Self-diagnosis Technology of Gas Mass Flow Controller

1. Self-diagnosis technology Self-diagnosis technology is to judge whether the equipment status is normal, the cause, location, degree and life prediction of the abnormality or failure through various detection and analysis without stopping the machine or basically not disassembling the machine. The main function of self-diagnosis technology is to obtain the result state information of the equipment, that is, to identify the state and abnormality of the product according to the comprehensive analysis of all state information such as the accuracy of the equipment under various working conditions, zero drift, and internal leakage. The nature of the type and severity of anomalies is a process that includes signal acquisition, information extraction, information synthesis, fault identification, and information utilization. The goal of self-diagnosis is to ensure the stable operation of the product in terms of function, accuracy, efficiency and reliability. Figure 1 The goal of self-diagnosis 2. The application of self-diagnosis technology in gas mass flow controllers Semiconductor equipment requires high precision for gas mass flow controllers. After a period of use of traditional gas mass flow controllers, Due to environmental temperature, gas pollution and other reasons, the accuracy may be out of tolerance, but due to the limitation of detection conditions, the user cannot test the accuracy of the gas mass flow controller. Therefore, it is necessary to study a self-diagnosis technology, through which the user can check the accuracy of the gas mass flow controller at any time. To increase the self-diagnosis function of the gas mass flow controller, the flow rate needs to be obtained through the primary flow measurement principle. If Qm is the mass flow rate of gas, the change curve of pressure with time can be established according to the change equation of pressure, temperature and gas flow, as shown in Figure 2: Figure 2 The change curve of pressure with time Through this figure, a gas mass flow controller can be established The accuracy corresponding table, in the process of self-diagnosis, compare with the information in this table, and judge whether the accuracy of the system is within the required range through the similarity of the two curves. The self-diagnosis technology greatly improves the reliability of the gas mass flow control system and improves the system functions. 3 Advantages of self-diagnosis technology Using the intelligent analysis of self-diagnosis technology, the mass flow controller can make intelligent detection, predict the possible failure of the equipment, and automatically eliminate it or make an alarm response based on the prediction , this process can achieve better economic benefits for the maintenance of the product itself, not only the workload of the staff can be effectively reduced, the self-diagnosis results can also be provided comprehensively, and the maintenance personnel can also respond to A more complete and effective maintenance plan will be formulated, and the maintenance and implementation will be more ideal.