Desktop Scanning Electron Microscope Vacuum Control System Design

The development and progress of science and technology,promote the scanning electron microscope(SEM)toward the high resolution,multi-function,portable miniaturization.In the 21st century,the desktop scanning electron microscope,marks a scanning electron microscope by the laboratory into the office application.Desktop scanning electron microscope with small size,easy operation,large magnification,high resolution,vacuum quickly,don't spray gold measuring non-conductive samples,etc.At present,FEI,the company in the United States launched the Phenom series desktop scanning electron microscope and Japan's Hitachi TM series desktop scanning electron microscope to dominate the world market.At home,independent brand desktop scanning electron microscope is still in the blank,it has been dependent on imports.Therefore,to speed up the domestic independent brand desktop scanning electron microscope research and development,to break the foreign monopoly,can meet the needs of domestic users,is of great significance.This paper mainly introduces the graduate workstation in the enterprise,combining with the enterprise of product research and development projects,this paper studies design desktop scanning electron microscope vacuum control system.The design content of this paper is mainly divided into three aspects,one is the design of the clean high vacuum system for desktop scanning electron microscope,mainly introduced based on the dry mechanical pump and a turbo molecular pump is designed to obtain clean high vacuum system;Second,the design of the vacuum control system hardware circuit,mainly introduced the design of the single-chip microcomputer control module,the design of power protection circuit,the design of vacuum acquisition circuit and the design of AD sampling circuit;Third,the software design of the vacuum control system,mainly introduces the design of the main program,the design of the deflated process program,the design of the extraction process program and the design of the fault alarm.This design mainly for desktop scanning electron microscope vacuum system miniaturization,low noise(suitable for office use),the characteristics of high reliability,fast and automatic control,etc.Main work and innovation point of this paper is as follows:(1)based on the dry mechanical pump and the turbo molecular pump is design to obtain a clean high vacuum system,and uses Pirani gauge,vacuum degree of vacuum gauge to measure,collect inside the tube,the vacuum degree to control module,the control system for the vacuum equipment.(2)the hardware circuit is based on C8051F005 MCU as the core control chip,the design of vacuum acquisition circuit,power protection circuit and AD sampling circuit.(3)the software design is based on Silicon IDE software development platform,using C language programming,control program design of vacuum system,vacuum system such as gas extraction,put work process and control of the state.(4)to simulate the vacuum system design,easy to control the hardware circuit and software program of the simulation debugging and testing,simulation debugging success after machine alignment with vacuum system,to avoid the possible faults in the debugging process and cause the damage to the vacuum equipment.