Dust-free control system for semiconductor ultra-trace analysis laboratory

Abstract

The invention discloses a semiconductor ultra-trace analysis laboratory dust-free control system, and belongs to the technical field of clean room control. The system comprises an environment sensing layer, a central control processing layer, an execution mechanism layer and an upper computer monitoring terminal. Aiming at the characteristics of fast exhaust air change and high cleanliness requirement of the semiconductor laboratory fume hood, a pressure control module based on chemical logic and clean logic fusion is designed, feedforward control is performed by detecting the height of a window, millisecond-level air supply compensation is realized, and polluted air is prevented from flowing backwards. Meanwhile, a matrix type fan filter unit visual energy-saving control module is introduced into the system, feedback of a particle counter is combined, and the running number of fans is dynamically adjusted through a checkerboard or quincuncial pile distribution model. According to the invention, the conflict between the exhaust safety and the cleanliness stability is effectively solved, the precise control and obvious energy saving of the laboratory environment are realized, and the method is suitable for the field of semiconductor analysis with extremely high environmental index requirements.

Description

Technical Field

[0001] This invention relates to the field of cleanroom environmental control technology, and in particular to a cleanroom control system for a semiconductor ultra-trace analysis laboratory. Background Technology

[0002] Semiconductor ultra-trace analysis laboratories are primarily used to detect extremely small amounts of metallic impurities in semiconductor materials and process chemicals. They have extremely stringent requirements for environmental cleanliness, typically requiring ISO Class 5 (Class 100) or even higher standards. Simultaneously, to ensure the safety of laboratory personnel when handling strong acids, strong alkalis, and volatile organic solvents, the laboratory must be equipped with multiple high-capacity fume hoods.

[0003] Existing laboratory control systems often face the technical challenge of control logic conflicts when dealing with high cleanliness and high exhaust volume requirements. Traditional control methods mostly employ a single feedback loop (PID control) based on differential pressure sensors, meaning the system only adjusts the fresh air volume to compensate when changes in fume hood exhaust volume cause fluctuations in indoor differential pressure. However, in semiconductor analysis experiments, the operation of pulling the fume hood window by researchers is often very rapid, causing drastic changes in exhaust volume within a short period. Due to the lag in feedback control, the laboratory is prone to instantaneous negative pressure, leading to the backflow of unclean air from the external corridor into the laboratory, contaminating ultra-trace analysis samples with background environmental contamination. Furthermore, to maintain high cleanliness, existing systems typically keep all fan filter units (FFUs) running at full capacity for extended periods, lacking a dynamic adjustment mechanism based on actual cleanliness requirements, resulting in significant energy waste and shortened HEPA filter replacement cycles.

[0004] Therefore, there is an urgent need for a laboratory cleanroom control system that can solve the dynamic balance between exhaust safety and environmental cleanliness, and can achieve refined energy-saving management. Summary of the Invention

[0005] The main objective of this invention is to provide a cleanroom control system for semiconductor ultra-trace analysis laboratories to solve the problems of lag in differential pressure control and excessive energy consumption of fan filter units in existing technologies when dealing with sudden changes in exhaust air from fume hoods.

[0006] The present invention adopts the following technical solution: A cleanroom control system for a semiconductor ultra-trace analysis laboratory comprises an environmental sensing layer, an actuator layer, a central control processing layer, and a host computer monitoring terminal. The environmental sensing layer collects various environmental parameters from inside and outside the laboratory, including micro-pressure difference, temperature and humidity, suspended particle concentration, and fume hood status data. The actuator layer regulates the laboratory's air supply volume, exhaust volume, and cleanliness level, primarily consisting of a fan filter unit array, fresh air handling units, exhaust variable air volume valves, and water-cooled unit pumps. The central control processing layer, as the core computing unit, connects to the environmental sensing layer and the actuator layer, executing control logic based on the collected parameters. The host computer monitoring terminal provides a visual human-machine interface. The central control processing layer integrates a pressure control module based on a fusion of chemical and cleanliness logic, and a visualized energy-saving control module for the matrix fan filter unit. The pressure control module automatically switches between chemical priority and cleanliness priority modes to coordinate fume hood exhaust demand with indoor pressure difference stability; the visualized energy-saving control module for the matrix fan filter unit dynamically adjusts the operating distribution model of the fan filter unit array according to cleanliness requirements.

[0007] As a preferred embodiment of the present invention, the pressure control module executes a feedforward control strategy in a chemical priority mode. When the window height sensor in the environmental perception layer detects a change in the height of the fume hood window, the central control processing layer does not wait for micro-pressure difference feedback, but directly calculates the expected exhaust volume increment based on the product of the window opening area and the set surface wind speed, and sends an instruction to the fresh air unit to increase the supply air volume before the micro-pressure difference value decreases.

[0008] As a preferred embodiment of the present invention, the pressure control module executes a feedback control strategy in a cleanliness-first mode. The central control processing layer uses the real-time measurement value of the micro-differential pressure sensor as the process variable and calculates the output through a proportional-integral-differential algorithm. This output simultaneously affects the overall speed adjustment of the fan filter unit array and the opening degree adjustment of the return air valve, thereby maintaining a slightly positive pressure state in the laboratory relative to the external area.

[0009] As a preferred embodiment of the present invention, the host computer monitoring terminal is equipped with an FFU array visualization interaction module. This module generates a rectangular array of graphic elements corresponding to the actual physical layout in the interface, with each graphic element logically mapping to a wind turbine filter unit with an independent address code. The system displays the operating status of the corresponding unit by changing the color of the graphic elements and allows maintenance personnel to perform single-point start / stop or speed adjustment operations on specific wind turbine filter units by clicking on the graphic elements.

[0010] As a preferred embodiment of the present invention, the matrix fan filter unit's visualized energy-saving control module possesses intelligent energy-saving logic. When the concentration of suspended particles collected by the online particle counter is lower than a set threshold, the algorithm automatically calculates the minimum airflow and minimum number of operating units required to maintain the target cleanliness level, and generates a specific activation scheme. This activation scheme includes a checkerboard distribution model or a staggered distribution model.

[0011] As a preferred embodiment of the present invention, under the checkerboard distribution model, the system controls the fan filter unit array to only activate units located in odd-numbered rows and odd-numbered columns or even-numbered rows and even-numbered columns; under the sparse distribution model, the system activates units according to a sparse distribution pattern. For units that are not activated, the central control processing layer controls them to enter an idling state or a stopped state to reduce energy consumption and prevent back pollution.

[0012] As a preferred embodiment of the present invention, the system further includes a precision water-cooled unit control module. The water-cooled unit pump set is equipped with a working pump, a standby pump, and a frequency converter. This module collects the pressure signal from the water supply pipeline and controls the speed of the working pump by adjusting the output frequency of the frequency converter to achieve constant pressure water supply, thereby meeting the stability requirements of the cooling water pressure for precision analytical instruments.

[0013] As a preferred embodiment of the present invention, the environmental sensing layer specifically includes a micro-differential pressure sensor installed between the laboratory and adjacent areas, an online particle counter arranged above the experimental operation area, and a face velocity sensor and a viewing window height sensor installed on the fume hood. The sampling flow rate of the online particle counter is set to 2.83 liters per minute or 1 cubic foot per minute. Each fan filtration unit consists of a variable speed fan, a high-efficiency air filter, and an address encoding module. The high-efficiency air filter is selected with a filtration efficiency of not less than 99.99% for particles of 0.3 micrometers.

[0014] As a preferred technical solution of the present invention, the host computer monitoring terminal is equipped with a data trend tracing module, which is used to automatically record and trace back the historical data curves of key parameters such as temperature, relative humidity, indoor and outdoor pressure difference and particle count, so as to facilitate environmental quality analysis and problem investigation.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a cleanroom control system for semiconductor ultra-trace analysis laboratories, which has the following advantages compared with the prior art: First, this invention addresses the pressure fluctuation problem caused by sudden changes in exhaust airflow from fume hoods by constructing a pressure control module based on the fusion of chemical and cleanroom logic, employing a feedforward control strategy. The system directly calculates the expected airflow change using a viewing window height sensor, instructing the fresh air unit to adjust its air supply before the pressure differential sensor reading changes, achieving a millisecond-level response speed. This control mechanism effectively prevents instantaneous pressure loss or negative pressure in the laboratory, eliminates the risk of backflow of contaminated external air, and ensures the accuracy of ultra-trace analysis data and the chemical safety of laboratory personnel.

[0016] Secondly, this invention introduces a visualized energy-saving control module for matrix-type fan filter units. By establishing a mapping between physical devices and virtual primitives, it achieves single-point addressing and batch control of high-density fan filter unit arrays. Combined with real-time feedback from an online particle counter, the system can dynamically adjust the number and position of operating units using a checkerboard or staggered distribution model, achieving on-demand cleaning. While ensuring cleanliness standards are met, this control strategy can reduce the energy consumption of the fan filter unit array by approximately 30% and significantly extend the service life of high-efficiency air filters.

[0017] Third, this invention integrates a precision water-cooled unit control module. Targeting the sensitivity of precision analytical instruments to cooling water parameters, it adopts variable frequency constant pressure control logic to control the fluctuation of cooling water pressure supplied to the instrument within a very small range, eliminating instrument reading drift caused by water pressure fluctuations and further ensuring the accuracy of experimental analysis. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall architecture of the cleanroom control system for a semiconductor ultra-trace analysis laboratory according to a preferred embodiment of the present invention; Figure 2 This is a flowchart of the pressure control logic based on the fusion of chemical logic and cleanliness logic in a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the interface of the FFU array visualization interaction module of the host computer monitoring terminal in a preferred embodiment of the present invention.

[0019] Explanation of reference numerals in the attached diagram: 100, Environmental sensing layer; 110, Micro-differential pressure sensor; 120, Temperature and humidity sensor; 130, Online particle counter; 140, Duct air velocity sensor; 150, Chemical gas leak detector; 200, Central control processing layer; 300, Actuator layer; 310, Fan filter unit array; 311, Variable speed fan; 312, High-efficiency air filter; 313, Address encoding module; 320, Fresh air handling unit; 330, Exhaust air variable volume valve; 340, Water-cooled unit pump set; 341. Working pump; 342, Standby pump; 343, Water tank; 344, Pressure sensor; 345, Liquid level sensor; 346, Supply and return water temperature difference sensor; 350, Return air valve; 400, Host computer monitoring terminal; 410, FFU array visualization interaction module; 420, Water cooling system monitoring module; 430, Global status display module; 440, Data trend tracing module; 450, Abnormal alarm management module; 500, Fume hood; 510, Face velocity sensor; 520, Viewing window height sensor. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] The cleanroom control system for semiconductor ultra-trace analysis laboratories provided by this invention comprises an environmental sensing layer 100, a central control processing layer 200, an actuator layer 300, and a host computer monitoring terminal 400. The environmental sensing layer 100 collects various environmental parameters inside and outside the laboratory. The central control processing layer 200 executes corresponding control logic based on the collected parameters. The actuator layer 300 performs actual environmental adjustments according to control commands. The host computer monitoring terminal 400 provides maintenance personnel with a visual human-computer interaction method.

[0022] The environmental sensing layer 100 is specifically configured with a micro differential pressure sensor 110, a temperature and humidity sensor 120, an online particle counter 130, a duct air velocity sensor 140, and a chemical gas leak detector 150. The micro differential pressure sensor 110 is installed in the wall or door frame between the laboratory and adjacent areas to monitor the pressure difference between the laboratory and the corridor or buffer room in real time. Its range should be selected between -50 Pascals and +50 Pascals, with a resolution of not less than 0.1 Pascals. The temperature and humidity sensor 120 is placed in a representative location within the laboratory, avoiding direct exposure to air vents and heat sources, to obtain temperature and humidity data that reflects the overall indoor conditions. The online particle counter 130 is selected to simultaneously detect particles with diameters of 0.3 micrometers and larger than 0.5 micrometers. Its sampling point is located above the experimental operating area or near key instruments, and the sampling flow rate is typically set to 2.83 liters per minute or 1 cubic foot per minute. The duct velocity sensor 140 is installed at an appropriate cross-section in the fresh air duct, exhaust air duct, and return air duct to monitor the real-time airflow of each duct. The chemical gas leak detector 150 is configured according to the types of chemicals used in the laboratory. For example, a hydrogen chloride detector can be configured for hydrochloric acid volatilization, and a nitrogen oxide detector can be configured for nitric acid volatilization. The detector is placed near the exhaust vent of the fume hood and in areas where leaks may occur indoors.

[0023] The actuator layer 300 includes a fan filter unit array 310, a fresh air handling unit 320, an exhaust variable air volume valve 330, and a water-cooled unit pump set 340. The fan filter unit array 310 is installed below the static pressure box on the laboratory ceiling. Each fan filter unit consists of a variable speed fan 311 and a high-efficiency air filter 312. The high-efficiency air filter 312 can be selected according to the cleanliness level requirements, using an ultra-low penetration rate air filter with a filtration efficiency of not less than 99.99% for 0.3-micron particles or a higher level. In this embodiment, each fan filter unit is equipped with an independent address encoding module 313, which is connected to the central control processing layer 200 via a communication bus, enabling the controller to individually address, read the status of, and issue control commands to each fan filter unit. The fresh air handling unit 320 provides the laboratory with clean fresh air that has undergone primary filtration, secondary filtration, and temperature and humidity control. Its fan uses a variable frequency drive, allowing continuous adjustment of the air volume within a set range according to control commands. The exhaust variable air volume valve 330 is installed on the exhaust branch pipe of the fume hood 500. Each fume hood 500 corresponds to one exhaust variable air volume valve 330. After receiving the controller signal, the valve actuator can adjust within the range of zero to 100% opening, with a response time of no more than three seconds. The water-cooled unit pump set 340 is used to provide constant temperature and pressure circulating cooling water to precision analytical instruments that are sensitive to cooling water temperature. The water-cooled unit pump set 340 adopts a one-in-one standby configuration, with automatic switching logic set between the working pump 341 and the standby pump 342.

[0024] The central control processing layer 200 uses a programmable logic controller (PLC) or a direct digital controller (DDC) as its core computing unit, and its core control logic is embedded internally. The central control processing layer 200 receives signals from various sensors through analog input modules, performs internal algorithm calculations, and then sends control commands to the actuator layer 300 through analog output modules or digital output modules. The central control processing layer 200 exchanges data with the host computer monitoring terminal 400 via industrial Ethernet or fieldbus.

[0025] The core control logic of this invention includes a pressure control module based on the integration of chemical logic and cleanliness logic, a matrix fan filter unit visualization energy-saving control module, and a precision water-cooled unit control module.

[0026] Regarding the pressure control module based on the integration of chemical and cleanroom logic, the system has two preset switchable interlocking operation modes. The first is the chemical priority mode, also known as the safety mode, in which the system prioritizes chemical safety exhaust. The fume hood 500 is equipped with a face velocity sensor 510. When the face velocity sensor 510 detects a sudden increase in exhaust demand, such as when a laboratory worker pulls up the fume hood window, increasing the opening area, the output signal of the face velocity sensor 510 changes accordingly. Upon recognizing this change, the central control processing layer 200 immediately prioritizes adjusting the opening of the corresponding fume hood 500's exhaust variable air volume valve 330, ensuring the exhaust volume quickly follows the change in opening area to maintain the set face velocity value, typically between 0.3 m / s and 0.5 m / s. Simultaneously, the central control processing layer 200, with a millisecond-level response time, activates the inverter of the fresh air handling unit 320, instructing it to increase the supply air volume to compensate for the increased exhaust volume, preventing a sudden pressure loss and backflow of external contaminated air into the laboratory due to a sudden increase in exhaust volume. In this embodiment, the central control processing layer 200 employs a feedforward control strategy to achieve the aforementioned linkage. Specifically, the fume hood 500 is also equipped with a window height sensor 520. When the window height sensor 520 detects a window opening signal, the central control processing layer 200 does not wait for the differential pressure value fed back by the micro differential pressure sensor 110 to decrease. Instead, it directly calculates the expected increase in exhaust volume based on the window opening and issues an instruction to the fresh air unit 320 to increase the supply air volume in advance. The calculation of this feedforward amount is based on the product relationship between the fume hood opening area and the set surface wind speed. Through the combination of feedforward control and feedback control, the pressure fluctuation in the laboratory can be controlled within ±1 Pascal.

[0027] The second mode is the cleanliness-first mode, also known as the working mode. This mode is suitable for normal working conditions where exhaust demand is relatively stable. In this mode, the opening of the exhaust variable air volume valve 330 is already stable, and the main task of the central control processing layer 200 is to maintain a slight positive pressure in the laboratory relative to the corridor through fine adjustment. The central control processing layer 200 internally runs a proportional-integral-derivative algorithm, using the real-time measurement value of the micro-differential pressure sensor 110 as the process variable and the set differential pressure value as the target value. The differential pressure set value is usually between ±5 Pascal and ±10 Pascal. The central control processing layer 200 calculates the output based on the deviation. This output simultaneously acts on the overall speed adjustment of the fan filter unit array 310 and the opening adjustment of the return air valve 350. When the measured differential pressure is lower than the set value, the central control processing layer 200 instructs the fan filter unit array 310 to increase its speed or instructs the return air valve 350 to decrease its opening to increase the indoor positive pressure; conversely, it decreases the speed of the fan filter unit array 310 or increases the opening of the return air valve 350. The parameters of the proportional-integral-derivative (PID) algorithm are tuned based on the actual volume of the laboratory space and the response characteristics of the air supply and exhaust system to achieve fast, stable, and overshoot-free control. Maintaining a slight positive pressure aims to prevent air from the corridor or adjacent areas from carrying contaminants such as metal ions into the laboratory, which could interfere with the accuracy of ultra-trace analysis.

[0028] An automatic switching logic is implemented between the chemical priority mode and the cleanliness priority mode. When the face velocity sensor 510 of any fume hood 500 detects a change in exhaust demand exceeding a set threshold, the system automatically switches to chemical priority mode; when the exhaust demand of all fume hoods 500 returns to stability for a duration exceeding a set delay, the system automatically switches back to cleanliness priority mode. The switching process between the two modes is smooth, avoiding drastic movements of the actuators.

[0029] Regarding the matrix fan filter unit visualization energy-saving control module, as shown in the figure, this embodiment configures an FFU array visualization interaction module 410 on the host computer monitoring terminal 400. This module establishes a virtual mapping that corresponds one-to-one with the physical space. Each fan filter unit on the ceiling is configured with an independent address code through the address encoding module 313. This encoding information is stored in the communication module built into the fan filter unit or in the configuration database of the central control processing layer 200. On the display screen generated by the FFU array visualization interaction module 410, several rectangular elements are arranged in an array according to the actual physical layout. Each element logically corresponds to an actually installed fan filter unit node. The FFU array visualization interaction module 410 changes the element color according to the received status data: green indicates that the unit is operating normally, gray indicates that the unit is in a stopped state, and red indicates that the unit has malfunctioned and requires maintenance personnel attention. Maintenance personnel can directly click on specific elements in the interface of the FFU array visualization interaction module 410 through the input device of the host computer monitoring terminal 400 to perform start, stop or speed adjustment operations on the fan filter unit. They can also select multiple fan filter units by box selection to perform batch operations.

[0030] The central control processing layer 200 operates an energy-saving algorithm for the fan filter unit array 310. The core idea of ​​this algorithm is on-demand cleanliness, dynamically adjusting the number and speed of the fan filter units based on the actual cleanliness requirements of the laboratory, rather than using a crude control method of turning all units on or off. When the laboratory is in duty mode or instrument standby mode, the central control processing layer 200 reads real-time measurement data from the online particle counter 130. If the number of particles larger than 0.5 micrometers per cubic foot of space is lower than a set threshold—for example, this threshold can be set to 350 in an area requiring Class 100 cleanliness, and can be relaxed accordingly in an area requiring Class 100 cleanliness—the central control processing layer 200 determines that there is a margin in the current cleanliness level and immediately activates the energy-saving operation strategy.

[0031] The energy-saving algorithm automatically calculates the minimum air supply volume required to maintain the target cleanliness level at the current pollutant generation rate, and determines the minimum number of fan filter units that need to be kept running accordingly. After determining the minimum number of operating units, the algorithm further generates a specific activation scheme. This scheme follows the principle of uniform spatial coverage to avoid uneven cleanliness distribution due to lack of air supply in local areas. This embodiment provides two typical interval operation models for selection. The first is a checkerboard distribution model, in which the fan filter units located in odd-numbered rows and odd-numbered columns or even-numbered rows and even-numbered columns are activated according to the black and white square distribution pattern of a chessboard in the FFU array visualization interaction module 410, while the remaining units are deactivated. Under this model, the number of operating units is approximately 50% of the total. The second is a sparse distribution model, in which the positions of the activated units are determined according to a sparse distribution pattern similar to cloverleaf piles in the FFU array visualization interaction module 410. Under this model, the number of operating units can be further reduced. The central control processing layer 200 dynamically selects the appropriate model based on the feedback from the online particle counter 130. When the cleanliness margin is large, a model with fewer running units is selected. When the cleanliness is close to the threshold, the model with more running units is switched to or all units are restored.

[0032] For fan filter units that are stopped, the central control processing layer 200 can choose to completely cut off their power supply or reduce the speed of the variable speed fan 311 to idle speed. The advantages of idling are that the fan bearings remain lubricated, the HEPA filter 312 maintains a slight positive pressure to prevent backflow, and the response is faster when a quick return to full operation is needed. The central control processing layer 200 also records the cumulative operating time of each fan filter unit. When the operating time of a unit approaches the replacement cycle of the HEPA filter 312, a notification is displayed on the host computer monitoring terminal 400, facilitating maintenance personnel to develop a replacement plan.

[0033] By employing a matrix-style single-point control strategy, the overall energy consumption of the fan filter unit array 310 can be reduced by more than 30% compared to the traditional full-operation mode. At the same time, since some units are in a stopped or idling state, the overall service life of the high-efficiency air filter 312 is extended, reducing the cost of consumable replacement.

[0034] Regarding the precision water-cooled unit control module, this embodiment addresses the extreme sensitivity of ultra-trace analyzers to cooling water temperature and pressure by integrating the water-cooled unit pump group 340 into a unified control system for management. As shown in the figure, the host computer monitoring terminal 400 runs a water-cooling system monitoring module 420, which displays the real-time operating status of the working pump 341 and the standby pump 342, the liquid level in the water tank 343, and the pressure difference between the supply and return water pipelines. Under normal operating conditions, the working pump 341 operates while the standby pump 342 is on standby. When the working pump 341 malfunctions or its outlet pressure falls below the set value, the central control processing layer 200 automatically switches to the standby pump 342 and issues an alarm message.

[0035] Both the working pump 341 and the standby pump 342 are equipped with frequency converters for their drive motors. The central control processing layer 200 regulates the pump speed and thus the water supply pressure by adjusting the output frequency of the frequency converters. The central control processing layer 200 collects signals from the pressure sensor 344 on the water supply pipeline and uses constant pressure water supply as the control target. When the water supply pressure is lower than the set value, the pump speed is increased; when the water supply pressure is higher than the set value, the pump speed is decreased. The set value of the water supply pressure is determined according to the requirements of the connected precision instruments, typically between 0.2 MPa and 0.4 MPa. Through frequency conversion constant pressure control, the fluctuation of the cooling water pressure supplied to the precision instruments can be controlled within a very small range, avoiding reading drift caused by changes in the internal flow rate of the instruments due to pressure fluctuations.

[0036] Water tank 343 is equipped with a level sensor 345 to monitor the water level in the cooling water system. When the level is below the lower limit, the central control processing layer 200 issues a water replenishment command or alarm message; when the level is above the upper limit, the water replenishment valve is closed. Supply and return water temperature difference sensor 346 monitors the amount of heat carried away by the cooling water. If the temperature difference is abnormally large, it may indicate insufficient water flow or abnormal instrument overheating, and the central control processing layer 200 will issue corresponding prompts or alarms accordingly.

[0037] Regarding the overall design of the host computer monitoring terminal 400, it is implemented using an industrial touch screen or industrial control computer running configuration software. Its software architecture includes a global status display module 430, which is configured to generate a system overview interface. Against the backdrop of the laboratory's floor plan, it overlays and displays the flow direction of each air path (fresh air, supply air, return air, exhaust air) and real-time values ​​of key parameters, including airflow or velocity, indoor temperature, indoor relative humidity, and indoor-outdoor pressure difference. Maintenance personnel can easily grasp the overall operating status of the laboratory environmental control system through the global status display module 430.

[0038] The FFU array visualization interaction module 410 is an independent functional unit, and its layout and functions have been described in detail above. This module supports operations such as zooming in and out, panning, and roaming, which facilitates viewing and operation when there are a large number of wind turbine filter units.

[0039] The data trend tracing module 440 is used to process and trace historical data. The system automatically records historical change curves of key parameters such as temperature, relative humidity, indoor and outdoor pressure difference, and particle count values ​​measured by the online particle counter 130. The recording period can be configured to once per minute or higher, and the storage duration can be configured from several weeks to several months depending on the storage space. When it is necessary to trace the experimental environment quality for a certain period of time, maintenance personnel can use the data trend tracing module 440 to call up the corresponding time range to view historical curves, and can also export the data for report preparation or problem analysis.

[0040] The anomaly alarm management module 450 is used to centrally process current alarm information and historical alarm records. Alarm information includes alarm occurrence time, alarm location name, alarm type and alarm value, etc., which makes it easier for operation and maintenance personnel to discover and handle abnormal situations in a timely manner.

[0041] The control system of this invention can be adaptively configured according to the specific conditions of the laboratory in practical applications. For laboratories with a small area and a limited number of fan filter units, the effect of matrix-style energy-saving control is relatively limited, and it can be simplified to zone control or overall speed regulation control. For large laboratories with multiple independent rooms, a distributed control architecture can be adopted, with each room equipped with an independent area controller. Each area controller communicates with the central control processing layer 200 through a network, realizing a combination of centralized monitoring and distributed control. The selection and number of sensors can be adjusted according to the cleanliness level requirements and control accuracy requirements of the laboratory. For critical areas with extremely high cleanliness requirements, the sensor density can be increased.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cleanroom control system for a semiconductor ultra-trace analysis laboratory, characterized in that, include: An environmental sensing layer is used to collect environmental parameters inside and outside the laboratory. These environmental parameters include at least micro-pressure difference, temperature and humidity, suspended particle concentration and fume hood status data. The actuator layer is used to regulate the air supply volume, exhaust volume, and cleanliness of the laboratory. The actuator layer includes a fan filter unit array, a fresh air unit, an exhaust variable air volume valve, and a water-cooled unit pump set. The central control processing layer, connected to the environmental perception layer and the actuator layer, is used to execute control logic and issue control commands based on the collected environmental parameters. as well as The host computer monitoring terminal is used to provide a visual human-computer interaction interface; The central control processing layer is equipped with a pressure control module based on the fusion of chemical logic and clean logic, as well as a matrix fan filter unit visual energy-saving control module. The pressure control module is configured to switch between a chemical priority mode and a cleanliness priority mode to coordinate the exhaust demand of the fume hood with the stability of the indoor pressure difference; the matrix fan filter unit visualization energy-saving control module is configured to dynamically adjust the operation distribution model of the fan filter unit array according to the cleanliness requirements.

2. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, The pressure control module executes a feedforward control strategy in the chemical priority mode: when the environmental sensing layer detects a change in the height of the fume hood window, the central control processing layer calculates the expected exhaust volume increment based on the product of the window opening area and the set surface wind speed, and sends an instruction to the fresh air unit to increase the supply air volume before the micro pressure difference value changes.

3. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, The pressure control module executes a feedback control strategy in cleanliness priority mode: the central control processing layer uses the real-time measurement value of the micro-pressure difference as the process variable, and calculates the output through a proportional-integral-differential algorithm. The output simultaneously acts on the overall speed adjustment of the fan filter unit array and the opening adjustment of the return air valve to maintain a slight positive pressure in the laboratory relative to the external area.

4. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, The host computer monitoring terminal is equipped with an FFU array visualization interaction module. The interface of this module contains a rectangular array of graphic elements corresponding to the actual physical layout. Each graphic element maps to a fan filter unit with an independent address code. The visualization interaction module is configured to display the operating status of the corresponding unit by changing the color of the graphic element, and supports single-point start / stop or speed control of a specific fan filter unit by clicking on the graphic element.

5. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 4, characterized in that, The matrix fan filter unit visualization energy-saving control module is configured to automatically calculate the minimum air volume and minimum number of operating units required to maintain the target cleanliness level when the concentration of suspended particles collected by the environmental sensing layer is lower than the set threshold, and generate an activation scheme; the activation scheme includes a checkerboard distribution model or a plum blossom pile distribution model.

6. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 5, characterized in that, The checkerboard distribution model controls the fan filter unit array to only activate units located in odd-numbered rows and columns or even-numbered rows and columns; the plum blossom pile distribution model controls the fan filter unit array to activate units according to a sparse distribution pattern; for units that are not activated, the central control processing layer controls them to enter an idle running state or a stopped state.

7. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, The central control processing layer is also equipped with a precision water-cooled unit control module. The water-cooled unit pump group includes a working pump, a standby pump, and a frequency converter. The precision water-cooled unit control module collects the pressure signal of the water supply pipeline and controls the speed of the working pump by adjusting the output frequency of the frequency converter to maintain a constant water supply pressure.

8. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, The environmental sensing layer includes a micro differential pressure sensor installed between the laboratory and the adjacent area, an online particle counter arranged above the experimental operation area, and a face velocity sensor and a viewing window height sensor installed on the fume hood; the sampling flow rate of the online particle counter is set to 2.83 liters per minute or 1 cubic foot per minute.

9. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, Each of the aforementioned fan filtration units consists of a variable speed fan, a high-efficiency air filter, and an address encoding module. The address encoding module is connected to the central control processing layer via a communication bus. The high-efficiency air filter is an ultra-low penetration air filter with a filtration efficiency of not less than 99.99% for particles of 0.3 micrometers.

10. The cleanroom control system for semiconductor ultra-trace analysis laboratory according to claim 1, characterized in that, The host computer monitoring terminal is equipped with a data trend tracing module, which is used to record and trace back historical data curves including temperature, relative humidity, indoor and outdoor pressure difference and particle count values. The recording period is configurable and the storage time is from several weeks to several months.

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