Study And Design On The Real-Time Online Measurement And Control System Of Laser Resistor Trim Machine

Laser Processing Technology is a new technology uprising at the end of eighties of this century, which includes optics, fine mechanics, electronics, computer control and measurement technologies. Laser Resistor Trimming Machine is an application of the laser processing equipments in electronic industry. This dissertation is involved in the studies of electronics, computer control and measurement technology of Laser Resistor Trimming Machine. The designing idea and method of Laser Resistor Trimming Machine is valuable for designing other laser processing equipments. In this dissertation, several studies and designs are made concentrating on the measurement and control system of Laser Resistor Trimming Machine.Analysis of structure and theory of W724 Laser Resistor Trimming Machine of GSI Inc. is made. According to the requirements of Laser Resistor Trimming Machine, the measurement and control system of Laser Resistor Trimming Machine are studied and designed by a review on the development of this domain.The main control board (central process unit board, CPU board) of measurement and control system is designed, and high accuracy programmable dual voltage source board (DVS board) is designed. Improving suggestions of the CPU board are brought forward.According to the properties of high accuracy demand for resistor measurement of Laser Resistor Trimming Machine, the theory of lessening or removing error of low resistance and high resistance measurement is studied.The error reasons of low resistance measurement are studied, the theory of removing line resistance error proves to be right with time-domain analysis method and frequency-domain analysis method, and the results proved to be true by the experiment datum with the statistics method.The error reasons of high resistance measurement are studied, and the theory removing line resistance error proves to be right. The model removing the leak resistor circuit is brought forward, and simulationexperiment about the model is made, and the result proves to be true. The compromise scenario is brought forward as practice condition. Improving suggestion of lessening the leak resistance is brought forward.According to need of the high efficient character of Laser Resistor Trimming Machine, the theory of high efficiency is studied, and the implementation steps are given.According the EMC theory, the sources of interference are analyzed, and the methods lessening the interference are brought forward.According to the need of control process of the Laser Resistor Trimming Machine, the program measuring and controlling the system is designed. The program is designed with message driven mechanism like Windows program, it makes the program be simple in structure, real-time, easy in maintenance, and easy in upgrade.As the need of communication with the superior computer, the serial communication program is designed. The thinking of state machine in hardware design is adopted in the serial communication program; it makes the serial communication program be simple in structure, real-time. A high efficient protocol of serial communication is brought forward, and proved to be efficient.