Quartz Wafer Thickness Detector Research And Design

With the rapid development of the electronic industry, the demands to the quantity, quality and performance of the quartz crystal products are more higher. So the crystal industry should enhance the research and exploitation of the manufacturing facilities and the quality measurements. The thickness gauge of the quartz crystal is discussed in the dissertation. It is designed for the quality measuring of the quartz crystal products to the national enterprises and can replace the expensive like products of overseas. And also can be used to check the grinding thickness in the production process.In this dissertation, the cureent status of our country's crystal industry and the research significance are briefly analysed in the first chapter. And the thickness gauges' current research status and its application in our country are discussed in the second chapter. On the base of above analysis, the thickness gauge's design idea, operating principle, constitution and function are separately detailed discussion. Then, in the subsequent chapters the principle of work and power of the differential transducer, the principle and constitution of data acquisition system, the data processing system and the functional configuration of the data display system are separately detailed discussed in modular circuits. At last, the anti-jamming means and the software functions are simply explained.Such jobs are finished in this research work: Use the high-sensitivity differential transformer sensor LVDT and the standand digital output interface circuit of the differential transducer AD2S93 constituted the thickness signal measurement, acquisition and regulation system. Its' function is to complete the conversion of the thickness signal to voltage signal, the twelve bit A/D transfer of analog voltage to digital signal and output the digital signal in serial mode to the microprocessor. Select the low power liquid crystal display and it's special driving slug HT1621 constituted the 6 bit LCD display system. It can be usedas the parameter modify display and the thickness signal's display ofthe data processing system. Use the powerful and reliable single chip microcomputer AT89C52and the peripheral interface chip constituted the thickness gaugesystem. To finish the following functions: parameter set, digital signalinput, signal process and the result output.The thickness gauge have some features: simple structure, operating convenience, stablized function, high accuracy etc. It can be extensive used to accurate measure the ultrathin objects. It has widely forground in application.