Pressure control principle of vacuum coating equipment
1. Background introduction
Vacuum coating equipment is a kind of equipment widely used in industrial production. Its main function is to put the material that needs to be coated into the vacuum coating chamber, and through the reaction under high temperature and high vacuum environment, the film layer is evenly deposited on the surface of the material. , and form a certain coating layer with special functions and characteristics. Among them, the vacuum degree and adhesion rate in the equipment are important indicators affecting the quality of the coating layer, and the stability of the vacuum degree depends on the pressure control in the equipment.
2. Principle of pressure control of vacuum coating equipment
1. Definition of vacuum degree
Before introducing the principle of pressure control, it is necessary to introduce what vacuum is. In physics, vacuum refers to a gas environment whose pressure is less than atmospheric pressure, so the degree of vacuum refers to the gas pressure in a certain space. In general, vacuum is usually measured in Pascals (Pa) or meters bar (mbar). In vacuum coating equipment, the usual range of vacuum is 10^-6Pa ~ 10^-2Pa.
2. The principle of pressure control
When the vacuum is too high or too low, it will affect the normal operation of the equipment. Therefore, it is necessary to control the vacuum level in the equipment through a certain method. Among them, pressure control is a relatively simple and efficient control method. Specifically, the principle of pressure control is to use a pressure controller to control the gas flow rate in the equipment by detecting the pressure of the controlled end, and then through the feedback mechanism, by controlling the opening of the valve, so as to achieve the purpose of controlling the pressure.
3. The basic composition of the pressure controller
In vacuum coating equipment, a pressure controller is generally used to control the pressure. Its basic composition includes four parts: detection sensor, controller, actuator and control system.
Detection sensor: It is mainly used to detect the pressure change of the controlled end and convert it into a corresponding electrical signal output for use by the controller.
Controller: It mainly receives the electrical signal output by the sensor, processes and analyzes it, and then feeds the analysis result back to the actuator to control the opening degree of the actuator.
Actuator: It mainly controls the flow rate of gas in the equipment by controlling the opening degree of the valve, so as to achieve the purpose of controlling the pressure.
Control system: It is mainly used to monitor and control various indicators in the equipment, such as temperature, vacuum degree, etc., and make a series of control strategies.
In summary, the principle of pressure control in vacuum coating equipment is to control the pressure in the equipment through a relatively simple and efficient feedback mechanism. To establish such a stable control system requires the technical support of various aspects of the equipment control system, such as parameter monitoring, control algorithm, actuator control, system linkage, etc. These technical factors require the cooperation of certain professional and technical personnel to ensure that the equipment can show more excellent performance.