The Application Of Micromachining Technology On High Precision Displacement Sensors

With the continuous development of science and technology and the rising standards of human life, there has been a wide variety of sensors appeared in recent years. High precision displacement sensor is a new type of sensors, and it has unique advantages than other large displacement sensors. The structure of this kind sensor is different, the main feature is the gate electrode shape, therefore also known as capacitive displacement sensors. The relative coverage area and capacitance will changed when electrode parallel moving, and accordingly to achieve geometric measurements. Thus, capacitive sensor has a wide range of applications.The first chapter introduces the development status of capacitive displacement sensors, and then focuses on the working principle of capacitive displacement sensors. There are three types of capacitive sensors, they are linear capacitive displacement sensors, circle described capacitive displacement sensors and cylindrical capacitive displacement sensors.Micromachining technology is the main develop process of high precision displacement sensor. The second chapter introduces the principles of micromachining technology, micromachining history as well as main steps of experiments. It includes magnetron sputtering, UV exposure lithography, etching.The third chapter describes the magnetron sputtering. Cleanliness of the glass substrates has a great impact on the experiment, to optimize the best way to clean the glass substrates is needed. Then introduce the vacuum system and give the steps of vacuum magnetron sputtering in experiments. We are focusing on the theory of magnetron sputtering and power supply. Finally, present magnetron sputtering process.The fourth chapter introduces the UV exposure. Various parameters were optimized by considering of each step in the graphics lithography, and illustrate the effect of each parameter, summed of fit parameter for the experiment. The fifth chapter focuses on the mechanism of etching and gives the main processes of etching. It includes Ion Beam Etching(IBE) and Inductively Coupled Plasma Etching(ICP). This chapter combines the etching machine and capacitive sensors layer structure in experiments, and get the best etching parameters. Last, we will give a summary of this paper and make prospects.