pa (i.e., it had no substantial impact on micro-positive pressure control), and this speed value was determined as the threshold. In this embodiment, the vertical threshold was set to 0.005 m / s, and the horizontal threshold was set to 0.005 m / s. When |Vz|>0.005 m / s, the vertical volume change rate... The first compensation gain G1 is used to amplify the effect of vertical motion. Its value is calibrated experimentally: by moving at different speeds in the vertical direction, the relationship between the actual pressure change and the theoretical volume change rate is measured, and the optimal gain is obtained through fitting. In this embodiment, the calibration value is 1.5. Vertical feedforward compensation amount. .when When the speed is >0.005 m / s, the horizontal volume change rate The second compensation gain G2 is less than G1 because horizontal motion has a smaller impact on pressure. It is obtained through experimental calibration, for example, a calibration value of 0.5. Horizontal feedforward compensation amount. .

[0053] Vertical feedforward compensation With horizontal feedforward compensation Algebraic addition yields the directional compensation amount. This directional compensation reflects the rate of change in the volume of gas expelled by the manipulator after directional-specific gain correction. Simultaneously, based on the instantaneous volume change rate... With fan flow rate calibration coefficient Determine the basic speed compensation amount.

[0054] In this embodiment, since the directional compensation amount already fully covers the differentiated effects of vertical and horizontal motion on pressure, the base rotational speed compensation amount is set to 0 (i.e., no additional independent compensation term based on the overall instantaneous volume change rate is introduced) to avoid redundant calculations. The directional compensation amount is then superimposed with the base rotational speed compensation amount (0) to obtain the total compensated volume change rate. Finally, multiply the total compensated volume change rate by the fan flow rate calibration factor. The final feedforward speed compensation amount is obtained.

[0055] In this embodiment, the three-dimensional motion direction vector of the robot arm is decomposed into vertical and horizontal components because their contribution mechanisms to chamber pressure changes differ: vertical motion directly alters the effective volume of the chamber, similar to piston motion, resulting in drastic and directional pressure changes; horizontal motion mainly causes airflow disturbances and local eddies, with a smaller and non-directional impact on overall pressure. Therefore, for the vertical component, a larger first compensation gain is used, and directional polarity is introduced, resulting in negative compensation (reducing fan speed) during upward motion and positive compensation (increasing fan speed) during downward motion. For the horizontal component, a smaller second compensation gain is used, and no polarity is introduced because the influence on pressure is the same regardless of the direction of horizontal motion. The two compensation amounts are calculated separately and then summed to obtain the directional compensation amount. This directional compensation amount is used as the total compensation volume change rate, which is then multiplied by the fan flow calibration coefficient to convert it into a speed adjustment value, thus obtaining the final feedforward speed compensation amount. In this way, refined feedforward is achieved through directional decomposition, and the logic of determining the basic compensation amount based on the instantaneous volume change rate is fully reflected.

[0056] As can be seen from the above, this embodiment achieves refined feedforward compensation for the robot's motion direction by distinguishing between vertical and horizontal motion and employing different compensation gains and polarity processing. This avoids the problems of insufficient compensation in vertical motion and overcompensation in horizontal motion inherent in traditional single-gain models. The vertical polarity processing ensures that the fan speed correctly responds to compression or suction effects, further improving the accuracy of pressure control. The use of an independent crosswind area and a smaller gain in the horizontal direction avoids unnecessary fan energy consumption and mechanical wear.

[0057] In one embodiment of this application, after correcting the initial wind speed regulation command based on the pressure difference disturbance to obtain the target wind speed regulation command, the method further includes: Obtain the fan's step response delay time, which is the time required from issuing the speed command to the fan's actual speed reaching the target value preset ratio; Calculate the feedforward advance based on the motion acceleration parameters and the step response delay time; The timing of the target wind speed adjustment command is advanced by a feedforward amount to compensate for the mechanical response delay of the fan.

[0058] In this embodiment, the fan's step response delay time This can be obtained through offline testing. According to automatic control theory, for a first-order inertial system, the time required for its unit step response to rise from the initial value to 63.2% of the final steady-state value is the system's time constant. Therefore, this embodiment uses this standard definition to calibrate the fan's response delay. The specific testing method is as follows: Install the fan in a standard test environment and send a speed step command (e.g., from 0 rpm to 1000 rpm) to the fan driver. Simultaneously, use a speed sensor or back EMF detection circuit to record the actual fan speed over time. The time elapsed from the moment the command is issued until the fan speed first reaches 63.2% of the target step value is the step response delay time. To improve calibration accuracy, the experiment was repeated multiple times and the average value was taken. For example, when the target step value is 1000 rpm, its 63.2% is 632 rpm. If the average time from the start of the command issuance to the first time the speed reaches 632 rpm is measured to be 0.08 seconds in multiple experiments, then... =0.08s. It should be noted that this value is only a specific example of this embodiment, and in actual applications, it can be calibrated accordingly based on different fan models and test conditions.

[0059] In this embodiment, the delay characteristics can be referred to Figure 2 (d) Fan speed response comparison curve: The dashed line represents the actual fan response without lead time. The rising edge of the fan speed is significantly delayed relative to the command issuance time. This delay time corresponds to the step response delay time. =80ms.

[0060] In one embodiment of this application, the current acceleration value of the robotic arm is used as the motion acceleration parameter; Based on the motion acceleration parameters and the step response delay time, calculate the feedforward lead, including: Based on the absolute value of the current acceleration, the corresponding adjustment coefficient is obtained from the preset acceleration-coefficient mapping table; the step response delay time is multiplied by the adjustment coefficient to obtain the initial advance time; If the initial lead time is greater than the preset maximum lead time, the maximum lead time will be used as the feedforward lead time; otherwise, the initial lead time will be used as the feedforward lead time.

[0061] In this embodiment, the timing pattern of a single complete movement of the robotic arm is as follows: Figure 2 As shown in (a) the acceleration curve and (b) the velocity curve of the robotic arm: the motion begins at 0.50s, first experiencing a positive uniform acceleration phase where the acceleration remains constant and positive; then entering a uniform velocity phase where the acceleration returns to zero; finally entering a reverse uniform deceleration phase where the acceleration remains constant and negative, and ultimately the velocity returns to zero, the overall velocity curve presents a standard trapezoidal trajectory. The current acceleration value 'a' is the motion acceleration parameter of the robotic arm, which can be read in real time from the robotic arm motion controller, and... Figure 2 The acceleration amplitudes at the corresponding times in (a) are consistent.

[0062] The acceleration-coefficient mapping table was obtained through experimental calibration: Typical movements were performed on the robotic arm with different acceleration values, and the relationship between the timing of pressure disturbances and the optimal lead time for fan response was measured to determine the adjustment coefficients corresponding to each acceleration range. The acceleration-coefficient mapping table can be stored in discrete point form, for example: when... When =0.1m / s², the adjustment coefficient =0.2; When =0.5m / s², =0.6; When =1.0m / s², =1.0; When = 2.0 m / s², =1.2; For acceleration values ​​not listed, linear interpolation is used to calculate the corresponding values. The physical meaning of the adjustment factor is to convert the fan's inherent delay time into an effective advance ratio adapted to the current acceleration. Initial advance time. .

[0063] In this embodiment, the maximum advance time The method for determining this is: read the remaining time of the robot arm's planned motion trajectory. The remaining time can be calculated based on the current time and the endpoint time of the pre-planned trajectory. To ensure safety, a setting is implemented. This means that at most 90% of the remaining time can be given in advance, to avoid issuing instructions before the movement has even started. (Comparison) and :like Then the final feedforward lead ;otherwise For example, if the current absolute value of acceleration is 1.2 m / s², the interpolation value is... =1.1, =0.08s, then =0.088s; if the remaining time =0.1s, then =0.09s, ,Pick =0.088s; if =0.08s, then =0.072s, ,Pick =0.072s.

[0064] The timing effects of the aforementioned feedforward advance are as follows: Figure 2 (c) The curves showing the predicted differential pressure disturbance and the advance command issuance are as follows: The predicted differential pressure disturbance is generated synchronously after the start of the robot's movement at 0.50s, while the advance command issuance time is... That is, at the beginning of the movement In advance =88ms to issue the target wind speed adjustment command, so that the fan speed adjustment action is earlier than the time when the pressure disturbance occurs, thus realizing predictive compensation.

[0065] In this embodiment, the absolute value of the current acceleration of the robotic arm is first obtained, as acceleration is a key factor determining the severity of pressure disturbances: the greater the acceleration, the more drastic the pressure change, requiring a larger lead time. Using a pre-generated acceleration-coefficient mapping table, the current acceleration is mapped to an adjustment coefficient, which reflects the factor by which the inherent delay time of the fan needs to be amplified at a specific acceleration. The step response delay time is multiplied by this coefficient to obtain the initial lead time. To avoid excessive lead time causing commands to be issued before the robotic arm has moved or has already stopped, a maximum lead time is set. This maximum lead time is determined by the remaining movement time of the robotic arm, and a certain percentage of this time is taken as a safety upper limit. Finally, the smaller value between the initial lead time and the maximum lead time is taken as the actual feedforward lead time.

[0066] As can be seen from the above, the acceleration-coefficient mapping table in this embodiment enables the lead time to continuously and adaptively change with acceleration. The lead time is small during low-speed motion, avoiding unnecessary advance; the lead time is large during high-speed motion, ensuring timely compensation. The maximum lead time limiting mechanism effectively prevents the command from being issued outside the motion window, avoiding fan malfunctions or reverse pressure fluctuations caused by premature command issuance.

[0067] The front-end module internally sets up a command preset queue, which can send commands with a specified time delay. Originally, the command to adjust the target wind speed should be issued immediately after calculation; now, the front-end module marks the target wind speed adjustment command as needing to be issued in advance and calculates the issuance time. (in (At the current moment). If If the instruction is earlier than the current time, it will be issued immediately; otherwise, the instruction will be temporarily stored and executed in a timer interrupt. Send at any time.

[0068] The effect of this timing compensation can be referenced. Figure 2 (d) Fan speed response comparison curve: Without lead time, the actual fan response (dashed line) lags behind the command. In terms of time, the rising edge of the fan speed is later than the start of the robot's movement. After introducing the feedforward lead, the rising edge of the fan's actual response (solid line) is basically aligned with the start of the robot's movement. The actual speed increase of the fan will be precisely matched in time with the pressure disturbance that the robot will generate.

[0069] The final pressure control effect is as follows Figure 2 The actual differential pressure control effect comparison curve (e) shows that the original disturbance without compensation (dotted line) has the largest differential pressure fluctuation amplitude; the differential pressure fluctuation is reduced by only using the feedback plus hysteresis feedforward scheme without advance (dashed line), but there is still a significant phase deviation, and the fluctuation peak exceeds the ideal range; after using the scheme with advance in this embodiment (solid line), the differential pressure fluctuation amplitude is reduced, and the pressure fluctuation throughout the process is effectively suppressed within a smaller range, corresponding to the pressure fluctuation suppression area in the figure, ensuring that the transmission chamber always maintains a stable micro-positive pressure state.

[0070] In this embodiment, the fan, as an electromechanical actuator, has inherent mechanical inertia from receiving the command to the actual change in speed. This delay causes feedforward compensation to always lag behind the movement of the robotic arm. This embodiment obtains the fan's step response delay time through pre-testing, which reflects the average lag between the fan receiving the command and the actual action. Then, based on the current acceleration of the robotic arm, the urgency of the impending pressure disturbance is estimated, and a lead time is calculated. Finally, the timing of the target wind speed adjustment command is advanced by this lead time, so that the change in fan speed occurs almost simultaneously with the pressure disturbance generated by the robotic arm's movement, thereby truly achieving the expected effect of feedforward compensation.

[0071] As can be seen from the above, this embodiment effectively overcomes the response lag caused by the mechanical inertia of the fan, changing the feedforward compensation from a following type to a predictive type, thus improving the real-time performance of pressure control. Because the lead time adapts to the acceleration, it is more advanced when the robot arm is moving at high speed and less advanced at low speed, avoiding overcompensation or undercompensation caused by a fixed lead time.

[0072] Corresponding to the pressure regulation method in the above embodiments, Figure 3 This is a structural block diagram of a pressure regulating device provided according to an embodiment of this application. For ease of explanation, only the parts relevant to the embodiment of this application are shown. References Figure 3The pressure regulating device 20 is applied to the front-end module, which includes a transmission chamber and a robotic arm configured in the transmission chamber for wafer transfer. The front-end module includes: a differential pressure acquisition module 21, an initial command determination module 22, a status acquisition module 23, a disturbance prediction module 24, and a command correction module 25. Among them, the differential pressure acquisition module 21 is used to acquire the actual differential pressure value between the inside of the transmission chamber and the external environment; The initial command determination module 22 is used to determine the initial wind speed adjustment command based on the deviation between the actual pressure difference value and the target pressure difference value. The target pressure difference value is a fixed value that is preset and located within the micro-positive pressure range. The status acquisition module 23 is used to acquire motion status parameters of the robot arm when it moves in the transmission chamber. The motion status parameters include motion speed parameters and motion acceleration parameters. The disturbance prediction module 24 is used to predict the amount of pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the robot arm, based on the motion velocity parameters, motion acceleration parameters, and the internal volume of the transmission chamber. The instruction correction module 25 is used to correct the initial wind speed adjustment instruction based on the pressure difference disturbance to obtain the target wind speed adjustment instruction; the target wind speed adjustment instruction is used to control the fan speed inside the transmission chamber so that the pressure value inside the transmission chamber is kept within the slightly positive pressure range.

[0073] In one embodiment of this application, the disturbance prediction module 24 is specifically used for: The current pose of the robot is determined based on the motion state parameters, and the equivalent windward area corresponding to the current pose is obtained from the preset mapping table. The preset mapping table contains the mapping relationship between pose and windward area. The instantaneous volumetric flow rate caused by the movement of the manipulator is calculated based on the product of the motion speed parameter and the equivalent windward area. The rate of change of instantaneous volumetric flow rate is calculated based on the motion acceleration parameters, and then the rate of change is superimposed with the instantaneous volumetric flow rate according to the first formula to obtain the target volumetric flow rate. The pressure difference disturbance is calculated based on the rate of change of the target volumetric flow rate, the internal volume, and the gas density within the transmission chamber. The first formula is: ; in, Indicates the target volumetric flow rate. Indicates instantaneous volumetric flow rate. Indicates the inertial compensation time constant. It represents the rate of change of instantaneous volumetric flow rate.

[0074] In one embodiment of this application, the initial wind speed adjustment command carries the fan's base speed, and the command correction module 25 is specifically used for: Obtain the three-dimensional motion direction vector of the robotic arm within the current control cycle; The normal velocity is obtained by projecting the three-dimensional motion direction vector onto the normal vector of the equivalent windward surface of the manipulator. The instantaneous volume change rate of the gas displaced by the manipulator is calculated based on the product of the normal velocity and the equivalent frontal area. The feedforward speed compensation is calculated based on the instantaneous volume change rate and the preset fan flow calibration coefficient. Based on the pressure difference disturbance, internal volume, and fan flow calibration coefficient, calculate the speed correction amount, and add the speed correction amount to the feedforward speed compensation amount to obtain the corrected feedforward speed compensation amount. The target fan speed is obtained by superimposing the base speed with the corrected feedforward speed compensation. Replace the base speed with the target speed and add it to the initial wind speed adjustment command as the target wind speed adjustment command.

[0075] In one embodiment of this application, the differential pressure acquisition module 21 is specifically used for: Acquire the raw internal pressure signal collected by the pressure sensor located inside the transmission chamber, and acquire the raw external pressure signal collected by the pressure sensor located outside the transmission chamber; Obtain the current motion state identifier of the robot arm, which is used to indicate whether the robot arm is currently in motion or stationary. When the motion status indicator indicates that the robot is currently in motion, the original internal pressure signal is low-pass filtered using the first cutoff frequency to obtain the internal filtered pressure signal. The first cutoff frequency is used to filter out the high-frequency pneumatic noise generated by the robot's movement. When the motion status indicator indicates that the robot is currently in a stationary state, the original internal pressure signal is low-pass filtered using the second cutoff frequency to obtain the internal filtered pressure signal. The second cutoff frequency is greater than the first cutoff frequency. The original external pressure signal is filtered by moving average to obtain a smooth external pressure signal, so as to filter out the low-frequency pulsation caused by the airflow in the external environment. Calculate the difference between the internal filtered pressure signal and the external smoothed pressure signal, and use the difference as the actual pressure difference value.

[0076] In one embodiment of this application, the instruction correction module 25 is further configured to: Obtain the equivalent crosswind area corresponding to the current pose from the preset mapping table; The three-dimensional motion direction vector is decomposed into a vertical velocity component perpendicular to the bottom surface of the transmission chamber and a horizontal velocity component parallel to the bottom surface of the transmission chamber; the vertical velocity component includes the vertical velocity amplitude and the vertical direction polarity value, and the horizontal velocity component includes the horizontal velocity amplitude. When the vertical velocity amplitude is greater than the preset vertical threshold, the product of the vertical velocity amplitude and the equivalent windward area is used as the vertical volume change rate; the preset first compensation gain, the vertical volume change rate and the vertical polarity value are multiplied together to obtain the vertical feedforward compensation amount. When the horizontal velocity amplitude is greater than the preset horizontal threshold, the product of the horizontal velocity amplitude and the equivalent crosswind area is used as the horizontal volume change rate; the preset second compensation gain is multiplied by the horizontal volume change rate to obtain the horizontal feedforward compensation amount, and the first compensation gain is greater than the second compensation gain. Add the vertical feedforward compensation amount to the horizontal feedforward compensation amount, and multiply the sum by the fan flow rate calibration coefficient to obtain the feedforward speed compensation amount.

[0077] In one embodiment of this application, the pressure regulating device 20 further includes: a correction module, used for: Obtain the fan's step response delay time, which is the time required from issuing the speed command to the fan's actual speed reaching the target value preset ratio; Calculate the feedforward advance based on the motion acceleration parameters and the step response delay time; The timing of the target wind speed adjustment command is advanced by a feedforward amount to compensate for the mechanical response delay of the fan.

[0078] In one embodiment of this application, the correction module is specifically used for: Obtain the current acceleration value of the robotic arm within the current control cycle; Based on the absolute value of the current acceleration, the corresponding adjustment coefficient is retrieved from the preset acceleration-coefficient mapping table; and the step response delay time is multiplied by the adjustment coefficient to obtain the initial advance time. If the initial lead time is greater than the preset maximum lead time, the maximum lead time will be used as the feedforward lead time; otherwise, the initial lead time will be used as the feedforward lead time. The maximum advance time is determined based on the shortest remaining time from the current moment to the end of the current movement of the robot arm, and the maximum advance time is less than the shortest remaining time.

[0079] See Figure 4 , Figure 4 This is a schematic block diagram of a front-end module provided in one embodiment of this application. Figure 4The front-end module 300 in this embodiment may include one or more processors 301, one or more input devices 302, one or more output devices 303, and one or more memories 304. The processors 301, input devices 302, output devices 303, and memories 304 communicate with each other via a communication bus 305. The memories 304 store computer programs, including program instructions. The processors 301 execute the program instructions stored in the memories 304. Specifically, the processors 301 are configured to invoke the program instructions to perform the functions of the modules in the above-described device embodiments, for example... Figure 3 The functions of the differential pressure acquisition module 21, initial command determination module 22, status acquisition module 23, disturbance prediction module 24, and command correction module 25 are shown.

[0080] It should be understood that, in the embodiments of this application, the processor 301 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0081] Input device 302 may include a touchpad, a fingerprint sensor (for collecting the user's fingerprint information and fingerprint orientation information), a microphone, etc., and output device 303 may include a display (LCD, etc.), a speaker, etc.

[0082] The memory 304 may include read-only memory and random access memory, and provides instructions and data to the processor 301. A portion of the memory 304 may also include non-volatile random access memory. For example, the memory 304 may also store information such as a preset mapping table.

[0083] In specific implementations, the processor 301, input device 302, and output device 303 described in the embodiments of this application can execute the implementation method described in the pressure regulation method provided in the embodiments of this application, or they can execute the implementation method of the front-end module described in the embodiments of this application, which will not be repeated here.

[0084] In another embodiment of this application, a computer-readable storage medium is provided. This computer-readable storage medium stores a computer program, which includes program instructions. When executed by a processor, the program instructions implement all or part of the processes in the methods described above. Alternatively, the computer program can instruct related hardware to complete the process. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0085] The computer-readable storage medium can be an internal storage unit of the front-end module in any of the foregoing embodiments, such as the hard disk or memory of the front-end module. The computer-readable storage medium can also be an external storage device of the front-end module, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the front-end module. Furthermore, the computer-readable storage medium can include both internal storage units and external storage devices of the front-end module. The computer-readable storage medium is used to store computer programs and other programs and data required by the front-end module. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0086] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0087] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the front-end modules and units described above can be referred to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0088] In the several embodiments provided in this application, it should be understood that the disclosed front-end modules and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces or units, or it may be an electrical, mechanical, or other form of connection.

[0089] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0090] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0091] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A pressure regulation method, executed by a front-end module, the front-end module including a transfer chamber, wherein a robotic arm is disposed within the transfer chamber for wafer transfer, characterized in that, include: Obtain the actual pressure difference between the inside of the transmission chamber and the external environment; The initial wind speed adjustment command is determined based on the deviation between the actual pressure difference value and the target pressure difference value, wherein the target pressure difference value is a fixed value that is preset and located within the range of slight positive pressure. The motion state parameters of the robotic arm as it moves within the transmission chamber are obtained, including motion velocity parameters and motion acceleration parameters. Based on the motion speed parameters, the motion acceleration parameters, and the internal volume of the transmission chamber, the pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the robotic arm is predicted. The initial wind speed adjustment command is corrected based on the pressure difference disturbance to obtain the target wind speed adjustment command; the target wind speed adjustment command is used to control the fan speed inside the transmission chamber so that the pressure value inside the transmission chamber is maintained within the micro-positive pressure range. The method of predicting the pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the robotic arm, based on the motion velocity parameters, the motion acceleration parameters, and the internal volume of the transmission chamber, includes: The current pose of the robot is determined based on the motion state parameters, and the equivalent windward area corresponding to the current pose is obtained from a preset mapping table. The preset mapping table contains the mapping relationship between pose and windward area. The instantaneous volumetric flow rate caused by the movement of the robotic arm is calculated based on the product of the motion speed parameter and the equivalent windward area. The rate of change of the instantaneous volumetric flow rate is calculated based on the motion acceleration parameters, and the rate of change is superimposed on the instantaneous volumetric flow rate according to the first formula to obtain the target volumetric flow rate; The pressure difference disturbance is calculated using a piston effect model based on the rate of change of the target volume flow rate, the internal volume, and the gas density within the transmission chamber. The first formula is: ； in, Indicates the target volumetric flow rate. Indicates instantaneous volumetric flow rate. Indicates the inertial compensation time constant. It represents the rate of change of instantaneous volumetric flow rate.

2. The pressure regulation method as described in claim 1, characterized in that, The initial wind speed adjustment command carries the fan's base speed. The step of correcting the initial wind speed adjustment command based on the pressure difference disturbance to obtain the target wind speed adjustment command includes: Obtain the three-dimensional motion direction vector of the robotic arm within the current control cycle; The three-dimensional motion direction vector is projected onto the normal vector of the equivalent windward surface of the manipulator to obtain the normal motion velocity; The instantaneous volume change rate of the gas displaced by the manipulator is calculated based on the product of the normal motion velocity and the equivalent windward area. The feedforward speed compensation is calculated based on the instantaneous volume change rate and the preset fan flow calibration coefficient. Based on the pressure difference disturbance, the internal volume, and the fan flow calibration coefficient, the speed correction amount is calculated, and the speed correction amount is added to the feedforward speed compensation amount to obtain the corrected feedforward speed compensation amount. The target fan speed is obtained by superimposing the base speed with the corrected feedforward speed compensation. The target rotational speed is added to the initial wind speed adjustment command, replacing the base rotational speed, as the target wind speed adjustment command.

3. The pressure regulation method as described in claim 1, characterized in that, The step of obtaining the actual pressure difference between the inside of the transmission chamber and the external environment includes: Acquire the internal raw pressure signal collected by the pressure sensor located inside the transmission chamber, and acquire the external raw pressure signal collected by the pressure sensor located outside the transmission chamber; Obtain the current motion state identifier of the robotic arm, which is used to indicate whether the robotic arm is currently in motion or stationary. When the motion state indicator indicates that the robot is currently in motion, the original internal pressure signal is low-pass filtered using a first cutoff frequency to obtain an internal filtered pressure signal. The first cutoff frequency is used to filter out high-frequency pneumatic noise generated by the movement of the robot. When the motion state indicator indicates that the robot is currently in a stationary state, the original internal pressure signal is low-pass filtered using a second cutoff frequency to obtain an internal filtered pressure signal, wherein the second cutoff frequency is greater than the first cutoff frequency. The original external pressure signal is filtered by moving average to obtain a smooth external pressure signal, so as to filter out low-frequency pulsations caused by the airflow in the external environment. Calculate the difference between the internal filtered pressure signal and the external smoothed pressure signal, and use the difference as the actual pressure difference value.

4. The pressure regulation method as described in claim 2, characterized in that, The step of calculating the feedforward speed compensation based on the instantaneous volume change rate and the preset fan flow calibration coefficient includes: Obtain the equivalent crosswind area corresponding to the current pose from the preset mapping table; The three-dimensional motion direction vector is decomposed into a vertical velocity component perpendicular to the bottom surface of the transmission chamber and a horizontal velocity component parallel to the bottom surface of the transmission chamber; the vertical velocity component includes a vertical velocity amplitude and a vertical direction polarity value, and the horizontal velocity component includes a horizontal velocity amplitude. When the vertical velocity amplitude is greater than a preset vertical threshold, the product of the vertical velocity amplitude and the equivalent windward area is taken as the vertical volume change rate; the preset first compensation gain, the vertical volume change rate and the vertical direction polarity value are multiplied together to obtain the vertical feedforward compensation amount. When the horizontal velocity amplitude is greater than a preset horizontal threshold, the product of the horizontal velocity amplitude and the equivalent crosswind area is taken as the horizontal volume change rate; the preset second compensation gain is multiplied by the horizontal volume change rate to obtain the horizontal feedforward compensation amount, wherein the first compensation gain is greater than the second compensation gain. The vertical feedforward compensation amount is added to the horizontal feedforward compensation amount to obtain the directional compensation amount; the base speed compensation amount is determined according to the instantaneous volume change rate and the fan flow calibration coefficient, and the base speed compensation amount is superimposed with the directional compensation amount to obtain the feedforward speed compensation amount.

5. The pressure regulation method as described in claim 1, characterized in that, After correcting the initial wind speed adjustment command based on the pressure difference disturbance to obtain the target wind speed adjustment command, the method further includes: The step response delay time of the fan is obtained, which is the time required from the issuance of the speed command to the actual fan speed reaching the target value preset ratio; Calculate the feedforward advance based on the motion acceleration parameters and the step response delay time; The target wind speed adjustment command is issued earlier by the feedforward advance to compensate for the mechanical response delay of the fan.

6. The pressure regulation method as described in claim 5, characterized in that, The current acceleration value of the robotic arm is used as the motion acceleration parameter; The step of calculating the feedforward advance based on the motion acceleration parameters and the step response delay time includes: Based on the absolute value of the current acceleration, the corresponding adjustment coefficient is obtained from the preset acceleration-coefficient mapping table; the step response delay time is multiplied by the adjustment coefficient to obtain the initial advance time; If the initial advance time is greater than the preset maximum advance time, then the maximum advance time is used as the feedforward advance amount; otherwise, the initial advance time is used as the feedforward advance amount.

7. A pressure regulating device applied to a front-end module, the front-end module including a transfer chamber, wherein a robotic arm is disposed within the transfer chamber for wafer transfer, characterized in that... include: The differential pressure acquisition module is used to acquire the actual differential pressure value between the inside of the transmission chamber and the external environment; The initial command determination module is used to determine the initial wind speed adjustment command based on the deviation between the actual pressure difference value and the target pressure difference value, wherein the target pressure difference value is a preset fixed value within the range of slight positive pressure. The status acquisition module is used to acquire motion status parameters of the robot arm when it moves in the transmission chamber. The motion status parameters include motion speed parameters and motion acceleration parameters. The disturbance prediction module is used to predict the amount of pressure difference disturbance caused by the instantaneous airflow triggered by the movement of the manipulator, based on the motion speed parameters, the motion acceleration parameters, and the internal volume of the transmission chamber. The instruction correction module is used to correct the initial wind speed adjustment instruction based on the pressure difference disturbance to obtain a target wind speed adjustment instruction; the target wind speed adjustment instruction is used to control the fan speed inside the transmission chamber so that the pressure value inside the transmission chamber is maintained within the micro-positive pressure range. The disturbance prediction module is specifically used for: The current pose of the robot is determined based on the motion state parameters, and the equivalent windward area corresponding to the current pose is obtained from the preset mapping table. The preset mapping table contains the mapping relationship between pose and windward area. The instantaneous volumetric flow rate caused by the movement of the manipulator is calculated based on the product of the motion speed parameter and the equivalent windward area. The rate of change of instantaneous volumetric flow rate is calculated based on the motion acceleration parameters, and then the rate of change is superimposed with the instantaneous volumetric flow rate according to the first formula to obtain the target volumetric flow rate. The pressure difference disturbance is calculated using the piston effect model based on the rate of change of the target volumetric flow rate, the internal volume, and the gas density in the transmission chamber. The first formula is: ； in, Indicates the target volumetric flow rate. Indicates instantaneous volumetric flow rate. Indicates the inertial compensation time constant. It represents the rate of change of instantaneous volumetric flow rate.

8. A front-end module, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 6.

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