Key Points in the Construction of Refrigeration System for Wafer Dust - free Workshop
2024.10.28
In the field of semiconductor manufacturing, the environmental control of the wafer dust - free workshop is of crucial importance. As the key facility for maintaining the constant - temperature and constant - humidity environment in the workshop, the construction of the refrigeration system has many key points that need to be strictly controlled. Today, Guangzhou Kunling Purification Equipment Co., Ltd. will analyze in detail the key points in the construction of the refrigeration system for the wafer dust - free workshop for you.
1. Precise Load Calculation
During the wafer production process, a large amount of heat is generated by numerous equipment, and the environmental temperature requirements are extremely strict. Therefore, before the construction of the refrigeration system, precise load calculation must be carried out. This should not only consider conventional factors such as heat dissipation of equipment, heat dissipation of lighting, and heat dissipation of personnel, but also pay special attention to the special heat dissipation requirements of wafer production equipment. For example, high - end equipment such as lithography machines and etching machines will release a large amount of heat during operation, and the heat dissipation distribution may be uneven. We need to accurately calculate the total cooling load of the workshop through detailed analysis of equipment parameters and on - site investigations, using professional heat load calculation software, so as to provide a scientific basis for the selection and configuration of the refrigeration system.
2. Efficient Selection of Refrigeration Equipment
2.1 Chiller
- For wafer dust - free workshops, centrifugal chillers and screw chillers are common choices. Centrifugal chillers have the advantages of large cooling capacity and high energy - efficiency ratio, which are suitable for the centralized cooling requirements of large - scale wafer factories. However, they have high requirements for operating conditions and large starting current. Screw chillers have the characteristics of compact structure, stable operation, and good part - load performance, and are suitable for medium - to - large - scale workshops or scenarios with flexible load - regulation requirements. When selecting, comprehensive considerations should be made based on the actual cooling capacity requirements, operation stability requirements, and energy efficiency of the workshop.
- At the same time, the selection of refrigerant for the chiller is also crucial. Currently, environmentally - friendly refrigerants such as R134a and R410A have gradually become the mainstream. They not only cause little damage to the ozone layer but also meet the requirements of environmental protection regulations. When selecting a refrigerant, its cooling performance, safety, and compatibility with the chiller system should also be considered.
2.2 Precision Air Conditioner
- Each area of the wafer dust - free workshop, such as the production area, equipment room, and storage area, needs to be equipped with a precision air conditioner to maintain precise temperature and humidity control. The precision air conditioner should have high - precision temperature adjustment (generally controllable within ± 0.5 °C) and humidity adjustment (relative humidity controllable within ± 3%) capabilities, and at the same time, have good air - filtering function to ensure that the air cleanliness sent into the workshop meets the requirements.
- When selecting, appropriate cooling capacity and air supply volume should be selected according to the area, heat load, and air cleanliness requirements of different areas. In addition, the reliability and stability of the precision air conditioner are also key considerations. Products with high - quality compressors, fans, and control systems should be selected to ensure long - term uninterrupted operation.
3. Stable Water System Design
3.1 Circulating Water System
- The circulating water system in the refrigeration system includes the chilled water circulation system and the cooling water circulation system. The chilled water circulation system is responsible for transporting the low - temperature chilled water produced by the chiller to various terminal equipment (such as precision air conditioners, fan - coil units, etc.) in the workshop, absorbing heat, and then returning to the chiller for cooling treatment. The cooling water circulation system is used to cool the condenser of the chiller and take away the heat in the condenser.
- When designing the circulating water system, the pipe diameter, flow velocity, and resistance should be reasonably determined to ensure that the water flow meets the requirements of refrigeration equipment and terminals, while avoiding excessive pressure loss. The pipe material should be selected from high - quality corrosion - resistant and pressure - resistant materials, such as stainless - steel pipes or PPR pipes, and good insulation measures should be taken to reduce energy loss and pipe condensation.
- To ensure the stable operation of the water system, necessary water - treatment equipment, such as water - softening devices, filters, and dosing devices, also need to be set up. The water - softening device can remove impurities such as calcium and magnesium ions in the water to prevent scaling of pipes and equipment; the filter can filter suspended solids and impurities in the water to protect pumps and refrigeration equipment; the dosing device can add biocides, corrosion inhibitors, and other chemicals according to the water quality to extend the service life of the equipment and ensure the cleanliness and stability of the water system.
3.2 Water Storage Cooling System (Optional)
- For some wafer dust - free workshops with extremely high requirements for refrigeration stability or large differences in electricity load peaks and valleys, a water storage cooling system can be considered. The water storage cooling system uses the off - peak electricity price period at night to make ice or store cold, and releases cold during the peak electricity consumption period during the day, playing a role of "peak - shaving and valley - filling". It can not only reduce the operation cost but also improve the reliability and emergency response ability of the refrigeration system.
- When designing the water storage cooling system, parameters such as the capacity of the storage tank, the storage temperature, and the release rate of cold should be reasonably determined. At the same time, a perfect automatic control system should be equipped to ensure that the system can automatically switch operation modes according to the actual load demand of the workshop to achieve high - efficiency and energy - saving operation.
4. Strict Air Treatment and Filtration
Wafer dust - free workshops have extremely high requirements for air quality. Tiny particles in the air can have a serious impact on wafer production. Therefore, during the operation of the refrigeration system, it must be closely coordinated with the air - treatment and - filtration system.
4.1 Fresh Air Treatment
- Introducing an appropriate amount of fresh air is an important measure to maintain the air quality and positive pressure in the workshop. The fresh air system should have functions such as filtering, dehumidifying, heating, and cooling to ensure that the fresh air entering the workshop meets the temperature, humidity, and cleanliness requirements. Generally, fresh air needs to go through three - stage filtration of primary - efficiency, medium - efficiency, and high - efficiency filters to remove impurities such as dust, pollen, and bacteria in the air.
- During the fresh air treatment process, the fresh air volume and the temperature and humidity of the fresh air should be reasonably controlled according to the actual requirements of the workshop and local climatic conditions. At the same time, attention should be paid to the mixing ratio of fresh air and return air to ensure the stability of the air environment in the workshop.
4.2 Air Filtration
- In addition to fresh air filtration, the circulating air in the workshop also needs to be strictly filtered. In the terminal equipment of the refrigeration system (such as precision air conditioners), high - efficiency particulate air (HEPA) filters or ultra - high - efficiency particulate air (ULPA) filters are usually installed, with a filtration efficiency of up to 99.99% or more, which can effectively remove tiny particles with a particle size of 0.3 μm and above in the air.
- Regular replacement and maintenance of air filters are the keys to ensuring the filtration effect. We should formulate a strict filter replacement plan, replace the filters in a timely manner according to factors such as the usage time and resistance change of the filters, and at the same time, pay attention to the installation quality of the filters to ensure good sealing and prevent air leakage.
5. Intelligent Control System
5.1 Temperature and Humidity Control
- The refrigeration system of the wafer dust - free workshop needs to be equipped with a high - precision temperature and humidity control system to achieve precise control of the workshop environment. The control system should use advanced sensors to monitor the temperature and humidity changes in the workshop in real - time and transmit the data to the controller. The controller automatically adjusts the running states of refrigeration equipment, heating equipment, humidifying equipment, and dehumidifying equipment according to the preset temperature and humidity values to ensure that the temperature and humidity in the workshop are always within the specified range.
- To improve the control precision and stability, the control system should also have functions such as adaptive control and fuzzy control. Adaptive control can automatically adjust the control parameters according to the actual load changes and environmental conditions of the workshop, so that the system is always in the best running state; fuzzy control can handle nonlinear and uncertain factors in the temperature and humidity control process, improving the accuracy and reliability of control.
5.2 Equipment Operation Monitoring and Management
- The intelligent control system should also have the function of real - time monitoring and management of the running status of refrigeration system equipment. By installing sensors and monitoring devices on the equipment, operation parameters such as voltage, current, power, temperature, and pressure of the equipment can be collected and transmitted to the monitoring center. Managers can view the running status of the equipment at any time through the monitoring interface, detect potential fault hazards in a timely manner, and conduct remote control and management.
- In addition, the control system should also have a fault - alarm and - diagnosis function. When the equipment fails, the system can automatically send an alarm signal and quickly determine the cause and location of the fault through data analysis and diagnostic algorithms, providing timely and accurate maintenance guidance for maintenance personnel, shortening the fault downtime, and improving production efficiency.
6. Professional Installation and Commissioning
6.1 Installation Team
- The installation of the refrigeration system for the wafer dust - free workshop requires a professional technical team with rich experience in refrigeration engineering installation and good professional quality. The installers should be familiar with the principles, structures, and installation processes of the refrigeration system, and strictly follow the design drawings and installation specifications for construction to ensure the installation quality of each link.
- During the installation process, attention should be paid to detail processing, such as pipe welding, valve installation, and equipment fixation. Pipe welding should adopt high - quality welding techniques to ensure that the welds are uniform and firm without leakage; valve installation should be in the correct direction, with flexible operation, and be convenient for maintenance and repair; equipment fixation should be firm and reliable to prevent vibration and displacement during operation.
6.2 Commissioning and Acceptance
- After the installation is completed, strict commissioning and acceptance work must be carried out. The commissioning process includes single - equipment commissioning, system - joint commissioning, and performance testing. During single - equipment commissioning, the operation parameters of each equipment should be checked whether they are normal, such as the rotation speed, current, and temperature of the motor, and the pressure and temperature of the compressor. System - joint commissioning should simulate the actual operating conditions to test the overall performance of the refrigeration system, including cooling capacity, temperature control precision, humidity control precision, and energy consumption.
- During the commissioning process, if any problems are found, they should be rectified and optimized in a timely manner. After the commissioning is completed, relevant personnel should be organized to conduct acceptance. The acceptance content includes equipment installation quality, system operation performance, and control functions. Only the refrigeration system that has passed the acceptance can be put into formal operation.
The construction of the refrigeration system for the wafer dust - free workshop is a complex and delicate project, which requires comprehensive control from load calculation, equipment selection, water system design, air treatment, control system to installation and commissioning. Guangzhou Kunling Purification Equipment Co., Ltd., relying on years of industry experience and a professional technical team, is committed to providing high - quality refrigeration system solutions for wafer dust - free workshops to ensure that wafer production can be carried out smoothly in a constant - temperature, constant - humidity, and clean environment. If you have any requirements or questions regarding the construction of wafer dust - free workshops or the construction of refrigeration systems, please feel free to contact us, and we will serve you wholeheartedly.
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